Modeling relationships among 217 fires using remote sensing of burn severity in southern pine forests

Treesearch

Sparkle L. Malone; Leda N. Kobziar; Christina L. Staudhammer; Amr Abd-Elrahman

2011-01-01

Pine flatwoods forests in the southeastern US have experienced severe wildfires over the past few decades, often attributed to fuel load build-up. These forest communities are fire dependent and require regular burning for ecosystem maintenance and health. Although prescribed fire has been used to reduce wildfire risk and maintain ecosystem integrity, managers are...

Protecting and restoring longleaf pine forests on the Kisatchie National Forest in Louisiana

Treesearch

James D. Haywood; Michael Elliot-Smith; Finis Harris; Alton Martin

2000-01-01

Longleaf pine (Pinus palustris Mill.) forests once constituted a major ecosystem in the Southern United States stretching from southeastern Virginia south to central Florida and west into East Texas. These forests covered a wide range of site conditions, from wet pine flatwoods to dry mountain slopes. Intensive exploitation reduced the extent of old-...

Measuring moisture dynamics to predict fire severity in longleaf pine forests.

Treesearch

Sue A. Ferguson; Julia E. Ruthford; Steven J. McKay; David Wright; Clint Wright; Roger Ottmar

2002-01-01

To understand the combustion limit of biomass fuels in a longleaf pine (Pinus palustris) forest, an experiment was conducted to monitor the moisture content of potentially flammable forest floor materials (litter and duff) at Eglin Air Force Base in the Florida Panhandle. While longleaf pine forests are fire dependent ecosystems, a long history of...

Longleaf Pine: An Updated Bibliography

Treesearch

John S. Kush; Ralph S. Meldahl; William D. Boyer; Charles K. McMahon

1996-01-01

The longleaf pine (Pinus palustris Mill.) forest figured prominently in the cultural and economic development of the South. What was once one of the most extensive forest ecosystems in North America has now become critically endangered (6). At the time of European settlement, this ecosystem dominated as much as 92 million acres throughout the...

Ecosystem carbon stocks in Pinus palustris forests

Treesearch

Lisa Samuelson; Tom Stokes; John R. Butnor; Kurt H. Johnsen; Carlos A. Gonzalez-Benecke; Pete Anderson; Jason Jackson; Lorenzo Ferrari; Tim A. Martin; Wendell P. Cropper

2014-01-01

Longleaf pine (Pinus palustris Mill.) restoration in the southeastern United States offers opportunities for carbon (C) sequestration. Ecosystem C stocks are not well understood in longleaf pine forests, which are typically of low density and maintained by prescribed fire. The objectives of this research were to develop allometric equations for...

Latent resilience in ponderosa pine forest: effects of resumed frequent fire

Treesearch

Andrew J. Larson; R. Travis Belote; C. Alina Cansler; Sean A. Parks; Matthew S. Dietz

2013-01-01

Ecological systems often exhibit resilient states that are maintained through negative feedbacks. In ponderosa pine forests, fire historically represented the negative feedback mechanism that maintained ecosystem resilience; fire exclusion reduced that resilience, predisposing the transition to an alternative ecosystem state upon reintroduction of fire. We evaluated...

Temperate pine barrens and tropical rain forests are both rich in undescribed fungi.

PubMed

Luo, Jing; Walsh, Emily; Naik, Abhishek; Zhuang, Wenying; Zhang, Keqin; Cai, Lei; Zhang, Ning

2014-01-01

Most of fungal biodiversity on Earth remains unknown especially in the unexplored habitats. In this study, we compared fungi associated with grass (Poaceae) roots from two ecosystems: the temperate pine barrens in New Jersey, USA and tropical rain forests in Yunnan, China, using the same sampling, isolation and species identification methods. A total of 426 fungal isolates were obtained from 1600 root segments from 80 grass samples. Based on the internal transcribed spacer (ITS) sequences and morphological characteristics, a total of 85 fungal species (OTUs) belonging in 45 genera, 23 families, 16 orders, and 6 classes were identified, among which the pine barrens had 38 and Yunnan had 56 species, with only 9 species in common. The finding that grass roots in the tropical forests harbor higher fungal species diversity supports that tropical forests are fungal biodiversity hotspots. Sordariomycetes was dominant in both places but more Leotiomycetes were found in the pine barrens than Yunnan, which may play a role in the acidic and oligotrophic pine barrens ecosystem. Equal number of undescribed fungal species were discovered from the two sampled ecosystems, although the tropical Yunnan had more known fungal species. Pine barrens is a unique, unexplored ecosystem. Our finding suggests that sampling plants in such unexplored habitats will uncover novel fungi and that grass roots in pine barrens are one of the major reservoirs of novel fungi with about 47% being undescribed species.

Limber pine forests on the leading edge of white pine blister rust distribution in Northern Colorado

Treesearch

Jennifer G. Klutsch; Betsy A. Goodrich; Anna W. Schoettle

2011-01-01

The combined threats of the current mountain pine beetle (Dendroctonus ponderosae, MPB) epidemic with the imminent invasion of white pine blister rust (caused by the non-native fungus Cronartium ribicola, WPBR) in limber pine (Pinus flexilis) forests in northern Colorado threatens the limber pine's regeneration cycle and ecosystem function. Over one million...

Ecosystem carbon density and allocation across a chronosequence of longleaf pine forests.

PubMed

Samuelson, Lisa J; Stokes, Thomas A; Butnor, John R; Johnsen, Kurt H; Gonzalez-Benecke, Carlos A; Martin, Timothy A; Cropper, Wendell P; Anderson, Pete H; Ramirez, Michael R; Lewis, John C

2017-01-01

Forests can partially offset greenhouse gas emissions and contribute to climate change mitigation, mainly through increases in live biomass. We quantified carbon (C) density in 20 managed longleaf pine (Pinus palustris Mill.) forests ranging in age from 5 to 118 years located across the southeastern United States and estimated above- and belowground C trajectories. Ecosystem C stock (all pools including soil C) and aboveground live tree C increased nonlinearly with stand age and the modeled asymptotic maxima were 168 Mg C/ha and 80 Mg C/ha, respectively. Accumulation of ecosystem C with stand age was driven mainly by increases in aboveground live tree C, which ranged from <1 Mg C/ha to 74 Mg C/ha and comprised <1% to 39% of ecosystem C. Live root C (sum of below-stump C, ground penetrating radar measurement of lateral root C, and live fine root C) increased with stand age and represented 4-22% of ecosystem C. Soil C was related to site index, but not to stand age, and made up 39-92% of ecosystem C. Live understory C, forest floor C, downed dead wood C, and standing dead wood C were small fractions of ecosystem C in these frequently burned stands. Stand age and site index accounted for 76% of the variation in ecosystem C among stands. The mean root-to-shoot ratio calculated as the average across all stands (excluding the grass-stage stand) was 0.54 (standard deviation of 0.19) and higher than reports for other conifers. Long-term accumulation of live tree C, combined with the larger role of belowground accumulation of lateral root C than in other forest types, indicates a role of longleaf pine forests in providing disturbance-resistant C storage that can balance the more rapid C accumulation and C removal associated with more intensively managed forests. Although other managed southern pine systems sequester more C over the short-term, we suggest that longleaf pine forests can play a meaningful role in regional forest C management. © 2016 by the Ecological Society of America.

Analyzing the complexity of cone production in longleaf pine by multiscale entropy

Treesearch

Xiongwen Chen; Qinfeng Guo; Dale G. Brockway

2016-01-01

The longleaf pine (Pinus palustris Mill.) forests are important ecosystems in the southeastern USA because of their ecological and economic value. Since European settlement, longleaf pine ecosystems have dramatically declined in extent, to the degree that they are now listed as endangered ecosystems. Its sporadic seed production, which...

Restoring fire-adapted forested ecosystems—research in longleaf pine on the Kisatchie National Forest.

Treesearch

James D. Haywood

2007-01-01

Prescribed burning research on the Kisatchie National Forest, Louisiana spanned the last five decades and led to a greater understanding of fire behavior and the importance of burning in longleaf pine (Pinus palustris P. Mill.) forests. Early research found that biennial burning in May favored the growth of longleaf pine seedlings. However, burning...

Price and Welfare Effects of Catastrophic Forest Damage from Southern Pine Beetle Epidemics

Treesearch

Thomas P. Holmes

1991-01-01

Southern pine beetle (Dendroctonus frontalis) epidemics are periodically responsible for catastrophic levels of mortality to southern yellow pine forests. Traditional forest damage appraisal techniques developed for site specific economic analysis are theoretically weak since they do not consider aggregate impacts across ecosystems and related markets. Because the...

[The concentration and distribution of 137Cs in soils of forest and agricultural ecosystems of Tula Region].

PubMed

Lipatov, D N; Shcheglov, A I; Tsvetnova, O B

2007-01-01

The paper deals with a comparative study of 137Cs contamination in forest, old arable and cultivated soils of Tula Region. Initial interception of Chernobyl derived 137Cs is higher in forest ecosystems: oak-forest > birch-forest > pine-forest > agricultural ecosystems. Vertical migration of 137Cs in deeper layers of soils was intensive in agricultural ecosystems: cultivated soils > old arable soils > birch-forest soils > oak-forest soils > pine-forest soils. In study have been evaluated spatial variability of 137Cs in soil and asymmetrical distribution, that is a skew to the right. Spatial heterogeneity of 137Cs in agricultural soils is much lower than in forest soils. For cultivated soil are determined the rate of resuspension, which equal to 6.1 x 10(-4) day(-1). For forest soils are described the 137Cs concentration in litter of different ecosystems. The role of main accumulation and barrier of 137Cs retain higher layers of soils (horizon A1(A1E) in forest, horizon Ap in agricultural ecosystems) in long-term forecast after Chernobyl accident.

Remnant fire disturbed montane longleaf pine forest in west central georgia

Treesearch

Robert Carter; Andrew J. Londo

2006-01-01

Fire disturbed ecosystems are characteristic of the Southeastern Coastal Plain of the United States. Less well known are fire disturbed mountainous regions of the Piedmont and Appalachian region that support longleaf pine (Pinus palustris P. Mill.) ecosystems. The Pine Mountain Range in the Piedmont of west central Georgia has remnant longleaf pine...

Factors affecting broadleaf woody vegetation in upland pine forests managed for longleaf pine restoration

Treesearch

Robert N. Addington; Benjamin O. Knapp; Geoffrey G. Sorrell; Michele L. Elmore; G. Geoff Wang; Joan L. Walker

2015-01-01

Controlling broadleaf woody plant abundance is one of the greatest challenges in longleaf pine (Pinus palustris Mill.) ecosystem restoration. Numerous factors have been associated with broadleaf woody plant abundance in longleaf pine ecosystems, including site quality, stand structure, and fire frequency and intensity, yet the way in which these...

Sensitivity of pine flatwoods hydrology to climate change and forest management in Florida, USA

Treesearch

Jianbiao Lu; Ge Sun; Steven G. McNulty; Nicholas B. Comerford

2009-01-01

Pine flatwoods (a mixture of cypress wetlands and managed pine uplands) is an important ecosystem in the southeastern U.S. However, long-term hydrologic impacts of forest management and climate change on this heterogeneous landscape are not well understood. Therefore, this study examined the sensitivity of cypress-pine flatwoods...

Impacts of logging and prescribed burning in longleaf pine forests managed under uneven-aged silviculture

Treesearch

Ferhat Kara; Edward Francis Loewenstein

2015-01-01

The longleaf pine (Pinus palustris Mill.) ecosystem has historically been very important in the southeastern United States due to its extensive area and high biodiversity. Successful regeneration of longleaf pine forests requires an adequate number of well distributed seedlings. Thus, mortality of longleaf pine seedlings during logging operations...

Ponderosa pine ecosystems

Treesearch

Russell T. Graham; Theresa B. Jain

2005-01-01

Ponderosa pine is a wide-ranging conifer occurring throughout the United States, southern Canada, and northern Mexico. Since the 1800s, ponderosa pine forests have fueled the economies of the West. In western North America, ponderosa pine grows predominantly in the moist and dry forests. In the Black Hills of South Dakota and the southern portion of its range, the...

CO2 flux studies of different hemiboreal forest ecosystems

NASA Astrophysics Data System (ADS)

Krasnova, Alisa; Krasnov, Dmitrii; Noe, Steffen M.; Uri, Veiko; Mander, Ülo; Niinemets, Ülo; Soosaar, Kaido

2017-04-01

Hemiboreal zone is a transition between boreal and temperate zones characterized by the combination of climatic and edaphic conditions inherent in both zones. Hemiboreal forests are typically presented by mixed forests types with different ratios of deciduous and conifer tree species. Dominating tree species composition affects the functioning of forest ecosystem and its influence on biogeochemical cycles. We present the result of ecosystem scale CO2 eddy-covariance fluxes research conducted in 4 ecosystems (3 forests sites and 1 clear-cut area) of hemiboreal zone in Estonia. All 4 sites were developing under similar climatic conditions, but different forest management practices resulted in different composition of dominating tree species: pine forest with spruce trees as a second layer (Soontaga site); spruce/birch forest with single alder trees (Liispõllu site); forest presented by sectors of pine, spruce, birch and clearcut areas (SMEAR Estonia site); 5-years old clearcut area (Kõnnu site).

Effects of fire season on vegetation in longleaf pine (Pinus palustris) forests

Treesearch

Bryan T. Mudder; G. Geoff Wang; Joan L. Walker; J. Drew Lanham; Ralph Costa

2010-01-01

Forest managers in the Southeastern United States are interested in the restoration of not only longleaf pine (Pinus palustris) trees, but also the characteristic forest structure and ground-layer vegetation of the longleaf pine ecosystem. Season of burn, fire intensity, and fire frequency are critical components of a fire regime that supports...

Temperate Pine Barrens and Tropical Rain Forests Are Both Rich in Undescribed Fungi

PubMed Central

Luo, Jing; Walsh, Emily; Naik, Abhishek; Zhuang, Wenying; Zhang, Keqin; Cai, Lei; Zhang, Ning

2014-01-01

Most of fungal biodiversity on Earth remains unknown especially in the unexplored habitats. In this study, we compared fungi associated with grass (Poaceae) roots from two ecosystems: the temperate pine barrens in New Jersey, USA and tropical rain forests in Yunnan, China, using the same sampling, isolation and species identification methods. A total of 426 fungal isolates were obtained from 1600 root segments from 80 grass samples. Based on the internal transcribed spacer (ITS) sequences and morphological characteristics, a total of 85 fungal species (OTUs) belonging in 45 genera, 23 families, 16 orders, and 6 classes were identified, among which the pine barrens had 38 and Yunnan had 56 species, with only 9 species in common. The finding that grass roots in the tropical forests harbor higher fungal species diversity supports that tropical forests are fungal biodiversity hotspots. Sordariomycetes was dominant in both places but more Leotiomycetes were found in the pine barrens than Yunnan, which may play a role in the acidic and oligotrophic pine barrens ecosystem. Equal number of undescribed fungal species were discovered from the two sampled ecosystems, although the tropical Yunnan had more known fungal species. Pine barrens is a unique, unexplored ecosystem. Our finding suggests that sampling plants in such unexplored habitats will uncover novel fungi and that grass roots in pine barrens are one of the major reservoirs of novel fungi with about 47% being undescribed species. PMID:25072783

Observations of bird numbers and species following a historic wildfire in Arizona ponderosa pine forests

Treesearch

Peter F. Ffolliott; Cody L. Stropki; Hui Chen; Daniel G. Neary

2009-01-01

The Rodeo-Chediski Wildfire, the largest in Arizona's history, damaged or destroyed ecosystem resources or disrupted ecosystem functioning in a mostly mosaic pattern throughout the ponderosa pine (Pinus ponderosa) forests exposed to the burn. Impacts of the wildfire on the occurrence of birds and their diversities were studied on...

Lessons learned from fire use for restoring southwestern ponderosa pine ecosystems

Treesearch

Stephen S. Sackett; Sally M. Haase; Michael G. Harrington

1996-01-01

Since European settlement, the southwestern ponderosa pine ecosystem has experienced large scale alterations brought about by heavy grazing and timbering and a policy of attempted fire exclusion. These alterations are most evident as large increases in tree numbers and in forest floor organic matter. These changes have resulted in forest health problems, such...

Chapter 5. Dynamics of ponderosa and Jeffrey pine forests

Treesearch

Penelope Morgan

1994-01-01

Ponderosa (Pinus ponderosa) and Jeffrey pine (Pinus jefferyi) forests are ecologically diverse ecosystems. The communities and landscapes in which these trees dominate are variable and often complex. Because of the economic value of resources, people have used these forests extensively.

Interaction of an invasive bark beetle with a native forest pathogen: Potential effect of dwarf mistletoe on range expansion of mountain pine beetle in jack pine forests

Treesearch

Jennifer Klutsch; Nadir Erbilgin

2012-01-01

In recent decades, climate change has facilitated shifts in species ranges that have the potential to significantly affect ecosystem dynamics and resilience. Mountain pine beetle (Dendroctonus ponderosae) is expanding east from British Columbia, where it has killed millions of pine trees, primarily lodgepole pine (Pinus contorta...

Forest response and recovery following disturbance in upland forests of the Atlantic Coastal Plain.

PubMed

Schäfer, Karina V R; Renninger, Heidi J; Carlo, Nicholas J; Vanderklein, Dirk W

2014-01-01

Carbon and water cycling of forests contribute significantly to the Earth's overall biogeochemical cycling and may be affected by disturbance and climate change. As a larger body of research becomes available about leaf-level, ecosystem and regional scale effects of disturbances on forest ecosystems, a more mechanistic understanding is developing which can improve modeling efforts. Here, we summarize some of the major effects of physical and biogenic disturbances, such as drought, prescribed fire, and insect defoliation, on leaf and ecosystem-scale physiological responses as well as impacts on carbon and water cycling in an Atlantic Coastal Plain upland oak/pine and upland pine forest. During drought, stomatal conductance and canopy stomatal conductance were reduced, however, defoliation increased conductance on both leaf-level and canopy scale. Furthermore, after prescribed fire, leaf-level stomatal conductance was unchanged for pines but decreased for oaks, while canopy stomatal conductance decreased temporarily, but then rebounded the following growing season, thus exhibiting transient responses. This study suggests that forest response to disturbance varies from the leaf to ecosystem level as well as species level and thus, these differential responses interplay to determine the fate of forest structure and functioning post disturbance.

Density-dependent vulnerability of forest ecosystems to drought

USGS Publications Warehouse

Bottero, Alessandra; D'Amato, Anthony W.; Palik, Brian J.; Bradford, John B.; Fraver, Shawn; Battaglia, Mike A.; Asherin, Lance A.

2017-01-01

1. Climate models predict increasing drought intensity and frequency for many regions, which may have negative consequences for tree recruitment, growth and mortality, as well as forest ecosystem services. Furthermore, practical strategies for minimizing vulnerability to drought are limited. Tree population density, a metric of tree abundance in a given area, is a primary driver of competitive intensity among trees, which influences tree growth and mortality. Manipulating tree population density may be a mechanism for moderating drought-induced stress and growth reductions, although the relationship between tree population density and tree drought vulnerability remains poorly quantified, especially across climatic gradients.2. In this study, we examined three long-term forest ecosystem experiments in two widely distributed North American pine species, ponderosa pine Pinus ponderosa (Lawson & C. Lawson) and red pine Pinus resinosa (Aiton), to better elucidate the relationship between tree population density, growth and drought. These experiments span a broad latitude and aridity range and include tree population density treatments that have been purposefully maintained for several decades. We investigated how tree population density influenced resistance (growth during drought) and resilience (growth after drought compared to pre-drought growth) of stand-level growth during and after documented drought events.3. Our results show that relative tree population density was negatively related to drought resistance and resilience, indicating that trees growing at lower densities were less vulnerable to drought. This result was apparent in all three forest ecosystems, and was consistent across species, stand age and drought intensity.4. Synthesis and applications. Our results highlighted that managing pine forest ecosystems at low tree population density represents a promising adaptive strategy for reducing the adverse impacts of drought on forest growth in coming decades. Nonetheless, the broader applicability of our findings to other types of forest ecosystems merits additional investigation.

Growth projection and valuation of restoration of the shortleaf pine-bluestem grass ecosystem

Treesearch

Difei Zhang; Michael M. Huebschmann; Thomas B. Lynch; James M. Guldin

2012-01-01

The fire-dependent shortleaf pine–bluestem grass ecosystem that existed prior to European settlement is being restored on approximately 62,700 ha in the Ouachita National Forest. The restoration effort's economic effects are not completely understood. This study will provide the Forest Service with a framework for better communicating the biological and economic...

Fire ecology of ponderosa pine and the rebuilding of fire-resilient ponderosa pine ecosystems

Treesearch

Stephen A. Fitzgerald

2005-01-01

The ponderosa pine ecosystems of the West have change dramatically since Euro-American settlement 140 years ago due to past land uses and the curtailment of natural fire. Today, ponderosa pine forests contain over abundance of fuel, and stand densities have increased from a range of 49-124 trees ha-1 (20-50 trees acre-1) to...

Ecosystem carbon density and allocation across a chronosequence of longleaf pine forests

Treesearch

Lisa J. Samuelson; Thomas A. Stokes; John R. Butnor; Kurt H. Johnsen; Carlos A. Gonzalez-Benecke; Timothy A. Martin; Wendell P. Cropper; Pete H. Anderson; Michael R. Ramirez; John C. Lewis

2017-01-01

Forests can partially offset greenhouse gas emissions and contribute to climate change mitigation, mainly through increases in live biomass. We quantified carbon (C) density in 20 managed longleaf pine (Pinus palustris Mill.) forests ranging in age from 5...

Changes in transpiration and foliage growth in lodgepole pine trees following mountain pine beetle attack and mechanical girdling

Treesearch

Robert M. Hubbard; Charles C. Rhoades; Kelly Elder; Jose Negron

2013-01-01

The recent mountain pine beetle outbreak in North American lodgepole pine forests demonstrates the importance of insect related disturbances in changing forest structure and ecosystem processes. Phloem feeding by beetles disrupts transport of photosynthate from tree canopies and fungi introduced to the tree's vascular system by the bark beetles inhibit water...

Reintroducing fire into a ponderosa pine forest with and without cattle grazing: understory vegetation response

Treesearch

Becky K. Kerns; Michelle Buonopane; Walter G. Thies; Christine. Niwa

2011-01-01

Reestablishing historical fire regimes is a high priority for North American coniferous forests, particularly ponderosa pine (Pinus ponderosa) ecosystems. These forests are also used extensively for cattle (Bos spp.) grazing. Prescribed fires are being applied on or planned for millions of hectares of these forests to reduce...

Longleaf Pine Ecosystem Restoration on Small and Mid-Sized Tracts

Treesearch

Joan L. Walker

1999-01-01

Speaking of restoring the longleaf pine ecosystem, conservationists may present images of open stands I trees, prescribed burning, grassy ground layers, and of providing habitat for red-cockaded woodpeckers. Unfortunately, planting a longleaf pine forest, using fire, and recovering an endangered woodpecker all seem require lands larger than a backyard. To many,...

Nitrogen cycling following mountain pine beetle disturbance in lodgepole pine forests of Greater Yellowstone

Treesearch

Jacob M. Griffin; Monica G. Turner; Martin Simard

2011-01-01

Widespread bark beetle outbreaks are currently affecting multiple conifer forest types throughout western North America, yet many ecosystem-level consequences of this disturbance are poorly understood. We quantified the effect of mountain pine beetle (Dendroctonus ponderosae) outbreak on nitrogen (N) cycling through litter, soil, and vegetation in...

Resistance to wildfire and early regeneration in natural broadleaved forest and pine plantation

NASA Astrophysics Data System (ADS)

Proença, Vânia; Pereira, Henrique M.; Vicente, Luís

2010-11-01

The response of an ecosystem to disturbance reflects its stability, which is determined by two components: resistance and resilience. We addressed both components in a study of early post-fire response of natural broadleaved forest ( Quercus robur, Ilex aquifolium) and pine plantation ( Pinus pinaster, Pinus sylvestris) to a wildfire that burned over 6000 ha in NW Portugal. Fire resistance was assessed from fire severity, tree mortality and sapling persistence. Understory fire resistance was similar between forests: fire severity at the surface level was moderate to low, and sapling persistence was low. At the canopy level, fire severity was generally low in broadleaved forest but heterogeneous in pine forest, and mean tree mortality was significantly higher in pine forest. Forest resilience was assessed by the comparison of the understory composition, species diversity and seedling abundance in unburned and burned plots in each forest type. Unburned broadleaved communities were dominated by perennial herbs (e.g., Arrhenatherum elatius) and woody species (e.g., Hedera hibernica, Erica arborea), all able to regenerate vegetatively. Unburned pine communities presented a higher abundance of shrubs, and most dominant species relied on post-fire seeding, with some species also being able to regenerate vegetatively (e.g., Ulex minor, Daboecia cantabrica). There were no differences in diversity measures in broadleaved forest, but burned communities in pine forest shared less species and were less rich and diverse than unburned communities. Seedling abundance was similar in burned and unburned plots in both forests. The slower reestablishment of understory pine communities is probably explained by the slower recovery rate of dominant species. These findings are ecologically relevant: the higher resistance and resilience of native broadleaved forest implies a higher stability in the maintenance of forest processes and the delivery of ecosystem services.

Effects of overstory retention, herbicides, and fertilization on sub-canopy vegetation structure and functional group composition in loblolly pine forests restored to longleaf pine

Treesearch

Benjamin O. Knapp; Joan L. Walker; G. Geoff Wang; Huifeng Hu; Robert N.  Addington

2014-01-01

The desirable structure of longleaf pine forests, which generally includes a relatively open canopy of pines, very few woody stems in the mid-story, and a well-developed, herbaceous ground layer, provides critical habitat for flora and fauna and contributes to ecosystem function. Current efforts to restore longleaf pine to upland sites dominated by second-growth...

Management guide to ecosystem restoration treatments: two-aged lodgepole pine forests of central Montana, USA

Treesearch

Sharon M. Hood; Helen Y. Smith; David K. Wright; Lance S. Glasgow

2012-01-01

Lodgepole pine is one of the most widely distributed conifers in North America, with a mixed-severity rather than stand-replacement fire regime throughout much of its range. These lodgepole pine forests are patchy and often two-aged. Fire exclusion can reduce two-aged lodgepole pine heterogeneity. This management guide summarizes the effects of thinning and prescribed...

The proactive strategy for sustaining five-needle pine populations: An example of its implementation in the southern Rocky Mountains

Treesearch

A. W. Schoettle; B. A. Goodrich; J. G. Klutsch; K. S. Burns; S. Costello; R. A. Sniezko

2011-01-01

The imminent invasion of the non-native fungus, Cronartium ribicola J.C. Fisch., that causes white pine blister rust (WPBR) and the current mountain pine beetle (Dendroctonus ponderosae Hopkins, MPB) epidemic in northern Colorado limber pine forests will severely affect the forest regeneration cycle necessary for functioning ecosystems. The slow growth and maturity of...

Monitoring of high-altitude terrestrial ecosystems in the Altai Mountains

NASA Astrophysics Data System (ADS)

Timoshok, E. E.; Timoshok, E. N.; Nikolaeva, S. A.; Savchuk, D. A.; Filimonova, E. O.; Skorokhodov, S. N.; Bocharov, A. Yu

2016-11-01

The Aktru mountain glacier basin (the North-Chuya Ridge, Altai Mountains) is a region of highly important ecosystems. We have been performing a monitoring of the autotrophic component of the basin ecosystems for the last 16 years. The primary indicator species with the most clearly defined response to climatic changes are Siberian stone pine and Siberian larch with their individuals and populations. The ecosystem level of the monitoring includes that of old forests, ecotone ecosystems, and ecosystems on the new moraines. The old forests have remained stable for about 1000 years. The reasons for this stability are the long lifespan and the long generative stage of stone pine and larch, their ability to produce several growth forms, optimal ecological conditions of the basin for these species and high a-diversity of the old forests. The treeline has moved up by 100-200 m for the last 150 years and by 40-90 m for the last 40 years, mostly because of an invasion of stone pine to the ecotone. The primary successions on the moraines are also relatively stable, although at present only stone pine has been involved in the successions. No regeneration of larch has been observed for the last 16 years in the entire basin.

Reference conditions for old-growth pine forests in the Upper West Gulf Coastal Plain

Treesearch

Don C. Bragg

2002-01-01

Ecosystem restoration has become an important component of forest management. especially on public lands. However, determination of manageable reference conditions has lagged behind the interest. This paper presents a case study from pine-dominated forests in the Upper West Gulf Coastal Plain (UWGCP), with special emphasis on southern Arkansas. Decades of forest...

Economic evaluation of restoring the shortleaf pine-bluestem grass ecosystem on the Ouachita National Forest

Treesearch

Michael M. Huebschmann; Daniel S. Tilley; Thomas B. Lynch; David K. Lewis; James M. Guldin

2002-01-01

The USDA Forest Service is restoring pre-European settlement forest conditions on about 10 percent (155,000 acres) of the Ouachita National Forest in western Arkansas. These conditions - characterized by large, scattered shortleaf pine and hardwoods maintained on 120-year rotations, with bluestem grass and associated herbaceous vegetation in the understory - are...

Whitebark pine vulnerability to climate-driven mountain pine beetle disturbance in the Greater Yellowstone Ecosystem.

PubMed

Logan, Jesse A; MacFarlane, William W; Willcox, Louisa

2010-06-01

Widespread outbreaks of mountain pine beetles (MPB) are occurring throughout the range of this native insect. Episodic outbreaks are a common occurrence in the beetles' primary host, lodgepole pine. Current outbreaks, however, are occurring in habitats where outbreaks either did not previously occur or were limited in scale. Herein, we address widespread, ongoing outbreaks in high-elevation, whitebark pine forests of the Greater Yellowstone Ecosystem, where, due to an inhospitable climate, past outbreaks were infrequent and short lived. We address the basic question: are these outbreaks truly unprecedented and a threat to ecosystem continuity? In order to evaluate this question we (1) present evidence that the current outbreak is outside the historic range of variability; (2) examine system resiliency to MPB disturbance based on adaptation to disturbance and host defenses to MPB attack; and (3) investigate the potential domain of attraction to large-scale MPB disturbance based on thermal developmental thresholds, spatial structure of forest types, and the confounding influence of an introduced pathogen. We conclude that the loss of dominant whitebark pine forests, and the ecological services they provide, is likely under continuing climate warming and that new research and strategies are needed to respond to the crisis facing whitebark pine.

Longleaf pine ecosystem restoration: the role of the USDA Forest Service

Treesearch

Charles K. McMahon; D.J. Tomczak; R.M. Jeffers

1998-01-01

The greater longleaf pine ecosystem once occupied over 90 million acres from southeastern Virginia, south to central Florida, and west to eastern Texas. Today less than 3 million acres remain, with much of the remaining understory communities in an unhealthy state. A number of public and private conservation organizations are conducting collaborative longleaf pine...

Two Case Histories For Using Prescribed Fire to Restore Ponderosa Pine Ecosystems in Northern Arizona

Treesearch

Stephen S. Sackett; Sally M. Haase

1998-01-01

Historic observations and research indicate that the ponderosa pine (Pinus ponderosa) ecosystem in the southwestern U.S. is now very different compared to pre-European settlement. Timber harvest, livestock grazing, and fire suppression have transformed an open ponderosa pine-bunch grass community into a dense forest overloaded with flammable...

Silviculture that sustains: the nexus between silviculture, frequent prescribed fire, and conservation of biodiversity in longleaf pine forests of the southeastern United States

Treesearch

R.J. Mitchell; J.K. Hiers; J.J. O' Brien; S.B. Jack; R.T. Engstrom

2006-01-01

The longleaf pine (Pinus palustris Mill.) forest ecosystem of the US southeastern Coastal Plain, among the most biologically diverse ecosystems in North America, originally covered over 24 x 106 ha but now occupy less than 5% of their original extent. The key factor for sustaining their high levels of diversity is the frequent...

Vegetation response to stand structure and prescribed fire in an interior ponderosa pine ecosystem

Treesearch

Jianwei Zhang; Martin W. Ritchie; William W. Oliver

2008-01-01

A large-scale interior ponderosa pine (Pinus ponderosa Dougl. ex P. & C. Laws.) study was conducted at the Blacks Mountain Experimental Forest in northeastern California. The primary purpose of the study was to determine the influence of structural diversity on the dynamics of interior pine forests at the landscape scale. High structural...

Ecosystem and understory water and energy exchange for a mature, naturally regenerated pine flatwoods forest in north Florida

Treesearch

Thomas L. Powell; Gregory Starr; Kenneth L. Clark; Timothy A. Martin; Henry L. Gholz

2005-01-01

Eddy covariance was used to measure energy fluxes from July 2000 - June 2002 above the tree canopy and above the understory in a mature, naturally regenerated slash pine (Pinus elliottii Engelm. var. elliottii) - longleaf pine (Pinus palustris Mill.) flatwoods forest. Understory latent energy (eE) and sensible...

Resiliency of an interior ponderosa pine forest to bark beetle infestations following fuel-reduction and forest-restoration treatments

Treesearch

Christopher J Fettig; Stephen R. McKelvey

2014-01-01

Mechanical thinning and the application of prescribed fire are commonly used to restore fire-adapted forest ecosystems in the western United States. During a 10-year period, we monitored the effects of fuel-reduction and forest-restoration treatments on levels of tree mortality in an interior ponderosa pine, Pinus ponderosa Dougl. ex Laws., forest...

Thermomechanical pulping of loblolly pine juvenile wood

Treesearch

Gary C. Myers

2002-01-01

Intensive forest management, with a heavy emphasis on ecosystem management and restoring or maintaining forest health, will result in the removal of smaller diameter materials from the forest. This increases the probability of higher juvenile wood content in the harvested materials. The purpose of this study was to compare the performance of loblolly pine juvenile and...

Structure and regrowth of longleaf pine forests following uneven-aged silviculture and hurricane disturbance at the Escambia Experimental Forest

Treesearch

Kimberly Bohn; Christel Chancy; Dale Brockway

2015-01-01

In recent decades, considerable attention has been placed on restoring and managing longleaf pine (Pinus palustris Mill.) ecosystems across the southeastern United States. Although, historically, these forests have been successfully regenerated following even-aged shelterwood reproduction methods, uneven-aged silviculture has received increasing...

Tree canopy types constrain plant distributions in ponderosa pine-Gambel oak forests, northern Arizona

Treesearch

Scott R. Abella

2009-01-01

Trees in many forests affect the soils and plants below their canopies. In current high-density southwestern ponderosa pine (Pinus ponderosa) forests, managers have opportunities to enhance multiple ecosystem values by manipulating tree density, distribution, and canopy cover through tree thinning. I performed a study in northern Arizona ponderosa...

Invasive pathogen threatens bird-pine mutualism: implications for sustaining a high-elevation ecosystem.

PubMed

McKinney, Shawn T; Fiedler, Carl E; Tomback, Diana F

2009-04-01

Human-caused disruptions to seed-dispersal mutualisms increase the extinction risk for both plant and animal species. Large-seeded plants can be particularly vulnerable due to highly specialized dispersal systems and no compensatory regeneration mechanisms. Whitebark pine (Pinus albicaulis), a keystone subalpine species, obligately depends upon the Clark's Nutcracker (Nucifraga columbiana) for dispersal of its large, wingless seeds. Clark's Nutcracker, a facultative mutualist with whitebark pine, is sensitive to rates of energy gain, and emigrates from subalpine forests during periods of cone shortages. The invasive fungal pathogen Cronartium ribicola, which causes white pine blister rust, reduces whitebark pine cone production by killing cone-bearing branches and trees. Mortality from blister rust reaches 90% or higher in some whitebark pine forests in the Northern Rocky Mountains, USA, and the rust now occurs nearly rangewide in whitebark pine. Our objectives were to identify the minimum level of cone production necessary to elicit seed dispersal by nutcrackers and to determine how cone production is influenced by forest structure and health. We quantified forest conditions and ecological interactions between nutcrackers and whitebark pine in three Rocky Mountain ecosystems that differ in levels of rust infection and mortality. Both the frequency of nutcracker occurrence and probability of seed dispersal were strongly related to annual whitebark pine cone production, which had a positive linear association with live whitebark pine basal area, and negative linear association with whitebark pine tree mortality and rust infection. From our data, we estimated that a threshold level of approximately 1000 cones/ha is needed for a high likelihood of seed dispersal by nutcrackers (probability > or = 0.7), and that this level of cone production can be met by forests with live whitebark pine basal area > 5.0 m2/ha. The risk of mutualism disruption is greatest in northern most Montana (USA), where three-year mean cone production and live basal area fell below predicted threshold levels. There, nutcracker occurrence, seed dispersal, and whitebark pine regeneration were the lowest of the three ecosystems. Managers can use these threshold values to differentiate between restoration sites requiring planting of rust-resistant seedlings and sites where nutcracker seed dispersal can be expected.

Vegetation indicators of transformation in the urban forest ecosystems of "Kuzminki-Lyublino" Park

NASA Astrophysics Data System (ADS)

Buyvolova, Anna; Trifonova, Tatiana; Bykova, Elena

2017-04-01

Forest ecosystems in the city are at the same time a component of its natural environment and part of urban developmental planning. It imposes upon urban forests a large functional load, both environmental (formation of environment, air purification, noise pollution reducing, etc.) and social (recreational, educational) which defines the special attitude to their management and study. It is not a simple task to preserve maximum accessibility to the forest ecosystems of the large metropolises with a minimum of change. The urban forest vegetates in naturally formed soil, it has all the elements of a morphological structure (canopy layers), represented by natural species of the zonal vegetation. Sometimes it is impossible for a specialist to distinguish between an urban forest and a rural one. However, the urban forests are changing, being under the threat of various negative influences of the city, of which pollution is arguably the most significant. This article presents some indicators of structural changes to the plant communities, which is a response of forest ecosystems to an anthropogenic impact. It is shown that the indicators of the transformation of natural ecosystems in the city can be a reduction of the projective cover of moss layer, until its complete absence (in the pine forest), increasing the role of Acer negundo (adventive species) in the undergrowth, high variability of floristic indicators of the ground herbaceous vegetation, and a change in the spatial arrangement of adventive species. The assessment of the impact of the urban environment on the state of vegetation in the "Kuzminki-Lyublino" Natural-Historical Park was conducted in two key areas least affected by anthropogenic impacts under different plant communities represented by complex pine and birch forests and in similar forest types in the Prioksko-Terrasny Biosphere Reserve. The selection of pine forests as a model is due to the fact that, according to some scientists, pine (Pinus Sylvestris L.), a very ductile and widespread species, is a sensitive indicator of anthropogenic burden, responding to the impact of defoliation and needles discoloration, and survives even at fairly high levels of pollution. The vegetation cover is one of the most dynamic components of the ecosystem and under the conditions of urban existence it is subject to transformation. The indicators of the transformation of natural ecosystems in the city can be a reduction of the projective cover of moss layer, until its complete absence (in the pine forest), increasing the role of Acer negundo (adventive species) in the undergrowth, high variability of floristic indicators of the ground herbaceous vegetation, and a change in the spatial arrangement of adventive species. The further study of plant communities with a view to identifying indicators of transformation in urban environmental conditions will help for the early detection of reversible changes in the ecosystems of urban forests and the development of rational urban forest care technologies.

An ecosystem services framework for multidisciplinary research in the Colorado River headwaters

USGS Publications Warehouse

Semmens, D.J.; Briggs, J.S.; Martin, D.A.

2009-01-01

A rapidly spreading Mountain Pine Beetle epidemic is killing lodgepole pine forest in the Rocky Mountains, causing landscape change on a massive scale. Approximately 1.5 million acres of lodgepoledominated forest is already dead or dying in Colorado, the infestation is still spreading rapidly, and it is expected that in excess of 90 percent of all lodgepole forest will ultimately be killed. Drought conditions combined with dramatically reduced foliar moisture content due to stress or mortality from Mountain Pine Beetle have combined to elevate the probability of large fires throughout the Colorado River headwaters. Large numbers of homes in the wildland-urban interface, an extensive water supply infrastructure, and a local economy driven largely by recreational tourism make the potential costs associated with such a fire very large. Any assessment of fire risk for strategic planning of pre-fire management actions must consider these and a host of other important socioeconomic benefits derived from the Rocky Mountain Lodgepole Pine Forest ecosystem. This paper presents a plan to focus U.S. Geological Survey (USGS) multidisciplinary fire/beetle-related research in the Colorado River headwaters within a framework that integrates a wide variety of discipline-specific research to assess and value the full range of ecosystem services provided by the Rocky Mountain Lodgepole Pine Forest ecosystem. Baseline, unburned conditions will be compared with a hypothetical, fully burned scenario to (a) identify where services would be most severely impacted, and (b) quantify potential economic losses. Collaboration with the U.S. Forest Service will further yield a distributed model of fire probability that can be used in combination with the ecosystem service valuation to develop comprehensive, distributed maps of fire risk in the Upper Colorado River Basin. These maps will be intended for use by stakeholders as a strategic planning tool for pre-fire management activities and can be updated and improved adaptively on an annual basis as tree mortality, climatic conditions, and management actions unfold. 

Longleaf pine agroforestry

Treesearch

Kristina Connor; Rebecca Barlow; Luben Dimov; Mark Smith

2012-01-01

While ecosystem restoration of longleaf pine (Pinus palustris Mill.) forests represents a worthy ideal, it is not always a practical alternative for landowners. Agroforestry systems, which can be developed in existing agricultural land, natural forest stands, plantations, or pasturelands, offer the opportunity to provide multiple benefits: high value...

Restoring longleaf pine forest ecosystems in the southern U.S

Treesearch

Dale G. Brockway; Kenneth W. Outcalt; Donald J. Tomczak; Everett E. Johnson

2005-01-01

Longleaf pine (Pinus palustris) ecosystems are native to nine states of the southern region of the U.S. Longleaf pine can grow on a variety of site types including wet flatwoods and savannas along the Atlantic and Gulf coastal plain, higher droughty sand deposits from the fall line sandhills to the central ridge of Florida (Stout and Marion 1993),...

Effects of thinning and herbicide application on vertebrate communities in longleaf pine plantations

Treesearch

Kristina J. Brunjes; Karl V. Miller; W. Mark Ford; Timothy B. Harrington; M. Boyd Edwards

2003-01-01

Currently, nearly 98% of the land area once dominated by longleaf pine ecosystems has been converted to other uses. The U.S. Forest Service is replanting logged areas with longleaf pine at the Savannah River Site, New Ellenton, South Carolina, in an effort to restore these ecosystems. To ascertain the effects of various silvicultural management techniques on the...

Ponderosa pine forest structure and northern goshawk reproduction: Response to Beier et al

Treesearch

Richard T. Reynolds; Douglas A. Boyce; Russell T. Graham

2012-01-01

Ecosystem-based forest management requires long planning horizons to incorporate forest dynamics - changes resulting from vegetation growth and succession and the periodic resetting of these by natural and anthropogenic disturbances such as fire, wind, insects, and timber harvests. Given these dynamics, ecosystem-based forest management plans should specify desired...

Trends in snag populations in drought-stressed mixed-conifer and ponderosa pine forests (1997-2007)

Treesearch

Joseph L. Ganey; Scott C. Vojta

2012-01-01

Snags provide important biological legacies, resources for numerous species of native wildlife, and contribute to decay dynamics and ecological processes in forested ecosystems. We monitored trends in snag populations from 1997 to 2007 in drought-stressed mixed-conifer and ponderosa pine (Pinus ponderosa Dougl. ex Laws) forests, northern Arizona. Median snag density...

A dendrochronological analysis of a disturbance-succession model for oak-pine forests of the Appalachian Mountains, USA

Treesearch

Patrick H. Brose; Thomas A. Waldrop

2010-01-01

Disturbance-succession models describe the relationship between the disturbance regime and the dominant tree species of a forest type. Such models are useful tools in ecosystem management and restoration, provided they are accurate. We tested a disturbance-succession model for the oak-pine (Quercus spp. - Pinus spp.) forests of the...

Beetles among us: Social and economic impacts of the MPB epidemic [Chapter 6

Treesearch

Krista Gebert; Greg Jones; Patty Champ; Mike Czaja; Chuck Oliver; Paul E. Cruz; Jessica Clement

2014-01-01

Healthy forest ecosystems provide many goods and services that are vital to human well-being. When forest ecosystems are impacted by disturbances, such as the widespread mountain pine beetle (MPB) epidemic, the services provided by these ecosystems are also affected. Likewise, management in response to large-scale forest disturbances impacts both the natural and human...

Volume, Mass, And Nutrients Of Down Woody Debris Following Initial Shortleaf Pine-Bluestem Grass Restoration Activities In The Ouachita Mountains Of Arkansas

Treesearch

Jessica C. Seifert; Hal O. Liechty; Martin A. Spetich; Daniel A. Marion

2004-01-01

Abstract - The Ouachita National Forest is restoring pine-mixed hardwood forests to a shortleaf pine-bluestem grass ecosystem through harvesting, midstory control, and the application of prescribed fire. Mean mass and volume of downed woody debris (DWD) in plots following initial harvesting and midstory-control were respectively 335 percent and 253...

Restoration planting options for limber pines in Colorado and Wyoming

Treesearch

Anne Marie Casper; William R. Jacobi; Anna W. Schoettle; Kelly S. Burns

2011-01-01

Limber Pine (Pinus flexilis) populations in the southern Rocky Mountains are severely threatened by the combined impacts of mountain pine beetles and white pine blister rust. Limber pineʼs critical role in these high elevation ecosystems heightens the importance of mitigating these impacts. To develop forest-scale planting methods, six limber pine seedling...

Using stand replacement fires to restore southern Appalachian pine-hardwood ecosystems: effects on mass, carbon, and nutrient pools

Treesearch

James M. Vose; Wayne T. Swank; Barton D. Clinton; Jennifer D. Knoepp; Lloyd W. Swift

1999-01-01

Pine-hardwood ecosystems in the Southern Appalachians are in serious decline due to fire exclusion and insect infestations. Fire has been advanced as a tool to restore these ecosystems, yet there are few studies evaluating overall ecosystem effects. The authors’ objectives were to evaluate the effects of stand restoration burning on forest floor nitrogen (N) and carbon...

Impact of forest seral stage on use of ant communities for rapid assessment of terrestrial ecosystem health.

PubMed

Wike, Lynn D; Martin, F Douglas; Paller, Michael H; Nelson, Eric A

2010-01-01

Bioassessment evaluates ecosystem health by using the responses of a community of organisms that integrate all aspects of the ecosystem. A variety of bioassessment methods have been applied to aquatic ecosystems; however, terrestrial methods are less advanced. The objective of this study was to examine baseline differences in ant communities at different seral stages from clear cut to mature pine plantation as a precursor to developing a broader terrestrial bioassessment protocol. Comparative sampling was conducted at nine sites having four seral stages: clearcut, 5 year recovery, 15 year recovery, and mature stands. Soil and vegetation data were also collected at each site. Ants were identified to genus. Analysis of the ant data indicated that ants respond strongly to habitat changes that accompany ecological succession in managed pine forests, and both individual genera and ant community structure can be used as indicators of successional change. Ants exhibited relatively high diversity in both early and mature seral stages. High ant diversity in mature seral stages was likely related to conditions on the forest floor favoring litter dwelling and cold climate specialists. While ants may be very useful in identifying environmental stress in managed pine forests, adjustments must be made for seral stage when comparing impacted and unimpacted forests.

Greenhouse gas balance of a Scots pine forest using biometric, eddy covariance and chamber measurements.

NASA Astrophysics Data System (ADS)

Gielen, Bert; De Vos, Bruno; Papale, Dario; Janssens, Ivan

2013-04-01

In recent years, the status of forests as sources or sinks of carbon has received much attention. Nonetheless, evidence-based long-term estimates of the magnitude of the carbon sequestration in forests are still scarce. In this study we present two independent estimates of net carbon sequestration in a temperate Scots pine dominated forest ecosystem over a 9 year period (2002-2010) and in addition, to determine the full greenhouse gas balance, the first results of automated chamber measurements of N2O and CH4. First, the net ecosystem carbon balance (NECB) was estimated from net ecosystem CO2 exchange as measured by the eddy covariance technique (NECBEC). To this end, the eddy covariance estimates were combined with non-CO2 carbon fluxes such as DOC leaching and VOC emissions. The second approach to determine the carbon sequestration was based on the changes in the ecosystem carbon stocks over time (NECBSC). For this NECBSC estimate, two assessments of the ecosystem carbon stocks (2002 and 2010) were compared. Results showed that the eddy covariance approach estimated a net uptake of 2.4 ± 1.25 tC ha-1 yr-1, while the stock based approach suggested a carbon sink of 1.8 ± 1.20 tC ha-1 yr-1. No significant change was observed in the mineral soil carbon, while the carbon stock of the litter layer slightly decreased. Phytomass was thus the main carbon sink (2.1 tC ha-1 yr-1) in the pine forest, predominantly in the stems (1.3 tC ha-1 yr-1). The fact that stem wood is the main carbon sink within the ecosystem implies that the future harvesting has the potential to fully offset the CO2 uptake by this Scots pine forest. Estimates of the impact of N2O and CH4 emissions from the soil on the total greenhouse gas budget will be presented.

The 2002 Rodeo-Chediski Wildfire's impacts on southwestern ponderosa pine ecosystems, hydrology, and fuels

Treesearch

Peter F. Ffolliott; Cody L. Stropki; Hui Chen; Daniel G. Neary

2011-01-01

The Rodeo-Chediski Wildfire burned nearly 462,600 acres in north-central Arizona in the summer of 2002. The wildfire damaged or destroyed ecosystem resources and disrupted the hydrologic functioning within the impacted ponderosa pine (Pinus ponderosa) forests in a largely mosaic pattern. Impacts of the wildfire on ecosystem resources, factors important to hydrologic...

Reptile and amphibian responses to restoration of fire-maintained pine woodlands

Treesearch

Roger W Perry; D. Craig Rudolph; Ronald E. Thill

2009-01-01

Fire-maintained woodlands and savannas are important ecosystems for vertebrates in many regions of the world. These ecosystems are being restored by forest managers, but little information exists on herpetofaunal responses to this restoration in areas dominated by shortleaf pine (Pinus echinata). We compared habitat characteristics and...

Restoration of southwestern ponderosa pine ecosystems with fire

Treesearch

Stephen S. Sackett; Sally M. Haase; Michael G. Harrington

1994-01-01

Heavy grazing and timbering during settlement by Europeans, and a policy of fire exclusion shortly after caused extensive structural and compositional changes to the southwestern ponderosa pine ecosystem. These changes have resulted in forest health problems, such as increased insect and disease epidemics, reduced wildlife habitat, and a serious wildfire hazard....

Restoring the shortleaf pine - bluestem grass ecosystem: An economic evaluation

Treesearch

M.M. Huebschmann; T.B. Lynch; D.K. Lewis; James M. Guldin

1999-01-01

The shortleaf pine (Pinus echinata Mill.) - bluestem grass (Andropogon spp.) ecosystem that existed prior to European settlement is being restored on 155,000 acres in the Ouachita National Forest of western Arkansas. Preliminary analyses indicate that revenues generated in the affected area will decline because of reduced sale...

Conserving genetic diversity in Ponderosa Pine ecosystem restoration

Treesearch

L.E. DeWald

2017-01-01

Restoration treatments in the ponderosa pine (Pinus ponderosa P. & C. Lawson) ecosystems of the southwestern United States often include removing over 80 percent of post-EuroAmerican settlement-aged trees to create healthier forest structural conditions. These types of stand density reductions can have negative effects on genetic diversity. Allozyme analyses...

Pinus sylvestris as a missing source of nitrous oxide and methane in boreal forest.

PubMed

Machacova, Katerina; Bäck, Jaana; Vanhatalo, Anni; Halmeenmäki, Elisa; Kolari, Pasi; Mammarella, Ivan; Pumpanen, Jukka; Acosta, Manuel; Urban, Otmar; Pihlatie, Mari

2016-03-21

Boreal forests comprise 73% of the world's coniferous forests. Based on forest floor measurements, they have been considered a significant natural sink of methane (CH4) and a natural source of nitrous oxide (N2O), both of which are important greenhouse gases. However, the role of trees, especially conifers, in ecosystem N2O and CH4 exchange is only poorly understood. We show for the first time that mature Scots pine (Pinus sylvestris L.) trees consistently emit N2O and CH4 from both stems and shoots. The shoot fluxes of N2O and CH4 exceeded the stem flux rates by 16 and 41 times, respectively. Moreover, higher stem N2O and CH4 fluxes were observed from wet than from dry areas of the forest. The N2O release from boreal pine forests may thus be underestimated and the uptake of CH4 may be overestimated when ecosystem flux calculations are based solely on forest floor measurements. The contribution of pine trees to the N2O and CH4 exchange of the boreal pine forest seems to increase considerably under high soil water content, thus highlighting the urgent need to include tree-emissions in greenhouse gas emission inventories.

Coarse woody debris assay in northern Arizona mixed-conifer and ponderosa pine forests

Treesearch

Joseph L. Ganey; Scott C. Vojta

2010-01-01

Coarse woody debris (CWD) provides important ecosystem services in forests and affects fire behavior, yet information on amounts and types of CWD typically is limited. To provide such information, we sampled logs and stumps in mixed-conifer and ponderosa pine (Pinus ponderosa) forests in north-central Arizona. Spatial variability was prominent for all CWD parameters....

Restoring eastside ponderosa pine ecosystems at the Blacks Mountain Experimental Forest: a case study

Treesearch

Jianwei Zhang; Martin W. Ritchie

2008-01-01

The ecological research project of interior ponderosa pine forests at the Blacks Mountain Experimental Forest in northeastern California was initiated by an interdisciplinary team of scientists in the early 1990s. The objectives of this study were to determine the effect of stand structure, and prescribed fire on vegetation growth, resilience, and sustainability of...

An analysis of modern pollen rain from the Maya lowlands of northern Belize

USGS Publications Warehouse

Bhattacharya, T.; Beach, T.; Wahl, D.

2011-01-01

In the lowland Maya area, pollen records provide important insights into the impact of past human populations and climate change on tropical ecosystems. Despite a long history of regional paleoecological research, few studies have characterized the palynological signatures of lowland ecosystems, a fact which lowers confidence in ecological inferences made from palynological data. We sought to verify whether we could use pollen spectra to reliably distinguish modern ecosystem types in the Maya lowlands of Central America. We collected 23 soil and sediment samples from eight ecosystem types, including upland, riparian, secondary, and swamp (bajo) forests; pine savanna; and three distinct wetland communities. We analyzed pollen spectra with non-metric multidimensional scaling (NMDS), and found significant compositional differences in ecosystem types' pollen spectra. Forested sites had spectra dominated by Moraceae/Urticaceae pollen, while non-forested sites had significant portions of Poaceae, Asteraceae, and Amaranthaceae pollen. Upland, bajo, and riparian forest differed in representation of Cyperaceae, Bactris-type, and Combretaceae/Melastomataceae pollen. High percentages of pine (Pinus), oak (Quercus), and the presence of Byrsonima characterized pine savanna. Despite its limited sample size, this study provides one of the first statistical analyses of modern pollen rain in the Maya lowlands. Our results show that pollen assemblages can accurately reflect differences between ecosystem types, which may help refine interpretations of pollen records from the Maya area. ?? 2010 Elsevier B.V.

Restoration of southern ecosystems

Treesearch

John A. Stanturf; Emile S. Gardiner; Kenneth Outcalt; William H. Conner; James M. Guldin

2004-01-01

Restoration of the myriad communities of bottomland hardwood and wetland forests and of the diverse communities of fire-dominated pine forests is the subject of intense interest in the Southern United States. Restoration practice is relatively advanced for bottomland hardwoods and longleaf pine (Pinus palustris Mill.), and less so for swamps and...

Resilience of ponderosa and lodgepole pine forests to mountain pine beetle disturbance and limited regeneration

USGS Publications Warehouse

Briggs, Jenny S.; Hawbaker, Todd J.; Vandendriesche, Don

2015-01-01

After causing widespread mortality in lodgepole pine forests in North America, the mountain pine beetle (MPB) has recently also affected ponderosa pine, an alternate host species that may have different levels of resilience to this disturbance. We collected field data in ponderosa pine- and lodgepole pine-dominated forests attacked by MPB in Colorado and then simulated stand growth over 200 years using the Forest Vegetation Simulator. We compared scenarios of no disturbance with scenarios of MPB-caused mortality, both with and without regeneration. Results indicated that basal area and tree density recovered to predisturbance levels relatively rapidly (within 1‐8 decades) in both forest types. However, convergence of the disturbed conditions with simulated undisturbed conditions took longer (12‐20+ decades) and was delayed by the absence of regeneration. In MPB-affected ponderosa pine forests without regeneration, basal area did not converge with undisturbed conditions within 200 years, implying lower resilience in this ecosystem. Surface fuels accumulated rapidly in both forest types after MPB-induced mortality, remaining high for 3‐6 decades in simulations. Our results suggest that future patterns of succession, regeneration, fuel loading, climate, and disturbance interactions over long time periods should be considered in management strategies addressing MPB effects in either forest type, but particularly in ponderosa pine.

The ecological classification of coastal wet longleaf pine (pinus palustris) of Florida from reference conditions

Treesearch

George L. McCaskill; Jose. Shibu

2012-01-01

Tropical storms, fire, and urbanization have produced a heavily fragmented forested landscape along Florida’s Gulf coast. The longleaf pine forest, one of the most threatened ecosystems in the US, makes up a major part of this fragmented landscape. These three disturbance regimes have produced a mosaic of differently-aged pine patches of single or two cohort structures...

Putting white pine in its place on the Hiawatha National Forest

Treesearch

Allen D. Saberniak

1995-01-01

White pine was once a very important part of the ecosysystem in the northern lake states. Turn of the century logging and wildfires removed white pine from many of the ecosystems of which it was an integral part. Early reforestation efforts were largely unsuccessful. The native white pine weevil and the exotic white pine blister rust made white pine establishment...

Ecosystem Nitrogen Retention Following Severe Bark Beetle and Salvage Logging Disturbance in Lodgepole Pine Forests: a 15N Enrichment Study

NASA Astrophysics Data System (ADS)

Avera, B.; Rhoades, C.; Paul, E. A.; Cotrufo, M. F.

2017-12-01

In recent decades, bark beetle outbreaks have caused high levels of tree mortality in lodgepole pine (Pinus contorta) dominated forests across western North America. Previous work has found increased soil mineral nitrogen (N) with tree mortality in beetle infested stands, but surprisingly little change in stream N export. These findings suggest an important role of residual live vegetation and altered soil microbial response for retaining surplus N and mitigating N losses from disturbed lodgepole forests. Post outbreak salvage of merchantable timber reduces fuel levels and promotes tree regeneration; however, the implications of the combined bark beetle and harvesting disturbances on ecosystem N retention and productivity are uncertain. To advance understanding of post-disturbance N retention we compare unlogged beetle-infested forests and salvage logged stands with post-harvest woody residue retention or removal. We applied 15N-labeled (2 atom%) and natural abundance ammonium sulfate to eight year old lodgepole pine seedlings in three replicate plots of the three forest management treatments. This approach allows us to quantify the relative contributions of N retention in soil, microbial biomass, and plant tissue. Our study targets gaps in understanding of the processes that regulate N utilization and transfer between soil and vegetation that result in effective N retention in lodgepole pine ecosystems. These findings will also help guide forest harvest and woody residue management practices in order to maintain soil productivity.

Forest Floor CO2 Flux From Two Contrasting Ecosystems in the Southern Appalachians

Treesearch

James M. Vose; Barton D. Clinton; Verl Emrick

1995-01-01

We measured forest floor CO2 flux in two contrasting ecosystems (white pine plantation and northern hardwood ecosystems at low and high elevations, respectively) in May and September 1993 to quantify differences and determine factors regulating CO2 fluxes. An automated IRGA based, flow through system was used with chambers...

Ecosystem Management Research in the Ouachita Mountains: Pretreatment Conditions and Preliminary Findings

Treesearch

James B. Baker

1994-01-01

In August 1990, USDA Forest Service researchers from the Southern Forest Experiment Station and resource managers from the Ouachita and Ozark National Forests embarked on a major ecosystem management (then called New Perspectives) research program aimed at formulating, implementing, and evaluating partial cutting methods in shortleaf pine-hardwood stands as...

Ecological research at the Blacks Mountain Experimental Forest in northeastern California

Treesearch

William W. Oliver

2000-01-01

At Blacks Mountain Experimental Forest in northeastern California, an interdisciplinary team of scientists developed and implemented a research project to study how forest structural complexity affects the health and vigor of interior ponderosa pine (Pinus ponderosa Dougl. ex Laws.) ecosystems, the ecosystem's resilience to natural and human-caused disturbances,...

Forest health in the Blue Mountains: a management strategy for fire-adapted ecosystems.

Treesearch

R.W. Mutch; S.F. Arno; J.K. Brown; C.E. Carlson; R.D. Ottmar; J.L. Peterson

1993-01-01

The fire-adapted forests of the Blue Mountains are suffering from a forest health problem of catastrophic proportions. Contributing to the decline of forest health are such factors as the extensive harvesting of the western larch and ponderosa pine overstory during the 1900s, attempted exclusion of fire from a fire-dependent ecosystem, and the continuing drought. The...

