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Sample records for riparian forest woody

  1. Perspectives on screening winter-flood-tolerant woody species in the riparian protection forests of the three gorges reservoir.

    PubMed

    Yang, Fan; Wang, Yong; Chan, Zhulong

    2014-01-01

    The establishment of riparian protection forests in the Three Gorges Reservoir (TGR) is an ideal measure to cope with the eco-environmental problems of the water-level fluctuation zone (WLFZ). Thus, the information for screening winter-flood-tolerant woody plant species is useful for the recovery and re-establishment of the riparian protection forests in the TGR WLFZ. Therefore, we discussed the possibilities of constructing and popularizing riparian protection forests in the TGR WLFZ from several aspects, including the woody plant species distribution in the WLFZ, the survival rate analyses of suitable candidate woody species under controlled flooding conditions, the survival rate investigation of some woody plant species planted in the TGR WLFZ, and the physiological responses of some woody plant species during the recovery stage after winter floods. The results of woody species investigation showed that most woody plant species that existed as annual seedlings in the TGR WLFZ are not suitable candidates for the riparian protection forests. However, arbor species (e.g., Salix matsudana, Populus×canadensis, Morus alba, Pterocarya stenoptera, Taxodium ascendens, and Metasequoia glyptostroboides) and shrub species (e.g., Salix variegata, Distylium chinensis, Lycium chinense, Myricaria laxiflora, and Rosa multiflora) might be considered suitable candidates for the riparian protection forests in the TGR WLFZ by survival rate analyses under controlled winter flooding conditions, and survival rate investigations of woody plant species planted in the TGR WLFZ, respectively. Physiological analyses showed that P.×canadensis, M. alba, L. chinense, and S. variegata could develop specific self-repairing mechanisms to stimulate biomass accumulation and carbohydrate synthesis via the increases in chlorophyll pigments and photosynthesis during recovery after winter floods. Our results suggested these woody plant species could endure the winter flooding stress and recover well

  2. Perspectives on Screening Winter-Flood-Tolerant Woody Species in the Riparian Protection Forests of the Three Gorges Reservoir

    PubMed Central

    Yang, Fan; Wang, Yong; Chan, Zhulong

    2014-01-01

    The establishment of riparian protection forests in the Three Gorges Reservoir (TGR) is an ideal measure to cope with the eco-environmental problems of the water-level fluctuation zone (WLFZ). Thus, the information for screening winter-flood-tolerant woody plant species is useful for the recovery and re-establishment of the riparian protection forests in the TGR WLFZ. Therefore, we discussed the possibilities of constructing and popularizing riparian protection forests in the TGR WLFZ from several aspects, including the woody plant species distribution in the WLFZ, the survival rate analyses of suitable candidate woody species under controlled flooding conditions, the survival rate investigation of some woody plant species planted in the TGR WLFZ, and the physiological responses of some woody plant species during the recovery stage after winter floods. The results of woody species investigation showed that most woody plant species that existed as annual seedlings in the TGR WLFZ are not suitable candidates for the riparian protection forests. However, arbor species (e.g., Salix matsudana, Populus×canadensis, Morus alba, Pterocarya stenoptera, Taxodium ascendens, and Metasequoia glyptostroboides) and shrub species (e.g., Salix variegata, Distylium chinensis, Lycium chinense, Myricaria laxiflora, and Rosa multiflora) might be considered suitable candidates for the riparian protection forests in the TGR WLFZ by survival rate analyses under controlled winter flooding conditions, and survival rate investigations of woody plant species planted in the TGR WLFZ, respectively. Physiological analyses showed that P.×canadensis, M. alba, L. chinense, and S. variegata could develop specific self-repairing mechanisms to stimulate biomass accumulation and carbohydrate synthesis via the increases in chlorophyll pigments and photosynthesis during recovery after winter floods. Our results suggested these woody plant species could endure the winter flooding stress and recover well

  3. Response of a depleted sagebrush steppe riparian system to grazing control and woody plantings. Forest Service research paper

    SciTech Connect

    Clary, W.P.; Shaw, N.L.; Dudley, J.G.; Saab, V.A.; Kinney, J.W.

    1996-12-01

    To find out if a depleted riparian system in the sagebrush steppe of eastern Oregon would respond quickly to improved management, five management treatments were applied for 7 years, ranging from ungrazed to heavily grazed treatments, including, in some cases, planting of woody species. While the results varied, all treatments were too limited to significantly restore the damaged areas within the 7-year span. Although some improvements were made in woody plant densities, little meaningful change occurred in the frequencies of herbaceous wetland plants, densities of small wildlife, or stream channel morphology. We concluded the restoration would take many years, possibly decades, without increased revegetation efforts and continued reductions in grazing in this riparian system damaged over 150 years.

  4. Fire and Grazing Influences on Rates of Riparian Woody Plant Expansion along Grassland Streams

    PubMed Central

    Veach, Allison M.; Dodds, Walter K.; Skibbe, Adam

    2014-01-01

    Grasslands are threatened globally due to the expansion of woody plants. The few remaining headwater streams within tallgrass prairies are becoming more like typical forested streams due to rapid conversion of riparian zones from grassy to wooded. Forestation can alter stream hydrology and biogeochemistry. We estimated the rate of riparian woody plant expansion within a 30 m buffer zone surrounding the stream bed across whole watersheds at Konza Prairie Biological Station over 25 years from aerial photographs. Watersheds varied with respect to experimentally-controlled fire and bison grazing. Fire frequency, presence or absence of grazing bison, and the historical presence of woody vegetation prior to the study time period (a proxy for proximity of propagule sources) were used as independent variables to predict the rate of riparian woody plant expansion between 1985 and 2010. Water yield was estimated across these years for a subset of watersheds. Riparian woody encroachment rates increased as burning became less frequent than every two years. However, a higher fire frequency (1–2 years) did not reverse riparian woody encroachment regardless of whether woody vegetation was present or not before burning regimes were initiated. Although riparian woody vegetation cover increased over time, annual total precipitation and average annual temperature were variable. So, water yield over 4 watersheds under differing burn frequencies was quite variable and with no statistically significant detected temporal trends. Overall, burning regimes with a frequency of every 1–2 years will slow the conversion of tallgrass prairie stream ecosystems to forested ones, yet over long time periods, riparian woody plant encroachment may not be prevented by fire alone, regardless of fire frequency. PMID:25192194

  5. Fire and grazing influences on rates of riparian woody plant expansion along grassland streams.

    PubMed

    Veach, Allison M; Dodds, Walter K; Skibbe, Adam

    2014-01-01

    Grasslands are threatened globally due to the expansion of woody plants. The few remaining headwater streams within tallgrass prairies are becoming more like typical forested streams due to rapid conversion of riparian zones from grassy to wooded. Forestation can alter stream hydrology and biogeochemistry. We estimated the rate of riparian woody plant expansion within a 30 m buffer zone surrounding the stream bed across whole watersheds at Konza Prairie Biological Station over 25 years from aerial photographs. Watersheds varied with respect to experimentally-controlled fire and bison grazing. Fire frequency, presence or absence of grazing bison, and the historical presence of woody vegetation prior to the study time period (a proxy for proximity of propagule sources) were used as independent variables to predict the rate of riparian woody plant expansion between 1985 and 2010. Water yield was estimated across these years for a subset of watersheds. Riparian woody encroachment rates increased as burning became less frequent than every two years. However, a higher fire frequency (1-2 years) did not reverse riparian woody encroachment regardless of whether woody vegetation was present or not before burning regimes were initiated. Although riparian woody vegetation cover increased over time, annual total precipitation and average annual temperature were variable. So, water yield over 4 watersheds under differing burn frequencies was quite variable and with no statistically significant detected temporal trends. Overall, burning regimes with a frequency of every 1-2 years will slow the conversion of tallgrass prairie stream ecosystems to forested ones, yet over long time periods, riparian woody plant encroachment may not be prevented by fire alone, regardless of fire frequency. PMID:25192194

  6. Does stream flow structure woody riparian vegetation in subtropical catchments?

    PubMed

    James, Cassandra S; Mackay, Stephen J; Arthington, Angela H; Capon, Samantha J; Barnes, Anna; Pearson, Ben

    2016-08-01

    The primary objective of this study was to test the relevance of hydrological classification and class differences to the characteristics of woody riparian vegetation in a subtropical landscape in Queensland, Australia. We followed classification procedures of the environmental flow framework ELOHA - Ecological Limits of Hydrologic Alteration. Riparian surveys at 44 sites distributed across five flow classes recorded 191 woody riparian species and 15, 500 individuals. There were differences among flow classes for riparian species richness, total abundance, and abundance of regenerating native trees and shrubs. There were also significant class differences in the occurrence of three common tree species, and 21 indicator species (mostly native taxa) further distinguished the vegetation characteristics of each flow class. We investigated the influence of key drivers of riparian vegetation structure (climate, depth to water table, stream-specific power, substrate type, degree of hydrologic alteration, and land use) on riparian vegetation. Patterns were explained largely by climate, particularly annual rainfall and temperature. Strong covarying drivers (hydrology and climate) prevented us from isolating the independent influences of these drivers on riparian assemblage structure. The prevalence of species considered typically rheophytic in some flow classes implies a more substantial role for flow in these classes but needs further testing. No relationships were found between land use and riparian vegetation composition and structure. This study demonstrates the relevance of flow classification to the structure of riparian vegetation in a subtropical landscape, and the influence of covarying drivers on riparian patterns. Management of environmental flows to influence riparian vegetation assemblages would likely have most potential in sites dominated by rheophytic species where hydrological influences override other controls. In contrast, where vegetation assemblages are

  7. Woody riparian vegetation of Great Basin National Park. Interim report

    SciTech Connect

    Douglas, C.L.; Smith, S.D.; Murray, K.J.; Landau, F.H.; Sala, A.

    1994-07-01

    The community composition and population structure of the woody riparian vegetation in Great Basin National Park are described. Community analyses were accomplished by sampling 229 plots placed in a systematic random fashion along elevational gradients of 8 major stream systems (Baker, Big Wash, Lehman, Pine, Pole, Shingle, Snake, and Strawberry Creeks) in the Park using the releve method. Stand demographics were determined for the four dominant tree species in the Park, based on absolute stem counts at 15 sites along 6 major watersheds. Elevational ranges of the dominant tree and shrub species along 8 major streams were determined via transect analysis and systematic reconnaissance efforts. TWINSPAN (two-way indicator analysis) indentified 4 primary species groups and 8 stand groups in the Park. Because of the homogeneity of riparian zones, both presence and abundance of species were important parameters in determining species groups. Although species such as Populus tremuloides (aspen), Abies concolor (white fir) and Rosa woodsii (Woods rose) are very common throughout the Park, they are particularly abundant at higher, upper intermediate, and lower intermediate elevations.

  8. Structure and composition of altered riparian forests in an agricultural Amazonian landscape.

    PubMed

    Nagy, R Chelsea; Porder, Stephen; Neill, Christopher; Brando, Paulo; Quintino, Raimundo Mota; do Nascimento, Sebastiâo Aviz

    2015-09-01

    Deforestation and fragmentation influence the microclimate, vegetation structure, and composition of remaining patches of tropical forest. In the southern Amazon, at the frontier of cropland expansion, forests are converted and fragmented in a pattern that leaves standing riparian forests whose dimensions are mandated by the Brazilian National Forest Code. These altered riparian forests share many characteristics of well-studied upland forest fragments, but differ because they remain connected to larger areas of forest downstream, and because they may experience wetter soil conditions because reduction of forest cover in the surrounding watershed raises groundwater levels and increases stream runoff. We compared forest regeneration, structure, composition, and diversity in four areas of intact riparian forest and four areas each of narrow, medium, and wide altered riparian forests that have been surrounded by agriculture since the early 1980s. We found that seedling abundance was reduced by as much as 64% and sapling abundance was reduced by as much as 67% in altered compared to intact riparian forests. The most pronounced differences between altered and intact forest occurred near forest edges and within the narrowest sections of altered riparian forests. Woody plant species composition differed and diversity was reduced in altered forests compared to intact riparian forests. However, despite being fragmented for several decades, large woody plant biomass and carbon storage, the number of live or dead large woody plants, mortality rates, and the size distribution of woody plants did not differ significantly between altered and intact riparian forests. Thus, even in these relatively narrow forests with high edge: area ratios, we saw no evidence of the increases in mortality and declines in biomass that have been found in other tropical forest fragment studies. However, because of the changes in both species community and reduced regeneration, it is unclear how long

  9. Ecohydrological Impacts of Woody Phreatophyte Invasion Within a Semiarid Riparian Environment

    NASA Astrophysics Data System (ADS)

    Scott, R. L.; Huxman, T. E.; Williams, D. G.; Goodrich, D. C.

    2005-12-01

    Along the Upper San Pedro River in southeastern Arizona deep-rooted woody phreatophytes such as the non-native Tamarix ramosissima (salt cedar) and the native Prosopis velutina (velvet mesquite) are expanding their range, but we have little understanding about how this change in vegetation composition will change the cycling of water and nutrients in these riparian ecosystems. We compared water and carbon dioxide fluxes over a grassland, a grassland-shrubland mosaic, and a fully developed woodland to evaluate potential consequences of woody plant encroachment on important ecosystem processes. Using fluxes measured by eddy covariance in 2003 we found that ecosystem evapotranspiration (ET) and net ecosystem exchange of carbon dioxide (NEE) increased with woody plant encroachment. The dominant grass or shrub at all sites accessed groundwater to some degree, but groundwater use increased with woody plant density. Greater access to groundwater for the deeper-rooted woody plants apparently decouples ecosystem evapotranspiration from gross ecosystem production (GEP) with respect to precipitation. The woody plants were better able to use the stable groundwater source, which increased net carbon dioxide gain during the dry periods by maintaining plant function. However, this enhanced plant activity leads to substantial accumulation of leaf litter on the soil surface that, during rainy periods, may lead to high microbial respiration rates that offset these photosynthetic fluxes. These initial data suggest that the ability of the woody plants to better exploit water resources in riparian areas results in enhanced carbon sequestration at the expense of increased groundwater use under current climate conditions, but the potential does not scale specifically as a function of woody plant density.

  10. Woody riparian vegetation near selected streamgages in the western United States

    USGS Publications Warehouse

    Auble, Gregor T.; Friedman, Jonathan M.; Shafroth, Patrick B.; Merigliano, Michael F.; Scott, Michael L.

    2012-01-01

    Areal cover and occupancy of woody riparian species near 456 streamgages in the western United States were obtained from site visits during the growing seasons of 1996-2002. We made concomitant estimates of grazing intensity, channel stabilization and incision, gradient, sediment particle size, and nearby planting of Russian olive. The purpose of this publication is to describe the data set and make it available to other investigators in an electronic format.

  11. Spatial-structural analysis of leafless woody riparian vegetation for hydraulic considerations

    NASA Astrophysics Data System (ADS)

    Weissteiner, Clemens; Jalonen, Johanna; Järvelä, Juha; Rauch, Hans Peter

    2013-04-01

    Woody riparian vegetation is a vital element of riverine environments. On one hand woody riparian vegetation has to be taken into account from a civil engineering point of view due to boundary shear stress and vegetation drag. On the other hand it has to be considered from a river ecological point of view due to shadowing effects and as a source of organic material for aquatic habitats. In hydrodynamic and hydro-ecological studies the effects of woody riparian vegetation on flow patterns are usually investigated on a very detailed level. On the contrary vegetation elements and their spatial patterns are generally analysed and discussed on the basis of an integral approach measuring for example basal diameters, heights and projected plant areas. For a better understanding of the influence of woody riparian vegetation on turbulent flow and on river ecology, it is essential to record and analyse plant data sets on the same level of quality as for hydrodynamic or hydro-ecologic purposes. As a result of the same scale of the analysis it is possible to incorporate riparian vegetation as a sub-model in the hydraulic analysis. For plant structural components, such as branches on different topological levels it is crucial to record plant geometrical parameters describing the habitus of the plant on branch level. An exact 3D geometrical model of real plants allows for an extraction of various spatial-structural plant parameters. In addition, allometric relationships help to summarize and describe plant traits of riparian vegetation. This paper focuses on the spatial-structural composition of leafless riparia woddy vegetation. Structural and spatial analyses determine detailed geometric properties of the structural components of the plants. Geometrical and topological parameters were recorded with an electro-magnetic scanning device. In total, 23 plants (willows, alders and birches) were analysed in the study. Data were recorded on branch level, which allowed for the

  12. Hiawatha National Forest Riparian Inventory: A Case Study

    NASA Astrophysics Data System (ADS)

    Abood, S. A.

    2014-12-01

    Riparian areas are dynamic, transitional ecotones between aquatic and terrestrial ecosystems with well-defined vegetation and soil characteristics. Riparian areas offers wildlife habitat and stream water quality, offers bank stability and protects against erosions, provides aesthetics and recreational value, and other numerous valuable ecosystem functions. Quantifying and delineating riparian areas is an essential step in riparian monitoring, riparian management/planning and policy decisions, and in preserving its valuable ecological functions. Previous approaches to riparian areas mapping have primarily utilized fixed width buffers. However, these methodologies only take the watercourse into consideration and ignore critical geomorphology, associated vegetation and soil characteristics. Other approaches utilize remote sensing technologies such as aerial photos interpretation or satellite imagery riparian vegetation classification. Such techniques requires expert knowledge, high spatial resolution data, and expensive when mapping riparian areas on a landscape scale. The goal of this study is to develop a cost effective robust workflow to consistently map the geographic extent and composition of riparian areas within the Hiawatha National Forest boundary utilizing the Riparian Buffer Delineation Model (RBDM) v3.0 and open source geospatial data. This approach recognizes the dynamic and transitional natures of riparian areas by accounting for hydrologic, geomorphic and vegetation data as inputs into the delineation process and the results would suggests incorporating functional variable width riparian mapping within watershed management planning to improve protection and restoration of valuable riparian functionality and biodiversity.

  13. Establishment of woody riparian vegetation in relation to annual patterns of streamflow, Bill Williams River, Arizona

    USGS Publications Warehouse

    Shafroth, P.B.; Auble, G.T.; Stromberg, J.C.; Patten, D.T.

    1998-01-01

    Previous studies have revealed the close coupling of components of annual streamflow hydrographs and the germination and establishment of Populus species. Key hydrograph components include the timing and magnitude of flood peaks, the rate of decline of the recession limb, and the magnitude of base flows. In this paper, we retrospectively examine establishment of four woody riparian species along the Bill Williams River, Arizona, USA, in the context of annual patterns of streamflow for the years 1993-1995. The four species examined were the native Populus fremontii, Salix gooddingii, and Baccharis salicifolia and the exotic Tamarix ramosissima. We modeled locations suitable for germination of each species along eight study transects by combining historic discharge data, calculated stage-discharge relationships, and seed-dispersal timing observations. This germination model was a highly significant predictor of seedling establishment. Where germination was predicted to occur, we compared values of several environmental variables in quadrats where we observed successful establishment with quadrats where establishment was unsuccessful. The basal area of mature woody vegetation, the maximum annual depth to ground water, and the maximum rate of water-table decline were the variables that best discriminated between quadrats with and without seedlings. The results of this study suggest that the basic components of models that relate establishment of Populus spp. to annual patterns of streamflow may also be applicable to other woody riparian species. Reach-to-reach variation in stage-discharge relationships can influence model parameters, however, and should be considered if results such as ours are to be used in efforts to prescribe reservoir releases to promote establishment of native riparian vegetation.

  14. Headwater riparian forest-floor invertebrate communities associated with alternative forest management practices.

    PubMed

    Rykken, Jessica J; Moldenke, Andrew R; Olson, Deanna H

    2007-06-01

    Headwater streams and their riparian zones are a common, yet poorly understood, component of Pacific Northwest, USA, landscapes. We describe the ecological importance of headwater stream riparian zones as habitat for forest-floor invertebrate communities and assess how alternative management strategies for riparian zones may impact these communities. We compared community composition of forest-floor invertebrates at increasing distances along trans-riparian (stream edge to upslope) transects in mature forests, clearcuts, and riparian buffers of approximately 30-m width with upslope clearcuts. Invertebrates were collected using pitfall traps in five replicate blocks of three treatments each in the Willamette National Forest, Oregon, USA. We measured microclimate and microhabitat variables at pitfall locations. Despite strong elevation and block effects on community composition, community analyses revealed a distinct "riparian" invertebrate community within 1 m of the stream edge in mature forest treatments, which was strongly related to cool, humid microclimate conditions. Invertebrate community composition in buffer treatments was far more similar to that of mature forests than to clearcuts; a pattern mirrored by microclimate. These results suggest that, within our study sites, forest-floor invertebrate distributions are strongly associated with microclimate and that riparian buffers of approximately 30-m width do provide habitat for many riparian and forest species. Riparian reserves may serve as effective forest refugia and/or dispersal corridors for invertebrates and other taxa, and their incorporation into watershed management plans likely will contribute to meeting persistence and connectivity objectives. PMID:17555226

  15. A Conceptual Model of Riparian Forest Response to Channel Abandonment on Meandering Rivers

    NASA Astrophysics Data System (ADS)

    Stella, J. C.; Hayden, M. K.; Battles, J. J.; Piegay, H.; Dufour, S.; Fremier, A. K.

    2008-12-01

    On alluvial rivers, hydrogeomorphic regimes exert a primary control on the regeneration of pioneer riparian forest stands and thus their composition and age structure. Seasonal flow patterns provide the necessary conditions for recruitment, and channel migration drives patterns of forest stand dynamics. To date, studies of pioneer riparian forest structure have focused primarily on point bar habitats, where woody vegetation typically recruits with decadal frequency in even-aged bands parallel to the river margin. However, there are indications that other recruitment pathways exist and can be important from a population and conservation perspective. On floodplains where channel migration occurs as infrequent cutoff or avulsion events, the geometry and position of the old channel relative to the new one determines rates and patterns of sedimentation and flood frequency. These conditions provide a brief opportunity for forest recruitment, and geomorphic evolution of the former channel habitat in turn influences forest dynamics. The population implications of this alternative forest regeneration pathway depend on the temporal dynamics of channel abandonment versus the rate of lateral channel migration. Preliminary analysis indicates that the geographic scope of this ecogeomorphological process is sizable. Along the Sacramento River (CA) and Ain River (France), for example, cottonwood-dominated stands associated with abandoned channels tend to be less frequent in number (38% of all stands) but larger in area (accounting for 53% of all forest area) relative to forest stands associated with laterally migrating point bars. Dendrochronological analysis confirms that tree ages in floodplain stands corresponds to the first decade after channel abandonment. These data indicate that changes to the rate and scale of channel abandonment due to human and climatic alterations to the flow regime will likely influence riparian corridor-wide tree population structure and forest

  16. AN INDICATOR OF POTENTIAL STREAM WOOD CONTRIBUTION FOR RIPARIAN FORESTS

    EPA Science Inventory

    In northwestern Oregon a key function of riparian forests is to provide wood to the stream network. This function is a prominent feature of Federal and State forest practices in the region. Thus, defining indicators which are associated with this function are important for desi...

  17. Water use sources of desert riparian Populus euphratica forests.

    PubMed

    Si, Jianhua; Feng, Qi; Cao, Shengkui; Yu, Tengfei; Zhao, Chunyan

    2014-09-01

    Desert riparian forests are the main body of natural oases in the lower reaches of inland rivers; its growth and distribution are closely related to water use sources. However, how does the desert riparian forest obtains a stable water source and which water sources it uses to effectively avoid or overcome water stress to survive? This paper describes an analysis of the water sources, using the stable oxygen isotope technique and the linear mixed model of the isotopic values and of desert riparian Populus euphratica forests growing at sites with different groundwater depths and conditions. The results showed that the main water source of Populus euphratica changes from water in a single soil layer or groundwater to deep subsoil water and groundwater as the depth of groundwater increases. This appears to be an adaptive selection to arid and water-deficient conditions and is a primary reason for the long-term survival of P. euphratica in the desert riparian forest of an extremely arid region. Water contributions from the various soil layers and from groundwater differed and the desert riparian P. euphratica forests in different habitats had dissimilar water use strategies. PMID:24816539

  18. PREDICTIONS OF STREAM WOOD RECRUITMENT FROM RIPARIAN FORESTS: EFFECTS OF DATA RESOLUTION

    EPA Science Inventory

    We evaluate whether different levels of detail of riparian forest characterizations result in different predictions of stream wood recruitment from riparian forests in northwestern Oregon. If less detailed information provides the same estimate of this function as more detailed i...

  19. Ground water nitrate removal in subsoil of forested and mowed riparian buffer zones

    SciTech Connect

    Addy, K.L.; Gold, A.J.; Groffman, P.M.; Jacinthe, P.A.

    1999-05-01

    The authors studied two similar riparian sites in southern New England and examined ground water nitrate (NO{sub 3}{sup {minus}}-N) removal in the subsurface of mowed (i.e., herbaceous) vs. forested (i.e., woody) vegetation. Each site consisted of poorly drained, fine to medium sands and contained adjacent areas of mowed and forested vegetation. They dosed mesocosms with bromide and {sup 15}N labeled NO{sub 3}{sup {minus}}-N amended ground water to simulate the shallow ground water NO{sub 3}{sup {minus}}-N dynamics of riparian buffers zones. Mesocosms were composed of undisturbed, horizontal soil cores extracted from seasonally saturated subsoil. The authors observed substantial ground water NO{sub 3}{sup {minus}}-N removal and denitrification at all locations. Ground water NO{sub 3}{sup {minus}}-N removal rates were significantly correlated with carbon-enriched patches of organic matter. This correlation supports previous work that patches function as hotspots of microbial activity in the subsoil. Within each site, they found no significant difference in ground water NO{sub 3}{sup {minus}}-N removal rates in the subsoil of forested and mowed areas and they noted tree roots throughout the subsoil of the mowed areas. They found that ground water NO{sub 3}{sup {minus}}-N removal rates differed significantly between similar sites. They caution against ascribing specific ground water NO{sub 3}{sup {minus}}-N removal rates to different riparian aboveground vegetation types without recognizing the importance of site differences, e.g., water table dynamics, land use legacy and adjacent vegetation. Riparian zones composed of a mix of forested and mowed vegetation, common in agroforestry and suburban land uses, may remove substantial amounts of ground water NO{sub 3}{sup {minus}}-N.

  20. EVALUATION OF METRIC PRECISION FOR A RIPARIAN FOREST SURVEY

    EPA Science Inventory

    This paper evaluates the performance of a protocol to monitor riparian forests in western Oregon based on the quality of the data obtained from a recent field survey. Precision and accuracy are the criteria used to determine the quality of 19 field metrics. The field survey con...

  1. RIPARIAN FOREST INDICATORS OF POTENTIAL FUTURE STREAM CONDITION

    EPA Science Inventory

    Large wood in streams can play an extraordinarily important role in influencing the physical structure of streams and in providing habitat for aquatic organisms. Since wood is continually lost from streams, predicting the future input of wood to streams from riparian forests is c...

  2. Abundance of Woody Riparian Species in the Western USA in Relation to Phenology, Climate, and Flow Regime

    NASA Astrophysics Data System (ADS)

    Auble, G. T.; Friedman, J. M.; Scott, M. L.; Shafroth, P. B.; Merigliano, M. M.; Freehling, M. D.; Evans, R. E.; Griffin, E. R.

    2004-12-01

    We randomly selected 475 long-term U.S. Geological Survey stream gaging stations in 17 western states to relate the presence and abundance of woody species to environmental factors. Along a 1.3-km reach near each station we measured the cover of all species on a list of the 44 most abundant large woody riparian species in the region. We used logistic regression to fit the response of four abundant species to growing degree days and mean precipitation. Then we related relative abundance of these 4 species to timing of the flood peak in sites where the likelihood of occurrence was greater than 0.5. The exotics Tamarix ramosissima (saltcedar) and Elaeagnus angustifolia (Russian-olive) are now the third and fourth most frequently occurring large woody riparian species in the western U.S. and the second and fifth most abundant. In climatically suitable areas, species differences in reproductive phenology produce different relations of abundance to flow regime. Because of its limited period of seed release and viability in early summer, cottonwood (Populus deltoides) is disadvantaged where floods occur in the spring or fall. Abundances of saltcedar, because of its long period of seed release; Russian-olive, because of seed dormancy; and Salix exigua, because of the importance of vegetative spread, are much less sensitive to flood timing.

  3. Establishment of woody riparian species from natural seedfall at a former gravel pit

    USGS Publications Warehouse

    Roelle, J.E.; Gladwin, D.N.

    1999-01-01

    Establishment of native riparian communities through natural seedfall may be a viable reclamation alternative at some alluvial sand and gravel mines where water level can be controlled in the abandoned pit. We experimented with this approach at a pit in Fort Collins, Colorado, where a drain culvert equipped with a screw gate allows water levels to be manipulated. From 1994 to 1996 we conducted a series of annual drawdowns during the period of natural seedfall of Populus deltoides subsp. monilifera (plains cottonwood), Salix amygdaloides (peachleaf willow), and S. exigua (sand-bar willow), thus providing the bare, moist substrate conducive to establishment of these species. Establishment was highly variable from year to year; in the fall following establishment, frequency of occurrence on 0.5-m2 sample plots ranged from 8.6% to 50.6% for cottonwood, 15.9% to 22.0% for peachleaf willow, and 21.7% to 50.0% for sandbar willow. Mean densities, however, were comparable to those reported for other locations. Concurrent establishment of the undesirable exotic Tamarix ramosissima (saltcedar) was a problem, but we were able to eradicate most saltcedar seedlings by reflooding the lower elevations of the annual drawdown zones each fall. At the end of the 3-year period, at least one of the three native woody species survived on 41.1% of the plots, while saltcedar was present on only 6.1%. In addition to the potential for establishing valuable native habitats, adaptations of the techniques described may require less earth moving than other reclamation approaches.

  4. Avian communities in riparian forests of different widths in Maryland and Delaware

    USGS Publications Warehouse

    Keller, C.M.E.; Robbins, C.S.; Hatfield, J.S.

    1993-01-01

    In agricultural landscapes, much of the remaining forest is in linear tracts along streams. These riparian forests provide habitat for forest birds, but their use by forest interior birds may depend on forest width. We conducted point-count surveys of birds in riparian forests on the Eastern shore of Maryland and Delaware to assess whether the presence of any species was dependent on corridor width. We surveyed 117 corridors that ranged from 25- to 800-m wide. Several area-sensitive neotropical migrants were encountered more frequently in wider riparian forests, and probabilities of occurrence increased most rapidly between 25 and 100 m. Based on these surveys, we recommend that riparian forests be at least 100-m wide to provide some nesting habitat for area-sensitive species. Wider riparian forests would be preferable and should be preserved.

  5. The interplay of sedimentation and carbon accretion in riparian forests

    NASA Astrophysics Data System (ADS)

    Rieger, Isaak; Lang, Friederike; Kowarik, Ingo; Cierjacks, Arne

    2014-06-01

    Sediment trapping and organic carbon (OC) accretion in soil are crucial ecosystem services of floodplain forests. However, interactions between the two processes have scarcely been analyzed at the ecosystem level. This study aimed at quantifying OC accretion parameters (CAP, including sedimentation rate, OC concentration, OC accretion) over roughly the last 50 years on both sides of a dike in a Danubian floodplain forest in Austria. Additionally, we determined soil OC stocks (0-100 cm in depth) and modeled both CAP and OC stocks in relation to environmental parameters. Overall, mean sedimentation rate and OC accretion of the riparian forest were 0.8 cm y- 1 and 3.3 t OC ha- 1 y- 1 and significantly higher in flooded riparian forest (FRF; 1.0 cm y- 1 and 4.1 t OC ha- 1 y- 1) than in diked riparian forest (DRF; 0.3 cm y- 1 and 1.5 t OC ha- 1 y- 1). In contrast, mean OC concentration (0.05 t OC m- 3) and OC stocks (238 t OC ha- 1) were significantly higher in the DRF than in FRF (0.05 vs. 0.04 t OC m- 3 and 286 vs. 201 t OC ha- 1). Modeling revealed tree species, fluctuation of groundwater table, and the distance to the river as valuable indicators for OC accretion rate. The OC concentration and distance to the river were positively and sedimentation negatively correlated with OC stock. The dike was consistently ruled out as a significant predictor variable. Consequently, differences among FRF and DRF seem to be related rather to longer term processes during the last centuries than directly to the dike. Our findings highlight the relevance of sediment quality (i.e., OC concentration) for building up long-term soil OC stocks, whereas sediment quantity is the main driver of recent OC accretion rates.

  6. Floodplain Stabilization by Woody Riparian Vegetation During an Extreme Flood Along Headwater Tributaries of East Plum Creek, Colorado.

    NASA Astrophysics Data System (ADS)

    Griffin, E. R.; Smith, J. D.

    2001-12-01

    Dense woody riparian vegetation acts to reduce flow velocities and boundary shear stresses on floodplain surfaces during large overbank flow events. Throughout the semi-arid west, woody riparian vegetation has been progressively thinned as the result of land use practices, such as grazing, and extensive reduction in beaver populations. Where woody vegetation is sparse, the floodplain surface is vulnerable to high rates of erosion during overbank flows. Unraveling of a floodplain surface occurs when flow is sufficiently deep and fast enough to erode the surface. Once erosion begins, it proceeds rapidly, leading to transformation from a narrow, single-threaded stream to a much wider, braided stream, as occurred along most of the mainstem of East Plum Creek, Colorado, during an extreme flood on June 16, 1965. Effects of this flood along headwater tributaries of East Plum Creek were documented in large scale (about 1:2,500) aerial photographs taken two days after the flood. The photographs along with available map information and field examination clearly show overbank flows were deep (on the order of 3 meters), yet the floodplain remained intact at sites with dense shrubs (sandbar willow). Two days after the flood, the shrubs were still lying bent over by the flood flow, and their canopy sizes and densities could be measured from the photographs. Within a 1.5-km reach, the downstream sequence of sites examined included: 1) locations where the floodplain surface and vegetation remained intact; 2) a location with less dense woody vegetation where the floodplain surface had just begun to erode; 3) locations with minimal woody vegetation, where the entire floodplain surface had begun to erode but a new channel had not yet formed; and 4) locations where erosion had caused a new, much wider channel to form and almost all pre-flood woody vegetation was removed. Estimates of pre-flood vegetation types and densities were made at each of these four sites. Boundary shear

  7. Riparian corridors enhance movement of a forest specialist bird in fragmented tropical forest

    PubMed Central

    Gillies, Cameron S.; St. Clair, Colleen Cassady

    2008-01-01

    Riparian corridors and fencerows are hypothesized to increase the persistence of forest animals in fragmented landscapes by facilitating movement among suitable habitat patches. This function may be critically important for forest birds, which have declined dramatically in fragmented habitats. Unfortunately, direct evidence of corridor use has been difficult to collect at landscape scales and this limits support for corridors in conservation planning. Using telemetry and handheld GPS units, we examined the movement of forest birds by translocating territorial individuals of barred antshrikes (Thamnophilus doliatus; a forest specialist) and rufous-naped wrens (Campylorhynchus rufinucha; a forest generalist) 0.7–1.9 km from their territories in the highly fragmented tropical dry forest of Costa Rica. In each translocation, the directly intervening habitat comprised 1 of 3 treatments: forested riparian corridor, linear living fencerow, or open pasture. Antshrikes returned faster and with greater success in riparian corridors relative to pasture treatments. This species also traveled more directly in riparian corridor treatments, detoured to use forested routes in the other 2 treatments, and did not use fencerows even when they led directly to their home territories. By contrast, wrens were more likely to use fencerows when returning, and return time and success were equivalent among the 3 treatments. Both species crossed fewer gaps in tree cover during riparian corridor treatments than in fencerow or pasture treatments. We conclude that antshrikes, which may be representative of other forest specialists, use forested corridors for movement in this landscape and that fencerows are avoided as movement conduits. PMID:19017794

  8. MODELING VARIABLE-WIDTH RIPARIAN BUFFERS, WITH AN APPLICATION TO WOODY DEBRIS RECRUITMENT

    EPA Science Inventory

    Effective management of riparian areas in watersheds requires that reach-scale knowlege of riparian functioning be carefully "scaled up" to provide models for entire stream networks. Weller et al. (1998: Ecological Applications 8, 1156-1169) describe a useful heuristic model for...

  9. Amphibian and reptile abundance in riparian and upslope areas of five forest types in western Oregon

    USGS Publications Warehouse

    Gomez, D.M.; Anthony, R.G.

    1996-01-01

    We compared species composition and relative abundance of herpetofauna between riparian and upslope habitats among 5 forest types (shrub, open sapling-pole, large sawtimber and old-growth conifer forests, and deciduous forests) in Western Oregon. Riparian- and upslope- associated species were identified based on capture frequencies from pitfall trapping. Species richness was similar among forest types but slightly greater in the shrub stands. The abundances of 3 species differed among forest types. Total captures was highest in deciduous forests, intermediate in the mature conifer forests, and lowest in the 2 young coniferous forests. Species richness was similar between stream and upslope habitats; however, captures were higher in riparian than upslope habitat. Tailed frogs (Ascaphus truei), Dunn's salamanders (Plethodon dunni), roughskin newts(Tanicha granulosa), Pacific giant salamanders (Dicamptodon tenebrosus) and red-legged frogs(Rana aurora) were captured more frequently in riparian than upslope habitats. Of these species the red-legged frog and Pacific giant salamander may depend on riparian habitat for at least part of their life requirements, while tailed frogs, Dunn's salamanders and roughskin newts appear to be riparian associated species. In addition, we found Oregon salamanders (Ensatina eschscholtzi) were associated with upslope habitats. We suggest riparian management zones should be al least 75-100 m on each side of the stream and that management for upslope/and or old forest associates may be equally as important as for riparian species.

  10. Evaluation of metric precision for a riparian forest survey.

    PubMed

    Barker, Jerry R; Bollman, Michael; Ringold, Paul L; Sackinger, Jennifer; Cline, Steven P

    2002-04-01

    This article evaluates the performance of a protocol to monitor riparian forests in western Oregon, United States based on the quality of the data obtained from a field survey. Precision is the criteria used to determine the quality of 19 field and 6 derived metrics. The derived metrics were calculated from the field data. The survey consisted of 110 riparian sites on public and private lands that were sampled during the summers of 1996 and 1997. In order to calculate metric precision, some of the field plots were re-measured. Metric precision was defined in terms of the coefficient of variability (CV) and standard deviation and then compared with a pre-defined data quality objective (DQO). A metric was considered precise if the CV met or exceeded the DQO. The geomorphology metrics were not precise while the forest stand inventory metrics and forest cover metrics, with some exceptions, were precise. The precision for many of the field and derived metrics compared favorably with the level of precision for similar metrics reported in the literature. Recommendations are made to improve the precision for some metrics and they include changing the way precision is calculated, re-defining the field protocol, or improving field training. PMID:15900665

  11. Woody biomass resource of Louisiana, 1991. Forest Service resource bulletin

    SciTech Connect

    Rosson, J.F.

    1993-09-01

    Data from the 1991 Louisiana forest survey were used to derive fresh and dry biomass estimates for all trees, on timberland, greater than 1.0 inch in diameter at breast height (d.b.h.). There are 470.0 million fresh tons in softwood species and 757.5 million fresh tons in hardwood species. The woody biomass resource averages 45.9 and 61.9 tons per acre for softwoods and hardwoods where they occur, respectively. Most of this biomass is in the stem portion of the trees--85 percent for softwoods and 75 percent for hardwoods. Nonindustrial private landowners hold 58 and 69 percent of the total softwood and hardwood biomass resource, respectively.

  12. Woody Debris: Denitrification Hotspots and N2O Production in Fluvial Systems

    EPA Science Inventory

    The maintenance and restoration of forested riparian cover is important for watershed nitrogen (N) cycling. Forested riparian zones provide woody debris to streams that may stimulate in-stream denitrification and control nitrous oxide (N2O) production. We examined the effects of ...

  13. Inundation and Fire Shape the Structure of Riparian Forests in the Pantanal, Brazil

    PubMed Central

    Arruda, Wellinton de Sá; Oldeland, Jens; Paranhos Filho, Antonio Conceição; Pott, Arnildo; Cunha, Nicolay L.; Ishii, Iria Hiromi; Damasceno-Junior, Geraldo Alves

    2016-01-01

    Inundation and fire can affect the structure of riparian vegetation in wetlands. Our aim was to verify if there are differences in richness, abundance, basal area, composition and topographic preference of woody species in riparian forests related to the fire history, flooding duration, or the interaction between both. The study was conducted in the riparian forests of the Paraguay River some of which were burned three times between 2001 and 2011. We sampled trees with a girth of at least 5 cm at breast height in 150 5 × 10 m plots (79 burned and 71 unburned). We also measured height of the flood mark and estimated the flooding duration of each plot. We performed Generalized Linear Mixed Models to verify differences in richness, basal area, and abundance of individuals associated to interaction of fire and inundation. We used an analysis of similarity (ANOSIM) and indicator species analysis to identify differences in composition of species and the association with burned and unburned area according to different levels of inundation. Finally, we used a hierarchical set of Generalized Linear Models (GLM), the so-called HOF models, to analyse each species’ specific response to inundation based on topography and to determine their preferred optimal topographic position for both burned as well as unburned areas. Richness was positively associated with elevation only in burned areas while abundance was negatively influenced by inundation only in burned areas. Basal area was negatively associated with time of inundation independent of fire history. There were 15 species which were significant indicators for at least one combination of the studied factors. We found nine species in burned areas and 15 in unburned areas, with response curves in HOF models along the inundation gradient. From these, five species shifted their optimal position along the inundation gradient in burned areas. The interaction of fire and inundation did not appear to affect the basal area, but it

  14. Inundation and Fire Shape the Structure of Riparian Forests in the Pantanal, Brazil.

    PubMed

    Arruda, Wellinton de Sá; Oldeland, Jens; Paranhos Filho, Antonio Conceição; Pott, Arnildo; Cunha, Nicolay L; Ishii, Iria Hiromi; Damasceno-Junior, Geraldo Alves

    2016-01-01

    Inundation and fire can affect the structure of riparian vegetation in wetlands. Our aim was to verify if there are differences in richness, abundance, basal area, composition and topographic preference of woody species in riparian forests related to the fire history, flooding duration, or the interaction between both. The study was conducted in the riparian forests of the Paraguay River some of which were burned three times between 2001 and 2011. We sampled trees with a girth of at least 5 cm at breast height in 150 5 × 10 m plots (79 burned and 71 unburned). We also measured height of the flood mark and estimated the flooding duration of each plot. We performed Generalized Linear Mixed Models to verify differences in richness, basal area, and abundance of individuals associated to interaction of fire and inundation. We used an analysis of similarity (ANOSIM) and indicator species analysis to identify differences in composition of species and the association with burned and unburned area according to different levels of inundation. Finally, we used a hierarchical set of Generalized Linear Models (GLM), the so-called HOF models, to analyse each species' specific response to inundation based on topography and to determine their preferred optimal topographic position for both burned as well as unburned areas. Richness was positively associated with elevation only in burned areas while abundance was negatively influenced by inundation only in burned areas. Basal area was negatively associated with time of inundation independent of fire history. There were 15 species which were significant indicators for at least one combination of the studied factors. We found nine species in burned areas and 15 in unburned areas, with response curves in HOF models along the inundation gradient. From these, five species shifted their optimal position along the inundation gradient in burned areas. The interaction of fire and inundation did not appear to affect the basal area, but it

  15. Importance of riparian forests in urban watersheds contingent on sediment and hydrologic regimes

    USGS Publications Warehouse

    Roy, A.H.; Freeman, Mary C.; Freeman, B.J.; Wenger, S.J.; Meyer, J.L.; Ensign, W.E.

    2006-01-01

    Forested riparian corridors are thought to minimize impacts of landscape disturbance on stream ecosystems; yet, the effectiveness of streamside forests in mitigating disturbance in urbanizing catchments is unknown. We expected that riparian forests would provide minimal benefits for fish assemblages in streams that are highly impaired by sediment or hydrologic alteration. We tested this hypothesis in 30 small streams along a gradient of urban disturbance (1?65% urban land cover). Species expected to be sensitive to disturbance (i.e., fluvial specialists and ?sensitive? species that respond negatively to urbanization) were best predicted by models including percent forest cover in the riparian corridor and a principal components axis describing sediment disturbance. Only sites with coarse bed sediment and low bed mobility (vs. sites with high amounts of fine sediment) had increased richness and abundances of sensitive species with higher percent riparian forests, supporting our hypothesis that response to riparian forests is contingent on the sediment regime. Abundances of Etheostoma scotti, the federally threatened Cherokee darter, were best predicted by models with single variables representing stormflow (r2 = 0.34) and sediment (r2 = 0.23) conditions. Lentic-tolerant species richness and abundance responded only to a variable representing prolonged duration of low-flow conditions. For these species, hydrologic alteration overwhelmed any influence of riparian forests on stream biota. These results suggest that, at a minimum, catchment management strategies must simultaneously address hydrologic, sediment, and riparian disturbance in order to protect all aspects of fish assemblage integrity.

  16. Importance of Coarse Woody Debris to Avian Communities in Loblolly Pine Forests

    SciTech Connect

    Lohr, S.M.; Gauthreaux, S.A.; Kilgo, J.C.

    2001-06-14

    Investigates the importance of standing and down coarse woody debris to bird communities in loblolly pine forests, researchers compared breeding and nonbreeding responses of birds among two coarse woody debris removal and control treatments. Quantification of vegetation layers to determine their effects on the experimental outcome coarse woody debris removal had no effect on the nonbreeding bird community. Most breeding and nonbreeding species used habitats with sparse midstory and well-developed understory, where as sparse canopy cover and dense midstory were important to some nonbreeding species. Snag and down coarse woody debris practices that maintain a dense understory, sparse midstory and canopy will create favorable breeding habitat.

  17. Forest transpiration from sap flux density measurements in a Southeastern Coastal Plain riparian buffer system

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Forested riparian buffers are prevalent throughout the Southeastern Coastal Plain Region of the United States (US). Because they make up a significant portion of the regional landscape, transpiration within these riparian buffers is believed to have an important impact on the hydrologic budget of r...

  18. Interplay of riparian forest and groundwater in the hillslope hydrology of Sudanian West Africa (northern Benin)

    NASA Astrophysics Data System (ADS)

    Richard, A.; Galle, S.; Descloitres, M.; Cohard, J.-M.; Vandervaere, J.-P.; Séguis, L.; Peugeot, C.

    2013-12-01

    Forests are thought to play an important role in the regional dynamics of the West African monsoon, through their capacity to extract water from a permanent and deep groundwater table to the atmosphere even during the dry season. It should be the case for riparian forests too, as these streambank forests are key landscape elements in Sudanian West Africa. The interplay of riparian forest and groundwater in the local hydrodynamics was investigated, by quantifying their contribution to the water balance. Field observations from a comprehensively instrumented hillslope in northern Benin were used. Particular attention was paid to measurements of actual evapotranspiration, soil water and deep groundwater levels. A vertical 2-D hydrological modelling approach using the Hydrus software was used as a testing tool to understand the interactions between the riparian area and the groundwater. The model was calibrated and evaluated using a multi-criteria approach (reference simulation). A virtual experiment, including three other simulations, was designed (no forest, no groundwater, neither forest nor groundwater). The model correctly simulated the hydrodynamics of the hillslope regarding vadose zone dynamics, deep groundwater fluctuation and actual evapotranspiration dynamics. The virtual experiment showed that the riparian forest transpiration depleted the deep groundwater table level and disconnected it from the river, which is consistent with the observations. The riparian forest and the deep groundwater table actually form an interacting transpiration system: the high transpiration rate in the riparian area was shown to be due to the existence of the water table, supplied by downslope lateral water flows within the hillslope soil layer. The simulated riparian transpiration rate was practically steady all year long, around 7.6 mm d-1. This rate lies within high-end values of similar study results. The riparian forest as simulated here contributes to 37% of the annual

  19. Managing coarse woody debris in forests of the Rocky Mountains. Forest Service research paper

    SciTech Connect

    Graham, R.T.; Harvey, A.E.; Jurgensen, M.F.; Jain, T.B.; Tonn, J.R.

    1994-09-01

    Recommendations for managing coarse woody debris after timber harvest were developed for 14 habitat types, ranging from ponderosa pine (Pinus ponderosa) habitat types of Arizona to subalpine fir (Abis lasiocarpa) habitat types of western Montana. Ectomycorrhizae were used as a bioindicator of health, productive forest soils. Undisturbed stands were studied to determine the optimum amounts of organic material for ectomycorrhizal activity. The management recommendations are intentionally conservative to ensure that enough organic matter is left after timber harvest to maintain long-term forest productivity.

  20. Riparian forest disturbances by a mountain flood - the influence of floated wood

    NASA Astrophysics Data System (ADS)

    Johnson, Sherri L.; Swanson, Frederick J.; Grant, Gordon E.; Wondzell, Steven M.

    2000-10-01

    Large floods can have major impacts on riparian forests. Here we examine the variability and spatial distribution of riparian forest responses along eight third- to fifth-order streams following a large flood (100 year recurrence interval) in the Cascade Mountain Range of Oregon. We categorized disturbance intensity (physical force) exerted on riparian trees during floods into three classes: (i) purely fluvial (high water flow only); (ii) fluvial supplemented by dispersed pieces of floating wood (uncongested wood transport); (iii) fluvial with movement of batches of wood (congested wood transport). These types of material transport and associated classes of disturbance intensity resulted in a gradient of biotic responses of disturbance severity ranging from standing riparian trees inundated by high water, to trees toppled but still partially rooted, to complete removal of trees. High within-stream and among-stream responses were influenced by pre-flood stream and riparian conditions as well as flood dynamics, especially the availability of individual pieces or congested batches of wood.Fluvial disturbance alone toppled fewer riparian trees than in reaches where floodwaters transported substantial amounts of wood. Debris flows delivered additional wood and sediment to parts of reaches of four of these study streams; riparian trees were removed and toppled for up to 1·5 km downstream of the debris flow tributary channel. Congested wood transport resulted in higher frequency of toppled trees and greater deposition of new wood levees along channel margins. The condition of the landscape at the time of a major flood strongly influenced responses of riparian forests. Recent and historic land-use practices, as well as the time since the previous large flood, influenced not only the structure and age of the riparian forests, but also the availability of agents of disturbance, such as large pieces of floating wood, that contribute to disturbance of riparian forests during

  1. Effects of sedimentation on soil nutrient dynamics in riparian forests.

    PubMed

    Lockaby, B G; Governo, R; Schilling, E; Cavalcanti, G; Hartsfield, C

    2005-01-01

    The influence of sedimentation rates on biogeochemistry of riparian forests was studied near ephemeral streams at Fort Benning, GA. Upper reaches of seven ephemeral streams had received varying rates of sedimentation stemming from erosion along unpaved roadways at the military installation. Two reference catchments were also included in the study. Decomposition of foliar litter, microbial C and N, N mineralization, and arthropod populations were compared within and among catchments. Rates of sedimentation over the past 25 yr ranged from 0 in references to 4.0 cm yr(-1). Decomposition rates declined exponentially with sedimentation rates as low as 0.20 to 0.32 cm yr(-1) and appeared to reach an equilibrium at a sedimentation rate of 0.5 cm yr(-1). Nitrogen mineralization and microbial C and N followed the same trend. Sedimentation had no discernible effect on arthropod populations. These data suggest that biogeochemical cycles may be altered by sedimentation rates that commonly occur in some floodplain forests. PMID:15647569

  2. Sediment dynamics in restored riparian forest with different widths and agricultural surroundings

    NASA Astrophysics Data System (ADS)

    Stucchi Boschi, Raquel; Simões da Silva, Laura; Ribeiro Rodrigues, Ricardo; Cooper, Miguel

    2016-04-01

    The riparian forests are essential to maintaining the quality of water resources, aquifer recharge and biodiversity. Due to the ecological services provided by riparian forests, these areas are considered by the law as Permanent Preservation Areas, being mandatory maintenance and restoration. However, the obligation of restoration and the extent of the Permanent Preservation Areas as defined by the Brazilian Forest Code, based on water body width, elucidates the lack of accurate scientific data on the influence of the size of the riparian forest in maintaining their ecological functions, particularly regarding the retention of sediments. Studies that evaluate the ideal width of riparian forests to guarantee their ecological functions are scarce and not conclusive, especially when we consider newly restored forests, located in agricultural areas. In this study, we investigate the dynamics of erosion and sedimentation in restored riparian forests with different widths situated in agricultural areas. The two study areas are located in a Semideciduous Tropical Forest inserted in sugarcane landscapes of São Paulo state, Brazil. The installed plots had 60 and 100 m in length and the riparian forest has a width of 15, 30 and 50 m. The characteristics of the sediments inside the plots were evaluated by detailed morphological and micromorphological studies as well as physical characterization. The dynamics of deposition and the amount of deposited sediments have been assessed with graded metal stakes partially buried inside the plots. The intensity, frequency and distribution of rainfall, as well as the occurrence of extreme events, have been evaluated by data collected from rain gauges installed in the areas. We expect that smaller widths are not able to retain sediments originated from the adjacent sugarcane areas. We also believe that extreme events are responsible for generating most of the sediments. The results will be important to support the discussion about an

  3. The affect of a clearcut environment on woody debris respiration rate dynamics, Harvard Forest, Massachusetts

    NASA Astrophysics Data System (ADS)

    Vanderhoof, M. K.; Williams, C. L.

    2011-12-01

    At an ecosystem scale, the distribution of carbon is largely a function of stand development and disturbance processes. Clearcut logging remains a common practice both in the United States and globally and typically results in elevated storage of carbon in onsite woody debris and detritus. The residence time and decomposition rate of this woody debris and detritus will affect the rate of CO2 efflux to the atmosphere and thus affect the long term consequences of such disturbances on carbon flux and storage. The removal of a forest canopy also affects a site's microclimate including the albedo, air temperature, air humidity, as well as soil temperature and moisture, many of the same factors that affect the rate of woody debris decomposition. Thus it could be expected that differences in woody debris characteristics (e.g. size, abundance, state of decay), as well as differences in microclimate, between mature and recently clearcut forest sites, would result in differences in piece and site-level woody debris decomposition rates. Although woody debris stocks post-harvest have been well characterized, few studies have explored post-disturbance woody debris respiration rates, which directly measures carbon emissions from woody debris, distinguishing decomposition from mass loss due to fragmentation or leaching. This study addressed the question: does a clearcut environment in a temperate forest affect the rate of decomposition of coarse woody debris? The rate of respiration of downed spruce logs were repeatedly measured in-situ using an LI-6250 gas analyzer in Harvard Forest, Petersham, Massachusetts. Treatments included clear-cut, shaded clear-cut, mature spruce stand, and transfer (from clearcut to spruce stand). Gas analyzer measurements were accompanied by measurements of log temperature and percent water, soil temperature, moisture and pH, as well as light levels, air temperature and humidity to determine dominant drivers of respiration rates.

  4. Structure Measurements of Leaf and Woody Components of Forests with Dual-Wavelength Lidar Scanning Data

    NASA Astrophysics Data System (ADS)

    Strahler, A. H.; Li, Z.; Schaaf, C.; Howe, G.; Martel, J.; Hewawasam, K.; Douglas, E. S.; Chakrabarti, S.; Cook, T.; Paynter, I.; Saenz, E. J.; Wang, Z.; Woodcock, C. E.; Jupp, D. L. B.; Schaefer, M.; Newnham, G.

    2014-12-01

    Forest structure plays a critical role in the exchange of energy, carbon and water between land and atmosphere and nutrient cycle. We can provide detailed forest structure measurements of leaf and woody components with the Dual Wavelength Echidna® Lidar (DWEL), which acquires full-waveform scans at both near-infrared (NIR, 1064 nm) and shortwave infrared (SWIR, 1548 nm) wavelengths from simultaneous laser pulses. We collected DWEL scans at a broadleaf forest stand and a conifer forest stand at Harvard Forest in June 2014. Power returned from leaves is much lower than from woody materials such as trunks and branches at the SWIR wavelength due to the liquid water absorption by leaves, whereas returned power at the NIR wavelength is similar from both leaves and woody materials. We threshold a normalized difference index (NDI), defined as the difference between returned power at the two wavelengths divided by their sum, to classify each return pulse as a leaf or trunk/branch hit. We obtain leaf area index (LAI), woody area index (WAI) and vertical profiles of leaf and woody components directly from classified lidar hits without empirical wood-to-total ratios as are commonly used in optical methods of LAI estimation. Tree heights, diameter at breast height (DBH), and stem count density are the other forest structure parameters estimated from our DWEL scans. The separation of leaf and woody components in tandem with fine-scale forest structure measurements will benefit studies on carbon allocation of forest ecosystems and improve our understanding of the effects of forest structure on ecosystem functions. This research is supported by NSF grant, MRI-0923389

  5. Importance of riparian forests in urban catchments contingent on sediment and hydrologic regimes

    USGS Publications Warehouse

    Roy, A.H.; Freeman, Mary C.; Freeman, B.J.; Wenger, S.J.; Meyer, J.L.; Ensign, W.E.

    2006-01-01

    Forested riparian corridors are thought to minimize impacts of landscape disturbance on stream ecosystems; yet, the effectiveness of streamside forests in mitigating disturbance in urbanizing catchments is unknown. We expected that riparian forests would provide minimal benefits for fish assemblages in streams that are highly impaired by sediment or hydrologic alteration. We tested this hypothesis in 30 small streams along a gradient of urban disturbance (1-65% urban land cover). Species expected to be sensitive to disturbance (i.e., fluvial specialists and "sensitive" species that respond negatively to urbanization) were best predicted by models including percent forest cover in the riparian corridor and a principal components axis describing sediment disturbance. Only sites with coarse bed sediment and low bed mobility (vs. sites with high amounts of fine sediment) had increased richness and abundances of sensitive species with higher percent riparian forests, supporting our hypothesis that response to riparian forests is contingent on the sediment regime. Abundances of Etheostoma scotti, the federally threatened Cherokee darter, were best predicted by models with single variables representing stormflow (r2 = 0.34) and sediment (r2 = 0.23) conditions. Lentic-tolerant species richness and abundance responded only to a variable representing prolonged duration of low-flow conditions. For these species, hydrologic alteration overwhelmed any influence of riparian forests on stream biota. These results suggest that, at a minimum, catchment management strategies must simultaneously address hydrologic, sediment, and riparian disturbance in order to protect all aspects of fish assemblage integrity. ?? 2006 Springer Science+Business Media, Inc.

  6. PATTERNS OF TREE DOMINANCE IN CONIFEROUS RIPARIAN FORESTS

    EPA Science Inventory

    This research quantified patterns of riparian tree dominance in western Oregon, USA and then compared the observed patterns with the expected patterns defined from the literature. Research was conducted at 110 riparian sites located on private and public lands. The field sites we...

  7. Geostatistical modeling of riparian forest microclimate and its implications for sampling

    USGS Publications Warehouse

    Eskelson, B.N.I.; Anderson, P.D.; Hagar, J.C.; Temesgen, H.

    2011-01-01

    Predictive models of microclimate under various site conditions in forested headwater stream - riparian areas are poorly developed, and sampling designs for characterizing underlying riparian microclimate gradients are sparse. We used riparian microclimate data collected at eight headwater streams in the Oregon Coast Range to compare ordinary kriging (OK), universal kriging (UK), and kriging with external drift (KED) for point prediction of mean maximum air temperature (Tair). Several topographic and forest structure characteristics were considered as site-specific parameters. Height above stream and distance to stream were the most important covariates in the KED models, which outperformed OK and UK in terms of root mean square error. Sample patterns were optimized based on the kriging variance and the weighted means of shortest distance criterion using the simulated annealing algorithm. The optimized sample patterns outperformed systematic sample patterns in terms of mean kriging variance mainly for small sample sizes. These findings suggest methods for increasing efficiency of microclimate monitoring in riparian areas.

  8. [Floristic composition and distribution of the Andean subtropical riparian forests of Lules River, Tucuman, Argentina].

    PubMed

    Sirombra, Martín G; Mesa, Leticia M

    2010-03-01

    We studied the floristic composition and distribution of the riparian forest of two hydrographical systems in a subtropical Andean region. Using uni and multivariate techniques, we tested the hypotheses that a differentiable riparian forest exists, composed by native vegetation typical of the Yungas phytogeographical province, and that the distribution of vegetation varied significantly with geomorphologic characteristics. Parallel transects along the water courses were used to collect presence-absence data of vegetation in eleven sites. Detrended Correspondence Analysis defined a group of common riparian species for the studied area (Solanum riparium, Phenax laevigatus, Tipuana tipu, Cestrum parqui, Carica quercifolia, Acacia macracantha, Celtis iguanaea, Juglans australis, Pisoniella arborescens, Baccharis salicifolia, Cinnamomum porphyrium and Eugenia uniflora) and identified two reference sites. The distribution of the riparian vegetation varied significantly with the geomorphic characteristics along the studied sites. Riparian habitats were composed by native and exotic species. A distinct riparian flora, different in structure and function from adjacent terrestrial vegetation, could not be identified. Riparian species were similar to the adjacent terrestrial strata. These species would not be limited by the proximity to the river. Anthropogenic impacts were important factors regulating the introduction and increase of exotic vegetation. The lack of regulation of some activities in the zone could cause serious problems in the integrity of this ecosystem. PMID:20411737

  9. Factors affecting songbird nest survival in riparian forests in a Midwestern agricultural landscape

    USGS Publications Warehouse

    Peak, R.G.; Thompson, F. R., III; Shaffer, T.L.

    2004-01-01

    We investigated factors affecting nest success of songbirds in riparian forest and buffers in northeastern Missouri. We used an information-theoretic approach to determine support for hypotheses concerning effects of nest-site, habitat-patch, edge, and temporal factors on nest success of songbirds in three narrow (55DS95 m) and three wide (400DS530 m) riparian forests with adjacent grasslandDSshrub buffer strips and in three narrow and three wide riparian forests without adjacent grasslandDSshrub buffer strips. We predicted that temporal effects would have the most support and that habitat-patch and edge effects would have little support, because nest predation would be great across all sites in the highly fragmented, predominantly agricultural landscape. Interval nest success was 0.404, 0.227, 0.070, and 0.186, respectively, for Gray Catbird (Dumetella carolinensis), Northern Cardinal (Cardinalis cardinalis), Indigo Bunting (Passerina cyanea), and forest interior species pooled (Acadian Flycatcher [Empidonax virescens], Wood Thrush [Hylocichla mustelina], Ovenbird [Seiurus aurocapillus], and Kentucky Warbler [Oporornis formosus]). The effect of nest stage on nest success had the most support; daily nest success for Gray Catbird and Indigo Bunting were lowest in the laying stage. We found strong support for greater nest success of Gray Catbird in riparian forests with adjacent buffer strips than in riparian forests without adjacent buffer strips. Patch width also occurred in the most supported model for Gray Catbird, but with very limited support. The null model received the most support for Northern Cardinal. Riparian forests provided breeding habitat for areas sensitive forest species and grassland-shrub nesting species. Buffer strips provided additional breeding habitat for grassland-shrub nesting species. Interval nest success for Indigo Bunting and area-sensitive forest species pooled, however, fell well below the level that is likely necessary to balance

  10. Factors affecting songbird nest survival in riparian forests in a midwestern agricultural landscape

    USGS Publications Warehouse

    Peak, R.G.; Thompson, F. R., III; Shaffer, T.L.

    2004-01-01

    We investigated factors affecting nest success of songbirds in riparian forest and buffers in northeastern Missouri. We used an information-theoretic approach to determine support for hypotheses concerning effects of nest-site, habitat-patch, edge, and temporal factors on nest success of songbirds in three narrow (55-95 m) and three wide (400-530 m) riparian forests with adjacent grassland-shrub buffer strips and in three narrow and three wide riparian forests without adjacent grassland-shrub buffer strips. We predicted that temporal effects would have the most support and that habitat-patch and edge effects would have little support, because nest predation would be great across all sites in the highly fragmented, predominantly agricultural landscape. Interval nest success was 0.404, 0.227, 0.070, and 0.186, respectively, for Gray Catbird (Dumetella carolinensis), Northern Cardinal (Cardinalis cardinalis), Indigo Bunting (Passerina cyanea), and forest interior species pooled (Acadian Flycatcher [Empidonax virescens], Wood Thrush [Hylocichla mustelina], Ovenbird [Seiurus aurocapillus], and Kentucky Warbler [Oporornis formosus]). The effect of nest stage on nest success had the most support; daily nest success for Gray Catbird and Indigo Bunting were lowest in the laying stage. We found strong support for greater nest success of Gray Catbird in riparian forests with adjacent buffer strips than in riparian forests without adjacent buffer strips. Patch width also occurred in the most-supported model for Gray Catbird, but with very limited support. The null model received the most support for Northern Cardinal. Riparian forests provided breeding habitat for area-sensitive forest species and grassland-shrub nesting species. Buffer strips provided additional breeding habitat for grassland-shrub nesting species. Interval nest success for Indigo Bunting and area-sensitive forest species pooled, however, fell well below the level that is likely necessary to balance juvenile

  11. Regulating riparian forests for aquatic productivity in the Pacific Northwest, USA: addressing a paradox.

    PubMed

    Newton, Michael; Ice, George

    2016-01-01

    Forested riparian buffers isolate streams from the influence of harvesting operations that can lead to water temperature increases. Only forest cover between the sun and stream limits stream warming, but that cover also reduces in-stream photosynthesis, aquatic insect production, and fish productivity. Water temperature increases that occur as streams flow through canopy openings decrease rapidly downstream, in as little as 150 m. Limiting management options in riparian forests restricts maintenance and optimization of various buffer contributions to beneficial uses, including forest products, fish, and their food supply. Some riparian disturbance, especially along cold streams, appears to benefit fish productivity. Options for enhancing environmental investments in buffers should include flexibility in application of water quality standards to address the general biological needs of fish and temporary nature of clearing induced warming. Local prescriptions for optimizing riparian buffers and practices that address long-term habitat needs deserve attention. Options and incentives are needed to entice landowners to actively manage for desirable riparian forest conditions. PMID:26611633

  12. Toward a woody plant list for Antigua and Barbuda: Past and present. Forest Service general technical report

    SciTech Connect

    Francis, J.; Rivera, C.; Figureroa, J.

    1994-06-01

    Beginning in the 17th century, the forest lands of Antigua and Barbuda were cleared for agriculture, burned, cut over, and grazed severely. A survey by personnel of the USDA Forest Service, International Institute of Tropical Forestry and previous surveys were used to assemble lists of native and exotic woody plants. A large majority of the original woody flora still grows on both islands.

  13. Arthropod prey for riparian associated birds in headwater forests of the Oregon Coast Range

    USGS Publications Warehouse

    Hagar, Joan C.; Li, Judith; Sobota, Janel; Jenkins, Stephanie

    2012-01-01

    Headwater riparian areas occupy a large proportion of the land base in Pacific Northwest forests, and thus are ecologically and economically important. Although a primary goal of management along small headwater streams is the protection of aquatic resources, streamside habitat also is important for many terrestrial wildlife species. However, mechanisms underlying the riparian associations of some terrestrial species have not been well studied, particularly for headwater drainages. We investigated the diets of and food availability for four bird species associated with riparian habitats in montane coastal forests of western Oregon, USA. We examined variation in the availability of arthropod prey as a function of distance from stream. Specifically, we tested the hypotheses that (1) emergent aquatic insects were a food source for insectivorous birds in headwater riparian areas, and (2) the abundances of aquatic and terrestrial arthropod prey did not differ between streamside and upland areas during the bird breeding season. We found that although adult aquatic insects were available for consumption throughout the study period, they represented a relatively small proportion of available prey abundance and biomass and were present in only 1% of the diet samples from only one of the four riparian-associated bird species. Nonetheless, arthropod prey, comprised primarily of insects of terrestrial origin, was more abundant in streamside than upland samples. We conclude that food resources for birds in headwater riparian areas are primarily associated with terrestrial vegetation, and that bird distributions along the gradient from streamside to upland may be related to variation in arthropod prey availability. Because distinct vegetation may distinguish riparian from upland habitats for riparian-associated birds and their terrestrial arthropod prey, we suggest that understory communities be considered when defining management zones for riparian habitat.

  14. Simulating impacts of Woody Biomass Harvesting on North Temperate Forest Carbon and Nitrogen Cycling and Storage

    NASA Astrophysics Data System (ADS)

    Hua, D.; Desai, A. R.; Bolstad, P.; Cook, B. D.; Scheller, R.

    2012-12-01

    Woody biomass harvesting is a common feature of forest management given its importance to society for acquisition of pulp and paper, lumber, and wood-based biofuel. Harvest affects many aspects of the forest environment such as biodiversity, soil nutrient quality, physical properties of soil, water quality, wildlife habitat, and climate feedbacks. In this study, we applied a modified CENTURY model to the Willow Creek, Wisconsin Ameriflux site for simulation of the impacts of woody biomass removal on forest carbon and nitrogen storage. Woody biomass harvesting scenarios with different harvesting types, interval, tree species, and soil properties were designed and tested in the model to explore the impact of harvesting on forest productivity, soil and biomass carbon and nitrogen storage, and net carbon exchange between terrestrial ecosystem and the atmosphere. Comparisons of the impacts among harvesting scenarios indicate that woody biomass harvesting significantly alters long-term net soil carbon and nitrogen storage as well as carbon exchange between terrestrial ecosystem and the atmosphere. The simulation results also provide a framework for incorporating carbon management into sustainable forest management practices.

  15. Woody biomass production lags stem-girth increase by over one month in coniferous forests.

    PubMed

    Cuny, Henri E; Rathgeber, Cyrille B K; Frank, David; Fonti, Patrick; Mäkinen, Harri; Prislan, Peter; Rossi, Sergio; Del Castillo, Edurne Martinez; Campelo, Filipe; Vavrčík, Hanuš; Camarero, Jesus Julio; Bryukhanova, Marina V; Jyske, Tuula; Gričar, Jožica; Gryc, Vladimír; De Luis, Martin; Vieira, Joana; Čufar, Katarina; Kirdyanov, Alexander V; Oberhuber, Walter; Treml, Vaclav; Huang, Jian-Guo; Li, Xiaoxia; Swidrak, Irene; Deslauriers, Annie; Liang, Eryuan; Nöjd, Pekka; Gruber, Andreas; Nabais, Cristina; Morin, Hubert; Krause, Cornelia; King, Gregory; Fournier, Meriem

    2015-01-01

    Wood is the main terrestrial biotic reservoir for long-term carbon sequestration(1), and its formation in trees consumes around 15% of anthropogenic carbon dioxide emissions each year(2). However, the seasonal dynamics of woody biomass production cannot be quantified from eddy covariance or satellite observations. As such, our understanding of this key carbon cycle component, and its sensitivity to climate, remains limited. Here, we present high-resolution cellular based measurements of wood formation dynamics in three coniferous forest sites in northeastern France, performed over a period of 3 years. We show that stem woody biomass production lags behind stem-girth increase by over 1 month. We also analyse more general phenological observations of xylem tissue formation in Northern Hemisphere forests and find similar time lags in boreal, temperate, subalpine and Mediterranean forests. These time lags question the extension of the equivalence between stem size increase and woody biomass production to intra-annual time scales(3, 4, 5, 6). They also suggest that these two growth processes exhibit differential sensitivities to local environmental conditions. Indeed, in the well-watered French sites the seasonal dynamics of stem-girth increase matched the photoperiod cycle, whereas those of woody biomass production closely followed the seasonal course of temperature. We suggest that forecasted changes in the annual cycle of climatic factors(7) may shift the phase timing of stem size increase and woody biomass production in the future. PMID:27251531

  16. Effects of fireplace use on forest vegetation and amount of woody debris in suburban forests in northwestern Switzerland.

    PubMed

    Hegetschweiler, K Tessa; van Loon, Nicole; Ryser, Annette; Rusterholz, Hans-Peter; Baur, Bruno

    2009-02-01

    Urban forests are popular recreation areas in Europe. Several of these temperate broad-leaved forests also have a high conservation value due to sustainable management over many centuries. Recreational activities, particularly the use of fireplaces, can cause extensive damage to soil, ground vegetation, shrubs, and trees. Firewood collection depletes woody debris, leading to a loss of habitat for specialized organisms. We examined the effects of fireplace use on forest vegetation and the amount of woody debris by comparing disturbed and control plots in suburban forests in northwestern Switzerland. At frequently used fireplaces, we found reduced species densities in the ground vegetation and shrub layer and changes in plant species composition due to human trampling within an area of 150-200 m(2). Picnicking and grilling also reduced the height and changed the age structure of shrubs and young trees. The amount of woody debris was lower in disturbed plots than in control plots. Pieces of wood with a diameter of 0.6-7.6 cm were preferentially collected by fireplace users. The reduction in woody debris volume extended up to a distance of 16 m from the fire ring, covering an area of 800 m(2) at each picnic site. In order to preserve the ecological integrity of urban forests and to maintain their attractiveness as important recreation areas, we suggest depositing logging residues to be used as firewood and to restrict visitor movements near picnic sites. PMID:18773236

  17. Analyzing riparian forest cover changes along the Firniz River in the Mediterranean City of Kahramanmaras in Turkey.

    PubMed

    Akay, Abdullah E; Sivrikaya, Fatih; Gulci, Sercan

    2014-05-01

    Riparian forests adjacent to surface water are important transitional zones which maintain and enrich biodiversity and ensure the sustainability in a forest ecosystem. Also, riparian forests maintain water quality, reduce sediment delivery, enhance habitat areas for aquatic life and wildlife, and provide ecological corridors between the upland and the downstream. However, the riparian ecosystems have been degraded mainly due to human development, forest operations, and agricultural activities. In order to evaluate the impacts of these factors on riparian forests, it is necessary to estimate trends in forest cover changes. This study aims to analyze riparian forest cover changes along the Firniz River located in Mediterranean city of Kahramanmaras in Turkey. Changes in riparian forest cover from 1989 to 2010 have been determined by implementing supervised classification method on a series of Landsat TM imagery of the study area. The results indicated that the classification process applied on 1989 and 2010 images provided overall accuracy of 80.08 and 75 %, respectively. It was found that the most common land use class within the riparian zone was productive forest, followed by degraded forest, agricultural areas, and other land use classes. The results also indicated that the areas of degraded forest and forest openings increased, while productive forest and agricultural areas decreased between the years of 1989 and 2010. The amount of agricultural areas decreased due to the reduction in the population of rural people. According to these results, it can be concluded that special forest management and operation techniques should be implemented to restore the forest ecosystem in riparian areas. PMID:24338054

  18. Distribution, recruitment, and geomorphic significance of large woody debris in an alluvial forest stream: Tonghi Creek, southeastern Australia

    NASA Astrophysics Data System (ADS)

    Webb, Ashley A.; Erskine, Wayne D.

