Science.gov

Sample records for passionfruit woodiness disease

  1. Genetic landmarks through philately: Woodrow Wilson 'Woody' Guthrie and Huntington disease.

    PubMed

    Innes, A M; Chudley, A E

    2002-04-01

    This brief account of Woody Guthrie is instructive to clinical geneticists. It tells the story of one famous man's understanding of, and struggle with, Huntington's disease. The philatelic illustration depicts Woody Guthrie playing his guitar in the years before advancement of the disease.

  2. The potyvirus associated with the dappled fruit of Passiflora edulis in Kagoshima prefecture, Japan is the third strain of the proposed new species East Asian Passiflora virus (EAPV) phylogenetically distinguished from strains of Passion fruit woodiness virus.

    PubMed

    Iwai, H; Yamashita, Y; Nishi, N; Nakamura, M

    2006-04-01

    A potyvirus (isolate IB) causing dappled or faded fruits and foliar mosaic symptoms of purple passionfruit, was found in the botanical garden of Kagoshima University, Japan. This isolate--differed in host range from isolates of Passion fruit woodiness virus (PWV)-AO, previously reported to cause "woodiness" in Japan. Isolates IB and AO had 83% amino acid identity in their coat proteins (CPs). In phylogenetic analysis, East Asian isolates IB, AO, and PWV-Taiwan clustered together, and were distinguishable from Australian PWV and Brazilian Cowpea aphid-borne mosaic virus isolates, which also cause "woodiness" in passionfruit. We propose the name "East Asian Passiflora virus (EAPV)" for the new potyvirus species.

  3. Genome Sequence of Euphorbia mosaic virus from Passionfruit and Euphorbia heterophylla in Florida.

    PubMed

    Polston, J E; Londoño, M A; Cohen, A L; Padilla-Rodriguez, M; Rosario, K; Breitbart, M

    2017-03-02

    Euphorbia mosaic virus (EuMV) was found in a symptomatic passionfruit (Passiflora edulis) plant from Homestead, Florida, USA, as well as in the symptomatic weed Euphorbia heterophylla This is the first identification of EuMV in Florida and the United States and the first report of a natural infection of passionfruit by EuMV.

  4. Genome Sequence of Euphorbia mosaic virus from Passionfruit and Euphorbia heterophylla in Florida

    PubMed Central

    Londoño, M. A.; Cohen, A. L.; Padilla-Rodriguez, M.; Rosario, K.; Breitbart, M.

    2017-01-01

    ABSTRACT Euphorbia mosaic virus (EuMV) was found in a symptomatic passionfruit (Passiflora edulis) plant from Homestead, Florida, USA, as well as in the symptomatic weed Euphorbia heterophylla. This is the first identification of EuMV in Florida and the United States and the first report of a natural infection of passionfruit by EuMV. PMID:28254981

  5. Common factors drive disease and coarse woody debris dynamics in forests impacted by sudden oak death

    Treesearch

    Richard C. Cobb; Maggie N. Chan; Ross K. Meentemeyer; David M. Rizzo

    2011-01-01

    Disease ecology has made important steps in describing how epidemiological processes control the impact of pathogens on populations and communities but fewer field or theoretical studies address disease effects at the ecosystem level. We demonstrate that the same epidemiological mechanisms drive disease intensity and coarse woody debris (CWD) dynamics...

  6. Characterization and distribution of a Potyvirus associated with passion fruit woodiness disease in Uganda

    USDA-ARS?s Scientific Manuscript database

    This paper describes the incidence and etiology of viral infection on passion fruit in Uganda. Viral disease symptoms, including those characteristic of Passion fruit woodiness disease (PWD), were observed in producing areas with an overall mean infection level of 27%. Electron microscopic observati...

  7. The Microflora of Frozen Passionfruit Nectar Base1

    PubMed Central

    Aea, Raymond T. F.; Bushnell, O. A.

    1962-01-01

    A considerable and varied microflora is introduced into passionfruit nectar base under present methods of production. In spite of the great acidity of the nectar base (pH range: 2.8 to 3.2), the high sucrose concentration (approximately 50%), and storage at -20 C, remnants of the microflora persist for a year or longer. During storage, however, there is a steady and gradual decrease, until after about 18 months the microflora is near to extinction. Sample regression lines show straight-line slopes for this diminution in numbers. A battery of nine media was used to grow a representative aerobic flora. Purified cultures of isolates were identified to genera. Yeasts were the most numerous organisms in all samples, followed by molds, bacteria, and streptomycetes. The bacteria were the first group to disappear during storage. No fecal streptococci or gram-negative bacilli were found in any samples. PMID:13859495

  8. Woody debris

    Treesearch

    Donna B. Scheungrab; Carl C. Trettin; Russ Lea; Martin F. Jurgensen

    2000-01-01

    Woody debris can be defined as any dead, woody plant material, including logs, branches, standing dead trees, and root wads. Woody debris is an important part of forest and stream ecosystems because it has a role in carbon budgets and nutrient cycling, is a source of energy for aquatic ecosystems, provides habitat for terrestrial and aquatic organisms, and contributes...

  9. Low Dose Gamma Irradiation Does Not Affect the Quality or Total Ascorbic Acid Concentration of "Sweetheart" Passionfruit (Passiflora edulis).

    PubMed

    Golding, John B; Blades, Barbara L; Satyan, Shashirekha; Spohr, Lorraine J; Harris, Anne; Jessup, Andrew J; Archer, John R; Davies, Justin B; Banos, Connie

    2015-08-26

    Passionfruit (Passiflora edulis, Sims, cultivar "Sweetheart") were subject to gamma irradiation at levels suitable for phytosanitary purposes (0, 150, 400 and 1000 Gy) then stored at 8 °C and assessed for fruit quality and total ascorbic acid concentration after one and fourteen days. Irradiation at any dose (≤1000 Gy) did not affect passionfruit quality (overall fruit quality, colour, firmness, fruit shrivel, stem condition, weight loss, total soluble solids level (TSS), titratable acidity (TA) level, TSS/TA ratio, juice pH and rot development), nor the total ascorbic acid concentration. The length of time in storage affected some fruit quality parameters and total ascorbic acid concentration, with longer storage periods resulting in lower quality fruit and lower total ascorbic acid concentration, irrespective of irradiation. There was no interaction between irradiation treatment and storage time, indicating that irradiation did not influence the effect of storage on passionfruit quality. The results showed that the application of 150, 400 and 1000 Gy gamma irradiation to "Sweetheart" purple passionfruit did not produce any deleterious effects on fruit quality or total ascorbic acid concentration during cold storage, thus supporting the use of low dose irradiation as a phytosanitary treatment against quarantine pests in purple passionfruit.

  10. Survival Times of Selected Enteropathogenic Bacteria in Frozen Passionfruit Nectar Base

    PubMed Central

    Aea, Raymond T. F.; Bushnell, O. A.

    1962-01-01

    Five test organisms were used: Escherichia coli, Salmonella typhosa, Salmonella schottmuelleri, Salmonella enteritidis, and Shigella paradysenteriae. Even when large inocula of these test cultures were introduced into fresh passionfruit nectar base, all test organisms were killed within 1 to 2 hr, provided the nectar base was held at room temperature for more than 1 hr before freezing. If the nectar base was frozen immediately after inoculation, four of the five test organisms were eliminated almost as quickly. But the fifth, Salmonella enteritidis, proved to be exceptional: it was being recovered after 90 days of storage at -20 C, when the last available sample was analyzed. PMID:13859494

  11. Effect of Simulated Dasiops inedulis (Diptera: Lonchaeidae) Injury on Yield and Fruit Quality Parameters in Yellow Passionfruit.

    PubMed

    Salamanca, Leidy; Manzano, Maria R; Baena, Diosdado; Tovar, Diego; Wyckhuys, Kris A G

    2015-02-01

    Yellow passionfruit (Passiflora edulis f. flavicarpa O. Deg.) is a tropical fruit crop that is meeting increasing demand both in local and international markets in South America. The lance fly, Dasiops inedulis (Diptera: Lonchaeidae), affects P. edulis floral buds and flowers, and is thought to cause important yield losses in this crop. In Colombia, D. inedulis are commonly controlled through calendar-based applications of chemically synthesized insecticides, and no scientific criteria exist to guide pest management. In the present study, we simulated D. inedulis injury to passionfruit plants, over the course of three production cycles. We assessed the effect of seven different categories of flower bud removal (from 0% to 79.9%) on passionfruit yield and fruit quality parameters. Removal rates above 20% caused a significant reduction in the number of flowers, while yield levels were lowest at 50-79.9% bud removal. With increasing rates of flower bud removal, we observed higher initial production of buds and lower levels of natural abortion of floral and fruiting structures. For the three consecutive harvests, maximum yield levels were 7.57±5.51 kg (mean±SD; with 0-9.9% damage), and minimum yield was 2.37±2.15 kg (60-69.9% damage) per plant. For fruit quality parameters, D. inedulis injury did not affect fruit pulp weight or the content of soluble solids (Brix). Our work provides insights into the impact of D. inedulis on yellow passionfruit production, and constitutes a basis for future integrated pest management programs for this pest. © The Authors 2015. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  12. Low Dose Gamma Irradiation Does Not Affect the Quality or Total Ascorbic Acid Concentration of “Sweetheart” Passionfruit (Passiflora edulis)

    PubMed Central

    Golding, John B.; Blades, Barbara L.; Satyan, Shashirekha; Spohr, Lorraine J.; Harris, Anne; Jessup, Andrew J.; Archer, John R.; Davies, Justin B.; Banos, Connie

    2015-01-01

    Passionfruit (Passiflora edulis, Sims, cultivar “Sweetheart”) were subject to gamma irradiation at levels suitable for phytosanitary purposes (0, 150, 400 and 1000 Gy) then stored at 8 °C and assessed for fruit quality and total ascorbic acid concentration after one and fourteen days. Irradiation at any dose (≤1000 Gy) did not affect passionfruit quality (overall fruit quality, colour, firmness, fruit shrivel, stem condition, weight loss, total soluble solids level (TSS), titratable acidity (TA) level, TSS/TA ratio, juice pH and rot development), nor the total ascorbic acid concentration. The length of time in storage affected some fruit quality parameters and total ascorbic acid concentration, with longer storage periods resulting in lower quality fruit and lower total ascorbic acid concentration, irrespective of irradiation. There was no interaction between irradiation treatment and storage time, indicating that irradiation did not influence the effect of storage on passionfruit quality. The results showed that the application of 150, 400 and 1000 Gy gamma irradiation to “Sweetheart” purple passionfruit did not produce any deleterious effects on fruit quality or total ascorbic acid concentration during cold storage, thus supporting the use of low dose irradiation as a phytosanitary treatment against quarantine pests in purple passionfruit. PMID:28231212

  13. Radium concentration factors in passionfruit (Passiflora foetida) from the Alligator Rivers Region, Northern Territory, Australia.

    PubMed

    Medley, Peter; Bollhöfer, Andreas; Parry, David; Martin, Paul

    2013-12-01

    In this study, uptake of Ra from soil into the edible fruit of the wild passionfruit species Passiflora foetida was investigated, using selective extraction from the soil samples. A wide range of environmental exposure conditions were represented by the locations that were sampled, including both natural soils, and soils influenced by past and present uranium mining activities. The bioavailable (226)Ra fraction in soils was found to be a better predictor of (226)Ra fruit activity concentrations than the total soil activity concentration, or any of the other fractions studied. Concentration Factors (CFs) derived using the bioavailable fraction varied by only a factor of 7 between different locations, whereas CFs derived using other fractions and total soil varied by up to two orders of magnitude. CFs were highest for those soils containing the lowest concentrations of Mg, Ca and Ba, and approached a saturation value at higher soil concentrations. This finding suggests that group II elements influence radium uptake, most likely the result of increased pressure on the plant to take up essential nutrient group II elements from soil with the lower concentrations, with Ra being taken up as an analogue element. It is also possible that at higher concentrations of bioavailable Ca and Mg in the soil, these ions will outcompete Ra for adsorption sites in the soil and/or on the root surfaces. The study also shows that (228)Ra can potentially be a significant contributor to ingestion doses and should also be considered when assessing committed effective doses from the ingestion of fruits. Crown Copyright © 2013. Published by Elsevier Ltd. All rights reserved.

  14. Can vessel dimension explain tolerance toward fungal vascular wilt diseases in woody plants? Lessons from Dutch elm disease and esca disease in grapevine.

    PubMed

    Pouzoulet, Jérôme; Pivovaroff, Alexandria L; Santiago, Louis S; Rolshausen, Philippe E

    2014-01-01

    This review illuminates key findings in our understanding of grapevine xylem resistance to fungal vascular wilt diseases. Grapevine (Vitis spp.) vascular diseases such as esca, botryosphaeria dieback, and eutypa dieback, are caused by a set of taxonomically unrelated ascomycete fungi. Fungal colonization of the vascular system leads to a decline of the plant host because of a loss of the xylem function and subsequent decrease in hydraulic conductivity. Fungal vascular pathogens use different colonization strategies to invade and kill their host. Vitis vinifera cultivars display different levels of tolerance toward vascular diseases caused by fungi, but the plant defense mechanisms underlying those observations have not been completely elucidated. In this review, we establish a parallel between two vascular diseases, grapevine esca disease and Dutch elm disease, and argue that the former should be viewed as a vascular wilt disease. Plant genotypes exhibit differences in xylem morphology and resistance to fungal pathogens causing vascular wilt diseases. We provide evidence that the susceptibility of three commercial V. vinifera cultivars to esca disease is correlated to large vessel diameter. Additionally, we explore how xylem morphological traits related to water transport are influenced by abiotic factors, and how these might impact host tolerance of vascular wilt fungi. Finally, we explore the utility of this concept for predicting which V. vinifera cultivars are most vulnerable of fungal vascular wilt diseases and propose new strategies for disease management.

  15. Can vessel dimension explain tolerance toward fungal vascular wilt diseases in woody plants? Lessons from Dutch elm disease and esca disease in grapevine

    PubMed Central

    Pouzoulet, Jérôme; Pivovaroff, Alexandria L.; Santiago, Louis S.; Rolshausen, Philippe E.

    2014-01-01

    This review illuminates key findings in our understanding of grapevine xylem resistance to fungal vascular wilt diseases. Grapevine (Vitis spp.) vascular diseases such as esca, botryosphaeria dieback, and eutypa dieback, are caused by a set of taxonomically unrelated ascomycete fungi. Fungal colonization of the vascular system leads to a decline of the plant host because of a loss of the xylem function and subsequent decrease in hydraulic conductivity. Fungal vascular pathogens use different colonization strategies to invade and kill their host. Vitis vinifera cultivars display different levels of tolerance toward vascular diseases caused by fungi, but the plant defense mechanisms underlying those observations have not been completely elucidated. In this review, we establish a parallel between two vascular diseases, grapevine esca disease and Dutch elm disease, and argue that the former should be viewed as a vascular wilt disease. Plant genotypes exhibit differences in xylem morphology and resistance to fungal pathogens causing vascular wilt diseases. We provide evidence that the susceptibility of three commercial V. vinifera cultivars to esca disease is correlated to large vessel diameter. Additionally, we explore how xylem morphological traits related to water transport are influenced by abiotic factors, and how these might impact host tolerance of vascular wilt fungi. Finally, we explore the utility of this concept for predicting which V. vinifera cultivars are most vulnerable of fungal vascular wilt diseases and propose new strategies for disease management. PMID:24971084

  16. Woody competition control

    Treesearch

    Robert F. Lowery

    1986-01-01

    Control of woody competition is necessary to maintain shortleaf pine (Pinus echinata Mill.) as an important component of natural stands and to maximize shortleaf pine plantation productivity in the Southeast. Competition control is key to maximizing timber production since growth is moisture-limited over much of its range. Volume growth gains of 40% have been reported...

  17. Gasification of Woody Biomass.

    PubMed

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

    2015-01-01

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

  18. First report of the Armillaria root-disease pathogen, Armillaria gallica, associated with several woody hosts in three states of Mexico

    Treesearch

    N. B. Klopfenstein; J. W. Hanna; P. G. Cannon; R. Medel-Ortiz; D. Alvarado-Rosales; F. Lorea-Hernandez; R. D. Elias-Roman; M. -S. Kim

    2014-01-01

    In September 2007, rhizomorphs with morphological characteristics of Armillaria were collected from woody hosts in forests of Mexico State, Veracruz, and Oaxaca, Mexico. Based on pairing tests, isolates were assigned to five somatically compatible genets or clones (MEX7R, MEX11R, MEX23R, MEX28R, and MEX30R). These genets were all identified as Armillaria gallica based...

  19. Woody plants and woody plant management: ecology, safety, environmental impact

    Treesearch

    James H. Miller

    2001-01-01

    Wise and effective woody plant management is an increasing necessity for many land uses and conservation practices, especially on forests and rangelands where native or exotic plants are affecting productivity, access, or critical habitat. Tools and approaches for managing woody plants have been under concerted development for the past 50 years, integrating mechanical...

  20. Taking inventory of woody residuals

    Treesearch

    David McKeever

    2003-01-01

    USDA Forest Service analysis finds 104 million tons of woody residuals available for recovery in the U.S., with wood in MSW and C&D debris streams comprising 28 million tons. The U.S. Department of Agriculture Forest Service conducts a variety of analyses to estimate the quantity of woody residuals in the United States. Its Forest Products Laboratory in Madison,...

  1. Woody biomass logistics [Chapter 14

    Treesearch

    Robert Keefe; Nathaniel Anderson; John Hogland; Ken Muhlenfeld

    2014-01-01

    The economics of using woody biomass as a fuel or feedstock for bioenergy applications is often driven by logistical considerations. Depending on the source of the woody biomass, the acquisition cost of the material is often quite low, sometimes near zero. However, the cost of harvesting, collection, processing, storage, and transportation from the harvest site to end...

  2. Backwater development by woody debris

    NASA Astrophysics Data System (ADS)

    Geertsema, Tjitske; Torfs, Paul; Teuling, Ryan; Hoitink, Ton

    2017-04-01

    Placement of woody debris is a common method for increasing ecological values in river and stream restoration, and is thus widely used in natural environments. Water managers, however, are afraid to introduce wood in channels draining agricultural and urban areas. Upstream, it may create backwater, depending on hydrodynamic characteristics including the obstruction ratio, the Froude number and the surface level gradient. Patches of wood may trigger or counter morphological activity, both laterally, through bank erosion and protection, and vertically, with pool and riffle formation. Also, a permeable construction composed of wood will weather over time. Both morphodynamic activity and weathering cause backwater effects to change in time. The purpose of this study is to quantify the time development of backwater effects caused by woody debris. Hourly water levels gauged upstream and downstream of patches and discharge are collected for five streams in the Netherlands. The water level drop over the woody debris patch relates to discharge in the streams. This relation is characterized by an increasing water level difference for an increasing discharge, up to a maximum. If the discharge increases beyond this level, the water level difference reduces to the value that may represent the situation without woody debris. This reduction depends primarily on the obstruction ratio of the woody debris in the channel cross-section. Morphologic adjustments in the stream and reorientation of the woody material reduce the water level drop over the patches in time. Our results demonstrate that backwater effects can be reduced by optimizing the location where woody debris is placed and manipulating the obstruction ratio. Current efforts are focussed on representing woody debris in a one-dimensional numerical model, aiming to obtain a generic tool to achieve a stream design with woody debris that minimizes backwater.

  3. Roles of Woody Root-Associated Fungi in Forest Ecosystem Processes: Recent Advances in Fungal Identification

    Treesearch

    Jill A. Hoff; Ned B. Klopfenstein; Jonalea R. Tonn; Geral I. McDonald; Paul J. Zambino; Jack D. Rogers; Tobin L. Peever; Lori M. Carris

    2004-01-01

    Interactions between fungi and woody roots may be critical factors that influence diverse forest ecosystems processes, such as wood decay (nutrient recycling); root diseases and their biological control; and endophytic, epiphytic, and mycorrhizal symbioses. However, few studies have characterized the diversity and the spatial and temporal distribution of woody root-...

  4. A sustainable woody biomass biorefinery.

    PubMed

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

    2012-01-01

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

  5. Nonstructural carbon in woody plants.

    PubMed

    Dietze, Michael C; Sala, Anna; Carbone, Mariah S; Czimczik, Claudia I; Mantooth, Joshua A; Richardson, Andrew D; Vargas, Rodrigo

    2014-01-01

    Nonstructural carbon (NSC) provides the carbon and energy for plant growth and survival. In woody plants, fundamental questions about NSC remain unresolved: Is NSC storage an active or passive process? Do older NSC reserves remain accessible to the plant? How is NSC depletion related to mortality risk? Herein we review conceptual and mathematical models of NSC dynamics, recent observations and experiments at the organismal scale, and advances in plant physiology that have provided a better understanding of the dynamics of woody plant NSC. Plants preferentially use new carbon but can access decade-old carbon when the plant is stressed or physically damaged. In addition to serving as a carbon and energy source, NSC plays important roles in phloem transport, osmoregulation, and cold tolerance, but how plants regulate these competing roles and NSC depletion remains elusive. Moving forward requires greater synthesis of models and data and integration across scales from -omics to ecology.

  6. The Woody Plant Seed Manual

    Treesearch

    Franklin T. Bonner; Robert P. Karrfalt

    2008-01-01

    The first comprehensive handbook on the seeds of trees and shrubs produced by the USDA Forest Service was USDA Misc. Pub. 654, Woody-Plant Seed Manual. The manuscript was ready for publication in 1941, but World War II delayed publication until 1948. The boom in tree planting in the 1950s and 1960s created a large demand for seeds and exposed the gaps in our knowledge...

  7. Woody biomass from short rotation energy crops

    Treesearch

    R.S. Zalesny; M.W. Cunningham; R.B. Hall; J. Mirck; D.L. Rockwood; John Stanturf; T.A. Volk

    2011-01-01

    Short rotation woody crops (SRWCs) are ideal for woody biomass production and management systems because they are renewable energy feedstocks for biofuels, bioenergy, and bioproducts that can be strategically placed in the landscape to conserve soil and water, recycle nutrients, and sequester carbon. This chapter is a synthesis of the regional implications of producing...

  8. [Bibliometrics of woody medical plants in China].

    PubMed

    Zhang, Guoquan; Si, Jinping; Zhu, Yuqiu

    2010-03-01

    Using the theory and method of bibliometrics, this paper made statistical analysis on the research papers of 16 main woody medical plants published in the period of 1998-2007, from aspects of years distribution, journals distribution, themes distribution, authors distribution and research institutes distribution, and so on. The results showed the studies, status quto and development potential of woody medical plants.

  9. Handbook for inventorying downed woody material

    Treesearch

    James K. Brown

    1974-01-01

    To facilitate debris management, procedures for inventorying downed woody material are presented. Instructions show how to estimate weights and volumes of downed woody material, fuel depth, and duff depth. Using the planar intersect technique, downed material is inventoried by 0- to 0.25-inch, 0.25- to 1-inch, and 1- to 3-inch diameter classes; and by 1-inch classes...

  10. Multiresource Inventories: Woody Biomass in North Carolina

    Treesearch

    Noel D. Cost

    1986-01-01

    North Carolina's 31.2 million acres of land area support 1.7 billion tons of woody biomass. Of this total, 94 percent is on timberland, 3 percent on nonforest areas, and 3 percent on reserved timberland and woodland areas. Over the next two decades, more than 12.8 million tons of woody biomass could be harvested annually from timberland without adversely...

  11. Regional Comparative Advantage for Woody Biofuels Production

    Treesearch

    Timothy M. Young; Donald G. Hodges; Robert C. Abt; Andy J. Hartsell; James H. Perdue

    2009-01-01

    The economic availability of woody biomass for the southeastern United States is summarized in this final report for the U.S. Department of Transportation, Southeastern Sun Grant Center research contract R11-0515-016 as administered by the University of Tennessee. Georeferenced economic supply curves (marginal cost curves) for woody biomass producers’ for the 13...

  12. Application of Somatic Embryogenesis in Woody Plants.

    PubMed Central

    Guan, Yuan; Li, Shui-Gen; Fan, Xiao-Fen; Su, Zhen-Hong

    2016-01-01

    Somatic embryogenesis is a developmental process where a plant somatic cell can dedifferentiate to a totipotent embryonic stem cell that has the ability to give rise to an embryo under appropriate conditions. This new embryo can further develop into a whole plant. In woody plants, somatic embryogenesis plays a critical role in clonal propagation and is a powerful tool for synthetic seed production, germplasm conservation, and cryopreservation. A key step in somatic embryogenesis is the transition of cell fate from a somatic cell to embryo cell. Although somatic embryogenesis has already been widely used in a number of woody species, propagating adult woody plants remains difficult. In this review, we focus on molecular mechanisms of somatic embryogenesis and its practical applications in economic woody plants. Furthermore, we propose a strategy to improve the process of somatic embryogenesis using molecular means. PMID:27446166

  13. New market potential: Torrefaction of Woody Biomass

    SciTech Connect

    Jaya Shankar Tumuluru; J. Richard Hess

    2015-07-01

    According to researchers in Idaho National Laboratory’s Bioenergy Program, torrefaction of woody biomass could reduce variability in biomass feedstock and enable development of a commodity-type product for green energy generation and usage.

  14. Multiresource inventories: woody biomass in Virginia

    Treesearch

    Noel D. Cost

    1988-01-01

    Virginia's 25 .. 4 million acres of land area support 1.5 billion J tons of woody biomass. Of this total, 93 percent is on timberland, I 5 percent on reserved timberland and woodland areas, and 2 percent I on nonforest areas. Over the next two decades, more than 9 million I t tons of woody biomass could be harvested annually from timberland I I without adversely...

  15. Determinants of woody cover in African savannas

    USGS Publications Warehouse

    Sankaran, M.; Hanan, N.P.; Scholes, R.J.; Ratnam, J.; Augustine, D.J.; Cade, B.S.; Gignoux, J.; Higgins, S.I.; Le, Roux X.; Ludwig, F.; Ardo, J.; Banyikwa, F.; Bronn, A.; Bucini, G.; Caylor, K.K.; Coughenour, M.B.; Diouf, A.; Ekaya, W.; Feral, C.J.; February, E.C.; Frost, P.G.H.; Hiernaux, P.; Hrabar, H.; Metzger, K.L.; Prins, H.H.T.; Ringrose, S.; Sea, W.; Tews, J.; Worden, J.; Zambatis, N.

    2005-01-01

    Savannas are globally important ecosystems of great significance to human economies. In these biomes, which are characterized by the co-dominance of trees and grasses, woody cover is a chief determinant of ecosystem properties 1-3. The availability of resources (water, nutrients) and disturbance regimes (fire, herbivory) are thought to be important in regulating woody cover1,2,4,5, but perceptions differ on which of these are the primary drivers of savanna structure. Here we show, using data from 854 sites across Africa, that maximum woody cover in savannas receiving a mean annual precipitation (MAP) of less than ???650 mm is constrained by, and increases linearly with, MAP. These arid and semi-arid savannas may be considered 'stable' systems in which water constrains woody cover and permits grasses to coexist, while fire, herbivory and soil properties interact to reduce woody cover below the MAP-controlled upper bound. Above a MAP of ???650 mm, savannas are 'unstable' systems in which MAP is sufficient for woody canopy closure, and disturbances (fire, herbivory) are required for the coexistence of trees and grass. These results provide insights into the nature of African savannas and suggest that future changes in precipitation 6 may considerably affect their distribution and dynamics. ?? 2005 Nature Publishing Group.

  16. Determinants of woody cover in African savannas.

    PubMed

    Sankaran, Mahesh; Hanan, Niall P; Scholes, Robert J; Ratnam, Jayashree; Augustine, David J; Cade, Brian S; Gignoux, Jacques; Higgins, Steven I; Le Roux, Xavier; Ludwig, Fulco; Ardo, Jonas; Banyikwa, Feetham; Bronn, Andries; Bucini, Gabriela; Caylor, Kelly K; Coughenour, Michael B; Diouf, Alioune; Ekaya, Wellington; Feral, Christie J; February, Edmund C; Frost, Peter G H; Hiernaux, Pierre; Hrabar, Halszka; Metzger, Kristine L; Prins, Herbert H T; Ringrose, Susan; Sea, William; Tews, Jörg; Worden, Jeff; Zambatis, Nick

    2005-12-08

    Savannas are globally important ecosystems of great significance to human economies. In these biomes, which are characterized by the co-dominance of trees and grasses, woody cover is a chief determinant of ecosystem properties. The availability of resources (water, nutrients) and disturbance regimes (fire, herbivory) are thought to be important in regulating woody cover, but perceptions differ on which of these are the primary drivers of savanna structure. Here we show, using data from 854 sites across Africa, that maximum woody cover in savannas receiving a mean annual precipitation (MAP) of less than approximately 650 mm is constrained by, and increases linearly with, MAP. These arid and semi-arid savannas may be considered 'stable' systems in which water constrains woody cover and permits grasses to coexist, while fire, herbivory and soil properties interact to reduce woody cover below the MAP-controlled upper bound. Above a MAP of approximately 650 mm, savannas are 'unstable' systems in which MAP is sufficient for woody canopy closure, and disturbances (fire, herbivory) are required for the coexistence of trees and grass. These results provide insights into the nature of African savannas and suggest that future changes in precipitation may considerably affect their distribution and dynamics.

  17. THE INTAKE OF FIBER MESOCARP PASSIONFRUIT (PASSIFLORA EDULIS) LOWERS LEVELS OF TRIGLYCERIDE AND CHOLESTEROL DECREASING PRINCIPALLY INSULIN AND LEPTIN

    PubMed Central

    Corrêa, E.M.; Medina, L.; Barros-Monteiro, J.; Valle, N.O.; Sales, R.; Magalães, A.; Souza, F.C.A.; Carvalho, T.B.; Lemos, J.R.; Lira, E.F.; Lima, E.S.; Galeno, D.M.L.; Morales, L.; Ortiz, C.; Carvalho, R.P.

    2014-01-01

    Background Diabetes mellitus (DM) is a major risk factor for coronary artery disease, renal failure, retinopathy, and neuropathy. Over the last years, there has been an increasing demand in folk medicine for natural sources that could help in the treatment of chronic diseases, including diabetes. The rind of passion fruit (Passiflora edulis f. Flavicarpa) is traditionally used as a functional food due to its high concentration of soluble and insoluble fiber. Objective The aim of this study was to determine the effect of high-fiber diet albedo of passion fruit on the metabolic and biochemical profile in diabetic rats induced by alloxan (2%). Design The passion fruit mesocarp fiber was dried in an oven with circulating air at 60°C and pulverized. We used 32 adult male rats, divided into 4 groups: Wistar group 1 control (GC), Wistar group 2, 15% fiber (GF15), Wistar group 3, 30% fiber (GF30), Wistar group 4, fiber disolved in water (GFH2O). The ratio of passion fruit was prepared according to the AIN 93M guidelines, varying only the source of dietary fiber. The corresponding diet for each group was offered to the animals for 60 days. Results There was a statically significant decrease in plasma glucose for GFH2O, GF15%, and GF30% groups with 27.0%, 37.4%, and 40.2%, respectively. Conclusion The use of mesocarp fiber of passion fruit at concentrations of 15% and 30% are an important dietary supplement for the treatment of DM due to its potential hypoglycemic effect, and its ability to reduce triglycerides and VLDL-cholesterol levels with a principal reduction of insulin and leptin. PMID:25346913

  18. Frost resistance in alpine woody plants

    PubMed Central

    Neuner, Gilbert

    2014-01-01

    This report provides a brief review of key findings related to frost resistance in alpine woody plant species, summarizes data on their frost resistance, highlights the importance of freeze avoidance mechanisms, and indicates areas of future research. Freezing temperatures are possible throughout the whole growing period in the alpine life zone. Frost severity, comprised of both intensity and duration, becomes greater with increasing elevation and, there is also a greater probability, that small statured woody plants, may be insulated by snow cover. Several frost survival mechanisms have evolved in woody alpine plants in response to these environmental conditions. Examples of tolerance to extracellular freezing and freeze dehydration, life cycles that allow species to escape frost, and freeze avoidance mechanisms can all be found. Despite their specific adaption to the alpine environment, frost damage can occur in spring, while all alpine woody plants have a low risk of frost damage in winter. Experimental evidence indicates that premature deacclimation in Pinus cembra in the spring, and a limited ability of many species of alpine woody shrubs to rapidly reacclimate when they lose snow cover, resulting in reduced levels of frost resistance in the spring, may be particularly critical under the projected changes in climate. In this review, frost resistance and specific frost survival mechanisms of different organs (leaves, stems, vegetative and reproductive over-wintering buds, flowers, and fruits) and tissues are compared. The seasonal dynamics of frost resistance of leaves of trees, as opposed to woody shrubs, is also discussed. The ability of some tissues and organs to avoid freezing by supercooling, as visualized by high resolution infrared thermography, are also provided. Collectively, the report provides a review of the complex and diverse ways that woody plants survive in the frost dominated environment of the alpine life zone. PMID:25520725

  19. Frost resistance in alpine woody plants.

    PubMed

    Neuner, Gilbert

    2014-01-01

    This report provides a brief review of key findings related to frost resistance in alpine woody plant species, summarizes data on their frost resistance, highlights the importance of freeze avoidance mechanisms, and indicates areas of future research. Freezing temperatures are possible throughout the whole growing period in the alpine life zone. Frost severity, comprised of both intensity and duration, becomes greater with increasing elevation and, there is also a greater probability, that small statured woody plants, may be insulated by snow cover. Several frost survival mechanisms have evolved in woody alpine plants in response to these environmental conditions. Examples of tolerance to extracellular freezing and freeze dehydration, life cycles that allow species to escape frost, and freeze avoidance mechanisms can all be found. Despite their specific adaption to the alpine environment, frost damage can occur in spring, while all alpine woody plants have a low risk of frost damage in winter. Experimental evidence indicates that premature deacclimation in Pinus cembra in the spring, and a limited ability of many species of alpine woody shrubs to rapidly reacclimate when they lose snow cover, resulting in reduced levels of frost resistance in the spring, may be particularly critical under the projected changes in climate. In this review, frost resistance and specific frost survival mechanisms of different organs (leaves, stems, vegetative and reproductive over-wintering buds, flowers, and fruits) and tissues are compared. The seasonal dynamics of frost resistance of leaves of trees, as opposed to woody shrubs, is also discussed. The ability of some tissues and organs to avoid freezing by supercooling, as visualized by high resolution infrared thermography, are also provided. Collectively, the report provides a review of the complex and diverse ways that woody plants survive in the frost dominated environment of the alpine life zone.

  20. Comparative genomics reveals genes significantly associated with woody hosts in the plant pathogen Pseudomonas syringae

    PubMed Central

    Laue, Bridget E.; Sharp, Paul M.; Green, Sarah

    2016-01-01

    Summary The diversification of lineages within Pseudomonas syringae has involved a number of adaptive shifts from herbaceous hosts onto various species of tree, resulting in the emergence of highly destructive diseases such as bacterial canker of kiwi and bleeding canker of horse chestnut. This diversification has involved a high level of gene gain and loss, and these processes are likely to play major roles in the adaptation of individual lineages onto their host plants. In order to better understand the evolution of P. syringae onto woody plants, we have generated de novo genome sequences for 26 strains from the P. syringae species complex that are pathogenic on a range of woody species, and have looked for statistically significant associations between gene presence and host type (i.e. woody or herbaceous) across a phylogeny of 64 strains. We have found evidence for a common set of genes associated with strains that are able to colonize woody plants, suggesting that divergent lineages have acquired similarities in genome composition that may form the genetic basis of their adaptation to woody hosts. We also describe in detail the gain, loss and rearrangement of specific loci that may be functionally important in facilitating this adaptive shift. Overall, our analyses allow for a greater understanding of how gene gain and loss may contribute to adaptation in P. syringae. PMID:27145446

  1. 48 CFR 1452.237-71 - Utilization of Woody Biomass.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... Biomass. 1452.237-71 Section 1452.237-71 Federal Acquisition Regulations System DEPARTMENT OF THE INTERIOR... Utilization of Woody Biomass. As prescribed in § 1437.7202, insert the following clause: Utilization of Woody Biomass (MAY 2005) (a) The contractor may remove and utilize woody biomass, if: (1) Project work is...

  2. 48 CFR 1452.237-71 - Utilization of Woody Biomass.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... Biomass. 1452.237-71 Section 1452.237-71 Federal Acquisition Regulations System DEPARTMENT OF THE INTERIOR... Utilization of Woody Biomass. As prescribed in § 1437.7202, insert the following clause: Utilization of Woody Biomass (MAY 2005) (a) The contractor may remove and utilize woody biomass, if: (1) Project work is...

  3. 48 CFR 1452.237-71 - Utilization of Woody Biomass.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... Biomass. 1452.237-71 Section 1452.237-71 Federal Acquisition Regulations System DEPARTMENT OF THE INTERIOR... Utilization of Woody Biomass. As prescribed in § 1437.7202, insert the following clause: Utilization of Woody Biomass (MAY 2005) (a) The contractor may remove and utilize woody biomass, if: (1) Project work is...

  4. 48 CFR 1452.237-71 - Utilization of Woody Biomass.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... Biomass. 1452.237-71 Section 1452.237-71 Federal Acquisition Regulations System DEPARTMENT OF THE INTERIOR... Utilization of Woody Biomass. As prescribed in § 1437.7202, insert the following clause: Utilization of Woody Biomass (MAY 2005) (a) The contractor may remove and utilize woody biomass, if: (1) Project work is...

  5. 48 CFR 1452.237-71 - Utilization of Woody Biomass.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... Biomass. 1452.237-71 Section 1452.237-71 Federal Acquisition Regulations System DEPARTMENT OF THE INTERIOR... Utilization of Woody Biomass. As prescribed in § 1437.7202, insert the following clause: Utilization of Woody Biomass (MAY 2005) (a) The contractor may remove and utilize woody biomass, if: (1) Project work is...

  6. Nitrogen dynamics post-harvest: the role of woody residues

    Treesearch

    Kathryn Piatek

    2007-01-01

    The role of woody residues in N dynamics in harvested forests has not been fully elucidated. Woody residues have been found to be an N sink, N source, and N neutral in different studies. To understand the implications of each of these scenarios, post-harvest N dynamics in high- and no- woody residue treatments were modeled for a Douglas-fir ecosystem. Nitrogen...

  7. Urban tree and woody yard residues : another wood resource

    Treesearch

    David B. McKeever; Kenneth E. Skog

    2003-01-01

    Urban tree and woody yard residues are an important component of the municipal solid waste (MSW) stream in the United States. In 2000, approximately 14.5 million tons of urban tree and woody yard residues was generated, nearly 7% of total MSW. Some woody residues are being recovered for recycling, composting, or other uses, but a large proportion is simply discarded....

  8. Woody plants of North America [product review

    Treesearch

    Don C. Bragg; Hope A. Bragg

    2001-01-01

    The authors review a 2-CD set created to aid in identifying woody plants. The product is intended to supplement (rather than replace) field instruction for identifying 470 of the most common native and introduced trees and shrubs in North America.

  9. Sampling coarse woody debris along spoked transects

    Treesearch

    Paul C. Van Deusen; Jeffery H. Gove

    2011-01-01

    Line transects are commonly used for sampling coarse woody debris (CWD). The USDA Forest Service Forest Inventory and Analysis programme uses a variant of this method that involves sampling for CWD along transects that radiate from the centre of a circular plot-like spokes on a wheel. A new approach for analysis of data collected with spoked transects is developed....

  10. Spatial modeling of potential woody biomass flow

    Treesearch

    Woodam Chung; Nathaniel Anderson

    2012-01-01

    The flow of woody biomass to end users is determined by economic factors, especially the amount available across a landscape and delivery costs of bioenergy facilities. The objective of this study develop methodology to quantify landscape-level stocks and potential biomass flows using the currently available spatial database road network analysis tool. We applied this...

  11. Forest biodiversity and woody biomass harvesting

    Treesearch

    Deahn M. Donner; T. Bently Wigley; Darren A. Miller

    2017-01-01

    With the expected increase in demand for woody biomass to help meet renewable energy needs, one principal sustainability question has been whether this material can be removed from forest stands while still conserving biological diversity and retaining ecosystem functioning (Hecht et al. 2009; Berch, Morris, and Malcolm 2011; Ridley et al. 2013). In general,...

  12. Parlin Creek large woody debris placement project

    Treesearch

    Barry W. Collins

    1999-01-01

    In August 1996 the Jackson Demonstration State Forest (JSDF) completed a fish habitat rehabilitation project in a 2.5 mile reach of Parlin Creek, a tributary to the Noyo River in Mendocino County, California. The purse of the project was to introduce large woody material to the stream channel to determine if higher quality habitat could be produced for anadromous...

  13. Extreme low temperature tolerance in woody plants

    Treesearch

    G. Richard Strimbeck; Paul G. Schaberg; Carl G. Fossdal; Wolfgang P. Schroder; Trygve D. Kjellsen

    2015-01-01

    Woody plants in boreal to arctic environments and high mountains survive prolonged exposure to temperatures below -40°C and minimum temperatures below -60°C, and laboratory tests show that many of these species can also survive immersion in liquid nitrogen at -196°C. Studies of biochemical changes that occur during acclimation, including recent proteomic and...

  14. 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...

  15. Coarse woody debris dynamics in two old-growth ecosystems

    SciTech Connect

    Harmon, M.E. ); Chen Hua )

    1991-10-01

    In this article, the dynamics of coarse woody debris are compound deciduous old-growth forest system Changbai Mountain Biosphere Reserve in China, and a coniferous old-growth forest system, H. J. Andrews Experimental Forest in Oregon. The objective is to compare in these two ecosystems the amount of coarse woody debris; the processes that affect coarse woody debris, such as tree mortality and decay rates; and the role of coarse woody debris in nutrient cycling. To assess importance in the global carbon budget, these two old-growth ecosystems are used to estimate the upper and lower limits of coarse woody debris mass for undisturbed temperate forests.

  16. Woodiness within the Spermacoceae–Knoxieae alliance (Rubiaceae): retention of the basal woody condition in Rubiaceae or recent innovation?

    PubMed Central

    Lens, Frederic; Groeninckx, Inge; Smets, Erik; Dessein, Steven

    2009-01-01

    Background and Aims The tribe Spermacoceae is essentially a herbaceous Rubiaceae lineage, except for some species that can be described as ‘woody’ herbs, small shrubs to treelets, or lianas. Its sister tribe Knoxieae contains a large number of herbaceous taxa, but the number of woody taxa is higher compared to Spermacoceae. The occurrence of herbaceous and woody species within the same group raises the question whether the woody taxa are derived from herbaceous taxa (i.e. secondary woodiness), or whether woodiness represents the ancestral state (i.e. primary woodiness). Microscopic observations of wood anatomy are combined with an independent molecular phylogeny to answer this question. Methods Observations of wood anatomy of 21 woody Spermacoceae and eight woody Knoxieae species, most of them included in a multi-gene molecular phylogeny, are carried out using light microscopy. Key Results Observations of wood anatomy in Spermacoceae support the molecular hypothesis that all the woody species examined are secondary derived. Well-known wood anatomical characters that demonstrate this shift from the herbaceous to the woody habit are the typically flat or decreasing length vs. age curves for vessel elements, the abundance of square and upright ray cells, or even the (near-) absence of rays. These so-called paedomorphic wood features are also present in the Knoxieae genera Otiophora, Otomeria, Pentas, Pentanisia and Phyllopentas. However, the wood structure of the other Knoxieae genera observed (Carphalea, Dirichletia and Triainolepis) is typical of primarily woody taxa. Conclusions In Spermacoceae, secondary woodiness has evolved numerous times in strikingly different habitats. In Knoxieae, there is a general trend from primary woodiness towards herbaceousness and back to (secondary) woodiness. PMID:19279041

  17. Ecosystem services of woody crop production systems

    Treesearch

    Ronald S. Zalesny Jr.; John A. Stanturf; Emile S. Gardiner; James H. Perdue; Timothy M. Young; David R. Coyle; William L. Headlee; Gary S. Ba??uelos; Amir Hass

    2016-01-01

    Short-rotation woody crops are an integral component of regional and national energy portfolios, as well as providing essential ecosystem services such as biomass supplies, carbon sinks, clean water, and healthy soils. We review recent USDA Forest Service Research and Development efforts from the USDA Biomass Research Centers on the provisioning of these ecosystem...

  18. Woody Debris in the mangrove forests of South Florida

    USGS Publications Warehouse

    Krauss, K.W.; Doyle, T.W.; Twilley, R.R.; Smith, T. J.; Whelan, K.R.T.; Sullivan, J.K.

    2005-01-01

    Woody debris is abundant in hurricane-impacted forests. With a major hurricane affecting South Florida mangroves approximately every 20 yr, carbon storage and nutrient retention may be influenced greatly by woody debris dynamics. In addition, woody debris can influence seedling regeneration in mangrove swamps by trapping propagules and enhancing seedling growth potential. Here, we report on line-intercept woody debris surveys conducted in mangrove wetlands of South Florida 9-10 yr after the passage of Hurricane Andrew. The total volume of woody debris for all sites combined was estimated at 67 m 3/ha and varied from 13 to 181 m3/ha depending upon differences in forest height, proximity to the storm, and maximum estimated wind velocities. Large volumes of woody debris were found in the eyewall region of the hurricane, with a volume of 132 m3/ha and a projected woody debris biomass of approximately 36 t/ha. Approximately half of the woody debris biomass averaged across all sites was associated as small twigs and branches (fine woody debris), since coarse woody debris >7.5 cm felled during Hurricane Andrew was fairly well decomposed. Much of the small debris is likely to be associated with post-hurricane forest dynamics. Hurricanes are responsible for large amounts of damage to mangrove ecosystems, and components of associated downed wood may provide a relative index of disturbance for mangrove forests. Here, we suggest that a fine:coarse woody debris ratio ???0.5 is suggestive of a recent disturbance in mangrove wetlands, although additional research is needed to corroborate such findings.

  19. Combining woody biomass for combustion with green waste composting: Effect of removal of woody biomass on compost quality.

    PubMed

    Vandecasteele, Bart; Boogaerts, Christophe; Vandaele, Elke

    2016-12-01

    The question was tackled on how the green waste compost industry can optimally apply the available biomass resources for producing both bioenergy by combustion of the woody fraction, and high quality soil improvers as renewable sources of carbon and nutrients. Compost trials with removal of woody biomass before or after composting were run at 9 compost facilities during 3 seasons to include seasonal variability of feedstock. The project focused on the changes in feedstock and the effect on the end product characteristics (both compost and recovered woody biomass) of this woody biomass removal. The season of collection during the year clearly affected the biochemical and chemical characteristics of feedstock, woody biomass and compost. On one hand the effect of removal of the woody fraction before composting did not significantly affect compost quality when compared to the scenario where the woody biomass was sieved from the compost at the end of the composting process. On the other hand, quality of the woody biomass was not strongly affected by extraction before or after composting. The holocellulose:lignin ratio was used in this study as an indicator for (a) the decomposition potential of the feedstock mixture and (b) to assess the stability of the composts at the end of the process. Higher microbial activity in green waste composts (indicated by higher oxygen consumption) and thus a lower compost stability resulted in higher N immobilization in the compost. Removal of woody biomass from the green waste before composting did not negatively affect the compost quality when more intensive composting was applied. The effect of removal of the woody fraction on the characteristics of the green waste feedstock and the extracted woody biomass is depending on the season of collection. Copyright © 2016 Elsevier Ltd. All rights reserved.

  20. Sensitivity Analysis of Down Woody Material Data Processing Routines

    Treesearch

    Christopher W. Woodall; Duncan C. Lutes

    2005-01-01

    Weight per unit area (load) estimates of Down Woody Material (DWM) are the most common requests by users of the USDA Forest Service's Forest Inventory and Analysis (FIA) program's DWM inventory. Estimating of DWM loads requires the uniform compilation of DWM transect data for the entire United States. DWM weights may vary by species, level of decay, woody...

  1. Woody debris dynamics in Interior West forests and woodlands

    Treesearch

    John D. Shaw; James Long; Raffaella Marzano; Matteo Garbarino

    2012-01-01

    Managers are interested in the dynamics of down woody material because of its role as a fuel component, a feature of wildlife habitat, a carbon pool, and other characteristics. We analyzed nearly 9,000 plots from the Interior West, spanning the range from sparse juniper and mesquite woodland to dense spruce-fir forests, in order to characterize down woody material as...

  2. Woody biomass from short rotation energy crops. Chapter 2

    Treesearch

    R.S., Jr. Zalesny Jr.; M.W. Cunningham; R.B. Hall; J. Mirck; D.L. Rockwood; J.A. Stanturf; T.A. Volk

    2011-01-01

    Short rotation woody crops (SRWCs) are ideal for woody biomass production and management systems because they are renewable energy feedstocks for biofuels, bioenergy, and bioproducts that can be strategically placed in the landscape to conserve soil and water, recycle nutrients, and sequester carbon. This chapter is a synthesis of the regional implications of producing...

  3. Determinants of woody encroachment and cover in African savannas.

    PubMed

    Devine, Aisling P; McDonald, Robbie A; Quaife, Tristan; Maclean, Ilya M D

    2017-04-01

    Savanna ecosystems are an integral part of the African landscape and sustain the livelihoods of millions of people. Woody encroachment in savannas is a widespread phenomenon but its causes are widely debated. We review the extensive literature on woody encroachment to help improve understanding of the possible causes and to highlight where and how future scientific efforts to fully understand these causes should be focused. Rainfall is the most important determinant of maximum woody cover across Africa, but fire and herbivory interact to reduce woody cover below the maximum at many locations. We postulate that woody encroachment is most likely driven by CO2 enrichment and propose a two-system conceptual framework, whereby mechanisms of woody encroachment differ depending on whether the savanna is a wet or dry system. In dry savannas, the increased water-use efficiency in plants relaxes precipitation-driven constraints and increases woody growth. In wet savannas, the increase of carbon allocation to tree roots results in faster recovery rates after disturbance and a greater likelihood of reaching sexual maturity. Our proposed framework can be tested using a mixture of experimental and earth observational techniques. At a local level, changes in precipitation, burning regimes or herbivory could be driving woody encroachment, but are unlikely to be the explanation of this continent-wide phenomenon.

  4. Perspectives on woody biomass fuel value and specifications in Alabama

    Treesearch

    Dana Mitchell

    2006-01-01

    Pulp and paper mills in Alabama buy woody biomass but the specifications required by the mills vary and are not widely known. Some characteristics of woody biomass that are often included in mill specifications include size, species, ash and moisture content. These characteristics are briefly reviewed in reference to how they impact the energy value, physical handling...

  5. Woody Vegetation on Levees? - Research Experiences and Design Suggestions

    NASA Astrophysics Data System (ADS)

    Lammeranner, Walter

    2013-04-01

    Recent flood events in Austria have reawakened practical and scientific interest in the stability of levees. One focus amongst others has been taken on the relationship between vegetation and levee stability with special reference to the role of woody plants. The effects of woody plants are undoubtedly manifold: On the one hand they can potentially have a negative influence and endanger levees, which is why many guidelines ban woody vegetation to preserve stability, visual inspection and unhindered flood-fight access. On the other hand woody vegetation can have several positive impacts on soil stability and which effects prevail depends largely on types and characteristics of plants. This shows how controversially woody plants on levees can be discussed and the strong need for further research in this field. In order to obtain new insights and widen horizons for this controversial issue, a research project carried out by the Institute of Soil Bioengineering and Landscape Construction - at the University of Natural Resources and Life Sciences, Vienna - was launched. This project deals with several aspects of effects of woody plants have on levees and focuses particularly on shrubby woody plants. The examined vegetation type is a dense stand of willows - Purple-Willows (Salix purpurea L.) - commonly used for stabilization of river embankments. The proposed contribution discusses the gained results with reference to levee stability and existing levee vegetation guidelines and gives design suggestions for compatible woody vegetation on levees.

  6. Southwestern Woody Riparian Vegetation and Succession: An Evolutionary Approach

    Treesearch

    R. Roy Johnson; Peter S. Bennett; Lois Haight

    1989-01-01

    Interrelationships between flooding and climax woody vegetation in riparian ecosystems of the desert Southwest are discussed. The lack of succession in woody desert upland and desert riparian plant communities results from opposite stresses, the former from aridity, the latter from flooding. Today's "wet riparian big five" are northern tree species of...

  7. Magnetic Wood Achieving a Harmony between Magnetic and Woody Functions

    NASA Astrophysics Data System (ADS)

    Oka, Hideo

    Magnetic wood, which was first introduced and developed by the Oka group in 1991, achieves a good balance of both woody and magnetic functions through the active addition of magnetic characteristics to the wood itself. In addition to showing magnetic characteristics, this magnetic wood also offers a woody texture, low specific gravity, humidity control, acoustic absorption and is very easy to process.