Native and exotic insects and diseases in forest ecosystems in the Hoosier-Shawnee ecological assessment area

Treesearch

Dwight Scarbrough; Jennifer Juzwik

2004-01-01

Various native and exotic insects and diseases affect the forest ecosystems of the Hoosier-Shawnee Ecological Assessment Area. Defoliating insects have had the greatest effects in forests where oak species predominate. Increases in oak decline are expected with the imminent establishment of the European gypsy moth. Insects and pathogens of the pine forests are...

Simulation of Landscape Pattern of Old Growth Forests of Korean Pine by Block Kringing

Treesearch

Wang Zhengquan; Wang Qingcheng; Zhang Yandong

1997-01-01

The study area was located in Liangshui Natural Reserve. Xaozing'an Mountains, Northeastern China. Korean pine forests are the typical forest ecosystems and landscapes in this region. It is a high degress of spatial and temporal heterogeneity at different scales, which effected on landscape pattern and processes. In this paper we used the data of 144 plots and...

Blacks Mountain Experimental Forest: bark beetle responses to differences in forest structure and the application of prescribed fire in interior ponderosa pine

Treesearch

Christopher J. Fettig; Robert R. Borys; Stephen R. McKelvey; Christopher P. Dabney

2008-01-01

Mechanical thinning and the application of prescribed fire are commonly used tools in the restoration of fire-adapted forest ecosystems. However, few studies have explored their effects on subsequent amounts of bark beetle caused tree mortality in interior ponderosa pine, Pinus ponderosa Dougl. ex P. & C. Laws. var. ponderosa. In...

Predicting plant species diversity in a longleaf pine landscape

Treesearch

L. Katherine Kirkman; P. Charles Goebel; Brian J. Palik; Larry T. West

2004-01-01

In this study, we used a hierarchical, multifactor ecological classification system to examine how spatial patterns of biodiversity develop in one of the most species-rich ecosystems in North America, the fire-maintained longleaf pine-wiregrass ecosystem and associated depressional wetlands and riparian forests. Our goal was to determine which landscape features are...

Structure and composition of historical longleaf pine ccosystems in Mississippi, USA

Treesearch

Brice B. Hanberry; Keith Coursey; John S. Kush

2018-01-01

Longleaf pine (Pinus palustris) historically was a widespread ecosystem composed of a simple tree canopy and grasslands ground layer. After widespread loss of this ecosystem due to logging and fire exclusion, little quantitative information exists about historical structure for restoration goals. We identified composition in De Soto National Forest and Pearl River...

The longleaf pine forest: trends and current conditions

Treesearch

Kenneth W. Outcalt; Raymond M. Sheffield

1996-01-01

Longleaf pine (Pinus palustris Mill.) ecosystems once occupied perhaps as much as 60 million acres in the Southeastern United States (fig. l), stretching from southeastern Virginia south to central Florida and west into eastern Texas (Stout and Marion 1993). These fire-dependent ecosystems covered a wide range of site conditions, from low, wet...

Lengthened cold stratification improves bulk whitebark pine germination

Treesearch

Nathan Robertson; Kent Eggleston; Emily Overton; Marie McLaughlin

2013-01-01

Crucial to the restoration of whitebark pine (Pinus albicaulis) ecosystems is the ability of forest managers to locate, propagate, and reintroduce viable, disease-resistant populations to these jeopardized systems. Currently, one of the most limiting steps in this process is the slow, labor-in - tensive, and expensive process of producing whitebark seedlings at forest...

The social and economic drivers of the southeastern forest landscape

Treesearch

R. Kevin McIntyre; Barrett B. McCall; David N. Wear

2018-01-01

The last quarter century has witnessed an unprecedented resurgence of interest in the management of longleaf pine (Pinus palustris) forests, a phenomenon that has been coupled with increased understanding of the ecology, management, and restoration of these ecosystems. As interest in longleaf pine becomes more mainstream among landowners and the...

EFFECTS OF CO2 AND O3 IN PONDEROSA PINE PLANT/LITTER/SOIL MESOCOSMS

EPA Science Inventory

Forested ecosysems are subjected to interacting conditions whose joint impacts may be quite different from those from single factors. To understand the impacts of CO2 and O3 on forest ecosystems, in April 1998, we initiated a four-year study of a Ponderosa pine seedling/soil/lit...

Restoring old-growth southern pine ecosystems: strategic lessons from long-term silvicultural research

Treesearch

Don C. Bragg; Michael G. Shelton; James M. Guldin

2008-01-01

The successful restoration of old-growth-like loblolly (Pinus taeda) and shortleaf (Pinus echinata) pine-dominated forests requires the integration of ecological information with long-term silvicultural research from places such as the Crossett Experimental Forest (CEF). Conventional management practices such as timber harvesting or competition control have supplied...

Contribution of actinorhizal shrubs to site fertility in a northern California mixed pine forest

Treesearch

Matt D. Busse; Martin F. Jurgensen; Deborah S. Page-Dumroese; Robert F. Powers

2007-01-01

Bitterbrush (Purshia tridentata) and mahala mat (Ceanothus prostratus) are common N-fixing shrubs in interior forests of the western United States, yet their contribution to ecosystem N pools is poorly characterized. We compared N fixation and soil N accretion by these shrubs in old-growth ponderosa pine (Pinus ponderosa...

Applied chemical ecology of the mountain pine beetle

Treesearch

Robert A. Progar; Nancy Gillette; Christopher J. Fettig; Kathryn Hrinkevich

2014-01-01

Mountain pine beetle, Dendroctonus ponderosae Hopkins, is a primary agent of forest disturbance in western North America. Episodic outbreaks occur at the convergence of favorable forest age and size class structure and climate patterns. Recent outbreaks have exceeded the historic range of variability of D. ponderosae-caused tree mortality affecting ecosystem goods and...

75 FR 2157 - Endangered and Threatened Wildlife and Plants; Permits; Timber Harvest in Williamsburg County, SC

Federal Register 2010, 2011, 2012, 2013, 2014

2010-01-14

... species' use of live pines may have evolved in response to living in a fire-maintained ecosystem where... declined primarily due to conversion of mature pine forests to young pine plantations, agricultural fields... wetlands, pine flatwoods, and agricultural fields, which are currently the only remaining foraging habitat...

Predictions of southern pine beetle populations using a forest ecosystem model

Treesearch

S.G. McNulty; P.L. Lorio; M.P. Ayres; J.D. Reeve

1998-01-01

Dendroctonus fiontaiis Zimm. (southern pine beetle (SPB)) has caused over $900 million in damage to pines in the southern United States between 1960 and 1990 (Price et al.. 1992). The damage of SPB to loblolly (Pinus tuedu L.), shortleaf (Pinus echinata Mill.), and pitch (Pinus rigida Mill.) pine has long been...

Restoring whitebark pine ecosystems in the face of climate change

Treesearch

Robert E. Keane; Lisa M. Holsinger; Mary F. Mahalovich; Diana F. Tomback

2017-01-01

Whitebark pine (Pinus albicaulis) forests have been declining throughout their range in western North America from the combined effects of mountain pine beetle (Dendroctonus ponderosae) outbreaks, fire exclusion policies, and the exotic disease white pine blister rust (Cronartium ribicola). Projected warming and drying trends in climate may exacerbate this decline;...

Restoration planting options for limber pines impacted by mountain pine beetles and/or white pine blister rust in the Southern Rocky Mountains

Treesearch

Anne Marie Casper; William R. Jacobi; Anna W. Schoettle; Kelly S. Burns

2010-01-01

Limber Pine (Pinus flexilis) populations in the southern Rock Mountains are severely threatened by the combined impacts of mountain pine beetles and white pine blister rust. Limber pine’s critical role these high elevation ecosystems heightens the importance of mitigating impacts. To develop forest-scale planting methods six seedling planting trial sites were installed...

Nitrogen Cycling Responses to Mountain Pine Beetle Disturbance in a High Elevation Whitebark Pine Ecosystem

PubMed Central

Keville, Megan P.; Reed, Sasha C.; Cleveland, Cory C.

2013-01-01

Ecological disturbances can significantly affect biogeochemical cycles in terrestrial ecosystems, but the biogeochemical consequences of the extensive mountain pine beetle outbreak in high elevation whitebark pine (WbP) (Pinus albicaulis) ecosystems of western North America have not been previously investigated. Mountain pine beetle attack has driven widespread WbP mortality, which could drive shifts in both the pools and fluxes of nitrogen (N) within these ecosystems. Because N availability can limit forest regrowth, understanding how beetle-induced mortality affects N cycling in WbP stands may be critical to understanding the trajectory of ecosystem recovery. Thus, we measured above- and belowground N pools and fluxes for trees representing three different times since beetle attack, including unattacked trees. Litterfall N inputs were more than ten times higher under recently attacked trees compared to unattacked trees. Soil inorganic N concentrations also increased following beetle attack, potentially driven by a more than two-fold increase in ammonium (NH4 +) concentrations in the surface soil organic horizon. However, there were no significant differences in mineral soil inorganic N or soil microbial biomass N concentrations between attacked and unattacked trees, implying that short-term changes in N cycling in response to the initial stages of WbP attack were restricted to the organic horizon. Our results suggest that while mountain pine beetle attack drives a pulse of N from the canopy to the forest floor, changes in litterfall quality and quantity do not have profound effects on soil biogeochemical cycling, at least in the short-term. However, continuous observation of these important ecosystems will be crucial to determining the long-term biogeochemical effects of mountain pine beetle outbreaks. PMID:23755166

Nitrogen cycling responses to mountain pine beetle disturbance in a high elevation whitebark pine ecosystem.

PubMed

Keville, Megan P; Reed, Sasha C; Cleveland, Cory C

2013-01-01

Ecological disturbances can significantly affect biogeochemical cycles in terrestrial ecosystems, but the biogeochemical consequences of the extensive mountain pine beetle outbreak in high elevation whitebark pine (WbP) (Pinus albicaulis) ecosystems of western North America have not been previously investigated. Mountain pine beetle attack has driven widespread WbP mortality, which could drive shifts in both the pools and fluxes of nitrogen (N) within these ecosystems. Because N availability can limit forest regrowth, understanding how beetle-induced mortality affects N cycling in WbP stands may be critical to understanding the trajectory of ecosystem recovery. Thus, we measured above- and belowground N pools and fluxes for trees representing three different times since beetle attack, including unattacked trees. Litterfall N inputs were more than ten times higher under recently attacked trees compared to unattacked trees. Soil inorganic N concentrations also increased following beetle attack, potentially driven by a more than two-fold increase in ammonium (NH₄⁺) concentrations in the surface soil organic horizon. However, there were no significant differences in mineral soil inorganic N or soil microbial biomass N concentrations between attacked and unattacked trees, implying that short-term changes in N cycling in response to the initial stages of WbP attack were restricted to the organic horizon. Our results suggest that while mountain pine beetle attack drives a pulse of N from the canopy to the forest floor, changes in litterfall quality and quantity do not have profound effects on soil biogeochemical cycling, at least in the short-term. However, continuous observation of these important ecosystems will be crucial to determining the long-term biogeochemical effects of mountain pine beetle outbreaks.

Nitrogen cycling responses to mountain pine beetle disturbance in a high elevation whitebark pine ecosystem

USGS Publications Warehouse

Keville, Megan P.; Reed, Sasha C.; Cleveland, Cory C.

2013-01-01

Ecological disturbances can significantly affect biogeochemical cycles in terrestrial ecosystems, but the biogeochemical consequences of the extensive mountain pine beetle outbreak in high elevation whitebark pine (WbP) (Pinus albicaulis) ecosystems of western North America have not been previously investigated. Mountain pine beetle attack has driven widespread WbP mortality, which could drive shifts in both the pools and fluxes of nitrogen (N) within these ecosystems. Because N availability can limit forest regrowth, understanding how beetle-induced mortality affects N cycling in WbP stands may be critical to understanding the trajectory of ecosystem recovery. Thus, we measured above- and belowground N pools and fluxes for trees representing three different times since beetle attack, including unattacked trees. Litterfall N inputs were more than ten times higher under recently attacked trees compared to unattacked trees. Soil inorganic N concentrations also increased following beetle attack, potentially driven by a more than two-fold increase in ammonium (NH4+) concentrations in the surface soil organic horizon. However, there were no significant differences in mineral soil inorganic N or soil microbial biomass N concentrations between attacked and unattacked trees, implying that short-term changes in N cycling in response to the initial stages of WbP attack were restricted to the organic horizon. Our results suggest that while mountain pine beetle attack drives a pulse of N from the canopy to the forest floor, changes in litterfall quality and quantity do not have profound effects on soil biogeochemical cycling, at least in the short-term. However, continuous observation of these important ecosystems will be crucial to determining the long-term biogeochemical effects of mountain pine beetle outbreaks.

Modeling forest harvesting effects on landscape pattern in the Northwest Wisconsin Pine Barrens

Treesearch

Volker C. Radeloff; David J. Mladenoff; Eric J. Gustafson; Robert M. Scheller; Patrick A. Zollner; Hong S. Heilman; H. Resit Akcakaya

2006-01-01

Forest management shapes landscape patterns, and these patterns often differ significantly from those typical for natural disturbance regimes. This may affect wildlife habitat and other aspects of ecosystem function. Our objective was to examine the effects of different forest management decisions on landscape pattern in a fire adapted ecosystem. We used a factorial...

Valuing the forest for the trees: Willingness to pay for white pine blister rust management

Treesearch

James R. Meldrum; Patricia A. Champ; Craig A. Bond

2011-01-01

The nearly two million acres of high elevation forests in the Western United States are not an important source of timber or any other market products. However, that does not mean that the forests are not highly valuable. Visitors and nonvisitors alike value the unique five-needle pine trees found in these high elevation ecosystems. In this study, we estimate the...

Contrasting impacts of climate and competition on large sugar pine growth and defense in a fire-excluded forest of the Central Sierra Nevada

Treesearch

Andrew Slack; Jeffrey Kane; Eric Knapp; Rosemary Sherriff

2017-01-01

Many forest ecosystems with a large pine component in the western United States have experienced environmental stress associated with climate change and increased competition with forest densification in the absence of fire. Information on how changes in climate and competition affect carbon allocation to tree growth and defense is needed to anticipate changes to tree...

Historical wildfire impacts on ponderosa pine tree overstories: An Arizona case study

Treesearch

Peter F. Ffolliott; Cody L. Stropki; Daniel G. Neary

2008-01-01

The Rodeo-Chediski Wildfire--the largest in Arizona's history--damaged or destroyed ecosystem resources and disrupted ecosystem functioning in a largely mosaic pattern throughout the ponderosa pine (Pinus ponderosa) forests exposed to the burn. Impacts of this wildfire on tree overstories were studied for 5 years (2002 to 2007) on two watersheds...

Biomass and nutrient distributions in central Oregon second-growth ponderosa pine ecosystems.

Treesearch

Susan N. Little; Lauri J. Shainsky

1995-01-01

We investigated the distribution of biomass and nutrients in second-growth ponderosa pine (Pinus ponderosa Dougl. ex Laws.) ecosystems in central Oregon. Destructive sampling of aboveground and belowground tree biomass was carried out at six sites in the Deschutes National Forest; three of these sites also were intensively sampled for biomass and...

Root disease and other unforeseen variables that confound restoration efforts

Treesearch

William J. Otrosina; Shi-Jean S. Sung; Stanley J. Zarnoch; Brian T. Sullivan; Charles H. Walkinshaw

2002-01-01

Unanticipated disease problems thwarting restoration efforts can emerge in forest ecosystems. An example is the longleaf pine (Pinus palustris Mill.) ecosystem. This species once occupied nearly 30 million ha but now its range is reduced to approximately 1.5 million ha. Restoring longleaf pine to many sites in its former range is an important goal...

The Moquah Barrens Research Natural Area: Loss of a pine barrens ecosystem

USGS Publications Warehouse

Ribic, Christine

2017-01-01

The Moquah Barrens Research Natural Area (RNA) was established by the Chequamegon National Forest and the Lakes States Forest Experiment Station in 1935 with a research objective well-suited to the needs of the Forest Service and the scientific understanding of ecosystem function prevalent at the time of establishment. The original research plan was never implemented, which led to a joint Forest-Station decision in 1956 to disestablish the RNA. However, that decision was never implemented. A series of management decisions made after 1956 led to the loss of the pine barrens ecosystem originally encompassed by the RNA. This loss is not irretrievable and the work necessary to recover the original ecosystem is possible under existing RNA management guidelines. The experience of the Moquah Barrens RNA can be used by the Forest Service to improve overall management of the entire system of research natural areas. Two main areas of opportunity are identified: 1) implement an improved approach to managing official records associated with RNAs; and 2) adopt a management framework suitable for long-term ecological projects.

Carbon exchange between the atmosphere and subtropical forested cypress and pine wetlands

USGS Publications Warehouse

Shoemaker, W. Barclay; Anderson, Frank E.; Barr, Jordan G.; Graham, Scott L.; Botkin, Daniel B.

2015-01-01

Carbon dioxide exchange between the atmosphere and forested subtropical wetlands is largely unknown. Here we report a first step in characterizing this atmospheric–ecosystem carbon (C) exchange, for cypress strands and pine forests in the Greater Everglades of Florida as measured with eddy covariance methods at three locations (Cypress Swamp, Dwarf Cypress and Pine Upland) for 2 years. Links between water and C cycles are also examined at these three sites, as are methane emission measured only at the Dwarf Cypress site. Each forested wetland showed net C uptake from the atmosphere both monthly and annually, as indicated by the net ecosystem exchange (NEE) of carbon dioxide (CO2). For this study, NEE is the difference between photosynthesis and respiration, with negative values representing uptake from the atmosphere that is retained in the ecosystem or transported laterally via overland flow (unmeasured for this study). Atmospheric C uptake (NEE) was greatest at the Cypress Swampp (−900 to −1000 g C m2 yr−1), moderate at the Pine Upland (−650 to −700 g C m2 yr−1) and least at the Dwarf Cypress (−400 to −450 g C m2 yr−1). Changes in NEE were clearly a function of seasonality in solar insolation, air temperature and flooding, which suppressed heterotrophic soil respiration. We also note that changes in the satellite-derived enhanced vegetation index (EVI) served as a useful surrogate for changes in NEE at these forested wetland sites.

Restoration of the Native Plant Communities in Longleaf Pine Landscapes on the Kisatchie National Forest, Louisiana

Treesearch

James D. Haywood; Alton Martin; Finis L. Harris; Michael L. Elliott-Smith

1998-01-01

In January 1993, the Kisatchie National Forest and Southern Research Station began monitoring the effects of various management practices on overstory and midstory trees, shrubs, and understory woody and herbaceous vegetation in several longleaf pine (Pinus palustris Mill.) stands. The monitoring of these stands is part of several Ecosystem...

Fire management and carbon sequestration in Pine Barren Forests

Treesearch

Kenneth L. Clark; Nicholas Skowronski; Michael Gallagher

2015-01-01

Prescribed burning is the major viable option that land managers have for reducing hazardous fuels and ensuring the regeneration of fire-dependent species in a cost-effective manner in Pine Barren ecosystems. Fuels management activities are directly linked to carbon (C) storage and rates of C sequestration by forests. To evaluate the effects of prescribed burning on...

Hazardous fuels management in mixed red pine and eastern white pine forest in the northern Lake States: A synthesis of knowledge

Treesearch

Eric Toman; David M. Hix; P. Charles Goebel; Stanley D. Gehrt; Robyn S. Wilson; Jennifer A. Sherry; Alexander Silvis; Priscilla Nyamai; Roger A. Williams; Sarah McCaffrey

2014-01-01

Fuels reduction decisions are made within a larger context of resource management characterized by multiple objectives including ecosystem restoration, wildlife management, commodity production (from timber to nontraditional forest products), and provision of recreation opportunities and amenity values. Implementation of fuels treatments is strongly influenced by their...

Soil and water management in the shortleaf pine ecosystem

Treesearch

Edwin L. Miller

1986-01-01

The opportunities for achieving watershed management goals in the process of timber management in the range of shortleaf pine are excellent. Water yield increases may occur with forest harvest but with little or no adverse watershed effects. Peak or flood flows for major storms are little affected by forest harvest. Serious erosion potentials exist when inappropriate...

Long-term management impacts on carbon storage in Lake States forests

Treesearch

Matthew Powers; Randall Kolka; Brian Palik; Rachel McDonald; Martin Jurgensen

2011-01-01

We examined carbon storage following 50+ years of forest management in two long-term silvicultural studies in red pine and northern hardwood ecosystems of North America’s Great Lakes region. The studies contrasted various thinning intensities (red pine) or selection cuttings, shelterwoods, and diameter-limit cuttings (northern hardwoods) to unmanaged controls of...

Effects of Disturbance on Carbon Sequestration in the New Jersey Pine Barrens

DOE Office of Scientific and Technical Information (OSTI.GOV)

Schafer, Karina; Bohrer, Gil

While carbon and water cycling of forests contribute significantly to the Earth's overall biogeochemical cycling, it may be affected by disturbance and climate change. In this research, we contributed to the body of research on leaf-level, ecosystem and regional scale effects of disturbances on forest ecosystems, in an effort to foster more mechanistic understanding, which in turn can improve modeling efforts. Here, we summarize some of the major findings in this research of physical and biogenic disturbances, such as drought, prescribed fire, and insect defoliation, on leaf and ecosystem-scale physiological responses as well as impacts on carbon and water cyclingmore » in an Atlantic Coastal Plain upland oak/pine and upland pine forest. Following we have incorporated some of our findings into a new version of the Finite-element Tree-Crown Hydrodynamics (model version 2) model, which improved timing and hysteresis of transpiration modeling for trees. Furthermore, incorporation of hydrodynamics into modeling transpiration improved latent heat flux estimates. In our study on the physiology of the trees, we showed that during drought, stomatal conductance and canopy stomatal conductance were reduced, however, defoliation increased conductance on both leaf-level and canopy scale. Furthermore, after prescribed fire, leaf-level stomatal conductance was unchanged for pines but decreased for oaks, while canopy stomatal conductance decreased temporarily, but then rebounded the following growing season, thus exhibiting transient responses. This study suggests that forest response to disturbance varies from the leaf to ecosystem level as well as species level and thus, these differential responses interplay to determine the fate of forest structure and functioning post disturbance. Incorporating this responses improves model outcome.« less

Modeling compensatory responses of ecosystem-scale water fluxes in forests affected by pine and spruce beetle mortality

NASA Astrophysics Data System (ADS)

Millar, D.; Ewers, B. E.; Peckham, S. D.; Mackay, D. S.; Frank, J. M.; Massman, W. J.; Reed, D. E.

2015-12-01

Mountain pine beetle (Dendroctonus ponderosae) and spruce beetle (Dendroctonus rufipennis) epidemics have led to extensive mortality in lodgepole pine (Pinus contorta) and Engelmann spruce (Picea engelmannii) forests in the Rocky Mountains of the western US. In both of these tree species, mortality results from hydraulic failure within the xylem, due to blue stain fungal infection associated with beetle attack. However, the impacts of these disturbances on ecosystem-scale water fluxes can be complex, owing to their variable and transient nature. In this work, xylem scaling factors that reduced whole-tree conductance were initially incorporated into a forest ecohydrological model (TREES) to simulate the impact of beetle mortality on evapotranspiration (ET) in both pine and spruce forests. For both forests, simulated ET was compared to observed ET fluxes recorded using eddy covariance techniques. Using xylem scaling factors, the model overestimated the impact of beetle mortality, and observed ET fluxes were approximately two-fold higher than model predictions in both forests. The discrepancy between simulated and observed ET following the onset of beetle mortality may be the result of spatial and temporal heterogeneity of plant communities within the foot prints of the eddy covariance towers. Since simulated ET fluxes following beetle mortality in both forests only accounted for approximately 50% of those observed in the field, it is possible that newly established understory vegetation in recently killed tree stands may play a role in stabilizing ecosystem ET fluxes. Here, we further investigate the unaccounted for ET fluxes in the model by breaking it down into multiple cohorts that represent live trees, dying trees, and understory vegetation that establishes following tree mortality.

The Moquah Barrens Research Natural Area: Loss of a pine barrens ecosystem

Treesearch

Christine A. Ribic; David J. Rugg; Deahn M. Donner; Albert J. Beck; BJ. Byers

2016-01-01

The Moquah Barrens Research Natural Area (RNA) was established by the Chequamegon National Forest and the Lakes States Forest Experiment Station in 1935 with a research objective well-suited to the needs of the Forest Service and the scientific understanding of ecosystem function prevalent at the time of establishment. The original research plan was never implemented,...

Soil Fungi Respond More Strongly Than Fine Roots to Elevated CO2 in a Model Regenerating Longleaf Pine-Wiregrass Ecosystem

USDA-ARS?s Scientific Manuscript database

Increasing atmospheric CO2 will have significant effects on belowground processes which will affect forest structure and function. A model regenerating longleaf pine-wiregrass community [consisting of longleaf pine (Pinus palustris), wiregrass (Aristida stricta), sand post oak (Quescus margaretta),...

Does tree diversity increase wood production in pine forests?

PubMed

Vilà, Montserrat; Vayreda, Jordi; Gracia, Carles; Ibáñez, Joan Josep

2003-04-01

Recent experimental advances on the positive effect of species richness on ecosystem productivity highlight the need to explore this relationship in communities other than grasslands and using non-synthetic experiments. We investigated whether wood production in forests dominated by Aleppo pine (Pinus halepensis) and Pyrenean Scots pine (Pinus sylvestris) differed between monospecific and mixed forests (2-5 species) using the Ecological and Forest Inventory of Catalonia (IEFC) database which contains biotic and environmental characteristics for 10,644 field plots distributed within a 31,944 km(2) area in Catalonia (NE Spain). We found that in Pyrenean Scots pine forests wood production was not significantly different between monospecific and mixed plots. In contrast, in Aleppo pine forests wood production was greater in mixed plots than in monospecific plots. However, when climate, bedrock types, radiation and successional stage per plot were included in the analysis, species richness was no longer a significant factor. Aleppo pine forests had the highest productivity in plots located in humid climates and on marls and sandstone bedrocks. Climate did not influence wood production in Pyrenean Scots pine forests, but it was highest on sandstone and consolidated alluvial materials. For both pine forests wood production was negatively correlated with successional stage. Radiation did not influence wood production. Our analysis emphasizes the influence of macroenvironmental factors and temporal variation on tree productivity at the regional scale. Well-conducted forest surveys are an excellent source of data to test for the association between diversity and productivity driven by large-scale environmental factors.

A significant carbon sink in temperate forests in Beijing: based on 20-year field measurements in three stands.

PubMed

Zhu, JianXiao; Hu, XueYang; Yao, Hui; Liu, GuoHua; Ji, ChenJun; Fang, JingYun

2015-11-01

Numerous efforts have been made to characterize forest carbon (C) cycles and stocks in various ecosystems. However, long-term observation on each component of the forest C cycle is still lacking. We measured C stocks and fluxes in three permanent temperate forest plots (birch, oak and pine forest) during 2011–2014, and calculated the changes of the components of the C cycle related to the measurements during 1992–1994 at Mt. Dongling, Beijing, China. Forest net primary production in birch, oak, and pine plots was 5.32, 4.53, and 6.73 Mg C ha-1 a-1, respectively. Corresponding net ecosystem production was 0.12, 0.43, and 3.53 Mg C ha-1 a-1. The C stocks and fluxes in 2011–2014 were significantly larger than those in 1992–1994 in which the biomass C densities in birch, oak, and pine plots increased from 50.0, 37.7, and 54.0 Mg C ha-1 in 1994 to 101.5, 77.3, and 110.9 Mg C ha-1 in 2014; soil organic C densities increased from 207.0, 239.1, and 231.7 Mg C ha-1 to 214.8, 241.7, and 238.4 Mg C ha-1; and soil heterotrophic respiration increased from 2.78, 3.49, and 1.81 Mg C ha-1 a-1 to 5.20, 4.10, and 3.20 Mg C ha-1 a-1. These results suggest that the mountainous temperate forest ecosystems in Beijing have served as a carbon sink in the last two decades. These observations of C stocks and fluxes provided field-based data for a long-term study of C cycling in temperate forest ecosystems.

Longleaf Pine Regeneration and Management: An Overstory Overview

Treesearch

William D. Boyer

1997-01-01

Longleaf pine is the key tree in fire-dependent ecosystems long native to the southeastern United States. Once the most extensive forest ecosystem in North America dominated by a single species, it now occupies only a small fraction of its former range. Longleaf has the reputation of being a slow-growing species that is nearly impossible to regenerate and so...

A collaborative fire hazard reduction/ecosystem restoration stewardship project in a Montana mixed ponderosa pine/Douglas-fir/western larch wildland urban interface

Treesearch

Steve Slaughter; Laura Ward; Michael Hillis; Jim Chew; Rebecca McFarlan

2004-01-01

Forest Service managers and researchers designed and evaluated alternative disturbance-based fire hazard reduction/ecosystem restoration treatments in a greatly altered low-elevation ponderosa pine/Douglas-fir/western larch wildland urban interface. Collaboratively planned improvement cutting and prescribed fire treatment alternatives were evaluated in simulations of...

Variability and persistence of post-fire biological legacies in jack pine-dominated ecosystems of northern Lower Michigan

Treesearch

Daniel Kashian; Gregory Corace; Lindsey Shartell; Deahn M. Donner; Philip Huber

2011-01-01

Stand-replacing wildfires have historically shaped the forest structure of dry, sandy jack pine-dominated ecosystems at stand and landscape scales in northern Lower Michigan. Unique fire behavior during large wildfire events often preserves long strips of unburned trees arranged perpendicular to the direction of fire spread. These biological legacies create...

The Longleaf Alliance: A Regional Longleaf Pine Recovery Effort

Treesearch

Dean Gjerstad; Rhett Johnson

2002-01-01

Longleaf pine was once the dominate forest over nearly 70 percent of Alabama, ranging from just south of the Tennessee Valley to the Gulf Coast. Today longleaf represents less than 3 percent of Alabama's forest acreage. However, a dramatic recovery of this most important southern ecosystem is underway with interest and support at an all time high among landowners...

Patterns and processes: Monitoring and understanding plant diversity in frequently burned longleaf pine (Pinus palustris) landscapes

Treesearch

J. O' Brien; L. Dyer; R. Mitchell; A. Hudak

2013-01-01

Longleaf pine (Pinus palustris) ecosystems are remarkably rich in plant species and represent the dominant upland forest type in several southeastern military installations. Management of these forests on installations is critical both to fulfill the military mission and to conserve this unique natural resource. The researchers will couple a series of field experiments...

Spatiotemporal Dynamics of Fire in Whitebark Pine Stands on two Mountains in the Lolo National Forest, Montana, USA.

NASA Astrophysics Data System (ADS)

Larson, E. R.; Grissino-Mayer, H. D.

2004-12-01

Whitebark pine (Pinus albicaulis) is a long-lived tree species that exists throughout high elevation and treeline forest communities of western North America. It is the foundation of a diminishing ecosystem that supports Clark's nutcrackers (Nucifraga columbiana), red squirrels (Tamiasciurus hudsonicus), grizzly bears (Ursus arctos), and black bears (U. americana). Several factors are directly linked to the decline of the whitebark pine ecosystem: mortality from recent and widespread mountain pine beetle (Dendroctonus ponderosae) outbreaks, infestation by the invasive white pine blister rust (Cronartium ribicola, an exotic fungal canker that weakens and eventually kills white pines), and fire suppression that may have altered the historic fire regime and enabled fire-intolerant tree species to encroach upon whitebark pine stands. The synergistic effects of these factors have led to a dramatic decline in whitebark pine communities throughout its native range, and in response land managers and conservationists have called for research to better understand the ecological dynamics of this little studied ecosystem. My research uses dendrochronology to investigate the fire history of whitebark pine stands on three mountains in the Lolo National Forest, Montana, via fire-scar and age structure analyses. I present here the results from the fire-scar analyses from Morrell Mountain where I obtained 40 cross sections from dead and down whitebark pines. Individual tree mean fire return intervals (MFRI) range from 33 to 119 years, with a stand MFRI of 49 years that includes fire scars dating to the 16th century. Fire events scarred multiple trees in AD 1754, 1796, and 1843, indicating a mixed-severity fire regime. The majority of the samples recorded a frost event in AD 1601, perhaps evidence of the AD 1600 eruption of Mt. Huaynapatina in the Peruvian Andes. My research not only provides an historical framework for land managers, but also provides an opportunity to examine long-term spatiotemporal dynamics of fire activity over the northern Rocky Mountains in terms of climate change and atmospheric teleconnections.

Fire effects in northeastern forests: jack pine.

Treesearch

Cary Rouse

1986-01-01

The jack pine ecosystem has evolved through fire. Jack pine, although easily killed by fire, has developed serotinous cones that depend upon high heat to open and release the seeds. Without a fire to enable the cones to open, jack pine would be replaced by another species. Prescribed fire can be an economical management tool for site preparation in either a natural...

White pine blister rust in high-elevation white pines: Screening for simply-inherited, hypersensitive resistance

Treesearch

Detlev R. Vogler; Annette Delfino-Mix; Anna W. Schoettle

2006-01-01

Recent concern about survival and recovery of high-elevation white pine ecosystems has returned white pine blister rust (caused by Cronartiurn ribicola) to prominence as a significant threat to forest health in the western U.S. (Sainman et al., 2003). This, in turn, has spurred new research into potential rust-resistance mechanisms in high-elevation...

Influence of deer, cattle grazing and timber harvest on plant species diversity in a longleaf pine bluestem ecosystem

Treesearch

Dale G. Brockway; Clifford E. Lewis

2003-01-01

Despite a recent slowing in the negative historical trend, losses of naturally-regenerated longleaf pine forests currently continue, largely as a result of conversion to plantations of faster growing pine species. Comparing the impacts of type conversion with silvicultural approaches that maintain longleaf pine and ascertaining their interaction with the influence of...

Evaluating future success of whitebark pine ecosystem restoration under climate change using simulation modeling

Treesearch

Robert E. Keane; Lisa M. Holsinger; Mary F. Mahalovich; Diana F. Tomback

2017-01-01

Major declines of whitebark pine forests throughout western North America from the combined effects of mountain pine beetle (Dendroctonus ponderosae) outbreaks, fire exclusion policies, and the exotic disease white pine blister rust (WPBR) have spurred many restoration actions. However, projected future warming and drying may further exacerbate the species’ decline and...

Extended benefit cost analysis as an instrument of economic valuated in Petungkriyono forest ecosystem services

NASA Astrophysics Data System (ADS)

Damayanti, Irma; Nur Bambang, Azis; Retnaningsih Soeprobowati, Tri

2018-05-01

Petungkriyono is the last tropical forest in Java and provides biodiversity including rare flora and fauna that must be maintained, managed and utilized in order to give meaning for humanity and sustainability. Services of Forest Ecosystem in Petungkriyono are included such as goods supply, soil-water conservation, climate regulation, purification environment and flora fauna habitats. The approach of this study is the literature review from various studies before perceiving the influenced of economic valuation in determining the measurement conservation strategies of Petungkriyono Natural Forest Ecosystem in Pekalongan Regency. The aims of this study are to analyzing an extended benefit cost of natural forest ecosystems and internalizing them in decision making. The method of quantification and valuation of forest ecosystem is Cost and Benefit Analysis (CBA) which is a standard economic appraisal tools government in development economics. CBA offers the possibility capturing impact of the project. By using productivity subtitution value and extended benefit cost analysis any comodity such as Backwoods,Pine Woods, Puspa woods and Pine Gum. Water value, preventive buildings of landslide and carbon sequestration have total economic value of IDR.163.065.858.080, and the value of Extended Benefit Cost Ratio in Petungkriyono is 281.35 %. However, from the result is expected the local government of Pekalongan to have high motivation in preserve the existence of Petungkriyono forest.

Coastal plain pond water quality and mercury contend of biota of the Long Island Central Pine Barrens and Mashomack Preserve: Effects of atmospheric deposition and human development

USGS Publications Warehouse

Lawrence, Gregory B.; Siemion, Jason; Lane, Oksana P.

2015-01-01

Pine barrens are considered an imperiled ecosystem in the northeastern U.S. The Suffolk County Pine Barrens, once the second largest in the Northeast, were substantially reduced and fragmented by development during the 20th century. The coastal plain ponds being considered in this study occur in central Suffolk County within the Long Island Central Pine Barrens region. This highly unique natural environment, embedded with forests and woodlands, resulted from its glacial origins and a land use history that predates European colonization. Included in this study was The Nature Conservancy’s Mashomack Preserve, located on Shelter Island between Peconic Bay and Gardiner’s Bay. There are no freshwater ponds in the Mashomack Preserve, but this area was included with the Central Pine Barrens investigation, because Shelter Island has a similar geologic and land-use history that has resulted in a similarly unique low-nutrient forest and woodland ecosystem with extremely coarse-textured soils.

A 20-year reassessment of the health and status of whitebark pine forests in the Bob Marshall Wilderness Complex, Montana

Treesearch

Molly L. Retzlaff; Signe B. Leirfallom; Robert E. Keane

2016-01-01

Whitebark pine plays a prominent role in high elevation ecosystems of the northern Rocky Mountains. It is an important food source for many birds and mammals as well as an essential component of watershed stabilization. Whitebark pine is vanishing from the landscape due to three main factors: white pine blister rust, mountain pine beetle outbreaks, and successional...

Proceedings of symposium on the shortleaf pine ecosystem; 1986 March 31-April 2; Little Rock, AR

Treesearch

Paul A. Murphy

1986-01-01

Shortleaf pine has the largest range of any of the southern pines, covering more than 440,000 square miles in 22 states, and has an inventory volume second only to loblolly pine. Despite this importance, shortleaf pine lags behind in terms of research information and management effort. This is generally due to the preference of forest managers for faster-growing...

Fire and high-elevation, five-needle pine (Pinus aristata & P. flexilis) ecosystems in the southern Rocky Mountains: What do we know?

Treesearch

Jonathan D. Coop; Anna W. Schoettle

2011-01-01

Rocky Mountain bristlecone pine (Pinus aristata Engelm) and limber pine (P. flexilis James) are high-elevation, fiveneedle pines of the southern Rocky Mountains. The pre-settlement role of fire in bristlecone and limber pine forests remains the subject of considerable uncertainty; both species likely experienced a wide range of fire regimes across gradients of site...

Fortifying the forest: thinning and burning increase resistance to a bark beetle outbreak and promote forest resilience.

PubMed

Hood, Sharon M; Baker, Stephen; Sala, Anna

2016-10-01

Fire frequency in low-elevation coniferous forests in western North America has greatly declined since the late 1800s. In many areas, this has increased tree density and the proportion of shade-tolerant species, reduced resource availability, and increased forest susceptibility to forest insect pests and high-severity wildfire. In response, treatments are often implemented with the goal of increasing ecosystem resilience by increasing resistance to disturbance. We capitalized on an existing replicated study of fire and stand density treatments in a ponderosa pine (Pinus ponderosa)-Douglas-fir (Pseudotsuga menziesii) forest in western Montana, USA, that experienced a naturally occurring mountain pine beetle (MPB; Dendroctonus ponderosae) outbreak 5 yr after implementation of fuels treatments. We explored whether treatment effects on tree-level defense and stand structure affected resistance to MPB. Mortality from MPB was highest in the denser, untreated control and burn-only treatments, with approximately 50% and 39%, respectively, of ponderosa pine killed during the outbreak, compared to almost no mortality in the thin-only and thin-burn treatments. Thinning treatments, with or without fire, dramatically increased tree growth and resin ducts relative to control and burn-only treatments. Prescribed burning did not increase resin ducts but did cause changes in resin chemistry that may have affected MPB communication and lowered attack success. While ponderosa pine remained dominant in the thin and thin-burn treatments after the outbreak, the high pine mortality in the control and burn-only treatment caused a shift in species dominance to Douglas-fir. The high Douglas-fir component in the control and burn-only treatments due to 20th century fire exclusion, coupled with high pine mortality from MPB, has likely reduced resilience of this forest beyond the ability to return to a ponderosa pine-dominated system in the absence of further fire or mechanical treatment. Our results show treatments designed to increase resistance to high-severity fire in ponderosa pine-dominated forests in the Northern Rockies can also increase resistance to MPB, even during an outbreak. This study suggests that fuel and restoration treatments in fire-dependent ponderosa pine forests that reduce tree density increase ecosystem resilience in the short term, while the reintroduction of fire is important for long-term resilience. © 2016 by the Ecological Society of America.

Using a terrestrial ecosystem survey to estimate the historical density of ponderosa pine trees

Treesearch

Scott R. Abella; Charles W. Denton; David G. Brewer; Wayne A. Robbie; Rory W. Steinke; W. Wallace Covington

2011-01-01

Maps of historical tree densities for project areas and landscapes may be useful for a variety of management purposes such as determining site capabilities and planning forest thinning treatments. We used the U.S. Forest Service Region 3 terrestrial ecosystem survey in a novel way to determine if the ecosystem classification is a useful a guide for estimating...

Ecohydrology of adjacent sagebrush and lodgepole pine ecosystems: the consequences of climate change and disturbance

USGS Publications Warehouse

Bradford, John B.; Schlaepfer, Daniel R.; Lauenroth, William K.

2014-01-01

Sagebrush steppe and lodgepole pine forests are two of the most widespread vegetation types in the western United States and they play crucial roles in the hydrologic cycle of these water-limited regions. We used a process-based ecosystem water model to characterize the potential impact of climate change and disturbance (wildfire and beetle mortality) on water cycling in adjacent sagebrush and lodgepole pine ecosystems. Despite similar climatic and topographic conditions between these ecosystems at the sites examined, lodgepole pine, and sagebrush exhibited consistent differences in water balance, notably more evaporation and drier summer soils in the sagebrush and greater transpiration and less water yield in lodgepole pine. Canopy disturbances (either fire or beetle) have dramatic impacts on water balance and availability: reducing transpiration while increasing evaporation and water yield. Results suggest that climate change may reduce snowpack, increase evaporation and transpiration, and lengthen the duration of dry soil conditions in the summer, but may have uncertain effects on drainage. Changes in the distribution of sagebrush and lodgepole pine ecosystems as a consequence of climate change and/or altered disturbance regimes will likely alter ecosystem water balance.

Species Composition, Tree Quality and Wood Properties of Southern Pine Stands Under Ecosystemm Management on National Forests in the Peidmont and Coastal Plain

Treesearch

Alexander Clark; James W. McMinn

1999-01-01

National Forests in the United States are under sustainable ecosystem management to conserve biodiversity, achieve sustainable conditions and improve the balance among forest values. This paper reports on a study established to identify the implications of ecosystem management strategies on natural stands in the Piedmont and Coastal Plain. The impact of partial...

Impact Assessment of Pine Wilt Disease Using the Species Distribution Model and the CLIMEX Model

NASA Astrophysics Data System (ADS)

KIM, J. U.; Jung, H.

2016-12-01

The plant disease triangle consists of the host plant, pathogen and environment, but their interaction has not been considered in climate change adaptation policy. Our objectives are to predict the changes of a coniferous forest, pine wood nematodes (Bursaphelenchus xylophilus) and pine sawyer beetles (Monochamus spp.), which is a cause of pine wilt disease in the Republic of Korea. We analyzed the impact of pine wilt disease on climate change by using the species distribution model (SDM) and the CLIMEX model. Area of coniferous forest will decline and move to northern and high-altitude area. But pine wood nematodes and pine sawyer beetles are going to spread because they are going to be in a more favorable environment in the future. Coniferous forests are expected to have high vulnerability because of the decrease in area and the increase in the risk of pine wilt disease. Such changes to forest ecosystems will greatly affect climate change in the future. If effective and appropriate prevention and control policies are not implemented, coniferous forests will be severely damaged. An adaptation policy should be created in order to protect coniferous forests from the viewpoint of biodiversity. Thus we need to consider the impact assessment of climate change for establishing an effective adaptation policy. The impact assessment of pine wilt disease using a plant disease triangle drew suitable results to support climate change adaptation policy.

Carbon stocks across a chronosequence of thinned and unmanaged red pine (Pinus resinosa) stands

USGS Publications Warehouse

Powers, Matthew D.; Kolka, Randall K.; Bradford, John B.; Palik, Brian J.; Fraver, Shawn; Jurgensen, Martin F.

2012-01-01

Forests function as a major global C sink, and forest management strategies that maximize C stocks offer one possible means of mitigating the impacts of increasing anthropogenic CO2 emissions. We studied the effects of thinning, a common management technique in many forest types, on age-related trends in C stocks using a chronosequence of thinned and unmanaged red pine (Pinus resinosa) stands ranging from 9 to 306 years old. Live tree C stocks increased with age to a maximum near the middle of the chronosequence in unmanaged stands, and increased across the entire chronosequence in thinned stands. C in live understory vegetation and C in the mineral soil each declined rapidly with age in young stands but changed relatively little in middle-aged to older stands regardless of management. Forest floor C stocks increased with age in unmanaged stands, but forest floor C decreased with age after the onset of thinning around age 40 in thinned stands. Deadwood C was highly variable, but decreased with age in thinned stands. Total ecosystem C increased with stand age until approaching an asymptote around age 150. The increase in total ecosystem C was paralleled by an age-related increase in total aboveground C, but relatively little change in total belowground C. Thinning had surprisingly little impact on total ecosystem C stocks, but it did modestly alter age-related trends in total ecosystem C allocation between aboveground and belowground pools. In addition to characterizing the subtle differences in C dynamics between thinned and unmanaged stands, these results suggest that C accrual in red pine stands continues well beyond the 60–100 year management rotations typical for this system. Management plans that incorporate longer rotations and thinning in some stands could play an important role in maximizing C stocks in red pine forests while meeting other objectives including timber extraction, biodiversity conservation, restoration, and fuel reduction goals.

Alterations on flow variability due to converting hardwood forests to pine

Treesearch

Yusuf Serengil; Wayne T. Swank; James M. Vose

2012-01-01

Flow variability is a potential indicator of land use impacts on aquatic ecosystems and a dominating factor for lotic habitats. Vegetation management effects on the stream habitat conditions must be better understood to propose forest management activities that are compatible with general ecosystem management objectives (integrity, diversity, sustainability, etc.). In...

Restoring Southern Pine Forests Ecosystems: Plant Community Response to Mechanical Midstory History Reduction and Prescribed Fire on Sandhills at Fort Benning Georgia

Treesearch

Dale Brockway; Kenneth W. Outcalt; Becky L. Estes

2003-01-01

Developed during periods of fire exclusion, dense midstory vegetation, that reduces understory plant diversity (competitive shading) and increases the risk of damaging Wildfire (fuel ladder from ground to canopy), has impeded restoration efforts to safely reintroduce prescribed burning in southern pine ecosystems. Our study evaluated the effects of midstory reduction...

Involving the public in restoring the role of fire in the longleaf pine ecosystem of Upland Island Wilderness

Treesearch

Brian P. Oswald; Ike McWhorter; Penny. Whisenant

2011-01-01

The 13,250-acre Upland Island Wilderness (UIW) in Texas was established in 1984 and is managed by the United States Forest Service (USFS). Historically, portions of it consisted of open and diverse longleaf pine (Pinus palustris) ecosystems which depend on frequent, low-intensity surface fires. As in many other relatively small wilderness areas, the...

Restoration of the ponderosa pine ecosystem and its understory

Treesearch

Lee E. Hughes

2008-01-01

Restoration of the Mt. Logan ponderosa pine ecosystem has been on-going since 1995. This effort included tree thinning to a density based on what the tree density was in 1870. The desired plant community objectives from the Mt. Trumbull Resource Conservation Area Plan had a forest objective as 50% trees to be in old-growth - i.e., a diameter class of 20-31.9+ inch...

Improving ecosystem-scale modeling of evapotranspiration using ecological mechanisms that account for compensatory responses following disturbance

NASA Astrophysics Data System (ADS)

Millar, David J.; Ewers, Brent E.; Mackay, D. Scott; Peckham, Scott; Reed, David E.; Sekoni, Adewale

2017-09-01

Mountain pine beetle outbreaks in western North America have led to extensive forest mortality, justifiably generating interest in improving our understanding of how this type of ecological disturbance affects hydrological cycles. While observational studies and simulations have been used to elucidate the effects of mountain beetle mortality on hydrological fluxes, an ecologically mechanistic model of forest evapotranspiration (ET) evaluated against field data has yet to be developed. In this work, we use the Terrestrial Regional Ecosystem Exchange Simulator (TREES) to incorporate the ecohydrological impacts of mountain pine beetle disturbance on ET for a lodgepole pine-dominated forest equipped with an eddy covariance tower. An existing degree-day model was incorporated that predicted the life cycle of mountain pine beetles, along with an empirically derived submodel that allowed sap flux to decline as a function of temperature-dependent blue stain fungal growth. The eddy covariance footprint was divided into multiple cohorts for multiple growing seasons, including representations of recently attacked trees and the compensatory effects of regenerating understory, using two different spatial scaling methods. Our results showed that using a multiple cohort approach matched eddy covariance-measured ecosystem-scale ET fluxes well, and showed improved performance compared to model simulations assuming a binary framework of only areas of live and dead overstory. Cumulative growing season ecosystem-scale ET fluxes were 8 - 29% greater using the multicohort approach during years in which beetle attacks occurred, highlighting the importance of including compensatory ecological mechanism in ET models.

Slash pile burning effects on soil biotic and chemical properties and plant establishment: Recommendations for amelioration

Treesearch

Julie E. Korb; Nancy C. Johnson; W. W. Covington

2004-01-01

Ponderosa pine forest restoration consists of thinning trees and reintroducing prescribed fire to reduce unnaturally high tree densities and fuel loads to restore ecosystem structure and function. A current issue in ponderosa pine restoration is what to do with the large quantity of slash that is created from thinning dense forest stands. Slash piling burning is...

Impact of Sustainable Forest Management on Harvest, Growth, and Regeneration of Southern Pine in the Piedmont After 5 Years of Monitoring

Treesearch

Alexander Clark; James W. McMinn

2002-01-01

This paper describes a study established to monitor the implications of ecosystem management choices on natural loblolly and shortleaf pine stands on the Oconee National Forests in the Piedmont of Georgia. The impact of partial harvests, group selection cuts, seed tree cuts and no human disturbance on growth, mortality, species composition, and regeneration were...

Influence of climate and land use on historical surface fires in pine-oak forests, Sierra Madre Occidental, Mexico

Treesearch

Emily K. Heyerdahl; Ernesto Alvarado

2003-01-01

The rugged mountains of the Sierra Madre Occidental, in north-central Mexico, support a mosaic of diverse ecosystems. Of these, the high-elevation, temperate pine-oak forests are ecologically significant for their extensiveness and biodiversity. They cover nearly half the land area in the states of Durango and Chihuahua (42%), and comprise a similar percentage of the...

What We Have Learned From 20+ Years of Research on Effects of Drought, Fire and Management on Carbon and Water Dynamics of Pacific Northwest Semi-Arid Forests

NASA Astrophysics Data System (ADS)

Law, B. E.; Berner, L. T.; Kwon, H.; Schmidt, A.

2016-12-01

Eco-climatic heterogeneity and proximity to oceans provides endless learning opportunities for eco-physiologists and modelers alike. We have been conducting measurements and modeling of ecosystem responses to climate and disturbance over Oregon's strong climatic gradient since 1990, and in the Metolius semi-arid region. Some of our findings have challenged common assumptions. Our first flux site was the Metolius old-growth ponderosa pine site (established 1996), followed by flux measurements at clusters of different age forests. We found that the old pine site continued to be an annual net carbon sink, contrary to expectations. Twenty years after stand-replacing disturbance, naturally regenerating young ponderosa pine was still a net carbon source, and a young pine plantation with removed debris (lower decomposition) was a weak sink. Physiological sensitivity to climate varies with tree size. Young pine forests responded to seasonal drought sooner and to a more severe degree. During extreme drought years, old pine showed only a small decline in water transport efficiency (11-24%), whereas efficiency declined by 46% in mature pine, and 80% in young pine. Thus, young trees risk hydraulic failure, which may account for higher mortality in young plantations nearby. Carbon uptake (GPP), soil fluxes, and evapotranspiration (calculated from sapflux or eddy flux data) are strongly coupled in the semi-arid ecosystems, suggesting it is feasible to combine sapflux and soil flux data along with water-use efficiency (GPP/LE) from high quality eddy flux data to estimate NEE in the landscape near flux sites or in patches of forests too small for EC measurements. Highlights show our key findings from development and application of multiple models, including SPA, Biome-BGC and CLM, and ideas for future directions.

Community structure, biodiversity, and ecosystem services in treeline whitebark pine communities: Potential impacts from a non-native pathogen

Treesearch

Diana F. Tomback; Lynn M. Resler; Robert E. Keane; Elizabeth R. Pansing; Andrew J. Andrade; Aaron C. Wagner

2016-01-01

Whitebark pine (Pinus albicaulis) has the largest and most northerly distribution of any white pine (Subgenus Strobus) in North America, encompassing 18° latitude and 21° longitude in western mountains. Within this broad range, however, whitebark pine occurs within a narrow elevational zone, including upper subalpine and treeline forests, and functions...

Management guide to ecosystem restoration treatments: Whitebark pine forests of the northern Rocky Mountains, U.S.A.

Treesearch

Robert E. Keane; Russell A. Parsons

2010-01-01

Whitebark pine is declining across much of its range in North America because of the combined effects of mountain pine beetle epidemics, fire exclusion policies, and widespread exotic blister rust infections. This management guide summarizes the extensive data collected at whitebark pine treatment sites for three periods: (1) pre-treatment, (2) 1 year post-treatment,...

[Early responses of soil fauna in three typical forests of south subtropical China to simulated N deposition addition].

PubMed

Xu, Guolian; Mo, Jiangming; Zhou, Guoyi

2005-07-01

In this paper, simulated N deposition addition (0, 50, 100 and 150 kg x hm(-2) x yr(-1)) by spreading water or NH4NO3 was conducted to study the early responses of soil fauna in three typical native forests (monsoon evergreen broadleaf forest, pine forest, and broadleaf-pine mixed forest) of subtropical China. The results showed that in monsoon evergreen broadleaf forest, N deposition addition had an obviously negative effect on the three indexes for soil fauna, but in pine forest, the positive effect was significant (P < 0. 05), and the soil fauna community could reach the level in mixed forest, even that in monsoon evergreen broadleaf forest at sometime. The responses in mixed forest were not obvious. In monsoon evergreen broadleaf forest, the negative effects were significant (P < 0.05) under medium N deposition, but not under low N deposition. In pine forest, the positive effect was significant (P < 0.05) under high N deposition, especially for the number of soil fauna groups. The results obtained might imply the N saturation-response mechanisms of forest ecosystems in subtropical China, and the conclusions from this study were also consisted with some related researches.

[Effect of pine plantations on soil arthropods in a high Andean forest].

PubMed

León-Gamboa, Alba Lucía; Ramos, Carolina; García, Mary Ruth

2010-09-01

One of the most common problems in the Colombian mountains has been the replacement of native vegetation by pine plantations. Soil arthropods are a fundamental component of forest ecosystem, since they participate in the organic matter fragmentation, previous to decomposition. This role is more valuable in high altitude environments, where low temperatures limit the dynamics of biological processes, where the effects of pine plantations on soil arthropods are still not well-known. In a remnant of high-andean forest (Neusa - Colombia) and a pine plantation of about 50 years-old, it was evaluated the composition, richness and abundance of arthropods at surface (S), organic horizon (O) and mineral horizon (A) of soil, to establish the differences associated to the soil use transformation. It was used "Pitfall" sampling to register the movement of the epigeous fauna, and extraction by funnel Berlese for determining the fauna density from O and A horizons. The Shannon and Simpson indexes estimated the diversity at different places and horizons, and the trophic structure of the community was evaluated. Overall, there were collected 38 306 individuals from forest and 17 386 individuals from pine plantation, mainly distributed in Collembola (42.4%), Acari (27%), Diptera (17.6%) and Coleoptera (4.6%). The most important differences were given in the surface, where the mobilization in forest (86 individuals/day) almost triplicates the one in pine plantation (33 individuals/day). The differences in composition were given in Collembola, Araneae, Hemiptera, Homoptera and Hymenoptera. The dynamics of richness and abundance along the year had significant high values in the native forest than in the pine plantation. The general trophic structure was dominated by saprophagous (75%), followed by predators (14%) and phytophagous (9%), but in two layers of the pine plantation soil (S and O) this structural pattern was not given. Based on the results, it was concluded that pine plantations affect the diversity, composition, community dynamic and trophic structure of soil arthropods. Also, some estimators of soil stability give signals that these effects are reducing the ecosystem function in the region.

Response of Planted Eastern White Pine (Pinus strobus L.) to Mechanical Release, Competition, and Drought in the Southern Appalachians

Treesearch

Barton D. Clinton; Katherine J. Elliott; Wayne T. Swank

1997-01-01

Conversion of low-quality, natural mixed pine hardwood ecosystems, containing a mountain laurel (Kalmia latifolia L.) dominated understory, to more productive eastern white pine (Pinus strobus L.)/mixed-hardwood systems is a common prescription on relatively xeric southern Appalachian forest sites. We examined the effects of...

Spatial patterns of longleaf pine (Pinus palustris) seedling eastablishment on the croatan national forest, North Carolina

Treesearch

Chadwick R. Avery; Susan Cohen; Kathleen C. Parker; John S. Kush

2004-01-01

Ecological research aimed at determining optimal conditions for longleaf pine regeneration has become increasingly important in efforts @ restore the longleaf pine ecosystem. Numerous authors have concluded that a negative relationship exists between the occurrence of seedlings and the occurrence of mature trees; however, observed field conditions in several North...

Proactive intervention to sustain high-elevation pine ecosystems threatened by white pine blister rust

Treesearch

Anna W. Schoettle; Richard A. Sniezko

2007-01-01

Only recently have efforts begun to address how management might prepare currently healthy forests to affect the outcome of invasion by established non-native pests. Cronartium ribicola, the fungus that causes the disease white pine blister rust (WPBR), is among the introductions into North America where containment and eradication have failed; the...

Gap-phase regeneration inlongleaf pine wiregrass ecosystems

Treesearch

D.G. Brockway; K.W. Outcalt

1998-01-01

Naturally regenerated seedlings of longleaf pine are typically observed to cluster in the center of tree fall canopy gaps and be encircled by a wide zone from which they are generally excluded. Twelve representative canopy gaps distributed across 600 ha of a naturally regenerated uneven-agedlongleaf pine forest in the sandhills of north central Florida were examined to...

Restoring composition and structure in Southwestern frequent-fire forests: A science-based framework for improving ecosystem resiliency

Treesearch

Richard T. Reynolds; Andrew J. Sanchez Meador; James A. Youtz; Tessa Nicolet; Megan S. Matonis; Patrick L. Jackson; Donald G. DeLorenzo; Andrew D. Graves

2013-01-01

Ponderosa pine and dry mixed-conifer forests in the Southwest United States are experiencing, or have become increasingly susceptible to, large-scale severe wildfire, insect, and disease episodes resulting in altered plant and animal demographics, reduced productivity and biodiversity, and impaired ecosystem processes and functions. We present a management framework...

Pro-B selection method for uneven-aged management of longleaf pine forests

Treesearch

Dale G. Brockway; Edward F. Loewenstein; Kenneth W. Outcalt

2015-01-01

Interest in uneven-aged silviculture has increased since advent of ecosystem management programs, which place greater emphasis on ecological values and ecosystem services while also harvesting timber from the forest. However, traditional uneven-aged approaches (e.g., BDq) are often criticized as too complex, costly, and requiring highly-trained staff. The Proportional-...

Sustainability and productivity of southern pine ecosystems: A thematic framework for integrating research and building partnerships

Treesearch

Charles K. McMahon; James P. Barnett

2000-01-01

In 1997, the USDA Forest Service Southern Research Station (SRS) published a Strategic Plan that formed a framework for addressing the Sustainability of Southern Forest Ecosystems. Six crosscutting themes were identified to facilitate research integration and partnership building among the widely dispersed SRS research work units. The Sustainability and Productivity of...

Ecology, management, and restoration of pinon-juniper and ponderosa pine ecosystems: combined proceedings of the 2005 St. George, Utah and 2006 Albuquerque, New Mexico workshops

Treesearch

Gerald J. Gottfried; John D. Shaw; Paulette L. Ford

2008-01-01

Southwestern pinon-juniper and juniper woodlands cover large areas of Arizona, New Mexico, Utah, and adjacent Colorado. Ponderosa pine forests are the most common timberland in the Southwest. All three ecosystems provide a variety of natural resources and economic benefits to the region. There are different perceptions of desired conditions. Public and private land...

Ecological restoration of southwestern ponderosa pine ecosystems: A broad perspective

USGS Publications Warehouse

Allen, Craig D.; Savage, Melissa; Falk, Donald A.; Suckling, Kieran F.; Swetnam, Thomas W.; Schulke, Todd; Stacey, Peter B.; Morgan, Penelope; Hoffman, Martos; Klingel, Jon T.