    2003-03-01

    The complex yet poorly understood interactions between riparian vegetation, large woody debris and fluvial geomorphology in an anthropogenically undisturbed reach of an alluvial, sand-bed forest stream in SE Australia have been determined. Riparian vegetation exhibits lateral and vertical zonation of understorey and overstorey species. The dominant riparian tree species, Tristaniopsis laurina (water gum), grows within the channel and on the floodplain within one channel width of the stream. Larger Eucalyptus species only grow on the highest parts of the floodplain and on a low Pleistocene river terrace. A complete large woody debris (LWD) census conducted in the 715-m-long study reach revealed that water gum comprises 17.6% of the total LWD loading, which, at 576 m 3 ha -1, is high for a stream with a catchment area of 187 km 2. Although most LWD has a small diameter (0.1-0.3 m), the greatest contribution to the total volume of LWD is by pieces with a diameter between 0.3 and 0.7 m. A high proportion of LWD (10.4%) has a blockage ratio greater than 10%. The spatial distribution of LWD is random both longitudinally and within individual meander bends. Dominant recruitment processes of LWD vary by species. T. laurina trees are recruited to the channel by minor bank erosion and senescence, while the Eucalyptus species are predominantly recruited from the highest parts of the floodplain/low-river terrace by episodic windthrow during large storms. Multiple radiocarbon dates of outer wood of immobile LWD indicate a maximum residence time of 240±40 years BP for T. laurina timber. The high loading of LWD combined with the extensive root systems of riparian vegetation stabilize Tonghi Creek. Log steps form natural wooden drop-structures with a mean height of 29 mm that were responsible for 20.5% of the total head loss under base flow conditions ( Q=0.08 m 3 s -1). Large woody debris is buried in the bed at depths of up to 2.3 m and is responsible for an estimated 49% of

  19. The width of riparian habitats for understory birds in an Amazonian forest.

    PubMed

    Bueno, Anderson Saldanha; Bruno, Renato Saragoça; Pimentel, Tania Pena; Sanaiotti, Tânia Margarete; Magnusson, William Ernest

    2012-03-01

    Riparian habitats are important for the maintenance of regional biodiversity. Many studies have compared bird distributions between riparian and non-riparian habitats but have not established how wide riparian habitats used by birds are, as measured by distance from the nearest stream. We investigated the distribution of understory birds along gradients of distance from streams, soil clay content, and slope in a central Amazonian forest, by mist-netting birds three times in 45 plots. We used nonmetric multidimensional scaling (NMDS) to reduce the dimensionality of species quantitative (abundance) and qualitative (presence-absence) composition to one multivariate axis. Estimates of the width of riparian habitats as indicated by understory birds depended on the community attribute considered, measuring 90 m for species quantitative composition and 140 m for species qualitative composition. Species distributions were correlated with clay content but were independent of slope, while distance from streams was positively correlated with clay content but independent of slope. Clay content affects plant species composition, which in turn, may influence bird species composition. However, distribution patterns of birds in relation to distance from streams are consistent among studies carried out in many different temperate and tropical regions, indicating an effect of distance from streams itself. Protection of riparian habitats is one of the most widely used conservation strategies, and Brazilian environmental legislation mandates the protection of a 30 m wide strip of riparian vegetation on either side of small streams. We show that the protected strip should be much wider and recommend strategies to place other forms of land protection contiguous with riparian areas so that Brazilian environmental legislation better fulfills its role of protecting biodiversity associated with riparian habitats. PMID:22611867

  20. Woody biomass resource of east Texas, 1992. Forest Service Resource Bulletin

    SciTech Connect

    Rosson, J.F.

    1993-09-01

    Data from the most recent east Texas forest survey were used to derive estimates of wood and bark biomass by counties. The information is important to resource managers, legislators, policymakers, and procurement specialists in regard to the extent, location, and potential availability of the woody biomass resource in the State. Wood and bark biomass estimates for all trees on timberland are summarized in the report. The resource is described by dimension (size), forest type, ownership, species, stand attributes, and tree merchantability class.

  1. Stream-grade variation and riparian- forest ecology along Passage Creek, Virginia.

    USGS Publications Warehouse

    Hupp, C.R.

    1982-01-01

    Passage Creek flows on relatively nonresistant shales, then cuts through a gorge underlain by resistant sandstone. In the gorge, the stream gradient steepens, the size of bed material increases, a braided channel forms, and riparian-forest composition and growth form changes relative to areas outside the gorge. Effects of flooding are intensified within the gorge and revealed in the pattern and deformation of streamside vegetation. Increased stream gradient within the gorge provides for high stream power and coarse sediment deposition relative to the flood plain outside the gorge. A more diverse upland forest grows on the flood plain in the gorge. The riparian forest in the gorge may be an example of a nonequilibrium forest, resulting from periodic disturbance by destructive floods.-from Author

  2. Impacts of stream flow and climate variability on native and invasive woody species in a riparian ecosystem of a semi-arid region of the Great Plains, USA

    NASA Astrophysics Data System (ADS)

    Skolaut, K.; Awada, T.; Cherubini, P.; Schapaugh, A.; Huddle, J.

    2012-04-01

    Riparian ecosystems support diverse plant communities that exert direct and indirect biological, physical and chemical influence on, and are influenced by, adjacent water through both above and below-ground interactions. Historically, riparian areas of the northern Great Plains (United States) have been dominated by the native Populus deltoides (eastern cottonwood). This species relies on regular floods for regeneration and groundwater access for success. Over the past sixty years, changes in flow management and agricultural practices, coupled with climate variability and drought, have altered stream flow and caused a dramatic decline in stream water yields and levels of groundwater. These and other biotic factors have promoted the expansion of the upland native woody species Juniperus virginiana (eastern redcedar), and the invasion of the non-native (introduced) Elaeagnus angustifolia (Russian olive) into riparian ecosystems. This invasion has further altered the water balance in the system and exasperated the problem of water scarcity with negative feedback on ecosystem services and growth of native woody species. The ability of P. deltoides to re-establish and grow is of concern for natural resource managers. The study utilizes tree ring analysis of annual growth rates and stable isotope ratios of 13C and 18O to determine 1) the response P. deltoides and invasive J. virginiana and E. angustifulia have to climate variation and stream flow regulation, and 2) the impacts of the two invasive species on the growth of native P. deltoides. Preliminary results have shown that P. deltoids annual growth rate (using basal area increment growth) continually declined over the last 40 yrs, while that of E. angustifolia steadily increased. Growth of both P. deltoides and J. virginiana displayed greater dependence on climatic factors than E. angustifolia. Ecological and hydrological significance of the results will be presented.

  3. Object-based class modelling for multi-scale riparian forest habitat mapping

    NASA Astrophysics Data System (ADS)

    Strasser, Thomas; Lang, Stefan

    2015-05-01

    Object-based class modelling allows for mapping complex, hierarchical habitat systems. The riparian zone, including forests, represents such a complex ecosystem. Forests within riparian zones are biologically high productive and characterized by a rich biodiversity; thus considered of high community interest with an imperative to be protected and regularly monitored. Satellite earth observation (EO) provides tools for capturing the current state of forest habitats such as forest composition including intermixture of non-native tree species. Here we present a semi-automated object based image analysis (OBIA) approach for the mapping of riparian forests by applying class modelling of habitats based on the European Nature Information System (EUNIS) habitat classifications and the European Habitats Directive (HabDir) Annex 1. A very high resolution (VHR) WorldView-2 satellite image provided the required spatial and spectral details for a multi-scale image segmentation and rule-base composition to generate a six-level hierarchical representation of riparian forest habitats. Thereby habitats were hierarchically represented within an image object hierarchy as forest stands, stands of homogenous tree species and single trees represented by sunlit tree crowns. 522 EUNIS level 3 (EUNIS-3) habitat patches with a mean patch size (MPS) of 12,349.64 m2 were modelled from 938 forest stand patches (MPS = 6868.20 m2) and 43,742 tree stand patches (MPS = 140.79 m2). The delineation quality of the modelled EUNIS-3 habitats (focal level) was quantitatively assessed to an expert-based visual interpretation showing a mean deviation of 11.71%.

  4. Woody biomass resource of Arkansas, 1988. Forest Service resource bulletin

    SciTech Connect

    Rosson, J.F.

    1993-04-01

    Data from the most recent Arkansas forest survey were used to derive estimates of wood and bark biomass by counties. Wood and bark biomass estimates for all trees on timberland are summarized in the report. The resource is described by dimension (size), forest type, ownership, species, stand attributes, and tree merchantability class. Also, estimates pertaining to timberland acreage were included.

  5. Flows for floodplain forests: a successful riparian restoration

    USGS Publications Warehouse

    Rood, Stewart B.; Gourley, Chad R.; Ammon, Elisabeth M.; Heki, Lisa G.; Klotz, Jonathan R.; Morrison, Michael L.; Mosley, Dan; Scoppettone, Gayton G.; Swanson, Sherman; Wagner, Paul L.

    2003-01-01

    Throughout the 20th century, the Truckee River that flows from Lake Tahoe into the Nevada desert was progressively dammed and dewatered, which led to the collapse of its aquatic and riparian ecosystems. The federal designation of the endemic cui-ui sucker (Chasmistes cujus) as endangered prompted a restoration program in the 1980s aimed at increasing spring flows to permit fish spawning. These flows did promote cui-ui reproduction, as well as an unanticipated benefit, the extensive seedling recruitment of Fremont cottonwood (Populus fremontii) and sandbar willow (Salix exigua). Recruitment was scattered in 1983 but extensive in 1987, when the hydrograph satisfied the riparian recruitment box model that had been developed for other rivers. That model was subsequently applied to develop flow prescriptions that were implemented from 1995 through 2000 and enabled further seedling establishment. The woodland recovery produced broad ecosystem benefits, as evidenced by the return by 1998 of 10 of 19 riparian bird species whose populations had been locally extirpated or had declined severely between 1868 and 1980. The dramatic partial recovery along this severely degraded desert river offers promise that the use of instream flow regulation can promote ecosystem restoration along other dammed rivers worldwide.

  6. Simulation of Soil Quality with Riparian Forests and Cultivated with Sugarcane

    NASA Astrophysics Data System (ADS)

    da Silva, Luiz Gabriel; Colato, Alexandre; Casagrande, José Carlos; Soares, Marcio Roberto; Perissatto Meneghin, Silvana

    2013-04-01

    Riparian forests are entrusted with important hydrological functions, such as riparian zone protection, filtering sediments and nutrients and mitigation of the amount of nutrients and xenobiotic molecules from the surrounding agro ecosystems. The soil was sampled in the depths of 0-0,2 and 0.2-0.4 m and its chemical (nutrient content and organic matter, cationic exchange capacity - CEC, sum of bases-SB, bases saturation, V%, and aluminum saturation, m%); physical (particle size distribution, density and porosity) and microbiological attributes (basal respiration and microbial biomass) were determined. This work aimed to study the liner method of combining data, figures of merit (FoM), weighing process and the scoring functions developed by Wymore and asses the quality of the soil (SQI) by means of chemical, physical and microbiological soil attributes, employing the additive pondered model for two areas of riparian forest at different stages of ecological succession and an adjacent area cultivated with sugar cane, located on the dam shores of Sugar Mill Saint Lucia-Araras/SP. Some hierarchical functions containing FoMs and their parameters were constructed, and from them weights were assigned to each FoM and parameter, in a way that cluster of structures with the same FoMs and parameters with different weights were formed. These clusters were used to calculate the SQI for all vegetal formations considering two types of soil (Oxisol and Podzol), in that way, the SQI was calculated for each combination of vegetation and soil. The SQIs values were usually higher in the oldest riparian forest, while the recent riparian forest showed the smallest SQI values, for both types of soil. The variation of values within a combination vegetation/soil was also different between all combinations, being that the set of values from the oldest riparian forest presented the lowest amplitude. It was also observed that the Oxisols, regardless of the vegetation, presented higher SQIs

  7. Assessing Extension's Ability to Promote Family Forests as a Woody Biomass Feedstock in the Northeast United States

    ERIC Educational Resources Information Center

    Germain, Rene' H.; Ghosh, Chandrani

    2013-01-01

    The study reported here surveyed Extension educators' awareness and knowledge of woody biomass energy and assessed their desire and ability to reach out to family forest owners-a critical feedstock source. The results indicate Extension educators are aware of the potential of woody biomass to serve as a renewable source of energy. Respondents…

  8. Fate of Herbicides and Their Degradation Products Entering a Forested Riparian Buffer Following Herbicides Application to an Adjacent Corn Field

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The fate of two herbicides, atrazine and metolachlor, were followed as they entered and moved through a forested riparian wetland located in the mid-Atlantic coastal plain of Maryland. The herbicides were applied as pre-emergent treatments to a 20-ha corn field directly upgradient of the riparian w...

  9. Surface Water and Groundwater Nitrogen Dynamics in a Well Drained Riparian Forest within a Poorly Drained Agricultural Landscape

    EPA Science Inventory

    The effectiveness of riparian zones in mitigating nutrients in ground and surface water depends on the climate, management and hydrogeomorphology of a site. The purpose of this study was to determine the efficacy of a well-drained, mixed-deciduous riparian forest to buffer a ri...

  10. Biological and Physical Drivers of Coarse Woody Debris Respiration Following Moderate Forest Disturbance

    NASA Astrophysics Data System (ADS)

    Schmid, A. V.; Franklin, R. B.; Vogel, C. S.; Liebman, E.; Curtis, P.; Gough, C. M.

    2014-12-01

    Forest disturbances that cause plant mortality alter the net carbon (C) balance by increasing heterotrophic respiration associated with coarse woody debris (CWD) decomposition. Whether a forest transitions from a C sink to source following disturbance is largely a function of the quantity of additional CWD produced and the rate of woody debris decomposition. Coarse woody debris temperature, moisture, and microbial community composition are known to drive rates of heterotrophic respiration, but rarely have these factors been studied together across a gradient of wood decay and over time following disturbance. We used a large-scale experimental disturbance, in which early successional aspen (Populus spp.) and birch (Betula papyrifera) were killed via stem girdling within a 39 ha area, to study the effects of moderate disturbance on the forest C cycle. We quantified changes over time in CWD mass for a decade, before and after disturbance. We then conducted point measurements of CWD respiration, temperature and moisture, and quantified extracellular enzyme activity of enzymes associated with wood decomposition for five classes varying in extent of decay and standing woody debris. Process and inventory data are being used to estimate ecosystem CO2 efflux from CWD, which we will contrast with net ecosystem production (NEP) determined from long-term eddy covariance measurements of net CO2 exchange between the forest and atmosphere at the University of Michigan Biological Station (US-UMd) Ameriflux site. Our results will improve ecosystem model predictions of CWD respiration by incorporating both physical factors, such as temperature and wood moisture content, and biological factors, such as extracellular enzymatic activity of different functional types of decomposers.

  11. BIODIVERSITY MANAGEMENT APPROACHES FOR STREAM-RIPARIAN AREAS: PERSPECTIVES FOR PACIFIC NORTHWEST HEADWATER FORESTS, MICROCLIMATES, AND AMPHIBIANS

    EPA Science Inventory

    Stream-riparian areas represent a nexus of biodiversity, with disproportionate numbers of species tied to and interacting within this key habitat. New research in Pacific Northwest headwater forests, especially the characterization of microclimates and amphibian distributions, is...

  12. A composite indicator for assessing habitat quality of riparian forests derived from Earth observation data

    NASA Astrophysics Data System (ADS)

    Riedler, Barbara; Pernkopf, Lena; Strasser, Thomas; Lang, Stefan; Smith, Geoff

    2015-05-01

    Riparian forests are precious, complex habitats fostering high biodiversity where effective monitoring of habitat quality is particularly important. We present a composite indicator, referred to as Riparian Forest composite Indicator: focus on Structure (RFI_S), for the assessment of habitat quality and identification of 'hot-spot' areas where conservation actions need to be taken. The RFI_S is composed of seven indicators derived from very high resolution (VHR) satellite imagery and LiDAR data, calculated on patch level. These indicators assess four important attributes of riparian forest quality: (1) tree species composition, (2) vertical forest structure, (3) horizontal forest structure and (4) water regime. For the aggregation of the RFI_S, two different weighting schemes, expert-based and statistical weighting, are applied. Forest patches with high cumulative RFI_S values represent patches of good habitat quality. These patches are primarily found along water bodies, reflecting the importance of water bodies for the structural complexity, an optimum water regime and tree species composition. For forest patches of low habitat quality the RFI_S helps to design suitable measures to improve habitat quality status through its decomposability into the underlying indicators. A sensitivity analysis to test the robustness of the RFI_S shows that the indicator variance in terrain roughness has the strongest influence on the composite indicator. Finally, a comparison with an existing expert-based map on conservation status reveals the potential of a complementary quantitative assessment of habitat quality in the study site. We hence conclude that the RFI_S has a high capability to support sustainable forest management complementing regularly gathered in situ data.

  13. Tree mortality, canopy turnover, and woody detritus in old cove forests of the southern Appalachians

    USGS Publications Warehouse

    Busing, R.T.

    2005-01-01

    A long-term study of tree mortality, canopy turnover, and coarse woody detritus inputs was conducted in cove forests of the Great Smoky Mountains, Tennessee, USA. Seven old-growth stands were studied over a 10-yr period using 0.6-1.0 ha plots. Annual mortality of trees >10 cm dbh was 0.5-1.4% among stands (mean 0.7%), The highest mortality rate among canopy trees was exhibited by trees >80 cm dbh. An increase in mortality rate with canopy tree size was evident for two (Tsuga canadensis and Acer saccharum) of the three most abundant species in the forest. The increase in mortality with tree size had implications for canopy turnover and detritus input. Gap disturbance frequency was estimated at 0.008-0.019 forest area/yr, giving a return interval of ???130 yr or less. Standing death was the most common mode of mortality (59%). Annual rates of snag formation were 1.4 snags/ha for trees >10 cm dbh and 0.4 snags/ha for trees >50 cm dbh. The density of large snags (>50 cm dbh) was 5 snags/ha. Snags accounted for 8% of the total standing tree basal area and 23% of the coarse woody detritus mass (total of 48 Mg/ ha). The mean annual rate of coarse woody detritus input was 3.0 Mg/ha. A decay rate constant was estimated at 0.07, yielding a detritus half-life of 10 yr. Although mean mortality rates and canopy turnover in old cove forests were moderate in comparison with other old forests of eastern North America, input and accumulation of coarse woody detritus were high for the region. This resulted, in part, from the relatively large sizes attained by canopy trees and the fact that larger trees tended to suffer higher mortality. In comparison to forests worldwide, rates of mortality, canopy gap formation, and decay of coarse woody detritus were intermediate.

  14. Evapotranspiration Rates of Riparian Forests, Platte River, Nebraska, 2002-06

    USGS Publications Warehouse

    Landon, Matthew K.; Rus, David L.; Dietsch, Benjamin J.; Johnson, Michaela R.; Eggemeyer, Kathleen D.

    2009-01-01

    Evapotranspiration (ET) in riparian areas is a poorly understood component of the regional water balance in the Platte River Basin, where competing demands have resulted in water shortages in the ground-water/surface-water system. From April 2002 through March 2006, the U.S. Geological Survey, Nebraska Platte River Cooperative Hydrology Study Group, and Central Platte Natural Resources District conducted a micrometeorological study of water and energy balances at two sites in central Nebraska near Odessa and Gothenburg to improve understanding of ET rates and factors affecting them in Platte River riparian forests. A secondary objective of the study was to constrain estimates of ground-water use by riparian vegetation to satisfy ET consumptive demands, a useful input to regional ground-water flow models. Both study sites are located on large islands within the Platte River characterized by a cottonwood-dominated forest canopy on primarily sandy alluvium. Although both sites are typical of riparian forests along the Platte River in Nebraska, the Odessa understory is dominated by deciduous shrubs, whereas the Gothenburg understory is dominated by eastern redcedars. Additionally, seasonal ground-water levels fluctuated more at Odessa than at Gothenburg. The study period of April 2002 through March 2006 encompassed precipitation conditions ranging from dry to wet. This study characterized the components of the water balance in the riparian zone of each site. ET was evaluated from eddy-covariance sensors installed on towers above the forest canopy at a height of 26.1 meters. Precipitation was measured both above and below the forest canopy. A series of sensors measured soil-moisture availability within the unsaturated zone in two different vertical profiles at each site. Changes in ground-water altitude were evaluated from piezometers. The areal footprint represented in the water balance extended up to 800 meters from each tower. During the study, ET was less variable

  15. Spatial and temporal patterns of beetles associated with coarse woody debris in managed bottomland hardwood forests.

    SciTech Connect

    Ulyshen, M., D.; Hanula, J., L.; Horn, S.; Kilgo, J., C.; Moorman, C., E.

    2004-05-13

    For. Ecol. and Mgt. 199:259-272. Malaise traps were used to sample beetles in artificial canopy gaps of different size (0.13 ha, 0.26 ha, and0.50 ha) and age in a South Carolina bottomland hardwood forest. Traps were placed at the center, edge, and in the surrounding forest of each gap. Young gaps (ý 1 year) had large amounts of coarse woody debris compared to the surrounding forest, while older gaps (ý 6 years) had virtually none. The total abundance and diversity of wood-dwelling beetles (Buprestidae, Cerambycidae, Brentidae, Bostrichidae, and Curculionidae (Scolytinae and Platypodinae)) was higher in the center of young gaps than in the center of old gaps. The abundance was higher in the center of young gaps than in the surrounding forest, while the forest surrounding old gaps and the edge of old gaps had a higher abundance and diversity of wood-dwelling beetles than did the center of old gaps. There was no difference in wood-dwelling beetle abundance between gaps of different size, but diversity was lower in 0.13 ha old gaps than in 0.26 ha or 0.50 ha old gaps. We suspect that gap size has more of an effect on woodborer abundance than indicated here because malaise traps sample a limited area. The predaceous beetle family Cleridae showed a very similar trend to that of the woodborers. Coarse woody debris is an important resource for many organisms, and our results lend further support to forest management practices that preserve coarse woody debris created during timber removal.

  16. Effect of emergent aquatic insects on bat foraging in a riparian forest.

    PubMed

    Fukui, Dai; Murakami, Masashi; Nakano, Shigeru; Aoi, Toshiki

    2006-11-01

    1. Riparian zones serve several ecological functions for bats. They provide a source of prey and likely provide favourable structural habitats and shelter from predators. Many studies have shown that bats use the space above streams, ponds or riparian vegetation as feeding habitat. These studies, however, have never distinguished between the effects of habitat structure and prey availability on the foraging activities of bats. Such effects can only be distinguished by an experimental approach. We predicted that bat activity along a stream is influenced by the number of emerged aquatic insects. 2. We evaluated the response of terrestrial consumers, insectivorous bats, to changes in the abundance of emergent aquatic insects by conducting a manipulative field experiment. In a deciduous riparian forest in Japan, aquatic insect flux from the stream to the riparian zone was controlled with an insect-proof cover over a 1.2 km stream reach. 3. We estimated the abundance of emergent aquatic and flying terrestrial arthropods near the treatment and control reaches using Malaise traps. The foraging activity of bats was evaluated in both treatment and control reaches using ultrasonic detectors. 4. The insect-proof cover effectively reduced the flux of emergent aquatic insects to the riparian zone adjacent to the treatment reach. Adjacent to the control reach, adult aquatic insect biomass was highest in spring, and then decreased gradually. Terrestrial insect biomass increased gradually during the summer at both treatment and control reaches. 5. Foraging activity of bats was correlated with insect abundance. In spring, foraging activity of bats at the control reach was significantly greater than at the treatment reach, and increased at both sites with increasing terrestrial insect abundance. 6. Our result suggests that the flux of aquatic insects emerging from streams is one of the most important factors affecting the distribution of riparian-foraging bats. As is the case with

  17. Assessing the extent and diversity of riparian ecosystems in Sonora, Mexico

    USGS Publications Warehouse

    Scott, M.L.; Nagler, P.L.; Glenn, E.P.; Valdes-Casillas, C.; Erker, J.A.; Reynolds, E.W.; Shafroth, P.B.; Gomez-Limon, E.; Jones, C.L.

    2009-01-01

    Conservation of forested riparian ecosystems is of international concern. Relatively little is known of the structure, composition, diversity, and extent of riparian ecosystems in Mexico. We used high- and low-resolution satellite imagery from 2000 to 2006, and ground-based sampling in 2006, to assess the spatial pattern, extent, and woody plant composition of riparian forests across a range of spatial scales for the state of Sonora, Mexico. For all 3rd and higher order streams, river bottomlands with riparian forests occupied a total area of 2,301 km2. Where forested bottomlands remained, on average, 34% of the area had been converted to agriculture while 39% remained forested. We estimated that the total area of riparian forest along the principal streams was 897 km2. Including fencerow trees, the total forested riparian area was 944 km2, or 0.5% of the total land area of Sonora. Ground-based sampling of woody riparian vegetation consisted of 92, 50 m radius circular plots. About 79 woody plant species were noted. The most important tree species, based on cover and frequency, were willow species Salix spp. (primarily S. goodingii and S. bonplandiana), mesquite species Prosopis spp. (primarily P. velutina), and Fremont cottonwood Populus fremontii. Woody riparian taxa at the reach scale showed a trend of increasing diversity from north to south within Sonora. Species richness was greatest in the willow-bald cypress Taxodium distichum var. mexicanum-Mexican cottonwood P. mexicana subsp. dimorphia ecosystem. The non-native tamarisk Tamarix spp. was rare, occurring at just three study reaches. Relatively natural stream flow patterns and fluvial disturbance regimes likely limit its establishment and spread. ?? 2008 Springer Science + Business Media BV.

  18. Different spatial organisation strategies of woody plant species in a montane cloud forest

    NASA Astrophysics Data System (ADS)

    Ledo, Alicia; Montes, Fernando; Condés, Sonia

    2012-01-01

    The coexistence of a high number of species in the forest is a central issue in tropical ecology. In this paper, we aim to characterise the spatial pattern of woody species in an Andean montane cloud forest to determine whether differences exist among the species in terms of spatial organization and if so, whether these differences are related to the life-form, primary dispersal mode, shade tolerance or the diameter distribution of the species. For this purpose, we analysed the spatial pattern of each species as well as the spatial relationships between young and adult individuals. Almost all the analysed species showed a cluster pattern, followed by a random pattern at larger distances. The cluster size is more evident for the young trees whereas adult trees tended to be more randomly distributed. The shade-tolerant species showed greater distances of aggregation than gap or medium-shade-tolerant species. Species primarily dispersed by wind and small birds showed larger distances of aggregation than species dispersed by mammals or big birds. All the under-story woody plants showed a notable cluster pattern, whereas canopy trees showed a variety of spatial patterns, with clustering at small scales being the most frequent. In the case of emergent trees, association was found between young and adult individuals on a large scale. Positive associations between young and adult individuals predominate at small scales for medium and shade tolerant species and at larger scales for bird-dispersed species whereas negative spatial associations at smaller scales were found for shade tolerant species and wind dispersed species. Our study confirms that conspecific organization varies among the woody plants in the analysed forest, and that the spatial pattern of woody plants is partially linked to shade tolerance, primary dispersal mode and life form of the species.

  19. Stream Community Structure: An Analysis of Riparian Forest Buffer Restoration in the Chesapeake Bay Watershed

    NASA Astrophysics Data System (ADS)

    Orzetti, L. L.; Jones, R. C.

    2005-05-01

    Forested riparian buffer zones have been proposed as an important aid in curtailing upland sources of pollution before they reach stream surface waters, and enhancing habitat for stream organisms. Our objective was to test the efficacy of restored forest riparian buffers along streams in the Chesapeake Bay watershed by examining the stream macrobenthic community structure. To test our hypothesis, we collected riffle benthic and water samples, and performed habitat evaluations at 30 stream sites in the mid-Atlantic Piedmont, ranging in buffer age from 0 to greater than 50 years of age. Results showed that habitat, water quality, and benthic macroinvertebrate metrics improved with age of restored buffer. Habitat scores were driven mostly by instream substrate availability and width and age of riparian buffer zones. Water quality parameters varied within buffer age groups depending age of surrounding forest vegetation. Benthic invertebrate taxa richness, % EPT, % Plecoptera, % Ephemeroptera, and the FBI all improved with age of buffer zone. Instream habitat quality was the greatest driver of benthic macroinvertebrate community diversity and health, and appeared to plateau within 10-15 years of restoration with noticeable improvements occurring within 5-10 years post restoration.

  20. Impacts of Stream Flow and Climate Variability on Native and Invasive Woody Species in a Riparian Ecosystem of a Semi-Arid Region of the Great Plains, USA

    NASA Astrophysics Data System (ADS)

    Skolaut, K.; Awada, T.; Cherubini, P.; Schapaugh, A.

    2012-12-01

    Riparian ecosystems support diverse plant communities that exert direct and indirect biological, physical and chemical influence on, and are influenced by, adjacent water through both above and below-ground interactions. Historically, riparian areas of the northern Great Plains, US have been dominated by the native Populus deltoides (eastern cottonwood). This species relies on regular floods for regeneration and groundwater access for success. Over the past sixty years, changes in flow management and agricultural practices, coupled with climate variability and drought have altered stream flow and caused a dramatic decline in stream water yields and levels of groundwater. These and other biotic and biotic factors have promoted the expansion of the upland native woody species Juniperus virginiana (eastern redcedar), and the invasion of the non-native (introduced) Elaeagnus angustifolia (Russian olive) into riparian ecosystems. This invasion has further altered the water balance in the system and exasperated the problem of water scarcity with negative feedback on ecosystem services and growth of native woody species. The ability of P. deltoides to re-establish and grow is of concern for natural resource managers. Tree ring analysis of annual growth rates were used to determine 1) the responses P. deltoides and invasive J. virginiana and E. angustifulia to climate variability and stream flow regulation, and 2) the impacts of the two invasive species on the growth of native P. deltoides. Results show a dependency of growth for P. deltoides on the previous year summer temperature, and a less significant correlation to annual stream flow. J. virginiana showed the highest correlation to annual stream flow, as well as some dependency on the previous growing season precipitation. While the growth of both P. deltoides and J. virginiana displayed greater dependence on climatic factors, E. angustifolia displayed the lowest mean basal area growth and deviation from the growth. E

  1. Reclamation of coppice forests in order to increase the potential of woody biomass in Serbia

    NASA Astrophysics Data System (ADS)

    Bjelanovic, I.; Krstic, M.

    2012-04-01

    Biomass makes 63% of the total renewable energy potential of Serbia. Here, the biomass from forests together with wood processing industry waste represent the second most important renewable source for energy production. The Action Plan for Biomass of Serbia (2010) shows that the technically exploitable biomass in the Republic of Serbia amounts annually 2.7 Mtoe. Here, the woody biomass (fuelwood, forest residue, wood processing industry residue, wood from trees outside the forest) accounts for 1.0 Mtoe while the rest originates from agricultural sources. According to the national forest inventory (2008), forest cover in Serbia accounts for 29% of the country area, having standing volume of 362.5 mil. m3 and annual increment of 9.1 mil. m3. More than half is state-owned and the rest 47% is in the private ownership. Coppice forests dominate in the forest stock (65%). According to Glavonjić (2010), northeastern and southwestern Serbia are the regions with greatest spatial forest distribution. The general forest condition is characterised by insufficient production volume, unsatisfactory stock density and forest cover, high percentage of degraded forests, unfavorable age structure, unfavorable health condition and weeded areas. Herewith, the basic measures for the improvement of forest fund (Forestry Development Strategy for Serbia, 2006) represent conversion of coppice forests, increase of forest cover and productivity of forest ecosystems by the ecologically, economically and socially acceptable methods. The actions include reclamation of degraded forests, re- and afforestation activities on abandoned agricultural, degraded and other treeless lands. The average standing volume of high forests is 254 m3·ha-1 with an annual increment of 5.5 m3·ha-1. On the contrary, coppice forests dispose 124 m3·ha-1 of standing volume, having an annual increment of 3.1 m3·ha-1. Here, estimated losses from coppice forests amount up to 3.5 mil. m3 wood annually. These data

  2. Effect of long-term understory prescribed burning on standing and down dead woody material in dry upland oak forests

    USGS Publications Warehouse

    Polo, John A.; Hallgren, S.W.; Leslie,, David M., Jr.

    2013-01-01

    Dead woody material, long ignored or viewed as a nuisance for forest management, has gained appreciation for its many roles in the forest including wildlife habitat, nutrient storage and cycling, energy for trophic webs, protection of soil, fuel for fire and carbon storage. The growing interest in managing dead woody material has created strong demand for greater understanding of factors controlling amounts and turnover. Prescribed burning, an important management tool, may have strong effects of dead woody material given fire’s capacity to create and consume dead woody material. We determined effects of long-term understory prescribed burning on standing and down woody material in upland oak forests in south-central North America. We hypothesized that as frequency of fire increased in these stands the amount of deadwood would decrease and the fine woody material would decrease more rapidly than coarse woody material. The study was conducted in forests dominated by post oak (Quercus stellata) and blackjack oak (Quercus marilandica) in wildlife management areas where understory prescribed burning had been practiced for over 20 years and the range of burn frequencies was 0 (unburned) fires per decade (FPD) to 4.6 FPD. The amount of deadwood was low compared with more productive forests in southeastern North America. The biomass (24.7 Mg ha-1) and carbon stocks (11.7 Mg ha-1) were distributed among standing dead (22%), coarse woody debris (CWD, dia. > 7.5 cm., 12%), fine woody debris (FWD, dia. < 7.5 cm., 23%), and forest floor (43%). There was no evidence that understory prescribed burning influenced the amount and size distribution of standing and down dead woody material. There were two explanations for the lack of a detectable effect. First, a high incidence of severe weather including ice storms and strong winds that produce large amounts of deadwood intermittently in an irregular pattern across the landscape may preclude detecting a strong effect of understory

  3. Woody species diversity in forest plantations in a mountainous region of Beijing, China: effects of sampling scale and species selection.

    PubMed

    Zhang, Yuxin; Zhang, Shuang; Ma, Keming; Fu, Bojie; Anand, Madhur

    2014-01-01

    The role of forest plantations in biodiversity conservation has gained more attention in recent years. However, most work on evaluating the diversity of forest plantations focuses only on one spatial scale; thus, we examined the effects of sampling scale on diversity in forest plantations. We designed a hierarchical sampling strategy to collect data on woody species diversity in planted pine (Pinus tabuliformis Carr.), planted larch (Larix principis-rupprechtii Mayr.), and natural secondary deciduous broadleaf forests in a mountainous region of Beijing, China. Additive diversity partition analysis showed that, compared to natural forests, the planted pine forests had a different woody species diversity partitioning pattern at multi-scales (except the Simpson diversity in the regeneration layer), while the larch plantations did not show multi-scale diversity partitioning patterns that were obviously different from those in the natural secondary broadleaf forest. Compare to the natural secondary broadleaf forests, the effects of planted pine forests on woody species diversity are dependent on the sampling scale and layers selected for analysis. Diversity in the planted larch forest, however, was not significantly different from that in the natural forest for all diversity components at all sampling levels. Our work demonstrated that the species selected for afforestation and the sampling scales selected for data analysis alter the conclusions on the levels of diversity supported by plantations. We suggest that a wide range of scales should be considered in the evaluation of the role of forest plantations on biodiversity conservation. PMID:25545860

  4. Woody Species Diversity in Forest Plantations in a Mountainous Region of Beijing, China: Effects of Sampling Scale and Species Selection

    PubMed Central

    Zhang, Yuxin; Zhang, Shuang; Ma, Keming; Fu, Bojie; Anand, Madhur

    2014-01-01

    The role of forest plantations in biodiversity conservation has gained more attention in recent years. However, most work on evaluating the diversity of forest plantations focuses only on one spatial scale; thus, we examined the effects of sampling scale on diversity in forest plantations. We designed a hierarchical sampling strategy to collect data on woody species diversity in planted pine (Pinus tabuliformis Carr.), planted larch (Larix principis-rupprechtii Mayr.), and natural secondary deciduous broadleaf forests in a mountainous region of Beijing, China. Additive diversity partition analysis showed that, compared to natural forests, the planted pine forests had a different woody species diversity partitioning pattern at multi-scales (except the Simpson diversity in the regeneration layer), while the larch plantations did not show multi-scale diversity partitioning patterns that were obviously different from those in the natural secondary broadleaf forest. Compare to the natural secondary broadleaf forests, the effects of planted pine forests on woody species diversity are dependent on the sampling scale and layers selected for analysis. Diversity in the planted larch forest, however, was not significantly different from that in the natural forest for all diversity components at all sampling levels. Our work demonstrated that the species selected for afforestation and the sampling scales selected for data analysis alter the conclusions on the levels of diversity supported by plantations. We suggest that a wide range of scales should be considered in the evaluation of the role of forest plantations on biodiversity conservation. PMID:25545860

  5. Methane and Carbon Dioxide Fluxes from Stems, Soils, and Coarse Woody Debris in a Temperate Forest

    NASA Astrophysics Data System (ADS)

    Warner, D. L.; Villarreal, S.; McWilliams, K.; Inamdar, S. P.; Vargas, R.

    2015-12-01

    Quantifying the magnitude and variability of greenhouse gas fluxes from different terrestrial carbon pools is necessary for enhancing understanding of terrestrial carbon cycling. While much more is known about variability CO2 fluxes, we have little information on how CH4 fluxes vary across multiple carbon pools within terrestrial ecosystems. We measured fluxes of CH4 and CO2 from living tree stems, soils, and coarse woody debris within a temperate forested watershed during the growing season (May-November). Fluxes of both CH4 and CO2 were significantly different among carbon pools. Living tree stems were weak sources of both CH4 and CO2 with seasonal means (± 1 SD) of 0.08 ± 0.19 nmol CH4 m-2 s-1 and 1.16 ± 1.21 μmol CO2 m-2 s-1. Soils were sinks of CH4 and sources of CO2 with seasonal means (± 1 SD) of -2.00 ± 1.41 nmol CH4 m-2 s-1 and 3.07 ± 2.10 μmol CO2 m-2 s-1. Fluxes of CH4 and CO2 from coarse woody debris were largely variable relative to the other pools with seasonal means (± 1 SD) of -0.21 ± 0.76 nmol CH4 m-2 s-1 and 2.61 ± 2.50 μmol CO2m-2 s-1. Gas fluxes varied significantly (p < 0.05) between sampling sites for both living stems and coarse woody debris, but not for soils. For living stems, this variability was explained by differences in tree species, where N. sylvatica had largest seasonal mean flux of CH4 and L. tulipifera had the largest seasonal mean flux of CO2. For woody debris sites, the variability was explained wood density, with dense, fresh wood acting as CH4 sources, and less dense, decayed wood acting as CH4 sinks. Our results show homogeneity in soil CH4 and CO2 fluxes, but a large heterogeneity in fluxes from tree stems and coarse woody debris. These results provide insights on how forest management strategies could influence greenhouse gas emissions from forested watersheds.

  6. Floodplain forest succession reveals fluvial processes: A hydrogeomorphic model for temperate riparian woodlands.

    PubMed

    Egger, Gregory; Politti, Emilio; Lautsch, Erwin; Benjankar, Rohan; Gill, Karen M; Rood, Stewart B

    2015-09-15

    River valley floodplains are physically-dynamic environments where fluvial processes determine habitat gradients for riparian vegetation. These zones support trees and shrubs whose life stages are adapted to specific habitat types and consequently forest composition and successional stage reflect the underlying hydrogeomorphic processes and history. In this study we investigated woodland vegetation composition, successional stage and habitat properties, and compared these with physically-based indicators of hydraulic processes. We thus sought to develop a hydrogeomorphic model to evaluate riparian woodland condition based on the spatial mosaic of successional phases of the floodplain forest. The study investigated free-flowing and dam-impacted reaches of the Kootenai and Flathead Rivers, in Idaho and Montana, USA and British Columbia, Canada. The analyses revealed strong correspondence between vegetation assessments and metrics of fluvial processes indicating morphodynamics (erosion and shear stress), inundation and depth to groundwater. The results indicated that common successional stages generally occupied similar hydraulic environments along the different river segments. Comparison of the spatial patterns between the free-flowing and regulated reaches revealed greater deviation from the natural condition for the braided channel segment than for the meandering segment. This demonstrates the utility of the hydrogeomorphic approach and suggests that riparian woodlands along braided channels could have lower resilience than those along meandering channels and might be more vulnerable to influences such as from river damming or climate change. PMID:26160662

  7. Assessing the Utility of Green LiDAR for Characterizing Forest Canopy Structure and Stream Bathymetry in Riparian Zones.

    NASA Astrophysics Data System (ADS)

    Moskal, L. M.; Richardson, J.

    2014-12-01

    Forested riparian zones serve many ecosystem functions from species habitat through stream shading and large woody debris recruitment, to improvements in water quality. Moreover, stream depth and bathymetry in forested environments is difficult and costly to measure in the field, but critically important for stream-dwelling organisms. Green (bathymetric) LiDAR (G-L) can be used to characterize stream bathymetry, but little is known of its ability to accurately characterize stream bathymetry in narrow (width less than 5 m), heavily forested streams. Canopy characterization with green LiDAR is also poorly understood. We compared canopy and digital elevation models (DEMs) derived from green and near-infrared LiDAR (NIR-L) to field measurements in a narrow, forested stream in Oregon, USA, as well as comparing the two canopy models and DEMs to each other along the length of the stream and to estimates of leaf area index. We observed that the canopy models from the G-L are lower in accuracy compared to NIR-L canopy models. Canopy height models from the G-L were up to 26% less accurate in dense stands, compared to the NIR-L accuracy of 94%. We attribute these errors in part to the lower quality of DEMs generated from the G-L as compared to the NIR-L DEMs. As for bathymetry, the G-L DEM was 0.05 cm higher in elevation than the field measured stream elevation, while the NIR-L ground model was 0.17mm higher. The elevation difference tended to increase with stream depth for both types of LiDAR-derived DEMs, but stream depth only explained a small portion of the variability (coefficient of determination equals 0.09 for NIR-L DEM and 0.05 for G-L DEM). Our results suggest that G-L may be limited in accurately characterizing the bathymetry of narrow streams in heavily forested environments due to difficulty penetrating canopy and interactions with complex topography.

  8. Seeing the Forest through the Trees: Citizen Scientists Provide Critical Data to Refine Aboveground Carbon Estimates in Restored Riparian Forests

    NASA Astrophysics Data System (ADS)

    Viers, J. H.

    2013-12-01

    Integrating citizen scientists into ecological informatics research can be difficult due to limited opportunities for meaningful engagement given vast data streams. This is particularly true for analysis of remotely sensed data, which are increasingly being used to quantify ecosystem services over space and time, and to understand how land uses deliver differing values to humans and thus inform choices about future human actions. Carbon storage and sequestration are such ecosystem services, and recent environmental policy advances in California (i.e., AB 32) have resulted in a nascent carbon market that is helping fuel the restoration of riparian forests in agricultural landscapes. Methods to inventory and monitor aboveground carbon for market accounting are increasingly relying on hyperspatial remotely sensed data, particularly the use of light detection and ranging (LiDAR) technologies, to estimate biomass. Because airborne discrete return LiDAR can inexpensively capture vegetation structural differences at high spatial resolution (< 1 m) over large areas (> 1000 ha), its use is rapidly increasing, resulting in vast stores of point cloud and derived surface raster data. While established algorithms can quantify forest canopy structure efficiently, the highly complex nature of native riparian forests can result in highly uncertain estimates of biomass due to differences in composition (e.g., species richness, age class) and structure (e.g., stem density). This study presents the comparative results of standing carbon estimates refined with field data collected by citizen scientists at three different sites, each capturing a range of agricultural, remnant forest, and restored forest cover types. These citizen science data resolve uncertainty in composition and structure, and improve allometric scaling models of biomass and thus estimates of aboveground carbon. Results indicate that agricultural land and horticulturally restored riparian forests store similar

  9. Use of Course Woody Debris by Cotton Mouse (Peromyscus gossypinus)in a Southeastern Pine Forest

    SciTech Connect

    T.S. McCay

    1999-03-22

    Course woody debris may be an important resource for many small mammals by providing protection and food sources. The author tracked cotton mice movements via radiotelemetry and powder in managed loblolly pine forests. Most day refuges for mice were associated with debris, including rotting stumps (69%), upturned root boles (14%) and under fallen logs (9%). Stumps used were more larger and more highly decomposed. Night time telemetry indicated that mice movements were more closely associated with the logs. Rooting stumps are an important resource for cotton mice.

  10. Accumulation and Connectivity of Coarse Woody Debris in Partial Harvest and Unmanaged Relict Forests

    PubMed Central

    Morrissey, Robert C.; Jenkins, Michael A.; Saunders, Michael R.

    2014-01-01

    When a tree dies, it continues to play an important ecological role within forests. Coarse woody debris (CWD), including standing deadwood (SDW) and downed deadwood (DDW), is an important functional component of forest ecosystems, particularly for many dispersal-limited saproxylic taxa and for metapopulation dynamics across landscapes. Processes, such as natural disturbance or management, modify forest composition and structure, thereby influencing CWD abundance and distribution. Many studies have compared older forests to forests managed with even-aged silvicultural systems and observed a prolonged period of low CWD occurrence after harvesting. With fine-scale spatial data, our study compares the long-term impacts of light partial harvesting on the CWD structure of eastern deciduous hardwood forests. We mapped and inventoried DDW and SDW using variable radius plots based on a 10 m×10 m grid throughout an unmanaged, structurally-complex relict forest and two nearby forests that were partially harvested over 46 years ago. The relict stand had significantly larger individual pieces and higher accumulations of DDW and SDW than both of the partially harvested stands. Connectivity of CWD was much higher in the relict stand, which had fewer, larger patches. Larger pieces and higher proportion of decay-resistant species (e.g. Quercus spp.) in the relict forest resulted in slower decomposition, greater accumulation and increased connectivity of CWD. Partial harvests, such that occur with selection forestry, are generally considered less disruptive of ecosystem services, but this study highlights the long-term impacts of even light partial harvests on CWD stocks and distribution. When planning harvesting events, forest managers should also consider alternative methods to ensure the sustainability of deadwood resources and function. PMID:25409459

  11. Accumulation and connectivity of coarse woody debris in partial harvest and unmanaged relict forests.

    PubMed

    Morrissey, Robert C; Jenkins, Michael A; Saunders, Michael R

    2014-01-01

    When a tree dies, it continues to play an important ecological role within forests. Coarse woody debris (CWD), including standing deadwood (SDW) and downed deadwood (DDW), is an important functional component of forest ecosystems, particularly for many dispersal-limited saproxylic taxa and for metapopulation dynamics across landscapes. Processes, such as natural disturbance or management, modify forest composition and structure, thereby influencing CWD abundance and distribution. Many studies have compared older forests to forests managed with even-aged silvicultural systems and observed a prolonged period of low CWD occurrence after harvesting. With fine-scale spatial data, our study compares the long-term impacts of light partial harvesting on the CWD structure of eastern deciduous hardwood forests. We mapped and inventoried DDW and SDW using variable radius plots based on a 10 m × 10 m grid throughout an unmanaged, structurally-complex relict forest and two nearby forests that were partially harvested over 46 years ago. The relict stand had significantly larger individual pieces and higher accumulations of DDW and SDW than both of the partially harvested stands. Connectivity of CWD was much higher in the relict stand, which had fewer, larger patches. Larger pieces and higher proportion of decay-resistant species (e.g. Quercus spp.) in the relict forest resulted in slower decomposition, greater accumulation and increased connectivity of CWD. Partial harvests, such that occur with selection forestry, are generally considered less disruptive of ecosystem services, but this study highlights the long-term impacts of even light partial harvests on CWD stocks and distribution. When planning harvesting events, forest managers should also consider alternative methods to ensure the sustainability of deadwood resources and function. PMID:25409459

  12. Measuring and Monitoring HydroBiogeochemical Flux in a Forested Riparian Floodplain of the Missouri Ozarks

    NASA Astrophysics Data System (ADS)

    Chinnasamy, P.; Hubbart, J. A.

    2009-12-01

    Forested riparian buffers play a vital role in protecting riparian ecosystems from natural and anthropogenic disturbances. Quantifying effective reach and catchment scale buffer designs is critical to achieve economic and riparian wetland natural resource sustainability. Advances in management of riparian wetlands require innovative reach-scale experimental studies and subsequent improvements in riparian modeling. Riparian recommended best management practices (BMPs) in Missouri (MO) have not been validated. Studies are therefore warranted to describe subsurface interactions between the stream, hyporheic zone (HZ), and adjoining riparian wetland/floodplain. Within the HZ groundwater discharge through highly permeable Karst geology can dramatically affect water quality. The following research is on-going in the Baskett Research and Education Area (BREA), a 9.17 km2 preserved wildland watershed located 8 km east of Ashland, in the Ozark border region of south-central MO. The climate at BREA is generally described as warm, humid, and continental, with mean January and August temperatures of -2.4 °C and 24.5 °C, respectively, and 1,022 mm mean annual precipitation. Limestone geology of Ordovician and Mississippian age underlies the BREA with dominant soils of Weller silt loam and Clinkenbeard clay loam. Vegetation at the BREA consists of northern and southern division oak dominated hickory forests. BREA offers a distinct opportunity to study wildland watershed processes to validate contemporary best management practices (BMP) in MO. To quantify hydrobiogeochemical flux, spatial and temporal (3 water years) variability in stream water temperatures, key nutrients (NO3, P, K, NH3) and hyporheic exchange are being monitored. Key hydrologic variables approaching a mass balance, plus groundwater monitoring (via piezometric arrays) are being studied. Results (beginning summer and fall 2009) will provide the necessary information to quantify the relationships between

  13. Riparian forest as a management tool for moderating future thermal conditions of lowland temperate streams

    NASA Astrophysics Data System (ADS)

    Kristensen, P. B.; Kristensen, E. A.; Riis, T.; Baisner, A. J.; Larsen, S. E.; Verdonschot, P. F. M.; Baattrup-Pedersen, A.

    2013-05-01

    Predictions of the future climate infer that stream water temperatures may increase in temperate lowland areas and that streams without riparian forest will be particularly prone to elevated stream water temperature. Planting of riparian forest is a potential mitigation measure to reduce water temperatures for the benefit of stream organisms. However, no studies have yet determined the length of a forested reach required to obtain a significant temperature decrease. To investigate this we measured the temperature in five small Danish lowland streams from June 2010 to July 2011, all showing a sharp transition between an upstream open reach and a downstream forested reach. In all stream reaches we also measured canopy cover and a range of physical variables characterizing the streams reaches. This allowed us to analyse differences in mean daily temperature and amplitude per month among forested and open sections as well as to study annual temperature regimes and the influence of physical conditions on temperature changes. Stream water temperature in the open reaches was affected by heating, and in July we observed an increase in temperature over the entire length of the investigated reaches, reaching temperatures higher than the incipient lethal limit for brown trout. Along the forest reaches a significant decrease in July temperatures was recorded immediately (100 m) when the stream moved into the forested area. In three of our study streams the temperature continued to decrease the longer the stream entered into the forested reach, and the temperature decline did not reach a plateau. The temperature increases along the open reaches were accompanied by stronger daily temperature variation; however, when the streams entered into the forest, the range in daily variation decreased. Multiple regression analysis of the combined effects on stream water temperature of canopy cover, Width/Depth ratio, discharge, current velocity and water temperature revealed that canopy

  14. Reach-scale effects of riparian forest cover on urban stream ecosystems

    USGS Publications Warehouse

    Roy, A.H.; Faust, C.L.; Freeman, Mary C.; Meyer, J.L.

    2005-01-01

    We compared habitat and biota between paired open and forested reaches within five small streams (basin area 10?20 km2) in suburban catchments (9%?49% urban land cover) in the Piedmont of Georgia, USA. Stream reaches with open canopies were narrower than forested reaches (4.1 versus 5.0 m, respectively). There were no differences in habitat diversity (variation in velocity, depth, or bed particle size) between open and forested reaches. However, absence of local forest cover corresponded to decreased large wood and increased algal chlorophyll a standing crop biomass. These differences in basal food resources translated into higher densities of fishes in open (9.0 individuals?m?2) versus forested (4.9 individuals?m?2) reaches, primarily attributed to higher densities of the herbivore Campostoma oligolepis. Densities of terrestrial invertebrate inputs were higher in open reaches; however, trends suggested higher biomass of terrestrial inputs in forested reaches and a corresponding higher density of terrestrial prey consumed by water column feeding fishes. Reach-scale biotic integrity (macroinvertebrates, salamanders, and fishes) was largely unaffected by differences in canopy cover. In urbanizing areas where catchment land cover drives habitat and biotic quality, management practices that rely exclusively on forested riparian areas for stream protection are unlikely to be effective at maintaining ecosystem integrity.

  15. Coevolution of floodplain and riparian forest dynamics on large, meandering rivers

    NASA Astrophysics Data System (ADS)

    Stella, J. C.; Riddle, J. D.; Battles, J. J.

    2012-12-01

    On large meandering rivers, riparian forests coevolve with the floodplains that support them. Floodplain characteristics such as local disturbance regime, deposition rates and sediment texture drive plant community dynamics, which in turn feed back to the abiotic processes. We investigated floodplain and riparian forest coevolution along the along the Sacramento River (California, USA), a large, mediterranean-climate river that has been extensively regulated for 70 years, but whose 160-km middle reach (Red Bluff to Colusa) retains some channel mobility and natural forest stands. Guided by maps of floodplain change over time and current vegetation cover, we conducted an extensive forest inventory and chronosequence analysis to quantify how abiotic conditions and forest structural characteristics such as tree density, basal area and biomass vary with floodplain age. We inventoried 285 fixed-area plots distributed across 19 large point bars within vegetation patches ranging in age from 4 to 107 years. Two successional trajectories were evident: (1) shifting species dominance over time within forested areas, from willow to cottonwood to walnut, boxelder and valley oak; and (2) patches of shrub willow (primarily Salix exigua) that maintained dominance throughout time. Sediment accretion was reduced in the persistent willow plots compared to the successional forest stands, suggesting an association between higher flood energy and arrested succession. Forested stands 40-60 years old were the most extensive across the chronosequence in terms of floodplain area, and supported the highest biomass, species diversity, and functional wildlife habitat. These stands were dominated by Fremont cottonwood (Populus fremontii) and reached their maxima in terms of tree size and biomass at age 50 years. The persistent willow stands reached their structural maxima earlier (32 years) and supported lower biomass. Basal area and abundance of large trees decreased in stands >90 years old

  16. Effects of high-frequency understorey fires on woody plant regeneration in southeastern Amazonian forests

    PubMed Central

    Balch, Jennifer K.; Massad, Tara J.; Brando, Paulo M.; Nepstad, Daniel C.; Curran, Lisa M.

    2013-01-01

    Anthropogenic understorey fires affect large areas of tropical forest, yet their effects on woody plant regeneration post-fire remain poorly understood. We examined the effects of repeated experimental fires on woody stem (less than 1 cm at base) mortality, recruitment, species diversity, community similarity and regeneration mode (seed versus sprout) in Mato Grosso, Brazil. From 2004 to 2010, forest plots (50 ha) were burned twice (B2) or five times (B5), and compared with an unburned control (B0). Stem density recovered within a year after the first burn (initial density: 12.4–13.2 stems m−2), but after 6 years, increased mortality and decreased regeneration—primarily of seedlings—led to a 63 per cent and 85 per cent reduction in stem density in B2 and B5, respectively. Seedlings and sprouts across plots in 2010 displayed remarkable community similarity owing to shared abundant species. Although the dominant surviving species were similar across plots, a major increase in sprouting occurred—almost three- and fourfold greater in B2 and B5 than in B0. In B5, 29 species disappeared and were replaced by 11 new species often present along fragmented forest edges. By 2010, the annual burn regime created substantial divergence between the seedling community and the initial adult tree community (greater than or equal to 20 cm dbh). Increased droughts and continued anthropogenic ignitions associated with frontier land uses may promote high-frequency fire regimes that may substantially alter regeneration and therefore successional processes. PMID:23610167

  17. Effects of high-frequency understorey fires on woody plant regeneration in southeastern Amazonian forests.

    PubMed

    Balch, Jennifer K; Massad, Tara J; Brando, Paulo M; Nepstad, Daniel C; Curran, Lisa M

    2013-06-01

    Anthropogenic understorey fires affect large areas of tropical forest, yet their effects on woody plant regeneration post-fire remain poorly understood. We examined the effects of repeated experimental fires on woody stem (less than 1 cm at base) mortality, recruitment, species diversity, community similarity and regeneration mode (seed versus sprout) in Mato Grosso, Brazil. From 2004 to 2010, forest plots (50 ha) were burned twice (B2) or five times (B5), and compared with an unburned control (B0). Stem density recovered within a year after the first burn (initial density: 12.4-13.2 stems m(-2)), but after 6 years, increased mortality and decreased regeneration--primarily of seedlings--led to a 63 per cent and 85 per cent reduction in stem density in B2 and B5, respectively. Seedlings and sprouts across plots in 2010 displayed remarkable community similarity owing to shared abundant species. Although the dominant surviving species were similar across plots, a major increase in sprouting occurred--almost three- and fourfold greater in B2 and B5 than in B0. In B5, 29 species disappeared and were replaced by 11 new species often present along fragmented forest edges. By 2010, the annual burn regime created substantial divergence between the seedling community and the initial adult tree community (greater than or equal to 20 cm dbh). Increased droughts and continued anthropogenic ignitions associated with frontier land uses may promote high-frequency fire regimes that may substantially alter regeneration and therefore successional processes. PMID:23610167

  18. Low thermal tolerances of stream amphibians in the Pacific Northwest: Implications for riparian and forest management

    USGS Publications Warehouse

    Bury, R.B.

    2008-01-01

    Temperature has a profound effect on survival and ecology of amphibians. In the Pacific Northwest, timber harvest is known to increase peak stream temperatures to 24??C or higher, which has potential to negatively impact cold-water stream amphibians. I determined the Critical Thermal Maxima (CT max) for two salamanders that are endemic to the Pacific Northwest. Rhyacotriton variegatus larvae acclimated at 10??C had mean CTmax of 26.7 ?? 0.7 SD??C and adults acclimated at 11??C had mean CT max of 27.9 ?? 1.1??C. These were among the lowest known values for any amphibian. Values were significantly higher for larval Dicamptodon tenebrosus acclimated at 14??C (x = 29.1 ?? 0.2??C). Although the smallest R. variegatus had some of the lowest values, size of larvae and adults did not influence CTmax in this species. Current forest practices retain riparian buffers along larger fish-bearing streams; however, such buffers along smaller headwaters and non-fish bearing streams may provide favorable habitat conditions for coldwater-associated species in the Pacific Northwest. The current study lends further evidence to the need for protection of Northwest stream amphibians from environmental perturbations. Forest guidelines that include riparian buffer zones and configurations of upland stands should be developed, while monitoring amphibian responses to determine their success. ?? 2008 Brill Academic Publishers.

  19. Woody plant richness and NDVI response to drought events in Catalonian (northeastern Spain) forests.

    PubMed

    Lloret, F; Lobo, A; Estevan, H; Maisongrande, P; Vayreda, J; Terradas, J

    2007-09-01

    The role of species diversity on ecosystem resistance in the face of strong environmental fluctuations has been addressed from both theoretical and experimental viewpoints to reveal a variety of positive and negative relationships. Here we explore empirically the relationship between the richness of forest woody species and canopy resistance to extreme drought episodes. We compare richness data from an extensive forest inventory to a temporal series of satellite imagery that estimated drought impact on forest canopy as NDVI (normalized difference vegetation index) anomalies of the dry summer in 2003 in relation to records of previous years. We considered five different types of forests that are representative of the main climatic and altitudinal gradients of the region, ranging from lowland Mediterranean to mountain boreal-temperate climates. The observed relationship differed among forest types and interacted with the climate, summarised by the Thorntwaite index. In Mediterranean Pinus halepensis forests, NDVI decreased during the drought. This decrease was stronger in forests with lower richness. In Mediterranean evergreen forests of Quercus ilex, drought did not result in an overall NDVI loss, but lower NDVI values were observed in drier localities with lower richness, and in more moist localities with higher number of species. In mountain Pinus sylvestris forests NDVI decreased, mostly due to the drought impact on drier localities, while no relation to species richness was observed. In moist Fagus sylvatica forests, NDVI only decreased in plots with high richness. No effect of drought was observed in the high mountain Pinus uncinata forests. Our results show that a shift on the diversity-stability relationship appears across the regional, climatic gradient. A positive relationship appears in drier localities, supporting a null model where the probability of finding a species able to cope with drier conditions increases with the number of species. However, in

  20. Mapping aboveground woody biomass using forest inventory, remote sensing and geostatistical techniques.

    PubMed

    Yadav, Bechu K V; Nandy, S

    2015-05-01

    Mapping forest biomass is fundamental for estimating CO₂ emissions, and planning and monitoring of forests and ecosystem productivity. The present study attempted to map aboveground woody biomass (AGWB) integrating forest inventory, remote sensing and geostatistical techniques, viz., direct radiometric relationships (DRR), k-nearest neighbours (k-NN) and cokriging (CoK) and to evaluate their accuracy. A part of the Timli Forest Range of Kalsi Soil and Water Conservation Division, Uttarakhand, India was selected for the present study. Stratified random sampling was used to collect biophysical data from 36 sample plots of 0.1 ha (31.62 m × 31.62 m) size. Species-specific volumetric equations were used for calculating volume and multiplied by specific gravity to get biomass. Three forest-type density classes, viz. 10-40, 40-70 and >70% of Shorea robusta forest and four non-forest classes were delineated using on-screen visual interpretation of IRS P6 LISS-III data of December 2012. The volume in different strata of forest-type density ranged from 189.84 to 484.36 m(3) ha(-1). The total growing stock of the forest was found to be 2,024,652.88 m(3). The AGWB ranged from 143 to 421 Mgha(-1). Spectral bands and vegetation indices were used as independent variables and biomass as dependent variable for DRR, k-NN and CoK. After validation and comparison, k-NN method of Mahalanobis distance (root mean square error (RMSE) = 42.25 Mgha(-1)) was found to be the best method followed by fuzzy distance and Euclidean distance with RMSE of 44.23 and 45.13 Mgha(-1) respectively. DRR was found to be the least accurate method with RMSE of 67.17 Mgha(-1). The study highlighted the potential of integrating of forest inventory, remote sensing and geostatistical techniques for forest biomass mapping. PMID:25930205

  1. Overcoming barriers to seedling regeneration during forest restoration on tropical pasture land and the potential value of woody weeds.

    PubMed

    Elgar, Amelia T; Freebody, Kylie; Pohlman, Catherine L; Shoo, Luke P; Catterall, Carla P

    2014-01-01

    Combating the legacy of deforestation on tropical biodiversity requires the conversion to forest of large areas of established pasture, where barriers to native plant regeneration include competition with pasture grasses and poor propagule supply (seed availability). In addition, initial woody plants that colonise pasture are often invasive, non-native species whose ecological roles and management in the context of forest regeneration are contested. In a restoration experiment at two 0.64 ha sites we quantified the response of native woody vegetation recruitment to (1) release from competition with introduced pasture grasses, and (2) local facilitation of frugivore-assisted seed dispersal provided by scattered woody plants and artificial bird perches. Herbicide pasture grass suppression during 20 months caused a significant but modest increase in density of native woody seedlings, together with abundant co-recruitment of the prominent non-native pioneer wild tobacco (Solanum mauritianum). Recruitment of native species was further enhanced by local structure in herbicide-treated areas, being consistently greater under live trees and dead non-native shrubs (herbicide-treated) than in open areas, and intermediate under bird perches. Native seedling recruitment comprised 28 species across 0.25 ha sampled but was dominated by two rainforest pioneers (Homalanthus novoguineensis, Polyscias murrayi). These early results are consistent with the expected increase in woody vegetation recruitment in response to release from competitive and dispersive barriers to rainforest regeneration. The findings highlight the need for a pragmatic consideration of the ecological roles of woody weeds and the potential roles of "new forests" more broadly in accelerating succession of humid tropical forest across large areas of retired agricultural land. PMID:24904602

  2. CO2 Flux from Coarse Woody Debris from a Tropical Forest at the FLONA Tapajos, Brazil

    NASA Astrophysics Data System (ADS)

    Silva, H.; Crill, P.; Keller, M.

    2004-12-01

    The release of carbon dioxide (CO2) from tropical forests has a strong effect on the global carbon cycle due to fast turnover rates of organic matter than for other biomes. Despite its importance coarse woody debris (CWD) pools have been overlooked for estimates of carbon balance and especially in tropical forests where few studies have been conducted. Measurements were made on CWD in areas of undisturbed tropical forests and areas under selective logging. CO2 emissions from CWD averaged 1.95 \\pm 1.95 \\mu mol CO2 m2 Wood surf^{-1}$ s^{-1} for undisturbed forests and 2.61 ± 1.44 μmol CO_{2} m^{2} Wood _{surf}-1 s^{-1} for selective logging areas. For selective logging areas, a chronosequence study was established to follow up the five years of logging. Three wood species were sorted due differences in density to be studied and observe differences in CO_{2} efflux. Andiroba (Carapa guianensis) showed a average flux of 3.15 ± 3.2 μmol CO_{2} m^{2} Wood _{surf}-1 s^{-1}, tauari (Couratari stellata) with 2.88 ± 2.03 μmol CO_{2} m^{2} Wood _{surf}-1 s^{-1} and macaranduba (Manilkara huberi) with an average flux of 1.69 ± 1.6 μmol CO_{2} m^{2} Wood _{surf}-1 s^{-1}. An area of undisturbed forest was studied to quantify the efflux of CO_{2} in natural conditions. CO_{2} emissions from CWD were of 3.76 Mg C ha^{-1} y{-1} in logged areas and 1.43 Mg C ha^{-1} y{-1} for undisturbed forests. Wood water content and wood decay classes (year of logging) were some of the factors studied on controlling of CO_{2}$ efflux from CWD.

  3. Climate and local geomorphic interactions drive patterns of riparian forest decline along a Mediterranean Basin river

    NASA Astrophysics Data System (ADS)

    Stella, John C.; Riddle, Jess; Piégay, Hervé; Gagnage, Matthieu; Trémélo, Marie-Laure

    2013-11-01

    discharge, and this will increase both chronic and acute water shortage for riparian trees. This study shows that drought-prone riparian forests are vulnerable to hydrogeomorphological changes, but the severity of impacts is conditioned by interactions between drivers at different scales, including regional climate variability, reach-based geomorphic alteration, and local lithological controls.

  4. On the potential of long wavelength imaging radars for mapping vegetation types and woody biomass in tropical rain forests

    NASA Technical Reports Server (NTRS)

    Rignot, Eric J.; Zimmermann, Reiner; Oren, Ram

    1995-01-01

    In the tropical rain forests of Manu, in Peru, where forest biomass ranges from 4 kg/sq m in young forest succession up to 100 kg/sq m in old, undisturbed floodplain stands, the P-band polarimetric radar data gathered in June of 1993 by the AIRSAR (Airborne Synthetic Aperture Radar) instrument separate most major vegetation formations and also perform better than expected in estimating woody biomass. The worldwide need for large scale, updated biomass estimates, achieved with a uniformly applied method, as well as reliable maps of land cover, justifies a more in-depth exploration of long wavelength imaging radar applications for tropical forests inventories.

  5. Coarse Woody Debris and Ecosystem Carbon Dynamics in a North Temperate Forest

    NASA Astrophysics Data System (ADS)

    Gough, C. M.; Vogel, C. S.; Nagal, L.; Kazanski, C.; Flower, C.; Curtis, P. S.

    2006-12-01

    Many aspen-dominated forests in the upper Great Lakes region of North America are past maturity and beginning to decline. As trees senesce in these aging forests, coarse woody debris (CWD) is expected to be increasingly important to the ecosystem carbon (C) balance. We used a biometric approach to quantify C mass and the annual respiratory C loss from CWD and other major ecosystem components for a typical mature deciduous forest in northern lower Michigan, USA. Coarse woody debris mass (2.2 Mg C ha-1) was less than that of soils (104.1 Mg C ha-1) and boles (71.7 Mg C ha-1), but similar to that of leaves (1.8 Mg C ha-1). CWD respiration (RCWD) increased with increasing temperature and water content. Higher RCWD in more decayed wood was due to greater water absorption and, consequently, higher water content rather than to a greater temperature sensitivity of respiration ( Q10). The Q10 of RCWD ranged from 2.20 to 2.57 and varied inconsistently with decay status. Daily RCWD varied seasonally in response to temperature and water content, increasing rapidly following snow melt in early April and peaking at 0.17 g C m-2 d-1 in early June. Daily RCWD in the early growing season (day 130-200) was 13 % greater than during the late growing season (day 201-279) since CWD water content was 69 % higher even though temperature was 1.5°C cooler. Annual CWD respiration (FCWD, 0.21 Mg C ha-1 yr-1) was 12 % of bole respiration, 8 % of leaf respiration, and 2 % of soil respiration. Compared to the 1.53 Mg C ha-1 yr-1 average annual C storage by our forest, FCWD is a small, but substantial flux that is expected to increase over the next several decades. We show how concurrent increases in CWD production and temperature in the near future may temporarily reduce regional forest C storage.

  6. Biomass, production and woody detritus in an old coast redwood (Sequoia sempervirens) forest

    USGS Publications Warehouse

    Busing, R.T.; Fujimori, T.

    2005-01-01

    We examined aboveground biomass dynamics, aboveground net primary production (ANPP), and woody detritus input in an old Sequoia sempervirens stand over a three-decade period. Our estimates of aboveground biomass ranged from 3300 to 5800 Mg ha-1. Stem biomass estimates ranged from 3000 to 5200 Mg ha-1. Stem biomass declined 7% over the study interval. Biomass dynamics were patchy, with marked declines in recent tree-fall patches <0.05 ha in size. Larger tree-fall patches approaching 0.2 ha in size were observed outside the study plot. Our estimates of ANPP ranged from 6 to 14 Mg ha -1yr-1. Estimates of 7 to 10 Mg ha-1yr -1 were considered to be relatively accurate. Thus, our estimates based on long-term data corroborated the findings of earlier short-term studies. ANPP of old, pure stands of Sequoia was not above average for temperate forests. Even though production was potentially high on a per stem basis, it was moderate at the stand level. We obtained values of 797 m3 ha -1 and 262 Mg ha-1 for coarse woody detritus volume and mass, respectively. Fine woody detritus volume and mass were estimated at 16 m3 ha-1 and 5 Mg ha-1, respectively. Standing dead trees (or snags) comprised 7% of the total coarse detritus volume and 8% of the total mass. Coarse detritus input averaged 5.7 to 6.9 Mg ha -1yr-1. Assuming steady-state input and pool of coarse detritus, we obtained a decay rate constant of 0.022 to 0.026. The old-growth stand of Sequoia studied had extremely high biomass, but ANPP was moderate and the amount of woody detritus was not exceptionally large. Biomass accretion and loss were not rapid in this stand partly because of the slow population dynamics and low canopy turnover rate of Sequoia at the old-growth stage. Nomenclature: Hickman (1993). ?? Springer 2005.

  7. Comparing riparian forest processes on large rivers to inform floodplain management and restoration

    NASA Astrophysics Data System (ADS)

    Stella, J. C.; Piegay, H.; Gruel, C.; Riddle, J.; Raepple, B.

    2014-12-01

    In populous, water-limited regions, humans have profoundly altered the river and floodplain environment to satisfy society's demands for water, power, navigation and safety. River management also profoundly alters riparian forests, which respond to changes in disturbance regimes and sediment dynamics. In this study, we compare forest and floodplain development along two of the most heavily modified rivers in mediterranean-climate regions, the middle Sacramento (California, USA) and the lower Rhône (SE France). The Sacramento was dammed in 1942 and is now managed for irrigation, hydropower and flood control. The Rhône channel was engineered for navigation prior to 1900, and since then has been dammed and diverted at 18 sites for hydropower and irrigation. We conducted extensive forest inventories and sampled fine sediment depth in regulated reaches within both systems, and compared pre- versus post-dam patterns of deposition and linked forest development. We sampled 441 plots (500 m2 each) along 160 km of the Sacramento, and 88 plots (1256 m2) stratified by management epoch (pre-river engineering, pre-dam, post-dam) along 160 km of the Rhône. On the Sacramento, forest composition showed shifting tree species dominance across a chronosequence of aerial photo dates over 110 years. The transition from willow to cottonwood (Populus) occurred within 20 years, and the transition to mixed forest started after 50-60 years. On the Rhône, the pre- versus post-dam surfaces at each site had distinct geomorphic and floristic characteristics. Floodplain areas that emerged and were forested in the pre-dam period were at higher elevation, and supported 30-50% more basal area, 20-30% more vine cover, and greater plant species diversity than those that emerged in the post-dam period. The shift from Populus dominance to other species began approximately a decade earlier on the Rhône compared to the Sacramento. Both rivers showed a strong understory presence on young floodplains

  8. Distribution of invasive and native riparian woody plants across the western USA in relation to climate, river flow, floodplain geometry and patterns of introduction

    USGS Publications Warehouse

    Ryan McShane; Daniel Auerbach; Friedman, Jonathan M.; Auble, Gregor T.; Shafroth, Patrick B.; Michael Merigliano; Scott, Michael L.; N. Leroy Poff

    2015-01-01

    Management of riparian plant invasions across the landscape requires understanding the combined influence of climate, hydrology, geologic constraints and patterns of introduction. We measured abundance of nine riparian woody taxa at 456 stream gages across the western USA. We constructed conditional inference recursive binary partitioning models to discriminate the influence of eleven environmental variables on plant occurrence and abundance, focusing on the two most abundant non-native taxa, Tamarix spp. and Elaeagnus angustifolia, and their native competitor Populus deltoides. River reaches in this study were distributed along a composite gradient from cooler, wetter higher-elevation reaches with higher stream power and earlier snowmelt flood peaks to warmer, drier lower-elevation reaches with lower power and later peaks. Plant distributions were strongly related to climate, hydrologic and geomorphic factors, and introduction history. The strongest associations were with temperature and then precipitation. Among hydrologic and geomorphic variables, stream power, peak flow timing and 10-yr flood magnitude had stronger associations than did peak flow predictability, low-flow magnitude, mean annual flow and channel confinement. Nearby intentional planting of Elaeagnus was the best predictor of its occurrence, but planting of Tamarix was rare. Higher temperatures were associated with greater abundance of Tamarix relative to P. deltoides, and greater abundance of P. deltoides relative toElaeagnus. Populus deltoides abundance was more strongly related to peak flow timing than was that of Elaeagnus or Tamarix. Higher stream power and larger 10-yr floods were associated with greater abundance of P. deltoides and Tamarix relative to Elaeagnus. Therefore, increases in temperature could increase abundance of Tamarix and decrease that of Elaeagnus relative to P. deltoides, changes in peak flow timing caused by climate change or dam operations could

  9. Surface water and groundwater nitrogen dynamics in a well drained riparian forest within a poorly drained agricultural landscape.