  8. Long-shoot/short-shoot phenomenon in woody plants

    Treesearch

    Ronald E. Sosebee

    2001-01-01

    Shoot growth in shrubs is often overlooked as an important component of phenological development in woody plants. However, shoot growth dictates the pattern of growth of deciduous trees or shrubs, especially following defoliation or canopy damage. In general, woody shoots are divided into short- and long-shoots. Short-shoots, sometimes called "spurs," are...

  9. Short Rotation Woody Crops Program: Project summaries

    SciTech Connect

    Not Available

    1986-11-01

    This document is a compilation of summaries describing research efforts in the US Department of Energy's Short Rotation Woody Crops Program (SRWCP). The SRWCP is sponsored by DOE's Biofuels and Municipal Waste Technology Division and is field-managed at Oak Ridge National Laboratory. The SRWCP is an integrated basic research program with 18 field research projects throughout the United States. The overall objective of the program is to improve the productivity and increase the cost efficiency of growing and harvesting woody trees and shrubs. In a competitive technical review, 25 projects were chosen to form a new research program. Although some of the original projects have ended and new ones have begun, many of the long-term research projects still form the core of the SRWCP. This document contains individual summaries of each of the 18 research projects in the SRWCP from October 1985 to October 1986. Each summary provides the following information: name and address of the contracting institution, principal investigator, project title, current subcontract or grant number, period of performance, and annual funding through fiscal year 1986. In addition, each summary contains a brief description of the project rationale, objective, approach, status, and future efforts. A list of publications that have resulted from DOE-sponsored research follows many of the summaries.

  10. Early deterioration of coarse woody debris.

    SciTech Connect

    Tainter, Frank, H.; McMinn, James, W.

    1999-02-16

    Tainter, F.H., and J.W. McMinn. 1999. Early deterioration of coarse woody debris. In: Proc. Tenth Bien. South. Silv. Res. Conf. Shreveport, LA, February 16-18, 1999. Pp. 232-237 Abstract - 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 xerlc) sites at the Savannah River Site and sampled over a I6-week period. Major changes were in moisture content and nonstructural carbohydrate content (total carbohydrates, reducing sugars, and starch) of sapwood. Early changes in nonstructural carbohydrate levels following placement of the bolts were likely due to reallocation of these materials by sapwood parenchyma cells. These carbohydrates later formed pools increasingly metabolized by bacteria and invading fungi. Most prevalent fungi in sapwood were Ceratocysfis spp. in pine and Hypoxy/on spp. in oak. Although pine sapwood became blue stained and oak sapwood exhibited yellow soft decay with black zone lines, estimators of decay (specific gravity, sodium hydroxide solubility, and holocellulose content) were unchanged during the 16-week study period. A small effect of site was detected for starch content of sapwood of both species. Fungal biomass in sapwood of both species, as measured by ergosterol content, was detectable at week zero, increased somewhat by week three and increased significantly by week 16.

  11. Parasitism of Woody Ornamentals by Meloidogyne hapla

    PubMed Central

    Bernard, E. C.; Witte, W. T.

    1987-01-01

    Meloidogyne hapla is the dominant root-knot nematode found in Tennessee woody ornamental nurseries. In greenhouse tests, M. hapla produced galls and formed egg masses on roots of Abelia x grandiflora, Comus florida, Hydrangea paniculata grandiflora, Photinia x fraseri, Spiraea x bumalda, Spiraea x vanhouttei, and Viburnum carlesii. Galls on H. grandiflora and V. carlesii were mostly large and fusiform. Galls on C. florida were spherical and usually terminal, whereas those on the other species were minute. Lateral roots grew from galls on all susceptible plants. Two Acer spp., two Buxus spp., three llex spp., five Prunus spp., three Rhododendron spp., Euonymus alata, Ligustrum sinense, Magnolia x soulangiana, Nandina domestica, and nine conifer species were nonhosts or very poor hosts. PMID:19290273

  12. Effects of fire on woody vegetation structure in African savanna.

    PubMed

    Smit, Izak P J; Asner, Gregory P; Govender, Navashni; Kennedy-Bowdoin, Ty; Knapp, David E; Jacobson, James

    2010-10-01

    Despite the importance of fire in shaping savannas, it remains poorly understood how the frequency, seasonality, and intensity of fire interact to influence woody vegetation structure, which is a key determinant of savanna biodiversity. We provide a comprehensive analysis of vertical and horizontal woody vegetation structure across one of the oldest savanna fire experiments, using new airborne Light Detection and Ranging (LiDAR) technology. We developed and compared high-resolution woody vegetation height surfaces for a series of large experimental burn plots in the Kruger National Park, South Africa. These 7-ha plots (total area approximately 1500 ha) have been subjected to fire in different seasons and at different frequencies, as well as no-burn areas, for 54 years. Long-term exposure to fire caused a reduction in woody vegetation up to the 5.0-7.5 m height class, although most reduction was observed up to 4 m. Average fire intensity was positively correlated with changes in woody vegetation structure. More frequent fires reduced woody vegetation cover more than less frequent fires, and dry-season fires reduced woody vegetation more than wet-season fires. Spring fires from the late dry season reduced woody vegetation cover the most, and summer fires from the wet season reduced it the least. Fire had a large effect on structure in the densely wooded granitic landscapes as compared to the more open basaltic landscapes, although proportionally, the woody vegetation was more reduced in the drier than in the wetter landscapes. We show that fire frequency and fire season influence patterns of vegetation three-dimensional structure, which may have cascading consequences for biodiversity. Managers of savannas can therefore use fire frequency and season in concert to achieve specific vegetation structural objectives.

  13. Pyrolysis of Woody Residues: Impact of Mineral Content

    SciTech Connect

    Iisa, Kristiina; Zacher, Alan; Sykes, Robert; Preto, Fernando; Bronson, Benjamin

    2014-11-21

    Woody residues represent a lower cost option for feedstocks for the production of biofuels. In this study, the pyrolysis of woody residues was investigated as part of Clean Energy Dialogue between the U.S. and Canada. Three pine-based hog fuels from saw mills and wood from pine beetle killed trees were chosen as the woody residue feedstocks and pine and birch as the reference clean feedstocks. The yields and quality of the oil were evaluated in a bubbling fluidized bed reactor and a laboratory-scale pyrolyzer connected to a molecular beam mass spectrometer.

  14. Patterns in woody vegetation structure across African savannas

    NASA Astrophysics Data System (ADS)

    Axelsson, Christoffer R.; Hanan, Niall P.

    2017-07-01

    Vegetation structure in water-limited systems is to a large degree controlled by ecohydrological processes, including mean annual precipitation (MAP) modulated by the characteristics of precipitation and geomorphology that collectively determine how rainfall is distributed vertically into soils or horizontally in the landscape. We anticipate that woody canopy cover, crown density, crown size, and the level of spatial aggregation among woody plants in the landscape will vary across environmental gradients. A high level of woody plant aggregation is most distinct in periodic vegetation patterns (PVPs), which emerge as a result of ecohydrological processes such as runoff generation and increased infiltration close to plants. Similar, albeit weaker, forces may influence the spatial distribution of woody plants elsewhere in savannas. Exploring these trends can extend our knowledge of how semi-arid vegetation structure is constrained by rainfall regime, soil type, topography, and disturbance processes such as fire. Using high-spatial-resolution imagery, a flexible classification framework, and a crown delineation method, we extracted woody vegetation properties from 876 sites spread over African savannas. At each site, we estimated woody cover, mean crown size, crown density, and the degree of aggregation among woody plants. This enabled us to elucidate the effects of rainfall regimes (MAP and seasonality), soil texture, slope, and fire frequency on woody vegetation properties. We found that previously documented increases in woody cover with rainfall is more consistently a result of increasing crown size than increasing density of woody plants. Along a gradient of mean annual precipitation from the driest (< 200 mm yr-1) to the wettest (1200-1400 mm yr-1) end, mean estimates of crown size, crown density, and woody cover increased by 233, 73, and 491 % respectively. We also found a unimodal relationship between mean crown size and sand content suggesting that maximal

  15. [Stress effects of simulant acid rain on three woody plants].

    PubMed

    Zhou, Qing; Huang, Xiaohua; Liu, Xiaolin

    2002-09-01

    Osmanthus fragrana, Chimonanthus praecox and Prunus persica were used as materials to investigate the effect of simulant acid rain on chlorophyll (Chl) content, cell membrane permeability(L%), the content of proline (Pro) and malondialdehyde (MDA) in three woody plants with different resistance, and effects of the light and dark conditions on acid rain injury. The results showed that the change degree of four kinds of physiological and biochemical indexes for these woody plants was as sequence: Osmanthus fragrana > Chimonanthus praecox > Prunus persica. The change of chlorophyll content in these woody plants was not obviously when acid rain stress was influenced by the light and dark.

  16. Testing woody fuel consumption models for application in Australian southern eucalypt forest fires

    Treesearch

    J.J. Hollis; S. Matthews; Roger Ottmar; S.J. Prichard; S. Slijepcevic; N.D. Burrows; B. Ward; K.G. Tolhurst; W.R. Anderson; J S. Gould

    2010-01-01

    Five models for the consumption of coarse woody debris or woody fuels with a diameter larger than 0.6 cm were assessed for application in Australian southern eucalypt forest fires including: CONSUME models for (1) activity fuels, (2) natural western woody and (3) natural southern woody fuels, (4) the BURNUP model and (5) the recommendation by the Australian National...

  17. Woody biomass for bioenergy and biofuels in the United States -- a briefing paper

    Treesearch

    Eric M. White

    2010-01-01

    Woody biomass can be used for the generation of heat, electricity, and biofuels. In many cases, the technology for converting woody biomass into energy has been established for decades, but because the price of woody biomass energy has not been competitive with traditional fossil fuels, bioenergy production from woody biomass has not been widely adopted. However,...

  18. Pretreatment of woody biomass for biofuel production: energy efficiency, technologies, and recalcitrance

    Treesearch

    J.Y. Zhu; Xuejun Pan; Ronald S. Jr. Zalesny

    2010-01-01

    This mini review discusses several key technical issues associated with cellulosic ethanol production from woody biomass: energy consumption for woody biomass pretreatment, pretreatment energy efficiency, woody biomass pretreatment technologies, and quantification of woody biomass recalcitrance. Both total sugar yield and pretreatment energy efficiency, defined as the...

  19. Quantifying the resistance of woody debris in natural streams

    NASA Astrophysics Data System (ADS)

    Clancy, K. A.

    2013-12-01

    Discharge is one of the most important natural stream variables affecting a system's ecology, water quality, hydroelectric power, and navigation. Hydrologists commonly use the friction factor equation to estimate water discharge in ungaged streams. In natural streams the equation does not accurately predict discharge in streams with woody debris and vegetation. The objective of this project is to develop a refined method of incorporating woody debris components, commonly found in natural streams, into the friction factor equation, resulting in a more accurate discharge estimation. Ten gaged gravel bed streams with 30% woody debris were surveyed. Discharge was measured and compared to values given by the friction factor. By incorporating a woody debris factor into the equation, discharge estimates match measured values closer by over twenty percent.

  20. Is Acarapis woodi a single species? A new PCR protocol to evaluate its prevalence.

    PubMed

    Cepero, A; Martín-Hernández, R; Prieto, L; Gómez-Moracho, T; Martínez-Salvador, A; Bartolomé, C; Maside, X; Meana, A; Higes, M

    2015-02-01

    Acarapisosis is a disease of the adult honey bee Apis mellifera L., caused by the tracheal mite Acarapis woodi (Rennie), that affects the prothoracic tracheas of worker honey bees. Although it is not usually considered a real problem for honey bee colonies in southern Europe (mainly Spain and Greece), where the majority of professional beekeepers are located in Europe, recent works have reported the constant presence of this mite in this area, making it a potential cofactor for colony losses. In this study, we developed a specific PCR diagnostic tool that improves the techniques used so far and allowed us to confirm the presence of this parasite in Spain, urging the need to monitor its prevalence and implications in the health of the colonies. Indeed, in a total of 635 apiaries analysed, the prevalence of A. woodi in 2010 was 8.3 and 4 % in 2011. The mite is present in bee colonies over time and should not be underestimated as a possible cofactor in the collapse of bee colonies. Additionally, some positive samples were cloned so a genetic analysis on the diversity within A. woodi isolates was also approached. This allowed us to identify different genetic variants within an isolate, even when they were present at low frequencies. And this genetic analysis revealed the existence of a different clade of Acarapis sequences that could represent a new species or subspecies, although more research is required to verify the identity of this novel lineage at genetic and morphological level.

  1. Aluminum exclusion and aluminum tolerance in woody plants

    PubMed Central

    Brunner, Ivano; Sperisen, Christoph

    2013-01-01

    The aluminum (Al) cation Al3+ is highly rhizotoxic and is a major stress factor to plants on acid soils, which cover large areas of tropical and boreal regions. Many woody plant species are native to acid soils and are well adapted to high Al3+ conditions. In tropical regions, both woody Al accumulator and non-Al accumulator plants occur, whereas in boreal regions woody plants are non-Al accumulators. The mechanisms of these adaptations can be divided into those that facilitate the exclusion of Al3+ from root cells (exclusion mechanisms) and those that enable plants to tolerate Al3+ once it has entered the root and shoot symplast (internal tolerance mechanisms). The biochemical and molecular basis of these mechanisms have been intensively studied in several crop plants and the model plant Arabidopsis. In this review, we examine the current understanding of Al3+ exclusion and tolerance mechanisms from woody plants. In addition, we discuss the ecology of woody non-Al accumulator and Al accumulator plants, and present examples of Al3+ adaptations in woody plant populations. This paper complements previous reviews focusing on crop plants and provides insights into evolutionary processes operating in plant communities that are widespread on acid soils. PMID:23781222

  2. Detoxification of cyanide by woody plants.

    PubMed

    Yu, Xiaozhang; Zhou, Puhua; Liu, Yunda; Hu, Hao

    2005-08-01

    Vascular plants possess an enzyme system that detoxifies cyanide by converting it to the amino acid asparagine. This paper examines the potential of three woody plants from the Salicaceae family to degrade cyanide. Pre-rooted trees were grown in carefully designed bioreactors with aqueous solution spiked with potassium cyanide at 23.0 +/- 1 degree C for a maximum of 144 h. Cyanide concentrations ranged from 0.95 to 1.15 CN mg/L. Cyanide in water and in plant tissues was analyzed spectrophotometrically. Results from the investigation indicated that significant reduction of aqueous cyanide was found during the presence of plants in all treatments. Little amounts of applied cyanide were detected in the tissues of plants, mainly in roots and bottom stem. Cyanide remaining in tissues varied with the species of plants, despite similar periods of exposure. The data also indicated that photolysis, hydrolysis, and microbial degradation were not occurring and that volatilization was minimal. In conclusion, transport and metabolism of cyanide in plants is most likely.

  3. Extreme low temperature tolerance in woody plants

    PubMed Central

    Strimbeck, G. Richard; Schaberg, Paul G.; Fossdal, Carl G.; Schröder, Wolfgang P.; Kjellsen, Trygve D.

    2015-01-01

    Woody plants in boreal to arctic environments and high mountains survive prolonged exposure to temperatures below -40°C and minimum temperatures below -60°C, and laboratory tests show that many of these species can also survive immersion in liquid nitrogen at -196°C. Studies of biochemical changes that occur during acclimation, including recent proteomic and metabolomic studies, have identified changes in carbohydrate and compatible solute concentrations, membrane lipid composition, and proteins, notably dehydrins, that may have important roles in survival at extreme low temperature (ELT). Consideration of the biophysical mechanisms of membrane stress and strain lead to the following hypotheses for cellular and molecular mechanisms of survival at ELT: (1) Changes in lipid composition stabilize membranes at temperatures above the lipid phase transition temperature (-20 to -30°C), preventing phase changes that result in irreversible injury. (2) High concentrations of oligosaccharides promote vitrification or high viscosity in the cytoplasm in freeze-dehydrated cells, which would prevent deleterious interactions between membranes. (3) Dehydrins bind membranes and further promote vitrification or act stearically to prevent membrane–membrane interactions. PMID:26539202

  4. Phloem exudation studies in selected woody trees

    SciTech Connect

    Costello, L.R.

    1980-10-01

    Chelating agents, particularly EDTA, were tested for their effectiveness in enhancing the exudation of phloem sugars from selected woody tree species. Of the species selected, Fraxinus uhdei (Evergreen Ash) proved most useful for exudation studies. Experiments using /sup 14/C labelled, excised leaflets of F. uhdei demonstrated that exudation was enhanced approximately 9-fold by a 2.0 mM EDTA treatment. An analysis of labelled products in the treatment solution showed that over 90% of label appeared in oligosaccharides and sucrose. These findings suggested that the sugars released into EDTA treatment solutions were principally derived from phloem sieve elements. Electron microscope studies of the fine structure of sieve plate pores after treatment with EDTA or H/sub 2/O showed substantially less callose appearing in sieve plates of leaflets treated with EDTA. It was proposed that EDTA enhances exudation by inhibiting or reducing callose formation in sieve plate pores. Subsequent experiments demonstrated that EDTA was effective in promoting exudation from whole plant specimens of F. uhdei as well as from excised leaflets. (MHR)

  5. Acetylation of woody lignocellulose: significance and regulation

    PubMed Central

    Pawar, Prashant Mohan-Anupama; Koutaniemi, Sanna; Tenkanen, Maija; Mellerowicz, Ewa J.

    2013-01-01

    Non-cellulosic cell wall polysaccharides constitute approximately one quarter of usable biomass for human exploitation. In contrast to cellulose, these components are usually substituted by O-acetyl groups, which affect their properties and interactions with other polymers, thus affecting their solubility and extractability. However, details of these interactions are still largely obscure. Moreover, polysaccharide hydrolysis to constituent monosaccharides is hampered by the presence of O-acetyl groups, necessitating either enzymatic (esterase) or chemical de-acetylation, increasing the costs and chemical consumption. Reduction of polysaccharide acetyl content in planta is a way to modify lignocellulose toward improved saccharification. In this review we: (1) summarize literature on lignocellulose acetylation in different tree species, (2) present data and current hypotheses concerning the role of O-acetylation in determining woody lignocellulose properties, (3) describe plant proteins involved in lignocellulose O-acetylation, (4) give examples of microbial enzymes capable to de-acetylate lignocellulose, and (5) discuss prospects for exploiting these enzymes in planta to modify xylan acetylation. PMID:23734153

  6. Knots Untie: Molecular Determinants Involved in Knot Formation Induced by Pseudomonas savastanoi in Woody Hosts

    PubMed Central

    Caballo-Ponce, Eloy; Murillo, Jesús; Martínez-Gil, Marta; Moreno-Pérez, Alba; Pintado, Adrián; Ramos, Cayo

    2017-01-01

    The study of the molecular basis of tree diseases is lately receiving a renewed attention, especially with the emerging perception that pathogens require specific pathogenicity and virulence factors to successfully colonize woody hosts. Pathosystems involving woody plants are notoriously difficult to study, although the use of model bacterial strains together with genetically homogeneous micropropagated plant material is providing a significant impetus to our understanding of the molecular determinants leading to disease. The gammaproteobacterium Pseudomonas savastanoi belongs to the intensively studied Pseudomonas syringae complex, and includes three pathogenic lineages causing tumorous overgrowths (knots) in diverse economically relevant trees and shrubs. As it occurs with many other bacteria, pathogenicity of P. savastanoi is dependent on a type III secretion system, which is accompanied by a core set of at least 20 effector genes shared among strains isolated from olive, oleander, and ash. The induction of knots of wild-type size requires that the pathogen maintains adequate levels of diverse metabolites, including the phytohormones indole-3-acetic acid and cytokinins, as well as cyclic-di-GMP, some of which can also regulate the expression of other pathogenicity and virulence genes and participate in bacterial competitiveness. In a remarkable example of social networking, quorum sensing molecules allow for the communication among P. savastanoi and other members of the knot microbiome, while at the same time are essential for tumor formation. Additionally, a distinguishing feature of bacteria from the P. syringae complex isolated from woody organs is the possession of a 15 kb genomic island (WHOP) carrying four operons and three other genes involved in degradation of phenolic compounds. Two of these operons mediate the catabolism of anthranilate and catechol and, together with another operon, are required for the induction of full-size tumors in woody hosts

  7. Introduction of the anti-apoptotic baculovirus p35 gene in passion fruit induces herbicide tolerance, reduced bacterial lesions, but does not inhibits passion fruit woodiness disease progress induced by cowpea aphid-borne mosaic virus (CABMV).

    PubMed

    de Freitas, Daniele Scandiucci; Coelho, Marly C Felipe; Souza, Manoel T; Marques, Abi; Ribeiro, E Bergmann Morais

    2007-01-01

    The introduction of anti-apoptotic genes into plants leads to resistance to environmental stress and broad-spectrum disease resistance. The anti-apoptotic gene (p35) from a baculovirus was introduced into the genome of passion fruit plants by biobalistics. Eleven regenerated plants showed the presence of the p35 gene by PCR and/or dot blot hybridization. Transcriptional analysis of regenerated plants showed the presence of specific p35 transcripts in 9 of them. Regenerated plants containing the p35 gene were inoculated with the cowpea aphid-borne mosaic virus (CABMV), the bacterium Xanthomonas axonopodis pv passiflorae, and the herbicide, glufosinate, (Syngenta). None of the plants showed resistance to CABMV. Regenerated plants (p35+) showed less than half of local lesions showed by non-transgenic plants when inoculated with X. axonopodis and some p35+ plants showed increased tolerance to the glufosinate herbicide when compared to non-transgenic plants.

  8. Can lemmings control the expansion of woody plants on tundra?

    NASA Astrophysics Data System (ADS)

    Oksanen, Lauri; Oksanen, Tarja; Olofsson, Johan; Virtanen, Risto; Hoset, Katrine; Tuomi, Maria; Kyrö, Kukka

    2013-04-01

    The ongoing expansion of woody vegetation in the arctic, due to global warming, creates a positive feed back loop. Increasing abundance of woody plants reduces surface albedo both directly and via speeding up snow melt. Thus a successively greater fraction of incoming solar radiation is absorbed and converted to heat. Browsing mammals - both big and small - can prevent this by consuming woody plants. However, the grazer/browser community of many tundra areas is dominated by brown/Norwegian lemmings (Lemmus spp.) which eat graminoids and mosses and cannot use woody plants as forage. It would seem a priori likely that in such areas, mammalian herbivores speed up the expansion of woody plants by improving the chances of their seedlings to get established. We studied the impact of lemmings on woody plants by constructing lemming proof exclosures within piece high-altitude tundra at Joatkanjávri, northernmost Norway. The exclosures were constructed in 1998, during a period of low lemming densities, in snow-beds, where Norwegian lemmings (L. lemmus) were the only ecologically significant herbivorous mammals. (Reindeer migrate through the area in May, when snow-beds are inaccessible for them; during the fall migration, the area represents a dead end and is therefore avoided.) We chose pairs of maximally similar vegetation patches of 0.5 by 0.5 m and randomly assigned one of each pair to become an exclosure while the other plot was left open. The initial state of the vegetation was documented by the point frequency method. In 2008, after the 2007 lemming outbreak, the same documentation was repeated; thereafter the plots were harvested, the vegetation was sorted to species, oven dried and weighed. Exclusion of lemmings resulted to pronounced increase in community level plant biomass. Evergreen woody plants were especially favored by the exclusion of lemming: their above-ground biomass in exclosures was 14 times as great as their biomass on open reference plots. The

  9. Evaluating Ecohydrological Theories of Woody Root Distribution in the Kalahari

    PubMed Central

    Bhattachan, Abinash; Tatlhego, Mokganedi; Dintwe, Kebonye; O'Donnell, Frances; Caylor, Kelly K.; Okin, Gregory S.; Perrot, Danielle O.; Ringrose, Susan; D'Odorico, Paolo

    2012-01-01

    The contribution of savannas to global carbon storage is poorly understood, in part due to lack of knowledge of the amount of belowground biomass. In these ecosystems, the coexistence of woody and herbaceous life forms is often explained on the basis of belowground interactions among roots. However, the distribution of root biomass in savannas has seldom been investigated, and the dependence of root biomass on rainfall regime remains unclear, particularly for woody plants. Here we investigate patterns of belowground woody biomass along a rainfall gradient in the Kalahari of southern Africa, a region with consistent sandy soils. We test the hypotheses that (1) the root depth increases with mean annual precipitation (root optimality and plant hydrotropism hypothesis), and (2) the root-to-shoot ratio increases with decreasing mean annual rainfall (functional equilibrium hypothesis). Both hypotheses have been previously assessed for herbaceous vegetation using global root data sets. Our data do not support these hypotheses for the case of woody plants in savannas. We find that in the Kalahari, the root profiles of woody plants do not become deeper with increasing mean annual precipitation, whereas the root-to-shoot ratios decrease along a gradient of increasing aridity. PMID:22470506

  10. Measuring Biomass and Carbon Stock in Resprouting Woody Plants

    PubMed Central

    Matula, Radim; Damborská, Lenka; Nečasová, Monika; Geršl, Milan; Šrámek, Martin

    2015-01-01

    Resprouting multi-stemmed woody plants form an important component of the woody vegetation in many ecosystems, but a clear methodology for reliable measurement of their size and quick, non-destructive estimation of their woody biomass and carbon stock is lacking. Our goal was to find a minimum number of sprouts, i.e., the most easily obtainable, and sprout parameters that should be measured for accurate sprout biomass and carbon stock estimates. Using data for 5 common temperate woody species, we modelled carbon stock and sprout biomass as a function of an increasing number of sprouts in an interaction with different sprout parameters. The mean basal diameter of only two to five of the thickest sprouts and the basal diameter and DBH of the thickest sprouts per stump proved to be accurate estimators for the total sprout biomass of the individual resprouters and the populations of resprouters, respectively. Carbon stock estimates were strongly correlated with biomass estimates, but relative carbon content varied among species. Our study demonstrated that the size of the resprouters can be easily measured, and their biomass and carbon stock estimated; therefore, resprouters can be simply incorporated into studies of woody vegetation. PMID:25719601

  11. CBTL Design Case Summary Conventional Feedstock Supply System - Woody

    SciTech Connect

    Christopher T. Wright; Erin M. Searcy

    2012-02-01

    A conventional woody feedstock design has been developed that represents supply system technologies, costs, and logistics that are achievable today for supplying woody biomass as a blendstock with coal for energy production. Efforts are made to identify bottlenecks and optimize the efficiency and capacities of this supply system, within the constraints and consideration of existing local feedstock supplies, equipment, and permitting requirements. The feedstock supply system logistics operations encompass all of the activities necessary to move woody biomass from the production location to the conversion reactor ready for blending and insertion. This supply system includes operations that are currently available such that costs and logistics are reasonable and reliable. The system modeled for this research project includes the use of the slash stream since it is a more conservative analysis and represents the material actually used in the experimental part of the project.

  12. Coarse woody debris: Managing benefits and fire hazard in the recovering forest

    Treesearch

    James K. Brown; Elizabeth D. Reinhardt; Kylie A. Kramer

    2003-01-01

    Management of coarse woody debris following fire requires consideration of its positive and negative values. The ecological benefits of coarse woody debris and fire hazard considerations are summarized. This paper presents recommendations for desired ranges of coarse woody debris. Example simulations illustrate changes in debris over time and with varying management....

  13. Investigation of the Entrainment of Single Woody Debris in Laboratory and Outdoor Experiment

    NASA Astrophysics Data System (ADS)

    Chih, L. M.; Chen, S. C.

    2016-12-01

    In recent years, the occurrence of natural disaster in Taiwan has turn into complex disaster from single disaster. For example, a single landslide disaster combined with large woody debris which could be conveyed by water flow to damage piers of bridges. Therefore, understanding the patterns, characteristics and hydrological conditions of woody debris deposition is a key point for preventing debris wood disaster. Previous studies mainly focused on engineering for woody debris disaster prevention and mitigation. However, hydraulic mechanism of woody debris were lack. Thus, this study conducted outdoor experiments in the Landao Creek, Huisun Forest, Central Taiwan, to simulate the entrainment condition of single woody debris on movable channel bed during flood events. In addition, we designed scaled experiments in laboratory for channels with movable bed to investigate how to influence the entrainment conditions o;f woody debris by physical characteristics (length, diameter and density), water depth, flow direction angle of woody debris placement and grain size of bed material. The result of outdoor experiment showed that the woody debris which is parallel or oblique to flow direction would move by rotation of axis during high flow discharge, then roll downstream, By contrast, the woody debris perpendicular to flow direction rolled downstream at the beginning. The results of laboratory experiment showed that the entrainment water depth of woody debris is significantly influenced by length, diameter, density and bed roughness factor. This study also suggested a function of woody debris entrainment, providing a function of woody debris entrainment ,providing a reference for future models or studies.

  14. Post-fire logging reduces surface woody fuels up to four decades following wildfire

    Treesearch

    David W. Peterson; Erich Kyle Dodson; Richy J. Harrod

    2015-01-01

    Severe wildfires create pulses of dead trees that influence future fuel loads, fire behavior, and fire effects as they decay and deposit surface woody fuels. Harvesting fire-killed trees may reduce future surface woody fuels and related fire hazards, but the magnitude and timing of post-fire logging effects on woody fuels have not been fully assessed. To address this...

  15. Postscript: Problems With the Security Motivation Model Remain Largely Unresolved: Response to Woody and Szechtman (2005)

    ERIC Educational Resources Information Center

    Taylor, Steven; McKay, Dean; Abramowitz, Jonathan S.

    2005-01-01

    This paper comments on the response offered by Szechtman and Woody to Taylor et al's initial comments on Szechtman and Woody's original article. Taylor et al highlight one problem with their model that Woody and Szechtman seem to think is unimportant: the treatment relevance of their model. The analogy of aspirin and colds was used, suggesting…

  16. Assessing the Effects of Woody Plant Traits on Understory Herbaceous Cover in a Semiarid Rangeland

    NASA Astrophysics Data System (ADS)

    Belay, Tamrat A.; Moe, Stein R.

    2015-07-01

    The ecological impact of woody plant encroachment in rangeland ecosystems has traditionally been evaluated based on correlation studies between densities of dissimilar woody plants and various ecosystem properties. However, ecosystem properties respond differently to woody plant encroachment because of variations in adaptation of co-occurring woody plants. The objective of this study is to predict the impact of woody plant encroachment on understory herbaceous cover based on analysis of key traits of woody plants. We conducted a vegetation survey in 4 savanna sites in southwestern Ethiopia and compared 9 different key traits of 19 co-occurring woody plants with understory herbaceous cover. Our results show that low understory herbaceous cover is associated with evergreen leaf phenology, shrubby growth form, smaller relative crown-base height and larger relative crown diameter. However, the N2-fixing ability and density of woody plants did not influence the understory herbaceous cover. This shows that traits of individual woody plants can predict the impact of woody plant encroachment on understory herbaceous cover better than density does. The finding improves our ability to accurately predict the impact of woody plant encroachment on various ecosystem properties in highly diverse savanna systems. This plant trait-based approach could be also used as an important management exercise to assess and predict the impact of encroaching woody species in several rangeland ecosystems.

  17. Spatial vegetation patterns and neighborhood competition among woody plants in an East African savanna

    USDA-ARS?s Scientific Manuscript database

    The majority of research on savanna vegetation dynamics has focused on the coexistence of woody and herbaceous vegetation; interactions among woody plants in savannas are relatively poorly understood. We present data from a 10-year longitudinal study of spatially explicit growth patterns of woody ve...

  18. Invertabrates Associated with Woody Debris in a Southeastern U.S. Forested Floodplain Wetland

    Treesearch

    Amy Braccia; Darold P. Batzer

    2001-01-01

    Woody debris is an ecologically important resource in upland forests and stream ecosystems. Although much is known about invertebrate-woody debris interactions in forests and streams, little information exists for forested wetlands. In this study, invertebrates associated with woody debris in a Southeastern U. S. forested floodplain are described and factors that shape...

  19. Textural analysis of historical aerial photography to characterize woody plant encroachment in South African savanna

    Treesearch

    Andrew T. Hudak; Carol A. Wessman

    1998-01-01

    Transitions from grassland to shrubland through woody plant encroachment result in potentially significant shifts in savanna ecosystem function. Given high resolution imagery, a textural index could prove useful for mapping woody plant densities and monitoring woody plant encroachment across savanna landscapes. Spatial heterogeneity introduced through mixtures of...

  20. Woody biomass utilization trends, barriers, and strategies: Perspectives of U.S. Forest Service managers

    Treesearch

    Shiloh Sundstrom; Max Nielsen-Pincus; Cassandra Moseley; Sarah. McCaffrey

    2012-01-01

    The use of woody biomass is being promoted across the United States as a means of increasing energy independence, mitigating climate change, and reducing the cost of hazardous fuels reduction treatments and forest restoration projects. The opportunities and challenges for woody biomass use on the national forest system are unique. In addition to making woody biomass...

  1. Postscript: Problems With the Security Motivation Model Remain Largely Unresolved: Response to Woody and Szechtman (2005)

    ERIC Educational Resources Information Center

    Taylor, Steven; McKay, Dean; Abramowitz, Jonathan S.

    2005-01-01

    This paper comments on the response offered by Szechtman and Woody to Taylor et al's initial comments on Szechtman and Woody's original article. Taylor et al highlight one problem with their model that Woody and Szechtman seem to think is unimportant: the treatment relevance of their model. The analogy of aspirin and colds was used, suggesting…

  2. Woody plants selected by beavers in the Appalacian Ridge and Valley Province

    Treesearch

    Hewlette S. Crawford; R. G. Hooper; R. F. Harlow

    1976-01-01

    The availability of woody plants and the selection of plants by beavers along mountain streams was studied in four areas of the Appalachian Ridge and Valley Province in Virginia. Beavers' choice of woody plants varied between areas. Many species of woody plants were cut by beavers. They climbed slopes with gradients up to 80 percent to cut trees. Large as well as...

  3. Woody landscape plant breeding in Minnesota (45°N): It's not all about cold hardiness

    Treesearch

    S.C. ​Hokanson; V.M. Whitaker; J.M. Bradeen; M.C. Long; S.K. Krebs; R.A. Blanchette; J. Juzwik; K. Zuzek; S. McNamara

    2010-01-01

    The Woody Landscape Plant Breeding project at the University of Minnesota has been in existence since 1954. The project was initiated largely to develop an extended palette of cold-hardy woody landscape plants for northern landscapes. Since its inception, it has been responsible for the release of 49 woody plant cultivars including large stature shade trees, small...

  4. Effect of controlling herbaceous and woody competing vegetation on wood quality of planted loblolly pine

    Treesearch

    Alexander Clark; Richard F. Daniels; James H. Miller

    2006-01-01

    Southern pine plantations are increasingly established using herbicides to control herbaceous and/or woody competing vegetation to enhance growth, but little is known about the effect on wood quality. A study was established at 13 southern locations in 1984 to examine the effects of complete control of woody, herbaceous, and woody plus herbaceous competition for the...

  5. Coarse woody debris metrics in a California oak woodland

    Treesearch

    William D. Tietje; Michael A. Hardy; Christopher C. Yim

    2015-01-01

    Little information is available on the metrics of coarse woody debris (CWD) in California oak woodland, most notably at the scale of the stand and woodland type. In a remote part of the National Guard Post, Camp Roberts, that has not burned in over a half century, we tallied 314 pieces of CWD in a blue oak (Quercus douglasii)-coast live oak (

  6. Estimates of Down Woody Materials in Eastern US Forests

    Treesearch

    David C. Chojnacky; Robert A. Mickler; Linda S. Heath; Christopher W. Woodall

    2004-01-01

    Down woody materials (WVMs) are an important part of forest ecosystems for wildlife habitat, carbon storage, structural diversity, wildfire hazard, and other large-scale ecosystem processes. To better manage forests for DWMs, available and easily accessible data on DWM components are needed. We examined data on DWMs, collected in 2001 by the US Department of...

  7. Ordination of Woody Vegetation in a Ouachita National Forest Watershed

    Treesearch

    Denise Marion; George Malanson

    2004-01-01

    Abstract - Species response to competition and other environmental gradients has important implications for forest ecosystem managers who desire to both maintain diversity and provide a sustained flow of forest goods and services. Woody species on a 140-acre watershed in the Ouachita National Forest are ordinated with detrended correspondence...

  8. Large woody debris budgets in the Caspar Creek Experimental Watersheds

    Treesearch

    Sue Hilton

    2012-01-01

    Monitoring of large woody debris (LWD) in the two mainstem channels of the Caspar Creek Experimental Watersheds since 1998, combined with older data from other work in the watersheds, gives estimates of channel wood input rates, survival, and outputs in intermediate-sized channels in coastal redwood forests. Input rates from standing trees for the two reaches over a 15...

  9. Developmental mechanisms regulating secondary growth in woody plants

    Treesearch

    Andrew Groover; Marcel Robischon

    2006-01-01

    Secondary growth results in the radial expansion of woody stems, and requires the coordination of tissue patterning, cell differentiation, and the maintenance of meristematic stem cells within the vascular cambium. Advances are being made towards describing molecular mechanisms that regulate these developmental processes, thanks in part to the application of new...

  10. Processing woody biomass with a modified horizontal grinder

    Treesearch

    Dana Mitchell; John Klepac

    2008-01-01

    This study documents the production rate and cost of producing woody biomass chips for use in a power plant. The power plant has specific raw material handling requirements. Output from a 3-knife chipper, a tub grinder, and a horizontal grinder was considered. None of the samples from these machines met the specifications needed. A horizontal grinder was modified to...

  11. Managing coarse woody debris in forests of the Rocky Mountains

    Treesearch

    Russell T. Graham; Alan E. Harvey; Martin F. Jurgensen; Theresa B. Jain; Jonalea R. Tonn; Deborah S. Page-Dumroese

    1994-01-01

    Recommendations for managing coarse woody debris after timber harvest were developed for 14 habitat types, ranging from ponderosa pine (Pinus ponderosa) habitat types of Arizona to subalpine fir (Abies lasiocarpa) habitat types of western Montana. Ectomycorrhizae were used as a bioindicator of healthy, productive forest soils....

  12. Woody tissue analysis using an element ratio technique (DRIS)

    Treesearch

    Kurt H. Riitters; L.F. Ohmann; D.F. Grigal

    1991-01-01

    The diagnosis and recommendation integrated system (DRIS) was used to describe the variation of 12 elements in woody tree tissue and balsam fir (Abies balsamae (L.) Mill.), sugar maple (Acer saccharum Marsh.), jack pine (Pinus banksiana Lamb.), red pine (Pinus resinosa alt.), and aspen (

  13. Southern Fruit Producing Woody Plants Used by Wildlife

    Treesearch

    Lowell K. Halls; [Editor

    1977-01-01

    Describes and provides illustrations of 106 woody plant species that produce fruit useful to wildlife in southern forests. It also includes information about plant growth requirements, management, and nutritional quality. Trees, shrubs, and vines that produce fleshy fruits or nuts are emphasized.

  14. Patterns, determinants and models of woody plant diversity in China.

    PubMed

    Wang, Zhiheng; Fang, Jingyun; Tang, Zhiyao; Lin, Xin

    2011-07-22

    What determines large-scale patterns of species richness remains one of the most controversial issues in ecology. Using the distribution maps of 11 405 woody species in China, we compared the effects of habitat heterogeneity, human activities and different aspects of climate, particularly environmental energy, water-energy dynamics and winter frost, and explored how biogeographic affinities (tropical versus temperate) influence richness-climate relationships. We found that the species richness of trees, shrubs, lianas and all woody plants strongly correlated with each other, and more strongly correlated with the species richness of tropical affinity than with that of temperate affinity. The mean temperature of the coldest quarter was the strongest predictor of species richness, and its explanatory power for species richness was significantly higher for tropical affinity than for temperate affinity. These results suggest that the patterns of woody species richness mainly result from the increasing intensity of frost filtering for tropical species from the equator/lowlands towards the poles/highlands, and hence support the freezing-tolerance hypothesis. A model based on these results was developed, which explained 76-85% of species richness variation in China, and reasonably predicted the species richness of woody plants in North America and the Northern Hemisphere.

  15. Does livestock grazing influence spatial patterns of woody plant proliferation?

    USDA-ARS?s Scientific Manuscript database

    Patterns of woody plant proliferation in grasslands and savannas influence rates of erosion, spread of disturbance, and nutrient pools.  Spatial pattern is the outcome of plant dispersal, recruitment, competition/facilitation, and disturbance. We quantified effects of livestock grazing, a widely cit...

  16. Is woody residue part of your plan for sustainable forestry?

    Treesearch

    Deborah Page-Dumroese

    2010-01-01

    The answer to the title question should be "yes"! Currently, there is a lot of chatter about sustainable forestry and alternative fuels, including conversion of wood to bioenergy. At first glance it may seem like there is a conflict - how can removal of woody biomass be sustainable? Whether you are a small woodlot owner doing sustainable harvesting, looking...

  17. Non-woody weed control in pine plantations

    Treesearch

    Phillip M. Dougherty; Bob Lowery

    1986-01-01

    The cost and benefits derived from controlling non-woody competitors in pine planations were reviewed. Cost considerations included both the capital cost and biological cost that may be incurred when weed control treatments are applied. Several methods for reducing the cost of herbicide treatments were explored. Cost reduction considerations included adjustments in...

  18. Coarse woody debris in oak woodlands of California.

    Treesearch

    William D. Tietje; Karen L. Waddell; Justin K. Vreeland; Charles L. Bolsinger

    2002-01-01

    An extensive forest inventory was conducted to estimate the amount and distribution of coarse woody debris (CWD) on 5.6 million ac of woodlands in California that are outside of national forests and reserved areas. Woodlands consist primarily of oak (Quercus spp.) types and are defined as forestland incapable of producing commercial quantities of...

  19. Improving coarse woody debris measurements: a taper-based technique

    Treesearch

    Christopher W. Woodall; James A. Westfall

    2007-01-01

    Coarse woody debris (CWD) are dead and down trees of a certain minimum size that are an important forest ecosystem component (e.g., wildlife habitat, carbon stocks, and fuels). Accurately measuring the dimensions of CWD is important for ensuring the quality of CWD estimates and hence for accurately assessing forest ecosystem attributes. To improve the quality of CWD...

  20. Bioenergy from forests: The power potential of woody biomass

    Treesearch

    John Kirkland; David Nicholls

    2015-01-01

    The elevated intensity of wildfire seasons in the American West combined with political, environmental, and economic issues surrounding the use of coal and oil are spurring a growing interest in the use of woody biomass as a fuel for heating and electrical generation.David Nicholls, a forest products technologist at the Alaska Wood Utilization Research and...

  1. Modeling population dynamics and woody biomass of Alaska coastal forest

    Treesearch

    Randy L. Peterson; Jingjing Liang; Tara M. Barrett

    2014-01-01

    Alaska coastal forest, 6.2 million ha in size, has been managed in the past mainly through clearcutting. Declining harvest and dwindling commercial forest resources over the past 2 decades have led to increased interest in management of young-growth stands and utilization of woody biomass for bioenergy. However, existing models to support these new management systems...

  2. Dynamic variation in sapwood specific conductivity in six woody species

    Treesearch

    Jean-Christophe Domec; Frederick C. Meinzer; Barbara Lachenbruch; Johann Housset

    2008-01-01

    Our goals were to quantify how non-embolism inducing pressure gradients influence trunk sapwood specific conductivity (ks) and to compare the impacts of constant and varying pressure gradients on ks with KCl and H20 as the perfusion solutions. We studied six woody species (three conifers and three...

  3. A distance limited method for sampling downed coarse woody debris

    Treesearch

    Jeffrey H. Gove; Mark J. Ducey; Harry T. Valentine; Michael S. Williams

    2012-01-01

    A new sampling method for down coarse woody debris is proposed based on limiting the perpendicular distance from individual pieces to a randomly chosen sample point. Two approaches are presented that allow different protocols to be used to determine field measurements; estimators for each protocol are also developed. Both protocols are compared via simulation against...

  4. Non-structural carbohydrates in woody plants compared among laboratories

    Treesearch

    Audrey G. Quentin; Elizabeth A. Pinkard; Michael G. Ryan; David T. Tissue; L. Scott Baggett; Henry D. Adams; Pascale Maillard; Jacqueline Marchand; Simon M. Landhausser; Andre Lacointe; Yves Gibon; William R. L. Anderegg; Shinichi Asao; Owen K. Atkin; Marc Bonhomme; Caroline Claye; Pak S. Chow; Anne Clement-Vidal; Noel W. Davies; L. Turin Dickman; Rita Dumbur; David S. Ellsworth; Kristen Falk; Lucía Galiano; Jose M. Grunzweig; Henrik Hartmann; Gunter Hoch; Sharon Hood; Joanna E. Jones; Takayoshi Koike; Iris Kuhlmann; Francisco Lloret; Melchor Maestro; Shawn D. Mansfield; Jordi Martinez-Vilalta; Mickael Maucourt; Nathan G. McDowell; Annick Moing; Bertrand Muller; Sergio G. Nebauer; Ulo Niinemets; Sara Palacio; Frida Piper; Eran Raveh; Andreas Richter; Gaelle Rolland; Teresa Rosas; Brigitte Saint Joanis; Anna Sala; Renee A. Smith; Frank Sterck; Joseph R. Stinziano; Mari Tobias; Faride Unda; Makoto Watanabe; Danielle A. Way; Lasantha K. Weerasinghe; Birgit Wild; Erin Wiley; David R. Woodruff

    2016-01-01

    Non-structural carbohydrates (NSC) in plant tissue are frequently quantified to make inferences about plant responses to environmental conditions. Laboratories publishing estimates of NSC of woody plants use many different methods to evaluate NSC. We asked whether NSC estimates in the recent literature could be quantitatively compared among studies. We also...

  5. Interactions of Woody Biofuel Feedstock Production Systems with Water Resources: Considerations for Sustainability

    SciTech Connect

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

    2008-04-15

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

  6. Botryosphaeria dothidea: a latent pathogen of global importance to woody plant health.

    PubMed

    Marsberg, Angelica; Kemler, Martin; Jami, Fahimeh; Nagel, Jan H; Postma-Smidt, Alisa; Naidoo, Sanushka; Wingfield, Michael J; Crous, Pedro W; Spatafora, Joseph W; Hesse, Cedar N; Robbertse, Barbara; Slippers, Bernard

    2016-09-28

    Botryosphaeria dothidea is the type species of Botryosphaeria (Botryosphaeriaceae, Botryosphaeriales). Fungi residing in this order are amongst the most widespread and important canker and dieback pathogens of trees worldwide, with B. dothidea one of the most common species on a large number of hosts. Its taxonomic circumscription has undergone substantial change in the past decade, making it difficult to interpret the large volume of literature linked to the name B. dothidea. This pathogen profile synthesizes the current understanding of B. dothidea pertaining to its distribution, host associations and role as a pathogen in managed and natural woody environments. The prolonged latent infection or endophytic phase is of particular importance, as it implies that the fungus can easily pass undetected by quarantine systems in traded living plants, fruits and other plant parts. Infections typically become obvious only under conditions of host stress, when disease symptoms develop. This study also considers the knowledge emerging from the recently sequenced B. dothidea genome, elucidating previously unknown aspects of the species, including mating and host infection strategies. Despite more than 150 years of research on B. dothidea, there is clearly much to be learned regarding this global tree pathogen. This is increasingly important given the stresses imposed on various woody hosts as a result of climate change.

  7. Suitable utilization of woody plants for hibitation on Mars

    NASA Astrophysics Data System (ADS)

    Tomita-Yokotani, Kaori; Baba, Keiichi; Suzuki, Toshisada; Kimura, Shunta; Sato, Seigo; Katoh, Hiroshi; Abe, Yusuke; Katayama, Takeshi

    2016-07-01

    We have been investigating the usefulness of woody plants for habitation on Mars. During our research, we have found that woody plants have several properties which can be utilized for therapy and materials for enrage and construction even on Mars. Japanese people traditionally believe that "Bonsai" have therapeudic properties. Trees can become carbon fuel which can be used as energy on Mars. Tree materials could be used as a tool in closed bio-ecosystems such as for the purification and/or separation of solutions in an environment in space. Here, we will show some results of their abilities, the water leakage and vacuum seal test, separation of solutions using carbon materials made from trees. At the initiation of this research, we named the trees used as material for the experiment related to space environments "CosmoBon", small bonsai tree. To establish our research, as the first step, we will try to do the experiment using "CosmoBon".

  8. Spatial vegetation patterns and neighborhood competition among woody plants in an East African savanna.

    PubMed

    Dohn, Justin; Augustine, David J; Hanan, Niall P; Ratnam, Jayashree; Sankaran, Mahesh

    2017-02-01

    The majority of research on savanna vegetation dynamics has focused on the coexistence of woody and herbaceous vegetation. Interactions among woody plants in savannas are relatively poorly understood. We present data from a 10-yr longitudinal study of spatially explicit growth patterns of woody vegetation in an East African savanna following exclusion of large herbivores and in the absence of fire. We examined plant spatial patterns and quantified the degree of competition among woody individuals. Woody plants in this semiarid savanna exhibit strongly clumped spatial distributions at scales of 1-5 m. However, analysis of woody plant growth rates relative to their conspecific and heterospecific neighbors revealed evidence for strong competitive interactions at neighborhood scales of up to 5 m for most woody plant species. Thus, woody plants were aggregated in clumps despite significantly decreased growth rates in close proximity to neighbors, indicating that the spatial distribution of woody plants in this region depends on dispersal and establishment processes rather than on competitive, density-dependent mortality. However, our documentation of suppressive effects of woody plants on neighbors also suggests a potentially important role for tree-tree competition in controlling vegetation structure and indicates that the balanced-competition hypothesis may contribute to well-known patterns in maximum tree cover across rainfall gradients in Africa.

  9. The woody biomass resource of East Texas, 1992

    Treesearch

    James F. Rosson

    1993-01-01

    Data from the 1992 east Texas forest survey was used to derive fresh and dry biomass estimates for all trees, on timberland, greater than 1.0 inch in diameter at breast height (d.b.h). There are 382.2 million fresh tons in softwood species and 492.9 million fresh tons in hardwood species. The woody biomass resource averages 43.2 and 45.4 tons per acre for softwoods and...

  10. Supply of large woody debris in a stream channel

    USGS Publications Warehouse

    Diehl, Timothy H.; Bryan, Bradley A.

    1993-01-01

    The amount of large woody debris that potentially could be transported to bridge sites was assessed in the basin of the West Harpeth River in Tennessee in the fall of 1992. The assessment was based on inspections of study sites at 12 bridges and examination of channel reaches between bridges. It involved estimating the amount of woody material at least 1.5 meters long, stored in the channel, and not rooted in soil. Study of multiple sites allowed estimation of the amount, characteristics, and sources of debris stored in the channel, and identification of geomorphic features of the channel associated with debris production. Woody debris is plentiful in the channel network, and much of the debris could be transported by a large flood. Tree trunks with attached root masses are the dominant large debris type. Death of these trees is primarily the result of bank erosion. Bank instability seems to be the basin characteristic most useful in identifying basins with a high potential for abundant production of debris.

  11. Sensitivity to zinc of Mediterranean woody species important for restoration.

    PubMed

    Disante, Karen B; Fuentes, David; Cortina, Jordi

    2010-04-15

    Heavy metals have increased in natural woodlands and shrublands over the last several decades as a consequence of anthropogenic activities. However, our knowledge of the effects of these elements on woody species is scarce. In this study, we examined the responses of six Mediterranean woody species to increasing levels of zinc in hydroponic culture and discussed the possible implications for the restoration of contaminated sites. The species used, Pinus pinea L., Pinus pinaster Ait., Pinus halepensis Mill., Tetraclinis articulata (Vahl) Mast., Rhamnus alaternus L. and Quercus suber L. represent a climatic gradient from dry sub-humid to semi-arid conditions. Zinc concentrations in shoots ranged from 53 microg g(-1) in Q. suber to 382 microg g(-1) in T. articulata and were well below the levels found in roots. Zinc inhibited root elongation and root biomass and changed the root length distribution per diameter class, but the magnitude of the effects was species-specific. Only P. halepensis and Q. suber showed toxicity symptoms in aboveground parts. Species more characteristic from xeric environments (T. articulata, R. alaternus and P. halepensis) were more sensitive to zinc than species from mesic environments (Q. suber, P. pinaster and P. pinea). According to the Zn responses and bioaccumulation, Q. suber P. pinea and P. halepensis are the best candidates for field trials to test the value of woody species to restore contaminated sites. None of the species tested seemed suitable for phytoremediation.

  12. [Research advance in seed germination of desert woody plants].