2002-01-01

The purpose of this paper is to promote a broad and flexible perspective on ecological restoration of Southwestern (U.S.) ponderosa pine forests. Ponderosa pine forests in the region have been radically altered by Euro-American land uses, including livestock grazing, fire suppression, and logging. Dense thickets of young trees now abound, old-growth and biodiversity have declined, and human and ecological communities are increasingly vulnerable to destructive crown fires. A consensus has emerged that it is urgent to restore more natural conditions to these forests. Efforts to restore Southwestern forests will require extensive projects employing varying combinations of young-tree thinning and reintroduction of low-intensity fires. Treatments must be flexible enough to recognize and accommodate: high levels of natural heterogeneity; dynamic ecosystems; wildlife and other biodiversity considerations; scientific uncertainty; and the challenges of on-the-ground implementation. Ecological restoration should reset ecosystem trends toward an envelope of “natural variability,” including the reestablishment of natural processes. Reconstructed historic reference conditions are best used as general guides rather than rigid restoration prescriptions. In the long term, the best way to align forest conditions to track ongoing climate changes is to restore fire, which naturally correlates with current climate. Some stands need substantial structural manipulation (thinning) before fire can safely be reintroduced. In other areas, such as large wilderness and roadless areas, fire alone may suffice as the main tool of ecological restoration, recreating the natural interaction of structure and process. Impatience, overreaction to crown fire risks, extractive economics, or hubris could lead to widespread application of highly intrusive treatments that may further damage forest ecosystems. Investments in research and monitoring of restoration treatments are essential to refine restoration methods. We support the development and implementation of a diverse range of scientifically viable restoration approaches in these forests, suggest principles for ecologically sound restoration that immediately reduce crown fire risk and incrementally return natural variability and resilience to Southwestern forests, and present ecological perspectives on several forest restoration approaches.

Fire management assessment of the Caribbean Pine (Pinus caribea) forest ecosystems on Andros and Abaco Islands, Bahamas

Treesearch

R. Myers; D. Wade; C. Bergh

2004-01-01

From 2-7 February 2003, a team of fire management and fire ecology experts visited the islands of Andros, Abaco, and New Providence in the Bahamas to gain insight into the fire issues facing the conservation of the Caribbean pine forests, which cover large percentages of each island. The objectives for the assessment were to: (1) Gather information on fire...

Wildfire effects on a ponderosa pine ecosystem: An Arizona case study

Treesearch

R. E. Campbell; Jr. Baker; P. F. Ffolliott; F. R. Larson; C. C. Avery

1977-01-01

A wildfire of variable severity swept through 717 acres (290 ha) of ponderosa pine forest in north-central Arizona in May 1972. Where the fire was intense it killed 90% of the small trees and 50% of the sawtimber, burned 2.6 in (6.5 cm) of forest floor to the mineral soil, and induced a water-repellent layer in the sandier soils. The reduced infiltration rates, which...

Stand restoration burning in oak-pine forests in the southern Applachians: effects on aboveground biomass and carbon and nitrogen cycling

Treesearch

Robert M. Hubbard; James M. Vose; Barton D. Clinton; Katherine J. Elliott; Jennifer D. Knoepp

2004-01-01

Understory prescribed burning is being suggested as a viable management tool for restoring degraded oak–pine forest communities in the southern Appalachians yet information is lacking on how this will affect ecosystem processes. Our objectives in this study were to evaluate the watershed scale effects of understory burning on total aboveground biomass, and the carbon...

Longleaf pine adaptation to fire: is early height growth pattern critical to fire survival?

Treesearch

G. Geoff Wang; Lauren S. Pile; Benjamin O. Knapp; Huifeng Hu

2016-01-01

Longleaf pine (Pinus palustris Mill.) forests are fire-dependent ecosystems because frequent surface fires prevent other species from being recruited into the canopy. The successful recruitment of longleaf pine has been attributed mainly to its unique fire adaptation – the grass stage. It is commonly believed that, while in the grass stage, longleaf pine seedlings...

On the difference in the net ecosystem exchange of CO2 between deciduous and evergreen forests in the southeastern United States

Treesearch

Kimberly A. Novick; A. Christopher Oishi; Eric J. Ward; Mario B.S. Siqueira; Jehn-Yih Juang; Paul C. Stoy

2015-01-01

The southeastern United States is experiencing a rapid regional increase in the ratio of pine to deciduous forest ecosystems at the same time it is experiencing changes in climate. This study is focused on exploring how these shifts will affect the carbon sink capacity of southeastern US forests, which we show here are among the strongest carbon sinks in the...

[Post-logging organic matter recovery in forest ecosystems of eastern Baikal region].

PubMed

Vedrova, E F; Mukhortova, L V; Ivanov, V V; Krivobokov, L V; Boloneva, M V

2010-01-01

The dynamics of organic matter accumulated in the soil and main vegetation elements was analyzed for post-logging forest ecosystem succession series in eastern Baikal region. The phytomass was found to allocate up 63 and 50% of carbon in undisturbed Scots pine and fir stands, respectively. The post-logging phytomass contribution to the total carbon pool appeared to decrease down to 16% in Scots pine and 6% in fir stands. In Scots pine stands, carbon storage was determined to account for almost 70% of the initial carbon 60 years after logging. In 50- to 55-year-old fir stands, carbon recovered its initial pool only by 10%. Soil carbon recorded in recently logged Scots pine and fir sites appeared to be 5 and 16 times that accumulated in the phytomass, respectively. The ratio between phytomass carbon and soil organic matter recovered back to the prelogging level in Scots pine stands by the age of 50-60 years. While phytomass carbon also increased in fir stand of the same age, it did not reach the level of the control stand.

Environmental and biological controls on water and energy exchange in Florida scrub oak and pine flatwoods ecosystems

NASA Astrophysics Data System (ADS)

Bracho, Rosvel; Powell, Thomas L.; Dore, Sabina; Li, Jiahong; Hinkle, C. Ross; Drake, Bert G.

2008-06-01

Scrub oak and pine flatwoods are two contrasting ecosystems common to the humid subtropical climate of Florida. Scrub oak forests are short in stature (<2 m) and occur on well-drained sandy soils, and pine flatwoods are much taller and occur in areas with poorly drained soils. Eddy covariance measurements were made from January 2001 to February 2003 over a scrub oak forest and from January 2002 to February 2003 over an adjacent pine flatwoods located on in central Florida, USA, and exposed to similar atmospheric conditions to evaluate how the dynamics of latent heat (λE) and sensible heat (H) exchanges are affected by environmental and biological variables. Annual evapotranspiration (Et) for the scrub oak was 737 and 713 mm in 2001 and 2002, respectively. Et was comparatively higher, 812 mm, in 2002 at the pine flatwoods due to higher soil moisture and leaf area. In both ecosystems, springtime increases in λE coincided with increasing leaf area and evaporative demand. However, H was the main energy-dissipating component in the spring due to the seasonal decrease in soil water content in the upper soil profile. In the spring, mean weekly Bowen ratio (β, i.e. H/λE) values reached 1.6 and 1.2 in the scrub oak and pine flatwoods, respectively. With the onset of the summertime rainy season, λE became the dominant energy flux and β fells to < 0.4. In both ecosystems, β was strongly controlled by the interaction between leaf area and soil moisture. The lowest values of the decoupling coefficient (Ω, 0.2 and 0.25 scrub oak and pine flatwoods, respectively) also occurred during the dry springtime period indicating that surface conductance (gs) was the mechanism controlling energy partitioning causing high β in both ecosystems. Et increases in the spring, when water in the upper soil profile was scarce and strongly retained by soil particles, indicated that plants in both ecosystems obtained water from deeper sources. The results from this research elucidate how energy partitioning differs and is regulated in contrasting ecosystems within the Florida landscape, which is important for refining regional hydrological and climate models.

[Biogeochemical cycles in natural forest and conifer plantations in the high mountains of Colombia].

PubMed

León, Juan Diego; González, María Isabel; Gallardo, Juan Fernando

2011-12-01

Plant litter production and decomposition are two important processes in forest ecosystems, since they provide the main organic matter input to soil and regulate nutrient cycling. With the aim to study these processes, litterfall, standing litter and nutrient return were studied for three years in an oak forest (Quercus humboldtii), pine (Pinus patula) and cypress (Cupressus lusitanica) plantations, located in highlands of the Central Cordillera of Colombia. Evaluation methods included: fine litter collection at fortnightly intervals using litter traps; the litter layer samples at the end of each sampling year and chemical analyses of both litterfall and standing litter. Fine litter fall observed was similar in oak forest (7.5 Mg ha/y) and in pine (7.8 Mg ha/y), but very low in cypress (3.5 Mg ha/y). Litter standing was 1.76, 1.73 and 1.3 Mg ha/y in oak, pine and cypress, respectively. The mean residence time of the standing litter was of 3.3 years for cypress, 2.1 years for pine and 1.8 years for oak forests. In contrast, the total amount of retained elements (N, P, S, Ca, Mg, K, Cu, Fe, Mn and Zn) in the standing litter was higher in pine (115 kg/ha), followed by oak (78 kg/ha) and cypress (24 kg/ha). Oak forests showed the lowest mean residence time of nutrients and the highest nutrients return to the soil as a consequence of a faster decomposition. Thus, a higher nutrient supply to soils from oaks than from tree plantations, seems to be an ecological advantage for recovering and maintaining the main ecosystem functioning features, which needs to be taken into account in restoration programs in this highly degraded Andean mountains.

Nationwide forestry applications program: Ten-Ecosystem Study (TES) site 5 report, Kershaw County, South Carolina, report 4

NASA Technical Reports Server (NTRS)

Dillman, R. D. (Principal Investigator)

1978-01-01

The author has identified the following significant results. The Kershaw County site, South Carolina, was selected to be representative of both the oak-pine ecosystem and the southeastern pine ecosystem. The following processing results have concluded that: (1) early spring LANDSAT data provide the best contrast between forest features; (2) level 2 forest features (softwood, hardwood, grassland, and water) can be classified with an accuracy of 70% + or - 5.7% at the 90% confidence level; (3) level 3 species classification was inconclusive; (4) temporal data did not provide a significant increase in classification accuracy of level 2 features, over single date classification to warrant the additional processing; and (5) training fields from only 10% of the site can be used to classify the entire site.

Patterns and determinants of plant biodiversity in non-commercial forests of eastern China

PubMed Central

Wu, Chuping; Vellend, Mark; Yuan, Weigao; Jiang, Bo; Liu, Jiajia; Shen, Aihua; Liu, Jinliang; Zhu, Jinru

2017-01-01

Non-commercial forests represent important habitats for the maintenance of biodiversity and ecosystem function in China, yet no studies have explored the patterns and determinants of plant biodiversity in these human dominated landscapes. Here we test the influence of (1) forest type (pine, mixed, and broad-leaved), (2) disturbance history, and (3) environmental factors, on tree species richness and composition in 600 study plots in eastern China. In total, we found 143 species in 53 families of woody plants, with a number of species rare and endemic in the study region. Species richness in mixed forest and broad-leaved forest was higher than that in pine forest, and was higher in forests with less disturbance. Species composition was influenced by environment factors in different ways in different forest types, with important variables including elevation, soil depth and aspect. Surprisingly, we found little effect of forest age after disturbance on species composition. Most non-commercial forests in this region are dominated by species poor pine forests and mixed young forests. As such, our results highlight the importance of broad-leaved forests for regional plant biodiversity conservation. To increase the representation of broad-leaved non-commercial forests, specific management practices such as thinning of pine trees could be undertaken. PMID:29161324

Patterns and determinants of plant biodiversity in non-commercial forests of eastern China.

PubMed

Wu, Chuping; Vellend, Mark; Yuan, Weigao; Jiang, Bo; Liu, Jiajia; Shen, Aihua; Liu, Jinliang; Zhu, Jinru; Yu, Mingjian

2017-01-01

Non-commercial forests represent important habitats for the maintenance of biodiversity and ecosystem function in China, yet no studies have explored the patterns and determinants of plant biodiversity in these human dominated landscapes. Here we test the influence of (1) forest type (pine, mixed, and broad-leaved), (2) disturbance history, and (3) environmental factors, on tree species richness and composition in 600 study plots in eastern China. In total, we found 143 species in 53 families of woody plants, with a number of species rare and endemic in the study region. Species richness in mixed forest and broad-leaved forest was higher than that in pine forest, and was higher in forests with less disturbance. Species composition was influenced by environment factors in different ways in different forest types, with important variables including elevation, soil depth and aspect. Surprisingly, we found little effect of forest age after disturbance on species composition. Most non-commercial forests in this region are dominated by species poor pine forests and mixed young forests. As such, our results highlight the importance of broad-leaved forests for regional plant biodiversity conservation. To increase the representation of broad-leaved non-commercial forests, specific management practices such as thinning of pine trees could be undertaken.

Entropy dynamics in cone production of longleaf pine forests in the southeastern United States

Treesearch

Xiongwen Chen; Dale G. Brockway; Qinfeng Guo

2016-01-01

Sporadic temporal patterns of seed production are a challenge for the regeneration and restoration of longleaf pine, which is a keystone component of an endangered ecosystem in the southeastern United States. In this study, long-term data for longleaf pine cone production, collected at six sites across the southeastern region, was examined from the perspective of...

Simulating the biogeochemical cycles in cypress wetland-pine upland ecosystems at a landscape scale with the wetland-DNDC model

Treesearch

G. Sun; C. Li; C. Tretting; J. Lu; S.G. McNulty

2005-01-01

A modeling framework (Wetland-DNDC) that described forested wetland ecosystem processes has been developed and validated with data from North America and Europe. The model simulates forest photosynthesis, respiration, carbon allocation, and liter production, soil organic matter (SOM) turnover, trace gas emissions, and N leaching. Inputs required by Wetland-DNDC...

Comparison of snag densities among regeneration treatments in mixed pine-hardwood forests

Treesearch

Roger W. Perry; Ronald E. Thill

2013-01-01

Standing dead trees (snags) are an important component of forest ecosystems, providing foraging, nesting, and roosting substrate for a variety of vertebrates. We examined the effects of four forest regeneration treatments on residual snag density and compared those with densities found in unharvested, naturally regenerated forests (controls) during the second, fourth,...

Tree cavity estimation and verification in the Missouri Ozarks

Treesearch

Randy G. Jensen; John M. Kabrick; Eric K. Zenner

2002-01-01

Missouri forest management guidelines require that cavity trees and snags be provided for wildlife. Missouri Ozark Forest Ecosystem Project (MOFEP) timber inventories provided opportunities to determine if cavity tree and snag densities in a mature second-growth oak-hickory-pine forest meet forest management guidelines, to evaluate the effects of the first-entry...

Sustaining Pinus flexilis ecosystems of the southern Rocky Mountains (USA) in the presence of Cronartium ribicola and Dendroctonus ponderosae in a changing climate

Treesearch

Anna W. Schoettle; Richard A. Sniezko; Kelly S. Burns

2009-01-01

Limber pine, Pinus flexilis James, is characterized by a patchy distribution that displays metapopulation dynamics and spans a broad latitudinal and elevational range in North America (Webster and Johnson 2000). In the southern Rocky Mountains limber pine grows from below the forest-grassland ecotone up to the forest-alpine ecotone, from ~1600 m above sea level in the...

Plant and bird diversity in natural forests and in native and exotic plantations in NW Portugal

NASA Astrophysics Data System (ADS)

Proença, Vânia M.; Pereira, Henrique M.; Guilherme, João; Vicente, Luís

2010-03-01

Forest ecosystems have been subjected to continuous dynamics between deforestation and forestation. Assessing the effects of these processes on biodiversity could be essential for conservation planning. We analyzed patterns of species richness, diversity and evenness of plants and birds in patches of natural forest of Quercus spp. and in stands of native Pinus pinaster and exotic Eucalyptus globulus in NW Portugal. We analyzed data of forest and non-forest species separately, at the intra-patch, patch and inter-patch scales. Forest plant richness, diversity and evenness were higher in oak forest than in pine and eucalypt plantations. In total, 52 species of forest plants were observed in oak forest, 33 in pine plantation and 28 in eucalypt plantation. Some forest species, such as Euphorbia dulcis, Omphalodes nitida and Eryngium juresianum, were exclusively or mostly observed in oak forest. Forest bird richness and diversity were higher in both oak and pine forests than in eucalypt forest; evenness did not differ among forests. In total, 16 species of forest birds were observed in oak forest, 18 in pine forest and 11 in eucalypt forest. Species such as Certhia brachydactyla, Sitta europaea and Dendrocopos major were common in oak and/or pine patches but were absent from eucalypt stands. Species-area relationships of forest plants and forest birds in oak patches had consistently a higher slope, at both the intra and inter-patch scales, than species-area relationships of forest species in plantations and non-forest species in oak forest. These findings demonstrate the importance of oak forest for the conservation of forest species diversity, pointing the need to conserve large areas of oak forest due to the apparent vulnerability of forest species to area loss. Additionally, diversity patterns in pine forest were intermediate between oak forest and eucalypt forest, suggesting that forest species patterns may be affected by forest naturalness.

In Land of Cypress and Pine: An Environmental History of the Santee Experimental Forest, 1683-1937

Treesearch

Hayden R. Smith

2012-01-01

The Santee Experimental Forest is a 6,100-acre research facility located within the Francis Marion National Forest, SC. Situated within the Huger Creek watershed in the headwaters of the East Branch of the Cooper River, the Santee Experimental Forest supports research in forest ecology, silviculture, prescribed fire, forest hydrology, ecosystem restoration, and...

Relating P-band AIRSAR backscatter to forest stand parameters

NASA Technical Reports Server (NTRS)

Wang, Yong; Melack, John M.; Davis, Frank W.; Kasischke, Eric S.; Christensen, Norman L., Jr.

1993-01-01

As part of research on forest ecosystems, the Jet Propulsion Laboratory (JPL) and collaborating research teams have conducted multi-season airborne synthetic aperture radar (AIRSAR) experiments in three forest ecosystems including temperate pine forest (Duke, Forest, North Carolina), boreal forest (Bonanza Creek Experimental Forest, Alaska), and northern mixed hardwood-conifer forest (Michigan Biological Station, Michigan). The major research goals were to improve understanding of the relationships between radar backscatter and phenological variables (e.g. stand density, tree size, etc.), to improve radar backscatter models of tree canopy properties, and to develop a radar-based scheme for monitoring forest phenological changes. In September 1989, AIRSAR backscatter data were acquired over the Duke Forest. As the aboveground biomass of the loblolly pine forest stands at Duke Forest increased, the SAR backscatter at C-, L-, and P-bands increased and saturated at different biomass levels for the C-band, L-band, and P-band data. We only use the P-band backscatter data and ground measurements here to study the relationships between the backscatter and stand density, the backscatter and mean trunk dbh (diameter at breast height) of trees in the stands, and the backscatter and stand basal area.

Rapid Turnover and Minimal Accretion of Mineral Soil Carbon During 60-Years of Pine Forest Growth on Previously Cultivated Land

NASA Astrophysics Data System (ADS)

Richter, D., Jr.; Mobley, M. L.; Billings, S. A.; Markewitz, D.

2016-12-01

At the Calhoun Long-Term Soil-Ecosystem field experiment (1957-present), reforestation of previously cultivated land over fifty years nearly doubled soil organic carbon (SOC) in surface soils (0 to 7.5-cm) but these gains were offset by significant SOC losses in subsoils (35 to 60-cm). Nearly all of the accretions in surface soils amounted to gains in light fraction SOC, whereas losses at depth were associated with silt and clay-sized particles. These changes are documented in the Calhoun Long-Term Soil-Ecosystem (LTSE) study that resampled soil from 16 plots about every five years and archived all soil samples from four soil layers within the upper 60-cm of mineral soil. We combined soil bulk density, density fractionation, stable isotopes, and radioisotopes to explore changes in SOC and soil organic nitrogen (SON) associated with five decades of the growth of a loblolly pine secondary forest. Isotopic signatures showed relatively large accumulations of contemporary forest-derived carbon in surface soils, and no accumulation of forest-derived carbon in subsoils. We interpret results to indicate that land-use change from cotton fields to secondary pine forests drove soil biogeochemical and hydrological changes that enhanced root and microbial activity and SOM decomposition in subsoils. As pine stands matured and are now transitioning to mixed pines and hardwoods, demands on soil organic matter for nutrients to support aboveground growth has eased due to pine mortality, and bulk SOM and SON and their isotopes in subsoils have stabilized. We anticipate major changes in the next fifty years as 1957 pine trees transition to hardwoods. This study emphasizes the importance of long-term experiments and deep soil measurements when characterizing SOC and SON responses to land use change. There is a remarkable paucity of E long-term soil data deeper than 30 cm.

Nitrogen retention in contrasting temperate forests exposed to high nitrogen deposition

NASA Astrophysics Data System (ADS)

Staelens, J.; Adriaenssens, S.; Wuyts, K.; Verheyen, K.; Boeckx, P. F.

2011-12-01

A better understanding of factors affecting nitrogen (N) retention is needed to assess the impact of changing anthropogenic N emissions and climatic conditions on N cycling and N loss by terrestrial ecosystems. Retention of N has been demonstrated for a wide range of forests, including ecosystems exposed to chronically enhanced N deposition, but it is still unclear which factors determine this N retention capacity. Therefore, we examined the possible effects of forest type on N retention using stable N isotopes. The study was carried out in adjacent equal-aged deciduous (pedunculate oak (Quercus robur L.)) and coniferous (Scots pine (Pinus sylvestris L.)) stands with a similar stand history and growing on a well-drained sandy soil in a region with enhanced N deposition (Belgium). The N input-output budgets and gross soil N transformation rates differed significantly between the two stands. The forest floor was exposed to a high inorganic N input from atmospheric deposition, which was nearly twice as high in the pine stand (33 ± 2 kg N ha-1 yr-1; mean ± standard error) as in the oak stand (18 ± 1 kg N ha-1 yr-1). The N input was reflected in the soil solution under the rooting zone, but the mean nitrate concentration was eight times higher under pine (19 ± 5 mg N L-1) than under oak (2.3 ± 0.9 mg N L-1). Gross N dynamics in the mineral topsoil were determined by in situ 15N labelling of undisturbed soil cores combined with numerical data analysis. Gross N mineralization was two times faster in the oak soil while nitrate production was two times faster in the pine soil, indicating a dominant effect of vegetation cover on soil N cycling. The higher gross nitrification, particularly due to oxidation of organic N, in the pine soil compared to the oak soil, combined with negligible nitrate immobilization, was in line with the higher nitrate leaching under the pine forest. On a larger spatial and temporal scale, the fate of dissolved inorganic N within these forests was studied by spraying three pulses of 15N onto the forest floor during the growing season, either as ammonium or as nitrate. Four months and one year after the first application, 15N recovery was determined in the organic and mineral soil layers, fine tree roots, soil water percolate, ferns, and tree foliage. As hypothesized, N retention in the forest floor and mineral soil horizons was lower in the pine stand compared to oak, while N retention was lower for nitrate than for ammonium in both stands. The differences in 15N retention confirm that tree species affect the N balance of ecosystems under high anthropogenic N inputs and agree with the findings on gross soil N dynamics and N input-output budgets. Overall, the research underlines the importance of considering the interaction between tree species and carbon and N turnover when assessing the response of forest ecosystems to global change scenarios.

Prescribed burning in southwestern ponderosa pine

Treesearch

Stephen S Sackett; Sally M Haase; Michael G Harrington

1996-01-01

Prescribed burning is an effective way of restoring the fire process to ponderosa pine (Pinus ponderosa Dougl. ex Laws.) ecosystems of the Southwest. If used judiciously, fire can provide valuable effects for hazard reduction, natural regeneration, thinning, vegetation revitalization, and in general, better forest health. Relatively short burning...

Longleaf pine growth and yield

Treesearch

John S. Kush; J.C.G. Goelz; Richard A. Williams; Douglas R. Carter; Peter E. Linehan

2006-01-01

Across the historical range of longleaf pine (Pinus palustris Mill.), less than 10% of lands previously occupied by longleaf ecosystems are currently in public ownership (Johnson and Gjerstad 1999; Alavalapati et al., this volume). The remainder is owned by private entities ranging from the forest industry, to timberland investment organizations,...

Temperature sensitivity of soil carbon dioxide and nitrous oxide emissions in mountain forest and meadow ecosystems in China

NASA Astrophysics Data System (ADS)

Zhang, Junjun; Peng, Changhui; Zhu, Qiuan; Xue, Wei; Shen, Yan; Yang, Yanzheng; Shi, Guohua; Shi, Shengwei; Wang, Meng

2016-10-01

An incubation experiment was conducted at three temperature levels (8, 18 and 28 °C) to quantify the response of soil CO2 and N2O emissions to temperature in three ecosystems (pine forest, oak forest, and meadow) located in the Qinling Mountains of China, which are considered to be susceptible to disturbance and climate changes, especially global warming. The soil CO2 emission rates increased with temperature and decreased with soil depth; they were the highest in the oak forest (broadleaf forest) and were lower in the pine forest (coniferous forest) and the meadow ecosystem. However, there was no significant difference in the soil N2O emission rates among the three ecosystems. The temperature sensitivity of CO2 and N2O was higher in the forest than in the meadow ecosystem. The Q10 values (temperature sensitivity coefficient) for CO2 and N2O were 1.07-2.25 and 0.82-1.22, respectively, for the three ecosystems. There was also evidence that the CO2 and N2O emission rates were positively correlated. The soil characteristics exhibited different effects on CO2 and N2O emissions among different ecosystems at the three temperature levels. Moreover, the soil dissolved organic carbon (DOC), specific ultraviolet absorbance (SUVA) and nitrate (NO3-) were important factors for CO2 emissions, whereas the soil ammonium (NH4+) and pH were the major controllers of N2O emissions. Unexpectedly, our results indicated that CO2 emissions are more sensitive to increasing temperature than N2O, noting the different feedback of CO2 and N2O emissions to global warming in this region. The different responses of greenhouse gas emissions in different forest types and a meadow ecosystem suggest that it is critical to conduct a comprehensive investigation of the complex mountain forest and meadow ecosystem in the transitional climate zone under global warming. Our research results provide new insight and advanced understanding of the variations in major greenhouse gas emissions (CO2 and N2O) and soil characteristics in response to warming.

AN EVALUATION OF OZONE EXPOSURE METRICS FOR A SEASONALLY DROUGHT STRESSED PONDEROSA PINE ECOSYSTEM. (R826601)

EPA Science Inventory

Ozone stress has become an increasingly significant factor in cases of forest decline reported throughout the world. Current metrics to estimate ozone exposure for forest trees are derived from atmospheric concentrations and assume that the forest is physiologically active at ...

[Impact of industrial pollution on emission of carbon dioxide by soils in the Kola Subarctic Region].

PubMed

Koptsik, G N; Kadulin, M S; Zakharova, A I

2015-01-01

Soil emission of carbon dioxide, the key component of carbon cycle and the characteristic of soil biological activity, has been studied in background and polluted ecosystems in the Kola subarctic, the large industrial region of Russia. Long-term air pollution by emissions of "Pechenganikel" smelter, the largest source of sulphur dioxide and heavy metals in Northern Europe, has caused the technogenic digression of forest ecosystems. As a result of the digression, the tree layer was destructed, the number of plant species was diminished, the activity of soil biota was weakened, the soils were polluted and exhausted, biogeochemical cycles of elements were disturbed and productivity of ecosystems shrunk. Field investigations revealed the decrease of the in.situ soil respiration in average from 190-230 mg C-CO2/m2 x per h in background pine forests to 130-160, 100, and 20 mg C-CO2/m2.per h at the stages of pine defoliation, sparse pine forest and technogenic barrens of the technogenic succession, respectively. The soil respira- tion in birch forests was more intense than in pine forests and tended to decrease from about 290 mg C-CO2/m2 x per h in background forests to 210-220 and 170-190 mg C-CO2/m2 x per h in defoliating forests and technogenic sparse forests, respectively. Due to high spatial variability of soil respiration in both pine and birch forests significant differences from the background level were found only in technogenic sparse forests and barrens. Soil respiration represents total production of carbon dioxide by plant roots and soil microorganisms. The decrease in share of root respiration in the total soil respiration with the rise of pollution from 38-57% in background forests up to zero in technogenic barrens has been revealed for the first time for this region. This indicates that plants seem to be more sensitive to pollution as compared to relatively resistant microorganisms. Soil respiration and the contribution of roots to the total respiration positively correlated with distance from the smelter and the content of carbon and nitrogen and negatively correlated with the content of available nickel and copper in the soils. Remediation of technogenic barrens promoted intensification of soil biological activity. At the same time, the willow planting along with grass seeding into the new constructed fertile soil layer was much more effective for activation of soil respiration and the contribution of roots to the total respiration than the planting into the limed and fertilized polluted soils (chemo-phytostabilization).

Soil-plant-atmosphere conditions regulating convective cloud formation above southeastern US pine plantations

Treesearch

Gabriele Manoli; Jean-Christophe Domec; Kimberly Novick; Andrew C. Oishi; Asko Noormets; Marco Marani; Gabriel Katul

2016-01-01

Loblolly pine trees (Pinus taeda L.) occupy more than 20% of the forested area in the southern United States, representmore than 50% of the standing pine volume in this region, and remove from the atmosphere about 500 g C m_2 per year through net ecosystem exchange. Hence, their significance as a major regional carbon sink can hardly be...

Resource use and efficiency, and stomatal responses to environmental drivers of oak and pine species in an Atlantic Coastal Plain forest

Treesearch

Heidi J. Renninger; Nicholas J. Carlo; Kenneth L. Clark; Karina V.R. Schäfer

2015-01-01

Pine-oak ecosystems are globally distributed even though differences in anatomy and leaf habit between many co-occurring oaks and pines suggest different strategies for resource use, efficiency and stomatal behavior. The New Jersey Pinelands contain sandy soils with low water- and nutrient-holding capacity providing an opportunity to examine trade-offs in resource...

The genetics of shortleaf pine (Pinus echinata mill.) with implications for restoration and management

Treesearch

John F. Stewart; Rodney E. Will; Barbara S. Crane; C. Dana Nelson

2016-01-01

Shortleaf pine (Pinus echinata Mill.) is an important commercial timber resource and forest ecosystem component in the southeastern USA. The species occurs in mainly drier sites as an early- to mid-successional species, is fireadapted, and it plays an important role in the fire ecology of the region. However, shortleaf pine genetics are not well-studied, especially in...

Site preparation burning to improve southern Appalachian pine-hardwood stands: aboveground biomass, forest floor mass, and nitrogen and carbon pools

Treesearch

J.M. Vose; W.T. Swank

1993-01-01

Prescribed fire is currently used as a site preparation treat-ment in mixed pine-hardwood ecosystems of the southern Appalachians.Stands receiving this treatment typically consist of mixtures of pitch pine (Pinus rigidu Mill.), scarlet oak (Quercus coccinea Muenchh.), chestnut oak (Quercus prinus L.), red maple (Acer rubrum L.), and dense under-stories dominated by...

Restoring forest structure and process stabilizes forest carbon in wildfire-prone southwestern ponderosa pine forests.

PubMed

Hurteau, Matthew D; Liang, Shuang; Martin, Katherine L; North, Malcolm P; Koch, George W; Hungate, Bruce A

2016-03-01

Changing climate and a legacy of fire-exclusion have increased the probability of high-severity wildfire, leading to an increased risk of forest carbon loss in ponderosa pine forests in the southwestern USA. Efforts to reduce high-severity fire risk through forest thinning and prescribed burning require both the removal and emission of carbon from these forests, and any potential carbon benefits from treatment may depend on the occurrence of wildfire. We sought to determine how forest treatments alter the effects of stochastic wildfire events on the forest carbon balance. We modeled three treatments (control, thin-only, and thin and burn) with and without the occurrence of wildfire. We evaluated how two different probabilities of wildfire occurrence, 1% and 2% per year, might alter the carbon balance of treatments. In the absence of wildfire, we found that thinning and burning treatments initially reduced total ecosystem carbon (TEC) and increased net ecosystem carbon balance (NECB). In the presence of wildfire, the thin and burn treatment TEC surpassed that of the control in year 40 at 2%/yr wildfire probability, and in year 51 at 1%/yr wildfire probability. NECB in the presence of wildfire showed a similar response to the no-wildfire scenarios: both thin-only and thin and burn treatments increased the C sink. Treatments increased TEC by reducing both mean wildfire severity and its variability. While the carbon balance of treatments may differ in more productive forest types, the carbon balance benefits from restoring forest structure and fire in southwestern ponderosa pine forests are clear.

Acute physiological stress and mortality following fire in a long-unburned longleaf pine ecosystem

Treesearch

J.J. O’Brien; J.K. Hiers; R.J. Mitchell; J.M. Varner; K. Mordecai

2010-01-01

One important legacy of fire exclusion in ecosystems dependent upon frequent fire is the development of organic soil horizons (forest floor) that can be colonized by fine roots. When fire is re-introduced, the forest floor is often consumed by fire and heavy overstory mortality, often delayed by months, results. We hypothesized that the delayed post-fire tree mortality...

Mechanisms of nitrogen retention in forest ecosystems - A field experiment

NASA Technical Reports Server (NTRS)

Vitousek, P. M.; Matson, P. A.

1984-01-01

Intensive forest management led to elevated losses of nitrogen from a recently harvested loblolly pine plantation in North Carolina. Measurements of nitrogen-15 retention in the field demonstrated that microbial uptake of nitrogen during the decomposition of residual organic material was the most important process retaining nitrogen. Management practices that remove this material cause increased losses of nitrogen to aquatic ecosystems and the atmosphere.

Biogeography: An interweave of climate, fire, and humans

USGS Publications Warehouse

Stambaugh, Michael C.; Varner, J. Morgan; Jackson, Stephen T.

2017-01-01

Longleaf pine (Pinus palustris) is an icon of the southeastern United States and has been considered a foundation species in forests, woodlands, and savannas of the region (Schwarz 1907; Platt 1999). Longleaf pine is an avatar for the extensive pine-dominated, fire-dependent ecosystems (Figure 2.1) that provide habitats for thousands of species and have largely vanished from the landscape. Longleaf pine is one of the world's most resilient and fire-adapted trees (Keeley and Zedler 1998), widely perceived as the sole dominant in forests across a large area of the Southeast (Sargent 1884; Mohr 1896; Wahlenberg 1946). Longleaf pine was once a primary natural resource, providing high-quality timber, resins, and naval stores that fueled social changes and economic growth through the 19th and early 20th centuries.

ROOT GROWTH AND TURNOVER IN DIFFERENT AGED PONDEROSA PINE STANDS IN OREGON, USA

EPA Science Inventory

The impacts of pollution and climate change on soil carbon dynamics are poorly understood, in part due to a lack of information regarding root production and turnover in natural ecosystems. In order to examine how root dynamics change with stand age in ponderosa pine forests (...

Longleaf pine regeneration ecology and methods

Treesearch

Dale G. Brockway; Kenneth W. Outcalt; William D. Boyer

2006-01-01

Regenerating longleaf pine (Pinus palustris) is key to its long-term sustainable production of forest resources and its perpetuation as the dominant tree species in a variety of important ecosystems ranging from xeric to mesic to hydric site conditions. Early regeneration to problems and the subsequent efforts to overcome these are significant...

Effects of Dwarf Mistletoe on Stand Structure of Lodgepole Pine Forests 21-28 Years Post-Mountain Pine Beetle Epidemic in Central Oregon

PubMed Central

Agne, Michelle C.; Shaw, David C.; Woolley, Travis J.; Queijeiro-Bolaños, Mónica E.

2014-01-01

Lodgepole pine (Pinus contorta) forests are widely distributed throughout North America and are subject to mountain pine beetle (Dendroctonus ponderosae) epidemics, which have caused mortality over millions of hectares of mature trees in recent decades. Mountain pine beetle is known to influence stand structure, and has the ability to impact many forest processes. Dwarf mistletoe (Arceuthobium americanum) also influences stand structure and occurs frequently in post-mountain pine beetle epidemic lodgepole pine forests. Few studies have incorporated both disturbances simultaneously although they co-occur frequently on the landscape. The aim of this study is to investigate the stand structure of lodgepole pine forests 21–28 years after a mountain pine beetle epidemic with varying levels of dwarf mistletoe infection in the Deschutes National Forest in central Oregon. We compared stand density, stand basal area, canopy volume, proportion of the stand in dominant/codominant, intermediate, and suppressed cohorts, average height and average diameter of each cohort, across the range of dwarf mistletoe ratings to address differences in stand structure. We found strong evidence of a decrease in canopy volume, suppressed cohort height, and dominant/codominant cohort diameter with increasing stand-level dwarf mistletoe rating. There was strong evidence that as dwarf mistletoe rating increases, proportion of the stand in the dominant/codominant cohort decreases while proportion of the stand in the suppressed cohort increases. Structural differences associated with variable dwarf mistletoe severity create heterogeneity in this forest type and may have a significant influence on stand productivity and the resistance and resilience of these stands to future biotic and abiotic disturbances. Our findings show that it is imperative to incorporate dwarf mistletoe when studying stand productivity and ecosystem recovery processes in lodgepole pine forests because of its potential to influence stand structure. PMID:25221963

Long term carbon fluxes in south eastern U.S. pine ecosystems.

NASA Astrophysics Data System (ADS)

Bracho, R. G.; Martin, T.; Gonzalez-Benecke, C. A.; Sharp, J.

2015-12-01

Forests in the southeastern U.S. are a critical component of the national carbon balance storing a third of the total forest carbon (C) in conterminous USA. South eastern forests occupy 60% of the land area, with a large fraction dominated by the genus Pinus distributed in almost equal proportions of naturally-regenerated and planted stands. These stands often differ in structure (e.g., stem density, leaf area index (LAI)) and in the intensity with which they are managed (e.g. naturally-regenerated, older pine stands are often managed less intensively, with prescribed fire). We measured C fluxes using the eddy covariance approach (net ecosystem production, -NEP) in planted (Pinus elliottii var. elliottii) and naturally-regenerated mixed stand of long leaf (Pinus palustris Mill) and slash pine (Pinus elliottii var. elliottii) accompanied by biometric estimations of C balance. Measurements spanned more than a decade and included interannual climatic variability ranging from severe droughts (e.g. Palmer Drought severity index (PDSI) averaged -2.7 from January 2000 to May 2002, and -3.3 from June 2006 to April 2008), to years with tropical storms. Annual NEP for the older, naturally-regenerated stand fluctuated from -1.60 to -5.38 Mg C ha-1 yr-1 with an average of -2.73 ± 1.17 Mg C ha-1 yr-1 while in plantations after canopy closure NEP fluctuated from -4.0 to -8.2 Mg C ha-1 yr-1 with an average of -6.17 ± 1.34 Mg C ha-1 yr-1. Annual NEP in naturally-regenerated pine was mainly driven by a combination of water availability and understory burning while in plantations it was driven by water availability after canopy closure. Woody and above ground net primary productivity (NPP) followed gross ecosystem carbon exchange (GEE) in both ecosystems. Naturally-regenerated and planted pine are a strong carbon sink under the current management and environmental fluctuations accumulating 28 and 130 Mg C ha-1 in a decade, respectively, and are among the most productive forests in the world.

An interdisciplinary, outcome-based approach to astmospheric CO2 mitigation with planted southern pine forests

NASA Astrophysics Data System (ADS)

Martin, T.; Fox, T.; Peter, G.; Monroe, M.

2012-12-01

The Pine Integrated Network: Education, Mitigation and Adaptation Project ("PINEMAP") was funded by National Institute of Food and Agriculture to produce outcomes of enhanced climate change mitigation and adaptation in planted southern pine ecosystems. The PINEMAP project leverages a strong group of existing networks to produce synergy and cooperation on applied forestry research in the region. Over the last 50 years, cooperative research on planted southern pine management among southeastern U.S. universities, government agencies, and corporate forest landowners has developed and facilitated the widespread implementation of improved genetic and silvicultural technology. The impact of these regional research cooperatives is difficult to overstate, with current members managing 55% of the privately owned planted pine forestland, and producing 95% of the pine seedlings planted each year. The PINEMAP team includes the eight major forestry cooperative research programs, scientists from eleven land grant institutions, the US Forest Service, and climate modeling and adaptation specialists associated with the multi-state SE Climate Consortium and state climate offices. Our goal is to create and disseminate the knowledge that enables landowners to: harness planted pine forest productivity to mitigate atmospheric CO2; more efficiently use nitrogen and other fertilizer inputs; and adapt their forest management to increase resilience in the face of changing climate. We integrate our team's infrastructure and expertise to: 1) develop breeding, genetic deployment and innovative management systems to increase C sequestration and resilience to changing climate of planted southern pine forests ; 2) understand interactive effects of policy, biology, and climate change on sustainable management; 3) transfer new management and genetic technologies to private industrial and non-industrial landowners; and 4) educate a diverse cross-section of the public about the relevance of forests, forest management, and climate change. These efforts will enable our stakeholders to enhance the productivity of southern pine forests, while maintaining social, economic, and ecological sustainability.

Driving factors of a vegetation shift from Scots pine to pubescent oak in dry Alpine forests.

PubMed

Rigling, Andreas; Bigler, Christof; Eilmann, Britta; Feldmeyer-Christe, Elisabeth; Gimmi, Urs; Ginzler, Christian; Graf, Ulrich; Mayer, Philipp; Vacchiano, Giorgio; Weber, Pascale; Wohlgemuth, Thomas; Zweifel, Roman; Dobbertin, Matthias

2013-01-01

An increasing number of studies have reported on forest declines and vegetation shifts triggered by drought. In the Swiss Rhone valley (Valais), one of the driest inner-Alpine regions, the species composition in low elevation forests is changing: The sub-boreal Scots pine (Pinus sylvestris L.) dominating the dry forests is showing high mortality rates. Concurrently the sub-Mediterranean pubescent oak (Quercus pubescens Willd.) has locally increased in abundance. However, it remains unclear whether this local change in species composition is part of a larger-scale vegetation shift. To study variability in mortality and regeneration in these dry forests we analysed data from the Swiss national forest inventory (NFI) on a regular grid between 1983 and 2003, and combined it with annual mortality data from a monitoring site. Pine mortality was found to be highest at low elevation (below 1000 m a.s.l.). Annual variation in pine mortality was correlated with a drought index computed for the summer months prior to observed tree death. A generalized linear mixed-effects model indicated for the NFI data increased pine mortality on dryer sites with high stand competition, particularly for small-diameter trees. Pine regeneration was low in comparison to its occurrence in the overstorey, whereas oak regeneration was comparably abundant. Although both species regenerated well at dry sites, pine regeneration was favoured at cooler sites at higher altitude and oak regeneration was more frequent at warmer sites, indicating a higher adaptation potential of oaks under future warming. Our results thus suggest that an extended shift in species composition is actually occurring in the pine forests in the Valais. The main driving factors are found to be climatic variability, particularly drought, and variability in stand structure and topography. Thus, pine forests at low elevations are developing into oak forests with unknown consequences for these ecosystems and their goods and services. © 2012 Blackwell Publishing Ltd.

Understory plant communities and the functional distinction between savanna trees, forest trees, and pines

DOE Office of Scientific and Technical Information (OSTI.GOV)

Veldman, Joseph W.; Mattingly, W. Brett; Brudvig, Lars A.

Although savanna trees and forest trees are thought to represent distinct functional groups with different effects on ecosystem processes, few empirical studies have examined these effects. In particular, it remains unclear if savanna and forest trees differ in their ability to coexist with understory plants, which comprise the majority of plant diversity in most savannas. We used structural equation modeling (SEM) and data from 157 sites across three locations in the southeastern United States to understand the effects of broadleaf savanna trees, broadleaf forest trees, and pine trees on savanna understory plant communities. After accounting for underlying gradients in firemore » frequency and soil moisture, abundances (i.e., basal area and stem density) of forest trees and pines, but not savanna trees, were negatively correlated with the cover and density (i.e., local-scale species richness) of C4 graminoid species, a defining savanna understory functional group that is linked to ecosystem flammability. In analyses of the full understory community, abundances of trees from all functional groups were negatively correlated with species density and cover. For both the C4 and full communities, fire frequency promoted understory plants directly, and indirectly by limiting forest tree abundance. There was little indirect influence of fire on the understory mediated through savanna trees and pines, which are more fire tolerant than forest trees. We conclude that tree functional identity is an important factor that influences overstory tree relationships with savanna understory plant communities. In particular, distinct relationships between trees and C4 graminoids have implications for grass-tree coexistence and vegetation-fire feedbacks that maintain savanna environments and their associated understory plant diversity.« less

Fire ecology and management of the major ecosystems of southern Utah

Treesearch

Sharon M. Hood; Melanie Miller

2007-01-01

This document provides managers with a literature synthesis of the historical conditions, current conditions, fire regime condition classes (FRCC), and recommended treatments for the major ecosystems in southern Utah. Sections are by ecosystems and include: 1) coniferous forests (ponderosa pine, mixed conifer, and Engelmann spruce-subalpine fir), 2) aspen, 3) pinyon-...

AmeriFlux US-Dk3 Duke Forest - loblolly pine

DOE Data Explorer

Novick, Kim [Indiana University; Oishi, Chris [USDA Forest Service; Stoy, Paul [Montana State University

2016-01-01

This is the AmeriFlux version of the carbon flux data for the site US-Dk3 Duke Forest - loblolly pine. Site Description - The site was established in 1983 following a clear cut and a burn. Pinus taeda L. (loblolly pine) seedlings were planted at 2.4m by 2.4m spacing and ecosystem development has not been managed after planting. Canopy height increased from 16m in 2001 to 18m in 2004. The canopy is comprised primarily of P. taeda with some emergent Liquidambar styraciflua L. and a diverse and growing understory with 26 different woody species of diameter breast height 42.5 cm. The flux tower lies upwind of the CO2-enriched components of the free atmosphere carbon enrichment (FACE) facility located in the same pine forest. EC instrumentation is at 20.2m on a 22m tower.

An ecosystem-scale model for the spread of a host-specific forest pathogen in the Greater Yellowstone Ecosystem

USGS Publications Warehouse

Hatala, J.A.; Dietze, M.C.; Crabtree, R.L.; Kendall, Katherine C.; Six, D.; Moorcroft, P.R.

2011-01-01

The introduction of nonnative pathogens is altering the scale, magnitude, and persistence of forest disturbance regimes in the western United States. In the high-altitude whitebark pine (Pinus albicaulis) forests of the Greater Yellowstone Ecosystem (GYE), white pine blister rust (Cronartium ribicola) is an introduced fungal pathogen that is now the principal cause of tree mortality in many locations. Although blister rust eradication has failed in the past, there is nonetheless substantial interest in monitoring the disease and its rate of progression in order to predict the future impact of forest disturbances within this critical ecosystem.This study integrates data from five different field-monitoring campaigns from 1968 to 2008 to create a blister rust infection model for sites located throughout the GYE. Our model parameterizes the past rates of blister rust spread in order to project its future impact on high-altitude whitebark pine forests. Because the process of blister rust infection and mortality of individuals occurs over the time frame of many years, the model in this paper operates on a yearly time step and defines a series of whitebark pine infection classes: susceptible, slightly infected, moderately infected, and dead. In our analysis, we evaluate four different infection models that compare local vs. global density dependence on the dynamics of blister rust infection. We compare models in which blister rust infection is: (1) independent of the density of infected trees, (2) locally density-dependent, (3) locally density-dependent with a static global infection rate among all sites, and (4) both locally and globally density-dependent. Model evaluation through the predictive loss criterion for Bayesian analysis supports the model that is both locally and globally density-dependent. Using this best-fit model, we predicted the average residence times for the four stages of blister rust infection in our model, and we found that, on average, whitebark pine trees within the GYE remain susceptible for 6.7 years, take 10.9 years to transition from slightly infected to moderately infected, and take 9.4 years to transition from moderately infected to dead. Using our best-fit model, we project the future levels of blister rust infestation in the GYE at critical sites over the next 20 years.

Chapter 8 - Status and trends of whitebark pine distribution and health in California, Oregon, and Washington (Project WC-EM-B-12-02)

Treesearch

Bianca N.I. Eskelson; Vicente J. Monleon

2018-01-01

Whitebark pine (Pinus albicaulis Engelm.) is a keystone species that provides a variety of ecosystem services, such as soil stabilization and protracted snowmelts. Found in many upper subalpine forests in Western North America (Arno and Hoff 1989), whitebark pine is an important high-elevation food source for grizzly bears (Bjoernlie and others 2014) and numerous other...

Influences of thinning, prescribed burning, and wildfire on soil processes and properties in southwestern ponderosa pine forests: A retrospective study

Treesearch

Kevin C. Grady; Stephen C. Hart

2006-01-01

Following Euro-American settlement in the late 1800s, fire suppression and livestock grazing in ponderosa pine-bunchgrass ecosystems of the southwestern US resulted in the replacement of grass openings with dense stands of ponderosa pine. This, in turn, has led to apparent decreases in decomposition, net N mineralization, and soil respiration (i.e., net soil CO2 efflux...

Soil ecosystem services in loblolly pine plantations 15 years after harvest, compaction, and vegetation control

Treesearch

D. Andrew Scott; Robert J. Eaton; Julie A. Foote; Benjamin Vierra; Thomas W. Boutton; Gary B. Blank; Kurt Johnsen

2014-01-01

Site productivity has long been identified as the primary ecosystem service to be sustained in timberlands. However, soil C sequestration and ecosystem biodiversity have emerged as critical services provided by managed forest soils that must also be sustained. These ecosystem services were assessed in response to gradients of organic matter removal, soil compaction,...

Vegetation composition and structure of southern coastal plain pine forests: An ecological comparison

USGS Publications Warehouse

Hedman, C.W.; Grace, S.L.; King, S.E.

2000-01-01

Longleaf pine (Pinus palustris) ecosystems are characterized by a diverse community of native groundcover species. Critics of plantation forestry claim that loblolly (Pinus taeda) and slash pine (Pinus elliottii) forests are devoid of native groundcover due to associated management practices. As a result of these practices, some believe that ecosystem functions characteristic of longleaf pine are lost under loblolly and slash pine plantation management. Our objective was to quantify and compare vegetation composition and structure of longleaf, loblolly, and slash pine forests of differing ages, management strategies, and land-use histories. Information from this study will further our understanding and lead to inferences about functional differences among pine cover types. Vegetation and environmental data were collected in 49 overstory plots across Southlands Experiment Forest in Bainbridge, GA. Nested plots, i.e. midstory, understory, and herbaceous, were replicated four times within each overstory plot. Over 400 species were identified. Herbaceous species richness was variable for all three pine cover types. Herbaceous richness for longleaf, slash, and loblolly pine averaged 15, 13, and 12 species per m2, respectively. Longleaf pine plots had significantly more (p < 0.029) herbaceous species and greater herbaceous cover (p < 0.001) than loblolly or slash pine plots. Longleaf and slash pine plots were otherwise similar in species richness and stand structure, both having lower overstory density, midstory density, and midstory cover than loblolly pine plots. Multivariate analyses provided additional perspectives on vegetation patterns. Ordination and classification procedures consistently placed herbaceous plots into two groups which we refer to as longleaf pine benchmark (34 plots) and non-benchmark (15 plots). Benchmark plots typically contained numerous herbaceous species characteristic of relic longleaf pine/wiregrass communities found in the area. Conversely, non-benchmark plots contained fewer species characteristic of relic longleaf pine/wiregrass communities and more ruderal species common to highly disturbed sites. The benchmark group included 12 naturally regenerated longleaf plots and 22 loblolly, slash, and longleaf pine plantation plots encompassing a broad range of silvicultural disturbances. Non-benchmark plots included eight afforested old-field plantation plots and seven cutover plantation plots. Regardless of overstory species, all afforested old fields were low either in native species richness or in abundance. Varying degrees of this groundcover condition were also found in some cutover plantation plots that were classified as non-benchmark. Environmental variables strongly influencing vegetation patterns included agricultural history and fire frequency. Results suggest that land-use history, particularly related to agriculture, has a greater influence on groundcover composition and structure in southern pine forests than more recent forest management activities or pine cover type. Additional research is needed to identify the potential for afforested old fields to recover native herbaceous species. In the interim, high-yield plantation management should initially target old-field sites which already support reduced numbers of groundcover species. Sites which have not been farmed in the past 50-60 years should be considered for longleaf pine restoration and multiple-use objectives, since they have the greatest potential for supporting diverse native vegetation. (C) 2000 Elsevier Science B.V.

Carbon and water fluxes from ponderosa pine forests disturbed by wildfire and thinning.

PubMed

Dore, S; Kolb, T E; Montes-Helu, M; Eckert, S E; Sullivan, B W; Hungate, B A; Kaye, J P; Hart, S C; Koch, G W; Finkral, A

2010-04-01

Disturbances alter ecosystem carbon dynamics, often by reducing carbon uptake and stocks. We compared the impact of two types of disturbances that represent the most likely future conditions of currently dense ponderosa pine forests of the southwestern United States: (1) high-intensity fire and (2) thinning, designed to reduce fire intensity. High-severity fire had a larger impact on ecosystem carbon uptake and storage than thinning. Total ecosystem carbon was 42% lower at the intensely burned site, 10 years after burning, than at the undisturbed site. Eddy covariance measurements over two years showed that the burned site was a net annual source of carbon to the atmosphere whereas the undisturbed site was a sink. Net primary production (NPP), evapotranspiration (ET), and water use efficiency were lower at the burned site than at the undisturbed site. In contrast, thinning decreased total ecosystem carbon by 18%, and changed the site from a carbon sink to a source in the first posttreatment year. Thinning also decreased ET, reduced the limitation of drought on carbon uptake during summer, and did not change water use efficiency. Both disturbances reduced ecosystem carbon uptake by decreasing gross primary production (55% by burning, 30% by thinning) more than total ecosystem respiration (TER; 33-47% by burning, 18% by thinning), and increased the contribution of soil carbon dioxide efflux to TER. The relationship between TER and temperature was not affected by either disturbance. Efforts to accurately estimate regional carbon budgets should consider impacts on carbon dynamics of both large disturbances, such as high-intensity fire, and the partial disturbance of thinning that is often used to prevent intense burning. Our results show that thinned forests of ponderosa pine in the southwestern United States are a desirable alternative to intensively burned forests to maintain carbon stocks and primary production.

Landscape dynamics of mountain pine beetles

Treesearch

John E. Lundquist; Robin M. Reich

2014-01-01

The magnitude and urgency of current mountain pine beetle outbreaks in the western United States and Canada have resulted in numerous studies of the dynamics and impacts of these insects in forested ecosystems. This paper reviews some of the aspects of the spatial dynamics and landscape ecology of this bark beetle. Landscape heterogeneity influences dispersal patterns...

Mitochondrial phylogeny of pine cone beetles (Scolytinae, Conophthorus) and their affiliation with geographic area and host

Treesearch

Anthony I. Cognato; Nancy E. Gillette; Rodolfo Campos Bolanos; Felix A.H. Sperling

2005-01-01

Pine cone beetles (Conophthorus spp.) feed and kill immature cones of Pinus species, thereby reducing seed production and seriously impairing reforestation of forest ecosystems. Population variation of Conophthorus reproductive behavior has hampered the development of semiochemical control of these pests. This diYculty is...

Litter decomposition across an air-pollution gradient in the San Bernardino Mountains

Treesearch

Mark E. Fenn; Paul H. Dunn

1989-01-01

Air pollution may affect forest ecosystems by altering nutrient cycling rates. The objective of this study was to compare decomposition rates of L-layer litter of ponderosa pine (Pinus ponderosa Laws.) and Jeffrey pine (Pinus jeffreyi Grev. & Balf,) collected from across an air-pollution gradient in the San Bernardino Mountains...

Pines

Treesearch

C. Plomion; D. Chagne; D. Pot; S. Kumar; P.L. Wilcox; R.D. Burdon; D. Prat; D.G. Peterson; J. Paiva; P. Chaumeil; G.G. Vendramin; F. Sebastiani; C.D. Nelson; C.S. Echt; O. Savolainen; T.L. Kubisiak; M.T. Cervera; N. de Maria; M.N. Islam-Faridi

2007-01-01

Pinus is the most important genus within the Family Pinaceae and also within the gymnosperms by the number of species (109 species recognized by Farjon 2001) and by its contribution to forest ecosystems. All pine species are evergreen trees or shrubs. They are widely distributed in the northern hemisphere, from tropical areas to northern areas in America and Eurasia....

Characteristics of gaps and natural regeneration in mature longleaf pine flatwoods ecosystems

Treesearch

Jennifer L. Gagnon; Eric J. Jokela; W.K. Moser; Dudley A. Huber

2004-01-01

Developing uneven-aged structure in mature stands of longleaf pine requires scientifically based silvicultural systems that are reliable, productive and sustainable. Understanding seedling responses to varying levels of site resource availability within forest gaps is essential for effectively converting even-aged stands to uneven-aged stands. A project was initiated...

Fate of Hexazinone and Picloram After Herbicide Site Preparation in a Cutover Northern Hardwood Forest

Treesearch

D.G. Neary; J.L. Michael; M.J.M. Wells

1985-01-01

Herbicides show promise to improve the efficiency and economics of forest stand conversion and regeneration. However, the impacts of herbicides on forest ecosystems and the ultimate fate of these chemicals are not completely understood. A major problem in pine regeneration in northern mixed hardwood forests is competition from fast-growing and easily sprouting species...

Integrating invasive grasses into carbon cycle projections: Cogongrass spread in southern pine forests

NASA Astrophysics Data System (ADS)

McCabe, T. D.; Flory, S. L.; Wiesner, S.; Dietze, M.

2017-12-01

Forested ecosystems are currently being disrupted by invasive species. One example is the invasive grass Imperata cylindrica (cogongrass), which is widespread in southeastern US pine forests. Pines forests dominate the forest cover of the southeast, and contribute to making the Southeast the United States' largest carbon sink. Cogongrass decreases the colonization of loblolly pine fine roots. If cogongrass continues to invade,this sink could be jeopardized. However, the effects of cogongrass invasion on carbon sequestration are largely unknown. We have projected the effects of elevated CO2 and changing climate on future cogongrass invasion. To test how pine stands are affected by cogongrass, cogongrass invasions were modeled using the Ecosystem Demography 2 (ED2) model, and parameterized using the Predictive Ecosystem Analyzer (PEcAn). ED2 takes into account local meteorological data, stand populations and succession, disturbance, and geochemical pools. PEcAn is a workflow that uses Bayesian sensitivity analyses and variance decomposition to quantify the uncertainty that each parameter contributes to overall model uncertainty. ED2 was run for four NEON and Ameriflux sites in the Southeast from the earliest available census of the site into 2010. These model results were compared to site measures to test for model accuracy and bias. To project the effect of elevated CO2 on cogongrass invasions, ED was run from 2006-2100 at four sites under four separate scenarios: 1) RPC4.5 CO2 and climate, 2) RPC4.5 climate only, with constant CO2 concentrations, 3) RPC4.5 Elevated CO2 only, with climate randomly selected from 2006-2026, 4) Present Day, made from randomly selected measures of CO2 and radiation from 2006-2026. Each scenario was run three times; once with cogongrass absent, once with a low cogongrass abundance, and once with a high cogongrass abundance. Model results suggest that many relevant parameters have high uncertainty due to lack of measurement. Further field work quantifying the carbon cycle, particularly belowground processes and respiration, could help constrain parameter uncertainty.

The response of ecosystem carbon pools to management approaches in loblolly pine (Pinus taeda L.) plantations

NASA Astrophysics Data System (ADS)

Vogel, J. G.; Bacon, A. R.; Bracho, R. G.; Gonzalez-Benecke, C. A.; Fox, T. D.; Laviner, M. A.; Kane, M.; Burkhart, H.; Martin, T.; Will, R.; Ross, C. W.; Grunwald, S.; Jokela, E. J.; Meek, C.

2016-12-01

Extending from Virginia to east Texas in the southeastern United States, managed pine plantations are an important component of the region's carbon cycle. An objective of the Pine Integrated Network: Education, Mitigation, and Adaptation project (PINEMAP) is to improve estimates of how ecosystem carbon pools respond to the management strategies used to increase the growth of loblolly pine plantations. Experimental studies (108 total) that have been used to understand plantation productivity and stand dynamics by university-forest industry cooperatives were measured for the carbon stored in the trees, roots, coarse-wood, detritus in soil, forest floor, understory and soils to 1-meter. The age of the studied plantations ranged from 4-26 years at the time of sampling, with 26 years very near the period when these plantations are commonly harvested. Across all study sites, 455 experimental plots were measured. The average C storage across all pools, sites, and treatments was 192 Mg C ha-1, with the average percentage of the total coming from soil (44%), tree biomass (40%), forest floor (8%), root (5%), soil detritus (2%), understory biomass (1%), and coarse-wood (<1%) pools. Plots had as a treatment either fertilization, competition control, and stand density control (thinning), and every possible combination of treatments including `no treatment'. A paired plot analysis was used where two plots at a site were examined for relative differences caused by a single treatment and these differences averaged across the region. Thinning as a stand-alone treatment significantly reduced forest floor mass by 60%, and the forest floor in the thinned plus either competition control or fertilization was 18.9% and 19.2% less, respectively, than unthinned stands combined with the same treatments. Competition control increased C storage in tree biomass by 12% and thinning decreased tree biomass by 32%. Thinning combined with fertilization had lower soil carbon (0-1 m) than unthinned-fertilized plots (22%), although the replication for this combination was relatively low (n=6). Overall these results suggest that maintaining higher tree densities increases ecosystem carbon storage across multiple pools of C in loblolly pine plantations.