    PubMed

    Davis, Jennifer H; Griffith, Stephen M; Wigington, Parker J

    2011-01-01

    The effectiveness of riparian zones in mitigating nutrient in ground and surface water depends on the climate, management, and hydrogeomorphology of a site. The purpose of this study was to determine the efficacy of a well drained, mixed-deciduous riparian forest to buffer a river from N originating from a poorly drained grass seed cropping system. The study site was adjacent to the Calapooia River in the Willamette Valley, Oregon. Water was found to move from the rapid drainage of swale surface water. During winter hydrological events, the riparian forest also received river water. Low nitrate (NO3-) concentrations (0.2-0.4 mg NO3- -NL(-1)) in the shallow groundwater of the cropping system were associated with low rates of mineralization and nitrification (33 kg N ha(-1) yr(-1)) and high grass seed crop uptake of N (155 kg N ha(-1) yr(-1)). The riparian forest soil had higher rates of mineralization (117 kg N ha(-1) yr(-1)) that produced quantities of soil N that were within the range of literature values for plant uptake, leading to relatively low concentrations of shallow groundwater NO3 (0.6-1.8 mg NO3- -NL(-1)). The swale that dissected the cropping system and riparian area was found to have the highest rates of denitrification and to contribute dissolved organic C to the river. Given the dynamic nature of the hydrology of the Calapooia River study site, data suggest that the riparian forest plays a role not only in reducing export of NO3- from the cropping system to the river but also in processing nutrients from river water. PMID:21520758

  10. Demographic responses of shrews to removal of coarse woody debris in a managed pine forest.

    SciTech Connect

    McCay, Timothy, S.; Komoroski, Mark, J.

    2004-01-01

    McCay, T.S., and M.J. Komoroski. 2004. Demographic responses of shrews to removal of coarse woody debris in a managed pine forest. For. Ecol., and Mgt. 189:387-395. We trapped shrews at six 9.3 ha plots from which logs ý 10 cm diameter (coarse woody debris; CWD) had been manually removed and six control plots inmanaged loblolly pine (Pinus taeda) forests of the southeastern coastal plain, USA. Trapping was conducted seasonally between autumn 1997 and summer 2001. Capture rates of Cryptotis parva were lower at plots from which CWD was removed than at control plots (P ¡ 0ý011) and declined at all plots over the study period (P ¡ 0ý001). Capture rates of Blarina carolinensis (P ¡ 0ý129) and Sorex longirostris (P ¡ 0ý432) did not differ between removal and control plots, but declined over the study period (P ¡ 0ý001). Age distributions of B. carolinensis differed between removal and control plots (P ¡ 0ý048) with a smaller proportion of individuals in young age categories at removal plots. Sensitivity of Cryptotis to the removal of CWD may have been due to its sociality or low population density at the study area. A reduction in the abundance of young B. carolinensis after removal of CWD may reflect reduced reproduction and immigration of older individuals from outside the plot. Effect of removal of CWD on populations of these shrews was relatively weak compared to strong seasonal and multi-year variation in abundance. However, weak treatment effects may have been partly due to low ambient levels of CWD at control plots.

  11. Overcoming barriers to seedling regeneration during forest restoration on tropical pasture land and the potential value of woody weeds

    PubMed Central

    Elgar, Amelia T.; Freebody, Kylie; Pohlman, Catherine L.; Shoo, Luke P.; Catterall, Carla P.

    2014-01-01

    Combating the legacy of deforestation on tropical biodiversity requires the conversion to forest of large areas of established pasture, where barriers to native plant regeneration include competition with pasture grasses and poor propagule supply (seed availability). In addition, initial woody plants that colonise pasture are often invasive, non-native species whose ecological roles and management in the context of forest regeneration are contested. In a restoration experiment at two 0.64 ha sites we quantified the response of native woody vegetation recruitment to (1) release from competition with introduced pasture grasses, and (2) local facilitation of frugivore-assisted seed dispersal provided by scattered woody plants and artificial bird perches. Herbicide pasture grass suppression during 20 months caused a significant but modest increase in density of native woody seedlings, together with abundant co-recruitment of the prominent non-native pioneer wild tobacco (Solanum mauritianum). Recruitment of native species was further enhanced by local structure in herbicide-treated areas, being consistently greater under live trees and dead non-native shrubs (herbicide-treated) than in open areas, and intermediate under bird perches. Native seedling recruitment comprised 28 species across 0.25 ha sampled but was dominated by two rainforest pioneers (Homalanthus novoguineensis, Polyscias murrayi). These early results are consistent with the expected increase in woody vegetation recruitment in response to release from competitive and dispersive barriers to rainforest regeneration. The findings highlight the need for a pragmatic consideration of the ecological roles of woody weeds and the potential roles of “new forests” more broadly in accelerating succession of humid tropical forest across large areas of retired agricultural land. PMID:24904602

  12. SWAT-REMM Linked Approach for Estimating Water Quality Benefits of Riparian Forest Buffers in the Little River Watershed

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Riparian forest buffers (RFBs) have considerable potential for improving water quality by filtering pollutants as they are transported from upland areas to streams. Insight into the benefits of the RFBs can be gained through appropriate computer simulation of the process. The Soil and Water Assessm...

  13. Delineating forested river habitats and riparian floodplain hydrology with LiDAR

    NASA Astrophysics Data System (ADS)

    Vondrasek, Chris

    Rivers and the riparian forest corridor comprise a valuable freshwater ecosystem that has been altered by human activities including timber management, road building, and other land conversions. The habitats of river dependent species in the Pacific Northwest, in particular salmon have often been degraded by these activities. Many salmon runs have become threatened with extinction and have been Endangered Species Act listed. New conservation planning and policies have developed around protecting freshwater habitats and restoring more natural river processes. In WA State, timber landowners, officials from State and Federal agencies, Native tribes, and other stakeholders developed Forest Practice rules and codified a Habitat Conservation Plan with dual goals of providing regulatory surety for timber land owners and helping to recover the threatened salmon runs in forested watersheds. Conserving critical stream ecological functions and potential fish habitats throughout watersheds while managing and regulating timber harvest across the State requires accurate and up-to-date delineation and mapping of channels, tributaries, and off-channel wetlands. Monitoring the effectiveness of protection efforts is necessary but can also be difficult. Agency staff and resources are limited for both day-to-day implementation of Forest Practice rules and adaptive management. The goal of this research has been to develop efficient and accessible methods to delineate wetlands, side-channels, tributaries, and pools and backwaters created by large log jams in forested watersheds. It was also essential to use publicly available LiDAR data and to model these waters at ecologically meaningful flows. I tested a hydraulic model at a 2-year and 50-year flows, and a relative height above river surface model and compared them. I completed two additional remote sensing investigations to correlate channel movement and the locations of off-channel wetlands: an analysis of historical aerial imagery

  14. Technical Note: Linking climate change and downed woody debris decomposition across forests of the eastern United States

    USGS Publications Warehouse

    Russell, Matthew B.; Woodall, Christopher W.; D'Amato, Anthony W.; Fraver, Shawn; Bradford, John B.

    2014-01-01

    Forest ecosystems play a critical role in mitigating greenhouse gas emissions. Forest carbon (C) is stored through photosynthesis and released via decomposition and combustion. Relative to C fixation in biomass, much less is known about C depletion through decomposition of woody debris, particularly under a changing climate. It is assumed that the increased temperatures and longer growing seasons associated with projected climate change will increase the decomposition rates (i.e., more rapid C cycling) of downed woody debris (DWD); however, the magnitude of this increase has not been previously addressed. Using DWD measurements collected from a national forest inventory of the eastern United States, we show that the residence time of DWD may decrease (i.e., more rapid decomposition) by as much as 13% over the next 200 years, depending on various future climate change scenarios and forest types. Although existing dynamic global vegetation models account for the decomposition process, they typically do not include the effect of a changing climate on DWD decomposition rates. We expect that an increased understanding of decomposition rates, as presented in this current work, will be needed to adequately quantify the fate of woody detritus in future forests. Furthermore, we hope these results will lead to improved models that incorporate climate change scenarios for depicting future dead wood dynamics in addition to a traditional emphasis on live-tree demographics.

  15. Technical Note: Linking climate change and downed woody debris decomposition across forests of the eastern United States

    NASA Astrophysics Data System (ADS)

    Russell, M. B.; Woodall, C. W.; D'Amato, A. W.; Fraver, S.; Bradford, J. B.

    2014-11-01

    Forest ecosystems play a critical role in mitigating greenhouse gas emissions. Forest carbon (C) is stored through photosynthesis and released via decomposition and combustion. Relative to C fixation in biomass, much less is known about C depletion through decomposition of woody debris, particularly under a changing climate. It is assumed that the increased temperatures and longer growing seasons associated with projected climate change will increase the decomposition rates (i.e., more rapid C cycling) of downed woody debris (DWD); however, the magnitude of this increase has not been previously addressed. Using DWD measurements collected from a national forest inventory of the eastern United States, we show that the residence time of DWD may decrease (i.e., more rapid decomposition) by as much as 13% over the next 200 years, depending on various future climate change scenarios and forest types. Although existing dynamic global vegetation models account for the decomposition process, they typically do not include the effect of a changing climate on DWD decomposition rates. We expect that an increased understanding of decomposition rates, as presented in this current work, will be needed to adequately quantify the fate of woody detritus in future forests. Furthermore, we hope these results will lead to improved models that incorporate climate change scenarios for depicting future dead wood dynamics in addition to a traditional emphasis on live-tree demographics.

  16. Technical Note: Linking climate change and downed woody debris decomposition across forests of the eastern United States

    NASA Astrophysics Data System (ADS)

    Russell, M. B.; Woodall, C. W.; D'Amato, A. W.; Fraver, S.; Bradford, J. B.

    2014-06-01

    Forest ecosystems play a critical role in mitigating greenhouse gas emissions. Long-term forest carbon (C) storage is determined by the balance between C fixation into biomass through photosynthesis and C release via decomposition and combustion. Relative to C fixation in biomass, much less is known about C depletion through decomposition of woody debris, particularly under a changing climate. It is assumed that the increased temperatures and longer growing seasons associated with projected climate change will increase the decomposition rates (i.e., more rapid C cycling) of downed woody debris (DWD); however, the magnitude of this increase has not been previously addressed. Using DWD measurements collected from a national forest inventory of the eastern United States, we show that the residence time of DWD may decrease (i.e., more rapid decomposition) by as much as 13% over the next 200 years depending on various future climate change scenarios and forest types. Although existing dynamic global vegetation models account for the decomposition process, they typically do not include the effect of a changing climate on DWD decomposition rates. We expect that an increased understanding of decomposition rates, as presented in this current work, will be needed to adequately quantify the fate of woody detritus in future forests. Furthermore, we hope these results will lead to improved models that incorporate climate change scenarios for depicting future dead wood dynamics, in addition to a traditional emphasis on live tree demographics.

  17. Simulation results of aboveground woody biomass and leaf litterfall for African tropical forest with a global terrestrial model

    NASA Astrophysics Data System (ADS)

    De Weirdt, Marjolein; Maignan, Fabienne; Peylin, Philippe; Poulter, Benjamin; Moreau, Inès; Ciais, Philippe; Defourny, Pierre; Steppe, Kathy; Verbeeck, Hans

    2014-05-01

    The response of tropical forest vegetation to global climate change could be central to predictions of future levels of atmospheric carbon dioxide. Tropical forests are believed to annually process approximately six times as much carbon via photosynthesis and respiration as humans emit from fossil fuel use. Of all tropical forests worldwide, the role of African tropical forest is not very well known and both the quantity as well as the dynamics of tropical forest carbon stocks and fluxes are very poorly quantified components of the global carbon cycle. Furthermore, African tropical forest spatial carbon stocks patterns as measured in the field are not as well represented by the global biogeochemical models as they are for temperate forests. In this study, a first simulation for the African tropical forest with the process based global terrestrial ecosystem model ORCHIDEE was done. In this work, ORCHIDEE included deep soils, seasonal leaf litterfall and phosphorus availability mechanisms for tropical evergreen forests included. The ORCHIDEE model run outputs are evaluated against reported field inventories, investigating seasonal variations in leaf litterfall and spatial variation in aboveground woody biomass. A comparison between modeled and measured leaf litterfall was made at a semi-deciduous Equatorial rainforest site in the Republic of Congo at the Biosphere reserve Dimonika south of Gabon. Also, simulated woody aboveground biomass was compared against site-level field inventories and satellite-based estimates based on a combination of MODIS imagery with field inventory data from Uganda, DRC and Cameroon. First comparison results seem promising and show that the radiation driven leaf litterfall model results correspond well with the field inventories and that the mean of the modelled aboveground woody biomass matches the available field inventory observations but there is still a need for more ground data to evaluate the model outcome over a large region like

  18. Classification of riparian forest species and health condition using multi-temporal and hyperspatial imagery from unmanned aerial system.

    PubMed

    Michez, Adrien; Piégay, Hervé; Lisein, Jonathan; Claessens, Hugues; Lejeune, Philippe

    2016-03-01

    Riparian forests are critically endangered many anthropogenic pressures and natural hazards. The importance of riparian zones has been acknowledged by European Directives, involving multi-scale monitoring. The use of this very-high-resolution and hyperspatial imagery in a multi-temporal approach is an emerging topic. The trend is reinforced by the recent and rapid growth of the use of the unmanned aerial system (UAS), which has prompted the development of innovative methodology. Our study proposes a methodological framework to explore how a set of multi-temporal images acquired during a vegetative period can differentiate some of the deciduous riparian forest species and their health conditions. More specifically, the developed approach intends to identify, through a process of variable selection, which variables derived from UAS imagery and which scale of image analysis are the most relevant to our objectives.The methodological framework is applied to two study sites to describe the riparian forest through two fundamental characteristics: the species composition and the health condition. These characteristics were selected not only because of their use as proxies for the riparian zone ecological integrity but also because of their use for river management.The comparison of various scales of image analysis identified the smallest object-based image analysis (OBIA) objects (ca. 1 m(2)) as the most relevant scale. Variables derived from spectral information (bands ratios) were identified as the most appropriate, followed by variables related to the vertical structure of the forest. Classification results show good overall accuracies for the species composition of the riparian forest (five classes, 79.5 and 84.1% for site 1 and site 2). The classification scenario regarding the health condition of the black alders of the site 1 performed the best (90.6%).The quality of the classification models developed with a UAS-based, cost-effective, and semi-automatic approach

  19. Riparian and in-stream controls on nutrient concentrations and fluxes in a headwater forested stream

    NASA Astrophysics Data System (ADS)

    Bernal, S.; Lupon, A.; Ribot, M.; Sabater, F.; Martí, E.

    2015-03-01

    Headwater streams are recipients of water sources draining through terrestrial ecosystems. At the same time, stream biota can transform and retain nutrients dissolved in stream water. Yet studies considering simultaneously these two sources of variation in stream nutrient chemistry are rare. To fill this gap of knowledge, we analyzed stream water and riparian groundwater concentrations and fluxes as well as in-stream net uptake rates for nitrate (NO3-), ammonium (NH4+), and soluble reactive phosphorus (SRP) along a 3.7 km reach on an annual basis. Chloride concentrations (used as conservative tracer) indicated a strong hydrological connection at the riparian-stream interface. However, stream and riparian groundwater nutrient concentrations showed a moderate to null correlation, suggesting high in-stream biogeochemical processing. In-stream net nutrient uptake (Fsw) was highly variable across contiguous segments and over time, but its temporal variation was not related to the vegetative period of the riparian forest. For NH4+, the occurrence of Fsw > 0 μg N m-1 s-1 (gross uptake > release) was high along the reach, while for NO3-, the occurrence of Fsw < 0 μg N m-1 s-1 (gross uptake < release) increased along the reach. Within segments and dates, Fsw, whether negative or positive, accounted for a median of 6, 18, and 20% of the inputs of NO3-, NH4+, and SRP, respectively. Whole-reach mass balance calculations indicated that in-stream net uptake reduced stream NH4+ flux up to 90%, while the stream acted mostly as a source of NO3- and SRP. During the dormant period, concentrations decreased along the reach for NO3-, but increased for NH4+ and SRP. During the vegetative period, NH4+ decreased, SRP increased, and NO3- showed a U-shaped pattern along the reach. These longitudinal trends resulted from the combination of hydrological mixing with terrestrial inputs and in-stream nutrient processing. Therefore, the assessment of these two sources of variation in stream

  20. Monitoring design for riparian forests in the Pacific northwest. Research plan

    SciTech Connect

    Ringold, P.L.; Barker, J.; Bollman, M.; Bradshaw, G.; Carson, W.

    1997-12-01

    The goal of this project is to recommend a broadly-acceptale efficient and effective methodology for characterizing streamside riparian attributes in forested settings at the site grain for regional monitoring. The authors consider monitoring design in the context of three interacting constraints: ecological functions, capabilities of technologies, and user needs. The focus is on fine grained remote methods. Comparison between candidate selected monitoring systems provides for an initial formulation of a monitoring design. A series of evaluations of these initial formulations provides for an initial recommendation. With the state`s interest in the status of coastal fishes, and the programmatic interest of EPA`s Western Ecology Division, the areas selected for study are in the Oregon coastal province and the Willamette basin.

  1. Dams, floodplain land use, and riparian forest conservation in the semiarid Upper Colorado River Basin, USA

    USGS Publications Warehouse

    Andersen, D.C.; Cooper, D.J.; Northcott, K.

    2007-01-01

    Land and water resource development can independently eliminate riparian plant communities, including Fremont cottonwood forest (CF), a major contributor to ecosystem structure and functioning in semiarid portions of the American Southwest. We tested whether floodplain development was linked to river regulation in the Upper Colorado River Basin (UCRB) by relating the extent of five developed land-cover categories as well as CF and other natural vegetation to catchment reservoir capacity, changes in total annual and annual peak discharge, and overall level of mainstem hydrologic alteration (small, moderate, or large) in 26 fourth-order subbasins. We also asked whether CF appeared to be in jeopardy at a regional level. We classified 51% of the 57,000 ha of alluvial floodplain examined along >2600 km of mainstem rivers as CF and 36% as developed. The proportion developed was unrelated to the level of mainstem hydrologic alteration. The proportion classified as CF was also independent of the level of hydrologic alteration, a result we attribute to confounding effects from development, the presence of time lags, and contrasting effects from flow alteration in different subbasins. Most CF (68% by area) had a sparse canopy (???5% cover), and stands with >50% canopy cover occupied <1% of the floodplain in 15 subbasins. We suggest that CF extent in the UCRB will decline markedly in the future, when the old trees on floodplains now disconnected from the river die and large areas change from CF to non-CF categories. Attention at a basinwide scale to the multiple factors affecting cottonwood patch dynamics is needed to assure conservation of these riparian forests. ?? 2007 Springer Science+Business Media, LLC.

  2. Remediation of heavy metal-contaminated forest soil using recycled organic matter and native woody plants.

    PubMed

    Helmisaari, H-S; Salemaa, M; Derome, J; Kiikkilä, O; Uhlig, C; Nieminen, T M

    2007-01-01

    The main aim of this study was to determine how the application of a mulch cover (a mixture of household biocompost and woodchips) onto heavy metal-polluted forest soil affects (i) long-term survival and growth of planted dwarf shrubs and tree seedlings and (ii) natural revegetation. Native woody plants (Pinus sylvestris, Betula pubescens, Empetrum nigrum, and Arctostaphylos uva-ursi) were planted in mulch pockets on mulch-covered and uncovered plots in summer 1996 in a highly polluted Scots pine stand in southwest Finland. Spreading a mulch layer on the soil surface was essential for the recolonization of natural vegetation and increased dwarf shrub survival, partly through protection against drought. Despite initial mortality, transplant establishment was relatively successful during the following 10 yr. Tree species had higher survival rates, but the dwarf shrubs covered a larger area of the soil surface during the experiment. Especially E. nigrum and P. sylvestris proved to be suitable for revegetating heavy metal-polluted and degraded forests. Natural recolonization of pioneer species (e.g., Epilobium angustifolium, Taraxacum coll., and grasses) and tree seedlings (P. sylvestris, Betula sp., and Salix sp.) was strongly enhanced on the mulched plots, whereas there was no natural vegetation on the untreated plots. These results indicate that a heavy metal-polluted site can be ecologically remediated without having to remove the soil. Household compost and woodchips are low-cost mulching materials that are suitable for restoring heavy metal-polluted soil. PMID:17596623

  3. Study on Woody Species Diversity in the Chestnut (Castanea sativa L.) Forests, Guilan, Iran

    NASA Astrophysics Data System (ADS)

    Poorbabaei, Hassan; Faghir, Marzia B.

    2008-01-01

    The purpose of this research was to study diversity of woody species in the Sweet chestnut (Castanea sativa L.) forests, Guilan, north of Iran. These forests are located in the Shafaroud and Emamzadeh Ebrahim regions. The Emamzadeh Ebrahim region is consisted of Visroud, Kishkhaleh, Askeh Koh, Male Lab, Doroudkhan, Galeroudkhan, Siahmazgy and Mali Anbar sites. Sampling was done in a selective manner in each site with a plot area of 50 m×50 m for tree and shrub layers and a circle 1000 m2 for tree saplings. In each plot, all trees ⩾10 cm in diameter at breast height (DBH) were identified and the DBH was measured, and shrub and tree sapling species were identified and recorded. In total, 68 sampling plots were taken using GPS device in the two regions. The results revealed that the mean richness, Simpson's index, Hill's N2, Shannon Wiener's function and N1 were higher in the Shafaroud region than other sites in tree, shrub and tree sapling layers. The highest and lowest mean values of evenness were obtained in the Kishkhaleh and Askekoh sites, respectively in tree layer, and similarly were in the Askekoh and Visroud in the shrub layer. The highest and lowest mean values of evenness were obtained in the Male Lab and Askeh Koh, respectively in the tree sapling layer.

  4. Composition, complexity, and tree mortality in riparian forests in the central Western Cascades of Oregon

    USGS Publications Warehouse

    Acker, Steve A.; Gregory, S.V.; Lienkaemper, G.; McKee, W.A.; Swanson, F.J.; Miller, S.D.

    2003-01-01

    Riparian forests contribute to the diversity and function of both terrestrial and aquatic ecosystems. To assess some of these contributions, we compared tree composition, stand complexity, and temporal patterns of tree mortality on permanent plots in seven mature and old-growth stands representing upland forests and forests along low- and mid-order streams in the Western Cascade Range of Oregon. We also assessed recruitment of large wood into stream channels due to tree mortality, both by direct measurement and by estimation from tree mortality and location data. Stands differed in composition due to both stream order and successional stage. Stands on mid-order streams had high abundance of hardwood trees and/or Thuja plicata. Stand complexity (variability in tree diameters, tree life-form diversity, and tree species diversity), was high in stands on mid-order streams and in the upland, old-growth stand. Tree mortality was exceptionally high in six of the seven stands in 1996, the year in which the largest flood during the study occurred. However, only in the one stand on an unconstrained reach of a mid-order stream was mortality primarily due to flooding. Estimated recruitment of wood was much higher from the stand on the unconstrained reach than from the other stands on mid-order streams, suggesting that unconstrained reaches may be important for efforts to maintain or restore large wood in streams.

  5. Leaf litter dynamics and nitrous oxide emission in a Mediterranean riparian forest: implications for soil nitrogen dynamics.

    PubMed

    Bernal, S; Butturini, A; Nin, E; Sabater, F; Sabater, S

    2003-01-01

    Mediterranean riparian zones can experience severe drought periods that lead to low soil moisture content, which dramatically affects their performance as nitrate removal systems. In the Mediterranean riparian zone of this study, we determined that N2O emission was practically nil. To understand the role of forest floor processes in nitrogen retention of a Mediterranean riparian area, we studied leaf litter dynamics of two tree species, London planetree [Platanus x acerifolia (Aiton) Willd.] and alder [Alnus glutinosa (L.) Gaertn.], for two years, along with soil nitrogen mineralization rates. Annual leaf litter fall equaled 562.6 +/- 10.1 (standard error) g dry wt. m(-2), 68% of which was planetree and 32% of which was alder. The temporal distribution of litterfall showed a two-peak annual cycle, one occurring in midsummer, the other in autumn. Planetree provided the major input of organic nitrogen to the forest floor, and the amount of planetree leaves remaining on the forest floor was equivalent to approximately four years of stock. Leaf litter decomposition was three times higher for alder (decay coefficient [k] = 1.13 yr(-1)) than for planetree (k = 0.365 yr(-1)). Mineralization rates showed a seasonal pattern, with the maximum rate in summer (1.92 mg N kg(-1) d(-1)). Although the forest floor was an important sink for nitrogen due to planetree leaf accumulation, 7.5% of this leaf litter was scoured to the streambed by wind. This loss was irrelevant for alder leaves. Due to the litter quality, the forest floor of this Mediterranean riparian forest acts as a nitrogen sink. PMID:12549558

  6. Riparian reserves within oil palm plantations conserve logged forest leaf litter ant communities and maintain associated scavenging rates

    PubMed Central

    Gray, Claudia L; Lewis, Owen T; Chung, Arthur Y C; Fayle, Tom M

    2015-01-01

    The expansion of oil palm plantations at the expense of tropical forests is causing declines in many species and altering ecosystem functions. Maintaining forest-dependent species and processes in these landscapes may therefore limit the negative impacts of this economically important industry. Protecting riparian vegetation may be one such opportunity; forest buffer strips are commonly protected for hydrological reasons, but can also conserve functionally important taxa and the processes they support. We surveyed leaf litter ant communities within oil palm-dominated landscapes in Sabah, Malaysia, using protein baits. As the scavenging activity of ants influences important ecological characteristics such as nutrient cycling and soil structure, we quantified species-specific rates of bait removal to examine how this process may change across land uses and establish which changes in community structure underlie observed shifts in activity. Riparian reserves had similar ant species richness, community composition and scavenging rates to nearby continuous logged forest. Reserve width and vegetation structure did not affect ant species richness significantly. However, the number of foraging individuals decreased with increasing reserve width, and scavenging rate increased with vegetation complexity. Oil palm ant communities were characterized by significantly lower species richness than logged forest and riparian reserves and also by altered community composition and reduced scavenging rates. Reduced scavenging activity in oil palm was not explained by a reduction in ant species richness, nor by replacement of forest ant species by those with lower per species scavenging rates. There was also no significant effect of land use on the scavenging activity of the forest species that persisted in oil palm. Rather, changes in scavenging activity were best explained by a reduction in the mean rate of bait removal per individual ant across all species in the community

  7. Effects of termite activities on coarse woody debris decomposition in an intact lowland mixed dipterocarp forest of Brunei Darussalam

    NASA Astrophysics Data System (ADS)

    Lee, Sohye; Kim, Seungjun; Roh, Yujin; Abu Salim, Kamariah; Lee, Woo-Kyun; Davies, Stuart; Son, Yowhan

    2016-04-01

    Tropical forests have been considered important ecosystems in terms of carbon cycle and climate change, because they sequester carbon more than any other terrestrial ecosystems. In addition, coarse woody debris is one of the main carbon storages, accounting for 10 ‑ 40% of the tropical forest carbon. Carbon in coarse woody debris is released by various activities of organisms, and particularly termite's feeding activities are known to be main process in tropical forests. Therefore, investigating the effects of termite activities on coarse woody debris decomposition is important to understanding carbon cycles of tropical forests. This study was conducted in an intact lowland mixed dipterocarp forest (MDF) of Brunei Darussalam, and three main MDF tree species (Dillenia beccariana, Macaranga bancana, and Elateriospermum tapos) were selected. Coarse woody debris samples of both 10 cm diameter and length were prepared, and half of samples were covered twice with nylon net (mesh size 1.5 mm × 1.5 mm) to prevent termite's approach. Three 2 m × 11 m permanent plots were installed in January, 2015 and eighteen samples per plot (3 species × 2 treatments × 3 repetitions) were placed at the soil surface. Weights of each sample were recorded at initial time, and weighed again in August, 2015. On average, uncovered and covered samples lost 18.9 % and 3.3 % of their initial weights, respectively. Weight loss percentage was highest in uncovered samples of M. bancana (23.9 %), and lowest in covered samples of E. tapos (7.8 %). Two-way ANOVA showed that tree species and termite exclusion treatment had statistically significant effects on coarse woody debris decomposition (P = 0.0001). The effect of species and termite exclusion treatment interaction was also statistically significant (P = 0.0001). The result reveals that termite activities promote the coarse woody debris decomposition and they influence differently along the wood species. However, many samples of D. beccariana

  8. Woody invasions of urban trails and the changing face of urban forests in the great plains, USA

    USGS Publications Warehouse

    Nemec, K.T.; Allen, C.R.; Alai, A.; Clements, G.; Kessler, A.C.; Kinsell, T.; Major, A.; Stephen, B.J.

    2011-01-01

    Corridors such as roads and trails can facilitate invasions by non-native plant species. The open, disturbed habitat associated with corridors provides favorable growing conditions for many non-native plant species. Bike trails are a corridor system common to many urban areas that have not been studied for their potential role in plant invasions. We sampled five linear segments of urban forest along bike trails in Lincoln, Nebraska to assess the invasion of woody non-native species relative to corridors and to assess the composition of these urban forests. The most abundant plant species were generally native species, but five non-native species were also present: white mulberry (Morus alba), common buckthorn (Rhamnus cathartica), tree-of-heaven (Ailanthus altissima), honeysuckle (Lonicera spp.) and elm (Ulmus spp.). The distribution of two of the woody species sampled, common buckthorn and honeysuckle, significantly decreased with increasing distance from a source patch of vegetation (P = 0.031 and 0.030). These linear habitats are being invaded by non-native tree and shrub species, which may change the structure of these urban forest corridors. If non-native woody plant species become abundant in the future, they may homogenize the plant community and reduce native biodiversity in these areas. ?? 2011 American Midland Naturalist.

  9. Estimation of aboveground woody biomass using HJ-1 and Radarsat-2 data for deciduous forests in Daxing'anling, China

    NASA Astrophysics Data System (ADS)

    Liu, Qian; Yang, Le; Liu, Qinhuo; Li, Jing

    2014-11-01

    Accurate estimation of forest aboveground biomass is important for global carbon budgets and ecosystem change studies. Most algorithms for regional or global aboveground biomass estimation using optical and microwave remote sensing data are based on empirical regression and non-parametric training methods, which require large amount of ground measurements for training and are lacking of explicit interaction mechanisms between electromagnetic wave and vegetation. In this study, we proposed an optical/microwave synergy method based on a coherent polarimetric SAR model to estimate woody biomass. The study area is sparse deciduous forest dominated by birch with understory of shrubs and herbs in Daxing'anling, China. HJ-1, Radarsat-2 images, and field LAI were collected during May to August in 2013, tree biophysical parameters were measured at the field campaign during August to September in 2012. The effects of understory and wet ground were evaluated by introducing the NDVI derived from HJ-1 image and rain rate. Field measured LAI was used as an input to the SAR model to define the scattering and attenuation of the green canopy to the total backscatter. Finally, an logarithmic equation between the backscatter coefficient of direct forest scattering mechanism and woody biomass was generated (R2=0.582). The retrieval results were validated with the ground biomass measurements (RMSE=29.01ton/ha). The results indicated the synergy of optical and microwave remote sensing data based on SAR model has the potential to improve the accuracy of woody biomass estimation.

  10. Boreal forest riparian zones regulate stream sulfate and dissolved organic carbon.

    PubMed

    Ledesma, José L J; Futter, Martyn N; Laudon, Hjalmar; Evans, Christopher D; Köhler, Stephan J

    2016-08-01

    In boreal forest catchments, solute transfer to streams is controlled by hydrological and biogeochemical processes occurring in the riparian zone (RZ). However, RZs are spatially heterogeneous and information about solute chemistry is typically limited. This is problematic when making inferences about stream chemistry. Hypothetically, the strength of links between riparian and stream chemistry is time-scale dependent. Using a ten-year (2003-2012) dataset from a northern Swedish catchment, we evaluated the suitability of RZ data to infer stream dynamics at different time scales. We focus on the role of the RZ versus upslope soils in controlling sulfate (SO4(2)(-)) and dissolved organic carbon (DOC). A priori, declines in acid deposition and redox-mediated SO4(2)(-) pulses control sulfur (S) fluxes and pool dynamics, which in turn affect dissolved organic carbon (DOC). We found that the catchment is currently a net source of S, presumably due to release of the S pool accumulated during the acidification period. In both, RZ and stream, SO4(2-) concentrations are declining over time, whereas DOC is increasing. No temporal trends in SO4(2-) and DOC were observed in upslope mineral soils. SO4(2-) explained the variation of DOC in stream and RZ, but not in upslope mineral soil. Moreover, as SO4(2-) decreased with time, temporal variability of DOC increased. These observations indicate that: (1) SO4(2-) is still an important driver of DOC trends in boreal catchments and (2) RZ processes control stream SO4(2-) and subsequently DOC independently of upslope soils. These phenomena are likely occurring in many regions recovering from acidification. Because water flows through a heterogeneous mosaic of RZs before entering the stream, upscaling information from limited RZ data to the catchment level is problematic at short-time scales. However, for long-term trends and annual dynamics, the same data can provide reasonable representations of riparian processes and support

  11. β-Diversity of Functional Groups of Woody Plants in a Tropical Dry Forest in Yucatan

    PubMed Central

    López-Martínez, Jorge Omar; Sanaphre-Villanueva, Lucía; Dupuy, Juan Manuel; Hernández-Stefanoni, José Luis; Meave, Jorge Arturo; Gallardo-Cruz, José Alberto

    2013-01-01

    Two main theories have attempted to explain variation in plant species composition (β-diversity). Niche theory proposes that most of the variation is related to environment (environmental filtering), whereas neutral theory posits that dispersal limitation is the main driver of β-diversity. In this study, we first explored how α- and β-diversity of plant functional groups defined by growth form (trees, shrubs and lianas, which represent different strategies of resource partitioning), and dispersal syndrome (autochory, anemochory and zoochory, which represent differences in dispersal limitation) vary with successional age and topographic position in a tropical dry forest. Second, we examined the effects of environmental, spatial, and spatially-structured environmental factors on β-diversity of functional groups; we used the spatial structure of sampling sites as a proxy for dispersal limitation, and elevation, soil properties and forest stand age as indicators of environmental filtering. We recorded 200 species and 22,245 individuals in 276 plots; 120 species were trees, 41 shrubs and 39 lianas. We found that β-diversity was highest for shrubs, intermediate for lianas and lowest for trees, and was slightly higher for zoochorous than for autochorous and anemochorous species. All three dispersal syndromes, trees and shrubs varied in composition among vegetation classes (successional age and topographic position), whilst lianas did not. β-diversity was influenced mostly by proxies of environmental filtering, except for shrubs, for which the influence of dispersal limitation was more important. Stand age and topography significantly influenced α-diversity across functional groups, but showed a low influence on β-diversity –possibly due to the counterbalancing effect of resprouting on plant distribution and composition. Our results show that considering different plant functional groups reveals important differences in both α- and β-diversity patterns and

  12. Novel plant communities limit the effects of a managed flood to restore riparian forests along a large regulated river

    USGS Publications Warehouse

    Cooper, D.J.; Andersen, D.C.

    2012-01-01

    Dam releases used to create downstream flows that mimic historic floods in timing, peak magnitude and recession rate are touted as key tools for restoring riparian vegetation on large regulated rivers. We analysed a flood on the 5th-order Green River below Flaming Gorge Dam, Colorado, in a broad alluvial valley where Fremont cottonwood riparian forests have senesced and little recruitment has occurred since dam completion in 1962. The stable post dam flow regime triggered the development of novel riparian communities with dense herbaceous plant cover. We monitored cottonwood recruitment on landforms inundated by a managed flood equal in magnitude and timing to the average pre-dam flood. To understand the potential for using managed floods as a riparian restoration tool, we implemented a controlled and replicated experiment to test the effects of artificially modified ground layer vegetation on cottonwood seedling establishment. Treatments to remove herbaceous vegetation and create bare ground included herbicide application (H), ploughing (P), and herbicide plus ploughing (H+P). Treatment improved seedling establishment. Initial seedling densities on treated areas were as much as 1200% higher than on neighbouring control (C) areas, but varied over three orders of magnitude among the five locations where manipulations were replicated. Only two replicates showed the expected seedling density rank of (H+P)>P>H>C. Few seedlings established in control plots and none survived 1 year. Seedling density was strongly affected by seed rain density. Herbivory affected growth and survivorship of recruits, and few survived nine growing seasons. Our results suggest that the novel plant communities are ecologically and geomorphically resistant to change. Managed flooding alone, using flows equal to the pre-dam mean annual peak flood, is an ineffective riparian restoration tool where such ecosystem states are present and floods cannot create new habitat for seedling establishment

  13. Carbon of Woody Debris in Plateau-type Karst Evergreen and Deciduous Broad-leaved Mixed Forest of Central Guizhou Province

    NASA Astrophysics Data System (ADS)

    Wu, Y.; Ni, J.; Liu, L.; Guo, C.

    2014-12-01

    Woody debris (WD) is an essential structural and functional component of forest ecosystems, and plays very significant roles for the biogeochemical cycling of carbon and nutrients. Coarse woody debris (CWD) is considered to be the major part in forest WD and it is primarily composed of logs, snags, stumps and large branches, while fine woody debris (FWD) mainly consists of small twigs. Composition, spatial distribution and carbon storage of WD have been studied in plateau-type karst evergreen and deciduous broad-leaved mixed forest in Tianlong Mountain of central Guizhou Province. Results showed that the carbon storage of WD in karst forests was less than non-karst forests. The major components of WD were fallen trees and snags with 10-20 cm in diameter. Fallen trees and snags with diameter greater than 20 cm were the smallest part of WD. The situation of WD in this region reflects the structural characteristics of WD in mid-late stage of plateau-type karst evergreen and deciduous broad-leaved mixed forest succession. The potential contribution of WD to the regional carbon cycle, and its relationship with climate change were finally discussed. The WD (especially CWD) plays an important role in the carbon cycle of karst forest. Forest WD production and decay rates may partially depend on climatic conditions, the accumulation of CWD and FWD carbon stocks in forests may be correlated with climate. Key words: woody debris, karst forests, carbon storage, spatial distribution, CWD, FWD.

  14. Water quality functions of riparian forest buffers in Chesapeake bay watersheds

    USGS Publications Warehouse

    Lowrance, R.; Altier, L.S.; Newbold, J.D.; Schnabel, R.R.; Groffman, P.M.; Denver, J.M.; Correll, D.L.; Gilliam, J.W.; Robinson, J.L.; Brinsfield, R.B.; Staver, K.W.; Lucas, W.; Todd, A.H.

    1997-01-01

    Maryland, Virginia, and Pennsylvania, USA, have agreed to reduce nutrient loadings to Chesapeake Bay by 40% by the year 2000. This requires control of nonpoint sources of nutrients much of which comes from agriculture. Riparian forest buffer systems (RFBS) provide effective control of nonpoint source (NPS) pollution in some types of agricultural watersheds. Control of NPS pollution is dependent on the type of pollutant and the hydrologic connection between pollution sources, the RFBS, and the stream. Water quality improvements are most likely in areas of where most of the excess precipitation moves across, in, or near the root zone of the RFBS. In areas such as the Inner Coastal Plain and Piedmont watersheds with thin soils RFBS should retain 50%-90% of the total loading of nitrate in shallow groundwater sediment in surface runoff and total N in born surface runoff and groundwater. Retention of phosphorus is generally much less. In regions with deeper soils and/or greater regional groundwater recharge (such as parts of the Piedmont and the Valley and Ridge), RFBS water quality improvements are probably much less. The expected levels of pollutant control by RFBS are identified for each of nine physiographic provinces of the Chesapeake Bay Watershed. Issues related to of establishment sustainability, and management are also discussed.

  15. Abundance and Morphological Effects of Large Woody Debris in Forested Basins of Southern Andes

    NASA Astrophysics Data System (ADS)

    Andreoli, A.; Comiti, F.; Lenzi, M. A.

    2006-12-01

    The Southern Andes mountain range represents an ideal location for studying large woody debris (LWD) in streams draining forested basins thanks to the presence of both pristine and managed woodland, and to the general low level of human alteration of stream corridors. However, no published investigations have been performed so far in such a large region. The investigated sites of this research are three basins (9-13 km2 drainage area, third-order channels) covered by Nothofagus forests: two of them are located in the Southern Chilean Andes (the Tres Arroyos in the Malalcahuello National Reserve and the Rio Toro within the Malleco Natural Reserve) and one basin lies in the Argentinean Tierra del Fuego (the Buena Esperanza basin, near the city of Ushuaia). Measured LWD were all wood pieces larger than 10 cm in diameter and 1 m in length, both in the active channel and in the adjacent active floodplain. Pieces forming log jams were all measured and the geometrical dimensions of jams were taken. Jam type was defined based on Abbe and Montgomery (2003) classification. Sediment stored behind log-steps and valley jams was evaluated approximating the sediment accumulated to a solid wedge whose geometrical dimensions were measured. Additional information relative to each LWD piece were recorded during the field survey: type (log, rootwad, log with rootwads attached), orientation to flow, origin (floated, bank erosion, landslide, natural mortality, harvest residuals) and position (log-step, in-channel, channel-bridging, channel margins, bankfull edge). In the Tres Arroyos, the average LWD volume stored within the bankfull channel is 710 m3 ha-1. The average number of pieces is 1,004 per hectare of bankfull channel area. Log-steps represent about 22% of all steps, whereas the elevation loss due to LWD (log-steps and valley jams) results in 27% loss of the total stream potential energy. About 1,600 m3 of sediment (assuming a porosity of 20%) is stored in the main channel

  16. Multi-scale Modeling of Energy Balance Fluxes in a Dense Tamarisk Riparian Forest

    NASA Astrophysics Data System (ADS)

    Neale, C. M.; Santos, C. A.; Watts, D.; Osterberg, J.; Hipps, L. E.; Sritharan, S. I.

    2008-12-01

    Remote sensing of energy balance fluxes has become operationally more viable over the last 10 years with the development of more robust multi-layer models and the availability of quasi-real time satellite imagery from most sensors. Riparian corridors in semi-arid and arid areas present a challenge to satellite based techniques for estimating evapotranspiration due to issues of scale and pixel resolution, especially when using the thermal infrared bands. This paper will present energy balance measurement and modeling results over a Salt Cedar (Tamarix Ramosissima) forest in the Cibola National Wildlife Refuge along the Colorado River south of Blythe, CA. The research site encompasses a 600 hectare area populated by mostly Tamarisk stands of varying density. Three Bowen ratio systems are installed on tall towers within varying densities of forest cover in the upwind footprint and growing under varying depths to the water table. An additional eddy covariance tower is installed alongside a Bowen ratio system on one of the towers. Flux data has been gathered continuously since early 2007. In the summer of 2007, a Scintec large aperture scintillometer was installed between two of the towers over 1 km apart and has been working continuously along with the flux towers. Two intensive field campaigns were organized in June 2007 and May 2008 to coincide with LANDSAT TM5, MODIS and ASTER overpasses. High resolution multispectral and thermal imagery was acquired at the same time with the USU airborne system to provide information for the up- scaling of the energy balance fluxes from tower to satellite scales. The paper will present comparisons between the different energy balance measuring techniques under the highly advective conditions of the experimental site, concentrating on the scintillometer data. Preliminary results of remotely sensed modeling of the fluxes at different scales and model complexity will also be presented.

  17. Soil Quality under Riparian Forest at Different Stages of Ecological Succession and Cultivated with Sugarcane

    NASA Astrophysics Data System (ADS)

    Silva, Luiz Gabriel; Casagrande, José Carlos; Colato, Alexandre; Soares, Marcio Roberto; Perissatto Meneghin, Silvana

    2014-05-01

    This work aimed at evaluating the quality of the soil through its chemical, physical and microbiological attributes, using additive pondered model, as well as studying the characteristics of the linear method of combination of data, figures of merit (FoMs), the process of assigning weights and standard score functions, using measurements collected in three areas (two riparian forests and a commercial crop of sugarcane) in two soil types (Oxisol and Podzol) located on the dam shores of Sugar Mill Saint Lucia-Araras/SP. The soil was sampled in the depths of 0-0.2 and 0.2-0.4m, and was determined some of its chemical attributes (nutrient content and organic matter, cationic exchange capacity - CEC, etc.), physical (particle size distribution, density and porosity) and microbiological (microbial biomass and basal respiration). Two models were built, one containing two hierarchical levels of FoMs (Mod1), and another containing three levels (Mod2), in order to try to isolate FoMs highly correlated from each other within a top-level FoM. At FoMs of Mod1 were assigned various combinations of weights, and those of Mod2 were assigned weights from three methods, distribution from fixed value, classification and pair-wise comparison. In the Mod1, in virtually all combinations of weights used, values of Soil Quality Index (SQI) were superior in older forests, while the most recent forest presented the lowest SQI, for both types of soil. The variation of SQI values obtained from the sets of weights used also differed between the combinations tested, with the set of values of the ancient forest showing smaller amplitude. It could also be observed that the sets of values of Oxisol showed higher SQI and lower amplitude in relation to that of Podzol. It was observed that these facts are due mainly to the soil organic matter content (MO), which differs between the vegetations and soil types, and influences many parameters used in the model. Thus, in the structures where MO had

  18. Flowering, die-back and recovery of a semelparous woody bamboo in the Atlantic Forest

    NASA Astrophysics Data System (ADS)

    Montti, Lía; Campanello, Paula I.; Goldstein, Guillermo

    2011-07-01

    Chusquea ramosissima is a semelparous woody bamboo growing in the understory of the semideciduous Atlantic Forest that increases in abundance after disturbance and consequently has profound effects on vegetation dynamics. Flowering and death of C. ramosissima may open a window of opportunity leaving space vacant for the recruitment of tree seedlings. We describe the flowering pattern and seedling demography of this species at different spatio-temporal scales between the years 2001 and 2009, and evaluate if tree seedling abundance of canopy species increased after the flowering event. At a landscape scale, flowering sites were interspersed with sites that did not flower. At a local scale, the flowering extended over 5 years, with flowering and non-flowering culms intermingled, also in small patches (i.e., 4 m 2). Seeds germinated soon after flowering and die-back. Four successive seedling cohorts were studied. Mortality rate was high during the first 4 months after seedling emergence but several fast-growing seedlings were able to become established successfully. At the end of the study, 10%-20% of the initial number of bamboo seedlings in each cohort survived. Seedling abundance of tree canopy species was similar in flowering and non-flowering sites. C. ramosissima was able to re-colonize and perpetuate in sites it previously occupied. The coexistence of flowering and non-flowering culms at different spatio-temporal scales and clonal growth by rhizomes, together with the successful bamboo seedlings establishment, enhanced bamboo persistence in gaps and disturbed sites. Flowering and death of C. ramosissima did not facilitate seedling growth of canopy tree species.

  19. Assessing Anthropogenic Influence and Edge Effect Influence on Forested Riparian Buffer Spatial Configuration and Structure: An Example Using Lidar Remote Sensing Methods

    NASA Astrophysics Data System (ADS)

    Wasser, L. A.; Chasmer, L. E.

    2012-12-01

    Forested riparian buffers (FRB) perform numerous critical ecosystem services. However, globally, FRB spatial configuration and structure have been modified by anthropogenic development resulting in widespread ecological degradation as seen in the Gulf of Mexico and the Chesapeake Bay. Riparian corridors within developed areas are particularly vulnerable to disturbance given two edges - the naturally occurring stream edge and the matrix edge. Increased edge length predisposes riparian vegetation to "edge effects", characterized by modified physical and environmental conditions at the interface between the forested buffer and the adjacent landuse, or matrix and forest fragment degradation. The magnitude and distance of edge influence may be further influenced by adjacent landuse type and the width of the buffer corridor at any given location. There is a need to quantify riparian buffer spatial configuration and structure over broad geographic extents and within multiple riparian systems in support of ecologically sound management and landuse decisions. This study thus assesses the influence of varying landuse types (agriculture, suburban development and undeveloped) on forested riparian buffer 3-dimensional structure and spatial configuration using high resolution Light Detection and Ranging (LiDAR) data collected within a headwater watershed. Few studies have assessed riparian buffer structure and width contiguously for an entire watershed, an integral component of watershed planning and restoration efforts such as those conducted throughout the Chesapeake Bay. The objectives of the study are to 1) quantify differences in vegetation structure at the stream and matrix influenced riparian buffer edges, compared to the forested interior and 2) assess continuous patterns of changes in vegetation structure throughout the buffer corridor beginning at the matrix edge and ending at the stream within buffers a) of varying width and b) that are adjacent to varying landuse

  20. Large Woody Debris Input and Its Influence on Channel Structure in Agricultural Lands of Southeast Brazil

    NASA Astrophysics Data System (ADS)

    Paula, Felipe Rossetti De; Ferraz, Silvio Frosini De Barros; Gerhard, Pedro; Vettorazzi, Carlos Alberto; Ferreira, Anderson

    2011-10-01

    Riparian forests are important for the structure and functioning of stream ecosystems, providing structural components such as large woody debris (LWD). Changes in these forests will cause modifications in the LWD input to streams, affecting their structure. In order to assess the influence of riparian forests changes in LWD supply, 15 catchments (third and fourth order) with riparian forests at different conservation levels were selected for sampling. In each catchment we quantified the abundance, volume and diameter of LWD in stream channels; the number, area and volume of pools formed by LWD and basal area and tree diameter of riparian forest. We found that riparian forests were at a secondary successional stage with predominantly young trees (diameter at breast height <10 cm) in all studied streams. Results showed that basal area and diameter of riparian forest differed between the stream groups (forested and non-forested), but tree density did not differ between groups. Differences were also observed in LWD abundance, volume, frequency of LWD pools with subunits and area and volume of LWD pools. LWD diameter, LWD that form pools diameter and frequency of LWD pools without subunits did not differ between stream groups. Regression analyses showed that LWD abundance and volume, and frequency of LWD pools (with and without subunits) were positively related with the proportion of riparian forest. LWD diameter was not correlated to riparian tree diameter. The frequency of LWD pools was correlated to the abundance and volume of LWD, but characteristics of these pools (area and volume) were not correlated to the diameter of LWD that formed the pools. These results show that alterations in riparian forest cause modifications in the LWD abundance and volume in the stream channel, affecting mainly the structural complexity of these ecosystems (reduction in the number and structural characteristics of LWD pools). Our results also demonstrate that riparian forest

  1. Woody encroachment and forest degradation in sub-Saharan Africa's woodlands and savannas 1982–2006

    PubMed Central

    Mitchard, Edward T. A.; Flintrop, Clara M.

    2013-01-01

    We review the literature and find 16 studies from across Africa's savannas and woodlands where woody encroachment dominates. These small-scale studies are supplemented by an analysis of long-term continent-wide satellite data, specifically the Normalized Difference Vegetation Index (NDVI) time series from the Global Inventory Modeling and Mapping Studies (GIMMS) dataset. Using dry-season data to separate the tree and grass signals, we find 4.0% of non-rainforest woody vegetation in sub-Saharan Africa (excluding West Africa) significantly increased in NDVI from 1982 to 2006, whereas 3.52% decreased. The increases in NDVI were found predominantly to the north of the Congo Basin, with decreases concentrated in the Miombo woodland belt. We hypothesize that areas of increasing dry-season NDVI are undergoing woody encroachment, but the coarse resolution of the study and uncertain relationship between NDVI and woody cover mean that the results should be interpreted with caution; certainly, these results do not contradict studies finding widespread deforestation throughout the continent. However, woody encroachment could be widespread, and warrants further investigation as it has important consequences for the global carbon cycle and land–climate interactions. PMID:23878342

  2. Effects of riparian forest removal on the trophic dynamics of a Neotropical stream fish assemblage.

    PubMed

    Lobón-Cerviá, J; Mazzoni, R; Rezende, C F

    2016-07-01

    The effects of riparian forest removal on a neotropical stream fish assemblage were assessed in the Mata Atlântica. Fish assemblage structure and fish feeding patterns were quantified at three sites along a pristine-to-deforested gradient in a Serra do Mar stream: (1) a pristine site fully covered by canopy with no light penetration and transparent waters, (2) an intermediate site with partially removed forest and (3) a fully removed forest site with no canopy and full light penetration where siltation and turbid waters predominate. Fish assemblage structure, fish densities and their feeding patterns differed widely among sites. Whilst the same five fish species occurred at the three sites, forest removal favoured the occurrence of sediment-tolerant iliophagous benthic species at the deforested site. At the pristine site, invertebrate prey predominated in water column fish diet and feeding overlap among species was low. Severe shifts in the feeding patterns were noticed in both deforested sites. Invertebrates were replaced by detritus, organic matter and algae at both sites and feeding overlap increased markedly. The overwhelming feeding adaptability of these neotropical fishes appeared capable of buffering the deleterious effects of forest removal on stream quality in terms of increased light penetration, siltation and water turbidity. Forest cutting in this Mata Atlântica stream clearly caused strong functional changes associated with forest clearance through important modifications in the assemblage organization and trophic patterns of the main species, but did not eliminate species. PMID:27220656

  3. Variability in Response of Instream Habitat, and Fish and Macroinvertebrate Assemblages, to Riparian Forest Harvest in Northern Minnesota

    NASA Astrophysics Data System (ADS)

    Atuke, D. M.; Schlesser, N. J.; Vondracek, B.; Newman, R. M.

    2005-05-01

    We are evaluating the effects of high and low levels of riparian forest harvest, along eight, northern Minnesota streams, on fish and macroinvertebrate assemblages and instream habitat. The study is part of a larger project that includes water quality, vegetation and bird monitoring. Our design pairs streams with a high residual basal area (RBA) and a low RBA treatment. At each stream, control plots with no harvest and no riparian harvest were established and stream reaches were sampled downstream, within and upstream of all plots. Preharvest (2003) and postharvest (2004) data were collected from each stream and compared at the reach level. Fish were collected in one pass with a backpack electroshocker. Benthic macroinvertebrates were assessed following the US EPA family-level composited, multi-habitat rapid bioassessment protocol. Stream habitat was evaluated with a Quantitative Habitat Evaluation Index (QHEI) modified from the Minnesota Pollution Control Agency's habitat assessment protocol. Initial results indicate substantial variability in flow among sites, a significant variation (p<0.05) between years in QHEI and IBI scores, and differences within and between sites in macroinvertebrate species composition and abundance (species richness and %EPT). Continued monitoring will be required to assess the effects of riparian harvest.

  4. Benthic invertebrate community structure is influenced by forest succession after clearcut logging in southeastern Alaska

    USGS Publications Warehouse

    Hernandez, O.; Merritt, R.W.; Wipfli, M.S.

    2005-01-01

    To assess the effects of timber harvesting on headwater streams in upland forests, benthic community structure was contrasted among four dominant forest management types (old growth, red alder-dominated young growth, conifer-dominated young growth, clearcut) and instream habitats (woody debris, cobble, gravel) in southeastern Alaska. Benthos in streams of previously harvested areas resulted in increased richness, densities and biomass relative to old growth types, particularly in young growth stands with a red alder-dominated riparian canopy. Woody debris and gravel habitats supported a combination of higher densities and biomass of invertebrates than cobble habitats. In addition, woody debris also supported a richer and more diverse invertebrate fauna than either cobble or gravel substrates. Maintaining both a woody debris source and a red alder component in regenerating riparian forests following timber harvesting should support greater invertebrate densities and diversity following clearcutting. ?? Springer 2005.

  5. The role of coarse woody debris in southeastern pine forests; preliminary results from a large-scale experiment.

    SciTech Connect

    McCay Timothy, S.; Hanula, James, L.; Loeb, Susan, C.; Lohr, Steven, M.; McMinn, James, W.; Wright-Miley. Bret, D.

    2002-08-01

    McCay, Timothy S., James L. Hanula, Susan C. Loeb, Steven M. Lohr, James W. McMinn, and Bret D. Wright-Miley. 2002. The role of coarse woody debris in southeastern pine forests; preliminary results from a large-scale experiment. 135-144. In: Proceedings of the symposium on the ecology and management of dead wood in western forests. 1999 November 2-4; Reno, NV. Gen. Tech. Rep. PSW-GTR-181. Albany, CA: Pacific Southwest Research Station, Forest Service, U.S. Department of Agriculture 949 p. ABSTRACT: We initiated a long-term experiment involving manipulation of coarse woody debris (CWD) at the Savannah River National Environmental Research Park in the upper Coastal Plain of South Carolina. Each of four 9.3-ha plots in each of four blocks was subject to one of the following treatments: removal of all snags and fallen logs, removal of fallen logs only, felling and girdling to simulate a catastrophic pulse of CWD, and control. Removal treatments were applied in 1996, and the felling or snag-creation treatment will be applied in 2000-2001. Monitoring of invertebrate, herptile, avian, and mammalian assemblages and CWD dynamics began immediately after CWD removal and continues through the present. Removal treatments resulted in a fivefold to tenfold reduction in CWD abundance. To date, significant differences among treatments have only been detected for a few animal taxa. However, preliminary results underscore the benefits of large-scale experiments. This experiment allowed unambiguous tests of hypotheses regarding the effect of CWD abundance on fauna. Coupled with studies of habitat use and trophic interactions, the experimental approach may result in stronger inferences regarding the function of CWD than results obtained through natural history observation or uncontrolled correlative studies.

  6. Modeling the effects of anadromous fish nitrogen on the carbon balance of riparian forests in central Idaho

    NASA Astrophysics Data System (ADS)

    Noble Stuen, A. J.; Kavanagh, K.; Wheeler, T.

    2010-12-01

    Wild anadromous fish such as Pacific Chinook salmon (Oncorynchus tshawytscha) and steelhead (Oncorhyncus mykiss) were once abundant in Idaho, where they deposited their carcasses, rich in marine-derived nutrients (MDN), in the tributaries of the Columbia River. Anadromous fish are believed to have been a historically important nutrient source to the relatively nutrient-poor inland ecosystems of central Idaho, but no longer reach many inland watersheds due to presence of dams. This study investigates the multi-decadal cumulative effect of presence versus absence of anadromous fish nitrogen on net ecosystem exchange (NEE), or net carbon uptake, of riparian forests along historically salmon-bearing streams in the North Fork Boise River watershed, Idaho, in the context of a changing climate. The ecosystem process model BIOME-BGC is used to develop a representative forest ecosystem and predict the impact of decades of addition and continuing absence of MDN on NEE and net primary production (NPP). The study has 2 objectives: 1) to determine whether BIOME-BGC can reasonably simulate the riparian forests of central Idaho. A potentially confounding factor is the complex terrain of the region, particularly regarding soil water: water accumulation in valley bottoms and their riparian zones may lead to discrepancies in soil moisture and productivity of the riparian forest and of the simulations. The model is parameterized using local ecophysiology and site data and validated using field measurements of leaf area and soil moisture. Objective 2): to determine the effects on forest carbon balance and productivity of the presence or ongoing absence of anadromous-fish derived nitrogen. The forest simulation developed in objective 1 is run under two scenarios into the mid-20th century; one continuing without any supplemental nitrogen and one with nitrogen added in levels consistent with estimates of historical deposition by anadromous fish. Both scenarios incorporate warming due to

  7. A conceptual framework for dryland aeolian sediment transport along the grassland-forest continuum: Effects of woody plant canopy cover and disturbance

    USGS Publications Warehouse

    Breshears, D.D.; Whicker, J.J.; Zou, C.B.; Field, J.P.; Allen, C.D.

    2009-01-01

    Aeolian processes are of particular importance in dryland ecosystems where ground cover is inherently sparse because of limited precipitation. Dryland ecosystems include grassland, shrubland, savanna, woodland, and forest, and can be viewed collectively as a continuum of woody plant cover spanning from grasslands with no woody plant cover up to forests with nearly complete woody plant cover. Along this continuum, the spacing and shape of woody plants determine the spatial density of roughness elements, which directly affects aeolian sediment transport. Despite the extensiveness of dryland ecosystems, studies of aeolian sediment transport have generally focused on agricultural fields, deserts, or highly disturbed sites where rates of transport are likely to be greatest. Until recently, few measurements have been made of aeolian sediment transport over multiple wind events and across a variety of types of dryland ecosystems. To evaluate potential trends in aeolian sediment transport as a function of woody plant cover, estimates of aeolian sediment transport from recently published studies, in concert with rates from four additional locations (two grassland and two woodland sites), are reported here. The synthesis of these reports leads to the development of a new conceptual framework for aeolian sediment transport in dryland ecosystems along the grassland-forest continuum. The findings suggest that: (1) for relatively undisturbed ecosystems, shrublands have inherently greater aeolian sediment transport because of wake interference flow associated with intermediate levels of density and spacing of woody plants; and (2) for disturbed ecosystems, the upper bound for aeolian sediment transport decreases as a function of increasing amounts of woody plant cover because of the effects of the height and density of the canopy on airflow patterns and ground cover associated with woody plant cover. Consequently, aeolian sediment transport following disturbance spans the largest

  8. Structural and compositional controls on transpiration in 40- and 450-year-old riparian forests in western Oregon, USA.

    PubMed

    Moore, Georgianne W; Bond, Barbara J; Jones, Julia A; Phillips, Nathan; Meinzer, Federick C

    2004-05-01

    Large areas of forests in the Pacific Northwest are being transformed to younger forests, yet little is known about the impact this may have on hydrological cycles. Previous work suggests that old trees use less water per unit leaf area or sapwood area than young mature trees of the same species in similar environments. Do old forests, therefore, use less water than young mature forests in similar environments, or are there other structural or compositional components in the forests that compensate for tree-level differences? We investigated the impacts of tree age, species composition and sapwood basal area on stand-level transpiration in adjacent watersheds at the H.J. Andrews Forest in the western Cascades of Oregon, one containing a young, mature (about 40 years since disturbance) conifer forest and the other an old growth (about 450 years since disturbance) forest. Sap flow measurements were used to evaluate the degree to which differences in age and species composition affect water use. Stand sapwood basal area was evaluated based on a vegetation survey for species, basal area and sapwood basal area in the riparian area of two watersheds. A simple scaling exercise derived from estimated differences in water use as a result of differences in age, species composition and stand sapwood area was used to estimate transpiration from late June through October within the entire riparian area of these watersheds. Transpiration was higher in the young stand because of greater sap flux density (sap flow per unit sapwood area) by age class and species, and greater total stand sapwood area. During the measurement period, mean daily sap flux density was 2.30 times higher in young compared with old Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) trees. Sap flux density was 1.41 times higher in young red alder (Alnus rubra Bong.) compared with young P. menziesii trees, and was 1.45 times higher in old P. menziesii compared with old western hemlock (Tsuga heterophylla (Raf

  9. Hydrological controls on denitrification in riparian zone of forested headwater catchment: Soil physical properties make difference in reduced environment

    NASA Astrophysics Data System (ADS)

    Ohte, N.; Watanabe, Y.; Oda, T.; Osaka, K.

    2010-12-01

    Riparian zone near stream plays important roles to control the solute discharge from hillslope to stream. Supply of inorganic nitrogen as an essential nutrient of aquatic primary producers is generally regulated by hydrological and biogeochemical processes such as denitrification in this unique landscape unit in headwaters. To elucidate how the denitrification is controlled by hydrological properties of riparian groundwater aquifer, we investigated two similar scaled forested headwater catchments with different soil physical properties in Japan. The Kiryu- Matsuzawa catchment (KEW, 0.6 ha) has weathered granitic bedrock, and its soils in riparian zones are sandy, while the Fukuroyama-sawa catchment (FEW, 1.1 ha) has Tertiary sedimentary bedrock, and has clayey soils. Concentrations, δ15N and δ18O of NO3- in soil water, groundwater and streamwater were monitored during 2007 - 2009. Enrichment in δ15N-NO3- was found in the perennial groundwater bodies both in KEW and FEW, indicating active denitrification occurred (Fig 1). In the same time, however, increase in δ18O-NO3- of KEW groundwater was unclear, while that of FEW was found clearly indicating the denitrification under a closed system without significant dissolved O2 (DO) and new NO3- supply. It was also suggested that the denitrification in the KEW groundwater occurred under condition with relatively high DO, and new NO3- recharge by lateral groundwater movement. These differences were explainable by hydrological features of soils holding groundwater: The mean residence time (MRT) of the groundwater in FEW was estimated as three times longer (>1000 days) than that in KEW (<300 days). Moreover, this difference in MRT of groundwater aquifer is essentially caused by difference in the soil water retention characteristics between sandy soil in KEW and clayey soil in FEW. Those indicated the possibility that the difference of soil physical properties can be reflected strongly on inorganic nitrogen discharge from

  10. STREAM TEMPERATURE SIMULATION OF FORESTED RIPARIAN AREAS: I. WATERSHED-SCALE MODEL DEVELOPMENT

    EPA Science Inventory

    To simulate stream temperatures on a watershed scale, shading dynamics of topography and riparian vegetation must be computed for estimating the amount of solar radiation that is actually absorbed by water for each stream reach. A series of computational procedures identifying th...

  11. River management impacts on riparian forest vegetation along the Middle Rio Grande: 1935-2014

    NASA Astrophysics Data System (ADS)

    Petrakis, Roy E.

    Riparian ecosystems of the southwestern United States are highly valuable to both the ecological and human communities which surround them. Over the past century, they have been subject to shifting management practices to maximize human use, control, ecosystem service, and conservation. This creates a complex relationship between water policy, management, and the natural ecosystem necessitating research on spatial and temporal dynamics of riparian vegetation. The San Acacia Reach of the Middle Rio Grande, a 60 mile stretch from the San Acacia Diversion Dam to San Marcial, has experienced multiple management and river flow fluctuations over the past 80 years, resulting in threats to riparian and aquatic ecosystems. This research was completed through the use and analysis of multi-source remote sensing data, GIS, and a review of the on-the-ground management decisions to better understand how the location and composition of the riparian vegetation has been affected by these shifting practices. This research focused on four phases, each highlighting different management practices and river flow patterns during the last 80-years. Each of these periods provides a unique opportunity to observe a direct relationship between river management and riparian land cover response and change. Overall, management practices reduced surface river flows and limited overbank flooding and resulted in changes in the composition, density, and spatial patterns of the vegetation, including increased non-native vegetation growth. Restoration efforts over the past few decades have begun to reduce the presence of non-native species. Despite these changes, this ecosystem was shown to be extremely resilient in maintaining its function/service throughout the entire study time frame.

  12. Influence of Vegetation Structure on Lidar-derived Canopy Height and Fractional Cover in Forested Riparian Buffers During Leaf-Off and Leaf-On Conditions

    PubMed Central

    Wasser, Leah; Day, Rick; Chasmer, Laura; Taylor, Alan

    2013-01-01

    Estimates of canopy height (H) and fractional canopy cover (FC) derived from lidar data collected during leaf-on and leaf-off conditions are compared with field measurements from 80 forested riparian buffer plots. The purpose is to determine if existing lidar data flown in leaf-off conditions for applications such as terrain mapping can effectively estimate forested riparian buffer H and FC within a range of riparian vegetation types. Results illustrate that: 1) leaf-off and leaf-on lidar percentile estimates are similar to measured heights in all plots except those dominated by deciduous compound-leaved trees where lidar underestimates H during leaf off periods; 2) canopy height models (CHMs) underestimate H by a larger margin compared to percentile methods and are influenced by vegetation type (conifer needle, deciduous simple leaf or deciduous compound leaf) and canopy height variability, 3) lidar estimates of FC are within 10% of plot measurements during leaf-on periods, but are underestimated during leaf-off periods except in mixed and conifer plots; and 4) depth of laser pulse penetration lower in the canopy is more variable compared to top of the canopy penetration which may influence within canopy vegetation structure estimates. This study demonstrates that leaf-off lidar data can be used to estimate forested riparian buffer canopy height within diverse vegetation conditions and fractional canopy cover within mixed and conifer forests when leaf-on lidar data are not available. PMID:23382966

  13. Pesticides in shallow ground water in the forested wetland riparian area of the Beasley Lake Watershed, Mississippi, USA, 2001-2005

    Technology Transfer Automated Retrieval System (TEKTRAN)

    We evaluated the movement of pesticides into shallow ground water in a Mississippi Delta forested natural wetland riparian area in the Beasley Lake watershed (Sunflower County, Mississippi, USA). Four well sites were established, each with depths of 0.6, 1.5, 3.0, and 4.6 m (2’, 5’, 10’, and 15’, re...

  14. Quantifying geomorphic controls on riparian forest dynamics using a linked physical-biological model: implications for river corridor conservation

    NASA Astrophysics Data System (ADS)

    Stella, J. C.; Harper, E. B.; Fremier, A. K.; Hayden, M. K.; Battles, J. J.

    2009-12-01

    In high-order alluvial river systems, physical factors of flooding and channel migration are particularly important drivers of riparian forest dynamics because they regulate habitat creation, resource fluxes of water, nutrients and light that are critical for growth, and mortality from fluvial disturbance. Predicting vegetation composition and dynamics at individual sites in this setting is challenging, both because of the stochastic nature of the flood regime and the spatial variability of flood events. Ecological models that correlate environmental factors with species’ occurrence and abundance (e.g., ’niche models’) often work well in infrequently-disturbed upland habitats, but are less useful in river corridors and other dynamic zones where environmental conditions fluctuate greatly and selection pressures on disturbance-adapted organisms are complex. In an effort to help conserve critical riparian forest habitat along the middle Sacramento River, CA, we are taking a mechanistic approach to quantify linkages between fluvial and biotic processes for Fremont cottonwood (Populus fremontii), a keystone pioneer tree in dryland rivers ecosystems of the U.S. Southwest. To predict the corridor-wide population effects of projected changes to the disturbance regime from flow regulation, climate change, and landscape modifications, we have coupled a physical model of channel meandering with a patch-based population model that incorporates the climatic, hydrologic, and topographic factors critical for tree recruitment and survival. We employed these linked simulations to study the relative influence of the two most critical habitat types--point bars and abandoned channels--in sustaining the corridor-wide cottonwood population over a 175-year period. The physical model uses discharge data and channel planform to predict the spatial distribution of new habitat patches; the population model runs on top of this physical template to track tree colonization and survival on

  15. Amphibian and reptile community response to coarse woody debris manipulations in upland loblolly pine (Pinus taeda) forests.

    SciTech Connect

    Owens, Audrey, K.; Moseley, Kurtis, R.; McCay, Timothy, S.; Castleberry, Steven, B .; Kilgo, John, C.; Ford, W., Mark

    2008-07-01

    Coarse woody debris (CWD) has been identified as a key microhabitat component for groups that are moisture and temperature sensitive such as amphibians and reptiles. However, few experimental manipulations have quantitatively assessed amphibian and reptile response to varying CWD volumes within forested environments. We assessed amphibian and reptile response to large-scale, CWD manipulation within managed loblolly pine stands in the southeastern Coastal Plain of the United States from 1998 to 2005. Our study consisted of two treatment phases: Phase I treatments included downed CWD removal (removal of all downed CWD), all CWD removal (removal of all downed and standing CWD), pre-treatment snag, and control; Phase II treatments included downed CWD addition (downed CWD volume increased 5-fold), snag addition (standing CWD volume increased 10-fold), all CWD removal (all CWD removed), and control. Amphibian and anuran capture rates were greater in control than all CWD removal plots during study Phase I. In Phase II, reptile diversity and richness were greater in downed CWD addition and all CWD removal than snag addition treatments. Capture rate of Rana sphenocephala was greater in all CWD removal treatment than downed CWD addition treatment. The dominant amphibian and snake species captured are adapted to burrowing in sandy soil or taking refuge under leaf litter. Amphibian and reptile species endemic to upland southeastern Coastal Plain pine forests may not have evolved to rely on CWD because the humid climate and short fire return interval have resulted in historically low volumes of CWD.

  16. Estimating aboveground biomass for broadleaf woody plants and young conifers in Sierra Nevada, California forests.

    USGS Publications Warehouse

    McGinnis, Thomas W.; Shook, Christine D.; Keeley, Jon E.

    2010-01-01

    Quantification of biomass is fundamental to a wide range of research and natural resource management goals. An accurate estimation of plant biomass is essential to predict potential fire behavior, calculate carbon sequestration for global climate change research, assess critical wildlife habitat, and so forth. Reliable allometric equations from simple field measurements are necessary for efficient evaluation of plant biomass. However, allometric equations are not available for many common woody plant taxa in the Sierra Nevada. In this report, we present more than 200 regression equations for the Sierra Nevada western slope that relate crown diameter, plant height, crown volume, stem diameter, and both crown diameter and height to the dry weight of foliage, branches, and entire aboveground biomass. Destructive sampling methods resulted in regression equations that accurately predict biomass from one or two simple, nondestructive field measurements. The tables presented here will allow researchers and natural resource managers to easily choose the best equations to fit their biomass assessment needs.