    PubMed

    Chang, Wei; Wu, Jian-guo; Liu, Yan-hong

    2007-02-01

    This paper reviewed the research methods of desert woody plants seed germination, and the effects of internal and external ecological factors on it. Most researchers use incubator and artificial climate chamber to dispose the seeds, while field investigation was few involved. Seed dormancy is the important physiological factor affecting germination, while seed size, mass and color are closely correlated with its maturity and vigor. The poor permeability of seed capsule is a barrier that restrains the germination, which can be weakened or eliminated by shaving, cutting, treating with low temperature, and dipping in chemical reagent, etc. Seed water content has a close correlation with its storage life and water-absorbing capability. Suitable temperature is the prerequisite of seed germination, while changing temperature can accelerate the germination. Soil moisture content is a limiting factor, while illumination is not so essential to the seed germination of most desert woody plants. Sand-burying plays an important role in the seed germination through regulating illumination, temperature, and soil moisture content. Salinity stress restrains the seed germination of desert woody plants observably. In further studies, the effects of multi-factors and the eco-physiological and molecular biological mechanisms of germination should be more concerned.

  13. Briquettability of lignite and woody wastes composite fuel

    SciTech Connect

    Beker, U.G.

    2000-03-01

    Woody wastes have favorable burning characteristics compared to lignite, as well as low ash content and reduced smoke emission. The aim of this study was to blend lignite with woody wastes to obtain a solid fuel that retains the advantageous characteristics of woody materials. Blends with lignite were made up with 7, 9, 12, 15, and 20% of waste and then briquetted under pressures of 400, 550, 700, and 800 MPa. Sunflower shell, sawdust, and paper mill wastes were used in different amounts with molasses as binder. Studies were carried out on a laboratory scale to determine optimum parameters for briquetting, such as moisture content of lignite and pressure. Briquetting of lignite without waste materials produces products of low strength. The strongest briquettes were obtained with waste contents of 12--20% and lignite moisture contents of 10--12% at briquetting pressures of 550, 700, and 800 MPa. Briquettes with adequate mechanical strength are obtained from lignite-waste blends with the addition of 8% molasses.

  14. Bacterial diseases affecting apple

    USDA-ARS?s Scientific Manuscript database

    Bacterial diseases of plants are usually difficult to control and often require a combination of control measures to successfully manage the disease. There are often stark differences between the means available to control bacterial diseases in annual crops versus a woody tree crop, such as apple. ...

  15. Mycorrhizal Productivity Following Woody Plant Invasion of Grassland

    NASA Astrophysics Data System (ADS)

    Boutton, T. W.; Rowe, H. I.; Ariza, M. C.; Miller, R. M.; Filley, T. R.

    2008-12-01

    Mycorrhizal fungi play an important role in soil carbon storage and dynamics through the production of recalcitrant organic compounds (e.g., glomalin and chitin), and through the production of hyphae which entangle and enmesh soil particles to form aggregates which physically protect organic matter from decomposer organisms. Despite these important functions, little is known regarding rates of mycorrhizal productivity and how these rates might be influenced by changes in plant community composition. We quantified mycorrhizal production in a subtropical savanna parkland in southern Texas where woody plants have invaded areas that were once open grassland. Mycorrhizal ingrowth bags (3 x 10 cm) were made from 50 μm nylon mesh, filled with sterile sand (200-600 μm particle size), and deployed in the field in triplicate in remnant grasslands (n=15), and in woody plant stands (n=13) ranging in age from 15 to 86 yrs. Ingrowth bags were installed in May and harvested in Oct 2007 after 156 days. Hyphae were isolated by flotation/filtration, cleaned thoroughly to remove sand, freeze-dried, and weighed. Microscopic examination indicated that nearly all hyphae recovered from ingrowth bags were from arbuscular mycorrhizal fungi. During the ingrowth period, nearly 4X more hyphal biomass accumulated in wooded areas (9.00 ± 3.84 g m- 2) compared to remnant grasslands (2.35 ± 0.56 g m-2). Hyphal productivity rates increased linearly with woody plant stand age (r = 0.89) from 15 ± 4 mg m-2 day-1 in grasslands (time 0) up to 58-98 mg m-2 day-1 in wooded areas >65 yrs old. When these productivity rates are annualized, we find that hyphal productivity represents approximately 4% of aboveground net primary productivity (ANPP) in wooded areas, and 2% of ANPP in remnant grasslands. These observations are consistent with concurrent studies showing that glomalin concentrations and chitinase enzyme activity both increase in soils with time following woody encroachment into grassland

  16. Spatial patterns of streambed morphology around woody debris: flume experiments and field observations on the effects of woody debris on streambed morphology

    NASA Astrophysics Data System (ADS)

    Leung, V.; Montgomery, D. R.

    2010-12-01

    The interactions between woody debris, fluid flow and sediment transport in rivers play a fundamental role in ecogeomorphology, affecting channel roughness, streambed morphology, and sediment transport and storage. In particular, woody debris increases the hydraulic and topographic complexity in rivers, leading to a greater diversity of aquatic habitats and an increase in the number of large pools that are important fish habitat and breeding grounds. In the past decade, engineered logjams have become an increasingly used tool in river management for simultaneously decreasing the rate of riverbank migration and improving aquatic habitat. Sediment deposits around woody debris build up riverbanks and counteract bank migration caused by erosion. Previous experiments of flow visualization around model woody debris suggest the amount of sediment scour and deposition are primarily related to the presence of roots and the obstructional area of the woody debris. We present the results of field surveys and sediment transport experiments of streambed morphology around stationary woody debris on a mobile bed. These experiments test the effects of root presence, root geometry and log orientation of individual stationary trees on streambed morphology. The flume contains a deformable sediment bed of medium sand, and has subcritical and turbulent flow, corresponding to flow conditions found in nature. Field surveys on the Hoh River, WA, measure the local streambed morphology around woody debris (e.g. pool and gravel-bar length, width and depth), as well as woody debris characteristics (e.g. tree diameter, tree length, root diameter and root depth). We quantified the amount of local sediment scour and deposition around woody debris of varying sizes, geometries and orientations relative to flow. We find that: 1) the presence of roots on woody debris leads to greater areas of both sediment scour and deposition; and 2) the amount of sediment scour and deposition are related to the

  17. Relationship of Course Woody Debris to Red-Cockaded Woodpecker Prey Diversity and Abundance

    SciTech Connect

    Horn, G.S.

    1999-09-03

    The abundance of diversity of prey commonly used by the red-cockaded woodpecker were monitored in experimental plots in which course woody debris was manipulated. In one treatment, all the woody debris over four inches was removed. In the second treatment, the natural amount of mortality remained intact. The overall diversity of prey was unaffected; however, wood roaches were significantly reduced by removal of woody debris. The latter suggests that intensive utilizations or harvesting practices may reduce foraging.

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

    SciTech Connect

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

    2001-06-14

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

  19. Woody encroachment over 70 years in South African savannahs: overgrazing, global change or extinction aftershock?

    PubMed

    Stevens, Nicola; Erasmus, B F N; Archibald, S; Bond, W J

    2016-09-19

    Woody encroachment in 'open' biomes like grasslands and savannahs is occurring globally. Both local and global drivers, including elevated CO2, have been implicated in these increases. The relative importance of different processes is unresolved as there are few multi-site, multi-land-use evaluations of woody plant encroachment. We measured 70 years of woody cover changes over a 1020 km(2) area covering four land uses (commercial ranching, conservation with elephants, conservation without elephants and communal rangelands) across a rainfall gradient in South African savannahs. Different directions of woody cover change would be expected for each different land use, unless a global factor is causing the increases. Woody cover change was measured between 1940 and 2010 using the aerial photo record. Detection of woody cover from each aerial photograph was automated using eCognitions' Object-based image analysis (OBIA). Woody cover doubled in all land uses across the rainfall gradient, except in conservation areas with elephants in low-rainfall savannahs. Woody cover in 2010 in low-rainfall savannahs frequently exceeded the maximum woody cover threshold predicted for African savannahs. The results indicate that a global factor, of which elevated CO2 is the likely candidate, may be driving encroachment. Elephants in low-rainfall savannahs prevent encroachment and localized megafaunal extinction is a probable additional cause of encroachment.This article is part of the themed issue 'Tropical grassy biomes: linking ecology, human use and conservation'.

  20. Analysis of the pattern of potential woody cover in Texas savanna

    NASA Astrophysics Data System (ADS)

    Yang, Xuebin; Crews, Kelley A.; Yan, Bowei

    2016-10-01

    While woody plant encroachment has been observed worldwide in savannas and adversely affected the ecosystem structure and function, a thorough understanding of the nature of this phenomenon is urgently required for savanna management and restoration. Among others, potential woody cover (the maximum realizable woody cover that a given site can support), especially its variation over environment has huge implication on the encroachment management in particular, and on tree-grass interactions in general. This project was designed to explore the pattern of potential woody cover in Texas savanna, an ecosystem with a large rainfall gradient in west-east direction. Substantial random pixels were sampled across the study area from MODIS Vegetation Continuous Fields (VCF) tree cover layer (250 m). Since potential woody cover is suggested to be limited by water availability, a nonlinear 99th quantile regression was performed between the observed woody cover and mean annual precipitation (MAP) to model the pattern of potential woody cover. Research result suggests a segmented relationship between potential woody cover and MAP at MODIS scale. Potential biases as well as the practical and theoretical implications were discussed. Through this study, the hypothesis about the primary role of water availability in determining savanna woody cover was further confirmed in a relatively understudied US-located savanna.

  1. PCR-based detection of a tracheal mite of the honey bee Acarapis woodi.

    PubMed

    Kojima, Yuriko; Yoshiyama, Mikio; Kimura, Kiyoshi; Kadowaki, Tatsuhiko

    2011-10-01

    The effects of the tracheal mite Acarapis woodi on the health of honey bees have been neglected since the prevalence of Varroa mites to Apis mellifera colonies. However, tracheal mite infestation of honey bee colonies still occurs worldwide and could impose negative impact on apiculture. The detection of A. woodi requires the dissection of honey bees followed by microscopic observation of the tracheal sacs. We thus developed PCR methods to detect A. woodi. These methods facilitate rapid and sensitive detection of A. woodi in many honey bee samples for epidemiologic surveys.

  2. Sugars from woody tissue photosynthesis reduce xylem vulnerability to cavitation.

    PubMed

    De Baerdemaeker, Niels J F; Salomón, Roberto Luis; De Roo, Linus; Steppe, Kathy

    2017-09-18

    Reassimilation of internal CO2 via woody tissue photosynthesis has a substantial effect on tree carbon income and wood production. However, little is known about its role in xylem vulnerability to cavitation and its implications in drought-driven tree mortality. Young trees of Populus nigra were subjected to light exclusion at the branch and stem levels. After 40 d, measurements of xylem water potential, diameter variation and acoustic emission (AE) were performed in detached branches to obtain acoustic vulnerability curves to cavitation following bench-top dehydration. Acoustic vulnerability curves and derived AE50 values (i.e. water potential at which 50% of cavitation-related acoustic emissions occur) differed significantly between light-excluded and control branches (AE50,light-excluded  = -1.00 ± 0.13 MPa; AE50,control  = -1.45 ± 0.09 MPa; P = 0.007) denoting higher vulnerability to cavitation in light-excluded trees. Woody tissue photosynthesis represents an alternative and immediate source of nonstructural carbohydrates (NSC) that confers lower xylem vulnerability to cavitation via sugar-mediated mechanisms. Embolism repair and xylem structural changes could not explain this observation as the amount of cumulative AE and basic wood density did not differ between treatments. We suggest that woody tissue assimilates might play a role in the synthesis of xylem surfactants for nanobubble stabilization under tension. © 2017 The Authors. New Phytologist © 2017 New Phytologist Trust.

  3. Variability in the composition of short rotation woody feedstocks

    SciTech Connect

    Davis, M.F.; Johnson, D.K.; Deutch, S.

    1995-11-01

    This paper discusses the variability in chemical composition caused by clonal, geographical, and environmental effects on short rotation woody feedstocks, mainly hybrid clones of poplar. The concentrations of major and minor components have been determined by chemical analysis and pyrolysis molecular beam mass spectrometry (PY-MBMS). The chemical composition was determined for a sample set consisting of debarked wood chips from three clones of deltoides x nigra (DN) and one clone of tristis x balsamifera that were grown on four replicate plots at two locations in Wisconsin. The composition of the wood chips determined by chemical analysis and Py-MBMS showed that the tristic clone was significantly different from that of all the DN clones. The composition of the DN clones studied in this sample set were relatively similar to other hybrid poplar samples that have been analyzed over the past three years. The level of compositional variation due to clonal, geographical and environmental factors observed in short rotation woody species to date indicates that they are a consistent and stable feedstock for biofuels production. The effects of storage on different short rotation woody crops has been studied. Results of the analysis of fresh and stored hybrid poplar using traditional wet chemical analysis showed differences in the chemical composition of the feedstocks because of storage. Also presented are results from a rapid analytical technique using pyrolysis-mass spectroscopy combined with multivariate statistical analysis to assess the influence of storage on the composition of different short rotation feedstocks. Because of the rapid nature of this technique, a large number of samples could be screened to determine the extent of degradation throughout the piles. The application of this technique to the samples in this study indicated changes in chemical composition occurred during the storage period.

  4. Closed Loop Short Rotation Woody Biomass Energy Crops

    SciTech Connect

    Brower, Michael

    2012-09-30

    CRC Development LLC is pursuing commercialization of shrub willow crops to evaluate and confirm estimates of yield, harvesting, transportation and renewable energy conversion costs and to provide a diverse resource in its supply portfolio.The goal of Closed Loop Short Rotation Woody Biomass Energy Crops is supply expansion in Central New York to facilitate the commercialization of willow biomass crops as part of the mix of woody biomass feedstocks for bioenergy and bioproducts. CRC Development LLC established the first commercial willow biomass plantation acreage in North America was established on the Tug Hill in the spring of 2006 and expanded in 2007. This was the first 230- acres toward the goal of 10,000 regional acres. This project replaces some 2007-drought damaged acreage and installs a total of 630-acre new planting acres in order to demonstrate to regional agricultural producers and rural land-owners the economic vitality of closed loop short rotation woody biomass energy crops when deployed commercially in order to motivate new grower entry into the market-place. The willow biomass will directly help stabilize the fuel supply for the Lyonsdale Biomass facility, which produces 19 MWe of power and exports 15,000 pph of process steam to Burrows Paper. This project will also provide feedstock to The Biorefinery in New York for the manufacture of renewable, CO2-neutral liquid transportation fuels, chemicals and polymers. This project helps end dependency on imported fossil fuels, adds to region economic and environmental vitality and contributes to national security through improved energy independence.

  5. Developmental mechanisms regulating secondary growth in woody plants.

    PubMed

    Groover, Andrew; Robischon, Marcel

    2006-02-01

    Secondary growth results in the radial expansion of woody stems, and requires the coordination of tissue patterning, cell differentiation, and the maintenance of meristematic stem cells within the vascular cambium. Advances are being made towards describing molecular mechanisms that regulate these developmental processes, thanks in part to the application of new genetic technologies to forest trees, and the extension of knowledge about evolutionarily conserved mechanisms from model annuals. New studies demonstrate a central role for developmental mechanisms that involve transcriptional regulators, phytohormones and the cell wall in regulating secondary growth.

  6. Age-related changes in photosynthesis of woody plants.

    PubMed

    Bond, B J

    2000-08-01

    Woody peoffnials do not appear to go through a defined senescence phase but do have predictable developmental stages. Reduced photosynthesis and stomatal conductance have been reported at all developmental transitions, although some studies have shown the opposite. What causes these changes and why do results differ among studies? Do these changes result from or cause changes in growth? What are the roles of genetics, size, changing conditions and cumulative environmental stress in aging trees? Definitive answers remain elusive but recent research is helping to clarify some of the processes associated with aging and to point the way for further study.

  7. Woody Plant Encroachment into Grasslands: Spatial Patterns of Functional Group Distribution and Community Development

    PubMed Central

    Liu, Feng; Archer, Steven R.; Gelwick, Frances; Bai, Edith; Boutton, Thomas W.; Wu, Xinyuan Ben

    2013-01-01

    Woody plant encroachment into grasslands has been globally widespread. The woody species invading grasslands represent a variety of contrasting plant functional groups and growth forms. Are some woody plant functional types (PFTs) better suited to invade grasslands than others? To what extent do local patterns of distribution and abundance of woody PFTs invading grasslands reflect intrinsic topoedaphic properties versus plant-induced changes in soil properties? We addressed these questions in the Southern Great Plains, United States at a subtropical grassland known to have been encroached upon by woody species over the past 50-100 years. A total of 20 woody species (9 tree-statured; 11 shrub-statured) were encountered along a transect extending from an upland into a playa basin. About half of the encroaching woody plants were potential N2-fixers (55% of species), but they contributed only 7% to 16 % of the total basal area. Most species and the PFTs they represent were ubiquitously distributed along the topoedaphic gradient, but with varying abundances. Overstory-understory comparisons suggest that while future species composition of these woody communities is likely to change, PFT composition is not. Canonical correspondence analysis (CCA) ordination and variance partitioning (Partial CCA) indicated that woody species and PFT composition in developing woody communities was primarily influenced by intrinsic landscape location variables (e.g., soil texture) and secondarily by plant-induced changes in soil organic carbon and total nitrogen content. The ubiquitous distribution of species and PFTs suggests that woody plants are generally well-suited to a broad range of grassland topoedaphic settings. However, here we only examined categorical and non-quantitative functional traits. Although intrinsic soil properties exerted more control over the floristics of grassland-to-woodland succession did plant modifications of soil carbon and nitrogen concentrations, the latter

  8. Woody plant encroachment into grasslands: spatial patterns of functional group distribution and community development.

    PubMed

    Liu, Feng; Archer, Steven R; Gelwick, Frances; Bai, Edith; Boutton, Thomas W; Wu, Xinyuan Ben

    2013-01-01

    Woody plant encroachment into grasslands has been globally widespread. The woody species invading grasslands represent a variety of contrasting plant functional groups and growth forms. Are some woody plant functional types (PFTs) better suited to invade grasslands than others? To what extent do local patterns of distribution and abundance of woody PFTs invading grasslands reflect intrinsic topoedaphic properties versus plant-induced changes in soil properties? We addressed these questions in the Southern Great Plains, United States at a subtropical grassland known to have been encroached upon by woody species over the past 50-100 years. A total of 20 woody species (9 tree-statured; 11 shrub-statured) were encountered along a transect extending from an upland into a playa basin. About half of the encroaching woody plants were potential N2-fixers (55% of species), but they contributed only 7% to 16 % of the total basal area. Most species and the PFTs they represent were ubiquitously distributed along the topoedaphic gradient, but with varying abundances. Overstory-understory comparisons suggest that while future species composition of these woody communities is likely to change, PFT composition is not. Canonical correspondence analysis (CCA) ordination and variance partitioning (Partial CCA) indicated that woody species and PFT composition in developing woody communities was primarily influenced by intrinsic landscape location variables (e.g., soil texture) and secondarily by plant-induced changes in soil organic carbon and total nitrogen content. The ubiquitous distribution of species and PFTs suggests that woody plants are generally well-suited to a broad range of grassland topoedaphic settings. However, here we only examined categorical and non-quantitative functional traits. Although intrinsic soil properties exerted more control over the floristics of grassland-to-woodland succession did plant modifications of soil carbon and nitrogen concentrations, the latter

  9. Multistage point relascope and randomized branch sampling for downed coarse woody debris estimation

    Treesearch

    Jeffrey H. Gove; Mark J. Ducey; Harry T. Valentine

    2002-01-01

    New sampling methods have recently been introduced that allow estimation of downed coarse woody debris using an angle gauge, or relascope. The theory behind these methods is based on sampling straight pieces of downed coarse woody debris. When pieces deviate from this ideal situation, auxillary methods must be employed. We describe a two-stage procedure where the...

  10. Large woody debris in a second-growth central Appalachian hardwood stand: volume, composition, and dynamics

    Treesearch

    M. B. Adams; T. M. Schuler; W. M. Ford; J. N. Kochenderfer

    2003-01-01

    We estimated the volume of large woody debris in a second-growth stand and evaluated the importance of periodic windstorms as disturbances in creating large woody debris. This research was conducted on a reference watershed (Watershed 4) on the Fernow Experimental Forest in West Virginia. The 38-ha stand on Watershed 4 was clearcut around 1911 and has been undisturbed...

  11. Processing woody debris biomass for co-milling with pulverized coal

    Treesearch

    Dana Mitchell; Bob Rummer

    2007-01-01

    The USDA, Forest Service, Forest Products Lab funds several grants each year for the purpose of studying woody biomass utilization. One selected project proposed removing small diameter stems and unmerchantable woody material from National Forest lands and delivering it to a coal-fired power plant in Alabama for energy conversion. The Alabama Power Company...

  12. The Importance of Woody Twig Ends to Deer in the Southeast

    Treesearch

    Charles T. Cushwa; Robert L. Downing; Richard F. Harlow; David F. Urbston

    1970-01-01

    One of the basic assumptions underlying research on wildlife habitat in the five Atlantic states of the Southeast is that white-tailed deer (Odocoileus virginianus) rely heavily on the ends of woody twigs during the winter. Considerable research has been undertaken to determine methods for increasing and measuring the availability of woody twigs to...

  13. Human population growth offsets climate-driven increase in woody vegetation in sub-Saharan Africa.

    PubMed

    Brandt, Martin; Rasmussen, Kjeld; Peñuelas, Josep; Tian, Feng; Schurgers, Guy; Verger, Aleixandre; Mertz, Ole; Palmer, John R B; Fensholt, Rasmus

    2017-03-06

    The rapidly growing human population in sub-Saharan Africa generates increasing demand for agricultural land and forest products, which presumably leads to deforestation. Conversely, a greening of African drylands has been reported, but this has been difficult to associate with changes in woody vegetation. There is thus an incomplete understanding of how woody vegetation responds to socio-economic and environmental change. Here we used a passive microwave Earth observation data set to document two different trends in land area with woody cover for 1992-2011: 36% of the land area (6,870,000 km(2)) had an increase in woody cover largely in drylands, and 11% had a decrease (2,150,000 km(2)), mostly in humid zones. Increases in woody cover were associated with low population growth, and were driven by increases in CO2 in the humid zones and by increases in precipitation in drylands, whereas decreases in woody cover were associated with high population growth. The spatially distinct pattern of these opposing trends reflects, first, the natural response of vegetation to precipitation and atmospheric CO2, and second, deforestation in humid areas, minor in size but important for ecosystem services, such as biodiversity and carbon stocks. This nuanced picture of changes in woody cover challenges widely held views of a general and ongoing reduction of the woody vegetation in Africa.

  14. Evaluation of techniques for determining the density of fine woody debris

    Treesearch

    Becky Fasth; Mark E. Harmon; Christopher W. Woodall; Jay. Sexton

    2010-01-01

    Evaluated various techniques for determining the density (i.e., bulk density) of fine woody debris during forest inventory activities. It was found that only experts in dead wood inventory may be able to identify fine woody debris stages of decay. Suggests various future research directions such as...

  15. Wild ungulate herbivory suppresses deciduous woody plant establishment following salmonid stream restoration

    Treesearch

    Joshua P. Averett; Bryan A. Endress; Mary M. Rowland; Bridgett J. Naylor; Michael J. Wisdom

    2017-01-01

    Domestic and wild ungulates can exert strong influences on riparian woody vegetation establishment, yet little is known about how wild ungulate herbivory affects riparian restoration in the absence of cattle. We evaluated elk (Cervus elaphus) and mule deer (Odocoileus hemionus) impacts on the establishment of deciduous woody...

  16. Response of Foliage of Young Loblolly Pine to Woody and Herbaceous Plant Control

    Treesearch

    Bruce R. Zutter; James H. Miller; H. Lee Allen; Shepard M. Zedake; M. Boyd Edwards; Ray A. Newbold

    1998-01-01

    Woody and herbaceous weeds have been shown to have a significant negative impact on survival and/or growth of planted loblolly pine (Pinus fueae L.) in the southeastern United States (Nelson et al. 1981, Zutter et al. 1986. Bacon and Zedaker 1987, Miller et al. 1987, 1991). Most research studies have focttsed on the effects of controlling only herbaceous, only woody,...

  17. 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...

  18. Physical pretreatment – woody biomass size reduction – for forest biorefinery

    Treesearch

    J.Y. Zhu

    2011-01-01

    Physical pretreatment of woody biomass or wood size reduction is a prerequisite step for further chemical or biochemical processing in forest biorefinery. However, wood size reduction is very energy intensive which differentiates woody biomass from herbaceous biomass for biorefinery. This chapter discusses several critical issues related to wood size reduction: (1)...

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

    Treesearch

    Carl C. Trettin; Devendra Amatya; Mark Coleman

    2008-01-01

    Water resources are important for the production of woody biofuel feedstocks. It is necessary to ensure that production systems do not adversely affect the quantity or quality of surface and ground water. The effects of woody biomass plantations on water resources are largely dependent on the prior land use and the management regime. Experience from both irrigated and...

  20. Linking Soils and Down Woody Material Inventories for Cohesive Assessments of Ecosystem Carbon Pools

    Treesearch

    Katherine P. O' Neill; Christopher Woodall; Michael Amacher; Geoffrey Holden

    2005-01-01

    The Soils and Down Woody Materials (DWM) indicators collected by the Forest Inventory and Analysis program provide the only data available for nationally consistent monitoring of carbon storage in soils, the forest floor, and down woody debris. However, these indicators were developed and implemented separately, resulting in field methods and compilation procedures...

  1. Characterization of fast pyrolysis products generated from several western USA woody species

    Treesearch

    Jacqueline M. Jarvis; Deborah S. Page-Dumroese; Nathaniel M. Anderson; Yuri Corilo; Ryan P. Rodgers

    2014-01-01

    Woody biomass has the potential to be utilized at an alternative fuel source through its pyrolytic conversion. Here, fast pyrolysis bio-oils derived from several western USA woody species are characterized by negative-ion electrospray ionization Fourier transform ion cyclotron resonance mass spectrometry (ESI FT-ICR MS) to determine molecular-level composition. The...

  2. Effect of woody debris abundance on daytime refuge use by cotton mice

    Treesearch

    Travis M. Hinkelman; Susan C. Loeb

    2007-01-01

    Daytime refuges are important to nocturnal rodents for protection from predators and environmental extremes. Because refuges of forest-dwelling rodents are often associated with woody debris, we examined refuge use by 37 radio-collared Peromyscus gossypinus (cotton mice) in experimental plots with different levels of woody debris. Treatment plots had...

  3. Interactions of woody biofuel feedstock production systems with water resources: considerations for sustainability

    Treesearch

    Carl C. Trettin; Devendra Amatya; Mark Coleman

    2008-01-01

    Water resources are important for the production of woody biofuel feedstocks. It is necessary to ensure that production systems do not adversely affect the quantity or quality of surface and ground water. The effects of woody biomass plantations on water resources are largely dependent on the prior land use and the management regime. Experience from both irrigated and...

  4. Use of Woody Debris by Cotton Mice (Peromyscus Gossypinus) in a Southeastern Pine Forest

    Treesearch

    Timothy S. McCay

    2000-01-01

    Coarse woody debris, which includes fallen logs, snags, and stumps, may be an important habitat component for many mammals. I examined use of woody debris by the cotton mouse (Peromyscus gossypinus) with radiotelemetry and fluorescent-powder tracking in a managed loblolly pine (Pinus taeda) forest. Most day refuges of cotton mice...

  5. The combustion of sound and rotten coarse woody debris: a review

    Treesearch

    Joshua C. Hyde; Alistair M.S. Smith; Roger D. Ottmar; Ernesto C. Alvarado; Penelope. Morgan

    2011-01-01

    Coarse woody debris serves many functions in forest ecosystem processes and has important implications for fire management as it affects air quality, soil heating and carbon budgets when it combusts. There is relatively little research evaluating the physical properties relating to the combustion of this coarse woody debris with even less specifically addressing...

  6. Influence of fire on dead woody material in forests of California and southwestern Oregon

    Treesearch

    Carl N. Skinner

    2002-01-01

    The frequent occurrence of fire in most forested areas of California and southwestern Oregon before this century has been well established. Likewise, the importance of dead woody material to various wildlife species as snags and downed logs has been well documented. It is unlikely that much large woody material survived fire long enough to decompose fully in fire...

  7. Late-Rotation Nitrogen Management in Deciduous Short Rotation Woody Crops

    USDA-ARS?s Scientific Manuscript database

    Idle agricultural land has the potential for producing woody crops as an energy or chemical feedstock. Short rotation woody crops (SRWCs) may improve soil health, water quality, and sequester soil carbon in these intensively farmed fields. Frequently, nitrogen is the limiting nutrient in these sys...

  8. Predicting duff and woody fuel consumed by prescribed fire in the Northern Rocky Mountains

    Treesearch

    James K. Brown; Michael A. Marsden; Kevin C. Ryan; Elizabeth D. Reinhardt

    1985-01-01

    Relationships for predicting duff reduction, mineral soil exposure, and consumption of downed woody fuel were determined to assist in planning prescribed fires. Independent variables included lower and entire duff moisture contents, loadings of downed woody fuels, duff depth, National Fire-Danger Rating System 1,000-hour moisture content, and Canadian Duff Moisture...

  9. Spatiotemporal soil and saprolite moisture dynamics across a semi-arid woody plant gradient

    USDA-ARS?s Scientific Manuscript database

    Woody plant cover has increased 10-fold over the last 140+ years in many parts of the semi-arid western USA. Woody plant cover can alter the timing and amount of plant available moisture in the soil and saprolite. To assess spatiotemporal subsurface moisture dynamics over two water years in a snow-d...

  10. Characterization of coarse woody debris across a 100 year chronosequence of upland oak-hickory forest

    Treesearch

    Travis W. Idol; Phillip E. Pope; Rebecca A. Figler; Felix Ponder Jr.

    1999-01-01

    Coarse woody debris is an important component influencing forest nutrient cycling and contributes to long-term soil productivity. The common practice of classifying coarse woody debris into different decomposition classes has seldom been related to the chemistry/biochemistry of the litter, which is the long term objective of our research. The objective of this...

  11. Modeling respiration from snags and coarse woody debris before and after an invasive gypsy moth disturbance

    Treesearch

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

    2014-01-01

    Although snags and coarse woody debris are a small component of ecosystem respiration, disturbances can significantly increase the mass and respiration from these carbon (C) pools. The objectives of this study were to (1) measure respiration rates of snags and coarse woody debris throughout the year in a forest previously defoliated by gypsy moths, (2) develop models...

  12. Fungal endophytes in woody roots of Douglas-fir (Pseudotsuga menziesii) and ponderosa pine (Pinus ponderosa)

    Treesearch

    J. A. Hoff; Ned B. Klopfenstein; Geral I. McDonald; Jonalea R. Tonn; Mee-Sook Kim; Paul J. Zambino; Paul F. Hessburg; J. D. Rodgers; T. L. Peever; L. M. Carris

    2004-01-01

    The fungal community inhabiting large woody roots of healthy conifers has not been well documented. To provide more information about such communities, a survey was conducted using increment cores from the woody roots of symptomless Douglas-fir (Pseudotsuga menziesii) and ponderosa pine (Pinus ponderosa) growing in dry forests...

  13. Effects of herbaceous and woody plant control on longleaf pine growth and understory plant cover

    Treesearch

    James D. Haywood

    2013-01-01

    To determine if either herbaceous or woody plants are more competitive with longleaf pine (Pinus palustris Mill.) trees, four vegetation management treatments— check, herbaceous plant control (HPC), woody plant control (WPC), and HPC+WPC—were applied in newly established longleaf pine plantings in a randomized complete block design in two studies....

  14. Woody encroachment in northern Great Plains grasslands: Perceptions, actions, and needs

    USGS Publications Warehouse

    Symstad, Amy; Leis, Sherry A.

    2017-01-01

    The United States Northern Great Plains (NGP) has a high potential for landscape-scale conservation, but this grassland landscape is threatened by encroachment of woody species. We surveyed NGP land managers to identify patterns in, and illustrate a broad range of, individual managers' perceptions on (1) the threat of woody encroachment to grasslands they manage, and (2) what management practices they use that may influence woody encroachment in this region. In the 34 surveys returned, which came from predominantly public lands in the study area, 79% of responses reported moderate or substantial woody encroachment. Eastern redcedar (Juniperus virginiana) and Rocky Mountain juniper (Juniperus scopulorum) were the most problematic encroachers. Thirty-one survey respondents said that prescribed fire was used on the lands they manage, and 64% of these responses reported that controlling woody encroachment was a fire management objective. However, only 18% of survey respondents using prescribed fire were achieving their desired fire return interval. Most respondents reported using mechanical and/or chemical methods to control woody species. In contrast to evidence from the central and southern Great Plains, few survey respondents viewed grazing as affecting encroachment. Although the NGP public land managers we surveyed clearly recognize woody encroachment as a problem and are taking steps to address it, many feel that the rate of their management is not keeping pace with the rate of encroachment. Developing strategies for effective woody plant control in a variety of NGP management contexts requires filling ecological science gaps and overcoming societal barriers to using prescribed fire.

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

    Treesearch

    Steven M Lohr; Sidney A. Gauthreaux; John C. Kilgo

    2002-01-01

    To investigate the importance of standing (snags) aud down course woody debris (DCWD)) to bird communities in loblolly pine (Pinus taeda) forests, we compared breeding (1997-1999) und nonbreeding (1997- 1998, 1998-1999) responses of birds among two course woody debris (CWD) removal and control treatments. In each of four blocks, we estahblished four...

  16. Influence of Bank Afforestation and Snag Angle-of-fall on Riparian Large Woody Debris Recruitment

    Treesearch

    Don C. Bragg; Jeffrey L. Kershner

    2002-01-01

    A riparian large woody debris (LWD) recruitment simulator (Coarse Woody Debris [CWD]) was used to test the impact of bank afforestation and snag fall direction on delivery trends. Combining all cumulative LWD recruitment across bank afforestation levels averaged 77.1 cubic meters per 100 meter reach (both banks forested) compared to 49.3 cubic meters per 100 meter...

  17. Expected international demand for woody and herbaceous feedstock

    SciTech Connect

    Lamers, Patrick; Jacobson, Jacob; Mohammad, Roni; Wright, Christopher

    2015-03-01

    The development of a U.S. bioenergy market and ultimately ‘bioeconomy’ has primarily been investigated with a national focus. Limited attention has been given to the potential impacts of international market developments. The goal of this project is to advance the current State of Technology of a single biorefinery to the global level providing quantitative estimates on how international markets may influence the domestic feedstock supply costs. The scope of the project is limited to feedstock that is currently available and new crops being developed to be used in a future U.S. bioeconomy including herbaceous residues (e.g., corn stover), woody biomass (e.g., pulpwood), and energy crops (e.g., switchgrass). The timeframe is set to the periods of 2022, 2030, and 2040 to align with current policy targets (e.g., the RFS2) and future updates of the Billion Ton data. This particular milestone delivers demand volumes for generic woody and herbaceous feedstocks for the main (net) importing regions along the above timeframes. The regional focus of the study is the European Union (EU), currently the largest demand region for U.S. pellets made from pulpwood and forest residues. The pellets are predominantly used in large-scale power plants (>5MWel) in the United Kingdom (UK), the Netherlands (NL), Belgium (BE), and Denmark (DK).

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

    NASA Astrophysics Data System (ADS)

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

    2015-04-01

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

  19. Flowering of Woody Bamboo in Tissue Culture Systems.

    PubMed

    Yuan, Jin-Ling; Yue, Jin-Jun; Gu, Xiao-Ping; Lin, Choun-Sea

    2017-01-01

    Flowering and subsequent seed set are not only normal activities in the life of most plants, but constitute the very reason for their existence. Woody bamboos can take a long time to flower, even over 100 years. This makes it difficult to breed bamboo, since flowering time cannot be predicted and passing through each generation takes too long. Another unique characteristic of woody bamboo is that a bamboo stand will often flower synchronously, both disrupting the supply chain within the bamboo industry and affecting local ecology. Therefore, an understanding of the mechanism that initiates bamboo flowering is important not only for biology research, but also for the bamboo industry. Induction of flowering in vitro is an effective way to both shorten the flowering period and control the flowering time, and has been shown for several species of bamboo. The use of controlled tissue culture systems allows investigation into the mechanism of bamboo flowering and facilitates selective breeding. Here, after a brief introduction of flowering in bamboo, we review the research on in vitro flowering of bamboo, including our current understanding of the effects of plant growth regulators and medium components on flower induction and how in vitro bamboo flowers can be used in research.

  20. Origin and evolution of fleshy fruit in woody bamboos.

    PubMed

    Ruiz-Sanchez, Eduardo; Sosa, Victoria

    2015-10-01

    Several hypotheses have been suggested to explain the origin of fleshy fruit in monocots. One is that they originated in the understory of tropical regions and another is that fleshy fruit originated in tropical rainforests where high year-round rainfall implies that seasonality is not a limiting factor. Here we identify the time of origin and ecological preferences of woody bamboos to understand the evolution of the fleshy fruit known as the bacoid caryopsis. Bayesian Inference, Maximum Likelihood and molecular dating analyses were run based on eight plastid and two nuclear regions for 68 bamboo species. Climate data and soil parameters were gathered for 464 localities for these species. The ancestral type of caryopsis was reconstructed by parsimony. According to these analyses the bacoid caryopsis may have evolved independently seven times from the Late Miocene to the Early Pliocene and Mid-Pliocene to Mid-Pleistocene via convergent evolution. Our results suggest that in bamboos neither current climatic variables nor soil parameters were significantly correlated with the appearance of this type of fruit, nor do they have a phylogenetic signal. It is remarkable, however, that the first appearance of the bacoid caryopsis in bamboos might be associated with historical preferences for warmer and wetter climate during the Miocene. Further research is needed to identify whether other factors, such as vivipary or dispersal by small animals, rather than climate, could be responsible for the evolution of this trait in woody bamboos.

  1. Experimental investigation of pyrolysis process of woody biomass mixture

    NASA Astrophysics Data System (ADS)

    Kosanić, Tijana R.; Ćeranić, Mirjana B.; Đurić, Slavko N.; Grković, Vojin R.; Milotić, Milan M.; Brankov, Saša D.

    2014-06-01

    This paper describes an experimental investigation of pyrolysis of woody biomass mixture. The mixture consists of oak, beech, fir, cherry, walnut and linden wood chips with equal mass fractions. During the experiment, the sample mass inside the reactor was 10 g with a particle diameter of 5-10 mm. The sample in the reactor was heated in the temperature range of 24-650°C. Average sample heating rates in the reactor were 21, 30 and 54 °C/min. The sample mass before, during and after pyrolysis was determined using a digital scale. Experimental results of the sample mass change indicate that the highest yield of pyrolytic gas was achieved at the temperature slightly above 650°C and ranged from 77 to 85%, while char yield ranged from 15 to 23%. Heating rate has significant influence on the pyrolytic gas and char yields. It was determined that higher pyrolysis temperatures and heating rates induce higher yields of pyrolytic gas, while the char mass reduces. Condensation of pyrolytic gas at the end of the pyrolysis process at 650°C produced 2.4-2.72 g of liquid phase. The results obtained represent a starting basis for determining material and heat balance of pyrolysis process as well as woody biomass pyrolysis equipment.

  2. Groundwater uptake by woody vegetation in a semiarid oak savanna

    NASA Astrophysics Data System (ADS)

    Miller, Gretchen R.; Chen, Xingyuan; Rubin, Yoram; Ma, Siyan; Baldocchi, Dennis D.

    2010-10-01

    Groundwater can serve as an important resource for woody vegetation in semiarid landscapes, particularly when soil water is functionally depleted and unavailable to plants. This study examines the uptake of groundwater by deciduous blue oak trees (Quercus douglasii) in a California oak savanna. Here we present a suite of direct and indirect methods that demonstrate its occurrence and quantify its rates. The study site is underlain by a thin soil layer and fractured metavolcanic bedrock. Typical depth to groundwater is approximately 8 m. A variety of water storage and flux measurements were collected from 2005 to 2008, including groundwater levels, soil moisture contents, sap flows, and latent heat fluxes. During the dry season, groundwater uptake rates ranged from 4 to 25 mm month-1 and approximately 80% of total ET during June, July, and August came from groundwater. Leaf and soil water potentials supported these results, indicating that groundwater uptake was thermodynamically favorable over soil water uptake for key portions of the growing season. These findings strongly suggest that blue oaks should be considered obligate phreatophytes and that groundwater reserves provide a buffer to rapid changes in their hydroclimate, if these assets are not otherwise depleted by prolonged drought or human consumption. While groundwater uptake may provide for short-term protection, it should be viewed not as a mechanism for continued plant growth. It allows the woody vegetation to subsist during the summer but not to flourish.

  3. Non-Linear Dynamics Approach to Assessing Woody-Encroachment in Grasslands

    NASA Astrophysics Data System (ADS)

    Brunsell, N. A.; Nippert, J. B.; Van Vleck, E.

    2015-12-01

    Woody species are encroaching on grasslands globally. Here, we investigate the spatial and temporal dynamics of this encroachment in relation to climate and fire regimes in the central U.S. A low-dimensional model is used to assess stability of species composition. Sixe years of eddy covariance data at a paired grassland and woody encroachment site at the Konza Prairie LTER site are used to verify carbon and water dynamics. Historical aerial photography and remote sensing data are used to quantify the spatial diffusion of woody tree fraction into grasslands. Non-linear dynamics approaches are used to quantify the stability of vegetation and the presence of tipping points in relation to woody fraction, fire frequency and precipitation and temperature variability. Understanding the roles of multiple confounding forcing factors operating at disparate timescales is essential for predicting future woody encroachment and the water and climate implications of land cover transitions.

  4. Climatic regions as an indicator of forest coarse and fine woody debris carbon stocks in the United States

    Treesearch

    Christopher W. Woodall; Greg C. Liknes

    2008-01-01

    Coarse and fine woody debris are substantial forest ecosystem carbon stocks; however, there is a lack of understanding how these detrital carbon stocks vary across forested landscapes. Because forest woody detritus production and decay rates may partially depend on climatic conditions, the accumulation of coarse and fine woody debris carbon stocks in forests may be...

  5. Regional assessment of woody biomass physical availability as an energy feedstock for combined combustion in the US northern region

    Treesearch

    Michael E. Goerndt; Francisco X. Aguilar; Patrick Miles; Stephen Shifley; Nianfu Song; Hank Stelzer

    2012-01-01

    Woody biomass is a renewable energy feedstock with the potential to reduce current use of nonrenewable fossil fuels. We estimated the physical availability of woody biomass for cocombustion at coal-fired electricity plants in the 20-state US northern region. First, we estimated the total amount of woody biomass needed to replace total annual coal-based electricity...

  6. Nutrient concentrations in coarse and fine woody debris of Populus tremuloides Michx.-dominated forests, northern Minnesota, USA

    USGS Publications Warehouse

    Klockow, Paul A.; D'Amato, Anthony W.; Bradford, John B.; Fraver, Shawn

    2014-01-01

    Contemporary forest harvesting practices, specifically harvesting woody biomass as a source of bioenergy feedstock, may remove more woody debris from a site than conventional harvesting. Woody debris, particularly smaller diameter woody debris, plays a key role in maintaining ecosystem nutrient stores following disturbance. Understanding nutrient concentrations within woody debris is necessary for assessing the long-term nutrient balance consequences of altered woody debris retention, particularly in forests slated for use as bioenergy feedstocks. Nutrient concentrations in downed woody debris of various sizes, decay classes, and species were characterized within one such forest type, Populus tremuloides Michx.-dominated forests of northern Minnesota, USA. Nutrient concentrations differed significantly between size and decay classes and generally increased as decay progressed. Fine woody debris (≤ 7.5 cm diameter) had higher nutrient concentrations than coarse woody debris (> 7.5 cm diameter) for all nutrients examined except Na and Mn, and nutrient concentrations varied among species. Concentrations of N, Mn, Al, Fe, and Zn in coarse woody debris increased between one and three orders of magnitude, while K decreased by an order of magnitude with progressing decay. The variations in nutrient concentrations observed here underscore the complexity of woody debris nutrient stores in forested ecosystems and suggest that retaining fine woody debris at harvest may provide a potentially important source of nutrients following intensive removals of bioenergy feedstocks.

  7. Mapping Woody Plant Encroachment in Grassland Using Multiple Source Remote Sensing images: Case Study in Oklahoma

    NASA Astrophysics Data System (ADS)

    Wang, J.; Xiao, X.; Qin, Y.; Dong, J.; Zhang, G.; Zhang, Y.; Zou, Z.; Zhou, Y.; Wu, X.; Bajgain, R.

    2015-12-01

    Woody plant encroachment (mainly Juniperus virginiana, a coniferous evergreen tree) in the native grassland has been rapidly increasing in the U.S. Southern Great Plains, largely triggered by overgrazing domestic livestock, fire suppression, and changing rainfall regimes. Increasing dense woody plants have significant implications for local grassland ecosystem dynamics, such as carbon storage, soil nutrient availability, herbaceous forage production, livestock, watershed hydrology and wildlife habitats. However, very limited data are available about the spatio-temporal dynamics of woody plant encroachment to the native grassland at regional scale. Data from remotes sensing could potentially provide relevant information and improve the conversion of native grassland to woody plant encroachment. Previous studies on woody detection in grassland mainly conducted at rangeland scale using airborne or high resolution images, which is sufficient to monitor the dynamics of woody plant encroachment in local grassland. This study examined the potential of medium resolution images to detect the woody encroachment in tallgrass prairie. We selected Cleveland county, Oklahoma, US. as case study area, where eastern area has higher woody coverage than does the western area. A 25-m Phased Array Type L-band Synthetic Aperture Radar (PALSAR, N36W98) image was used to map the trees distributed in the grassland. Then, maximum enhanced vegetation index (EVI) and normalized difference vegetation index (NDVI) in the winter calculated from time-series Landsat images was used to identify the invaded woody species (Juniperus virginiana) through phenology-based algorithm. The resulting woody plant encroachment map was compared with the results extracted from the high resolution images provided by the National Agriculture Imagery Program (NAIP). Field photos were also used to validate the accuracy. These results showed that integrating PALSAR and Landsat had good performance to identify the

  8. Non-structural carbohydrates in woody plants compared among laboratories.

    PubMed

    Quentin, Audrey G; Pinkard, Elizabeth A; Ryan, Michael G; Tissue, David T; Baggett, L Scott; Adams, Henry D; Maillard, Pascale; Marchand, Jacqueline; Landhäusser, Simon M; Lacointe, André; Gibon, Yves; Anderegg, William R L; Asao, Shinichi; Atkin, Owen K; Bonhomme, Marc; Claye, Caroline; Chow, Pak S; Clément-Vidal, Anne; Davies, Noel W; Dickman, L Turin; Dumbur, Rita; Ellsworth, David S; Falk, Kristen; Galiano, Lucía; Grünzweig, José M; Hartmann, Henrik; Hoch, Günter; Hood, Sharon; Jones, Joanna E; Koike, Takayoshi; Kuhlmann, Iris; Lloret, Francisco; Maestro, Melchor; Mansfield, Shawn D; Martínez-Vilalta, Jordi; Maucourt, Mickael; McDowell, Nathan G; Moing, Annick; Muller, Bertrand; Nebauer, Sergio G; Niinemets, Ülo; Palacio, Sara; Piper, Frida; Raveh, Eran; Richter, Andreas; Rolland, Gaëlle; Rosas, Teresa; Saint Joanis, Brigitte; Sala, Anna; Smith, Renee A; Sterck, Frank; Stinziano, Joseph R; Tobias, Mari; Unda, Faride; Watanabe, Makoto; Way, Danielle A; Weerasinghe, Lasantha K; Wild, Birgit; Wiley, Erin; Woodruff, David R

    2015-11-01

    Non-structural carbohydrates (NSC) in plant tissue are frequently quantified to make inferences about plant responses to environmental conditions. Laboratories publishing estimates of NSC of woody plants use many different methods to evaluate NSC. We asked whether NSC estimates in the recent literature could be quantitatively compared among studies. We also asked whether any differences among laboratories were related to the extraction and quantification methods used to determine starch and sugar concentrations. These questions were addressed by sending sub-samples collected from five woody plant tissues, which varied in NSC content and chemical composition, to 29 laboratories. Each laboratory analyzed the samples with their laboratory-specific protocols, based on recent publications, to determine concentrations of soluble sugars, starch and their sum, total NSC. Laboratory estimates differed substantially for all samples. For example, estimates for Eucalyptus globulus leaves (EGL) varied from 23 to 116 (mean = 56) mg g(-1) for soluble sugars, 6-533 (mean = 94) mg g(-1) for starch and 53-649 (mean = 153) mg g(-1) for total NSC. Mixed model analysis of variance showed that much of the variability among laboratories was unrelated to the categories we used for extraction and quantification methods (method category R(2) = 0.05-0.12 for soluble sugars, 0.10-0.33 for starch and 0.01-0.09 for total NSC). For EGL, the difference between the highest and lowest least squares means for categories in the mixed model analysis was 33 mg g(-1) for total NSC, compared with the range of laboratory estimates of 596 mg g(-1). Laboratories were reasonably consistent in their ranks of estimates among tissues for starch (r = 0.41-0.91), but less so for total NSC (r = 0.45-0.84) and soluble sugars (r = 0.11-0.83). Our results show that NSC estimates for woody plant tissues cannot be compared among laboratories. The relative changes in NSC between treatments measured within a laboratory

  9. Woody biomass size reduction with selective material orientation

    DOE PAGES

    Dooley, James H.; Lanning, David N.; Lanning, Christopher J.

    2013-01-01

    Roundwood logs from forests and energy plantations must be chipped, ground, or otherwise comminuted into small particles prior to conversion to solid or liquid biofuels. Rotary veneer followed by cross-grain shearing is demonstrated to be a novel and low energy consuming method for primary breakdown of logs into a raw material having high transport and storage density. Processing of high moisture raw logs into 2.5 – 4.2 mm particles prior to drying or conversion consumes less than 20% of the energy required for achieving similar particle size with hammer mills while producing a more uniform particle shape and size. Asmore » a result, energy savings from the proposed method may reduce the comminution cost of woody feedstocks by more than half.« less

  10. Woody biomass size reduction with selective material orientation

    SciTech Connect

    Dooley, James H.; Lanning, David N.; Lanning, Christopher J.

    2013-01-01

    Roundwood logs from forests and energy plantations must be chipped, ground, or otherwise comminuted into small particles prior to conversion to solid or liquid biofuels. Rotary veneer followed by cross-grain shearing is demonstrated to be a novel and low energy consuming method for primary breakdown of logs into a raw material having high transport and storage density. Processing of high moisture raw logs into 2.5 – 4.2 mm particles prior to drying or conversion consumes less than 20% of the energy required for achieving similar particle size with hammer mills while producing a more uniform particle shape and size. As a result, energy savings from the proposed method may reduce the comminution cost of woody feedstocks by more than half.

  11. Hydrothermal fractionation of woody biomass: Lignin effect on sugars recovery.

    PubMed

    Yedro, Florencia M; Cantero, Danilo A; Pascual, Marcos; García-Serna, Juan; Cocero, M José

    2015-09-01

    Subcritical water was employed to fractionate woody biomass into carbohydrates and lignin. Nine urban trees species (hardwood and softwood) from Spain were studied. The experiments were carried out in a semi-continuous reactor at 250 °C for 64 min. The hemicellulose and cellulose recovery yields were between 30%wt. and 80%wt. while the lignin content in the solid product ranged between 32%wt. and 92%wt. It was observed that an increment of solubilized lignin disfavored the hydrolysis of hemicelluloses. It was determined that the maximum extraction of hemicellulose was achieved at 20 min of solid reaction time while the extraction of celluloses not exhibited a maximum value. The hydrolysis of hemicellulose and cellulose would be governed by the hydrolysis kinetic and the polymers accessibility. In addition, the extraction of hemicellulose was negatively affected by the lignin content in the raw material while cellulose hydrolysis was not affected by this parameter. Copyright © 2015 Elsevier Ltd. All rights reserved.

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

    SciTech Connect

    Rosson, J.F.

    1993-09-01

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

  13. Relationship Between Woody Plant Colonization and Typha L. Encroachment in Stormwater Detention Basins

    NASA Astrophysics Data System (ADS)

    Plumb, Priscilla Bocskor; Day, Susan D.; Wynn-Thompson, Theresa M.; Seiler, John R.