[Effects of selective cutting on the carbon density and net primary productivity of a mixed broadleaved-Korean pine forest in Northeast China].

PubMed

Liu, Qi; Cai, Hui-Ying; Jin, Guang-Ze

2013-10-01

To accurately quantify forest carbon density and net primary productivity (NPP) is of great significance in estimating the role of forest ecosystems in global carbon cycle. By using the forest inventory and allometry approaches, this paper measured the carbon density and NPP of the virgin broadleaved-Korean pine (Pinus koraiensis) forest and of the broadleaved-Korean pine forest after 34 years selective-cutting (the cutting intensity was 30%, and the cutting trees were in large diameter class). The total carbon density of the virgin and selective-cutting broadleaved-Korean pine forests was (397.95 +/- 93.82) and (355.61 +/- 59.37) t C x hm(-2), respectively. In the virgin forest, the carbon density of the vegetation, debris, and soil accounted for 31.0%, 3.1%, and 65.9% of the total carbon pool, respectively; in the selective-cutting forest, the corresponding values were 31.7%, 2.9%, and 65.4%, respectively. No significant differences were observed in the total carbon density and the carbon density of each component between the two forests. The total NPP of the virgin and selective-cutting forests was (36.27 +/- 0.36) and (6.35 +/- 0.70) t C x hm(-2) x a(-1), among which, the NPP of overstory, understory, and fine roots in virgin forest and selective-cutting forest accounted for 60.3%, 2.0%, and 37.7%, and 66.1%, 2.0%, and 31.2%, respectively. No significant differences were observed in the total NPP and the contribution rate of each component between the two forests. However, the ratios of the needle and broadleaf NPPs of the virgin and selective-cutting forests were 47.24:52.76 and 20.48:79.52, respectively, with a significant difference. The results indicated that the carbon density and NPP of the broadleaved-Korean pine forest after 34 years selective-cutting recovered to the levels of the virgin broadleaved-Korean pine forest.

An evaluation of ozone exposure metrics for a seasonally drought-stressed ponderosa pine ecosystem.

PubMed

Panek, Jeanne A; Kurpius, Meredith R; Goldstein, Allen H

2002-01-01

Ozone stress has become an increasingly significant factor in cases of forest decline reported throughout the world. Current metrics to estimate ozone exposure for forest trees are derived from atmospheric concentrations and assume that the forest is physiologically active at all times of the growing season. This may be inaccurate in regions with a Mediterranean climate, such as California and the Pacific Northwest, where peak physiological activity occurs early in the season to take advantage of high soil moisture and does not correspond to peak ozone concentrations. It may also misrepresent ecosystems experiencing non-average climate conditions such as drought years. We compared direct measurements of ozone flux into a ponderosa pine canopy with a suite of the most common ozone exposure metrics to determine which best correlated with actual ozone uptake by the forest. Of the metrics we assessed, SUM0 (the sum of all daytime ozone concentrations > 0) best corresponded to ozone uptake by ponderosa pine, however the correlation was only strong at times when the stomata were unconstrained by site moisture conditions. In the early growing season (May and June). SUM0 was an adequate metric for forest ozone exposure. Later in the season, when stomatal conductance was limited by drought. SUM0 overestimated ozone uptake. A better metric for seasonally drought-stressed forests would be one that incorporates forest physiological activity, either through mechanistic modeling, by weighting ozone concentrations by stomatal conductance, or by weighting concentrations by site moisture conditions.

Pine Forest Harvest Leads to Decade-Scale Alterations in Soil Fungal Communities

NASA Astrophysics Data System (ADS)

Boutton, T. W.; Mushinski, R. M.; Gentry, T. J.

2016-12-01

Forestlands provide a multitude of ecosystem services, and sustainable management is crucial to maintaining the benefits of these ecosystems. Intensive organic matter removal (OMR) of logging residues and forest litter during forest harvest may result in long-term alterations to soil properties and processes. Because fungal activity regulates essential biogeochemical processes in forestlands, changes in soil fungal community structure following OMR may translate into altered soil function. Using a replicated field experiment in southern pine forest in eastern Texas, USA, we sampled soil to a depth of 1 m to assess the impact of intensive OMR on soil fungal communities. Soils were collected from replicated (n = 3 ) loblolly pine (Pinus taeda L.) stands subjected to 3 different harvest intensities (i.e., unharvested old growth stands, bole-only harvest stands, and whole-tree harvest + forest floor removal stands) in 1997. Nearly two decades after trees were harvested and replanted, next generation sequencing of the fungal internal transcribed spacer showed the diversity and community structure of the entire fungal community was altered relative to the unharvested stands. The relative abundance of Ascomycetes increased as OMR intensity increased and was positively correlated to concurrent changes in soil pH. The community composition of fungal functional groups (e.g., ecto- and arbuscular mycorrhizal, saprophytic fungi) was also altered by OMR. The most abundant taxa, Russula exhibited significant reductions in response to increasing intensity of OMR. Results of this study illustrate a linkage between anthropogenically-induced aboveground perturbation, edaphic factors, and belowground soil fungal communities of southern pine forests. Also, these results indicate that tree harvesting effects on soil fungal communities can persist for decades post-harvest, with potential implications for soil functional characteristics.

The response of ecosystem carbon pools to management approaches that increase the growth of loblolly pine (Pinus taeda L.)

NASA Astrophysics Data System (ADS)

Vogel, J. G.; Bacon, A. R.; Bracho, R. G.; Grunwald, S.; Gonzalez-Benecke, C. A.; Jokela, E. J.; Markewitz, D.; Cucinella, J.; Akers, K.; Ross, C. W.; Peter, G. F.; Fox, T. D.; Martin, T.; Kane, M.

2015-12-01

Extending from Virginia to east Texas in the southeastern United States, managed pine forests are an important component of the region's carbon cycle. One objective of the Pine Integrated Network: Education, Mitigation, and Adaptation project (PINEMAP) is to improve estimates of how ecosystem carbon pools respond to the management strategies used to increase the growth of loblolly pine forests. Experimental studies (108 total) that had historically been used to understand forest productivity and stand dynamics by university-forest industry cooperatives have now been measured for the carbon stored in the trees, coarse-wood, forest floor, understory and soils to 1-meter (0-10 cm, 10-20 cm, 20-50 cm, and 50-100 cm). The age of the studied forests ranged from 4-26 years at the time of sampling, with 26 years very near the period when these forests are commonly harvested. The study sites encapsulated a wide regional range in precipitation (1080 mm -1780 mm) and potential evapotranspiration (716 mm - 1200 mm). The most prevalent three soil orders measured were Ultisols (62%), Alfisols (19%), and Spodosols (10%) with Entisols, Inceptisols and 1 Histosol making up the remainder (9%). Across all study sites, 455 experimental plots were measured. The plots had as a treatment either fertilization, competition control, and stand density control (thinning), including every possible combination of treatments and also 'no treatment'. The most common treatment regime, at 36% of the total number of plots, was the combination of competition control, fertilization, and thinning. The distribution of treatments relative to soils and climate prevented a simple analysis of single treatment effects and instead necessitated an examination how the carbon accumulation rate in wood, which is commonly measured and modeled in these forests, corresponded to the response of other C pools (e.g. forest floor and soil).

Prediction of understory vegetation cover with airborne lidar in an interior ponderosa pine forest

Treesearch

Brian M. Wing; Martin W. Ritchie; Kevin Boston; Warren B. Cohen; Alix Gitelman; Michael J. Olsen

2012-01-01

Forest understory communities are important components in forest ecosystems providing wildlife habitat and influencing nutrient cycling, fuel loadings, fire behavior and tree species composition over time. One of the most widely utilized understory component metrics is understory vegetation cover, often used as a measure of vegetation abundance. To date, understory...

Leaf area index (LAI) of loblolly pine and emergent vegetation following a harvest

Treesearch

D.A. Sampson; D.M. Amatya; C.D. Blanton Lawson; R.W. Skaggs

2011-01-01

Forests provide goods and services to society and, often, refugia for plants and animals; forest managers utilize silviculture to provide ecosystem services and to create habitat. On the Coastal Plain of North Carolina, forest management objectives typically include wood fiber production but may also include the maintenance of environmental quality and, sometimes,...

Lizard Microhabitat and Microclimate Relationships in Southeastern Pine-Hardwood Forests Managed With Prescribed Burning and Thinning

Treesearch

W.B. Sutton; Y. Wang; C.J. Schweitzer; D.A. Steen

2014-01-01

Understanding the impacts of disturbances in forest ecosystems is essential for long-term biodiversity conservation. Many studies have evaluated wildlife responses to various disturbances but most generally do not use changes in microclimate features or crohabitat structure to explain these responses. We examined lizard responses to two common forest management...

Fuel management strategies in 60-year-old douglas-fir/ponderosa pine stands in the Squamish Forest district, British Columbia

Treesearch

Robert W. Gray; Bruce A. Blackwell

2008-01-01

The restoration of dry forest ecosystems in the Squamish Forest District in the past has focused on treating stands with no prior history of selective harvest and containing a large population of remnant historical stand structure. Many 60 to 90 year old stands that date...

Varied ecosystems need different fire protection

USGS Publications Warehouse

Gutsell, Sheri L.; Johnson, Edward A.; Miyanishi, Kiyoko; Keeley, Jon E.; Dickinson, Matthew; Bridge, Simon R. J.

2001-01-01

Covington states in his Commentary1 that the open ponderosa pine forests of the western United States are "in widespread collapse" because fire suppression by humans has eliminated the low-intensity surface fire regime that maintained the open, park-like structure of these forests. He fears this will lead to an "unprecedented" crown fire regime that will eliminate forests.

Age-related patterns of forest complexity and carbon storage in pine and aspen-birch ecosystems of northern Minnesota, USA

Treesearch

John B. Bradford; Douglas N. Kastendick

2010-01-01

Forest managers are seeking strategies to create stands that can adapt to new climatic conditions and simultaneously help mitigate increases in atmospheric CO2. Adaptation strategies often focus on enhancing resilience by maximizing forest complexity in terms of species composition and size structure, while mitigation involves sustaining carbon...

Nutrient fluxes in forests of the eastern Sierra Nevada: comparisons with humid forest systems

Treesearch

Dale W. Johnson; Richard B. Susfalk; Randy A. Dahlgreen; Virginia Boucher; Andrzej Bytnerowicz

1998-01-01

Preliminary results of studies on nutrient fluxes in forests of the eastern Sierra Nevada were compared to those from more humid and polluted ecosystems. Snowmelt, soil solution, soil, and streamwater were collected from Jeffrey and lodgepole pine (Pinus jeffreyii [Grev. and Balf.] and Pinus contorta Dougl.) stands in Little Valley...

Effects of tree size and spatial distribution on growth of ponderosa pine forests under alternative management scenarios

Treesearch

C.W. Woodall; C.E. Fiedler; R.E. McRoberts

2009-01-01

Forest ecosystems may be actively managed toward heterogeneous stand structures to provide both economic (e.g., wood production and carbon credits) and environmental benefits (e.g., invasive pest resistance). In order to facilitate wider adoption of possibly more sustainable forest stand structures, defining growth expectations among alternative management scenarios is...

Effect of Herbicides on Soil Productivity and Water Quality

Treesearch

Daniel G. Neary; Jerry L. Michael

1989-01-01

The southern yellow pine and hardwood forests of the South constitute some of the most intensively managed forest ecosystems in the world (Stone 1983; Kellison and Gingrich 1982). These forests also occur in a region with one of the fastest growing human populations in the United States. Furthermore, future resource demands in the South will certainly intensify...

Development of ecological restoration experiments in fire adapted forests at Grand Canyon National Park

Treesearch

Thomas A. Heinlein; W. Wallace Covington; Peter Z. Fule; Margaret H. Moore; Hiram B. Smith

2000-01-01

The management of national park and wilderness areas dominated by forest ecosystems adapted to frequent, low-intensity fires, continues to be a tremendous challenge. Throughout the inland West and particularly in the Southwest, ponderosa pine (Pinus ponderosa) and mixed conifer forests have become dense and structurally homogeneous after periods of...

Contemporary patterns of burn severity heterogeneity from fires in the Northwestern U.S.

Treesearch

R. Travis Belote

2015-01-01

Historically, frequent, low-severity fires maintained opengrown structure of dry ponderosa pine forests (Hessburg and Agee 2003). Thus, an open forest structure may be a reasonable template for ecological restoration in those particular forest types (Allen and others 2002). In contrast, setting goals for ecosystem management and restoration targets in the vast majority...

Mitigation benefits of forestation greatly varies on short spatial scale

NASA Astrophysics Data System (ADS)

Yakir, Dan; Rotenberg, Eyal; Rohatin, Shani; Ramati, Efrat; Asaf, David; Dicken, Uri

2016-04-01

Mitigation of global warming by forestation is controversial because of its linkage to increasing surface energy load and associated surface warming. Such tradeoffs between cooling associated with carbon sequestration and warming associated with radiative effects have been considered predominantly on large spatial scales, indicating benefits of forestation mainly in the tropics but not in the boreal regions. Using mobile laboratory for measuring CO2, water and energy flux in forest and non-forest ecosystem along the climatic gradient in Israel over three years, we show that the balance between cooling and warming effects of forestation can be transformed across small spatial scale. While converting shrubland to pine forest in a semi-arid site (280 mm annual precipitations) requires several decades of carbon sequestration to balance the radiative warming effects, similar land use change under moist Mediterranean conditions (780 mm annual precipitation) just ~200 km away showed reversal of this balance. Specifically, the results indicated that in the study region (semi-arid to humid Mediterranean), net absorb radiation in pine forests is always larger than in open space ecosystems, resulting in surface warming effects (the so-called albedo effect). Similarly, depression of thermal radiation emission, mainly due canopy skin surface cooling associated with the 'convector effect' in forests compared with shrubland ecosystems also appears in all sites. But both effects decrease by about 1/2 in going from the semi-arid to the humid Mediterranean sites, while enhanced productivity of forest compared to grassland increase about fourfold. The results indicate a greater potential for forestation as climate change mitigation strategy than previously assumed.

Influence of repeated prescribed fire on tree growth and mortality in Pinus resinosa forests, northern Minnesota

USGS Publications Warehouse

Bottero, Alessandra; D'Amato, Anthony W.; Palik, Brian J.; Kern, Christel C.; Bradford, John B.; Scherer, Sawyer S.

2017-01-01

Prescribed fire is widely used for ecological restoration and fuel reduction in fire-dependent ecosystems, most of which are also prone to drought. Despite the importance of drought in fire-adapted forests, little is known about cumulative effects of repeated prescribed burning on tree growth and related response to drought. Using dendrochronological data in red pine (Pinus resinosa Ait.)-dominated forests in northern Minnesota, USA, we examined growth responses before and after understory prescribed fires between 1960 and 1970, to assess whether repeated burning influences growth responses of overstory trees and vulnerability of overstory tree growth to drought. We found no difference in tree-level growth vulnerability to drought, expressed as growth resistance, resilience, and recovery, between areas receiving prescribed fire treatments and untreated forests. Annual mortality rates during the period of active burning were also low (less than 2%) in all treatments. These findings indicate that prescribed fire can be effectively integrated into management plans and climate change adaptation strategies for red pine forest ecosystems without significant short- or long-term negative consequences for growth or mortality rates of overstory trees.

Rapid increase in log populations in drought-stressed mixed-conifer and ponderosa pine forests in northern Arizona

Treesearch

Joseph L. Ganey; Scott C. Vojta

2012-01-01

Down logs provide important ecosystem services in forests and affect surface fuel loads and fire behavior. Amounts and kinds of logs are influenced by factors such as forest type, disturbance regime, forest man-agement, and climate. To quantify potential short-term changes in log populations during a recent global- climate-change type drought, we sampled logs in mixed-...

Exotic Forest Insect Pests and Their Impact on Forest Management

Treesearch

Therese M. Poland; Robert A. Haack

2003-01-01

More than 4500 exotic organisms are now established in the United States, of which over 400 are insects that feed on trees and shrubs. While most exotic insects cause little or no damage, a few have become serious pests and have greatly altered native forest ecosystems. Three of the most recently introduced exotic forest pests are the pine shoot beetle, the Asian...

Ectomycorrhizal communities of ponderosa pine and lodgepole pine in the south-central Oregon pumice zone

Treesearch

Maria O. Garcia; Jane E. Smith; Daniel L. Luoma; Melanie D. Jones

2016-01-01

Forest ecosystems of the Pacific Northwest of the USA are changing as a result of climate change. Specifically, rise of global temperatures, decline of winter precipitation, earlier loss of snowpack, and increased summer drought are altering the range of Pinus contorta. Simultaneously, flux in environmental conditions within the historic ...

INTERACTIVE EFFECTS OF CO2 AND O3 ON A PONDEROSA PINE PLANT/LITTER/SOIL MESOCOSM

EPA Science Inventory

To study individual and combined impacts of two important atmospheric trace gases, CO2 and O3, on C and N cycling in forest ecosystems; a four-year experiment using a small-scale ponderosa pine (Pinus ponderosa Laws.) seedling/soil/litter system was initiated in April, 1998. Th...

Ecological, political and social challenges of prescribed fire restoration in east Texas pineywoods ecosystems: a case study

Treesearch

Sandra Rideout; Brian P. Oswald; Michael H. Legg

2003-01-01

The effectiveness of prescribed fire restoration of forested sites in three state parks in east Texas, USA was studied. Two sites consisted of mixed shortleaf (Pinus echinata Mill.) or loblolly pine (Pinus taeda L.) and broadleaf overstoreys. The third site was a longleaf pine (Pinus palustris Mill.)/little...

Power laws in cone production of longleaf pine across its native range in the United States

Treesearch

Xiongwen Chen; Qinfeng Guo; Dale G. Brockway

2017-01-01

Longleaf pine (Pinus palustris Mill.) forests in the southeastern United States are considered endangered ecosystems, because of their dramatic decrease in area since European colonization and poor rates of recovery related to episodic natural regeneration. Sporadic seed production constrains restoration efforts and complicates sustainable management of this species....

Whitebark pine ecosystem restoration in western Montana

Treesearch

Robert E. Keane; Stephen F. Arno

1996-01-01

Whitebark pine (Pinus albicaulis) is a major tree species of upper subalpine forests of the northern Rocky Mountains (Schmidt and McDonald 1990). It is an important nutritional and structural component of wildlife habitat (Arno and Hoff 1990; Schmidt and McDonald 1990). Its large, nutlike seeds are a major food source for many birds and mammals (...

Plant competition, facilitation, and other overstory-understory interactions in longleaf pine ecosystems.

Treesearch

Timothy B. Harrington

2006-01-01

Many of the stand structural characteristics of longleaf pine (Pinus palustris Mill.) forests that existed prior to European colonization have been altered or lost from past disturbance histories (Frost this volume). For example, often missing are the widely spaced, large-diameter trees, the all-aged stand structure that included a vigorous cohort...

Growth of a 45-year-old ponderosa pine plantation: An Arizona case study

Treesearch

Peter F. Ffolliott; Gerald J. Gottfried; Cody L. Stropki; L. J. Heidmann

2008-01-01

Information on the growth of forest plantations is necessary for planning of ecosystem-based management of the plantations. This information is also useful in validating or refining computer simulators that estimate plantation growth into the future. Such growth information has been obtained from a 45-year-old ponderosa pine (Pinus ponderosa)...

Effects of multiple interacting disturbances and salvage logging on forest carbon stocks

USGS Publications Warehouse

Bradford, J.B.; Fraver, S.; Milo, A.M.; D'Amato, A.W.; Palik, B.; Shinneman, D.J.

2012-01-01

Climate change is anticipated to increase the frequency of disturbances, potentially impacting carbon stocks in terrestrial ecosystems. However, little is known about the implications of either multiple disturbances or post-disturbance forest management activities on ecosystem carbon stocks. This study quantified how forest carbon stocks responded to stand-replacing blowdown and wildfire, both individually and in combination with and without post-disturbance salvage operations, in a sub-boreal jack pine ecosystem. Individually, blowdown or fire caused similar decreases in live carbon and total ecosystem carbon. However, whereas blowdown increased carbon in down woody material and forest floor, fire increased carbon in standing snags, a difference that may have consequences for long-term carbon cycling patterns. Fire after the blowdown caused substantial additional reduction in ecosystem carbon stocks, suggesting that potential increases in multiple disturbance events may represent a challenge for sustaining ecosystem carbon stocks. Salvage logging, as examined here, decreased carbon stored in snags and down woody material but had no significant effect on total ecosystem carbon stocks.

Threats to North American forests from southern pine beetle with warming winters

NASA Astrophysics Data System (ADS)

Lesk, Corey; Coffel, Ethan; D'Amato, Anthony W.; Dodds, Kevin; Horton, Radley

2017-10-01

In coming decades, warmer winters are likely to ease range constraints on many cold-limited forest insects. Recent unprecedented expansion of the southern pine beetle (SPB, Dendroctonus frontalis) into New Jersey, New York and Connecticut in concert with warming annual temperature minima highlights the risk that this insect pest poses to the pine forests of the northern United States and Canada under continued climate change. Here we present projections of northward expansion in SPB-suitable climates using a statistical bioclimatic range modelling approach and current-generation general circulation model output under Representative Concentration Pathways 4.5 and 8.5. Results show that by the middle of the twenty-first century, the climate is likely to be suitable for SPB expansion into vast areas of previously unaffected forests throughout the northeastern United States and into southeastern Canada. This scenario would pose a significant economic and ecological risk to the affected regions, including disruption of local ecosystem services, shifts in forest structure, and threats to native biodiversity.

Threats to North American Forests from Southern Pine Beetle with Warming Winters

NASA Technical Reports Server (NTRS)

Lesk, Corey; Coffel, Ethan; D'Amato, Anthony W.; Dodds, Kevin; Horton, Radley M.

2016-01-01

In coming decades, warmer winters are likely to lift range constraints on many cold-limited forest insects. Recent unprecedented expansion of the southern pine beetle (SPB, Dendroctonus frontalis) into New Jersey, New York, Connecticut, and Massachusetts in concert with warming annual temperature minima highlights the risk that this insect pest poses to the pine forests of the northern United States and Canada under continued climate change. Here we present the first projections of northward expansion in SPB-suitable climates using a statistical bioclimatic range modeling approach and current-generation general circulation model (GCM) output under the RCP 4.5 and 8.5 emissions scenarios. Our results show that by the middle of the 21st century, the climate is likely to be suitable for SPB expansion into vast areas of previously unaffected forests throughout the northeastern United States and into southeastern Canada. This scenario would pose a significant economic and ecological risk to the affected regions, including disruption oflocal ecosystem services, dramatic shifts in forest structure, and threats to native biodiversity.

The transformation of vegetation vertical zonality affected by anthropogenic impact in East Fennoscandia (Russia)

NASA Astrophysics Data System (ADS)

Sidorik, Vadim; Miulgauzen, Daria

2017-04-01

Ecosystems of East Fennoscandia have been affected by intensive anthropogenic influence that resulted in their significant transformation. Study of ecosystems in the framework of vegetation vertical zonality disturbance as well as its recovery allows to understand the trends of anthropogenically induced changes. The aim of the present research is the comparative analysis of vegetation vertical zonality of the two uplands in East Fennoscandia which may be considered as unaffected and affected by anthropogenic impact. The objects of key studies carried out in the north-west of Kola Peninsula in the vicinity of the Pechenganikel Mining and Metallurgical Plant are represented by ecosystems of Kalkupya (h 357 m) and Hangaslachdenvara (h 284 m) uplands. They are characterized by the similarity in sequence of altitudinal belts due to the position on the northern taiga - forest-tundra boundary. Plant communities of Kalkupya upland have no visible signs of anthropogenic influence, therefore, they can be considered as model ecosystems of the area. The sequence of altitudinal belts is the following: - up to 200 m - pine subshrub and green moss ("zonal") forest replaced by mixed pine and birch forest near the upper boundary; - 200-300 m - birch crooked subshrub wood; - above 300 m - tundra subshrub and lichen communities. Ecosystems of Hangaslachdenvara upland have been damaged by air pollution (SO2, Ni, Cu emissions) of the Pechenganikel Plant. This impact has led to plant community suppression and formation of barren lands. Besides the soil cover was significantly disturbed, especially upper horizons. Burying of soil profiles, represented by Podzols (WRB, 2015), also manifested itself in the exploited part of the area. The vegetation cover of Hangaslachdenvara upland is the following: - up to 130 m - birch and aspen subshrub and grass forest instead of pine forest ("zonal"); - 130-200 m - barren lands instead of pine forest ("zonal"); - above 200 m - barren lands instead of birch crooked subshrub wood, which stretched to the north-east, proving the leading role of prevailing southwestern winds in pollution spreading in the area. As the anthropogenic impact decreases due to the Plant's emissions decline, there have been identified signs of ecosystem restoration. The beginning restoration helps parvifoliate forests to grow in barren lands, including the above-mentioned birch and aspen forest on Hangaslachdenvara upland. Reductive processes of soil formation are responsible for the development of soddy or raw humus horizons in the substrate overlaying the well-developed Podzols. Nevertheless, there is no restoration above 130 m on Hangaslachdenvara upland owing to the barrier effect, in other words, intensive deposition and accumulation of air pollutants on the upland's top. Thus, there has been defined that the anthropogenic impact led to total vegetation vertical zonality modification and physical disturbance of soil cover in East Fennoscandia. The typical taiga scheme of "coniferous forest - birch crooked wood - tundra subshrub and lichen communities" altitudinal belts was replaced by that of "parvifoliate forest - barren land" altitudinal belts. However, after the reduction of anthropogenic influence "zonal" plant communities begin to restore gradually and weak developed soils are forming.

Frequent Prescribed Burning as a Long-term Practice in Longleaf Pine Forests Does Not Affect Detrital Chemical Composition.

PubMed

Coates, T Adam; Chow, Alex T; Hagan, Donald L; Wang, G Geoff; Bridges, William C; Dozier, James H

2017-09-01

The O horizon, or detrital layer, of forest soils is linked to long-term forest productivity and health. Fuel reduction techniques, such as prescribed fire, can alter the thickness and composition of this essential ecosystem component. Developing an understanding of the changes in the chemical composition of forest detritus due to prescribed fire is essential for forest managers and stakeholders seeking sustainable, resilient, and productive ecosystems. In this study, we evaluated fuel quantity, fuel structure, and detrital chemical composition in longleaf pine ( Miller) forests that have been frequently burned for the last 40 yr at the Tom Yawkey Wildlife Center in Georgetown, SC. Our results suggest that frequent prescribed fire reduces forest fuel quantity ( < 0.01) and vertical structure ( = 0.01). Using pyrolysis-gas chromatography/mass spectrometry as a molecular technique to analyze detrital chemical composition, including aromatic compounds and polycyclic aromatic hydrocarbons, we found that the chemical composition of forest detritus was nearly uniform for both unburned and burned detritus. Our burning activities varied in the short term, consisting of annual dormant, annual growing, and biennial dormant season burns. Seasonal distinctions were present for fuel quantity and vertical fuel structure, but these differences were not noted for the benzene/phenol ratio. These results are significant as more managers consider burning existing longleaf stands while determining effective management practices for longleaf stands yet to be established. Managers of such stands can be confident that frequent, low-intensity, low-severity prescribed burns in longleaf pine forests do little to affect the long-term chemical composition of forest detritus. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.

Soil processes and tree growth at shooting ranges in a boreal forest reflect contamination history and lead-induced changes in soil food webs.

PubMed

Selonen, Salla; Setälä, Heikki

2015-06-15

The effects of shooting-derived lead (Pb) on the structure and functioning of a forest ecosystem, and the recovery of the ecosystem after range abandonment were studied at an active shotgun shooting range, an abandoned shooting range where shooting ceased 20 years earlier and an uncontaminated control site. Despite numerous lead-induced changes in the soil food web, soil processes were only weakly related to soil food web composition. However, decomposition of Scots pine (Pinus sylvestris) needle litter was retarded at the active shooting range, and microbial activity, microbial biomass and the rate of decomposition of Pb-contaminated grass litter decreased with increasing soil Pb concentrations. Tree (P. sylvestris) radial growth was suppressed at the active shooting range right after shooting activities started. In contrast, the growth of pines improved at the abandoned shooting range after the cessation of shooting, despite reduced nitrogen and phosphorus contents of the needles. Higher litter degradation rates and lower Pb concentrations in the topmost soil layer at the abandoned shooting range suggest gradual recovery after range abandonment. Our findings suggest that functions in lead-contaminated coniferous forest ecosystems depend on the successional stage of the forest as well as the time since the contamination source has been eliminated, which affects, e.g., the vertical distribution of the contaminant in the soil. However, despite multiple lead-induced changes throughout the ecosystem, the effects were rather weak, indicating high resistance of coniferous forest ecosystems to this type of stress. Copyright © 2015 Elsevier B.V. All rights reserved.

Explaining the inter-annual variability in the ecosystem fluxes of the Brasschaat Scots pine forest: 20 years of eddy flux and pollution monitoring

NASA Astrophysics Data System (ADS)

Horemans, Joanna; Roland, Marilyn; Janssens, Ivan; Ceulemans, Reinhart

2017-04-01

Because of their ecological and recreational value, the health of forest ecosystems and their response to global change and pollution are of high importance. At a number of EuroFlux and ICOS ecosystem sites in Europe - as the Brasschaat forest site - the measurements of ecosystem fluxes of carbon and other gases are combined with vertical profiles of air pollution within the framework of the ICP-Forest monitoring program. The Brasschaat forest is dominated by 80-year old Scots pines (Pinus sylvestris L.), and has a total area of about 150 ha. It is situated near an urban area in the Campine region of Flanders, Belgium and is characterized by a mean annual temperature of 9.8 °C and an annual rainfall of 830 mm. In this contribution we report on a long-term analysis (1996-2016) of the ecosystem carbon and water fluxes, the energy exchanges and the pollutant concentrations (ozone, NOx, NH3, SO2). Particular interest goes to the inter-annual variation of the carbon fluxes and the carbon allocation patterns. The impact of the long-term (aggregated) and the short-term variability in both the meteorological drivers and in the main tropospheric pollutants on the carbon fluxes is examined, as well as their mutual interactive effects and their potential memory effect. The effect of variability in the drivers during the phenological phases (seasonality) on the inter-annual variability of the fluxes is also examined. Basic statistical techniques as well as spectral analyses and data mining techniques are being used.

Return of the giants: Restoring white pine ecosystems by breeding and aggressive planting of blister rust-resistant white pines

Treesearch

Lauren Fins; James Byler; Dennis Ferguson; Al Harvey; Mary Francis Mahalovich; Geral I. McDonald; Dan Miller; John Schwandt; Art Zack

2001-01-01

In 1883, when the Northern Pacific Railroad made its way through northern Idaho, western white pines dominated the moist, mid-elevation, mixed-species forests of the Inland Northwest between 2,000 and 6,000 feet. These majestic trees often lived to 350 years but could reach the ripe old ages of 400 and even 500 years. They were an integral part of the most productive...

Concluding remarks

Treesearch

Stephen F. Arno; Michael G. Harrington

1999-01-01

The 88-year photo sequences, descriptions of historical changes, and the initial results from ecosystembased management treatments at Lick Creek portray a dynamic, ever-changing forest. The goals of ecosystem- based management at Lick Creek are to continuously maintain an open forest containing old growth as well as younger age classes of ponderosa pine. Half a century...

Predicting the distribution of a novel bark beetle and its pine hosts under future climate conditions

Treesearch

Steven E. Smith; Ma.G. Mendoza; Gerardo Zuniga; Kandres Kalbrook; J.L. Hayes; D.N. Byrne

2013-01-01

Understanding the distribution of key biotic elements of forest ecosystems is essential in contemporary forest management and in planning to meet future management needs. Habitat distribution (niche) models based on known occurrences provide geographical structure for such management as the environmental factors change....

Forest Modeling of Jack Pine Trees for BOREAS

NASA Technical Reports Server (NTRS)

Moghhadam, Mahta; Saatchi, Sasan

1994-01-01

As a part of the intensive field campaign for the Boreal forest ecosystem-atmosphere research (BOREAS) project in August 1993, the NASA/JPL AIRSAR covered an area of about 100 km by 100 km near the Prince Albert National Park in Saskatchewan, Canada. At the same time, ground-truth measurements were made in several stands which have been selected as the primary study sites, as well as in some auxiliary sites. This paper focuses on an area including Jack Pine stands in the Nipawin area near the park.

Forest floor depth mediates understory vigor in xeric Pinus palustris ecosystems

Treesearch

J. Kevin Hiers; Joseph J. O' Brien; Rodney E. Will; Robert J. Mitchell

2007-01-01

Longleaf pine (Pinus palustris) woodlands and savannas are among the most frequently burned ecosystems in the world with fire return intervals of 1–10 years. This fire regime has maintained high levels of biodiversity in terms of both species richness and endemism. Land use changes have reduced the area of this ecosystem by .95%, and inadequate fire...

Decade-long bird community response to the spatial pattern of variable retention harvesting in red pine (Pinus resinosa) forests

Treesearch

Eddie L. Shea; Lisa A. Schulte; Brian J. Palik

2017-01-01

Structural complexity is widely recognized as an inherent characteristic of unmanaged forests critical to their function and resilience, but often reduced in their managed counterparts. Variable retention harvesting (VRH) has been proposed as a way to restore or enhance structural complexity in managed forests, and thereby sustain attendant biodiversity and ecosystem...

Fuel loadings in southwestern ecosystems of the United States

Treesearch

Stephen S. Sackett; Sally M Haase

1996-01-01

Natural forest fuel loadings cause extreme fire behavior during dry, windy weather experienced during most fire seasons in the Southwest. Fire severity is also exacerbated from burning heavy fuels, including heavy humus layers on the forest floor. Ponderosa pine and mixed conifer stands possess more than 21.7 and 44.1 tons per acre of total forest floor fuel,...

Postfire changes in forest carbon storage over a 300-year chronosequence of Pinus contorta-dominated forests

Treesearch

Daniel M. Kashian; William H. Romme; Daniel B. Tinker; Monica G. Turner; Michael G. Ryan

2013-01-01

A warming climate may increase the frequency and severity of stand-replacing wildfires, reducing carbon (C) storage in forest ecosystems. Understanding the variability of postfire C cycling on heterogeneous landscapes is critical for predicting changes in C storage with more frequent disturbance. We measured C pools and fluxes for 77 lodgepole pine (Pinus contorta...

Plant recruitment in a northern Arizona ponderosa pine forest: Testing seed- and leaf litter-limitation hypotheses (P-53)

Treesearch

Scott R. Abella

2008-01-01

Seed availability and leaf litter limit plant establishment in some ecosystems. To evaluate the hypothesis that these factors limit understory plant recruitment in Pinus ponderosa forests, I conducted a seeding and litter removal experiment at six thinned sites in the Fort Valley Experimental Forest, northern Arizona. Experimental seeding of four native species (...

Plant recruitment in a northern Arizona ponderosa pine forest: Testing seed- and leaf litter-limitation hypotheses

Treesearch

Scott R. Abella

2008-01-01

Seed availability and leaf litter limit plant establishment in some ecosystems. To evaluate the hypothesis that these factors limit understory plant recruitment in Pinus ponderosa forests, I conducted a seeding and litter removal experiment at six thinned sites in the Fort Valley Experimental Forest, northern Arizona. Experimental seeding of four native species (

Carbon storage in managed forests of the northern Great Lake States

Treesearch

Jeanette L. Rollinger; Terry F. Strong

1996-01-01

Carbon (C) storage in forest ecosystems is a significant part of the total terrestrial C pool, and may potentially be manipulated as an important C sink. The influence of management on C pools must be understood before guidelines can be suggested for maximizing C sequestration in forests. Studies of hardwood, red pine (Pinus resinosa Ait.), aspen and...

Cloud shading and fog drip influence the metabolism of a coastal pine ecosystem.

PubMed

Carbone, Mariah S; Park Williams, A; Ambrose, Anthony R; Boot, Claudia M; Bradley, Eliza S; Dawson, Todd E; Schaeffer, Sean M; Schimel, Joshua P; Still, Christopher J

2013-02-01

Assessing the ecological importance of clouds has substantial implications for our basic understanding of ecosystems and for predicting how they will respond to a changing climate. This study was conducted in a coastal Bishop pine forest ecosystem that experiences regular cycles of stratus cloud cover and inundation in summer. Our objective was to understand how these clouds impact ecosystem metabolism by contrasting two sites along a gradient of summer stratus cover. The site that was under cloud cover ~15% more of the summer daytime hours had lower air temperatures and evaporation rates, higher soil moisture content, and received more frequent fog drip inputs than the site with less cloud cover. These cloud-driven differences in environmental conditions translated into large differences in plant and microbial activity. Pine trees at the site with greater cloud cover exhibited less water stress in summer, larger basal area growth, and greater rates of sap velocity. The difference in basal area growth between the two sites was largely due to summer growth. Microbial metabolism was highly responsive to fog drip, illustrated by an observed ~3-fold increase in microbial biomass C with increasing summer fog drip. In addition, the site with more cloud cover had greater total soil respiration and a larger fractional contribution from heterotrophic sources. We conclude that clouds are important to the ecological functioning of these coastal forests, providing summer shading and cooling that relieve pine and microbial drought stress as well as regular moisture inputs that elevate plant and microbial metabolism. These findings are important for understanding how these and other seasonally dry coastal ecosystems will respond to predicted changes in stratus cover, rainfall, and temperature. © 2012 Blackwell Publishing Ltd.

Effects of tornado damage, prescribed fire, and salvage logging on natural oak (Quercus spp.) regeneration in a xeric southern USA Coastal Plain oak/pine forest

Treesearch

Jeffery B. Cannon; J. Stephen Brewer

2013-01-01

Due in large part to fire exclusion, many oak-dominated (Quercus spp.) forests, woodlands, and savannas throughout eastern North America are being replaced by less diverse forest ecosystems. In the interior coastal plain of the southern United States, these forests are dominated in the mid- and understory by mesophytic species such as Acer...

Extreme late-summer drought causes neutral annual carbon balance in southwestern ponderosa pine forests and grasslands

NASA Astrophysics Data System (ADS)

Kolb, Thomas; Dore, Sabina; Montes-Helu, Mario

2013-03-01

We assessed the impacts of extreme late-summer drought on carbon balance in a semi-arid forest region in Arizona. To understand drought impacts over extremes of forest cover, we measured net ecosystem production (NEP), gross primary production (GPP), and total ecosystem respiration (TER) with eddy covariance over five years (2006-10) at an undisturbed ponderosa pine (Pinus ponderosa) forest and at a former forest converted to grassland by intense burning. Drought shifted annual NEP from a weak source of carbon to the atmosphere to a neutral carbon balance at the burned site and from a carbon sink to neutral at the undisturbed site. Carbon fluxes were particularly sensitive to drought in August. Drought shifted August NEP at the undisturbed site from sink to source because the reduction of GPP (70%) exceeded the reduction of TER (35%). At the burned site drought shifted August NEP from weak source to neutral because the reduction of TER (40%) exceeded the reduction of GPP (20%). These results show that the lack of forest recovery after burning and the exposure of undisturbed forests to late-summer drought reduce carbon sink strength and illustrate the high vulnerability of forest carbon sink strength in the southwest US to predicted increases in intense burning and precipitation variability.

Frequent fire protects shortleaf pine (Pinus echinata) from introgression by loblolly pine (P. taeda).

Treesearch

John F Stewart; Rodney E Will; Kevin M Robertson; Dana Nelson

2014-01-01

Across much of the globe, fire is a major disturbance agent of forest and grassland communities. The removal of fire from previously fire-maintained ecosystems, which has occurred in many areas, changes species composition, favoring later less fire tolerant species over fire-adapted ones. A recent measured increase in the rate of hybridization between the fire-adapted...

Below-ground carbon input to soil is controlled by nutrient availability and fine root dynamics in loblolly pine

Treesearch

John S. King; Timothy J. Albaugh; H. Lee Allen; Boyd R. Strain; Phillip Dougherty

2002-01-01

Availability of growth limiting resources may alter root dynamics in forest ecosystems, possibly affecting the land-atmosphere exchange of carbon. This was evaluated for a commercially important southern timber species by installing a factorial experiment of fertilization and irrigation treatments in an 8-yr-old loblolly pine (Pinus taeda) plantation...

Growth of a 45-year-old ponderosa pine plantation: An Arizona case study (P-53)

Treesearch

Peter F. Ffolliott; Gerald J. Gottfried; Cody L. Stropki; L. J. Heidmann

2008-01-01

Information on the growth of forest plantations is necessary for planning of ecosystem-based management of the plantations. This information is also useful in validating or refining computer simulators that estimate plantation growth into the future. Such growth information has been obtained from a 45-year-old ponderosa pine (Pinus ponderosa) plantation in the Hart...

Fire Impacts on Mixed Pine-oak Forests Assessed with High Spatial Resolution Imagery, Imaging Spectroscopy, and LiDAR

NASA Astrophysics Data System (ADS)

Meng, R.; Wu, J.; Zhao, F. R.; Kathy, S. L.; Dennison, P. E.; Cook, B.; Hanavan, R. P.; Serbin, S.

2016-12-01

As a primary disturbance agent, fire significantly influences forest ecosystems, including the modification or resetting of vegetation composition and structure, which can then significantly impact landscape-scale plant function and carbon stocks. Most ecological processes associated with fire effects (e.g. tree damage, mortality, and vegetation recovery) display fine-scale, species specific responses but can also vary spatially within the boundary of the perturbation. For example, both oak and pine species are fire-adapted, but fire can still induce changes in composition, structure, and dominance in a mixed pine-oak forest, mainly because of their varying degrees of fire adaption. Evidence of post-fire shifts in dominance between oak and pine species has been documented in mixed pine-oak forests, but these processes have been poorly investigated in a spatially explicit manner. In addition, traditional field-based means of quantifying the response of partially damaged trees across space and time is logistically challenging. Here we show how combining high resolution satellite imagery (i.e. Worldview-2,WV-2) and airborne imaging spectroscopy and LiDAR (i.e. NASA Goddard's Lidar, Hyperspectral and Thermal airborne imager, G-LiHT) can be effectively used to remotely quantify spatial and temporal patterns of vegetation recovery following a top-killing fire that occurred in 2012 within mixed pine-oak forests in the Long Island Central Pine Barrens Region, New York. We explore the following questions: 1) what are the impacts of fire on species composition, dominance, plant health, and vertical structure; 2) what are the recovery trajectories of forest biomass, structure, and spectral properties for three years following the fire; and 3) to what extent can fire impacts be captured and characterized by multi-sensor remote sensing techniques from active and passive optical remote sensing.

Pyrene degradation in forest humus microcosms with or without pine and its mycorrhizal fungus.

PubMed

Koivula, Teija T; Salkinoja-Salonen, Mirja; Peltola, Rainer; Romantschuk, Martin

2004-01-01

The mineralization potential of forest humus and the self-cleaning potential of a boreal coniferous forest environment for polycyclic aromatic hydrocarbon (PAH) compounds was studied using a model ecosystem of acid forest humus (pH = 3.6) and pyrene as the model compound. The matrix was natural humus or humus mixed with oil-polluted soil in the presence and absence of Scots pine (Pinus sylvestris L.) and its mycorrhizal fungus (Paxillus involutus). The rates of pyrene mineralization in the microcosms with humus implants (without pine) were initially insignificant but increased from Day 64 onward to 47 microg kg(-1) d(-1) and further to 144 microg kg(-1) d(-1) after Day 105. In the pine-planted humus microcosms the rate of mineralization also increased, reaching 28 microg kg(-1) d(-1) after Day 105. The 14CO2 emission was already considerable in nonplanted microcosms containing oily soil at Day 21 and the pyrene mineralization continued throughout the study. The pyrene was converted to CO2 at rates of 0.07 and 0.6 microg kg(-1) d(-1) in the oily-soil implanted microcosms with and without pine, respectively. When the probable assimilation of 14CO2 by the pine and ground vegetation was taken into account the most efficient microcosm mineralized 20% of the 91.2 mg kg(-1) pyrene in 180 d. The presence of pine and its mycorrhizal fungus had no statistically significant effect on mineralization yields. The rates of pyrene mineralization observed in this study for forest humus exceeded the total annual deposition rate of PAHs in southern Finland. This indicates that accumulation in forest soil is not to be expected.

Heavy metals accumulation in wood tissues of the forest-forming species growed in the Steppe technogenic landscapes in Ukraine

NASA Astrophysics Data System (ADS)

Lovinska, Viktoriia; Wiche, Oliver

2016-04-01

Territory of Steppe in Ukraine is affected by significant anthropogenic impact caused with mining, metallurgical, chemicalplants and heat power stations. The priority pollutants of the region emissions of these enterprises are presented such heavy metals as Cd, Pb, Cu, Zn, Ni, Mn. The regional forest ecosystems can be considered as potential concentrators of pollutants borned with different technogenic impact. It is necessary to study an ability of forests wood to accumulate heavy metals because accumulated toxins are eliminated from biogeochemical cycle in forest ecosystem for a long time. This study goal is to determine the accumulation properties of forest-forming species - Pinus sylvestris (Scots pine) and Robinia pseudoacacia (black locust) difference age group in relation to heavy metals. It was considerable also to assess the heavy metal distribution in the wood tissue of referred species.Heavy metals content were determined with atomic absorption spectrophotometer using. Scots pine and black locust are the main forest-forming species of natural and artificial forests within Northern Steppe.They can be seen as transformers of the heavy metals cycle and selective concentrators of toxic elements, under the conditions of their excessive concentrations in the environment.It was established that wood tissue of Scots pine and black locust accumulated cadmium in high concentrations according to the age in both species. Indexes of zinc accumulation in the wood of Scots pine exceeded the maximal value in the wood tissue of black locust. The results of our research demonstrated antagonistic interaction of cadmium and zinc. The highest copper concentrations was found for the trees at the age of 45 years. Lead has been identified in wood sample of all ages. Accumulation maximum was fixed in the oldest samples. The trend of concentration increasing of metal didn't find for both species. As for nickel there was established the opposite tendention for both studied species. Nickel maximum accumulation in black locust was fixed for the youngest copies. The same tendency was observed for Scots pine in copies of 45 years old. We did not see relation with age for mangan content in both studied species. The absolute value of the amount of mangan for Scots pine is much higher comparatevelly to black locust.

Trial by fire: Restoration of Middle Rio Grande upland ecosystems

Treesearch

Samuel R. Loftin

1999-01-01

The majority of upland ecosystems (desert scrub, grassland, pinyon-juniper, ponderosa pine and higher elevation conifer forests) in the Middle Rio Grande Basin were historically dependent on periodic fire to maintain their composition, productivity, and distribution. The cultural practices of European man have altered the function, structure, and composition of...

Close Encounters with Deadly Dangers: Riveting Reads and Classroom Ideas.

ERIC Educational Resources Information Center

Haven, Kendall

This book presents 15 tales that bring the animal world into the classroom. The stories in this book are divided into two sections: stories from aquatic ecosystems (both fresh- and saltwater systems), and from terrestrial systems, including desert, meadow, woodland, mountain, Arctic tundra, savanna, pine forest, and jungle ecosystems. All predator…

Influence of forest disturbance on stable nitrogen isotope ratios in soil and vegetation profiles

Treesearch

Jennifer D. Knoepp; Scott R. Taylor; Lindsay R. Boring; Chelcy F. Miniat

2015-01-01

Soil and plant stable nitrogen isotope ratios (15 N) are influenced by atmospheric nitrogen (N) inputs and processes that regulate organic matter (OM) transformation and N cycling. The resulting 15N patterns may be useful for discerning ecosystem differences in N cycling. We studied two ecosystems; longleaf pine wiregrass (...

Associations between regional moisture gradient, tree species dominance, and downed wood abundance

NASA Astrophysics Data System (ADS)

Johnson, A. C.; Mills, J.

2007-12-01

Downed wood functions as a source of nurse logs, physical structure in streams, food, and carbon. Because downed wood is important in upland and aquatic habitats, an understanding of wood recruitment along a continuum from wet to dry landscapes is critical for both preservation of biodiversity and restoration of natural ecosystem structure and function. We assessed downed wood in public and private forests of Washington and Oregon by using a subset of the Forest Inventory and Analysis (FIA) database including 15,842 sampled conditions. Multivariate regression trees, ANOVA, and t-tests were used to discern environmental conditions most closely associated with abundance of woody debris. Of the 16 parameters included in the analysis, rainfall, forest ownership, number of damaged standing trees, and forest elevation were most indicative of woody debris abundance. The Hemlock/spruce Group, including hemlock, spruce, cedar, and white pine, most associated with wetter soils, had significantly more downed wood than 12 other forest groups. The Ponderosa Pine Group, indicative of drier sites with higher fire frequencies, included ponderosa pine, sugar pine, and incense cedar, and had significantly less downed wood volume. Overall, the amount of woody debris in either the Spruce/hemlock Group or the Ponderosa Pine Group did not change significantly as tree age increased from 5 to 350 years. Plots within the Hemlock/spruce with greater standing tree volume also had significantly greater downed wood volume. In contrast, greater downed wood volume was not associated with greater standing tree volume in the Ponderosa Pine Group. Knowledge of linkages among environmental variables and stand characteristics are useful in development of regional forest models aimed at understanding the effects of climate change and disturbance on forest succession.

Testing DRAINMOD-FOREST for predicting evapotranspiration in a mid-rotation pine plantation

Treesearch

Shiying Tian; Mohamed A. Youssef; Ge Sun; George M. Chescheir; Asko Noormets; Devendra M. Amatya; R. Wayne Skaggs; John S. King; Steve McNulty; Michael Gavazzi; Guofang Miao; Jean-Christophe Domec

2015-01-01

Evapotranspiration (ET) is a key component of the hydrologic cycle in terrestrial ecosystems and accurate description of ET processes is essential for developing reliable ecohydrological models. This study investigated the accuracy of ET prediction by the DRAINMOD-FOREST after its calibration/validation for predicting commonly measured hydrological variables. The model...

Sustainability and productivity of southern pine ecosystems

Treesearch

Jim Barnett; Rod Busby; Floyd Bridgwater; Don English; Jim Hanula; Nancy Herbert; Kurt Johnsen; Brad Kard; Kier Klepzig; Charlie McMahon; Jeff Prestemon; Tim Rials; Bob Rummer; Mike Shelton; Ron Thill; Tom Waldrop; Joan Walker; Nancy Walters

2000-01-01

Scientist at the Southern Research Station (SRS) have developed a means to address critical forest resource needs in the 21st century. Throughout the South, we are working with public and private land owners to face unprecedented natural resource challenges (United States Department of Agriculture, forest Service 1997). By providing access to research results and...

The role of silviculture in ecosystem management: a practice in transition

Treesearch

Russell T. Graham; Jonalea R. Tonn; Theresa B. Jain; David L. Adams

1994-01-01

The cedar (Thuja plicata) -hemlock (Tsuga heterophylla) -white pine (Pinus monticola) forests are some of the most productive in North America. Silvicultural practices used in these forests originated in Europe and usually concentrated on producing high-value commercial products.Beginning in the 1960s society's interest in the management of...

Fate of Hexazinone and Picloram in Southern United States Forest Watersheds

Treesearch

D.G. Neary; P.B. Bush; J.L. Michael

1986-01-01

Herbicides are being used more frequently in the intensively managed forest ecosystems of the southeastern United States. Host of this increased use occurs during site preparation prior to replanting cutover or converted stands. Herbicides provide a cost effective tool for controlling herbaceous and woody weed competition which adversely affects pine establishment and...

Influencing factors on vegetative cogongrass spread into pine forests on the Mississippi gulf coast

Treesearch

Jon D. Prevost; Donald L. Grebner; Jeanne C. Jones; Stephen C. Grado; Keith L. Belli; John D. Byrd

2010-01-01

Cogongrass [Imperata cylindrical (L.) Beauv.] is an invasive species that is spreading throughout forested ecosystems across the Southeastern United States. A field experiment was conducted in Hancock County, MS to determine if mid-rotation mechanical disturbance increased the rate of growth and spread of roadside cogongrass patches into adjacent...

Fate of Hexazinone and Picloram in Southern Forest Watersheds

Treesearch

Daniel G. Neary; Parshall B. Bush; Jerry L. Michael

1987-01-01

Herbicides are being used more frequently in the intensively managed forest ecosystems of the southeastern United States. Most of this increased use occurs during site preparation prior to replanting cutover or converted stands. Herbicides provide a cost-effective tool for controlling herbaceous and weed cunpetition which adversely affects pine establishnent and early...

Poultry litter application to loblolly pine forests: growth and nutrient containment

Treesearch

Alexander L. Friend; Scott D. Roberts; Stephen H. Schoenholtz; Juanita A. Mobley; Patrick D. Gerard

2006-01-01

Forestland application of poultry manure offers an alternative to the conventional practice of pastureland application. Before such a practice is considered viable, however, it must be demonstrated that the forest ecosystem is capable of absorbing the nutrients contained in poultry manure, especially nitrogen (N) and phosphorus (P). From the forestry perspective, it...

Post-wildfire effects on carbon and water vapour dynamics in a Spanish black pine forest.

PubMed

Dadi, T; Rubio, E; Martínez-García, E; López-Serrano, F R; Andrés-Abellán, M; García-Morote, F A; De las Heras, J

2015-04-01

Two eddy covariance systems were installed in a high-severity burned zone (BZ) and an adjacent unburned (UNB) zone to monitor water vapour and carbon dioxide fluxes for 21 months (from June 2011 to February 2013) at a Spanish black pine forest affected by a stand-replacing wildfire and located in a mountainous area of central-eastern Spain. The differences between both sites were significant especially during the growing season, affecting gross primary productivity (GPP) more than ecosystem respiration (Reco). Net ecosystem exchange (NEE) for 2012 was -3.97 and 1.80 t C ha(-1) year(-1) for the unburned and burned sites, respectively, the GPP being 64% lower for the BZ than the UNB zone. Evapotranspiration (ET) at the UNB was 18% greater than at the BZ. Difference between sites was 160 mm during the whole studied period. This study reflects the effect of one of the major disturbances that can affect Mediterranean ecosystems, showing that carbon fluxes are more dramatically concerned than water vapour fluxes.

Fires of differing intensities rapidly select distinct soil fungal communities in a Northwest US ponderosa pine forest ecosystem

Treesearch

C. Reazin; S. Morris; Jane Smith; A.D. Cowan; A. Jumpponen

2016-01-01

Environmental change and long-term fire management in the western United States have created conditions that facilitate high-intensity burn areas in forested systems. Such burns may have dramatic effects on the soil microbial communities. In this study, we utilized experimental infrastructure in the Pringle Falls Experimental Forest in Oregon, where ten pairs of sites...

Fire exclusion as a disturbance in the temperate forests of the USA: examples from longleaf pine forests

Treesearch

W. Keith Moser; Dale D. Wade

2005-01-01

Forest fires are a disturbance where the effects can range from benign to extreme devastation within a given ecosystem. The stage of stand development coupled with prior management dictates the amount and composition of potential fuels. Thus, fire policy exerts a strong influence on fire effects. Changes in cultural acceptance and use of tire typically drive fire...

Estimating Chemical Exchange between Atmospheric Deposition and Forest Canopy in Guizhou, China.

PubMed

Li, Wei; Gao, Fang; Liao, Xueqin

2013-01-01

To evaluate the effects of atmospheric deposition on forest ecosystems, wet-only precipitation and throughfall samples were collected in two forest types (Masson pine [ Lamb.] forests and mixed conifer and broadleaf forests) in the Longli forest in the Guizhou province of southwestern China for a period of 21 successive months from April 2007 to December 2008. The pH and chemical components of precipitation and throughfall were analyzed. In addition, the canopy budget model was applied to distinguish between in-canopy and atmospheric sources of chemical compounds. Canopy leaching and total potentially acidifying deposition fluxes were calculated. The results showed that the average pH and the concentration of ions in throughfall were higher than those in precipitation, with the exception of the NH concentration. Dry deposition of S and N accumulated more in Masson pine forests than in mixed conifer and broadleaf forests. Canopy leaching was the most significant source of base cations in forest throughfall, which was higher in the mixed forests than in the coniferous forests. Anions in throughfall deposition in Masson pine forests exceeded those in the mixed forests. Higher total potentially acidifying deposition fluxes reflected the more effective amounts of acid delivered to Masson pine forests compared with mixed conifer and broadleaf forests. In addition, acid deposition induced the leaching and loss of nutrient ions such as Mg, K, and Ca. Although the trees of the studied areas have not shown any symptoms of cation loss, a potentially harmful influence was engendered by atmospheric deposition in the two forest types in the Longli area. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.

Indiana bats, northern long-eared bats, and prescribed fire in the Appalachians: challenges and considerations.

Treesearch

Susan Loeb; Joy O' Keefe

2014-01-01

The Indiana bat (Myotis sodalist) is an endangered species and the northern long-eared bat (M. septentrionalis) has been proposed for listing as endangered. Both species are found throughout the Appalachians, and they commonly inhabit fire-dependent ecosystems such as pine and pine-oak forests. Due to their legal status, prescribed burns in areas where these species...

Site preparation burning to improve southern Appalachian pine-hardwood stands: vegetation composition and diversity of 13-year-old stands

Treesearch

Barton D. Clinton; J.M. Vose; W.T. Swank

1993-01-01

Stand restoration of low-quality, mixed pine-hardwood ecosystems containing a Kalmia Zatifolia L. dominated understory, through cutting, burning, and planting of Pinus strobus L., is common on xeric southern Appalachian forest sites. We examined the effects of this treatment on early vegetation composition and diversity. Four 13-year-old stands were examined. Two of...

Age and size comparisons of regenerating shortleaf pine seedlings burned multiple times in ecosysten restoration areas

Treesearch

David C. Clabo; Jim Guldin; Wayne K. Clatterbuck

2016-01-01

Shortleaf pine (Pinus echinata Mill.) ecosystem restoration has been a major management goal in the Ouachita National Forest since the early to mid-1990s. Restoration efforts have focused on periodic prescribed burning and thinning operations to restore disturbance dependent vegetation communities suitable for the recovery of the endangered red-...

Influence of residual basal area on longleaf pine (Pinus palustris Mill.) first year germination and establishment under selection silviculture

Treesearch

Ferhat Kara; Edward F. Loewenstein

2015-01-01

Even-aged silvicultural methods have been successfully used to manage longleaf pine (Pinus palustris Mill.) forests for wood production; however, successful use of uneven-aged methods to manage this ecosystem is less well documented. In this study, the effects of varying levels of residual basal area (RBA) (9.2, 13.8, and 18.4 m2...

The role of harvest residue in rotation cycle carbon balance in loblolly pine plantations

Treesearch

Asko Noormets; Steve G. Mcnulty; Jean-Christophe Domec; Michael Gavazzi; Ge Sun; John S. King

2012-01-01

Timber harvests remove a significant portion of ecosystem carbon. While some of the wood products moved off-site may last past the harvest cycle of the particular forest crop, the effect of the episodic disturbances on long-term on-site carbon sequestration is unclear. The current study presents a 25 year carbon budget estimate for a typical commercial loblolly pine...

Simulated impacts of mountain pine beetle and wildfire disturbances on forest vegetation composition and carbon stocks in the Southern Rocky Mountains

USGS Publications Warehouse

Caldwell, Megan K.; Hawbaker, Todd J.; Briggs, Jenny S.; Cigan, P.W.; Stitt, Susan

2013-01-01

Forests play an important role in sequestering carbon and offsetting anthropogenic greenhouse gas emissions, but changing disturbance regimes may compromise the capability of forests to store carbon. In the Southern Rocky Mountains, a recent outbreak of mountain pine beetle (Dendroctonus ponderosae; MPB) has caused levels of tree mortality that are unprecedented in recorded history. To evaluate the long-term impacts of both this insect outbreak and another characteristic disturbance in these forests, high-severity wildfire, we simulated potential changes in species composition and carbon stocks using the Forest Vegetation Simulator (FVS). Simulations were completed for 3 scenarios (no disturbance, actual MPB infestation, and modeled wildfire) using field data collected in 2010 at 97 plots in the lodgepole pine-dominated forests of eastern Grand County, Colorado, which were heavily impacted by MPB after 2002. Results of the simulations showed that (1) lodgepole pine remained dominant over time in all scenarios, with basal area recovering to pre-disturbance levels 70–80 yr after disturbance; (2) wildfire caused a greater magnitude of change than did MPB in both patterns of succession and distribution of carbon among biomass pools; (3) levels of standing-live carbon returned to pre-disturbance conditions after 40 vs. 50 yr following MPB vs. wildfire disturbance, respectively, but took 120 vs. 150 yr to converge with conditions in the undisturbed scenario. Lodgepole pine forests appear to be relatively resilient to both of the disturbances we modeled, although changes in climate, future disturbance regimes, and other factors may significantly affect future rates of regeneration and ecosystem response.