  17. Estimating aboveground biomass for broadleaf woody plants and young conifers in Sierra Nevada, California, forests

    USGS Publications Warehouse

    McGinnis, T.W.; Shook, C.D.; Keeley, J.E.

    2010-01-01

    Quantification of biomass is fundamental to a wide range of research and natural resource management goals. An accurate estimation of plant biomass is essential to predict potential fire behavior, calculate carbon sequestration for global climate change research, assess critical wildlife habitat, and so forth. Reliable allometric equations from simple field measurements are necessary for efficient evaluation of plant biomass. However, allometric equations are not available for many common woody plant taxa in the Sierra Nevada. In this report, we present more than 200 regression equations for the Sierra Nevada western slope that relate crown diameter, plant height, crown volume, stem diameter, and both crown diameter and height to the dry weight of foliage, branches, and entire aboveground biomass. Destructive sampling methods resulted in regression equations that accurately predict biomass from one or two simple, nondestructive field measurements. The tables presented here will allow researchers and natural resource managers to easily choose the best equations to fit their biomass assessment needs.

  18. Long-term reproductive behaviour of woody plants across seven Bornean forest types in the Gunung Palung National Park (Indonesia): suprannual synchrony, temporal productivity and fruiting diversity.

    PubMed

    Cannon, Charles H; Curran, Lisa M; Marshall, Andrew J; Leighton, Mark

    2007-10-01

    For 68 months, we observed the reproductive behaviour of 7288 woody plants (172 figs, 1457 climbers and 5659 trees) spanning major soil and elevational gradients. Two 2-3 month community-wide supra-annual fruiting events were synchronized across five forest types, coinciding with ENSO events. At least 27 genera in 24 families restricted their reproduction to these events, which involved a substantial proportion of tree diversity (> 80% of phylogenetic diversity). During these events, mean reproductive levels (8.5%) represented an almost four-fold increase compared with other months. These patterns indicate a strong behavioural advantage to this unusual reproductive behaviour. Montane forest experienced a single, separate fruiting peak while the peat swamp forest did not participate. Excluding these events, no temporal reproductive pattern was detectable, at either the landscape or forest type. These phenological patterns have major implications for the conservation of frugivore communities, with montane and swamp forests acting as 'keystone' forests. PMID:17845296

  19. Riparian litter inputs to streams in the central Oregon Coast Range

    USGS Publications Warehouse

    Hart, Stephanie K.; Hibbs, David E.; Perakis, Steven S.

    2013-01-01

    Riparian-zone vegetation can influence terrestrial and aquatic food webs through variation in the amount, timing, and nutritional content of leaf and other litter inputs. We investigated how riparian-forest community composition, understory density, and lateral slope shaped vertical and lateral litter inputs to 16 streams in the Oregon Coast Range. Riparian forests dominated by deciduous red alder delivered greater annual vertical litter inputs to streams (504 g m−2 y−1) than did riparian forests dominated by coniferous Douglas-fir (394 g m−2 y−1). Deciduous forests also contributed greater lateral litter inputs per meter of stream bank on one side (109 g m−1 y−1) than did coniferous forests (63 g m−1 y−1). Total litter inputs from deciduous forests exceeded those from coniferous forests most strongly in November, coincident with an autumn peak in litter inputs. Lateral litter inputs contributed most to total inputs during winter in both forest types. Annual lateral litter movement increased with slope at deciduous sites, but only in spring/summer months at coniferous sites. Neither experimental removal of understory vegetation nor installation of mesh fences to block downslope litter movement affected lateral litter inputs to streams, suggesting that ground litter moves <5 m downslope annually. N concentrations of several litter fractions were higher at deciduous sites and, when combined with greater litter amounts, yielded twice as much total litter N flux to streams in deciduous than coniferous sites. The presence of red alder in riparian forests along many small streams of the deeply incised and highly dendritic basins of the Oregon Coast Range enhances total fluxes and seasonality of litter delivery to both terrestrial and aquatic food webs in this region and complements the shade and large woody debris provided by large coniferous trees.

  20. PLANT INVASIONS IN RHODE ISLAND RIPARIAN ZONES

    EPA Science Inventory

    The vegetation in riparian zones provides valuable wildlife habitat while enhancing instream habitat and water quality. Forest fragmentation, sunlit edges, and nutrient additions from adjacent development may be sources of stress on riparian zones. Landscape plants may include no...

  1. Isotopologue ratios of N2O and N2 measurements underpin the importance of denitrification in differently N-loaded riparian alder forests.

    PubMed

    Mander, Ulo; Well, Reinhard; Weymann, Daniel; Soosaar, Kaido; Maddison, Martin; Kanal, Arno; Lõhmus, Krista; Truu, Jaak; Augustin, Jürgen; Tournebize, Julien

    2014-10-21

    Known as biogeochemical hotspots in landscapes, riparian buffer zones exhibit considerable potential concerning mitigation of groundwater contaminants such as nitrate, but may in return enhance the risk for indirect N2O emission. Here we aim to assess and to compare two riparian gray alder forests in terms of gaseous N2O and N2 fluxes and dissolved N2O, N2, and NO3(-) in the near-surface groundwater. We further determine for the first time isotopologue ratios of N2O dissolved in the riparian groundwater in order to support our assumption that it mainly originated from denitrification. The study sites, both situated in Estonia, northeastern Europe, receive contrasting N loads from adjacent uphill arable land. Whereas N2O emissions were rather small at both sites, average gaseous N2-to-N2O ratios inferred from closed-chamber measurements and He-O laboratory incubations were almost four times smaller for the heavily loaded site. In contrast, groundwater parameters were less variable among sites and between landscape positions. Campaign-based average (15)N site preferences of N2O (SP) in riparian groundwater ranged between 11 and 44 ‰. Besides the strong prevalence of N2 emission over N2O fluxes and the correlation pattern between isotopologue and water quality data, this comparatively large range highlights the importance of denitrification and N2O reduction in both riparian gray alder stands. PMID:25264900

  2. δ15N patterns of Douglas-fir and red alder riparian forests in the Oregon Coast Range

    USGS Publications Warehouse

    Scott, E.E.; Perakis, S.S.; Hibbs, D.E.

    2008-01-01

    We used naturally occurring stable isotopes of N to compare N dynamics in near-stream and upslope environments along riparian catenas in N-fixing red alder (Alnus rubra) and Douglas-fir (Pseudotsuga menziesii) forests in the Coast Range of western Oregon. Based on the existing literature, we expected soil δ15N to be enriched closer to streams owing to inputs of isotopically heavy, marine-derived N by spawning salmon, higher rates of denitrification near the stream, or both. However, it has been unclear what effect red alder might have on soil δ15N patterns near streams. We found a consistent −1‰ δ15N signature in red alder foliage, and δ15N of total N in soils under red alder averaged 2.2‰ along sampling transects extending 20 m upslope from the stream. Surprisingly, δ15N of total N in soil under Douglas-fir was progressively depleted nearer to streams, opposite from the pattern expected from N losses by denitrification or N inputs from anadromous salmon. Instead, δ15N of total N in soil under Douglas-fir converged toward soil δ15N values typical of red alder sites. We consider that the historic presence of red alder may have contributed a legacy of lower soil δ15N nearer to streams on sites that are currently dominated by young Douglas-fir forest.

  3. Multi-Scale Drivers of Riparian Forest Decline Along a Mediterranean-Climate River

    NASA Astrophysics Data System (ADS)

    Stella, J. C.; Riddle, J.; Piégay, H.; Gagnage, M.; Trémolo, M.

    2010-12-01

    Variation in water availability is a major driver of ecological communities and ecosystem health in riverine and riparian ecosystems, particularly in Mediterranean and other semi-arid regions. Competition for water resources from humans has stressed these ecosystems worldwide, and population growth, land use and climate change threaten to further impair already vulnerable ecological communities. In riparian zones, there is a need to develop tools to measure these impacts on the key biological and physical processes that sustain ecosystem health and potential recovery. We used dendrochronology of Populus nigra, a riparian tree that is vulnerable to changes in local hydrology, to analyze ecosystem response following gravel mining along the Drôme River, a Mediterranean-climate stream in southern France. We cored trees (N=55) at seven floodplain sites, measured ring widths, and calculated site-based indices of growth to compare the severity and timing of local growth decline along the river. Results indicate that tree growth has declined at some sites coincident with documented channel incision, and that patterns of low growth and crown dieback are consistent with stress due to reduced water supply. Sites varied significantly in recent tree growth rate (F6,34=3.55, p<0.01) and this was not due to tree age, individual size at an early age, or stand density. The site-based, age-corrected index of recent radial growth varied 5-fold between sites (range 0.5±0.08 to 2.3±0.60 unitless growth index, mean 1±SE). Growth index was negatively correlated with proportion of dead crown (r = -0.71), though the relationship was non-linear, with low growth for the three sites that experienced the greatest crown dieback. Regime Shift Detection analysis of site chronologies showed significant sustained growth decline (p<0.05) at four sites after 1980, following the period of intensive instream mining downstream. Site growth declines were not simultaneous, however, nor sequenced in a

  4. Shade Trading: An Emerging Riparian Forest-Based Payment for Ecosystem Services Market in Oregon, USA

    NASA Astrophysics Data System (ADS)

    Guillozet, Kathleen

    2015-10-01

    This paper describes the regulatory and compliance context for Oregon's emerging ecosystem services (ES) market in riparian shade to meet water quality obligations. In Oregon's market as with many other ES programs, contracts and other regulatory documents not only delimit the obligations and liabilities of different parties, but also constitute a primary mechanism through which ES service delivery is measured. Through a review of compliance criteria I find that under Oregon's shade trades, permittees are held to a number of input-based criteria, which essentially affirm that parties comply with predetermined practices and procedures, and one `pseudo output based' criterion, in which ES delivery is estimated through a model. The case presented in the paper critically engages with the challenges of measuring ES and in assessing the outcomes of ES projects. It places these challenges as interrelated and proposes that market designers, policymakers, and other stakeholders should consider explicit efficacy, efficiency, and equity targets.

  5. Shade Trading: An Emerging Riparian Forest-Based Payment for Ecosystem Services Market in Oregon, USA.

    PubMed

    Guillozet, Kathleen

    2015-10-01

    This paper describes the regulatory and compliance context for Oregon's emerging ecosystem services (ES) market in riparian shade to meet water quality obligations. In Oregon's market as with many other ES programs, contracts and other regulatory documents not only delimit the obligations and liabilities of different parties, but also constitute a primary mechanism through which ES service delivery is measured. Through a review of compliance criteria I find that under Oregon's shade trades, permittees are held to a number of input-based criteria, which essentially affirm that parties comply with predetermined practices and procedures, and one 'pseudo output based' criterion, in which ES delivery is estimated through a model. The case presented in the paper critically engages with the challenges of measuring ES and in assessing the outcomes of ES projects. It places these challenges as interrelated and proposes that market designers, policymakers, and other stakeholders should consider explicit efficacy, efficiency, and equity targets. PMID:26099569

  6. Woody biomass resource of major tree taxa for the Midsouth states. Forest Service Resource Bulletin

    SciTech Connect

    Rosson, J.F.

    1992-02-01

    Data from the most recent State forest surveys were used to derive estimates of wood and bark biomass for the Midsouth region. For clarification of these data, appendix 1 defines relevant terms. Species that occurred in the Midsouth sample are listed in appendix 2. Appendix 3 tables 1 through 3 describe the Midsouth timberland area by State. Tables 4 through 48 describe the biomass resource by species group (4-6), ownership class (7-12), forest type (13-18), tree class (19-30), diameter class (31-36), basal area class (37-42), and height class (43-48). See the list of tables for a more detailed description of table content. Appendix 4 figures 1 through 7 describe the extent of biomass resource by yield class.

  7. Elevational change in woody tissue CO2 efflux in a tropical mountain rain forest in southern Ecuador.

    PubMed

    Zach, Alexandra; Horna, Viviana; Leuschner, Christoph

    2008-01-01

    Much uncertainty exists about the magnitude of woody tissue respiration and its environmental control in highly diverse tropical moist forests. In a tropical mountain rain forest in southern Ecuador, we measured the apparent diurnal gas exchange of stems and coarse roots (diameter 1-4 cm) of trees from representative families along an elevational transect with plots at 1050, 1890 and 3050 m a.s.l. Mean air temperatures were 20.8, 17.2 and 10.6 degrees C, respectively. Stem and root CO(2) efflux of 13 to 21 trees per stand from dominant families were investigated with an open gas exchange system while stand microclimate was continuously monitored. Substantial variation in respiratory activity among and within species was found at all sites. Mean daily CO(2) release rates from stems declined 6.6-fold from 1.38 micromol m(-2) s(-1) at 1050 m to 0.21 micromol m(-2) s(-1) at 3050 m. Mean daily CO(2) release from coarse roots decreased from 0.35 to 0.20 micromol m(-2) s(-1) with altitude, but the differences were not significant. There was, thus, a remarkable shift from a high ratio of stem to coarse root respiration rates at the lowest elevation to an apparent equivalence of stem and coarse root CO(2) efflux rates at the highest elevation. We conclude that stem respiration, but not root respiration, greatly decreases with elevation in this transect, coinciding with a substantial decrease in relative stem diameter increment and a large increase in fine and coarse root biomass production with elevation. PMID:17938115

  8. Riparian Vegetation Influence on Stream Channel Dimensions: Key Driving Mechanisms and Their Timescales

    NASA Astrophysics Data System (ADS)

    McBride, M.; Hession, W.; Rizzo, D. M.; Thompson, D. M.

    2006-05-01

    Combined results from field-based investigations and flume experiments demonstrated key mechanisms driving channel widening following the reforestation of riparian zones in small streams. Riparian reforestation is a common occurrence either due to restoration efforts, intended to improve water quality, temperature regimes, and in-stream physical habitat or due to passive reforestation that is common when agricultural land uses decline. Previous studies have documented the influence of riparian vegetation on channel size, but driving mechanisms and the timescales at which they operate have not been evaluated. Field-based investigations were conducted in the Sleepers River basin in northeastern Vermont to revisit streams that were previously surveyed in the 1960s. We measured channel dimensions, large woody debris (LWD), and steam velocities in reaches with non-forested and forested riparian vegetation, in reaches currently in transition between vegetation types, and reaches with no change in riparian vegetation over the last 40 years. Flume experiments were performed with a 1:5 scale, fixed-bed model of a tributary to Sleepers River. Two types of riparian vegetation scenarios were simulated: 1) forested, with rigid, wooden dowels; and 2) non-forested, with synthetic grass carpeting. Three-dimensional velocities were measured during flume runs to determine turbulent kinetic energy (TKE) during overbank flows. Results showed that stream reaches with recently reforested vegetation have widened since the mid 1960s, but are not as wide as reaches with older riparian forests. LWD was more abundant in reaches with older riparian forests than in reaches with younger forests; however, scour around LWD did not appear to be a significant driving mechanism for channel widening. Velocity and TKE measurements from the prototype stream and the flume model indicate that TKE was significantly elevated in reforested reaches. Given that bed and bank erosion can be amplified in flows

  9. Estimating aboveground biomass of broadleaved woody plants in the understory of Florida Keys pine forests

    USGS Publications Warehouse

    Sah, J.P.; Ross, M.S.; Koptur, S.; Snyder, J.R.

    2004-01-01

    Species-specific allometric equations that provide estimates of biomass from measured plant attributes are currently unavailable for shrubs common to South Florida pine rocklands, where fire plays an important part in shaping the structure and function of ecosystems. We developed equations to estimate total aboveground biomass and fine fuel of 10 common hardwood species in the shrub layer of pine forests of the lower Florida Keys. Many equations that related biomass categories to crown area and height were significant (p < 0.05), but the form and variables comprising the best model varied among species. We applied the best-fit regression models to structural information from the shrub stratum in 18 plots on Big Pine Key, the most extensive pine forest in the Keys. Estimates based on species-specific equations indicated clearly that total aboveground shrub biomass and shrub fine fuel increased with time since last fire, but the relationships were non-linear. The relative proportion of biomass constituted by the major species also varied with stand age. Estimates based on mixed-species regressions differed slightly from estimates based on species-specific models, but the former could provide useful approximations in similar forests where species-specific regressions are not yet available. ?? 2004 Elsevier B.V. All rights reserved.

  10. Decomposition of New Woody Inputs as a Dry Tropical Forest Regenerates

    NASA Astrophysics Data System (ADS)

    Schilling, J. S.; Powers, J. S.; Ayres, A.; Kaffenberger, J. T.

    2015-12-01

    Modeling deadwood dynamics is limited by our empirical understanding of decomposition patterns and drivers. This gap is significant in dry tropical forests (and in the tropics, broadly) where forest regeneration is a management priority but where decision-making lacks resources. Our goal was to track decomposition and its biological drivers in tree boles added to the forest floor of a regenerating dry forest. We cut and then placed logs (~18 cm dia) of eight representative tree species in ground contact at two different sites (n=8, per site). We tracked density loss and element import/export in both sapwood and heartwood each 6 months over two years. We measured initial and final lignin, structural carbohydrates, nitrogen, and extractives. We also quantified insect gallery volumes, and used two residue 'signatures' to determine dominant fungal rot type: 1) dilute alkali solubility (DAS) and lignin:glucan loss. By year 2, mean density losses in sapwood were 11.6 - 44.4% among tree species, excluding one species that decomposed completely. The best predictor of density loss in sapwood was initial pH, but the correlation was negative rather than positive, as has been reported in temperate systems. Decay was consistently more advanced in sapwood than in heartwood, and although extractives were as high as 16.4% in heartwood, trait-density loss correlations were insignificant. Insects contributed little at this stage to density loss (<3%), and both lignin:glucan loss and DAS confirmed that white rot fungi dominated decomposition. Although element import dynamics broadly resembled those from temperate studies (e.g., Ca gain, P, K loss), there was high spatial variability. This perhaps related to zone line (spalting) complexity, suggesting intense competition among fungi colonizing small territories within the wood. Estimated CO2 fluxes from the test logs ranged from ~25 to 75% of the annual fluxes from litter fall at these sites. Collectively, these results implicate wood

  11. Riparian responses to extreme climate and land-use change scenarios.

    PubMed

    Fernandes, Maria Rosário; Segurado, Pedro; Jauch, Eduardo; Ferreira, Maria Teresa

    2016-11-01

    Climate change will induce alterations in the hydrological and landscape patterns with effects on riparian ecotones. In this study we assess the combined effect of an extreme climate and land-use change scenario on riparian woody structure and how this will translate into a future risk of riparian functionality loss. The study was conducted in the Tâmega catchment of the Douro basin. Boosted Regression Trees (BRTs) were used to model two riparian landscape indicators related with the degree of connectivity (Mean Width) and complexity (Area Weighted Mean Patch Fractal Dimension). Riparian data were extracted by planimetric analysis of high spatial-resolution Word Imagery Layer (ESRI). Hydrological, climatic and land-use variables were obtained from available datasets and generated with process-based modeling using current climate data (2008-2014), while also considering the high-end RCP8.5 climate-change and "Icarus" socio-economic scenarios for the 2046-2065 time slice. Our results show that hydrological and land-use changes strongly influence future projections of riparian connectivity and complexity, albeit to diverse degrees and with differing effects. A harsh reduction in average flows may impair riparian zones while an increase in extreme rain events may benefit connectivity by promoting hydrologic dynamics with the surrounding floodplains. The expected increase in broad-leaved woodlands and mixed forests may enhance the riparian galleries by reducing the agricultural pressure on the area in the vicinity of the river. According to our results, 63% of river segments in the Tâmega basin exhibited a moderate risk of functionality loss, 16% a high risk, and 21% no risk. Weaknesses and strengths of the method are highlighted and results are discussed based on a resilience perspective with regard to riparian ecosystems. PMID:27341115

  12. Headwater Stream Temperature Response to Forest Harvesting in Coastal British Columbia, Canada: Influences of Riparian Buffer Width, Channel Morphology and Weather

    NASA Astrophysics Data System (ADS)

    Moore, R.; Gomi, T.; Dhakal, A.

    2003-12-01

    Forest harvesting can influence stream temperature regimes, and the potentially deleterious impacts of higher temperatures on salmonids and other species have generated significant debate. One common approach to protecting streams is to leave a riparian buffer to provide shade. However, little information has been collected on the effectiveness of different buffer widths. We report the results of a 6-year field experiment to evaluate the effects of different riparian buffer widths on stream and riparian ecosystems, including stream temperature response, in headwater streams in coastal British Columbia. The experiment included 13 streams, with at least three being assigned to each of four treatments, including no harvesting (80 yr-old second growth conifer riparian forest), clear-cut harvesting with 10 m and 30 m riparian buffers, and clear-cut harvesting with no buffer. Regression analysis was used to calibrate the pre-harvest data for each treatment stream with one of the control streams, to provide a basis for estimating post-harvest treatment effects. Autoregressive and heteroskedastic errors were included in the regression model, because stream temperature exhibited serial correlation and the error variance increased with stream temperature. Temperature response was substantial in the clearcut treatments with no buffers, with maximum temperatures increasing by up to 8 degrees C. The magnitude of temperature response amongst the no-buffer treatments varied with channel morphology, particularly in relation to bank shading and stream depth. The treatment effect for daily maximum water temperature increased with decreasing flow and increasing maximum air temperature on the current day, and also exhibited significant autocorrelation, indicating that the sequence of daily weather conditions can influence the magnitude of temperature response.

  13. Recent Changes in the Riparian Forest of a Large Regulated Mediterranean River: Implications for Management

    NASA Astrophysics Data System (ADS)

    González, Eduardo; González-Sanchis, María; Cabezas, Álvaro; Comín, Francisco A.; Muller, Etienne

    2010-04-01

    The structure of the floodplain forests of the Middle Ebro River (NE Spain) was examined at patch and landscape scales along a three-step chronosequence defined according to the extent of flow regulation-induced hydrogeomorphic changes, with the ultimate purpose of producing baseline information to guide through management and restoration plans. At patch scale, a total of 6,891 stems within 39 plots were registered for species, diameter and health status. The stem density, size class distribution, canopy dieback and mortality were further compared by means of non-parametric tests. At landscape scale, the temporal evolution of the area occupied by forest stands of different ages in the floodplain along the chronosequence was evaluated using four sets of aerial photographs dated in 1927, 1957, 1981 and 2003. The within-patch structure of pioneer forests (<25-30 years old) was characterized by dense and healthy populations of pioneer species ( Populus nigra, Salix alba and Tamarix spp.), but the area occupied by these forest types has progressively decreased (up to 37%) since the intensification of river regulation (ca. 1957). In contrast, non-pioneer forests (>25-30 years old) were characterized by declining and sparse P. nigra- S. alba- Tamarix spp. stands, where late-seral species such as Ulmus minor and Fraxinus angustifolia were frequent, but only as small-size stems. At landscape scale, these type of senescent forests have doubled their surface after river regulation was intensified. Populus alba only appeared in the oldest plots recorded (colonized before 1957), suggesting sexual regeneration failure during the last five decades, but usually as healthy and dense stands. Based on these findings, measures principally aimed at recovering some hydrogeomorphic dynamism are recommended to guarantee the self-sustainability of the floodplain forest ecosystem.

  14. Repeated prescribed fires decrease stocks and change attributes of coarse woody debris in a temperate eucalypt forest.

    PubMed

    Aponte, Cristina; Tolhurst, Kevin G; Bennett, Lauren T

    2014-07-01

    Previous studies have found negligible effects of single prescribed fires on coarse woody debris (CWD), but the cumulative effects of repeated low-intensity prescribed fires are unknown. This represents a knowledge gap for environmental management because repeated prescribed fires are a key tool for mitigating wildfire risk, and because CWD is recognized as critical to forest biodiversity and functioning. We examined the effects of repeated low-intensity prescribed fires on the attributes and stocks of (fallen) CWD in a mixed-species eucalypt forest of temperate Australia. Prescribed fire treatments were a factorial combination of two seasons (Autumn, Spring) and two frequencies (three yearly High, 10 yearly Low), were replicated over five study areas, and involved two to seven low-intensity fires over 27 years. Charring due to prescribed fires variously changed carbon and nitrogen concentrations and C to N ratios of CWD pieces depending on decay class, but did not affect mean wood density. CWD biomass and C and N stocks were significantly less in Fire than Control treatments. Decreases in total CWD C stocks of -8 Mg/ha in Fire treatments were not balanced by minor increases in pyrogenic (char) C (-0.3 Mg/ha). Effects of prescribed fire frequency and season included significantly less C and N stocks in rotten CWD in High than Low frequency treatments, and in the largest CWD pieces in Autumn than Spring treatments. Our study demonstrates that repeated low-intensity prescribed fires have the potential to significantly decrease CWD stocks, in pieces of all sizes and particularly decayed pieces, and to change CWD chemical attributes. CWD is at best a minor stock of pyrogenic C under such fire regimes. These findings suggest a potential trade-off in the management of temperate eucalypt forests between sustained reduction of wildfire risk, and the consequences of decreased CWD C stocks, and of changes in CWD as a habitat and biogeochemical substrate. Nonetheless

  15. Quantifying Forested Riparian Buffer Ability to Ameliorate Stream Temperature in a Missouri Ozark Border Stream of the Central U.S

    NASA Astrophysics Data System (ADS)

    Bulliner, E. A.; Hubbart, J. A.

    2009-12-01

    Riparian buffers play an important role in modulating stream water quality, including temperature. There is a need to better understand riparian form and function to validate and improve contemporary management practices. Further studies are warranted to characterize energy attenuation by forested riparian canopy layers that normally buffer stream temperature, particularly in the central hardwood forest regions of the United States where relationships between canopy density and stream temperature are unknown. To quantify these complex processes, two intensively instrumented hydroclimate stations were installed along two stream reaches of a riparian stream in central Missouri, USA in the winter of 2008. Hydroclimate stations are located along stream reaches oriented in both cardinal directions, which will allow interpolation of results to other orientations. Each station consists of an array of instrumentation that senses the flux of water and energy into and out of the riparian zone. Reference data are supplied from a nearby flux tower (US DOE) located on top of a forested ridge. The study sites are located within a University of Missouri preserved wildland area on the border of the southern Missouri’s Ozark region, an ecologically distinct region in the central United States. Limestone underlies the study area, resulting in a distinct semi-Karst hydrologic system. Vegetation forms a complex, multi-layered canopy extending from the stream edge through the riparian zone and into surrounding hills. Climate is classified as humid continental, with approximate average annual temperature and precipitation of 13.2°C and 970mm, respectively. Preliminary results (summer 2009 data) indicate incoming short-wave radiation is 24.9% higher at the N-S oriented stream reach relative to the E-W oriented reach. Maximum incoming short wave radiation during the period was 64.5% lower at the N-S reach relative to E-W reach. Average air temperature for the E-W reach was 0.3°C lower

  16. Runoff water quality from a sierran upland forest, transition ecotone, and riparian wet meadow

    Technology Transfer Automated Retrieval System (TEKTRAN)

    High concentrations of inorganic N, P, and S have been reported in overland and litter interflow within forested uplands of the Tahoe basin and surrounding watersheds. In this study we compared runoff nutrient concentration and load as well as soil nutrient fluxes at three watershed locations; an up...

  17. Simulation of Management Effect on Runoff and Sediment Transport in Riparian Forest Buffers by APEX Model

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Hydrologic/water quality models are increasingly used to explore management and policy alternatives for managing water quality and quantity from intensive silvicultural practices with Best Management Practices (BMPs) in forested watersheds due to the limited number of studies and the cost of conduct...

  18. Riparian Zone Analysis for Forest Land Cover for the Conterminous US

    EPA Science Inventory

    One data layer describing the amount of forest land cover contained within a buffer area extending 30 meters to each side of all streams contained within the basin (Watershed Boundary Dataset (WBD) 12-digit Hydrologic Unit Code (HUC)) and from the edge of water bodies such as la...

  19. Incorporating Climate Change and Exotic Species into Forecasts of Riparian Forest Distribution

    PubMed Central

    Ikeda, Dana H.; Grady, Kevin C.; Shuster, Stephen M.; Whitham, Thomas G.

    2014-01-01

    We examined the impact climate change (CC) will have on the availability of climatically suitable habitat for three native and one exotic riparian species. Due to its increasing prevalence in arid regions throughout the western US, we predicted that an exotic species, Tamarix, would have the greatest increase in suitable habitat relative to native counterparts under CC. We used an ecological niche model to predict range shifts of Populus fremontii, Salix gooddingii, Salix exigua and Tamarix, from present day to 2080s, under five general circulation models and one climate change scenario (A1B). Four major findings emerged. 1) Contrary to our original hypothesis, P. fremontii is projected to have the greatest increase in suitable habitat under CC, followed closely by Tamarix. 2) Of the native species, S. gooddingii and S. exigua showed the greatest loss in predicted suitable habitat due to CC. 3) Nearly 80 percent of future P. fremontii and Salix habitat is predicted to be affected by either CC or Tamarix by the 2080s. 4) By the 2080s, 20 percent of S. gooddingii habitat is projected to be affected by both Tamarix and CC concurrently, followed by S. exigua (19 percent) and P. fremontii (13 percent). In summary, while climate change alone will negatively impact both native willow species, Tamarix is likely to affect a larger portion of all three native species' distributions. We discuss these and other results in the context of prioritizing restoration and conservation efforts to optimize future productivity and biodiversity. As we are accounting for only direct effects of CC and Tamarix on native habitat, we present a possible hierarchy of effects- from the direct to the indirect- and discuss the potential for the indirect to outweigh the direct effects. Our results highlight the need to account for simultaneous challenges in the face of CC. PMID:25216285

  20. Woody vegetation cover monitoring with multi-temporal Landsat data and Random Forests: the case of the Northwest Province (South Africa)

    NASA Astrophysics Data System (ADS)

    Symeonakis, Elias; Higginbottom, Thomas; Petroulaki, Kyriaki

    2016-04-01

    Land degradation and desertification (LDD) are serious global threats to humans and the environment. Globally, 10-20% of drylands and 24% of the world's productive lands are potentially degraded, which affects 1.5 billion people and reduces GDP by €3.4 billion. In Africa, LDD processes affect up to a third of savannahs, leading to a decline in the ecosystem services provided to some of the continent's poorest and most vulnerable communities. Indirectly, LDD can be monitored using relevant indicators. The encroachment of woody plants into grasslands, and the subsequent conversion of savannahs and open woodlands into shrublands, has attracted a lot of attention over the last decades and has been identified as an indicator of LDD. According to some assessments, bush encroachment has rendered 1.1 million ha of South African savanna unusable, threatens another 27 million ha (~17% of the country), and has reduced the grazing capacity throughout the region by up to 50%. Mapping woody cover encroachment over large areas can only be effectively achieved using remote sensing data and techniques. The longest continuously operating Earth-observation program, the Landsat series, is now freely-available as an atmospherically corrected, cloud masked surface reflectance product. The availability and length of the Landsat archive is thus an unparalleled Earth-observation resource, particularly for long-term change detection and monitoring. Here, we map and monitor woody vegetation cover in the Northwest Province of South Africa, a mosaic of 12 Landsat scenes that expands over more than 100,000km2. We employ a multi-temporal approach with dry-season TM, ETM+ and OLI data from 15 epochs between 1989 to 2015. We use 0.5m-pixel colour aerial photography to collect >15,000 samples for training and validating a Random Forest model to map woody cover, grasses, crops, urban and bare areas. High classification accuracies are achieved, especially so for the two cover types indirectly

  1. Surface Layer Flux Processes During Cloud Intermittency and Advection above a Middle Rio Grande Riparian Forest, New Mexico

    NASA Astrophysics Data System (ADS)

    Cleverly, J. R.; Prueger, J.; Cooper, D. I.; Hipps, L.; Eichinger, W.

    2002-12-01

    An intensive field campaign was undertaken to bring together state-of-the-art methodologies for investigating surface layer physical characteristics over a desert riparian forest. Three-dimensional sonic eddy covariance (3SEC), LIDAR, SODAR, Radiosonde, one-dimensional propeller eddy covariance (1PEC), heat dissipation sap flux, and leaf gas exchange were simultaneously in use 13 -- 21 June 1999 at Bosque del Apache National Wildlife Refuge (NWR) in New Mexico. A one hour period of intense advection was identified by /line{v} >> 0 and /line{u} = 0, indicating that wind direction was transverse to the riparian corridor. The period of highest /line{v} was 1400 h on 20 June; this hour experienced intermittent cloud cover and enhanced mesoscale forcing of surface fluxes. High-frequency (20 Hz) time series of u, v, w, q, θ , and T were collected for spectral, cospectral, and wavelet analyses. These time series analyses illustrate scales at which processes co-occur. At high frequencies (> 0.015 Hz), /line{T' q'} > 0, and (KH)/ (KW) = 1. At low frequencies, however, /line{T' q'} < 0, and (KH)/(KW) !=q 1. Under these transient conditions, frequencies below 0.015 Hz are associated with advection. While power cospectra are useful in associating processes at certain frequencies, further analysis must be performed to determine whether such examples of aphasia are localized to transient events or constant through time. Continuous wavelet transformation (CWT) sacrifices localization in frequency space for localization in time. Mother wavelets were evaluated, and Daubechies order 10 wavelet was found to reduce red noise and leakage near the spectral gap. The spectral gap is a frequency domain between synoptic and turbulent scales. Low frequency turbulent structures near the spectral gap in the time series of /line{T' q'}, /line{w' T'}, and /line{w' q'} followed a perturbation--relaxation pattern to cloud cover. Further cloud cover in the same hour did not produce the low

  2. Scaling up and error analysis of transpiration for Populus euphratica in a desert riparian forest

    NASA Astrophysics Data System (ADS)

    Si, J.; Li, W.; Feng, Q.

    2013-12-01

    Water consumption information of the forest stand is the most important factor for regional water resources management. However, water consumption of individual trees are usually measured based on the limited sample trees , so, it is an important issue how to realize eventual scaling up of data from a series of sample trees to entire stand. Estimation of sap flow flux density (Fd) and stand sapwood area (AS-stand) are among the most critical factors for determining forest stand transpiration using sap flow measurement. To estimate Fd, the various links in sap flow technology have great impact on the measurement of sap flow, to estimate AS-stand, an appropriate indirect technique for measuring each tree sapwood area (AS-tree) is required, because it is impossible to measure the AS-tree of all trees in a forest stand. In this study, Fd was measured in 2 mature P. euphratic trees at several radial depths, 0~10, 10~30mm, using sap flow sensors with the heat ratio method, the relationship model between AS-tree and stem diameter (DBH), growth model of AS-tree were established, using investigative original data of DBH, tree-age, and AS-tree. The results revealed that it can achieve scaling up of transpiration from sample trees to entire forest stand using AS-tree and Fd, however, the transpiration of forest stand (E) will be overvalued by 12.6% if using Fd of 0~10mm, and it will be underestimated by 25.3% if using Fd of 10~30mm, it implied that major uncertainties in mean stand Fd estimations are caused by radial variations in Fd. E will be obviously overvalued when the AS-stand is constant, this result imply that it is the key to improve the prediction accuracy that how to simulate the AS-stand changes in the day scale; They also showed that the potential errors in transpiration with a sample size of approximately ≥30 were almost stable for P.euphrtica, this suggests that to make an allometric equation it might be necessary to sample at least 30 trees.

  3. Comparing the Sexual Reproductive Success of Two Exotic Trees Invading Spanish Riparian Forests vs. a Native Reference

    PubMed Central

    2016-01-01

    A widely accepted hypothesis in invasion ecology is that invasive species have higher survival through the early stages of establishment than do non-invasive species. In this study we explore the hypothesis that the sexual reproductive success of the invasive trees Ailanthus altissima (Mill.) Swingle and Robinia pseudoacacia L. is higher than that of the native Fraxinus angustifolia Vahl., all three species coexisting within the riparian forests of Central Spain. We compared different stages of the early life cycle, namely seed rain, seed infestation by insects, seed removal by local fauna, seed germination under optimal conditions and seedling abundance between the two invasive trees and the native, in order to assess their sexual reproductive success. The exotic species did not differ from the native reference (all three species displaying high seed rain and undergoing seed losses up to 50% due to seed removal by the local fauna). Even if the exotic R. pseudoacacia showed a high percentage of empty and insect-parasited seeds along with a low seedling emergence and the exotic A. altissima was the species with more viable seeds and of higher germinability, no differences were found regarding these variables when comparing them with the native F. angustifolia. Unsuitable conditions might have hampered either seedling emergence and survival, as seedling abundance in the field was lower than expected in all species -especially in R. pseudoacacia-. Our results rather suggest that the sexual reproductive success was not higher in the exotic trees than in the native reference, but studies focusing on long-term recruitment would help to shed light on this issue. PMID:27529695

  4. Comparing the Sexual Reproductive Success of Two Exotic Trees Invading Spanish Riparian Forests vs. a Native Reference.

    PubMed

    Cabra-Rivas, Isabel; Castro-Díez, Pilar

    2016-01-01

    A widely accepted hypothesis in invasion ecology is that invasive species have higher survival through the early stages of establishment than do non-invasive species. In this study we explore the hypothesis that the sexual reproductive success of the invasive trees Ailanthus altissima (Mill.) Swingle and Robinia pseudoacacia L. is higher than that of the native Fraxinus angustifolia Vahl., all three species coexisting within the riparian forests of Central Spain. We compared different stages of the early life cycle, namely seed rain, seed infestation by insects, seed removal by local fauna, seed germination under optimal conditions and seedling abundance between the two invasive trees and the native, in order to assess their sexual reproductive success. The exotic species did not differ from the native reference (all three species displaying high seed rain and undergoing seed losses up to 50% due to seed removal by the local fauna). Even if the exotic R. pseudoacacia showed a high percentage of empty and insect-parasited seeds along with a low seedling emergence and the exotic A. altissima was the species with more viable seeds and of higher germinability, no differences were found regarding these variables when comparing them with the native F. angustifolia. Unsuitable conditions might have hampered either seedling emergence and survival, as seedling abundance in the field was lower than expected in all species -especially in R. pseudoacacia-. Our results rather suggest that the sexual reproductive success was not higher in the exotic trees than in the native reference, but studies focusing on long-term recruitment would help to shed light on this issue. PMID:27529695

  5. Fuel reduction and coarse woody debris dynamics with early season and late season prescribed fire in a Sierra Nevada mixed conifer forest

    USGS Publications Warehouse

    Knapp, E.E.; Keeley, J.E.; Ballenger, E.A.; Brennan, T.J.

    2005-01-01

    Fire exclusion has led to an unnatural accumulation and greater spatial continuity of organic material on the ground in many forests. This material serves both as potential fuel for forest fires and habitat for a large array of forest species. Managers must balance fuel reduction to reduce wildfire hazard with fuel retention targets to maintain other forest functions. This study reports fuel consumption and changes to coarse woody debris attributes with prescribed burns ignited under different fuel moisture conditions. Replicated early season burn, late season burn, and unburned control plots were established in old-growth mixed conifer forest in Sequoia National Park that had not experienced fire for more than 120 years. Early season burns were ignited during June 2002 when fuels were relatively moist, and late season burns were ignited during September/October 2001 when fuels were dry. Fuel loading and coarse woody debris abundance, cover, volume, and mass were evaluated prior to and after the burns. While both types of burns reduced fuel loading, early season burns consumed significantly less of the total dead and down organic matter than late season burns (67% versus 88%). This difference in fuel consumption between burning treatments was significant for most all woody fuel components evaluated, plus the litter and duff layers. Many logs were not entirely consumed - therefore the number of logs was not significantly changed by fire - but burning did reduce log length, cover, volume, and mass. Log cover, volume, and mass were reduced to a lesser extent by early season burns than late season burns, as a result of higher wood moisture levels. Early season burns also spread over less of the ground surface within the burn perimeter (73%) than late season burns (88%), and were significantly patchier. Organic material remaining after a fire can dam sediments and reduce erosion, while unburned patches may help mitigate the impact of fire on fire-sensitive species by

  6. How to Regenerate and Protect Desert Riparian Populus euphratica Forest in Arid Areas

    PubMed Central

    Ling, Hongbo; Zhang, Pei; Xu, Hailiang; Zhao, Xinfeng

    2015-01-01

    We found that the most suitable flooding disturbance model for regenerating Populus euphratica forest was two to three times per year with a duration of 15–20 days and an intensity of 25–30 m3/s. The flooding should take place during the seed emergence to young tree growth stages, and should be based on flooding experiments and data from vegetation quadrats and ecological water conveyance. Furthermore, we found that tree-ring width index for P. euphratica declined as the groundwater depth increased, and ascertained that the minimum groundwater depths for young trees, near-mature trees, mature trees and over-mature trees were 4.0 m, 5.0–5.4 m, 6.9 m and 7.8 m, respectively. These were derived from a quantitative relationship model between groundwater depth and tree-ring width index. The range for ecological water conveyance volume was 311–320 million m3 in the lower reaches of the Tarim River. This study not only provides a technical basis for sustainable ecological water conveyance in the Tarim River Basin, but also offers a theoretical guide and scientific information that could be used in similar areas to regenerate and protect Populus euphratica around the world. PMID:26481290

  7. How to Regenerate and Protect Desert Riparian Populus euphratica Forest in Arid Areas

    NASA Astrophysics Data System (ADS)

    Ling, Hongbo; Zhang, Pei; Xu, Hailiang; Zhao, Xinfeng

    2015-10-01

    We found that the most suitable flooding disturbance model for regenerating Populus euphratica forest was two to three times per year with a duration of 15-20 days and an intensity of 25-30 m3/s. The flooding should take place during the seed emergence to young tree growth stages, and should be based on flooding experiments and data from vegetation quadrats and ecological water conveyance. Furthermore, we found that tree-ring width index for P. euphratica declined as the groundwater depth increased, and ascertained that the minimum groundwater depths for young trees, near-mature trees, mature trees and over-mature trees were 4.0 m, 5.0-5.4 m, 6.9 m and 7.8 m, respectively. These were derived from a quantitative relationship model between groundwater depth and tree-ring width index. The range for ecological water conveyance volume was 311-320 million m3 in the lower reaches of the Tarim River. This study not only provides a technical basis for sustainable ecological water conveyance in the Tarim River Basin, but also offers a theoretical guide and scientific information that could be used in similar areas to regenerate and protect Populus euphratica around the world.

  8. How to Regenerate and Protect Desert Riparian Populus euphratica Forest in Arid Areas.

    PubMed

    Ling, Hongbo; Zhang, Pei; Xu, Hailiang; Zhao, Xinfeng

    2015-01-01

    We found that the most suitable flooding disturbance model for regenerating Populus euphratica forest was two to three times per year with a duration of 15-20 days and an intensity of 25-30 m(3)/s. The flooding should take place during the seed emergence to young tree growth stages, and should be based on flooding experiments and data from vegetation quadrats and ecological water conveyance. Furthermore, we found that tree-ring width index for P. euphratica declined as the groundwater depth increased, and ascertained that the minimum groundwater depths for young trees, near-mature trees, mature trees and over-mature trees were 4.0 m, 5.0-5.4 m, 6.9 m and 7.8 m, respectively. These were derived from a quantitative relationship model between groundwater depth and tree-ring width index. The range for ecological water conveyance volume was 311-320 million m(3) in the lower reaches of the Tarim River. This study not only provides a technical basis for sustainable ecological water conveyance in the Tarim River Basin, but also offers a theoretical guide and scientific information that could be used in similar areas to regenerate and protect Populus euphratica around the world. PMID:26481290

  9. The Effects of Coarse Woody Debris and Vegetation Structure on Avian Communities of Southeastern Loblolly Pine (Pinus taeda) Forests

    SciTech Connect

    Lohr, S.M.

    1999-09-01

    Avian community richness and abundance were compared among several treatments in which coarse woody debris was manipulated. Treatments included a control, all dead wood removed less than four inches, and all down wood less than four inches removed. Avian communities were compared during the winter and spring nesting periods. In general, no differences in community parameters were detected during the winter months. However, during the spring nesting season several species of cavity nesting species like woodpeckers were significantly reduced where all snags were removed. Diversity was highest on the control. In addition, the woody debris appeared to benefit several ground nesting species such as the Carolina wren.

  10. Assessing the impact of riparian processes on streambank erosion

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Soil water dynamics within a streambank and riparian vegetation greatly affect streambank erosion. The integrated computer models CONCEPTS and REMM, which were developed to simulate stream channel morphology and riparian ecosystem function, were previously used to study the effectiveness of woody a...

  11. Push-pull tests to determine in-situ nitrogen processing in groundwaters of a tropical riparian forest, Luquillo Mountains, Puerto Rico

    NASA Astrophysics Data System (ADS)

    Brereton, R. L.

    2012-12-01

    Riparian zones are biogeochemical hot spots known to control the flux of dissolved nitrogen (N) from groundwater to surface waters by providing favorable conditions for N removal and retention. In many watersheds with agricultural or urban inputs, N enters groundwater after being leached from soils in the form of nitrate, which is then removed from solution by denitrification in the anoxic riparian groundwater. Certain tropical forested watersheds, however, display spatial patterns in groundwater N chemistry that cannot be explained by simple denitrification. High ammonium concentrations (>0.5 mg/L), in comparison to other reference watersheds, exist in groundwaters directly adjacent to streams carrying little or no ammonium. The N speciation is accompanied by dramatic shifts in redox conditions from hillslope to riparian zone to stream. A valuable ecosystem service is being provided by these tropical ecosystems but that service has not been adequately described by science. What is the source and fate of this ammonium? The push-pull test is a recently developed method to determine in-situ reaction rates by the addition of reactive substrates and a conservative tracer to groundwater, followed by an incubation period and sampling over time. In the Rio Icacos watershed in the Luquillo Experimental Forest of Puerto Rico, push-pull tests were conducted to determine the reaction pathways of ammonium production and consumption. Shallow groundwater wells (1-4 m below soil surface) in a riparian zone of a tributary the Rio Icacos were tested in two locations: immediately adjacent to the stream and at the topographic break between the hillslope and the floodplain. 10 L "push" solutions with ammonium, nitrate, or both and a chloride or bromide tracer were added and incubated over a 20-40 hr period (depending on the hydraulic conductivity of the individual well). Initial results were consistent with coupled nitrification-denitrification occurring at both the hillslope

  12. Multi-Temporal Land Cover Analysis in the Mid-Willamette Basin, Oregon: Assessment of Riparian Forest Canopy Using Landsat Thematic Mapper Data

    NASA Astrophysics Data System (ADS)

    Stanley, R. J.; Taylor, S. B.

    2010-12-01

    The 11,500 sq. mi. Willamette Basin is home to 70% of Oregon’s population and is associated with an extensive post-settlement history of land cover modification. Existing assessments estimate that between 30 and 44% of riparian zones have been subject to anthropogenic disturbances, which in turn have negatively impacted TMDL levels for temperature and sediment loading (Oregon DEQ, 2009). As such, riparian forest restoration is cited as one of the primary management objectives needed to improve habitat quality. This study involves a regional multi-temporal land cover analysis utilizing Landsat Thematic Mapper (TM) satellite imagery and supervised image classification to document changes in canopy cover (Landsat acquisition years 2000 and 2009). The rectangular study site is oriented north-south and extends from Yamhill to Eugene, occupying a 3,133 sq. mi. footprint that captures the dynamic landuse interface between urban centers, lowland riparian habitats, and Oregon Coast Range forests. Landsat 5 TM data for the study site were acquired via the USGS Global Visualization Viewer with multispectral imagery including 6 reflected bands suited for quantifying broad-scale land cover regimes, including vegetation. Classification training sites for water, forest, and agricultural land-cover categories were selected to accurately represent within-class spectral variability. A supervised classification scheme was employed to compare training signatures against the six reflective bands in each image year. A maximum likelihood algorithm was utilized to delineate land-cover classes with overlapping spectral signatures. Other processing techniques included radiometric normalization of brightness values, and derivation of NDVI and Tasseled Cap vegetative indices. Final classification accuracy was assessed by randomly assigning 100 spatially distributed point samples per class and comparing each to available ground truth. Two distinct landuse domains were delineated within the

  13. Postfire logging in riparian areas.

    PubMed

    Reeves, Gordon H; Bisson, Peter A; Rieman, Bruce E; Benda, Lee E

    2006-08-01

    We reviewed the behavior of wildfire in riparian zones, primarily in the western United States, and the potential ecological consequences of postfire logging. Fire behavior in riparian zones is complex, but many aquatic and riparian organisms exhibit a suite of adaptations that allow relatively rapid recovery after fire. Unless constrained by other factors, fish tend to rebound relatively quickly, usually within a decade after a wildfire. Additionally, fire and subsequent erosion events contribute wood and coarse sediment that can create and maintain productive aquatic habitats over time. The potential effects of postfire logging in riparian areas depend on the landscape context and disturbance history of a site; however available evidence suggests two key management implications: (1) fire in riparian areas creates conditions that may not require intervention to sustain the long-term productivity of the aquatic network and (2) protection of burned riparian areas gives priority to what is left rather than what is removed. Research is needed to determine how postfire logging in riparian areas has affected the spread of invasive species and the vulnerability of upland forests to insect and disease outbreaks and how postfire logging will affect the frequency and behavior of future fires. The effectiveness of using postfire logging to restore desired riparian structure and function is therefore unproven, but such projects are gaining interest with the departure of forest conditions from those that existed prior to timber harvest, fire suppression, and climate change. In the absence of reliable information about the potential consequence of postfire timber harvest, we conclude that providing postfire riparian zones with the same environmental protections they received before they burned isjustified ecologically Without a commitment to monitor management experiments, the effects of postfire riparian logging will remain unknown and highly contentious. PMID:16922216

  14. Perceptions of environmental change and use of traditional knowledge to plan riparian forest restoration with relocated communities in Alcântara, Eastern Amazon

    PubMed Central

    2014-01-01

    Background Riparian forests provide ecosystem services that are essential for human well-being. The Pepital River is the main water supply for Alcântara (Brazil) and its forests are disappearing. This is affecting water volume and distribution in the region. Promoting forest restoration is imperative. In deprived regions, restoration success depends on the integration of ecology, livelihoods and traditional knowledge (TEK). In this study, an interdisciplinary research framework is proposed to design riparian forest restoration strategies based on ecological data, TEK and social needs. Methods This study takes place in a region presenting a complex history of human relocation and land tenure. Local populations from seven villages were surveyed to document livelihood (including ‘free-listing’ of agricultural crops and homegarden tree species). Additionally, their perceptions toward environmental changes were explored through semi-structured interviews (n = 79). Ethnobotanical information on forest species and their uses were assessed by local-specialists (n = 19). Remnants of conserved forests were surveyed to access ecological information on tree species (three plots of 1,000 m2). Results included descriptive statistics, frequency and Smith’s index of salience of the free-list results. Results The local population depends primarily on slash-and-burn subsistence agriculture to meet their needs. Interviewees showed a strong empirical knowledge about the environmental problems of the river, and of their causes, consequences and potential solutions. Twenty-four tree species (dbh > 10 cm) were found at the reference sites. Tree density averaged 510 individuals per hectare (stdv = 91.6); and 12 species were considered the most abundant (density > 10ind/ha). There was a strong consensus among plant-specialists about the most important trees. The species lists from reference sites and plant-specialists presented an important convergence

  15. Nitrous Oxide Emissions from Riparian Forest Buffers, Warm-Season and Cool-Season Grass Filters, and Crop Fields

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Increasing denitrification rates in riparian buffers may be trading the problem of nonpoint source (NPS) pollution of surface waters for atmospheric deterioration and increased global warming potential because denitrification produces nitrous oxide (N2O), a greenhouse gas also involved in stratosphe...

  16. Riparian forest effects on nitrogen export to an agricultural stream inferred from experimental data and a model

    EPA Science Inventory

    The effects of riparian vegetation on the reduction of agricultural nitrogen export to streams have been well described experimentally, but a clear understanding of process-level hydrological and biogeochemical controls can be difficult to ascertain from data alone. We apply a ne...

  17. Surface water and groundwater nitrogen dynamics in a well drained riparian forest within a poorly drainged agricultural landscape

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Riparian ecosystems, through their unique position in the agricultural landscape and ability to influence nutrient cycles, can potentially reduce nutrient loading to surface and ground waters. The primary purpose of this study was to determine the efficacy of a well-drained, mixed-deciduous riparia...

  18. Equations for estimating biomass of herbaceous and woody vegetation in early-successional southern Appalachian pine-hardwood forests. Forest Service research note

    SciTech Connect

    Elliott, K.J.; Clinton, B.D.

    1993-03-31

    Allometric equations were developed to predict aboveground dry weight of herbaceous and woody species on prescribe-burned sites in the Southern Appalachians. Best-fit least-square regression models were developed using diameter, height, or both, as the independent variables and dry weight as the dependent variable. Coefficients of determination for the selected total biomass models ranged from 0.620 to 0.992 for herbaceous species and from 0.698 to 0.999 for the wood species. Equations for foliage biomass generally had lower coefficients of determination than did equations for either stem or total biomass of woody species.

  19. Avian Diversity and Feeding Guilds in a Secondary Forest, an Oil Palm Plantation and a Paddy Field in Riparian Areas of the Kerian River Basin, Perak, Malaysia

    PubMed Central

    Azman, Nur Munira; Latip, Nurul Salmi Abdul; Sah, Shahrul Anuar Mohd; Akil, Mohd Abdul Muin Md; Shafie, Nur Juliani; Khairuddin, Nurul Liyana

    2011-01-01

    The diversity and the feeding guilds of birds in three different habitats (secondary forest, oil palm plantation and paddy field) were investigated in riparian areas of the Kerian River Basin (KRB), Perak, Malaysia. Point-count observation and mist-netting methods were used to determine bird diversity and abundance. A total of 132 species of birds from 46 families were recorded in the 3 habitats. Species diversity, measured by Shannon’s diversity index, was 3.561, 3.183 and 1.042 in the secondary forest, the paddy field and the oil palm plantation, respectively. The vegetation diversity and the habitat structure were important determinants of the number of bird species occurring in an area. The relative abundance of the insectivore, insectivore-frugivore and frugivore guilds was greater in the forest than in the monoculture plantation. In contrast, the relative abundance of the carnivore, granivore and omnivore guilds was higher in the plantation. The results of the study show that the conversion of forest to either oil palm plantation or paddy fields produced a decline in bird diversity and changes in the distribution of bird feeding guilds. PMID:24575217

  20. Regional framework of early growth response for loblolly pine relative to herbaceous, woody, and complete competition control: The comproject. Forest Service general technical report

    SciTech Connect

    Miller, J.H.; Zutter, B.R.; Zedaker, S.M.; Edwards, M.B.; Newbold, R.A.

    1995-09-01

    A common study design has been installed at 13 locations throughout the Southeastern United States to track the growth of loblolly pine (Pinus taeda L.) plantations established with four different competition control treatments: no control (only chopping-burning), woody control for 5 years, herbaceous control for 4 years, and total control after site preparation. This regionwide investigation is known as the competition Omission Monitoring Project, a coordinated study with the Auburn University Silvicultural Herbicide Cooperative (Study HB-4F). Data summaries for each location are presented for loblolly pine growth and competition intensities for the first 8 years. Approximately 10,000 loblolly pine seedlings have been measured annually. Responses from this network of studies should be useful in assessing and reporting relative growth of loblolly pines for other studies and operational plantings. These data sets should also be useful for the future forest growth modeling efforts.

  1. Study of floristic diversity and the structural dynamics of some species providers of non woody forest products in the vegetable formations of the Centre East of Burkina Faso.

    PubMed

    Ky, J M K; Gnoula, C; Zerbo, P; Simpore, J; Nikiema, J B; Canini, A; Millogo-Rasolodimby, J

    2009-07-15

    The goal of this study is to contribute to a better knowledge of certain species providing Non Woody Forest Products (NWFP) in the Centre East of Burkina Faso. This study aims to determine the state of the resources in Vitellaria paradoxa, Balanites aegyptiaca, Tamarindus indica and Lannea microcarpa. For this purpose, an inventory of the vegetation was carried out in circular pieces of land of 1250 m2, as a sample of the zone of work, based on the chart of occupation of the grounds. We are identified 158 species comprising 90 genera and 47 families. Those species represent more than 90% of the trees from which various parts are used in food, traditional pharmacopeia and the craft industry. We also showed that because of the strong anthropisation of the zone, the bad pedoclimatic conditions and the permanent bush fires, the regeneration and growth of Vitellaria paradoxa, Balanites aegyptiaca, Tamarindus indica and Lannea microcarpa are disturbed. PMID:19947178

  2. Ground-water surface-water interactions and long-term change in riverine riparian vegetation in the southwestern United States

    USGS Publications Warehouse

    Webb, R.H.; Leake, S.A.

    2006-01-01

    Riverine riparian vegetation has changed throughout the southwestern United States, prompting concern about losses of habitat and biodiversity. Woody riparian vegetation grows in a variety of geomorphic settings ranging from bedrock-lined channels to perennial streams crossing deep alluvium and is dependent on interaction between ground-water and surface-water resources. Historically, few reaches in Arizona, southern Utah, or eastern California below 1530 m elevation had closed gallery forests of cottonwood and willow; instead, many alluvial reaches that now support riparian gallery forests once had marshy grasslands and most bedrock canyons were essentially barren. Repeat photography using more than 3000 historical images of rivers indicates that riparian vegetation has increased over much of the region. These increases appear to be related to several factors, notably the reduction in beaver populations by trappers in the 19th century, downcutting of arroyos that drained alluvial aquifers between 1880 and 1910, the frequent recurrence of winter floods during discrete periods of the 20th century, an increased growing season, and stable ground-water levels. Reductions in riparian vegetation result from agricultural clearing, excessive ground-water use, complete flow diversion, and impoundment of reservoirs. Elimination of riparian vegetation occurs either where high ground-water use lowers the water table below the rooting depth of riparian species, where base flow is completely diverted, or both. We illustrate regional changes using case histories of the San Pedro and Santa Cruz Rivers, which are adjacent watersheds in southern Arizona with long histories of water development and different trajectories of change in riparian vegetation.

  3. Analysis of water use strategies of the desert riparian forest plant community in inland rivers of two arid regions in northwestern China

    NASA Astrophysics Data System (ADS)

    Chen, Y. N.; Li, W. H.; Zhou, H. H.; Chen, Y. P.; Hao, X. M.; Fu, A. H.; Ma, J. X.

    2014-10-01

    Studies of the water use of the desert riparian forest plant community in arid regions and analyses of the response and adaptive strategies of plants to environmental stress are of great significance to the formulation of effective ecological conservation and restoration strategies. Taking two inland rivers in the arid regions of northwestern China, downstream of the Tarim River and Heihe River Basin as the research target regions, this paper explored the stem water potential, sap flow, root hydraulic lift, and characteristics of plant water sources of the major constructive species in the desert riparian forest, Populus euphratica and Tamarix ramosissima. Specifically, this was accomplished by combining the monitoring of field physiological and ecological indicators, and the analysis of laboratory tests. Then, the water use differences of species in different ecological environments and their ecological significance were analyzed. This study indicated that: (1) in terms of water sources, Populus euphratica and Tamarix ramosissima mainly used deep subsoil water and underground water, but the plant root system in the downstream of the Tarim River was more diversified than that in the downstream of the Heihe River in water absorption, (2) in terms of water distribution, Populus euphratica root possessed hydraulic lift capacity, but Populus euphratica root in the downstream of the Tarim River presented stronger hydraulic lift capacity and more significant ecological effect of water redistribution, (3) in terms of water transport, the plants in the downstream of the Heihe River can adapt to the environment through the current limiting of branch xylem, while plants in the downstream of the Tarim River substantially increased the survival probability of the whole plant by sacrificing weak branches and improving the water acquisition capacity of dominant branches; and (4) in terms of water dissipation, the water use and consumption of Populus euphratica at night exhibited

  4. [Woody plant species composition and community structure in residual fragments of broad-leaved Korean pine mixed forests in Changbai Mountains area].

    PubMed

    Song, Hou-Juan; Ye, Ji; Shi, Shuai; Zhang, Zhao-Chen; Kuang, Xu; Xing, Ding-Liang; Yuan, Zuo-Qiang; Lin, Fei; Wang, Xu-Gao; Hao, Zhan-Qing

    2014-05-01

    The broad-leaved Korean pine mixed forest represents the typical vegetation type of the eastern mountain area in Northeast China. However, due to the interference of human activities, the natural broad-leaved Korean pine forest only distributes in some residual fragments with unequal areas in Changbai Mountains and Small Hinggan Mountains. To compare and analyze the similarities and differences of broad-leaved Korean pine mixed forests in the different areas, we established six forest plots following the field protocol of the 50 hm2 forest plot in Panama (Barro Colorado Island, BCI) in 2012 in Changbai Mountain National Nature Reserve in Jilin Province and the eastern mountain area in Liaoning Province. All free-standing plant species with DBH (diameter at breast height) > or = 1 cm were mapped, tagged and identified to species. The results showed that there were 69 woody species in the six plots, comprising 42 genera and24 families. Aceraceae was the most species-rich family in all six plots. Most species belonged to the plant type of North Temperate Zone, with a minor subtropical plant species component. The statistics of species abundance, basal area, mean DBH, and importance value showed that there were obviously dominant species in each community. The DBH distribution of all individuals showed a reversed "J" type. However, the percentage of individuals in small size-class and large size-class varied in the six communities, which indicated that these communities were at different successional stages. Ranked by the importance value, the DBH distribution of the top three species in the six plots showed four distribution types: reversed "J" distribution, reversed "L" distribution, unimodal distribution, and partial peak distribution. Spatial distribution patterns of the main species in the six plots changed differently with species and size-class, and the distribution patterns of the same species varied in the different plots. PMID:25129921

  5. Riparian buffer transpiration and watershed scale impacts

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Forested riparian buffers are prevalent throughout the Southeastern Coastal Plain Region of the United States (US). Because they make up a significant portion of the regional landscape, transpiration within these riparian buffers is believed to have an important impact on the hydrologic budget of r...

  6. Riparian vegetation structure under desertification scenarios

    NASA Astrophysics Data System (ADS)

    Rosário Fernandes, M.; Segurado, Pedro; Jauch, Eduardo; Ferreira, M. Teresa

    2015-04-01

    Riparian areas are responsible for many ecological and ecosystems services, including the filtering function, that are considered crucial to the preservation of water quality and social benefits. The main goal of this study is to quantify and understand the riparian variability under desertification scenario(s) and identify the optimal riparian indicators for water scarcity and droughts (WS&D), henceforth improving river basin management. This study was performed in the Iberian Tâmega basin, using riparian woody patches, mapped by visual interpretation on Google Earth imagery, along 130 Sampling Units of 250 m long river stretches. Eight riparian structural indicators, related with lateral dimension, weighted area and shape complexity of riparian patches were calculated using Patch Analyst extension for ArcGis 10. A set of 29 hydrological, climatic, and hydrogeomorphological variables were computed, by a water modelling system (MOHID), using monthly meteorological data between 2008 and 2014. Land-use classes were also calculated, in a 250m-buffer surrounding each sampling unit, using a classification based system on Corine Land Cover. Boosted Regression Trees identified Mean-width (MW) as the optimal riparian indicator for water scarcity and drought, followed by the Weighted Class Area (WCA) (classification accuracy =0.79 and 0.69 respectively). Average Flow and Strahler number were consistently selected, by all boosted models, as the most important explanatory variables. However, a combined effect of hidrogeomorphology and land-use can explain the high variability found in the riparian width mainly in Tâmega tributaries. Riparian patches are larger towards Tâmega river mouth although with lower shape complexity, probably related with more continuous and almost monospecific stands. Climatic, hydrological and land use scenarios, singly and combined, were used to quantify the riparian variability responding to these changes, and to assess the loss of riparian

  7. Implications of the results of colonization experiments for designing riparian restoration projects adjacent to agricultural headwater streams

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Many headwater streams and their riparian habitats in the Midwestern United States have been modified for agricultural drainage. Agricultural drainage often results in reductions of physical habitat diversity, shifts from woody to herbaceous riparian vegetation, and the loss of riparian habitat. T...

  8. Edaphic, salinity, and stand structural trends in chronosequences of native and non-native dominated riparian forests along the Colorado River, USA

    USGS Publications Warehouse

    Merritt, David M.; Shafroth, Patrick B.

    2012-01-01

    Tamarix spp. are introduced shrubs that have become among the most abundant woody plants growing along western North American rivers. We sought to empirically test the long-held belief that Tamarix actively displaces native species through elevating soil salinity via salt exudation. We measured chemical and physical attributes of soils (e.g., salinity, major cations and anions, texture), litter cover and depth, and stand structure along chronosequences dominated by Tamarix and those dominated by native riparian species (Populus or Salix) along the upper and lower Colorado River in Colorado and Arizona/California, USA. We tested four hypotheses: (1) the rate of salt accumulation in soils is faster in Tamarix-dominated stands than stands dominated by native species, (2) the concentration of salts in the soil is higher in mature stands dominated by Tamarix compared to native stands, (3) soil salinity is a function of Tamarix abundance, and (4) available nutrients are more concentrated in native-dominated stands compared to Tamarix-dominated stands. We found that salt concentration increases at a faster rate in Tamarix-dominated stands along the relatively free-flowing upper Colorado but not along the heavily-regulated lower Colorado. Concentrations of ions that are known to be preferentially exuded by Tamarix (e.g., B, Na, and Cl) were higher in Tamarix stands than in native stands. Soil salt concentrations in older Tamarix stands along the upper Colorado were sufficiently high to inhibit germination, establishment, or growth of some native species. On the lower Colorado, salinity was very high in all stands and is likely due to factors associated with floodplain development and the hydrologic effects of river regulation, such as reduced overbank flooding, evaporation of shallow ground water, higher salt concentrations in surface and ground water due to agricultural practices, and higher salt concentrations in fine-textured sediments derived from naturally saline

  9. Fluctuating asymmetry and wing size of Argia tinctipennis Selys (Zygoptera: Coenagrionidae) in relation to riparian forest preservation status.

    PubMed

    Pinto, N S; Juen, L; Cabette, H S R; De Marco, P

    2012-06-01

    Effects of riparian vegetation removal on body size and wing fluctuating asymmetry (FA) of Argia tinctipennis Selys (Odonata: Coenagrionidae) were studied in the River Suiá-Miçú basin, which is part of the Xingu basin in Brazilian Amazonia. A total of 70 specimens (n = 33 from preserved and n = 37 from degraded areas) was measured. Five wing measures of each wing (totalizing ten measured characters) were taken. Preserved and degraded points presented non-overlapped variations of a Habitat Integrity Index, supporting the environmental differentiation between these two categories. FA increases in degraded areas approximately four times for the width between the nodus and proximal portion of the pterostigma of forewings (FW), two times for the width of the wing in the region of nodus of FW, and approximately 1.7 times for the number of postnodal cells of FW. The increase is almost five times for the width between the nodus and the proximal portion of the pterostigma of hind wings (HW), three times for the number of postnodal cells of HW, and approximately 1.6 times the width between quadrangle and nodus of HW. Individuals of preserved sites were nearly 3.3% larger than for degraded sites, based on mean hind wing length. Our results supports that the development of A. tinctipennis in degraded areas is affected by riparian vegetation removal and may reflect in wing FA variations. Consequently, these FA measures may be a useful tool for bioassessment using Odonata insects as a model. PMID:23950041

  10. Sap flow characteristics and their response to environmental variables in a desert riparian forest along lower Heihe River Basin, Northwest China.

    PubMed

    Li, Wei; Yu, TengFei; Li, XiaoYan; Zhao, ChunYan

    2015-10-01

    Hysteresis, related to tree sap flow and associated environmental variables, plays a critical ecological role in the comprehensive understanding of forest water use dynamics. Nevertheless, only limited researches related to this unique ecological phenomenon have been conducted to date in desert riparian forests under extreme arid regions. Populus euphratica Oliv sap flow velocity (VS) was measured during the 2012 growing season using the heat ratio method, at the same time as environmental variables, such as photosynthetically active radiation (PAR), vapor pressure deficit (VPD), and leaf water potential. We found clockwise patterns of hysteresis between VS and VPD but anticlockwise patterns between VS and PAR. Pronounced hysteretic VS lag time, a function of PAR and VPD, was approximately 1.0~1.5 and -0.5 h, respectively. Hysteresis was primarily caused by the biophysical declining in canopy conductance. Sigmoid response of VS to synthetic meteorological variables was enhanced by approximately 56 % after hysteresis calibration to sunny days. Consequently, hysteresis can be seen as a protection mechanism for plants to avoid the overlapping of peak VS and environmental variables. Furthermore, the consistent presence of hysteresis suggested that estimating of plant water use in large temporal and spatial models may require certain provisions to different VS responses to variables between morning and afternoon and between seasons. PMID:27624743

  11. Riparian indicators of flow frequency in a tropical montane stream network

    NASA Astrophysics Data System (ADS)

    Pike, Andrew S.; Scatena, Frederick N.

    2010-03-01

    SummaryMany field indicators have been used to approximate the magnitude and frequency of flows in a variety of streams and rivers, yet due to a scarcity of long-term flow records in tropical mountain streams, little to no work has been done to establish such relationships between field features and the flow regime in these environments. Furthermore, the transition between the active channel of a river and the adjacent flood zone (i.e. bankfull) is an important geomorphologic and ecological boundary, but is rarely identifiable in steep mountain channels that lack alluvial flood plains. This study (a) quantifies relationships between field indicators and flow frequency in alluvial and steepland channels in a tropical mountain stream network and (b) identifies a reference active channel boundary in these channels, based on statistically defined combinations of riparian features, that corresponds to the same flow frequency of the bankfull stage and the effective discharge in adjacent alluvial channels. The relative elevation of transitions in riparian vegetation, soil, and substrate characteristics were first surveyed at nine stream gages in and around the Luquillo Experimental Forest in Northeastern Puerto Rico. The corresponding discharge, flow frequency, and recurrence intervals associated with these features was then determined from long-term 15-min discharge records and a partial duration series analysis. Survey data indicate that mosses and short grasses dominate at a stage often inundated by sub-effective flows. Herbaceous vegetation is associated with intermediate discharges that correspond to the threshold for sediment mobilization. Near-channel woody shrubs and trees establish at elevations along the channel margin inundated by a less frequent discharge that is coincident with the effective discharge of bed load sediment transport. Our data demonstrate that in alluvial channels in the study, both the bankfull stage (as marked by a flood plain) and the

  12. The contrasting nature of woody plant species in different neotropical forest biomes reflects differences in ecological stability.

    PubMed

    Pennington, R Toby; Lavin, Matt

    2016-04-01

    25 I. 25 II. 26 III. 27 IV. 27 V. 28 VI. 32 VII. 33 VIII. 34 35 References 35 SUMMARY: A fundamental premise of this review is that distinctive phylogenetic and biogeographic patterns in clades endemic to different major biomes illuminate the evolutionary process. In seasonally dry tropical forests (SDTFs), phylogenies are geographically structured and multiple individuals representing single species coalesce. This pattern of monophyletic species, coupled with their old species stem ages, is indicative of maintenance of small effective population sizes over evolutionary timescales, which suggests that SDTF is difficult to immigrate into because of persistent resident lineages adapted to a stable, seasonally dry ecology. By contrast, lack of coalescence in conspecific accessions of abundant and often widespread species is more frequent in rain forests and is likely to reflect large effective population sizes maintained over huge areas by effective seed and pollen flow. Species nonmonophyly, young species stem ages and lack of geographical structure in rain forest phylogenies may reflect more widespread disturbance by drought and landscape evolution causing resident mortality that opens up greater opportunities for immigration and speciation. We recommend full species sampling and inclusion of multiple accessions representing individual species in phylogenies to highlight nonmonophyletic species, which we predict will be frequent in rain forest and savanna, and which represent excellent case studies of incipient speciation. PMID:26558891

  13. Use of standardized visual assessments of riparian and stream condition to manage riparian bird habitat in eastern Oregon.

    PubMed

    Cooke, Hilary A; Zack, Steve

    2009-07-01

    The importance of riparian vegetation to support stream function and provide riparian bird habitat in semiarid landscapes suggests that standardized assessment tools that include vegetation criteria to evaluate stream health could also be used to assess habitat conditions for riparian-dependent birds. We first evaluated the ability of two visual assessments of woody vegetation in the riparian zone (corridor width and height) to describe variation in the obligate riparian bird ensemble along 19 streams in eastern Oregon. Overall species richness and the abundances of three species all correlated significantly with both, but width was more important than height. We then examined the utility of the riparian zone criteria in three standardized and commonly used rapid visual riparian assessment protocols--the USDI BLM Proper Functioning Condition (PFC) assessment, the USDA NRCS Stream Visual Assessment Protocol (SVAP), and the U.S. EPA Habitat Assessment Field Data Sheet (HAFDS)--to assess potential riparian bird habitat. Based on the degree of correlation of bird species richness with assessment ratings, we found that PFC does not assess obligate riparian bird habitat condition, SVAP provides a coarse estimate, and HAFDS provides the best assessment. We recommend quantitative measures of woody vegetation for all assessments and that all protocols incorporate woody vegetation height. Given that rapid assessments may be the only source of information for thousands of kilometers of streams in the western United States, incorporating simple vegetation measurements is a critical step in evaluating the status of riparian bird habitat and provides a tool for tracking changes in vegetation condition resulting from management decisions. PMID:18574622

  14. Use of Standardized Visual Assessments of Riparian and Stream Condition to Manage Riparian Bird Habitat in Eastern Oregon

    NASA Astrophysics Data System (ADS)

    Cooke, Hilary A.; Zack, Steve

    2009-07-01

    The importance of riparian vegetation to support stream function and provide riparian bird habitat in semiarid landscapes suggests that standardized assessment tools that include vegetation criteria to evaluate stream health could also be used to assess habitat conditions for riparian-dependent birds. We first evaluated the ability of two visual assessments of woody vegetation in the riparian zone (corridor width and height) to describe variation in the obligate riparian bird ensemble along 19 streams in eastern Oregon. Overall species richness and the abundances of three species all correlated significantly with both, but width was more important than height. We then examined the utility of the riparian zone criteria in three standardized and commonly used rapid visual riparian assessment protocols—the USDI BLM Proper Functioning Condition (PFC) assessment, the USDA NRCS Stream Visual Assessment Protocol (SVAP), and the U.S. EPA Habitat Assessment Field Data Sheet (HAFDS)—to assess potential riparian bird habitat. Based on the degree of correlation of bird species richness with assessment ratings, we found that PFC does not assess obligate riparian bird habitat condition, SVAP provides a coarse estimate, and HAFDS provides the best assessment. We recommend quantitative measures of woody vegetation for all assessments and that all protocols incorporate woody vegetation height. Given that rapid assessments may be the only source of information for thousands of kilometers of streams in the western United States, incorporating simple vegetation measurements is a critical step in evaluating the status of riparian bird habitat and provides a tool for tracking changes in vegetation condition resulting from management decisions.