    2013-10-01

    We studied stormwater detention basins where woody vegetation removal was suspended for 2 years in Virginia, USA to determine if woody vegetation can control Typha populations and how early woody plant succession interacts with Typha, other herbaceous vegetation, and site factors. Distribution and composition of woody vegetation, Typha and non- Typha herbaceous vegetation biomass, and site factors were assessed at 100 plots in four basins ranging in age from 7 to 17 years. A greenhouse study examined the interaction of shade and soil moisture on Typha biomass and persistence. Principal component analysis identified an environmental gradient associated with greater water table depths and decreased elevation that favored Typha but negatively influenced woody vegetation. Elevation was correlated with litter layer distribution, suggesting that initial topography influences subsequent environmental characteristics and thus plant communities. Soil organic matter at 0-10 cm ranged from 5.4 to 12.7 %. Woody plants present were native species with the exception of Ailanthus altissima and Pyrus calleryana. In the greenhouse, shade and reduced soil moisture decreased Typha biomass and rhizome length. The shade effect was strongest in flooded plants and the soil moisture effect was strongest for plants in full sun. Typha in dry soil and heavy shade had 95 % less total biomass and 83 % smaller rhizomes than Typha in flooded soil and full sun, but even moderate soil moisture reductions decreased above- and below-ground biomass by 63 and 56 %, respectively. Suspending maintenance allows restoration of woody vegetation dominated by native species and may suppress Typha invasion.

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

    SciTech Connect

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

    2011-10-01

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

  15. Phytoliths in woody plants from the Miombo woodlands of Mozambique

    PubMed Central

    Mercader, Julio; Bennett, Tim; Esselmont, Chris; Simpson, Steven; Walde, Dale

    2009-01-01

    Background and Aims There are no descriptions of phytoliths produced by plants from the ‘Zambezian’ zone, where Miombo woodlands are the dominant element of the largest single phytochorion in sub-Saharan Africa. The preservation of phytoliths in fossil records of Africa makes phytoliths a tool to study early plant communities. Paleo-ethnobotanical interpretation of phytoliths relies on the comparison of ancient types with morphotypes extracted from living reference collections. Methods Phytoliths were extracted from plant samples representing 41 families, 77 genera and 90 species through sonic cleaning, dry ashing and acid treatment; and phytoliths thus extracted were quantified. For each species, an average of 216 phytoliths were counted. The percentage of each morphotype identified per species was calculated, and types were described according to the descriptors from the International Code for Phytolith Nomenclature. Phytolith assemblages were subject to discriminant analysis, cluster analysis and principal component analysis. Key Results Phytoliths were grouped into 57 morphotypes (two were articulated forms and 55 were discrete shapes), and provide a reference collection of phytolith assemblages produced by Miombo woody species. Common and unique morphotypes are described and taxonomic and grouping variables are looked into from a statistical perspective. Conclusions The first quantitative taxonomy of phytoliths from Miombos is presented here, including new types and constituting the most extensive phytolith key for any African ecoregion. Evidence is presented that local woody species are hypervariable silica producers and their phytolith morphotypes are highly polymorphic. The taxonomic significance of these phytoliths is largely poor, but there are important exceptions that include the morphotypes produced by members from >10 families and orders. The typical phytolithic signal that would allow scientists to identify ancient woodlands of

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

    PubMed

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

    2016-08-01

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

  17. BAAD: a Biomass And Allometry Database for woody plants

    SciTech Connect

    Falster, Daniel; Duursma, Remko; Ishihara, Masae; Barneche, Diego; Fitzjohn, Richard; Varhammar, Angelica; Aiba, Masahiro; Ando, M.; Anten, Niels; Aspinwall, Michael J.; Baltzer, Jennifer; Baraloto, Christopher; Battaglia, Michael; Battles, John; Bond-Lamberty, Benjamin; van Breugel, Michiel; Camac, James; Claveau, Yves; Coll Mir, Llus; Dannoura, Dannoura; Delagrange, Sylvain; Domec, Jean-Cristophe; Fatemi, Farrah; Feng, Wang; Gargaglione, Veronica; Goto, Yoshiaki; Hagihara, Akio; Hall, Jefferson S.; Hamilton, Steve; Harja, Degi; Hiura, Tsutom; Holdaway, Robert; Hutley, L. B.; Ichie, Tomoaki; Jokela, Eric; Kantola, Anu; Kelly, Jeffery W.; Kenzo, Tanaka; King, David A.; Kloeppel, Brian; Kohyama, Takashi; Komiyama, Akira; Laclau, Jean-Paul; Lusk, Christopher; Maguire, Doug; le Maire, Guerric; Makela, Annikki; Markesteijn, Lars; Marshall, John; McCulloh, Kate; Miyata, Itsuo; Mokany, Karen; Mori, Shigeta; Myster, Randall; Nagano, Masahiro; Naidu, Shawna; Nouvellon, Yann; O'Grady, Anthony; O'Hara, Kevin; Ohtsuka, Toshiyuki; Osada, Noriyuki; Osunkoya, Olusegun O.; Luis Peri, Pablo; Petritan, Mary; Poorter, Lourens; Portsmuth, Angelika; Potvin, Catherine; Ransijn, Johannes; Reid, Douglas; Ribeiro, Sabina C.; Roberts, Scott; Rodriguez, Rolando; Saldana-Acosta, Angela; Santa-Regina, Ignacio; Sasa, Kaichiro; Gailia Selaya, Nadezhda; Sillett, Stephen; Sterck, Frank; Takagi, Kentaro; Tange, Takeshi; Tanouchi, Hiroyuki; Tissue, David; Umehara, Tohru; Utsugi, Hajime; Vadeboncoeur, Matthew; Valladares, Fernando; Vanninen, Petteri; Wang, Jian; Wenk, Elizabeth; Williams, Dick; Ximenes, Fabiano de Aquino; Yamaba, Atsushi; Yamada, Toshihiro; Yamakura, Takuo; Yanai, Ruth; York, Robert

    2015-05-07

    Quantifying the amount of mass or energy invested in plant tissues is of fundamental interest across a range of disciplines, including ecology, forestry, ecosystem science, and climate change science (Niklas, 1994; Chave et al. 2005; Falster et al. 2011). The allocation of net primary production into different plant components is an important process affecting the lifetime of carbon in ecosystems, and resource use and productivity by plants (Cannell & Dewar, 1994; Litton et al. 2007; Poorter et al. 2012). While many studies in have destructively harvested woody plants in the name of science, most of these data have only been made available in the form of summary tables or figures included in publications. Until now, the raw data has resided piecemeal on the hard drives of individual scientists spread around the world. Several studies have gathered together the fitted (allometric) equations for separate datasets (Ter-Mikaelian & Korzukhin, 1997; Jenkins et al. 2003; Zianis et al. 2005; Henry et al. 2013), but none have previously attempted to organize and share the raw individual plant data underpinning these equations on a large scale. Gathered together, such data would represent an important resource for the community, meeting a widely recognised need for rich, open data resources to solve ecological problems (Costello et al. 2013; Fady et al. 2014; Harfoot & Roberts, 2014; Costello et al. 2013). We (D.S. Falster and R.A. Duursma, with the help of D.R. Barneche, R.G. FitzJohn and A. Vårhammar) set out to create such a resource, by asking authors directly whether they would be willing to make their raw data files freely available. The response was overwhelming: nearly everyone we contacted was interested to contribute their raw data. Moreover, we were invited to incorporate another compilation led by M. Ishihara and focussing on Japanese literature. As a result, we present BAAD: a Biomass And Allometry Database for woody plants, comprising data collected in 174

  18. Phytoliths in woody plants from the Miombo woodlands of Mozambique.

    PubMed

    Mercader, Julio; Bennett, Tim; Esselmont, Chris; Simpson, Steven; Walde, Dale

    2009-07-01

    There are no descriptions of phytoliths produced by plants from the 'Zambezian' zone, where Miombo woodlands are the dominant element of the largest single phytochorion in sub-Saharan Africa. The preservation of phytoliths in fossil records of Africa makes phytoliths a tool to study early plant communities. Paleo-ethnobotanical interpretation of phytoliths relies on the comparison of ancient types with morphotypes extracted from living reference collections. Phytoliths were extracted from plant samples representing 41 families, 77 genera and 90 species through sonic cleaning, dry ashing and acid treatment; and phytoliths thus extracted were quantified. For each species, an average of 216 phytoliths were counted. The percentage of each morphotype identified per species was calculated, and types were described according to the descriptors from the International Code for Phytolith Nomenclature. Phytolith assemblages were subject to discriminant analysis, cluster analysis and principal component analysis. Phytoliths were grouped into 57 morphotypes (two were articulated forms and 55 were discrete shapes), and provide a reference collection of phytolith assemblages produced by Miombo woody species. Common and unique morphotypes are described and taxonomic and grouping variables are looked into from a statistical perspective. The first quantitative taxonomy of phytoliths from Miombos is presented here, including new types and constituting the most extensive phytolith key for any African ecoregion. Evidence is presented that local woody species are hypervariable silica producers and their phytolith morphotypes are highly polymorphic. The taxonomic significance of these phytoliths is largely poor, but there are important exceptions that include the morphotypes produced by members from >10 families and orders. The typical phytolithic signal that would allow scientists to identify ancient woodlands of 'Zambezian' affiliation comprises only half of the original number of

  19. Sensitivity of Mediterranean woody seedlings to copper, nickel and zinc.

    PubMed

    Fuentes, David; Disante, Karen B; Valdecantos, Alejandro; Cortina, Jordi; Vallejo, V Ramón

    2007-01-01

    The restoration of heavy metal contaminated areas requires information on the response of native plant species to these contaminants. The sensitivity of most Mediterranean woody species to heavy metals has not been established, and little is known about phytotoxic thresholds and environmental risks. We have evaluated the response of four plant species commonly used in ecological restoration, Pinus halepensis, Pistacia lentiscus, Juniperus oxycedrus, and Rhamnus alaternus, grown in nutrient solutions containing a range of copper, nickel and zinc concentrations. Seedlings of these species were exposed to 0.048, 1 and 4 microM of Cu; 0, 25 and 50 microM of Ni; and 0.073, 25 and 100 microM of Zn in a hydroponic silica sand culture for 12 weeks. For all four species, the heavy metal concentration increased in plants as the solution concentration increased and was always higher in roots than in shoots. Pinus halepensis and P. lentiscus showed a higher capacity to accumulate metals in roots than J. oxycedrus and R. alaternus, while the allocation to shoots was considerably higher in the latter two. Intermediate heavy-metal doses enhanced biomass accumulation, whereas the highest doses resulted in reductions in biomass. Decreases in shoot biomass occurred at internal concentrations ranging from 25 to 128 microg g-1 of Zn, and 1.7 to 4.1 microg g( -1) of Cu. Nickel phytoxicity could not be established within the range of doses used. Rhamnus alaternus and J. oxycedrus showed higher sensitivity to Cu and Zn than P. halepensis and, especially, P. lentiscus. Contrasted responses to heavy metals must be taken into account when using Mediterranean woody species for the restoration of heavy metal contaminated sites.

  20. Patterns of woody plant invasion in an Argentinean coastal grassland

    NASA Astrophysics Data System (ADS)

    Alberio, Constanza; Comparatore, Viviana

    2014-01-01

    Coastal dune grasslands are fragile ecosystems that have historically been subjected to various types of uses and human activities. In Buenos Aires Province (Argentina), these areas are frequently afforested for urban and touristic development. The introduction and subsequent spread of exotic tree species is one of the main threats to conservation of natural grasslands as invasive trees strongly transform their structure and composition. The aim of this study was to identify patterns of woody plant invasion comparing plant communities and environmental variables between invaded and non-invaded areas surrounding the coastal village of Mar Azul, Argentina. Coastal grasslands in this area are being invaded by Populus alba (white poplar) and Acacia longifolia (coast wattle). The height of the saplings and the richness of the accompanying vegetation were evaluated in relation to the distance from the edge of the mature tree patches. Also, the cover, richness and diversity of all species in the invaded and non-invaded areas were measured, as well as soil pH, temperature and particle size. Negative correlations were found between the height of the saplings and distance to mature tree patches in all areas. The richness of the accompanying vegetation was negatively and positively correlated with the distance from the poplar and acacia area, respectively. The most abundant native species was Cortaderia selloana. Less cover, richness and diversity of native plant species and greater soil particle size were found in invaded areas, where the proportion of bare soil was higher. Also, a higher proportion of leaf litter in the invaded areas was registered. The results emphasize the invasive capacity of P. alba and A. longifolia advancing on the native communities and reducing their richness. Knowledge of the impact of invasive woody plants in coastal grasslands is important to design active management strategies for conservation purposes.

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

    PubMed Central

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

    2014-01-01

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

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

    PubMed

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

    2014-01-01

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

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

    NASA Astrophysics Data System (ADS)

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

    2011-12-01

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

  4. The influence of large woody debris and a bankfull flood on movement of adult resident coastal cutthroat trout (Oncorhynchus clarki) during fall and winter

    Treesearch

    Bret C. Harvey; Rodney J. Nakamoto; Jason L. White

    1999-01-01

    Abstract - To improve understanding of the significance of large woody debris to stream fishes, we examined the influence of woody debris on fall and winter movement by adult coastal cutthroat trout (Oncorhynchus clarki) using radiotelemetry. Fish captured in stream pools containing large woody debris moved less than fish captured in pools lacking large woody debris or...

  5. Interplanting woody nurse crops promotes differential growth of black walnut saplings

    Treesearch

    J. O. Dawson; J. W. Van Sambeek

    1993-01-01

    Interplanting black walnut (Juglans nigra) with four different nitrogen fixing, woody nurse crops (Alnus glutinosa, Elaeagnus umbellata, E. angustifolia or Caragana arborescens) increased annual walnut height and stem diameter (dbh) growth overall by as much as 50% and...

  6. Trees, Shrubs, and Woody Vines of the Bluff Experimental Forest, Warren County, Mississippi

    Treesearch

    Robert L. Johnson; Elbert L. Little

    1967-01-01

    Nearly 100 species of trees, shrubs, and woody vines grow naturally on the 450-acre Bluff Experimental Forest in west-central Mississippi. This publication lists the plants and provides information on silvical characteristics of the tree species.

  7. Estimation of above ground biomass for multi-stemmed short-rotation woody crops

    Treesearch

    Brian A. Byrd; Wilson G. Hood; Michael C. Tyree; Dylan N. Dillaway

    2015-01-01

    With the increasing interest in short-rotation woody crop (SRWC) systems, an accurate yet quick, non-destructive means for determining aboveground biomass is necessary from both management and research perspectives.

  8. Woody cover and hominin environments in the past 6million years

    NASA Astrophysics Data System (ADS)

    Cerling, Thure E.; Wynn, Jonathan G.; Andanje, Samuel A.; Bird, Michael I.; Korir, David Kimutai; Levin, Naomi E.; Mace, William; Macharia, Anthony N.; Quade, Jay; Remien, Christopher H.

    2011-08-01

    The role of African savannahs in the evolution of early hominins has been debated for nearly a century. Resolution of this issue has been hindered by difficulty in quantifying the fraction of woody cover in the fossil record. Here we show that the fraction of woody cover in tropical ecosystems can be quantified using stable carbon isotopes in soils. Furthermore, we use fossil soils from hominin sites in the Awash and Omo-Turkana basins in eastern Africa to reconstruct the fraction of woody cover since the Late Miocene epoch (about 7 million years ago). 13C/12C ratio data from 1,300 palaeosols at or adjacent to hominin sites dating to at least 6million years ago show that woody cover was predominantly less than ~40% at most sites. These data point to the prevalence of open environments at the majority of hominin fossil sites in eastern Africa over the past 6million years.

  9. Pretreatment of woody biomass for biofuel production: energy efficiency, technologies, and recalcitrance.

    PubMed

    Zhu, J Y; Pan, Xuejun; Zalesny, Ronald S

    2010-07-01

    This mini review discusses several key technical issues associated with cellulosic ethanol production from woody biomass: energy consumption for woody biomass pretreatment, pretreatment energy efficiency, woody biomass pretreatment technologies, and quantification of woody biomass recalcitrance. Both total sugar yield and pretreatment energy efficiency, defined as the total sugar recovery divided by total energy consumption for pretreatment, should be used to evaluate the performance of a pretreatment process. A post-chemical pretreatment wood size-reduction approach was proposed to significantly reduce energy consumption. The review also emphasizes using a low liquid-to-wood ratio (L/W) to reduce thermal energy consumption for any thermochemical/physical pretreatment in addition to reducing pretreatment temperature.

  10. The prevalence of Acarapis woodi in Spanish honey bee (Apis mellifera) colonies.

    PubMed

    Garrido-Bailón, Encarna; Bartolomé, Carolina; Prieto, Lourdes; Botías, Cristina; Martínez-Salvador, Amparo; Meana, Aránzazu; Martín-Hernández, Raquel; Higes, Mariano

    2012-12-01

    Acarapis woodi is an internal obligate parasite of the respiratory system of honey bees which provokes significant economic losses in many geographical areas. The main aim of this study was assess the A. woodi role in the "higher honey bee colony losses phenomenon" in Spain. Therefore, a new polymerase chain reaction (PCR) was developed to amplify the mitochondrial cytochrome oxidase I gene (COI) and so the actual prevalence of A. woodi in Spanish honey bee colonies in 2006 and 2007 was determined as part of a wider survey. The results revealed a greater prevalence than expected in most of the geographical areas studied where has been generally underestimated One problem encountered in this study was to distinguish between A. woodi and other species (Acarapis dorsalis and Acarapis externus) at the molecular level. Furthermore, the patterns of genetic divergence across sequences raised serious doubts about the current classification of these organisms. Copyright © 2012 Elsevier Inc. All rights reserved.

  11. Invertebrates Associated with Coarse Woody Debris in Streams, Upland Forests, and Wetlands: A Review

    Treesearch

    A. Braccia; D.P. Batzer

    1999-01-01

    We reviewed literature on the inbvertebrate groups associated with coarse woody debris in forests, streams, and wetlands, and contrasted patterns of invertebrate community development and wood decomposition among ecosystems.

  12. Soricid response to coarse woody debris manipulations in Coastal Plain loblolly pine forests.

    Treesearch

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

    2009-01-01

    We assessed shrew (soricids) response to coarse woody debris (CWD) manipulations in managed upland loblolly pine (Pinus taeda) stands in the upper Coastal Plain of South Carolina over multiple years and...

  13. Genomic resources for valuable woody ornamental landscape plants such as hydrangea macrophylla

    USDA-ARS?s Scientific Manuscript database

    New and improved ornamental landscape plants are typically produced by conventional breeding. Unfortunately, long generation times for woody plants can significantly slow progress. Incorporating genomic and biotechnology resources provides more information when designing breeding strategies and ac...

  14. Woody Plant Cover Dynamics in Sahelian Drylands from Earth Observation Based Seasonal Metrics

    NASA Astrophysics Data System (ADS)

    Brandt, M.; Hiernaux, P.; Fensholt, R.; Tagesson, T.; Rasmussen, K.; Mbow, C.

    2015-12-01

    Woody plants play an important role in drylands primary productivity and peoples' livelihood, however, due to their scattered appearance, quantifying and monitoring their abundance over a large area is challenging. From in situ measured woody cover we develop a phenology driven model to estimate the canopy cover of woody species in the Sahelian drylands. Annual maps are applied to monitor dynamics of woody populations in relation to climate and anthropogenic interference. The model estimates the total canopy cover of all woody phanerophytes and the concept is based on the significant difference in phenophases of dryland trees, shrubs and bushes as compared to that of the herbaceous plants. Whereas annual herbaceous are only green during the rainy season and senescence occurs shortly after flowering towards the last rains, most woody plants remain photosynthetically active over large parts of the year. We use Moderate Resolution Imaging Spectroradiometer (MODIS) and SPOT VEGETATION (VGT) seasonal metrics representing the dry season to reproduce in situ woody cover at 77 field sites (178 observations in 3x3 km plots between 2000 and 2014) in Niger, Mali and Senegal. The extrapolation to Sahel scale shows agreement between VGT and MODIS at an almost nine times higher woody cover than in the global tree cover product MOD44B which only captures trees of a certain minimum size. Trends over 15 years show that the pattern is closely related to population density and land cover/use. A negative woody cover change can be observed in densely populated areas, but a positive change is seen in sparsely populated regions. Whereas woody cover in cropland is generally stable, it is strongly positive in savannas and woodland. Discrepancies between the countries are huge and also deforestation can be observed at a more local scale. The method is applicable and derived woody cover maps of the Sahel are freely available. They represent an improvement of existing products and a

  15. Boron deficiency in woody plants: various responses and tolerance mechanisms

    PubMed Central

    Wang, Nannan; Yang, Chengquan; Pan, Zhiyong; Liu, Yongzhong; Peng, Shu’ang

    2015-01-01

    Boron (B) is an essential microelement for higher plants, and its deficiency is widespread around the world and constrains the productivity of both agriculture and forestry. In the last two decades, numerous studies on model or herbaceous plants have contributed greatly to our understanding of the complex network of B-deficiency responses and mechanisms for tolerance. In woody plants, however, fewer studies have been conducted and they have not well been recently synthesized or related to the findings on model species on B transporters. Trees have a larger body size, longer lifespan and more B reserves than do herbaceous plants, indicating that woody species might undergo long-term or mild B deficiency more commonly and that regulation of B reserves helps trees cope with B deficiency. In addition, the highly heterozygous genetic background of tree species suggests that they may have more complex mechanisms of response and tolerance to B deficiency than do model plants. Boron-deficient trees usually exhibit two key visible symptoms: depression of growing points (root tip, bud, flower, and young leaf) and deformity of organs (root, shoot, leaf, and fruit). These symptoms may be ascribed to B functioning in the cell wall and membrane, and particularly to damage to vascular tissues and the suppression of both B and water transport. Boron deficiency also affects metabolic processes such as decreased leaf photosynthesis, and increased lignin and phenol content in trees. These negative effects will influence the quality and quantity of wood, fruit and other agricultural products. Boron efficiency probably originates from a combined effect of three processes: B uptake, B translocation and retranslocation, and B utilization. Root morphology and mycorrhiza can affect the B uptake efficiency of trees. During B translocation from the root to shoot, differences in B concentration between root cell sap and xylem exudate, as well as water use efficiency, may play key roles in

  16. Plant diversity and ecosystem multifunctionality peak at intermediate levels of woody cover in global drylands

    PubMed Central

    Soliveres, Santiago; Maestre, Fernando T.; Eldridge, David J.; Delgado-Baquerizo, Manuel; Quero, José Luis; Bowker, Matthew A.; Gallardo, Antonio

    2015-01-01

    Aim The global spread of woody plants into grasslands is predicted to increase over the coming century. While there is general agreement regarding the anthropogenic causes of this phenomenon, its ecological consequences are less certain. We analyzed how woody vegetation of differing cover affects plant diversity (richness and evenness) and multiple ecosystem functions (multifunctionality) in global drylands, and how this changes with aridity. Location 224 dryland sites from all continents except Antarctica widely differing in their environmental conditions (from arid to dry-subhumid sites) and woody covers (from 0 to 100%). Methods Using a standardized field survey, we measured the cover, richness and evenness of perennial vegetation. At each site, we measured 14 ecosystem functions related to soil fertility and the build-up of nutrient pools. These functions are critical for maintaining ecosystem function in drylands. Results Species richness and ecosystem multifunctionality were strongly influenced by woody vegetation, with both variables peaking at relative woody covers (RWC) of 41-60%. This relationship shifted with aridity. We observed linear positive effects of RWC in dry-subhumid sites. These positive trends shifted to hump-shaped RWC-diversity and multifunctionality relationships under semiarid environments. Finally, hump-shaped (richness, evenness) or linear negative (multifunctionality) effects of RWC were found under the most arid conditions. Main conclusions Plant diversity and multifunctionality peaked at intermediate levels of woody cover, although this relationship became increasingly positive under wetter environments. This comprehensive study accounts for multiple ecosystem attributes across a range of woody covers and environmental conditions. Our results help us to reconcile contrasting views of woody encroachment found in current literature and can be used to improve predictions of the likely effects of encroachment on biodiversity and ecosystem

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

    SciTech Connect

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

    1996-12-31

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

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

    PubMed

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

    2016-10-01

    Incentivizing carbon storage can be a win-win pathway to conserving biodiversity and mitigating climate change. In savannas, however, the situation is more complex. Promoting carbon storage through woody encroachment may reduce plant diversity of savanna endemics, even as the diversity of encroaching forest species increases. This trade-off has important implications for the management of biodiversity and carbon in savanna habitats, but has rarely been evaluated empirically. We quantified the nature of carbon-diversity relationships in the Brazilian Cerrado by analyzing how woody plant species richness changed with carbon storage in 206 sites across the 2.2 million km(2) region at two spatial scales. We show that total woody plant species diversity increases with carbon storage, as expected, but that the richness of endemic savanna woody plant species declines with carbon storage both at the local scale, as woody biomass accumulates within plots, and at the landscape scale, as forest replaces savanna. The sharpest trade-offs between carbon storage and savanna diversity occurred at the early stages of carbon accumulation at the local scale but the final stages of forest encroachment at the landscape scale. Furthermore, the loss of savanna species quickens in the final stages of forest encroachment, and beyond a point, savanna species losses outpace forest species gains with increasing carbon accumulation. Our results suggest that although woody encroachment in savanna ecosystems may provide substantial carbon benefits, it comes at the rapidly accruing cost of woody plant species adapted to the open savanna environment. Moreover, the dependence of carbon-diversity trade-offs on the amount of savanna area remaining requires land managers to carefully consider local conditions. Widespread woody encroachment in both Australian and African savannas and grasslands may present similar threats to biodiversity. © 2016 John Wiley & Sons Ltd.

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

    NASA Astrophysics Data System (ADS)

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

    2005-12-01

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

  20. Mapping gains and losses in woody vegetation across global tropical drylands.

    PubMed

    Tian, Feng; Brandt, Martin; Liu, Yi Y; Rasmussen, Kjeld; Fensholt, Rasmus

    2017-04-01

    Woody vegetation in global tropical drylands is of significant importance for both the interannual variability of the carbon cycle and local livelihoods. Satellite observations over the past decades provide a unique way to assess the vegetation long-term dynamics across biomes worldwide. Yet, the actual changes in the woody vegetation are always hidden by interannual fluctuations of the leaf density, because the most widely used remote sensing data are primarily related to the photosynthetically active vegetation components. Here, we quantify the temporal trends of the nonphotosynthetic woody components (i.e., stems and branches) in global tropical drylands during 2000-2012 using the vegetation optical depth (VOD), retrieved from passive microwave observations. This is achieved by a novel method focusing on the dry season period to minimize the influence of herbaceous vegetation and using MODerate resolution Imaging Spectroradiometer (MODIS) Normalized Difference Vegetation Index (NDVI) data to remove the interannual fluctuations of the woody leaf component. We revealed significant trends (P < 0.05) in the woody component (VODwood ) in 35% of the areas characterized by a nonsignificant trend in the leaf component (VODleaf modeled from NDVI), indicating pronounced gradual growth/decline in woody vegetation not captured by traditional assessments. The method is validated using a unique record of ground measurements from the semiarid Sahel and shows a strong agreement between changes in VODwood and changes in ground observed woody cover (r(2)  = 0.78). Reliability of the obtained woody component trends is also supported by a review of relevant literatures for eight hot spot regions of change. The proposed approach is expected to contribute to an improved assessment of, for example, changes in dryland carbon pools.

  1. A 6 year longitudinal study of post-fire woody carbon dynamics in California's forests

    Treesearch

    Bianca N.I. Eskelson; Vicente J. Monleon; Jeremy S. Fried

    2016-01-01

    We examined the dynamics of aboveground forest woody carbon pools — live trees, standing dead trees, and down wood—during the first 6 years following wildfire across a wide range of conditions, which are characteristic of California forest fires. From repeated measurements of the same plots, we estimated change in woody carbon pools as a function of crown fire severity...

  2. Woody pretzels: spirocycles from vetiver to patchouli and Georgywood.

    PubMed

    Kraft, Philip

    2008-06-01

    This review, including new experimental results, is the summary of a talk at the RSC/SCI conference 'flavours & fragrances 2007' in London, Imperial College, 24-26 September, 2007. Though the third dimension of the receptor models of J. E. Amoore rarely was exceeding 4 A, the world of woody odorants such as (+)-cedrol (3; cedarwood), (-)-khusimone (4; vetiver), and (-)-patchoulol (5; patchouli) is anything but flat. Any tricyclic skeleton with a zero-bridge contains a spirocyclic ring system determining its 3D structure, so spirocycles (spira, Lat. pretzel) are the fastest access to the third dimension. In the vetiver family, a spirocyclic mimic 9 of (-)-khusimone (4) was first discovered by chance by Büchi in 1976, and also by chance, we obtained another system, 12, with a characteristic vetiver smell by tandem-Rupe-Nazarov reaction of alkyne diols. A 5-A distance between a quaternary C-atom and a carbonyl group (or alternative HB acceptor) with an alpha-methyl or methylene branching is proposed to be the key to their vetiver odor. Upon scale-up of one of these odorants, 24, we discovered a very powerful (0.067 ng/l) impurity with a most typical patchouli scent: the spirocyclic, sterically crowded hydroxy ketone 33--a most unusual structure for a patchouli odorant. Several spirocyclic hydroxy ketone analogs, also with inverted ring systems such as in 70 and 84, provided new insights into the structure-odor correlation of this family. A superposition analysis indicated the carbonyl function of the hydroxy ketone to overlay on the geminal dimethyl motive of (-)-patchoulol. And indeed, the corresponding hydroxy ketone of patchoulol, 59, synthesized in 13 steps from Cyclal C (63), also emanated a patchouli odor. Finally, the synthesis and olfactory properties of twelve rigid spirocyclic analogs, 95-97, 99-102, and 106-110, of Georgywood (91) are presented that highlight stereochemical requirements for woody odorants and raise doubts about an alpha-helical binding

  3. Woody encroachment reduces nutrient limitation and promotes soil carbon sequestration

    PubMed Central

    Blaser, Wilma J; Shanungu, Griffin K; Edwards, Peter J; Olde Venterink, Harry

    2014-01-01

    During the past century, the biomass of woody species has increased in many grassland and savanna ecosystems. As many of these species fix nitrogen symbiotically, they may alter not only soil nitrogen (N) conditions but also those of phosphorus (P). We studied the N-fixing shrub Dichrostachys cinerea in a mesic savanna in Zambia, quantifying its effects upon pools of soil N, P, and carbon (C), and availabilities of N and P. We also evaluated whether these effects induced feedbacks upon the growth of understory vegetation and encroaching shrubs. Dichrostachys cinerea shrubs increased total N and P pools, as well as resin-adsorbed N and soil extractable P in the top 10-cm soil. Shrubs and understory grasses differed in their foliar N and P concentrations along gradients of increasing encroachment, suggesting that they obtained these nutrients in different ways. Thus, grasses probably obtained them mainly from the surface upper soil layers, whereas the shrubs may acquire N through symbiotic fixation and probably obtain some of their P from deeper soil layers. The storage of soil C increased significantly under D. cinerea and was apparently not limited by shortages of either N or P. We conclude that the shrub D. cinerea does not create a negative feedback loop by inducing P-limiting conditions, probably because it can obtain P from deeper soil layers. Furthermore, C sequestration is not limited by a shortage of N, so that mesic savanna encroached by this species could represent a C sink for several decades. We studied the effects of woody encroachment on soil N, P, and C pools, and availabilities of N and P to Dichrostachys cinerea shrubs and to the understory vegetation. Both N and P pools in the soil increased along gradients of shrub age and cover, suggesting that N fixation by D. cinerea did not reduce the P supply. This in turn suggests that continued growth and carbon sequestration in this mesic savanna ecosystems are unlikely to be constrained by nutrient

  4. The multiple fuzzy origins of woodiness within Balsaminaceae using an integrated approach. Where do we draw the line?

    PubMed Central

    Lens, Frederic; Eeckhout, Sharon; Zwartjes, Rosa; Smets, Erik; Janssens, Steven B.

    2012-01-01

    Background and Aims The family Balsaminaceae is essentially herbaceous, except for some woodier species that can be described as ‘woody’ herbs or small shrubs. The family is nested within the so-called balsaminoid clade of Ericales, including the exclusively woody families Tetrameristaceae and Marcgraviaceae, which is sister to the remaining families of the predominantly woody order. A molecular phylogeny of Balsaminaceae is compared with wood anatomical observations to find out whether the woodier species are derived from herbaceous taxa (i.e. secondary woodiness), or whether woodiness in the family represents the ancestral state for the order (i.e. primary woodiness). Methods Wood anatomical observations of 68 Impatiens species and Hydrocera triflora, of which 47 are included in a multigene phylogeny, are carried out using light and scanning electron microscopy and compared with the molecular phylogenetic insights. Key Results There is much continuous variation in wood development between the Impatiens species studied, making the distinction between herbaceousness and woodiness difficult. However, the most woody species, unambiguously considered as truly woody shrubs, all display paedomorphic wood features pointing to secondary woodiness. This hypothesis is further supported by the molecular phylogeny, demonstrating that these most woody species are derived from herbaceous (or less woody) species in at least five independent clades. Wood formation in H. triflora is mostly confined to the ribs of the stems and shows paedomorphic wood features as well, suggesting that the common ancestor of Balsaminaceae was probably herbaceous. Conclusions The terms ‘herbaceousness’ and ‘woodiness’ are notoriously difficult to use in Balsaminaceae. However, anatomical observations and molecular sequence data show that the woodier species are derived from less woody or clearly herbaceous species, demonstrating that secondary woodiness has evolved in parallel. PMID

  5. Independent allopolyploidization events preceded speciation in the temperate and tropical woody bamboos.

    PubMed

    Triplett, Jimmy K; Clark, Lynn G; Fisher, Amanda E; Wen, Jun

    2014-10-01

    The objectives of the current study were to investigate the origin of polyploidy in the woody bamboos and examine putative hybrid relationships in one major lineage (the temperate woody bamboos, tribe Arundinarieae). Phylogenetic analyses were based on sequence data from three nuclear loci and 38 species in 27 genera. We identify six ancestral genome donors for contemporary bamboo lineages: temperate woody bamboos (tribe Arundinarieae) contain genomes A and B, tropical woody bamboos (tribe Bambuseae) contain genomes C and D, and herbaceous bamboos (tribe Olyreae) contain genome H; some hexaploid paleotropical bamboos contain genome E in addition to C and D. Molecular data indicate that allopolyploidy arose independently in temperate (AABB) and tropical woody lineages (CCDD and CCDDEE), and speciation occurred subsequent to polyploidization. Moreover, hybridization has played a surprising and recurrent role in bamboo evolution, generating allohexaploid species in the paleotropical clade and intergeneric hybrids among the allotetraploid temperate bamboos. We suggest this complex history of reticulate evolution is at least partially responsible for the taxonomic difficulty associated with the woody bamboos. This newly-resolved phylogenetic framework reflects a major step forward in our understanding of bamboo biodiversity and has important implications for the interpretation of bamboo phylogenomics. © 2014 The Authors New Phytologist © 2014 New Phytologist Trust.

  6. Woody debris in north Iberian streams: influence of geomorphology, vegetation, and management.

    PubMed

    Diez, J R; Elosegi, A; Pozo, J

    2001-11-01

    The effect of stream geomorphology, maturity, and management of riparian forests on abundance, role, and mobility of wood was evaluated in 20 contrasting reaches in the Agüera stream catchment (northern Iberian Peninsula). During 1 year the volume of woody debris exceeding 1 cm in diameter was measured in all reaches. All large woody debris (phi > 5 cm) pieces were tagged, their positions mapped, and their subsequent changes noted. Volume of woody debris was in general low and ranged from 40 to 22,000 cm3 m-2; the abundance of debris dams ranged from 0 to 5.5 per 100 m of channel. Wood was especially rare and unstable in downstream reaches, or under harvested forests (both natural or plantations). Results stress that woody debris in north Iberian streams has been severely reduced by forestry and log removal. Because of the important influence of woody debris on structure and function of stream systems, this reduction has likely impacted stream communities. Therefore, efforts to restore north Iberian streams should include in-channel and riparian management practices that promote greater abundance and stability of large woody debris whenever possible.

  7. Distribution and drivers of woody cover change in Southern African savannahs, 1984-2014.

    NASA Astrophysics Data System (ADS)

    Higginbottom, Thomas; Symeonakis, Elias

    2017-04-01

    Savannah ecosystems cover 20% of the Earth's surface, and 65% of the African continent. These systems, comprised of a dynamic mosaic of open-canopy woody coverage and grasses, provide important ecosystem services and livelihoods to some of the poorest World's communities. Yet there is concern over the stability of many savannah regions. In particular, increases in the coverage and density of woody species at the expense of grasses poses a pronounced threat in southern Africa. Yet quantified estimates on the extent and drivers of this phenomenon remain elusive, inhibiting effective remediation efforts and incurring uncertainty in global carbon accounting systems. In this study, we use batch processing of the Landsat archive to map the fractional woody cover of a cross border section of the Limpopo catchment over 40 years. We quantified the change in woody coverage between 1984 and 2014, and used a series of Generalised Additive Models to ascertain the drivers of the observed change. Results show that woody encroachment is best explained by regional changes in rainfall, with land use or tenure playing only a minor role. Furthermore, the presence of large herbivores stabilises woody cover levels, helping to maintain national parks. These results contribute to understanding the drivers of poorly understood processes that have a widespread impact on ecosystem Carbon budgets, in southern Africa and beyond.

  8. Woody plant encroachment of grasslands: a comparison of terrestrial and wetland settings.

    PubMed

    Saintilan, Neil; Rogers, Kerrylee

    2015-02-01

    A global trend of woody plant encroachment of terrestrial grasslands is co-incident with woody plant encroachment of wetland in freshwater and saline intertidal settings. There are several arguments for considering tree encroachment of wetlands in the context of woody shrub encroachment of grassland biomes. In both cases, delimitation of woody shrubs at regional scales is set by temperature thresholds for poleward extent, and by aridity within temperature limits. Latitudinal expansion has been observed for terrestrial woody shrubs and mangroves, following recent warming, but most expansion and thickening has been due to the occupation of previously water-limited grassland/saltmarsh environments. Increases in atmospheric CO₂, may facilitate the recruitment of trees in terrestrial and wetland settings. Improved water relations, a mechanism that would predict higher soil moisture in grasslands and saltmarshes, and also an enhanced capacity to survive arid conditions, reinforces local mechanisms of change. The expansion of woody shrubs and mangroves provides a negative feedback on elevated atmospheric CO₂ by increasing carbon sequestration in grassland and saltmarsh, and is a significant carbon sink globally. These broad-scale vegetation shifts may represent a new stable state, reinforced by positive feedbacks between global change drivers and endogenic mechanisms of persistence in the landscape.

  9. Utilization characteristics and importance of woody biomass resources on the rural-urban fringe in botswana.

    PubMed

    Nkambwe, Musisi; Sekhwela, Mogodisheng B M

    2006-02-01

    This article examines the utilization characteristics and importance of woody biomass resources in the rural-urban fringe zones of Botswana. In the literature for Africa, attention has been given to the availability and utilization of biomass in either urban or rural environments, but the rural-urban fringe has been neglected. Within southern Africa, this neglect is not justified; the rural-urban fringe, not getting the full benefits available in urban environments in Botswana, has developed problems in woody biomass availability and utilization that require close attention. In this article, socioeconomic data on the importance of woody biomass in the Batlokwa Tribal Territory, on the rural-urban fringe of Gaborone, Botswana, were collected together with ecologic data that reveal the utilization characteristics and potential for regrowth of woody biomass. The analysis of these results show that local woody biomass is very important in the daily lives of communities in the rural-urban fringe zones and that there is a high level of harvesting. However, there is no effort in planning land use in the tribal territory to either conserve this resource or provide alternatives to its utilization. The future of woody biomass resources in Botswana's rural-urban fringe is uncertain. The investigators recommend that a comprehensive policy for the development of the rural-urban fringe consider the importance of this resource. The neglect of this resource will have far-reaching implications on the livelihoods of residents as well as the environment in this zone.

  10. Savannah fractional woody vegetation cover mapping with optical and radar data and machine learning

    NASA Astrophysics Data System (ADS)

    Symeonakis, Elias; Marqués-Mateu, Ángel; Petroulaki, Kyriaki; Higginbottom, Thomas

    2017-04-01

    The fraction of woody vegetation plays an important role in natural and anthropogenic processes of savannah ecosystems. We investigate the optimal combination of Landsat optical and thermal bands as well as ALOS PALSAR L-band radar data from both wet and dry seasons for the mapping of fractional woody vegetation cover in southern African savannah environments. We employ colour aerial photography for sampling and validation and a random forest classification approach to map the fraction of woody cover in the Northwest Province of South Africa. Our results from random forests classifications show that the most accurate estimates are produced from the model that incorporates all parameters: Landsat optical and thermal bands and vegetation indices for the dry and wet seasons, and HH and HV polarised ALOS PALSAR L-band data. However, the combination of the six Landsat bands from either the wet or the dry season with either the HH or the HV PALSAR band, appears to be sufficient for achieving fractional woody cover balanced accuracies of >85%. Dry season optical bands alone are able to map fractional woody cover with more than 80% balanced accuracy. Our findings can provide much needed assistance to woody vegetation monitoring efforts in southern African savannahs where its expansion over the last decades is partly attributed to bush encroachment and land degradation brought about by recent climatic changes and/or land mismanagement.

  11. Woody riparian vegetation response to different alluvial water table regimes

    USGS Publications Warehouse

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

    2000-01-01

    Woody riparian vegetation in western North American riparian ecosystems is commonly dependent on alluvial groundwater. Various natural and anthropogenic mechanisms can cause groundwater declines that stress riparian vegetation, but little quantitative information exists on the nature of plant response to different magnitudes, rates, and durations of groundwater decline. We observed groundwater dynamics and the response of Populus Fremontii, Salix gooddingii, and Tamarix ramosissima saplings at 3 sites between 1995 and 1997 along the Bill Williams River, Arizona. At a site where the lowest observed groundwater level in 1996 (-1.97 m) was 1.11 m lower than in 1995 (-0.86 m), 92-100% of Populus and Salix saplings died, whereas 0-13% of the Tamarix stems died. A site with greater absolute water table depths in 1996 (-2.55 m), but less change from the 1995 condition (0.55 m), showed less Populus and Salix mortality and increased basal area. Excavations of sapling roots suggest that root distribution is related to groundwater history. Therefore, a decline in water table relative to the condition under which roots developed may strand plant roots where they cannot obtain sufficient moisture. Plant response is likely mediated by other factors such as soil texture and stratigraphy, availability of precipitation-derived soil moisture, and physiological and morphological adaptations to water stress, and tree age. An understanding of the relationships between water table declines and plant response may enable land and water managers to avoid activities that are likely to stress desirable riparian vegetation.

  12. Units of freezing of deep supercooled water in woody xylem.

    PubMed

    Hong, S G; Sucoff, E

    1980-07-01

    The low temperature exotherms (LTE) of 1-year-old twigs of Haralson apple (Malus pumila Mill.), shagbark hickory (Carya ovata [Mill.] K. Koch), green ash (Fraxinus pennsylvanica Marsh), honey locust (Gleditsia triacanthos L.), American chestnut (Castanea dentata [Marsh] Borkh.), and red oak (Quercus rubra L.) were determined by differential thermal analysis (DTA). In one type of experiment freezing during a DTA experiment was halted for up to 2.5 hours after part of the supercooled water had frozen at temperatures between -25 and -42 C. Upon resumption of cooling the freezing started within 2 C of the stopping temperature. In a second type of experiment living and dead cells were microscopically observed in the same ray after partial freezing in the DTA apparatus. In another experiment, the LTE persisted even after tangential and radial sectioning of the twig to 0.13 millimeters. In a final experiment the LTE of a single multiseriate ray of red oak had the same shape as the LTE of wood with many uniseriate rays.These experiments confirm that the deep supercooled water in woody xylem or pith freezes in numerous independent events over a span of as much as 20 C. The units which freeze in an event are single cells or small groups of cells. Ice grows very slowly if at all from these units, and water moves very slowly from unfrozen cells to frozen ones. Deep supercooling of ray parenchyma does not require an intact ray.

  13. Flow and scour constraints on uprooting of pioneer woody seedlings

    NASA Astrophysics Data System (ADS)

    Bywater-Reyes, Sharon; Wilcox, Andrew C.; Stella, John C.; Lightbody, Anne F.

    2015-11-01

    Scour and uprooting during flood events is a major disturbance agent that affects plant mortality rates and subsequent vegetation composition and density, setting the trajectory of physical-biological interactions in rivers. During flood events, riparian plants may be uprooted if they are subjected to hydraulic drag forces greater than their resisting force. We measured the resisting force of woody seedlings established on river bars with in situ lateral pull tests that simulated flood flows with and without substrate scour. We quantified the influence of seedling size, species (Populus and Tamarix), water-table depth, and scour depth on resisting force. Seedling size and resisting force were positively related with scour depth and water-table depth—a proxy for root length—exerting strong and opposing controls on resisting force. Populus required less force to uproot than Tamarix, but displayed a greater increase in uprooting force with seedling size. Further, we found that calculated mean velocities required to uproot seedlings were greater than modeled flood velocities under most conditions. Only when plants were either shallowly rooted or subjected to substrate scour (≥0.3 m) did the calculated velocities required for uprooting decrease to within the range of modeled flood velocities, indicating that drag forces alone are unlikely to uproot seedlings in the absence of extreme events or bar-scale sediment transport. Seedlings on river bars are most resilient to uprooting when they are large, deeply rooted, and unlikely to experience substrate scour, which has implications for ecogeomorphic evolution and river management.

  14. Distorted Froude-scaled Flume Analysis of Large Woody Debris

    NASA Astrophysics Data System (ADS)

    Wallerstein, N. P.; Alonso, C. V.; Bennett, S. J.; Thorne, C. R.

    2001-12-01

    This paper presents the results of a movable-boundary, distorted, Froude-scaled hydraulic model based on Abiaca Creek, a sand-bedded channel in northern Mississippi. The model was used to examine the geomorphic and hydraulic impact of simplified Large Woody Debris (LWD) elements. The theory of physical scale models is discussed and the method used to construct the LWD test channel is developed. The channel model had bed and banks molded from 0.8 mm sand, and flow conditions were just below the threshold of motion so that any sediment transport and channel adjustment were the result of the debris element. Dimensions and positions of LWD elements were determined using a Debris Jam Classification Model (Wallerstein et al., 1997). Elements were attached to a dynamometer to measure element drag forces, and channel adjustment was determined through detailed topographic surveys. The fluid drag force on the element decreased asymptotically over time as the channel boundary eroded around the element due to locally increased boundary shear stress. Total time for geomorphic adjustment computed for the prototype channel at the Q2 discharge (discharge occurring once every two years on average) was as short as 45 hours. The size, depth and position of scour holes, bank erosion and bars created by flow acceleration past the elements were found to be related to element length and position within the channel cross-section. Morphologies created by each debris element in the model channel were comparable with similar jams observed in the prototype channel.

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

    SciTech Connect

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

    1994-07-01

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

  16. Fertilization in short-rotation woody crops plantations

    SciTech Connect

    Johnson, D.W.

    1984-08-27

    Short-rotation woody crops (SRWC) plantations may be more responsive to fertilization than mature forests because they are in a nutrient-accumulating rather than a steady-state stage of stand development. On the other hand, the nutrient removals with more frequent harvesting (via biomass removal, leaching, erosion, etc.) may cause greater fertilizer loss from SRWC plantations than from mature forests. A knowledge of the mechanisms of fertilizer response is needed to optimize fertilization schemes for maximum response and to minimize losses and the undesirable environmental consequences associated with such losses. Nitrogen does not accumulate in mineral forms in soils, and, thus, responses must be due primarily to N conservation within plants themselves (translocation), within nutrient cycles, or by elevating non-mineral but labile soil N fractions. Nitrogen fertilization schemes in SRWC plantations most probably must rely on conservation within plants and elevating soil labile N levels to provide prolonged growth response. Attempts to keep soil mineral N levels elevated may very well lead to excessive nitrification, nitrate leaching, and associated problems with groundwater pollution. On the other hand, phosphorus and potassium may be retained in ionic forms in soils, and fertilizer schemes may be designed to take advantage of this property, as well as internal plant conservation in the case of phosphorus, to promote long-term responses. 27 references, 1 figure.

  17. Laser Capture Microdissection Protocol for Xylem Tissues of Woody Plants

    PubMed Central

    Blokhina, Olga; Valerio, Concetta; Sokołowska, Katarzyna; Zhao, Lei; Kärkönen, Anna; Niittylä, Totte; Fagerstedt, Kurt

    2017-01-01

    Laser capture microdissection (LCM) enables precise dissection and collection of individual cell types from complex tissues. When applied to plant cells, and especially to woody tissues, LCM requires extensive optimization to overcome such factors as rigid cell walls, large central vacuoles, intercellular spaces, and technical issues with thickness and flatness of the sections. Here we present an optimized protocol for the laser-assisted microdissection of developing xylem from mature trees: a gymnosperm (Norway spruce, Picea abies) and an angiosperm (aspen, Populus tremula) tree. Different cell types of spruce and aspen wood (i.e., ray cells, tracheary elements, and fibers) were successfully microdissected from tangential, cross and radial cryosections of the current year’s growth ring. Two approaches were applied to achieve satisfactory flatness and anatomical integrity of the spruce and aspen specimens. The commonly used membrane slides were ineffective as a mounting surface for the wood cryosections. Instead, in the present protocol we use glass slides, and introduce a glass slide sandwich assembly for the preparation of aspen sections. To ascertain that not only the anatomical integrity of the plant tissue, but also the molecular features were not compromised during the whole LCM procedure, good quality total RNA could be extracted from the microdissected cells. This showed the efficiency of the protocol and established that our methodology can be integrated in transcriptome analyses to elucidate cell-specific molecular events regulating wood formation in trees. PMID:28101088

  18. Direct hydrodeoxygenation of raw woody biomass into liquid alkanes.

    PubMed

    Xia, Qineng; Chen, Zongjia; Shao, Yi; Gong, Xueqing; Wang, Haifeng; Liu, Xiaohui; Parker, Stewart F; Han, Xue; Yang, Sihai; Wang, Yanqin

    2016-03-30

    Being the only sustainable source of organic carbon, biomass is playing an ever-increasingly important role in our energy landscape. The conversion of renewable lignocellulosic biomass into liquid fuels is particularly attractive but extremely challenging due to the inertness and complexity of lignocellulose. Here we describe the direct hydrodeoxygenation of raw woods into liquid alkanes with mass yields up to 28.1 wt% over a multifunctional Pt/NbOPO4 catalyst in cyclohexane. The superior performance of this catalyst allows simultaneous conversion of cellulose, hemicellulose and, more significantly, lignin fractions in the wood sawdust into hexane, pentane and alkylcyclohexanes, respectively. Investigation on the molecular mechanism reveals that a synergistic effect between Pt, NbOx species and acidic sites promotes this highly efficient hydrodeoxygenation of bulk lignocellulose. No chemical pretreatment of the raw woody biomass or separation is required for this one-pot process, which opens a general and energy-efficient route for converting raw lignocellulose into valuable alkanes.

  19. Direct hydrodeoxygenation of raw woody biomass into liquid alkanes

    PubMed Central

    Xia, Qineng; Chen, Zongjia; Shao, Yi; Gong, Xueqing; Wang, Haifeng; Liu, Xiaohui; Parker, Stewart F.; Han, Xue; Yang, Sihai; Wang, Yanqin

    2016-01-01

    Being the only sustainable source of organic carbon, biomass is playing an ever-increasingly important role in our energy landscape. The conversion of renewable lignocellulosic biomass into liquid fuels is particularly attractive but extremely challenging due to the inertness and complexity of lignocellulose. Here we describe the direct hydrodeoxygenation of raw woods into liquid alkanes with mass yields up to 28.1 wt% over a multifunctional Pt/NbOPO4 catalyst in cyclohexane. The superior performance of this catalyst allows simultaneous conversion of cellulose, hemicellulose and, more significantly, lignin fractions in the wood sawdust into hexane, pentane and alkylcyclohexanes, respectively. Investigation on the molecular mechanism reveals that a synergistic effect between Pt, NbOx species and acidic sites promotes this highly efficient hydrodeoxygenation of bulk lignocellulose. No chemical pretreatment of the raw woody biomass or separation is required for this one-pot process, which opens a general and energy-efficient route for converting raw lignocellulose into valuable alkanes. PMID:27025898

  20. Soil organic carbon responses to grazing and woody plant encroachment in a semi-desert grassland

    NASA Astrophysics Data System (ADS)

    Throop, H. L.; Archer, S. R.; McClaran, M.; Ojima, D.; Keough, C.; Parton, W.