Significant Threat to North American forests from Southern Pine Beetle with Warming Winters

NASA Astrophysics Data System (ADS)

Horton, R. M.; Lesk, C.; Coffel, E.; D'Amato, A. W.

2016-12-01

In coming decades, warmer winters are likely to lift range constraints on many cold-limited forest insects. Recent unprecedented expansion of the southern pine beetle (SPB, Dendroctonus frontalis) into New Jersey, New York, Connecticut, and Massachusetts in concert with warming annual temperature minima highlights the risk that this insect pest poses to the pine forests of the northern United States and Canada under continued climate change. Here we present the first projections of northward expansion in SPB-suitable climates using a statistical bioclimatic range modeling approach and current-generation general circulation model (GCM) output under the RCP 4.5 and 8.5 emissions scenarios. Our results show that by the middle of the 21st century, the climate is likely to be suitable for SPB expansion into vast areas of previously unaffected forests throughout the northeastern United States and into southeastern Canada. This scenario would pose a significant economic and ecological risk to the affected regions, including disruption of local ecosystem services, dramatic shifts in forest structure, and threats to native biodiversity.

Soils of Mountainous Forests and Their Transformation under the Impact of Fires in Baikal Region

NASA Astrophysics Data System (ADS)

Krasnoshchekov, Yu. N.

2018-04-01

Data on postpyrogenic dynamics of soils under mountainous taiga cedar ( Pinus sibirica) and pine ( Pinus sylvestris) forests and subtaiga-forest-steppe pine ( Pinus sylvestris) forests in the Baikal region are analyzed. Ground litter-humus fires predominating in this region transform the upper diagnostic organic soil horizons and lead to the formation of new pyrogenic organic horizons (Opir). Adverse effects of ground fires on the stock, fractional composition, and water-physical properties of forest litters are shown. Some quantitative parameters of the liquid and solid surface runoff in burnt areas related to the slope gradient, fire intensity, and the time passed after the fire are presented. Pyrogenic destruction of forest ecosystems inevitably induces the degradation of mountainous soils, whose restoration after fires takes tens of years. The products of soil erosion from the burnt out areas complicate the current situation with the pollution of coastal waters of Lake Baikal.

The vertebrate fauna of Ichauway, Baker County, GA

USGS Publications Warehouse

Smith, L.L.; Steen, D.A.; Stober, J.M.; Freeman, Mary C.; Golladay, S.W.; Conner, L.M.; Cochrane, J.

2006-01-01

Less than 4% of the once extensive Pinus palustris (longleaf pine) ecosystem remains today. Although longleaf pine habitats are recognized for their high species diversity, few published accounts document the vertebrate faunas of remaining tracts. Here we report on the vertebrate species richness of lchauway, an 11,300-ha property in Baker County, GA. The property includes ca. 7300 ha of longleaf pine with native ground cover, along with more than 30 seasonal wetlands and ca. 45 km of riparian habitat associated with Ichawaynochaway Creek, Big Cypress Creek, and the Flint River. The fauna includes 61 species of fish, 31 amphibians, 53 reptiles, 191 birds, and 41 mammals. Despite the relative isolation of the property from other natural ecosystems, the vertebrate fauna of lchauway is remarkably diverse and may offer an example of reference conditions to guide restoration of longleaf pine forests, associated seasonal wetlands, and riparian areas elsewhere in the southeastern U S.

Fungal and bacterial community succession differs for three wood types during decay in a forest soil.

PubMed

Prewitt, Lynn; Kang, Youngmin; Kakumanu, Madhavi L; Williams, Mark

2014-08-01

Wood decomposition by soil microorganisms is vital to carbon and nutrient cycles of forested ecosystems. Different wood types decompose at different rates; however, it is not known if there are differences in microbial community succession associated with the decay of different wood types. In this study, the microbial community associated with the decay of pine (decay-susceptible wood), western red cedar (decay resistant) and ACQ-treated pine (Ammoniacal Copper Quaternary, preservative-treated pine for decay resistance) in forest soil was characterized using DNA sequencing, phospholipid fatty acid (PLFA) analysis, and microbial activity over a 26-month period. Bray-Curtis ordination using an internal transcribed spacer (ITS) sequence and PLFA data indicated that fungal communities changed during succession and that wood type altered the pattern of succession. Nondecay fungi decreased over the 26 months of succession; however, by 18 months of decay, there was a major shift in the fungal communities. By this time, Trametes elegans dominated cedar and Phlebia radiata dominated pine and ACQ-treated pine. The description of PLFA associated with ACQ-treated pine resembled cedar more than pine; however, both PLFA and ITS descriptions indicated that fungal communities associated with ACQ-treated pine were less dynamic, perhaps a result of the inhibition by the ACQ preservative, compared with pine and cedar. Overall, fungal community composition and succession were associated with wood type. Further research into the differences in community composition will help to discern their functional importance to wood decay.

Constraining Night Time Ecosystem Respiration by Inverse Approaches

NASA Astrophysics Data System (ADS)

Juang, J.; Stoy, P. C.; Siqueira, M. B.; Katul, G. G.

2004-12-01

Estimating nighttime ecosystem respiration remains a key challenge in quantifying ecosystem carbon budgets. Currently, nighttime eddy-covariance (EC) flux measurements are plagued by uncertainties often attributed to poor mixing within the canopy volume, non-turbulent transport of CO2 into and out of the canopy, and non-stationarity and intermittency. Here, we explore the use of second-order closure models to estimate nighttime ecosystem respiration by mathematically linking sources of CO2 to mean concentration profiles via the continuity and the CO2 flux budget equation modified to include thermal stratification. By forcing this model to match, in a root-mean squared sense, the nighttime measured mean CO2 concentration profiles within the canopy the above ground CO2 production and forest floor respiration can be estimated via multi-dimensional optimization techniques. We show that in a maturing pine and a mature hardwood forest, these optimized CO2 sources are (1) consistently larger than the eddy covariance flux measurements above the canopy, and (2) agree well with chamber-based measurements. We also show that by linking the optimized nighttime ecosystem respiration to temperature measurements, the estimated annual ecosystem respiration from this approach agrees well with biometric estimates, at least when compared to eddy-covariance methods conditioned on a friction velocity threshold. The difference between the annual ecosystem respiration obtained by this optimization method and the friction-velocity thresholded night-time EC fluxes can be as large as 700 g C m-2 (in 2003) for the maturing pine forest, which is about 40% of the ecosystem respiration. For 2001 and 2002, the annual ecosystem respiration differences between the EC-based and the proposed approach were on the order of 300 to 400 g C m-2.

Simulating Carbon cycle and phenology in complex forests using a multi-layer process based ecosystem model; evaluation and use of 3D-CMCC-Forest Ecosystem Model in a deciduous and an evergreen neighboring forests, within the area of Brasschaat (Be)

NASA Astrophysics Data System (ADS)

Marconi, S.; Collalti, A.; Santini, M.; Valentini, R.

2013-12-01

3D-CMCC-Forest Ecosystem Model is a process based model formerly developed for complex forest ecosystems to estimate growth, water and carbon cycles, phenology and competition processes on a daily/monthly time scale. The Model integrates some characteristics of the functional-structural tree models with the robustness of the light use efficiency approach. It treats different heights, ages and species as discrete classes, in competition for light (vertical structure) and space (horizontal structure). The present work evaluates the results of the recently developed daily version of 3D-CMCC-FEM for two neighboring different even aged and mono specific study cases. The former is a heterogeneous Pedunculate oak forest (Quercus robur L. ), the latter a more homogeneous Scot pine forest (Pinus sylvestris L.). The multi-layer approach has been evaluated against a series of simplified versions to determine whether the improved model complexity in canopy structure definition increases its predictive ability. Results show that a more complex structure (three height layers) should be preferable to simulate heterogeneous scenarios (Pedunculate oak stand), where heights distribution within the canopy justify the distinction in dominant, dominated and sub-dominated layers. On the contrary, it seems that using a multi-layer approach for more homogeneous stands (Scot pine stand) may be disadvantageous. Forcing the structure of an homogeneous stand to a multi-layer approach may in fact increase sources of uncertainty. On the other hand forcing complex forests to a mono layer simplified model, may cause an increase in mortality and a reduction in average DBH and Height. Compared with measured CO2 flux data, model results show good ability in estimating carbon sequestration trends, on both a monthly/seasonal and daily time scales. Moreover the model simulates quite well leaf phenology and the combined effects of the two different forest stands on CO2 fluxes.

Recovery of ponderosa pine ecosystem carbon and water fluxes from thinning and stand-replacing fire.

PubMed

Dore, Sabina; Montes-Helu, Mario; Hart, Stephen C; Hungate, Bruce A; Koch, George W; Moon, John B; Finkral, Alex J; Kolb, Thomas E

2012-10-01

Carbon uptake by forests is a major sink in the global carbon cycle, helping buffer the rising concentration of CO 2 in the atmosphere, yet the potential for future carbon uptake by forests is uncertain. Climate warming and drought can reduce forest carbon uptake by reducing photosynthesis, increasing respiration, and by increasing the frequency and intensity of wildfires, leading to large releases of stored carbon. Five years of eddy covariance measurements in a ponderosa pine (Pinus ponderosa)-dominated ecosystem in northern Arizona showed that an intense wildfire that converted forest into sparse grassland shifted site carbon balance from sink to source for at least 15 years after burning. In contrast, recovery of carbon sink strength after thinning, a management practice used to reduce the likelihood of intense wildfires, was rapid. Comparisons between an undisturbed-control site and an experimentally thinned site showed that thinning reduced carbon sink strength only for the first two posttreatment years. In the third and fourth posttreatment years, annual carbon sink strength of the thinned site was higher than the undisturbed site because thinning reduced aridity and drought limitation to carbon uptake. As a result, annual maximum gross primary production occurred when temperature was 3 °C higher at the thinned site compared with the undisturbed site. The severe fire consistently reduced annual evapotranspiration (range of 12-30%), whereas effects of thinning were smaller and transient, and could not be detected in the fourth year after thinning. Our results show large and persistent effects of intense fire and minor and short-lived effects of thinning on southwestern ponderosa pine ecosystem carbon and water exchanges. © 2012 Blackwell Publishing Ltd.

Impacts of insect disturbance on the structure, composition, and functioning of oak-pine forests

NASA Astrophysics Data System (ADS)

Medvigy, D.; Schafer, K. V.; Clark, K. L.

2011-12-01

Episodic disturbance is an essential feature of terrestrial ecosystems, and strongly modulates their structure, composition, and functioning. However, dynamic global vegetation models that are commonly used to make ecosystem and terrestrial carbon budget predictions rarely have an explicit representation of disturbance. One reason why disturbance is seldom included is that disturbance tends to operate on spatial scales that are much smaller than typical model resolutions. In response to this problem, the Ecosystem Demography model 2 (ED2) was developed as a way of tracking the fine-scale heterogeneity arising from disturbances. In this study, we used ED2 to simulate an oak-pine forest that experiences episodic defoliation by gypsy moth (Lymantria dispar L). The model was carefully calibrated against site-level data, and then used to simulate changes in ecosystem composition, structure, and functioning on century time scales. Compared to simulations that include gypsy moth defoliation, we show that simulations that ignore defoliation events lead to much larger ecosystem carbon stores and a larger fraction of deciduous trees relative to evergreen trees. Furthermore, we find that it is essential to preserve the fine-scale nature of the disturbance. Attempts to "smooth out" the defoliation event over an entire grid cells led to large biases in ecosystem structure and functioning.

Post-fire ecosystem recovery trajectories along burn severity gradients

NASA Astrophysics Data System (ADS)

Newingham, B. A.; Hudak, A. T.; Bright, B. C.; Smith, A. G.; Henareh Khalyani, A.

2017-12-01

Burn severity is a term used to describe the longer-term, second-order effects of fire on ecosystems. Plant communities are assumed to recover more slowly at higher burn severities; however, this likely depends on plant community type and climate. We assessed vegetation recovery approximately a decade post-fire across North American forests (moist mixed conifer, dry mixed conifer, ponderosa pine) and shrublands (mountain big sagebrush and Wyoming big sagebrush) distributed across climate and burn severity gradients. We assessed vegetation recovery across these ecosystems as indicated by the differenced Normalized Burn Ratio derived from 1984-2016 Landsat time series imagery (LandTrendr). Additionally, we used field vegetation measurements to examine local topographic controls on burn severity and post-fire vegetation recovery. Ecosystem responses were related to climate predictors derived from downscaled 1993-2011 climate normals. We hypothesized that drier and hotter ecosystems would take longer to recover. We also predicted areas with higher burn severity to have slower recovery. We found post-fire recovery to be strongly predicted by precipitation with the slowest recovery in shrublands and ponderosa pine forest, the driest vegetation types considered. We conclude that climate and burn severity interact to determine ecosystem recovery trajectories after fire, with burn severity having larger influence in the short term, and climate having larger influence in the long term.

Fire history of a western Montana ponderosa pine grassland: A pilot study

Treesearch

Don V. Gayton; Marc H. Weber; Mick Harrington; Emily K. Heyerdahl; Elaine K. Sutherland; Bob Brett; Cindy Hall; Micahel Hartman; Liesl Peterson; Carolynne Merrel

2006-01-01

A primary goal in the management of forests and grasslands is to maintain community structure and disturbance processes within their historical range of variation. If, within a managed ecosystem, either is found to lie outside that range, restoration may be necessary. Both maintenance and restoration are currently guided by the principles of ecosystem management, which...

Tree harvest in an experimental sand ecosystem: plant effects on nutrient dynamics and solute generation.

Treesearch

C. K. Keller; R. O' Brien; J. R. Havig; J. L. Smith; B. T. Bormann; D. Wang

2006-01-01

The hydrochemical signatures of forested ecosystems are known to be determined by a time-variant combination of physical-hydrologic, geochemical, and biologic processes. We studied subsurface potassium (K), calcium (Ca), and nitrate (NO3) in an experimental red-pine mesocosm to determine how trees affect the behavior of these nutrients in soil...

Carbonyl sulfide exchange in a temperate loblolly pine forest grown under ambient and elevated CO2

NASA Astrophysics Data System (ADS)

White, M. L.; Zhou, Y.; Russo, R. S.; Mao, H.; Talbot, R.; Varner, R. K.; Sive, B. C.

2009-08-01

Vegetation, soil and ecosystem level carbonyl sulfide (COS) exchange was observed at Duke Forest, a temperate loblolly pine forest, grown under ambient (Ring 1, R1) and elevated (Ring 2, R2) carbon dioxide (CO2). During calm meteorological conditions, ambient COS mixing ratios at the top of the forest canopy followed a distinct diurnal pattern in both CO2 growth regimes, with maximum COS mixing ratios during the day (R1=380±4 pptv and R2=373±3 pptv, daytime mean ±standard error) and minimums at night (R1=340±6 pptv and R2=346±5 pptv, nighttime mean ±standard error) reflecting a significant nighttime sink. Nocturnal vegetative uptake (-11 to -21 pmol m-2 s-1, negative values indicate uptake from the atmosphere) dominated nighttime net ecosystem COS flux estimates (-10 to -30 pmol m-2 s-1) in both CO2 regimes. In comparison, soil uptake (-0.8 to -1.7 pmol m-2 s-1) was a minor component of net ecosystem COS flux. In both CO2 regimes, loblolly pine trees exhibited substantial COS consumption overnight (50% of daytime rates) that was independent of CO2 assimilation. This suggests current estimates of the global vegetative COS sink, which assume that COS and CO2 are consumed simultaneously, may need to be reevaluated. Ambient COS mixing ratios, species specific diurnal patterns of stomatal conductance, temperature and canopy position were the major factors influencing the vegetative COS flux at the branch level. While variability in branch level vegetative COS consumption measurements in ambient and enhanced CO2 environments could not be attributed to CO2 enrichment effects, estimates of net ecosystem COS flux based on ambient canopy mixing ratio measurements suggest less nighttime uptake of COS in R2, the CO2 enriched environment.

Carbonyl sulfide exchange in a temperate loblolly pine forest grown under ambient and elevated CO2

NASA Astrophysics Data System (ADS)

White, M. L.; Zhou, Y.; Russo, R. S.; Mao, H.; Talbot, R.; Varner, R. K.; Sive, B. C.

2010-01-01

Vegetation, soil and ecosystem level carbonyl sulfide (COS) exchange was observed at Duke Forest, a temperate loblolly pine forest, grown under ambient (Ring 1, R1) and elevated (Ring 2, R2) CO2. During calm meteorological conditions, ambient COS mixing ratios at the top of the forest canopy followed a distinct diurnal pattern in both CO2 growth regimes, with maximum COS mixing ratios during the day (R1=380±4 pptv and R2=373±3 pptv, daytime mean ± standard error) and minimums at night (R1=340±6 pptv and R2=346±5 pptv, nighttime mean ± standard error) reflecting a significant nighttime sink. Nocturnal vegetative uptake (-11 to -21 pmol m-2s-1, negative values indicate uptake from the atmosphere) dominated nighttime net ecosystem COS flux estimates (-10 to -30 pmol m-2s-1) in both CO2 regimes. In comparison, soil uptake (-0.8 to -1.7 pmol m-2 s-1) was a minor component of net ecosystem COS flux. In both CO2 regimes, loblolly pine trees exhibited substantial COS consumption overnight (50% of daytime rates) that was independent of CO2 assimilation. This suggests current estimates of the global vegetative COS sink, which assume that COS and CO2 are consumed simultaneously, may need to be reevaluated. Ambient COS mixing ratios, species specific diurnal patterns of stomatal conductance, temperature and canopy position were the major factors influencing the vegetative COS flux at the branch level. While variability in branch level vegetative COS consumption measurements in ambient and enhanced CO2 environments could not be attributed to CO2 enrichment effects, estimates of net ecosystem COS flux based on ambient canopy mixing ratio measurements suggest less nighttime uptake of COS in R2, the CO2 enriched environment.

Spatial Distribution of Overstory Retention Influences Resources and Growth of Longleaf Pine Seedlings

Treesearch

Brian Palik; Robert J. Mitchell; Stephen Pecot; Mike Battaglia; Mou Pu

2003-01-01

Increasingly, overstory retention is being used in forests traditionally managed for single-cohort structure. One rationale for retention is that residual stand structure better resembles the complex structure of forests after natural disturbance, helping to perpetuate ecosystem fuctions dependent on that structure. The benefits of retention come at the cost of reduced...

Using spatially variable overstory retention to restore structural and compositional complexity in pine ecosystems

Treesearch

Brian J. Palik; Christel C. Kern; Robert Mitchell; Stephen Pecot

2005-01-01

Increasingly, forest managers incorporate overstory retention into silvicultural prescriptions for forests traditionally managed for single-cohort structure. The ecological benefits of retention may come at the cost of reduced growth of tree regeneration because of competition with residual trees. An important question in retention research, and its application, is how...

Density and abundance of black-backed woodpeckers in a Ponderosa pine ecosystem

Treesearch

Sean R. Mohren; Mark A. Rumble; Stanley H. Anderson

2014-01-01

Black-backed woodpeckers (Picoides arcticus) are usually associated with forest disturbance resulting in recently killed trees. While black-backed woodpeckers are attracted to areas affected by these disturbances, in the Black Hills they exist during interim disturbance periods in largely undisturbed forests. In 2012, a petition for listing black-backed woodpeckers in...

Seasonality and abundance of truffles from oak woodlands to red fir forests

Treesearch

Malcolm P. North

2002-01-01

Truffles are an important food source for many small mammals in forest ecosystems; however, we know little about the seasonality, abundance, or diversity of the truffle community in the Sierra Nevada. This study examined how truffle abundance and diversity varied between oak woodland, ponderosa pine (Pinus ponderosa), mixed-conifer, and red fir (

Understory plant response to site preparation and fertilization of loblolly and shortleaf pine forests

Treesearch

Dale G. Brockway; Gale L. Wolters; H.A. Pearson; Ronald E. Thill; V. Clark Baldwin; A. Martin

1998-01-01

In developing an improved understanding of the dynamics of understory plant composition and productivity in Coastal Plaii forest ecosystems, we examined theiniluenceof site preparation and phosphorus fertilization on the successional trends of shrubs and herbaceous plants growing on lands of widely ranging subsoil texture in Arkansas, Louisiana, and Texas which are...

Effects of variable retention harvesting on natural tree regeneration in Pinus resinosa (red pine) forests

Treesearch

Margaret W. Roberts; Anthony W. D' Amato; Christel C. Kern; Brian J. Palik

2017-01-01

Concerns over loss of ecosystem function and biodiversity in managed forests have led to the development of silvicultural approaches that meet ecological goals as well as sustain timber production. Variable Retention Harvest (VRH) practices, which maintain mature overstory trees across harvested areas, have been suggested as an approach to balance these objectives;...

Developing contemporary and historical live tree biomass estimates for old pine-hardwood stands of the Midsouth, USA

Treesearch

Don C. Bragg

2012-01-01

Calculating stand biomass potential is an increasingly important aspect of silviculture, particularly when attempting to restore forest ecosystems or determining additionality in sequestered carbon. However, the lumbering of the original forests of the Midsouth region of the United States of America, coupled with the accelerating conversion of unmanaged natural-origin...

New cohort growth and survival in variable retention harvests of a pine ecosystem in Minnesota, USA

Treesearch

Rebecca A. Montgomery; Brian J. Palik; Suzanne B. Boyden; Peter B. Reich

2013-01-01

There is significant interest in silvicultural systems such as variable retention harvesting (VRH) that emulate natural disturbance and increase structural complexity, spatial heterogeneity, and biological diversity in managed forests. However, the consequences of variable retention harvesting for new cohort growth and survival are not well characterized in many forest...

Effects of prescribed fire and season of burn on direct and indirect levels of tree mortality in Ponderosa and Jeffrey Pine Forests in California, USA.

Treesearch

Christopher Fettig; Stephen McKelvey; Daniel Cluck; Smith Sheri; William Otrosina

2010-01-01

Many forests that historically experienced frequent low-intensity wildfires have undergone extensive alterations during the past century. Prescribed fire is now commonly used to restore these fire-adapted forest ecosystems. In this study, we examined the influence of prescribed burn season on levels of tree mortality attributed to prescribed fire effects (direct...

Vertical and seasonal dynamics of fungal communities in boreal Scots pine forest soil.

PubMed

Santalahti, Minna; Sun, Hui; Jumpponen, Ari; Pennanen, Taina; Heinonsalo, Jussi

2016-11-01

Fungal communities are important for carbon (C) transformations in boreal forests that are one of the largest C pools in terrestrial ecosystems, warranting thus further investigation of fungal community dynamics in time and space. We investigated fungal diversity and community composition seasonally and across defined soil horizons in boreal Scots pine forest in Finland using 454 pyrosequencing. We collected a total of 120 samples from five vertical soil horizons monthly from March to October; in March, under snow. Boreal forest soil generally harbored diverse fungal communities across soil horizons. The communities shifted drastically and rapidly over time. In late winter, saprotrophs dominated the community and were replaced by ectomycorrhizal fungi during the growing season. Our studies are among the first to dissect the spatial and temporal dynamics in boreal forest ecosystems and highlights the ecological importance of vertically distinct communities and their rapid seasonal dynamics. As climate change is predicted to result in warmer and longer snow-free winter seasons, as well as increase the rooting depth of trees in boreal forest, the seasonal and vertical distribution of fungal communities may change. These changes are likely to affect the organic matter decomposition by the soil-inhabiting fungi and thus alter organic C pools. © FEMS 2016. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Carbon allocation to biomass production of leaves, fruits and woody organs at seasonal and annual scale in a deciduous- and evergreen temperate forest

NASA Astrophysics Data System (ADS)

Campioli, M.; Gielen, B.; Granier, A.; Verstraeten, A.; Neirynck, J.; Janssens, I. A.

2010-10-01

Carbon taken up by the forest canopy is allocated to tree organs for biomass production and respiration. Because tree organs have different life span and decomposition rate, the tree C allocation determines the residence time of C in the ecosystem and its C cycling rate. The study of the carbon-use efficiency, or ratio between net primary production (NPP) and gross primary production (GPP), represents a convenient way to analyse the C allocation at the stand level. Previous studies mostly focused on comparison of the annual NPP-GPP ratio among forests of different functional types, biomes and age. In this study, we extend the current knowledge by assessing (i) the annual NPP-GPP ratio and its interannual variability (for five years) for five tree organs (leaves, fruits, branches, stem and coarse roots), and (ii) the seasonal dynamic of NPP-GPP ratio of leaves and stems, for two stands dominated by European beech and Scots pine. The average NPP-GPP ratio for the beech stand (38%) was similar to previous estimates for temperate deciduous forests, whereas the NPP-GPP ratio for the pine stand (17%) is the lowest recorded till now in the literature. The proportion of GPP allocated to leaf NPP was similar for both species, whereas beech allocated a remarkable larger proportion of GPP to wood NPP than pine (29% vs. 6%, respectively). The interannual variability of the NPP-GPP ratio for wood was substantially larger than the interannual variability of the NPP-GPP ratio for leaves, fruits and overall stand and it is likely to be controlled by previous year air temperature (both species), previous year drought intensity (beech) and thinning (pine). Seasonal pattern of NPP-GPP ratio greatly differed between beech and pine, with beech presenting the largest ratio in early season, and pine a more uniform ratio along the season. For beech, NPP-GPP ratio of leaves and stems peaked during the same period in the early season, whereas they peaked in opposite periods of the growing season for pine. Seasonal differences in C allocation are likely due to functional differences between deciduous and evergreen species and temporal variability of the sink strength. The similar GPP and autotrophic respiration between stands and the remarkable larger C allocation to wood at the beech stand indicate that at the beech ecosystem C has a longer residence time than at the pine ecosystem. Further research on belowground production and particularly on fine roots and ectomycorrhizal fungi likely represents the most important step to progress our knowledge on C allocation dynamics.

Soil-plant-atmosphere conditions regulating convective cloud formation above southeastern US pine plantations.

PubMed

Manoli, Gabriele; Domec, Jean-Christophe; Novick, Kimberly; Oishi, Andrew Christopher; Noormets, Asko; Marani, Marco; Katul, Gabriel

2016-06-01

Loblolly pine trees (Pinus taeda L.) occupy more than 20% of the forested area in the southern United States, represent more than 50% of the standing pine volume in this region, and remove from the atmosphere about 500 g C m-2 per year through net ecosystem exchange. Hence, their significance as a major regional carbon sink can hardly be disputed. What is disputed is whether the proliferation of young plantations replacing old forest in the southern United States will alter key aspects of the hydrologic cycle, including convective rainfall, which is the focus of the present work. Ecosystem fluxes of sensible (Hs) and latent heat (LE) and large-scale, slowly evolving free atmospheric temperature and water vapor content are known to be first-order controls on the formation of convective clouds in the atmospheric boundary layer. These controlling processes are here described by a zero-order analytical model aimed at assessing how plantations of different ages may regulate the persistence and transition of the atmospheric system between cloudy and cloudless conditions. Using the analytical model together with field observations, the roles of ecosystem Hs and LE on convective cloud formation are explored relative to the entrainment of heat and moisture from the free atmosphere. Our results demonstrate that cloudy-cloudless regimes at the land surface are regulated by a nonlinear relation between the Bowen ratio Bo=Hs/LE and root-zone soil water content, suggesting that young/mature pines ecosystems have the ability to recirculate available water (through rainfall predisposition mechanisms). Such nonlinearity was not detected in a much older pine stand, suggesting a higher tolerance to drought but a limited control on boundary layer dynamics. These results enable the generation of hypotheses about the impacts on convective cloud formation driven by afforestation/deforestation and groundwater depletion projected to increase following increased human population in the southeastern United States. © 2016 John Wiley & Sons Ltd.

Small bugs with big impacts: Ecosystem and watershed-level responses to the MPB epidemic [Chapter 7

Treesearch

Rob Hubbard; Kelly Elder; Chuck Rhoades; Polly Hays; Bruce Sims

2014-01-01

Mountain pine beetle (MPB) outbreaks have the potential for prolonged impacts on the delivery of clean water from infested subalpine watersheds throughout the West. Sixty-five percent of the West’s water supply originates on forested land (Brown and others 2008), much of which has been affected by an unprecedented MPB epidemic over the past decade. Some lodgepole pine...

First look at smoke emissions from prescribed burns in long-unburned longleaf pine forests

Treesearch

Sheryl K. Akagi; Robert J. Yokelson; Ian R. Burling; David R. Weise; James Reardon; Shawn Urbanski; Timothy J. Johnson

2014-01-01

While fire has long played a role in the longleaf pine ecosystem, there are still some stands in the southeastern United States where fire has not been reintroduced and fuels have accumulated for 50 years or more. As part of a larger study examining fuel loading and smoke emissions on Department of Defense installations in the southeastern U.S., fuels and trace...

Influence of long-term dormant-season burning and fire exclusion on ground-dwelling arthropod populations in longleaf pine flatwoods ecosystems

Treesearch

James L. Hanula; Dale D. Wade

2003-01-01

Frequent dormant-season prescribed burns were applied at 1-, 2- and 4-year intervals to longleaf pine stands, Pinus palustris, for over 40 years on the Osceola National Forest in Baker County, Florida. Control plots were unburned for the same period of time. Pitfall traps were operated from November 1994 to October 1999 to measure the short- and long...

Endemic forest disturbances and stand structure of ponderosa pine (Pinus ponderosa) in the Upper Pine Creek Research Natural Area, South Dakota, USA

Treesearch

John E. Lundquist; Jose F. Negron

2000-01-01

Disturbances are natural and essential components of healthy ecosystems, but their ecological roles in the maintenance of endemic conditions for an area (that is, long-established levels of activity that are of low magnitude and relatively static intensity and cause unnoticed or relatively low amounts of tree killing, defoliation, or deformation) are poorly understood...

Resilience of Mediterranean terrestrial ecosystems and fire severity in semiarid areas: Responses of Aleppo pine forests in the short, mid and long term.

PubMed

González-De Vega, S; De Las Heras, J; Moya, D

2016-12-15

In recent decades, the fire regime of the Mediterranean Basin has been disturbed by various factors: climate change; forest management policies; land cover; changed landscape. Size and severity have notably increased, which in turn have increased large fires events with >500ha burned (high severity). In spite of Mediterranean ecosystems' high resilience to fire, these changes have implied more vulnerability and reduced natural recovery with irreparable long-term negative effects. Knowledge of the response of ecosystems to increasing severity, mainly in semiarid areas, is still lacking, which is needed to rehabilitate and restore burned areas. Our approach assessed the resilience concept by focusing on the recovery of ecosystem functions and services, measured as changes in the composition and diversity of plant community vegetation and structure. This will be validated in the long term as a model of ecosystem response. Also, depending on the pre-fire characteristics of vegetation, fire severity and the post-fire management, this approach will lead to tools that can be applied to implement post-fire restoration efforts in order to help decision making in planning activities. Regarding Mediterranean ecosystems' ability to recover after wildfires, this study concludes that pre-fire communities are resilient in these fire-prone areas, but the window for natural recovery in semiarid areas of Aleppo pine forest in SE Iberian Peninsula varied from 3 to 15 post-fire years. Fire severity was also key for effects on the ecosystem: the vegetation types of areas burned with low and medium severity recovered naturally, while those areas with a high-severity burn induced shrublands. We concluded that very strong regeneration activity exists in the short term, and that the negative effects of medium- and high-severity fire are evidenced in the mid and long term, which affect natural recovery. Adaptive forest management to rehabilitate and restore burned Mediterranean ecosystems should be implemented. Copyright © 2016 Elsevier B.V. All rights reserved.

Workshop proceedings: research and management in whitebark pine ecosystems

USGS Publications Warehouse

Kendall, Katherine C.; Coen, Brenda

1994-01-01

The purpose of this workshop is to exchange information on on-going and soon-to-be-initiated whitebark pine research and management projects. By doing so we hope to encourage future work on this valuable species. We also hope to promote the use of consistent methods for evaluation and investigation of whitebark pine, and to provide avenues of collaboration. Speakers will present information on a variety of topics related to whitebark pine management and research. Featured presentation topics include anthropomorphic utilization of whitepark pine forests, whitebark pine natural regeneration, blister rust and the decline of whitebark pine, blister rust resistance studies, ecological mapping of the species, restoration and management projects, and survey/monitoring techniques. Information gained from these presentations may hopefully be used in the planning of future projects for the conservation of whitebark pine.

Strong resilience of soil respiration components to drought-induced die-off resulting in forest secondary succession.

PubMed

Barba, Josep; Curiel Yuste, Jorge; Poyatos, Rafael; Janssens, Ivan A; Lloret, Francisco

2016-09-01

How forests cope with drought-induced perturbations and how the dependence of soil respiration on environmental and biological drivers is affected in a warming and drying context are becoming key questions. The aims of this study were to determine whether drought-induced die-off and forest succession were reflected in soil respiration and its components and to determine the influence of climate on the soil respiration components. We used the mesh exclusion method to study seasonal variations in soil respiration (R S) and its components: heterotrophic (R H) and autotrophic (R A) [further split into fine root (R R) and mycorrhizal respiration (R M)] in a mixed Mediterranean forest where Scots pine (Pinus sylvestris L.) is undergoing a drought-induced die-off and is being replaced by holm oak (Quercus ilex L.). Drought-induced pine die-off was not reflected in R S nor in its components, which denotes a high functional resilience of the plant and soil system to pine die-off. However, the succession from Scots pine to holm oak resulted in a reduction of R H and thus in an important decrease of total respiration (R S was 36 % lower in holm oaks than in non-defoliated pines). Furthermore, R S and all its components were strongly regulated by soil water content-and-temperature interaction. Since Scots pine die-off and Quercus species colonization seems to be widely occurring at the driest limit of the Scots pine distribution, the functional resilience of the soil system over die-off and the decrease of R S from Scots pine to holm oak could have direct consequences for the C balance of these ecosystems.

Whitebark pine mortality related to white pine blister rust, mountain pine beetle outbreak, and water availability

USGS Publications Warehouse

Shanahan, Erin; Irvine, Kathryn M.; Thoma, David P.; Wilmoth, Siri K.; Ray, Andrew; Legg, Kristin; Shovic, Henry

2016-01-01

Whitebark pine (Pinus albicaulis) forests in the western United States have been adversely affected by an exotic pathogen (Cronartium ribicola, causal agent of white pine blister rust), insect outbreaks (Dendroctonus ponderosae, mountain pine beetle), and drought. We monitored individual trees from 2004 to 2013 and characterized stand-level biophysical conditions through a mountain pine beetle epidemic in the Greater Yellowstone Ecosystem. Specifically, we investigated associations between tree-level variables (duration and location of white pine blister rust infection, presence of mountain pine beetle, tree size, and potential interactions) with observations of individual whitebark pine tree mortality. Climate summaries indicated that cumulative growing degree days in years 2006–2008 likely contributed to a regionwide outbreak of mountain pine beetle prior to the observed peak in whitebark mortality in 2009. We show that larger whitebark pine trees were preferentially attacked and killed by mountain pine beetle and resulted in a regionwide shift to smaller size class trees. In addition, we found evidence that smaller size class trees with white pine blister rust infection experienced higher mortality than larger trees. This latter finding suggests that in the coming decades white pine blister rust may become the most probable cause of whitebark pine mortality. Our findings offered no evidence of an interactive effect of mountain pine beetle and white pine blister rust infection on whitebark pine mortality in the Greater Yellowstone Ecosystem. Interestingly, the probability of mortality was lower for larger trees attacked by mountain pine beetle in stands with higher evapotranspiration. Because evapotranspiration varies with climate and topoedaphic conditions across the region, we discuss the potential to use this improved understanding of biophysical influences on mortality to identify microrefugia that might contribute to successful whitebark pine conservation efforts. Using tree-level observations, the National Park Service-led Greater Yellowstone Interagency Whitebark Pine Long-term Monitoring Program provided important ecological insight on the size-dependent effects of white pine blister rust, mountain pine beetle, and water availability on whitebark pine mortality. This ongoing monitoring campaign will continue to offer observations that advance conservation in the Greater Yellowstone Ecosystem.

Physical Processes Dictate Early Biogeochemical Dynamics of Soil Pyrogenic Organic Matter in a Subtropical Forest Ecosystem

NASA Astrophysics Data System (ADS)

Stuart, Jason M.; Anderson, Russell; Lazzarino, Patrick; Kuehn, Kevin A.; Harvey, Omar R.

2018-05-01

Quantifying links between pyOM dynamics, environmental factors and processes is central to predicting ecosystem function and response to future perturbations. In this study, changes in carbon (TC), nitrogen (TN) , pH and relative recalcitrance (R50) for pine- and cordgrass-derived pyOM were measured at 3-6 weeks intervals throughout the first year of burial in the soil. Objectives were to 1) identify key environmental factors and processes driving early-stage pyOM dynamics, and 2) develop quantitative relationships between environmental factors and changes in pyOM properties. The study was conducted in sandy soils of a forested ecosystem in the Longleaf pine range, US with a focus on links between changes in pyOM properties, fire history (FH), cumulative precipitation (Pcum), average temperature (Tavg) and soil residence time (SRT). Pcum, SRT and Tavg were the main factors controlling TC and TN accounting for 77-91% and 64-96% of their respective variability. Fire history, along with Pcum, SRT and Tavg, exhibited significant controlling effects on pyOM, pH and R50 - accounting for 48-91% and 88-93% of respective variability. Volatilization of volatiles and leaching of water-soluble components (in summer) and the sorption of exogenous organic matter (fall through spring) were most plausibly controlling pyOM dynamics in this study. Overall, our results point to climatic and land management factors and physicochemical process as the main drivers of pyOM dynamics in the pine ecosystems of the Southeastern US.

Response of carbon fluxes to drought in a coastal plain loblolly pine forest

Treesearch

Asko Noormets; Michael J. Gavazzi; Steve G. McNulty; Jean-Christophe Domec; Ge Sun; John S. King; Jiquan Chen

2010-01-01

Full accounting of ecosystem carbon (C) pools and fluxes in coastal plain ecosystems remains less studied compared with upland systems, even though the C stocks in these systems may be up to an order of magnitude higher, making them a potentially important component in regional C cycle. Here, we report C pools and CO2 exchange rates...

A simple method for estimating gross carbon budgets for vegetation in forest ecosystems.

PubMed

Ryan, Michael G.

1991-01-01

Gross carbon budgets for vegetation in forest ecosystems are difficult to construct because of problems in scaling flux measurements made on small samples over short periods of time and in determining belowground carbon allocation. Recently, empirical relationships have been developed to estimate total belowground carbon allocation from litterfall, and maintenance respiration from tissue nitrogen content. I outline a method for estimating gross carbon budgets using these empirical relationships together with data readily available from ecosystem studies (aboveground wood and canopy production, aboveground wood and canopy biomass, litterfall, and tissue nitrogen contents). Estimates generated with this method are compared with annual carbon fixation estimates from the Forest-BGC model for a lodgepole pine (Pinus contorta Dougl.) and a Pacific silver fir (Abies amabilis Dougl.) chronosequence.

Forest fuel reduction alters fire severity and long-term carbon storage in three Pacific Northwest ecosystems.

PubMed

Mitchell, Stephen R; Harmon, Mark E; O'Connell, Kari E B

2009-04-01

Two forest management objectives being debated in the context of federally managed landscapes in the U.S. Pacific Northwest involve a perceived trade-off between fire restoration and carbon sequestration. The former strategy would reduce fuel (and therefore C) that has accumulated through a century of fire suppression and exclusion which has led to extreme fire risk in some areas. The latter strategy would manage forests for enhanced C sequestration as a method of reducing atmospheric CO2 and associated threats from global climate change. We explored the trade-off between these two strategies by employing a forest ecosystem simulation model, STANDCARB, to examine the effects of fuel reduction on fire severity and the resulting long-term C dynamics among three Pacific Northwest ecosystems: the east Cascades ponderosa pine forests, the west Cascades western hemlock-Douglas-fir forests, and the Coast Range western hemlock-Sitka spruce forests. Our simulations indicate that fuel reduction treatments in these ecosystems consistently reduced fire severity. However, reducing the fraction by which C is lost in a wildfire requires the removal of a much greater amount of C, since most of the C stored in forest biomass (stem wood, branches, coarse woody debris) remains unconsumed even by high-severity wildfires. For this reason, all of the fuel reduction treatments simulated for the west Cascades and Coast Range ecosystems as well as most of the treatments simulated for the east Cascades resulted in a reduced mean stand C storage. One suggested method of compensating for such losses in C storage is to utilize C harvested in fuel reduction treatments as biofuels. Our analysis indicates that this will not be an effective strategy in the west Cascades and Coast Range over the next 100 years. We suggest that forest management plans aimed solely at ameliorating increases in atmospheric CO2 should forgo fuel reduction treatments in these ecosystems, with the possible exception of some east Cascades ponderosa pine stands with uncharacteristic levels of understory fuel accumulation. Balancing a demand for maximal landscape C storage with the demand for reduced wildfire severity will likely require treatments to be applied strategically throughout the landscape rather than indiscriminately treating all stands.

Quantifying thermal constraints on carbon and water fluxes in a mixed-conifer sky island ecosystem

NASA Astrophysics Data System (ADS)

Braun, Z.; Minor, R. L.; Potts, D. L.; Barron-Gafford, G. A.

2012-12-01

Western North American forests represent a potential, yet uncertain, sink for atmospheric carbon. Revealing how predicted climatic conditions of warmer temperatures and longer inter-storm periods of moisture stress might influence the carbon status of these forests requires a fuller understanding of plant functional responses to abiotic stress. While data related to snow dominated montane ecosystems has become more readily available to parameterize ecosystem function models, there is a paucity of data available for Madrean sky island mixed-conifer forests, which receive about one third of their precipitation from the North American Monsoon. Thus, we quantified ecophysiological responses to moisture and temperature stress in a Madrean mixed-conifer forest near Tucson, Arizona, within the footprint of the Mt. Bigelow Eddy Covariance Tower. In measuring a series of key parameters indicative of carbon and water fluxes within the dominant species across pre-monsoon and monsoon conditions, we were able to develop a broader understanding of what abiotic drivers are most restrictive to plant performance in this ecosystem. Within Pinus ponderosa (Ponderosa Pine), Pseudotsuga menziesii (Douglas Fir), and Pinus strobiformis (Southwestern White Pine) we quantified: (i) the optimal temperature (Topt) for maximum photosynthesis (Amax), (ii) the range of temperatures over which photosynthesis was at least 50% of Amax (Ω50), and (iii) each conifer's water use efficiency (WUE) to relate to the balance between carbon uptake and water loss in this high elevation semiarid ecosystem. Our findings support the prediction that photosynthesis decreases under high temperatures (>30°C) among the three species we measured, regardless of soil moisture status. However, monsoon moisture reduced sensitivity to temperature extremes and fluctuations (Ω50), which substantially magnified total photosynthetic productivity. In particular, wet conditions enhanced Amax the most dramatically for P. menziesii, elevating rates by 590%, while Ω50 grew most substantially for P. strobifomis (by 180%). Interspecific differences in temperature optima (Topt) elucidated possible species dominance predictions for seasonal and gradual temperature changes. P. menziesii may out-perform the pine species in the event that temperatures rise in conjunction with abundant summer moisture. However, if monsoon rains fail to accumulate, P. menziesii may remain at subsistence levels of photosynthesis. Together, these data will enable the parameterization of models to approximate the productivity and, ultimately, the composition of Madrean sky island mixe d-conifer forests under forecasted climate conditions of increased temperatures and more frequent drought.

CARBON AND NUTRIENT FLOW THROUGH MULTIPLE TROPHIC LEVELS IN A CO2-ENRICHED SOUTHERN PINE FOREST COMMUNITY - FINAL TECHNICAL REPORT

USDA-ARS?s Scientific Manuscript database

The ability to predict the consequences of global change is predicated on our understanding of controls of energy and material flows through ecosystems. Research was conducted at the Forest Atmosphere CO2 Transfer and Storage-1 (FACTS-1) site at Duke University. This is a flagship experiment of the ...

Introducing close-range photogrammetry for characterizing forest understory plant diversity and surface fuel structure at fine scales

Treesearch

Benjamin C. Bright; E. Louise Loudermilk; Scott M. Pokswinski; Andrew T. Hudak; Joseph J. O' Brien

2016-01-01

Methods characterizing fine-scale fuels and plant diversity can advance understanding of plant-fire interactions across scales and help in efforts to monitor important ecosystems such as longleaf pine (Pinus palustris Mill.) forests of the southeastern United States. Here, we evaluate the utility of close-range photogrammetry for measuring fuels and plant...

Stream Nitrate Response to Different Burning Treatments in Southern Appalachian Forests

Treesearch

Barton D. Clinton; James M. Vose; Jennifer D. Knoepp; Katherine J. Elliott

2003-01-01

Southern Appalachian forests are undergoing considerable change due to altered disturbance regimes. For example, fire exclusion has had a major impact on the structure and function of pine-hardwood ecosystems. Recently, fire has been prescribed for a variety of applications: 1) stand-replacement in the form of a mimicked wildfire, 2) site-preparation as part of a fell-...

Time series analysis of forest carbon dynamics: recovery of Pinus palustris physiology following a prescribed fire

Treesearch

G. Starr; C. L. Staudhammer; H. W. Loescher; R. Mitchell; A. Whelan; J. K. Hiers; J. J. O’Brien

2015-01-01

Frequency and intensity of fire determines the structure and regulates the function of savanna ecosystems worldwide, yet our understanding of prescribed fire impacts on carbon in these systems is rudimentary. We combined eddy covariance (EC) techniques and fuel consumption plots to examine the short-term response of longleaf pine forest carbon dynamics to one...

Effects of heat and drought on carbon and water dynamics in a regenerating semi-arid pine forest: a combined experimental and modeling approach

NASA Astrophysics Data System (ADS)

Ruehr, N. K.; Law, B. E.; Quandt, D.; Williams, M.

2014-01-01

Increasing summer temperatures and a reduction in precipitation will enhance drought stress in Mediterranean and semi-arid ecosystems. Predicting the net effects on forests' carbon and water balance will depend on our ability to disentangle the sensitivity of component fluxes responding to increasing soil and atmospheric drought. Here we studied carbon and water dynamics in a semi-arid regenerating ponderosa pine forest using field observations and process based modeling. Field observations of two summer dry seasons were used to calibrate a soil-plant-atmosphere (SPA) model. In addition, the ecosystem's response to reduced soil drought was quantified based on a field watering experiment and evaluated with the model. Further, the SPA model was used to estimate the relative effects of increasing soil and atmospheric drought over time, by simulating temperature and precipitation scenarios for 2040 and 2080. The seasonality and drought response of ecosystem fluxes was well captured by the calibrated SPA model. Dramatic increases in summer water availability during seasonal drought had a small effect on pine physiology in both the watering experiment and the model. This clearly demonstrates that atmospheric drought induced a strong limitation on carbon uptake in young ponderosa pine due to tight regulation of stomatal conductance. Moreover, simulations showed that net ecosystem exchange (NEE) and gross primary productivity (GPP) were about three times more affected by summer heat and increased evaporative demand than by reductions in summer precipitation. Annual NEE decreased by 38% in response to extreme summer conditions as predicted to occur in 2080 (June-August: +4.5 °C), because of a strong decline in GPP (-17%) while heterotrophic respiration was relatively unaffected (-1%). Considering warming trends across all seasons (September-May: +3 °C and June-August: +4.5 °C), the negative drought effects were largely compensated by an earlier initiation of favorable growing conditions and bud break, enhancing early season GPP and needle biomass. An adverse effect, triggered by changes in early season allocation patterns, was the decline of wood and root biomass. This imbalance may increase water stress over the long-term to a threshold at which ponderosa pine may not survive, and highlights the need for an integrated process understanding of the combined effects of trends and extremes.

Interactive effects of nocturnal transpiration and climate change on the root hydraulic redistribution and carbon and water budgets of southern United States pine plantations

Treesearch

Jean-Christophe Domec; Jérôme Ogée; Asko Noormets; Julien Jouangy; Michael Gavazzi; Emrys Treasure; Ge Sun; Steve G. McNulty; John S. King

2012-01-01

Deep root water uptake and hydraulic redistribution (HR) have been shown to play a major role in forest ecosystems during drought, but little is known about the impact of climate change, fertilization and soil characteristics on HR and its consequences on water and carbon fluxes. Using data from three mid-rotation loblolly pine plantations, and simulations with the...

Bi-directional exchange of ammonia in a pine forest ecosystem - a model sensitivity analysis

NASA Astrophysics Data System (ADS)

Moravek, Alexander; Hrdina, Amy; Murphy, Jennifer

2016-04-01

Ammonia (NH3) is a key component in the global nitrogen cycle and of great importance for atmospheric chemistry, neutralizing atmospheric acids and leading to the formation of aerosol particles. For understanding the role of NH3 in both natural and anthropogenically influenced environments, the knowledge of processes regulating its exchange between ecosystems and the atmosphere is essential. A two-layer canopy compensation point model is used to evaluate the NH3 exchange in a pine forest in the Colorado Rocky Mountains. The net flux comprises the NH3 exchange of leaf stomata, its deposition to leaf cuticles and exchange with the forest ground. As key parameters the model uses in-canopy NH3 mixing ratios as well as leaf and soil emission potentials measured at the site in summer 2015. A sensitivity analysis is performed to evaluate the major exchange pathways as well as the model's constraints. In addition, the NH3 exchange is examined for an extended range of environmental conditions, such as droughts or varying concentrations of atmospheric pollutants, in order to investigate their influence on the overall net exchange.

An integrated model of environmental effects on growth, carbohydrate balance, and mortality of Pinus ponderosa forests in the southern Rocky Mountains.

PubMed

Tague, Christina L; McDowell, Nathan G; Allen, Craig D

2013-01-01

Climate-induced tree mortality is an increasing concern for forest managers around the world. We used a coupled hydrologic and ecosystem carbon cycling model to assess temperature and precipitation impacts on productivity and survival of ponderosa pine (Pinus ponderosa). Model predictions were evaluated using observations of productivity and survival for three ponderosa pine stands located across an 800 m elevation gradient in the southern Rocky Mountains, USA, during a 10-year period that ended in a severe drought and extensive tree mortality at the lowest elevation site. We demonstrate the utility of a relatively simple representation of declines in non-structural carbohydrate (NSC) as an approach for estimating patterns of ponderosa pine vulnerability to drought and the likelihood of survival along an elevation gradient. We assess the sensitivity of simulated net primary production, NSC storage dynamics, and mortality to site climate and soil characteristics as well as uncertainty in the allocation of carbon to the NSC pool. For a fairly wide set of assumptions, the model estimates captured elevational gradients and temporal patterns in growth and biomass. Model results that best predict mortality risk also yield productivity, leaf area, and biomass estimates that are qualitatively consistent with observations across the sites. Using this constrained set of parameters, we found that productivity and likelihood of survival were equally dependent on elevation-driven variation in temperature and precipitation. Our results demonstrate the potential for a coupled hydrology-ecosystem carbon cycling model that includes a simple model of NSC dynamics to predict drought-related mortality. Given that increases in temperature and in the frequency and severity of drought are predicted for a broad range of ponderosa pine and other western North America conifer forest habitats, the model potentially has broad utility for assessing ecosystem vulnerabilities.

An integrated model of environmental effects on growth, carbohydrate balance, and mortality of Pinus ponderosa forests in the southern Rocky Mountains

USGS Publications Warehouse

Tague, Christina L.; McDowell, Nathan G.; Allen, Craig D.

2013-01-01

Climate-induced tree mortality is an increasing concern for forest managers around the world. We used a coupled hydrologic and ecosystem carbon cycling model to assess temperature and precipitation impacts on productivity and survival of ponderosa pine (Pinus ponderosa). Model predictions were evaluated using observations of productivity and survival for three ponderosa pine stands located across an 800 m elevation gradient in the southern Rocky Mountains, USA, during a 10-year period that ended in a severe drought and extensive tree mortality at the lowest elevation site. We demonstrate the utility of a relatively simple representation of declines in non-structural carbohydrate (NSC) as an approach for estimating patterns of ponderosa pine vulnerability to drought and the likelihood of survival along an elevation gradient. We assess the sensitivity of simulated net primary production, NSC storage dynamics, and mortality to site climate and soil characteristics as well as uncertainty in the allocation of carbon to the NSC pool. For a fairly wide set of assumptions, the model estimates captured elevational gradients and temporal patterns in growth and biomass. Model results that best predict mortality risk also yield productivity, leaf area, and biomass estimates that are qualitatively consistent with observations across the sites. Using this constrained set of parameters, we found that productivity and likelihood of survival were equally dependent on elevation-driven variation in temperature and precipitation. Our results demonstrate the potential for a coupled hydrology-ecosystem carbon cycling model that includes a simple model of NSC dynamics to predict drought-related mortality. Given that increases in temperature and in the frequency and severity of drought are predicted for a broad range of ponderosa pine and other western North America conifer forest habitats, the model potentially has broad utility for assessing ecosystem vulnerabilities.

An Integrated Model of Environmental Effects on Growth, Carbohydrate Balance, and Mortality of Pinus ponderosa Forests in the Southern Rocky Mountains

PubMed Central

Tague, Christina L.; McDowell, Nathan G.; Allen, Craig D.

2013-01-01

Climate-induced tree mortality is an increasing concern for forest managers around the world. We used a coupled hydrologic and ecosystem carbon cycling model to assess temperature and precipitation impacts on productivity and survival of ponderosa pine (Pinus ponderosa). Model predictions were evaluated using observations of productivity and survival for three ponderosa pine stands located across an 800 m elevation gradient in the southern Rocky Mountains, USA, during a 10-year period that ended in a severe drought and extensive tree mortality at the lowest elevation site. We demonstrate the utility of a relatively simple representation of declines in non-structural carbohydrate (NSC) as an approach for estimating patterns of ponderosa pine vulnerability to drought and the likelihood of survival along an elevation gradient. We assess the sensitivity of simulated net primary production, NSC storage dynamics, and mortality to site climate and soil characteristics as well as uncertainty in the allocation of carbon to the NSC pool. For a fairly wide set of assumptions, the model estimates captured elevational gradients and temporal patterns in growth and biomass. Model results that best predict mortality risk also yield productivity, leaf area, and biomass estimates that are qualitatively consistent with observations across the sites. Using this constrained set of parameters, we found that productivity and likelihood of survival were equally dependent on elevation-driven variation in temperature and precipitation. Our results demonstrate the potential for a coupled hydrology-ecosystem carbon cycling model that includes a simple model of NSC dynamics to predict drought-related mortality. Given that increases in temperature and in the frequency and severity of drought are predicted for a broad range of ponderosa pine and other western North America conifer forest habitats, the model potentially has broad utility for assessing ecosystem vulnerabilities. PMID:24282532

Effects of thinning and herbicide application on vertebrate communities in longleaf pine plantations

DOE Office of Scientific and Technical Information (OSTI.GOV)

Brunjes, Kristina J.; Miller, Karl V.; Ford, Mark W.

Currently, nearly 98% of the land area once dominated by longleaf pine ecosystems has been converted to other uses. The U.S. Forest Service is replanting logged areas with longleaf pine at the Savannah River Site, New Ellenton, South Carolina, in an effort to restore these ecosystems. To ascertain the effects of various silvicultural management techniques on the vertebrate communities, we surveyed small mammal, herpetofaunal, and avian communities in six 10- to 13-year-old longleaf pine plantations subjected to various thinning and herbicide regimes. Areas within each plantation were randomly assigned one of four treatments: thinning, herbicide spraying, thinning and herbicide, andmore » an untreated control. For all vertebrate groups, abundance and species diversity tended to be less in the controls than treated areas. Birds and small mammals were most abundant and diverse in thinned treatments versus spray only and control. Herpetofauna capture rates were low and, thus, we were unable to detect treatment-related differences. Silvicultural treatments that reduce hardwood stem density and pine basal area can enhance habitat conditions for numerous vertebrate species.« less

Integration of ground and satellite data to model Mediterranean forest processes

NASA Astrophysics Data System (ADS)

Chiesi, M.; Fibbi, L.; Genesio, L.; Gioli, B.; Magno, R.; Maselli, F.; Moriondo, M.; Vaccari, F. P.

2011-06-01

The current work presents the testing of a modeling strategy that has been recently developed to simulate the gross and net carbon fluxes of Mediterranean forest ecosystems. The strategy is based on the use of a NDVI-driven parametric model, C-Fix, and of a biogeochemical model, BIOME-BGC, whose outputs are combined to simulate the behavior of forest ecosystems at different development stages. The performances of the modeling strategy are evaluated in three Italian study sites (San Rossore, Lecceto and Pianosa), where carbon fluxes are being measured through the eddy correlation technique. These sites are characterized by variable Mediterranean climates and are covered by different types of forest vegetation (pine wood, Holm oak forest and Macchia, respectively). The results of the tests indicate that the modeling strategy is generally capable of reproducing monthly GPP and NEE patterns in all three study sites. The highest accuracy is obtained in the most mature, homogenous pine wood of San Rossore, while the worst results are found in the Lecceto forest, where there are the most heterogeneous terrain, soil and vegetation conditions. The main error sources are identified in the inaccurate definition of the model inputs, particularly those regulating the site water budgets, which exert a strong control on forest productivity during the Mediterranean summer dry season. In general, the incorporation of NDVI-derived fAPAR estimates corrects for most of these errors and renders the forest flux simulations more stable and accurate.

Net Ecosystem Fluxes of Hydrocarbons from a Ponderosa Pine Forest in Colorado

NASA Astrophysics Data System (ADS)

Rhew, R. C.; Turnipseed, A. A.; Ortega, J. V.; Smith, J. N.; Guenther, A. B.; Shen, S.; Martinez, L.; Koss, A.; Warneke, C.; De Gouw, J. A.; Deventer, M. J.

2015-12-01

Light (C2-C4) alkenes, light alkanes and isoprene (C5H8) are non-methane hydrocarbons that play important roles in the photochemical production of tropospheric ozone and in the formation of secondary organic aerosols. Natural terrestrial fluxes of the light hydrocarbons are poorly characterized, with global emission estimates based on limited field measurements. In 2014, net fluxes of these compounds were measured at the Manitou Experimental Forest Observatory, a semi-arid ponderosa pine forest in the Colorado Rocky Mountains and site of the prior BEACHON campaigns. Three field intensives were conducted between June 17 and August 10, 2014. Net ecosystem flux measurements utilized a relaxed eddy accumulation system coupled to an automated gas chromatograph. Summertime average emissions of ethene and propene were up to 90% larger than those observed from a temperate deciduous forest. Ethene and propene fluxes were also correlated to each other, similar to the deciduous forest study. Emissions of isoprene were small, as expected for a coniferous forest, and these fluxes were not correlated with either ethene or propene. Unexpected emissions of light alkanes were also observed, and these showed a distinct diurnal cycle. Understory flux measurements allowed for the partitioning of fluxes between the surface and the canopy. Full results from the three field intensives will be compared with environmental variables in order to parameterize the fluxes for use in modeling emissions.

The wildland fuel cell concept: an approach to characterize fine-scale variation in fuels and fire in frequently burned longleaf pine forests

Treesearch

J. Kevin Hiers; Joseph J. O’Brien; R. J. Mitchell; John M. Grego; E. Louise Loudermilk

2009-01-01

In ecosystems with frequent surface fire regimes, fire and fuel heterogeneity has been largely overlookedowing to the lack of unburned patches and the difficulty in measuring fire behavior at fine scales (0.1–10 m). The diversevegetation in these ecosystems varies at these fine scales. This diversity could be...

[Eco-value level classification and ecosystem management strategy of broad-leaved Korean pine forest in Changbai Mountain].