  15. Closely-related taxa influence woody species discrimination via DNA barcoding: evidence from global forest dynamics plots.

    PubMed

    Pei, Nancai; Erickson, David L; Chen, Bufeng; Ge, Xuejun; Mi, Xiangcheng; Swenson, Nathan G; Zhang, Jin-Long; Jones, Frank A; Huang, Chun-Lin; Ye, Wanhui; Hao, Zhanqing; Hsieh, Chang-Fu; Lum, Shawn; Bourg, Norman A; Parker, John D; Zimmerman, Jess K; McShea, William J; Lopez, Ida C; Sun, I-Fang; Davies, Stuart J; Ma, Keping; Kress, W John

    2015-01-01

    To determine how well DNA barcodes from the chloroplast region perform in forest dynamics plots (FDPs) from global CTFS-ForestGEO network, we analyzed DNA barcoding sequences of 1277 plant species from a wide phylogenetic range (3 FDPs in tropics, 5 in subtropics and 5 in temperate zone) and compared the rates of species discrimination (RSD). We quantified RSD by two DNA barcode combinations (rbcL + matK and rbcL + matK + trnH-psbA) using a monophyly-based method (GARLI). We defined two indexes of closely-related taxa (Gm/Gt and S/G ratios) and correlated these ratios with RSD. The combination of rbcL + matK averagely discriminated 88.65%, 83.84% and 72.51% at the local, regional and global scales, respectively. An additional locus trnH-psbA increased RSD by 2.87%, 1.49% and 3.58% correspondingly. RSD varied along a latitudinal gradient and were negatively correlated with ratios of closely-related taxa. Successes of species discrimination generally depend on scales in global FDPs. We suggested that the combination of rbcL + matK + trnH-psbA is currently applicable for DNA barcoding-based phylogenetic studies on forest communities. PMID:26456472

  16. Closely-related taxa influence woody species discrimination via DNA barcoding: evidence from global forest dynamics plots

    PubMed Central

    Pei, Nancai; Erickson, David L.; Chen, Bufeng; Ge, Xuejun; Mi, Xiangcheng; Swenson, Nathan G.; Zhang, Jin-Long; Jones, Frank A.; Huang, Chun-Lin; Ye, Wanhui; Hao, Zhanqing; Hsieh, Chang-Fu; Lum, Shawn; Bourg, Norman A.; Parker, John D.; Zimmerman, Jess K.; McShea, William J.; Lopez, Ida C.; Sun, I-Fang; Davies, Stuart J.; Ma, Keping; Kress, W. John

    2015-01-01

    To determine how well DNA barcodes from the chloroplast region perform in forest dynamics plots (FDPs) from global CTFS-ForestGEO network, we analyzed DNA barcoding sequences of 1277 plant species from a wide phylogenetic range (3 FDPs in tropics, 5 in subtropics and 5 in temperate zone) and compared the rates of species discrimination (RSD). We quantified RSD by two DNA barcode combinations (rbcL + matK and rbcL + matK + trnH-psbA) using a monophyly-based method (GARLI). We defined two indexes of closely-related taxa (Gm/Gt and S/G ratios) and correlated these ratios with RSD. The combination of rbcL + matK averagely discriminated 88.65%, 83.84% and 72.51% at the local, regional and global scales, respectively. An additional locus trnH-psbA increased RSD by 2.87%, 1.49% and 3.58% correspondingly. RSD varied along a latitudinal gradient and were negatively correlated with ratios of closely-related taxa. Successes of species discrimination generally depend on scales in global FDPs. We suggested that the combination of rbcL + matK + trnH-psbA is currently applicable for DNA barcoding-based phylogenetic studies on forest communities. PMID:26456472

  17. Passive restoration potential of riparian areas invaded by giant reed (Arundo donax) in Texas

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Giant reed (Arundo donax L.) is a rhizomatous woody non-native grass that has invaded much of the riparian areas of the southwest. By forming thick impenetrable swaths along riverbanks and waterways, giant reed has driven riparian ecosystem decline and displaced native biodiversity. It’s document...

  18. Using Airborne Lidar to Predict Leaf Area Index in Cottonwood Trees and Refine Riparian Water Use Estimates 1877

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Quantification of riparian forest structure is important for developing a better understanding of how riparian forest ecosystems function. Additionally, estimation of riparian forest structural attributes, such as Leaf Area Index (LAI), is an important step in identifying the amount of water use in ...

  19. Human uses of forested watersheds and riparian corridors: hazard mitigation as an ecosystem service, with examples from Panama, Puerto Rico, and Venezuela

    NASA Astrophysics Data System (ADS)

    Larsen, M. C.

    2015-12-01

    Humans have long favored settlement along rivers for access to water supply for drinking and agriculture, for transport corridors, and for food sources. Additionally, settlement in or near montane forests include benefits such as food sources, wood supply, esthetic values, and high quality water resources derived from watersheds where upstream human disturbance and environmental degradation is generally reduced. However, the advantages afforded by these riparian and montane settings pose episodic risks for communities located there as floods, landslides, and wildfires cause loss of life, destroy infrastructure, and damage or destroy crops. A basic understanding of flood probability and magnitude as well as hillslope stability by residents in these environments can mitigate these risks. Early humans presumably developed some degree of knowledge about these risks by means of their long periods of occupation in these environments and their observations of seasonal and storm rainfall patterns and river discharge, which became more refined as agriculture developed over the past 10,000 years. Modern global urbanization, particularly in regions of rapid economic growth, has resulted in much of this "organic" knowledge being lost, as rural populations move into megacities, many of which encroach on floodplains and mountain fronts. Moreover, the most likely occupants of these hazardous locations are often economically constrained, increasing their vulnerabity. Effective stewardship of river floodplains and upstream montane forests yields a key ecosystem service, which in addition to the well-known services, ie. water, hydroelectric energy, etc., provides a risk mitigation service, by reducing hazard and vulnerability. Puerto Rico, Panama, and Venezuela illustrate a range of practices and results, providing useful examples for planners and land use managers.

  20. Relationship between the Decomposition Process of Coarse Woody Debris and Fungal Community Structure as Detected by High-Throughput Sequencing in a Deciduous Broad-Leaved Forest in Japan

    PubMed Central

    Yamashita, Satoshi; Masuya, Hayato; Abe, Shin; Masaki, Takashi; Okabe, Kimiko

    2015-01-01

    We examined the relationship between the community structure of wood-decaying fungi, detected by high-throughput sequencing, and the decomposition rate using 13 years of data from a forest dynamics plot. For molecular analysis and wood density measurements, drill dust samples were collected from logs and stumps of Fagus and Quercus in the plot. Regression using a negative exponential model between wood density and time since death revealed that the decomposition rate of Fagus was greater than that of Quercus. The residual between the expected value obtained from the regression curve and the observed wood density was used as a decomposition rate index. Principal component analysis showed that the fungal community compositions of both Fagus and Quercus changed with time since death. Principal component analysis axis scores were used as an index of fungal community composition. A structural equation model for each wood genus was used to assess the effect of fungal community structure traits on the decomposition rate and how the fungal community structure was determined by the traits of coarse woody debris. Results of the structural equation model suggested that the decomposition rate of Fagus was affected by two fungal community composition components: one that was affected by time since death and another that was not affected by the traits of coarse woody debris. In contrast, the decomposition rate of Quercus was not affected by coarse woody debris traits or fungal community structure. These findings suggest that, in the case of Fagus coarse woody debris, the fungal community structure is related to the decomposition process of its host substrate. Because fungal community structure is affected partly by the decay stage and wood density of its substrate, these factors influence each other. Further research on interactive effects is needed to improve our understanding of the relationship between fungal community structure and the woody debris decomposition process

  1. Emission of the Greenhouse Gas Nitrous Oxide (N2O) from Riparian Forest Buffers, Warm-Season and Cool-Season Grass Filters and Crop Fields

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Denitrification is recognized as the major mechanism for reducing nitrate in riparian buffers coping with non-point source pollution (NPS) of surface water bodies. However, there are still questions about the quantity and products of denitrification that different kinds of riparian buffer vegetatio...

  2. Controls on denitrification in riparian soils in headwater catchments of a hardwood forest in the Catskill Mountains, U.S.A.

    USGS Publications Warehouse

    Ashby, J.A.; Bowden, W.B.; Murdoch, Peter S.

    1998-01-01

    Denitrification in riparian soils is thought to be an important factor that reduces hydrologic export of nitrate from forested and agricultural catchments. A 2-y study to identify the soil factors most closely associated with denitrification in riparian soils in headwater catchments within the Catskill Mountains of New York, included field surveys of surface and subsurface denitrification rates, and an amendment experiment to assess the relative effects of increases in available carbon and substrate NO-/3 on denitrification rates. Denitrification rates were measured by acetylene inhibition during incubation of intact soil cores from eight soil types representing a range of drainage classes. Soil cores were analyzed for organic matter, total P, extractable NO-/3-N and NH+/4-N, organic N, pH, moisture, porosity, and water-filled pore space, to determine which of these factors were most closely associated with denitrification. The distribution of denitrification rates found during the field surveys was highly skewed, with many low or zero values and few high values. Denitrification rates were positively associated with high soil organic matter, total P, and water-filled pore space, and were highest in seep (poorly-drained) soils, toeslope (seasonally-drained) soils, and stream-edge (poorly- to moderately well-drained) soils in which these three soil characteristics were typically high. Denitrification rates in these wet locations were also positively associated with soil NH+/4-N concentration and pH, but not with NO-/3-N concentration, suggesting that the rate of NO-/3 supply (via nitrification or hydrologic transport) was more important than the instantaneous concentration of NO-/3-N in the soils. The amendment experiment indicated that denitrification in soil types studied was most responsive to added glucose alone or with NO-/3. Thus, in these soils, a combination of slow rates of NO-/3 supply and low available carbon appears to limit denitrification. Annual

  3. Riparian Ficus Tree Communities: The Distribution and Abundance of Riparian Fig Trees in Northern Thailand

    PubMed Central

    Pothasin, Pornwiwan; Compton, Stephen G.; Wangpakapattanawong, Prasit

    2014-01-01

    Fig trees (Ficus) are often ecologically significant keystone species because they sustain populations of the many seed-dispersing animals that feed on their fruits. They are prominent components of riparian zones where they may also contribute to bank stability as well as supporting associated animals. The diversity and distributions of riparian fig trees in deciduous and evergreen forests in Chiang Mai Province, Northern Thailand were investigated in 2010–2012. To record the diversity and abundance of riparian fig trees, we (1) calculated stem density, species richness, and diversity indices in 20×50 m randomly selected quadrats along four streams and (2) measured the distances of individual trees from four streams to determine if species exhibit distinct distribution patterns within riparian zones. A total of 1169 individuals (from c. 4 ha) were recorded in the quadrats, representing 33 Ficus species (13 monoecious and 20 dioecious) from six sub-genera and about 70% of all the species recorded from northern Thailand. All 33 species had at least some stems in close proximity to the streams, but they varied in their typical proximity, with F. squamosa Roxb. and F. ischnopoda Miq the most strictly stream-side species. The riparian forests in Northern Thailand support a rich diversity and high density of Ficus species and our results emphasise the importance of fig tree within the broader priorities of riparian area conservation. Plans to maintain or restore properly functioning riparian forests need to take into account their significance. PMID:25310189

  4. A 70-year perspective on tropical forest regeneration.

    PubMed

    Abbas, Sawaid; Nichol, Janet E; Fischer, Gunter A

    2016-02-15

    Forested areas of the world decreased by 129 million hectare during the past quarter-century, and only 35 % of remainder is primary forest. Secondary forests are therefore relatively more important for biodiversity conservation, catchment protection, climate control, and the ecological services they provide. Many governments expend large resources on afforestation projects, which may not be supported by objective data on rates and pathways of natural succession in secondary forest. This paper describes a 70-year succession of tropical forest in Hong Kong under different management regimes including afforestation programs, frequent fire, and fire protection. From complete destruction of its forest during the Second World War, forest has established rapidly in areas where a shrub cover was able to colonize. The practice of afforestation as a nursery stage on degraded hillsides, for establishment of forest seedlings by natural invasion is not supported by the evidence, as when the native Pinus massoniana plantations were eliminated by disease during the 1970s, no forest or woody species were seen in the areas affected. In fact there was a reversion to grassland, which persisted there for almost three decades, until recent shrub invasion. The fastest period of forest regeneration, at 10.9% annually between 1989 and 2001, occurred when shrubland edge was greatest and forest was able to colonize across interfluves between linear-shaped riparian shrublands in valley bottoms. After 2001, succession to forest was slower, at 7.8% annually, as forest patches consolidated and edge habitats reduced. Effective forest management policies could include seeding of native shrubs extending linearly from established forest, to maximize edge length between woody species and grasslands, and planting of late successional species in areas where forest pioneers are in decline. PMID:26674683

  5. Animal water balance drives top-down effects in a riparian forest-implications for terrestrial trophic cascades.

    PubMed

    McCluney, Kevin E; Sabo, John L

    2016-08-17

    Despite the clear importance of water balance to the evolution of terrestrial life, much remains unknown about the effects of animal water balance on food webs. Based on recent research suggesting animal water imbalance can increase trophic interaction strengths in cages, we hypothesized that water availability could drive top-down effects in open environments, influencing the occurrence of trophic cascades. We manipulated large spider abundance and water availability in 20 × 20 m open-air plots in a streamside forest in Arizona, USA, and measured changes in cricket and small spider abundance and leaf damage. As expected, large spiders reduced both cricket abundance and herbivory under ambient, dry conditions, but not where free water was added. When water was added (free or within moist leaves), cricket abundance was unaffected by large spiders, but spiders still altered herbivory, suggesting behavioural effects. Moreover, we found threshold-type increases in herbivory at moderately low soil moisture (between 5.5% and 7% by volume), suggesting the possibility that water balance may commonly influence top-down effects. Overall, our results point towards animal water balance as an important driver of direct and indirect species interactions and food web dynamics in terrestrial ecosystems. PMID:27534953

  6. Effect of Severe Winter Cold on the Photosynthetic Potentials of Three Co-occurring Evergreen Woody Species in a Mediterranean Forest, Catalonia (Spain)

    NASA Astrophysics Data System (ADS)

    Sperlich, Dominik; Gracia, Carlos; Peñuelas, Josep; Sabaté, Santi

    2013-04-01

    Evergreen tree species in the Mediterranean region have to cope with a wide range of environmental stress conditions from summer drought to winter cold. The winter period can lead to photoinhibition due to a combination of high solar irradiances and chilling temperatures which can reduce the light saturation point. However, Mediterranean winter mildness can lead periodically to favourable environmental conditions above the threshold for positive carbon balance benefitting evergreen woody species in contrast to winter deciduous species. The advantage of being able to photosynthesis all year round with a significant fraction in the winter month is compensating for the lower photosynthetic potentials during spring and summer in comparison to deciduous species. In this work, we investigated the physiological behaviour of three evergreen tree species (Quercus ilex, Pinus halepensis, Arbutus undeo) co-occurring in a natural and mature Mediterranean forest after a period of mild winter conditions and their response to a sudden period of intense cold weather. Therefore, we examined in each period the photosynthetic potentials by estimating the maximum carboxylation rate (Vcmax) and the maximum electron transport rate (Jmax) through gas exchange measurements. The results indicate that all species exhibited extraordinary high photosynthetic potentials during the first period of measurement as a response to the mild conditions. However, the sudden cold period affected negatively the photosynthetic potentials of Quercus ilex and A. unedo with reduction ranging between 37 to 45 %, whereas they were observed to be only insignificantly reduced in Pinus halepensis. Our results can be explained by previous classifications into photoinhibition-avoiding (P. halpensis) and photoinhibition-tolerant (Q. ilex, A. undeo) species on the basis of their susceptibility to dynamic photoinhibition (Martinez Ferri 2000). Photoinhibition tolerant species are characterised with a more dynamic

  7. Riparian Wetlands: Mapping

    EPA Science Inventory

    Riparian wetlands are critical systems that perform functions and provide services disproportionate to their extent in the landscape. Mapping wetlands allows for better planning, management, and modeling, but riparian wetlands present several challenges to effective mapping due t...

  8. Effects of Stream and Elevation Resolution on Riparian Metrics and Restoration Identification

    EPA Science Inventory

    Even though riparian areas attenuate nutrients and sediments from agricultural runoff at the field scale, best management practices and locations for restoring riparian areas should be determined at watershed scales. Riparian metrics (e.g., percent forest within 100m of stream)...

  9. Riverine Landscape Patch Heterogeneity Drives Riparian Ant Assemblages in the Scioto River Basin, USA

    PubMed Central

    Tagwireyi, Paradzayi; Sullivan, S. Mažeika P.

    2015-01-01

    Although the principles of landscape ecology are increasingly extended to include riverine landscapes, explicit applications are few. We investigated associations between patch heterogeneity and riparian ant assemblages at 12 riverine landscapes of the Scioto River, Ohio, USA, that represent urban/developed, agricultural, and mixed (primarily forested, but also wetland, grassland/fallow, and exurban) land-use settings. Using remotely-sensed and ground-collected data, we delineated riverine landscape patch types (crop, grass/herbaceous, gravel, lawn, mudflat, open water, shrub, swamp, and woody vegetation), computed patch metrics (area, density, edge, richness, and shape), and conducted coordinated sampling of surface-active Formicidae assemblages. Ant density and species richness was lower in agricultural riverine landscapes than at mixed or developed reaches (measured using S [total number of species], but not using Menhinick’s Index [DM]), whereas ant diversity (using the Berger-Park Index [DBP]) was highest in agricultural reaches. We found no differences in ant density, richness, or diversity among internal riverine landscape patches. However, certain characteristics of patches influenced ant communities. Patch shape and density were significant predictors of richness (S: R2 = 0.72; DM: R2=0.57). Patch area, edge, and shape emerged as important predictors of DBP (R2 = 0.62) whereas patch area, edge, and density were strongly related to ant density (R2 = 0.65). Non-metric multidimensional scaling and analysis of similarities distinguished ant assemblage composition in grass and swamp patches from crop, gravel, lawn, and shrub as well as ant assemblages in woody vegetation patches from crop, lawn, and gravel (stress = 0.18, R2 = 0.64). These findings lend insight into the utility of landscape ecology to river science by providing evidence that spatial habitat patterns within riverine landscapes can influence assemblage characteristics of riparian arthropods

  10. Riverine Landscape Patch Heterogeneity Drives Riparian Ant Assemblages in the Scioto River Basin, USA.

    PubMed

    Tagwireyi, Paradzayi; Sullivan, S Mažeika P

    2015-01-01

    Although the principles of landscape ecology are increasingly extended to include riverine landscapes, explicit applications are few. We investigated associations between patch heterogeneity and riparian ant assemblages at 12 riverine landscapes of the Scioto River, Ohio, USA, that represent urban/developed, agricultural, and mixed (primarily forested, but also wetland, grassland/fallow, and exurban) land-use settings. Using remotely-sensed and ground-collected data, we delineated riverine landscape patch types (crop, grass/herbaceous, gravel, lawn, mudflat, open water, shrub, swamp, and woody vegetation), computed patch metrics (area, density, edge, richness, and shape), and conducted coordinated sampling of surface-active Formicidae assemblages. Ant density and species richness was lower in agricultural riverine landscapes than at mixed or developed reaches (measured using S [total number of species], but not using Menhinick's Index [DM]), whereas ant diversity (using the Berger-Park Index [DBP]) was highest in agricultural reaches. We found no differences in ant density, richness, or diversity among internal riverine landscape patches. However, certain characteristics of patches influenced ant communities. Patch shape and density were significant predictors of richness (S: R2 = 0.72; DM: R2=0.57). Patch area, edge, and shape emerged as important predictors of DBP (R2 = 0.62) whereas patch area, edge, and density were strongly related to ant density (R2 = 0.65). Non-metric multidimensional scaling and analysis of similarities distinguished ant assemblage composition in grass and swamp patches from crop, gravel, lawn, and shrub as well as ant assemblages in woody vegetation patches from crop, lawn, and gravel (stress = 0.18, R2 = 0.64). These findings lend insight into the utility of landscape ecology to river science by providing evidence that spatial habitat patterns within riverine landscapes can influence assemblage characteristics of riparian arthropods. PMID

  11. Conceptual Assessment Framework for Forested Wetland Restoration: The Pen Branch Experience. Restoration of a Severely Impacted Riparian Wetland System - The Pen Branch Project

    SciTech Connect

    Kolka, R.; Nelson, E.A.; Trettin, C.C.

    2000-10-01

    Development of an assessment framework and indicators can be used to evaluate effectiveness of wetland restoration. Example of these include index of biotic integrity and the hydrogeomorphic method. Both approaches provide qualitative ranks. We propose a new method based on the EPA wetland research program. Similar to other methods, indexes are compared to reference communities; however, the comparisons are quantitative. In this paper we discuss the results of our framework using the Pen Branch riparian wetland system as an example.

  12. Reduced riparian zone width compromises aquatic macroinvertebrate communities in streams of southern Brazil.

    PubMed

    Moraes, Aline Bianca; Wilhelm, Andréia Emília; Boelter, Thaíse; Stenert, Cristina; Schulz, Uwe H; Maltchik, Leonardo

    2014-11-01

    Recent changes in Brazilian legislation reduced the width of riparian forest buffer needed to be preserved in private properties from 30 to 15 m or less. The consequences of these modifications can be dramatic, mainly because riparian buffer width is an important parameter for riparian forest structure and functioning. Our study assessed whether (1) macroinvertebrate family richness and Ephemeroptera, Plecoptera, and Trichoptera (EPT) family richness decrease with reduced riparian buffer width; (2) taxonomic composition and functional feeding group (FFG) composition of macroinvertebrates vary with a reduced riparian buffer width; and (3) reduced riparian buffer width similarly influence the macroinvertebrate community in different stream substrates. We selected three fragments with different riparian buffer widths (>40, <30, and <15 m) in three streams (fourth and fifth orders) in the Sinos River watershed, southern Brazil. Our results show that on all substrate types, reducing the width of the riparian buffer altered neither the macroinvertebrate richness nor EPT richness. However, EPT richness was greater in the substrates stone and gravel than leaf litter, independent of riparian buffer width. There was a significant difference in macroinvertebrate composition among riparian buffer widths. The macroinvertebrate composition and FFG differed among substrates, independent of riparian buffer width. This study showed that riparian buffer widths <15 m altered the macroinvertebrate community. A width greater than 15 m is necessary to maintain the composition and trophic conditions of macroinvertebrate families similar to those found in reference states of conservation. PMID:25052327

  13. Quantifying Riparian Evapotranspiration 1918

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A multi-disciplinary group of government scientists and university researchers has been working to better understand the hydrological functioning of riparian systems in the Southwest. Perhaps the most socially-relevant facet of this research has been the quantification of riparian evapotranspiratio...

  14. Riparian influences on stream fish assemblage structure in urbanizing streams

    USGS Publications Warehouse

    Roy, A.H.; Freeman, B.J.; Freeman, Mary C.

    2007-01-01

    We assessed the influence of land cover at multiple spatial extents on fish assemblage integrity, and the degree to which riparian forests can mitigate the negative effects of catchment urbanization on stream fish assemblages. Riparian cover (urban, forest, and agriculture) was determined within 30 m buffers at longitudinal distances of 200 m, 1 km, and the entire network upstream of 59 non-nested fish sampling locations. Catchment and riparian land cover within the upstream network were highly correlated, so we were unable to distinguish between those variables. Most fish assemblage variables were related to % forest and % urban land cover, with the strongest relations at the largest spatial extent of land cover (catchment), followed by riparian land cover in the 1-km and 200-m reach, respectively. For fish variables related to urban land cover in the catchment, we asked whether the influence of riparian land cover on fish assemblages was dependent on the amount of urban development in the catchment. Several fish assemblage metrics (endemic richness, endemic:cosmopolitan abundance, insectivorous cyprinid richness and abundance, and fluvial specialist richness) were all best predicted by single variable models with % urban land cover. However, endemic:cosmopolitan richness, cosmopolitan abundance, and lentic tolerant abundance were related to % forest cover in the 1-km stream reach, but only in streams that had <15% catchment urban land cover. In these cases, catchment urbanization overwhelmed the potential mitigating effects of riparian forests on stream fishes. Together, these results suggest that catchment land cover is an important driver of fish assemblages in urbanizing catchments, and riparian forests are important but not sufficient for protecting stream ecosystems from the impacts of high levels of urbanization.

  15. Microbial community dynamics and methane, carbon dioxide, oxygen, and nitrous oxide concentrations in upland forest and riparian soils across a seasonal gradient of fully saturated soils to completely dried soils

    NASA Astrophysics Data System (ADS)

    Jones, R. T.; McGlynn, B. L.; McDermott, T.; Dore, J. E.

    2015-12-01

    Gas concentrations (CH4, CO2, N2O, and O2), soil properties (soil water content and pH), and microbial community composition were measured from soils at 32 sites across the Stringer Creek Watershed in the Tenderfoot Creek Experimental Forest 7 times between June 3, 2013 and September 20, 2013. Soils were fully saturated during the initial sampling period and dried down over the course of the summer. Soils and gas were sampled from 5cm and 20cm at each site and also at 50cm at eight riparian sites. In total, 496 individual soil samples were collected. Soil moisture ranged from 3.7% to fully saturated; soil pH ranged from 3.60 to 6.68. Methane concentrations in soils ranged from 0.426 ppm to 218 ppm; Carbon dioxide concentrations ranged from 550 ppm to 42,990 ppm; Nitrous oxide concentrations ranged from 0.220 ppm to 2.111 ppm; Oxygen concentrations ranged from 10.2% to 21.5%. Soil microbial communities were characterized by DNA sequences covering the V4 region of the 16S rRNA gene. DNA sequences were generated (~30,000,000 sequences) from the 496 soil samples using the Illumina MiSeq platform. Operational Taxonomic Units were generated using USEARCH, and representative sequences were taxonomically classified according the Ribosomal Database Project's taxonomy scheme. Analysis of similarity revealed that microbial communities found within a landscape type (high upland forest, low upland forest, riparian) were more similar than among landscape types (R = 0.600; p<0.001). Similarly, communities from unique site x depths were similar across the 7 collection periods (R = 0.646; p<0.001) despite changes in soil moisture. Euclidean distances of soil properties and gas concentrations were compared to Bray-Curtis community dissimilarity matrices using Mantel tests to determine how community structure co-varies with the soil environment and gas concentrations. All variables measured significantly co-varied with microbial community membership (pH: R = 0.712, p < 0.001; CO2: R

  16. Sustainable cropping systems using cover crops, native species field borders and riparian buffers for environmental quality

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This presentation will focus on the application of sustainable management practices for no-till cultivation using cover crops, native species field borders, and fast growing woody species integrated in vegetative strips and riparian buffers. An ongoing field project at the Bradford Research and Exte...

  17. Influence of Herbaceous Riparian Buffers on Channelized Headwater Streams in Central Ohio

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Herbaceous riparian buffers are a widely used conservation practice in the United States for reducing nutrient, pesticide, and sediment loadings in agricultural streams. The importance of forested riparian buffers for headwater streams has been documented, but the ecological impacts of herbaceous ri...

  18. Large woody debris mobility and accumulation by an extreme flood - an example from the Dyje River, Czech Republic

    NASA Astrophysics Data System (ADS)

    Macka, Zdenek; Krejci, Lukas

    2010-05-01

    Large woody debris (LWD) in the form of logs, branches and their fragments play an important geomorphic and ecological role in forested watersheds. Especially when organized in accumulations and jams, LWD have been found to change hydraulic, morphological, sedimentary and biological characteristics of fluvial ecosystems. Our study focuses on LWD jams distribution and properties within the 44 km long forested reach of the Dyje River in south-eastern Czech Republic. The study reach is located between two large water reservoirs and the flow is regulated showing significant daily fluctuation of discharges due to water releases for power generation. River flows in the deeply incised meandering valley with the narrow and patchy floodplain. In 2002, and especially 2006 large volumes of LWD have been transported by river and the water reservoir downstream was congested with wood. Peak discharge of 2006 flood equalled 306 m3.s-1 which was estimated as 500 year flood. The flood caused significant mobility and redistribution of woody debris as in aquatic, so in riparian segment of the river corridor. The high rate of LWD transport is favoured by large bankfull channel width which exceeds the average tree height. LWD jams were defined as aggregations of three or more wood pieces with diameter ≥ 0.1 m and length ≥ 1 m. We surveyed LWD jams in 62 river reaches, which have been located at meander apexes, inflections and intermediate positions; the length of the reaches was 200 m. The overall number of registered LWD jams was 200. Majority of jams consist of solely allochthonous (transported) wood pieces (65 %), some jams are combination of large key trees and trapped transported pieces (29%), and only small proportion are jams formed by locally uprooted trees (12,6%). Number of wood pieces varies greatly from 3 to 98, the most common being the interval 5 - 10 pieces per jam. Spatial distribution of jams is longitudinally and transversally irregular within the river corridor

  19. Cost of riparian buffer zones: A comparison of hydrologically adapted site-specific riparian buffers with traditional fixed widths

    NASA Astrophysics Data System (ADS)

    Tiwari, T.; Lundström, J.; Kuglerová, L.; Laudon, H.; Öhman, K.; Ågren, A. M.

    2016-02-01

    Traditional approaches aiming at protecting surface waters from the negative impacts of forestry often focus on retaining fixed width buffer zones around waterways. While this method is relatively simple to design and implement, it has been criticized for ignoring the spatial heterogeneity of biogeochemical processes and biodiversity in the riparian zone. Alternatively, a variable width buffer zone adapted to site-specific hydrological conditions has been suggested to improve the protection of biogeochemical and ecological functions of the riparian zone. However, little is known about the monetary value of maintaining hydrologically adapted buffer zones compared to the traditionally used fixed width ones. In this study, we created a hydrologically adapted buffer zone by identifying wet areas and groundwater discharge hotspots in the riparian zone. The opportunity cost of the hydrologically adapted riparian buffer zones was then compared to that of the fixed width zones in a meso-scale boreal catchment to determine the most economical option of designing riparian buffers. The results show that hydrologically adapted buffer zones were cheaper per hectare than the fixed width ones when comparing the total cost. This was because the hydrologically adapted buffers included more wetlands and low productive forest areas than the fixed widths. As such, the hydrologically adapted buffer zones allows more effective protection of the parts of the riparian zones that are ecologically and biogeochemically important and more sensitive to disturbances without forest landowners incurring any additional cost than fixed width buffers.

  20. Using Mechanistic Studies to Model Riparian Tree Establishment Under Environmental Flow Scenarios on Regulated Rivers

    NASA Astrophysics Data System (ADS)

    Stella, J. C.; Battles, J. J.; McBride, J. R.; Orr, B. K.

    2007-12-01

    In the Central Valley of California, pioneer cottonwood and willow species dominate the near-river forests. Historically, seedling recruitment for these disturbance-adapted species coincided with spring floods. Changes in flow timing and magnitude due to river regulation have decreased the success of seedling cohorts and contributed to the decline of these riparian tree populations. In order to address gaps in our understanding of these species and potential restoration strategies, we field-calibrated a conceptual model of seedling recruitment for the dominant pioneer woody species, Populus fremontii, Salix gooddingii, and S. exigua. We conducted experiments to identify seedling desiccation thresholds and seed longevity, used field studies to measure seedling competition and seasonal seed release patterns, and modeled interannual differences in dispersal timing using a degree-day model. These studies were integrated into a recruitment model that generates annual estimates of seedling density and bank elevation based on inputs of seasonal river discharge, seed dispersal timing, and seedling mortality from desiccation. The model predictions successfully captured interannual and species-level patterns in recruitment observed independently throughout a 20-km reach of the lower Tuolumne River from 2002-04. The model correctly predicted that seedling densities were highest in 2004 and lowest in 2003, and that S. exigua recruitment would be less extensive than for the two tree species. This work shows promise as both a quantitative approach linking hydrology, climate and plant community dynamics, and as a process-based framework for guiding flow releases and other management actions to restore riparian tree population along Central Valley rivers.

  1. Carbon storage of headwater riparian zones in an agricultural landscape

    PubMed Central

    2012-01-01

    Background In agricultural regions, streamside forests have been reduced in age and extent, or removed entirely to maximize arable cropland. Restoring and reforesting such riparian zones to mature forest, particularly along headwater streams (which constitute 90% of stream network length) would both increase carbon storage and improve water quality. Age and management-related cover/condition classes of headwater stream networks can be used to rapidly inventory carbon storage and sequestration potential if carbon storage capacity of conditions classes and their relative distribution on the landscape are known. Results Based on the distribution of riparian zone cover/condition classes in sampled headwater reaches, current and potential carbon storage was extrapolated to the remainder of the North Carolina Coastal Plain stream network. Carbon stored in headwater riparian reaches is only about 40% of its potential capacity, based on 242 MgC/ha stored in sampled mature riparian forest (forest > 50 y old). The carbon deficit along 57,700 km headwater Coastal Plain streams is equivalent to about 25TgC in 30-m-wide riparian buffer zones and 50 TgC in 60-m-wide buffer zones. Conclusions Estimating carbon storage in recognizable age-and cover-related condition classes provides a rapid way to better inventory current carbon storage, estimate storage capacity, and calculate the potential for additional storage. In light of the particular importance of buffer zones in headwater reaches in agricultural landscapes in ameliorating nutrient and sediment input to streams, encouraging the restoration of riparian zones to mature forest along headwater reaches worldwide has the potential to not only improve water quality, but also simultaneously reduce atmospheric CO2. PMID:22333213

  2. Riparian Zones and the Role of Hyporheic Exchange in the Carbon Budget of a Small, Forested, Headwater Stream, Western Oregon, USA.

    NASA Astrophysics Data System (ADS)

    Wondzell, S. M.; Corson-Rikert, H.; Dosch, N.; Haggerty, R.

    2014-12-01

    Recent estimates have identified streams as important conduits in the global carbon budget. Stream waters are typically super-saturated with CO2. This CO2 is assumed to come from carbon fixed in the upland terrestrial environment and then transported to the stream via soil water or groundwater. Evasion of CO2 occurs at the stream surface, which usually comprises less than 2% of the watershed area, yet this flux might account for as much as 30% of the net ecosystem exchange in a watershed. This view does not consider the role of hyporheic exchange, despite the fact that hyporheic exchange fluxes can be very large in headwater streams, which drain the majority of the landscape. Using continuously recording probes, we show that pCO2 averages 890 ppmv in stream water and 7,680 ppmv in hyporheic water in a 96-ha watershed. Independent estimates show that stream water turn-over lengths through the hyporheic zone are less than 100 m at baseflow, which suggests that stream water is continuously recharged with CO2 every time it is cycled through the hyporheic zone. We monitored DIC and DOC in a co-located well network and show that DOC decreases, and DIC increases, with travel time through the hyporheic zone. However, respiration of stream-source DOC can only account for approximately 10% of the increase in DIC. Previous hydrologic studies suggest that lateral inputs of soil water or groundwater are limited within this study reach, so the large increases in DIC must come from particulate organic matter buried in the hyporheic zone and from the overlying soil. These measurements suggest that riparian zones supply, via hyporheic exchange, a disproportionately large fraction of carbon to headwater streams and may therefore play an outsized role in the global carbon cycle.

  3. Edaphic, structural and physiological contrasts across Amazon Basin forest-savanna ecotones suggest a role for potassium as a key modulator of tropical woody vegetation structure and function

    NASA Astrophysics Data System (ADS)

    Lloyd, J.; Domingues, T. F.; Schrodt, F.; Ishida, F. Y.; Feldpausch, T. R.; Saiz, G.; Quesada, C. A.; Schwarz, M.; Torello-Raventos, M.; Gilpin, M.; Marimon, B. S.; Marimon-Junior, B. H.; Ratter, J. A.; Grace, J.; Nardoto, G. B.; Veenendaal, E.; Arroyo, L.; Villarroel, D.; Killeen, T. J.; Steininger, M.; Phillips, O. L.

    2015-11-01

    Sampling along a precipitation gradient in tropical South America extending from ca. 0.8 to 2.0 m a-1, savanna soils had consistently lower exchangeable cation concentrations and higher C / N ratios than nearby forest plots. These soil differences were also reflected in canopy averaged leaf traits with savanna trees typically having higher leaf mass per unit area but lower mass-based nitrogen (Nm) and potassium (Km). Both Nm and Km also increased with declining mean annual precipitation (PA), but most area-based leaf traits such as leaf photosynthetic capacity showed no systematic variation with PA or vegetation type. Despite this invariance, when taken in conjunction with other measures such as mean canopy height, area-based soil exchangeable potassium content, [K]sa , proved to be an excellent predictor of several photosynthetic properties (including 13C isotope discrimination). Moreover, when considered in a multivariate context with PA and soil plant available water storage capacity (θP) as covariates, [K]sa also proved to be an excellent predictor of stand-level canopy area, providing drastically improved fits as compared to models considering just PA and/or θP. Neither calcium, nor magnesium, nor soil pH could substitute for potassium when tested as alternative model predictors (ΔAIC > 10). Nor for any model could simple soil texture metrics such as sand or clay content substitute for either [K]sa or θP. Taken in conjunction with recent work in Africa and the forests of the Amazon Basin, this suggests - in combination with some newly conceptualised interacting effects of PA and θP also presented here - a critical role for potassium as a modulator of tropical vegetation structure and function.

  4. Gilliam County Riparian Buffers; 2003-2004 Annual Reports.

    SciTech Connect

    Coiner, Josh

    2004-06-01

    Interest appears to be at an all-time high for riparian conservation programs in Gilliam County. With the recently added Herbaceous Buffer and the already established CREP program interest is booming. However, more and more people are turning towards the herbaceous buffer because of expense. The riparian forest buffer is becoming too expensive. Even with the excellent cost share and incentives landowners are having trouble with Farm Service Agency's payment limitation. Because of this payment limitation landowners are not receiving their full rental and incentive payments, usually in year one. This has cooled the installation of riparian forest buffers and peaked interest in the CP-29 (Herbaceous Buffer for Wildlife). Either way, riparian lands are being enhanced and water quality is being improved. Year three should be very similar to the accomplishments of year 2. There has already been several projects proposed that may or may not be approved during year 3. I am currently working on three projects that are all over 2.5 miles long on each side and total anywhere from 60 to 250 acres in size. Along with these three projects there at least seven small projects being proposed. Four of those projects are riparian forest buffers and the remaining are herbaceous buffers.

  5. Gasification of Woody Biomass.

    PubMed

    Dai, Jianjun; Saayman, Jean; Grace, John R; Ellis, Naoko

    2015-01-01

    Interest in biomass to produce heat, power, liquid fuels, hydrogen, and value-added chemicals with reduced greenhouse gas emissions is increasing worldwide. Gasification is becoming a promising technology for biomass utilization with a positive environmental impact. This review focuses specifically on woody biomass gasification and recent advances in the field. The physical properties, chemical structure, and composition of biomass greatly affect gasification performance, pretreatment, and handling. Primary and secondary catalysts are of key importance to improve the conversion and cracking of tars, and lime-enhanced gasification advantageously combines CO2 capture with gasification. These topics are covered here, including the reaction mechanisms and biomass characterization. Experimental research and industrial experience are investigated to elucidate concepts, processes, and characteristics of woody biomass gasification and to identify challenges. PMID:26247289

  6. Prescribed fires as ecological surrogates for wildfires: A stream and riparian perspective

    USGS Publications Warehouse

    Arkle, R.S.; Pilliod, D.S.

    2010-01-01

    Forest managers use prescribed fire to reduce wildfire risk and to provide resource benefits, yet little information is available on whether prescribed fires can function as ecological surrogates for wildfire in fire-prone landscapes. Information on impacts and benefits of this management tool on stream and riparian ecosystems is particularly lacking. We used a beyond-BACI (Before, After, Control, Impact) design to investigate the effects of a prescribed fire on a stream ecosystem and compared these findings to similar data collected after wildfire. For 3 years after prescribed fire treatment, we found no detectable changes in periphyton, macroinvertebrates, amphibians, fish, and riparian and stream habitats compared to data collected over the same time period in four unburned reference streams. Based on changes in fuels, plant and litter cover, and tree scorching, this prescribed fire was typical of those being implemented in ponderosa pine forests throughout the western U.S. However, we found that the extent and severity of riparian vegetation burned was substantially lower after prescribed fire compared to nearby wildfires. The early-season prescribed fire did not mimic the riparian or in-stream ecological effects observed following a nearby wildfire, even in catchments with burn extents similar to the prescribed fire. Little information exists on the effects of long-term fire exclusion from riparian forests, but a "prescribed fire regime" of repeatedly burning upland forests while excluding fire in adjacent riparian forests may eliminate an important natural disturbance from riparian and stream habitats.

  7. Riparian buffer zones as pesticide filters of no-till crops.

    PubMed

    Aguiar, Terencio R; Bortolozo, F R; Hansel, F A; Rasera, K; Ferreira, M T

    2015-07-01

    Several studies have pointed to the potential benefits of riparian vegetation as buffer zones for agricultural and industrial pollutants harmful to aquatic ecosystems. However, other studies have called into question its use as an ecological filter, questioning the widths and conditions for which they are effective as a filter. In this work, we have investigated the buffering capacity of the riparian one to retain pesticides in the water-saturated zone, on 27 sites composed by riparian buffer zones with different vegetation structure (woody, shrubs, or grass vegetation) and width (12, 36, and 60 m). Five pesticides were analyzed. The effectiveness of the filtering was largely influenced by the width and vegetation type of the buffer zone. In general, decreasing pesticide removal followed in this order wood > shrubs > grass. The 60 m woody buffer zone was the most effective in the removal of all the pesticides. Only atrazine was detected in this case (0.3 μg L(-1)). Furthermore, a linear correlation (R (2) > 0.97) was observed in their removal for all compounds and buffer zones studied. Thus, preserving the woody vegetation in the riparian zone is important for watershed management and groundwater quality in the no-tillage system in temperate climate. PMID:25744820

  8. Comparison of riparian plant communities under four land management systems in southwestern Wisconsin

    USGS Publications Warehouse

    Paine, L.K.; Ribic, C.A.

    2002-01-01

    Riparian plant community composition is influenced by moisture, erosion, original native plant communities, and current and past land use. This study compared riparian plant communities under four types of management: woody buffer strip, grassy buffer strip, rotational grazing, and continuous grazing. Study sites were located along spring-fed streams in the unglaciated region of southwestern Wisconsin, USA. At each site, plant community surveys were conducted using a point transect method. Among the treatments, woody buffer strips, rotationally grazed and continuously grazed riparian areas had greater plant species richness than grassy buffer strips, and woody buffer strips had the greatest native plant species richness. Reed canary grass (Phalaris arundinacea L.) was prevalent in grassy buffer strips (44% of all observations), common in woody buffer strips (15%), and rare in sites that were rotationally or continuously grazed (3 and 5%, respectively). Pasture sites had greater proportions of native grasses and grass relatives and moderate levels of overall native species richness. Considered a water quality best management practice, well-managed rotational grazing may be a reasonable alternative to buffer strips which can contribute to protection and enhancement of native vegetation biodiversity. ?? 2002 Elsevier Science B.V. All rights reserved.

  9. Riparian vegetation and water yield: A synthesis

    NASA Astrophysics Data System (ADS)

    Salemi, Luiz Felippe; Groppo, Juliano Daniel; Trevisan, Rodrigo; Marcos de Moraes, Jorge; de Paula Lima, Walter; Martinelli, Luiz Antonio

    2012-08-01

    SummaryForested riparian zones perform numerous ecosystem functions, including the following: storing and fixing carbon; serving as wildlife habitats and ecological corridors; stabilizing streambanks; providing shade, organic matter, and food for streams and their biota; retaining sediments and filtering chemicals applied on cultivated/agricultural sites on upslope regions of the catchments. In this paper, we report a synthesis of a different feature of this type of vegetation, which is its effect on water yield. By synthesizing results from studies that used (i) the nested catchment and (ii) the paired catchment approaches, we show that riparian forests decrease water yield on a daily to annual basis. In terms of the treated area increases on average were 1.32 ± 0.85 mm day-1 and 483 ± 309 mm yr-1, respectively; n = 9. Similarly, riparian forest plantation or regeneration promoted reduced water yield (on average 1.25 ± 0.34 mm day-1 and 456 ± 125 mm yr-1 on daily and annual basis, respectively, when prorated to the catchment area subjected to treatment; n = 5). Although there are substantially fewer paired catchment studies assessing the effect of this vegetation type compared to classical paired catchment studies that manipulate the entire vegetation of small catchments, our results indicate the same trend. Despite the occurrence of many current restoration programs, measurements of the effect on water yield under natural forest restoration conditions are still lacking. We hope that presenting these gaps will encourage the scientific community to enhance the number of observations in these situations as well as produce more data from tropical regions.

  10. Stereophotogrammetry in studies of riparian vegetation dynamics

    NASA Astrophysics Data System (ADS)

    Hortobagyi, Borbala; Vautier, Franck; Corenblit, Dov; Steiger, Johannes

    2014-05-01

    Riparian vegetation responds to hydrogeomorphic disturbances and also controls sediment deposition and erosion. Spatio-temporal riparian vegetation dynamics within fluvial corridors have been quantified in many studies using aerial photographs and GIS. However, this approach does not allow the consideration of woody vegetation growth rates (i.e. vertical dimension) which are fundamental when studying feedbacks between the processes of fluvial landform construction and vegetation establishment and succession. We built 3D photogrammetric models of vegetation height based on aerial argentic and digital photographs from sites of the Allier and Garonne Rivers (France). The models were realized at two different spatial scales and with two different methods. The "large" scale corresponds to the reach of the river corridor on the Allier river (photograph taken in 2009) and the "small" scale to river bars of the Allier (photographs taken in 2002, 2009) and Garonne Rivers (photographs taken in 2000, 2002, 2006 and 2010). At the corridor scale, we generated vegetation height models using an automatic procedure. This method is fast but can only be used with digital photographs. At the bar scale, we constructed the models manually using a 3D visualization on the screen. This technique showed good results for digital and also argentic photographs but is very time-consuming. A diachronic study was performed in order to investigate vegetation succession by distinguishing three different classes according to the vegetation height: herbs (<1 m), shrubs (1-4 m) or trees (>4 m). Both methods, i.e. automatic and manual, were employed to study the evolution of the three vegetation classes and the recruitment of new vegetation patches. A comparison was conducted between the vegetation height given by models (automatic and manual) and the vegetation height measured in the field. The manually produced models (small scale) were of a precision of 0.5-1 m, allowing the quantification of woody

  11. Biomass Estimation of Dry Tropical Woody Species at Juvenile Stage

    PubMed Central

    Chaturvedi, R. K.; Raghubanshi, A. S.; Singh, J. S.

    2012-01-01

    Accurate characterization of biomass in different forest components is important to estimate their contribution to total carbon stock. Due to lack of allometric equations for biomass estimation of woody species at juvenile stage, the carbon stored in this forest component is ignored. We harvested 47 woody species at juvenile stage in a dry tropical forest and developed regression models for the estimation of above-ground biomass (AGB). The models including wood-specific gravity (ρ) exhibited higher R2 than those without ρ. The model consisting of ρ, stem diameter (D), and height (H) not only exhibited the highest R2 value but also had the lowest standard error of estimate. We suggest that ρ-based regression model is a viable option for nondestructive estimation of biomass of forest trees at juvenile stage. PMID:22448139

  12. 77 FR 5755 - Request for Proposals: 2012 Hazardous Fuels Woody Biomass Utilization Grant Program

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-02-06

    ...The Department of Agriculture (USDA), Forest Service, State and Private Forestry (S&PF), Technology Marketing Unit, located at the Forest Products Laboratory, request proposals for wood energy projects that require engineering services. These projects will use woody biomass, such as material removed from forest restoration activities, wildfire hazardous fuel treatments, insect and disease......

  13. Riparian Sediment Delivery Ratio: Stiff Diagrams and Artifical Neural Networks

    EPA Science Inventory

    Various methods are used to estimate sediment transport through riparian buffers and grass jilters with the sediment delivery ratio having been the most widely applied. The U.S. Forest Service developed a sediment delivery ratio using the stiff diagram and a logistic curve to int...

  14. Effects of experimental floods on riparian and aquatic ecosystems: Bill Williams River, Arizona

    NASA Astrophysics Data System (ADS)

    Shafroth, P. B.; Andersen, D. C.; Wilcox, A. C.; Kui, L.; Stella, J. C.

    2013-12-01

    Development of flow prescriptions for environmental purposes along rivers is relatively common, but implementation of these 'environmental flows' occurs infrequently. Implementation is critical for testing hypotheses relating flow regime to biotic response, which ultimately can inform adaptive flow management. We describe the development of flow prescriptions and evaluate responses of riparian vegetation, beaver dams, and associated aquatic habitat to experimental floods and intervening base flows associated with an environmental flow program on the Bill Williams River (BWR), in semiarid Arizona. First, we assessed effects of flow releases between 1993 and 2009 designed to favor the establishment and maintenance of native riparian trees (Populus and Salix) and disfavor an invasive, nonnative shrub (Tamarix spp.) downstream of Alamo Dam on the BWR. Our data are multi-scaled and include a several-decade assessment of changes to major vegetation types based on a time series of aerial photography, an assessment of species composition and abundance sampled in permanent vegetation quadrats, and targeted seedling surveys following experimental floods. Between 1993 and 2009, we observed significant increases in Populus and Salix forests and essentially no change in Tamarix. Experimental floods in 2006 and 2007 resulted in higher mortality of Tamarix seedlings than Salix. These results illustrate the potential for managing streamflow to influence riparian vegetation dynamics, including management of nonnative species. Second, we examined the role of beaver as ecosystem engineers in the BWR and linkages to flow releases between 2004 and 2013. Beaver convert lotic stream habitat to lentic through dam construction and maintenance during low flow periods, and the process is reversed when a flood or other event causes dam failure. We estimated the extent of lotic and beaver-created lentic (beaver pond) habitat along the BWR and related the likelihood of damage or destruction of

  15. Development and Evaluation of a Riparian Buffer Mapping Tool

    USGS Publications Warehouse

    Milheim, Lesley E.; Claggett, Peter R.

    2008-01-01

    Land use and land cover within riparian areas greatly affect the conditions of adjacent water features. In particular, riparian forests provide many environmental benefits, including nutrient uptake, bank stabilization, steam shading, sediment trapping, aquatic and terrestrial habitat, and stream organic matter. In contrast, residential and commercial development and associated transportation infrastructure increase pollutant and nutrient loading and change the hydrologic characteristics of the landscape, thereby affecting both water quality and habitat. Restoring riparian areas is a popular and cost effective restoration technique to improve and protect water quality. Recognizing this, the Chesapeake Executive Council committed to restoring 10,000 miles of riparian forest buffers throughout the Chesapeake Bay watershed by the year 2010. In 2006, the Chesapeake Executive Council further committed to 'using the best available...tools to identify areas where retention and expansion of forests is most needed to protect water quality'. The Chesapeake Bay watershed encompasses 64,000 square miles, including portions of six States and Washington, D.C. Therefore, the interpretation of remotely sensed imagery provides the only effective technique for comprehensively evaluating riparian forest protection and restoration opportunities throughout the watershed. Although 30-meter-resolution land use and land cover data have proved useful on a regional scale, they have not been equally successful at providing the detail required for local-scale assessment of riparian area characteristics. Use of high-resolution imagery (HRI) provides sufficient detail for local-scale assessments, although at greater cost owing to the cost of the imagery and the skill and time required to process the data. To facilitate the use of HRI for monitoring the extent of riparian forest buffers, the U.S. Forest Service and the U.S. Geological Survey Eastern Geographic Science Center funded the

  16. Impact of riparian land use on stream insects of Kudremukh National Park, Karnataka state, India

    PubMed Central

    Subramanian, K.A.; Sivaramakrishnan, K.G.; Gadgil, Madhav

    2005-01-01

    The impact of riparian land use on the stream insect communities was studied at Kudremukh National Park located within Western Ghats, a tropical biodiversity hotspot in India. The diversity and community composition of stream insects varied across streams with different riparian land use types. The rarefied family and generic richness was highest in streams with natural semi evergreen forests as riparian vegetation. However, when the streams had human habitations and areca nut plantations as riparian land use type, the rarefied richness was higher than that of streams with natural evergreen forests and grasslands. The streams with scrub lands and iron ore mining as the riparian land use had the lowest rarefied richness. Within a landscape, the streams with the natural riparian vegetation had similar community composition. However, streams with natural grasslands as the riparian vegetation, had low diversity and the community composition was similar to those of paddy fields. We discuss how stream insect assemblages differ due to varied riparian land use patterns, reflecting fundamental alterations in the functioning of stream ecosystems. This understanding is vital to conserve, manage and restore tropical riverine ecosystems. PMID:17119631

  17. Riparian land-use and rehabilitation: impact on organic matter input and soil respiration.

    PubMed

    Oelbermann, Maren; Raimbault, Beverly A; Gordon, A M

    2015-02-01

    Rehabilitated riparian zones in agricultural landscapes enhance environmental integrity and provide environmental services such as carbon (C) sequestration. This study quantified differences in organic matter input, soil biochemical characteristics, and soil respiration in a 25-year-old rehabilitated (RH), grass (GRS), and undisturbed natural forest (UNF) riparian zone. Input from herbaceous vegetation was significantly greater (P < 0.05) in the GRS riparian zone, whereas autumnal litterfall was significantly greater (P < 0.05) in the RH riparian zone. Soil bulk density was significantly greater (P < 0.05) in the RH riparian zone, but its soil chemical characteristics were significantly lower. Soil respiration rates were lowest (P < 0.05) in the UNF (106 C m(-2) h(-1)), followed by the RH (169 mg C m(-2) h(-1)) and GRS (194 C m(-2) h(-1)) riparian zones. Soil respiration rates were significantly different (P < 0.05) among seasons, and were significantly correlated with soil moisture (P < 0.05) and soil temperature (P < 0.05) in all riparian zones. Soil potential microbial activity indicated a significantly different (P < 0.05) response of the microbial metabolic diversity in the RH compared to the GRS and UNF riparian zones, and principle component analysis showed a distinct difference in microbial activity among the riparian land-use systems. Rehabilitating degraded riparian zones with trees rather than GRS is a more effective approach to the long-term mitigation of CO2. Therefore, the protection of existing natural/undisturbed riparian forests in agricultural landscapes is equally important as their rehabilitation with trees, given their higher levels of soil organic C and lower soil respiration rates. PMID:25432450

  18. Riparian Land-Use and Rehabilitation: Impact on Organic Matter Input and Soil Respiration

    NASA Astrophysics Data System (ADS)

    Oelbermann, Maren; Raimbault, Beverly A.

    2015-02-01

    Rehabilitated riparian zones in agricultural landscapes enhance environmental integrity and provide environmental services such as carbon (C) sequestration. This study quantified differences in organic matter input, soil biochemical characteristics, and soil respiration in a 25-year-old rehabilitated (RH), grass (GRS), and undisturbed natural forest (UNF) riparian zone. Input from herbaceous vegetation was significantly greater ( P < 0.05) in the GRS riparian zone, whereas autumnal litterfall was significantly greater ( P < 0.05) in the RH riparian zone. Soil bulk density was significantly greater ( P < 0.05) in the RH riparian zone, but its soil chemical characteristics were significantly lower. Soil respiration rates were lowest ( P < 0.05) in the UNF (106 C m-2 h-1), followed by the RH (169 mg C m-2 h-1) and GRS (194 C m-2 h-1) riparian zones. Soil respiration rates were significantly different ( P < 0.05) among seasons, and were significantly correlated with soil moisture ( P < 0.05) and soil temperature ( P < 0.05) in all riparian zones. Soil potential microbial activity indicated a significantly different ( P < 0.05) response of the microbial metabolic diversity in the RH compared to the GRS and UNF riparian zones, and principle component analysis showed a distinct difference in microbial activity among the riparian land-use systems. Rehabilitating degraded riparian zones with trees rather than GRS is a more effective approach to the long-term mitigation of CO2. Therefore, the protection of existing natural/undisturbed riparian forests in agricultural landscapes is equally important as their rehabilitation with trees, given their higher levels of soil organic C and lower soil respiration rates.

  19. How Riparian Vegetation Influences Stream Morphology and Process: Implications for Restoration

    NASA Astrophysics Data System (ADS)

    Pizzuto, J. E.

    2005-05-01

    Vegetation is often used to enhance bank stabilization efforts and as part of more generalized restoration designs, but the influence of vegetation on geomorphic processes is poorly understood. Recent research suggests that changes in riparian vegetation can influence channel morphology, rates of erosion and deposition, and by extension, the entire sediment budget of a reach. In recent studies in the Mid-Atlantic region, reaches with forested riparian vegetation were compared to immediately adjacent non-forested (grassy) riparian vegetation to explain why channels with forested vegetation are wider than their non-forested counterparts. At study sites, erosion occurs at cutbanks in curving reaches, while deposition is localized on active floodplains at the insides of bends. In narrow, non-forested reaches, rates of bank erosion and channel migration are high, while in wide, forested reaches, rates of bank erosion and channel migration are low. These results may be explained using the ratio of two dimensionless parameters, alpha and E. Alpha represents the influence of vegetation on rates of active floodplain deposition (it is very high in non-forested reaches, and very low in forested reaches), while E is proportional to rates of cutbank migration (it is high in non-forested areas and low in forested areas). The width is proportional to E/alpha. These results could lead to improved assessment of the geomorphic effects of restoration designs that involve changes in riparian vegetation.

  20. Interactions between river channel processes and riparian vegetation - an example from the Lužnice River, Czech Republic

    NASA Astrophysics Data System (ADS)

    Krejci, Lukas; Macka, Zdenek

    2010-05-01

    -stream wood load and lowest rate of the present day bank erosion. Downstream reach woody vegetation is discontinuous, alternating with pastures. Riparian trees are the mixture of poplar, willow, alder and oak. The reach is highly sinuous with distinct meanders and laterally very dynamic. The channel width and depth are 15 m and 3,7 m respectively, the mean cross section area is 55,5 m2. The highest bank erosion was noted at the locations with pastures. The specific feature of this reach are fossil oak logs, which are exhumed from the alluvial sediments by the rapid lateral erosion. The enhanced incision and lateral erosion is the combined effect of riparian forest clearance and river training works (canalisation) downstream. The planform changes of the river since 1952 have been studied by analysis of the aerial images. It was derived that floodplain area of 12 450 m2, 16 318 m2 and 20 687 m2 was eroded, of which 10 465 m2, 8496 m2 and 10 733 m2 was wooded land at the upstream, middle and downstream reaches. We estimated that this rate of bank erosion delivered 644, 510 and 628 trees to the river channel since 1952. These numbers represent 390%, 1130% and 285% of the present day number of LW pieces in the river channel. Approximate turnover rates of LW can be estimated from these data. Present day rate of bank erosion and LW input is monitored at selected concave banks by repeated geodetic surveying. The Lužnice River has a sandy bed and LW modifies bed and bank morphology profoundly. We found that 33%, 29% and 36% of LW pieces caused localized erosion (pool formation) and 37%, 24% and 21 % caused local deposition at upstream, middle and downstream river reaches. The research was supported by Czech Science Foundation, grant no. 205/08/0926.

  1. Floodplain Heterogeneity Drives Riparian Vegetation Composition and Structure Through Channel Meander Migration and Channel Abandonment

    NASA Astrophysics Data System (ADS)

    Fremier, A. K.; Viers, J. H.; Hayden, M. K.; Stella, J. C.

    2008-12-01

    Riparian vegetation composition and structure reflect the legacy of fine- and coarse-scale patterns of hydrology, geomorphology and ecology. Understanding the dynamics of complex systems requires scaling-up mechanistic patterns and processes. Coupling hydro-geomorphic processes with vegetation development is an integral step in understanding habitat evolution in riparian corridors. We quantified floodplain deposition dynamics and topographic complexity to better understand how riparian forest structure and composition changed through time and over the floodplain. We used LiDAR data and a temporally-rich dataset of aerial photography coupled with field data to analyze landscape-scale patterns with species composition and floodplain dynamics. We examined the significance of two definable large-scale floodplain processes - meander migration and channel abandonment - that set-up the spatial structure of riparian forest dynamics. In addition, we analyzed the potential feedback of riparian vegetation on floodplain formation. Canopy structure and floodplain heterogeneity generally showed a log-linear relationship over time and were highly correlated with species composition changes over time and with a range of past hydrologies (inter- and intra- annual patterns). These data suggest that analysis of landscape formation processes, in particularly during the early stages, improves our understanding of riparian forest dynamics and that channel abandonment can be a significant alternative pathway to cottonwood recruitment. By analyzing the coupled eco-geomorphic processes we can more effectively scale-up riparian vegetation patterns by applying a functional knowledge of the corridor-wide channel dynamics and floodplain hydrology.

  2. Dew formation and its long-term trend in a desert riparian forest ecosystem on the eastern edge of the Taklimakan Desert in China

    NASA Astrophysics Data System (ADS)

    ayup, mubarek; Hao, Xing-ming

    2013-04-01

    Dewfall can be a substantial water resource crucial for maintaining water balance in desert ecosystems such as the hyper-arid zone of the Taklimakan Desert in China. However, little is known about the formation, quantitative characteristics, and factors influencing dewfall in this region. This study elucidates dew formation and its long-term trend in this region using observation data, including flux, meteorological, and soil water content data obtained using the Eddy covariance system and those recorded by weather station in the area. The results are as follows: (1) Dew forms in the Populus forest, with nighttime dewfall duration being about 2 h. The average daily dewfall amount during the observation period (June 4-October 24,2011) was 0.12 mm. The number of dewfall days was 104 days (73% of total days), and the cumulative dewfall amount was 12.87 mm. (2) The dewfall days and amount on the canopy and soil surfaces were 86 days and 8.64 mm, and 38 days and 4.23 mm, respectively. The top soil can absorb more water vapor than condensed dew. (3) At different time scales (half-hour, day, and half-year), obvious variations in dewfall duration, dewfall amounts, and meteorological factors occurred. (4) Over the past 51 years, changes in the number of dewfall days during the summer (June - October) exhibited a trend similar to that of changes in total dewfall amount during the same period. The average dewfall amount during the summer half-year was 17.2 mm, which is about 64% of the summer half-year rainfall and 50% of the annual rainfall. In particular, the total dewfall amount was higher than the annual rainfall amount during the one -fifth of the past 51 years. The study proved dewfall is one of the important water resources in the arid Taklimakan Desert region, and it also significantly influenced the water balance. Keywords: Dewfall; canopy condensation; Eddy covariance; meteorological factors; long-term trend

  3. Influence of Herbaceous Riparian Buffers on Fish and Amphibian Communities Within Channelized Headwater Streams in Central Ohio

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Herbaceous riparian buffers are a widely used conservation practice in the United States for reducing nutrient, pesticide, and sediment loadings in agricultural streams. The importance of forested riparian zones for headwater streams has been documented, but the ecological impacts of herbaceous ripa...

  4. Water relations of riparian plants from warm desert regions

    USGS Publications Warehouse

    Smith, S.D.; Devitt, Dale A.; Cleverly, James R.; Busch, David E.

    1998-01-01

    Riparian plants have been classified as 'drought avoiders' due to their access to an abundant subsurface water supply. Recent water-relations research that tracks water sources of riparian plants using the stable isotopes of water suggests that many plants of the riparian zone use ground water rather than stream water, and not all riparian plants are obligate phreatophytes (dependent on ground water as a moisture source) but may occasionally be dependent of unsaturated soil moisture sources. A more thorough understanding of riparian plant-water relations must include water-source dynamics and how those dynamics vary over both space and time. Many rivers in the desert Southwest have been invaded by the exotic shrub Tamarix ramosissima (saltcedar). Our studies of Tamarix invasion into habitats formerly dominated by native riparian forests of primarily Populus and Salix have shown that Tamarix successfully invades these habitats because of its (1) greater tolerance to water stress and salinity, (2) status as a facultative, rather than obligate, phreatophyte and, therefore, its ability to recover from droughts and periods of ground-water drawdown, and (3) superior regrowth after fire. Analysis of water- loss rates indicate that Tamarix-dominated stands can have extremely high evapotranspiration rates when water tables are high but not necessarily when water tables are lower. Tamarix has leaf-level transpiration rates that are comparable to native species, whereas sap-flow rates per unit sapwood area are higher than in natives, suggesting that Tamarix maintains higher leaf area than can natives, probably due to its greater water stress tolerance. Tamarix desiccates and salinizes floodplains, due to its salt exudation and high transpiration rates, and may also accelerate fire cycles, thus predisposing these ecosystems to further loss of native taxa. Riparian species on regulated rivers can be exposed to seasonal water stress due to depression of floodplain water tables

  5. Trade-offs between savanna woody plant diversity and carbon storage in the Brazilian Cerrado.

    PubMed

    Pellegrini, Adam F A; Socolar, Jacob B; Elsen, Paul R; Giam, Xingli

    2016-10-01

    Incentivizing carbon storage can be a win-win pathway to conserving biodiversity and mitigating climate change. In savannas, however, the situation is more complex. Promoting carbon storage through woody encroachment may reduce plant diversity of savanna endemics, even as the diversity of encroaching forest species increases. This trade-off has important implications for the management of biodiversity and carbon in savanna habitats, but has rarely been evaluated empirically. We quantified the nature of carbon-diversity relationships in the Brazilian Cerrado by analyzing how woody plant species richness changed with carbon storage in 206 sites across the 2.2 million km(2) region at two spatial scales. We show that total woody plant species diversity increases with carbon storage, as expected, but that the richness of endemic savanna woody plant species declines with carbon storage both at the local scale, as woody biomass accumulates within plots, and at the landscape scale, as forest replaces savanna. The sharpest trade-offs between carbon storage and savanna diversity occurred at the early stages of carbon accumulation at the local scale but the final stages of forest encroachment at the landscape scale. Furthermore, the loss of savanna species quickens in the final stages of forest encroachment, and beyond a point, savanna species losses outpace forest species gains with increasing carbon accumulation. Our results suggest that although woody encroachment in savanna ecosystems may provide substantial carbon benefits, it comes at the rapidly accruing cost of woody plant species adapted to the open savanna environment. Moreover, the dependence of carbon-diversity trade-offs on the amount of savanna area remaining requires land managers to carefully consider local conditions. Widespread woody encroachment in both Australian and African savannas and grasslands may present similar threats to biodiversity. PMID:26919289

  6. Riparian vegetation controls on the hydraulic geometry of streams

    NASA Astrophysics Data System (ADS)

    McBride, M.

    2010-12-01

    A synthesis of field measurements, remote observations, and numerical modeling techniques highlights the significance of riparian vegetation in determining the geometry of streams and impacting sediment transport dynamics in temperate, Piedmont regions. Specifically, forested and grassy riparian vegetation establish streams with significantly different widths and with different timescales for attaining a state of dynamic equilibrium. The interactions between riparian vegetation, channel form, and channel dynamics are scale dependent. Scale dependency arises because of variations in ratios of vegetation length scales and geomorphic scales (e.g., channel width and depth). Stream reaches with grassy vegetation experience more frequent overbank discharges, migrate more quickly, and exhibit a more classic dynamic equilibrium than forested reaches. These phenomena are relevant to current watershed management efforts that aim to reduce sediment and nutrient loads to receiving water bodies, such as the Chesapeake Bay. The reforestation of riparian buffers is a common restoration technique that intends to improve water quality, temperature regimes, and in-stream physical habitat. Passive reforestation of riparian areas along a tributary to Sleepers River in Danville, VT, USA caused an increase in channel width and cross-sectional area over a 40-year period. From a comparison of historical records and current cross-sectional dimensions, the channel widening resulted in the mobilization of approximately 85 kg/ha/yr of floodplain sediments. Long-term monitoring of suspended sediments in an adjacent watershed indicates that this sediment source may account for roughly 40 percent of the total suspended sediment load. In some instances, increased sediment loads associated with channel widening may be an unforeseen consequence that compromises riparian restoration efforts.

  7. RIPARIAN CHARACTERIZATION USING SUB-PIXEL ANALYSIS OF LANDSAT TM IMAGERY FOR USE IN ECOLOGICAL RISK ASSESSMENT

    EPA Science Inventory

    Landuse/land cover and riparian corridor characterization for 7 major watersheds in western Ohio was accomplished using sub-pixel analysis and traditional classification techniques. Areas
    representing forest, woodland, shrub, and herbaceous vegetation were delineated using a ...

  8. Landowners' Knowledge, Attitudes, and Aspirations towards Woody Biomass Markets in North Carolina

    ERIC Educational Resources Information Center

    Shaw, Jasmine; Hazel, Dennis; Bardon, Robert; Jayaratne, K. S. U.

    2012-01-01

    Non-industrial private forest (NIPF) landowners are often not included in discussions of emerging woody biomass markets for energy, yet they will likely be principal suppliers of the resource. Surveys administered to 475 forest landowners before and after an Extension Forestry education program in 10 counties across North Carolina indicated that…

  9. Riparian deforestation, stream narrowing, and loss of stream ecosystem services.

    PubMed

    Sweeney, Bernard W; Bott, Thomas L; Jackson, John K; Kaplan, Louis A; Newbold, J Denis; Standley, Laurel J; Hession, W Cully; Horwitz, Richard J

    2004-09-28

    A study of 16 streams in eastern North America shows that riparian deforestation causes channel narrowing, which reduces the total amount of stream habitat and ecosystem per unit channel length and compromises in-stream processing of pollutants. Wide forest reaches had more macroinvertebrates, total ecosystem processing of organic matter, and nitrogen uptake per unit channel length than contiguous narrow deforested reaches. Stream narrowing nullified any potential advantages of deforestation regarding abundance of fish, quality of dissolved organic matter, and pesticide degradation. These findings show that forested stream channels have a wider and more natural configuration, which significantly affects the total in-stream amount and activity of the ecosystem, including the processing of pollutants. The results reinforce both current policy of the United States that endorses riparian forest buffers as best management practice and federal and state programs that subsidize riparian reforestation for stream restoration and water quality. Not only do forest buffers prevent nonpoint source pollutants from entering small streams, they also enhance the in-stream processing of both nonpoint and point source pollutants, thereby reducing their impact on downstream rivers and estuaries. PMID:15381768

  10. Riparian deforestation, stream narrowing, and loss of stream ecosystem services

    PubMed Central

    Sweeney, Bernard W.; Bott, Thomas L.; Jackson, John K.; Kaplan, Louis A.; Newbold, J. Denis; Standley, Laurel J.; Hession, W. Cully; Horwitz, Richard J.

    2004-01-01

    A study of 16 streams in eastern North America shows that riparian deforestation causes channel narrowing, which reduces the total amount of stream habitat and ecosystem per unit channel length and compromises in-stream processing of pollutants. Wide forest reaches had more macroinvertebrates, total ecosystem processing of organic matter, and nitrogen uptake per unit channel length than contiguous narrow deforested reaches. Stream narrowing nullified any potential advantages of deforestation regarding abundance of fish, quality of dissolved organic matter, and pesticide degradation. These findings show that forested stream channels have a wider and more natural configuration, which significantly affects the total in-stream amount and activity of the ecosystem, including the processing of pollutants. The results reinforce both current policy of the United States that endorses riparian forest buffers as best management practice and federal and state programs that subsidize riparian reforestation for stream restoration and water quality. Not only do forest buffers prevent nonpoint source pollutants from entering small streams, they also enhance the in-stream processing of both nonpoint and point source pollutants, thereby reducing their impact on downstream rivers and estuaries. PMID:15381768

  11. METHODS TO PRIORITIZE PLACEMENT OF RIPARIAN BUFFERS FOR IMPROVED WATER QUALITY

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Riparian forest buffers can improve stream water quality, provided they intercept and remove contaminants from surface runoff and/or shallow groundwater. Soils, topography, hydrology, and surficial geology determine the capability of forest buffers to intercept and treat these flows. This paper desc...

  12. Bryophyte species associations with coarse woody debris and stand ages in Oregon

    USGS Publications Warehouse

    Rambo, T.; Muir, Patricia S.

    1998-01-01

    We quantified the relationships of 93 forest floor bryophyte species, including epiphytes from incorporated litterfall, to substrate and stand age in Pseudotsuga menziesii-Tsuga heterophylla stands at two sites in western Oregon. We used the method of Dufr??ne and Legendre that combines a species' relative abundance and relative frequency, to calculate that species' importance in relation to environmental variables. The resulting 'indicator value' describes a species' reliability for indicating the given environmental parameter. Thirty-nine species were indicative of either humus, a decay class of coarse woody debris, or stand age. Bryophyte community composition changed along the continuum of coarse woody debris decomposition from recently fallen trees with intact bark to forest floor humus. Richness of forest floor bryophytes will be enhanced when a full range of coarse woody debris decay classes is present. A suite of bryophytes indicated old-growth forest. These were mainly either epiphytes associated with older conifers or liverworts associated with coarse woody debris. Hardwood-associated epiphytes mainly indicated young stands. Mature conifers, hardwoods, and coarse woody debris are biological legacies that can be protected when thinning managed stands to foster habitat complexity and biodiversity, consistent with an ecosystem approach to forest management.