    2006-12-01

    The majority of carbon (C) in grassland and savanna ecosystems is belowground. Recent estimates suggest the historic and ongoing proliferation of woody plants in these systems may account for a significant fraction of the Northern Hemisphere carbon (C) sink. A large degree of uncertainty in the direction and magnitude of soil C pool response to woody encroachment exists, however. Soil organic C (SOC) response to woody encroachment may be modified by current and historical land management patterns, but the nature of these relationships is poorly understood. We used CENTURY, a process-based ecosystem model, to explore historical patterns and project future changes in SOC in response to Prosopis velutina encroachment and livestock grazing in a southern Arizona semi-desert grassland. We parameterized and adapted CENTURY for our study site using woody and herbaceous biomass data and P. velutina growth rate estimates. Modeled contemporary SOC levels were +/- 15% of measured levels. Simulations of historical grazing management suggest that grassland SOC dropped nearly 50% (from 1020 to 530 g C m-2) in response to heavy, continuous livestock grazing initiated around 1850. SOC recovery varied with the degree of relaxation of grazing intensity, with nearly full recovery occurring in areas where grazing was excluded between 1903 and 2005 (modeled SOC = 930 g C m-2 in 2005). Woody encroachment, beginning around 1900, had a strong positive influence on modeled SOC, with the greatest accumulations associated with plants greater than 60 years old. Grazing mediated this response, such that sub-canopy SOC in grazed areas was 200-300 g C m-2 less than that in ungrazed areas. Forward simulations suggest that SOC will continue to increase until woody plant stands reach ca. 130 years of age, at which point SOC will stabilize around 3300 g C m^{- 2} for grazed sites and 3000 g C m-2 for ungrazed sites. Results indicate that woody plant encroachment has strong positive influence on SOC

  1. Contributions of woody and herbaceous vegetation to tropical savanna ecosystem productivity: a quasi-global estimate.

    PubMed

    Lloyd, Jon; Bird, Michael I; Vellen, Lins; Miranda, Antonio Carlos; Veenendaal, Elmar M; Djagbletey, Gloria; Miranda, Heloisa S; Cook, Garry; Farquhar, Graham D

    2008-03-01

    To estimate the relative contributions of woody and herbaceous vegetation to savanna productivity, we measured the 13C/12C isotopic ratios of leaves from trees, shrubs, grasses and the surface soil carbon pool for 22 savannas in Australia, Brazil and Ghana covering the full savanna spectrum ranging from almost pure grassland to closed woodlands on all three continents. All trees and shrubs sampled were of the C3 pathway and all grasses of the C4 pathway with the exception of Echinolaena inflexa (Poir.) Chase, a common C3 grass of the Brazilian cerrado. By comparing the carbon isotopic compositions of the plant and carbon pools, a simple model relating soil delta 13C to the relative abundances of trees + shrubs (woody plants) and grasses was developed. The model suggests that the relative proportions of a savanna ecosystem's total foliar projected cover attributable to grasses versus woody plants is a simple and reliable index of the relative contributions of grasses and woody plants to savanna net productivity. Model calibrations against woody tree canopy cover made it possible to estimate the proportion of savanna productivity in the major regions of the world attributable to trees + shrubs and grasses from ground-based observational maps of savanna woodiness. Overall, it was estimated that 59% of the net primary productivity (Np) of tropical savannas is attributable to C4 grasses, but that this proportion varies significantly within and between regions. The C4 grasses make their greatest relative contribution to savanna Np in the Neotropics, whereas in African regions, a greater proportion of savanna Np is attributable to woody plants. The relative contribution of C4 grasses in Australian savannas is intermediate between those in the Neotropics and Africa. These differences can be broadly ascribed to large scale differences in soil fertility and rainfall.

  2. Relationship between woody plant colonization and Typha L. encroachment in stormwater detention basins.

    PubMed

    Plumb, Priscilla Bocskor; Day, Susan D; Wynn-Thompson, Theresa M; Seiler, John R

    2013-10-01

    We studied stormwater detention basins where woody vegetation removal was suspended for 2 years in Virginia, USA to determine if woody vegetation can control Typha populations and how early woody plant succession interacts with Typha, other herbaceous vegetation, and site factors. Distribution and composition of woody vegetation, Typha and non-Typha herbaceous vegetation biomass, and site factors were assessed at 100 plots in four basins ranging in age from 7 to 17 years. A greenhouse study examined the interaction of shade and soil moisture on Typha biomass and persistence. Principal component analysis identified an environmental gradient associated with greater water table depths and decreased elevation that favored Typha but negatively influenced woody vegetation. Elevation was correlated with litter layer distribution, suggesting that initial topography influences subsequent environmental characteristics and thus plant communities. Soil organic matter at 0-10 cm ranged from 5.4 to 12.7%. Woody plants present were native species with the exception of Ailanthus altissima and Pyrus calleryana. In the greenhouse, shade and reduced soil moisture decreased Typha biomass and rhizome length. The shade effect was strongest in flooded plants and the soil moisture effect was strongest for plants in full sun. Typha in dry soil and heavy shade had 95% less total biomass and 83% smaller rhizomes than Typha in flooded soil and full sun, but even moderate soil moisture reductions decreased above- and below-ground biomass by 63 and 56%, respectively. Suspending maintenance allows restoration of woody vegetation dominated by native species and may suppress Typha invasion.

  3. Dynamic aspects of large woody debris in river channels

    NASA Astrophysics Data System (ADS)

    Vergaro, Alexandra; Caporali, Enrica; Becchi, Ignazio

    2015-04-01

    Large Woody Debris (LWD) are an integral component of the fluvial environment. They represent an environmental resource, but without doubt they represent also a risk factor for the amplification that could give to the destructive power of a flood event. While countless intervention in river channels have reintroduced wood in rivers with restoration and banks protection aims, during several flash flood events LWD have had a great part in catastrophic consequences, pointing out the urgency of an adequate risk assessment procedure. At present wood dynamics in rivers is not systematically considered within the procedures for the elaboration of hazard maps resulting in loss of prediction accuracy and underestimation of hazard impacts. The assessment inconsistency comes from the complexity of the question: several aspects in wood processes are not yet well known and the superposition of different physical phenomena results in great difficulty to predict critical scenarios. The presented research activity has been aimed to improve management skills for the assessment of the hydrologic risk associated to the presence of large woody debris in rivers, improving knowledge about LWD dynamic processes and proposing effective tools for monitoring and mapping river catchments vulnerability. Utilizing critical review of the published works, field surveys and experimental investigations LWD damaging potential has been analysed to support the identification of the exposed sites and the redaction of hazard maps, taking into account that a comprehensive procedure has to involve: a) Identification of the critical cross sections; b) Evaluation of wood availability in the river catchment; c) Prediction of hazard scenarios through the estimation of water discharge, wood recruitment and entrainment, wood transport and destination. Particularly, a survey sheets form for direct measurements has been implemented and tested in field to provide an investigation instruments for wood and river

  4. Photosynthetic pathway alters hydraulic structure and function in woody plants.

    PubMed

    Kocacinar, Ferit; Sage, Rowan F

    2004-04-01

    Xylem structure and function is proposed to reflect an evolutionary balance between demands for efficient movement of water to the leaf canopy and resistance to cavitation during high xylem tension. Water use efficiency (WUE) affects this balance by altering the water cost of photosynthesis. Therefore species of greater WUE, such as C(4) plants, should have altered xylem properties. To evaluate this hypothesis, we assessed the hydraulic and anatomical properties of 19 C(3) and C(4) woody species from arid regions of the American west and central Asia. Specific conductivity of stem xylem ( K(s) ) was 16%-98% lower in the C(4) than C(3) shrubs from the American west. In the Asian species, the C(3) Nitraria schoberi had similar and Halimodendron halodendron higher K(s) values compared with three C(4) species. Leaf specific conductivity ( K(L); hydraulic conductivity per leaf area) was 60%-98% lower in the C(4) than C(3) species, demonstrating that the presence of the C(4) pathway alters the relationship between leaf area and the ability of the xylem to transport water. C(4) species produced similar or smaller vessels than the C(3) shrubs except in Calligonum, and most C(4) shrubs exhibited higher wood densities than the C(3) species. Together, smaller conduit size and higher wood density indicate that in most cases, the C(4) shrubs exploited higher WUE by altering xylem structure to enhance safety from cavitation. In a minority of cases, the C(4) shrubs maintained similar xylem properties but enhanced the canopy area per branch. By establishing a link between C(4) photosynthesis and xylem structure, this study indicates that other phenomena that affect WUE, such as atmospheric CO(2) variation, may also affect the evolution of wood structure and function.

  5. The Geomorphic Role of Large Woody Debris in River Avulsions

    NASA Astrophysics Data System (ADS)

    Stout, J. C.; Grove, J. R.; Rutherfurd, I.; Marren, P.

    2014-12-01

    The avulsion or abandonment of a river channel in favor of a new course on the floodplain is integral to the development and maintenance of anabranching planforms. Avulsions tend to occur on rivers where the rate of vertical aggradation outpaces lateral migration. In fine cohesive floodplain sediments, avulsions evolve through five stages dependent on the amount of flow and sediment being captured by the new channel. There is limited data available to allow the prediction of autogenic and allogenic controls on: the time over which an avulsion is active; its likely location; the frequency of occurrence; and the length of the interavulsion period. The delivery of wood to the river channel is an autogenic process which has received much attention over the last three decades. Surprisingly it has not previously been considered in anabranch avulsions, apart from where log-jams entirely block channels. The presence of large woody debris in the channel acts as a roughness element, trapping, and impeding the movement of sediments and deflecting flow onto the floodplain. We hypothesize that the delivery rates of wood to the channel, and its subsequent configuration (i.e. dimension, amount, volume, spatial arrangement and blockage ratio), alters flow and sediment routing through the channel. These changes directly influence the stages of avulsion development. To test this conceptual model we have used eleven floodplain cores to reconstruct the timing of a Holocene avulsion. The morphology of the channel in each evolutionary stage was used to estimate the relative role of wood as a roughness element. This was done by coupling a mass balance wood delivery model, run in a Monte Carlo simulation, to the geomorphic processes of each evolutionary stage of the avulsion. Our results allow us to quantify the importance of in-channel wood during each stage of the avulsion. These data highlight that there are critical points in the evolution of anabranching channels when large wood

  6. Drivers of belowground C accrual in response to woody plant encroachment of grasslands

    NASA Astrophysics Data System (ADS)

    Creamer, C. A.; Filley, T. R.; Boutton, T. W.; Kantola, I. B.; Stott, D.

    2011-12-01

    A combination of long-term fire suppression and livestock overgrazing has resulted in the progressive encroachment of C3 woodlands into native C4-dominanted grasslands in the Rio Grande Plains region of southern Texas. This common land-cover change alters the biogeochemical cycling of nutrients in the sandy loam soils of southern Texas so that C and N accrue belowground with increasing woody stand age. C and N increases are predominantly in physically unprotected particulate soil organic matter fractions, where changes in the abundance and chemistry of lignin and aliphatic biopolymers suggest that selective accrual of purportedly more recalcitrant plant molecules may facilitate belowground C stabilization. To evaluate the importance of changing plant input chemistry and soil organic carbon (SOC) accessibility in belowground SOC stabilization, we measured the quantity and isotopic composition of respired CO2 during long term laboratory incubations of whole soil and size (>250 μm) and density (<1.0 g cm-3) separated soil fractions along a chronosequence of woody encroachment. During the two soil fraction incubations a greater proportion of total SOC was respired from younger woody stands (14-23 yrs) and grasslands than from older woody stands (34-86 yrs), suggesting that increases in biochemically recalcitrant polymers with woody encroachment decreased microbial respiration from physically unprotected soil fractions. However, in the whole soil proportional respiration was higher from older woody stands than from younger woody stands and grasslands. This was due to the greater overall allocation of SOC into physically unprotected soil fractions in older woody soils, revealing that microbial accessibility to SOC was more important than SOC chemistry during the whole soil incubation. The effects of changing plant chemistry and SOC accessibility with woody encroachment were also reflected in microbial community structure and function, as the ratio of fungal to bacterial

  7. Assessing Woody Vegetation Trends in Sahelian Drylands Using MODIS Based Seasonal Metrics

    NASA Technical Reports Server (NTRS)

    Brandt, Martin; Hiernaux, Pierre; Rasmussen, Kjeld; Mbow, Cheikh; Kergoat, Laurent; Tagesson, Torbern; Ibrahim, Yahaya Z.; Wele, Abdoulaye; Tucker, Compton J.; Fensholt, Rasmus

    2016-01-01

    Woody plants play a major role for the resilience of drylands and in peoples' livelihoods. However, due to their scattered distribution, quantifying and monitoring woody cover over space and time is challenging. We develop a phenology driven model and train/validate MODIS (MCD43A4, 500m) derived metrics with 178 ground observations from Niger, Senegal and Mali to estimate woody cover trends from 2000 to 2014 over the entire Sahel. The annual woody cover estimation at 500 m scale is fairly accurate with an RMSE of 4.3 (woody cover %) and r(exp 2) = 0.74. Over the 15 year period we observed an average increase of 1.7 (+/- 5.0) woody cover (%) with large spatial differences: No clear change can be observed in densely populated areas (0.2 +/- 4.2), whereas a positive change is seen in sparsely populated areas (2.1 +/- 5.2). Woody cover is generally stable in cropland areas (0.9 +/- 4.6), reflecting the protective management of parkland trees by the farmers. Positive changes are observed in savannas (2.5 +/- 5.4) and woodland areas (3.9 +/- 7.3). The major pattern of woody cover change reveals strong increases in the sparsely populated Sahel zones of eastern Senegal, western Mali and central Chad, but a decreasing trend is observed in the densely populated western parts of Senegal, northern Nigeria, Sudan and southwestern Niger. This decrease is often local and limited to woodlands, being an indication of ongoing expansion of cultivated areas and selective logging.We show that an overall positive trend is found in areas of low anthropogenic pressure demonstrating the potential of these ecosystems to provide services such as carbon storage, if not over-utilized. Taken together, our results provide an unprecedented synthesis of woody cover dynamics in theSahel, and point to land use and human population density as important drivers, however only partially and locally offsetting a general post-drought increase.

  8. Field and flume investigations of the effects of logjams and woody debris on streambed morphology

    NASA Astrophysics Data System (ADS)

    Leung, V.; Montgomery, D. R.; McHenry, M. L.

    2014-12-01

    Interactions among wood debris, fluid flow and sediment transport in rivers are first-order controls on channel morphodynamics, affecting streambed morphology, sediment transport, sediment storage and aquatic habitat. Woody debris increases the hydraulic and topographic complexity in rivers, leading to a greater diversity of aquatic habitats and an increase in the number of large pools that are important fish habitat and breeding grounds. In the past decade, engineered logjams have become an increasingly used tool in river management for simultaneously decreasing the rate of riverbank migration and improving aquatic habitat. Sediment deposits around woody debris build up riverbanks and counteract bank migration caused by erosion. Previous experiments on flow visualization around model woody debris suggest the amount of sediment scour and deposition are primarily related to the presence of roots and the obstructional area of the woody debris. We present the results of fieldwork and sediment transport experiments of streambed morphology around stationary woody debris. Field surveys on the Hoh River and the Elwha River, WA, measure the local streambed morphology around logjams and individual pieces of woody debris. We quantified the amount of local scour and dam-removal related fine sediment deposition around natural and engineered logjams of varying sizes and construction styles, located in different geomorphic settings. We also quantified the amount of local scour around individual pieces of woody debris of varying sizes, geometries and orientations relative to flow. The flume experiments tested the effects of root geometry and log orientation of individual stationary trees on streambed morphology. The flume contained a deformable sediment bed of medium sand. We find that: 1) the presence of roots on woody debris leads to greater areas of both sediment scour and deposition; and 2) the amount of sediment scour and deposition are related to the wood debris cross

  9. Induced somatic sector analysis of cellulose synthase (CesA) promoter regions in woody stem tissues.

    PubMed

    Creux, Nicky M; Bossinger, Gerd; Myburg, Alexander A; Spokevicius, Antanas V

    2013-03-01

    The increasing focus on plantation forestry as a renewable source of cellulosic biomass has emphasized the need for tools to study the unique biology of woody genera such as Eucalyptus, Populus and Pinus. The domestication of these woody crops is hampered by long generation times, and breeders are now looking to molecular approaches such as marker-assisted breeding and genetic modification to accelerate tree improvement. Much of what is known about genes involved in the growth and development of plants has come from studies of herbaceous models such as Arabidopsis and rice. However, transferring this information to woody plants often proves difficult, especially for genes expressed in woody stems. Here we report the use of induced somatic sector analysis (ISSA) for characterization of promoter expression patterns directly in the stems of Populus and Eucalyptus trees. As a case study, we used previously characterized primary and secondary cell wall-related cellulose synthase (CesA) promoters cloned from Eucalyptus grandis. We show that ISSA can be used to elucidate the phloem and xylem expression patterns of the CesA genes in Eucalyptus and Populus stems and also show that the staining patterns differ in Eucalyptus and Populus stems. These findings show that ISSA is an efficient approach to investigate promoter function in the developmental context of woody plant tissues and raise questions about the suitability of heterologous promoters for genetic manipulation in plant species.

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

    USGS Publications Warehouse

    Rambo, T.; Muir, Patricia S.

    1998-01-01

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

  11. Grass competition surpasses the effect of defoliation on a woody plant invader

    NASA Astrophysics Data System (ADS)

    Aranda, Melina J.; Tognetti, Pedro M.; Mazía, Noemí

    2015-10-01

    Woody encroachment in grasslands represents a global phenomenon with strong consequences on ecosystem functioning. While the causes triggering this process can be multiple, there is consensus on the fact that anthropogenic activities play a central role in woody expansion. In particular, the loss of grass cover increases the chances of woody invasion, whereas the role of defoliation is less known. In this study our objective was to assess the simultaneous effect of competition generated by resident vegetation and woody seedling defoliation on the growth and survival of Gleditsia triacanthos seedlings, a woody invader in Argentina. We established a factorial pot experiment with two main factors: Gleditsia defoliation (2 levels: with and without defoliation) and pasture competition (3 levels: without pasture, clipped pasture and intact pasture). Our results showed that pasture competition reduced Gleditsia survival and tree growth, but that the effect of tree defoliation on tree growth depended on the magnitude of pasture competition. More widely, our results stress the existence of a hierarchy order of factors controlling Gleditsia establishment (survival + growth): grass competition was the main control and tree defoliation became important only in the absence of competition. This evidence suggests that maintaining a competitive grass cover along with a frequency of tree defoliation could diminish tree establishment in herbaceous communities.

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

    PubMed

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

    2015-10-26

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

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

    USGS Publications Warehouse

    Allen, J.A.

    1997-01-01

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

  14. Intertidal coarse woody debris: A spatial subsidy as shelter or feeding habitat for gastropods?

    NASA Astrophysics Data System (ADS)

    Storry, Kristin A.; Weldrick, Christine K.; Mews, Malte; Zimmer, Martin; Jelinski, Dennis E.

    2006-01-01

    Coarse woody debris (CWD) in the intertidal region of rocky shores serves as a potential source of nutrients as well as habitat or refugia from predation, ecologically linking the adjacent marine and terrestrial habitats. In a series of field and laboratory experiments, the affinity of slow-moving motile intertidal gastropods to CWD either as food source or as shelter that increases habitat complexity was tested. In intertidal pools, CWD did not increase colonization by Littorina spp., while it did so in supratidal pools. Habitat complexity, brought about by algal cover and barnacles, was apparently sufficient in intertidal pools without woody debris, while the increase in habitat complexity by CWD increased the attractiveness of supratidal pools with little natural complexity to Littorina spp. Overall, however, comparison of pools containing woody debris and those containing artificial shelter provided evidence for CWD, and/or its biofilm, serving as food source rather than refugium per se. Similarly, Tegula funebralis chose CWD as food source rather than as shelter as indicated by comparison of autoclaved and unmanipulated woody debris. Further, both unfed and fed snails from a site where CWD was present significantly preferred CWD over macroalgae. Among snails from a site without woody debris, fed individuals showed no preference, while unfed snails significantly preferred macroalgae. From this, experience appears to be a factor that mediates the role of CWD. Overall, however, CWD appears to provide supplementary food to snails in the inter- and supratidal zone.

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

    PubMed

    Mitchard, Edward T A; Flintrop, Clara M

    2013-01-01

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

  16. Trends in soil erosion and woody shrub encroachment in Ngqushwa district, Eastern Cape Province, South Africa.

    PubMed

    Manjoro, Munyaradzi; Kakembo, Vincent; Rowntree, Kate M

    2012-03-01

    Woody shrub encroachment severely impacts on the hydrological and erosion response of rangelands and abandoned cultivated lands. These processes have been widely investigated at various spatial scales, using mostly field experimentation. The present study used remote sensing to investigate spatial and temporal patterns of soil erosion and encroachment by a woody shrub species, Pteronia incana, in a catchment in Ngqushwa district, Eastern Cape Province, South Africa between 1998 and 2008. The extreme categories of soil erosion and shrub encroachment were mapped with higher accuracy than the intermediate ones, particularly where lower spatial resolution data were used. The results showed that soil erosion in the worst category increased simultaneously with dense woody shrub encroachment on the hill slopes. This trend is related to the spatial patterning of woody shrub vegetation that increases bare soil patches--leading to runoff connectivity and concentration of overland flow. The major changes in soil erosion and shrub encroachment analysed during the 10-year period took place in the 5-9° slope category and on the concave slope form. Multi-temporal analyses, based on remote sensing, can extend our understanding of the dynamics of soil erosion and woody shrub encroachment. They may help benchmark the processes and assist in upscaling field studies.

  17. Island colonization and evolution of the insular woody habit in Echium L. (Boraginaceae).

    PubMed Central

    Böhle, U R; Hilger, H H; Martin, W F

    1996-01-01

    Numerous island-inhabiting species of predominantly herbaceous angiosperm genera are woody shrubs or trees. Such "insular woodiness" is strongly manifested in the genus Echium, in which the continental species of circummediterranean distribution are herbaceous, whereas endemic species of islands along the Atlantic coast of north Africa are woody perennial shrubs. The history of 37 Echium species was traced with 70 kb of noncoding DNA determined from both chloroplast and nuclear genomes. In all, 239 polymorphic positions with 137 informative sites, in addition to 27 informative indels, were found. Island-dwelling Echium species are shown to descend from herbaceous continental ancestors via a single island colonization event that occurred < 20 million years ago. Founding colonization appears to have taken place on the Canary Islands, from which the Madeira and Cape Verde archipelagos were invaded. Colonization of island habitats correlates with a recent origin of perennial woodiness from herbaceous habit and was furthermore accompanied by intense speciation, which brought forth remarkable diversity of forms among contemporary island endemics. We argue that the origin of insular woodiness involved response to counter-selection of inbreeding depression in founding island colonies. Images Fig. 1 Fig. 3 PMID:8876207

  18. The contribution of woody plant materials on the several conditions in a space environment

    NASA Astrophysics Data System (ADS)

    Tomita-Yokotani, Kaori; Baba, Keiichi; Suzuki, Toshisada; Kimura, Shunta; Sato, Seigo; Katoh, Hiroshi; Abe, Yusuke; Katayama, Takeshi

    Woody plant materials have several utilization elements in our habitation environment on earth. The studies of woody plants under a space-environment in the vegetable kingdom have a high contribution to the study of various and exotic environmental responses, too. Woody plants can produce an excess oxygen, woody materials for the living cabin, and provide a biomass by cultivating crops and other species of creatures. Tree material would become to be a tool in closed bio-ecosystems such as an environment in a space. We named the trees used as material for the experiment related to space environments “CosmoBon”, small tree bonsai. Japanese cherry tree, “Sakura”, is famous and lovely tree in Japan. One species of “Sakura”, “Mamezakura, Prunus incisa”, is not only lovely tree species, but also suitable tree for the model tree of our purpose. The species of Prunus incisa is originally grown in volcano environment. That species of Sakura is originally grown on Mt. Fuji aria, oligotrophic place. We will try to build the best utilization usage of woody plant under the space environment by “Mamezakura” as a model tree. Here, we will show the importance of uniformity of materials when we will use the tree materials in a space environment. We will also discuss that tree has a high possibility of utilization under the space environments by using our several results related to this research.

  19. Predicting the Effects of Woody Encroachment on Mammal Communities, Grazing Biomass and Fire Frequency in African Savannas

    PubMed Central

    Smit, Izak P. J.; Prins, Herbert H. T.

    2015-01-01

    With grasslands and savannas covering 20% of the world’s land surface, accounting for 30–35% of worldwide Net Primary Productivity and supporting hundreds of millions of people, predicting changes in tree/grass systems is priority. Inappropriate land management and rising atmospheric CO2 levels result in increased woody cover in savannas. Although woody encroachment occurs world-wide, Africa’s tourism and livestock grazing industries may be particularly vulnerable. Forecasts of responses of African wildlife and available grazing biomass to increases in woody cover are thus urgently needed. These predictions are hard to make due to non-linear responses and poorly understood feedback mechanisms between woody cover and other ecological responders, problems further amplified by the lack of long-term and large-scale datasets. We propose that a space-for-time analysis along an existing woody cover gradient overcomes some of these forecasting problems. Here we show, using an existing woody cover gradient (0–65%) across the Kruger National Park, South Africa, that increased woody cover is associated with (i) changed herbivore assemblage composition, (ii) reduced grass biomass, and (iii) reduced fire frequency. Furthermore, although increased woody cover is associated with reduced livestock production, we found indigenous herbivore biomass (excluding elephants) remains unchanged between 20–65% woody cover. This is due to a significant reorganization in the herbivore assemblage composition, mostly as a result of meso-grazers being substituted by browsers at increasing woody cover. Our results suggest that woody encroachment will have cascading consequences for Africa’s grazing systems, fire regimes and iconic wildlife. These effects will pose challenges and require adaptation of livelihoods and industries dependent on conditions currently prevailing. PMID:26379249

  20. Predicting the Effects of Woody Encroachment on Mammal Communities, Grazing Biomass and Fire Frequency in African Savannas.

    PubMed

    Smit, Izak P J; Prins, Herbert H T

    2015-01-01

    With grasslands and savannas covering 20% of the world's land surface, accounting for 30-35% of worldwide Net Primary Productivity and supporting hundreds of millions of people, predicting changes in tree/grass systems is priority. Inappropriate land management and rising atmospheric CO2 levels result in increased woody cover in savannas. Although woody encroachment occurs world-wide, Africa's tourism and livestock grazing industries may be particularly vulnerable. Forecasts of responses of African wildlife and available grazing biomass to increases in woody cover are thus urgently needed. These predictions are hard to make due to non-linear responses and poorly understood feedback mechanisms between woody cover and other ecological responders, problems further amplified by the lack of long-term and large-scale datasets. We propose that a space-for-time analysis along an existing woody cover gradient overcomes some of these forecasting problems. Here we show, using an existing woody cover gradient (0-65%) across the Kruger National Park, South Africa, that increased woody cover is associated with (i) changed herbivore assemblage composition, (ii) reduced grass biomass, and (iii) reduced fire frequency. Furthermore, although increased woody cover is associated with reduced livestock production, we found indigenous herbivore biomass (excluding elephants) remains unchanged between 20-65% woody cover. This is due to a significant reorganization in the herbivore assemblage composition, mostly as a result of meso-grazers being substituted by browsers at increasing woody cover. Our results suggest that woody encroachment will have cascading consequences for Africa's grazing systems, fire regimes and iconic wildlife. These effects will pose challenges and require adaptation of livelihoods and industries dependent on conditions currently prevailing.

  1. Environmental Determinants of Woody Plant Diversity at a Regional Scale in China

    PubMed Central

    Qian, Hong

    2013-01-01

    Understanding what drives the geographic variation of species richness across the globe is a fundamental goal of ecology and biogeography. Environmental variables have been considered as drivers of global diversity patterns but there is no consensus among ecologists on what environmental variables are primary drivers of the geographic variation of species richness. Here, I examine the relationship of woody plant species richness at a regional scale in China with sixteen environmental variables representing energy availability, water availability, energy-water balance, seasonality, and habitat heterogeneity. I found that temperature seasonality is the best predictor of woody species richness in China. Other important environmental variables include annual precipitation, mean temperature of the coldest month, and potential evapotranspiration. The best model explains 85% of the variation in woody plant species richness at the regional scale in China. PMID:24086642

  2. Biological approach for pulping and bleaching of non-woody plants

    SciTech Connect

    Sabharwal, H.S.; Young, R.A.; Blanchette, R.A.

    1996-10-01

    In recent years the pulp and paper industry has expressed serious concerns regarding energy reduction and pollution abatement. These concerns are being vigorously addressed in a variety of ways including the use of biological approaches for pulping and bleaching of wood. We are also evaluating the substitution of wood with non-woody plants for the conservation of forests. Our initial investigation on biomechanical pulping of bast fibers has given very promising results with respect to saving in energy consumption and enhancement of pulp strength properties. Preliminary studies on a biomimetic approach for delignification of non-woody plant pulps using natural bovine heme and synthetic tetraphenyl-porphyrin iron (III) chloride in combination with tert-butyl hydroperoxide (TBH) have also been conducted with some promise. The paper also briefly reviews the advancements made in biological approach for pulping and bleaching of non-woody plants.

  3. Genetic engineering of woody plants: current and future targets in a stressful environment.

    PubMed

    Osakabe, Yuriko; Kajita, Shinya; Osakabe, Keishi

    2011-06-01

    Abiotic stress is a major factor in limiting plant growth and productivity. Environmental degradation, such as drought and salinity stresses, will become more severe and widespread in the world. To overcome severe environmental stress, plant biotechnologies, such as genetic engineering in woody plants, need to be implemented. The adaptation of plants to environmental stress is controlled by cascades of molecular networks including cross-talk with other stress signaling mechanisms. The present review focuses on recent studies concerning genetic engineering in woody plants for the improvement of the abiotic stress responses. Furthermore, it highlights the recent advances in the understanding of molecular responses to stress. The review also summarizes the basis of a molecular mechanism for cell wall biosynthesis and the plant hormone responses to regulate tree growth and biomass in woody plants. This would facilitate better understanding of the control programs of biomass production under stressful conditions. Copyright © Physiologia Plantarum 2011.

  4. The toughness of secondary cell wall and woody tissue

    PubMed Central

    Lucas, P. W.; Tan, H. T. W.; Cheng, P. Y.

    1997-01-01

    The 'across grain' toughness of 51 woods has been determined on thin wet sections using scissors. The moisture content of sections and the varying sharpness of the scissor blades had little effect on the results. In thin sections (less than 0.6mm), toughness rose linearly with section thickness. The intercept toughness at zero thickness, estimated from regression analysis, was proportional to relative density, consistent with values reported for non-woody plant tissues. Extrapolation of the intercept toughness of these woods and other plant tissues/materials to a relative density of 1.0 predicted a toughness of 3.45kJ m-2 , which we identify with the intrinsic toughness of the cell wall. This quantity appears to predict published results from KIC tests on woods and is related to the propensity for crack deflection. The slope of the relationship between section thickness and toughness, describing the work of plastic buckling of cells, was not proportional to relative density, the lightest (balsa) and heaviest (lignum vitae) woods fracturing with less plastic work than predicted. The size of the plastic zone around the crack tip was estimated to be 0.5mm in size. From this, the hypothetical overall toughness of a thick (greater than 1 mm) block of solid cell wall material was calculated as 39.35 kJ m-2, due to both cell wall resistance (10 per cent) and the plastic buckling of cells (90 per cent). This value successfully predicts the toughness of most commercial woods (of relative densities between 0.2 and 0.8) from 'work area' tests in tension and bending. Though density was the most important factor, both fibre width/fibre length (in hardwoods) and lignin/cellulose ratios were negatively correlated with the work of plastic buckling, after correcting for density. At low densities the work of plastic buckling in the longitudinal radial (LR) direction exceeded that in longitudinal tangential (LT), but the reverse was true for relative densities above 0.25. This could

  5. Nitrogen uptake and turnover in riparian woody vegetation.

    PubMed

    Chambers, Chris; Marshall, John D; Danehy, Robert J

    2004-06-01

    The nutrient balance of streams and adjacent riparian ecosystems may be modified by the elimination of anadromous fish runs and perhaps by forest fertilization. To better understand nitrogen (N) dynamics within stream and riparian ecosystems we fertilized two streams and their adjacent riparian corridors in central Idaho. On each stream two nitrogen doses were applied to a swathe approximately 35 m wide centered on the stream. The fertilizer N was enriched in 15N to 18 per thousand. This enrichment is light relative to many previous labeling studies, yet sufficient to yield a traceable signal in riparian and stream biota. This paper reports pre-treatment differences in delta15N and the first-year N response to fertilizer within the riparian woody plant community. Future papers will describe the transfer of allochthonous litter N to the stream and its subsequent processing by stream biota. Pre-treatment delta15N differed between the two creeks (P=0.0002), possibly due to residual salmon nitrogen in one of the creeks. Pre-treatment delta15N of current-year needles was enriched compared to leaf litter, which was in turn enriched compared to needles aged 4 years and older. We conclude that fractionation due to retranslocation occurs in at least two phases. The first phase, which optimizes allocation of N in younger needle age classes, is distinctly different from the second, which conserves N prior to abscission. The delta15N difference between creeks was eliminated by the fertilization (P=0.42). In the two dominant conifer species, Abies lasiocarpa and Picea engelmannii, most fertilizer N was found in the current-year foliage; little was found in older needles and none was detected in litter (P=0.53). The only N-fixing shrub species, Alnus incana, took up only a small amount of fertilizer N [mean percent N derived from fertilizer (%Ndff) 5.0+/-1.6% (SE)]. Far more fertilizer N was taken up by other deciduous shrubs (mean %Ndff=33.9+/-4.5%). Fertilizer N made up 25

  6. Dynamic variation in sapwood specific conductivity in six woody species.

    PubMed

    Domec, Jean-Christophe; Meinzer, Frederick C; Lachenbruch, Barbara; Housset, Johann

    2007-10-01

    Our goals were to quantify how non-embolism-inducing pressure gradients influence trunk sapwood specific conductivity (k(s)) and to compare the impacts of constant and varying pressure gradients on k(s) with KCl and H2O as the perfusion solutions. We studied six woody species (three conifers and three angiosperms) which varied in pit membrane structure, pit size and frequency of axial water transport across pits (long versus short conduits). Both stepwise ("steady") and nonlinear continuous ("non-steady") decreases in the pressure gradient led to decreased k(s) in all species but white oak (Quercus garryana Dougl. ex Hook), a ring-porous and long-vesseled angiosperm. In one diffuse-porous angiosperm (red alder, Alnus rubra Bong.) and two conifers (western red cedar, Thuja plicata Donn. ex D. Don, and Douglas-fir, Pseudotsuga menziesii (Mirb.) Franco), k(s) was 10-30% higher under steady pressure gradients than under non-steady pressure gradients, and a decrease in the pressure gradient from 0.15 to 0.01 MPa m(-1) caused a 20-42% decrease in k(s). In another diffuse-porous angiosperm (maple, Acer macrophyllum Pursh) and in a third coniferous species (western hemlock, Tsuga heterophylla (Raf.) Sarg), there was no difference between k(s) measured under steady and non-steady pressure gradients. With the exception of western red cedar, a conifer with simple pit membranes, the differences in k(s) between low and high pressure gradients tended to be lower in the conifers than in the diffuse-porous angiosperms. In Douglas-fir, western red cedar and the diffuse-porous angiosperms, k(s) was higher when measured with KCl than with H2O. In white oak, there were no differences in k(s) whether measured under steady or non-steady pressure gradients, or when xylem was perfused with KCl or H2O. The species differences in the behavior of k(s) suggest that elasticity of the pit membrane was the main factor causing k(s) to be disproportionate to the pressure gradient and to the

  7. Thermochemical pretreatment of underutilized woody biomass for manufacturing wood composites

    NASA Astrophysics Data System (ADS)

    Pelaez Samaniego, Manuel Raul

    Prescribed fires, one method for reducing hazardous fuel loads from forest lands in the US, are limited by geographical, environmental, and social impacts. Mechanical operations are an alternative type of fuel treatment but these processes are constrained by the difficulty of economically harvesting and/or using large amounts of low-value woody biomass. Adoption and integration of new technologies into existing wood composite facilities offer better utilization of this material. A pretreatment that enables integration of technologies in a typical composite facility will aid with diversification of product portfolio (e.g. wood composites, fuel pellets, liquid fuels, chemicals). Hot water extraction (HWE) is an option for wood pretreatment. This work provides a fundamental understanding of the physicochemical changes to wood resulting from HWE, and how these changes impact processing and performance of composites. Specific objectives were to: 1) review literature on studies related to the manufacture of composites produced with thermally pretreated wood, 2) manufacture wood plastic composites (WPC) and particleboard using HWE wood and evaluate the impacts of pretreatment on product properties, 3) develop an understanding of the effect of HWE on lignin properties, specifically lignin at the cells surface level after migration from cell walls and middle lamella, 4) discern the influence of lignin on the fiber surface on processing WPCs, and, 5) investigate the effect of changing the pretreatment environment (inert gas instead of water) on lignin behavior. Results show that HWE enhances the resistance of both WPCs and particleboard to water with positive or no effect on mechanical properties. Reduction of hemicelluloses and lignin property changes are suggested as the main reasons for enhancing interaction between wood fiber and resins during composite processing. Lignin on the surface of particles after HWE interacts with thermoplastics during WPCs compounding, thus

  8. Changes in flowering phenology of woody plants in North China

    NASA Astrophysics Data System (ADS)

    Dai, Junhu

    2016-04-01

    Over the past several decades, abundant evidences proved that the first flowering date of plants in northern hemisphere became earlier in response to climate warming. However, the existing results about impact of climate change on flowering duration are controversial. In this study, we studied temporal trends in first flowering date (FFD), end of flowering date (EFD) and flowering duration (FD) of 94 woody plants from 1963 to 2014 at three stations (Harbin, Beijing and Xi'an) in North China. Meanwhile, we analyzed the relationship between length of flowering periods and temperature using two phenological models (including regression model and growing degree day model). At all stations, more than 90% of observed species showed earlier flowering over time from 1963 to 2014. The average trends in FFD were 1.33, 1.77 and 3.01 days decade-1 at Harbin, Beijing and Xi'an, respectively. During the same period, EFD also became earlier by a mean rate of 2.19, 1.39 and 2.00 days decade-1, respectively. Regarding FD, a significant shortening of FD was observed at Harbin (-0.86 days decade-1), but FD extended by 0.37 and 1.01 days decade-1 at Beijing and Xi'an, respectively. At interspecific level, the plant species with longer FD tend to have stronger trends of FD extension. Through regression analyses, we found more than 85% of time series revealed a significant negative relationship between FFD (or EFD) and preseason temperature. The regression model could simulate the interannual changes in FFD and EFD with the mean goodness of fit (R2) ranging from 0.38 to 0.67, but failed to simulate the FD accurately, as R2 ranging from 0.09 to 0.18. Regarding to FFD and EFD, the growing degree day model could improved R2 of simuation, but also could not simulate FD accurately. Therefore, we concluded that the FFD and EFD advanced notably in recent six decades as a result of climate warming, but the direction of FD changes depended on locations and the species involved. In addition, the

  9. Lidar-derived estimate and uncertainty of carbon sink in successional phases of woody encroachment

    USGS Publications Warehouse

    Sankey, Temuulen; Shrestha, Rupesh; Sankey, Joel B.; Hardgree, Stuart; Strand, Eva

    2013-01-01

    Woody encroachment is a globally occurring phenomenon that contributes to the global carbon sink. The magnitude of this contribution needs to be estimated at regional and local scales to address uncertainties present in the global- and continental-scale estimates, and guide regional policy and management in balancing restoration activities, including removal of woody plants, with greenhouse gas mitigation goals. The objective of this study was to estimate carbon stored in various successional phases of woody encroachment. Using lidar measurements of individual trees, we present high-resolution estimates of aboveground carbon storage in juniper woodlands. Segmentation analysis of lidar point cloud data identified a total of 60,628 juniper tree crowns across four watersheds. Tree heights, canopy cover, and density derived from lidar were strongly correlated with field measurements of 2613 juniper stems measured in 85 plots (30 × 30 m). Aboveground total biomass of individual trees was estimated using a regression model with lidar-derived height and crown area as predictors (Adj. R2 = 0.76, p 2. Uncertainty in carbon storage estimates was examined with a Monte Carlo approach that addressed major error sources. Ranges predicted with uncertainty analysis in the mean, individual tree, aboveground woody C, and associated standard deviation were 0.35 – 143.6 kg and 0.5 – 1.25 kg, respectively. Later successional phases of woody encroachment had, on average, twice the aboveground carbon relative to earlier phases. Woody encroachment might be more successfully managed and balanced with carbon storage goals by identifying priority areas in earlier phases of encroachment where intensive treatments are most effective.

  10. Dynamic Characteristics of PEM-FC/Woody Biomass Engine Hybrid Micro Grid

    NASA Astrophysics Data System (ADS)

    Obara, Shin'ya; Kito, Shunsuke; Hoshi, Akira; Sasaki, Seizi

    The combustion exhaust heat of woody biomass engine using Stirling cycle is high temperature. This exhaust heat is used for the city gas reforming reaction of a proton exchange membrane fuel cell (PEM-FC) system. The woody biomass engine generator has the characteristic that the greenhouse gas amount of emission with power generation is greatly reducible. In this paper, the micro grid system that introduces PEM-FC/woody biomass engine hybrid cogeneration (PWHC) is proposed. It depends on the dynamic characteristics of the grid for the power quality at the time of load fluctuation being added to the micro grid. Especially, the dynamic characteristics of the independent micro grid are important on security of power quality. So, in this paper, the response characteristic of PEM-FC and woody biomass engine was investigated by the experiment and the numerical analysis. Furthermore, the response characteristic of the PWHC independent micro grid including auxiliary machinery was investigated by the numerical simulation. Moreover, an improvement of dynamic characteristics is proposed using the method of adding proportional-plus-integral control to PWHC. If woody biomass engine is introduced into a house, 10.2s will be required to stabilize power quality at the maximum. On the other hand, when woody biomass engine corresponds to a base load and PEM-FC corresponds to the load exceeding the base load, settling time is less than 1.6 s. In this study, relation between the system configuration of the PWHC micro grid and the dynamic characteristics of the power was clarified.

  11. Modeling wave effects on limits of woody vegetation in Catahoula Lake, LA, USA

    NASA Astrophysics Data System (ADS)

    Edwards, B. L.; Curcic, M.; Keim, R.

    2014-12-01

    Exposure to water waves in lakes is an important control on the structure and distribution of both submerged and shoreline vegetative communities. Wave exposure incident on the shoreline limits the distribution of shrubs on both lake and coastal margins by preventing establishment of seedlings via bed disturbance and uprooting. The goal of this study is to investigate the relationship between bed stress due to wave action and the spatial distribution of woody seedling establishment in Catahoula Lake, Louisiana, USA. The lake bed consists of a broad, seasonally inundated flat bordered by a band of woody shrubs. Annual summer de-watering of the lake allows the lake bed to support a moist-soil herbaceous vegetation community, but recent encroachment by woody shrubs over the past ~70 years threatens ecosystem conversion. We use the University of Miami Wave Model (UMWM) to simulate surface wave evolution and bed shear stress for a range of dominant wind conditions and water levels. UMWM is a 3rdgeneration ocean wave model that solves the wave energy balance equation given wind forcing input. While the model has been previously validated in deep water and coastal ocean applications, this study validates the model in very shallow water where bed-induced wave dissipation is a significant process. Model results show that waves of sufficient energy to prevent establishment or to uproot seedlings are common in areas of the lake that are experiencing the least woody encroachment. Areas of the lake bed that are experiencing encroachment are often sheltered from the strongest waves due to the lakes orientation with respect to dominant winds and prior establishment of woody growth, which dissipates wave energy significantly. Results are consistent with some otherwise-unexplained conditions at the lake such as spatially inconsistent relationships between elevation and vegetation communities. We use model results to investigate feedbacks between woody encoachment (both new and

  12. Woody plant richness does not influence invertebrate community reassembly trajectories in a tree diversity experiment.

    PubMed

    Yeeles, Peter; Lach, Lori; Hobbs, Richard J; van Wees, Mary; Didham, Raphael K

    2017-02-01

    Understanding the relationship between plant diversity and diversity at higher trophic levels is important from both conservation and restoration perspectives. Although there is strong evidence for bottom-up maintenance of biodiversity, this is based largely on studies of simplified grassland systems. Recently, studies in the TreeDivNet global network of tree diversity experiments have begun to test whether these findings are generalizable to more complex ecosystems, such as woodlands. We monitored invertebrate community reassembly over 5 yr of experimental woodland restoration at the TreeDivNet Ridgefield site in southwest Australia, testing the effects of woody plant species richness and herb-layer manipulation on invertebrate community structure and ant species composition. From 2010 to 2014, we sampled ground-dwelling invertebrates using pitfall traps in herbicide vs. no-herbicide subplots nested within each of 10 woody plant treatments varying in richness from zero (bare controls) to eight species, which produced a total of 211, 235 invertebrates, including 98, 979 ants belonging to 74 species. In mixed model analyses, the presence of woody plants was an important driver of faunal community reassembly (relative to bare control plots), but faunal responses to woody plant treatment combinations were idiosyncratic and unrelated to woody plant richness across treatments. We also found that a herbicide-induced reduction in herbaceous plant cover and richness had a positive effect on ant richness and caused more rapid convergence of invertebrate community composition toward the composition of a woodland reference site. These findings show that woody plant richness did not have direct positive effects on the diversity and community reassembly trajectories of higher trophic levels in our woodland system. From a management perspective, this suggests that even low-diversity restoration or carbon sequestration plantings can potentially lead to faunal reassembly outcomes

  13. Lidar-derived estimate and uncertainty of carbon sink in successional phases of woody encroachment

    NASA Astrophysics Data System (ADS)

    Sankey, Temuulen; Shrestha, Rupesh; Sankey, Joel B.; Hardegree, Stuart; Strand, Eva

    2013-07-01

    encroachment is a globally occurring phenomenon that contributes to the global carbon sink. The magnitude of this contribution needs to be estimated at regional and local scales to address uncertainties present in the global- and continental-scale estimates, and guide regional policy and management in balancing restoration activities, including removal of woody plants, with greenhouse gas mitigation goals. The objective of this study was to estimate carbon stored in various successional phases of woody encroachment. Using lidar measurements of individual trees, we present high-resolution estimates of aboveground carbon storage in juniper woodlands. Segmentation analysis of lidar point cloud data identified a total of 60,628 juniper tree crowns across four watersheds. Tree heights, canopy cover, and density derived from lidar were strongly correlated with field measurements of 2613 juniper stems measured in 85 plots (30 × 30 m). Aboveground total biomass of individual trees was estimated using a regression model with lidar-derived height and crown area as predictors (Adj. R2 = 0.76, p < 0.001, RMSE = 0.58 kg). The predicted mean aboveground woody carbon storage for the study area was 677 g/m2. Uncertainty in carbon storage estimates was examined with a Monte Carlo approach that addressed major error sources. Ranges predicted with uncertainty analysis in the mean, individual tree, aboveground woody C, and associated standard deviation were 0.35 - 143.6 kg and 0.5 - 1.25 kg, respectively. Later successional phases of woody encroachment had, on average, twice the aboveground carbon relative to earlier phases. Woody encroachment might be more successfully managed and balanced with carbon storage goals by identifying priority areas in earlier phases of encroachment where intensive treatments are most effective.

  14. Landsat-Based Woody Vegetation Cover Monitoring in Southern African Savannahs

    NASA Astrophysics Data System (ADS)

    Symeonakis, E.; Petroulaki, K.; Higginbottom, T.

    2016-06-01

    Mapping woody cover over large areas can only be effectively achieved using remote sensing data and techniques. The longest continuously operating Earth-observation program, the Landsat series, is now freely-available as an atmospherically corrected, cloud masked surface reflectance product. The availability and length of the Landsat archive is thus an unparalleled Earth-observation resource, particularly for long-term change detection and monitoring. Here, we map and monitor woody vegetation cover in the Northwest Province of South Africa, an area of more than 100,000 km2 covered by 11 Landsat scenes. We employ a multi-temporal approach with dry-season data from 7 epochs between 1990 to 2015. We use 0.5 m-pixel colour aerial photography to collect > 15,000 point samples for training and validating Random Forest classifications of (i) woody vegetation cover, (ii) other vegetation types (including grasses and agricultural land), and (iii) non-vegetated areas (i.e. urban areas and bare land). Overall accuracies for all years are around 80 % and overall kappa between 0.45 and 0.66. Woody vegetation covers a quarter of the Province and is the most accurately mapped class (balanced accuracies between 0.74-0.84 for the 7 epochs). There is a steady increase in woody vegetation cover over the 25-year-long period of study in the expense of the other vegetation types. We identify potential woody vegetation encroachment 'hot-spots' where mitigation measures might be required and thus provide a management tool for the prioritisation of such measures in degraded and food-insecure areas.

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

    NASA Astrophysics Data System (ADS)

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

    2014-12-01

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

  16. First steps in studying the origins of secondary woodiness in Begonia (Begoniaceae): combining anatomy, phylogenetics, and stem transcriptomics

    Treesearch

    Catherine Kidner; Andrew Groover; Daniel C. Thomas; Katie Emelianova; Claudia Soliz-Gamboa; Frederic Lens

    2015-01-01

    Since Darwin's observation that secondary woodiness is common on islands, the evolution of woody plants from herbaceous ancestors has been documented in numerous angiosperm groups. However, the evolutionary processes that give rise to this phenomenon are poorly understood. To begin addressing this we have used a range of approaches to study the anatomical and...

  17. Wood and coal cofiring in interior Alaska: utilizing woody biomass from wildland defensible-space fire treatments and other sources.

    Treesearch

    David L. Nicholls; Stephen E. Patterson; Erin. Uloth

    2006-01-01

    Cofiring wood and coal at Fairbanks, Alaska, area electrical generation facilities represents an opportunity to use woody biomass from clearings within the borough's wildland-urban interface and from other sources, such as sawmill residues and woody material intended for landfills. Potential benefits of cofiring include air quality improvements, reduced greenhouse...

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

    ERIC Educational Resources Information Center

    Germain, Rene' H.; Ghosh, Chandrani

    2013-01-01

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

  19. Analysis of Pre-treatment Woody Vegetation and Environmental Data for the Missouri Ozark Forest Ecosystem Project

    Treesearch

    John M. Kabrick; David R. Larsen; Stephen R. Shifley

    1997-01-01

    We conducted a study to identify pre-treatment trends in woody species density, diameter, and basal area among MOFEP sites, blocks, and treatment areas; relate woody species differences among sites, blocks, and treatment areas to differences in environmental conditions; and identify potential treatment response differences based upon our fmdings. Sites 2 through 5 had...

  20. Effects of herbaceous and woody plant control on Pinus palustris growth and foliar nutrients through six growing seasons

    Treesearch

    James D. Haywood

    2005-01-01

    To determine if either herbaceous or woody plants are more competitive with longleaf pine (Pinuspalustris P. Mill.) seedlings, two vegetation management treatments-herbaceous plant control (HPC, No or Yes) and woody plant control (WPC, No or Yes) were applied in newly established longleaf pine plantings in a randomized complete block 2 x 2 factorial...

  1. Presence or frequency of woody plants in vegetation samples in the costal plain and interior low plateau of Tennessee

    Treesearch

    H.R. Deselm; W.L. Patterson; Vernon Bates; D.B. Durham; R.K. Abernethy; D.C. Eagar; R.P. Ford; Paul.B. Hamel

    1999-01-01

    Records of the woody flora, based on nearly 1500 plotslstands of mainly forest vegetation of West and Middle Tennessee, have been compiled. The data are from 1155 transects (data collected 1993-1995) and 343 0.1 ha plots (data collected 1985-1986). Taxa total 246 species and lesser forms. The dominant woody plants sort into many community types occupying the small...

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

    ERIC Educational Resources Information Center

    Germain, Rene' H.; Ghosh, Chandrani

    2013-01-01

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

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

    SciTech Connect

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

    1994-06-01

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

  4. A STELLA model to estimate water and nitrogen dynamics in a short-rotation woody crop plantation

    Treesearch

    Ying Ouyang; Jiaen Zhang; Theodor D. Leininger; Brent R. Frey

    2015-01-01

    Although short-rotation woody crop biomass production technology has demonstrated a promising potential to supply feedstocks for bioenergy production, the water and nutrient processes in the woody crop planation ecosystem are poorly understood. In this study, a computer model was developed to estimate the dynamics of water and nitrogen (N) species (e.g., NH4...

  5. Response of loblolly pine to complete woody and herbaceous control: projected yields and economic outcomes - the COMProject

    Treesearch

    James H. Miller; R.L. Busby; B.R. Zutter; S.M. Zedaker; M.B. Edwards; R.A. Newbold

    1995-01-01

    Abstract.Age-8 and -9 data from the 13 study plantations of the Competition Omission Monitoring Project (COMP) were used to project yields and derive economic outcomes for loblolly pine (Pinus taeda L.). COMP treatments were chop-burn, complete woody plant control, complete herbaceous plant control for 4 years, and complete woody...

  6. Invertebrate community response to coarse woody debris removal for bioenergy production from intensively managed forests.