PubMed

Zheng, Jingming; Jiang, Fengqi; Zeng, Dehui

2003-06-01

To realize the sustainable management of forest ecosystems, we should explicitly clarify the types and differences of the ecosystem services provided by different ecosystems under different conditions, with rethinking about the value of forest ecosystems; then solid management strategies and measurements will be enacted and applied to achieve the objects. The broad-leaved Korean pine forest (BLKPF) in Changbai Mountain is a unique and important forest type in China, owing to its many important ecosystem services such as preventing soil erosion, regulating climates, nutrient cycling, providing wood and non-timber forest products, etc. This paper is a preliminary study on the management strategy of BLKPF on the basis of analyzing the characters of the ecosystems and the relative importance of services they provided in this region. Based on the latest research of ecosystem services of BLKPF in Changbai Mountain, an idea of eco-value level (EVL) was introduced, and accordingly, management strategies were summarized by adopting the advanced theories in ecosystem management science and by analyzing field survey data. EVL means the relative amount of the value of ecosystem services provided by certain ecosystem, which can indicate the difference between services in given objects. The EVL classification of BLKPF implies the relative amount of the eco-value of different ecosystems including virgin forest, secondary forest, forest with human disturbance, and man-made forest in the clear-cutting sites. Analytical Hierarchical Processing method was used to formulate the equation for EVL index. Eight factors, namely, slope, soil depth, stability of soil maternal material, coverage of above-ground canopy, species diversity, regeneration rate of the stand, life span of dominant tree species, and intensity of human disturbance were chosen to build the formula. These factors belonged to three aspects affecting ecosystem services including the physical environment, community, and disturbance regime, and their selection and scaling were based on the previous studies on the BLKPF. The equation of EVL index (EI) was expressed as: EI = 0.542A1 + 0.171A2 + 0.072A3 + 0.067B1 + 0.043B2 + 0.014B3 + 0.010B4 + 0.081C1. According to the range of EI, ecosystems were classified into three types: low EVL type with EI from 1.000 to 1.874, medium EVL type with EI 1.874-2.749, and high EVL type with EI 2.749-3.623. Typical plots were surveyed and scaled with EI, and the predominant characters of each EVL type were summarized. Most forests of high EVL type were those in sites at high risk of soil erosion and hard to recover after disrupted. Forests of medium EVL type were those with worse community structure and composition, and were disturbed by human activities in relative steep sites. Forest of low EVL type were those in plane site with serious disruption or some young man-made stands. Based on the analyses of the characters of these three types, different management strategies were put forward. For high EVL type forest, strictly protection is most important to maintain the forest in natural succession and its eco-services. For medium EVL type forest, the key points of management are restoring their health and vigor by regulating their composition and structure in a seminatural way. For low EVL type forest, some area could be used to extensive exploration for economic benefits, and the rests should be reconstructed towards the original stand in composition and structure, based on the 'shadow ecosystem' in a close-to-nature way to promote the capacity of providing more eco-services.

Modelling the limits on the response of net carbon exchange to fertilization in a south-eastern pine forest

Treesearch

Chun-Tai. Lai; G. Katul; J. Butnor; M. Siqueira; D. Ellsworth; C. Maier; Kurt Johnsen; S. Mickeand; R. Oren

2002-01-01

Using a combination of model simulations and detailed measurements at a hierarchy of scales conducted at a sandhills forest site, the effect of fertilization on net ecosystem exchange (NEE) and its components in 6-year-old Pinus taeda stands was quantified. The detailed measurements, collected over a 20-d period in September and October, included gas...

Late Holocene geomorphic record of fire in ponderosa pine and mixed-conifer forests, Kendrick Mountain, northern Arizona, USA

Treesearch

Sara E. Jenkins; Carolyn Hull Sieg; Diana E. Anderson; Darrell S. Kaufman; Philip A. Pearthree

2011-01-01

Long-term fire history reconstructions enhance our understanding of fire behaviour and associated geomorphic hazards in forested ecosystems. We used 14C ages on charcoal from fire-induced debris-flow deposits to date prehistoric fires on Kendrick Mountain, northern Arizona, USA. Fire-related debris-flow sedimentation dominates Holocene fan deposition in the study area...

Climate change and fire regimes in the Sierra de Manantlan, Mexico

Treesearch

Brooke A. Cassell; Ernesto Alvarado; Emily Heyerdahl; Diego Perez-Salicrup; Enrique Jardel-Pelaez

2010-01-01

Fire has been attributed as one of the most influential factors in vegetation community and succession in the Sierra de Manantlán Biosphere Reserve in Jalisco and Colima, México. A mosaic of low, mixed and high severity fire regimes characterizes the landscape with ecosystems ranging from mesophyllous mountain forest to higher elevation pine and oak forest. Research...

Database of in-situ field measurements for estimates of fuel consumption and fire emissions in Siberia

NASA Astrophysics Data System (ADS)

Kukavskaya, Elena; Conard, Susan; Buryak, Ludmila; Ivanova, Galina; Soja, Amber; Kalenskaya, Olga; Zhila, Sergey; Zarubin, Denis; Groisman, Pavel

2016-04-01

Wildfires show great variability in the amount of fuel consumed and carbon emitted to the atmosphere. Various types of models are used to calculate global or large scale regional fire emissions. However, in the databases used to estimate fuel consumptions, data for Russia are typically under-represented. Meanwhile, the differences in vegetation and fire regimes in the boreal forests in North America and Eurasia argue strongly for the need of regional ecosystem-specific data. For about 15 years we have been collecting field data on fuel loads and consumption in different ecosystem types of Siberia. We conducted a series of experimental burnings of varying fireline intensity in Scots pine and larch forests of central Siberia to obtain quantitative and qualitative data on fire behavior and carbon emissions. In addition, we examined wildfire behavior and effects in different vegetation types including Scots pine, Siberian pine, fir, birch, poplar, and larch-dominated forests; evergreen coniferous shrubs; grasslands, and peats. We investigated various ecosystem zones of Siberia (central and southern taiga, forest-steppe, steppe, mountains) in the different subjects of the Russian Federation (Krasnoyarsk Kray, Republic of Khakassia, Republic of Buryatia, Tuva Republic, Zabaikalsky Kray). To evaluate the impact of forest practices on fire emissions, burned and unburned logged sites and forest plantations were examined. We found large variations of fuel consumption and fire emission rates among different vegetation types depending on growing conditions, fire behavior characteristics and anthropogenic factors. Changes in the climate system result in an increase in fire frequency, area burned, the number of extreme fires, fire season length, fire season severity, and the number of ignitions from lightning. This leads to an increase of fire-related emissions of carbon to the atmosphere. The field measurement database we compiled is required for improving accuracy of existing biomass burning models and for use by air quality agencies in developing regional strategies to mitigate negative smoke impacts on human health and environment. The research was supported by the Grant of the President of the Russian Federation MK-4646.2015.5, RFBR grant # 15-04-06567, and the NASA LCLUC Program.

Carbon balance of a partially-harvested mixed conifer forest following mountain pine beetle attack and its comparison to a clearcut

NASA Astrophysics Data System (ADS)

Mathys, A.; Black, T. A.; Nesic, Z.; Nishio, G.; Brown, M.; Spittlehouse, D. L.; Fredeen, A. L.; Bowler, R.; Jassal, R. S.; Grant, N. J.; Burton, P. J.; Trofymow, J. A.

2013-03-01

The recent mountain pine beetle (MPB) outbreak has had an impact on the carbon (C) cycling of lodgepole pine forests in British Columbia. This study examines how partial harvesting as a forest management response to MPB infestation affects the net ecosystem production (NEP) of a mixed conifer forest (MPB-09) in Interior BC. MPB-09 is a 70-yr old stand that was partially harvested in 2009 after it had been attacked by MPB. Using the eddy-covariance technique, the C dynamics of the stand were studied over two years and compared to an adjacent clearcut (MPB-09C) over the growing season. The annual NEP at MPB-09 increased from -108 g C m-2 in 2010 to -57 g C m-2 in 2011. The increase of NEP was due to the associated increase in annual gross ecosystem photosynthesis (GEP) from 812 g C m-2 in 2010 to 954 g C m-2 in 2011 exceeding the increase in annual respiration (Re) from 920 g C m-2 to 1011 g C m-2 during the two years. During the growing season of 2010, NEP at MPB-09C was -132 g C m-2 indicating high C losses in the clearcut. MPB-09 was a C sink during the growing season of both years, increasing from 9 g C m-2 in 2010 to 47 g C m-2 in 2011. The increase of NEP in the partially-harvested stand amounted to a recovery corresponding to a 25% increase in the maximum assimilation rate in the second year. This study shows that retaining the healthy residual forest can result in higher C sequestration of MPB-attacked stands compared to clearcut harvesting.

Using High Spatial Resolution Satellite Imagery to Map Forest Burn Severity Across Spatial Scales in a Pine Barrens Ecosystem

NASA Technical Reports Server (NTRS)

Meng, Ran; Wu, Jin; Schwager, Kathy L.; Zhao, Feng; Dennison, Philip E.; Cook, Bruce D.; Brewster, Kristen; Green, Timothy M.; Serbin, Shawn P.

2017-01-01

As a primary disturbance agent, fire significantly influences local processes and services of forest ecosystems. Although a variety of remote sensing based approaches have been developed and applied to Landsat mission imagery to infer burn severity at 30 m spatial resolution, forest burn severity have still been seldom assessed at fine spatial scales (less than or equal to 5 m) from very-high-resolution (VHR) data. We assessed a 432 ha forest fire that occurred in April 2012 on Long Island, New York, within the Pine Barrens region, a unique but imperiled fire-dependent ecosystem in the northeastern United States. The mapping of forest burn severity was explored here at fine spatial scales, for the first time using remotely sensed spectral indices and a set of Multiple Endmember Spectral Mixture Analysis (MESMA) fraction images from bi-temporal - pre- and post-fire event - WorldView-2 (WV-2) imagery at 2 m spatial resolution. We first evaluated our approach using 1 m by 1 m validation points at the sub-crown scale per severity class (i.e. unburned, low, moderate, and high severity) from the post-fire 0.10 m color aerial ortho-photos; then, we validated the burn severity mapping of geo-referenced dominant tree crowns (crown scale) and 15 m by 15 m fixed-area plots (inter-crown scale) with the post-fire 0.10 m aerial ortho-photos and measured crown information of twenty forest inventory plots. Our approach can accurately assess forest burn severity at the sub-crown (overall accuracy is 84% with a Kappa value of 0.77), crown (overall accuracy is 82% with a Kappa value of 0.76), and inter-crown scales (89% of the variation in estimated burn severity ratings (i.e. Geo-Composite Burn Index (CBI)). This work highlights that forest burn severity mapping from VHR data can capture heterogeneous fire patterns at fine spatial scales over the large spatial extents. This is important since most ecological processes associated with fire effects vary at the less than 30 m scale and VHR approaches could significantly advance our ability to characterize fire effects on forest ecosystems.

Using high spatial resolution satellite imagery to map forest burn severity across spatial scales in a Pine Barrens ecosystem

DOE Office of Scientific and Technical Information (OSTI.GOV)

Meng, Ran; Wu, Jin; Schwager, Kathy L.

As a primary disturbance agent, fire significantly influences local processes and services of forest ecosystems. Although a variety of remote sensing based approaches have been developed and applied to Landsat mission imagery to infer burn severity at 30 m spatial resolution, forest burn severity have still been seldom assessed at fine spatial scales (≤ 5 m) from very-high-resolution (VHR) data. Here we assessed a 432 ha forest fire that occurred in April 2012 on Long Island, New York, within the Pine Barrens region, a unique but imperiled fire-dependent ecosystem in the northeastern United States. The mapping of forest burn severitymore » was explored here at fine spatial scales, for the first time using remotely sensed spectral indices and a set of Multiple Endmember Spectral Mixture Analysis (MESMA) fraction images from bi-temporal — pre- and post-fire event — WorldView-2 (WV-2) imagery at 2 m spatial resolution. We first evaluated our approach using 1 m by 1 m validation points at the sub-crown scale per severity class (i.e. unburned, low, moderate, and high severity) from the post-fire 0.10 m color aerial ortho-photos; then, we validated the burn severity mapping of geo-referenced dominant tree crowns (crown scale) and 15 m by 15 m fixed-area plots (inter-crown scale) with the post-fire 0.10 m aerial ortho-photos and measured crown information of twenty forest inventory plots. Our approach can accurately assess forest burn severity at the sub-crown (overall accuracy is 84% with a Kappa value of 0.77), crown (overall accuracy is 82% with a Kappa value of 0.76), and inter-crown scales (89% of the variation in estimated burn severity ratings (i.e. Geo-Composite Burn Index (CBI)). Lastly, this work highlights that forest burn severity mapping from VHR data can capture heterogeneous fire patterns at fine spatial scales over the large spatial extents. This is important since most ecological processes associated with fire effects vary at the < 30 m scale and VHR approaches could significantly advance our ability to characterize fire effects on forest ecosystems.« less

Using high spatial resolution satellite imagery to map forest burn severity across spatial scales in a Pine Barrens ecosystem

DOE PAGES

Meng, Ran; Wu, Jin; Schwager, Kathy L.; ...

2017-01-21

As a primary disturbance agent, fire significantly influences local processes and services of forest ecosystems. Although a variety of remote sensing based approaches have been developed and applied to Landsat mission imagery to infer burn severity at 30 m spatial resolution, forest burn severity have still been seldom assessed at fine spatial scales (≤ 5 m) from very-high-resolution (VHR) data. Here we assessed a 432 ha forest fire that occurred in April 2012 on Long Island, New York, within the Pine Barrens region, a unique but imperiled fire-dependent ecosystem in the northeastern United States. The mapping of forest burn severitymore » was explored here at fine spatial scales, for the first time using remotely sensed spectral indices and a set of Multiple Endmember Spectral Mixture Analysis (MESMA) fraction images from bi-temporal — pre- and post-fire event — WorldView-2 (WV-2) imagery at 2 m spatial resolution. We first evaluated our approach using 1 m by 1 m validation points at the sub-crown scale per severity class (i.e. unburned, low, moderate, and high severity) from the post-fire 0.10 m color aerial ortho-photos; then, we validated the burn severity mapping of geo-referenced dominant tree crowns (crown scale) and 15 m by 15 m fixed-area plots (inter-crown scale) with the post-fire 0.10 m aerial ortho-photos and measured crown information of twenty forest inventory plots. Our approach can accurately assess forest burn severity at the sub-crown (overall accuracy is 84% with a Kappa value of 0.77), crown (overall accuracy is 82% with a Kappa value of 0.76), and inter-crown scales (89% of the variation in estimated burn severity ratings (i.e. Geo-Composite Burn Index (CBI)). Lastly, this work highlights that forest burn severity mapping from VHR data can capture heterogeneous fire patterns at fine spatial scales over the large spatial extents. This is important since most ecological processes associated with fire effects vary at the < 30 m scale and VHR approaches could significantly advance our ability to characterize fire effects on forest ecosystems.« less

Growth-climate relationships across topographic gradients in the northern Great Lakes

USGS Publications Warehouse

Dymond, S.F.; D'Amato, A.W.; Kolka, R.K.; Bolstad, P.V.; Sebestyen, S.D.; Bradford, John B.

2016-01-01

Climatic conditions exert important control over the growth, productivity, and distribution of forests, and characterizing these relationships is essential for understanding how forest ecosystems will respond to climate change. We used dendrochronological methods to develop climate–growth relationships for two dominant species, Populus tremuloides (quaking aspen) and Pinus resinosa (red pine), in the upper Great Lakes region to understand how climate and water availability influence annual forest productivity. Trees were sampled along a topographic gradient at the Marcell Experimental Forest (Minnesota, USA) to assess growth response to variations in temperature and different water availability metrics (precipitation, potential evapotranspiration (PET), cumulative moisture index (CMI), and soil water storage). Climatic variables were able to explain 33–58% of the variation in annual growth (as measured by ring-width increment) for quaking aspen and 37–74% of the variation for red pine. Climate–growth relationships were influenced by topography for quaking aspen but not for red pine. Annual ring growth for quaking aspen decreased with June CMI on ridges, decreased with temperature in the November prior to the growing season on sideslopes, and decreased with June PET on toeslopes. Red pine growth increased with increasing July PET across all topographic positions. These results indicate the sensitivity of both quaking aspen and red pine to local climate and show several vulnerabilities of these species to shifts in water supply and temperature because of climate change.

Subalpine Forest Carbon Cycling Short- and Long-Term Influence ofClimate and Species

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kueppers, L.; Harte, J.

2005-08-23

Ecosystem carbon cycle feedbacks to climate change comprise one of the largest remaining sources of uncertainty in global model predictions of future climate. Both direct climate effects on carbon cycling and indirect effects via climate-induced shifts in species composition may alter ecosystem carbon balance over the long term. In the short term, climate effects on carbon cycling may be mediated by ecosystem species composition. We used an elevational climate and tree species composition gradient in Rocky Mountain subalpine forest to quantify the sensitivity of all major ecosystem carbon stocks and fluxes to these factors. The climate sensitivities of carbon fluxesmore » were species-specific in the cases of relative above ground productivity and litter decomposition, whereas the climate sensitivity of dead wood decay did not differ between species, and total annual soil CO2 flux showed no strong climate trend. Lodge pole pine relative productivity increased with warmer temperatures and earlier snowmelt, while Engelmann spruce relative productivity was insensitive to climate variables. Engelmann spruce needle decomposition decreased linearly with increasing temperature(decreasing litter moisture), while lodgepole pine and subalpine fir needle decay showed a hump-shaped temperature response. We also found that total ecosystem carbon declined by 50 percent with a 2.88C increase in mean annual temperature and a concurrent 63 percent decrease ingrowing season soil moisture, primarily due to large declines in mineral soil and dead wood carbon. We detected no independent effect of species composition on ecosystem C stocks. Overall, our carbon flux results suggest that, in the short term, any change in subalpine forest net carbon balance will depend on the specific climate scenario and spatial distribution of tree species. Over the long term, our carbon stock results suggest that with regional warming and drying, Rocky Mountain subalpine forest will be a net source of carbon to the atmosphere.« less

Application of BIOME-BGC to Managed Forest Ecosystems in Europe

NASA Astrophysics Data System (ADS)

Pietsch, S. A.; Petritsch, R.; Hasenauer, H.

2007-05-01

European forests have been severely modified by humans resulting in a reduction of forest covered land area, a change in tree species distribution and the deterioration of forest soils. One option to assess forest management impacts on the cycling of carbon, nitrogen and water is the use of BGC-Models. Such models are considered as diagnostic tools for studying sustainability of forest ecosystems and have been used for climate change impact studies on forest growth and carbon sequestration issues. In our efforts to develop an appropriate diagnostic tool to assess the dynamics of carbon, nitrogen, water and energy flux for sustainable forest ecosystem management and climate change studies, we have selected BIOME-BGC. The main reason was that the general model structure is flexible enough to integrate large scale, regional as well as forest stand level information. During the last years we worked on the following extensions: (1) Tested and extended algorithms to interpolate daily climate input data as they are needed to run the model for any location within the country; (2) We developed a set of species specific parameters for all major tree species in Central Europe: Norway spruce (two variants highland and lowlands), Scots pine, Stone pine, larch, common beech and oak forests. These parameters sets are important since in BIOME-BGC vegetation is distinguished in biomes or plant functional types but the impacts of forest management (e.g. changes in stand density) may differ substantially among the tree species assigned to a single biome. (3) We extended the model to cover the full variation ranging from conditions including temperature extremes at the timberline to periodic ground water access or flooding in lowlands. (4) We adapted the spinup procedure to ensure unbiased predictions on forest status in the absence of past and present management impacts. (5) Explicitly addressed the effects of past and present forest management as they may differ by species and silvicultural practice. (6) We assess climate change impacts on managed forests and discuss the impacts of our results on forest management practices.

Modeling mountain pine beetle disturbance in Glacier National Park using multiple lines of evidence

USGS Publications Warehouse

Assal, Timothy; Sibold, Jason

2013-01-01

Temperate forest ecosystems are subject to various disturbances which contribute to ecological legacies that can have profound effects on the structure of the ecosystem. Impacts of disturbance can vary widely in extent, duration and severity over space and time. Given that global climate change is expected to increase rates of forest disturbance, an understanding of these events are critical in the interpretation of contemporary forest patterns and those of the near future. We seek to understand the impact of the 1970s mountain pine beetle outbreak on the landscape of Glacier National Park and investigate any connection between this event and subsequent decades of extensive wildfire. The lack of spatially explicit data on the mountain pine beetle disturbance represents a major data gap and inhibits our ability to test for correlations between outbreak severity and fire severity. To overcome this challenge, we utilized multiple lines of evidence to model forest canopy mortality as a proxy for outbreak severity. We used historical aerial and landscape photos, reports, aerial survey data, a six year collection of Landsat imagery and abiotic data in combination with regression analysis. The use of remotely sensed data is critical in large areas where subsequent disturbance (fire) has erased some of the evidence from the landscape. Results indicate that this method is successful in capturing the spatial heterogeneity of the outbreak in a topographically complex landscape. Furthermore, this study provides an example on the use of existing data to reduce levels of uncertainty associated with an historic disturbance.

Remote Assessment of Forest Ecosystem Stress (RAFES): Development of a Real Time Decision Support Tool for the Eastern U.S

NASA Astrophysics Data System (ADS)

Clinton, B.; Vose, J.; Novick, K.; Liu, Y.

2011-12-01

Drier and warmer conditions predicted with climate change models are likely to significantly impact forest ecosystems over the next several decades. The U.S. has experienced significant droughts over the past several years that have increased the susceptibility of forests to insect outbreaks, disease, and wildfire. Weather data collected with traditional approaches provide an indirect measure of drought or temperature stress; however, the significance of short-term or prolonged climate-related stress varies considerably across the landscape as topography, elevations, edaphic condition and antecedent conditions vary. This limits the capacity of land managers to anticipate and initiate management activities that could offset the impacts of climate-related forest stress. Decision support tools are needed that allow fine scale monitoring of stress conditions in forest ecosystems in real time to help land managers evaluate response strategies. To assist land managers in managing the impacts of climate change, we are developing a stress monitoring and decision support system across multiple sites in the eastern U.S. that (1) provides remote data capture of environmental parameters that quantify climate-related forest stress, (2) links remotely captured data with physiologically-based indices of tree water stress, and (3) provides a PC-based analytical tool for land managers to monitor and assess the severity of climate-related stress. Currently the network represents southern coastal plain pine plantation, Atlantic coastal flatwoods mixed pine-hardwood, southern piedmont upland mixed pine-hardwood, southern Appalachian dry ridge and mesic riparian, southern Arkansas managed mature pine, and northern Minnesota mature aspen. The strategy for selecting additional sites for the network will be a focus on at-risk ecosystems deemed particularly vulnerable to the affects of predicted climate change such as those in ecotonal transition regions, or those at the fringes of their ranges. The sensor arrays at each site detect water and temperature stress variables and transmit those data to a field office. Sensors include air and soil temperature, relative humidity, fuel moisture and temperature, xylem sap flux density, soil moisture and matric potential, precipitation, and solar radiation. Data are transmitted in real-time to the NOAA Geostationary Operational Environmental Satellite (GOES). A PC-based software program that downloads monitoring data from the GOES satellite, analyzes the data, and provides the land manager with an assessment of climate-related stress conditions and potential forest health threat levels in real time is under development. Data collection began in early 2010 on most sites, and we have at least one year of data from all nine sites within the network. We are currently comparing estimates of stress levels on our sites with estimates of stress from common drought indices. For this presentation, we are comparing and contrasting four sites representing an environmental gradient within the network.

Assessing Forest NPP: BIOME-BGC Predictions versus BEF Derived Estimates

NASA Astrophysics Data System (ADS)

Hasenauer, H.; Pietsch, S. A.; Petritsch, R.

2007-05-01

Forest productivity has always been a major issue within sustainable forest management. While in the past terrestrial forest inventory data have been the major source for assessing forest productivity, recent developments in ecosystem modeling offer an alternative approach using ecosystem models such as Biome-BGC to estimate Net Primary Production (NPP). In this study we compare two terrestrial driven approaches for assessing NPP: (i) estimates from a species specific adaptation of the biogeochemical ecosystem model BIOME-BGC calibrated for Alpine conditions; and (ii) NPP estimates derived from inventory data using biomass expansion factors (BEF). The forest inventory data come from 624 sample plots across Austria and consist of repeated individual tree observations and include growth as well as soil and humus information. These locations are covered with spruce, beech, oak, pine and larch stands, thus addressing the main Austrian forest types. 144 locations were previously used in a validating effort to produce species-specific parameter estimates of the ecosystem model. The remaining 480 sites are from the Austrian National Forest Soil Survey carried out at the Federal Research and Training Centre for Forests, Natural Hazards and Landscape (BFW). By using diameter at breast height (dbh) and height (h) volume and subsequently biomass of individual trees were calculated, aggregated for the whole forest stand and compared with the model output. Regression analyses were performed for both volume and biomass estimates.

Soil Temperature Triggers the Onset of Photosynthesis in Korean Pine

PubMed Central

Wu, Jiabing; Guan, Dexin; Yuan, Fenhui; Wang, Anzhi; Jin, Changjie

2013-01-01

In forest ecosystems, the onset of spring photosynthesis may have an important influence on the annual carbon balance. However, triggers for the onset of photosynthesis have yet to be clearly identified, especially for temperate evergreen conifers. The effects of climatic factors on recovery of photosynthetic capacity in a Korean pine forest were investigated in the field. No photosynthesis was detectable when the soil temperature was below 0°C even if the air temperature was far beyond 15°C. The onset of photosynthesis and sap flow was coincident with the time of soil thawing. The rates of recovery of photosynthetic capacity highly fluctuated with air temperature after onset of photosynthesis, and intermittent frost events remarkably inhibited the photosynthetic capacity of the needles. The results suggest that earlier soil thawing is more important than air temperature increases in triggering the onset of photosynthesis in Korean pine in temperate zones under global warming scenarios. PMID:23755227

Influence of harvesting intensity on the floristic composition of natural Mediterranean maritime pine forest

NASA Astrophysics Data System (ADS)

Alday, Josu G.; Martínez-Ruiz, Carolina; Marrs, Rob H.; Bravo, Felipe

2010-05-01

Understorey plant species composition is an important part of forest ecosystems and its conservation is becoming an increasingly frequent objective in forest management plans. However, there is a lack of knowledge of the effect of timber harvesting on the characteristic understorey species in the Mediterranean region. We investigated the effects of three different harvest intensities on the short-term dynamics of understorey vegetation in a natural Maritime pine forest in Spain, and compared the results with uncut controls. Clear-cutting induced both qualitative and quantitative differences with respect to the controls, but intermediate levels of harvesting (25% and 50% removal) induced only quantitative differences. Harvesting reduced the frequency and cover of 56% of characteristic forest species, but only 22% showed an increase. Of the most abundant plant families only the Fabaceae showed a significant response with respect to harvesting intensity. Our findings suggest that Light- and Medium-harvest regimes are better management options than clear-cutting if the aim is to conserve the understorey vegetation.

Long term changes in atmospheric N and S throughfall deposition and effects on soil solution chemistry in a Scots pine forest in the Netherlands.

PubMed

Boxman, Andries W; Peters, Roy C J H; Roelofs, Jan G M

2008-12-01

In a Scots pine forest the throughfall deposition and the chemical composition of the soil solution was monitored since 1984. (Inter)national legislation measures led to a reduction of the deposition of nitrogen and sulphur. The deposition of sulphur has decreased by approximately 65%. The total mineral-nitrogen deposition has decreased by ca. 25%, which is mainly due to a reduction in ammonium-N deposition (-40%), since nitrate-N deposition has increased (+50%). The nitrogen concentration in the upper mineral soil solution at 10 cm depth has decreased, leading to an improved nutritional balance, which may result in improved tree vitality. In the drainage water at 90 cm depth the fluxes of NO3(-) and SO4(2-) have decreased, resulting in a reduced leeching of accompanying base cations, thus preserving nutrients in the ecosystem. It may take still several years, however, before this will meet the prerequisite of a sustainable ecosystem.

The Effects of Disturbance and Climate on Carbon Storage and the Exchanges of CO 2 Water Vapor and Energy Exchange of Evergreen Coniferous Forests in the Pacific Northwest: Integration of Eddy Flux, Plant and Soil Measurements at a Cluster of Supersites. Final report

DOE Office of Scientific and Technical Information (OSTI.GOV)

Beverly E. Law; Thomas, Christoph K.

This is the final technical report containing a summary of all findings with regard to the following objectives of the project: (1) To quantify and understand the effects of wildfire on carbon storage and the exchanges of energy, CO2, and water vapor in a chronosequence of ponderosa pine (disturbance gradient); (2) To investigate the effects of seasonal and interannual variation in climate on carbon storage and the exchanges of energy, CO2, and water vapor in mature conifer forests in two climate zones: mesic 40-yr old Douglas-fir and semi-arid 60-yr old ponderosa pine (climate gradient); (3) To reduce uncertainty in estimatesmore » of CO2 feedbacks to the atmosphere by providing an improved model formulation for existing biosphere-atmosphere models; and (4) To provide high quality data for AmeriFlux and the NACP on micrometeorology, meteorology, and biology of these systems. Objective (1): A study integrating satellite remote sensing, AmeriFlux data, and field surveys in a simulation modeling framework estimated that the pyrogenic carbon emissions, tree mortality, and net carbon exchange associated with four large wildfires that burned ~50,000 hectares in 2002-2003 were equivalent to 2.4% of Oregon statewide anthropogenic carbon emissions over the same two-year period. Most emissions were from the combustion of the forest floor and understory vegetation, and only about 1% of live tree mass was combusted on average. Objective (2): A study of multi-year flux records across a chronosequence of ponderosa pine forests yielded that the net carbon uptake is over three times greater at a mature pine forest compared with young pine. The larger leaf area and wetter and cooler soils of the mature forest mainly caused this effect. A study analyzing seven years of carbon and water dynamics showed that interannual and seasonal variability of net carbon exchange was primarily related to variability in growing season length, which was a linear function of plant-available soil moisture in spring and early summer. A multi-year drought (2001-2003) led to a significant reduction of net ecosystem exchange due to carry-over effects in soil moisture and carbohydrate reserves in plant-tissue. In the same forest, the interannual variability in the rate carbon is lost from the soil and forest floor is considerable and related to the variability in tree growth as much as it is to variability in soil climatic conditions. Objective (3): Flux data from the mature ponderosa pine site support a physical basis for filtering nighttime data with friction velocity above the canopy. An analysis of wind fields and heat transport in the subcanopy at the mesic 40-year old Douglas site yielded that the non-linear structure and behavior of spatial temperature gradients and the flow field require enhanced sensor networks to estimate advective fluxes in the subcanopy of forest to close the surface energy balance in forests. Reliable estimates for flux uncertainties are needed to improve model validation and data assimilation in process-based carbon models, inverse modeling studies and model-data synthesis, where the uncertainties may be as important as the fluxes themselves. An analysis of the time scale dependence of the random and flux sampling error yielded that the additional flux obtained by increasing the perturbation timescale beyond about 10 minutes is dominated by random sampling error, and therefore little confidence can be placed in its value. Artificial correlation between gross ecosystem productivity (GEP) and ecosystem respiration (Re) is a consequence of flux partitioning of eddy covariance flux data when GEP is computed as the difference between NEE and computed daytime Re (e.g. using nighttime Re extrapolated into daytime using soil or air temperatures). Tower-data must be adequately spatially averaged before comparison to gridded model output as the time variability of both is inherently different. The eddy-covariance data collected at the mature ponderosa pine site and the mesic Douglas fir site were used to develop and evaluate a new method to extract the signal of ecosystem respiration directly from daytime net ecosystem exchange. This approach may help reducing uncertainty in carbon budgets by providing direct measurements of ecosystem respiration during daylight conditions by replacing modeled estimates. Objective (4): We submitted our flux and biological and ancillary data to the AmeriFlux web site and to Fluxnet. This includes atmospheric carbon, water, and heat fluxes, soil fluxes, NPP, carbon stocks, LAI, and disturbance history. Fluxnet is updating the original La Thuile files and will include the more recent years of data. They will be using a new approach to compute GPP, following discussions within the network about the need to improve GPP methodology« less

Latitudinal Gradients in the Stable Carbon and Oxygen Isotopes of Tree-Ring Cellulose Reveal Differential Climate Influences of the North American Monsoon

NASA Astrophysics Data System (ADS)

Szejner, P.; Wright, W. E.; Babst, F.; Belmecheri, S.; Trouet, V.; Ehleringer, J. R.; Leavitt, S. W.; Monson, R. K.

2015-12-01

Summer rainfall plays an important role sustaining different types of ecosystems in the Southwestern US. The arrival of the monsoon breaks the early summer hyper-arid period in the region providing unique seasonal conditions for these ecosystems to thrive. It is unknown to what extent monsoon rainfall is used by Ponderosa pine forests, which occupy many mountain ecosystems in the Western US. While these forests clearly rely on winter snowpack to drive much of their annual net primary productivity, the extent to which they supplement winter moisture, with summer monsoon moisture needs to be clarified. It is likely that there are north-south gradients in the degree to which forests rely on monsoon moisture, as the summer monsoon system tends to become diminished as it moves progressively northward. We addressed these gaps in our knowledge about the monsoon by studying stable Carbon and Oxygen isotopes in earlywood and latewood α-cellulose from cores taken from trees in eleven sites along a latitudinal gradient extending from Southern Arizona and New Mexico toward Utah. Here we show evidence that Ponderosa pine trees from most of these sites use monsoon water to support growth during the late summer, and the fractional use of monsoon precipitation is strongest in the southernmost sites. This study provides new physiological evidence on the influence of the North American monsoon and winter precipitation on tree growth in montane ecosystems of the Western US. Using these results, we predict differences in the susceptibility of southern and northern montane forests to future climate change. ACKNOWLEDGMENTS: This work was funded by an NSF Macrosystems Grant #1065790

Utilization of forest slash to sequester carbon in loblolly pine plantations in the lower coastal plain

Treesearch

F. Sanchez; E.A. Carter; W. Edwards

2002-01-01

Soil-organic matter (SOM) is a complex array of components including soil fauna and flora at different stages of decomposition (Berg et al., 1982). Its concentration in soils can vary from 0.5% in mineral soils to almost 100% in peat soils (Brady, 1974). Organic matter (OM) in the surface mineral soil is considered a major determinant of forest ecosystem productivity...

Ecological Health and Water Quality Assessments in Big Creek Lake, AL

NASA Astrophysics Data System (ADS)

Childs, L. M.; Frey, J. W.; Jones, J. B.; Maki, A. E.; Brozen, M. W.; Malik, S.; Allain, M.; Mitchell, B.; Batina, M.; Brooks, A. O.

2008-12-01

Big Creek Lake (aka J.B. Converse Reservoir) serves as the water supply for the majority of residents in Mobile County, Alabama. The area surrounding the reservoir serves as a gopher tortoise mitigation bank and is protected from further development, however, impacts from previous disasters and construction have greatly impacted the Big Creek Lake area. The Escatawpa Watershed drains into the lake, and of the seven drainage streams, three have received a 303 (d) (impaired water bodies) designation in the past. In the adjacent ecosystem, the forest is experiencing major stress from drought and pine bark beetle infestations. Various agencies are using control methods such as pesticide treatment to eradicate the beetles. There are many concerns about these control methods and the run-off into the ecosystem. In addition to pesticide control methods, the Highway 98 construction projects cross the north area of the lake. The community has expressed concern about both direct and indirect impacts of these construction projects on the lake. This project addresses concerns about water quality, increasing drought in the Southeastern U.S., forest health as it relates to vegetation stress, and state and federal needs for improved assessment methods supported by remotely sensed data to determine coastal forest susceptibility to pine bark beetles. Landsat TM, ASTER, MODIS, and EO-1/ALI imagery was employed in Normalized Difference Vegetation Index (NDVI) and Normalized Difference Moisture Index (NDMI), as well as to detect concentration of suspended solids, chlorophyll and water turbidity. This study utilizes NASA Earth Observation Systems to determine how environmental conditions and human activity relate to pine tree stress and the onset of pine beetle invasion, as well as relate current water quality data to community concerns and gain a better understanding of human impacts upon water resources.

Use of lodgepole pine cover types by Yellowstone grizzly bears

USGS Publications Warehouse

Mattson, D.J.

1997-01-01

Lodgepole pine (Pinus contorta) forests are a large and dynamic part of grizzly bear (Ursus arctos) habitat in the Yellowstone ecosystem. Research in other areas suggests that grizzly bears select for young open forest stands, especially for grazing and feeding on berries. Management guidelines accordingly recommend timber harvest as a technique for improving habitat in areas potentially dominated by lodgepole pine. In this paper I examine grizzly bear use of lodgepole pine forests in the Yellowstone area, and test several hypotheses with relevance to a new generation of management guidelines. Differences in grizzly bear selection of lodgepole pine cover types (defined on the basis of stand age and structure) were not pronounced. Selection furthermore varied among years, areas, and individuals. Positive selection for any lodgepole pine type was uncommon. Estimates of selection took 5-11 years or 4-12 adult females to stabilize, depending upon the cover type. The variances of selection estimates tended to stabilize after 3-5 sample years, and were more-or-less stable to slightly increasing with progressively increased sample area. There was no conclusive evidence that Yellowstone's grizzlies favored young (<40 yr) stands in general or for their infrequent use of berries. On the other hand, these results corroborated previous observations that grizzlies favored open and/or young stands on wet and fertile sites for grazing. These results also supported the proposition that temporally and spatially robust inferences require extensive, long-duration studies, especially for wide-ranging vertebrates like grizzly bears.

Seasonality and Management Affect Land Surface Temperature Differences Between Loblolly Pine and Switchgrass Ecosystems in Central Virginia

NASA Astrophysics Data System (ADS)

Ahlswede, B.; Thomas, R. Q.; O'Halloran, T. L.; Rady, J.; LeMoine, J.

2017-12-01

Changes in land-use and land management can have biogeochemical and biophysical effects on local and global climate. While managed ecosystems provide known food and fiber benefits, their influence on climate is less well quantified. In the southeastern United States, there are numerous types of intensely managed ecosystems but pine plantations and switchgrass fields represent two biogeochemical and biophysical extremes; a tall, low albedo forest with trees harvested after multiple decades vs. a short, higher albedo C4 grass field that is harvested annually. Despite the wide spread use of these ecosystems for timber and bioenergy, a quantitative, empirical evaluation of the net influence of these ecosystems on climate is lacking because it requires measuring both the greenhouse gas and energy balance of the ecosystems while controlling for the background weather and soil environment. To address this need, we established a pair of eddy flux towers in these ecosystems that are co-located (1.5 km apart) in Central Virginia and measured the radiative energy, non-radiative energy and carbon fluxes, along with associated biometeorology variables; the paired site has run since April 2016. During the first 1.5 years (two growing seasons), we found strong seasonality in the difference in surface temperature between the two ecosystems. In the growing seasons, both sites had similar surface temperature despite higher net radiation in pine. Following harvest of the switchgrass in September, the switchgrass temperatures increased relative to pine. In the winter, the pine ecosystem was warmer. We evaluate the drivers of these intra-annual dynamics and compare the climate influence of these biophysical differences to the differences in carbon fluxes between the sites using a suite of established climate regulation services metrics. Overall, our results show tradeoffs exist between the biogeochemical and biophysical climate services in managed ecosystems in the southeastern United States and highlight the importance of seasonality when quantifying how land-use and land-cover change influence climate. These data, when combined with earth system models, will help inform our understanding of how land-use and land change decisions in the southeastern United States will influence local, regional, and global climate.

AmeriFlux US-Blo Blodgett Forest

DOE Data Explorer

Goldstein, Allen [University of California, Berkeley

2016-01-01

This is the AmeriFlux version of the carbon flux data for the site US-Blo Blodgett Forest. Site Description - The flux tower site at Blodgett Forest is on a 1200 ha parcel of land owned by Sierra Pacific Industries in the Sierra Nevada range near Georgetown, California. The field site was established in May 1997 with continuous operation since May 1999. The site is situated in a ponderosa pine plantation, mixed-evergreen coniferous forest, located adjacent to Blodgett Forest Research Station. The Mediterranean-type climate of California is characterized by a protracted summer drought, with precipitation occurring mainly from October through May. The infrastructure for the ecosystem scale flux measurements includes a walkup measurement tower, two temperature controlled instrument buildings, and an electrical generation system powered by a diesel generator. Typical wind patterns at the site include upslope flow during the day (from the west) and downslope flow at night (from the east). The plantation is relatively flat, and contains a homogenous mixture of evenly aged ponderosa pine with other trees and shrubs scattered throughout the ecosystem making up less than 30% of the biomass. The daytime fetch for the tower measurements extends approximately 200 m to the southwest of the tower (this region contributes ~90% of the daytime flux), thus remote sensing images to be used for modeling should probably be centered approximately 100 m from the tower at an angle of 225 deg.

Distinguishing Bark Beetle-infested Vegetation by Tree Species Types and Stress Levels using Landsat Data

NASA Astrophysics Data System (ADS)

Sivanpillai, R.; Ewers, B. E.; Speckman, H. N.; Miller, S. N.

2015-12-01

In the Western United States, more than 3 million hectares of lodgepole pine forests have been impacted by the Mountain pine beetle outbreak, while another 166,000 hectares of spruce-fir forests have been attacked by Spruce beetle. Following the beetle attack, the trees lose their hydraulic conductivity thus altering their carbon and water fluxes. These trees go through various stages of stress until mortality, described by color changes in their needles prior to losing them. Modeling the impact of these vegetation types require thematically precise land cover data that distinguishes lodgepole pine and spruce-fir forests along with the stage of impact since the ecosystem fluxes are different for these two systems. However, the national and regional-scale land cover datasets derived from remotely sensed data do not have this required thematic precision. We evaluated the feasibility of multispectral data collected by Landsat 8 to distinguish lodgepole pine and spruce fir, and subsequently model the different stages of attack using field data collected in Medicine Bow National Forest (Wyoming, USA). Operational Land Imager, onboard Landsat 8 has more spectral bands and higher radiometric resolution (12 bit) in comparison to sensors onboard earlier Landsat missions which could improve the ability to distinguish these vegetation types and their stress conditions. In addition to these characteristics, its repeat coverage, rigorous radiometric calibration, wide swath width, and no-cost data provide unique advantages to Landsat data for mapping large geographic areas. Initial results from this study highlight the importance of SWIR bands for distinguishing different levels of stress, and the need for ancillary data for distinguishing species types. Insights gained from this study could lead to the generation of land cover maps with higher thematic precision, and improve the ability to model various ecosystem processes as a result of these infestations.

Forest Fires as a Possible Source of Isotopically Light Marine Fe Aerosols

NASA Astrophysics Data System (ADS)

Tegler, L. A.; Sherry, A. M.; Romaniello, S. J.; Anbar, A. D.

2016-12-01

Iron (Fe) is an important limiting micronutrient for primary productivity in many high-nutrient, low-chlorophyll (HNLC) regions of the ocean. These marine systems receive a significant fraction of their Fe from atmospheric deposition, which is thought to be dominated by mineral dust with an Fe isotopic composition at or above 0‰. However, Mead et al. (2013) observed isotopically light Fe in marine aerosols smaller than 2.5 μm, which is difficult to reconcile with known sources of marine aerosols. Based on previous experimental work, we hypothesize that biomass burning is the source of isotopically light Fe in atmospheric particles and suggest that biomass burning might represent an underappreciated source of Fe to marine ecosystems. While Guelke et al (2007) demonstrated that Fe in agricultural plants is isotopically light, few studies have examined the Fe isotope composition of naturally occurring forests likely to be a significant source of Fe during forest fires. To address this question, we measured the isotopic composition of Ponderosa pine growing in northern Arizona. Ponderosa pine is one the most common forest types in the western US and thus representative of an important North American fire region. Pine needles were chosen because they are susceptible to complete combustion during biomass burning events. To determine the Fe isotopic composition of pine trees, pine needles were sampled at various tree heights. We found that these samples had δ56Fe values between -1.5 and 0‰, indicating that pine needles can be isotopically light compared to local grasses and soil. These results support the hypothesis that biomass burning may contribute isotopically light Fe to marine aerosols.

Climate change will restrict ponderosa pine forest regeneration in the 21st century in absence of disturbance

NASA Astrophysics Data System (ADS)

Petrie, M. D.; Bradford, J. B.; Hubbard, R. M.; Lauenroth, W. K.; Andrews, C.

2016-12-01

The persistence of ponderosa pine forests and the ability for these forests to colonize new habitats in the 21st century will be influenced by how climate change supports ponderosa pine regeneration through the demographic processes of seed production, germination and survival. Yet, the way that climate change may support or restrict the frequency of successful regeneration is unclear. We developed a quantitative, criteria-based framework to estimate ponderosa pine regeneration potential (RP: a metric from 0-1) in response to climate forcings and environmental conditions. We used the SOILWAT ecosystem water balance model to simulate drivers of air and soil temperature, evaporation and soil moisture availability for 47 ponderosa pine sites across the western United States, using meteorological data from 1910-2014, and projections from nine General Circulation Models and the RCP 8.5 emissions scenario for 2020-2099. Climate change simulations increased the success of early developmental stages of seed production and germination, and supported 49.7% higher RP in 2020-2059 compared to averages from 1910-2014. As temperatures increased in 2060-2099, survival scores decreased, and RP was reduced by 50.3% compared to 1910-2014. Although the frequency of years with high RP did not change in 2060-2099 (12% of years), the frequency of years with very low RP increased from 25% to 58% of years. Thus, climate change will initially support higher RP and more favorable years in 2020-2059, yet will reduce average RP and the frequency of years with moderate regeneration support in 2060-2099. Forest regeneration is complex and not fully-understood, but our results suggest it is likely that climate change alone will instigate restrictions to the persistence and expansion of ponderosa pine in the 21st century.

Plant hydraulic controls over ecosystem responses to climate-enhanced disturbances

NASA Astrophysics Data System (ADS)

Mackay, D. S.; Ewers, B. E.; Reed, D. E.; Pendall, E.; McDowell, N. G.

2012-12-01

Climate-enhanced disturbances such as drought and insect infestation range in severity, contributing minor to severe stress to forests including forest mortality. While neither form of disturbance has been unambiguously implicated as a mechanism of mortality, both induce changes in water, carbon, and nutrient cycling that are key to understanding forest ecosystem response to, and recovery from, disturbance. Each disturbance type has different biophysical, ecohydrological, and biogeochemical signatures that potentially complicate interpretation and development of theory. Plant hydraulic function is arguably a unifying control over these responses to disturbance because it regulates stomatal conductance, leaf biochemistry, carbon (C) uptake and utilization, and nutrient cycling. We demonstrated this idea by focusing on water and C, including non-structural (NSC), resources, and nitrogen (N) uptake across a spectrum of forest ecosystems (e.g., northern temperate mixed forests, lodgepole pine forests in the Rocky Mountains, and pinon pine - juniper woodlands in New Mexico) using the Terrestrial Regional Ecosystem Exchange Simulator (TREES). TREES is grounded in the biophysics of water movement through soil and plants, respectively via hydraulic conductivity of the soil and cavitation of xylem. It combines this dynamic plant hydraulic conductance with canopy biochemical controls over photosynthesis, and the dynamics of structural and non-structural carbon through a carbon budget that responds to plant hydraulic status. As such, the model can be used to develop testable hypotheses on a multitude of disturbance and recovery responses including xylem dysfunction, stomatal and non-stomatal controls on photosynthesis and carbon allocation, respiration, and allocation to defense compounds. For each of the ecosystems we constrained and evaluated the model with allometry, sap flux and/or eddy covariance data, leaf gas exchange measurements, and vulnerability to cavitation data. Disturbances included declining water tables and canopy defoliators (northern temperature forests), bark beetles and associated blue-stain fungi (coniferous forests), and prolonged drought with bark beetles (semi-arid woodland). We show that C dynamics in trees that experience water-limitation, insect attack, or a combination of both disturbance types cannot be explained solely from hydraulic status or NSC, but are better explained by a combination of both in conjunction with N uptake. Results show that the use of plant hydraulics can yield parsimonious explanations of biophysical, ecohydrological, and biogeochemical responses to disturbance.

The Southern Global Change Program: Determining the relationship between air pollutants, climate change and forests

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mickler, R.A.; Fox, S.A.

The mission of the SGCP is to conduct research and monitoring in the southern region of the US; to determine the interactive responses among forest ecosystems, atmospheric pollution, and climate change; and to use this knowledge to manage and protect forest ecosystems. The first 5 years of research have emphasized the interactions and impacts of five stresses: CO{sub 2}, ozone, temperature, moisture, and nutrients in pine ecosystems. Hierarchial research approaches include correlational studies, experimental field and lab studies, and modeling Across individual-tree to regional levels. The results from 36 projects suggest: elevated CO{sub 2} increases carbon gain and suppress respirationmore » across site-resource conditions; genotypes are differentially affected by climate events; and competition and reproductive biology are likely to be impacted by climate change. An overview of five years of research results will be discussed.« less

Latent heat exchange in the boreal and arctic biomes.

PubMed

Kasurinen, Ville; Alfredsen, Knut; Kolari, Pasi; Mammarella, Ivan; Alekseychik, Pavel; Rinne, Janne; Vesala, Timo; Bernier, Pierre; Boike, Julia; Langer, Moritz; Belelli Marchesini, Luca; van Huissteden, Ko; Dolman, Han; Sachs, Torsten; Ohta, Takeshi; Varlagin, Andrej; Rocha, Adrian; Arain, Altaf; Oechel, Walter; Lund, Magnus; Grelle, Achim; Lindroth, Anders; Black, Andy; Aurela, Mika; Laurila, Tuomas; Lohila, Annalea; Berninger, Frank

2014-11-01

In this study latent heat flux (λE) measurements made at 65 boreal and arctic eddy-covariance (EC) sites were analyses by using the Penman-Monteith equation. Sites were stratified into nine different ecosystem types: harvested and burnt forest areas, pine forests, spruce or fir forests, Douglas-fir forests, broadleaf deciduous forests, larch forests, wetlands, tundra and natural grasslands. The Penman-Monteith equation was calibrated with variable surface resistances against half-hourly eddy-covariance data and clear differences between ecosystem types were observed. Based on the modeled behavior of surface and aerodynamic resistances, surface resistance tightly control λE in most mature forests, while it had less importance in ecosystems having shorter vegetation like young or recently harvested forests, grasslands, wetlands and tundra. The parameters of the Penman-Monteith equation were clearly different for winter and summer conditions, indicating that phenological effects on surface resistance are important. We also compared the simulated λE of different ecosystem types under meteorological conditions at one site. Values of λE varied between 15% and 38% of the net radiation in the simulations with mean ecosystem parameters. In general, the simulations suggest that λE is higher from forested ecosystems than from grasslands, wetlands or tundra-type ecosystems. Forests showed usually a tighter stomatal control of λE as indicated by a pronounced sensitivity of surface resistance to atmospheric vapor pressure deficit. Nevertheless, the surface resistance of forests was lower than for open vegetation types including wetlands. Tundra and wetlands had higher surface resistances, which were less sensitive to vapor pressure deficits. The results indicate that the variation in surface resistance within and between different vegetation types might play a significant role in energy exchange between terrestrial ecosystems and atmosphere. These results suggest the need to take into account vegetation type and phenology in energy exchange modeling. © 2014 John Wiley & Sons Ltd.

Impact of the Mountain Pine Beetle on the Forest Carbon Cycle in British Columbia from 1999 TO 2008 (Invited)

NASA Astrophysics Data System (ADS)

Chen, J. M.; Czurylowicz, P.; Mo, G.; Black, T. A.

2013-12-01

The unprecedented mountain pine beetle (Dendroctonus ponderosae) (MPB) outbreak in British Columbia starting in 1998 affected about 50% of the lodgepole pine (Pinus contorta var. latifolia) forests occupying about 50% of the land area of the province. The impact of this outbreak on the C cycle is assessed in this study. Annual leaf area index (LAI) maps of the affected area from 1999 to 2008 were produced using SPOT VEGETATION data, and net ecosystem production (NEP) was modeled using inputs of LAI, land cover, soil texture and daily meteorological data with the Boreal Ecosystem Productivity Simulator (BEPS). Both LAI and NEP were validated using field measurements. LAI was found to decrease on average by 20% compared to pre-outbreak conditions, while NEP decreased on average by 90%. Annual NEP values ranged from 2.4 to -8.0 Tg C between 1999 and 2008, with the ecosystem changing from a carbon sink to a carbon source in 2000. The annual average NEP was -2.9 Tg C over the 10 years, resulting in a total loss of carbon of 29 Tg C to the atmosphere. The inter-annual variability of both LAI and NEP was characterized by substantial initial decreases followed by steady increases from 2006 to 2008 with NEP returning to near carbon neutrality in 2008 (-1.8 Pg C/y). The impact of this MPB outbreak appears to be less dramatic than previously anticipated. The apparent fast recovery of LAI and NEP after MPB attacks is examined under the framework of ecosystem resilience which was manifested in the form of secondary overstory and understory growth and increased production of non-attacked host trees.

Estimating the avoided fuel-reatment costs of wildfire

Treesearch

Geoffrey H. Donovan; Thomas C. Brown

2008-01-01

Although the importance of wildfire to fire-adapted ecosystems is widely recognized, wildfire management has historically placed less emphasis on the beneficial effects of wildfire. We estimate the avoided fuel treatment cost for 10 ponderosa pine (Pinus ponderosa) stands on the Umatilla National Forest in the Pacific Northwest. Results show that...

Fire applications in ecosystem management

Treesearch

Michael G. Harrington

2000-01-01

Decades of fire absence from ponderosa pine/Douglas-fir forests has resulted in overstocked, unhealthy, and severe fireprone stands requiring management attention. Prescribed fire can be used in three general situations during restoration management. First is when fuel loadings are excessive from either natural accumulation or harvest slash. Second is when dense...

Understory plant biomass dynamics of prescribed burned Pinus palustris stands

Treesearch

C.A. Gonzalez-Benecke; L.J. Samuelson; T.A. Stokes; W.P. Cropper Jr; T.A. Martin; K.H. Johnsen

2015-01-01

Longleaf pine (Pinus palustris Mill.) forests are characterized by unusually high understory plant species diversity, but models describing understory ground cover biomass, and hence fuel load dynamics, are scarce for this fire-dependent ecosystem. Only coarse scale estimates, being restricted on accuracy and geographical extrapolation,...

EFFECTS OF CARBON DIOXIDE AND OZONE ON NITROGEN RETRANSLOCATION IN PONDEROSA PINE NEEDLES

EPA Science Inventory

Changes in leaf N concentration can be an important response to air pollutants in trees, with implications both for tree growth and N cycling through forest ecosystems. Ozone causes premature leaf senescence, which may be associated with a shift in N from the senescing leaves to...

Influence of ecosystem restoration for red-cockaded woodpeckers on breeding bird and small mammal communities

Treesearch

Ronald E. Masters; Christopher W. Wilson; Douglas S. Cram; George A. Bukenhofer; Robert L. Lochmiller

2002-01-01

Shortleaf pine-bluestem (Pinus echinata Mill.- Andropogon spp.) restoration for red-cockaded woodpeckers (Picoides borealis) has been underway for more than 2 decades on the Ouachita National Forest, Arkansas. Restoration efforts consist of modifying stand structure to basal areas similar to presettlement times...

Gambel oak growth forms: Management opportunities for increasing ecosystem diversity

Treesearch

Scott R. Abella

2008-01-01

Gambel oak (Quercus gambelii) clones have several different growth forms in southwestern ponderosa pine (Pinus ponderosa) forests, and these growth forms each provide unique wildlife habitat and resource values. The purposes of this note are to review published growth-form classifications for Gambel oak, provide examples of...

Water and Energy Balances of Loblolly Pine Plantation Forests during a Full Stand Rotation

NASA Astrophysics Data System (ADS)

Sun, G.; Mitra, B.; Domec, J. C.; Gavazi, M.; Yang, Y.; Tian, S.; Zietlow, D.; McNulty, S.; King, J.; Noormets, A.

2017-12-01

Loblolly pine (Pinus taeda) plantations in the southern U.S. are well recognized for their ecosystem services in supplying clean and stable water and mitigating climate change through carbon sequestration and solar energy partitioning. Since 2004, we have monitored energy, water, and carbon fluxes in a chronosequence of three drained loblolly pine plantations using integrated methods that include eddy covariance, sap flux, watershed hydrometeorology, remote sensing, and process-based simulation modeling. Study sites were located on the eastern North Carolina coastal plain, representing highly productive ecosystems with high groundwater table, and designated in the Ameriflux network as NC1 (0-10 year old), NC2 (12-25 year old) and NC3 (0-3 years old). The 13-year study spanned a wide range of annual precipitation (900-1600 mm/yr) including two exceptionally dry years during 2007-2008. We found that the mature stand (NC2) had higher net radiation (Rn) flux due to its lower albedo (α =0.11-12), compared with the young stands (NC1, NC3) (α=0.15-0.18). Annually about 75%-80% of net radiation was converted to latent heat in the pine plantations. In general, the mature stand had higher latent heat flux (LE) (i.e. evapotranspiration (ET)) rates than the young stands, but ET rates were similar during wet years when the groundwater table was at or near the soil surface. During a historic drought period (i.e., 2007-2008), total stand annual ET exceeded precipitation, but decreased about 30% at NC2 when compared to a normal year (e.g., 2006). Field measurements and remote sensing-based modeling suggested that annual ET rates increased linearly from planting age (about 800 mm) to age 15 (about 1050 mm) and then stabilized as stand leaf area index leveled-off. Over a full stand rotation, approximately 70% (young stand) to 90% (mature stand) of precipitation was returned to the atmosphere through ET. We conclude that both climatic variability and canopy structure controlled the partitioning of precipitation and solar energy in pine forests. In addition, we conclude that accessible groundwater was important factor for stabilizing forest water and energy balances during a drought in the lower coastal ecosystems.

BOREAS TE-9 In Situ Understory Spectral Reflectance Within the NSA

NASA Technical Reports Server (NTRS)

Hall, Forrest G. (Editor); Curd, Shelaine (Editor); Supronowicz, Jan; Edwards, Geoffrey; Viau, Alain; Thomson, Keith

2000-01-01

The Boreal Ecosystem-Atmospheric Study (BOREAS) TE-9 (Terrestrial Ecology) team collected several data sets related to chemical and photosynthetic properties of leaves in boreal forest tree species. Spectral reflection coefficients of the forest understory at the ground level, in three boreal forest sites of Northern Manitoba (56 N latitude and 98 W longitude), were obtained and analyzed in 1994. In particular, angular variation of the reflection coefficients in the old jack pine and young jack pine forests, as well as nadir reflection coefficient in the young aspen forest, were investigated. The complexity of understory composition and the light patterns limited quantitative conclusions; however, a number of interesting trends in the behavior of the measured values can be inferred. In particular, the unique spectral profiles of lichens show very strongly in the old jack pine understory, yet are definitely less conspicuous for young jack pine, and virtually absent in the aspen forest. The angular variation of the reflection coefficient by the young pine understory seems to be significantly toned down by fine-structured branches and their shadows. Our study also indicates how difficult the ground reflection coefficient problem in a forest is, compared to certain previously investigated areas that have a more uniform appearance, such as prairie grassland, bare soil, or agricultural crops. This is due to several factors, generally typical of a forest environment, that may influence the overall understory reflection coefficient, including: (1) a strong diversity of the forest floor due to the presence of dead tree trunks, holes in the ground, patches of different types of vegetation or litter, etc.; (2) pronounced 3-D structures at the ground level, such as shrubs, bushes, and young trees; and (3) an irregular shadow mosaic, which not only varies with the time of the day, causing intensity variations, but likely also effectively modifies the spectrum of the illuminating light and hence the reflection coefficient signal as well The data are stored in tabular ASCII files. The data files are available on a CD-ROM (see document number 20010000884), or from the Oak Ridge National Laboratory (ORNL) Distributed Active Archive Center (DAAC).

Leveraging 35 years of Pinus taeda research in the southeastern US to constrain forest carbon cycle predictions: regional data assimilation using ecosystem experiments

DOE Office of Scientific and Technical Information (OSTI.GOV)

Thomas, R. Quinn; Brooks, Evan B.; Jersild, Annika L.

Predicting how forest carbon cycling will change in response to climate change and management depends on the collective knowledge from measurements across environmental gradients, ecosystem manipulations of global change factors, and mathematical models. Formally integrating these sources of knowledge through data assimilation, or model–data fusion, allows the use of past observations to constrain model parameters and estimate prediction uncertainty. Data assimilation (DA) focused on the regional scale has the opportunity to integrate data from both environmental gradients and experimental studies to constrain model parameters. Here, we introduce a hierarchical Bayesian DA approach (Data Assimilation to Predict Productivity for Ecosystems and Regions,more » DAPPER) that uses observations of carbon stocks, carbon fluxes, water fluxes, and vegetation dynamics from loblolly pine plantation ecosystems across the southeastern US to constrain parameters in a modified version of the Physiological Principles Predicting Growth (3-PG) forest growth model. The observations included major experiments that manipulated atmospheric carbon dioxide (CO 2) concentration, water, and nutrients, along with nonexperimental surveys that spanned environmental gradients across an 8.6 × 10 5 km 2 region. We optimized regionally representative posterior distributions for model parameters, which dependably predicted data from plots withheld from the data assimilation. While the mean bias in predictions of nutrient fertilization experiments, irrigation experiments, and CO 2 enrichment experiments was low, future work needs to focus modifications to model structures that decrease the bias in predictions of drought experiments. Predictions of how growth responded to elevated CO 2 strongly depended on whether ecosystem experiments were assimilated and whether the assimilated field plots in the CO 2 study were allowed to have different mortality parameters than the other field plots in the region. We present predictions of stem biomass productivity under elevated CO 2, decreased precipitation, and increased nutrient availability that include estimates of uncertainty for the southeastern US. Overall, we (1) demonstrated how three decades of research in southeastern US planted pine forests can be used to develop DA techniques that use multiple locations, multiple data streams, and multiple ecosystem experiment types to optimize parameters and (2) developed a tool for the development of future predictions of forest productivity for natural resource managers that leverage a rich dataset of integrated ecosystem observations across a region.« less

Leveraging 35 years of Pinus taeda research in the southeastern US to constrain forest carbon cycle predictions: regional data assimilation using ecosystem experiments

DOE PAGES

Thomas, R. Quinn; Brooks, Evan B.; Jersild, Annika L.; ...