  13. Interactions of woody biofuel feedstock production systems with water resources: Considerations for sustainability.

    SciTech Connect

    Trettin, Carl,C.; Amatya, Devendra; Coleman, Mark.

    2008-07-01

    Abstract. Water resources are important for the production of woody biofuel feedstocks. It is necessary to ensure that production systems do not adversely affect the quantity or quality of surface and ground water. The effects of woody biomass plantations on water resources are largely dependent on the prior land use and the management regime. Experience from both irrigated and non-irrigated systems has demonstrated that woody biofuel production systems do not impair water quality. Water quality actually improves from conversion of idle or degraded agricultural lands to woody biomass plantations. Site water balance may be altered by cultivation of woody biomass plantations relative to agricultural use, due to increases in evapostranspiration (ET) and storage. Incorporation of woody biomass production plantations within the landscape provides an opportunity to improve the quality of runoff water and soil conservation. Given the centrality of water resources to the sustainability of ecosystem services and other values derived, the experience with woody biofuels feedstock production systems is positive. Keywords. Short rotation woody crop, forest hydrology, water quality, hardwood plantation.

  14. Evaluating woody material transport and deposition in alpine rivers and deducing risk mitigation approaches

    NASA Astrophysics Data System (ADS)

    Mazzorana, B.; Zischg, A.; Hübl, J.; Largiader, A.

    2009-04-01

    The impact levels of recent flashflood events in Switzerland and Western Austria in 2005 have significantly been accentuated by a considerable amount of transported woody material. As a consequence, either protection measures or bridges suffered considerable damage. Furthermore, cross-sectional obstructions due to woody material entrapment caused unexpected floodplain inundations resulting in severe damage to elements at risk. Until now, these woody material transport phenomena are neither sufficiently taken into account nor systematically considered, leading to a decrease in prediction accuracy during the procedure of hazard mapping. To close this gap, a procedure is proposed that (1) allows for the estimation of woody material recruitment from wood covered bankslopes and floodplains within the perimeter of the considered extreme flood event; and (2) permits the analysis of, the disposition for woody material entrainment and transport to selected critical configurations along the channel. The proposed procedure had been implemented into an ArcGIS-environment and provided indications for potential accentuation of flood hazards due to the transport of woody material. Results from a case study suggested the general applicability of the concept. The computational results can be used to devise effective risk mitigation strategies that comprise: (1) selective woody material volume reduction within the source areas, (2) thinning measures to increase the elasticity of the forest structure, (3) preventive interception of transported woody material and (4) redesign of the critical configurations.

  15. Influence of riparian habitat on aquatic macroinvertebrate community colonization within riparian zones of agricultural headwater streams

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Little is known about aquatic macroinvertebrate colonization of aquatic habitats within riparian zones of headwater streams in the Midwestern United States. Many headwater streams and their riparian habitats in this region have been modified for agricultural drainage. Riparian habitat modifications ...

  16. Multiyear riparian evapotranspiration and groundwater use for a semiarid watershed

    USGS Publications Warehouse

    Scott, R.L.; Cable, W.L.; Huxman, T. E.; Nagler, P.L.; Hernandez, M.; Goodrich, D.C.

    2008-01-01

    Riparian evapotranspiration (ET) is a major component of the surface and subsurface water balance for many semiarid watersheds. Measurement or model-based estimates of ET are often made on a local scale, but spatially distributed estimates are needed to determine ET over catchments. In this paper, we document the ET that was quantified over 3 years using eddy covariance for three riparian ecosystems along the Upper San Pedro River of southeastern Arizona, USA, and we use a water balance equation to determine annual groundwater use. Riparian evapotranspiration and groundwater use for the watershed were then determined by using a calibrated, empirical model that uses 16-day, 250-1000 m remote-sensing products for the years of 2001-2005. The inputs for the model were derived entirely from the NASA MODIS sensor and consisted of the Enhanced Vegetation Index and land surface temperature. The scaling model was validated using subsets of the entire dataset (omitting different sites or years) and its capable performance for well-watered sites (MAD=0.32 mm day-1, R2=0.93) gave us confidence in using it to determine ET over the watershed. Three years of eddy covariance data for the riparian sites reveal that ET and groundwater use increased as woody plant density increased. Groundwater use was less variable at the woodland site, which had the greatest density of phreatophytes. Annual riparian groundwater use within the watershed was nearly constant over the study period despite an on-going drought. For the San Pedro alone, the amounts determined in this paper are within the range of most recently reported values that were derived using an entirely different approach. However, because of our larger estimates for groundwater use for the main tributary of the San Pedro, the watershed totals were higher. The approach presented here can provide riparian ET and groundwater use amounts that reflect real natural variability in phreatophyte withdrawals and improve the accuracy of a

  17. Predicting the impact of water demand and river flow regulation over riparian vegetation through mathematical modeling

    NASA Astrophysics Data System (ADS)

    Garcia-Arias, A.; Pons, C.; Frances, F.

    2013-12-01

    The vegetation of the riversides is a main part of the complex riparian ecosystems and has an important role maintaining the fluvial ecosystems. Biotic and abiotic interactions between the river and the riverbank are essential for the subsistence and the development of both ecosystems. In semi-arid Mediterranean areas, the riparian vegetation growth and distribution is especially controlled by the water accessibility, determining the limit between the lush riparian bands and the sparse upland. Human intervention can alter the river hydrology determining the riparian vegetation wellbeing and its distribution and, in consequence, affecting both riparian and fluvial ecosystems. Predictive models are necessary decision support tools for adequate river management and restoration initiatives. In this context, the RibAV model is useful to predict the impact of water demand and river flow regulation on the riparian vegetation. RibAV is able to reproduce the vegetation performance on the riverside allowing the scenarios analysis in terms of vegetation distribution and wellbeing. In this research several flow regulation and water demand scenarios are proposed and the impacts over three plant functional types (PFTs) are analyzed. The PFTs group the herbaceous riparian plants, the woody riparian plants and the terrestrial vegetation. The study site is the Terde reach at the Mijares River, a 539m length reach located in a semi-arid Mediterranean area in Spain. The scenarios represent river flow alterations required to attend different human demands. These demands encompass different seasonality, magnitude and location. The seasonality is represented as hydroelectric (constant all over the year), urban (increased during the summer period) and agricultural demands (monthly seasonality). The magnitude is varied considering the 20%, the 40% and the 80% of the mean daily flow. Two locations are considered, upstream or downstream the study site. To attend the demands located

  18. Remote sensing approach to map riparian vegetation of the Colorado River Ecosystem, Grand Canyon area, Arizona

    NASA Astrophysics Data System (ADS)

    Nguyen, U.; Glenn, E.; Nagler, P. L.; Sankey, J. B.

    2015-12-01

    Riparian zones in the southwestern U.S. are usually a mosaic of vegetation types at varying states of succession in response to past floods or droughts. Human impacts also affect riparian vegetation patterns. Human- induced changes include introduction of exotic species, diversion of water for human use, channelization of the river to protect property, and other land use changes that can lead to deterioration of the riparian ecosystem. This study explored the use of remote sensing to map an iconic stretch of the Colorado River in the Grand Canyon National Park, Arizona. The pre-dam riparian zone in the Grand Canyon was affected by annual floods from spring run-off from the watersheds of Green River, the Colorado River and the San Juan River. A pixel-based vegetation map of the riparian zone in the Grand Canyon, Arizona, was produced from high-resolution aerial imagery. The map was calibrated and validated with ground survey data. A seven-step image processing and classification procedure was developed based on a suite of vegetation indices and classification subroutines available in ENVI Image Processing and Analysis software. The result was a quantitative species level vegetation map that could be more accurate than the qualitative, polygon-based maps presently used on the Lower Colorado River. The dominant woody species in the Grand Canyon are now saltcedar, arrowweed and mesquite, reflecting stress-tolerant forms adapted to alternated flow regimes associated with the river regulation.

  19. A sustainable woody biomass biorefinery.

    PubMed

    Liu, Shijie; Lu, Houfang; Hu, Ruofei; Shupe, Alan; Lin, Lu; Liang, Bin

    2012-01-01

    Woody biomass is renewable only if sustainable production is imposed. An optimum and sustainable biomass stand production rate is found to be one with the incremental growth rate at harvest equal to the average overall growth rate. Utilization of woody biomass leads to a sustainable economy. Woody biomass is comprised of at least four components: extractives, hemicellulose, lignin and cellulose. While extractives and hemicellulose are least resistant to chemical and thermal degradation, cellulose is most resistant to chemical, thermal, and biological attack. The difference or heterogeneity in reactivity leads to the recalcitrance of woody biomass at conversion. A selection of processes is presented together as a biorefinery based on incremental sequential deconstruction, fractionation/conversion of woody biomass to achieve efficient separation of major components. A preference is given to a biorefinery absent of pretreatment and detoxification process that produce waste byproducts. While numerous biorefinery approaches are known, a focused review on the integrated studies of water-based biorefinery processes is presented. Hot-water extraction is the first process step to extract value from woody biomass while improving the quality of the remaining solid material. This first step removes extractives and hemicellulose fractions from woody biomass. While extractives and hemicellulose are largely removed in the extraction liquor, cellulose and lignin largely remain in the residual woody structure. Xylo-oligomers, aromatics and acetic acid in the hardwood extract are the major components having the greatest potential value for development. Higher temperature and longer residence time lead to higher mass removal. While high temperature (>200°C) can lead to nearly total dissolution, the amount of sugars present in the extraction liquor decreases rapidly with temperature. Dilute acid hydrolysis of concentrated wood extracts renders the wood extract with monomeric sugars

  20. Reforestation of bottomland hardwoods and the issue of woody species diversity

    USGS Publications Warehouse

    Allen, J.A.

    1997-01-01

    Bottomland hardwood forests in the southcentral United States have been cleared extensively for agriculture, and many of the remaining forests are fragmented and degraded. During the last decade, however, approximately 75,000 ha of land-mainly agricultural fields-have been replanted or contracted for replanting, with many more acres likely to be reforested in the near future. The approach used in most reforestation projects to date has been to plant one to three overstory tree species, usually Quercus spp. (oaks), and to rely on natural dispersal for the establishment of other woody species. I critique this practice by two means. First, a brief literature review demonstrates that moderately high woody species diversity occurs in natural bottomland hardwood forests in the region. This review, which relates diversity to site characteristics, serves as a basis for comparison with stands established by means of current reforestation practices. Second, I reevaluate data on the invasion of woody species from an earlier study of 10 reforestation projects in Mississippi,with the goal of assessing the likelihood that stands with high woody species diversity will develop. I show that natural invasion cannot always be counted on to produce a diverse stand, particularly on sites more than about 60 m from an existing forest edge. I then make several recommendations for altering current reforestation pactices in order to establish stands with greater woody species diversity, a more natural appearance,and a more positive environmental impact at scales larger than individual sites.

  1. Size of coarse woody debris 5 years after girdling and removal treatments in 50-year-old Loblolly PIne Plantations

    SciTech Connect

    Edwards, M. Boyd

    2004-01-01

    PP 108 -113 in: Connor, Kristina F., ed. 2004. Proceedings of the 12th biennial southern silvicultural research conference. Gen. Tech. Rep. SRS71. Asheville, NC: U.S. Department of Agriculture, Forest Service, Southern Research Station. 594 p. Abstract: In 1996, a study began at Savannah River Site to investigate large-scale replicated forest areas to control coarse woody debris for integrated biodiversity objectives. Research design was a randomized complete block with four treatments replicated in four blocks, resulting in 16 plots. The treatments applied to 50-year-old loblolly pine stands were (1) control, (2) girdling of 25 percent of trees to create catastrophic simulation, (3) annual removal of down woody debris > 10 cm in diameter, and (4) annual removal of both standing and down woody debris > 10 cm in diameter. The study tracks coarse woody debris recruitment and loading, rates of decomposition, and effects on the forest ecosystem.

  2. Structure and diversity of phyllostomid bat assemblages on riparian corridors in a human-dominated tropical landscape

    PubMed Central

    de la Peña-Cuéllar, Erika; Benítez-Malvido, Julieta; Avila-Cabadilla, Luis Daniel; Martínez-Ramos, Miguel; Estrada, Alejandro

    2015-01-01

    Tropical forests around the world have been lost, mainly because of agricultural activities. Linear elements like riparian vegetation in fragmented tropical landscapes help maintain the native flora and fauna. Information about the role of riparian corridors as a reservoir of bat species, however, is scanty. We assessed the value of riparian corridors on the conservation of phyllostomid bat assemblage in an agricultural landscape of southern Mexico. For 2 years (2011–2013), mist-netting at ground level was carried out twice during the dry season (December to May) and twice during the wet season (June to November) in different habitats: (1) riparian corridors in mature forest, (2) riparian corridors in pasture, (3) continuous forest away from riparian vegetation, and (4) open pastures. Each habitat was replicated three times. To determine the influence of vegetation structure on bat assemblages, all trees (≥10 cm dbh) were sampled in all habitats. Overall, 1752 individuals belonging to 28 species of Phyllostomidae were captured with Sternodermatinae being the most rich and abundant subfamily. Riparian corridors in mature forest and pastures had the greatest species richness and shared 65% of all species. Open pastures had the lowest richness and abundance of bats with no Phyllostominae species recorded. Six of the 18 species recorded could be considered as habitat indicators. There was a positive relationship between bat species composition and tree basal area. Our findings suggest that contrary to our expectations, bats with generalist habits and naturally abundant could be useful detector taxa of habitat modification, rather than bats strongly associated with undisturbed forest. Also in human-dominated landscapes, the maintenance of habitat elements such as large trees in riparian corridors can serve as reservoirs for bat species, especially for those that are strongly associated with undisturbed forest. PMID:25750716

  3. Structure and diversity of phyllostomid bat assemblages on riparian corridors in a human-dominated tropical landscape.

    PubMed

    de la Peña-Cuéllar, Erika; Benítez-Malvido, Julieta; Avila-Cabadilla, Luis Daniel; Martínez-Ramos, Miguel; Estrada, Alejandro

    2015-02-01

    Tropical forests around the world have been lost, mainly because of agricultural activities. Linear elements like riparian vegetation in fragmented tropical landscapes help maintain the native flora and fauna. Information about the role of riparian corridors as a reservoir of bat species, however, is scanty. We assessed the value of riparian corridors on the conservation of phyllostomid bat assemblage in an agricultural landscape of southern Mexico. For 2 years (2011-2013), mist-netting at ground level was carried out twice during the dry season (December to May) and twice during the wet season (June to November) in different habitats: (1) riparian corridors in mature forest, (2) riparian corridors in pasture, (3) continuous forest away from riparian vegetation, and (4) open pastures. Each habitat was replicated three times. To determine the influence of vegetation structure on bat assemblages, all trees (≥10 cm dbh) were sampled in all habitats. Overall, 1752 individuals belonging to 28 species of Phyllostomidae were captured with Sternodermatinae being the most rich and abundant subfamily. Riparian corridors in mature forest and pastures had the greatest species richness and shared 65% of all species. Open pastures had the lowest richness and abundance of bats with no Phyllostominae species recorded. Six of the 18 species recorded could be considered as habitat indicators. There was a positive relationship between bat species composition and tree basal area. Our findings suggest that contrary to our expectations, bats with generalist habits and naturally abundant could be useful detector taxa of habitat modification, rather than bats strongly associated with undisturbed forest. Also in human-dominated landscapes, the maintenance of habitat elements such as large trees in riparian corridors can serve as reservoirs for bat species, especially for those that are strongly associated with undisturbed forest. PMID:25750716

  4. Population structure, physiology and ecohydrological impacts of dioecious riparian tree species of western North America.

    PubMed

    Hultine, K R; Bush, S E; West, A G; Ehleringer, J R

    2007-11-01

    The global water cycle is intimately linked to vegetation structure and function. Nowhere is this more apparent than in the arid west where riparian forests serve as ribbons of productivity in otherwise mostly unproductive landscapes. Dioecy is common among tree species that make up western North American riparian forests. There are intrinsic physiological differences between male and female dioecious riparian trees that may influence population structure (i.e., the ratio of male to female trees) and impact ecohydrology at large scales. In this paper, we review the current literature on sex ratio patterns and physiology of dioecious riparian tree species. Then develop a conceptual framework of the mechanisms that underlie population structure of dominant riparian tree species. Finally, we identify linkages between population structure and ecohydrological processes such as evapotranspiration and streamflow. A more thorough understanding of the mechanisms that underlie population structure of dominant riparian tree species will enable us to better predict global change impacts on vegetation and water cycling at multiple scales. PMID:17665219

  5. Effect of downed woody debris on small mammal anti-predator behavior.

    SciTech Connect

    Hinkleman, Travis, M.; Orrock, John, L.; Loeb, Susan, C.

    2011-10-01

    Anti-predator behavior can affect prey growth, reproduction, survival, and generate emergent effects in food webs. Small mammals often lower the cost of predation by altering their behavior in response to shrubs,but the importance of other microhabitat features, such as downed woody debris, for anti-predator behavior is unknown. We used givingup densities to quantify the degree to which downed woody debris alters perceived predation risk by small mammals in southeastern pineforests. We placed 14 foraging trays next to large downed woody debris,shrubs, and in open areas for 12 consecutive nights. Moon illumination, a common indicator of predation risk, led to a similar reduction in small mammal foraging in all three microhabitats (open, downed woody debris,and shrub). Small mammals perceived open microhabitats as riskier than shrub microhabitats, with downed woody debris habitats perceived as being of intermediate risk between shrub and open microhabitats. Despite the presumed benefits of the protective cover of downed woody debris, small mammals may perceive downed woody debris as a relatively risky foraging site in southeastern pine forests where the high diversity and abundance of rodent-eating snakes may provide a primary predatory threat.

  6. Long-term decrease in satellite vegetation indices in response to environmental variables in an iconic desert riparian ecosystem: the Upper San Pedro, Arizona, USA

    Technology Transfer Automated Retrieval System (TEKTRAN)

    1. The Upper San Pedro River is one of the few remaining undammed rivers that maintains a vibrant riparian ecosystem in the southwest U.S. Its riparian forest is threatened by diminishing groundwater and surface water inputs, attributed by different studies to either (1) changes in watershed charact...

  7. The spatial pattern and dominant drivers of woody cover change in Latin America and Caribbean from 2001 to 2010

    NASA Astrophysics Data System (ADS)

    Clark, M.; Aide, T.; Riner, G.; Redo, D.; Grau, H.; Bonilla-Moheno, M.; Lopez-Carr, D.; Levy, M.

    2011-12-01

    Change in woody vegetation (i.e., forests, shrublands) is a major component of global environmental change: it directly affects biodiversity, the global carbon budget, and ecosystem function. For several decades, remote sensing technology has been used to document deforestation in Latin America and the Caribbean (LAC), although mostly at local to regional scales (e.g., moist forests of the Amazon basin). Most studies have focused on forest loss, some local-scale studies have mapped forest recovery, with contrasting forest dynamics attributed to shifting demographic and socio-economic factors. For example, local population change (rural-urban migration) can stimulate forest recovery on abandoned land, while increasing global food demand may drive regional expansion of mechanized agriculture. However, there are no studies in LAC that simultaneously map both loss and gain in woody vegetation at continental, national, and municipality scales with consistent data sources, methods and accuracy; and thus, we lack a comprehensive assessment of the spatial distribution of woody vegetation change and the relative importance of the multi-scale drivers of this change. We overcame this limitation by producing annual land-cover maps between 2001 and 2010 for each of the >16,000 municipalities in LAC. We focused on mapping municipality-scale trends in three broad classes: woody vegetation, mixed woody/plantations, and agriculture/herbaceous vegetation. Our area estimates show that woody vegetation change during the past decade was dominated by deforestation, or loss (-541,830 km2), particularly in the Amazon basin moist forest and the tropical-subtropical Cerrado and Chaco ecoregions, where large swaths of forest have been transformed to pastures and agricultural lands. Extensive areas (362,431 km2) in LAC also gained woody vegetation, particularly in regions too dry or too steep for modern agriculture, including the desert/xeric shrub biome in NE Brazil and northern Mexico, the

  8. Fire effects on tropical woody vegetation structure have been exaggerated?

    NASA Astrophysics Data System (ADS)

    Veenendaal, Elmar; Torello-Raventos, Mireia; Miranda, Heloisa; Sato, Naomi; Oliveras-Menor, Imma; Van Langevelde, Frank; Lloyd, Jon

    2015-04-01

    Since the beginning of the 20th century scientists, particularly those working in Africa, have proposed a major impact of fire frequency and intensity on woody vegetation leading to concepts such as "fire derived" savannas and "fire-mediated" feedbacks. Particularly in contact zones between forests and savannas the role of fire has been proposed as the driving agent of replacement of fire-sensitive forest-associated species with fire sensitive "fire resistant" savanna species and transition from closed forest vegetation to open savanna vegetation. In this presentation we will provide a global synthesis of the fire experiment literature with an aim to determine if general patterns can be established in terms of magnitude of fire effects on tropical vegetation structure in terms of (a) season and frequency of burning; (b) vegetation structure in the absence of fire and (c) climate. With this body of empirical data and a simple simulation model we examine if, the impact of fire on tropical woody cover as currently presented in the literature and the role of fire-mediated feedbacks in forest-savanna transitions can be justified by empirical data emanating from long term fire experiments

  9. The role of short-rotation woody crops in sustainable development

    SciTech Connect

    Shepard, J.P.; Tolbert, V.R.

    1996-12-31

    One answer to increase wood production is by increasing management intensity on existing timberland, especially in plantation forests. Another is to convert land currently in agriculture to timberland. Short-rotation woody crops can be used in both cases. But, what are the environmental consequences? Short-rotation woody crops can provide a net improvement in environmental quality at both local and global scales. Conversion of agricultural land to short-rotation woody crops can provide the most environmental quality enhancement by reducing erosion, improving soil quality, decreasing runoff, improving groundwater quality, and providing better wildlife habitat. Forest products companies can use increased production from intensively managed short-rotation woody crop systems to offset decreased yield from the portion of their timberland that is managed less intensively, e.g. streamside management zones and other ecologically sensitive or unique areas. At the global scale, use of short-rotation woody crops for bioenergy is part of the solution to reduce greenhouse gases produced by burning fossil fuels. Incorporating short-rotation woody crops into the agricultural landscape also increases storage of carbon in the soil, thus reducing atmospheric concentrations. In addition, use of wood instead of alternatives such as steel, concrete, and plastics generally consumes less energy and produces less greenhouse gases. Cooperative research can be used to achieve energy, fiber, and environmental goals. This paper will highlight several examples of ongoing cooperative research projects that seek to enhance the environmental aspects of short-rotation woody crop systems. Government, industry, and academia are conducting research to study soil quality, use of mill residuals, nutrients in runoff and groundwater, and wildlife use of short-rotation woody crop systems in order to assure the role of short-rotation crops as a sustainable way of meeting society`s needs.

  10. Maximizing Benefits from Riparian Revegetation Efforts: Local- and Landscape-Level Determinants of Avian Response

    NASA Astrophysics Data System (ADS)

    Gardali, Thomas; Holmes, Aaron L.

    2011-07-01

    With limited financial resources available for habitat restoration, information that ensures and/or accelerates success is needed to economize effort and maximize benefit. In the Central Valley of California USA, riparian habitat has been lost or degraded, contributing to the decline of riparian-associated birds and other wildlife. Active restoration of riparian plant communities in this region has been demonstrated to increase local population sizes and species diversity of landbirds. To evaluate factors related to variation in the rate at which bird abundance increased after restoration, we examined bird abundance as a function of local (restoration design elements) and landscape (proportion of riparian vegetation in the landscape and riparian patch density) metrics at 17 restoration projects within five project areas along the Sacramento River. We developed a priori model sets for seven species of birds and used an information theoretic approach to identify factors associated with the rate at which bird abundance increased after restoration. For six of seven species investigated, the model with the most support contained a variable for the amount of riparian forest in the surrounding landscape. Three of seven bird species were positively correlated with the number of tree species planted and three of seven were positively correlated with the planting densities of particular tree species. Our results indicate that restoration success can be enhanced by selecting sites near existing riparian habitat and planting multiple tree species. Hence, given limited resources, efforts to restore riparian habitat for birds should focus on landscape-scale site selection in areas with high proportions of existing riparian vegetation.

  11. Determinants of Tree Assemblage Composition at the Mesoscale within a Subtropical Eucalypt Forest

    PubMed Central

    Hero, Jean-Marc; Butler, Sarah A.; Lollback, Gregory W.; Castley, James G.

    2014-01-01

    A variety of environmental processes, including topography, edaphic and disturbance factors can influence vegetation composition. The relative influence of these patterns has been known to vary with scale, however, few studies have focused on environmental drivers of composition at the mesoscale. This study examined the relative importance of topography, catchment flow and soil in influencing tree assemblages in Karawatha Forest Park; a South-East Queensland subtropical eucalypt forest embedded in an urban matrix that is part of the Terrestrial Ecosystem Research Network South-East Queensland Peri-urban SuperSite. Thirty-three LTER plots were surveyed at the mesoscale (909 ha), where all woody stems ≥1.3 m high rooted within plots were sampled. Vegetation was divided into three cohorts: small (≥1–10 cm DBH), intermediate (≥10–30 cm DBH), and large (≥30 cm DBH). Plot slope, aspect, elevation, catchment area and location and soil chemistry and structure were also measured. Ordinations and smooth surface modelling were used to determine drivers of vegetation assemblage in each cohort. Vegetation composition was highly variable among plots at the mesoscale (plots systematically placed at 500 m intervals). Elevation was strongly related to woody vegetation composition across all cohorts (R2: 0.69–0.75). Other topographic variables that explained a substantial amount of variation in composition were catchment area (R2: 0.43–0.45) and slope (R2: 0.23–0.61). Soil chemistry (R2: 0.09–0.75) was also associated with woody vegetation composition. While species composition differed substantially between cohorts, the environmental variables explaining composition did not. These results demonstrate the overriding importance of elevation and other topographic features in discriminating tree assemblage patterns irrespective of tree size. The importance of soil characteristics to tree assemblages was also influenced by topography, where ridge top sites were

  12. Determinants of tree assemblage composition at the mesoscale within a subtropical eucalypt forest.

    PubMed

    Hero, Jean-Marc; Butler, Sarah A; Lollback, Gregory W; Castley, James G

    2014-01-01

    A variety of environmental processes, including topography, edaphic and disturbance factors can influence vegetation composition. The relative influence of these patterns has been known to vary with scale, however, few studies have focused on environmental drivers of composition at the mesoscale. This study examined the relative importance of topography, catchment flow and soil in influencing tree assemblages in Karawatha Forest Park; a South-East Queensland subtropical eucalypt forest embedded in an urban matrix that is part of the Terrestrial Ecosystem Research Network South-East Queensland Peri-urban SuperSite. Thirty-three LTER plots were surveyed at the mesoscale (909 ha), where all woody stems ≥1.3 m high rooted within plots were sampled. Vegetation was divided into three cohorts: small (≥1-10 cm DBH), intermediate (≥10-30 cm DBH), and large (≥30 cm DBH). Plot slope, aspect, elevation, catchment area and location and soil chemistry and structure were also measured. Ordinations and smooth surface modelling were used to determine drivers of vegetation assemblage in each cohort. Vegetation composition was highly variable among plots at the mesoscale (plots systematically placed at 500 m intervals). Elevation was strongly related to woody vegetation composition across all cohorts (R2: 0.69-0.75). Other topographic variables that explained a substantial amount of variation in composition were catchment area (R2: 0.43-0.45) and slope (R2: 0.23-0.61). Soil chemistry (R2: 0.09-0.75) was also associated with woody vegetation composition. While species composition differed substantially between cohorts, the environmental variables explaining composition did not. These results demonstrate the overriding importance of elevation and other topographic features in discriminating tree assemblage patterns irrespective of tree size. The importance of soil characteristics to tree assemblages was also influenced by topography, where ridge top sites were typically drier

  13. Estimating pesticide retention efficacy for edge-of-field buffers using the Riparian Ecosystem Management Model (REMM) in a Southeastern Plains Landscape

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Erosion and agrichemical runoff are persistent natural resource concerns. Remedial practices designed to reduce impacts including replacing conventional with conservation-tillage management and maintaining and restoring riparian forests and wetlands as buffers for water resource protection. To effec...

  14. Vulnerability of riparian ecosystems to elevated CO2 and climate change in arid and semiarid western North America

    USGS Publications Warehouse

    Perry, Laura G.; Andersen, Douglas C.; Reynolds, Lindsay V.; Nelson, S. Mark; Shafroth, Patrick B.

    2012-01-01

    Riparian ecosystems, already greatly altered by water management, land development, and biological invasion, are being further altered by increasing atmospheric CO2 concentrations ([CO2]) and climate change, particularly in arid and semiarid (dryland) regions. In this literature review, we (1) summarize expected changes in [CO2], climate, hydrology, and water management in dryland western North America, (2) consider likely effects of those changes on riparian ecosystems, and (3) identify critical knowledge gaps. Temperatures in the region are rising and droughts are becoming more frequent and intense. Warmer temperatures in turn are altering river hydrology: advancing the timing of spring snow melt floods, altering flood magnitudes, and reducing summer and base flows. Direct effects of increased [CO2] and climate change on riparian ecosystems may be similar to effects in uplands, including increased heat and water stress, altered phenology and species geographic distributions, and disrupted trophic and symbiotic interactions. Indirect effects due to climate-driven changes in streamflow, however, may exacerbate the direct effects of warming and increase the relative importance of moisture and fluvial disturbance as drivers of riparian ecosystem response to global change. Together, climate change and climate-driven changes in streamflow are likely to reduce abundance of dominant, native, early-successional tree species, favor herbaceous species and both drought-tolerant and late-successional woody species (including many introduced species), reduce habitat quality for many riparian animals, and slow litter decomposition and nutrient cycling. Climate-driven changes in human water demand and associated water management may intensify these effects. On some regulated rivers, however, reservoir releases could be managed to protect riparian ecosystem. Immediate research priorities include determining riparian species' environmental requirements and monitoring riparian

  15. Soil Methane and Carbon Dioxide Fluxes from Cropland and Riparian Buffers in Different Hydrogeomorphic Settings.

    PubMed

    Jacinthe, P A; Vidon, P; Fisher, K; Liu, X; Baker, M E

    2015-07-01

    Riparian buffers contribute to the mitigation of nutrient pollution in agricultural landscapes, but there is concern regarding their potential to be hot spots of greenhouse gas production. This study compared soil CO and CH fluxes in adjacent crop fields and riparian buffers (a flood-prone forest and a flood-protected grassland along an incised channel) and examined the impact of water table depth (WTD) and flood events on the variability of gas fluxes in riparian zones. Results showed significantly ( < 0.001) higher CO emission in riparian areas than in adjoining croplands (6.8 ± 0.6 vs. 3.6 ± 0.5 Mg CO-C ha yr; mean ± SE). Daily flux of CO and soil temperature were significantly related ( < 0.002), with Q values ranging between 1.75 and 2.53. Significant relationships ( < 0.05) were found between CH daily flux and WTD. Flood events resulted in enhanced CH emission (up to +44.5 mg CH-C m d in a swale) under warm soil conditions (>22°C), but the effect of flooding was less pronounced in early spring (emission <1.06 mg CH-C m d), probably due to low soil temperature. Although CH flux direction alternated at all sites, overall the croplands and the flood-affected riparian forest were CH sources, with annual emission averaging +0.04 ± 0.17 and +0.92 ± 1.6 kg CH-C ha, respectively. In the riparian forest, a topographic depression (<8% of the total area) accounted for 78% of the annual CH emission, underscoring the significance of landscape heterogeneity on CH dynamics in riparian buffers. The nonflooded riparian grassland, however, was a net CH sink (-1.08 ± 0.22 kg CH-C ha yr), probably due to the presence of subsurface tile drains and a dredged/incised channel at that study site. Although these hydrological alterations may have contributed to improvement in the CH sink strength of the riparian grassland, this must be weighed against the water quality maintenance functions and other ecological services provided by riparian buffers. PMID:26437089

  16. Scott river riparian woodland revegetation demonstration project, FY 1994. Final report

    SciTech Connect

    Jopson, T.M.

    1995-04-01

    The purpose of this project was to demonstrate techniques that could lead to the successful restoration of riparian woodland along the Scott River and elsewhere at a reasonable cost. Three sites were selected for the projects on the basis of need for restoration (i.e. the lack of vegetation), the applicability of the site as a demonstration area (how typical of other areas it was), exclusionary fencing, and the willingness of the landowner to participate. Three woody plant species, black cottonwood (Populus nigra), willow (Salix sp.) and Ponderosa pine (Pinus ponderosa) were chosen for planting on the site. These species were known to occur naturally in the riparian zone of the river, were relatively easy to grow in the available time, would produce a variety of habitats when mature, and would grow tall enough to provide shade for the water.

  17. The role of large predators in maintaining riparian plant communities and river morphology

    NASA Astrophysics Data System (ADS)

    Beschta, Robert L.; Ripple, William J.

    2012-07-01

    Studies assessing the potential for large predators to affect, via trophic cascades, the dynamics of riparian plant communities and the morphology of river channels have been largely absent in the scientific literature. Herein, we consider the results of recent studies involving three national parks in the western United States: Yellowstone, Olympic, and Zion. Within each park, key large predators were extirpated or displaced in the early 1900s and subsequent browsing pressure by native ungulates initiated long-term declines in recruitment (i.e., growth of seedlings/sprouts into tall saplings and trees) of palatable woody species and impairment of other resources. Channel responses to browsing-suppressed riparian vegetation included increased widths of active channels via accelerated bank erosion, erosion of floodplains and erraces, increased area of unvegetated alluvium, channel incision, and increased braiding. A reduced frequency of overbank flows indicated these rivers have become increasingly disconnected from historical floodplains because of channel widening/incision. Results from Zion National Park also identified major biodiversity affects (e.g., reduced abundance of plant and animal species). Although these studies were conducted in national parks, results may have implications concerning riparian plant communities, biodiversity, and channel morphology for streams and rivers draining other public lands in the western US. It is on these lands that native and introduced ungulates have often heavily utilized riparian areas, largely in the absence of key predators, with significant consequences to plant communities and channels.

  18. Vegetation types, dominant compositions, woody plant diversity and stand structure in Trishna Wildlife Sanctuary of Northeast India.

    PubMed

    Majumdar, Koushik; Datta, B K

    2015-03-01

    Present study was carried out to assess the vegetation types, diversity and phytosociological status of woody plants in Trishna Wildlife Sanctuary of Tripura, Northeast India. Vegetation data was derived by 25 line transects (10 m wide and 500 m length, each 0.5 ha size). All woody species at >10 cm gbh (Girth at Breast Height) within each plots were measured and counted. A total of six forest types were classified by cluster analysis using Importance Value Index (IVI) of 289 woody species. Species diversity, forest structure and woody community associations were evaluated and discussed. One way ANOVA revealed significant differences in all species diversity measures and stand structure along the forest types. Distribution of stem density at ten different gbh classes showed reverse J-shaped curves. Population status of woody plants was also examined through grouping of all individuals into four population age stages viz. sapling (<30 cm gbh), adult (> or = 30 - <120 cm gbh), mature (>120 - 210 cm gbh) and old (> or =210 cm). To observe dominant composition and species population trend, IVI of top ten dominant species from all forest types were tabulated. The present study suggested that Trishna Wildlife Sanctuary is an important habitat in Tripura from floristic point of view and it should be conserved on priority basis for remaining wildlife endurances and monitor for forest livelihoods products for sustainable biodiversity conservation in this region. PMID:25895264

  19. Reach-scale characterization of large woody debris in a low-gradient, Midwestern U.S.A. river system

    NASA Astrophysics Data System (ADS)

    Martin, Derek J.; Pavlowsky, Robert T.; Harden, Carol P.

    2016-06-01

    Addition of large woody debris (LWD) to rivers has increasingly become a popular stream restoration strategy, particularly in river systems of the Midwestern United States. However, our knowledge of LWD dynamics is mostly limited to high gradient montane river systems, or coastal river systems. The LWD-related management of low-gradient, Midwestern river systems is thus largely based on higher gradient analogs of LWD dynamics. This research characterizes fluvial wood loads and investigates the relationships between fluvial wood, channel morphology, and sediment deposition in a relatively low-gradient, semiconfined, alluvial river. The LWD and channel morphology were surveyed at nine reaches along the Big River in southeastern Missouri to investigate those relationships in comparison to other regions. Wood loads in the Big River are low (3-114 m3/100 m) relative to those of higher gradient river systems of the Pacific Northwest, but high relative to lower-gradient river systems of the Eastern United States. Wood characteristics such as size and orientation suggest that the dominant LWD recruitment mechanism in the Big River is bank erosion. Also, ratios of wood geometry to channel geometry show that the Big River maintains a relatively high wood transport capacity for most of its length. Although LWD creates sites for sediment storage, the overall impact on reach-scale sediment storage in the Big River is low (< 4.2% of total in-channel storage). However, wood loads, and thus opportunities for sediment storage, have the potential to grow in the future as Midwestern riparian forests mature. This study represents the first of its kind within this particular type of river system and within this region and thus serves as a basis for understanding fluvial wood dynamics in low-gradient river systems of the Midwestern United States.

  20. Restoration of a Severely Impacted Riparian Wetland System-The Pen Branch Project

    SciTech Connect

    Barton, C.; Nelson, E.A.; Kolka, R.F.; McLeod, K.W.; Conner, W.H.; Lakly, M.; Wigginton, J.; Trettin, C.C.; Wisiniewski, j.

    2000-10-01

    The Pen Banch riparian wetland system was impacted by hot water releases from the reactor operations at the SRS. Several hundred acres of swamp and bottomland forest were destroyed and degraded as a result of thermal effects and sedimentation. The SRS developed a plan to restore the system based upon planting both early and last successional tree species. The goal was to develop a

  1. GPR Detection and 3D Mapping of Lateral Macropores II. Riparian Application

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The morphology and prevalence of 1-10 cm diameter macropores in forested riparian wetland buffers is largely unknown despite their importance as a source of preferential nutrient delivery to stream channels. Here, we validated in situ procedures for detecting and mapping the three-dimensional struct...

  2. Potential of Co-firing of Woody Biomass in Coal Fired Power Plant

    NASA Astrophysics Data System (ADS)

    Makino, Yosuke; Kato, Takeyoshi; Suzuoki, Yasuo

    Taking the distributing woody biomass supply into account, this paper assesses the potential of a co-firing of woody biomass in utility's coal power plant from the both energy-saving and economical view points. Sawmill wastes, trimming wastes from fruit farms and streets, and thinning residues from forests in Aichi Prefecture are taken into account. Even though transportation energy is required, almost all of woody biomass can be more efficiently used in co-firing with coal than in a small-scale fuel cell system with gasification as a distributed utilization. When the capital cost of fuel cell system with 25% of total efficiency, including preprocess, gasification and power generation, is higher than 170× 103yen/kW, almost all of thinning residues can be more economically used in co-firing. The cost of woody biomass used in co-firing is also compared with the transaction cost of renewable power in the current RPS scheme. The result suggests the co-firing of woody biomass in coal fired power plant can be feasible measure for effective utilization of woody biomass.

  3. Headwater riparian invertebrate communities associated with red alder and conifer wood and leaf litter in southeastern Alaska

    USGS Publications Warehouse

    LeSage, C.M.; Merritt, R.W.; Wipfli, M.S.

    2005-01-01

    We examined how management of young upland forests in southeastern Alaska affect riparian invertebrate taxa richness, density, and biomass, in turn, potentially influencing food abundance for fish and wildlife. Southeastern Alaska forests are dominated by coniferous trees including Sitka spruce (Picea sitchensis (Bong.) Carr.), western hemlock (Tsuga heterophylla (Raf.) Sarg.), with mixed stands of red cedar (Thuja plicata Donn.). Red alder (Alnus rubra Bong.) is hypothesized to influence the productivity of young-growth conifer forests and through forest management may provide increased riparian invertebrate abundance. To compare and contrast invertebrate densities between coniferous and alder riparian habitats, leaf litter and wood debris (early and late decay classes) samples were collected along eleven headwater streams on Prince of Wales Island, Alaska, during the summers of 2000 and 2001. Members of Acarina and Collembola were the most abundant taxa collected in leaf litter with alder litter having significantly higher mean taxa richness than conifer litter. Members of Acarina were the most abundant group collected on wood debris and alder wood had significantly higher mean taxa richness and biomass than conifer wood. Alder wood debris in more advanced decay stages had the highest mean taxa richness and biomass, compared to other wood types, while conifer late decay wood debris had the highest densities of invertebrates. The inclusion of alder in young-growth conifer forests can benefit forest ecosystems by enhancing taxa richness and biomass of riparian forest invertebrates. ?? 2005 by the Northwest Scientific Association. All rights reserved.

  4. Fuel reduction management practices in riparian areas of the Western USA.

    PubMed

    Stone, Katharine R; Pilliod, David S; Dwire, Kathleen A; Rhoades, Charles C; Wollrab, Sherry P; Young, Michael K

    2010-07-01

    Two decades of uncharacteristically severe wildfires have caused government and private land managers to actively reduce hazardous fuels to lessen wildfire severity in western forests, including riparian areas. Because riparian fuel treatments are a fairly new management strategy, we set out to document their frequency and extent on federal lands in the western U.S. Seventy-four USDA Forest Service Fire Management Officers (FMOs) in 11 states were interviewed to collect information on the number and characteristics of riparian fuel reduction treatments in their management district. Just under half of the FMOs surveyed (43%) indicated that they were conducting fuel reduction treatments in riparian areas. The primary management objective listed for these projects was either fuel reduction (81%) or ecological restoration and habitat improvement (41%), though multiple management goals were common (56%). Most projects were of small extent (93% < 300 acres), occurred in the wildland-urban interface (75%), and were conducted in ways to minimize negative impacts on species and habitats. The results of this survey suggest that managers are proceeding cautiously with treatments. To facilitate project planning and implementation, managers recommended early coordination with resource specialists, such as hydrologists and fish and wildlife biologists. Well-designed monitoring of the consequences of riparian fuel treatments on fuel loads, fire risk, and ecological effects is needed to provide a scientifically-defensible basis for the continued and growing implementation of these treatments. PMID:20499233

  5. Fuel Reduction Management Practices in Riparian Areas of the Western USA

    NASA Astrophysics Data System (ADS)

    Stone, Katharine R.; Pilliod, David S.; Dwire, Kathleen A.; Rhoades, Charles C.; Wollrab, Sherry P.; Young, Michael K.

    2010-07-01

    Two decades of uncharacteristically severe wildfires have caused government and private land managers to actively reduce hazardous fuels to lessen wildfire severity in western forests, including riparian areas. Because riparian fuel treatments are a fairly new management strategy, we set out to document their frequency and extent on federal lands in the western U.S. Seventy-four USDA Forest Service Fire Management Officers (FMOs) in 11 states were interviewed to collect information on the number and characteristics of riparian fuel reduction treatments in their management district. Just under half of the FMOs surveyed (43%) indicated that they were conducting fuel reduction treatments in riparian areas. The primary management objective listed for these projects was either fuel reduction (81%) or ecological restoration and habitat improvement (41%), though multiple management goals were common (56%). Most projects were of small extent (93% < 300 acres), occurred in the wildland-urban interface (75%), and were conducted in ways to minimize negative impacts on species and habitats. The results of this survey suggest that managers are proceeding cautiously with treatments. To facilitate project planning and implementation, managers recommended early coordination with resource specialists, such as hydrologists and fish and wildlife biologists. Well-designed monitoring of the consequences of riparian fuel treatments on fuel loads, fire risk, and ecological effects is needed to provide a scientifically-defensible basis for the continued and growing implementation of these treatments.

  6. Integrated riparian evaluation guide: Intermountain region

    SciTech Connect

    Not Available

    1992-03-01

    Riparian areas consist of riparian ecosystems, aquatic ecosystems, and wetlands. They may be associated with lakes, reservoirs, estuaries, potholes, marshes, springs, bogs, wet meadows, and intermittent or perennial streams where free and unbound water is available. Though riparian areas constitute only a fraction of the total land area, they are more productive in terms of both plant and animal species diversity and biomass per unit area than the remainder of the land base. The guide provides an integrated approach for: Stratifying and classifying riparian areas according to their natural inherent characteristics, and their respective existing or conditions; Data collection; Evaluation of riparian areas; Future development and linkage of a riparian data base; and Preparation of a written narrative to interpret the data and suggest management applications.

  7. Impacts of grazing, fire, and precipitation variability on woody plant cover expansion in semi-arid grasslands of southeastern Arizona

    NASA Astrophysics Data System (ADS)

    O'neal, K. J.

    2011-12-01

    Northern Chihuahuan semi-arid grasslands are highly managed systems supporting rich biodiversity and many endemic species as well as providing a valuable economic resource for cattle-ranching livelihoods, with 90% of grasslands open to grazing. Chihuahuan grasslands share many characteristics with other managed grazing systems, which occupy 25% of the global land surface and are the most extensive form of land use. These grasslands are experiencing land-cover modification from woody plant cover expansion, leading to diminished biodiversity and grazing capacity. Ongoing research indicates that grazing, fire suppression, and precipitation variability are the primary drivers causing increased woody plant cover in Chihuahuan grasslands; however, there is debate concerning the dominant driver. While it is understood that historical land use and climate variation have facilitated initial woody encroachment in the region, the current relative influence of the three drivers remains unclear. This research explores how grazing, fire/suppression, and seasonal precipitation variability influence woody plant cover in the semi-arid grasslands of southeastern Arizona and identifies the dominant driver behind observed changes. This research used the Landsat Thematic Mapper record from 1984 to 2008 to map changes in woody plant cover and identify spatial patterns and temporal trends of woody plant cover expansion. Spectral mixture analysis (SMA) was used to quantify the percent of woody plant cover in each pixel; trend analysis was used to track per-pixel changes over the time-series. Trend analysis was further refined by segmenting trends around fire events to accommodate abrupt and non-monotonic effects of fire on woody plant cover. The overall trend in the region shows increasing woody plant cover with most values ranging between 5-20% over the 25-year period and significant spatial variability in expansion amounts across the region. The Random Forests decision tree approach was

  8. Predicting historic riparian vegetation in the Columbia River basin

    NASA Astrophysics Data System (ADS)

    Imaki, H.; Beechie, T. J.

    2009-12-01

    vector machine (SVM), random forest (RF), and k-nearest neighbor (KNN) to predict riparian vegetation types. Overall accuracy of models for large reaches was 68.3% (LDA), 73.0% (SVM), 71.4 (RF), and 68.3% (KNN), and 59.3%, 66.3%, 51.2%, and 47.7% for small reaches. We tested each model against data points outside of the training set, and found that overall accuracies were 47% to 48% for the large streams and 43% (all models) for small reaches. Even though overall accuracies were relatively low, we recognized that structure of error matrices reflected vegetation responses against environment variables. We are currently developing species occurrence models. We believe that, using the predicted vegetation group and species occurrence map along with vegetation response curves, we can reasonably estimate reference riparian condition in the Columbia River basin and our approach can be applicable to other areas in the US.

  9. On the measure of large woody debris in an alpine catchment

    NASA Astrophysics Data System (ADS)

    D'Agostino, V.; Bertoldi, G.; Rigon, E.

    2012-04-01

    The management of large woody debris (LWD) in Alpine torrents is a complex and ambiguous task. On one side the presence of LWD contributes to in-channel and floodplain morphological processes and plays an important role in landscape ecology and biodiversity. On the other side LWD increases considerably flood hazards when some river cross-sections result critical for the human interface (e.g. culverts, bridges, artificial channels). Only few studies provide quantitative data of LWD volumes in Alpine torrents. Research is needed both at basin scale processes (LWD recruiting from hillslopes) and at channel scale processes (feeding from river bank, storage/transport/deposition of LWD along the river bed). Our study proposes an integrate field survey methodology to assess the overall LWD amount which can be entrained by a flood. This knowledge is mandatory for the scientific research, for the implementation of LWD transport models, and for a complete hazard management in mountain basins. The study site is the high-relief basin of the Cordevole torrent (Belluno Province, Central Alps, Italy) whose outlet is located at the Saviner village (basin area of 109 square kilometers). In the November 1966 an extreme flood event occurred and some torrent reaches were heavily congested by LWD enhancing the overall damages due to long-duration overflows. Currently, the LWD recruitment seems to be strictly correlated with bank erosion and hillslope instability and the conditions of forest stand suggest LWD hazard is still high. Previous studies on sub-catchments of the Cordevole torrent have also shown an inverse relation between the drainage area and the LWD storage in the river-bed. Present contribution analyzes and quantifies the presence of LWD in the main valley channel of the Cordevole basin. A new sampling methodology was applied to integrate surveys of riparian vegetation and LWD storage. Data inventory confirms the previous relationship between LWD volumes and drainage area

  10. Groundwater management institutions to protect riparian habitat

    NASA Astrophysics Data System (ADS)

    Orr, Patricia; Colby, Bonnie

    2004-12-01

    Groundwater pumping affects riparian habitat when it causes the water table to drop beyond the reach of riparian plants. Riparian habitat provides services that are not directly traded in markets, as is the case with many environmental amenities. There is no direct market where one may buy or sell the mix of services provided by a riparian corridor. The objective of this article is to review groundwater management mechanisms and assess their strengths and weaknesses for preserving the ecological integrity of riparian areas threatened by groundwater pumping. Policy instruments available to those concerned with the effects of groundwater pumping on riparian areas fall into three broad categories: (1) command and control (CAC), (2) incentive-based economic instruments, and (3) cooperative/suasive strategies. The case of the San Pedro River illustrates multiple and overlapping strategies applied in an ongoing attempt to reverse accumulating damage to a riparian ecosystem. Policy makers in the United States can choose among a broad menu of policy options to protect riparian habitat from groundwater pumping. They can capitalize on the clarity of command-and-control strategies, the flexibility and less obtrusive nature of incentive-based economic strategies, and the benefits that collaborative efforts can bring in the form of mutual consideration. While collaborative problem solving and market-based instruments are important policy tools, experience indicates that a well-formulated regulatory structure to limit regional groundwater pumping is an essential component of an effective riparian protection strategy.

  11. Flow recommendations for maintaining riparian vegetation along the Upper Missouri River, Montana

    USGS Publications Warehouse

    Scott, Michael L.; Auble, Gregor T.; Friedman, Jonathan M.; Ischinger, Lee S.; Eggleston, Erik D.; Wondzell, Mark A.; Shafroth, Patrick B.; Back, Jennifer T.; Jordan, Mette S.

    1993-01-01

    Montana Power Company, Inc. (MPC) submitted a final license application to the Federal Energy Regulatory Commission (FERC) on November 30, 1992. In this application, MPC proposed a plan for the protection of fish, wildlife, habitat, and water-quality resources. One concern was maintenance of woody riparian vegetation along the Missouri River, especially along the Wild and Scenic reach of the river, where the riparian forest occurs in relatively small discontinuous stands. The objectives of this project were 1) to recommend flows that would protect and enhance riparian forests along the Missouri River, and 2) to develop elements of an environmental monitoring program that could be used to assess the effectiveness of the recommended flows. Plains cottonwood (Populus deltoides subsp. monilifera) is the key structural component of riparian forests along the Missouri River. Therefore, we focused our analysis on factors affecting populations of this species. Previous work had demonstrated that the age structure of cottonwood populations is strongly influenced by aspects of flow that promote successfully establishment. In this study our approach was to determine the precise age of plains cottonwood trees growing along the Upper Missouri River and to relate years of establishment to the flow record. Our work was carried out between Coal Banks Landing and the Fred G. Robinson Bridge within the Wild and Scenic portion of the Missouri River. This segment of the river occupies a narrow valley and exhibits little channel migration. Maps and notes from the journals of Lewis and Clark (1804-1806) suggest that the present distribution and abundance of cottonwoods within the study reach is generally similar to presettlement conditions. Flows in the study reach are influenced by a number of dams and diversions, most importantly, Canyon Ferry and Tiber Dams. Although flow regulation has decreased peak flows and increased low flows, the gross seasonal pattern of flow has not been

  12. Flow and scour constraints on uprooting of pioneer woody seedlings

    NASA Astrophysics Data System (ADS)

    Bywater-Reyes, Sharon; Wilcox, Andrew C.; Stella, John C.; Lightbody, Anne F.

    2015-11-01

    Scour and uprooting during flood events is a major disturbance agent that affects plant mortality rates and subsequent vegetation composition and density, setting the trajectory of physical-biological interactions in rivers. During flood events, riparian plants may be uprooted if they are subjected to hydraulic drag forces greater than their resisting force. We measured the resisting force of woody seedlings established on river bars with in situ lateral pull tests that simulated flood flows with and without substrate scour. We quantified the influence of seedling size, species (Populus and Tamarix), water-table depth, and scour depth on resisting force. Seedling size and resisting force were positively related with scour depth and water-table depth—a proxy for root length—exerting strong and opposing controls on resisting force. Populus required less force to uproot than Tamarix, but displayed a greater increase in uprooting force with seedling size. Further, we found that calculated mean velocities required to uproot seedlings were greater than modeled flood velocities under most conditions. Only when plants were either shallowly rooted or subjected to substrate scour (≥0.3 m) did the calculated velocities required for uprooting decrease to within the range of modeled flood velocities, indicating that drag forces alone are unlikely to uproot seedlings in the absence of extreme events or bar-scale sediment transport. Seedlings on river bars are most resilient to uprooting when they are large, deeply rooted, and unlikely to experience substrate scour, which has implications for ecogeomorphic evolution and river management.

  13. Ground-based LiDAR to investigate landscape engineering by woody riparian trees

    NASA Astrophysics Data System (ADS)

    Bywater-Reyes, S.; Wilcox, A. C.; Manners, R.; Lightbody, A.

    2013-12-01

    Plant-scale disruption to flow can result in upstream scour and downstream deposition, creating 'tail bars'. Tail bars have been postulated to exhibit airfoil geometries that reduce drag, causing a positive feedback whereby additional deposition of sediment results in growth of pioneer islands. We quantify the relative influence of vegetation morphology and grain size on morphodynamics by using ground-based LiDAR to scan trees and associated scour and tail bar features. We scanned trees of various growth stages and morphologies (Populus and Tamarix) in both sand- and gravel-bed settings. We post-process vegetation scans for hydrodynamic vegetation density, a proxy for leaf area index that we use in stress partitioning calculations to compare the magnitude of grain versus vegetation roughness. We also quantify the dimensions of upstream scour (maximum depth and volume) and downstream tail bar deposits (maximum height, width, length, volume). The vegetation and ground scans will be used to evaluate whether scour and tail bar geometries can be predicted from hydrodynamic vegetation density, and whether tail bars exhibit airfoil geometries in a manner that reduces drag. Field observations indicate single-stem trees (e.g. Populus) produce greater upstream scour but more subdued tail bar deposits, whereas multi-stem trees (e.g. Tamarix) produce less upstream scour but more tail bar deposition. Scour and tail bar features are more dramatic in the sand-bed setting compared to the gravel-bed, where grain roughness may play a larger role. Our research quantifies the magnitude of vegetation-morphodynamic feedbacks, with implications for plant community and landscape evolution in a multitude of riverine settings.

  14. RESEARCH NEEDS IN RIPARIAN BUFFER RESTORATION

    EPA Science Inventory

    Riparian buffer restorations are used as management tools to produce favorable water quality impacts; moreover, the basis for riparian buffers as an instrument of water quality restoration rests on a relatively firm foundation. However, the extent to which buffers can restore rip...

  15. Nitrous oxide emission from cropland and adjacent riparian buffers in contrasting hydrogeomorphic settings.

    PubMed

    Fisher, K; Jacinthe, P A; Vidon, P; Liu, X; Baker, M E

    2014-01-01

    Riparian buffers are important nitrate (NO) sinks in agricultural watersheds, but limited information is available regarding the intensity and control of nitrous oxide (NO) emission from these buffers. This study monitored (December 2009-May 2011) NO fluxes at two agricultural riparian buffers in the White River watershed in Indiana to assess the impact of land use and hydrogeomorphologic (HGM) attributes on emission. The study sites included a riparian forest in a glacial outwash/alluvium setting (White River [WR]) and a grassed riparian buffer in tile-drained till plains (Leary Weber Ditch [LWD]). Adjacent corn ( L.) fields were monitored for land use assessment. Analysis of variance identified season, land use (riparian buffer vs. crop field), and site geomorphology as major drivers of NO fluxes. Strong relationships between N mineralization and NO fluxes were found at both sites, but relationships with other nutrient cycling indicators (C/N ratio, dissolved organic C, microbial biomass C) were detected only at LWD. Nitrous oxide emission showed strong seasonal variability; the largest NO peaks occurred in late spring/early summer as a result of flooding at the WR riparian buffer (up to 27.8 mg NO-N m d) and N fertilizer application to crop fields. Annual NO emission (kg NO-N ha) was higher in the crop fields (WR: 7.82; LWD: 6.37) than in the riparian areas. A significant difference ( < 0.02) in annual NO emission between the riparian buffers was detected (4.32 vs. 1.03 kg NO-N ha at WR and LWD, respectively), and this difference was attributed to site geomorphology and flooding (WR is flood prone; no flooding occurred at tile-drained LWD). The study results demonstrate the significance of landscape geomorphology and land-stream connection (i.e., flood potential) as drivers of NO emission in riparian buffers and therefore argue that an HGM-based approach should be especially suitable for determination of regional NO budget in riparian ecosystems. PMID:25602568

  16. Riparian Vegetation Status and Rates of Water Use from Satellite Data

    NASA Astrophysics Data System (ADS)

    Sheffield, K.; Abuzar, M.; Whitfield, D.; McAllister, A.; O'Connell, M.

    2012-07-01

    Hydrology and water availability are key determinants of the health of riparian vegetation systems, and an understanding of the interactions between vegetation and hydrology is a prerequisite for the maintenance and improvement of these systems under managed water regimes. Changes to natural flooding cycles, caused by the regulation of river flows and irrigation activities, have changed the composition and amount of vegetation, and the distribution of species within riparian areas (Chong and Ladson, 2003; Lawrence and Colloff, 2008). The extent and frequency of flooding cycles are key issues for the health of riparian ecosystems under controlled water management regimes. This paper demonstrates the potential contribution of satellite-based measurements to an improved understanding of the changes in vegetation status of riparian systems, and, also, of their water requirement. Evapotranspiration (ET) and Normalised Difference Vegetation Index (NDVI) of the Barmah Forest were derived from satellite imagery over a number of years. NDVI provided a general measure of vegetation status and cover. ET measures provided an indication of the availability of water to the existing vegetation, and an assessment of areas under water-stress (Anderson et al., 2012). Previous work has demonstrated that these indicators provide a comprehensive measure of riparian vegetation status (Sheffield et al., 2011), and estimates of vegetation water requirement (Whitfield et al., 2010a; Sheffield et al., 2011). This paper addresses changes in NDVI and ET rate of major vegetation classes in the Barmah Forest over the period, 1993 - 2008. Measures of ET and NDVI, analysed in conjunction with rainfall and river flow data, provided insights into the response of vegetation to changes in water availability, which may be used to evaluate impacts of management practices and water regime within riparian zones.

  17. Do beavers promote the invasion of non-native Tamarix in the Grand Canyon riparian zone

    USGS Publications Warehouse

    Mortenson, S.G.; Weisberg, P.J.; Ralston, B.E.

    2008-01-01

    Beavers (Castor canadensis Kuhl) can influence the competitive dynamics of plant species through selective foraging, collection of materials for dam creation, and alteration of hydrologic conditions. In the Grand Canyon National Park, the native Salix gooddingii C.R.Ball (Goodding's willow) and Salix exigua Nutt. (coyote willow) are a staple food of beavers. Because Salix competes with the invasive Tamarix ramosissima Ledeb., land mangers are concerned that beavers may cause an increase in Tamarix through selective foraging of Salix. A spatial analysis was conducted to assess whether the presence of beavers correlates with the relative abundance of Salix and Tamarix. These methods were designed to detect a system-wide effect of selective beaver foraging in this large study area (367 linear km of riparian habitat). Beavers, Salix, and Tamarix co-occurred at the broadest scales because they occupied similar riparian habitat, particularly geomorphic reaches of low and moderate resistivity. Once the affinity of Salix for particular reach types was accounted for, the presence of Salix was independent of beaver distribution. However, there was a weak positive association between beaver presence and Salix cover. Salix was limited to geomorphic settings with greater sinuosity and distinct terraces, while Tamarix occurred in sinuous and straighter sections of river channel (cliffs, channel margins) where it dominated the woody species composition. After accounting for covariates representing river geomorphology, the proportion of riparian surfaces covered by Tamarix was significantly greater for sites where beavers were present. This indicates that either Tamarix and beavers co-occur in similar habitats, beavers prefer habitats that have high Tamarix cover, or beavers contribute to Tamarix dominance through selective use of its native woody competitors. The hypothesis that beaver herbivory contributes to Tamarix dominance should be considered further through more

  18. Riparian hydraulic gradient and stream-groundwater exchange dynamics in steep headwater valleys

    NASA Astrophysics Data System (ADS)

    Voltz, Thomas; Gooseff, Michael; Ward, Adam S.; Singha, Kamini; Fitzgerald, Michael; Wagener, Thorsten

    2013-06-01

    of riparian hydraulic gradients and stream-groundwater exchange in headwater catchments provide the hydrologic context for important ecological processes. Although the controls are relatively well understood, their dynamics during periods of hydrologic change is not. We investigate riparian hydraulic gradients over three different time scales in two steep, forested, headwater catchments in Oregon (WS01 and WS03) to determine the potential controls of reach-scale valley slope and cross-sectional valley geometry. Groundwater and stream stage data collected at high spatial and temporal resolutions over a period encompassing a 1.25 year storm and subsequent seasonal baseflow recession indicate that hydraulic gradients in both riparian aquifers exhibit strong persistence of down-valley dominance. Responses to rainfall do not support the simple conceptual models of increased riparian hydraulic gradient toward streams. Hydraulic gradient response in WS01 to both the seasonal baseflow recession and the storm suggested the potential for increased stream-groundwater exchange, but there was less evidence for this in WS03. Results from four constant-rate tracer injections in each stream showed a high baseline level of exchange overall, and both a slight seasonal increase (WS01) and slight decrease (WS03) in the riparian intrusion of tracer-labeled stream water as stream discharge receded. These results indicate that steep headwater valley floors host extensive stream water exchange and very little change in the water table gradients over 3 orders of magnitude of stream discharge.

  19. Denitrification potential in stormwater control structures and natural riparian zones in an urban landscape.

    PubMed

    Bettez, Neil D; Groffman, Peter M

    2012-10-16

    Humans have significantly altered urban landscapes, creating impervious surfaces, and changing drainage patterns that increase volume and velocity as well as frequency and timing of runoff following precipitation events. These changes in runoff have impaired streams and riparian areas that previously reduced watershed nitrogen (N) flux through uptake and denitrification. Stormwater control measures (SCM) are used most frequently to mitigate these hydrologic impacts. While SCM control runoff, their ability to remove N compared to natural riparian areas is not well-known. In this study we compared potential denitrification [as denitrification enzyme activity (DEA)] in five types of SCM (wet ponds, dry detention ponds, dry extended detention, infiltration basin, and filtering practices) and forested and herbaceous riparian areas in Baltimore, MD. DEA was higher in SCM (1.2 mg N kg(-1) hr(-1)) than in riparian areas (0.4 mg N kg(-1) hr(-1)). While DEA was highly correlated with soil moisture, organic matter, microbial biomass, and soil respiration areas across sites, it was always higher in SCM at equivalent levels of these variables. SCM appear to function as denitrification hotspots and, despite having similar microbial biomass, have higher potential denitrification than natural riparian areas. PMID:22963127

  20. Influence of a riparian wetland on nitrate and herbicides exported from an agricultural field.

    PubMed

    Angier, Jonathan T; McCarty, Gregory W; Rice, Clifford P; Bialek, Krystyna

    2002-07-17

    Agrochemicals are a major source of nonpoint pollution. Forested corridors along stream channels (riparian zones) are thought to be potential sites for removal of agricultural contaminants from ground and surface waters. First-order riparian wetlands are reputed to be especially effective at groundwater remediation. The study site is a fairly typical (for eastern Maryland) small, first-order stream in an agricultural watershed. Preferential flow supplies most of the stream water within the riparian headwater wetland. This upstream area also contains the highest average stream N and pesticide loads in the entire first-order riparian system. Zones of active groundwater emergence onto the surface display high concentrations of nitrate throughout the soil profile and in the exfiltrating water, whereas inactive areas (where there is no visible upwelling) show rapid attenuation of nitrate with decreasing depths. Atrazine degradation products appear to penetrate more readily through the most active upwelling zones, and there is a correlation between zones of high nitrate and high atrazine metabolite levels. Deethylatrazine/atrazine ratios (DAR) seem to indicate that stream flow is dominated by ground water and that much of the ground water may have reached the stream via preferential flow. Remediative processes appear to be very complex, heterogeneous, and variable in these systems, so additional research is needed before effective formulation and application of riparian zone initiatives and guidelines can be accomplished. PMID:12105980

  1. Spatiotemporal patterns of water table fluctuations and evapotranspiration induced by riparian vegetation in a semiarid area

    NASA Astrophysics Data System (ADS)

    Yue, Weifeng; Wang, Tiejun; Franz, Trenton E.; Chen, Xunhong

    2016-03-01

    Groundwater evapotranspiration (ETg) links various ecohydrological processes and is an important component in regional water budgets. In this study, an extensive monitoring network was established in a semiarid riparian area to investigate various controls on the spatiotemporal pattern of water table fluctuations (WTFs) and ETg induced by riparian vegetation. Along a vegetation gradient (˜1200 m), diurnal WTFs were observed during a growing season in areas covered by woody species (Populus sect. Aigeiros and Juniperus virginiana) and wet slough vegetation (Panicum virgatum and Bromus inermis) with deeper root systems; whereas, no diurnal WTFs were found in the middle section with shallower-rooted grasses (Poa pratensis and Carex sp.). The occurrence of diurnal WTFs was related to temperature-controlled plant phenology at seasonal scales and to radiation at subdaily scales. Daily ETg in the mid-growing season was calculated using the White method. The results revealed that depth to water table (DTWT) was the dominant control on ETg, followed by potential evapotranspiration (ETp). By combining the effects of DTWT and ETp, it was found that at shallower depths, ETg was more responsive to changes in ETp, due to the closer linkage of land surface processes with shallower groundwater. Finally, exponential relationships between ETg/ETp and DTWT were obtained at the study site, although those relationships varied considerably across the sites. This study demonstrates the complex interactions of WTFs and ETg with surrounding environmental variables and provides further insight into modeling ETg over different time scales and riparian vegetation.

  2. Modeling respiration from snags and coarse woody debris before and after an invasive gypsy moth disturbance

    NASA Astrophysics Data System (ADS)

    Renninger, Heidi J.; Carlo, Nicholas; Clark, Kenneth L.; Schäfer, Karina V. R.

    2014-04-01

    Although snags and coarse woody debris are a small component of ecosystem respiration, disturbances can significantly increase the mass and respiration from these carbon (C) pools. The objectives of this study were to (1) measure respiration rates of snags and coarse woody debris throughout the year in a forest previously defoliated by gypsy moths, (2) develop models for dead stem respiration rates, (3) model stand-level respiration rates of dead stems using forest inventory and analysis data sets and environmental variables predisturbance and postdisturbance, and (4) compare total dead stem respiration rates with total ecosystem respiration and net ecosystem exchange. Respiration rates were measured on selected Pinus and Quercus snags and coarse woody debris each month for 1 year in a northeastern U.S. temperate forest. Multiple linear regression using environmental and biometric variables including wood temperature, diameter, density, species, and decay class was used to model respiration rates of dead stems. The mass of snags and coarse woody debris increased more than fivefold after disturbance and respiration rates increased more than threefold. The contribution of dead stems to total ecosystem respiration more than tripled from 0.85% to almost 3% and respiration from dead stems alone was approximately equal to the net ecosystem exchange of the forest in 2011 (fourth year postdisturbance). This study highlights the importance of dead stem C pools and fluxes particularly during disturbance and recovery cycles. With climate change increasing the ranges of many forest pests and pathogens, these data become particularly important for accurately modeling future C cycling.

  3. Application of Somatic Embryogenesis in Woody Plants.

    PubMed Central

    Guan, Yuan; Li, Shui-Gen; Fan, Xiao-Fen; Su, Zhen-Hong

    2016-01-01

    Somatic embryogenesis is a developmental process where a plant somatic cell can dedifferentiate to a totipotent embryonic stem cell that has the ability to give rise to an embryo under appropriate conditions. This new embryo can further develop into a whole plant. In woody plants, somatic embryogenesis plays a critical role in clonal propagation and is a powerful tool for synthetic seed production, germplasm conservation, and cryopreservation. A key step in somatic embryogenesis is the transition of cell fate from a somatic cell to embryo cell. Although somatic embryogenesis has already been widely used in a number of woody species, propagating adult woody plants remains difficult. In this review, we focus on molecular mechanisms of somatic embryogenesis and its practical applications in economic woody plants. Furthermore, we propose a strategy to improve the process of somatic embryogenesis using molecular means. PMID:27446166

  4. New market potential: Torrefaction of Woody Biomass

    SciTech Connect

    Jaya Shankar Tumuluru; J. Richard Hess

    2015-07-01

    According to researchers in Idaho National Laboratory’s Bioenergy Program, torrefaction of woody biomass could reduce variability in biomass feedstock and enable development of a commodity-type product for green energy generation and usage.

  5. Stream temperature response to three riparian vegetation scenarios by use of a distributed temperature validated model.

    PubMed

    Roth, T R; Westhoff, M C; Huwald, H; Huff, J A; Rubin, J F; Barrenetxea, G; Vetterli, M; Parriaux, A; Selkeer, J S; Parlange, M B

    2010-03-15

    Elevated in-stream temperature has led to a surge in the occurrence of parasitic intrusion proliferative kidney disease and has resulted in fish kills throughout Switzerland's waterways. Data from distributed temperature sensing (DTS) in-stream measurements for three cloud-free days in August 2007 over a 1260 m stretch of the Boiron de Merges River in southwest Switzerland were used to calibrate and validate a physically based one-dimensional stream temperature model. Stream temperature response to three distinct riparian conditions were then modeled: open, in-stream reeds, and forest cover. Simulation predicted a mean peak stream temperature increase of 0.7 °C if current vegetation was removed, an increase of 0.1 °C if dense reeds covered the entire stream reach, and a decrease of 1.2 °C if a mature riparian forest covered the entire reach. Understanding that full vegetation canopy cover is the optimal riparian management option for limiting stream temperature, in-stream reeds, which require no riparian set-aside and grow very quickly, appear to provide substantial thermal control, potentially useful for land-use management. PMID:20131784

  6. Impacts of hydroelectric dams on alluvial riparian plant communities in Eastern Brazilian Amazonian.

    PubMed

    Ferreira, Leandro Valle; Cunha, Denise A; Chaves, Priscilla P; Matos, Darley C L; Parolin, Pia

    2013-09-01

    The major rivers of the Amazon River basin and their biota are threatened by the planned construction of large hydroelectric dams that are expected to have strong impacts on floodplain plant communities. The present study presents forest inventories from three floodplain sites colonized by alluvial riparian vegetation in the Tapajós, Xingu and Tocantins River basins in eastern Amazonian. Results indicate that tree species of the highly specialized alluvial riparian vegetation are clearly distinct among the three river basins, although they are not very distinct from each other and environmental constraints are very similar. With only 6 of 74 species occurring in all three inventories, most tree and shrub species are restricted to only one of the rivers, indicating a high degree of local distribution. Different species occupy similar environmental niches, making these fragile riparian formations highly valuable. Conservation plans must consider species complementarily when decisions are made on where to place floodplain forest conservation units to avoid the irreversible loss of unique alluvial riparian vegetation biodiversity. PMID:24068089

  7. Determinants of woody cover in African savannas

    USGS Publications Warehouse

    Sankaran, M.; Hanan, N.P.; Scholes, R.J.; Ratnam, J.; Augustine, D.J.; Cade, B.S.; Gignoux, J.; Higgins, S.I.; Le, Roux X.; Ludwig, F.; Ardo, J.; Banyikwa, F.; Bronn, A.; Bucini, G.; Caylor, K.K.; Coughenour, M.B.; Diouf, A.; Ekaya, W.; Feral, C.J.; February, E.C.; Frost, P.G.H.; Hiernaux, P.; Hrabar, H.; Metzger, K.L.; Prins, H.H.T.; Ringrose, S.; Sea, W.; Tews, J.; Worden, J.; Zambatis, N.

    2005-01-01

    Savannas are globally important ecosystems of great significance to human economies. In these biomes, which are characterized by the co-dominance of trees and grasses, woody cover is a chief determinant of ecosystem properties 1-3. The availability of resources (water, nutrients) and disturbance regimes (fire, herbivory) are thought to be important in regulating woody cover1,2,4,5, but perceptions differ on which of these are the primary drivers of savanna structure. Here we show, using data from 854 sites across Africa, that maximum woody cover in savannas receiving a mean annual precipitation (MAP) of less than ???650 mm is constrained by, and increases linearly with, MAP. These arid and semi-arid savannas may be considered 'stable' systems in which water constrains woody cover and permits grasses to coexist, while fire, herbivory and soil properties interact to reduce woody cover below the MAP-controlled upper bound. Above a MAP of ???650 mm, savannas are 'unstable' systems in which MAP is sufficient for woody canopy closure, and disturbances (fire, herbivory) are required for the coexistence of trees and grass. These results provide insights into the nature of African savannas and suggest that future changes in precipitation 6 may considerably affect their distribution and dynamics. ?? 2005 Nature Publishing Group.

  8. Cross-stratified Wood: Enigmatic Woody Debris Deposits in Warm-Polar Fluvial Sediments (Pliocene Beaufort Formation, Nunavut)

    NASA Astrophysics Data System (ADS)

    Davies, N. S.; Gosse, J. C.; Rybczynski, N.