    PubMed

    Grodsky, Steven M; Moorman, Christopher E; Fritts, Sarah R; Campbell, Joshua W; Sorenson, Clyde E; Bertone, Matthew A; Castleberry, Steven B; Wigley, T Bently

    2017-09-26

    Increased market viability of harvest residues as forest bioenergy feedstock may escalate removal of coarse woody debris in managed forests. Meanwhile, many forest invertebrates use coarse woody debris for cover, food, and reproduction. Few studies have explicitly addressed effects of operational-scale woody biomass harvesting on invertebrates following clearcutting. Therefore, we measured invertebrate community response to large-scale harvest residue removal and micro-site manipulations of harvest residue availability in recently clearcut, intensively managed loblolly pine (Pinus taeda) forests in North Carolina (NC; n = 4) and Georgia (GA; n = 4), USA. We captured 39,794 surface-active invertebrates representing 171 taxonomic groups using pitfall traps situated among micro-site locations (i.e., purposefully retained piles of hardwood stems and piles of conifer stems and areas without coarse woody debris in NC; windrows and no windrows in GA). Micro-site locations were located within six, large-scale treatments (7.16 - 14.3 ha) in clearcuts. Large-scale treatments represented intensive harvest residue removal, 15% and 30% harvest residue retention, and no harvest residue removal. In NC, ground beetles (Coleoptera: Carabidae) and crickets (Orthoptera: Gryllidae) were three times more abundant in treatments with no harvest residue removal than those with the most intensive harvest residue removal and were reduced in treatments that retained 15% or 30% of harvest residues, although not significantly. Invertebrate taxa richness was greater at micro-site locations with retained hardwood and pine (Pinus spp.) harvest residues than those with minimal amounts of coarse woody debris. In both states, relative abundances of several invertebrate taxa, including cave crickets (Orthoptera: Rhaphidophoridae), fungus gnats (Diptera: Mycetophilidae and Sciaridae), millipedes (Diplopoda), and wood roaches (Blattodea: Ectobiidae), were greater at micro-site locations with retained

  7. Interactions Among Water, Carbon, And Nutrient Cycles With Woody Plant Encroachment Into Grasslands

    NASA Astrophysics Data System (ADS)

    Jackson, R. B.; Engel, V.; Jobbagy, E. G.; McElrone, A. J.; Pockman, W. T.

    2003-12-01

    The expansion of woody plants into deserts, grasslands, and savannas alters water and nutrient cycling, affecting some one-fifth of the world's population. In this talk, research along precipitation gradients in North and South America will be used to examine interactions among water, carbon and nutrients in the southwestern U.S. and in grasslands of Argentina and Uruguay. Those interactions include groundwater uptake, carbon sequestration, changes in salinity and pH, and new evidence for the direct uptake of nutrients at depth using stable isotopes. The talk will end with a discussion of key unanswered research questions at the boundary of hydrology, biology, and geochemistry associated with woody plant encroachment.

  8. Climatic regions as an indicator of forest coarse and fine woody debris carbon stocks in the United States

    PubMed Central

    Woodall, Christopher W; Liknes, Greg C

    2008-01-01

    Background Coarse and fine woody debris are substantial forest ecosystem carbon stocks; however, there is a lack of understanding how these detrital carbon stocks vary across forested landscapes. Because forest woody detritus production and decay rates may partially depend on climatic conditions, the accumulation of coarse and fine woody debris carbon stocks in forests may be correlated with climate. This study used a nationwide inventory of coarse and fine woody debris in the United States to examine how these carbon stocks vary by climatic regions and variables. Results Mean coarse and fine woody debris forest carbon stocks vary by Köppen's climatic regions across the United States. The highest carbon stocks were found in regions with cool summers while the lowest carbon stocks were found in arid desert/steppes or temperate humid regions. Coarse and fine woody debris carbon stocks were found to be positively correlated with available moisture and negatively correlated with maximum temperature. Conclusion It was concluded with only medium confidence that coarse and fine woody debris carbon stocks may be at risk of becoming net emitter of carbon under a global climate warming scenario as increases in coarse or fine woody debris production (sinks) may be more than offset by increases in forest woody detritus decay rates (emission). Given the preliminary results of this study and the rather tenuous status of coarse and fine woody debris carbon stocks as either a source or sink of CO2, further research is suggested in the areas of forest detritus decay and production. PMID:18541029

  9. Obtaining biophysical measurements of woody vegetation from high resolution digital aerial photography in tropical and arid environments: Northern Territory, Australia

    NASA Astrophysics Data System (ADS)

    Staben, G. W.; Lucieer, A.; Evans, K. G.; Scarth, P.; Cook, G. D.

    2016-10-01

    Biophysical parameters obtained from woody vegetation are commonly measured using field based techniques which require significant investment in resources. Quantitative measurements of woody vegetation provide important information for ecological studies investigating landscape change. The fine spatial resolution of aerial photography enables identification of features such as trees and shrubs. Improvements in spatial and spectral resolution of digital aerial photographic sensors have increased the possibility of using these data in quantitative remote sensing. Obtaining biophysical measurements from aerial photography has the potential to enable it to be used as a surrogate for the collection of field data. In this study quantitative measurements obtained from digital aerial photography captured at ground sampling distance (GSD) of 15 cm (n = 50) and 30 cm (n = 52) were compared to woody biophysical parameters measured from 1 ha field plots. Supervised classification of the aerial photography using object based image analysis was used to quantify woody and non-woody vegetation components in the imagery. There was a high correlation (r ≥ 0.92) between all field measured woody canopy parameters and aerial derived green woody cover measurements, however only foliage projective cover (FPC) was found to be statistically significant (paired t-test; α = 0.01). There was no significant difference between measurements derived from imagery captured at either GSD of 15 cm and 30 cm over the same field site (n = 20). Live stand basal area (SBA) (m2 ha-1) was predicted from the aerial photographs by applying an allometric equation developed between field-measured live SBA and woody FPC. The results show that there was very little difference between live SBA predicted from FPC measured in the field or from aerial photography. The results of this study show that accurate woody biophysical parameters can be obtained from aerial photography from a range of woody vegetation

  10. Eleventh-year response of loblolly pine and competing vegetation to woody and herbaceous plant control on a Georgia flatwoods site

    Treesearch

    Bruce R. Zutter; James H. Miller

    1998-01-01

    Through 11 growing seasons, growth of loblolly pine (Pinus taeda L.) increased after control of herbaceous, woody, or both herbaceous and woody vegetation (total control) for the first 3 years after planting on a bedded site in the Georgia coastal flatwoods. Gains in stand volume index from controlling either herbaceous or woody vegetation alone were approximately two-...

  11. How Are Short Rotations Woody Crops Affected By Institutional Factors in the Southern United States?

    Treesearch

    Donald L. Grebner; Rodney L. Busby

    2004-01-01

    Short-rotation woody crops (SRWC) produce a variety of forest products useful to consumers such as pulp, energy biomass, and solid wood. The establishment and management of these crops before conversion into manufactured products are affected by several institutional factors. The first objective of this study was to identify and document institutional structures and...

  12. Phototropic bending of non-elongating and radially growing woody stems results from asymmetrical xylem formation.

    PubMed

    Matsuzaki, Jun; Masumori, Masaya; Tange, Takeshi

    2007-05-01

    Active phototropic bending of non-elongating and radially growing portion of stems (woody stems) has not been previously documented, whereas negative gravitropic bending is well known. We found phototropic bending in woody stems and searched for the underlying mechanism. We inclined 1-year-old Quercus crispula Blume seedlings and unilaterally illuminated them from a horizontal direction perpendicular to ('normal' illumination) or parallel to ('parallel' illumination) the inclination azimuth. With normal illumination, active phototropic bending and xylem formation could be evaluated separately from the negative gravitropic response and vertical deflection resulting from the weight of the seedlings. One-year-old stems with normal illumination bent significantly, with asymmetrical xylem formation towards the illuminated upper surface and side of the stem, whereas those with parallel illumination showed non-significant lateral bending, with asymmetrical xylem formation only on the upper side. A mechanical model was built on the assumption that a bending moment resulted from the asymmetrical xylem formation during phototropic bending of the woody stems. The model fitted the relationship between the observed spatial distributions of the xylem and the observed lateral bending, and thus supported the hypothesis that phototropic bending of woody stems results from asymmetrical xylem formation, as such occurs during gravitropism.

  13. Perennial grasses reduce woody plant seedlings...on mixed conifer fuel-break

    Treesearch

    Harry E. Schimke Lisle R. Green Danny Heavilin

    1970-01-01

    After initial clearing, parts of a fuelbreak on the Stanislaus Nationd Forest, central California, were planted to perennial grasses; other parts were not. After 5 years, a comparison between adjacent seeded sand unseeded strips shows that the perernnials had reduced the number of woody plant seedlings by a factor of 8, height of seedlings by 50 percent, and amount of...

  14. Woody overstorey effects on soil carbon and nitrogen pools in South African savanna

    Treesearch

    A. T. Hudak; C. A. Wessman; T. R. Seastedt

    2003-01-01

    Woody plant encroachment in savannas may alter carbon (C) and nitrogen (N) pools over the longterm, which could have regional or global biogeochemical implications given the widespread encroachment observed in the vast savanna biome. Soil and litter %C and %N were surveyed across four soil types in two encroached, semiarid savanna landscapes in northern South Africa....

  15. Regional gradient analysis and spatial pattern of woody plant communities in Oregon forests.

    Treesearch

    J.L. Ohmann; T.A. Spies

    1998-01-01

    Knowledge of regional-scale patterns of ecological community structure, and of factors that control them, is largely conceptual. Regional- and local-scale factors associated with regional variation in community composition have not been quantified. We analyzed data on woody plant species abundance from 2443 field plots across natural and seminatural forests and...

  16. Growth and foliar nitrogen concentrations of interplanted native woody legumes and pecan

    Treesearch

    J.W. Van Sambeek; Nadia E. Navarrete-Tindall; Kenneth L. Hunt

    2008-01-01

    The interplanting and underplanting of nodulated nitrogen-fixing plants in tree plantings can increase early growth and foliage nitrogen content of hardwoods, especially black walnut and pecan. Recent studies have demonstrated that some non-nodulated woody legumes may be capable of fixing significant levels of atmospheric nitrogen. The following nine nurse crop...

  17. 78 FR 11622 - Request for Proposals: 2013 Hazardous Fuels Woody Biomass Utilization Grant Program

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-02-19

    .... Total Points 15 d. Amount and type of fossil fuel offset in therms/year and increased system fuel use... facts and benefits, such as local employment rate, per capita income and fossil fuel impacts with and...; ] DEPARTMENT OF AGRICULTURE Forest Service Request for Proposals: 2013 Hazardous Fuels Woody Biomass...

  18. Attributes of down woody materials in hardwood forests of the Eastern United States

    Treesearch

    Christopher W. Woodall; Sonja N. Oswalt; Randall S. Morin

    2007-01-01

    The Forest Inventory and Analysis Program (FIA) of the USDA Forest Service conducts a national inventory of down woody materials (DWM) on forestland in the United States. Estimates of DWM for inventory plots occurring in eastern U.S. hardwood forests facilitate large-scale assessment of hardwood forest fuel loadings and wildlife habitat. Therefore, the objectives of...

  19. Biomass and carbon attributes of downed woody materials in forests of the United States

    Treesearch

    C.W. Woodall; B.F. Walters; S.N. Oswalt; G.M. Domke; C. Toney; A.N. Gray

    2013-01-01

    Due to burgeoning interest in the biomass/carbon attributes of forest downed and dead woody materials (DWMs) attributable to its fundamental role in the carbon cycle, stand structure/diversity, bioenergy resources, and fuel loadings, the U.S. Department of Agriculture has conducted a nationwide field-based inventory of DWM. Using the national DWM inventory, attributes...

  20. Sampling protocol, estimation, and analysis procedures for the down woody materials indicator of the FIA program

    Treesearch

    Christopher W. Woodall; Vicente J. Monleon

    2008-01-01

    The USDA Forest Service's Forest Inventory and Analysis program conducts an inventory of forests of the United States including down woody materials (DWM). In this report we provide the rationale and context for a national inventory of DWM, describe the components sampled, discuss the sampling protocol used and corresponding estimation procedures, and provide...

  1. Sampling protocol, estimation, and analysis procedures for the down woody materials indicator of the FIA program

    Treesearch

    Christopher Woodall; Michael Williams

    2005-01-01

    The Forest Inventory and Analysis (FIA) program of the USDA Forest Service conducts a national inventory of forests of the United States. A subset of FIA permanent inventory plots are sampled every year for numerous indicators of forest health ranging from soils to understory vegetation. Down woody material (DWM) is an FIA indicator that provides estimates of forest...

  2. Spatial Modeling of Industrial Windfall on Soils to Detect Woody Species with Potential for Bioremediation

    Treesearch

    S. Salazar; M. Mendoza; A. M. Tejeda

    2006-01-01

    A spatial model is presented to explain the concentration of heavy metals (Fe, Cu, Zn, Ni, Cr, Co and Pb), in the soils around the industrial complex near the Port of Veracruz, Mexico. Unexpected low concentration sites where then tested to detect woody plant species that may have the capability to hiperacumulate these contaminants, hence having a potential for...

  3. Humidity does not appear to trigger leaf out in woody plants

    NASA Astrophysics Data System (ADS)

    Zipf, Lucy; Primack, Richard B.

    2017-08-01

    In order to anticipate the ecological impacts of climate change and model changes to forests, it is important to understand the factors controlling spring leaf out. Leaf out phenology in woody trees and shrubs is generally considered to be strongly controlled by a combination of spring warming, winter chilling requirement, and photoperiod. However, researchers have recently suggested that temperature-related air humidity, rather than temperature itself, might be the main trigger of the spring leaf-out of woody plants. Here, we sought to examine the relationship between air humidity and leaf-out across a range of humidities and plant functional groups. We did not find any consistent, measurable effect of high humidity advancing leaf-out in the 15 woody shrubs and trees examined in this study, and we did not see progressive patterns of earlier leaf-out in successively higher humidities. Our results indicate that more work must be done on this topic before researchers can properly determine the effect of humidity on the leafing out process for woody species.

  4. Immigrant phytophagous insects on woody plants in the United States and Canada: an annotated list.

    Treesearch

    William J. Mattson; P. Niemela; I. Millers; Y. Inguanzo

    1994-01-01

    Nearly 2,000 foreign plants and 2,000 foreign insect species have become naturalized in North America during the past 500 years. This publication documents those immigrant phytophagous insect species which have become established on woody plants or their products in the continental United States and Canada. Of these 368 immigrant insects, 72% came from Europe.

  5. Response of a depleted sagebrush steppe riparian system to grazing control and woody plantings

    Treesearch

    Warren P. Clary; Nancy L. Shaw; Jonathan G. Dudley; Victoria A. Saab; John W. Kinney; Lynda C. Smithman

    1996-01-01

    To find out if a depleted riparian system in the sagebrush steppe of eastern Oregon would respond quickly to improved management, five management treatments were applied for 7 years, ranging from ungrazed to heavily grazed treatments, including in some cases, planting of woody species. While the results varied, all treatments were too limited to significantly restore...

  6. Relationships among woody and herbaceous competition and loblolly pine through mid-rotation (COMP)

    Treesearch

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

    2002-01-01

    To gain baseline data, this study examined loblolly pine (Pinus taeda L.) plantations, across 13 southeastern sites, grown with near-complete control of woody and/or herbaceous competitors for the first 3-5 years. Data through 15 years was analyzed. Contrary to the wide spread assumption that hardwoods out compete pines, the hardwood proportion of...

  7. Ecosystem and restoration consequences of invasive woody species removal in Hawaiian lowland wet forest

    Treesearch

    R. Ostertag; S. Cordell; J. Michaud; T.C. Cole; J.R. Schulten; K.M. Publico; J.H. Enoka

    2009-01-01

    A removal experiment was used to examine the restoration potential of a lowland wet forest in Hawaii, a remnant forest type that has been heavily invaded by non-native species and in which there is very little native species regeneration. All non-native woody and herbaceous biomass (approximately 45% of basal area) was removed in four 100-m² removal plots;...

  8. Woody debris volume depletion through decay: Implications for biomass and carbon accounting

    Treesearch

    Shawn Fraver; Amy M. Milo; John B. Bradford; Anthony W. D’Amato; Laura Kenefic; Brian J. Palik; Christopher W. Woodall; John. Brissette

    2013-01-01

    Woody debris decay rates have recently received much attention because of the need to quantify temporal changes in forest carbon stocks. Published decay rates, available for many species, are commonly used to characterize deadwood biomass and carbon depletion. However, decay rates are often derived from reductions in wood density through time, which when used to model...

  9. Effects of invasive woody plants on avian nest site selection and nesting success in shrublands

    Treesearch

    S. Schlossberg; D.I. King

    2010-01-01

    Exotic, invasive plants are a growing conservation problem. Birds frequently use invasive plants as nest substrates, but effects of invasives on avian nesting success have been equivocal in past studies. In 2004 and 2005, we assessed effects of invasive woody plants on avian nest-site selection and nesting success in western Massachusetts shrublands. At the nest scale...

  10. Evaluation of short-rotation woody crops to stabilize a decommissioned swine lagoon

    Treesearch

    K.C. Dipesh; Rodney E. Will; Thomas C. Hennessey; Chad J. Penn

    2012-01-01

    Fast growing tree stands represent an environmentally friendly, less expensive method for stabilization of decommissioned animal production lagoons than traditional lagoon closure. We tested the feasibility of using short-rotation woody crops (SRWCs) in central Oklahoma to close a decommissioned swine lagoon by evaluating the growth performance and nutrient uptake of...

  11. Patterns of Genetic Variation in Woody Plant Species in the Missouri Ozark Forest Ecosystem Project

    Treesearch

    Victoria L. Sork; Anthony Koop; Marie Ann de la Fuente; Paul Foster; Jay. Raveill

    1997-01-01

    We quantified current patterns of genetic variation of three woody plant species—Carya tomentosa (Juglandaceae), Quercus alba (Fagaceae), and Sassafras albidum (Lauraceae)—distributed throughout the nine Missouri Ozark Forest Ecosystem Project (MOFEP) study sites and evaluated the data in light of the MOFEP...

  12. Modeling large woody debris recruitment for small streams of the Central Rocky Mountains

    Treesearch

    Don C. Bragg; Jeffrey L. Kershner; David W. Roberts

    2000-01-01

    As our understanding of the importance of large woody debris (LWD) evolves, planning for its production in riparian forest management is becoming more widely recognized. This report details the development of a model (CWD, version 1.4) that predicts LWD inputs, including descriptions of the field sampling used to parameterize parts of the model, the theoretical and...

  13. Seedling growth and heavy metal accumulation of candidate woody species for revegetating Korean mine spoils

    Treesearch

    Kyung Won Seo; Yowhan Son; Charles C. Rhoades; Nam Jin Noh; Jin Woo Koo; Jeong-Gyu Kim

    2008-01-01

    Selecting plant species that can overcome harsh soil and microclimatic conditions and speed the recovery of degraded minelands remains a worldwide restoration challenge. This study evaluated the potential of three woody species and various organic and inorganic fertilization treatments for revegetating abandoned metalliferous mines in Korea. We compared survival,...

  14. Predictors, spatial distribution, and occurrence of woody invasive plants in subtropical urban ecosystems

    Treesearch

    Christina L. Staudhammer; Francisco J. Escobedo; Nathan Holt; Linda J. Young; Thomas J. Brandeis; Wayne Zipperer; Other

    2015-01-01

    We examined the spatial distribution, occurrence, and socioecological predictors of woody invasive plants (WIP) in two subtropical, coastal urban ecosystems: San Juan, Puerto Rico and Miami-Dade, United States. These two cities have similar climates and ecosystems typical of subtropical regions but differ in socioeconomics, topography, and urbanization processes. Using...

  15. Nutrient concentration of down woody debris in mixedwood forests in central Maine, USA

    Treesearch

    Mike R. Saunders; Shawn Fraver; Robert G. Wagner

    2011-01-01

    Both nutrient concentrations and pre- and post-harvest pool sizes were determined across down woody debris decay classes of several hardwood and softwood species in a long-term, natural disturbance based, silvicultural experiment in central Maine. Concentrations of N, P, Ca, Mg, Cu, Fe, and Zn generally increased 2- to 5-fold with increasing decay class. Concentrations...

  16. Instrumental texture characteristics of broiler pectoralis major with the woody breast condition

    USDA-ARS?s Scientific Manuscript database

    The objective was to characterize texture properties of raw and cooked broiler fillets (pectoralis major) with the woody breast condition (WBC) using instrumental texture techniques Meullenet-Owens Razor Shear (MORS) and texture profile analysis (TPA). Deboned (3 h postmortem) broiler fillets were c...

  17. Relationships between fire frequency and woody canopy cover in a semi-arid African savanna

    Treesearch

    Andrew T. Hudak; Bruce H. Brockett

    2003-01-01

    Landscape-scale fire patterns result from complex interactions among weather, ignition sources, vegetation type and the biophysical environment (Hargrove et al. 2000, Morgan et al. 2001, Keane et al. 2002, Hudak, Fairbanks & Brockett in press). Patch characteristics (e.g. woody canopy cover) influence fire characteristics, which in turn influence patch...

  18. Coarse woody debris in undisturbed and logged forests in the eastern Brazilian Amazon.

    Treesearch

    Michael Keller; Michael Palace; Gregory P. Asner; Rodrigo Jr. Pereira; Jose Natalino M. Silva

    2004-01-01

    Coarse woody debris (CWD) is an important component of the carbon cycle in tropical forests. We measured the volume and density of fallen CWD at two sites, Cauaxi and Tapajós in the Eastern Amazon. At both sites we studied undisturbed forests (UFs) and logged forests 1 year after harvest. Conventional logging (CL) and reduced impact logging (RIL) were...

  19. The Impacts of the Woody Biomass Utilization Grant Program in Eastern Oregon and Eastern Arizona

    Treesearch

    Emily Jane Davis; Yeon-Su Kim; Cassandra Moseley; Max Niel Sen-Pincus; Ted Bilek

    2014-01-01

    From 2005–10, the USDA Forest Service’s Woody Biomass Utilization Grant program provided grants for equipment acquisition and technical assistance to rural businesses and other entities. These grants were intended to encourage enterprise development, address market barriers to biomass utilization (ranging from small-diameter sawtimber to chips and logging residues),...

  20. Comparing three sampling techniques for estimating fine woody down dead biomass

    Treesearch

    Robert E. Keane; Kathy Gray

    2013-01-01

    Designing woody fuel sampling methods that quickly, accurately and efficiently assess biomass at relevant spatial scales requires extensive knowledge of each sampling method's strengths, weaknesses and tradeoffs. In this study, we compared various modifications of three common sampling methods (planar intercept, fixed-area microplot and photoload) for estimating...

  1. A comprehensive comparison of perpendicular distance sampling methods for sampling downed coarse woody debris

    Treesearch

    Jeffrey H. Gove; Mark J. Ducey; Harry T. Valentine; Michael S. Williams

    2013-01-01

    Many new methods for sampling down coarse woody debris have been proposed in the last dozen or so years. One of the most promising in terms of field application, perpendicular distance sampling (PDS), has several variants that have been progressively introduced in the literature. In this study, we provide an overview of the different PDS variants and comprehensive...

  2. Critical length sampling: a method to estimate the volume of downed coarse woody debris

    Treesearch

    G& #246; ran St& #229; hl; Jeffrey H. Gove; Michael S. Williams; Mark J. Ducey

    2010-01-01

    In this paper, critical length sampling for estimating the volume of downed coarse woody debris is presented. Using this method, the volume of downed wood in a stand can be estimated by summing the critical lengths of down logs included in a sample obtained using a relascope or wedge prism; typically, the instrument should be tilted 90° from its usual...

  3. On fixed-area plot sampling for downed coarse woody debris

    Treesearch

    Jeffrey H. Gove; Paul C. Van Deusen

    2011-01-01

    The use of fixed-area plots for sampling down coarse woody debris is reviewed. A set of clearly defined protocols for two previously described methods is established and a new method, which we call the 'sausage' method, is developed. All methods (protocols) are shown to be unbiased for volume estimation, but not necessarily for estimation of population...

  4. Distance-limited perpendicular distance sampling for coarse woody debris: theory and field results

    Treesearch

    Mark J. Ducey; Micheal S. Williams; Jeffrey H. Gove; Steven Roberge; Robert S. Kenning

    2013-01-01

    Coarse woody debris (CWD) has been identified as an important component in many forest ecosystem processes. Perpendicular distance sampling (PDS) is one of the several efficient new methods that have been proposed for CWD inventory. One drawback of PDS is that the maximum search distance can be very large, especially if CWD diameters are large or the volume factor...

  5. Estimating the quadratic mean diameters of fine woody debris in forests of the United States

    Treesearch

    Christopher W. Woodall; Vicente J. Monleon

    2010-01-01

    Most fine woody debris (FWD) line-intersect sampling protocols and associated estimators require an approximation of the quadratic mean diameter (QMD) of each individual FWD size class. There is a lack of empirically derived QMDs by FWD size class and species/forest type across the U.S. The objective of this study is to evaluate a technique known as the graphical...

  6. Forest operations and woody biomass logistics to improve efficiency, value, and sustainability

    Treesearch

    Nathaniel Anderson; Dana Mitchell

    2016-01-01

    This paper reviews the most recent work conducted by scientists and engineers of the Forest Service of the US Department of Agriculture (USDA) in the areas of forest operations and woody biomass logistics, with an emphasis on feedstock supply for emerging bioenergy, biofuels, and bioproducts applications. This work is presented in the context of previous...

  7. 77 FR 10718 - Request for Proposals: 2012 Hazardous Fuels Woody Biomass Utilization Grant Program

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-02-23

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF AGRICULTURE Forest Service Request for Proposals: 2012 Hazardous Fuels Woody Biomass Utilization Grant Program AGENCY... regulations, contact your appropriate Forest Service Regional Biomass Coordinator as listed in the addresses...

  8. Grazing effect on woody plant recruitment in a Sonoran Desert grassland across space and time

    USDA-ARS?s Scientific Manuscript database

    Livestock grazing is a commonly cited factor contributing to shrub encroachment in savannas and grasslands. Patterns of woody plant proliferation are known to influence rates of erosion and spread of disturbance and are of practical importance to livestock management with regard to forage distribut...

  9. Woody residues and solid waste wood available for recovery in the United States, 2002

    Treesearch

    David B. McKeever; Robert H. Falk

    2004-01-01

    Large amounts of woody residues and solid wood waste are generated annually in the United States from the extraction of timber from forests, from forestry cultural operations, in the conversion of forest land to nonforest uses, in the initial processing of roundwood timber into usable products, in the construction and demolition of buildings and structures, and in the...

  10. Implications of seed banking for recruitment of Southern Appalachian woody species

    Treesearch

    Janneke Hille Ris Lambers; James S. Clark; Michael Lavine

    2002-01-01

    Seed dormancy is assumed to be unimportant for population dynamics of temperate woody species, because seeds occur at low densities and are short lived in forest soils. However, low soil seed densities may result from low seed production, and even modest seed longevity can buffer against fluctuating seed production, potentially limiting density-dependent mortality and...

  11. Processes preventing nocturnal equilibration between leaf and soil water potential in tropical savanna woody species.

    Treesearch

    Sandra Bucci; Fabian G. Scholz; Guillermo Goldstein; Frederick C. Meinzer; Jose A. Hinojosa; William A. Hoffman; Augusto C. Franco

    2004-01-01

    The impact of nocturnal water loss and recharge of stem water storage on predawn disequilibrium between leaf (ΨL) and soil (Ψ S) water potentials was studied in three dominant tropical savanna woody species in central Brazil (Cerrado). Sap flow continued throughout the night during the dry season and...

  12. Promise of combined hydrothermal/chemical and mechanical refining for pretreatment of woody and herbaceous biomass

    USDA-ARS?s Scientific Manuscript database

    Production of advanced biofuels from woody and herbaceous feedstocks is moving into commercialization. Biomass needs to be pretreated to overcome the physicochemical properties of biomass that hinder enzyme accessibility, impeding the conversion of the plant cell walls to fermentable sugars. Pretrea...

  13. Apical dominance and apical control in multiple flushing of temperate woody species.

    Treesearch

    M. Cline; C. Harrington

    2007-01-01

    In young plants of many woody species, the first flush of growth in the spring may be followed by one or more flushes of the terminal shoot if growing conditions are favorable. The occurrence of these additional flushes may significantly affect crown form and structure. Apical dominance (AD) and apical control (AC) are thought to be important control mechanisms in this...

  14. Descriptive texture analyses of cooked patties made of chicken breast with the woody breast condition

    USDA-ARS?s Scientific Manuscript database

    The woody breast (WB) condition is known to negatively influence the texture characteristics and quality of intact broiler breast fillets, but the impact of WB on comminuted meat products are unknown. The objective of this study was to evaluate the effects of WB on the texture and cooking properties...

  15. Is Obsessive-Compulsive Disorder a Disturbance of Security Motivation? Comment on Szechtman and Woody (2004)

    ERIC Educational Resources Information Center

    Taylor, Steven; McKay, Dean; Abramowitz, Jonathan S.

    2005-01-01

    H. Szechtman and E. Woody proposed that obsessive-compulsive disorder (OCD) is caused by a malfunctioning brain security motivation system. In the current article, the authors' review of the model suggests that it is limited in the following ways: (a) It is built on a selective review of the empirical literature, (b) it offers no explanation for…

  16. Application of a conductive polymer electronic-nose device to identify aged woody samples

    Treesearch

    Alphus D. Wilson

    2012-01-01

    The identification of aged woody samples is often a difficult task as a result of weathering and physical deterioration over time which removes or obscures distinguishing anatomical features and characteristics required for visual taxonomic determinations. Fortunately, the chemical characteristics of aged woods usually are preserved better than physical characteristics...

  17. Inventories of woody residues and solid wood waste in the United States, 2002

    Treesearch

    David B. McKeever

    2004-01-01

    Large amounts of woody residues and wood waste are generated annually in the United States. In 2002, an estimated 240 million metric tons was generated during the extraction of timber from the Nation’s forests, from forestry cultural operations, in the conversion of forest land to nonforest uses, in the initial processing of roundwood timber into usable products, in...

  18. Unique technical innovations for short rotation woody crops research and development

    Treesearch

    Adam H. Wiese; Ronald S., Jr. Zalesny

    2006-01-01

    Often technology that is available to conduct short rotation woody crops (SRWC) research is too expensive, difficult to operate, cumbersome, and/or impractical for meeting sample size requirements. Thus, we have designed, constructed, and tested technical innovations that have allowed us to meet our specific experimental needs.

  19. An investigation of the influence of heating modes on ignition and pyrolysis of woody wildland fuel

    Treesearch

    B.L. Yashwanth; B. Shotorban; S. Mahalingam; D.R. Weise

    2015-01-01

    The ignition of woody wildland fuel modeled as a one-dimensional slab subject to various modes of heating was investigated using a general pyrolysis code, Gpyro. The heating mode was varied by applying different convective and/or radiative, time-dependent heat flux boundary conditions on one end of the slab while keeping the other end insulated. Dry wood properties...

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

    ERIC Educational Resources Information Center

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

    2012-01-01

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

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

    ERIC Educational Resources Information Center

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

    2012-01-01

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

  2. A Computer-Based Simulation for Teaching Heat Transfer across a Woody Stem

    ERIC Educational Resources Information Center

    Maixner, Michael R.; Noyd, Robert K.; Krueger, Jerome A.

    2010-01-01

    To assist student understanding of heat transfer through woody stems, we developed an instructional package that included an Excel-based, one-dimensional simulation model and a companion instructional worksheet. Guiding undergraduate botany students to applying principles of thermodynamics to plants in nature is fraught with two main obstacles:…

  3. Phylogenetic diversity of macromycetes and woody plants along an elevational gradient in Eastern Mexico

    Treesearch

    Marko Gomez-Hernandez; Guadalupe Williams-Linera; D. Jean Lodge; Roger Guevara; Eduardo Ruiz-Sanchez; Etelvina Gandara

    2016-01-01

    Phylogenetic information provides insight into the ecological and evolutionary processes that organize species assemblages. We compared patterns of phylogenetic diversity among macromycete and woody plant communities along a steep elevational gradient in eastern Mexico to better understand the evolutionary processes that structure their communities. Macrofungi and...

  4. A Plumber's-Eye View of Xylem Water Transport in Woody Plants

    ERIC Educational Resources Information Center

    Martinez-Vilalta, Jordi; Pinol, Josep

    2004-01-01

    We present a practical for university-level students aimed at measuring and comparing xylem hydraulic properties of co-existing plant species. After sampling branches of several woody species in the field, their main hydraulic properties were measured using a simple set-up. Hydraulic conductivity ("K[subscript h]") was calculated as the ratio…

  5. A Plumber's-Eye View of Xylem Water Transport in Woody Plants

    ERIC Educational Resources Information Center

    Martinez-Vilalta, Jordi; Pinol, Josep

    2004-01-01

    We present a practical for university-level students aimed at measuring and comparing xylem hydraulic properties of co-existing plant species. After sampling branches of several woody species in the field, their main hydraulic properties were measured using a simple set-up. Hydraulic conductivity ("K[subscript h]") was calculated as the ratio…

  6. Cheatgrass invasion and woody species encroachment in the Great Basin: benefits of conservation

    USDA-ARS?s Scientific Manuscript database

    The Great Basin is the largest North American desert covering more than 122.5 million acres. Two of the biggest threats to ecosystem stability and integrity in the Great Basin are invasive annual grasses and expansion of native woody plants. The alteration of native plant communities by these invas...

  7. From Nehemiah Grew to Genomics: the emerging field of evo-devo research for woody plants

    Treesearch

    Andrew Groover; Quentin Cronk

    2013-01-01

    Wood has played a primary role in the evolution of land plants (Spicer and Groover 2010), but our understanding of the genes and mechanisms underlying wood evolution and development has been limited until recently. Importantly, many of the fundamental questions of woody plant evolution and development are now tractable using genomics and high-capacity sequencing...

  8. Converging patterns of uptake and hydraulic redistribution of soil water in contrasting woody vegetation types.

    Treesearch

    F.C. Meinzer; J.R. Brooks; S. Bucci; G. Goldstein; F.G. Scholz; J.M. Arren

    2004-01-01

    We used concurrent measurements of soil water content and soil water potential (Ψsoil) to assess the effects of Ψsoil on uptake and hydraulic redistribution (HR) of soil water by roots during seasonal drought cycles at six sites characterized by differences in the types and amounts of woody vegetations and...

  9. A Computer-Based Multimedia Instruction Program for Woody Plant Identification.

    ERIC Educational Resources Information Center

    Seiler, J. R.; Peterson, J. A.; Taylor, C. D.; Feret, P. P.

    1997-01-01

    Discusses a multimedia-based program designed to provide students with a self-paced study of woody plants using color images of twigs, leaves, bark, fruit, and flowers. The program uses Authorware, software that can be used on both Macintosh- and Windows-compatible platforms. This program is intended for use as a supplement to field-study…

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

    NASA Astrophysics Data System (ADS)

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

    2012-12-01

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

  11. Effects of mesh bag enclosure and termites on fine woody debris decomposition in a subtropical forest

    Treesearch

    Allison M. Stoklosa; Michael D. Ulyshen; Zhaofei Fan; Morgan Varner; Sebastian Seibold; Jorg Muller

    2016-01-01

    The role of insects in terrestrial decomposition remains poorly resolved, particularly for infrequently studied substrates like small diameter woody debris.  Uncertainty about how mesh bags used to exclude arthropods may affect decomposition rates continues to impede progress in this area.  We sought to (1) measure how insects affect the decomposition of small diameter...

  12. Residence times and decay rates of downed woody debris biomass/carbon in eastern US forests

    Treesearch

    Matthew B. Russell; Christopher W. Woodall; Shawn Fraver; Anthony W. D' Amato; Grant M. Domke; Kenneth E. Skog

    2014-01-01

    A key component in describing forest carbon (C) dynamics is the change in downed dead wood biomass through time. Specifically, there is a dearth of information regarding the residence time of downed woody debris (DWD), which may be reflected in the diversity of wood (for example, species, size, and stage of decay) and site attributes (for example, climate) across the...

  13. Transcriptional and Hormonal Regulation of Gravitropism of Woody Stems in Populus

    Treesearch

    Suzanne Gerttula; Matthew S. Zinkgraf; Gloria K. Muday; Daniel R. Lewis; Farid M. Ibatullin; Harry Brumer; Foster Hart; Shawn D. Mansfield; Vladimir Filkov; Andrew Groover

    2015-01-01

    Angiosperm trees reorient their woody stems by asymmetrically producing a specialized xylem tissue, tension wood, which exerts a strong contractile force resulting in negative gravitropism of the stem. Here, we show, in Populus trees, that initial gravity perception and response occurs in specialized cells through sedimentation of starch-filled...

  14. Fascicle Nutrient and Biomass Responses of Young Loblolly Pine to Control of Woody and Herbaceous Competitors

    Treesearch

    Bruce R. Zutter; James H. Miller; H.L. Allen; S.M. Xedaker; M.B. Edwards; R.A. Newbold

    1999-01-01

    Individual fascicle mass and foliar nutrient content and concentration of young loblolly pine (Pinus taeda L.) wen evaluated on 13 locations of a regionwide competition study in the southeastern United States. The study included a factorial combination of two levels of weed control txatmalt (none, treated) and two levels of woody treatment (none,...

  15. Responses of small mammals to coarse woody debris in a southeastern pine forest

    Treesearch

    Susan C. Loeb

    1999-01-01

    The importance of coarse woody debris (CWD) to small mammals in a managed pine forest in South Carolina was tested experimentally during summer and autumn 1990 and winter and spring 1991-1994. Abundance and demographics of small mammals were compared between plots with abundant CWD created by a tornado (unsalvaged plots) and plots where tornado-created CWD had been...

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

    Treesearch

    Timothy S. McCay; Mark J. Komoroski

    2004-01-01

    We trapped shrews at six 9.3 ha plots from which logs ≥10 cm diameter (coarse woody debris; CWD) had been manually removed and six control plots in managed loblolly pine (Pinus taeda) forests of the southeastern coastal plain, USA. Trapping was conducted seasonally between antumn 1997 and summer 2001. Capture rates of Cryptotis...

  17. Fifth-year pine growth response to woody release treatments in young loblolly plantations

    Treesearch

    A.W. Ezell; J.L. Yeiser; L.R. Nelson

    2013-01-01

    The efficacy of adding Oust® XP to woody release treatments was evaluated on second-year pine plantations in Texas, Mississippi, and South Carolina. Overall, the residual control of herbaceous weeds on these sites was excellent the growing season following application. Pine height and diameter growth was evaluated for 5 years following application. Generally, the...

  18. Ethanol production from woody biomass: Silvicultural opportunities for suppressed western conifers

    Treesearch

    Andrew Youngblood; Junyong Zhu; C. Tim. Scott

    2010-01-01

    The 2007 Energy Security and Independence Act (ESIA) requires 16 billion gallons of ethanol to be produced from lignocellulose biomass by 2022 in the United States. Forests can be a key source of renewable lignocellulose for ethanol production if cost and conversion efficiency barriers can be overcome. We explored opportunities for using woody biomass from thinning...

  19. Status of exotic woody species in big cypress national preserve. Technical report

    SciTech Connect

    Gunderson, L.H.

    1983-12-01

    The current status of exotic woody plants in Big Cypress National Preserve is documented. A map of the distribution of principal pest species, Melaleuca quinquenervia, Schinus terebinthifolius, and Casuarina sp., is presented. Prognoses of population increases of these problem species are determined utilizing the current distributions and assessing environmental conditions. Some potential problem species are also identified.

  20. Use of financial and economic analyses by federal forest managers for woody biomass removal

    Treesearch

    Todd A. Morgan; Jason P. Brandt; John D. Baldridge; Dan R. Loeffler

    2011-01-01

    This study was sponsored by the Joint Fire Science Program to understand and enhance the ability of federal land managers to address financial and economic (F&E) aspects of woody biomass removal as a component of fire hazard reduction. Focus groups were conducted with nearly 100 federal land managers throughout the western United States. Several issues and...

  1. Trout use of woody debris and habitat in Wine Spring Creek, North Carolina

    Treesearch

    Patricia A. Flebbe

    1999-01-01

    Wine Spring Creek basin, in the mountains of North Carolina's Nantahala National Forest, is an ecosystem management demonstration site, in which ecological concepts for management and restoration are tested. Large woody debris (LWD) is an important link between streams and the adjacent riparian forest, but evidence for the connection between LWD and trout in the...

  2. Soil water availability and rooting depth as determinants of hydraulic architecture of Patagonian woody species

    Treesearch

    Sandra J. Bucci; Fabian G. Scholz; Guillermo Goldstein; Frederick C. Meinzer; Maria E. Arce

    2009-01-01

    We studied the water economy of nine woody species differing in rooting depth in a Patagonian shrub steppe from southern Argentina to understand how soil water availability and rooting depth determine their hydraulic architecture. Soil water content and potentials, leaf water potentials (Leaf) hydraulic conductivity, wood density (Pw), rooting depth, and specific leaf...

  3. Woody debris as a component of ecological diversity in thinned and unthinned northern hardwood forests

    Treesearch

    Christine E. Hura; Thomas R. Crow

    2004-01-01

    We examined the effects of management on coarse woody debris, both standing and downed, in thinned and unthinned northern hardwood forests in upper Michigan. The unthinned conditions included old growth and second growth, while the thinned conditions included both even- and uneven-aged management. The structural features analyzed were stem diameter, density, basal area...

  4. Changes to soil organic N dynamics with leguminous woody plant encroachment into grasslands

    USDA-ARS?s Scientific Manuscript database

    The encroachment of nitrogen-fixing trees and shrubs into grasslands and savannas occurs worldwide. In the Rio Grande Plains region of southern Texas, previous studies have shown that woody encroachment by leguminous Prosopis glandulosa (mesquite) trees increases soil and microbial biomass nitrogen ...

  5. Degradation of 2,4,5-Trichlorophenoxyacetic Acid in Woody Plants 1

    PubMed Central

    Fitzgerald, Charles H.; Brown, Claud L.; Beck, Edwin G.

    1967-01-01

    Woody plants were sprayed with an aqueous homogenate of the n-butyl ester of 2,4,5-trichlorophenoxyacetic acid. Leaf extracts were studied by gas-liquid chromatography, and 2,4,5-trichlorophenol was always present. The formation of 2,4,5-trichloroanisole apparently did not occur. PMID:16656527

  6. Estimating the carbon in coarse woody debris with perpendicular distance sampling. Chapter 6

    Treesearch

    Harry T. Valentine; Jeffrey H. Gove; Mark J. Ducey; Timothy G. Gregoire; Michael S. Williams

    2008-01-01

    Perpendicular distance sampling (PDS) is a design for sampling the population of pieces of coarse woody debris (logs) in a forested tract. In application, logs are selected at sample points with probability proportional to volume. Consequently, aggregate log volume per unit land area can be estimated from tallies of logs at sample points. In this chapter we provide...

  7. Field results for line intersect distance sampling of coarse woody debris

    Treesearch

    David L. R. Affleck

    2009-01-01

    A growing recognition of the importance of downed woody materials in forest ecosystem processes and global carbon budgets has sharpened the need for efficient sampling strategies that target this resource. Often the aggregate volume, biomass, or carbon content of the downed wood is of primary interest, making recently developed probability proportional-to-volume...

  8. Perpendicular distance sampling: an alternative method for sampling downed coarse woody debris

    Treesearch

    Michael S. Williams; Jeffrey H. Gove

    2003-01-01

    Coarse woody debris (CWD) plays an important role in many forest ecosystem processes. In recent years, a number of new methods have been proposed to sample CWD. These methods select individual logs into the sample using some form of unequal probability sampling. One concern with most of these methods is the difficulty in estimating the volume of each log. A new method...

  9. Effects of large woody debris placement on stream channels and benthic macroinvertebrates

    Treesearch

    Robert H. Hilderbrand; A. Dennis Lemly; C. Andrew Dolloff; Kelly L. Harpster

    1997-01-01

    Large woody debris (LWD)was added as an experimental stream restoration techniquein two streams in southwest Virginia. Additions were designed to compare human judgement in log placements against a randomized design and an unmanipulated reach, &d also to compare effectiveness in a low- and a high-gradient stream. Pool area increased 146% in the systematic placement...

  10. Woody biomass outreach in the southern United States: A case study

    Treesearch

    Martha Monroe; Annie Oxarart

    2011-01-01

    Woody biomass is one potential renewable energy source that is technically feasible where environmental and economic factors are promising. It becomes a realistic option when it is also socially acceptable. Public acceptance and support of wood to energy proposals require community education and outreach. The Wood to Energy Outreach Program provides science-based...

  11. Soil carbon and nitrogen across a chronosequence of woody plant expansion in North Dakota

    USDA-ARS?s Scientific Manuscript database

    Woody plant expansion has been documented on grasslands worldwide as a result of overgrazing and fire suppression, but the changes in ecosystem structure and function accompanying this phenomenon have yet to be extensively studied in the temperate semi-arid grasslands of North America. The primary o...

  12. Critical point relascope sampling for unbiased volume estimation of downed coarse woody debris

    Treesearch

    Jeffrey H. Gove; Michael S. Williams; Goran Stahl; Mark J. Ducey; Mark J. Ducey

    2005-01-01

    Critical point relascope sampling is developed and shown to be design-unbiased for the estimation of log volume when used with point relascope sampling for downed coarse woody debris. The method is closely related to critical height sampling for standing trees when trees are first sampled with a wedge prism. Three alternative protocols for determining the critical...

  13. Carbon in down woody materials of eastern U.S. forests

    Treesearch

    David C. Chojnacky; Robert A. Mickler; Linda S. Heath

    2003-01-01

    To better manage global carbon storage and other ecosystem processes, there is a need for accessible carbon data on components of down woody materials (DWM) in forests. We examined the feasibility of linking available data on DWM to the U.S. Department of Agriculture (USDA) Forest Inventory Analysis (FIA) database, which covers the nation's forest lands. We...

  14. Woody plant communities along urban, suburban, and rural streams in Louisville, Kentucky, USA

    Treesearch

    R. Jonathan White; Margaret M. Carreiro; Wayne C. Zipperer

    2014-01-01

    Anthropogenic changes in land use and cover (LULC) in stream catchments can alter the composition of riparian plant communities, which can affect ecosystem functions of riparian areas and streams from local to landscape scales.We conducted a study to determine if woody plant species composition and abundance along headwater streams were correlated with categorical and...

  15. Case studies on sugar production from underutilized woody biomass using sulfite chemistry

    Treesearch

    J.Y. Zhu; M. Subhosh Chandra; Roland Gleisner; William Gilles; Johnway Gao; Gevan Marrs; Dwight Anderson; John Sessions

    2015-01-01

    We examined two case studies to demonstrate the advantages of sulfite chemistry for pretreating underutilized woody biomass to produce sugars through enzymatic saccharification. In the first case study, we evaluated knot rejects from a magnesium-basedsulfite mill for direct enzymatic sugar production.We found that the sulfite mill rejects are an excellent feedstock for...

  16. The National Inventory of Down Woody Materials: Methods, Outputs, and Future Directions

    Treesearch

    Christopher W. Woodall

    2003-01-01

    The Forest Inventory and Analysis Program (FIA) of the USDA Forest Service conducts a national inventory of forests of the United States. A subset of FIA permanent inventory plots are sampled every year for numerous forest health indicators ranging fiom soils to understory vegetation. Down woody material (DWM) is an FIA indicator that refines estimation of forest...

  17. Development of a downed woody debris forecasting tool using strategic-scale multiresource forest inventories

    Treesearch

    Matthew B. Russell; Christopher W. Woodall

    2017-01-01

    The increasing interest in forest biomass for energy or carbon cycle purposes has raised the need for forest resource managers to refine their understanding of downed woody debris (DWD) dynamics. We developed a DWD forecasting tool using field measurements (mean size and stage of stage of decay) for three common forest types across the eastern United States using field...

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

    EPA Science Inventory

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

  19. Overstory and understory relationships in longleaf pine plantations 14 years after thinning and woody control

    Treesearch

    Timothy B. Harrington

    2011-01-01

    To develop silvicultural strategies for restoring longleaf pine (Pinus palustris Mill.) savannas, mortality and growth of overstory pines and midstory hardwoods and abundance and species richness of herbs were studied for 14 years after pine thinning and nonpine woody control. Pine cover in thinned stands was about half of that in nonthinned stands...

  20. Spatio-temporal variation of coarse woody debris input in woodland key habitats in central Sweden

    Treesearch

    Mari Jonsson; Shawn Fraver; Bengt Gunnar. Jonsson

    2011-01-01

    The persistence of many saproxylic (wood-living) species depends on a readily available supply of coarse woody debris (CWD). Most studies of CWD inputs address stand-level patterns, despite the fact that many saproxylic species depend on landscape-level supplies of CWD. In the present study we used dated CWD inputs (tree mortality events) at each of 14 Norway spruce (...

  1. [Frost-resistance of subtropical evergreen woody plants: an evaluation based on plant functional traits].

    PubMed

    Xu, Yi-Lu; Yang, Xiao-Dong; Xu, Yue; Xie, Yi-Ming; Wang, Liang-Yan; Yan, En-Rong

    2012-12-01

    Evaluating the frost-resistance of evergreen woody plants is of significance in guiding the species selection in forest management in subtropical region. In this paper, an investigation was made on the functional traits (including specific leaf area, stem wood density, leaf area, leaf dry matter content, leaf relative electrical conductance, and twig wood density) of 64 common evergreen broad-leaved and coniferous woody plant species in the Ningbo region of Zhejiang Province, East China, after a severe snowstorm in early 2008, aimed to select the evergreen woody plants with high ability of freeze-tolerance, and to establish a related evaluation system. By using a hierarchy analysis approach, the weight values of the functional traits of each species were determined, and an index system for evaluating the plants tolerance ability against freeze and mechanical damage was established. Based on this system, 23 evergreen plant species with high tolerance ability against freeze and mechanical damage, such as Cyclobalanopsis gilva, Cyclobalanopsis nubium, Neolitsea aurata, and Vacciniuim mandarinorum, were selected. In the meantime, on the basis of the ordering with each of the functional traits, the ordering of the tolerance ability of the 64 plant species against freeze and mechanical damage was made, and a list for the frost-resistance ability of the subtropical evergreen woody plant species in Ningbo region was constituted.

  2. Coarse Woody Debris Ecology in a Second-Growth Sequoia sempervirens Forest Stream

    Treesearch

    Matthew D. O' Connor; Robert R. Ziemer

    1989-01-01

    Coarse woody debris (CWD) contributes to high quality habitat for anadromous fish. CWD volume, species, and input mechanisms was inventoried in North Fork Caspar Creek to assess rates of accumulation and dominant sources of CWD in a 100-year-old second-growth redwood (Sequoia sempervirens) forest. CWD accumulation in the active stream channel and in...

  3. Controlling coarse woody debris inventory quality: taper and relative size methods

    Treesearch

    C.W. Woodall; J.A. Westfall

    2008-01-01

    Accurately measuring the dimensions of coarse woody debris (CWD) is critical for ensuring the quality of CWD estimates and, hence, for accurately estimating forest ecosystem attributes (e.g., CWD carbon stocks). To improve the quality of CWD dimensional measurements, the distribution of taper (ratio of change in diameter and length) and relative size (RS; ratio of...

  4. Woody plant establishment in grassed reclamation areas of the Athabasca oil sands

    SciTech Connect

    Fedkenheuer, A.W.

    1980-12-01

    The primary end land use for areas disturbed by the Syncrude Canada Ltd. oil sands surface mining venture is forest cover. Short term erosion control is of concern, however, and this results in the early establishment of a grass and legume cover. Problems have subsequently been encountered in attempts to establish woody plants in the grass and legume cover. Vegetation competition for soil moisture and nutrients and rodent damage to woody seedlings have been the major problem areas. A study was initiated in 1978 to evaluate methods of manipulating the grass and legume cover sufficiently to improve success rates in establishing a variety of shrubs and trees. Five replicated treatments using the chemical herbicide glyphosate, soil scarification and fire alone plus soil scarification were established on an area seeded to grass and legumes in spring 1976. Woody plant survival and rodent damage, populations and distribution are being assessed annually in spring and fall. Rodent damage to woody seedlings was heavy in fall 1978 with 80 percent of the deciduous seedlings on non-scarified plots being damaged. In June 1979, 98 percent of the deciduous plants on the control and herbicide treatment areas were damaged. Damage to conifers was approximately 30 percent less during this time. Prescribed burning and mechanical scarification substantially reduced rodent damage. Seedling survival was variable with Amelanchier alnifolia, Pinus contorta and Populus tremuloides consistently exhibiting the highest survival rates.