2017-07-26

Predicting how forest carbon cycling will change in response to climate change and management depends on the collective knowledge from measurements across environmental gradients, ecosystem manipulations of global change factors, and mathematical models. Formally integrating these sources of knowledge through data assimilation, or model–data fusion, allows the use of past observations to constrain model parameters and estimate prediction uncertainty. Data assimilation (DA) focused on the regional scale has the opportunity to integrate data from both environmental gradients and experimental studies to constrain model parameters. Here, we introduce a hierarchical Bayesian DA approach (Data Assimilation to Predict Productivity for Ecosystems and Regions,more » DAPPER) that uses observations of carbon stocks, carbon fluxes, water fluxes, and vegetation dynamics from loblolly pine plantation ecosystems across the southeastern US to constrain parameters in a modified version of the Physiological Principles Predicting Growth (3-PG) forest growth model. The observations included major experiments that manipulated atmospheric carbon dioxide (CO 2) concentration, water, and nutrients, along with nonexperimental surveys that spanned environmental gradients across an 8.6 × 10 5 km 2 region. We optimized regionally representative posterior distributions for model parameters, which dependably predicted data from plots withheld from the data assimilation. While the mean bias in predictions of nutrient fertilization experiments, irrigation experiments, and CO 2 enrichment experiments was low, future work needs to focus modifications to model structures that decrease the bias in predictions of drought experiments. Predictions of how growth responded to elevated CO 2 strongly depended on whether ecosystem experiments were assimilated and whether the assimilated field plots in the CO 2 study were allowed to have different mortality parameters than the other field plots in the region. We present predictions of stem biomass productivity under elevated CO 2, decreased precipitation, and increased nutrient availability that include estimates of uncertainty for the southeastern US. Overall, we (1) demonstrated how three decades of research in southeastern US planted pine forests can be used to develop DA techniques that use multiple locations, multiple data streams, and multiple ecosystem experiment types to optimize parameters and (2) developed a tool for the development of future predictions of forest productivity for natural resource managers that leverage a rich dataset of integrated ecosystem observations across a region.« less

Leveraging 35 years of Pinus taeda research in the southeastern US to constrain forest carbon cycle predictions: regional data assimilation using ecosystem experiments

NASA Astrophysics Data System (ADS)

Quinn Thomas, R.; Brooks, Evan B.; Jersild, Annika L.; Ward, Eric J.; Wynne, Randolph H.; Albaugh, Timothy J.; Dinon-Aldridge, Heather; Burkhart, Harold E.; Domec, Jean-Christophe; Fox, Thomas R.; Gonzalez-Benecke, Carlos A.; Martin, Timothy A.; Noormets, Asko; Sampson, David A.; Teskey, Robert O.

2017-07-01

Predicting how forest carbon cycling will change in response to climate change and management depends on the collective knowledge from measurements across environmental gradients, ecosystem manipulations of global change factors, and mathematical models. Formally integrating these sources of knowledge through data assimilation, or model-data fusion, allows the use of past observations to constrain model parameters and estimate prediction uncertainty. Data assimilation (DA) focused on the regional scale has the opportunity to integrate data from both environmental gradients and experimental studies to constrain model parameters. Here, we introduce a hierarchical Bayesian DA approach (Data Assimilation to Predict Productivity for Ecosystems and Regions, DAPPER) that uses observations of carbon stocks, carbon fluxes, water fluxes, and vegetation dynamics from loblolly pine plantation ecosystems across the southeastern US to constrain parameters in a modified version of the Physiological Principles Predicting Growth (3-PG) forest growth model. The observations included major experiments that manipulated atmospheric carbon dioxide (CO2) concentration, water, and nutrients, along with nonexperimental surveys that spanned environmental gradients across an 8.6 × 105 km2 region. We optimized regionally representative posterior distributions for model parameters, which dependably predicted data from plots withheld from the data assimilation. While the mean bias in predictions of nutrient fertilization experiments, irrigation experiments, and CO2 enrichment experiments was low, future work needs to focus modifications to model structures that decrease the bias in predictions of drought experiments. Predictions of how growth responded to elevated CO2 strongly depended on whether ecosystem experiments were assimilated and whether the assimilated field plots in the CO2 study were allowed to have different mortality parameters than the other field plots in the region. We present predictions of stem biomass productivity under elevated CO2, decreased precipitation, and increased nutrient availability that include estimates of uncertainty for the southeastern US. Overall, we (1) demonstrated how three decades of research in southeastern US planted pine forests can be used to develop DA techniques that use multiple locations, multiple data streams, and multiple ecosystem experiment types to optimize parameters and (2) developed a tool for the development of future predictions of forest productivity for natural resource managers that leverage a rich dataset of integrated ecosystem observations across a region.

The Effects of Degradational Factors on the Ecosystem of Mount Madra

NASA Astrophysics Data System (ADS)

Efe, R.; Soykan, A.; Sönmez, S.; Cürebal, I.

2009-04-01

Significant degradation has been observed in Turkey's Mediterranean woodlands and mountainous areas. Mediterranean climate prevails in the southern and western part of Turkey. Mount Madra, which is located on Turkey's western Aegean coast, is part of a rangeland which is particularly exposed to the effects of degradation resulting from human activities. The principal factors in the degradation are inappropriate land use, destruction of forests, mining, construction, overgrazing and transhumance. Mount Madra and its environs benefit from a Mediterranean climate, experiencing dry, hot summers and cool, wet winters. The average yearly rainfall is 700-1000 mm, of which most occurs in the winter months. The mountain extends from east to west, and between the South and North slopes there is great variety in terms of plant species and biodiversity. The regeneration of the lost plant cover has been hindered by the mountain's geomorphologic characteristics. The slopes have suffered destruction of vegetation and, as a result of severe erosion, the soil has been swept away and in many places the bedrock has become exposed. The Kozak plateau on mount Madra is notable for the richness of its natural vegetation. This plateau, covered in pine forest (Pinus pinea), is the site for the traditional transhumance of over 500 families. Pine nuts and livestock breeding are livelihood of these families. Mount Madra and its surrounding area is one of the most important locations with gold mining potential in Turkey and it is estimated that it has 16.7 tons of gold reserve. The gold mining which took place on the west of the Madra Mountain around Ovacik village in 1994 led to serious land degradation in the surrounding area. The new mining on the study area and the proposed feldspar mining on the Madra riverbed poses a serious threat to the region's ecosystem and biodiversity. The removal of increasing amounts of granite and other quarrying has had a negative impact on the natural environment of Kozak Plataeu, and in addition to this, quarrying activity has recently begun in the area around Burhaniye. All these activities have led to problems such as erosion, decreased biodiversity, and pollution of water sources on Mount Madra. The forest clearances which have been made, for various reasons, on the northern and southern slopes of Mount Madra, have caused the topsoil to be worn away by surface water. The most striking examples of this can be seen on Mount Şabla (1111m) and on the southern slopes of Maya peak (1344m). The trimming recently carried out by the Forestry Commission on sections of Mount Madra has badly damaged the forest's vegetation and in a short space of time caused irreversible harm to the ecosystem of the mountain. For thousands of years, parts of the top of Mount Madra and the Kozak plateau have been used as summer grounds and, as a result, the forest has been cleared from a wide section. On the north-facing slopes of Mount Madra, the number of chestnut trees (Castanea sativa) found within pine woods is increasing daily. The pine trees around the chestnuts are being chopped down in order to increase the number of chestnut trees, whose fruit are harvested for the economic benefit they bring. The pine forests are, for this reason, in constant decline. Forest roads, both planned and unplanned, have led to further destruction of forest vegetation. Apart from the forest vegetation of the Mountain, other natural resources are under threat; particularly water sources. Facilities for fish farming have been built with no pre-planning or research, leading to the clearance of forest and pollution of the environment. Mount Madra is an important water source for the rivers in the surrounding areas. It is the source of the Madra and Karınca Rivers which flow into the Aegean Sea, the Kocaçay River which feeds Manyas Lake and several tributaries of the Bakırçay River. The protection of Mount Madra and its freshwater sources and biodiversity is therefore of great importance. Around 90 plant species, including 19 endemic species are found on the study area and it is vital that its ecosystem is protected, the threats are eliminated, and the sustainable use of its resources is secured. Key words: Madra Mountains, Degradation, Human Activities, Mediterranean Ecosystem, Biodiversity, Turkey.

Effect of coarse woody debris manipulation on soricid and herpetofaunal communities in upland pine stands of the southeastern coastal plain.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Davis, Justin, Charles

2009-04-01

Abstract -The majority of studies investigating the importance of coarse woody debris (CWD) to forest- floor vertebrates have taken place in the Pacific Northwest and southern Appalachian Mountains, while comparative studies in the southeastern Coastal Plain are lacking. My study was a continuation of a long-term project investigating the importance of CWD as a habitat component for shrew and herpetofaunal communities within managed pine stands in the southeastern Coastal Plain. Results suggest that addition of CWD can increase abundance of southeastern and southern short-tailed shrews. However, downed wood does not appear to be a critical habitat component for amphibians andmore » reptiles. Rising petroleum costs and advances in wood utilization technology have resulted in an emerging biofuels market with potential to decrease CWD volumes left in forests following timber harvests. Therefore, forest managers must understand the value of CWD as an ecosystem component to maintain economically productive forests while conserving biological diversity.« less

N-15 tracing helps explaining N leaching losses from contrasting forest ecosystems

NASA Astrophysics Data System (ADS)

Staelens, J.; Rütting, T.; Huygens, D.; Müller, C.; Verheyen, K.; Boeckx, P.

2009-04-01

Despite chronically enhanced nitrogen (N) deposition to forest ecosystems in Europe and NE America, considerable N retention by forests has been observed, reducing N leaching losses. Organic and mineral soil layers typically immobilize more N than the aboveground biomass, but it is unclear which factors determine N retention in forest ecoystems. However, this knowledge is crucial to assess the impact of changing anthropogenic N emissions on future N cycling and N loss of forests. For coniferous and deciduous forest stands at comparable sites, it is known that both N deposition onto the forest floor as well as N loss by leaching below the rooting zone are significantly higher in coniferous stands. In addition, the N loss in coniferous stands is often more enhanced than can be explained by the higher N input only. This suggests lower N retention by coniferous stands, and may be related to differences in litter and soil characteristics, microbial activity, and N uptake by plant roots. To test this hypothesis, we studied the effect of forest type on N retention using 15N tracing techniques: a field tracer experiment and a combination of in situ isotope pool dilution and a tracing model. The N dynamics were examined for two adjacent forest stands (pedunculate oak (Quercus robur L.) and Scots pine (Pinus sylvestris L.)) on a well-drained sandy soil and with a similar stand history, located in a region with high N deposition (Belgium). Input-output N budgets were established by quantifying atmospheric deposition and leaching below the rooting zone, and confirmed the above finding of higher N deposition and disproportionately higher N loss for the pine stand compared to the oak stand. First, the fate of inorganic N within the ecosystems was studied by spraying three pulses of dissolved 15N, either as ammonium or as nitrate, onto the forest floor in 12 plots of 25 m2. The organic and mineral soil layers, tree roots, soil water percolate, ferns, and tree foliage were sampled and analyzed for total N and 15N four times in the year after 15N application. Here we present results of the 15N recovery four months after the first application, and compare the recovery between the two forest stands and the two N treatments. Second, gross N transformation rates in the undisturbed mineral forest soils were determined via 15N pool dilution and advanced trace modelling. Using five spatial replicates per stand, three 15N treatments were applied in the field to 'virtual' soil cores (0-10 cm) that were disturbed only at sampling. Each treatment solution contained ammonium, nitrate, and nitrite, with one of the N forms labelled with 15N at 99% at. excess. Intact soil cores were sampled at six time intervals over a 12-day period, and analyzed for N and 15N content in different mineral and organic pools. The parameters of different simultaneously occurring process rates were optimized using a Markov Chain Monte Carlo algorithm. In both stands, heterotrophic nitrification of the organic soil pool was more important than autotrophic nitrification of ammonium. Significantly different process rates between the two forest stands were found for mineralization, heterotrophic and autotrophic nitrification, and ammonium and nitrate immobilization. Gross mineralization and ammonium immobilization rates were higher in the oak soil than in the pine soil. Gross nitrate production, in contrast, was faster in the pine soil, while nitrate immobilization was slower. These different soil nitrate dynamics likely contribute to the observed higher nitrate leaching loss in the pine than oak stand. In addition to the faster nitrate immobilization in the oak soil, our results strongly suggested the occurrence of a second N-conserving process under oak, i.e. dissimilatory nitrate reduction to ammonium (DNRA). This is unexpected for a temperate forest soil under enhanced N deposition, as this process has mainly been described for unpolluted soils.

Climate influences on whitebark pine mortality from mountain pine beetle in the Greater Yellowstone Ecosystem.

PubMed

Buotte, Polly C; Hicke, Jeffrey A; Preisler, Haiganoush K; Abatzoglou, John T; Raffa, Kenneth F; Logan, Jesse A

2016-12-01

Extensive mortality of whitebark pine, beginning in the early to mid-2000s, occurred in the Greater Yellowstone Ecosystem (GYE) of the western USA, primarily from mountain pine beetle but also from other threats such as white pine blister rust. The climatic drivers of this recent mortality and the potential for future whitebark pine mortality from mountain pine beetle are not well understood, yet are important considerations in whether to list whitebark pine as a threatened or endangered species. We sought to increase the understanding of climate influences on mountain pine beetle outbreaks in whitebark pine forests, which are less well understood than in lodgepole pine, by quantifying climate-beetle relationships, analyzing climate influences during the recent outbreak, and estimating the suitability of future climate for beetle outbreaks. We developed a statistical model of the probability of whitebark pine mortality in the GYE that included temperature effects on beetle development and survival, precipitation effects on host tree condition, beetle population size, and stand characteristics. Estimated probability of whitebark pine mortality increased with higher winter minimum temperature, indicating greater beetle winter survival; higher fall temperature, indicating synchronous beetle emergence; lower two-year summer precipitation, indicating increased potential for host tree stress; increasing beetle populations; stand age; and increasing percent composition of whitebark pine within a stand. The recent outbreak occurred during a period of higher-than-normal regional winter temperatures, suitable fall temperatures, and low summer precipitation. In contrast to lodgepole pine systems, area with mortality was linked to precipitation variability even at high beetle populations. Projections from climate models indicate future climate conditions will likely provide favorable conditions for beetle outbreaks within nearly all current whitebark pine habitat in the GYE by the middle of this century. Therefore, when surviving and regenerating trees reach ages suitable for beetle attack, there is strong potential for continued whitebark pine mortality due to mountain pine beetle. © 2016 by the Ecological Society of America.

The assessment of environmentally sensitive forest road construction in Calabrian pine forest areas of Turkey.

PubMed

Tunay, Metin

2006-07-01

Forest road construction by bulldozers in Calabrian Pine (Pinus brutia Ten.) forests on mountainous terrain of Turkey causes considerable damage to the environment and the forest standing alongside the road. This situation obliges a study of environmentally sound road construction in Turkey. This study was carried out in 4 sample sites of Antalya Forest Directorate in steep (34-50% gradient) and very steep terrain (51-70% gradient) conditions with bulldozer and excavator machine and direct damages to forest during road construction was determined, including forest area losses and damages to downhill trees in mountainous areas. It was determined that in steep terrain when excavators were used, less forest area (22.16%) was destroyed compared to bulldozers and 26.54% less area in very steep terrain. The proportion of damage on trees where bulldozer worked was nearly twofold higher than excavator was used. The results of this research show that the environmentally sensitive techniques applied for the road construction projects are considerably superior to the traditional use of bulldozers on steep slopes. The environmentally sound forest road construction by use of excavator must be considered an appropriate and reliable solution for mountainous terrain where areas of sensitive forest ecosystems are to be opened up.

The future of subalpine forests in the Southern Rocky Mountains: Trajectories for Pinus aristata genetic lineages

PubMed Central

2018-01-01

Like many other high elevation alpine tree species, Rocky Mountain bristlecone pine (Pinus aristata Engelm.) may be particularly vulnerable to climate change. To evaluate its potential vulnerability to shifts in climate, we defined the suitable climate space for each of four genetic lineages of bristlecone pine and for other subalpine tree species in close proximity to bristlecone pine forests. Measuring changes in the suitable climate space for lineage groups is an important step beyond models that assume species are genetically homogenous. The suitable climate space for bristlecone pine in the year 2090 is projected to decline by 74% and the proportional distribution of suitable climate space for genetic lineages shifts toward those associated with warmer and wetter conditions. The 2090 climate space for bristlecone pine exhibits a bimodal distribution along an elevation gradient, presumably due to the persistence of the climate space in the Southern Rocky Mountains and exclusion at mid-elevations by conditions that favor the climate space of other species. These shifts have implications for changes in fire regimes, vulnerability to pest and pathogens, and altered carbon dynamics across the southern Rockies, which may reduce the likelihood of bristlecone pine trees achieving exceptional longevity in the future. The persistence and expansion of climate space for southern bristlecone pine genetic lineage groups in 2090 suggests that these sources may be the least vulnerable in the future. While these lineages may be more likely to persist and therefore present opportunities for proactive management (e.g., assisted migration) to maintain subalpine forest ecosystem services in a warmer world, our findings also imply heighted conservation concern for vulnerable northern lineages facing range contractions. PMID:29554097

Summary of preliminary step-trend analysis from the Interagency Whitebark Pine Long-termMonitoring Program—2004-2013

USGS Publications Warehouse

Legg, Kristin; Shanahan, Erin; Daley, Rob; Irvine, Kathryn M.

2014-01-01

In mixed and dominant stands, whitebark pine (Pinus albicaulis) occurs in over two million acres within the six national forests and two national parks that comprise the Greater Yellowstone Ecosystem (GYE). Currently, whitebark pine, an ecologically important species, is impacted by multiple ecological disturbances; white pine blister rust (Cronartium ribicola), mountain pine beetle (Dendroctonus ponderosae), wildfire, and climate change all pose significant threats to the persistence of whitebark pine populations. Substantial declines in whitebark pine populations have been documented throughout its range.Under the auspices of the Greater Yellowstone Coordinating Committee (GYCC), several agencies began a collaborative, long-term monitoring program to track and document the status of whitebark pine across the GYE. This alliance resulted in the formation of the Greater Yellowstone Whitebark Pine Monitoring Working Group (GYWPMWG), which consists of representatives from the U.S. Forest Service (USFS), National Park Service (NPS), U.S. Geological Survey (USGS), and Montana State University (MSU). This groundbased monitoring program was initiated in 2004 and follows a peer-reviewed protocol (GYWPMWG 2011). The program is led by the Greater Yellowstone Inventory and Monitoring Network (GRYN) of the National Park Service in coordination with multiple agencies. More information about this monitoring effort is available at: http://science. nature.nps.gov/im/units/gryn/monitor/whitebark_pine.cfm. The purpose of this report is to provide a draft summary of the first step-trend analysis for the interagency, long-term monitoring of whitebark pine health to the Interagency Grizzly Bear Study Team (IGBST) as part of a synthesis of the state of whitebark pine in the GYE. Due to the various stages of the analyses and reporting, this is the most efficient way to provide these results to the IGBST.

Forest canopy temperatures: dynamics, controls, and relationships with ecosystem fluxes

NASA Astrophysics Data System (ADS)

Still, C. J.; Griffith, D.; Kim, Y.; Law, B. E.; Hanson, C. V.; Kwon, H.; Schulze, M.; Detto, M.; Pau, S.

2017-12-01

Temperature strongly affects enzymatic reactions, ecosystem biogeochemistry, and species distributions. Although most focus is on air temperature, the radiative or skin temperature of plants is more relevant. Canopy skin temperature dynamics reflect biophysical, physiological, and anatomical characteristics and interactions with the environment, and can be used to examine forest responses to stresses like droughts and heat waves. Thermal infrared (TIR) imaging allows for extensive temporal and spatial sampling of canopy temperatures, particularly compared to spot measurements using thermocouples. We present results of TIR imaging of forest canopies at eddy covariance flux tower sites in the US Pacific Northwest and in Panama. These forests range from an old-growth temperate rainforest to a second growth semi-arid pine forest to a semi-deciduous tropical forest. Canopy temperature regimes at these sites are highly variable. Canopy temperatures at all forest sites displayed frequent departures from air temperature, particularly during clear sky conditions, with elevated canopy temperatures during the day and depressed canopy temperatures at night compared to air temperature. Comparison of canopy temperatures to fluxes of carbon dioxide, water vapor, and energy reveals stronger relationships than those found with air temperature. Daytime growing season net ecosystem exchange at the pine forest site is better explained by canopy temperature (r2 = 0.61) than air temperature (r2 = 0.52). At the semi-deciduous tropical forest, canopy photosynthesis is highly correlated with canopy temperature (r2 = 0.51), with a distinct optimum temperature for photosynthesis ( 31 °C) that agrees with leaf-level measurements. During the peak of one heat wave at an old-growth temperate rainforest, hourly averaged air temperature exceeded 35 °C, 10 °C above average. Peak hourly canopy temperature approached 40 °C, and leaf-to-air vapor pressure deficit exceeded 6 kPa. These extreme conditions had a dramatic effect on forest carbon and energy exchanges: the canopy switched from daytime net carbon uptake prior to the heatwave to net carbon release during and immediately after the heat wave. The latent heat flux from evapotranspiration increased during the heat wave, while sensible heat fluxes were lower.

Historical dominance of low-severity fire in dry and wet mixed-conifer forest habitats of the endangered terrestrial Jemez Mountains salamander (Plethodon neomexicanus)

USGS Publications Warehouse

Margolis, Ellis; Malevich, Steven B.

2016-01-01

Anthropogenic alteration of ecosystem processes confounds forest management and conservation of rare, declining species. Restoration of forest structure and fire hazard reduction are central goals of forest management policy in the western United States, but restoration priorities and treatments have become increasingly contentious. Numerous studies have documented changes in fire regimes, forest stand structure and species composition following a century of fire exclusion in dry, frequent-fire forests of the western U.S. (e.g., ponderosa pine and dry mixed-conifer). In contrast, wet mixed-conifer forests are thought to have historically burned infrequently with mixed- or high-severity fire—resulting in reduced impacts from fire exclusion and low restoration need—but data are limited. In this study we quantified the current forest habitat of the federally endangered, terrestrial Jemez Mountains salamander (Plethodon neomexicanus) and compared it to dendroecological reconstructions of historical habitat (e.g., stand structure and composition), and fire regime parameters along a gradient from upper ponderosa pine to wet mixed-conifer forests. We found that current fire-free intervals in Jemez Mountains salamander habitat (116–165 years) are significantly longer than historical intervals, even in wet mixed-conifer forests. Historical mean fire intervals ranged from 10 to 42 years along the forest gradient. Low-severity fires were historically dominant across all forest types (92 of 102 fires). Although some mixed- or highseverity fire historically occurred at 67% of the plots over the last four centuries, complete mortality within 1.0 ha plots was rare, and asynchronous within and among sites. Climate was an important driver of temporal variability in fire severity, such that mixed- and high-severity fires were associated with more extreme drought than low-severity fires. Tree density in dry conifer forests historically ranged from open (90 trees/ha) to moderately dense (400 trees/ha), but has doubled on average since fire exclusion. Infill of fire-sensitive tree species has contributed to the conversion of historically dry mixedconifer to wet mixed-conifer forest. We conclude that low-severity fire, which has been absent for over a century, was a critical ecosystem process across the forest gradient in Jemez Mountains salamander habitat, and thus is an important element of ecosystem restoration, resilience, and rare species recovery.

Management Options for a High Elevation Forest in the Alps

NASA Astrophysics Data System (ADS)

Jandl, R.; Jandl, N.; Schindlbacher, A.

2013-12-01

We explored different management strategies for a Cembran pine forest close to the timber line with respect to maintenance of the stand structure, the sequestration of carbon in the biomass and the soil, and the economical relevance of timber production. We used the forest growth simulation model Caldis for the implementation of three management intensities (zero managment, thinning every 30 years, thinning every 50 years) under two climate scenarios (IPCC A1B and B1). The soil carbon dynamics were analyzed with the simulation model Yasso07. The ecological evaluation of our simulation data showed that the extensive management with cutting interventions every 50 years allows the maintenance of the ecosystem carbon pool. Zero managment leads to the build-up of the carbon pool because the forest stand is rather unvulnerable to disturbances (bark beetle, storm). The more intensive mangement causes a decline in the ecosystem carbon pool. The economical evaluation showed the marginal relevance of the income generated by timber production. The main challenge is the compensation for the high harvesting costs (long-distance cable logging system). Even at extremely favorable market prices for timber from Cembran pine it is impossible to extract an appropriate amount of timber to justify the temporary instalment of the harvesting system and to maintain a stand density expected for a protection forest. We conclude that timber production is not a feasible object for mountain forests close to the timber line. Even in a warmer climate the productivity situation of forests close to the timberline will not change sufficiently. Therefore it will require public subsidies and personal efforts to maintain the silvicultural intensity at a level that is required for the sustainable maintenance of protection forests.

Carbon and Water Exchanges in a Chronosequence of Temperate White Pine Forest

NASA Astrophysics Data System (ADS)

Arain, M.; Restrepo, N.; Pejam, M.; Khomik, M.

2003-12-01

Quantification of carbon sink or source strengths of temperate forest ecosystems, growing in northern mid-latitudes, is essential to resolve uncertainties in carbon balance of the world's terrestrial ecosystems. Long-term flux measurements are needed to quantify seasonal and annual variability of carbon and water exchanges from these ecosystems and to relate the variability to environmental and physiological factors. Such long-term measurements are of particular interest for different stand developmental stages. An understanding of environmental control factors is necessary to improve predictive capabilities of terrestrial carbon and water cycles. A long-term year-round measurement program has been initiated to observe energy, water vapour, and carbon dioxide fluxes in a chronosequence of white pine (Pinus Strobus) forests in southeastern Canada. White pine is an important species in the North American landscape because of its ability to adapt to dry environments. White pine efficiently grows on coarse and sandy soils, where other deciduous and conifer species cannot survive. Generally, it is the first woody species to flourish after disturbances such as fire and clearing. The climate at the study site is temperate, with a mean annual temperature of 8 degree C and a mean annual precipitation of about 800 mm. The growing season is one of the longest in Canada, with at least 150 frost-free days. Measurements at the site began in June 2002 and are continuing at present. Flux measurements at the 60 year old stand are being made using a close-path eddy covariance (EC) system, while fluxes at the three younger stands (30, 15 and 1 year old) are being measured over 10 to 20 day periods using a roving open-path EC system Soil respiration is being measured every 2-weeks across 50-m transects at all four sites using a mobile chamber system (LI-COR 6400). The mature stand was a sink of carbon with annual NEP value of 140 g C m-2 from June 2002 to May 2003. Gross ecosystem productivity (GEP) and ecosystem respiration (R) for 2002-03 were 1290 and 1150 g C m-2, respectively. A processed-based carbon simulation model was created by incorporating canopy physiology (photosynthesis - sunlit and shaded leaf, conductance), plant phenology (leaf out, senescence), and carbon balance (plant and soil respiration, ecosystem productivity) algorithms in the Canadian Land Surface Scheme. In this study, we compare observed and simulated energy, water vapour, and carbon dioxide fluxes of the mature stand with those of the younger stands. This comparison will help to resolve scaling issues for estimating water and carbon budgets from stands to regions.

Surface Fire Influence on Carbon Balance Components in Scots Pine Forest of Siberia, Russia

NASA Astrophysics Data System (ADS)

Kukavskaya, E.; Ivanova, G. A.; Conard, S. G.; Soja, A. J.

2008-12-01

Wildfire is one of the most important disturbances in boreal forests, and it can have a profound effect on forest-atmosphere carbon exchange. Pinus sylvestris (Scots pine) stands of Siberia are strongly impacted by fires of low to high severity. Biomass distribution in mature lichen/feathermoss Scots pine stands indicates that they are carbon sinks before fire. Fires contribute significantly to the carbon budget resulting in a considerable carbon efflux, initially through direct consumption of forest fuels and later as a result of tree mortality and decomposition of dead material accumulated on the forest floor. In initial postfire years these processes dominate over photosynthetic carbon assimilation, and the ecosystems become a carbon source. Over several postfire years, above-ground carbon in dead biomass tends to increase, with the increase depending significantly on fire severity. High-severity fire enhances dead biomass carbon, while moderate- and low-severity fires have minimal effect on above-ground carbon distribution in Scots pine ecosystems. Dead stand biomass carbon increases, primarily during the first two years following fires, due to tree mortality. This increase can account for up to 12.4% of the total stand biomass after low- and moderate- intensity fires. We found tree dieback following a high-intensity fire is an order of magnitude higher, and thus the dead biomass increases up to 88.1% of total above-ground biomass. Photosynthetic CO2 uptake decreases with increasing tree mortality, and needle foliage and bark are incorporated into the upper layer of the forest floor in the course of years. Ground vegetation and duff carbon were >90, 71-83, and 82% of prefire levels after fires of low, moderate, and high severity, respectively for the first 4 to 5 years after fire. Fires of low and moderate severity caused down woody fuel carbon to increase by 2.1 and 3.6 t ha-1 respectively by four years after burning as compared to the pre-fire values. Climate change and increasing drought length observed in recent decades have increased the probability of high-intensity fire occurrence. Areas burned have increased in extent and severity across Siberia, resulting in increased carbon emissions to the atmosphere from fuel combustion and post fire decomposition.

Potential contribution of exposed resin to ecosystem emissions of monoterpenes

NASA Astrophysics Data System (ADS)

Eller, Allyson S. D.; Harley, Peter; Monson, Russell K.

2013-10-01

Conifers, especially pines, produce and store under pressure monoterpene-laden resin in canals located throughout the plant. When the plants are damaged and resin canals punctured, the resin is exuded and the monoterpenes are released into the atmosphere, a process that has been shown to influence ecosystem-level monoterpene emissions. Less attention has been paid to the small amounts of resin that are exuded from branches, expanding needles, developing pollen cones, and terminal buds in the absence of any damage. The goal of this study was to provide the first estimate of the potential of this naturally-exposed resin to influence emissions of monoterpenes from ponderosa pine (Pinus ponderosa) ecosystems. When resin is first exuded as small spherical beads from undamaged tissues it emits monoterpenes to the atmosphere at a rate that is four orders of magnitude greater than needle tissue with an equivalent exposed surface area and the emissions from exuded beads decline exponentially as the resin dries. We made measurements of resin beads on the branches of ponderosa pine trees in the middle of the growing season and found, on average, 0.15 cm2 of exposed resin bead surface area and 1250 cm2 of total needle surface area per branch tip. If the resin emerged over the course of 10 days, resin emissions would make up 10% of the ecosystem emissions each day. Since we only accounted for exposed resin at a single point in time, this is probably an underestimate of how much total resin is exuded from undamaged pine tissues over the course of a growing season. Our observations, however, reveal the importance of this previously unrecognized source of monoterpenes emitted from pine forests and its potential to influence regional atmospheric chemistry dynamics.

Effects of thinning intensities on soil infiltration and water storage capacity in a Chinese pine-oak mixed forest.

PubMed

Chen, Lili; Yuan, Zhiyou; Shao, Hongbo; Wang, Dexiang; Mu, Xingmin

2014-01-01

Thinning is a crucial practice in the forest ecosystem management. The soil infiltration rate and water storage capacity of pine-oak mixed forest under three different thinning intensity treatments (15%, 30%, and 60%) were studied in Qinling Mountains of China. The thinning operations had a significant influence on soil infiltration rate and water storage capacity. The soil infiltration rate and water storage capacity in different thinning treatments followed the order of control (nonthinning): <60%, <15%, and <30%. It demonstrated that thinning operation with 30% intensity can substantially improve soil infiltration rate and water storage capacity of pine-oak mixed forest in Qinling Mountains. The soil initial infiltration rate, stable infiltration rate, and average infiltration rate in thinning 30% treatment were significantly increased by 21.1%, 104.6%, and 60.9%, compared with the control. The soil maximal water storage capacity and noncapillary water storage capacity in thinning 30% treatment were significantly improved by 20.1% and 34.3% in contrast to the control. The soil infiltration rate and water storage capacity were significantly higher in the surface layer (0~20 cm) than in the deep layers (20~40 cm and 40~60 cm). We found that the soil property was closely related to soil infiltration rate and water storage capacity.

USING ANT COMMUNITIES FOR RAPID ASSESSMENT OF TERRESTRIAL ECOSYSTEM HEALTH

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wike, L; Doug Martin, D; Michael Paller, M

2007-01-12

Ecosystem health with its near infinite number of variables is difficult to measure, and there are many opinions as to which variables are most important, most easily measured, and most robust, Bioassessment avoids the controversy of choosing which physical and chemical parameters to measure because it uses responses of a community of organisms that integrate all aspects of the system in question. A variety of bioassessment methods have been successfully applied to aquatic ecosystems using fish and macroinvertebrate communities. Terrestrial biotic index methods are less developed than those for aquatic systems and we are seeking to address this problem here.more » This study had as its objective to examine the baseline differences in ant communities at different seral stages from clear cut back to mature pine plantation as a precursor to developing a bioassessment protocol. Comparative sampling was conducted at four seral stages; clearcut, 5 year, 15 year and mature pine plantation stands. Soil and vegetation data were collected at each site. All ants collected were preserved in 70% ethyl alcohol and identified to genus. Analysis of the ant data indicates that ants respond strongly to the habitat changes that accompany ecological succession in managed pine forests and that individual genera as well as ant community structure can be used as an indicator of successional change. Ants exhibited relatively high diversity in both early and mature seral stages. High ant diversity in the mature seral stages was likely related to conditions on the forest floor which favored litter dwelling and cool climate specialists.« less

Tree species classification in subtropical forests using small-footprint full-waveform LiDAR data

NASA Astrophysics Data System (ADS)

Cao, Lin; Coops, Nicholas C.; Innes, John L.; Dai, Jinsong; Ruan, Honghua; She, Guanghui

2016-07-01

The accurate classification of tree species is critical for the management of forest ecosystems, particularly subtropical forests, which are highly diverse and complex ecosystems. While airborne Light Detection and Ranging (LiDAR) technology offers significant potential to estimate forest structural attributes, the capacity of this new tool to classify species is less well known. In this research, full-waveform metrics were extracted by a voxel-based composite waveform approach and examined with a Random Forests classifier to discriminate six subtropical tree species (i.e., Masson pine (Pinus massoniana Lamb.)), Chinese fir (Cunninghamia lanceolata (Lamb.) Hook.), Slash pines (Pinus elliottii Engelm.), Sawtooth oak (Quercus acutissima Carruth.) and Chinese holly (Ilex chinensis Sims.) at three levels of discrimination. As part of the analysis, the optimal voxel size for modelling the composite waveforms was investigated, the most important predictor metrics for species classification assessed and the effect of scan angle on species discrimination examined. Results demonstrate that all tree species were classified with relatively high accuracy (68.6% for six classes, 75.8% for four main species and 86.2% for conifers and broadleaved trees). Full-waveform metrics (based on height of median energy, waveform distance and number of waveform peaks) demonstrated high classification importance and were stable among various voxel sizes. The results also suggest that the voxel based approach can alleviate some of the issues associated with large scan angles. In summary, the results indicate that full-waveform LIDAR data have significant potential for tree species classification in the subtropical forests.

Regime Shifts and Weakened Environmental Gradients in Open Oak and Pine Ecosystems

PubMed Central

Hanberry, Brice B.; Dey, Dan C.; He, Hong S.

2012-01-01

Fire suppression allows tree species that are intolerant of fire stress to increase their distribution, potentially resulting in disruption of historical species-environmental relationships. To measure changes between historical General Land Office surveys (1815 to 1850) and current USDA Forest Inventory and Assessment surveys (2004 to 2008), we compared composition, distribution, and site factors of 21 tree species or species groups in the Missouri Ozarks. We used 24 environmental variables and random forests as a classification method to model distributions. Eastern redcedar, elms, maples, and other fire-sensitive species have increased in dominance in oak forests, with concurrent reductions by oak species; specific changes varied by ecological subsection. Ordinations displayed loss of separation between formerly distinctive oak and fire-sensitive tree species groups. Distribution maps showed decreased presence of disturbance-dependent oak and pine species and increased presence of fire-sensitive species that generally expanded from subsections protected from fire along rivers to upland areas, except for eastern redcedar, which expanded into these subsections. Large scale differences in spatial gradients between past and present communities paralleled reduced influence of local topographic gradients in the varied relief of the Missouri Ozarks, as fire-sensitive species have moved to higher, drier, and sunnier sites away from riverine corridors. Due to changes in land use, landscapes in the Missouri Ozarks, eastern United States, and world-wide are changing from open oak and pine-dominated ecosystems to novel oak-mixed species forests, although at fine scales, forests are becoming more diverse in tree species today. Fire suppression weakened the influence by environmental gradients over species dominance, allowing succession from disturbance-dependent oaks to an alternative state of fire-sensitive species. Current and future research and conservation that rely on historical relationships and ecological principles based on disturbance across the landscape will need to incorporate modern interactions among species for resources into management plans and projections. PMID:22848467

Carbon balance of a partially harvested mixed conifer forest following mountain pine beetle attack and its comparison to a clear-cut

NASA Astrophysics Data System (ADS)

Mathys, A.; Black, T. A.; Nesic, Z.; Nishio, G.; Brown, M.; Spittlehouse, D. L.; Fredeen, A. L.; Bowler, R.; Jassal, R. S.; Grant, N. J.; Burton, P. J.; Trofymow, J. A.; Meyer, G.

2013-08-01

The recent mountain pine beetle (MPB) outbreak has had an impact on the carbon (C) cycling of lodgepole pine forests in British Columbia. This study examines how partial harvesting as a forest management response to MPB infestation affects the net ecosystem production (NEP) of a mixed conifer forest (MPB-09) in Interior BC. MPB-09 is a 70-year-old stand that was partially harvested in 2009 after it had been attacked by MPB. Using the eddy-covariance technique, the C dynamics of the stand were studied over two years and compared to an adjacent clear-cut (MPB-09C) over the summertime. The annual NEP at MPB-09 increased from -108 g C m-2 in 2010 to -57 g C m-2 in 2011. The increase of NEP was due to the associated increase in annual gross ecosystem photosynthesis (GEP) from 812 g C m-2 in 2010 to 954 g C m-2 in 2011, exceeding the increase in annual respiration (Re) from 920 g C m-2 to 1011 g C m-2 during the two years. During the four month period between June and September 2010, NEP at MPB-09C was -103 g C m-2, indicating high C losses in the clear-cut. MPB-09 was a C sink during the growing season of both years, increasing from 9 g C m-2 in 2010 to 47 g C m-2 in 2011. The increase of NEP in the partially harvested stand amounted to a recovery corresponding to a 26% increase in the maximum assimilation rate in the second year. This study shows that retaining the healthy residual forest can result in higher C sequestration of MPB-attacked stands compared to clear-cut harvesting.

Regime shifts and weakened environmental gradients in open oak and pine ecosystems.

PubMed

Hanberry, Brice B; Dey, Dan C; He, Hong S

2012-01-01

Fire suppression allows tree species that are intolerant of fire stress to increase their distribution, potentially resulting in disruption of historical species-environmental relationships. To measure changes between historical General Land Office surveys (1815 to 1850) and current USDA Forest Inventory and Assessment surveys (2004 to 2008), we compared composition, distribution, and site factors of 21 tree species or species groups in the Missouri Ozarks. We used 24 environmental variables and random forests as a classification method to model distributions. Eastern redcedar, elms, maples, and other fire-sensitive species have increased in dominance in oak forests, with concurrent reductions by oak species; specific changes varied by ecological subsection. Ordinations displayed loss of separation between formerly distinctive oak and fire-sensitive tree species groups. Distribution maps showed decreased presence of disturbance-dependent oak and pine species and increased presence of fire-sensitive species that generally expanded from subsections protected from fire along rivers to upland areas, except for eastern redcedar, which expanded into these subsections. Large scale differences in spatial gradients between past and present communities paralleled reduced influence of local topographic gradients in the varied relief of the Missouri Ozarks, as fire-sensitive species have moved to higher, drier, and sunnier sites away from riverine corridors. Due to changes in land use, landscapes in the Missouri Ozarks, eastern United States, and world-wide are changing from open oak and pine-dominated ecosystems to novel oak-mixed species forests, although at fine scales, forests are becoming more diverse in tree species today. Fire suppression weakened the influence by environmental gradients over species dominance, allowing succession from disturbance-dependent oaks to an alternative state of fire-sensitive species. Current and future research and conservation that rely on historical relationships and ecological principles based on disturbance across the landscape will need to incorporate modern interactions among species for resources into management plans and projections.

Effects of a Community Restoration Fire on Small Mammals and Herpetofauna in the Southern Appalachains

Treesearch

William M. Ford; M. Alex Menzel; David W. McGill; Joshua Laerm; Timothy S. McCay

1999-01-01

As part of the Wine Spring Creek ecosystem management project on the Nantahala National forest, North Carolina, we assessed effects of a community restoration fire on small mammals and herpetofauna in the upper slope pitch pine (Pinus rigida) stands, neighboring midslope oak (Quercus spp.) stands and rhododendron (...

Effects of fuel load and moisture content on fire behaviour and heating in masticated litter-dominated fuels

Treesearch

Jesse K. Kreye; Leda N. Kobziar; Wayne C. Zipperer

2013-01-01

Mechanical fuels treatments are being used in fire-prone ecosystems where fuel loading poses a hazard, yetlittle research elucidating subsequent fire behaviour exists, especially in litter-dominated fuelbeds. To address this deficiency, we burned constructed fuelbeds from masticated sites in pine flatwoods forests in northern Florida...

Fire and mice: Seed predation moderates fire's influence on conifer recruitment

Treesearch

Rafal Zwolak; Dean E. Pearson; Yvette K. Ortega; Elizabeth E. Crone

2010-01-01

In fire-adapted ecosystems, fire is presumed to be the dominant ecological force, and little is known about how consumer interactions influence forest regeneration. Here, we investigated seed predation by deer mice (Peromyscus maniculatus) and its effects on recruitment of ponderosa pine (Pinus ponderosa) and Douglas-fir (Pseudotsuga menziesii) seedlings in unburned...

The physiological basis for regeneration response to variable retention harvest treatments in three pine species

Treesearch

Matthew D. Powers; Kurt S. Pregitzer; Brian J. Palik; Christopher R. Webster

2011-01-01

Variable retention harvesting (VRH) is promoted for enhancing biodiversity and ecosystem processes in managed forests, but regeneration responses to the complex stand structures that result from VRH are poorly understood. We analyzed foliar stable carbon isotope ratios (δ13C), oxygen isotope ratios (δ18O...

Early fire history near Seguin Falls, Ontario

Treesearch

Daniel C. Dey; Richard P. Guyette

1996-01-01

This report is one of a series of site-specfic fire histories being developed for red oak (Quercus rubra L.)-pine ecosystems in central Ontario. Collectively, these studies documents the role of fire in upland oak forests. this information also provides an ecological basis for developing silviculture prescriptions that use prescribed burning to...

HYDRAULIC REDISTRIBUTION OF SOIL WATER DURING SUMMER DROUGHT IN TWO CONTRASTING PACIFIC NORTHWEST CONIFEROUS FORESTS

EPA Science Inventory

The magnitude of hydraulic redistribution of soil water by roots and its impact on soil water balance were estimated by monitoring time courses of soil water status at multiple depths and root sap flow during droughted conditions in a dry ponderosa pine ecosystem and a moist Doug...

Effects of short-rotation controlled burning on amphibians and reptiles in pine woodlands

Treesearch

Roger W. Perry; D. Craig Rudolph; Ronald E. Thill

2012-01-01

Fire is being used increasingly as a forest management tool throughout North America, but its effects on reptiles and amphibians in many ecosystems are unclear. Open woodlands with understories dominated by herbaceous vegetation benefit many wildlife species, but maintaining these woodlands requires frequent burning. Although many studies have compared herpetofaunal...

Variation in selection of microhabitats by Merriam's turkey brood hens

Treesearch

Mark A. Rumble; Stanley H. Anderson

1997-01-01

We studied microhabitats of Merriam‘s turkey (Meleagris gallopavo merriami) brood hens in a ponderosa pine (Pinus ponderosa) ecosystem in South Dakota from 1986 to 1988. Cluster analysis indicated three groups of microhabitats, open-shrub, open-grasslforb and forest, based on vegetation characteristics at sites selected by brood...

Regime shifts and weakened environmental gradients in open oak and pine ecosystems

Treesearch

Brice B. Hanberry; Dan C. Dey; Hong S. He

2012-01-01

Fire suppression allows tree species that are intolerant of fire stress to increase their distribution, potentially resulting in disruption of historical species-environmental relationships. To measure changes between historical General Land Office surveys (1815 to 1850) and current USDA Forest Inventory and Assessment surveys (2004 to 2008), we compared composition,...

Modeling the Carbon Implications of Ecologically Based Forest Management

DTIC Science & Technology

2015-08-20

richness across an environmental gradient in a fire-dependent ecosystem. American Journal of Botany 88, 2119-2128. Kolb, T.E., and J.E. Stone. 2000...litter. Canadian Journal of Botany 61(3):872-879 Loudermilk, E.L., Cropper, W.P., Mitchell, R.J., Lee, H., 2011. Longleaf pine (Pinus palustris) and

Modeling the Carbon Implications of Ecologically-Based Forest Management

DTIC Science & Technology

2015-08-01

richness across an environmental gradient in a fire-dependent ecosystem. American Journal of Botany 88, 2119-2128. Kolb, T.E., and J.E. Stone. 2000...litter. Canadian Journal of Botany 61(3):872-879 Loudermilk, E.L., Cropper, W.P., Mitchell, R.J., Lee, H., 2011. Longleaf pine (Pinus palustris) and

Influence of repeated canopy scorching on soil CO2 efflux

Treesearch

DP Aubrey; B Martazavi; Joseph O' Brien; JD McGee; JJ Hendricks; KA Kuehn; RJ Mitchell

2012-01-01

Forest ecosystems experience various disturbances that can affect belowground carbon cycling to different degrees. Here, we investigate if successive annual foliar scorching events will result in a large and rapid decline in soil CO2 efflux, similar to that observed in girdling studies. Using the fire-adapted longleaf pine (Pinus...

Trees as methane sources: A case study of West Siberian South taiga

NASA Astrophysics Data System (ADS)

Churkina, A. I.; Mochenov, S. Yu; Sabrekov, S. F.; Glagolev, M. V.; Il’yasov, D. V.; Terentieva, I. E.; Maksyutov, S. S.

2018-03-01

Within this study, we were measuring methane emission from the tree trunks, leaves and branches in the seasonally flooded forest and in the forested bogs (pine-shrub-sphagnum ecosystems or “ryams”) in south taiga zone of Western Siberia. Our results suggest that the tree trunks may act as a methane conductor from the soil to the atmosphere bypassing the methanotrophically active zones of soil. The tree methane flux depends on a trunk diameter and an ecosystem type. The average methane emission from tree trunks was 0.0061±0.0003 mg CH4·m-2·h-1 per unit of ground area. The methane emission from branches and leaves was zero.

From the stand-scale to the landscape-scale: predicting the spatial patterns of forest regeneration after disturbance.

PubMed

Shive, Kristen L; Preisler, Haiganoush K; Welch, Kevin R; Safford, Hugh D; Butz, Ramona J; O'Hara, Kevin L; Stephens, Scott L

2018-05-29

Shifting disturbance regimes can have cascading effects on many ecosystems processes. This is particularly true when the scale of the disturbance no longer matches the regeneration strategy of the dominant vegetation. In the yellow pine and mixed conifer forests of California, over a century of fire exclusion and the warming climate are increasing the incidence and extent of stand-replacing wildfire; such changes in severity patterns are altering regeneration dynamics by dramatically increasing the distance from live tree seed sources. This has raised concerns about limitations to natural reforestation and the potential for conversion to non-forested vegetation types, which in turn has implications for shifts in many ecological processes and ecosystem services. We used a California region-wide dataset with 1,848 plots across 24 wildfires in yellow pine and mixed conifer forests to build a spatially-explicit habitat suitability model for forecasting postfire forest regeneration. To model the effect of seed availability, the critical initial biological filter for regeneration, we used a novel approach to predicting spatial patterns of seed availability by estimating annual seed production from existing basal area and burn severity maps. The probability of observing any conifer seedling in a 60m 2 area (the field plot scale) was highly dependent on 30-year average annual precipitation, burn severity and seed availability. We then used this model to predict regeneration probabilities across the entire extent of a "new' fire (the 2014 King Fire), which highlights the spatial variability inherent in postfire regeneration patterns. Such accurate forecasts of postfire regeneration patterns are of importance to land managers and conservationists interested in maintaining forest cover on the landscape. Our tool can also help anticipate shifts in ecosystem properties, supporting researchers interested in investigating questions surrounding alternative stable states, and the interaction of altered disturbance regimes and the changing climate. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

Unexpected extreme events drive the inter-annual variabilty in carbon exchange at the Pine forest in Netherlands.

NASA Astrophysics Data System (ADS)

Sethi, Sanjna; Moors, Eddy; Jamir, Chubamenla

2017-04-01

The carbon exchange between vegetation and the atmosphere tends to vary on an annual basis. This change is a continuous process its trend emerging over a period of years can be analysed. In any such trend over a prolonged period, some years stand out more than the others on account of extreme events. Explaining deviations from the expected average emissions may help to understand the drivers behind these interannual deviations. Such noticeable deviations in trend maybe on account of extreme events and need to be analysed in overall context of the ecosystem. This research's focus is to identify the main drivers responsible for the deviations, and how extreme events impact the variability over a prolonged period of time. The hypothesis being that extreme events are driving these deviations. Carbon flux data done for multiple years (1997-2015) for a site at the Loobos Pine Forest is used and compared with an ecosystem model, LPJ-GUESS (Lund-Potsdam-Jena General Ecosystem Simulator) to understand if the deviation of measured data from the simulated data is on account of extreme events on a monthly and daily basis. A Principal Component Analysis is performed on the identified deviations between measured and simulated carbon exchange to pin point the main cause behind their occurrence.​

Functional outcomes of fungal community shifts driven by tree genotype and spatial-temporal factors in Mediterranean pine forests.

PubMed

Pérez-Izquierdo, Leticia; Zabal-Aguirre, Mario; Flores-Rentería, Dulce; González-Martínez, Santiago C; Buée, Marc; Rincón, Ana

2017-04-01

Fungi provide relevant ecosystem services contributing to primary productivity and the cycling of nutrients in forests. These fungal inputs can be decisive for the resilience of Mediterranean forests under global change scenarios, making necessary an in-deep knowledge about how fungal communities operate in these ecosystems. By using high-throughput sequencing and enzymatic approaches, we studied the fungal communities associated with three genotypic variants of Pinus pinaster trees, in 45-year-old common garden plantations. We aimed to determine the impact of biotic (i.e., tree genotype) and abiotic (i.e., season, site) factors on the fungal community structure, and to explore whether structural shifts triggered functional responses affecting relevant ecosystem processes. Tree genotype and spatial-temporal factors were pivotal structuring fungal communities, mainly by influencing their assemblage and selecting certain fungi. Diversity variations of total fungal community and of that of specific fungal guilds, together with edaphic properties and tree's productivity, explained relevant ecosystem services such as processes involved in carbon turnover and phosphorous mobilization. A mechanistic model integrating relations of these variables and ecosystem functional outcomes is provided. Our results highlight the importance of structural shifts in fungal communities because they may have functional consequences for key ecosystem processes in Mediterranean forests. © 2017 Society for Applied Microbiology and John Wiley and Sons Ltd.

Carbon dynamics after forest harvest in Central Siberia: the ZOTTO footprint area

NASA Astrophysics Data System (ADS)

Panov, Alexey; Zrazhevskaya, Galina; Shibistova, Olga; Onuchin, Alexander; Heimann, Martin

2013-04-01

Temperate and boreal forests of the Northern Hemisphere have been recognized as important carbon sinks. Accurate calculation of forest carbon budget and estimation of the temporal variations of forest net carbon fluxes are important topics to elucidate the ''missing sink'' question and follow up the changing carbon dynamics in forests. In the frame of the ongoing Russian-German partner project the Zotino Tall Tower Observatory (ZOTTO; www.zottoproject.org) a unique international research platform for large-scale climatic observations is operational about 20 km west of the Yenisei river (60.8°N; 89.35°E). The data of the ongoing greenhouse gas and aerosol measurements at the tall tower are used in atmospheric inversions studies to infer the distribution of carbon sinks and sources over the whole Northern Eurasia. The tall tower footprint area estimates of carbon stocks and fluxes are highly demanded for bottom-up validation of inversion estimates. The ZOTTO site lies in a vast region of forests and wetlands, still relatively undisturbed by anthropogenic influences, but a moderate human impact on vegetation, represented mainly by logging activities, becomes essential. Therefore, accurate estimates of carbon pools in vegetation and soil following harvesting are essential to inversion studies for ZOTTO and critical to predictions of both local ecosystem sustainability and global C exchange with the atmosphere. We present our investigation of carbon dynamics after forest harvest in the tall tower footprint area (~1000 km2). The changes in C pools and annual sequestration were quantified among several clear-cut lichen pine (Pinus sylvestris Lamb.) stands representing various stages of secondary succession with a "space-for-time substitution" technique. When viewed as a chronosequence, these stands represent snapshots showing how the effects of logging may propagate through time. The study concluded that ecosystems during the first 15 yrs after forest harvest become C sources to the atmosphere which is attributed to increases in decomposition rates and decreases in litter inputs due to the ecosystem disturbed. Pine stands nearly 15-20-year-old after harvesting have been recognized as weak carbon sinks, and the ecosystem of 25-40-year-old represents a relatively strong C uptake. The work was supported financially by ISTC Project # 2757p "Biogeochemical Responses to Rapid Climate Changes in Eurasia".

Effects of drought and irrigation on ecosystem functioning in a mature Scots pine forest

NASA Astrophysics Data System (ADS)

Dobbertin, Matthias; Brunner, Ivano; Egli, Simon; Eilmann, Britta; Graf Pannatier, Eisabeth; Schleppi, Patrick; Zingg, Andreas; Rigling, Andreas

2010-05-01

Climate change is expected to increase temperature and reduce summer precipitation in Switzerland. To study the expected effects of increased drought in mature forests two different approaches are in general possible: water can be partially or completely removed from the ecosystems via above- or below-canopy roofs or water can be added to already drought-prone ecosystems. Both methods have advantages and disadvantages. In our study water was added to a mature 90-year old Scots pine (Pinus sylvestris L.) forest with a few singe pubescent oaks (Quercus pubescens Willd.), located in the valley bottom of the driest region of Switzerland (Valais). In Valais, Scots pines are declining, usually with increased mortality rates following drought years. It was therefore of special interest to study here how water addition is changing forest ecosystem functioning. The irrigation experiment started in the summer of 2003. Out of eight 0.1 ha experimental plots, four were randomly selected for irrigation, the other four left as a control. Irrigation occurred during rainless nights between April and October, doubling the annual rainfall amount from 650 to 1300 mm. Irrigation water, taken from a near-by irrigation channel, added some nutrients to the plots, but nutrients which were deficient on the site, e.g. nitrogen and phosphorus, were not altered. Tree diameter, tree height and crown width were assessed before the start of the irrigation in winter 2002/2003 and after 7 years of the experiment in 2009/2010. Tree crown transparency (lack of foliage) and leaf area index (LAI) were annually assessed. Additionally, tree mortality was annually evaluated. Mycorrhizal fruit bodies were identified and counted at weekly intervals from 2003 until 2007. Root samples were taken in 2004 and 2005. In 2004 and 2005 wood formation of thirteen trees was analysed in weekly or biweekly intervals using the pinning method. These trees were felled in 2006 for stem, shoot and needle growth analysis. Soil water content was significantly reduced during irrigation periods. Irrigation doubled tree stem growth, increased shoot growth and thus increased volume growth and crown dimensions. Annual tree mortality rates were reduced by 50% in irrigated plots. The growing period for stem growth was extended in pines as a result of irrigation. Altogether, increased growth and reduced mortality significantly increased tree stem basal area at breast height per ha. As irrigation also increased needle length, estimated mean foliage amount per tree and stand leaf area index significantly increased. However, the number of needle generations was not altered or even reduced due to irrigation. Root growth, was less affected by irrigation and only resulted in increased fine root length. Species richness and fruit body numbers of mycorrhizal fungi were several times higher on the irrigated plots. Overall, it can be concluded that water availability was the main ecosystem limiting factor and that any changes in water availability will result in changes in ecosystem functioning. References Brunner I, Graf-Pannatier E, Frey B, Rigling A, Landolt W, Dobbertin M (2009) Morphological and physiological responses of Scots pine fine roots to water supply in a climatic dry area in Switzerland. Tree Physiology 29:541-550. Dobbertin M, Eilmann B, Bleuler P, Giuggiola A, Graf Pannatier E, Landolt W, Schleppi P, Rigling A (2010) Effect of irrigation on needle, shoot and stem growth in natural drought-exposed Pinus sylvestris forests, Tree Physiology, doi:10.1093/treephys/tpp123. Eilmann B, Zweifel R, Buchmann N, Fonti P, Rigling A (2009) Drought induced adaptation of the xylem in Pinus sylvestris and Quercus pubescens. Tree Physiology 29:1011-1020.

Patterns of biomass and carbon distribution across a chronosequence of Chinese pine (Pinus tabulaeformis) forests.

PubMed

Zhao, Jinlong; Kang, Fengfeng; Wang, Luoxin; Yu, Xiaowen; Zhao, Weihong; Song, Xiaoshuai; Zhang, Yanlei; Chen, Feng; Sun, Yu; He, Tengfei; Han, Hairong

2014-01-01

Patterns of biomass and carbon (C) storage distribution across Chinese pine (Pinus tabulaeformis) natural secondary forests are poorly documented. The objectives of this study were to examine the biomass and C pools of the major ecosystem components in a replicated age sequence of P. tabulaeformis secondary forest stands in Northern China. Within each stand, biomass of above- and belowground tree, understory (shrub and herb), and forest floor were determined from plot-level investigation and destructive sampling. Allometric equations using the diameter at breast height (DBH) were developed to quantify plant biomass. C stocks in the tree and understory biomass, forest floor, and mineral soil (0-100 cm) were estimated by analyzing the C concentration of each component. The results showed that the tree biomass of P. tabulaeformis stands was ranged from 123.8 Mg·ha-1 for the young stand to 344.8 Mg·ha-1 for the mature stand. The understory biomass ranged from 1.8 Mg·ha-1 in the middle-aged stand to 3.5 Mg·ha-1 in the young stand. Forest floor biomass increased steady with stand age, ranging from 14.9 to 23.0 Mg·ha-1. The highest mean C concentration across the chronosequence was found in tree branch while the lowest mean C concentration was found in forest floor. The observed C stock of the aboveground tree, shrub, forest floor, and mineral soil increased with increasing stand age, whereas the herb C stock showed a decreasing trend with a sigmoid pattern. The C stock of forest ecosystem in young, middle-aged, immature, and mature stands were 178.1, 236.3, 297.7, and 359.8 Mg C ha-1, respectively, greater than those under similar aged P. tabulaeformis forests in China. These results are likely to be integrated into further forest management plans and generalized in other contexts to evaluate C stocks at the regional scale.