    2012-04-01

    Woody debris has been an important sediment component and a significant geomorphic agent in pristine fluvial systems since the Devonian. In recent years a large volume of research has focussed on various aspects of the importance of woody debris within the fluvial realm; from the evolutionary significance of fossil wood accumulations in the rock record to studies of the biogeomorphological and ecological importance of woody debris in modern rivers. In this presentation we describe cross-stratified woody debris deposits comprising organic detritus from a boreal-type treeline forest that included species of pine, birch, poplar, alder, spruce, eastern cedar, and larch, in both shrub and tree form. The cross-stratified wood is an enigmatic subset of fine woody debris which, to our knowledge, has never before been described from either the global stratigraphic record or modern fluvial environments. The deposits we describe are located within the Pliocene Beaufort Formation on Meighen Island, Nunavut, Canada, at a latitude of 80°N, and are compared with other cross-stratified woody debris deposits that have been noted elsewhere in the Pliocene of the Canadian Arctic. We make the robust observation that these deposits appear to be geographically and stratigraphically restricted to polar latitudes from a period of warm climatic conditions during the Pliocene (15-20 °C warmer mean annual temperature than the present day). In this regard it is possible to speculate that the transport of large amounts of woody debris as bedload is potentially a unique feature of forested high latitude rivers. Such bedload deposition requires a large amount of woody debris with a greater density than the fluid transporting it. The softwood composition of the debris suggests that this was most likely attained by saturation and subsequent entrainment of extensive accumulations of deadwood, promoted by unusually high rates of tree mortality and low rates of bacterial decomposition arising from

  9. Spatio-temporal variability in the distribution of ground-dwelling riparian spiders and their potential role in water-to-land energy transfer along Hong Kong forest streams

    PubMed Central

    Yuen, Elaine Y.L.

    2015-01-01

    Terrestrial predators have been shown to aggregate along stream margins during periods when the emergence of adult aquatic insects is high. Such aggregation may be especially evident when terrestrial surroundings are relatively unproductive, and there are steep productivity gradients across riparia. In tropical forests, however, the productivity of inland terrestrial habitats may decrease the resource gradient across riparia, thus lessening any tendency of terrestrial predators to aggregate along stream margins. We elucidated the spatio-temporal variability in the distribution of ground-dwelling spiders and terrestrial arthropod prey within the riparia of two forest streams in tropical Hong Kong by sampling arthropods along transects at different distances from the streams during the wet and dry seasons. Environmental variables that may have influenced spider distributions were also measured. The vast majority of ground-dwelling predators along all transects at both sites were spiders. Of the three most abundant spiders captured along stream margins, Heteropoda venatoria (Sparassidae) and Draconarius spp. (Agelenidae) were terrestrially inclined and abundant during both seasons. Only Pardosa sumatrana (Lycosidae) showed some degree of aggregation at the stream banks, indicating a potential reliance on aquatic insect prey. Circumstantial evidence supports this notion, as P. sumatrana was virtually absent during the dry season when aquatic insect emergence was low. In general, forest-stream riparia in Hong Kong did not appear to be feeding hotspots for ground-dwelling predators. The lack of aggregation in ground-dwelling spiders in general may be attributed to the low rates of emergence of aquatic insects from the study streams compared to counterpart systems, as well as the potentially high availability of terrestrial insect prey in the surrounding forest. Heteropoda venatoria, the largest of the three spiders maintained a high biomass (up to 28 mg dry weight/m2) in

  10. Demonstration of the BioBaler harvesting system for collection of small-diameter woody biomass

    SciTech Connect

    Langholtz, Matthew H; Caffrey, Kevin R; Barnett, Elliott J; Webb, Erin; Brummette, Mark W; Downing, Mark

    2011-12-01

    As part of a project to investigate sustainable forest management practices for producing wood chips on the Oak Ridge Reservation (ORR) for the ORNL steam plant, the BioBaler was tested in various Oak Ridge locations in August of 2011. The purpose of these tests and the subsequent economic analysis was to determine the potential of this novel woody biomass harvesting method for collection of small-diameter, low value woody biomass. Results suggest that opportunities may exist for economical harvest of low-value and liability or negative-cost biomass. (e.g., invasives). This could provide the ORR and area land managers with a tool to produce feedstock while improving forest health, controlling problem vegetation, and generating local employment.

  11. Microsite abundance and distribution of woody seedlings in a South Carolina cypress-tupelo swamp

    SciTech Connect

    Huenneke, L.F.; Sharitz, R.R.

    1986-05-01

    At least 16 types of microsites or substrates for vascular plant seedlings can be distinguished in bald cypress-water tupelo (Taxodium distichum-Nyssa aquatica) swamps. We measured the relative abundances of these microsite types, and the distribution of woody seedlings on them, in two riverine swamp forests on the Savannah River floodplain, South Carolina. Microsite abundances in a little disturbed forest differed significantly from those in a more open stand which had experienced much recent sediment deposition from upstream erosion, as well as higher water temperatures. Woody seedlings were distributed nonrandomly among microsite types (i.e., not in proportion to the abundance of a given microsite type). There were significant differences in microsite distribution patterns among growth forms (tree spp. vs. shrubs vs. vines) and among species within growth form. Many human activities may alter substrate nature and abundance in a wetland, thus indirectly altering the abundance and species composition of seedling recruitment.

  12. Recovery times of riparian vegetation

    NASA Astrophysics Data System (ADS)

    Vesipa, R.; Camporeale, C.; Ridolfi, L.

    2016-04-01

    Riparian vegetation is a key element in a number of processes that determine the ecogeomorphological features of the river landscape. Depending on the river water stage fluctuations, vegetation biomass randomly switches between growth and degradation phases and exhibits relevant temporal variations. A full understanding of vegetation dynamics is therefore only possible if the hydrological stochastic forcing is considered. In this vein, we focus on the recovery time of vegetation, namely the typical time taken by vegetation to recover a well-developed state starting from a low biomass value (induced, for instance, by an intense flood). The analytical expression of the plot-dependent recovery time is given, the role of hydrological and biological parameters is discussed, and the impact of river-induced randomness is highlighted. Finally, the effect of man-induced hydrological changes (e.g., river damming or climate changes) is explored.

  13. Expected international demand for woody and herbaceous feedstock

    SciTech Connect

    Lamers, Patrick; Jacobson, Jacob; Mohammad, Roni; Wright, Christopher

    2015-03-01

    The development of a U.S. bioenergy market and ultimately ‘bioeconomy’ has primarily been investigated with a national focus. Limited attention has been given to the potential impacts of international market developments. The goal of this project is to advance the current State of Technology of a single biorefinery to the global level providing quantitative estimates on how international markets may influence the domestic feedstock supply costs. The scope of the project is limited to feedstock that is currently available and new crops being developed to be used in a future U.S. bioeconomy including herbaceous residues (e.g., corn stover), woody biomass (e.g., pulpwood), and energy crops (e.g., switchgrass). The timeframe is set to the periods of 2022, 2030, and 2040 to align with current policy targets (e.g., the RFS2) and future updates of the Billion Ton data. This particular milestone delivers demand volumes for generic woody and herbaceous feedstocks for the main (net) importing regions along the above timeframes. The regional focus of the study is the European Union (EU), currently the largest demand region for U.S. pellets made from pulpwood and forest residues. The pellets are predominantly used in large-scale power plants (>5MWel) in the United Kingdom (UK), the Netherlands (NL), Belgium (BE), and Denmark (DK).

  14. Recovery times of riparian vegetation

    NASA Astrophysics Data System (ADS)

    Vesipa, Riccardo; Camporeale, Carlo; Ridolfi, Luca

    2016-04-01

    Riparian vegetation is a key element in a number of processes that determine the eco-geomorphological features of the river landscape. Depending on the river water stage fluctuations, vegetation biomass randomly switches between growth and decay phases, and its biomass exhibits relevant temporal variations. A full understanding of vegetation dynamics is therefore only possible if the hydrological stochastic forcing is considered. In this vein, we focus on the recovery time of vegetation, namely the typical time taken by vegetation to recover a health state starting from a low biomass value (induced, for instance, by an intense flood). The minimalistic stochastic modeling approach is used for describing vegetation dynamics (i.e., the noise-driven alternation of growth and decay phases). The recovery time of biomass is then evaluated according to the theory of the mean first passage time in systems driven by dichotomous noise. The effect of the main hydrological and biological parameters on the vegetation recovery was studied, and the dynamics along the riparian transect was described in details. The effect of climate change and human interventions (e.g., river damming) was also investigated. We found that: (i) the oscillations of the river stage delay the recovery process (up to one order of magnitude, with respect to undisturbed conditions); (ii) hydrological/biological alterations (due to climate change, damming, exotic species invasion) modify the timescales of the recovery. The result provided can be a useful tool for the management of the river. They open the way to the estimation of: (i) the recovery time of vegetation after devastating floods, clear cutting or fires and; (ii) the timescale of the vegetation response to hydrological and biological alterations.

  15. Riparian ecosystems in human cancers

    PubMed Central

    Alfarouk, Khalid O; Ibrahim, Muntaser E; Gatenby, Robert A; Brown, Joel S

    2013-01-01

    Intratumoral evolution produces extensive genetic heterogeneity in clinical cancers. This is generally attributed to an increased mutation rate that continually produces new genetically defined clonal lineages. Equally important are the interactions between the heritable traits of cancer cells and their microenvironment that produces natural selection favoring some clonal ‘species’ over others. That is, while mutations produce the heritable variation, environmental selection and cellular adaptation govern the strategies (and genotypes) that can proliferate within the tumor ecosystem. Here we ask: What are the dominant evolutionary forces in the cancer ecosystem? We propose that the tumor vascular network is a common and primary cause of intratumoral heterogeneity. Specifically, variations in blood flow result in variability in substrate, such as oxygen, and metabolites, such as acid, that serve as critical, but predictable, environmental selection forces. We examine the evolutionary and ecological consequences of variable blood flow by drawing an analogy to riparian habitats within desert landscapes. We propose that the phenotypic properties of cancer cells will exhibit predictable spatial variation within tumor phenotypes as a result of proximity to blood flow. Just as rivers in the desert create an abrupt shift from the lush, mesic riparian vegetation along the banks to sparser, xeric and dry-adapted plant species in the adjacent drylands, we expect blood vessels within tumors to promote similarly distinct communities of cancer cells that change abruptly with distance from the blood vessel. We propose vascular density and blood flow within a tumor as a primary evolutionary force governing variations in the phenotypic properties of cancer cells thus providing a unifying ecological framework for understanding intratumoral heterogeneity. PMID:23396634

  16. Dissolved Organic Carbon in Headwater Streams and Riparian Soil Organic Carbon along an Altitudinal Gradient in the Wuyi Mountains, China

    PubMed Central

    Huang, Wei; McDowell, William H.; Zou, Xiaoming; Ruan, Honghua; Wang, Jiashe; Li, Liguang

    2013-01-01

    Stream water dissolved organic carbon (DOC) correlates positively with soil organic carbon (SOC) in many biomes. Does this relationship hold in a small geographic region when variations of temperature, precipitation and vegetation are driven by a significant altitudinal gradient? We examined the spatial connectivity between concentrations of DOC in headwater stream and contents of riparian SOC and water-soluble soil organic carbon (WSOC), riparian soil C:N ratio, and temperature in four vegetation types along an altitudinal gradient in the Wuyi Mountains, China. Our analyses showed that annual mean concentrations of headwater stream DOC were lower in alpine meadow (AM) than in subtropical evergreen broadleaf forest (EBF), coniferous forest (CF), and subalpine dwarf forest (SDF). Headwater stream DOC concentrations were negatively correlated with riparian SOC as well as WSOC contents, and were unrelated to riparian soil C:N ratio. Our findings suggest that DOC concentrations in headwater streams are affected by different factors at regional and local scales. The dilution effect of higher precipitation and adsorption of soil DOC to higher soil clay plus silt content at higher elevation may play an important role in causing lower DOC concentrations in AM stream of the Wuyi Mountains. Our results suggest that upscaling and downscaling of the drivers of DOC export from forested watersheds when exploring the response of carbon flux to climatic change or other drivers must done with caution. PMID:24265737

  17. Dissolved organic carbon in headwater streams and riparian soil organic carbon along an altitudinal gradient in the Wuyi Mountains, China.

    PubMed

    Huang, Wei; McDowell, William H; Zou, Xiaoming; Ruan, Honghua; Wang, Jiashe; Li, Liguang

    2013-01-01

    Stream water dissolved organic carbon (DOC) correlates positively with soil organic carbon (SOC) in many biomes. Does this relationship hold in a small geographic region when variations of temperature, precipitation and vegetation are driven by a significant altitudinal gradient? We examined the spatial connectivity between concentrations of DOC in headwater stream and contents of riparian SOC and water-soluble soil organic carbon (WSOC), riparian soil C:N ratio, and temperature in four vegetation types along an altitudinal gradient in the Wuyi Mountains, China. Our analyses showed that annual mean concentrations of headwater stream DOC were lower in alpine meadow (AM) than in subtropical evergreen broadleaf forest (EBF), coniferous forest (CF), and subalpine dwarf forest (SDF). Headwater stream DOC concentrations were negatively correlated with riparian SOC as well as WSOC contents, and were unrelated to riparian soil C:N ratio. Our findings suggest that DOC concentrations in headwater streams are affected by different factors at regional and local scales. The dilution effect of higher precipitation and adsorption of soil DOC to higher soil clay plus silt content at higher elevation may play an important role in causing lower DOC concentrations in AM stream of the Wuyi Mountains. Our results suggest that upscaling and downscaling of the drivers of DOC export from forested watersheds when exploring the response of carbon flux to climatic change or other drivers must done with caution. PMID:24265737

  18. SUBSURFACE CHARACTERIZATION OF UPLAND RIPARIAN MEADOWS IN CENTRAL NEVADA USING AN INNOVATIVE DIRECT-PUSH EXPLORATION RIG

    EPA Science Inventory

    The U.S. EPA and the USDA Forest Service are conducting a joint investigation to better understand the interactions between geomorphology, hydrology, and vegetation associated with riparian meadow ecosystems in upland watersheds in central Nevada. Stream incision is a major threa...

  19. Assessing water quality at large geographic scales: relations among land use, water physicochemistry, riparian condition, and fish community structure.

    PubMed

    Meador, Michael R; Goldstein, Robert M

    2003-04-01

    Data collected from 172 sites in 20 major river basins between 1993 and 1995 as part of the US Geological Survey's National Water-Quality Assessment Program were analyzed to assess relations among basinwide land use (agriculture, forest, urban, range), water physicochemistry, riparian condition, and fish community structure. A multimetric approach was used to develop regionally referenced indices of fish community and riparian condition. Across large geographic areas, decreased riparian condition was associated with water-quality constituents indicative of nonpoint source inputs-total nitrogen and suspended sediment and basinwide urban land use. Decreased fish community condition was associated with increases in total dissolved solids and rangeland use and decreases in riparian condition and agricultural land use. Fish community condition was relatively high even in areas where agricultural land use was relatively high (>50% of the basin). Although agricultural land use can have deleterious effects on fish communities, the results of this study suggest that other factors also may be important, including practices that regulate the delivery of nutrients, suspended sediments, and total dissolved solids into streams. Across large geographic scales, measures of water physicochemistry may be better indicators of fish community condition than basinwide land use. Whereas numerous studies have indicated that riparian restorations are successful in specific cases, this analysis suggests the universal importance of riparian zones to the maintenance and restoration of diverse fish communities in streams. PMID:12677296

  20. Assessing water quality at large geographic scales: Relations among land use, water physicochemistry, riparian condition, and fish community structure

    USGS Publications Warehouse

    Meador, M.R.; Goldstein, R.M.

    2003-01-01

    Data collected from 172 sites in 20 major river basins between 1993 and 1995 as part of the US Geological Survey's National Water-Quality Assessment Program were analyzed to assess relations among basinwide land use (agriculture, forest, urban, range), water physicochemistry, riparian condition, and fish community structure. A multimetric approach was used to develop regionally referenced indices of fish community and riparian condition. Across large geographic areas, decreased riparian condition was associated with water-quality constituents indicative of nonpoint source inputs-total nitrogen and suspended sediment and basin-wide urban land use. Decreased fish community condition was associated with increases in total dissolved solids and rangeland use and decreases in riparian condition and agricultural land use. Fish community condition was relatively high even in areas where agricultural land use was relatively high (>50% of the basin). Although agricultural land use can have deleterious effects on fish communities, the results of this study suggest that other factors also may be important, including practices that regulate the delivery of nutrients, suspended sediments, and total dissolved solids into streams. Across large geographic scales, measures of water physicochemistry may be better indicators of fish community condition than basinwide land use. Whereas numerous studies have indicated that riparian restorations are successful in specific cases, this analysis suggests the universal importance of riparian zones to the maintenance and restoration of diverse fish communities in streams.

  1. Linking channel hydrology with riparian wetland accretion in tidal rivers

    NASA Astrophysics Data System (ADS)

    Ensign, Scott H.; Noe, Gregory B.; Hupp, Cliff R.

    2014-01-01

    hydrologic processes by which tide affects river channel and riparian morphology within the tidal freshwater zone are poorly understood yet are fundamental to predicting the fate of coastal rivers and wetlands as sea level rises. We investigated patterns of sediment accretion in riparian wetlands along the nontidal through oligohaline portion of two coastal plain rivers in Maryland, U.S., and how flow velocity, water level, and suspended sediment concentration (SSC) in the channel may have contributed to those patterns. Sediment accretion was measured over a 1 year period using artificial marker horizons, channel hydrology was measured over a 1 month period using acoustic Doppler current profilers, and SSC was predicted from acoustic backscatter. Riparian sediment accretion was lowest at the nontidal sites (mean and standard deviation = 8 ± 8 mm yr-1), highest at the upstream tidal freshwater forested wetlands (TFFW) (33 ± 28 mm yr-1), low at the midstream TFFW (12 ± 9 mm yr-1), and high at the oligohaline (fresh-to-brackish) marshes (19 ± 8 mm yr-1). Channel maximum flood and ebb velocity was twofold faster at the oligohaline than tidal freshwater zone on both tidal rivers, corresponding with the differences in in-channel SSC: The oligohaline zone's SSC was more than double the tidal freshwater zone's and was greater than historical SSC at the nontidal gages. The tidal wave characteristics differed between rivers, leading to significantly greater in-channel SSC during floodplain inundation in the weakly convergent than the strongly convergent tidal river. High sediment accretion at the upstream TFFW was likely due to high river discharge following a hurricane.

  2. Frost resistance in alpine woody plants.

    PubMed

    Neuner, Gilbert

    2014-01-01

    This report provides a brief review of key findings related to frost resistance in alpine woody plant species, summarizes data on their frost resistance, highlights the importance of freeze avoidance mechanisms, and indicates areas of future research. Freezing temperatures are possible throughout the whole growing period in the alpine life zone. Frost severity, comprised of both intensity and duration, becomes greater with increasing elevation and, there is also a greater probability, that small statured woody plants, may be insulated by snow cover. Several frost survival mechanisms have evolved in woody alpine plants in response to these environmental conditions. Examples of tolerance to extracellular freezing and freeze dehydration, life cycles that allow species to escape frost, and freeze avoidance mechanisms can all be found. Despite their specific adaption to the alpine environment, frost damage can occur in spring, while all alpine woody plants have a low risk of frost damage in winter. Experimental evidence indicates that premature deacclimation in Pinus cembra in the spring, and a limited ability of many species of alpine woody shrubs to rapidly reacclimate when they lose snow cover, resulting in reduced levels of frost resistance in the spring, may be particularly critical under the projected changes in climate. In this review, frost resistance and specific frost survival mechanisms of different organs (leaves, stems, vegetative and reproductive over-wintering buds, flowers, and fruits) and tissues are compared. The seasonal dynamics of frost resistance of leaves of trees, as opposed to woody shrubs, is also discussed. The ability of some tissues and organs to avoid freezing by supercooling, as visualized by high resolution infrared thermography, are also provided. Collectively, the report provides a review of the complex and diverse ways that woody plants survive in the frost dominated environment of the alpine life zone. PMID:25520725

  3. Frost resistance in alpine woody plants

    PubMed Central

    Neuner, Gilbert

    2014-01-01

    This report provides a brief review of key findings related to frost resistance in alpine woody plant species, summarizes data on their frost resistance, highlights the importance of freeze avoidance mechanisms, and indicates areas of future research. Freezing temperatures are possible throughout the whole growing period in the alpine life zone. Frost severity, comprised of both intensity and duration, becomes greater with increasing elevation and, there is also a greater probability, that small statured woody plants, may be insulated by snow cover. Several frost survival mechanisms have evolved in woody alpine plants in response to these environmental conditions. Examples of tolerance to extracellular freezing and freeze dehydration, life cycles that allow species to escape frost, and freeze avoidance mechanisms can all be found. Despite their specific adaption to the alpine environment, frost damage can occur in spring, while all alpine woody plants have a low risk of frost damage in winter. Experimental evidence indicates that premature deacclimation in Pinus cembra in the spring, and a limited ability of many species of alpine woody shrubs to rapidly reacclimate when they lose snow cover, resulting in reduced levels of frost resistance in the spring, may be particularly critical under the projected changes in climate. In this review, frost resistance and specific frost survival mechanisms of different organs (leaves, stems, vegetative and reproductive over-wintering buds, flowers, and fruits) and tissues are compared. The seasonal dynamics of frost resistance of leaves of trees, as opposed to woody shrubs, is also discussed. The ability of some tissues and organs to avoid freezing by supercooling, as visualized by high resolution infrared thermography, are also provided. Collectively, the report provides a review of the complex and diverse ways that woody plants survive in the frost dominated environment of the alpine life zone. PMID:25520725

  4. Multiscale remote sensing analysis to monitor riparian and upland semiarid vegetation

    NASA Astrophysics Data System (ADS)

    Nguyen, Uyen

    The health of natural vegetation communities is of concern due to observed changes in the climatic-hydrological regime and land cover changes particularly in arid and semiarid regions. Monitoring vegetation at multi temporal and spatial scales can be the most informative approach for detecting change and inferring causal agents of change and remediation strategies. Riparian communities are tightly linked to annual stream hydrology, ground water elevations and sediment transport. These processes are subject to varying magnitudes of disturbance overtime and are candidates for multi-scale monitoring. My first research objective focused on the response of vegetation in the Upper San Pedro River, Arizona, to reduced base flows and climate change. I addressed the correlation between riparian vegetation and hydro-climate variables during the last three decades in one of the remaining undammed rivers in the southwestern U.S. Its riparian forest is threatened by the diminishing base flows, attributed by different studies either to increases in evapotranspiration (ET) due to conversion of grasslands to mesquite shrublands in the adjacent uplands, or to increased regional groundwater pumping to serve growing populations in surrounding urban areas and or to some interactions of those causes. Landsat 5 imagery was acquired for pre- monsoon period, when riparian trees had leafed out but before the arrival of summer monsoon rains in July. The result has showed Normalized Difference Vegetation Index (NDVI) values from both Landsat and Moderate Resolution Imaging Spectrometer (MODIS) had significant decreases which positively correlated to river flows, which decreased over the study period, and negatively correlated with air temperatures, which have increased by about 1.4°C from 1904 to the present. The predictions from other studies that decreased river flows could negatively impact the riparian forest were supported by this study. The pre-monsoon Normalized Different Vegetation

  5. Legal mechanisms for protecting riparian resource values

    USGS Publications Warehouse

    Lamb, Berton L.; Lord, Eric

    1992-01-01

    Riparian resources include the borders of rivers, lakes, ponds, and potholes. These border areas are very important for a number of reasons, including stream channel maintenance, flood control, aesthetics, erosion control, fish and wildlife habitat, recreation, and water quality maintenance. These diverse functions are not well protected by law or policy. We reviewed law and policies regarding endangered species habitat designation, land use planning, grazing management, water allocation, takings, and federal permits and licenses, along with the roles of federal, state, and local governments. We discuss the politics of implementing these policies, focusing on the difficulties in changing entrenched water and land use practices. Our review indicates a lack of direct attention to riparian ecosystem issues in almost all environmental and land use programs at every level of government. Protection of riparian resource values requires a means to integrate existing programs to focus on riparian zones.

  6. Legal mechanisms for protecting riparian resource values

    SciTech Connect

    Lamb, B.L.; Lord, E. )

    1992-04-01

    Riparian resources include the borders of rivers, lakes, ponds, and potholes. These border areas are very important for a number of reasons, including stream channel maintenance, flood control, aesthetics, erosion control, fish and wildlife habitat, recreation, and water quality maintenance. These diverse functions are not well protected by law or policy. The authors reviewed law and policies regarding endangered species habitat designation, land use planning, grazing management, water allocation, takings, and federal permits and licenses, along with the roles of federal, state, and local governments. They discuss the politics of implementing these policies, focusing on the difficulties in changing entrenched water and land use practices. Their review indicates a lack of direct attention to riparian ecosystem issues in almost all environmental and land use programs at every level of government. Protection of riparian resource values requires a means to integrate existing programs to focus on riparian zones.

  7. Landsat-Based Woody Vegetation Cover Monitoring in Southern African Savannahs

    NASA Astrophysics Data System (ADS)

    Symeonakis, E.; Petroulaki, K.; Higginbottom, T.

    2016-06-01

    Mapping woody cover over large areas can only be effectively achieved using remote sensing data and techniques. The longest continuously operating Earth-observation program, the Landsat series, is now freely-available as an atmospherically corrected, cloud masked surface reflectance product. The availability and length of the Landsat archive is thus an unparalleled Earth-observation resource, particularly for long-term change detection and monitoring. Here, we map and monitor woody vegetation cover in the Northwest Province of South Africa, an area of more than 100,000 km2 covered by 11 Landsat scenes. We employ a multi-temporal approach with dry-season data from 7 epochs between 1990 to 2015. We use 0.5 m-pixel colour aerial photography to collect > 15,000 point samples for training and validating Random Forest classifications of (i) woody vegetation cover, (ii) other vegetation types (including grasses and agricultural land), and (iii) non-vegetated areas (i.e. urban areas and bare land). Overall accuracies for all years are around 80 % and overall kappa between 0.45 and 0.66. Woody vegetation covers a quarter of the Province and is the most accurately mapped class (balanced accuracies between 0.74-0.84 for the 7 epochs). There is a steady increase in woody vegetation cover over the 25-year-long period of study in the expense of the other vegetation types. We identify potential woody vegetation encroachment 'hot-spots' where mitigation measures might be required and thus provide a management tool for the prioritisation of such measures in degraded and food-insecure areas.

  8. Growing stock and woody biomass assessment in Asola-Bhatti Wildlife Sanctuary, Delhi, India.

    PubMed

    Kushwaha, S P S; Nandy, S; Gupta, Mohini

    2014-09-01

    Biomass is an important entity to understand the capacity of an ecosystem to sequester and accumulate carbon over time. The present study, done in collaboration with the Delhi Forest Department, focused on the estimation of growing stock and the woody biomass in the so-called lungs of Delhi--the Asola-Bhatti Wildlife Sanctuary in northern Aravalli hills. The satellite-derived vegetation strata were field-inventoried using stratified random sampling procedure. Growing stock was calculated for the individual sample plots using field data and species-specific volume equations. Biomass was estimated from the growing stock and the specific gravity of the wood. Among the four vegetation types, viz. Prosopis juliflora, Anogeissus pendula, forest plantation and the scrub, the P. juliflora was found to be the dominant vegetation in the area, covering 23.43 km(2) of the total area. The study revealed that P. juliflora forest with moderate density had the highest (10.7 m(3)/ha) while A. pendula forest with moderate density had the lowest (3.6 m(3)/ha) mean volume. The mean woody biomass was also found to be maximum in P. juliflora forest with moderate density (10.3 t/ha) and lowest in A. pendula forest with moderate density (3.48 t/ha). The total growing stock was estimated to be 20,772.95 m(3) while total biomass worked out to be 19,366.83 t. A strong correlation was noticed between the normalized difference vegetation index (NDVI) and the growing stock (R(2) = 0.84)/biomass (R(2) = 0.88). The study demonstrated that growing stock and the biomass of the woody vegetation in Asola-Bhatti Wildlife Sanctuary could be estimated with high accuracy using optical remote sensing data. PMID:24859859

  9. Ecological health of river basins in forested regions of eastern Washington and Oregon. Forest Service general technical report

    SciTech Connect

    Wissmar, R.C.; Smith, J.E.; McIntosh, B.A.; Li, H.W.; Reeves, G.H.

    1994-02-01

    A retrospective examination of the history of the cumulative influences of past land water uses on the ecological health of select river basins in forest regions of eastern Washington and Oregon indicates the loss of fish and riparian habitat diversity and quality since the 19th century. The study focuses on impacts of timber harvest, fire management, live stock grazing, mining and irrigation management practices on stream and riparian ecosystems. An examination of past environmental management approaches for assessing stream, riparian, and watershed conditions in forest regions shows numerous advantages and shortcomings. Rcommendations for ecosystem management with emphasis on monitoring and restoration activities are provided.

  10. Assessing the potential impacts to riparian ecosystems resulting from hemlock mortality in Great Smoky Mountains National Park.

    PubMed

    Roberts, Scott W; Tankersley, Roger; Orvis, Kenneth H

    2009-08-01

    Hemlock Woolly Adelgid (Adelges tsugae) is spreading across forests in eastern North America, causing mortality of eastern hemlock (Tsuga canadensis [L.] Carr.) and Carolina hemlock (Tsuga caroliniana Engelm.). The loss of hemlock from riparian forests in Great Smoky Mountains National Park (GSMNP) may result in significant physical, chemical, and biological alterations to stream environments. To assess the influence of riparian hemlock stands on stream conditions and estimate possible impacts from hemlock loss in GSMNP, we paired hardwood- and hemlock-dominated streams to examine differences in water temperature, nitrate concentrations, pH, discharge, and available photosynthetic light. We used a Geographic Information System (GIS) to identify stream pairs that were similar in topography, geology, land use, and disturbance history in order to isolate forest type as a variable. Differences between hemlock- and hardwood-dominated streams could not be explained by dominant forest type alone as forest type yields no consistent signal on measured conditions of headwater streams in GSMNP. The variability in the results indicate that other landscape variables, such as the influence of understory Rhododendron species, may exert more control on stream conditions than canopy composition. The results of this study suggest that the replacement of hemlock overstory with hardwood species will have minimal impact on long-term stream conditions, however disturbance during the transition is likely to have significant impacts. Management of riparian forests undergoing hemlock decline should, therefore, focus on facilitating a faster transition to hardwood-dominated stands to minimize long-term effects on water quality. PMID:19495859

  11. On the relative importance of pool morphology and woody debris to distributions of shrimp in a Puerto Rican headwater stream

    USGS Publications Warehouse

    Pyron, M.; Covich, A.P.; Black, R.W.

    1999-01-01

    In this paper, we report the sizes and distributional orientation of woody debris in a headwater rainforest stream in the Luquillo Experimental Forest (LEF), Puerto Rico. We also provide results of a 4-month study of a wood addition experiment designed to increase cover for benthic macroinvertebrates (freshwater shrimp). We added branch-sized woody debris to 20 pools in three streams. We trapped four species of freshwater shrimp (two species of benthic detritivores and two predatory shrimp species) during each of the 4 months following wood additions. An analysis of pool morphology (maximum depth, surface area and volume) provided a useful predictor of shrimp abundances. In general, numbers of shrimps increased with sizes of stream pools. A repeated measures ANOVA demonstrated no effect of woody debris additions on total numbers of shrimp per pool area. Two detritivore species (Atya lanipes, a filter feeder and Xiphocaris elongata, a shredder) decreased in abundance with increased woody debris and there was no statistical relationship between woody debris additions and predators (Macrobrachium carcinus and M. crenulatum). Small woody debris additions may have altered flow velocities that were important to filter-feeding Atya at the microhabitat scale, although the overall velocities within pools were not altered by wood additions. Lower numbers of Atya and Xiphocaris in two of the three streams may result from the occurrence of two predaceous fishes (American eel and mountain mullet) and more predatory Macrobrachium in these streams. One likely interpretation of the results of this study is that the stream pools in these study reaches had sufficient habitat structure provided by numerous rock crevices (among large rocks and boulders) to provide refuge from predators. Addition of woody debris did not add significantly to the existing structure. These results may not apply to stream channels with sand and gravel substrata where crevices and undercut banks are lacking

  12. Elwha River Riparian Vegetation Response to Dams and Dam Removal

    NASA Astrophysics Data System (ADS)

    Shafroth, P. B.; Brown, R. L.; Clausen, A. J.; Chenoweth, J.

    2012-12-01

    Riparian vegetation is highly diverse and influences habitat of aquatic and terrestrial wildlife. Riparian vegetation dynamics are driven by stream flow regime, and fluxes of sediment and large woody debris, all of which can be altered by river damming. Dam removal is often implemented, in part, to help restore degraded riparian vegetation by reversing the alteration of these key drivers. However, increased disturbance and sediment flux associated with transport and exposure of trapped reservoir sediment can complicate a simple return to pre-dam conditions and can favor exotic species. We are studying the effects of dams and their removal on riparian vegetation along the Elwha River in Washington State, where removal of two large dams began in September 2011. To characterize vegetation composition, structure, and diversity prior to dam removal, we sampled 60-150 vegetation plots in 2004, 2005, and 2010 along five cross-valley transects in each of three river reaches: above both dams (upper reach), between the dams (middle reach), and downstream of both dams (lower reach). In summer 2012, we resampled a subset of our plots in the lower and middle reaches to evaluate vegetation and geomorphic change. We also sampled vegetation, topography, and grain size along newly-established transects within the exposed former reservoir behind Elwha Dam, which was removed in 2011 and 2012. Plant community distribution on bottomland geomorphic surfaces along the Elwha is typical of other systems in the region. We identified 8 overstory and 26 understory communities using multivariate analyses. Young bar surfaces (5-20 yrs) were dominated by willow, red alder, and black cottonwood. Floodplains and transitional fluvial terraces (<90yrs) were generally dominated by alder and cottonwood. Mature terraces (>90yrs) were often dominated by big-leaf maple. Douglas fir occurred on both young and old floodplains and terraces. Overstory species composition was more stable from 2005 to 2010

  13. Responses of Riparian Cottonwoods to Alluvial Water Table Declines

    NASA Astrophysics Data System (ADS)

    Scott, Michael L.; Shafroth, Patrick B.; Auble, Gregor T.

    1999-04-01

    extent of morphological responses and mortality of Populus to the rate, depth, and duration of water table declines can assist in the design of management prescriptions to minimize impacts of alluvial groundwater depletion on existing riparian Populus forests.

  14. Interannual trends in water use efficiency in declining riparian woodlands

    NASA Astrophysics Data System (ADS)

    Stella, J. C.; Riddle, J. D.; Piégay, H.; Teece, M.; Trémelo, M.

    2012-12-01

    Riparian ecosystems in water limited regions are under stress worldwide from flow regulation, land use and climate change. We analyzed tree-ring growth and stable carbon isotope geochemistry in pioneer trees to identify shifts in riparian tree water use as it affects forest condition. We cored individuals of Populus nigra, a riparian species that is vulnerable to changes in local groundwater levels, at floodplain sites along the Drôme River, in the Mediterranean-climate zone of southern France, to analyze the relative ecological impacts of in-stream gravel mining and climate-induced flow reductions on tree growth, crown dieback, and ecohydrological function. Regime Shift Detection analysis of site chronologies showed a divergent pattern among sites, with four sites maintaining stable growth and three others with sharply declining trends in growth to less than 30 cm2 basal area increment (BAI) in all recent years. At sites with stable growth, there was a negative relationship between growth and δ13C (slope = -0.37 to -0.55, p<0.01), indicating that the highest growth occurred when water was abundant. At declining sites, there was a positive relationship between growth and δ13C (slope = 0.33 to 0.52, p<0.01). These trends suggest that the highest water stress occurred in high growth years, and is consistent with limited groundwater capacity. Trees with the greatest crown dieback evident from low-altitude aerial photos had the greatest increase in water use efficiency. Growth declines and increased 13C enrichment were initiated in years of meteorological droughts that occurred after (but never prior to) the mining period, and were spatially distributed to suggest local bedrock controls on soil depth. The combined results indicate that these semi-arid riparian woodlands are vulnerable to multiple physical drivers, but that the severity of impacts is conditioned by interactions between drivers at different scales, including regional climate variability, reach

  15. Instream Large Wood: Dentrification Hotspots With Low N2O Production

    EPA Science Inventory

    The maintenance and restoration of forested riparian cover is important for watershed nitrogen (N) cycling. Forested riparian zones provide woody debris to streams that may stimulate in-stream denitrification and nitrous oxide (N2O) production. We examined the effects of woody an...

  16. Carbon Exchange and Water Use in Karst Landscapes: Impact of Woody Encroachment

    NASA Astrophysics Data System (ADS)

    Heilman, J. L.; Litvak, M. E.

    2008-05-01

    Woody plant invasion into grasslands and savannas, and its impact on water use are critical issues in karst landscapes because 25% of the world's population obtains its water from karst aquifers. It is well documented that woody encroachment increases carbon sequestration, but its impact on water use is less clear. It is widely presumed that woody plants increase evapotranspiration (ET), in part because deep root systems provide access to a more stable supply of water than what is available to grasses. If this is true, woody encroachment should reduce the sensitivity of carbon exchange and ET to rainfall pulses and water deficits, and vulnerability to drought. Since 2004, we have been investigating, via eddy covariance, carbon exchange and water use on a grassland, a savanna with approximately 35% woody cover, and a dense live oak-Ashe juniper forest on the karst Edwards Plateau in south and west central Texas. The Plateau is a 93,000 km2 karst ecoregion that is dominated by live oak-Ashe juniper savannas underlain by mixed C3/C4 grasses, and soils are generally shallow. The Plateau contains the Edwards Aquifer which supplies drinking water to over 2 million people, and is home to a number of threatened and endangered species, many of them aquatic. Populations of juniper are expanding due to suppression of wildfires, and public funds are being spent to remove juniper in an attempt to increase water availability. Our measurements show large differences in carbon sequestration among the ecosystems (highest in savanna and lowest in grassland), and small differences in ET (~0.2 mm day-1 higher in the forest than in the grassland). We attribute increased ET to increases in net radiation, and proportionally greater partitioning of available energy into sensible heat flux at the expense of latent heat flux. We found little differences in response of carbon exchange and ET to rainfall and water deficits, regardless of the amount of woody cover, intensity of rainfall, or

  17. [Frost-resistance of subtropical evergreen woody plants: an evaluation based on plant functional traits].

    PubMed

    Xu, Yi-Lu; Yang, Xiao-Dong; Xu, Yue; Xie, Yi-Ming; Wang, Liang-Yan; Yan, En-Rong

    2012-12-01

    Evaluating the frost-resistance of evergreen woody plants is of significance in guiding the species selection in forest management in subtropical region. In this paper, an investigation was made on the functional traits (including specific leaf area, stem wood density, leaf area, leaf dry matter content, leaf relative electrical conductance, and twig wood density) of 64 common evergreen broad-leaved and coniferous woody plant species in the Ningbo region of Zhejiang Province, East China, after a severe snowstorm in early 2008, aimed to select the evergreen woody plants with high ability of freeze-tolerance, and to establish a related evaluation system. By using a hierarchy analysis approach, the weight values of the functional traits of each species were determined, and an index system for evaluating the plants tolerance ability against freeze and mechanical damage was established. Based on this system, 23 evergreen plant species with high tolerance ability against freeze and mechanical damage, such as Cyclobalanopsis gilva, Cyclobalanopsis nubium, Neolitsea aurata, and Vacciniuim mandarinorum, were selected. In the meantime, on the basis of the ordering with each of the functional traits, the ordering of the tolerance ability of the 64 plant species against freeze and mechanical damage was made, and a list for the frost-resistance ability of the subtropical evergreen woody plant species in Ningbo region was constituted. PMID:23479868

  18. Woody plant establishment in grassed reclamation areas of the Athabasca oil sands

    SciTech Connect

    Fedkenheuer, A.W.

    1980-12-01

    The primary end land use for areas disturbed by the Syncrude Canada Ltd. oil sands surface mining venture is forest cover. Short term erosion control is of concern, however, and this results in the early establishment of a grass and legume cover. Problems have subsequently been encountered in attempts to establish woody plants in the grass and legume cover. Vegetation competition for soil moisture and nutrients and rodent damage to woody seedlings have been the major problem areas. A study was initiated in 1978 to evaluate methods of manipulating the grass and legume cover sufficiently to improve success rates in establishing a variety of shrubs and trees. Five replicated treatments using the chemical herbicide glyphosate, soil scarification and fire alone plus soil scarification were established on an area seeded to grass and legumes in spring 1976. Woody plant survival and rodent damage, populations and distribution are being assessed annually in spring and fall. Rodent damage to woody seedlings was heavy in fall 1978 with 80 percent of the deciduous seedlings on non-scarified plots being damaged. In June 1979, 98 percent of the deciduous plants on the control and herbicide treatment areas were damaged. Damage to conifers was approximately 30 percent less during this time. Prescribed burning and mechanical scarification substantially reduced rodent damage. Seedling survival was variable with Amelanchier alnifolia, Pinus contorta and Populus tremuloides consistently exhibiting the highest survival rates.

  19. Riparian Planting Projects Completed within Asotin Creek Watershed : 2000-2002 Asotin Creek Riparian Final Report of Accomplishments.

    SciTech Connect

    Johnson, B. J.

    2002-01-01

    The Asotin County Conservation District (ACCD) is the primary entity coordinating habitat projects on both private and public lands within the Asotin Creek watershed. The watershed covers approximately 325 square miles in the Blue Mountains of southeastern Washington in Water Resource Inventory Area (WRIA) 35. According to Washington Department of Fish and Wildlife's (WDFW) Priority WRIA's by ''At-Risk Stock Significance Map'', it is the highest priority WRIA in southeastern Washington. Summer steelhead, bull trout, and Snake River spring chinook salmon which are listed under the Endangered Species Act (ESA), are present in the watershed. WDFW manages it as a Wild Steelhead Reserve; no hatchery fish have been released here since 1997. The ACCD has been working with landowners, Bonneville Power Administration (BPA), Washington State Conservation Commission (WCC), Natural Resource Conservation Service (NRCS), Washington Department of Fish and Wildlife (WDFW), U.S. Forest Service, Pomeroy Ranger District (USFS), Nez Perce Tribe, Washington Department of Ecology (DOE), National Marine Fisheries Service (NMFS), and U.S. Fish and Wildlife Service (USFWS) to address habitat projects in Asotin County. Local students, volunteers and Salmon Corps members from the Nez Perce Tribe have been instrumental in the success of the Model Watershed Program on Asotin Creek. ACCD began coordinating habitat projects in 1995 with the help of BPA funding. Approximately two hundred and seventy-six projects have been implemented as of 1999. The Washington State Legislature was successful in securing funding for threatened and endangered salmon and steelhead recovery throughout the State in 1998. While these issues were new to most of the State, the ACCD has been securing and administering funding for threatened salmonids since 1994. The Asotin Creek Riparian Planting 2000-053-00 and Asotin Creek Riparian Fencing 2000-054-00 teamed BPA and the Governor's Salmon Recovery Funding to plant

  20. Vertical distribution of total carbon, nitrogen and phosphorus in riparian soils of Walnut Creek, southern Iowa

    USGS Publications Warehouse

    Schilling, K.E.; Palmer, J.A.; Bettis, E. Arthur, III; Jacobson, P.; Schultz, R.C.; Isenhart, T.M.

    2009-01-01

    Subsurface lithology plays an important role in many riparian zone processes, but few studies have examined how sediment nutrient concentrations vary with depth. In this study, we evaluated concentrations of nutrients (N, C and P) with depth in a riparian zone of the glaciated Midwest. A total of 146 sediment samples were collected from 24 cores that extended to a maximum depth of 3.6??m at eight sites in the riparian zone of Walnut Creek. Subsurface deposits were predominantly silt loam, becoming coarser and more variable with depth. Nitrogen and carbon content ranged from < 0.01 to 0.42% and < 0.01 to 7.08%, respectively, and exhibited a strong trend of decreasing nutrient content with depth. In contrast, P concentrations averaged 574??mg/kg and did not vary systematically. Systematic variations in texture and nutrient content with depth largely corresponded to stratigraphic differentiation among the Camp Creek, Roberts Creek and Gunder members of the regionally recognized Holocene-age DeForest Formation. Variations in subsurface nutrient content were not found to be significantly related to present land cover, but land cover may have influenced nutrient content at the time of original sediment accumulation. Subsurface lithology and stratigraphy should be considered an important component in riparian zone studies where nutrient losses to streams via streambank erosion or groundwater discharge are assessed. ?? 2009 Elsevier B.V. All rights reserved.

  1. Determining effects of woody vegetation on flood flow and sediment transport

    NASA Astrophysics Data System (ADS)

    Griffin, E. R.; Smith, J. D.; Friedman, J. M.; Vincent, K. R.

    2008-12-01

    Predicting the outcome of flow and sediment transport events quantitatively has been difficult due to the complex nature of stream systems and the effects of woody vegetation on flow. Predictive, process-based models of flow and sediment transport developed by our group during the past decade compute flow from fluid mechanical theory without empirically adjusted coefficients. Our models generate local hydraulic roughness fields from known physical characteristics and distributions of woody vegetation and topography determined from field measurements. An opportunity has arisen to apply these models to reconstruct a recent flood that caused large-scale geomorphic change and to test model predictions using data from field observations and satellite imagery. In 2003 application of an herbicide by helicopter for control of saltcedar (Tamarix spp.) killed almost all woody riparian vegetation along a 12-km reach of the Rio Puerco in north-central New Mexico. Subsequently, a large flood in August 2006 caused widespread erosion of the channel banks in the sprayed reach, where the channel widened by 84 percent on average. About 680,000 m3 of sediment eroded from the banks was deposited within 5 to 10 km downstream. Channel and floodplain widths remained virtually the same as prior to the flood upstream and downstream from the sprayed reach. Because of our previous work in the area, we were fortunate to have a large dataset of channel and floodplain geometry prior to the flood, including long-term channel cross sections, a detailed longitudinal profile, high-resolution imagery, and LIDAR topography. After the flood we resurveyed cross sections and the longitudinal profile and acquired post-flood imagery. Flood water-surface elevations determined from surveyed high-water marks provide constraints on the flood- flow depth with distance downstream and provide water-surface slopes. Satellite imagery and GPS survey data acquired after the flood are used to test the coupled

  2. 48 CFR 1452.237-71 - Utilization of Woody Biomass.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... Biomass. 1452.237-71 Section 1452.237-71 Federal Acquisition Regulations System DEPARTMENT OF THE INTERIOR... Utilization of Woody Biomass. As prescribed in § 1437.7202, insert the following clause: Utilization of Woody Biomass (MAY 2005) (a) The contractor may remove and utilize woody biomass, if: (1) Project work...

  3. 48 CFR 1452.237-71 - Utilization of Woody Biomass.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... Biomass. 1452.237-71 Section 1452.237-71 Federal Acquisition Regulations System DEPARTMENT OF THE INTERIOR... Utilization of Woody Biomass. As prescribed in § 1437.7202, insert the following clause: Utilization of Woody Biomass (MAY 2005) (a) The contractor may remove and utilize woody biomass, if: (1) Project work...

  4. 48 CFR 1452.237-71 - Utilization of Woody Biomass.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... Biomass. 1452.237-71 Section 1452.237-71 Federal Acquisition Regulations System DEPARTMENT OF THE INTERIOR... Utilization of Woody Biomass. As prescribed in § 1437.7202, insert the following clause: Utilization of Woody Biomass (MAY 2005) (a) The contractor may remove and utilize woody biomass, if: (1) Project work...

  5. 48 CFR 1452.237-71 - Utilization of Woody Biomass.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... Biomass. 1452.237-71 Section 1452.237-71 Federal Acquisition Regulations System DEPARTMENT OF THE INTERIOR... Utilization of Woody Biomass. As prescribed in § 1437.7202, insert the following clause: Utilization of Woody Biomass (MAY 2005) (a) The contractor may remove and utilize woody biomass, if: (1) Project work...

  6. 48 CFR 1452.237-71 - Utilization of Woody Biomass.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... Biomass. 1452.237-71 Section 1452.237-71 Federal Acquisition Regulations System DEPARTMENT OF THE INTERIOR... Utilization of Woody Biomass. As prescribed in § 1437.7202, insert the following clause: Utilization of Woody Biomass (MAY 2005) (a) The contractor may remove and utilize woody biomass, if: (1) Project work...

  7. Estimating Riparian ET through Remote Sensing

    NASA Astrophysics Data System (ADS)

    Samani, Z.; Bawazir, S.; Bleiweiss, M.; Skaggs, R.; Schmugge, T.

    2005-12-01

    Riparian evapotranspiration (ET) along the Rio Grande River has become a major hydrological as well as political issue in New Mexico. The State of New Mexico has spent millions of dollars in recent years to eradicate riparian vegetation without being able to quantify the change in regional ET. Many studies have focused on measuring evapotranspiration of individual riparian vegetation types, mainly saltcedar and native cottonwood. However, the riparian vegetation on the Middle Rio Grande varies in density and species.. Spatial variation in climate, soil type and depth to groundwater causes variation in ET, as well. It is obvious that in order to obtain more accuracy in measurements, multiple sampling points are needed; thus, making the process costly and impractical An alternative solution, which is also cost-effective, is measuring ET by using remote sensing technology. Remote sensing combines regional satellite data with localized ET measurement to calculate regional ET. REEM (Regional ET Estimation Model) is a process that uses the energy balance at the top of the canopy to estimate ET. REEM has been using ASTER images for values of surface temperature, albedo and NDVI to calculate net radiation (Rn), ground heat flux (G) and sensible heat flux (H). The ET is then calculated as residual of the energy components. The REEM model is being used to calculate regional ET values for the Riparian vegetation of the Middle Rio Grande. The paper compares the ET values for various vegetation types using remote sensing and ET derived from Eddy Covariance Flux Towers.

  8. ASSESSING ARID RIPARIAN LANDSCAPES USING REMOTE SENSING: THE FIRST STEP

    EPA Science Inventory

    Riparian ecosystems are of great value in the Southwest yet they are also extremely fragile and susceptible to natural and anthropogenic disturbances. Riparian ecosystems establish in patterns per the hydrologic and geomorphologic processes that dictate terrestrial plant success...

  9. VEGETATION CHARACTERIZATION OF THREE CONTRASTING RIPARIAN SITES, WILLAMETTE VALLEY, OR

    EPA Science Inventory

    Much of the native riparian vegetation of the Willamette Valley, Oregon, has been replaced with agricultural crops or invasive non-native plant species. Detailed information about current Willamette Valley riparian vegetation is generally lacking. Plant species composition data...

  10. META-ANALYSIS OF NITROGEN REMOVAL IN RIPARIAN BUFFERS

    EPA Science Inventory

    Riparian buffer zones, the vegetated region adjacent to streams and wetlands, are thought to be effective at intercepting and controlling nitrogen loads entering water bodies. Riparian buffer width may be positively related to nitrogen removal effectiveness by influencing nitrog...

  11. MULTISTAGE CHARACTERIZATION OF RIPARIAN PATCHES IN THE ARID SOUTHWEST

    EPA Science Inventory

    Some ecologically critical riparian ecosystems in the and Southwest are spatially and temporally discontinuous making their location and/or condition difficult to distinguish when studying the desert landscape. When conditions permit, riparian patches in the desert are distinct b...

  12. RIPARIAN RESTORATION: CURRENT STATUS AND THE REACH TO THE FUTURE

    EPA Science Inventory

    Nine articles in the special issure of Restoration Ecology addressing the subject of site selection for riparian restoration activities were critically examined for this review. The approaches described make significant and original contributions to the field of riparian restorat...

  13. MECHANICS OF STREAM-BORNE WOODY DEBRIS

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Large woody debris is increasingly regarded as an integral component of stream stabilization and restoration programs. Unravelling the dynamics of complex interaction of multiple logs among themselves and with the stream environs must start with a correct specification of all the forces acting on i...

  14. Riparian Vegetation, Sediment Dynamics and Hydrologic Change in the Minnesota River Basin

    NASA Astrophysics Data System (ADS)

    Batts, V. A.; Triplett, L.; Gran, K. B.; Lenhart, C. F.

    2014-12-01

    In the last three decades the Minnesota River Basin (MRB) has experienced increased precipitation and anthropogenic alteration to the drainage network, which contributes to higher flows and increased sediment loading. From field and laboratory approaches, this study investigates the implications of hydrologic change on the colonization of riparian vegetation on pointbars, and of vegetation loss on near-channel sediment storage within the lower Minnesota River. Field surveys consisted of vegetation surveys along pointbars, which were then related to flow records. Surveys revealed a dominance of woody seedlings over older established saplings, and high frequencies of species with alternative forms of propagation that tolerate high flows such as sandbar willow (Salix interior), and beggarticks (Bidens sp.). Surveys also showed in increase in elevation of plant establishment from measurements taken in 1979, resulting in higher area of exposed pointbar and easier mobilization of sediment. Geospatial analysis completed at each sampling location found decreased area of exposed pointbar in association with increases in pointbar vegetation between lower flow years and increased area of exposed pointbar in association with decreased pointbar vegetation between higher flow years. An experimental approach addresses implications of vegetation loss on pointbar sediment storage. In a 1.5m x 6m flume, we are conducting experiments to measure the efficiency of bar vegetation in trapping fine sediment as a function of stem density. Self-formed pointbars are vegetated at varying densities with Medicago sativa (alfalfa) sprouts to represent riparian woody saplings, then flooded with fine sediment-rich water to simulate summer flooding. Sediment deposited at each stem density is then measured to estimate efficiency. While results of these experiments are currently ongoing, we hypothesize that a threshold density exists at which trapping efficiency declines substantially. Preliminary

  15. Effect of Woody Debris abundance on daytime refuge use by cotton mice.

    SciTech Connect

    Hinkelman, Travis, M.; Loeb, Susan, C.

    2007-07-01

    Abstract - Daytime refuges are important to nocturnal rodents for protection from predators and environmental extremes. Because refuges of forest-dwelling rodents are often associated with woody debris, we examined refuge use by 37 radio-collared Peromyscus gossypinus (cotton mice) in experimental plots with different levels of woody debris. Treatment plots had six times (≈ 60 m3/ha) the volume of woody debris as control plots (≈ 10 m3/ha). Of 247 refuges, 159 were in rotting stumps (64%), 32 were in root boles (13%), 19 were in brush piles (8%), and 16 were in logs (6%); 10 refuges could not be identified. Stumps were the most common refuge type in both treatments, but the distribution of refuge types was significantly different between treatment and control plots. Root boles and brush piles were used more on treatment plots than on control plots, and logs were used more on control plots than on treatment plots. Refuge type and vegetation cover were the best predictors of refuge use by cotton mice; root bole refuges and refuges with less vegetation cover received greater-than-expected use by mice. Abundant refuges, particularly root boles, may improve habitat quality for cotton mice in southeastern pine forests.

  16. Historical climates explain contrasting dormancy-breaking requirements in North American, Asian, and European woody species

    NASA Astrophysics Data System (ADS)

    Zohner, Constantin M.; Benito, Blas M.; Fridley, Jason D.; Svenning, Jens-Christian; Renner, Susanne S.

    2016-04-01

    Leaf-out times in temperate woody species are determined by winter chilling and spring warming, with day length playing a minor role. The species-specific relative importance of these phenological cues determines the sensitivity of leaf unfolding to climate warming in the globe's temperate forests. Using experimental and monitoring data on leaf-out cues in 495 woody species [about 1/3rd each from Asia, Europe, and North America (NA)], we show that NA species have higher winter chilling and spring warming requirements than do European and Asian species of similar genetic stock. The continent effect remained significant when controlling for the modern climates that species are adapted to, suggesting that contrasting historic climate conditions led to the differentiation of leaf-out strategies among NA, European, and Asian plants. The NA flora experienced more and longer periods of climatic instability and harshness (esp. since the Pliocene) than did southern Europe and East Asia, which may explain why NA species have higher dormancy requirements and leaf-out later than Asian species, which are characterized by a more shallow dormancy. That species from Asia require significantly less chilling than their NA relatives suggests contrasting responses of NA and Asian temperate forests to continued climate warming. Earlier leaf-out in NA trees and shrubs will be constrained by unmet chilling requirements as winters get warmer, whereas Asian woody species generally lack such temperature limitations.

  17. Characterizing Woody Vegetation Spectral and Structural Parameters with a 3-D Scene Model

    NASA Astrophysics Data System (ADS)

    Qin, W.; Yang, L.

    2004-05-01

    Quantification of structural and biophysical parameters of woody vegetation is of great significance in understanding vegetation condition, dynamics and functionality. Such information over a landscape scale is crucial for global and regional land cover characterization, global carbon-cycle research, forest resource inventories, and fire fuel estimation. While great efforts and progress have been made in mapping general land cover types over large area, at present, the ability to quantify regional woody vegetation structural and biophysical parameters is limited. One approach to address this research issue is through an integration of physically based 3-D scene model with multiangle and multispectral remote sensing data and in-situ measurements. The first step of this work is to model woody vegetation structure and its radiation regime using a physically based 3-D scene model and field data, before a robust operational algorithm can be developed for retrieval of important woody vegetation structural/biophysical parameters. In this study, we use an advanced 3-D scene model recently developed by Qin and Gerstl (2000), based on L-systems and radiosity theories. This 3-D scene model has been successfully applied to semi-arid shrubland to study structure and radiation regime at a regional scale. We apply this 3-D scene model to a more complicated and heterogeneous forest environment dominated by deciduous and coniferous trees. The data used in this study are from a field campaign conducted by NASA in a portion of the Superior National Forest (SNF) near Ely, Minnesota during the summers of 1983 and 1984, and supplement data collected during our revisit to the same area of SNF in summer of 2003. The model is first validated with reflectance measurements at different scales (ground observations, helicopter, aircraft, and satellite). Then its ability to characterize the structural and spectral parameters of the forest scene is evaluated. Based on the results from this study

  18. Woody plant encroachment effect on soil organic carbon dynamics: results from a latitudinal gradient in Italy

    NASA Astrophysics Data System (ADS)

    Pellis, Guido; Chiti, Tommaso; Moscatelli, Maria Cristina; Marinari, Sara; Papale, Dario

    2016-04-01

    Woody plant encroachment into pastures and grasslands represents a significant land cover change phenomenon, with a considerable impact on carbon dynamics at an ecosystem level. It was estimated that 7.64% of the Southern Europe land was subject to that process between 1950 to 2010. As a result of woody encroachment, changes in vegetation composition can produce substantial changes to the soil organic carbon (SOC) cycle. Despite the numerous papers published on land-use change, an evaluation of the IPCC terrestrial carbon pools changes occurring during woody encroachment on abandoned pastures and grasslands is still lacking, particularly for the Italian territory. Therefore, the aim of this study was to investigate the role of woody encroachment on carbon sequestration over abandoned pastures and grasslands in Alpine and Apennine ecosystems, with a particular focus on the SOC. We applied a chronosequence approach to seven selected sites located along a latitudinal gradient in Italy. Each chronosequence consisted of a pasture currently managed, three sites abandoned at different times in the past and, finally, a mature forest stand representing the last phase of the succession. The European Commission sampling protocols to certify SOC changes was adopted to estimate the variations following woody encroachment. Soil samples were collected at different depths in the topsoil (0-30 cm) and subsoil (30-70 cm), despite the original protocol formulation being limited to the topsoil only. In addition, aboveground living biomass (AGB), dead wood and litter were also measured following international protocols. Considering all C pools together, woody plant encroachment leads to a progressive C stock accumulation in all the chronosequences. The total C stock of mature forest stands ranges from 1.78±0.11 times (Eastern Alps) to 2.48±0.31 times (central Apennine) the initial value on pastures. Unsurprisingly, the C stocks of AGB, dead wood and litter all increase during the

  19. Riparian Vegetation Mapping Along the Hanford Reach

    SciTech Connect

    FOGWELL, T.W.

    2003-07-11

    During the biological survey and inventory of the Hanford Site conducted in the mid-1990s (1995 and 1996), preliminary surveys of the riparian vegetation were conducted along the Hanford Reach. These preliminary data were reported to The Nature Conservancy (TNC), but were not included in any TNC reports to DOE or stakeholders. During the latter part of FY2001, PNNL contracted with SEE Botanical, the parties that performed the original surveys in the mid 1990s, to complete the data summaries and mapping associated with the earlier survey data. Those data sets were delivered to PNNL and the riparian mapping by vegetation type for the Hanford Reach is being digitized during the first quarter of FY2002. These mapping efforts provide the information necessary to create subsequent spatial data layers to describe the riparian zone according to plant functional types (trees, shrubs, grasses, sedges, forbs). Quantification of the riparian zone by vegetation types is important to a number of DOE'S priority issues including modeling contaminant transport and uptake in the near-riverine environment and the determination of ecological risk. This work included the identification of vegetative zones along the Reach by changes in dominant plant species covering the shoreline from just to the north of the 300 Area to China Bar near Vernita. Dominant and indicator species included Agropyron dasytachyudA. smithii, Apocynum cannabinum, Aristida longiseta, Artemisia campestris ssp. borealis var scouleriana, Artemisa dracunculus, Artemisia lindleyana, Artemisia tridentata, Bromus tectorum, Chrysothamnus nauseosus, Coreopsis atkinsoniana. Eleocharis palustris, Elymus cinereus, Equisetum hyemale, Eriogonum compositum, Juniperus trichocarpa, Phalaris arundinacea, Poa compressa. Salk exigua, Scirpus acutus, Solidago occidentalis, Sporobolus asper,and Sporobolus cryptandrus. This letter report documents the data received, the processing by PNNL staff, and additional data gathered in FY2002

  20. A scientific assessment of the effectiveness of riparian management practices

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The CEAP Riparian Team reviewed the influence of riparian management practices (RMP) on vegetation, soils and ecosystem services. We developed a conceptual model that links management practices to riparian vegetation and soil attributes and then links these attributes to ecosystem services such as w...

  1. Riparian Areas of the Southwest: Learning from Repeat Photographs

    ERIC Educational Resources Information Center

    Zaimes, George N.; Crimmins, Michael A.

    2010-01-01

    Spatial and temporal variability of riparian areas, as well as potential impacts from climate change, are concepts that land and water managers and stakeholders need to understand to effectively manage and protect riparian areas. Rapid population growth in the southwestern United States, and multiple-use designation of most riparian areas, makes…

  2. Molecular evidence for multiple origins of woodiness and a New World biogeographic connection of the Macaronesian Island endemic Pericallis (Asteraceae: Senecioneae)

    PubMed Central

    Panero, Jose L.; Francisco-Ortega, Javier; Jansen, Robert K.; Santos-Guerra, Arnoldo

    1999-01-01

    The prevalence of woody species in oceanic islands has attracted the attention of evolutionary biologists for more than a century. We used a phylogeny based on sequences of the internal-transcribed spacer region of nuclear ribosomal DNA to trace the evolution of woodiness in Pericallis (Asteraceae: Senecioneae), a genus endemic to the Macaronesian archipelagos of the Azores, Madeira, and Canaries. Our results show that woodiness in Pericallis originated independently at least twice in these islands, further weakening some previous hypotheses concerning the value of this character for tracing the continental ancestry of island endemics. The same data suggest that the origin of woodiness is correlated with ecological shifts from open to species-rich habitats and that the ancestor of Pericallis was an herbaceous species adapted to marginal habitats of the laurel forest. Our results also support Pericallis as closely related to New World genera of the tribe Senecioneae. PMID:10570168

  3. The Phytophthora species assemblage and diversity in riparian alder ecosystems of western Oregon, USA.

    PubMed

    Sims, Laura Lee; Sutton, Wendy; Reeser, Paul; Hansen, Everett M

    2015-01-01

    Phytophthora species were systematically sampled, isolated, identified and compared for presence in streams, soil and roots of alder (Alnus species) dominated riparian ecosystems in western Oregon. We describe the species assemblage and evaluate Phytophthora diversity associated with alder. We recovered 1250 isolates of 20 Phytophthora species. Only three species were recovered from all substrates (streams, soil, alder roots): P. gonapodyides, the informally described "P. taxon Pgchlamydo", and P. siskiyouensis. P. alni ssp. uniformis along with five other species not previously recovered in Oregon forests are included in the assemblage: P.citricola s.l., P. gregata, P. gallica, P. nicotianae and P. parsiana. Phytophthora species diversity was greatest in downstream riparian locations. There was no significant difference in species diversity comparing soil and unwashed roots (the rhizosphere) to stream water. There was a difference between the predominating species from the rhizosphere compared to stream water. The most numerous species was the informally described "P. taxon Oaksoil", which was mainly recovered from, and most predominant in, stream water. The most common species from riparian forest soils and alder root systems was P. gonapodyides. PMID:26240311

  4. Bottom-up factors influencing riparian willow recovery in Yellowstone National Park

    USGS Publications Warehouse

    Tercek, M.T.; Stottlemyer, R.; Renkin, R.

    2010-01-01

    After the elimination of wolves (Canis lupis L.) in the 1920s, woody riparian plant communities on the northern range of Yellowstone National Park (YNP) declined an estimated 50%. After the reintroduction of wolves in 19951996, riparian willows (Salix spp.) on YNP's northern range showed significant growth for the first time since the 1920s. However, the pace of willow recovery has not been uniform. Some communities have exceeded 400 cm, while others are still at pre-1995 levels of 250 cm max. height) willow sites where willows had escaped elk (Cervus elaphus L.) browsing with "short" willow sites that could still be browsed. Unlike studies that manipulated willow height with fences and artificial dams, we examined sites that had natural growth differences in height since the reintroduction of wolves. Tall willow sites had greater water availability, more-rapid net soil nitrogen mineralization, greater snow depth, lower soil respiration rates, and cooler summer soil temperatures than nearby short willow sites. Most of these differences were measured both in herbaceous areas adjacent to the willow patches and in the willow patches themselves, suggesting that they were not effects of varying willow height recovery but were instead preexisting site differences that may have contributed to increased plant productivity. Our results agree with earlier studies in experimental plots which suggest that the varying pace of willow recovery has been influenced by abiotic limiting factors that interact with top-down reductions in willow browsing by elk. ?? 2010 Western North American Naturalist.

  5. Assessment of using Imaging software Image J to determine percentage woody cover from half meter resolution satellite images

    NASA Astrophysics Data System (ADS)

    Mace, W. D.; Cerling, T. E.

    2010-12-01

    The percentage of woody cover over a landscape has been shown to be related to the d13C in soil organic matter because of the difference in carbon isotope discrimination between plants using C3 and C4 photosynthetic pathways. Woody plants such as those found in dense forests predominantly use the C3 pathway; whereas plants that are found to grow in arid grasslands are predominantly using the C4 pathway. Therefore it has also been shown that it is possible to determine the vegetation of current and past ecosystems using d13C in soil organic matter. With the introduction of very high resolution remote sensing it is becoming possible to make detailed maps based on d13C and estimate percentage woody cover. Using these maps it may be possible to create large scale representations of prehistoric ecosystems. Here we asses the use of a widely available imaging software, Image J to survey the percentage of woody cover of tropical ecosystems in East Africa. These results are compared with canopy gap fraction that has been calculated from in-situ ground-up circular fisheye images. We find that in areas where the percentage woody cover is less than 0.5, Image J is an effective method of analysis; however as the percentage cover becomes greater than 0.5 it becomes difficult to distinguish between true canopy and shadows.

  6. Impacts of Extreme Events on Phenology: Drought-Induced Changes in Productivity of Mixed Woody-Herbaceous Ecosystems

    NASA Astrophysics Data System (ADS)

    Rich, P. M.; Breshears, D. D.; White, A. B.

    2006-12-01

    Ecosystem responses to key climate drivers are reflected in phenological dynamics such as the timing and degree of "greenup" that integrate responses over spatial scales from individual plants to ecosystems. This integration is clearest in ecosystems dominated by a single species or life form, such as seasonally dynamic grasslands or more temporally constant evergreen forests. Yet many ecosystems have substantial contribution of cover from both herbaceous and woody evergreen plants. Responses of mixed woody- herbaceous ecosystems to climate are of increasing concern due to their extensive nature, the potential for such systems to yield more complex responses than those dominated by a single life form, and projections that extreme climate and weather events will increase in frequency and intensity with global warming. We present responses of a mixed woody-herbaceous ecosystem type to an extreme event: regional scale piñon pine mortality following an extended drought and the subsequent herbaceous greenup following the first wet period after the drought. This example highlights how reductions in greenness of the slower, more stable evergreen woody component can rapidly be offset by increases associated with resources made available to the relatively more responsive herbaceous component. We hypothesize that such two-phase phenological responses to extreme events are characteristic of many mixed woody-herbaceous ecosystems.

  7. Effects of riparian timber harvesting on instream habitat and fish assemblages in northern Minnesota streams

    USGS Publications Warehouse

    Chizinski, Christopher J.; Vondracek, Bruce C.; Blinn, Charles R.; Newman, Raymond M.; Atuke, Dickson M.; Fredricks, Keith; Hemstad, Nathaniel A.; Merten, Eric; Schlesser, Nicholas

    2010-01-01

    Relatively few evaluations of aquatic macroinvertebrate and fish communities have been published in peer-reviewed literature detailing the effect of varying residual basal area (RBA) after timber harvesting in riparian buffers. Our analysis investigated the effects of partial harvesting within riparian buffers on aquatic macroinvertebrate and fish communities in small streams from two experiments in northern Minnesota northern hardwood-aspen forests. Each experiment evaluated partial harvesting within riparian buffers. In both experiments, benthic macroinvertebrates and fish were collected 1 year prior to harvest and in each of 3 years after harvest. We observed interannual variation for the macroinvertebrate abundance, diversity and taxon richness in the single-basin study and abundance and diversity in the multiple-basin study, but few effects related to harvest treatments in either study. However, interannual variation was not evident in the fish communities and we detected no significant changes in the stream fish communities associated with partially harvested riparian buffers in either study. This would suggest that timber harvesting in riparian management zones along reaches ≤200 m in length on both sides of the stream that retains RBA ≥ 12.4 ± 1.3 m2 ha−1 or on a single side of the stream that retains RBA ≥ 8.7 ± 1.6 m2 ha−1 may be adequate to protect macroinvertebrate and fish communities in our Minnesota study systems given these specific timber harvesting techniques.

  8. Mapping of riparian invasive species with supervised classification of Unmanned Aerial System (UAS) imagery

    NASA Astrophysics Data System (ADS)

    Michez, Adrien; Piégay, Hervé; Jonathan, Lisein; Claessens, Hugues; Lejeune, Philippe

    2016-02-01

    Riparian zones are key landscape features, representing the interface between terrestrial and aquatic ecosystems. Although they have been influenced by human activities for centuries, their degradation has increased during the 20th century. Concomitant with (or as consequences of) these disturbances, the invasion of exotic species has increased throughout the world's riparian zones. In our study, we propose a easily reproducible methodological framework to map three riparian invasive taxa using Unmanned Aerial Systems (UAS) imagery: Impatiens glandulifera Royle, Heracleum mantegazzianum Sommier and Levier, and Japanese knotweed (Fallopia sachalinensis (F. Schmidt Petrop.), Fallopia japonica (Houtt.) and hybrids). Based on visible and near-infrared UAS orthophoto, we derived simple spectral and texture image metrics computed at various scales of image segmentation (10, 30, 45, 60 using eCognition software). Supervised classification based on the random forests algorithm was used to identify the most relevant variable (or combination of variables) derived from UAS imagery for mapping riparian invasive plant species. The models were built using 20% of the dataset, the rest of the dataset being used as a test set (80%). Except for H. mantegazzianum, the best results in terms of global accuracy were achieved with the finest scale of analysis (segmentation scale parameter = 10). The best values of overall accuracies reached 72%, 68%, and 97% for I. glandulifera, Japanese knotweed, and H. mantegazzianum respectively. In terms of selected metrics, simple spectral metrics (layer mean/camera brightness) were the most used. Our results also confirm the added value of texture metrics (GLCM derivatives) for mapping riparian invasive species. The results obtained for I. glandulifera and Japanese knotweed do not reach sufficient accuracies for operational applications. However, the results achieved for H. mantegazzianum are encouraging. The high accuracies values combined to

  9. Industry/government collaborations on short-rotation woody crops for energy, fiber and wood products

    SciTech Connect

    Wright, L.L.; Berg, S.

    1996-12-31

    More than twenty-five organizations can be identified in the US and Canada that have research plantings of 20 ha in size or greater of short-rotation woody crops and most of those are well-established forest products companies. In 1990, only 9 forest products companies had commercial or substantial research plantings of short-rotation woody crops. The recent harvest and use of hybrid poplars for pulp and paper production in the Pacific Northwest has clearly stimulated interest in the use of genetically superior hybrid poplar clones across North America. Industry and government supported research cooperatives have been formed to develop sophisticated techniques for producing genetically superior hybrid poplars and willows suited for a variety of locations in the US. While the primary use of commercially planted short-rotation woody crops is for pulp and paper, energy is a co-product in most situations. A document defining a year 2020 technology vision for America`s forest, wood and paper industry affirms that {open_quotes}biomass will be used not only for building materials and paper and paperboard products, but also increasingly for steam, power, and liquid fuel production.{close_quotes} To accomplish the goals of {open_quotes}Agenda 2020{close_quotes} a new collaborative research effort on sustainable forestry has been initiated by the Department of Energy (DOE) and the American Forest and Paper Association (AF&PA). Both the new and old collaborative efforts are focusing on achieving substantial and sustainable gains in U.S. wood production for both energy and traditional wood products. AF&PA and DOE hope that industry and government partnerships addressing the competitiveness and energy efficiency of U.S. industries, can serve as a model for future research efforts.

  10. Ecogeomorphic feedbacks and flood loss of riparian tree seedlings in meandering channel experiments

    NASA Astrophysics Data System (ADS)

    Kui, Li; Stella, John C.; Lightbody, Anne; Wilcox, Andrew C.