  5. Decomposition rates of American chestnut (Castanea dentata) wood and implications for coarse woody debris pools

    Treesearch

    Arjan de Bruijn; Eric J. Gustafson; Daniel M. Kashian; Harmony J. Dalgleish; Brian R. Sturtevant; Douglass F. Jacobs

    2014-01-01

    Observations of the rapid growth and slow decomposition of American chestnut (Castanea dentata (Marsh.) Borkh.) suggest that its reintroduction could enhance terrestrial carbon (C) sequestration. A suite of decomposition models was fit with decomposition data from coarse woody debris (CWD) sampled in Wisconsin and Virginia, U.S. The optimal (two-...

  6. Specific gravity of coarse woody debris for some central Appalachian hardwood forest species

    Treesearch

    M.B. Adams; D.R. Owens

    2001-01-01

    Although coarse woody debris (CWD) may play an important role in nutrient cycling in eastern hardwood forests, it rarely is included in nutrient budgets for most ecosystems. Meaningful nutrient budgets require reliable estimates of biomass and nutrient concentrations. The CWD of 21 tree species was sampled in a central Appalachian forest within the Fernow Experimental...

  7. Design considerations for a roll crusher/splitter for woody biomass

    Treesearch

    Donald L. Sirois; Colin Ashmore

    1986-01-01

    The principal focus of biomass harvesting in the past has been the use of chipping systems to reduce a wide variety of woody materials down to small pieces for easier handling and transporting. However, chipping systems have several short comings that limit their operational environments. For example, a conventional chipping system might not be applicable for...

  8. Transpirational drying and costs for transporting woody biomass - a preliminary review

    Treesearch

    Bryce J. Stokes; Bryce J. McDonaStokes; Timothy P. McDonald; Tyrone Kelley

    1993-01-01

    High transport costs arc a factor to consider in the use of forest residues for fuel. Costs can be reduced by increasing haul capacities, reducing high moisture contents, and improving trucking efficiency. The literature for transpirational drying and the economics of hauling woody biomass is summarized here. Some additional, unpublished roundwood and chipdrying test...

  9. Estimating combustion of large downed woody debris from residual white ash

    Treesearch

    Alistair M. S. Smith; Andrew T. Hudak

    2005-01-01

    The production of residual white ash patches within wildfires represents near-complete combustion of the available fuel and releases a considerable quantity of gases to the atmosphere. These patches are generally produced from combustion of large downed woody debris (LDWD) such as fallen trees and snags. However, LDWD are generally ignored in calculations of fuel...

  10. Pinus Taeda L. response to fertilization, Herbaceous plant control, and woody plant control

    Treesearch

    Allan E. Tiarks; James D. Haywood

    1986-01-01

    On an intensively prepared site, a complete fertilizer applied at planting, and control of herbaceous and woody plants for the first 4 years, increased Pinus taeda L. volume at age 5 to 25.9 m3/ha compared to 11.8 m3/ha without the treatments. The fertilizer and competition control factors affected pine...

  11. Cambial activity in dry and rainy season on branches from woody species growing in Brazilian Cerrado

    Treesearch

    Carmen R. Marcati; Silvia R. Machado; Diego Sotto Podadera; Natalia O. Totti de Lara; Fabio Bosio; Alex C. Wiedenhoeft

    2016-01-01

    Seasonal cambial activity was investigated in one- to three-year-old branch modules (branch constructional units) of ten woody species from cerrado sensu stricto, a savanna-like ecosystem, of southernBrazil. Relationships between cambial activity and environmental factors (precipitation, temperature,day length) and leaf production were tested using...

  12. A Computer-Based Simulation for Teaching Heat Transfer across a Woody Stem

    ERIC Educational Resources Information Center

    Maixner, Michael R.; Noyd, Robert K.; Krueger, Jerome A.

    2010-01-01

    To assist student understanding of heat transfer through woody stems, we developed an instructional package that included an Excel-based, one-dimensional simulation model and a companion instructional worksheet. Guiding undergraduate botany students to applying principles of thermodynamics to plants in nature is fraught with two main obstacles:…

  13. Linking climate change and downed woody debris decomposition across forests of the eastern United States

    Treesearch

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

    2014-01-01

    Forest ecosystems play a critical role in mitigating greenhouse gas emissions. Forest carbon (C) is stored through photosynthesis and released via decomposition and combustion. Relative to C fixation in biomass, much less is known about C depletion through decomposition of woody debris, particularly under a changing climate. It is assumed that the increased...

  14. Estimates of downed woody debris decay class transitions for forests across the eastern United States

    Treesearch

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

    2013-01-01

    Large-scale inventories of downed woody debris (DWD; downed dead wood of a minimum size) often record decay status by assigning pieces to classes of decay according to their visual/structural attributes (e.g., presence of branches, log shape, and texture and color of wood). DWD decay classes are not only essential for estimating current DWD biomass and carbon stocks,...

  15. Future market scenarios for pulpwood supply from agricultural short-rotation woody crops

    Treesearch

    Alexander N. Moiseyev; Daniel G. de la Torre Ugarte; Peter J. Ince

    2000-01-01

    The North American Pulp And Paper (NAPAP) model and USDA POLYSYS agricultural policy analysis model were linked to project future market scenarios for pulpwood supply from agricultural short-rotation woody crops in the United States. Results suggest that pulpwood supply from fast- growing hybrid poplars and cottonwoods will become marginally economical but fairly...

  16. Seasonal Biennial Burning and Woody Plant Control Influence Native Vegetation in Loblolly Pine Stands

    Treesearch

    James D. Haywood; Alton Martin; Henry A. Pearson; Harold E. Grelen

    1998-01-01

    This paper documents the results of a study to determine the effects of selectedvegetation-management treatments in loblolly pine. Vegetation in precommercially thinned, 6-year-old stands was subjected to five biennial growing season burns in either early March, May, or July coupled with hand felling of residual woody stems. Using a randomized complete block design, we...

  17. 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....

  18. Nitrogen immobilization by decomposing woody debris and the recovery of tropical wet forest from hurricane disturbance

    Treesearch

    Jess K. Zimmerman; William M. Pulliam; D. Jean Lodge; Vanessa Quinones-Orfila; Ned Fetcher; Sandra Guzman-Grajales; John A. Parrotta; Clyde E. Asbury; Lars R. Walker; Robert B. Waide

    1995-01-01

    Following damage caused by Hurricane Hugo (September 1989) we monitored inorga­nic nitrogen availability in soil twice in 1990, leaf area index in 1991 and 1993, and litter production from 1990 through 1992 in subtropical wet forest of eastem Puerto Rico. Experimental removal of litter and woody debris generated by the hurricane (plus any standing stocks present before...

  19. Coarse woody debris carbon storage across a mean annual temperature gradient in tropical montane wet forest

    Treesearch

    Darcey K. Iwashita; Creighton M. Litton; Christian P. Giardina

    2013-01-01

    Coarse woody debris (CWD; defined here as fallen and standing dead trees and tree ferns) is a critical structural and functional component of forest ecosystems that typically comprises a large proportion of total aboveground carbon (C) storage. However, CWD estimates for the tropics are uncommon, and little is known about how C storage in CWD will respond to climate...

  20. Polyamines and inorganic ions extracted from woody tissues by freeze-thawing

    Treesearch

    Rakesh Minocha; Walter C. Shortle

    1994-01-01

    A simple and fast method for extraction of major inorganic ions (Ca, Mg, Mn, K, and P) and cellular polyamines from small quantities of wood and woody plant tissues is described. The method involves repeated freezing and thawing of samples instead of homogenization or wet ash digestion. The efficiency of extraction of both polyamines and inorganic ions by these methods...

  1. End-point diameter and total length coarse woody debris models for the United States

    Treesearch

    C.W. Woodall; J.A. Westfall; D.C. Lutes; S.N. Oswalt

    2008-01-01

    Coarse woody debris (CWD) may be defined as dead and down trees of a certain minimumsize that are an important forest ecosystem component (e.g., wildlife habitat, carbon stocks, and fuels). Due to field efficiency concerns, some natural resource inventories only measure the attributes of CWD pieces at their point of intersection with a sampling transect (e.g., transect...

  2. Trout Use of Woody Debris and Habitat in Appalachian Wilderness Streams of North Carolina

    Treesearch

    Patricia A. Flebbe; C. Andrew Dolloff

    1995-01-01

    Wilderness areas in the Appalachian Mountains of North Carolina are set aside to preserve characteristics of both old-growth and second-growth forests and associated streams. Woody debris loadings, trout habitat, and trout were inventoried in three southern Appalachian wilderness streams in North Carolina by the basin-wide visual estimation technique. Two streams in...

  3. Application of conductive polymer analysis for wood and woody plant identifications

    Treesearch

    A. Dan Wilson; D.G. Lester; Charisse S. Oberle

    2005-01-01

    An electronic aroma detection (EAD) technology known as conductive polymer analysis (CPA) was evaluated as a means of identifying and discriminating woody samples of angiosperms and gymnosperms using an analytical instrument (electronic nose) that characterizes the aroma profiles of volatiles released from excised wood into sampled headspace. The instrument measures...

  4. Response of native Hawaiian woody species to lava-ignited wildfires in tropical forests and shrublands

    Treesearch

    Alison Ainsworth; J. Boone Kauffman

    2009-01-01

    Wildfires are rare in the disturbance history of Hawaiian forests but may increase in prevalence due to invasive species and global climate change. We documented survival rates and adaptations facilitating persistence of native woody species following 2002–2003 wildfires in Hawaii Volcanoes National Park, Hawaii. Fires occurred during an El Niño drought and were...

  5. Woody plants and the prediction of climate-change impacts on bird diversity

    PubMed Central

    Kissling, W. D.; Field, R.; Korntheuer, H.; Heyder, U.; Böhning-Gaese, K.

    2010-01-01

    Current methods of assessing climate-induced shifts of species distributions rarely account for species interactions and usually ignore potential differences in response times of interacting taxa to climate change. Here, we used species-richness data from 1005 breeding bird and 1417 woody plant species in Kenya and employed model-averaged coefficients from regression models and median climatic forecasts assembled across 15 climate-change scenarios to predict bird species richness under climate change. Forecasts assuming an instantaneous response of woody plants and birds to climate change suggested increases in future bird species richness across most of Kenya whereas forecasts assuming strongly lagged woody plant responses to climate change indicated a reversed trend, i.e. reduced bird species richness. Uncertainties in predictions of future bird species richness were geographically structured, mainly owing to uncertainties in projected precipitation changes. We conclude that assessments of future species responses to climate change are very sensitive to current uncertainties in regional climate-change projections, and to the inclusion or not of time-lagged interacting taxa. We expect even stronger effects for more specialized plant–animal associations. Given the slow response time of woody plant distributions to climate change, current estimates of future biodiversity of many animal taxa may be both biased and too optimistic. PMID:20513712

  6. Forest structure and downed woody debris in boreal temperate, and tropical forest fragments

    Treesearch

    William A. Gould; Grizelle Gonzalez; Andrew T. Hudak; Teresa Nettleton Hollingsworth; Jamie Hollingsworth

    2008-01-01

    Forest fragmentation affects the heterogeneity of accumulated fuels by increasing the diversity of forest types and by increasing forest edges. This heterogeneity has implications in how we manage fuels, fire, and forests. Understanding the relative importance of fragmentation on woody biomass within a single climatic regime, and along climatic gradients, will improve...

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

    Treesearch

    Travis M. Hinkelman; John L. Orrock; Susan C Loeb

    2011-01-01

    Anti-Predator behavior can affect prey growth, reproduction, survival, and generate emergent effects in food webs. Small mammals often lower the cost of predation by altering their behavior in response to shrubs, but the importance of other microhabitat features, such as downed woody debris, for anti-predator behavior is unknown. We used giving-up densities to quantify...

  8. Disturbance and diversity of wood-inhabiting fungi: effects of canopy gaps and downed woody debris

    Treesearch

    Nicholas J. Brazee; Daniel L. Lindner; Anthony W. D' Amato; Shawn Fraver; Jodi A. Forrester; David J. Mladenoff

    2014-01-01

    Experimental canopy gap formation and additions of coarse woody debris (CWD) are techniques intended to mimic the disturbance regime and accelerate the development of northern hardwood forests. The effects of these techniques on biodiversity and ecosystem functioning were investigated by surveying the abundance and diversity of wood-inhabiting fungi in six treatments...

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

    EPA Science Inventory

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

  10. Lidar-derived estimate and uncertainty of carbon sink in successional phases of woody encroachment

    USDA-ARS?s Scientific Manuscript database

    Woody encroachment is a globally occurring phenomenon that is thought to contribute significantly to the global carbon (C) sink. The C contribution needs to be estimated at regional and local scales to address large uncertainties present in the global- and continental-scale estimates and guide regio...

  11. Woody biomass pretreatment for cellulosic ethanol production : technology and energy consumption evaluation

    Treesearch

    Junyong Zhu; X.J. Pan

    2010-01-01

    This review presents a comprehensive discussion of the key technical issues in woody biomass pretreatment: barriers to efficient cellulose saccharification, pretreatment energy consumption, in particular energy consumed for wood-size reduction, and criteria to evaluate the performance of a pretreatment. A post-chemical pretreatment size-reduction approach is proposed...

  12. Energy product options for Eucalyptus species grown as short rotation woody crops

    Treesearch

    Donald Rockwood; Alan W. Rudie; Sally A. Ralph; J.Y. Zhu; Jerrold E. Winandy

    2008-01-01

    Eucalyptus species are native to Australia but grown extensively worldwide as short rotation hardwoods for a variety of products and as ornamentals. We describe their general importance with specific emphasis on existing and emerging markets as energy products and the potential to maximize their productivity as short rotation woody crops. Using experience in Florida...

  13. A Regional Study on the Influence of Woody and Herbaceous Competition on Early Loblolly Pine Growth

    Treesearch

    James H. Miller; Bruce R. Zutter; Shepard M. Zedaker; M. Boyd Edward; James D. Haywood

    1991-01-01

    A common study design has been installed at 14 locatoins Southwide to track the growth of loblolly pine established with four different competition control treatments: (a) no control, (b) woody control, (c) herbaceous control, and (d) total control after site preparation. This regionwide investigation is the Competition Omission Monitoring Project (COMP). During the...

  14. Soil physical properties regulate lethal heating during burning of woody residues

    Treesearch

    Matt Busse; Carol Shestak; Ken Hubbert; Eric Knapp

    2010-01-01

    Temperatures well in excess of the lethal threshold for roots (60°C) have been measured in forest soils when woody fuels are burned. Whether this heat pulse is strongly moderated by soil moisture or soil texture is not fully understood, however. We measured soil heat profi les during 60 experimental burns, identifying changes in maximum soil temperature and heat...

  15. Displacement of native riparian shrubs by woody exotics: Effects on arthropod and pollinator community composition

    Treesearch

    Rosemary L. Pendleton; Burton K. Pendleton; Deborah Finch

    2011-01-01

    Throughout the southwestern U.S., riparian gallery forests of cottonwood and willow are being invaded by woody exotics, primarily Russian olive and salt cedar. We wondered what effect this might have on native pollinator populations. Pollinators are indispensable contributors to biodiversity, ecosystem health, and human food production. Recent declines in pollinator...

  16. Effects of woody debris on anadromous salmonid habitat, Prince of Wales Island, southeast Alaska

    Treesearch

    Thomas E. Lisle

    1986-01-01

    Abstract - The effects of woody debris on anadromous salmonid habitat in eight streams on Prince of Wales Island, southeast Alaska, were investigated by comparing low-gradient (1-9%) first- or second-order streams flowing through either spruce-hemlock forests or 6-10-year-old clearcuts, and by observing changes after debris was selectively removed from clear-cut...

  17. Carbon Exchange and Water Use in Karst Landscapes: Impact of Woody Encroachment

    NASA Astrophysics Data System (ADS)

    Heilman, J. L.; Litvak, M. E.

    2008-05-01

    Woody plant invasion into grasslands and savannas, and its impact on water use are critical issues in karst landscapes because 25% of the world's population obtains its water from karst aquifers. It is well documented that woody encroachment increases carbon sequestration, but its impact on water use is less clear. It is widely presumed that woody plants increase evapotranspiration (ET), in part because deep root systems provide access to a more stable supply of water than what is available to grasses. If this is true, woody encroachment should reduce the sensitivity of carbon exchange and ET to rainfall pulses and water deficits, and vulnerability to drought. Since 2004, we have been investigating, via eddy covariance, carbon exchange and water use on a grassland, a savanna with approximately 35% woody cover, and a dense live oak-Ashe juniper forest on the karst Edwards Plateau in south and west central Texas. The Plateau is a 93,000 km2 karst ecoregion that is dominated by live oak-Ashe juniper savannas underlain by mixed C3/C4 grasses, and soils are generally shallow. The Plateau contains the Edwards Aquifer which supplies drinking water to over 2 million people, and is home to a number of threatened and endangered species, many of them aquatic. Populations of juniper are expanding due to suppression of wildfires, and public funds are being spent to remove juniper in an attempt to increase water availability. Our measurements show large differences in carbon sequestration among the ecosystems (highest in savanna and lowest in grassland), and small differences in ET (~0.2 mm day-1 higher in the forest than in the grassland). We attribute increased ET to increases in net radiation, and proportionally greater partitioning of available energy into sensible heat flux at the expense of latent heat flux. We found little differences in response of carbon exchange and ET to rainfall and water deficits, regardless of the amount of woody cover, intensity of rainfall, or

  18. Long-term livestock exclusion facilitates native woody plant encroachment in a sandy semiarid rangeland

    PubMed Central

    Su, Hua; Liu, Wei; Xu, Hong; Wang, Zongshuai; Zhang, Huifang; Hu, Haixiao; Li, Yonggeng

    2015-01-01

    The role of livestock grazing in regulating woody cover and biomass in grass-dominant systems is well recognized. However, the way in which woody plant populations in respond when livestock are removed from grazing in the absence of other disturbances, such as fire, remains unclear. We conducted a 10-year, replicated fencing experiment in a sandy semiarid rangeland in northern China (which has a mean annual rainfall of 365 mm), where fires have been actively suppressed for decades. Fencing dramatically influenced the growth and age structure of the native tree species, Ulmus pumila, which is the sole dominant tree in the area. After a decade, the density of the U. pumila tree population in the fencing plots increased doubly and canopy cover increased triply. The proportion of both saplings (U2) and young trees (U3) increased in fencing plots but decreased in grazing plots after the 10-year treatment period. The effects of fencing on U. pumila trees varied by age class, with potential implications for the future structure of the U. pumila tree community. Decadal fencing led to approximately 80-fold increase in recruitment and a nearly 2.5-fold decrease in the mortality of both U2 and U3. Further, livestock grazing generated a “browsing trap” to the recruitment of both U2 and U3, and had a small impact on the mortality of old trees. A long-term, fencing-driven shift in woody species composition was mediated via its effects on both recruitment and mortality rates. Synthesis and applications. Our results demonstrate that in the long-term absence of both fire and livestock, native woody plant encroachment tends to occur in sandy rangelands, transforming the woody plant demography in the process. The feasibility of full livestock exclusion in sandy rangelands requires further discussion. A balanced amount of livestock grazing may provide critical ecosystem services by regulating woody cover and mediating woody plant encroachment. PMID:26120433

  19. Changes in soil phosphorus fractions following woody plant invasion of grassland

    NASA Astrophysics Data System (ADS)

    Kantola, I. B.; Boutton, T. W.; Filley, T. R.; Hallmark, C. T.

    2010-12-01

    Many grass-dominated ecosystems around the world have experienced woody plant encroachment over the last century due to livestock grazing, fire suppression, and/or changes in climate and atmospheric chemistry. In the Rio Grande Plains of Texas, subtropical thorn woodlands dominated by N-fixing tree legumes have largely replaced grasslands and altered the biogeochemistry of this region. The purpose of this study was to assess the impact of this grassland-to-woodland transition on the size, distribution, and availability of soil P pools. A modified Hedley method was employed to fractionate soil P into pools based on organic and inorganic forms and relative plant-availability. Soil samples (0-10 cm) were collected in remnant grasslands and near the centers of woody plant clusters ranging in age from 14 to 86 years in a subtropical savanna parkland in southern Texas. Soil P was fractionated into resin-extractable inorganic P, bicarbonate-extractable organic and inorganic P, hydroxide-extractable organic and inorganic P, acid-extractable inorganic P, and residual inorganic P forms. P concentrations in these fractions were determined by colorimetry, and soil total P was determined by lithium fusion. Organic P was calculated from the difference between total and inorganic P. Total P in whole soils increased dramatically from 102 mg P/kg soil in remnant grasslands to 166 mg P/kg soil in the oldest woody plant stands (70-85 years). P concentrations in all pools increased linearly with increasing woody plant stand age except acid-extractable phosphorus. The most dramatic increases were observed in the resin-extractable fraction (plant-available P), which increased from 3 to 13 mg P/kg soil, and in hydroxide-extractable P (the majority of the organic P in the system), which increased from 15 mg P/kg soil in grasslands to 26 mg P/kg soil in the wooded clusters. Although the exact mechanisms by which soil P increases following woody invasion remain unknown, we suggest that the

  20. Changes in Soil Phosphorus Fractions Following Woody Plant Invasion of Grassland

    NASA Astrophysics Data System (ADS)

    Boutton, T. W.; Kantola, I. B.; Filley, T. R.

    2012-12-01

    Many grass-dominated ecosystems around the world have experienced woody plant encroachment over the last century due to livestock grazing, fire suppression, and/or changes in climate and atmospheric chemistry. In the Rio Grande Plains of Texas, subtropical thorn woodlands dominated by N-fixing tree legumes have largely replaced grasslands and altered the biogeochemistry of this region. The purpose of this study was to assess the impact of this grassland-to-woodland transition on the size, distribution, and availability of soil P pools. A modified Hedley method was employed to fractionate soil P into pools based on organic and inorganic forms and relative plant-availability. Soil samples (0-10 cm) were collected in remnant grasslands and near the centers of woody plant clusters ranging in age from 14 to 86 yrs in a subtropical savanna parkland in southern Texas. Soil P was fractionated into resin-extractable inorganic P, bicarbonate-extractable organic and inorganic P, hydroxide-extractable organic and inorganic P, acid-extractable inorganic P, and residual inorganic P forms. P concentrations in these fractions were determined by colorimetry, and soil total P was determined by lithium fusion. Organic P was calculated from the difference between total and inorganic P. Total P in whole soils increased dramatically from 98 mg P kg-1 soil in remnant grasslands to 168 mg P kg-1 soil in the oldest woody plant stands (70-85 yrs). P concentrations in all pools increased linearly with increasing woody plant stand age except acid-extractable phosphorus. The most dramatic increases were observed in the resin-extractable fraction (plant-available P), which increased from 3 to 13 mg P kg-1 soil, and in hydroxide-extractable P (the majority of the organic P in the system), which increased from 15 mg P kg-1 soil in grasslands to 26 mg P kg-1 soil in the wooded clusters. Although the exact mechanisms by which soil P increases following woody invasion remain unknown, we suggest that

  1. Long-term livestock exclusion facilitates native woody plant encroachment in a sandy semiarid rangeland.

    PubMed

    Su, Hua; Liu, Wei; Xu, Hong; Wang, Zongshuai; Zhang, Huifang; Hu, Haixiao; Li, Yonggeng

    2015-06-01

    The role of livestock grazing in regulating woody cover and biomass in grass-dominant systems is well recognized. However, the way in which woody plant populations in respond when livestock are removed from grazing in the absence of other disturbances, such as fire, remains unclear.We conducted a 10-year, replicated fencing experiment in a sandy semiarid rangeland in northern China (which has a mean annual rainfall of 365 mm), where fires have been actively suppressed for decades.Fencing dramatically influenced the growth and age structure of the native tree species, Ulmus pumila, which is the sole dominant tree in the area. After a decade, the density of the U. pumila tree population in the fencing plots increased doubly and canopy cover increased triply. The proportion of both saplings (U 2 ) and young trees (U 3 ) increased in fencing plots but decreased in grazing plots after the 10-year treatment period. The effects of fencing on U. pumila trees varied by age class, with potential implications for the future structure of the U. pumila tree community. Decadal fencing led to approximately 80-fold increase in recruitment and a nearly 2.5-fold decrease in the mortality of both U 2 and U 3 . Further, livestock grazing generated a "browsing trap" to the recruitment of both U 2 and U 3 , and had a small impact on the mortality of old trees. A long-term, fencing-driven shift in woody species composition was mediated via its effects on both recruitment and mortality rates.Synthesis and applications. Our results demonstrate that in the long-term absence of both fire and livestock, native woody plant encroachment tends to occur in sandy rangelands, transforming the woody plant demography in the process. The feasibility of full livestock exclusion in sandy rangelands requires further discussion. A balanced amount of livestock grazing may provide critical ecosystem services by regulating woody cover and mediating woody plant encroachment.

  2. Woody-to-total area ratio determination with a multispectral canopy imager.

    PubMed

    Zou, Jie; Yan, Guangjian; Zhu, Ling; Zhang, Wuming

    2009-08-01

    Leaf area index (LAI) - defined as one half of the total green leaf area per unit ground surface area - can be determined by direct or indirect methods. Three major sources of errors exist in indirect LAI measurements: within-shoot clumping, beyond-shoot clumping and non-photosynthetic components. The effect of non-photosynthetic components on LAI measurements can be described by the woody-to-total area ratio, alpha; however, no convenient and efficient indirect methods have been developed to estimate alpha, especially the variations in alpha with zenith angle , alpha(theta). We describe the development and use of a multispectral canopy imager (MCI) to estimate alpha and alpha(theta) by considering the effects of non-random distributions of canopy elements and woody components and the overestimation of needle-to-shoot area ratio on woody components. The MCI, which mainly comprises a near-infrared band camera (Fujifilm IS-1), two visible band cameras (Canon 40D), filters and a pan tilt, was developed to measure clumping index, woody-to-total area ratio and geometric parameters of isolated trees. Two typical sampling plots (Plots 1 and 5) chosen from among 16 permanent forest experiment plots were selected for the estimation of alpha and alpha(theta). The non-random distributions of canopy elements and woody components were estimated separately at eight zenith angles (from 0 degrees to 70 degrees in increments of 10 degrees) using MCI images based on the gap size distribution theory. The visible/near-infrared image pairs captured by the MCI were able to discriminate among sky, leaves, cloud and woody components. Based on three methods of estimation, we obtained woody-to-total area ratios of 0.24, 0.19, 0.19 for Plot 1 and 0.23, 0.18, 0.17 for Plot 5. If clumping effects were ignored, alpha values were overestimated by as much as 21% and 24% at Plots 1 and 5, respectively. We demonstrated that alpha(theta) varied with the zenith angle, with variations in the range of

  3. Effects of woody encroachment on savanna nitrogen dynamics: Combining biogeochemistry and remote sensing

    NASA Astrophysics Data System (ADS)

    Martin, Roberta Enders

    Woody encroachment, the increase of woody plant density relative to herbaceous vegetation, has contributed to documented biophysical and biogeochemical changes world-wide, and locally in the southwestern U.S. In North Texas rangelands, encroaching mesquite (Prosopis glandulosa var. glandulosa ), a known nitrogen (N)-fixing species, has caused changes in aboveground biomass. However, the impacts of woody encroachment on N cycling have not been well studied, despite the central role that N dynamics play in controlling carbon (C) cycling and many other ecological processes across all spatial scales from microbial soil processes to global plant productivity. Airborne remote sensing is arguably the only approach available to develop a spatially-explicit understanding of ecosystem processes. The main goal of this research was to determine whether remotely sensible parameters of vegetation structure could be used to quantify biogeochemical changes in N at the local, landscape and regional scale. To accomplish this goal, I first characterized the impact of woody encroachment on soil nitrogen oxide (nitric-NO and nitrous-N2O oxide) emissions. I examined biotic (vegetation type and soil organic and inorganic N dynamics) and abiotic (soil moisture, temperature, and soil texture) controls over soil NO and N2O emissions across a gradient of aboveground (AG) Prosopis biomass growing on two soil types. I concluded that mesquite encroachment in these grasslands increased NO emissions in a spatially explicit manner influenced by the AG biomass and soil type, which was then temporally mediated by temperature and secondarily by precipitation. Based on these results, I combined hyperspectral remote sensing and field measurements to quantify spatial patterns and to estimate regional fluxes of soil NO emissions across 120 km2 of semi-arid rangeland in North Texas. This analysis captured the high spatial variability of NO emissions as they co-varied with vegetation cover and soil type

  4. Evaluating nurse plants for restoring native woody species to degraded subtropical woodlands

    USGS Publications Warehouse

    Yelenik, Stephanie G.; DiManno, Nicole; D’Antonio, Carla M.

    2015-01-01

    Harsh habitats dominated by invasive species are difficult to restore. Invasive grasses in arid environments slow succession toward more desired composition, yet grass removal exacerbates high light and temperature, making the use of “nurse plants” an appealing strategy. In this study of degraded subtropical woodlands dominated by alien grasses in Hawai'i, we evaluated whether individuals of two native (Dodonaea viscosa, Leptocophylla tameiameia) and one non-native (Morella faya) woody species (1) act as natural nodes of recruitment for native woody species and (2) can be used to enhance survivorship of outplanted native woody species. To address these questions, we quantified the presence and persistence of seedlings naturally recruiting beneath adult nurse shrubs and compared survival and growth of experimentally outplanted seedlings of seven native woody species under the nurse species compared to intact and cleared alien-grass plots. We found that the two native nurse shrubs recruit their own offspring, but do not act as establishment nodes for other species. Morella faya recruited even fewer seedlings than native shrubs. Thus, outplanting will be necessary to increase abundance and diversity of native woody species. Outplant survival was the highest under shrubs compared to away from them with few differences between nurse species. The worst habitat for native seedling survival and growth was within the unmanaged invasive grass matrix. Although the two native nurse species did not differentially affect outplant survival, D. viscosa is the most widespread and easily propagated and is thus more likely to be useful as an initial nurse species. The outplanted species showed variable responses to nurse habitats that we attribute to resource requirements resulting from their typical successional stage and nitrogen fixation capability.

  5. Effects of topoclimatic complexity on the composition of woody plant communities

    PubMed Central

    Oldfather, Meagan F.; Britton, Matthew N.; Papper, Prahlad D.; Koontz, Michael J.; Halbur, Michelle M.; Dodge, Celeste; Flint, Alan L.; Flint, Lorriane E.; Ackerly, David D.

    2016-01-01

    Topography can create substantial environmental variation at fine spatial scales. Shaped by slope, aspect, hill-position and elevation, topoclimate heterogeneity may increase ecological diversity, and act as a spatial buffer for vegetation responding to climate change. Strong links have been observed between climate heterogeneity and species diversity at broader scales, but the importance of topoclimate for woody vegetation across small spatial extents merits closer examination. We established woody vegetation monitoring plots in mixed evergreen-deciduous woodlands that spanned topoclimate gradients of a topographically heterogeneous landscape in northern California. We investigated the association between the structure of adult and regenerating size classes of woody vegetation and multidimensional topoclimate at a fine scale. We found a significant effect of topoclimate on both single-species distributions and community composition. Effects of topoclimate were evident in the regenerating size class for all dominant species (four Quercus spp., Umbellularia californica and Pseudotsuga menziesii) but only in two dominant species (Quercus agrifolia and Quercus garryana) for the adult size class. Adult abundance was correlated with water balance parameters (e.g. climatic water deficit) and recruit abundance was correlated with an interaction between the topoclimate parameters and conspecific adult abundance (likely reflecting local seed dispersal). However, in all cases, the topoclimate signal was weak. The magnitude of environmental variation across our study site may be small relative to the tolerance of long-lived woody species. Dispersal limitations, management practices and patchy disturbance regimes also may interact with topoclimate, weakening its influence on woody vegetation distributions. Our study supports the biological relevance of multidimensional topoclimate for mixed woodland communities, but highlights that this relationship might be mediated by

  6. A model of the extent and distribution of woody linear features in rural Great Britain.

    PubMed

    Scholefield, Paul; Morton, Dan; Rowland, Clare; Henrys, Peter; Howard, David; Norton, Lisa

    2016-12-01

    Hedges and lines of trees (woody linear features) are important boundaries that connect and enclose habitats, buffer the effects of land management, and enhance biodiversity in increasingly impoverished landscapes. Despite their acknowledged importance in the wider countryside, they are usually not considered in models of landscape function due to their linear nature and the difficulties of acquiring relevant data about their character, extent, and location. We present a model which uses national datasets to describe the distribution of woody linear features along boundaries in Great Britain. The method can be applied for other boundary types and in other locations around the world across a range of spatial scales where different types of linear feature can be separated using characteristics such as height or width. Satellite-derived Land Cover Map 2007 (LCM2007) provided the spatial framework for locating linear features and was used to screen out areas unsuitable for their occurrence, that is, offshore, urban, and forest areas. Similarly, Ordnance Survey Land-Form PANORAMA®, a digital terrain model, was used to screen out where they do not occur. The presence of woody linear features on boundaries was modelled using attributes from a canopy height dataset obtained by subtracting a digital terrain map (DTM) from a digital surface model (DSM). The performance of the model was evaluated against existing woody linear feature data in Countryside Survey across a range of scales. The results indicate that, despite some underestimation, this simple approach may provide valuable information on the extents and locations of woody linear features in the countryside at both local and national scales.

  7. Evaluating nurse plants for restoring native woody species to degraded subtropical woodlands.

    PubMed

    Yelenik, Stephanie G; DiManno, Nicole; D'Antonio, Carla M

    2015-01-01

    Harsh habitats dominated by invasive species are difficult to restore. Invasive grasses in arid environments slow succession toward more desired composition, yet grass removal exacerbates high light and temperature, making the use of "nurse plants" an appealing strategy. In this study of degraded subtropical woodlands dominated by alien grasses in Hawai'i, we evaluated whether individuals of two native (Dodonaea viscosa, Leptocophylla tameiameia) and one non-native (Morella faya) woody species (1) act as natural nodes of recruitment for native woody species and (2) can be used to enhance survivorship of outplanted native woody species. To address these questions, we quantified the presence and persistence of seedlings naturally recruiting beneath adult nurse shrubs and compared survival and growth of experimentally outplanted seedlings of seven native woody species under the nurse species compared to intact and cleared alien-grass plots. We found that the two native nurse shrubs recruit their own offspring, but do not act as establishment nodes for other species. Morella faya recruited even fewer seedlings than native shrubs. Thus, outplanting will be necessary to increase abundance and diversity of native woody species. Outplant survival was the highest under shrubs compared to away from them with few differences between nurse species. The worst habitat for native seedling survival and growth was within the unmanaged invasive grass matrix. Although the two native nurse species did not differentially affect outplant survival, D. viscosa is the most widespread and easily propagated and is thus more likely to be useful as an initial nurse species. The outplanted species showed variable responses to nurse habitats that we attribute to resource requirements resulting from their typical successional stage and nitrogen fixation capability.

  8. Large woody debris and flow resistance in step-pool channels, Cascade Range, Washington

    USGS Publications Warehouse

    Curran, Janet H.; Wohl, Ellen E.

    2003-01-01

    Total flow resistance, measured as Darcy-Weisbach f, in 20 step-pool channels with large woody debris (LWD) in Washington, ranged from 5 to 380 during summer low flows. Step risers in the study streams consist of either (1) large and relatively immobile woody debris, bedrock, or roots that form fixed, or “forced,” steps, or (2) smaller and relatively mobile wood or clasts, or a mixture of both, arranged across the channel by the stream. Flow resistance in step-pool channels may be partitioned into grain, form, and spill resistance. Grain resistance is calculated as a function of particle size, and form resistance is calculated as large woody debris drag. Combined, grain and form resistance account for less than 10% of the total flow resistance. We initially assumed that the substantial remaining portion is spill resistance attributable to steps. However, measured step characteristics could not explain between-reach variations in flow resistance. This suggests that other factors may be significant; the coefficient of variation of the hydraulic radius explained 43% of the variation in friction factors between streams, for example. Large woody debris generates form resistance on step treads and spill resistance at step risers. Because the form resistance of step-pool channels is relatively minor compared to spill resistance and because wood in steps accentuates spill resistance by increasing step height, we suggest that wood in step risers influences channel hydraulics more than wood elsewhere in the channel. Hence, the distribution and function, not just abundance, of large woody debris is critical in steep, step-pool channels.

  9. Evaluating nurse plants for restoring native woody species to degraded subtropical woodlands

    PubMed Central

    Yelenik, Stephanie G; DiManno, Nicole; D'Antonio, Carla M

    2015-01-01

    Harsh habitats dominated by invasive species are difficult to restore. Invasive grasses in arid environments slow succession toward more desired composition, yet grass removal exacerbates high light and temperature, making the use of “nurse plants” an appealing strategy. In this study of degraded subtropical woodlands dominated by alien grasses in Hawai'i, we evaluated whether individuals of two native (Dodonaea viscosa, Leptocophylla tameiameia) and one non-native (Morella faya) woody species (1) act as natural nodes of recruitment for native woody species and (2) can be used to enhance survivorship of outplanted native woody species. To address these questions, we quantified the presence and persistence of seedlings naturally recruiting beneath adult nurse shrubs and compared survival and growth of experimentally outplanted seedlings of seven native woody species under the nurse species compared to intact and cleared alien-grass plots. We found that the two native nurse shrubs recruit their own offspring, but do not act as establishment nodes for other species. Morella faya recruited even fewer seedlings than native shrubs. Thus, outplanting will be necessary to increase abundance and diversity of native woody species. Outplant survival was the highest under shrubs compared to away from them with few differences between nurse species. The worst habitat for native seedling survival and growth was within the unmanaged invasive grass matrix. Although the two native nurse species did not differentially affect outplant survival, D. viscosa is the most widespread and easily propagated and is thus more likely to be useful as an initial nurse species. The outplanted species showed variable responses to nurse habitats that we attribute to resource requirements resulting from their typical successional stage and nitrogen fixation capability. PMID:25709807

  10. Forest structure and downed woody debris in boreal, temperate, and tropical forest fragments.

    PubMed

    Gould, William A; González, Grizelle; Hudak, Andrew T; Hollingsworth, Teresa Nettleton; Hollingsworth, Jamie

    2008-12-01

    Forest fragmentation affects the heterogeneity of accumulated fuels by increasing the diversity of forest types and by increasing forest edges. This heterogeneity has implications in how we manage fuels, fire, and forests. Understanding the relative importance of fragmentation on woody biomass within a single climatic regime, and along climatic gradients, will improve our ability to manage forest fuels and predict fire behavior. In this study we assessed forest fuel characteristics in stands of differing moisture, i.e., dry and moist forests, structure, i.e., open canopy (typically younger) vs. closed canopy (typically older) stands, and size, i.e., small (10-14 ha), medium (33 to 60 ha), and large (100-240 ha) along a climatic gradient of boreal, temperate, and tropical forests. We measured duff, litter, fine and coarse woody debris, standing dead, and live biomass in a series of plots along a transect from outside the forest edge to the fragment interior. The goal was to determine how forest structure and fuel characteristics varied along this transect and whether this variation differed with temperature, moisture, structure, and fragment size. We found nonlinear relationships of coarse woody debris, fine woody debris, standing dead and live tree biomass with mean annual median temperature. Biomass for these variables was greatest in temperate sites. Forest floor fuels (duff and litter) had a linear relationship with temperature and biomass was greatest in boreal sites. In a five-way multivariate analysis of variance we found that temperature, moisture, and age/structure had significant effects on forest floor fuels, downed woody debris, and live tree biomass. Fragment size had an effect on forest floor fuels and live tree biomass. Distance from forest edge had significant effects for only a few subgroups sampled. With some exceptions edges were not distinguishable from interiors in terms of fuels.

  11. Effects of topoclimatic complexity on the composition of woody plant communities.

    PubMed

    Oldfather, Meagan F; Britton, Matthew N; Papper, Prahlad D; Koontz, Michael J; Halbur, Michelle M; Dodge, Celeste; Flint, Alan L; Flint, Lorriane E; Ackerly, David D

    2016-01-01

    Topography can create substantial environmental variation at fine spatial scales. Shaped by slope, aspect, hill-position and elevation, topoclimate heterogeneity may increase ecological diversity, and act as a spatial buffer for vegetation responding to climate change. Strong links have been observed between climate heterogeneity and species diversity at broader scales, but the importance of topoclimate for woody vegetation across small spatial extents merits closer examination. We established woody vegetation monitoring plots in mixed evergreen-deciduous woodlands that spanned topoclimate gradients of a topographically heterogeneous landscape in northern California. We investigated the association between the structure of adult and regenerating size classes of woody vegetation and multidimensional topoclimate at a fine scale. We found a significant effect of topoclimate on both single-species distributions and community composition. Effects of topoclimate were evident in the regenerating size class for all dominant species (four Quercus spp., Umbellularia californica and Pseudotsuga menziesii) but only in two dominant species (Quercus agrifolia and Quercus garryana) for the adult size class. Adult abundance was correlated with water balance parameters (e.g. climatic water deficit) and recruit abundance was correlated with an interaction between the topoclimate parameters and conspecific adult abundance (likely reflecting local seed dispersal). However, in all cases, the topoclimate signal was weak. The magnitude of environmental variation across our study site may be small relative to the tolerance of long-lived woody species. Dispersal limitations, management practices and patchy disturbance regimes also may interact with topoclimate, weakening its influence on woody vegetation distributions. Our study supports the biological relevance of multidimensional topoclimate for mixed woodland communities, but highlights that this relationship might be mediated by

  12. Competitive interactions between established grasses and woody plant seedlings under elevated CO₂ levels are mediated by soil water availability.

    PubMed

    Manea, A; Leishman, M R

    2015-02-01

    The expansion of woody plants into grasslands has been observed worldwide and is likely to have widespread ecological consequences. One proposal is that woody plant expansion into grasslands is driven in part by the rise in atmospheric CO2 concentrations. We have examined the effect of CO2 concentration on the competitive interactions between established C4 grasses and woody plant seedlings in a model grassland system. Woody plant seedlings were grown in mesocosms together with established C4 grasses in three competition treatments (root competition, shoot competition and root + shoot competition) under ambient and elevated CO2 levels. We found that the growth of the woody plant seedlings was suppressed by competition from grasses, with root and shoot competition having similar competitive effects on growth. In contrast to expectations, woody plant seedling growth was reduced at elevated CO2 levels compared to that at the ambient CO2 level across all competition treatments, with the most plausible explanation being reduced light and soil water availability in the elevated CO2 mesocosms. Reduced light and soil water availability in the elevated CO2 mesocosms was associated with an increased leaf area index of the grasses which offset the reductions in stomatal conductance and increased rainfall interception. The woody plant seedlings also had reduced 'escapability' (stem biomass and stem height) under elevated compared to ambient CO2 levels. Our results suggest that the expansion of woody plants into grasslands in the future will likely be context-dependent, with the establishment success of woody plant seedlings being strongly coupled to the CO2 response of competing grasses and to soil water availability.

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

    PubMed

    Yang, Fan; Wang, Yong; Chan, Zhulong

    2014-01-01

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

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

    PubMed Central

    Yang, Fan; Wang, Yong; Chan, Zhulong

    2014-01-01

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

  15. Seeing through the Canopy: Relationship between Coarse Woody Debris and Forest Structure measured by Airborne Lidar in the Brazilian Amazon

    NASA Astrophysics Data System (ADS)

    Scaranello, M. A., Sr.; Keller, M. M.; dos-Santos, M. N.; Longo, M.; Pinagé, E. R.; Leitold, V.

    2016-12-01

    Coarse woody debris is an important but infrequently quantified carbon pool in tropical forests. Based on studies at 12 sites spread across the Brazilian Amazon, we quantified coarse woody debris stocks in intact forests and forests affected by different intensities of degradation by logging and/or fire. Measurement were made in-situ and for the first time field measurements of coarse woody debris were related to structural metrics derived from airborne lidar. Using the line-intercept method we established 84 transects for sampling fallen coarse woody debris and associated inventory plots for sampling standing dead wood in intact, conventional logging, reduced impact logging, burned and burned after logging forests. Overall mean and standard deviation of total coarse woody debris were 50.0 Mg ha-1 and 26.4 Mg ha-1 respectively. Forest degradation increased coarse woody debris stocks compared to intact forests by a factor of 1.7 in reduced impact logging forests and up to 3-fold in burned forests, in a side-by-side comparison of nearby areas. The ratio between coarse woody debris and biomass increased linearly with number of degradation events (R²: 0.67, p<0.01). Individual lidar-derived structural variables strongly correlated with coarse woody debris in intact and reduced impact logging forests: the 5th percentile of last returns for in intact forests (R²: 0.78, p<0.01) and forest gap area, mapped using lidar-derived canopy height model, for reduced impact logging forests (R²: 0.63, p<0.01). Individual gap area also played a weak but significant role in determining coarse woody debris in burned forests (R2: 0.21, p<0.05), but with contrasting trend. Both degradation-specific and general multiple models using lidar-derived variables were good predictor of coarse woody debris stocks in different degradation levels in the Brazilian Amazon. The strong relation of coarse woody debris with lidar derived structural variables suggests an approach for quantifying

  16. Woody plant encroachment effect on soil organic carbon dynamics: results from a latitudinal gradient in Italy

    NASA Astrophysics Data System (ADS)

    Pellis, Guido; Chiti, Tommaso; Moscatelli, Maria Cristina; Marinari, Sara; Papale, Dario

    2016-04-01

    Woody plant encroachment into pastures and grasslands represents a significant land cover change phenomenon, with a considerable impact on carbon dynamics at an ecosystem level. It was estimated that 7.64% of the Southern Europe land was subject to that process between 1950 to 2010. As a result of woody encroachment, changes in vegetation composition can produce substantial changes to the soil organic carbon (SOC) cycle. Despite the numerous papers published on land-use change, an evaluation of the IPCC terrestrial carbon pools changes occurring during woody encroachment on abandoned pastures and grasslands is still lacking, particularly for the Italian territory. Therefore, the aim of this study was to investigate the role of woody encroachment on carbon sequestration over abandoned pastures and grasslands in Alpine and Apennine ecosystems, with a particular focus on the SOC. We applied a chronosequence approach to seven selected sites located along a latitudinal gradient in Italy. Each chronosequence consisted of a pasture currently managed, three sites abandoned at different times in the past and, finally, a mature forest stand representing the last phase of the succession. The European Commission sampling protocols to certify SOC changes was adopted to estimate the variations following woody encroachment. Soil samples were collected at different depths in the topsoil (0-30 cm) and subsoil (30-70 cm), despite the original protocol formulation being limited to the topsoil only. In addition, aboveground living biomass (AGB), dead wood and litter were also measured following international protocols. Considering all C pools together, woody plant encroachment leads to a progressive C stock accumulation in all the chronosequences. The total C stock of mature forest stands ranges from 1.78±0.11 times (Eastern Alps) to 2.48±0.31 times (central Apennine) the initial value on pastures. Unsurprisingly, the C stocks of AGB, dead wood and litter all increase during the

  17. Controls on microbial accessibility to soil organic carbon following woody plant encroachment into grasslands

    NASA Astrophysics Data System (ADS)

    Creamer, Courtney; Boutton, Thomas; Olk, Dan; Filley, Timothy

    2010-05-01

    Woody plant encroachment (WPE) into savannas and grasslands is a global phenomenon that alters soil organic carbon (SOC) dynamics through changes in litter quality and quantity, soil structure, microbial ecology, and hydrology. To elucidate the controls on microbial accessibility to SOC, bulk soils from a chronosequence of progressive WPE into native grasslands at the Texas Agrilife La Copita Research Area were incubated for one year. The quantity and stable carbon isotope composition of respired CO2, and plant biopolymer chemistry in SOC were tracked. Respiration rates declined exponentially over the course of the experiment with 15-25% of the total CO2 respired released in the first month of incubation. Between 8 and 18% of the total SOC was mineralized to CO2 throughout the incubation. After day 84 a significantly (p<0.05) greater portion of SOC was mineralized from soils of older woody clusters (34-86 years) than from soils of younger woody clusters (14-23 years) and the native grassland. Invading woody stands of ≃≥35 years of age represent a transition point in WPE where respiration dynamics become distinct in wooded elements compared to grasslands; this distinction has been previously observed through changes in belowground SOC accrual, C input chemistry, and mycorrhizal productivity. Despite documented SOC accrual following WPE at La Copita, we observed no evidence of enhanced SOC stabilization in these respiration experiments. In fact, a greater proportion of total SOC was lost from the soil of mature woody stands than from young stands, suggesting SOC accumulation observed with WPE may be due to greater input rates or microbial dynamics not captured in the laboratory incubation. Compound-specific analyses indicated there was a significant (p<0.05) loss of C from carbohydrates, amino acids, and amino sugars during the incubation. Amino nitrogen tended to become more concentrated during the incubation, although the trend was not significant. Relatively

  18. Development and Deployment of a Short Rotation Woody Crops Harvesting System Based on a Case New Holland Forage Harvester and SRC Woody Crop Header

    SciTech Connect

    Eisenbies, Mark; Volk, Timothy; Abrahamson, Lawrence; Shuren, Richard; Stanton, Brian; Posselius, John; McArdle, Matt; Karapetyan, Samvel; Patel, Aayushi; Shi, Shun; Zerpa, Jose

    2014-10-03

    Biomass for biofuels, bioproducts and bioenergy can be sourced from forests, agricultural crops, various residue streams, and dedicated woody or herbaceous crops. Short rotation woody crops (SRWC), like willow and hybrid poplar, are perennial cropping systems that produce a number of environmental and economic development benefits in addition to being a renewable source of biomass that can be produced on marginal land. Both hybrid poplar and willow have several characteristics that make them an ideal feedstock for biofuels, bioproducts, and bioenergy; these include high yields that can be obtained in three to four years, ease of cultivar propagation from dormant cuttings, a broad underutilized genetic base, ease of breeding, ability to resprout after multiple harvests, and feedstock composition similar to other sources of woody biomass. Despite the range of benefits associated with SRWC systems, their deployment has been restricted by high costs, low market acceptance associated with inconsistent chip quality (see below for further explanation), and misperceptions about other feedstock characteristics (see below for further explanation). Harvesting of SRWC is the largest single cost factor (~1/3 of the final delivered cost) in the feedstock supply system. Harvesting is also the second largest input of primary fossil energy in the system after commercial N fertilizer, accounting for about one third of the input. Therefore, improving the efficiency of the harvesting system has the potential to reduce both cost and environmental impact. At the start of this project, we projected that improving the overall efficiency of the harvesting system by 25% would reduce the delivered cost of SRWC by approximately $0.50/MMBtu (or about $7.50/dry ton). This goal was exceeded over the duration of this project, as noted below.

  19. Activities of Extracellular Enzymes in Soils Following Woody Plant Invasion of Grassland

    NASA Astrophysics Data System (ADS)

    Filley, T. R.; Stott, D. E.; Dooling, V.; Sorg, L.; Boutton, T.

    2008-12-01

    Extracellular enzymes produced by microbes and immobilize in the soil environment are the principle means by which complex plant and microbial compounds are degraded. The concentration of these enzymes and their ability to interact with litter and soil organic matter contributes both to the stabilization and destabilization of soil carbon. We quantified the activities of three extracellular enzymes, B-glucosidase, B- glucosaminidase, polyphenol oxidase (PPO), and a general marker for hydrolytic activity through fluorescein diacetate (FDA) hydrolysis activity, in a subtropical savanna parkland in southern Texas where woody plants have invaded a once open grassland. Previous research has demonstrated that areas which have shifted to woody vegetation are accruing soil carbon, undergoing a dramatic shift in the chemistry of plant input, and increasing in hyphal biomass. Soils were obtained along a successional chronosequence from grassland dominated by C4 grasses to woody patches dominated by C3 trees/shrubs in Oct 2006 and stored immediately frozen until thawing for enzyme assay. Most enzymes, with the exception of PPO, show distinct behavior when comparing grassland and clusters in that grasslands exhibit far lower mass normalized activity than clusters and no activity trend with respect to age of the adjacent cluster. Both FDA and B- glucosaminidase activities are positively correlated with the age of the woody clusters and increase their activity by as much as 10-fold across the age gradient from 14 yr to 86 yr old clusters. The cellulose degrading enzyme, B-glucosidase, always exhibited greater activity (1.5 -4 fold) in woody clusters than in grasslands, but did not exhibit a trend with increasing cluster age. The PPO activity is anomalous in that there is no quantitative difference in mass normalized activity between grassland and cluster and no trend with cluster age. The results for the FDA and B-glucosaminidase assays are consistent with concurrent studies

  20. Woody fuels reduction in Wyoming big sagebrush communities

    USDA-ARS?s Scientific Manuscript database

    Wyoming big sagebrush (Artemisia tridentata Nutt. ssp. wyomingensis Beetle & Young) ecosystems historically have been subject to disturbances that reduce or remove shrubs primarily by fire, although insect outbreaks and disease have also been important. Depending on site productivity, fire return in...