Patterns of Biomass and Carbon Distribution across a Chronosequence of Chinese Pine (Pinus tabulaeformis) Forests

PubMed Central

Wang, Luoxin; Yu, Xiaowen; Zhao, Weihong; Song, Xiaoshuai; Zhang, Yanlei; Chen, Feng; Sun, Yu; He, Tengfei; Han, Hairong

2014-01-01

Patterns of biomass and carbon (C) storage distribution across Chinese pine (Pinus tabulaeformis) natural secondary forests are poorly documented. The objectives of this study were to examine the biomass and C pools of the major ecosystem components in a replicated age sequence of P. tabulaeformis secondary forest stands in Northern China. Within each stand, biomass of above- and belowground tree, understory (shrub and herb), and forest floor were determined from plot-level investigation and destructive sampling. Allometric equations using the diameter at breast height (DBH) were developed to quantify plant biomass. C stocks in the tree and understory biomass, forest floor, and mineral soil (0–100 cm) were estimated by analyzing the C concentration of each component. The results showed that the tree biomass of P. tabulaeformis stands was ranged from 123.8 Mg·ha–1 for the young stand to 344.8 Mg·ha–1 for the mature stand. The understory biomass ranged from 1.8 Mg·ha–1 in the middle-aged stand to 3.5 Mg·ha–1 in the young stand. Forest floor biomass increased steady with stand age, ranging from 14.9 to 23.0 Mg·ha–1. The highest mean C concentration across the chronosequence was found in tree branch while the lowest mean C concentration was found in forest floor. The observed C stock of the aboveground tree, shrub, forest floor, and mineral soil increased with increasing stand age, whereas the herb C stock showed a decreasing trend with a sigmoid pattern. The C stock of forest ecosystem in young, middle-aged, immature, and mature stands were 178.1, 236.3, 297.7, and 359.8 Mg C ha–1, respectively, greater than those under similar aged P. tabulaeformis forests in China. These results are likely to be integrated into further forest management plans and generalized in other contexts to evaluate C stocks at the regional scale. PMID:24736660

Management effects on carbon fluxes in boreal forests (Invited)

NASA Astrophysics Data System (ADS)

Lindroth, A.; Mölder, M.; Lagergren, F.; Vestin, P.; Hellström, M.; Sundqvist, E.; Norunda Bgs Team

2010-12-01

Disturbance by management or natural causes such as wind throw or fire are believed to be one of the main factors that are controlling the carbon balance of vegetation. In Northern Europe a large fraction of the forest area is managed with clear cutting and thinning as the main silvicultural methods. The effect of clear-cutting on carbon dioxide exchanges were studied in different chrono-sequences located in Sweden, Finland, UK and France, respectively. The combined results from these studies showed that a simple model could be developed describing relative net ecosystem exchange as a function of relative rotation length (age). A stand with a rotation length of 100 years, typical for Swedish conditions, looses substantial amounts of carbon during the first 12-15 years and the time it takes to reach cumulative balance after clear-cut, is 25-30 years. The mean net ecosystem exchange over the whole rotation length equals 50% of the maximum uptake. An interesting question is if it is possible to harvest without the substantial carbon losses that take place after clear-cutting. Selective harvest by thinning could potentially be such a method. We therefore studied the effect of thinning on soil and ecosystem carbon fluxes in a mixed pine and spruce forest in Central Sweden, the Norunda forest, located in the semi-boreal zone at 60.08°N, 17.48 °E. The CO2 fluxes from the forest were measured by eddy covariance method and soil effluxes were measured by automatic chambers. Maximum canopy height of the ca. 100 years-old forest was 28 m. The stand was composed of ca 72% pine, 28% before the thinning while the composition after the thinning became 82% pine and 18% spruce. The thinning was made in November/December 2008 in a half- circle from the tower with a radius of 200 m. The LAI decreased from 4.5 to 2.8 after the thinning operation. Immediately after the thinning, we found significantly higher soil effluxes, probably due to increased decomposition of dead roots. The stand level flux measurements showed no effect on total ecosystem respiration, probably because of reduced autotrophic respiration from canopy layer. Initially the GPP was slightly reduced as compared to the non-thinned sector but already after 6-7 months, no effect of the thinning on GPP could be detected. We attributed this fast recovery to increased resource availability (nutrients and light) to the remaining trees and possibly also to the ground vegetation. The results indicate that selective harvest such as thinning has a potential to increase the mean net ecosystem exchange over the rotation length mainly because of avoiding the emissions that occur after a heavy disturbance such as that caused by clear-cutting. An important question in this context is how successful the re-growth after thinning will be but that is out of scope of this presentation.

Numerical and functional responses of forest bats to a major insect pest in pine plantations.

PubMed

Charbonnier, Yohan; Barbaro, Luc; Theillout, Amandine; Jactel, Hervé

2014-01-01

Global change is expected to modify the frequency and magnitude of defoliating insect outbreaks in forest ecosystems. Bats are increasingly acknowledged as effective biocontrol agents for pest insect populations. However, a better understanding is required of whether and how bat communities contribute to the resilience of forests to man- and climate-driven biotic disturbances.We studied the responses of forest insectivorous bats to a major pine defoliator, the pine processionary moth Thaumetopoea pityocampa, which is currently expanding its range in response to global warming [corrected]. We used pheromone traps and ultrasound bat recorders to estimate the abundance and activity of moths and predatory bats along the edge of infested pine stands. We used synthetic pheromone to evaluate the effects of experimentally increased moth availability on bat foraging activity. We also evaluated the top-down regulation of moth population by estimating T. pityocampa larval colonies abundance on the same edges the following winter. We observed a close spatio-temporal matching between emergent moths and foraging bats, with bat activity significantly increasing with moth abundance. The foraging activity of some bat species was significantly higher near pheromone lures, i.e. in areas of expected increased prey availability. Furthermore moth reproductive success significantly decreased with increasing bat activity during the flight period of adult moths. These findings suggest that bats, at least in condition of low prey density, exhibit numerical and functional responses to a specific and abundant prey, which may ultimately result in an effective top-down regulation of the population of the prey. These observations are consistent with bats being useful agents for the biocontrol of insect pest populations in plantation forests.

Ectomycorrhizal communities of ponderosa pine and lodgepole pine in the south-central Oregon pumice zone.

PubMed

Garcia, Maria O; Smith, Jane E; Luoma, Daniel L; Jones, Melanie D

2016-05-01

Forest ecosystems of the Pacific Northwest of the USA are changing as a result of climate change. Specifically, rise of global temperatures, decline of winter precipitation, earlier loss of snowpack, and increased summer drought are altering the range of Pinus contorta. Simultaneously, flux in environmental conditions within the historic P. contorta range may facilitate the encroachment of P. ponderosa into P. contorta territory. Furthermore, successful pine species migration may be constrained by the distribution or co-migration of ectomycorrhizal fungi (EMF). Knowledge of the linkages among soil fungal diversity, community structure, and environmental factors is critical to understanding the organization and stability of pine ecosystems. The objectives of this study were to establish a foundational knowledge of the EMF communities of P. ponderosa and P. contorta in the Deschutes National Forest, OR, USA, and to examine soil characteristics associated with community composition. We examined EMF root tips of P. ponderosa and P. contorta in soil cores and conducted soil chemistry analysis for P. ponderosa cores. Results indicate that Cenococcum geophilum, Rhizopogon salebrosus, and Inocybe flocculosa were dominant in both P. contorta and P. ponderosa soil cores. Rhizopogon spp. were ubiquitous in P. ponderosa cores. There was no significant difference in the species composition of EMF communities of P. ponderosa and P. contorta. Ordination analysis of P. ponderosa soils suggested that soil pH, plant-available phosphorus (Bray), total phosphorus (P), carbon (C), mineralizable nitrogen (N), ammonium (NH4), and nitrate (NO3) are driving EMF community composition in P. ponderosa stands. We found a significant linear relationship between EMF species richness and mineralizable N. In conclusion, P. ponderosa and P. contorta, within the Deschutes National Forest, share the same dominant EMF species, which implies that P. ponderosa may be able to successfully establish within the historic P. contorta range and dominant EMF assemblages may be conserved.

Dynamics of biomass and carbon sequestration across a chronosequence of masson pine plantations

NASA Astrophysics Data System (ADS)

Justine, Meta Francis; Yang, Wanqin; Wu, Fuzhong; Khan, Muhammad Naeem

2017-03-01

The changes of forest biomass stock and carbon (C) sequestration with stand ages at fixed intervals in the different vegetation components remain unknown. Using the masson pine (Pinus massoniana) relative growth equation, biomass carbon stocks were obtained in four masson pine plantations at 12 year intervals (3 years, 15 years, 27 years, and 39 years). Meanwhile, the changes in soil organic C (SOC) stock with stand ages were also estimated. The biomass stock varied from 1.41 to 265.33 Mg ha-1, 6.87 to 7.49 Mg ha-1, and 2.66 to 4.86 Mg ha-1 in the tree, shrub, and herb layers. Carbon concentrations in plant tissues were 51.6%, 39.0%, and 42.2% in the tree, shrub, and herb layers. The aboveground biomass C contributed 81.7% and 60.5% in the tree and shrub layers, and the root to shoot (R/S) ratio of the tree and shrub layer biomass averaged 0.23 and 0.69. Biomass C stock increased significantly (p < 0.05) with forest age, whereas the changes in biomass accumulation rate decreased significantly (p < 0.05). The annual net C sequestration increased with age from 0.47 to 9.83 Mg ha-1 yr-1 in the tree layer but decreased in the shrub and herb layers. The SOC content decreased with soil depth but increased with age, whereas the SOC stock increased with depth and age. However, the total ecosystem C stock increased significantly (p < 0.05) with stand age suggesting that age is the controlling factor of photosynthetic and biological processes and thus changes in biomass accumulation and C sequestration in masson pine plantations. Therefore, in-depth studies are needed for continuous monitoring of the changes in nutrients and elements cycling with stand ages in this forest ecosystem.

Forests tend to cool the land surface in the temperate zone: An analysis of the mechanisms controlling radiometric surface temperature change in managed temperate ecosystems

NASA Astrophysics Data System (ADS)

Stoy, P. C.; Katul, G. G.; Juang, J.; Siqueira, M. B.; Novick, K. A.; Essery, R.; Dore, S.; Kolb, T. E.; Montes-Helu, M. C.; Scott, R. L.

2010-12-01

Vegetation is an important control on the surface energy balance and thereby surface temperature. Boreal forests and arctic shrubs are thought to warm the land surface by absorbing more radiation than the vegetation they replace. The surface temperatures of tropical forests tend to be cooler than deforested landscapes due to enhanced evapotranspiration. The effects of reforestation on surface temperature change in the temperate zone is less-certain, but recent modeling efforts suggest forests have a global warming effect. We quantified the mechanisms driving radiometric surface changes following landcover changes using paired ecosystem case studies from the Ameriflux database with energy balance models of varying complexity. Results confirm previous findings that deciduous and coniferous forests in the southeastern U.S. are ca. 1 °C cooler than an adjacent field on an annual basis because aerodynamic/ecophysiological cooling of 2-3 °C outweighs an albedo-related warming of <1 °C. A 50-70% reduction in the aerodynamic resistance to sensible and latent heat exchange in the forests dominated the cooling effect. A grassland ecosystem that succeeded a stand-replacing ponderosa pine fire was ca. 1 °C warmer than unburned stands because a 1.5 °C aerodynamic warming offset a slight surface cooling due to greater albedo and soil heat flux. An ecosystem dominated by mesquite shrub encroachment was nearly 2 °C warmer than a native grassland ecosystem as aerodynamic and albedo-related warming outweighed a small cooling effect due to changes in soil heat flux. The forested ecosystems in these case studies are documented to have higher carbon uptake than the non-forested systems. Results suggest that temperate forests tend to cool the land surface and suggest that previous model-based findings that forests warm the Earth’s surface globally should be reconsidered.Changes to radiometric surface temperature (K) following changes in vegetation using paired ecosystem case studies C4 grassland and shrub ecosystem surface temperatures were adjusted for differences in air temperature across sites.

Evaluating the influence of fire history on dissolved pyrogenic C exported from coniferous and deciduous forest soils in northern Great Lakes Region

NASA Astrophysics Data System (ADS)

Santos, F.; Wagner, S.; Rothstein, D.; Miesel, J. R.; Jaffe, R.

2015-12-01

Pyrogenic carbon (PyC) is formed from the thermal decomposition of plant biomass and fossil fuels, and accounts for a significant portion of the dissolved organic matter pool in rivers worldwide. While PyC mobilization and leaching from fire-impacted terrestrial ecosystems are thought to be the primary source of dissolved PyC (DPC) in riverine environments, the influence of recent biomass burning on the fluxes of DPC leached from soils remains poorly quantified. Here we examined differences in DPC leaching fluxes between (1) red pine sites that experienced post-logging slash burning in the late 19th century, and (2) sugar maple sites that show no evidence of burning in the past 200 years. We collected spring snowmelt leachates from zero-tension lysimeters installed underneath O and E soil horizons of Spodosols in both red pine and sugar maple ecosystems. We quantified DPC in leachates by measuring Benzene Polycarboxylic Acids. We also determined DPC in leachates collected from lysimeters installed beneath B horizons in the red pine ecosystem. Average concentrations of DPC leached from O and E horizons in red pine and sugar maple sites were 1.22 ± 0.33 mg L-1 and 0.96 ±0.58 mg L-1, respectively. Although DPC concentrations in either the O or E horizon leachates did not differ between the two ecosystem types, the proportion of DPC in the dissolved organic C pool was 62% higher in red pine than in sugar maple in E horizon leachates. In red pine sites, DPC concentrations were significantly lower in the B horizon leachates than in the upper soil horizons leachates, likely due to DPC immobilization in the mineral subsoil. Our preliminary results showed that a single production of PyC was not the main source of DPC exported from soils, suggesting that DPC mobilized and released from the ecosystems studied here likely integrates PyC produced at a millennial time-scale in the Great Lakes Region.

Remote sensing for prediction of 1-year post-fire ecosystem condition

Treesearch

Leigh B. Lentile; Alistair M. S. Smith; Andrew T. Hudak; Penelope Morgan; Michael J. Bobbitt; Sarah A. Lewis; Peter R. Robichaud

2009-01-01

Appropriate use of satellite data in predicting >1 year post-fire effects requires remote measurement of surface properties that can be mechanistically related to ground measures of post-fire condition. The present study of burned ponderosa pine (Pinus ponderosa) forests in the Black Hills of South Dakota evaluates whether immediate fractional cover estimates of...

Urban-Wildland Fire Defense Strategy, Precision Prescribed Fire: The Los Angeles County Approach

Treesearch

Scott E. Franklin

1987-01-01

In the County of Los Angeles, critical conditions at the urban-wildland interface range from concentrated development to dispersed development; elevations from sea levelto 5000 feet with diverse ecosystems characterized by coastal sage scrub, Chamise, sumac, Ceanothus, Toyon, oak woodlands, pine forests, and desert sage; air quality impacts; sediment production; public...

Early fire history near Papineau lake, Ontario

Treesearch

Daniel C. Dey; Richard P. Guyette

1996-01-01

Research that defines the role of fire in upland red oak-pine ecosystems in central Ontario is being conducted by the Great Lakes-St. Lawrence Silviculture program. Site-specific fire histories are being developed that document fire frequency, fire behavior, fire effects on forest regeneration and grwoth, and the influnce of human activites on fire disturbances. This...

Effects of a prescribed fire on water use and photosynthetic capacity of pitch pines

Treesearch

Heidi J. Renninger; Kenneth L. Clark; Nicholas Skowronski; Karina V.R. Schäfer

2013-01-01

Although wildfires are important in many forested ecosystems, increasing suburbanization necessitates management with prescribed fires. The physiological responses of overstory trees to prescribed fire has received little study and may differ from typical wildfires due to the lower intensity and timing of prescribed fire in the dormant season. Trees may be negatively...

Early Deterioration of Coarse Woody Debris

Treesearch

F.H. Tainter; J.W. McMinn

1999-01-01

Coarse woody debris (CWD) is an important structural component of southern forest ecosystems. CWD loading may be affected by different decomposition rates on sites of varying quality. Bolts of red oak and loblolly pine were placed on plots at each of three (hydric, mesic. and xeric) sites at the Savannah River Site and sampled over a 16-week period. Major changes...

Effect of overstorey trees on understorey vegetation in California (USA) ponderosa pine plantations

Treesearch

Jianwei Zhang; David H. Young; William W. Oliver; Gary O. Fiddler

2016-01-01

Understorey vegetation plays a significant role in the structure and function of forest ecosystems. Controlling understorey vegetation has proven to be an effective tool in increasing tree growth and overstorey development. However, a long-term consequence of the practice on plant diversity is not fully understood. Here, we analyzed early development of overstorey and...

Short- and long-term influence of stand density on soil microbial communities in ponderosa pine forests

Treesearch

Steven T. Overby

2009-01-01

Soil microbial communities process plant detritus and returns nutrients needed for plant growth. Increased knowledge of this intimate linkage between plant and soil microbial communities will provide a better understanding of ecosystem response to changing abiotic and biotic conditions. This dissertation consists of three studies to determine soil microbial community...

Overview Of Ecosystem Management Research In The Ouachita And Ozark Mountains: Phases I–III

Treesearch

James M. Guldin

2004-01-01

Abstract - When the shift away from clearcutting and planting on the Ouachita National Forest was implemented in the early 1990s, it became apparent that research support for reproduction cutting methods that employ natural regeneration in shortleaf pine stands in the Interior Highlands was lacking. To fill that need, research scientists and land...

Exposure to an enriched CO2 atmosphere alters carbon assimilation and allocation in a pine forest ecosystem

Treesearch

Karina V.R. Schafer; Ram Oren; David S. Ellsworth; Chun-Ta Lai; Jeffrey D. Herricks; Adrien C. Finzi; Daniel D. Richter; Gabriel G. Katul

2003-01-01

We linked a leaf-level C02 assimilation model with a model that accounts for light attenuation in the canopy and measurements of sap-flux-based canopy conductance into a new canopy conductance-constrained carbon assimilation (4C-A) model. We estimated canopy C02 uptake (AnC) at...

Chapter 8 - Effects of prescribed fire on upland oak forest ecosystems in Missouri Ozarks (Project NC-F-06-02)

Treesearch

Zhaofei Fan; Daniel C. Dey

2014-01-01

Fire in the Ozark Highlands was historically used by Native Americans (Guyette and others 2002). Early European settlers continued to burn the landscape to manage livestock forage. In the late 1800s, people began to harvest timber, cutting first pine trees and later oak (Flader 2008).

From Attack to Emergence: Interactions between Southern Pine Beetle, Mites, Microbes, and Trees

Treesearch

Kier D. Klepzig; Richard W. Hofstetter

2011-01-01

Bark beetles are among the most ecologically and economically influential organisms in forest ecosystems worldwide. These important organisms are consistently associated in complex symbioses with fungi. Despite this, little is known of the net impacts of the fungi on their vectors, and mites are often completely overlooked. In this chapter, we will describe...

A reconnaissance of small mammal communities in Garland and Government prairies, Arizona

Treesearch

Joseph L. Ganey; Carol L. Chambers

2011-01-01

Small mammals play key ecological roles in grassland ecosystems, yet little is known regarding small mammal communities in large (>50 km2), high-elevation prairies embedded in ponderosa pine (Pinus ponderosa) forests in north central Arizona. To provide information on community composition and habitat relationships, we live-trapped small mammals on 6 transects in 2...

Response of a rare endemic, Penstemon clutei, to burning and reduced belowground competition

Treesearch

Peter Z. Fule; Judith D. Springer; David W. Huffman; W. Wallace Covington

2001-01-01

Penstemon clutei, a rare perennial beardtongue endemic to the ponderosa pine forest of the Sunset Crater volcanic field of northern Arizona, presents an opportunity to test the hypothesis that restoration of historic ecosystem conditions may enhance the sustainability of a rare species. We tested prescribed burning and root trenching treatments as proxies for the...

Fire history of the Appalachian region: a review and synthesis

Treesearch

Charles W. Lafon; Adam T. Naito; Henri D. Grissino-Mayer; Sally P. Horn; Thomas A. Waldrop

2017-01-01

The importance of fire in shaping Appalachian vegetation has become increasingly apparent over the last 25 years. This period has seen declines in oak (Quercus) and pine (Pinus) forests and other fire-dependent ecosystems, which in the near-exclusion of fire are being replaced by fire-sensitive mesophytic vegetation. These vegetation changes imply that Appalachian...

Convergence of the effect of root hydraulic functioning and root hydraulic redistribution on ecosystem water and carbon balance across divergent forest ecosystems

NASA Astrophysics Data System (ADS)

domec, J.; King, J. S.; Ogée, J.; Noormets, A.; Warren, J.; Meinzer, F. C.; Sun, G.; Jordan-Meille, L.; Martineau, E.; Brooks, R. J.; Laclau, J.; Battie Laclau, P.; McNulty, S.

2012-12-01

INVITED ABSTRACT: Deep root water uptake and hydraulic redistribution (HR) play a major role in forest ecosystems during drought, but little is known about the impact of climate change on root-zone processes influencing HR and its consequences on water and carbon fluxes. Using data from two old growth sites in the western USA, two mature sites in the eastern USA, one site in southern Brazil, and simulations with the process-based model MuSICA, our objectives were to show that HR can 1) mitigate the effects of soil drying on root functioning, and 2) have important implications for carbon uptake and net ecosystem exchange (NEE). In a dry, old-growth ponderosa pine (USA) and a eucalyptus stand (Brazil) both characterized by deep sandy soils, HR limited the decline in root hydraulic conductivity and increased dry season tree transpiration (T) by up to 30%, which impacted NEE through major increases in gross primary productivity (GPP). The presence of deep-rooted trees did not necessarily imply high rates of HR unless soil texture allowed large water potential gradients to occur, as was the case in the wet old-growth Douglas-fir/mixed conifer stand. At the Duke mixed hardwood forest characterized by a shallow clay-loam soil, modeled HR was low but not negligible, representing annually up to 10% of T, and maintaining root conductance high. At this site, in the absence of HR, it was predicted that annual GPP would have been diminished by 7-19%. At the coastal loblolly pine plantation, characterized by deep organic soil, HR limited the decline in shallow root conductivity by more than 50% and increased dry season T by up to 40%, which increased net carbon gain by the ecosystem by about 400 gC m-2 yr-1, demonstrating the significance of HR in maintaining the stomatal conductance and assimilation capacity of the whole ecosystem. Under future climate conditions (elevated atmospheric [CO2] and temperature), HR is predicted to be reduced by up to 50%; reducing the resilience of trees to droughts. Under future conditions, T is predicted to stay the same at the Duke mixed hardwood forest, but to decline slightly at the coastal loblolly pine plantation and slightly increase at the old-growth ponderosa pine stand and the eucalyptus plantation. As a consequence, water use efficiency in all sites was predicted to improve dramatically under future climate conditions. Our simulations also showed that the negative effect of drier nights on HR would be greater under future climate conditions. Assuming no increase in stomatal control with increasing drier nights, increased vapor pressure deficit at night under future conditions was sufficient to drive significant nighttime T at all sites , which reduced HR, because the plant and the atmosphere became a sink for hydraulically redistributed water . We concluded that the predicted reductions in HR under future climate conditions are expected to play an important regulatory role in land-atmosphere interactions by affecting whole ecosystem carbon and water balance. We suggest that root distribution should be treated dynamically in response to climate change and that HR and its interactions with rooting depth and soil texture should be implemented in soil-vegetation-atmosphere transfer models.

An appraisal of the classic forest succession paradigm with the shade tolerance index.

PubMed

Lienard, Jean; Florescu, Ionut; Strigul, Nikolay

2015-01-01

In this paper we revisit the classic theory of forest succession that relates shade tolerance and species replacement and assess its validity to understand patch-mosaic patterns of forested ecosystems of the USA. We introduce a macroscopic parameter called the "shade tolerance index" and compare it to the classic continuum index in southern Wisconsin forests. We exemplify shade tolerance driven succession in White Pine-Eastern Hemlock forests using computer simulations and analyzing approximated chronosequence data from the USDA FIA forest inventory. We describe this parameter across the last 50 years in the ecoregions of mainland USA, and demonstrate that it does not correlate with the usual macroscopic characteristics of stand age, biomass, basal area, and biodiversity measures. We characterize the dynamics of shade tolerance index using transition matrices and delimit geographical areas based on the relevance of shade tolerance to explain forest succession. We conclude that shade tolerance driven succession is linked to climatic variables and can be considered as a primary driving factor of forest dynamics mostly in central-north and northeastern areas in the USA. Overall, the shade tolerance index constitutes a new quantitative approach that can be used to understand and predict succession of forested ecosystems and biogeographic patterns.

Ethene, propene, butene and isoprene emissions from a ponderosa pine forest measured by relaxed eddy accumulation

NASA Astrophysics Data System (ADS)

Rhew, Robert C.; Deventer, Malte Julian; Turnipseed, Andrew A.; Warneke, Carsten; Ortega, John; Shen, Steve; Martinez, Luis; Koss, Abigail; Lerner, Brian M.; Gilman, Jessica B.; Smith, James N.; Guenther, Alex B.; de Gouw, Joost A.

2017-11-01

Alkenes are reactive hydrocarbons that influence local and regional atmospheric chemistry by playing important roles in the photochemical production of tropospheric ozone and in the formation of secondary organic aerosols. The simplest alkene, ethene (ethylene), is a major plant hormone and ripening agent for agricultural commodities. The group of light alkenes (C2-C4) originates from both biogenic and anthropogenic sources, but their biogenic sources are poorly characterized, with limited field-based flux observations. Here we report net ecosystem fluxes of light alkenes and isoprene from a semiarid ponderosa pine forest in the Rocky Mountains of Colorado, USA using the relaxed eddy accumulation (REA) technique during the summer of 2014. Ethene, propene, butene and isoprene emissions have strong diurnal cycles, with median daytime fluxes of 123, 95, 39 and 17 µg m-2 h-1, respectively. The fluxes were correlated with each other, followed general ecosystem trends of CO2 and water vapor, and showed similar sunlight and temperature response curves as other biogenic VOCs. The May through October flux, based on measurements and modeling, averaged 62, 52, 24 and 18 µg m-2 h-1 for ethene, propene, butene and isoprene, respectively. The light alkenes contribute significantly to the overall biogenic source of reactive hydrocarbons: roughly 18 % of the dominant biogenic VOC, 2-methyl-3-buten-2-ol. The measured ecosystem scale fluxes are 40-80 % larger than estimates used for global emissions models for this type of ecosystem.

Response of water use efficiency to summer drought in a boreal Scots pine forest in Finland

NASA Astrophysics Data System (ADS)

Gao, Yao; Markkanen, Tiina; Aurela, Mika; Mammarella, Ivan; Thum, Tea; Tsuruta, Aki; Yang, Huiyi; Aalto, Tuula

2017-09-01

The influence of drought on plant functioning has received considerable attention in recent years, however our understanding of the response of carbon and water coupling to drought in terrestrial ecosystems still needs to be improved. A severe soil moisture drought occurred in southern Finland in the late summer of 2006. In this study, we investigated the response of water use efficiency to summer drought in a boreal Scots pine forest (Pinus sylvestris) on the daily time scale mainly using eddy covariance flux data from the Hyytiälä (southern Finland) flux site. In addition, simulation results from the JSBACH land surface model were evaluated against the observed results. Based on observed data, the ecosystem level water use efficiency (EWUE; the ratio of gross primary production, GPP, to evapotranspiration, ET) showed a decrease during the severe soil moisture drought, while the inherent water use efficiency (IWUE; a quantity defined as EWUE multiplied with mean daytime vapour pressure deficit, VPD) increased and the underlying water use efficiency (uWUE, a metric based on IWUE and a simple stomatal model, is the ratio of GPP multiplied with a square root of VPD to ET) was unchanged during the drought. The decrease in EWUE was due to the stronger decline in GPP than in ET. The increase in IWUE was because of the decreased stomatal conductance under increased VPD. The unchanged uWUE indicates that the trade-off between carbon assimilation and transpiration of the boreal Scots pine forest was not disturbed by this drought event at the site. The JSBACH simulation showed declines of both GPP and ET under the severe soil moisture drought, but to a smaller extent compared to the observed GPP and ET. Simulated GPP and ET led to a smaller decrease in EWUE but a larger increase in IWUE because of the severe soil moisture drought in comparison to observations. As in the observations, the simulated uWUE showed no changes in the drought event. The model deficiencies exist mainly due to the lack of the limiting effect of increased VPD on stomatal conductance during the low soil moisture condition. Our study provides a deeper understanding of the coupling of carbon and water cycles in the boreal Scots pine forest ecosystem and suggests possible improvements to land surface models, which play an important role in the prediction of biosphere-atmosphere feedbacks in the climate system.

Land-use history as a major driver for long-term forest dynamics in the Sierra de Guadarrama National Park (central Spain) during the last millennia: implications for forest conservation and management

NASA Astrophysics Data System (ADS)

Morales-Molino, César; Colombaroli, Daniele; Valbuena-Carabaña, María; Tinner, Willy; Salomón, Roberto L.; Carrión, José S.; Gil, Luis

2017-05-01

In the Mediterranean Basin, long-lasting human activities have largely resulted in forest degradation or destruction. Consequently, conservation efforts aimed at preserving and restoring Mediterranean forests often lack well-defined targets when using current forest composition and structure as a reference. In the Iberian mountains, the still widespread Pinus sylvestris and Quercus pyrenaica woodlands have been heavily impacted by land-use. To assess future developments and as a baseline for planning, forest managers are interested in understanding the origins of present ecosystems to disclose effects on forest composition that may influence future vegetation trajectories. Quantification of land-use change is particularly interesting to understand vegetation responses. Here we use three well-dated multi-proxy palaeoecological sequences from the Guadarrama Mountains (central Spain) to quantitatively reconstruct changes occurred in P. sylvestris forests and the P. sylvestris-Q. pyrenaica ecotone at multi-decadal to millennial timescales, and assess the driving factors. Our results show millennial stability of P. sylvestris forests under varying fire and climate conditions, with few transient declines caused by the combined effects of fire and grazing. The high value of pine timber in the past would account for long-lasting pine forest preservation and partly for the degradation of native riparian vegetation (mostly composed of Betula and Corylus). Pine forests further spread after planned forest management started at 1890 CE. In contrast, intensive coppicing and grazing caused Q. pyrenaica decline some centuries ago (ca. 1500-1650 CE), with unprecedented grazing during the last decades seriously compromising today's oak regeneration. Thus, land-use history played a major role in determining vegetation changes. Finally, we must highlight that the involvement of forest managers in this work has guaranteed a practical use of palaeoecological data in conservation and management practice.

Effect of Climate Variability and Management Practices on Carbon, Water and Energy Fluxes of a Young Ponderosa Pine Plantation at the Blodgett Forest Ameriflux Site

NASA Astrophysics Data System (ADS)

Misson, L.; McKay, M.; Goldstein, A. H.

2003-12-01

Our research at Blodgett Forest in the Sierra Nevada mountains of California seeks to better understand how fluxes of CO2, H2O, and energy in a mid-elevation, young pine plantation change interannually in response to climate variability, and how they are impacted by management practices such as shrub removal and thinning. Ecosystem scale fluxes have been measured by the eddy covariance method since 1997, along with meteorological parameters. During winter, the young Ponderosa pine plantation at Blodgett acted mainly as a sink of carbon. Strong variations in winter carbon sequestration occurred due to changes in leaf area index and frequency of freezing temperatures. Interannual variations in springtime carbon flux occurred mainly due to differences in the timing of seasonally increasing temperatures. Drought is a regular feature of the California climate, making water availability the major controller of gas exchange in summer and fall. In late summer 2001, drought stress reduced ecosystem carbon uptake by 1/5, while the Bowen ratio increased by 1/3. Thinning is a widespread procedure in plantation management carried out to reduce stand density, improve forest health, and optimize tree growth. In spring 2000, 2/3 of the trees were removed by mastication, the process of mechanically chewing up unwanted trees, which is becoming a widespread method for pre-commercial thinning in the U.S. During and after thinning, the plantation remained a sink of carbon. Thinning at the Blodgett site reduced the leaf area index from ~3 to ~1.5 m2 m-2, and created branch and stem debris of 400-500 g m-2. During summer 2000, mastication decreased ecosystem carbon uptake by 1/3. Ecosystem water use efficiency decreased by 1/5 and the Bowen ratio increased by 1/3. This indicates the increasing heat lost as sensible versus latent heat as the water flux decreased due to the reduction in leaf area index. After thinning, leaf area index rapidly increased to ~2.5 m2 m-2 by the end of 2000, and to ~3.5 m2 m-2 in 2001. As a result, the uptake of carbon by the ecosystem increased by 1/3 in early summer 2001 in comparison to the pre-thinning value. By summer 2001 the Bowen ratio returned to its pre-thinning value, and the ecosystem water use efficiency increased by 1/3. Higher ecosystem water use efficiency was maintained in summer 2002 and 2003, indicating that the thinning led to better optimization of ecosystem water use for at least the following three years, increasing the ratio of carbon gained to water lost over the growing season.

Southwestern Pine Forests Likely to Disappear

ScienceCinema

McDowell, Nathan

2018-01-16

A new study, led by Los Alamos National Laboratory's Nathan McDowell, suggests that widespread loss of a major forest type, the pine-juniper woodlands of the Southwestern U.S., could be wiped out by the end of this century due to climate change, and that conifers throughout much of the Northern Hemisphere may be on a similar trajectory. New results, reported in the journal Nature Climate Change, suggest that global models may underestimate predictions of forest death. McDowell and his large international team strove to provide the missing pieces of understanding tree death at three levels: plant, regional and global. The team rigorously developed and evaluated multiple process-based and empirical models against experimental results, and then compared these models to results from global vegetation models to examine independent simulations. They discovered that the global models simulated mortality throughout the Northern Hemisphere that was of similar magnitude, but much broader spatial scale, as the evaluated ecosystem models predicted for in the Southwest.

Southwestern Pine Forests Likely to Disappear

DOE Office of Scientific and Technical Information (OSTI.GOV)

McDowell, Nathan

A new study, led by Los Alamos National Laboratory's Nathan McDowell, suggests that widespread loss of a major forest type, the pine-juniper woodlands of the Southwestern U.S., could be wiped out by the end of this century due to climate change, and that conifers throughout much of the Northern Hemisphere may be on a similar trajectory. New results, reported in the journal Nature Climate Change, suggest that global models may underestimate predictions of forest death. McDowell and his large international team strove to provide the missing pieces of understanding tree death at three levels: plant, regional and global. The teammore » rigorously developed and evaluated multiple process-based and empirical models against experimental results, and then compared these models to results from global vegetation models to examine independent simulations. They discovered that the global models simulated mortality throughout the Northern Hemisphere that was of similar magnitude, but much broader spatial scale, as the evaluated ecosystem models predicted for in the Southwest.« less

Fuel Treatment Effects on Water Use Efficiency in Western Pine Forests Under Fire Suppression Evaluated Using Tree Ring Carbon Isotopes

NASA Astrophysics Data System (ADS)

Taylor, A. H.; Belmecheri, S.; Harris, L. B.

2016-12-01

We identified variation on water use efficiency interpreted from carbon 13 in tree ring cellulose in dense ponderosa pines forests in Washington and Arizona. Historically, these forests burned every decade until fires were suppressed beginning in the early twentieth century. The reduction in fire caused large increases in forest density and forest biomass and potential for intense fire. Forests with hazardous fuels are common in the western United States and these types of forests are treated with mechanical thinning and mechanical thinning and burning to reduce hazardous fuels and fire intensity. At each site we extracted tree ring samples from five trees in each treatment type and a control to identify the effects of fuel treatment of concentration of carbon 13 in tree ring cellulose. Water use efficiency as measured by carbon 13 increased after fuel treatments. Treatment effects were larger for the mechanical plus burn treatment than for the mechanical treatment in each study area compared to the control stands Our results suggest that fuel treatments reduce sensitivity of tree growth to climate and increase water use efficiency. Since tree ring carbon 13 is related to plant productivity, carbon 13 in tree rings can be used as a metric of change in ecosystem function for evaluating fuel treatments.

Medium-long term soil resilience against different disturbances: wildfires, silvicultural treatments and climate change

NASA Astrophysics Data System (ADS)

Hedo de Santiago, Javier; Borja, Manuel Esteban Lucas; de las Heras, Jorge

2016-04-01

Soils of semiarid Mediterranean forest ecosystems are very fragile and sensitive to changes due to different anthropogenic and natural disturbances. The increasing vulnerability of semiarid lands within this world framework has generated growing awareness in the field of research, with highly intensified study into soils properties. One of the main problems of Mediterranean forests is wildfire disturbance. Fire should be considered more an ecological factor but, in contrast to the role of fire, it is now a closely related factor to human action. On the other hand, to improve the recovery of forest communities after fire, silvicultural treatments are needed and, for that matter, another disturbance is added to the ecosystem. By last, climate change is also affecting the fire regime increasing fire frequency and burned area, enhancing the destructiveness to Mediterranean ecosystems. After all of these three disturbances, changes in vegetation dynamics and soil properties are expected to occur due to the plant-soil feedback. Soil plays an essential role in the forest ecosystem's fertility and stability and specifically soil microorganisms, which accomplish reactions to release soil nutrients for vegetation development, for that is essential to enlarge knowledge about soil properties resilience in semiarid forest ecosystems. Physico-chemical and microbiological soil properties, and enzyme activities have been studied in two Aleppo pine forest stands that have suffered three disturbances: 1) a wildfire event, 2) silvicultural treatments (thinning) and 3) an artificial drought (simulating climate change) and results showed that soil recovered after 15 years. Final results showed that soils have been recovered from the three disturbances at the medium-long term.

The Forest Canopy as a Temporally and Spatially Dynamic Ecosystem: Preliminary Results of Biomass Scaling and Habitat Use from a Case Study in Large Eastern White Pines (Pinus Strobus)

NASA Astrophysics Data System (ADS)

Martin, J.; Laughlin, M. M.; Olson, E.

2017-12-01

Canopy processes can be viewed at many scales and through many lenses. Fundamentally, we may wish to start by treating each canopy as a unique surface, an ecosystem unto itself. By doing so, we can may make some important observations that greatly influence our ability to scale canopies to landscape, regional and global scales. This work summarizes an ongoing endeavor to quantify various canopy level processes on individual old and large Eastern white pine trees (Pinus strobus). Our work shows that these canopies contain complex structures that vary with height and as the tree ages. This phenomenon complicates the allometric scaling of these large trees using standard methods, but detailed measurements from within the canopy provided a method to constrain scaling equations. We also quantified how these canopies change and respond to canopy disturbance, and documented disproportionate variation of growth compared to the lower stem as the trees develop. Additionally, the complex shape and surface area allow these canopies to act like ecosystems themselves; despite being relatively young and more commonplace when compared to the more notable canopies of the tropics and the Pacific Northwestern US. The white pines of these relatively simple, near boreal forests appear to house various species including many lichens. The lichen species can cover significant portions of the canopy surface area (which may be only 25 to 50 years old) and are a sizable source of potential nitrogen additions to the soils below, as well as a modulator to hydrologic cycles by holding significant amounts of precipitation. Lastly, the combined complex surface area and focused verticality offers important habitat to numerous animal species, some of which are quite surprising.

Soil microbiological properties and enzymatic activities of long-term post-fire recovery in dry and semiarid Aleppo pine (Pinus halepensis M.) forest stands

NASA Astrophysics Data System (ADS)

Hedo, J.; Lucas-Borja, M. E.; Wic, C.; Andrés-Abellán, M.; de Las Heras, J.

2015-02-01

Wildfires affecting forest ecosystems and post-fire silvicultural treatments may cause considerable changes in soil properties. The capacity of different microbial groups to recolonise soil after disturbances is crucial for proper soil functioning. The aim of this work was to investigate some microbial soil properties and enzyme activities in semiarid and dry Aleppo pine (Pinus halepensis M.) forest stands. Different plots affected by a wildfire event 17 years ago without or with post-fire silvicultural treatments 5 years after the fire event were selected. A mature Aleppo pine stand, unaffected by wildfire and not thinned was used as a control. Physicochemical soil properties (soil texture, pH, carbonates, organic matter, electrical conductivity, total N and P), soil enzymes (urease, phosphatase, β-glucosidase and dehydrogenase activities), soil respiration and soil microbial biomass carbon were analysed in the selected forests areas and plots. The main finding was that long time after this fire event produces no differences in the microbiological soil properties and enzyme activities of soil after comparing burned and thinned, burned and not thinned, and mature plots. Moreover, significant site variation was generally seen in soil enzyme activities and microbiological parameters. We conclude that total vegetation recovery normalises post-fire soil microbial parameters, and that wildfire and post-fire silvicultural treatments are not significant factors affecting soil properties after 17 years.

Effects of Thinning Intensities on Soil Infiltration and Water Storage Capacity in a Chinese Pine-Oak Mixed Forest

PubMed Central

Chen, Lili; Yuan, Zhiyou; Shao, Hongbo; Wang, Dexiang; Mu, Xingmin

2014-01-01

Thinning is a crucial practice in the forest ecosystem management. The soil infiltration rate and water storage capacity of pine-oak mixed forest under three different thinning intensity treatments (15%, 30%, and 60%) were studied in Qinling Mountains of China. The thinning operations had a significant influence on soil infiltration rate and water storage capacity. The soil infiltration rate and water storage capacity in different thinning treatments followed the order of control (nonthinning): <60%, <15%, and <30%. It demonstrated that thinning operation with 30% intensity can substantially improve soil infiltration rate and water storage capacity of pine-oak mixed forest in Qinling Mountains. The soil initial infiltration rate, stable infiltration rate, and average infiltration rate in thinning 30% treatment were significantly increased by 21.1%, 104.6%, and 60.9%, compared with the control. The soil maximal water storage capacity and noncapillary water storage capacity in thinning 30% treatment were significantly improved by 20.1% and 34.3% in contrast to the control. The soil infiltration rate and water storage capacity were significantly higher in the surface layer (0~20 cm) than in the deep layers (20~40 cm and 40~60 cm). We found that the soil property was closely related to soil infiltration rate and water storage capacity. PMID:24883372

Ecosystem Resilience and Limitations Revealed by Soil Bacterial Community Dynamics in a Bark Beetle-Impacted Forest

PubMed Central

Brouillard, Brent M.; Bokman, Chelsea M.; Sharp, Jonathan O.

2017-01-01

ABSTRACT Forested ecosystems throughout the world are experiencing increases in the incidence and magnitude of insect-induced tree mortality with large ecologic ramifications. Interestingly, correlations between water quality and the extent of tree mortality in Colorado montane ecosystems suggest compensatory effects from adjacent live vegetation that mute responses in less severely impacted forests. To this end, we investigated whether the composition of the soil bacterial community and associated functionality beneath beetle-killed lodgepole pine was influenced by the extent of surrounding tree mortality. The most pronounced changes were observed in the potentially active bacterial community, where alpha diversity increased in concert with surrounding tree mortality until mortality exceeded a tipping point of ~30 to 40%, after which diversity stabilized and decreased. Community structure also clustered in association with the extent of surrounding tree mortality with compositional trends best explained by differences in NH4+ concentrations and C/N ratios. C/N ratios, which were lower in soils under beetle-killed trees, further correlated with the relative abundance of putative nitrifiers and exoenzyme activity. Collectively, the response of soil microorganisms that drive heterotrophic respiration and decay supports observations of broader macroscale threshold effects on water quality in heavily infested forests and could be utilized as a predictive mechanism during analogous ecosystem disruptions. PMID:29208740

Quantifying the Carbon Balance of Forest Restoration and Wildfire under Projected Climate in the Fire-Prone Southwestern US.

PubMed

Hurteau, Matthew D

2017-01-01

Climate projections for the southwestern US suggest a warmer, drier future and have the potential to impact forest carbon (C) sequestration and post-fire C recovery. Restoring forest structure and surface fire regimes initially decreases total ecosystem carbon (TEC), but can stabilize the remaining C by moderating wildfire behavior. Previous research has demonstrated that fire maintained forests can store more C over time than fire suppressed forests in the presence of wildfire. However, because the climate future is uncertain, I sought to determine the efficacy of forest management to moderate fire behavior and its effect on forest C dynamics under current and projected climate. I used the LANDIS-II model to simulate carbon dynamics under early (2010-2019), mid (2050-2059), and late (2090-2099) century climate projections for a ponderosa pine (Pinus ponderosa) dominated landscape in northern Arizona. I ran 100-year simulations with two different treatments (control, thin and burn) and a 1 in 50 chance of wildfire occurring. I found that control TEC had a consistent decline throughout the simulation period, regardless of climate. Thin and burn TEC increased following treatment implementation and showed more differentiation than the control in response to climate, with late-century climate having the lowest TEC. Treatment efficacy, as measured by mean fire severity, was not impacted by climate. Fire effects were evident in the cumulative net ecosystem exchange (NEE) for the different treatments. Over the simulation period, 32.8-48.9% of the control landscape was either C neutral or a C source to the atmosphere and greater than 90% of the thin and burn landscape was a moderate C sink. These results suggest that in southwestern ponderosa pine, restoring forest structure and surface fire regimes provides a reasonable hedge against the uncertainty of future climate change for maintaining the forest C sink.

Secondary Circulations between an isolated semi-arid Pine Forest and the surrounding Shrub Land: A LES Study

NASA Astrophysics Data System (ADS)

Kroeniger, K.; De Roo, F.; Huq, S.; Brugger, P.; Mauder, M.

2017-12-01

Afforestation in semi-arid regions is a topic of growing interest in times of changing climate. However, due to the extreme environmental conditions in these regions, survival of artificial eco-systems is not guaranteed a priori and therefore needs to be investigated. As an example of an artificially planted semi-arid forest, we study the Israeli pine forest Yatir, which is located at the northern edge of the Negev desert. The coincidence of large global radiation with the low forest albedo results in net radiation intensities of more than 700 W m-2, requiring an efficient mechanism of heat removal, indispensable for tree survival. In the distinct dry summer periods evaporative cooling becomes negligible, while a substantially enhanced sensible heat flux removes the largest part of the incoming energy load. This enhanced sensible heat flux above the forest is believed to be amplified by the albedo difference between the forest and the surrounding shrub land, generating secondary circulations between these two eco-systems. The focus of our work is studying the interconnection of enhanced sensible heat flux and secondary circulations in varying conditions. We perform large eddy simulations (LES) for a region that is sufficiently large to model the forest and parts of the surrounding shrub land (20 km x 20 km) with a grid resolution of 2.5 m. This fine resolution allows us to explicitly resolve the forest canopy, to obtain more realistic results than by applying roughness length parametrizations. The LES are initialized by measured data from several field campaigns, eddy covariance towers and satellite images. By varying the background wind and the underlying topography in several LES, we study the influence of those parameters on the canopy-atmosphere exchange. Additional, we compare the LES output to LIDAR measurements taken above and upstream of the forest for model validation.

Quantifying the Carbon Balance of Forest Restoration and Wildfire under Projected Climate in the Fire-Prone Southwestern US

PubMed Central

2017-01-01

Climate projections for the southwestern US suggest a warmer, drier future and have the potential to impact forest carbon (C) sequestration and post-fire C recovery. Restoring forest structure and surface fire regimes initially decreases total ecosystem carbon (TEC), but can stabilize the remaining C by moderating wildfire behavior. Previous research has demonstrated that fire maintained forests can store more C over time than fire suppressed forests in the presence of wildfire. However, because the climate future is uncertain, I sought to determine the efficacy of forest management to moderate fire behavior and its effect on forest C dynamics under current and projected climate. I used the LANDIS-II model to simulate carbon dynamics under early (2010–2019), mid (2050–2059), and late (2090–2099) century climate projections for a ponderosa pine (Pinus ponderosa) dominated landscape in northern Arizona. I ran 100-year simulations with two different treatments (control, thin and burn) and a 1 in 50 chance of wildfire occurring. I found that control TEC had a consistent decline throughout the simulation period, regardless of climate. Thin and burn TEC increased following treatment implementation and showed more differentiation than the control in response to climate, with late-century climate having the lowest TEC. Treatment efficacy, as measured by mean fire severity, was not impacted by climate. Fire effects were evident in the cumulative net ecosystem exchange (NEE) for the different treatments. Over the simulation period, 32.8–48.9% of the control landscape was either C neutral or a C source to the atmosphere and greater than 90% of the thin and burn landscape was a moderate C sink. These results suggest that in southwestern ponderosa pine, restoring forest structure and surface fire regimes provides a reasonable hedge against the uncertainty of future climate change for maintaining the forest C sink. PMID:28046079

Natural range of variation for yellow pine and mixed-conifer forests in the Sierra Nevada, southern Cascades, and Modoc and Inyo National Forests, California, USA

Treesearch

Hugh D. Safford; Jens T. Stevens

2017-01-01

Yellow pine and mixed-conifer (YPMC) forests are the predominant montane forest type in the Sierra Nevada, southern Cascade Range, and neighboring forested areas on the Modoc and Inyo National Forests (the "assessment area"). YPMC forests occur above the oak woodland belt and below red fir forests, and are dominated by the yellow pines (ponderosa pine [

Effects of ionizing radiation upon natural populations and ecosystems. Final report. [Ecological perspectives in land use planning

DOE Office of Scientific and Technical Information (OSTI.GOV)

McCormick, J.F.

Accomplishments throughout a 10-year period summarized include: a study of the effects of radiation from a ..gamma.. source on the ecology of the El Verde rain forest in Puerto Rico, with emphasis on the role of secondary succession in the recovery of forest ecosystems following irradiation; the effects of light and temperature on gaseous exchange in trees using /sup 14/CO/sub 2/ as a tracer in Palcourea; the nature of the sensitivity of pine trees to ionizing radiation and the possible synergistic effects of elevated ozone levels on radiosensitivity; the combined effects of radioactive and thermal effluents on plant communities ofmore » a swamp hardwood forest; and the development of a new conceptual approach to the evaluation of environmental quality, with emphasis on ecological perspectives in land use planning. (CH)« less

Modelling drought-induced dieback of Aleppo pine at the arid timberline

NASA Astrophysics Data System (ADS)

Wingate, Lisa; Preisler, Yakir; Bert, Didier; Rotenberg, Eyal; Yakir, Dan; Maseyk, Kadmiel; Ogee, Jerome

2016-04-01

During the mid 1960's an ambitious afforestation programme was initiated in the Negev desert of Israel. After five decades enduring harsh growing conditions, the Aleppo pine forest of Yatir is now exhibiting signs of 'drought-induced' dieback. Since 2010, 5-10% of the entire Yatir population have died, however the pattern of mortality is extremely patchy with some areas exhibiting >80% mortality whilst others display none. In this presentation, we reflect on historic climatic and edaphic conditions that have triggered this landscape mosaic of survival and mortality and how physiological and hydraulic traits vary within this patchwork. In addition, we explore how these pine trees have responded physiologically over recent years (1996-2010) to a series of severe drought events using a combined approach that brings together micrometeorological, dendro-isotopic and dendro-climatological datasets alongside process-based modelling. In particular the dataset trends were investigated with the isotope-enabled ecosystem model MuSICA to explore the consequences of subsequent droughts and embolism on modelled carbohydrate and water pool dynamics and their impact on carbon allocation and ecosystem function.

Restoring a disappearing ecosystem: the Longleaf Pine Savanna.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Harrington, Timothy B.; Miller, Karl V.; Park, Noreen

Longleaf pine (Pinus palustris) savannas of the southeastern United States contain some of the worlds most diverse plant communities, along with a unique complement of wildlife. Their traditionally open canopy structure and rich understory of grasses and herbs were critical to their vigor. However, a long history of land-use practices such as logging, farming, and fire exclusion have reduced this once-widespread ecosystem to only 3 percent of its original range. At six longleaf pine plantations in South Carolina, Tim Harrington with the Pacific Northwest Research Station and collaborators with the Southern Research Station used various treatments (including prescribed burns, treemore » thinning, and herbicide applications) to alter the forest structure and tracked how successful each one was in advancing savanna restoration over a 14-year period. They found that typical planting densities for wood production in plantations create dense understory shade that excludes many native herbaceous species important to savannas and associated wildlife. The scientists found that although tree thinning alone did not result in sustained gains, a combination of controlled burning, thinning, and herbicide treatments to reduce woody plants was an effective strategy for recovering the savanna ecosystem. The scientists also found that these efforts must be repeated periodically for enduring benefits.« less

Upland Trees Contribute to Exchange of Nitrous Oxide (N2O) in Forest Ecosystems

NASA Astrophysics Data System (ADS)

Tian, H.; Thompson, R.; Canadell, J.; Winiwarter, W.; Machacova, K.; Maier, M.; Halmeenmäki, E.; Svobodova, K.; Lang, F.; Pihlatie, M.; Urban, O.

2017-12-01

The increase in atmospheric nitrous oxide (N2O) concentration contributes to the acceleration of the greenhouse effect. However, the role of trees in the N2O exchange of forest ecosystems is still an open question. While the soils of temperate and boreal forests were shown to be a natural source of N2O, trees have been so far overlooked in the forest N2O inventories. We determined N2O fluxes in common tree species of boreal and temperate forests: Scots pine (Pinus sylvestris), Norway spruce (Picea abies), downy and silver birch (Betula pubescens, B. pendula), and European beech (Fagus sylvatica). We investigated (1) whether these tree species exchange N2O with the atmosphere under natural field conditions, (2) how the tree N2O fluxes contribute to the forest N2O balance, and (3) whether these fluxes show seasonal dynamics. The studies were performed in a boreal forest (SMEAR II station, Finland; June 2014 - May 2015) and two temperate mountain forests (White Carpathians, Czech Republic; Black Forest, Germany; June and July 2015). Fluxes of N2O in mature tree stems and forest floor were measured using static chamber systems followed by chromatographic and photo-acoustic analyses of N2O concentration changes. Pine, spruce and birch trees were identified as net annual N2O sources. Spruce was found the strongest emitter (0.27 mg ha-1 h-1) amounting thus up to 2.5% of forest floor N2O emissions. All tree species showed a substantial seasonality in stem N2O flux that was related to their physiological activity and climatic variables. In contrast, stems of beech trees growing at soils consuming N2O may act as a substantial sink of N2O from the atmosphere. Consistent N2O consumption by tree stems ranging between -12.1 and -35.2 mg ha-1 h-1 and contributing by up to 3.4% to the forest floor N2O uptake is a novel finding in contrast to current studies presenting trees as N2O emitters. To understand these fluxes, N2O exchange of photoautotrophic organisms associated with beech bark (lichens, mosses and algae) was quantified. All the organisms were net N2O sinks at full rehydration with consumption rates comparable to stem consumption rates. All tree species studied contribute to N2O exchange in forest ecosystems and these fluxes have to be included in the forest N2O emission inventories.

[Energy and mass exchange and the productivity of the main ecosystems of Siberia (from eddy covariance measurements). 1. Heat balance structure in the vegetation season].

PubMed

Chebakova, N M; Vygodskaia, N N; Arnet, A; Belelli Markezini, L; Kolle, O; Kurbatova, Iu A; Parfenova, E I; Valentini, R; Vaganov, E A; Shul'tse, E D

2013-01-01

Direct measurements of heat balance (turbulent heat transfer and evaporation heat consumption) by the method of turbulent pulsations in 1998-2000 and 2002-2004 were used to obtain information on the daily, seasonal, and annual dynamics of energy fluxes and mass transfer between the atmosphere and the typical ecosystems of Siberia (middle-taiga pine forest and raised bog, true four-grass steppe, with the use of data for typical tundra) along the Yenisei meridian (90 degrees E).

Modeling mountain pine beetle habitat suitability within Sequoia National Park

NASA Astrophysics Data System (ADS)

Nguyen, Andrew

Understanding significant changes in climate and their effects on timber resources can help forest managers make better decisions regarding the preservation of natural resources and land management. These changes may to alter natural ecosystems dependent on historical and current climate conditions. Increasing mountain pine beetle (MBP) outbreaks within the southern Sierra Nevada are the result of these alterations. This study better understands MPB behavior within Sequoia National Park (SNP) and model its current and future habitat distribution. Variables contributing to MPB spread are vegetation stress, soil moisture, temperature, precipitation, disturbance, and presence of Ponderosa (Pinus ponderosa) and Lodgepole (Pinus contorta) pine trees. These variables were obtained using various modeled, insitu, and remotely sensed sources. The generalized additive model (GAM) was used to calculate the statistical significance of each variable contributing to MPB spread and also created maps identifying habitat suitability. Results indicate vegetation stress and forest disturbance to be variables most indicative of MPB spread. Additionally, the model was able to detect habitat suitability of MPB with a 45% accuracy concluding that a geospatial driven modeling approach can be used to delineate potential MPB spread within SNP.

A survey of cavity-nesting bees and wasps in loblolly pine stands of the Savannah River Site, Aiken County, South Carolina.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Horn, S.; Hanula, J., L.

2004-03-10

Horn, Scott, and James L. Hanula. 2004. A survey of cavity-nesting bees and wasps in loblolly pine stands of the Savannah River Site, Aiken County, South Carolina. 39(3): 464-469. Abstract: In recent years concern over widespread losses in biodiversity has grown to include a possible decline of many native pollinators, primarily bees. Factors such as habitat fragmentation, agricultural practices, use of pesticides, the introduction of invasive species, or changes in land use may negatively impact these vital organisims. Most reported studies show that human impacts on pollinators are overwhelmingly negative. Reductions in pollinator populations may profoundly impact plant population dynamicsmore » and ecosystem function. Little baseline data exists on the diversity and relative abundance of bees and wasps in southern forests. The objective of this study was to develop a simple, effective method of surveying cavity-nesting bees and wasps and to determine species diversity in mature forests of loblolly pine, the most widely planted tree species in the southern United States.« less

Effects of Climate Variability and Accelerated Forest Thinning on Watershed-Scale Runoff in Southwestern USA Ponderosa Pine Forests

PubMed Central

Robles, Marcos D.; Marshall, Robert M.; O'Donnell, Frances; Smith, Edward B.; Haney, Jeanmarie A.; Gori, David F.

2014-01-01

The recent mortality of up to 20% of forests and woodlands in the southwestern United States, along with declining stream flows and projected future water shortages, heightens the need to understand how management practices can enhance forest resilience and functioning under unprecedented scales of drought and wildfire. To address this challenge, a combination of mechanical thinning and fire treatments are planned for 238,000 hectares (588,000 acres) of ponderosa pine (Pinus ponderosa) forests across central Arizona, USA. Mechanical thinning can increase runoff at fine scales, as well as reduce fire risk and tree water stress during drought, but the effects of this practice have not been studied at scales commensurate with recent forest disturbances or under a highly variable climate. Modifying a historical runoff model, we constructed scenarios to estimate increases in runoff from thinning ponderosa pine at the landscape and watershed scales based on driving variables: pace, extent and intensity of forest treatments and variability in winter precipitation. We found that runoff on thinned forests was about 20% greater than unthinned forests, regardless of whether treatments occurred in a drought or pluvial period. The magnitude of this increase is similar to observed declines in snowpack for the region, suggesting that accelerated thinning may lessen runoff losses due to warming effects. Gains in runoff were temporary (six years after treatment) and modest when compared to mean annual runoff from the study watersheds (0–3%). Nonetheless gains observed during drought periods could play a role in augmenting river flows on a seasonal basis, improving conditions for water-dependent natural resources, as well as benefit water supplies for downstream communities. Results of this study and others suggest that accelerated forest thinning at large scales could improve the water balance and resilience of forests and sustain the ecosystem services they provide. PMID:25337823

Effects of climate variability and accelerated forest thinning on watershed-scale runoff in southwestern USA ponderosa pine forests.

PubMed

Robles, Marcos D; Marshall, Robert M; O'Donnell, Frances; Smith, Edward B; Haney, Jeanmarie A; Gori, David F

2014-01-01

The recent mortality of up to 20% of forests and woodlands in the southwestern United States, along with declining stream flows and projected future water shortages, heightens the need to understand how management practices can enhance forest resilience and functioning under unprecedented scales of drought and wildfire. To address this challenge, a combination of mechanical thinning and fire treatments are planned for 238,000 hectares (588,000 acres) of ponderosa pine (Pinus ponderosa) forests across central Arizona, USA. Mechanical thinning can increase runoff at fine scales, as well as reduce fire risk and tree water stress during drought, but the effects of this practice have not been studied at scales commensurate with recent forest disturbances or under a highly variable climate. Modifying a historical runoff model, we constructed scenarios to estimate increases in runoff from thinning ponderosa pine at the landscape and watershed scales based on driving variables: pace, extent and intensity of forest treatments and variability in winter precipitation. We found that runoff on thinned forests was about 20% greater than unthinned forests, regardless of whether treatments occurred in a drought or pluvial period. The magnitude of this increase is similar to observed declines in snowpack for the region, suggesting that accelerated thinning may lessen runoff losses due to warming effects. Gains in runoff were temporary (six years after treatment) and modest when compared to mean annual runoff from the study watersheds (0-3%). Nonetheless gains observed during drought periods could play a role in augmenting river flows on a seasonal basis, improving conditions for water-dependent natural resources, as well as benefit water supplies for downstream communities. Results of this study and others suggest that accelerated forest thinning at large scales could improve the water balance and resilience of forests and sustain the ecosystem services they provide.

The role of CVS (and FIA) data and genetic tests in assessing species vulnerability to invasive pests and changing climate

Treesearch

R.A. Sniezko; H.E. Lintz

2017-01-01

United States tree species and their associated ecosystems, managed forests, and urban plantings are increasingly vulnerable to non-native invasive pathogens and insects as well as effects associated with a changing climate. Some species, such as whitebark pine (Pinus albicaulis), have been proposed for listing under the Endangered Species Act. To...

Predicting the Effects of Ecosystem Management Harvesting Treatments on Breeding Birds in Pine-Hardwood Forests

Treesearch

Lisa J. Petit; Daniel R. Petit; Thomas E. Martin

1993-01-01

Habitat relationships of birds are well known compared to those of other taxa. However, a major obstacle to developing rigorous management plans for birds is the collation and transfer of information from widely scattered technical and academic publications to a form that can be applied directly to the management of species. Recognizing this dilemma, Hamel (1992)...

Hydraulic redistribution of soil water during summer drought in two contrasting Pacific Northwest coniferous forests.

Treesearch

J. Renee Brooks; Frederick C. Meinzer; Rob Coulombe; Jillian Gregg

2002-01-01

The magnitude of hydraulic redistribution of soil water by roots and its impact on soil water balance were estimated by monitoring time courses of soil water status and multiple depths and root sap flow under drought conditions in a dry ponderosa pine (Pinus ponderosa Dougl. ex Laws) ecosystem and in a moist Douglas-fir (Pseudotsuga...