    2014-12-01

    During floods, fluvial forces interact with riparian plants to influence evolution of river morphology and floodplain plant community development. Understanding of these interactions, however, is constrained by insufficient precision and control of drivers in field settings, and insufficient realism in laboratory studies. We completed a novel set of flume experiments using woody seedlings planted on a sandbar within an outdoor meandering stream channel. We quantified effects on local sedimentation and seedling loss to scour and burial across realistic ranges of woody plant morphologies (Populus versus Tamarix species), densities (240 plants m-2 versus 24 m-2), and sediment supply (equilibrium versus deficit). Sedimentation was higher within Tamarix patches than Populus patches, reflecting Tamarix's greater crown frontal area and lower maximum crown density. Plant dislodgement occurred rarely (1% of plants) and was induced in plants with shorter roots. Complete burial was most frequent for small Tamarix that occurred at high densities. Burial risk decreased 3% for Populus and 13% for Tamarix for every centimeter increment in stem height, and was very low for plants >50 cm tall. These results suggest that Tamarix are proportionally more vulnerable than Populus when small (<20 cm tall), but that larger plants of both species are resistant to both burial and scour. Thus, plant morphological traits and development windows must be considered in addition to physical drivers when designing process-based restoration efforts on regulated rivers such as flow releases to benefit native tree species.

  11. Functional redundancy as a tool for bioassessment: A test using riparian vegetation.

    PubMed

    Bruno, D; Gutiérrez-Cánovas, C; Velasco, J; Sánchez-Fernández, D

    2016-10-01

    There is an urgent need to track how natural systems are responding to global change in order to better guide management efforts. Traditionally, taxonomically based metrics have been used as indicators of ecosystem integrity and conservation status. However, functional approaches offer promising advantages that can improve bioassessment performance. In this study, we aim to test the applicability of functional redundancy (FR), a functional feature related to the stability, resistance and resilience of ecosystems, as a tool for bioassessment, looking at woody riparian communities in particular. We used linear mixed-effect models to investigate the response of FR and other traditional biomonitoring indices to natural (drought duration) and anthropogenic stress gradients (flow regulation and agriculture) in a Mediterranean basin. Such indices include species richness, a taxonomic index, and the Riparian Quality Index, which is an index of ecological status. Then, we explored the ability of FR and the other indices to discriminate between different intensities of human alteration. FR showed higher explanatory capacity in response to multiple stressors, although we found significant negative relationships between all the biological indices (taxonomic, functional and ecological quality) and stress gradients. In addition, FR was the most accurate index to discriminate among different categories of human alteration in both perennial and intermittent river reaches, which allowed us to set threshold values to identify undisturbed (reference condition), moderately disturbed and highly disturbed reaches in the two types of river. Using these thresholds and the best-fitting model, we generated a map of human impact on the functional redundancy of riparian communities for all the stretches of the river network. Our results demonstrate that FR presents clear advantages over traditional methods, which suggests that it should be part of the biomonitoring toolbox used for

  12. Woody vegetation composition and structure in peri-urban Chongming Island, China.

    PubMed

    Zhao, Min; Escobedo, Francisco J; Wang, Ruijing; Zhou, Qiaolan; Lin, Wenpeng; Gao, Jun

    2013-05-01

    Chongming, the world's largest alluvial island, is located within the municipality of Shanghai, China. Recent projects have now linked peri-urban Chongming to Shanghai's urban core and as a result will soon undergo substantial changes from urbanization. We quantitatively analyzed the structure and composition of woody vegetation across subtropical, peri-urban Chongming as a basis for sustainable management of these rapidly urbanizing subtropical ecosystems elsewhere. We used 178 permanent, random plots to statistically and spatially analyze woody plant composition and tree structure across the 1,041 km(2) of Chongming. A total of 2,251 woody plants were measured comprising 42 species in 37 genera. We statistically and geospatially analyzed field data according to land uses and modeled air pollution removal by trees. Average tree diameter at breast height, total height, and crown widths on transportation land uses were greater than other land uses. These same values were lowest on forest land use and greater tree cover was associated with areas of increased anthropogenic activity. Less than 20 % of the woody vegetation was exotic and a species richness index was significantly different between land uses due to legacy effects. Composition of agriculture and forest land uses were similar to residential and transportation. Tree cover across Chongming was also estimated to annually remove 1,400 tons of air pollutants. We propose that this integrated and quantitative method can be used in other subtropical, peri-urban areas in developing countries to establish baseline trends for future sustainability objectives and to monitor the effects of urbanization and climate change. PMID:23494057

  13. Woody Vegetation Composition and Structure in Peri-urban Chongming Island, China

    NASA Astrophysics Data System (ADS)

    Zhao, Min; Escobedo, Francisco J.; Wang, Ruijing; Zhou, Qiaolan; Lin, Wenpeng; Gao, Jun

    2013-05-01

    Chongming, the world's largest alluvial island, is located within the municipality of Shanghai, China. Recent projects have now linked peri-urban Chongming to Shanghai's urban core and as a result will soon undergo substantial changes from urbanization. We quantitatively analyzed the structure and composition of woody vegetation across subtropical, peri-urban Chongming as a basis for sustainable management of these rapidly urbanizing subtropical ecosystems elsewhere. We used 178 permanent, random plots to statistically and spatially analyze woody plant composition and tree structure across the 1,041 km2 of Chongming. A total of 2,251 woody plants were measured comprising 42 species in 37 genera. We statistically and geospatially analyzed field data according to land uses and modeled air pollution removal by trees. Average tree diameter at breast height, total height, and crown widths on transportation land uses were greater than other land uses. These same values were lowest on forest land use and greater tree cover was associated with areas of increased anthropogenic activity. Less than 20 % of the woody vegetation was exotic and a species richness index was significantly different between land uses due to legacy effects. Composition of agriculture and forest land uses were similar to residential and transportation. Tree cover across Chongming was also estimated to annually remove 1,400 tons of air pollutants. We propose that this integrated and quantitative method can be used in other subtropical, peri-urban areas in developing countries to establish baseline trends for future sustainability objectives and to monitor the effects of urbanization and climate change.

  14. Methods for evaluating riparian habitats with applications to management

    USGS Publications Warehouse

    Platts, William S.; Armour, C.L.; Booth, G.D.; Bryant, M.; Bufford, J.L.; Cuplin, P.; Jensen, S.; Lienkaemper, G.W.; Minshall, G.W.; Monsen, S.T.; Nelson, R.L.; Sedell, J.R.; Tuhy, J.S.

    1987-01-01

    Riparian area planning and management is a major national issues today--something that should have been the case a century ago. A century of additive effects of land use has resulted in major impacts on many riparian stream habitats and their fisheries, wildlife, and domestic livestock use. Before scientists can evaluate the influences of various land and water uses on riparian environments, they must first understand these environments. This means being able to detect and measure with confidence the natural and artificial variation and instantaneous conditions of the riparian habitat. These conditions must then be related to the production capability of riparian habitat and any extraneous factors affecting this production potential.

  15. Mapping preferential flow pathways in a riparian wetland using ground-penetrating radar

    NASA Astrophysics Data System (ADS)

    Gormally, Kevin Hill

    Preferential flow of water through channels in the soil has been implicated as a vehicle for groundwater and surface water contamination in forested riparian wetland buffers. Water conducted through these by-pass channels can circumvent interaction with wetland biota, biomass, and soils, thereby reducing the buffering capacity of the riparian strips for adsorption and uptake of excess nutrient loads from neighboring agricultural fields and urbanized lands. Models of riparian function need to account for preferential flow to accurately estimate nutrient flux to stream channels, but there are currently no methods for determining the form and prevalence of these pathways outside of extensive destructive sampling. This research developed, tested, and validated a new application of non-invasive ground-penetrating radar technology (GPR) for mapping the three-dimensional structure of near-surface (0-1 m) lateral preferential flow channels. Manual and automated detection methodologies were created for analyzing GPR scan data to locate the channels in the subsurface. The accuracy of the methodologies was assessed in two field test plots with buried PVC pipes simulating the riparian channels. The manual methodology had a 0% Type I error rate and 8% Type II error rate; the automated version had a <1% Type I error rate and 29% Type II error rate. An automated mapping algorithm was also created to reconstruct channel geometries from the scan data detections. The algorithm was shown to robustly track the connectivity of PVC pipe segments arranged in a branching structure hypothesized to exist in the riparian soils. These methods and algorithms were then applied at a riparian wetland study site at USDA Beltsville Agricultural Research Center in Beltsville, MD. The predicted structure of preferential flow channels in the wetland was validated by transmission of tracer dye through the study site and ground truth generated from soil core samples (92% accurate). These GPR tools will

  16. Woody plant encroachment, and its removal, impact bacterial and fungal communities across stream and terrestrial habitats in a tallgrass prairie ecosystem.

    PubMed

    Veach, Allison M; Dodds, Walter K; Jumpponen, Ari

    2015-10-01

    Woody plant encroachment has become a global threat to grasslands and has caused declines in aboveground richness and changes in ecosystem function; yet we have a limited understanding on the effects of these phenomena on belowground microbial communities. We completed riparian woody plant removals at Konza Prairie Biological Station, Kansas and collected soils spanning land-water interfaces in removal and woody vegetation impacted areas. We measured stream sediments and soils for edaphic variables (C and N pools, soil water content, pH) and bacterial (16S rRNA genes) and fungal (ITS2 rRNA gene repeat) communities using Illumina MiSeq metabarcoding. Bacterial richness and diversity decreased with distance from streams. Fungal richness decreased with distance from the stream in wooded areas, but was similar across landscape position while Planctomycetes and Basidiomycota relative abundance was lower in removal areas. Cyanobacteria, Ascomycota, Chytridiomycota and Glomeromycota relative abundance was greater in removal areas. Ordination analyses indicated that bacterial community composition shifted more across land-water interfaces than fungi yet both were marginally influenced by treatment. This study highlights the impacts of woody encroachment restoration on grassland bacterial and fungal communities which likely subsequently affects belowground processes and plant health in this ecosystem. PMID:26347079

  17. Facilitation contributes to Mediterranean woody plant diversity but does not shape the diversity-productivity relationship along aridity gradients.

    PubMed

    Rey, Pedro J; Alcántara, Julio M; Manzaneda, Antonio J; Sánchez-Lafuente, Alfonso M

    2016-07-01

    The diversity-productivity relationship (humped-back model (HBM)) and the stress-gradient (SGH) hypotheses may be connected when productivity is limited primarily by aridity. We analytically connect both hypotheses and assess the contribution of facilitation to woody plant richness along the aridity gradient of the Western Mediterranean floristic region. We monitored regeneration niches of woody plants, obtaining rarefied species richness and plant relative interaction indices in 54 forests and scrublands in a 1750-km geographical range across Spain, Morocco and the Canary Islands. We verified the monotonic increase in facilitation with aridity postulated by SGH and the humped-shape pattern of species richness expected from HBM, which became manifest after expanding the aridity gradient or crossing vegetation types. Along the gradient, interaction balance turned into facilitation earlier in forest than in scrublands. The effects of aridity and interaction balance on species diversity were additive rather than interdependent. Facilitation is an important driver of woody species richness at macroecological scales because it added up to diversity in most sites, with enhanced contribution with increased stress. The HBM was not shaped by species interactions. Results suggest that facilitation may act in Mediterranean vegetation buffering against critical transitions between states allowing woody plant communities to cope with the rise in aridity expected with global warming. PMID:26959084

  18. Biomass in Serbia - potential of beech forests

    NASA Astrophysics Data System (ADS)

    Brasanac-Bosanac, Lj.; Cirkovic-Mitrovic, T.; Popovic, V.; Jokanovic, D.

    2012-04-01

    As for the renewable sources for energy production, biomass from forests and wood processing industry comes to the second place. The woody biomass accounts for 1.0 Mtoe, that is equivalent with 1.0 Mtoe of oil. Due to current evaluations, the greatest part of woody biomass would be used for briquettes and pallets production. As the biomass from forests is increasingly becoming the interest of national and international market, a detailed research on overall potential of woody supply from Serbian forests is required. Beech forests account for 29.4 % of forest cover of Serbia. They also have the greatest standing volume (42.4 % of the overall standing volume) and the greatest mean annual increment (32.3 %)(Bankovic,et.al.2009). Herewith, the aim of this poster is to determine the long-term biomass production of these forests.For this purpose a management unit called Lomnicka reka has been chosen. As these beech forests have similar structural development, this location is considered representative for whole Serbia. DBH of all trees were measured with clipper and the accuracy of 0.01 mm, and the heights with a Vertex 3 device (with accuracy of 0.1 m). All measurements were performed on the fields each 500 m2 (square meters). The overall quantity of root biomass was calculated using the allometric equations. The poster shows estimated biomass stocks of beech forests located in Rasina area. Dates are evaluated using non-linear regression (Wutzler,T.et.al.2008). Biomass potential of Serbian beech forests will enable the evaluation of long-term potential of energy generation from woody biomass in agreement with principles of sustainable forest management. The biomass from such beech forests can represent an important substitution for energy production from fossil fuels (e.g. oil) and herewith decrease the CO2 emissions.

  19. Mechanisms driving the seasonality of catchment scale nitrate export: Evidence for riparian ecohydrologic controls

    NASA Astrophysics Data System (ADS)

    Duncan, Jonathan M.; Band, Lawrence E.; Groffman, Peter M.; Bernhardt, Emily S.

    2015-06-01

    Considerable variability in the seasonal patterns of stream water nitrate (NO3-) has been observed in forested watersheds throughout the world. While many forested headwater catchments exhibit winter and early spring peaks in NO3- concentrations, several watersheds have peak concentrations during the summer months. Pond Branch, a headwater catchment in Maryland monitored for over 10 years, exhibits recurrent and broad summer peaks in both NO3- concentrations and watershed export. Higher NO3- export from June to September is particularly surprising, given that these summer months typically have the year's lowest discharge. A key challenge is identifying the source(s) of NO3- and the mechanism(s) by which it is transported to the watershed outlet during the summer. In this study, we assessed multiple hypotheses (not mutually exclusive) that could account for the seasonal trend including proximal controls of groundwater-surface water interactions, instream processes, and riparian groundwater-N cycling interactions, as well as two distal controls: geochemical weathering and senescence of riparian vegetation. A combination of long-term weekly and limited duration high-frequency sensor data reveals the importance of riparian ecohydrologic processes during base flow. In this watershed, patterns of seasonal stream water NO3- concentrations and fluxes depend fundamentally on interactions between groundwater dynamics and nitrogen (N) cycling in the riparian zone. Groundwater tables control nitrification-denitrification dynamics as well as hydrologic transport. Our results suggest that in many watersheds, a more sophisticated exploration of NO3- production and NO3- transport mechanisms is required to identify critical points in the landscape and over time that disproportionately drive patterns of watershed NO3- export.

  20. HERBICIDE ABATEMENT BY A RIPARIAN WETLAND SYSTEM

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Riparian buffers are touted for their ability to remove agricultural contaminants; however, little is known about the specific processes that function to arrest pesticide movement and transport. Five years of data have been gathered on the movement and fate of atrazine and metolachlor into a ripari...

  1. Herbicide Abatement by a Riparian Wetland System

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Riparian buffers are touted for their ability to remove agricultural contaminants. However, little is known about the specific processes that function to arrest pesticide movement and transport. Five years of data have been gathered on the movement and fate of atrazine and metolachlor into a ripar...

  2. Woodiness within the Spermacoceae–Knoxieae alliance (Rubiaceae): retention of the basal woody condition in Rubiaceae or recent innovation?

    PubMed Central

    Lens, Frederic; Groeninckx, Inge; Smets, Erik; Dessein, Steven

    2009-01-01

    Background and Aims The tribe Spermacoceae is essentially a herbaceous Rubiaceae lineage, except for some species that can be described as ‘woody’ herbs, small shrubs to treelets, or lianas. Its sister tribe Knoxieae contains a large number of herbaceous taxa, but the number of woody taxa is higher compared to Spermacoceae. The occurrence of herbaceous and woody species within the same group raises the question whether the woody taxa are derived from herbaceous taxa (i.e. secondary woodiness), or whether woodiness represents the ancestral state (i.e. primary woodiness). Microscopic observations of wood anatomy are combined with an independent molecular phylogeny to answer this question. Methods Observations of wood anatomy of 21 woody Spermacoceae and eight woody Knoxieae species, most of them included in a multi-gene molecular phylogeny, are carried out using light microscopy. Key Results Observations of wood anatomy in Spermacoceae support the molecular hypothesis that all the woody species examined are secondary derived. Well-known wood anatomical characters that demonstrate this shift from the herbaceous to the woody habit are the typically flat or decreasing length vs. age curves for vessel elements, the abundance of square and upright ray cells, or even the (near-) absence of rays. These so-called paedomorphic wood features are also present in the Knoxieae genera Otiophora, Otomeria, Pentas, Pentanisia and Phyllopentas. However, the wood structure of the other Knoxieae genera observed (Carphalea, Dirichletia and Triainolepis) is typical of primarily woody taxa. Conclusions In Spermacoceae, secondary woodiness has evolved numerous times in strikingly different habitats. In Knoxieae, there is a general trend from primary woodiness towards herbaceousness and back to (secondary) woodiness. PMID:19279041

  3. Breeding bird response to partially harvested riparian management zones

    USGS Publications Warehouse

    Chizinski, Christopher J.; Peterson, Anna; Hanowski, JoAnn; Blinn, Charles R.; Vondracek, Bruce C.; Niemi, Gerald

    2011-01-01

    We compared avian communities among three timber harvesting treatments in 45-m wide even-age riparian management zones (RMZs) placed between upland clearcuts and along one side of first- or second-order streams in northern Minnesota, USA. The RMZs had three treatments: (1) unharvested, (2) intermediate residual basal area (RBA) (targeted goal 11.5 m2/ha, realized 16.0 m2/ha), and (3) low RBA (targeted goal 5.7 m2/ha, realized 8.7 m2/ha). Surveys were conducted one year pre-harvest and three consecutive years post-harvest. There was no change in species richness, diversity, or total abundance associated with harvest but there were shifts in the types of birds within the community. In particular, White-throated Sparrows (Zonotrichia albicollis) and Chestnut-sided Warblers (Dendroica pensylvanica) increased while Ovenbirds (Seiurus aurocapilla) and Red-eyed Vireos (Vireo olivaceus) decreased. The decline of avian species associated with mature forest in the partially harvested treatments relative to controls indicates that maintaining an unharvested RMZ adjacent to an upland harvest may aid in maintaining avian species associated mature forest in Minnesota for at least three years post-harvest. However, our observations do not reflect reproductive success, which is an area for future research.

  4. Woody debris flow behavior from experimental analysis

    NASA Astrophysics Data System (ADS)

    Bateman, Allen; Medina, Vicente; Morloti, Emanuele; Renaud, Alexis

    2010-05-01

    A consequence of debris flow in streams are well known, the collapse of the stream flooding all over the land. The high momentum flux of those flows can devastate houses, drag and crushes cars, etc. The presence of woody debris into the flow rise the flow depth and increment the collapse of the streams, bridges and structures. The present preliminary study offer a qualitative comparison between a debris flow and a woody debris flow with similar flow characteristics. To obtain this a series of experiments were performed in the Morph-dynamic Laboratory of the Hydraulic, Marine and Environmental Department. A high slope flume of 9 meters length, 40 cm width and 60 cm high was used. Up to 5 experiments were running in the flume. Initially the material was placed dry in the bed conforming a 20 cm depth of granular material changing the way of water wave entrance. Always water wave was introduced as a step function with different step size and different flow duration in order to introduce the same volume of water, just enough to saturate all the material in the channel. The flow was filmed with a handycam in order to see the general flow characteristics and with a high speed camera, just in a section, to visualize the flow velocities. Several woody pieces were placed along the channel to simulate the presence of wood and tress in the stream. Each tree was constructed in such a way that each one have a root made by rocks simulating a real root and different mass distribution. The comparison with experiments without wood was clever to understand the influence of woods in the debris flow. The woody debris flow alone creates natural dams along the stream without presence of inciters obstacles along the reach.

  5. Breeding Bird Community Continues to Colonize Riparian Buffers Ten Years after Harvest

    PubMed Central

    2015-01-01

    Riparian ecosystems integrate aquatic and terrestrial communities and often contain unique assemblages of flora and fauna. Retention of forested buffers along riparian habitats is a commonly employed practice to reduce potential negative effects of land use on aquatic systems. However, very few studies have examined long-term population and community responses to buffers, leading to considerable uncertainty about effectiveness of this practice for achieving conservation and management outcomes. We examined short- (1–2 years) and long-term (~10 years) avian community responses (occupancy and abundance) to riparian buffer prescriptions to clearcut logging silvicultural practices in the Pacific Northwest USA. We used a Before-After-Control-Impact experimental approach and temporally replicated point counts analyzed within a Bayesian framework. Our experimental design consisted of forested control sites with no harvest, sites with relatively narrow (~13m) forested buffers on each side of the stream, and sites with wider (~30m) and more variable width unharvested buffer. Buffer treatments exhibited a 31–44% increase in mean species richness in the post-harvest years, a pattern most evident 10 years post-harvest. Post-harvest, species turnover was much higher on both treatments (63–74%) relative to the controls (29%). We did not find evidence of local extinction for any species but found strong evidence (no overlap in 95% credible intervals) for an increase in site occupancy on both Narrow (short-term: 7%; long-term 29%) and Wide buffers (short-term: 21%; long-term 93%) relative to controls after harvest. We did not find a treatment effect on total avian abundance. When assessing relationships between buffer width and site level abundance of four riparian specialists, we did not find strong evidence of reduced abundance in Narrow or Wide buffers. Silviculture regulations in this region dictate average buffer widths on small and large permanent streams that range

  6. Do Wildfires Promote Woody Species Invasion in a Fire-Adapted Ecosystem? Post-fire Resprouting of Native and Non-native Woody Plants in Central Argentina

    NASA Astrophysics Data System (ADS)

    Herrero, M. Lucrecia; Torres, Romina C.; Renison, Daniel

    2016-02-01

    We asked whether prescribed fire could be a useful management tool to reduce invasion by non-native plants in an ecosystem where native plants are supposed to be adapted to fires. Specifically, we compare the post-fire resprouting response of native and non-native woody species in Chaco Serrano forest of central Argentina. The measurements were carried out in five burnt areas where we selected ten native and seven non-native species. Our response variables were (1) post-fire survival, (2) types of resprouts, and (3) the growth of the resprouts. Our main results show that one year after the fire, survivals of native and non-native species were 0.84 and 0.89, respectively, with variances in survival seven times smaller in the native species group. Type of resprout was also less variable in native species, while growth of the resprouts was similar in native and non-native groups. We interpret that in most cases, the burning a forest with mixed native and non-native plants through prescribed fires will not differentially stop the invasion by non-native woody species even in ecosystems which are presumed to be relatively resistant to fires such as our study area.

  7. Do Wildfires Promote Woody Species Invasion in a Fire-Adapted Ecosystem? Post-fire Resprouting of Native and Non-native Woody Plants in Central Argentina.

    PubMed

    Herrero, M Lucrecia; Torres, Romina C; Renison, Daniel

    2016-02-01

    We asked whether prescribed fire could be a useful management tool to reduce invasion by non-native plants in an ecosystem where native plants are supposed to be adapted to fires. Specifically, we compare the post-fire resprouting response of native and non-native woody species in Chaco Serrano forest of central Argentina. The measurements were carried out in five burnt areas where we selected ten native and seven non-native species. Our response variables were (1) post-fire survival, (2) types of resprouts, and (3) the growth of the resprouts. Our main results show that one year after the fire, survivals of native and non-native species were 0.84 and 0.89, respectively, with variances in survival seven times smaller in the native species group. Type of resprout was also less variable in native species, while growth of the resprouts was similar in native and non-native groups. We interpret that in most cases, the burning a forest with mixed native and non-native plants through prescribed fires will not differentially stop the invasion by non-native woody species even in ecosystems which are presumed to be relatively resistant to fires such as our study area. PMID:26423569

  8. Paleo-shade: woody cover, stable isotopes, soil temperature, and soil organic matter in tropical ecosystems (Invited)

    NASA Astrophysics Data System (ADS)

    Cerling, T. E.; Andanje, S.; Kimutai, D.; Levin, N. E.; Mace, W. D.; Macharia, A. N.; Passey, B. H.; Remien, C.; Wynn, J. G.

    2010-12-01

    The δ13C value of soil carbon is directly related to the fraction of C4 biomass in soils because of the difference in isotope discrimination between plants using the C3 (trees, shrubs, and herbs) and C4 (primarily tropical grasses) photosynthetic pathways. Almost all woody plants use the C3 photosynthetic pathway, and therefore the fraction of woody cover in tropical ecosystems has an important influence on the fraction of C4 biomass in soils. Surveys of tropical ecosystems from East Africa and Australia show that little C4 biomass is evident until woody cover fraction falls below 0.5. This is due to several factors, including the shading effect of woody cover and retention of soil moisture; these decrease the daily maximum ground surface temperature and decrease water stress. Thus, C3 photosynthesis is favored relative to C4 photosynthesis in well-shaded environments compared to nearby open environments. Between 0.0 and 0.5 fraction woody cover, the δ13C of soil organic matter is strongly correlated with the fraction of woody cover. However, as the woody cover approaches 0, in some semi-arid ecosystems a significant fraction of C3 herbaceous plants are present. Thus some “grasslands” may have a significant fraction of C3 herbaceous cover. Paleosols are an indicator of the fraction of C4 biomass because of their preserved δ13C values in organic matter and in pedogenic carbonate. This δ13C signal can be used as an indicator of “paleo-shade” or fraction of woody-cover in the geological record. Δ47C values of paleosols for much of the past 4 Ma in the Turkana Basin in northern Kenya and the Awash Basin in Ethiopia indicate ecosystems similar to modern grasslands to woody grasslands (using the UNESCO classification for tropical ecosystems); these are commonly known as savannas. Thus some of the most important localities documenting hominin evolution show strong evidence for a savanna environment. This interpretation is supported by independent evidence

  9. Woody biomass-based bioenergy development at the Atikokan Power Generating Station: Local perceptions and public opinions

    NASA Astrophysics Data System (ADS)

    Baten, Cassia Sanzida

    To tackle climate change, reduce air pollution and promote development of renewable energy, the Ontario government is investing in the conversion of the coal-based Atikokan Power Generating Station (APGS) in Atikokan, Ontario, to woody biomass feedstock. This research offers one of the first looks at the perspectives of different individuals and groups on converting woody biomass to energy. Using a combination of study instruments which include literature review, surveys, interviews with key informants, semi-structured interviews, and focus group discussions, this dissertation uses qualitative research to provide a picture of the public's opinions and attitudes towards the APGS biomass energy development. Given Ontario's huge and sustainably managed forest resource, woody biomass is expected to be a major component of renewable energy production in Ontario. The move towards renewable energy that replaces fossil fuels with woody biomass will have considerable socio-economic implications for local and First Nation communities living in and around the bioenergy power generating station. Findings indicate that there is wide support for biomass utilization at the APGS by local people, especially since the project would create sustainable employment. The connection of woody biomass-based energy generation and rural community development provides opportunities and challenges for Atikokan's economic development. Respondents identified economic, environmental and social barriers to biomass utilization, and emphasized trust and transparency as key elements in the successful implementation of the APGS project. As demand for woody biomass-based energy increases, special attention will be needed to ensure and maintain the social, economic and environmental sustainability of biomass use at the APGS. In this research, respondents' views about biomass utilization for energy mainly focused on forest-related issues rather than energy. In Atikokan much of the project's social

  10. Phytophthora ramorum: A Pathogen with a Remarkably Wide Host Range Causing Sudden Oak Death on Oaks and Ramorum Blight on Woody Ornamentals

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Phytophthora ramorum is an oomycete plant pathogen classified in the kingdom Stramenopiles. P. ramorum is the causal agent of sudden oak death on coast live oak and tanoak as well as Ramorum blight on woody ornamental and forest understory plant hosts. It causes stem cankers on trees, and leaf bligh...

  11. Decreased carbon and nutrient input to boreal lakes from particulate organic matter following riparian clear-cutting

    NASA Astrophysics Data System (ADS)

    France, Robert; Culbert, Heather; Peters, Robert

    1996-07-01

    The plankton communities of oligotrophic Canadian Shield lakes are strongly regulated by the allochthonous supply of total phosphorus (TP) and dissolved organic carbon (DOC), a proportion of both of which originate from particulate organic matter. Although decreased inputs of allochthonous leaf litter have been documented for small streams whose riparian forests have been removed, no such data exist for boreal lakes. Through estimates of airborne litter input from forested and clear-cut shorelines and laboratory measurements of concentrations released from leaf leachate, we determined that riparian deforestation resulted in reductions of DOC from 17.8 to 0.4 g/m shoreline/yr and of TP from 2.9 to 0.3 g/m shoreline/yr. Previous predictive models indicate that such reductions may be substantial enough to decrease basic metabolic processes of lake plankton communities by as much as 9% in primary production and 17% in respiration.

  12. Decreased Carbon and Nutrient Input to Boreal Lakes from Particulate Organic Matter Following Riparian Clear-Cutting

    PubMed

    France; Culbert; Peters

    1996-07-01

    The plankton communities of oligotrophic Canadian Shield lakes are strongly regulated by the allochthonous supply of total phosphorus (TP) and dissolved organic carbon (DOC), a proportion of both of which originate from particulate organic matter. Although decreased inputs of allochthonous leaf litter have been documented for small streams whose riparian forests have been removed, no such data exist for boreal lakes. Through estimates of airborne litter input from forested and clear-cut shorelines and laboratory measurements of concentrations released from leaf leachate, we determined that riparian deforestation resulted in reductions of DOC from 17.8 to 0.4 g/m shoreline/yr and of TP from 2.9 to 0.3 g/m shoreline/yr. Previous predictive models indicate that such reductions may be substantial enough to decrease basic metabolic processes of lake plankton communities by as much as 9% in primary production and 17% in respiration. PMID:8661623

  13. Hydrogeologic and Biogeochemical Controls on the Fate and Transport of Nitrate and Pesticides in the Riparian Zone of Cow Castle Creek, South Carolina

    NASA Astrophysics Data System (ADS)

    Puckett, L. J.; Hughes, W. B.

    2001-12-01

    Riparian zones often contain large amounts of organic carbon and small concentrations of dissolved oxygen (DO) resulting in reducing conditions that favor removal of nitrate through denitrification, and in some cases pesticides. We investigated the transport and fate of nitrate, several commonly used pesticides, and selected metabolites at a farm in South Carolina adjacent to Cow Castle Creek. Sixteen shallow water-table wells were installed to map the water table and ground water was sampled using 7 multi-port wells installed at depths ranging from 0.5 to 10 m along a 1-km flow system bracketing several types of land use including a cornfield, pine forest, hay field, riparian forest, and the discharge area at Cow Castle Creek. Ground-water recharge dates, based on CFC age dating, were from the mid-to-late 1970s below the riparian zone and Cow Castle Creek indicating a maximum residence time of approximately 23-years. Organic carbon under the riparian zone was as high as 0.97 percent. DO concentrations were variable with the smallest values immediately under the riparian zone. Nitrate-nitrogen concentrations varied over the site from about 28 mg/L immediately down gradient of the cornfield to below detection (<0.05 mg/L) under the hayfield. Large decreases in nitrate-nitrogen were detected at the edge of the riparian zone and immediately below it. Nitrate concentrations initially increased with depth below the riparian zone then decreased again in deeper samples while beneath Cow Castle Creek they varied from 2.8 to 4.7 mg/L. Excess nitrogen gas concentrations, presumably derived from denitrification, varied from 1.4 to 4.1 mg/L under the riparian zone. Atrazine, metolachlor and their metabolites were the most commonly detected pesticides and were generally restricted to samples collected under and adjacent to the cornfield however, there were a few detections of atrazine, simazine, chlorpyrifos, and deethyl atrazine under and adjacent to the riparian zone. Flow

  14. Bat activity in harvested and intact forest stands in the allegheny mountains

    USGS Publications Warehouse

    Owen, S.F.; Menzel, M.A.; Edwards, J.W.; Ford, W.M.; Menzel, J.M.; Chapman, B.R.; Wood, P.B.; Miller, K.V.

    2004-01-01

    We used Anabat acoustical monitoring devices to examine bat activity in intact canopy forests, complex canopy forests with gaps, forests subjected to diameter-limit harvests, recent deferment harvests, clearcuts and unmanaged forested riparian areas in the Allegheny Mountains of West Virginia in the summer of 1999. We detected eight species of bats, including the endangered Indiana bat (Myotis sodalis). Most bat activity was concentrated in forested riparian areas. Among upland habitats, activity of silver-haired bats (Lasionycteris noctivagans) and hoary bats (Lasiurus cinereus) was higher in open, less cluttered vegetative types such as recent deferment harvests and clearcuts. Our results suggest that bat species in the central Appalachians partially segregate themselves among vegetative conditions based on differences in body morphology and echolocation call characteristics. From the standpoint of conserving bat foraging habitat for the maximum number of species in the central Appalachians, special emphasis should be placed on protecting forested riparian areas.

  15. Modeling aboveground tree woody biomass using national-scale allometric methods and airborne lidar

    NASA Astrophysics Data System (ADS)

    Chen, Qi

    2015-08-01

    Estimating tree aboveground biomass (AGB) and carbon (C) stocks using remote sensing is a critical component for understanding the global C cycle and mitigating climate change. However, the importance of allometry for remote sensing of AGB has not been recognized until recently. The overarching goals of this study are to understand the differences and relationships among three national-scale allometric methods (CRM, Jenkins, and the regional models) of the Forest Inventory and Analysis (FIA) program in the U.S. and to examine the impacts of using alternative allometry on the fitting statistics of remote sensing-based woody AGB models. Airborne lidar data from three study sites in the Pacific Northwest, USA were used to predict woody AGB estimated from the different allometric methods. It was found that the CRM and Jenkins estimates of woody AGB are related via the CRM adjustment factor. In terms of lidar-biomass modeling, CRM had the smallest model errors, while the Jenkins method had the largest ones and the regional method was between. The best model fitting from CRM is attributed to its inclusion of tree height in calculating merchantable stem volume and the strong dependence of non-merchantable stem biomass on merchantable stem biomass. This study also argues that it is important to characterize the allometric model errors for gaining a complete understanding of the remotely-sensed AGB prediction errors.

  16. Survival, reproduction, and recruitment of woody plants after 14 years on a reforested landfill

    NASA Astrophysics Data System (ADS)

    Robinson, George R.; Handel, Steven N.; Schmalhofer, Victoria R.

    1992-03-01

    With the advent of modern sanitary landfill closure techniques, the opportunity exists for transforming municipal landfills into urban woodlands. While costs of fullscale reforestation are generally prohibitive, a modest planting of clusters of trees and shrubs could initiate or accelerate population expansions and natural plant succession from open field to diverse forest. However, among woody species that have been screened for use on landfills, these ecological potentials have not yet been investigated. We examined a 14-yr-old landfill plantation in New Jersey, USA, established to test tolerance of 19 species of trees and shrubs to landfill environments. We measured survivorship, reproduction, and recruitment within and around the experimental installation. Half of the original 190 plants were present, although survival and growth rates varied widely among species. An additional 752 trees and shrubs had colonized the plantation and its perimeter, as well as 2955 stems of vines. However, the great majority (>95%) of woody plants that had colonized were not progeny of the planted cohort, but instead belonged to 18 invading species, mostly native, bird-dispersed, and associated with intermediate stages of secondary plant succession. Based on this evidence, we recommend that several ecological criteria be applied to choices of woody species for the restoration of municipal landfills and similar degraded sites, in order to maximize rapid and economical establishment of diverse, productive woodlands.

  17. Quantitative woody cover reconstructions from eastern continental Asia of the last 22 kyr reveal strong regional peculiarities

    NASA Astrophysics Data System (ADS)

    Tian, Fang; Cao, Xianyong; Dallmeyer, Anne; Ni, Jian; Zhao, Yan; Wang, Yongbo; Herzschuh, Ulrike

    2016-04-01

    We present a calibration-set based on modern pollen and satellite-based Advanced Very High Resolution Radiometer (AVHRR) observations of woody cover (including needleleaved, broadleaved and total tree cover) in eastern continental Asia, which shows good performance under cross-validation with the modern analogue technique (all the coefficients of determination between observed and predicted values are greater than 0.65). The calibration-set is used to reconstruct woody cover from a taxonomically harmonized and temporally standardized fossil pollen dataset (including 274 cores) with 500-year resolution over the last 22 kyr. The spatial range of forest has not noticeably changed in eastern continental Asia during the last 22 kyr, although woody cover has, especially at the margin of the eastern Tibetan Plateau and in the forest-steppe transition area of north-central China. Vegetation was sparse during the LGM in the present forested regions, but woody cover increased markedly at the beginning of the Bølling/Allerød period (B/A; ca. 14.5 ka BP) and again at the beginning of the Holocene (ca. 11.5 ka BP), and is related to the enhanced strength of the East Asian Summer Monsoon. Forest flourished in the mid-Holocene (ca. 8 ka BP) possibly due to favourable climatic conditions. In contrast, cover was stable in southern China (high cover) and arid central Asia (very low cover) throughout the investigated period. Forest cover increased in the north-eastern part of China during the Holocene. Comparisons of these regional pollen-based results with simulated forest cover from runs of a global climate model (for 9, 6 and 0 ka BP (ECHAM5/JSBACH ∼1.125° spatial resolution)) reveal many similarities in temporal change. The Holocene woody cover history of eastern continental Asia is different from that of other regions, likely controlled by different climatic variables, i.e. moisture in eastern continental Asia; temperature in northern Eurasia and North America.

  18. Influences of Herbivory and Canopy Opening Size on Forest Regeneration in a Southern Bottomland Hardwood Forest

    SciTech Connect

    Castleberry, S.B.; Ford, W.M.; Miller, K.V.; Smith, W.P.

    1999-07-06

    Examination of the effects on white-tail deer browsing and canopy opening size on relative abundance and diversity of woody and herbaceous regeneration in various sized forest openings in a Southern bottomland hardwood forest over three growing seasons (1995-1997). Herbaceous richness, diversity or evenness did not differ among exclosure types in any year of the study. Overall browsing rates on both woody and herbaceous vegetation were low throughout all the three years of the study. Low browsing rates reflect seasonal changes in habitat use by deer. Other factors may have influenced the initial vegetative response more than herbivory or gap size.

  19. Floodflow effects on riparian vegetation in Arizona

    USGS Publications Warehouse

    Phillips, J.V.; Hjalmarson, H.W.

    1994-01-01

    A relation for estimating changes in the condition of riparian vegetation as a function of stream power was developed for stream channels in central Arizona. Flood and vegetation data were collected from 13 flows at 11 sites. Stream power was computed at cross sections and plotted against the average height of vegetation for each flow. The effect of the flow - no effect, little effect, laid over, or removed - on the riparian vegetation is related to stream power and vegetation height. As vegetation height increases, the magnitude of stream power needed to affect the vegetation also increases. Stream power of about 72 Newton-meters per second per meter squared is needed to lay over 1-meter-high vegetation, and stream power of about 580 Newton-meters per second per meter squared is needed to lay over 5.5-meter-high vegetation. This relation can be used to estimate vegetation conditions at the time of peak floodflow.

  20. Soil Carbon Budget During Establishment of Short Rotation Woody Crops

    NASA Astrophysics Data System (ADS)

    Coleman, M. D.

    2003-12-01

    Carbon budgets were monitored following forest harvest and during re-establishment of short rotation woody crops. Soil CO2 efflux was monitored using infared gas analyzer methods, fine root production was estimated with minirhizotrons, above ground litter inputs were trapped, coarse root inputs were estimated with developed allometric relationships, and soil carbon pools were measured in loblolly pine and cottonwood plantations. Our carbon budget allows evaluation of errors, as well as quantifying pools and fluxes in developing stands during non-steady-state conditions. Soil CO2 efflux was larger than the combined inputs from aboveground litter fall and root production. Fine-root production increased during stand development; however, mortality was not yet equivalent to production, showing the belowground carbon budget was not yet in equilibrium and root carbon standing crop was accruing. Belowground production was greater in cottonwood than pine, but the level of pine soil CO2 efflux was equal to or greater than that of cottonwood, indicating heterotrophic respiration was higher for pine. Comparison of unaccounted efflux with soil organic carbon changes provides verification of loss or accrual.

  1. Precipitation v. River Discharge Controls on Water Availability to Riparian Trees in the Rhône River Delta

    NASA Astrophysics Data System (ADS)

    Singer, M. B.; Sargeant, C. I.; Vallet-Coulomb, C.; Evans, C.; Bates, C. R.

    2014-12-01

    Water availability to riparian trees in lowlands is controlled through precipitation and its infiltration into floodplain soils, and through river discharge additions to the hyporheic water table. The relative contributions of both water sources to the root zone within river floodplains vary through time, depending on climatic fluctuations. There is currently limited understanding of how climatic fluctuations are expressed at local scales, especially in 'critical zone' hydrology, which is fundamental to the health and sustainability of riparian forest ecosystems. This knowledge is particularly important in water-stressed Mediterranean climate systems, considering climatic trends and projections toward hotter and drier growing seasons, which have the potential to dramatically reduce water availability to riparian forests. Our aim is to identify and quantify the relative contributions of hyporheic (discharge) water v. infiltrated precipitation to water uptake by riparian Mediterranean trees for several distinct hydrologic years, selected to isolate contrasts in water availability from these sources. Our approach includes isotopic analyses of water and tree-ring cellulose, mechanistic modeling of water uptake and wood production, and physically based modeling of subsurface hydrology. We utilize an extensive database of oxygen isotope (δ18O) measurements in surface water and precipitation alongside recent measurements of δ18O in groundwater and soil water and in tree-ring cellulose. We use a mechanistic model to back-calculate source water δ18O based on δ18O in cellulose and climate data. Finally, we test our results via 1-D hydrologic modeling of precipitation infiltration and water table rise and fall. These steps enable us to interpret hydrologic cycle variability within the 'critical zone' and their potential impact on riparian trees.

  2. Influences of upland and riparian land use patterns on stream biotic integrity

    USGS Publications Warehouse

    Snyder, C.D.; Young, J.A.; Villella, R.; Lemarie, D.P.

    2003-01-01

    We explored land use, fish assemblage structure, and stream habitat associations in 20 catchments in Opequon Creek watershed, West Virginia. The purpose was to determine the relative importance of urban and agriculture land use on stream biotic integrity, and to evaluate the spatial scale (i.e., whole-catchment vs riparian buffer) at which land use effects were most pronounced. We found that index of biological integrity (IBI) scores were strongly associated with extent of urban land use in individual catchments. Sites that received ratings of poor or very poor based on IBI scores had > 7% of urban land use in their respective catchments. Habitat correlations suggested that urban land use disrupted flow regime, reduced water quality, and altered stream channels. In contrast, we found no meaningful relationship between agricultural land use and IBI at either whole-catchment or riparian scales despite strong correlations between percent agriculture and several important stream habitat measures, including nitrate concentrations, proportion of fine sediments in riffles, and the abundance of fish cover. We also found that variation in gradient (channel slope) influenced responses of fish assemblages to land use. Urban land use was more disruptive to biological integrity in catchments with steeper channel slopes. Based on comparisons of our results in the topographically diverse Opequon Creek watershed with results from watersheds in flatter terrains, we hypothesize that the potential for riparian forests to mitigate effects of deleterious land uses in upland portions of the watershed is inversely related to gradient.

  3. Geophysical Evidence to Link Terrestrial Insect Diversity and Groundwater Availability in Non-Riparian Ecosystems

    NASA Astrophysics Data System (ADS)

    Pehringer, M.; Carr, G.; Long, H.; Parsekian, A.

    2015-12-01

    Wyoming, the third driest state in the United States, is home to a high level of biodiversity. In many cases, ecosystems are dependent on the vast systems of water resting just below the surface. This groundwater supports a variety of organisms that live far from surface water and its surrounding riparian zone, where more than 70% of species reside. In order to observe the correlation of groundwater presence and biodiversity in non-riparian ecosystems, a study was conducted to look specifically at terrestrial insect species linked to groundwater in Bighorn National Forest, WY. It was hypothesized that the more groundwater present, the greater the diversity of insects would be. Sample areas were randomly selected in non-riparian zones and groundwater was evaluated using a transient electromagnetic (TEM) geophysical instrument. Electrical pulses were transmitted through a 40m by 40m square of wire to measure levels of resistivity from near the surface to several hundred meters below ground. Pulses are echoed back to the surface and received by a smaller 10m by 10m square of wire, and an even smaller 1m by 1m square of wire set inside the larger transmitting wire. An insect population and species count was then conducted within the perimeter set by the outer transmitting wire. The results were not as hypothesized. More inferred groundwater below the surface resulted in a smaller diversity of species. Inversely, the areas with a smaller diversity held a larger total population of terrestrial insects.

  4. Disproportionate contribution of riparian inputs to organic carbon in freshwater systems.

    NASA Astrophysics Data System (ADS)

    Marwick, Trent Richard; Van Acker, Kristof; Darchambeau, François; Vieira Borges, Alberto; Bouillon, Steven

    2014-05-01

    A lack of appropriate proxies has traditionally hampered our ability to distinguish riverine organic carbon (OC) sources at the landscape scale. However, the dissection of tropical and sub-tropical C4 savannah grasslands by C3 riparian vegetation, and the distinct carbon stable isotope signature (δ13C) of these two photosynthetic pathways, provides a unique setting to assess the relative contribution of riparian and more distant sources to riverine C pools. Here, we show through the comparison of δ13C signatures of bulk sub-basin vegetation (δ13CVEG) with those of riverine OC pools, that in contrasting C3- and C4-dominated sub-tropical drainage basins, riverine OC is disproportionately sourced from bordering riparian vegetation, irrespective of climatic season. Our findings carry implications for the use of sedimentary δ13C signatures as proxies for past forest-grassland distribution and climate, as the C4 component may be considerably underestimated due to its disconnection from riverine OC pools.

  5. Cost-benefit analysis of riparian protection in an eastern Canadian watershed.

    PubMed

    Trenholm, Ryan; Lantz, Van; Martínez-Espiñeira, Roberto; Little, Shawn

    2013-02-15

    Forested riparian buffers have proved to be an effective management practice that helps maintain ecological goods and services in watersheds. In this study, we assessed the non-market benefits and opportunity costs associated with implementing these buffers in an eastern Canadian watershed using contingent valuation and wood supply modeling methods, respectively. A number of buffer scenarios were considered, including 30 and 60 m buffers on woodlots and on all land (including woodlots, agricultural, and residential lands) in the watershed. Household annual WTP estimates ranged from -$6.80 to $42.85, and total present value benefits ranged from -$11.7 to $121.7 million (CDN 2007), depending on the buffer scenario, affected population, time horizon, and econometric modeling assumptions considered. Opportunity cost estimates range from $1.3 to $10.4 million in present value terms, depending on silvicultural and agriculture land rental rate assumptions. Overall, we found that the net present value of riparian buffers was positive for the majority of scenarios and assumptions. Some exceptions were found under more conservative benefit, and higher unit cost, assumptions. These results provide decision makers with data on stated benefits and opportunity costs of riparian buffers, as well as insight into the importance of modeling assumptions when using this framework of analysis. PMID:23291404

  6. Creation of a Digital Surface Model and Extraction of Coarse Woody Debris from Terrestrial Laser Scans in an Open Eucalypt Woodland

    NASA Astrophysics Data System (ADS)

    Muir, J.; Phinn, S. R.; Armston, J.; Scarth, P.; Eyre, T.

    2014-12-01

    Coarse woody debris (CWD) provides important habitat for many species and plays a vital role in nutrient cycling within an ecosystem. In addition, CWD makes an important contribution to forest biomass and fuel loads. Airborne or space based remote sensing instruments typically do not detect CWD beneath the forest canopy. Terrestrial laser scanning (TLS) provides a ground based method for three-dimensional (3-D) reconstruction of surface features and CWD. This research produced a 3-D reconstruction of the ground surface and automatically classified coarse woody debris from registered TLS scans. The outputs will be used to inform the development of a site-based index for the assessment of forest condition, and quantitative assessments of biomass and fuel loads. A survey grade terrestrial laser scanner (Riegl VZ400) was used to scan 13 positions, in an open eucalypt woodland site at Karawatha Forest Park, near Brisbane, Australia. Scans were registered, and a digital surface model (DSM) produced using an intensity threshold and an iterative morphological filter. The DSMs produced from single scans were compared to the registered multi-scan point cloud using standard error metrics including: Root Mean Squared Error (RMSE), Mean Squared Error (MSE), range, absolute error and signed error. In addition the DSM was compared to a Digital Elevation Model (DEM) produced from Airborne Laser Scanning (ALS). Coarse woody debris was subsequently classified from the DSM using laser pulse properties, including: width and amplitude, as well as point spatial relationships (e.g. nearest neighbour slope vectors). Validation of the coarse woody debris classification was completed using true-colour photographs co-registered to the TLS point cloud. The volume and length of the coarse woody debris was calculated from the classified point cloud. A representative network of TLS sites will allow for up-scaling to large area assessment using airborne or space based sensors to monitor forest

  7. Southern Arizona riparian habitat: Spatial distribution and analysis

    NASA Technical Reports Server (NTRS)

    Lacey, J. R.; Ogden, P. R.; Foster, K. E.

    1975-01-01

    The objectives of this study were centered around the demonstration of remote sensing as an inventory tool and researching the multiple uses of riparian vegetation. Specific study objectives were to: (1) map riparian vegetation along the Gila River, San Simon Creek, San Pedro River, Pantano Wash, (2) determine the feasibility of automated mapping using LANDSAT-1 computer compatible tapes, (3) locate and summarize existing mpas delineating riparian vegetation, (4) summarize data relevant to Southern Arizona's riparian products and uses, (5) document recent riparian vegetation changes along a selected portion of the San Pedro River, (6) summarize historical changes in composition and distribution of riparian vegetation, and (7) summarize sources of available photography pertinent to Southern Arizona.

  8. Topo-edaphic Controls over Woody Biomass in South African Savannas

    NASA Astrophysics Data System (ADS)

    Colgan, M.; Asner, G. P.; Levick, S. R.

    2009-12-01

    The influence of substrate type on woody plant growth is well documented in the granite and basalt savannas of Kruger National Park, South Africa. Over the past two decades field studies and airborne photography have shown the gradually undulating granitic landscapes support higher woody cover than the basaltic plains. Yet nested within these broader trends are significant variations in biomass at the hillslope scale (0.5-1km), and it is debated to what extent the gradual slopes and subtle relief exert a catena influence on woody biomass. These trends have been qualitatively observed in the field, especially on the granite substrates, but drawing clear correlations between vegetation and terrain is hampered in the field by limited visibility due to relatively gradual (1-2°) and long (hundreds of meters) hillslopes. Here airborne LiDAR reveals clear, quantifiable biomass trends at the hillslope spatial scale and at the resolution (~1m) necessary to resolve the heterogeneity inherent in an open-canopy system. Our aim is to investigate the importance of hillslope topographic and soil properties in controlling woody biomass relative to regional differences in parent material. Aboveground woody biomass (AGWB) was estimated using airborne LiDAR over seven sites in Kruger National Park (KNP) in April-May 2008. Sites were selected to encompass the park’s range of substrate types, as well as variation in precipitation, topography, and dominant vegetation types. Throughout these seven sites 202 field plots were collected during the same period to inform and validate airborne biomass estimates. Basal diameter, height, and species of 4,500+ trees spanning 50+ woody species were recorded, and existing field allometry was applied to estimate dry AGWB. When regressed individually, canopy height and canopy cover each explained approximately the same variation in biomass (R2=0.60). Using canopy cover from three height classes significantly improved goodness of fit (R2=0.80) and

  9. Environmental effects of harvesting forests for energy

    SciTech Connect

    Van Hook, R. I.; Johnson, D. W.; West, D. C.; Mann, L. K.

    1980-01-01

    Present interest in decreasing US dependence on foreign oil by increasing the use of wood for energy may bring about a change in our forest utilization policies. In the past, forests have been removed in areas believed to be suited for agriculture, or sawtimber and pulp have been the only woody material removed in any quantity from land not generally considered tillable. The new demands on wood for energy are effecting a trend toward (1) removing all woody biomass from harvested areas, (2) increasing the frequency of harvesting second growth forests, and (3) increasing production with biomass plantations. Considering the marginal quality of much of the remaining forested land, the impacts of these modes of production could be significant. For example, it is anticipated that increased losses of nutrients and carbon will occur by direct forest removal and through erosion losses accelerated by forest clearing. There are, however, control measures that can be utilized in minimizing both direct and indirect effects of forest harvesting while maximizing woody biomass production.

  10. State wetlands and riparian area protection programs

    NASA Astrophysics Data System (ADS)

    Steiner, Frederick; Pieart, Scott; Cook, Edward; Rich, Jacqueline; Coltman, Virginia

    1994-03-01

    The protection of wetlands and riparian areas has emerged as an important environmental planning issue. In the United States, several federal and state laws have been enacted to protect wetlands and riparian areas. Specifically, the federal Clean Water Act includes protection requirements in Sections 301 and 303 for state water quality standards, Section 401 for state certification of federal actions (projects, permits, and licenses), and Section 404 for dredge and fill permits. The Section 401 water quality state certification element has been called the “sleeping giant” of wetlands protection because it empowers state officials to veto or condition federally permitted or licensed activities that do not comply with state water quality standards. State officials have used this power infrequently. The purpose of this research was to analyze the effectiveness of state wetland and riparian programs. Contacts were established with officials in each state and in the national and regional offices of key federal agencies. Based on interviews and on a review of federal and state laws, state program effectiveness was analyzed. From this analysis, several problems and opportunities facing state wetland protection efforts are presented.

  11. Sediment retention in rangeland riparian buffers.

    PubMed

    Hook, Paul B

    2003-01-01

    Controlling nonpoint-source sediment pollution is a common goal of riparian management, but there is little quantitative information about factors affecting performance of rangeland riparian buffers. This study evaluated the influence of vegetation characteristics, buffer width, slope, and stubble height on sediment retention in a Montana foothills meadow. Three vegetation types (sedge wetland, rush transition, bunchgrass upland) were compared using twenty-six 6- x 2-m plots spanning 2 to 20% slopes. Plots were clipped moderately (10-15 cm stubble) or severely (2-5 cm stubble). Sediment (silt + fine sand) was added to simulated overland runoff 6, 2, or 1 m above the bottom of each plot. Runoff was sampled at 15-s to > 5-min intervals until sediment concentrations approached background levels. Sediment retention was affected strongly by buffer width and moderately by vegetation type and slope, but was not affected by stubble height. Mean sediment retention ranged from 63 to > 99% for different combinations of buffer width and vegetation type, with 94 to 99% retention in 6-m-wide buffers regardless of vegetation type or slope. Results suggest that rangeland riparian buffers should be at least 6 m wide, with dense vegetation, to be effective and reliable. Narrower widths, steep slopes, and sparse vegetation increase risk of sediment delivery to streams. Vegetation characteristics such as biomass, cover, or density are more appropriate than stubble height for judging capacity to remove sediment from overland runoff, though stubble height may indirectly indicate livestock impacts that can affect buffer performance. PMID:12809315

  12. Comparative use of riparian corridors and oases by migrating birds in southeast Arizona

    USGS Publications Warehouse

    Skagen, S.K.; Melcher, C.P.; Howe, W.H.; Knopf, F.L.

    1998-01-01

    The relative importance of cottonwood-willow riparian corridors and isolated oases to land birds migrating across southeastern Arizona was evaluated during four spring migrations, 1989 to 1994, based on patterns of species richness, relative abundance, density, and body condition of birds. We surveyed birds in 13 study sites ranging in size and connectivity from small isolated patches to extensive riparian forest, sampled vegetation and insects, and captured birds in mistnets. The continuous band of riparian vegetation along the San Pedro River does not appear to be functioning as a corridor for many migrating species, although it may for a few, namely Yellow-breasted Chats (Icteria virens), Summer Tanagers (Piranga rubra), and Northern Rough-winged Swallows (Steldigopteryx serripennis), which account for fewer than 10% of the individuals migrating through the area. Small, isolated oases hosted more avian species than the corridor sites, and the relative abundances of most migrating birds did not differ between sites relative to size-connectivity. There were few differences in between-year variability in the relative abundances of migrating birds between corridor and oasis sites. Between-year variability decreased with overall abundance of species and was greater for species with breeding ranges that centered north of 50??N latitude. Body condition of birds did not differ relative to the size-connectivity of the capture site, but individuals of species with more northerly breeding ranges had more body fat than species that breed nearby. Peak migration densities of several bird species far exceeded breeding densities reported for the San Pedro River, suggesting that large components of these species were en route migrants. Peak densities of Yellow Warblers (Dendroica petechia) reached 48.0 birds/ha, of Wilson's Warblers (Wilsonia pusilla) 33.7 birds/ha, and of Yellow-rumped Warblers (D. coronata) 30.1 birds/ha. Riparian vegetation is limited in extent in the

  13. Red River Stream Improvement Final Design Nez Perce National Forest.

    SciTech Connect

    Watershed Consulting, LLC

    2007-03-15

    This report details the final stream improvement design along the reach of Red River between the bridge below Dawson Creek, upstream for approximately 2 miles, Idaho County, Idaho. Geomorphic mapping, hydrologic profiles and cross-sections were presented along with existing fish habitat maps in the conceptual design report. This information is used to develop a stream improvement design intended to improve aquatic habitat and restore riparian health in the reach. The area was placer mined using large bucket dredges between 1938 and 1957. This activity removed most of the riparian vegetation in the stream corridor and obliterated the channel bed and banks. The reach was also cut-off from most valley margin tributaries. In the 50 years since large-scale dredging ceased, the channel has been re-established and parts of the riparian zone have grown in. However, the recruitment of large woody debris to the stream has been extremely low and overhead cover is poor. Pool habitat makes up more than 37% of the reach, and habitat diversity is much better than the project reach on Crooked River. There is little large woody debris in the stream to provide cover for spawning and juvenile rearing, because the majority of the woody debris does not span a significant part of the channel, but is mainly on the side slopes of the stream. Most of the riparian zone has very little soil or subsoil left after the mining and so now consists primarily of unconsolidated cobble tailings or heavily compacted gravel tailings. Knapweed and lodgepole pine are the most successful colonizers of these post mining landforms. Tributary fans which add complexity to many other streams in the region, have been isolated from the main reach due to placer mining and road building.

  14. The geomorphic function and characteristics of large woody debris in low gradient rivers, coastal Maine, USA

    NASA Astrophysics Data System (ADS)

    Magilligan, F. J.; Nislow, K. H.; Fisher, G. B.; Wright, J.; Mackey, G.; Laser, M.

    2008-05-01

    The role, function, and importance of large woody debris (LWD) in rivers depend strongly on environmental context and land use history. The coastal watersheds of central and northern Maine, northeastern U.S., are characterized by low gradients, moderate topography, and minimal influence of mass wasting processes, along with a history of intensive commercial timber harvest. In spite of the ecological importance of these rivers, which contain the last wild populations of Atlantic salmon ( Salmo salar) in the U.S., we know little about LWD distribution, dynamics, and function in these systems. We conducted a cross-basin analysis in seven coastal Maine watersheds, documenting the size, frequency, volume, position, and orientation of LWD, as well as the association between LWD, pool formation, and sediment storage. In conjunction with these LWD surveys, we conducted extensive riparian vegetation surveys. We observed very low LWD frequencies and volumes across the 60 km of rivers surveyed. Frequency of LWD ≥ 20 cm diameter ranged from 15-50 pieces km - 1 and wood volumes were commonly < 10-20 m 3 km - 1 . Moreover, most of this wood was located in the immediate low-flow channel zone, was oriented parallel to flow, and failed to span the stream channel. As a result, pool formation associated with LWD is generally lacking and < 20% of the wood was associated with sediment storage. Low LWD volumes are consistent with the relatively young riparian stands we observed, with the large majority of trees < 20 cm DBH. These results strongly reflect the legacy of intensive timber harvest and land clearing and suggest that the frequency and distribution of LWD may be considerably less than presettlement and/or future desired conditions.

  15. On the global relationships between photosynthetic water-use efficiency, leaf mass per unit area and atmospheric demand in woody and herbaceous plants

    NASA Astrophysics Data System (ADS)

    Letts, M. G.; Fox, T. A.; Gulias, J.; Galmes, J.; Hikosaka, K.; Wright, I.; Flexas, J.; Awada, T.; Rodriguez-Calcerrada, J.; Tobita, H.

    2013-12-01

    A global dataset was compiled including woody and herbaceous C3 species from forest, Mediterranean and grassland-shrubland ecosystems, to elucidate the dependency of photosynthetic water-use efficiency on vapour pressure deficit (D) and leaf traits. Mean leaf mass per unit area (LMA) was lower and mass-based leaf nitrogen content (Nmass) was higher in herbaceous species. Higher mean stomatal conductance (gs), transpiration rate (E) and net CO2 assimilation rate under light saturating conditions (Amax) were observed in herbs, but photosynthetic and intrinsic water-use efficiencies (WUE = Amax/E and WUEi = Amax/gs) were lower than in woody plants. Woody species maintained stricter stomatal regulation of water loss at low D, resulting in a steeper positive and linear relationship between log D and log E. Herbaceous species possessed very high gs at low D, resulting in higher ratio of substomatal to atmospheric CO2 concentrations (ci/ca) and E, but lower WUE and WUEi than woody plants, despite higher Amax. The lower WUE and higher rates of gas exchange were most pronounced in herbs with low LMA and high Nmass. Photosynthetic water use also differed between species from grassland-shrubland and Mediterranean or forest environments. Water-use efficiency showed no relationship with either D or LMA in grassland-shrubland species, but showed a negative relationship with D in forest and chaparral. The distinct photosynthetic water-use of woody and herbaceous plants is consistent with the opportunistic growth strategy of herbs and the more conservative growth strategy of woody species. Further research is recommended to examine the implications of these functional group and ecosystem differences in the contexts of climate and atmospheric change.

  16. Influence of Gully Erosion Control on Amphibian and Reptile Communities within Riparian Zones of Channelized Streams

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Riparian zones of streams in northwestern Mississippi have been impacted by agriculture, channelization, channel incision, and gully erosion. Riparian gully formation has resulted in the fragmentation of remnant riparian zones within agricultural watersheds. One widely used conservation practice for...

  17. BLM Density Management and Riparian Buffer Study: Establishment Report and Study Plan

    USGS Publications Warehouse

    Cissel, J.H.; Anderson, P.D.; Olson, Deanna H.; Puettmann, Klaus; Berryman, Shanti; Chan, Samuel; Thompson, Charley

    2006-01-01

    The Bureau of Land Management (BLM), Pacific Northwest Research Station (PNW), U.S. Geological Survey (USGS), and Oregon State University (OSU) established the BLM Density Management and Riparian Buffer Study (DMS) in 1994 to demonstrate and test options for young stand management to meet Northwest Forest Plan objectives in western Oregon. The primary objectives of the DMS are to evaluate the effects of alternative forest density management treatments in young stands on the development of important late-successional forest habitat attributes and to assess the combined effects of density management and alternative riparian buffer widths on aquatic and riparian ecosystems. The DMS consists of three integrated studies: initial thinning, rethinning, and riparian buffer widths. The initial thinning study was installed in 50- to 80-year-old stands that had never been commercially thinned. Four stand treatments of 30-60 acres each were established at each of seven study sites: (1) unthinned control, (2) high density retention [120 trees per acre (TPA)], (3) moderate density retention (80 TPA), and (4) variable density retention (40-120 TPA). Small (1/4 to 1 acre in size) leave islands were included in all treatments except the control, and small patch cuts (1/4 to 1 acre in size) were included in the moderate and variable density treatments. An eighth site, Callahan Creek, contains a partial implementation of the study design. The rethinning study was installed in four 70- to 90-year-old stands that previously had been commercially thinned. Each study stand was split into two parts: one part as an untreated control and the other part as a rethinning (30-60 TPA). The riparian buffer study was nested within the moderate density retention treatment at each of the eight initial thinning study sites and two rethinning sites. Alternative riparian buffer widths included: (1) streamside retention (one tree canopy width, or 20-25 feet), (2) variable width (follows topographic and

  18. Diatom Responses to Watershed Development and Potential Moderating Effects of Near-Stream Forest and Wetland Cover

    EPA Science Inventory

    Watershed development alters hydrology and delivers anthropogenic stressors to streams via pathways affected by impervious cover. We characterized relationships of diatom communities and metrics with upstream watershed % impervious cover (IC) and with riparian % forest and wetlan...

  19. Changes in ecosystem structure related to the type and extent of woody cover alter carbon dynamics and surface energy exchange in central Texas ecosystems.

    NASA Astrophysics Data System (ADS)

    Litvak, M. E.; Heilman, J.; McInnes, K.; Owens, K.; Kjelgaard, J.; Thijs, A.

    2006-12-01

    Rangeland ecosystems account for almost two thirds the total land area in Texas. Over the past century, heavy livestock grazing and fire suppression coupled with changes in climate have facilitated the expansion of woody species into rangelands throughout the state. Based in part on the assumption that woody species use more water than their herbaceous counterparts, land managers have used a variety of techniques to reduce tree and shrub abundance to combat the loss of forage for cattle. As a result, the structure of rangelands in Texas is complex, characterized by woody vegetation that is patchy in distribution, and continually changing between grassland, savanna and woodland. Despite the large areal extent of Texas rangelands, very little is known about how the observed changes in ecosystem structure impact carbon cycle dynamics and surface energy exchange. To reduce these uncertainties, we explored explicit relationships between structure and function in these ecosystems by comparing tower-based measurements of carbon and water vapor exchange made simultaneously from July 2004-Dec 2005 across three representative land covers in central Texas: open grassland, savanna with 30% Ashe juniper and honey mesquite cover, and closed canopy woodland. Here we report our findings on what impact the type and pattern of woody plant cover has on biological controls and patterns of carbon sequestration, evapotranspiration, and sensitivity to precipitation pulses. Monthly measurements of leaf level gas exchange, soil respiration rates, herbaceous net ecosystem exchange, and sap flow measurements on dominant woody species were used to augment eddy covariance estimates of ecosystem-atmosphere exchange. The addition of woody species significantly increased carbon sequestration in these ecosystems. Net ecosystem production from July 05-Jun 05 in the grassland, savanna and forest ecosystems was -14 g C m-2, -413 g C m-2, -450 g C m-2, respectively. Evapotranspiration was less

  20. Short Rotation Woody Crops Program: Project summaries

    SciTech Connect

    Not Available

    1986-11-01

    This document is a compilation of summaries describing research efforts in the US Department of Energy's Short Rotation Woody Crops Program (SRWCP). The SRWCP is sponsored by DOE's Biofuels and Municipal Waste Technology Division and is field-managed at Oak Ridge National Laboratory. The SRWCP is an integrated basic research program with 18 field research projects throughout the United States. The overall objective of the program is to improve the productivity and increase the cost efficiency of growing and harvesting woody trees and shrubs. In a competitive technical review, 25 projects were chosen to form a new research program. Although some of the original projects have ended and new ones have begun, many of the long-term research projects still form the core of the SRWCP. This document contains individual summaries of each of the 18 research projects in the SRWCP from October 1985 to October 1986. Each summary provides the following information: name and address of the contracting institution, principal investigator, project title, current subcontract or grant number, period of performance, and annual funding through fiscal year 1986. In addition, each summary contains a brief description of the project rationale, objective, approach, status, and future efforts. A list of publications that have resulted from DOE-sponsored research follows many of the summaries.

  1. Woody biomass phytoremediation of contaminated brownfield land.

    PubMed

    French, Christopher J; Dickinson, Nicholas M; Putwain, Philip D

    2006-06-01

    Economic and environmental regeneration of post-industrial landscapes frequently involves some element of re-afforestation or tree planting. We report field trials that evaluate whether woody biomass production is compatible with managing residual trace element contamination in brownfield soils. Large-scale mapping of contamination showed a heterogenous dispersion of metals and arsenic, and highly localised within-site hotspots. Yields of Salix, Populus and Alnus were economically viable, showing that short-rotation coppice has a potentially valuable role in community forestry. Mass balance modelling demonstrated that phytoextraction potentially could reduce contamination hotspots of more mobile elements (Cd and Zn) within a 25-30-year life cycle of the crops. Cd and Zn in stems and foliage of Salix were 4-13 times higher than EDTA-extractable soil concentrations. Lability of other trace elements (As, Pb, Cu, Ni) was not increased 3 years after planting the coppice; woody biomass may provide an effective reduction of exposure (phyto-stabilization) to these less mobile contaminants. PMID:16271426

  2. Woody biomass production in waste recycling systems

    SciTech Connect

    Rockwood, D.L.; Snyder, G.H.; Sprinkle, R.R.

    1994-12-31

    Combining woody biomass production with waste recycling offers many mutual advantages, including increased tree growth and nutrient and water reclamation. Three biomass/recycling studies collectively involving Eucalyptus amplifolia, E. camaldulensis, and E. grandis, rapidly growing species potentially tolerant of high water and nutrient levels, are (1) evaluating general potential for water/nutrient recycling systems to enhance woody biomass production and to recycle water and nutrients, (2) documenting Eucalyptus growth, water use, and nutrient uptake patterns, and (3) identifying Eucalyptus superior for water and nutrient uptake in central and southern Florida. In a 1992-93 study assessing the three Eucalyptus species planted on the outside berms of sewage effluent holding ponds, position on the berms (top to bottom) and genotypes influenced tree size. The potential of the trees to reduce effluent levels in the ponds was assessed. In a stormwater holding pond planted in 1993, these Eucalyptus genotypes varied significantly for tree size but not for survival. E. camaldulensis appears generally superior when flooded with industrial stormwater. Potential sizes of ponds needed for different stormwater applications were estimated. Prolonged flooding of 4- and 5-year-old E. camaldulensis with agricultural irrigation runoff has had no observable effects on tree growth or survival. Younger E. camaldulensis, E. amplifolia, and E. grandis were assessed for water use and nutrient uptake during a Summer 1994 flooding.

  3. Simulating riparian disturbance: Reach scale impacts on aquatic habitat in gravel bed streams

    NASA Astrophysics Data System (ADS)

    Davidson, S. L.; Eaton, B. C.

    2015-09-01

    Large wood governs channel morphology, as well as the availability of in-stream habitat, in many forested streams. In this paper, we use a stochastic, physically based model to simulate wood recruitment and in-stream geomorphic processes, in order to explore the influence of disturbance history on the availability of aquatic habitat. Specifically, we consider the effects of fire on a range of stream sizes by varying the rate of tree toppling over time in a simulated forest characterized by a tree height of 30 m. We also consider the effects of forest harvesting with various riparian buffer sizes, by limiting the lateral extent of the riparian stand. Our results show that pulsed inputs of wood increase the availability and variability of physical habitat in the postfire period; reach-averaged pool area and deposit area double in small streams, while side channels increase by over 50% in intermediate-sized channels. By contrast, forest harvesting reduces the availability of habitat within the reach, though the effects diminish with increasing buffer size or stream width; in laterally stable streams the effects are minimal so long as buffer width is large enough for key pieces to be recruited to the reach. This research emphasizes the importance of natural disturbance in creating and maintaining habitat heterogeneity and shows that scenario-based numerical modeling provides a useful tool for assessing the historical range of variability associated with natural disturbance, as well as changes in habitat relevant to fish. It can be also used to inform forest harvesting and management.

  4. Magnetic Wood Achieving a Harmony between Magnetic and Woody Functions

    NASA Astrophysics Data System (ADS)

    Oka, Hideo

    Magnetic wood, which was first introduced and developed by the Oka group in 1991, achieves a good balance of both woody and magnetic functions through the active addition of magnetic characteristics to the wood itself. In addition to showing magnetic characteristics, this magnetic wood also offers a woody texture, low specific gravity, humidity control, acoustic absorption and is very easy to process.

  5. Woody Vegetation on Levees? - Research Experiences and Design Suggestions

    NASA Astrophysics Data System (ADS)

    Lammeranner, Walter

    2013-04-01

    Recent flood events in Austria have reawakened practical and scientific interest in the stability of levees. One focus amongst others has been taken on the relationship between vegetation and levee stability with special reference to the role of woody plants. The effects of woody plants are undoubtedly manifold: On the one hand they can potentially have a negative influence and endanger levees, which is why many guidelines ban woody vegetation to preserve stability, visual inspection and unhindered flood-fight access. On the other hand woody vegetation can have several positive impacts on soil stability and which effects prevail depends largely on types and characteristics of plants. This shows how controversially woody plants on levees can be discussed and the strong need for further research in this field. In order to obtain new insights and widen horizons for this controversial issue, a research project carried out by the Institute of Soil Bioengineering and Landscape Construction - at the University of Natural Resources and Life Sciences, Vienna - was launched. This project deals with several aspects of effects of woody plants have on levees and focuses particularly on shrubby woody plants. The examined vegetation type is a dense stand of willows - Purple-Willows (Salix purpurea L.) - commonly used for stabilization of river embankments. The proposed contribution discusses the gained results with reference to levee stability and existing levee vegetation guidelines and gives design suggestions for compatible woody vegetation on levees.

  6. A critical review of field techniques employed in the survey of large woody debris in river corridors: a central European perspective.

    PubMed

    Máčka, Zdeněk; Krejčí, Lukáš; Loučková, Blanka; Peterková, Lucie

    2011-10-01

    In forested watersheds, large woody debris (LWD) is an integral component of river channels and floodplains. Fallen trees have a significant impact on physical and ecological processes in fluvial ecosystems. An enormous body of literature concerning LWD in river corridors is currently available. However, synthesis and statistical treatment of the published data are hampered by the heterogeneity of methodological approaches. Likewise, the precision and accuracy of data arising out of published surveys have yet to be assessed. For this review, a literature scrutiny of 100 randomly selected research papers was made to examine the most frequently surveyed LWD variables and field procedures. Some 29 variables arose for individual LWD pieces, and 15 variables for wood accumulations. The literature survey revealed a large variability in field procedures for LWD surveys. In many studies (32), description of field procedure proved less than adequate, rendering the results impossible to reproduce in comparable fashion by other researchers. This contribution identifies the main methodological problems and sources of error associated with the mapping and measurement of the most frequently surveyed variables of