  1. Developing woody crops for the enhancement of ecosystem services under changing climates in the north central United States

    Treesearch

    Ronald S. Zalesny; William L. Headlee

    2015-01-01

    Short rotation woody crops belonging to the genera Populus L., Salix L., Pinus L., and Eucalyptus LHer. have provided broad economic and ecological benefits throughout the world, including afforestation and reforestation along urban to rural gradients. Within the genus Populus...

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

    SciTech Connect

    Edwards, M. Boyd

    2004-01-01

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

  3. Photo guide for appraising downed woody fuels in Montana forests: lodgepole pine and Engelmann spruce - subalpine fir cover types

    Treesearch

    William C. Fischer

    1981-01-01

    Two series of color photographs show different levels of downed woody material resulting from natural processes in two forest cover types in Montana. Each photo is supplemented by fuel inventory data and potential fire· behavior ratings.

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

    USGS Publications Warehouse

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

    2013-01-01

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

  5. Cross-stratified Wood: Enigmatic Woody Debris Deposits in Warm-Polar Fluvial Sediments (Pliocene Beaufort Formation, Nunavut)

    NASA Astrophysics Data System (ADS)

    Davies, N. S.; Gosse, J. C.; Rybczynski, N.

    2012-04-01

    Woody debris has been an important sediment component and a significant geomorphic agent in pristine fluvial systems since the Devonian. In recent years a large volume of research has focussed on various aspects of the importance of woody debris within the fluvial realm; from the evolutionary significance of fossil wood accumulations in the rock record to studies of the biogeomorphological and ecological importance of woody debris in modern rivers. In this presentation we describe cross-stratified woody debris deposits comprising organic detritus from a boreal-type treeline forest that included species of pine, birch, poplar, alder, spruce, eastern cedar, and larch, in both shrub and tree form. The cross-stratified wood is an enigmatic subset of fine woody debris which, to our knowledge, has never before been described from either the global stratigraphic record or modern fluvial environments. The deposits we describe are located within the Pliocene Beaufort Formation on Meighen Island, Nunavut, Canada, at a latitude of 80°N, and are compared with other cross-stratified woody debris deposits that have been noted elsewhere in the Pliocene of the Canadian Arctic. We make the robust observation that these deposits appear to be geographically and stratigraphically restricted to polar latitudes from a period of warm climatic conditions during the Pliocene (15-20 °C warmer mean annual temperature than the present day). In this regard it is possible to speculate that the transport of large amounts of woody debris as bedload is potentially a unique feature of forested high latitude rivers. Such bedload deposition requires a large amount of woody debris with a greater density than the fluid transporting it. The softwood composition of the debris suggests that this was most likely attained by saturation and subsequent entrainment of extensive accumulations of deadwood, promoted by unusually high rates of tree mortality and low rates of bacterial decomposition arising from

  6. On the relative importance of pool morphology and woody debris to distributions of shrimp in a Puerto Rican headwater stream

    USGS Publications Warehouse

    Pyron, M.; Covich, A.P.; Black, R.W.

    1999-01-01

    In this paper, we report the sizes and distributional orientation of woody debris in a headwater rainforest stream in the Luquillo Experimental Forest (LEF), Puerto Rico. We also provide results of a 4-month study of a wood addition experiment designed to increase cover for benthic macroinvertebrates (freshwater shrimp). We added branch-sized woody debris to 20 pools in three streams. We trapped four species of freshwater shrimp (two species of benthic detritivores and two predatory shrimp species) during each of the 4 months following wood additions. An analysis of pool morphology (maximum depth, surface area and volume) provided a useful predictor of shrimp abundances. In general, numbers of shrimps increased with sizes of stream pools. A repeated measures ANOVA demonstrated no effect of woody debris additions on total numbers of shrimp per pool area. Two detritivore species (Atya lanipes, a filter feeder and Xiphocaris elongata, a shredder) decreased in abundance with increased woody debris and there was no statistical relationship between woody debris additions and predators (Macrobrachium carcinus and M. crenulatum). Small woody debris additions may have altered flow velocities that were important to filter-feeding Atya at the microhabitat scale, although the overall velocities within pools were not altered by wood additions. Lower numbers of Atya and Xiphocaris in two of the three streams may result from the occurrence of two predaceous fishes (American eel and mountain mullet) and more predatory Macrobrachium in these streams. One likely interpretation of the results of this study is that the stream pools in these study reaches had sufficient habitat structure provided by numerous rock crevices (among large rocks and boulders) to provide refuge from predators. Addition of woody debris did not add significantly to the existing structure. These results may not apply to stream channels with sand and gravel substrata where crevices and undercut banks are lacking

  7. Economic potential of short-rotation woody crops on agricultural land for pulp fiber production in the United States.

    Treesearch

    Ralph J. Alig; Darius M. Adams; Bruce A. McCarl; Peter J. Ince

    2000-01-01

    A model of the U.S. forestry and agricultural sectors is used to simulate the consequences of growing short-rotation woody crops on agricultural lands as a fiber source for pulp and paper production. Hybrid poplar, a short-rotation woody crop, annually produces 4 to 7 dry tons per acre of hardwood pulpwood over a 6- to 10-year rotation. When harvested, the material...

  8. Rapid characterization of woody biomass digestibility and chemical composition using near-infrared spectroscopy.

    PubMed

    Hou, Shen; Li, Laigeng

    2011-02-01

    Rapid determination of the properties of lignocellulosic material is highly desirable for biomass production and utilization. In the present study, measurements of woody biomass digestibility and chemical composition using near-infrared reflectance (NIR) spectroscopy were calibrated. Poplar and eucalyptus materials were recorded in NIR spectrum as well as determined for their chemical compositions of Klason lignin, α-cellulose, holocellulose, lignin syringyl/guaiacyl (S/G) ratio and enzymatic digestibility. Fitting of the NIR information with chemical properties and digestibility by partial least-squares (PLS) regression generated a group of trained NIR models that were able to be used for rapid biomass measurement. Applying the models for woody biomass measurements led to a reliable evaluation of the chemical composition and digestibility, suggesting the feasibility of using NIR spectroscopy in the rapid characterization of biomass properties. © 2011 Institute of Botany, Chinese Academy of Sciences.

  9. Heavy Metal Bioaccumulation Capability of Woody Plants in Mine wasteland of Karst Areas

    NASA Astrophysics Data System (ADS)

    Xiuru, Wang; Zhongliang, Huang; Xuan, Zhang; Zijian, Wu

    2017-04-01

    The bioaccumulation capability and transfer characteristics of Pb, Zn, Cu and Cd in soil and 6 different woody plants collected from a typical lead-zinc mine wasteland of Karst area, Hunan province were investigated, including Cunninghamia lanceolata(Lamb.) Hook., Swida wilsoniana (Wanger.), Koelreuteria paniculata, Paulownia., Cinnamomum camphora (L.) Presl., and Sapium sebiferum (L.) Roxb. The results showed that the 6 plants could adapt to the heavy metal polluted environment, and there was a positive correlation between the heavy metal content in plants and soil.Swida wilsoniana (Wanger.) and Sapium sebiferum (L.) Roxb. had the largest Pb bioaccumulation factor of 0.03; Paulownia. had the highest Zn bioaccumulation factor of 0.37; the largest Pb transfer factor of 1.31 were found in Koelreuteria paniculata; and Zn transfer factor of Paulownia. reached 1.45. These 4 woody plants are suitable for phytoremediation of mine wasteland of Karst areas.

  10. A Database of Woody Vegetation Responses to Elevated Atmospheric CO2 (NDP-072)

    SciTech Connect

    Curtis, Peter S; Cushman, Robert M; Brenkert, Antoinette L

    1999-01-01

    To perform a statistically rigorous meta-analysis of research results on the response by woody vegetation to increased atmospheric CO2 levels, a multiparameter database of responses was compiled. Eighty-four independent CO2-enrichment studies, covering 65 species and 35 response parameters, met the necessary criteria for inclusion in the database: reporting mean response, sample size, and variance of the response (either as standard deviation or standard error). Data were retrieved from the published literature and unpublished reports. This numeric data package contains a 29-field data set of CO2-exposure experiment responses by woody plants (as both a flat ASCII file and a spreadsheet file), files listing the references to the CO2-exposure experiments and specific comments relevant to the data in the data set, and this documentation file (which includes SAS and Fortran codes to read the ASCII data file; SAS is a registered trademark of the SAS Institute, Inc., Cary, North Carolina 27511).

  11. Woody hardness - a novel classification for the radiotherapy-treated neck.

    PubMed

    Colbert, S D; Mitchell, D A; Brennan, P A

    2015-04-01

    The term 'woody neck' is widely used by surgeons and oncologists to describe the fibrosis that can occur following radiotherapy for head and neck malignancy. These soft tissue and skin changes can be compounded by neck dissection, either before or after radiotherapy. To our knowledge, there is no classification published in the literature to describe the degree of woody hardness following treatment. We propose a simple ABC classification for varying degrees of indurated oedema and neck fibrosis secondary to radiotherapy or long-standing pathology, using the hardness of different woods to enable a suitable description to be made of severity. Copyright © 2015 The British Association of Oral and Maxillofacial Surgeons. Published by Elsevier Ltd. All rights reserved.

  12. Effects of Experimental Manipulations of Course Woody Debris on Sorcids and Other Fauna

    SciTech Connect

    McCay, T.S.; Komoroski, M.J.; Ford, W.M.; Laerm, J.; Reitz, E.J.

    2001-06-10

    The authors studied the relationship between the level of course woody debris in experimental plots of mature loblolly pine and the richness and abundance of shrews, reptiles and amphibians. Comparisons were made between plots in which all down and standing debris were removed and plots that were not treated. Removal of woody debris resulted in a week treatment effect. The capture of southeastern shrews declined through the period perhaps due to drought. The least common shrew demonstrated the strongest effects from removal.In sampling 37 species of amphibians were observed. The Carolina anole and the red salamander were captured more frequently on removal plots. No difference were found between removal and controls with regard to reptiles.

  13. Downed dead woody fuel and biomass in the Northern Rocky Mountains

    NASA Astrophysics Data System (ADS)

    Brown, J. K.; See, T. E.

    1981-07-01

    Weights and volumes of downed woody material in diameter classes of one-fourth to 1, 1 to 3, and greater than 3 inches and forest floor duff depths were summarized from extensive inventories in nothern Idaho and Montana. Biomass loadings are shown by cover types and habitat types within National Forests. Total downed woody biomass ranged from 5 tons per acre in ponderosa pine to 33 tons per acre in cedar-hemlock. Loadings generally increased with increased productivity, but varied greatly with stand age. Fuels tended to become predictably high in overmature stands but unpredictable in young, immature, and mature stands. Forest fuel succession is discussed in relation to tree mortality, fuel buildup, and depletion.

  14. Application of Buckmaster Electrolyte Ion Leakage Test to Woody Biofuel Feedstocks

    SciTech Connect

    Broderick, Thomas F; Dooley, James H

    2014-08-28

    In an earlier ASABE paper, Buckmaster reported that ion conductivity of biomass leachate in aqueous solution was directly correlated with activity access to plant nutrients within the biomass materials for subsequent biological or chemical processing. The Buckmaster test involves placing a sample of the particles in a beaker of constant-temperature deionized water and monitoring the change in electrical conductivity over time. We adapted the Buckmaster method to a range of woody biomass and other cellulosic bioenergy feedstocks. Our experimental results suggest differences of electrolyte leakage between differently processed woody biomass particles may be an indicator of their utility for conversion in bioenergy processes. This simple assay appears to be particularly useful to compare different biomass comminution techniques and particle sizes for biochemical preprocessing.

  15. Recent advancements in various steps of ethanol, butanol, and isobutanol productions from woody materials.

    PubMed

    Fatehi, Pedram

    2013-01-01

    In this review, the recent advancements and technical challenges associated with the production of ethanol, butanol, and isobutanol via bioconversion routes from celluloses of woody materials are reviewed. Physicochemical processes, e.g. steam explosion, seem to be the most viable process for pretreating woody materials. Although enzymatic hydrolysis is selective, it is rather a slow process. Acid hydrolysis is a relatively fast process with a high yield, but it produces inhibitory compounds of fermentation, which necessitates a detoxification process before the fermentation. Presently, the major challenges in the production of ethanol, butanol, and isobutanol via biological conversions are the rather low production yield and the sensitivity of microorganisms to the presence of inhibitors and products in fermentation media. In this study, the recent advancements in the applications of Saccharomyces cerevisiae, Clostridium acetobutylicum, and Corynebacterium glutamicum, the most promising microorganisms, for ethanol, butanol, and isobutanol production are also discussed. Copyright © 2013 American Institute of Chemical Engineers.

  16. Somatic Embryogenesis in Broad-Leaf Woody Plants: What We Can Learn from Proteomics.

    PubMed

    Correia, Sandra I; Alves, Ana C; Veríssimo, Paula; Canhoto, Jorge M

    2016-01-01

    Proteomic approaches have been used to understand several regulatory aspects of plant development. Somatic embryogenesis is one of those developmental pathways that have beneficiated from the integration of proteomics data to the understanding of the molecular mechanisms that control embryogenic competence acquisition, somatic embryo development and conversion into viable plants. Nevertheless, most of the results obtained are based on the traditional model systems, very often not easily compared with the somatic embryogenesis systems of economical relevant woody species. The aim of this work is to summarize some of the applications of proteomics in the understanding of particular aspects of the somatic embryogenesis process in broad-leaf woody plants (model and non-model systems).

  17. Demonstration of the BioBaler harvesting system for collection of small-diameter woody biomass

    SciTech Connect

    Langholtz, Matthew H; Caffrey, Kevin R; Barnett, Elliott J; Webb, Erin; Brummette, Mark W; Downing, Mark

    2011-12-01

    As part of a project to investigate sustainable forest management practices for producing wood chips on the Oak Ridge Reservation (ORR) for the ORNL steam plant, the BioBaler was tested in various Oak Ridge locations in August of 2011. The purpose of these tests and the subsequent economic analysis was to determine the potential of this novel woody biomass harvesting method for collection of small-diameter, low value woody biomass. Results suggest that opportunities may exist for economical harvest of low-value and liability or negative-cost biomass. (e.g., invasives). This could provide the ORR and area land managers with a tool to produce feedstock while improving forest health, controlling problem vegetation, and generating local employment.

  18. Do Wildfires Promote Woody Species Invasion in a Fire-Adapted Ecosystem? Post-fire Resprouting of Native and Non-native Woody Plants in Central Argentina

    NASA Astrophysics Data System (ADS)

    Herrero, M. Lucrecia; Torres, Romina C.; Renison, Daniel

    2016-02-01

    We asked whether prescribed fire could be a useful management tool to reduce invasion by non-native plants in an ecosystem where native plants are supposed to be adapted to fires. Specifically, we compare the post-fire resprouting response of native and non-native woody species in Chaco Serrano forest of central Argentina. The measurements were carried out in five burnt areas where we selected ten native and seven non-native species. Our response variables were (1) post-fire survival, (2) types of resprouts, and (3) the growth of the resprouts. Our main results show that one year after the fire, survivals of native and non-native species were 0.84 and 0.89, respectively, with variances in survival seven times smaller in the native species group. Type of resprout was also less variable in native species, while growth of the resprouts was similar in native and non-native groups. We interpret that in most cases, the burning a forest with mixed native and non-native plants through prescribed fires will not differentially stop the invasion by non-native woody species even in ecosystems which are presumed to be relatively resistant to fires such as our study area.

  19. Do Wildfires Promote Woody Species Invasion in a Fire-Adapted Ecosystem? Post-fire Resprouting of Native and Non-native Woody Plants in Central Argentina.

    PubMed

    Herrero, M Lucrecia; Torres, Romina C; Renison, Daniel

    2016-02-01

    We asked whether prescribed fire could be a useful management tool to reduce invasion by non-native plants in an ecosystem where native plants are supposed to be adapted to fires. Specifically, we compare the post-fire resprouting response of native and non-native woody species in Chaco Serrano forest of central Argentina. The measurements were carried out in five burnt areas where we selected ten native and seven non-native species. Our response variables were (1) post-fire survival, (2) types of resprouts, and (3) the growth of the resprouts. Our main results show that one year after the fire, survivals of native and non-native species were 0.84 and 0.89, respectively, with variances in survival seven times smaller in the native species group. Type of resprout was also less variable in native species, while growth of the resprouts was similar in native and non-native groups. We interpret that in most cases, the burning a forest with mixed native and non-native plants through prescribed fires will not differentially stop the invasion by non-native woody species even in ecosystems which are presumed to be relatively resistant to fires such as our study area.

  20. Woody vegetation composition and structure in peri-urban Chongming Island, China.

    PubMed

    Zhao, Min; Escobedo, Francisco J; Wang, Ruijing; Zhou, Qiaolan; Lin, Wenpeng; Gao, Jun

    2013-05-01

    Chongming, the world's largest alluvial island, is located within the municipality of Shanghai, China. Recent projects have now linked peri-urban Chongming to Shanghai's urban core and as a result will soon undergo substantial changes from urbanization. We quantitatively analyzed the structure and composition of woody vegetation across subtropical, peri-urban Chongming as a basis for sustainable management of these rapidly urbanizing subtropical ecosystems elsewhere. We used 178 permanent, random plots to statistically and spatially analyze woody plant composition and tree structure across the 1,041 km(2) of Chongming. A total of 2,251 woody plants were measured comprising 42 species in 37 genera. We statistically and geospatially analyzed field data according to land uses and modeled air pollution removal by trees. Average tree diameter at breast height, total height, and crown widths on transportation land uses were greater than other land uses. These same values were lowest on forest land use and greater tree cover was associated with areas of increased anthropogenic activity. Less than 20 % of the woody vegetation was exotic and a species richness index was significantly different between land uses due to legacy effects. Composition of agriculture and forest land uses were similar to residential and transportation. Tree cover across Chongming was also estimated to annually remove 1,400 tons of air pollutants. We propose that this integrated and quantitative method can be used in other subtropical, peri-urban areas in developing countries to establish baseline trends for future sustainability objectives and to monitor the effects of urbanization and climate change.

  1. Short-rotation woody-crops program. Quarterly progress report for period ending May 31, 1981

    SciTech Connect

    Cushman, J.H.; Ranney, J.W.

    1982-04-01

    Progress of twenty projects in the Short Rotation Woody Crops Program is summarized for the period March 1 through May 31, 1981. Individual quarterly reports included from each of the projects discuss accomplishments within specific project objectives and identify recent papers and publications resulting from the research. The major project activities are species screening and genetic selection, stand establishment and cultural treatment, and harvest, collection, transportation, and storage.

  2. Short-rotation woody-crops program. Quarterly progress report for period ending August 31, 1981

    SciTech Connect

    Cushman, J.H.; Ranney, J.W.

    1982-04-01

    Progress of twenty-one projects in the Short Rotation Woody Crops Program is summarized for the period June 1 through August 31, 1981. Individual quarterly reports included from each of the projects discuss accomplishments within specific project objectives and identify recent papers and publications resulting from the research. The major program activities are species screening and genetic selection, stand establishment and cultural treatment, and harvest, collection, transportation, and storage.

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

    NASA Astrophysics Data System (ADS)

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

    2014-12-01

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

  4. Woody-Herbaceous Species Coexistence in Mulga Hillslopes: Modelling Structure and Function

    NASA Astrophysics Data System (ADS)

    Soltanjalili, M. J.; Saco, P. M.; Willgoose, G. R.

    2016-12-01

    The fundamental processes underlying the coexistence of woody and herbaceous species in arid and semi-arid areas have been a topic of intense research during the last few decades. Experimental and modelling studies have both supported and disputed alternative hypotheses explaining this phenomenon. Vegetation models including the key processes that drive coexistence can be used to understand vegetation pattern dynamics and structure under current climate conditions, and to predict changes under future conditions. Here we present work done towards linking the observations to modelling. The model captures woody-herbaceous coexistence along a rainfall gradient characteristic of typical conditions on Mulga ecosystems in Australia. The dynamic vegetation model simulates the spatial dynamics of overland flow, soil moisture and vegetation growth of two species. It incorporates key mechanisms for coexistence and pattern formation, including facilitation by evaporation reduction through shading, and infiltration feedbacks, local and non-local seed dispersal, competition for water uptake. Model outcomes, obtained including diflerent mechanisms, are qualitatively compared to typical vegetation cover patterns in the Australian Mulga bioregion where bush fire is very infrequent and the fate of vegetation cover is mostly determined by intra- and interspecies interactions. Through these comparisons, and by drawing on the large number of recent studies that have delivered new insights into the dynamics of such ecosystems, we identify main mechanisms that need an improved representation in the dynamic vegetation models. We show that a realistic parameterization of the model leads to results which are aligned with the observations reported in the literature. At the lower end of the rainfall gradient woody species coexist with herbaceous species within a sparse banded pattern, while at higher rainfall woody species tend to dominate the landscape.

  5. Assessment of carbon in woody plants and soil across a vineyard-woodland landscape.

    PubMed

    Williams, John N; Hollander, Allan D; O'Geen, A Toby; Thrupp, L Ann; Hanifin, Robert; Steenwerth, Kerri; McGourty, Glenn; Jackson, Louise E

    2011-11-09

    Quantification of ecosystem services, such as carbon (C) storage, can demonstrate the benefits of managing for both production and habitat conservation in agricultural landscapes. In this study, we evaluated C stocks and woody plant diversity across vineyard blocks and adjoining woodland ecosystems (wildlands) for an organic vineyard in northern California. Carbon was measured in soil from 44 one m deep pits, and in aboveground woody biomass from 93 vegetation plots. These data were combined with physical landscape variables to model C stocks using a geographic information system and multivariate linear regression. Field data showed wildlands to be heterogeneous in both C stocks and woody tree diversity, reflecting the mosaic of several different vegetation types, and storing on average 36.8 Mg C/ha in aboveground woody biomass and 89.3 Mg C/ha in soil. Not surprisingly, vineyard blocks showed less variation in above- and belowground C, with an average of 3.0 and 84.1 Mg C/ha, respectively. This research demonstrates that vineyards managed with practices that conserve some fraction of adjoining wildlands yield benefits for increasing overall C stocks and species and habitat diversity in integrated agricultural landscapes. For such complex landscapes, high resolution spatial modeling is challenging and requires accurate characterization of the landscape by vegetation type, physical structure, sufficient sampling, and allometric equations that relate tree species to each landscape. Geographic information systems and remote sensing techniques are useful for integrating the above variables into an analysis platform to estimate C stocks in these working landscapes, thereby helping land managers qualify for greenhouse gas mitigation credits. Carbon policy in California, however, shows a lack of focus on C stocks compared to emissions, and on agriculture compared to other sectors. Correcting these policy shortcomings could create incentives for ecosystem service provision

  6. Technoeconomic Comparison of Biofuels: Ethanol, Methanol, and Gasoline from Gasification of Woody Residues (Presentation)

    SciTech Connect

    Tarud, J.; Phillips, S.

    2011-08-01

    This presentation provides a technoeconomic comparison of three biofuels - ethanol, methanol, and gasoline - produced by gasification of woody biomass residues. The presentation includes a brief discussion of the three fuels evaluated; discussion of equivalent feedstock and front end processes; discussion of back end processes for each fuel; process comparisons of efficiencies, yields, and water usage; and economic assumptions and results, including a plant gate price (PGP) for each fuel.

  7. The value of woody hedgerows for moth diversity on organic and conventional farms.

    PubMed

    Boutin, C; Baril, A; McCabe, S K; Martin, P A; Guy, M

    2011-06-01

    Habitat destruction and degradation are important drivers of biodiversity loss within agro-ecosystems. However, little is known about the effect of farming practices and the value of woody hedgerows on Lepidoptera in North America. The purpose of this work was to study moth diversity in woody hedgerows and croplands of organic and conventional farms. In addition, the influence of vegetation composition and abiotic variables on species richness, abundance, and composition was examined. Moths were sampled with light traps during six weeks in the summer of 2001. Vegetation data and abiotic variables were obtained for all sites. In total, 26,020 individuals from 12 families and 408 species were captured. Most species were uncommon. Only 35 species included >100 individuals while for 71% of species <10 individuals were found. The Noctuidae represented 221 species and 85% of all individuals captured. Woody hedgerows harbored more species and in greater number than croplands. There was no significant difference in moth diversity between organic and conventional farms, except that the Notodontidae were significantly more species rich in organic than in conventional sites. Results show that species richness, abundance, and composition were greatly influenced by habitat types (hedgerow versus crop field) and abiotic variables (minimum temperature which was correlated to moon illumination, rainfall, and cloud cover). Moth species composition was significantly correlated to vegetation composition. This study broadens our understanding of the factors driving moth diversity and expands our knowledge of their geographic range. The maintenance of noncrop habitats such as woody hedgerows within agro-ecosystems seems paramount to preserving the biodiversity and abundance of many organisms, including moths.

  8. Soil and water quality implications of production of herbaceous and woody energy crops

    SciTech Connect

    Tolbert, V.R.; Lindberg, J.E.; Green, T.H.

    1997-10-01

    Field-scale studies in three physiographic regions of the Tennessee Valley in the Southeastern US are being used to address the environmental effects of producing biomass energy crops on former agricultural lands. Comparison of erosion, surface water quality and quantity, and subsurface movement of water and nutrients from woody crops, switchgrass and agricultural crops began with crop establishment in 1994. Nutrient cycling, soil physical changes, and productivity of the different crops are also being monitored at the three sites.

  9. Assessment of carbon in woody plants and soil across a vineyard-woodland landscape

    PubMed Central

    2011-01-01

    Background Quantification of ecosystem services, such as carbon (C) storage, can demonstrate the benefits of managing for both production and habitat conservation in agricultural landscapes. In this study, we evaluated C stocks and woody plant diversity across vineyard blocks and adjoining woodland ecosystems (wildlands) for an organic vineyard in northern California. Carbon was measured in soil from 44 one m deep pits, and in aboveground woody biomass from 93 vegetation plots. These data were combined with physical landscape variables to model C stocks using a geographic information system and multivariate linear regression. Results Field data showed wildlands to be heterogeneous in both C stocks and woody tree diversity, reflecting the mosaic of several different vegetation types, and storing on average 36.8 Mg C/ha in aboveground woody biomass and 89.3 Mg C/ha in soil. Not surprisingly, vineyard blocks showed less variation in above- and belowground C, with an average of 3.0 and 84.1 Mg C/ha, respectively. Conclusions This research demonstrates that vineyards managed with practices that conserve some fraction of adjoining wildlands yield benefits for increasing overall C stocks and species and habitat diversity in integrated agricultural landscapes. For such complex landscapes, high resolution spatial modeling is challenging and requires accurate characterization of the landscape by vegetation type, physical structure, sufficient sampling, and allometric equations that relate tree species to each landscape. Geographic information systems and remote sensing techniques are useful for integrating the above variables into an analysis platform to estimate C stocks in these working landscapes, thereby helping land managers qualify for greenhouse gas mitigation credits. Carbon policy in California, however, shows a lack of focus on C stocks compared to emissions, and on agriculture compared to other sectors. Correcting these policy shortcomings could create

  10. Energy Product Options for Eucalyptus Species Grown as Short Rotation Woody Crops

    PubMed Central

    Rockwood, Donald L.; Rudie, Alan W.; Ralph, Sally A.; Zhu, J.Y.; Winandy, Jerrold E.

    2008-01-01

    Eucalyptus species are native to Australia but grown extensively worldwide as short rotation hardwoods for a variety of products and as ornamentals. We describe their general importance with specific emphasis on existing and emerging markets as energy products and the potential to maximize their productivity as short rotation woody crops. Using experience in Florida USA and similar locations, we document their current energy applications and assess their productivity as short-term and likely long-term energy and related products. PMID:19325808

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

    USGS Publications Warehouse

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

    2012-01-01

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

  12. Woody Vegetation Composition and Structure in Peri-urban Chongming Island, China

    NASA Astrophysics Data System (ADS)

    Zhao, Min; Escobedo, Francisco J.; Wang, Ruijing; Zhou, Qiaolan; Lin, Wenpeng; Gao, Jun

    2013-05-01

    Chongming, the world's largest alluvial island, is located within the municipality of Shanghai, China. Recent projects have now linked peri-urban Chongming to Shanghai's urban core and as a result will soon undergo substantial changes from urbanization. We quantitatively analyzed the structure and composition of woody vegetation across subtropical, peri-urban Chongming as a basis for sustainable management of these rapidly urbanizing subtropical ecosystems elsewhere. We used 178 permanent, random plots to statistically and spatially analyze woody plant composition and tree structure across the 1,041 km2 of Chongming. A total of 2,251 woody plants were measured comprising 42 species in 37 genera. We statistically and geospatially analyzed field data according to land uses and modeled air pollution removal by trees. Average tree diameter at breast height, total height, and crown widths on transportation land uses were greater than other land uses. These same values were lowest on forest land use and greater tree cover was associated with areas of increased anthropogenic activity. Less than 20 % of the woody vegetation was exotic and a species richness index was significantly different between land uses due to legacy effects. Composition of agriculture and forest land uses were similar to residential and transportation. Tree cover across Chongming was also estimated to annually remove 1,400 tons of air pollutants. We propose that this integrated and quantitative method can be used in other subtropical, peri-urban areas in developing countries to establish baseline trends for future sustainability objectives and to monitor the effects of urbanization and climate change.

  13. Frequent fire affects soil nitrogen and carbon in an African savanna by changing woody cover.

    PubMed

    Coetsee, Corli; Bond, William J; February, Edmund C

    2010-04-01

    When tropical and sub-tropical ecosystems burn, considerable amounts of N present in the biomass fuel may be released. This ultimately results in a loss of fixed N to the atmosphere. It is often assumed that this volatilization loss of N with frequent fire will result in a reduction of plant-available N and total system N. By changing the amount of woody biomass fire may, however, also have indirect effects on N and C dynamics. Here we consider the effects of 50 years of frequent fire on total soil N and soil organic C (SOC) and total soil N in a mesic savanna in the Kruger National Park, South Africa. We also determine how changes in woody biomass may affect total soil N and SOC. We measured soil and fine root N and C concentrations as well as total soil N and SOC pools in four burning treatments, including fire exclusion, of a long-term fire experiment. Our results show that regardless of soil depth, fire treatment had no significant effect on total soil N and SOC. Our results also show that under trees total soil N and SOC concentrations of the surface soil increase, and pools of N and SOC increase to a depth of 7 cm. However, the extent to which soil N and C dynamics differed under canopies and away from canopies was dependent on fire treatment. Our results show that the effect of fire on soil N and C is mediated both through the indirect effect of changes in woody cover and the direct effects of fire (volatilization losses of nutrients). We suggest that woody thickening in this mesic savanna will have pronounced effects on long-term N and C dynamics.

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

    Treesearch

    Michael D. Ulyshen; James L. Hanula; Scott Horn; John C. Kilgo; Christopher E. Moorman

    2004-01-01

    Malaise traps were used to sample beetles in artificial canopy gaps of different size (0.13 ha, 0.26 ha, and 0.50 ha) and age in a South Carolina bottomland hardwood forest. Traps were placed at the center, edge, and in the surrounding forest of each gap. Young gaps (~1 year) had large amounts of coarse woody debris compared to the surrounding forest, while older gaps...

  15. Spatial partitioning of water use by herbaceous and woody lifeforms in semiarid woodlands

    SciTech Connect

    Breshears, D.D.

    1993-12-31

    Ecological studies of soil moisture, plant water uptake, and community composition in semiarid regions have focused on differences with depth in the soil profile, yet there are many reasons to expect that moisture also varies with the presence or absence of woody vegetation. Plant and soil moisture relationships for three dominant species in a semiarid woodland, Bouteloua gracilis, Juniperus monosperma, and Pinus edulis, were studied for 1.5 years. Soil moisture varied by type of plant cover as well as by depth. Plant water potential and conductance differed among species and was related to spatial variability in soil moisture. Water potential for blue grama was most correlated with soil moisture in the 0-15 cm layer of intercanopies; juniper water potential was highly correlated with soil moisture in the 0-15 cm layer beneath tree canopies of either species, and pinyon water potential was only weakly correlated with soil moisture in the 15-30 cm depth interval beneath pinyons. Pinyons had consistently greater maximum conductance rates than junipers, even though pinyon conductance was more sensitive to reductions in soil moisture. The results from this study indicate that horizontal differences in the soil moisture profile associated with type of plant cover may be as important as differences in depth for predicting plant-water relationships. A simple model was hypothesized for predicting community composition of three lifeforms: Herbaceous plants, shallow-rooted woody plants, and deeper-rooted woody plants. Distributions of roots of each lifeform and plant-available water were defined with respect to four soil compartments that distinguish upper vs. lower and canopy vs. intercanopy soil regions. The model predicts that multiple combinations of herbaceous and woody biomass can exist at a site and was qualitatively consistent with field data from a climatic gradient.

  16. An assessment of coarse woody debris dynamics in an urban forest

    Treesearch

    Michael K. Crosby; Helen Petre; Justin Sims; Rachel Butler

    2016-01-01

    Determining the amount of coarse woody debris (CWD) in an urban forest is essential to developing management strategies to maintain ecosystem function while minimizing hazards to local residents. It is also an essential variable used for the assessment and monitoring of carbon dynamics and fire fuel loads in forests. Plots were established and CWD measured in Marshall...

  17. Modeling respiration from snags and coarse woody debris before and after an invasive gypsy moth disturbance

    NASA Astrophysics Data System (ADS)

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

    2014-04-01

    Although snags and coarse woody debris are a small component of ecosystem respiration, disturbances can significantly increase the mass and respiration from these carbon (C) pools. The objectives of this study were to (1) measure respiration rates of snags and coarse woody debris throughout the year in a forest previously defoliated by gypsy moths, (2) develop models for dead stem respiration rates, (3) model stand-level respiration rates of dead stems using forest inventory and analysis data sets and environmental variables predisturbance and postdisturbance, and (4) compare total dead stem respiration rates with total ecosystem respiration and net ecosystem exchange. Respiration rates were measured on selected Pinus and Quercus snags and coarse woody debris each month for 1 year in a northeastern U.S. temperate forest. Multiple linear regression using environmental and biometric variables including wood temperature, diameter, density, species, and decay class was used to model respiration rates of dead stems. The mass of snags and coarse woody debris increased more than fivefold after disturbance and respiration rates increased more than threefold. The contribution of dead stems to total ecosystem respiration more than tripled from 0.85% to almost 3% and respiration from dead stems alone was approximately equal to the net ecosystem exchange of the forest in 2011 (fourth year postdisturbance). This study highlights the importance of dead stem C pools and fluxes particularly during disturbance and recovery cycles. With climate change increasing the ranges of many forest pests and pathogens, these data become particularly important for accurately modeling future C cycling.

  18. Effect of Woody Debris abundance on daytime refuge use by cotton mice.

    SciTech Connect

    Hinkelman, Travis, M.; Loeb, Susan, C.

    2007-07-01

    Abstract - Daytime refuges are important to nocturnal rodents for protection from predators and environmental extremes. Because refuges of forest-dwelling rodents are often associated with woody debris, we examined refuge use by 37 radio-collared Peromyscus gossypinus (cotton mice) in experimental plots with different levels of woody debris. Treatment plots had six times (≈ 60 m3/ha) the volume of woody debris as control plots (≈ 10 m3/ha). Of 247 refuges, 159 were in rotting stumps (64%), 32 were in root boles (13%), 19 were in brush piles (8%), and 16 were in logs (6%); 10 refuges could not be identified. Stumps were the most common refuge type in both treatments, but the distribution of refuge types was significantly different between treatment and control plots. Root boles and brush piles were used more on treatment plots than on control plots, and logs were used more on control plots than on treatment plots. Refuge type and vegetation cover were the best predictors of refuge use by cotton mice; root bole refuges and refuges with less vegetation cover received greater-than-expected use by mice. Abundant refuges, particularly root boles, may improve habitat quality for cotton mice in southeastern pine forests.

  19. Scaling Chromosomes for an Evolutionary Karyotype: A Chromosomal Tradeoff between Size and Number across Woody Species

    PubMed Central

    Liang, Guolu; Chen, Hong

    2015-01-01

    This study aims to examine the expected scaling relationships between chromosome size and number across woody species and to clarify the importance of the scaling for the maintenance of chromosome diversity by analyzing the scaling at the inter- & intra-chromosomal level. To achieve for the goals, chromosome trait data were extracted for 191 woody species (including 56 evergreen species and 135 deciduous species) from the available literature. Cross-species analyses revealed a tradeoff among chromosomes between chromosome size and number, demonstrating there is selective mechanism crossing chromosomes among woody species. And the explanations for the result were presented from intra- to inter-chromosome contexts that the scaling may be compromises among scale symmetry, mechanical requirements, and resource allocation across chromosomes. Therein, a 3/4 scaling pattern was observed between total chromosomes and m-chromosomes within nucleus which may imply total chromosomes may evolve from more to less. In addition, the primary evolutionary trend of karyotype and the role of m-chromosomes in the process of karyotype evolution were also discussed. PMID:26657837

  20. Overstory and understory relationships in longleaf pine plantations 14 years after thinning and woody control.

    SciTech Connect

    Harrington, Timothy, B.

    2011-09-09

    To develop silvicultural strategies for restoring longleaf pine (Pinus palustris Mill.) savannas, mortality and growth of overstory pines and midstory hardwoods and abundance and species richness of herbs were studied for 14 years after pine thinning and nonpine woody control. Pine cover in thinned stands was about half of that in nonthinned stands through year 5, but it lagged by only 8% and 3% in years 9 and 14, respectively, because of vigorous crown responses. Despite a cumulative mortality of 64% of hardwood stems from prescribed fires in years 0, 4, and 9, hardwood basal area in thinned stands (2.1 m2/ha) was three times that in nonthinned stands (0.7 m2/ha) in year 14. Thinning was associated with 13%-22% more cover and six to eight more species of herbs in years 3-8 but only 6% more cover and two more species in year 14 because of accelerated growth of pine cover and hardwood basal area. However, similar increases in cover and richness of herb species in the woody control treatment were retained through year 14 because it had sustained reductions in hardwood and shrub abundance. Silvicultural strategies that substantially delay encroachment by pines, hardwoods, and shrubs will be those most effective at retaining herb species in longleaf pine savannas, including planting pines at wide spacing, periodic thinning and woody control, and frequent burning.

  1. Biogenic volatile organic compounds (BVOC) emitted and accumulated by herbaceous and woody California crops

    NASA Astrophysics Data System (ADS)

    Ormeño, E.; Fares, S.; Park, J.; Gentner, D. R.; Karlik, J. F.; Goldstein, A. H.

    2009-12-01

    Emissions from vegetation may substantially influence regional air quality in California. However, the emission potentials of many important crop species have not been extensively studied, although they comprise extensive areas of landcover within this state. A better knowledge of the emission rate at the species-specific level is critical for reducing uncertainties in emission inventories and evaluating emission model performance. In the present study we identify and quantify BVOC produced (emitted and stored) by leaves of 22 dominant agricultural woody and herbaceous crops in California. Emissions were studied by means of a dynamic cuvette system where a whole plant (herbaceous species) or a branch (woody species) was enclosed. Emitted BVOC were collected by passing air from the cuvette enclosing the branch through a glass tube packed with carbon based adsorbents. The adsorbents were later liquid extracted and concentrated in the laboratory. BVOCs stored in the plant tissues were extracted with an organic solvent, after plant grinding. Both BVOC emitted and BVOC stored were identified and quantified using the same GC-MS equipment. Most identified leaf emissions and stored compounds were terpenoids, but BVOC from other biosynthetic classes (benzenoids and fatty acid derivates)were not negligible. The relationship between different BVOC classes and between emitted and stored terpenoids will be presented. Differences between herbaceous and woody crops, and a variety of foliar secretory structures (e.g. secretory cavities, secretory ducts, glandular trichomes, and glands), will be evaluated in terms of BVOC content and emissions to the atmosphere.

  2. Woody encroachment and its consequences on hydrological processes in the savannah.

    PubMed

    Honda, Eliane A; Durigan, Giselda

    2016-09-19

    Woody encroachment due to changes in climate or in the disturbance regimes (fire and herbivory) has been observed throughout the savannah biome over the last century with ecological, hydrological and socioeconomic consequences. We assessed changes in tree density and basal area and estimated changes in rain interception by the canopies across a 5-year period over a biomass gradient in Cerrado vegetation protected from fire. We modelled throughfall, stemflow and net rainfall on the basis of tree basal area (TBA). Tree density increased by an average annual rate of 6.7%, basal area at 5.7% and rain interception by the canopies at 0.6% of the gross rainfall. Independent of the vegetation structure, we found a robust relationship of 0.9% less rainfall reaching the ground as TBA increases by 1 m(2) ha(-1) Increases in tree biomass with woody encroachment may potentially result in less water available for uptake by plants and to recharge rivers and groundwater reserves. Given that water is a seasonally scarce resource in all savannahs, woody encroachment may threaten the ecosystem services related to water resources.This article is part of the themed issue 'Tropical grassy biomes: linking ecology, human use and conservation'.

  3. Survival, reproduction, and recruitment of woody plants after 14 years on a reforested landfill

    NASA Astrophysics Data System (ADS)

    Robinson, George R.; Handel, Steven N.; Schmalhofer, Victoria R.

    1992-03-01

    With the advent of modern sanitary landfill closure techniques, the opportunity exists for transforming municipal landfills into urban woodlands. While costs of fullscale reforestation are generally prohibitive, a modest planting of clusters of trees and shrubs could initiate or accelerate population expansions and natural plant succession from open field to diverse forest. However, among woody species that have been screened for use on landfills, these ecological potentials have not yet been investigated. We examined a 14-yr-old landfill plantation in New Jersey, USA, established to test tolerance of 19 species of trees and shrubs to landfill environments. We measured survivorship, reproduction, and recruitment within and around the experimental installation. Half of the original 190 plants were present, although survival and growth rates varied widely among species. An additional 752 trees and shrubs had colonized the plantation and its perimeter, as well as 2955 stems of vines. However, the great majority (>95%) of woody plants that had colonized were not progeny of the planted cohort, but instead belonged to 18 invading species, mostly native, bird-dispersed, and associated with intermediate stages of secondary plant succession. Based on this evidence, we recommend that several ecological criteria be applied to choices of woody species for the restoration of municipal landfills and similar degraded sites, in order to maximize rapid and economical establishment of diverse, productive woodlands.

  4. Identification of putative orthologous genes for the phylogenetic reconstruction of temperate woody bamboos (Poaceae: Bambusoideae).

    PubMed

    Zhang, Li-Na; Zhang, Xian-Zhi; Zhang, Yu-Xiao; Zeng, Chun-Xia; Ma, Peng-Fei; Zhao, Lei; Guo, Zhen-Hua; Li, De-Zhu

    2014-09-01

    The temperate woody bamboos (Arundinarieae) are highly diverse in morphology but lack a substantial amount of genetic variation. The taxonomy of this lineage is intractable, and the relationships within the tribe have not been well resolved. Recent studies indicated that this tribe could have a complex evolutionary history. Although phylogenetic studies of the tribe have been carried out, most of these phylogenetic reconstructions were based on plastid data, which provide lower phylogenetic resolution compared with nuclear data. In this study, we intended to identify a set of desirable nuclear genes for resolving the phylogeny of the temperate woody bamboos. Using two different methodologies, we identified 209 and 916 genes, respectively, as putative single copy orthologous genes. A total of 112 genes was successfully amplified and sequenced by next-generation sequencing technologies in five species sampled from the tribe. As most of the genes exhibited intra-individual allele heterozygotes, we investigated phylogenetic utility by reconstructing the phylogeny based on individual genes. Discordance among gene trees was observed and, to resolve the conflict, we performed a range of analyses using BUCKy and HybTree. While caution should be taken when inferring a phylogeny from multiple conflicting genes, our analysis indicated that 74 of the 112 investigated genes are potential markers for resolving the phylogeny of the temperate woody bamboos. © 2014 John Wiley & Sons Ltd.

  5. The floral transcriptomes of four bamboo species (Bambusoideae; Poaceae): support for common ancestry among woody bamboos.

    PubMed

    Wysocki, William P; Ruiz-Sanchez, Eduardo; Yin, Yanbin; Duvall, Melvin R

    2016-05-20

    Next-generation sequencing now allows for total RNA extracts to be sequenced in non-model organisms such as bamboos, an economically and ecologically important group of grasses. Bamboos are divided into three lineages, two of which are woody perennials with bisexual flowers, which undergo gregarious monocarpy. The third lineage, which are herbaceous perennials, possesses unisexual flowers that undergo annual flowering events. Transcriptomes were assembled using both reference-based and de novo methods. These two methods were tested by characterizing transcriptome content using sequence alignment to previously characterized reference proteomes and by identifying Pfam domains. Because of the striking differences in floral morphology and phenology between the herbaceous and woody bamboo lineages, MADS-box genes, transcription factors that control floral development and timing, were characterized and analyzed in this study. Transcripts were identified using phylogenetic methods and categorized as A, B, C, D or E-class genes, which control floral development, or SOC or SVP-like genes, which control the timing of flowering events. Putative nuclear orthologues were also identified in bamboos to use as phylogenetic markers. Instances of gene copies exhibiting topological patterns that correspond to shared phenotypes were observed in several gene families including floral development and timing genes. Alignments and phylogenetic trees were generated for 3,878 genes and for all genes in a concatenated analysis. Both the concatenated analysis and those of 2,412 separate gene trees supported monophyly among the woody bamboos, which is incongruent with previous phylogenetic studies using plastid markers.

  6. Historical climates explain contrasting dormancy-breaking requirements in North American, Asian, and European woody species

    NASA Astrophysics Data System (ADS)

    Zohner, Constantin M.; Benito, Blas M.; Fridley, Jason D.; Svenning, Jens-Christian; Renner, Susanne S.

    2016-04-01

    Leaf-out times in temperate woody species are determined by winter chilling and spring warming, with day length playing a minor role. The species-specific relative importance of these phenological cues determines the sensitivity of leaf unfolding to climate warming in the globe's temperate forests. Using experimental and monitoring data on leaf-out cues in 495 woody species [about 1/3rd each from Asia, Europe, and North America (NA)], we show that NA species have higher winter chilling and spring warming requirements than do European and Asian species of similar genetic stock. The continent effect remained significant when controlling for the modern climates that species are adapted to, suggesting that contrasting historic climate conditions led to the differentiation of leaf-out strategies among NA, European, and Asian plants. The NA flora experienced more and longer periods of climatic instability and harshness (esp. since the Pliocene) than did southern Europe and East Asia, which may explain why NA species have higher dormancy requirements and leaf-out later than Asian species, which are characterized by a more shallow dormancy. That species from Asia require significantly less chilling than their NA relatives suggests contrasting responses of NA and Asian temperate forests to continued climate warming. Earlier leaf-out in NA trees and shrubs will be constrained by unmet chilling requirements as winters get warmer, whereas Asian woody species generally lack such temperature limitations.

  7. Biofuel manufacturing from woody biomass: effects of sieve size used in biomass size reduction.

    PubMed

    Zhang, Meng; Song, Xiaoxu; Deines, T W; Pei, Z J; Wang, Donghai

    2012-01-01

    Size reduction is the first step for manufacturing biofuels from woody biomass. It is usually performed using milling machines and the particle size is controlled by the size of the sieve installed on a milling machine. There are reported studies about the effects of sieve size on energy consumption in milling of woody biomass. These studies show that energy consumption increased dramatically as sieve size became smaller. However, in these studies, the sugar yield (proportional to biofuel yield) in hydrolysis of the milled woody biomass was not measured. The lack of comprehensive studies about the effects of sieve size on energy consumption in biomass milling and sugar yield in hydrolysis process makes it difficult to decide which sieve size should be selected in order to minimize the energy consumption in size reduction and maximize the sugar yield in hydrolysis. The purpose of this paper is to fill this gap in the literature. In this paper, knife milling of poplar wood was conducted using sieves of three sizes (1, 2, and 4 mm). Results show that, as sieve size increased, energy consumption in knife milling decreased and sugar yield in hydrolysis increased in the tested range of particle sizes.

  8. Quantitative resistance traits and suitability of woody plant species for a polyphagous scarab, Popillia japonica Newman.

    PubMed

    Keathley, Craig P; Potter, Daniel A

    2008-12-01

    The Japanese beetle, Popillia japonica Newman, has an unusually broad host range among deciduous woody plants, yet it feeds only sparingly, or not at all, on certain species in the field. We evaluated beetles' preference, survival over time and fecundity on eight woody plant species historically rated as susceptible or resistant and, after verifying those ratings, tested whether resistance is correlated with so-called quantitative defense traits including leaf toughness, low nutrient content (water, nitrogen, and sugars), and relatively high amounts of tannins or saponins, traditionally associated with such plants. We further tested whether species unsuitable for Japanese beetles are also rejected by fall webworms, Hyphantria cunea (Drury) (Lepidoptera: Arctiidae), the expected outcome if the aforementioned traits serve as broad-based defenses against generalists. Choice tests supported historical resistance ratings for the selected species: tuliptree, lilac, dogwood, and Bradford callery pear were rejected by Japanese beetles, whereas sassafras, cherry plum, Virginia creeper, and littleleaf linden were readily eaten. Rejected species also were unsuitable for survival over time, or egg-laying, indicating beetles' inability to overcome the resistance factors through habituation, compensatory feeding, or detoxification. None of the aforementioned leaf traits was consistently higher or lower in the resistant or susceptible plants, and plant species rejected by Japanese beetles often were not rejected by fall webworms. Specialized secondary chemistry, not quantitative defenses, likely determines the Japanese beetle's dietary range among deciduous woody plant species it may encounter.

  9. A dynamic leaf gas-exchange strategy is conserved in woody ...

    EPA Pesticide Factsheets

    Rising atmospheric [CO2], ca, is expected to affect stomatal regulation of leaf gas-exchange of woody plants, thus influencing energy fluxes as well as carbon (C), water and nutrient cycling of forests. Researchers have reported that stomata regulate leaf gas-exchange around “set points” that include a constant leaf internal [CO2], ci, a constant drawdown in CO2 (ca - ci), and a constant ci/ca. Because these set points can result in drastically different consequences for leaf gas-exchange, it will be essential for the accuracy of Earth systems models that generalizable patterns in leaf gas-exchange responses to ca be identified if any do exist. We hypothesized that the concept of optimal stomatal behavior, exemplified by woody plants shifting along a continuum of these set point strategies, would provide a unifying framework for understanding leaf gas-exchange responses to ca. We analyzed studies reporting C stable isotope ratio (δ13C) or photosynthetic discrimination (∆13C) from woody plant taxa that grew across ca spanning at least 100 ppm for each species investigated. From these data we calculated ci, and in combination with known or estimated ca, leaf gas-exchange regulation strategies were assessed. Overall, our analyses does not support the hypothesis that trees are canalized towards any of the proposed set points, particularly so for a constant ci. Rather, the results are consistent with the hypothesis that stomatal optimization regulates leaf gas

  10. Responses to environmental stresses in woody plants: key to survive and longevity.

    PubMed

    Osakabe, Yuriko; Kawaoka, Akiyoshi; Nishikubo, Nobuyuki; Osakabe, Keishi

    2012-01-01

    Environmental stresses have adverse effects on plant growth and productivity, and are predicted to become more severe and widespread in decades to come. Especially, prolonged and repeated severe stresses affecting growth and development would bring down long-lasting effects in woody plants as a result of its long-term growth period. To counteract these effects, trees have evolved specific mechanisms for acclimation and tolerance to environmental stresses. Plant growth and development are regulated by the integration of many environmental and endogenous signals including plant hormones. Acclimation of land plants to environmental stresses is controlled by molecular cascades, also involving cross-talk with other stresses and plant hormone signaling mechanisms. This review focuses on recent studies on molecular mechanisms of abiotic stress responses in woody plants, functions of plant hormones in wood formation, and the interconnection of cell wall biosynthesis and the mechanisms shown above. Understanding of these mechanisms in depth should shed light on the factors for improvement of woody plants to overcome severe environmental stress conditions.

  11. Field note: comparative efficacy of a woody evapotranspiration landfill cover following the removal of aboveground biomass.

    PubMed

    Schnabel, William; Munk, Jens; Byrd, Amanda

    2015-01-01

    Woody vegetation cultivated for moisture management on evapotranspiration (ET) landfill covers could potentially serve a secondary function as a biomass crop. However, research is required to evaluate the extent to which trees could be harvested from ET covers without significantly impacting their moisture management function. This study investigated the drainage through a six-year-old, primarily poplar/cottonwood ET test cover for a period of one year following the harvest of all woody biomass exceeding a height of 30 cm above ground surface. Results were compared to previously reported drainage observed during the years leading up to the coppice event. In the first year following coppice, the ET cover was found to be 93% effective at redirecting moisture during the spring/summer season, and 95% effective during the subsequent fall/winter season. This was slightly lower than the 95% and 100% efficacy observed in the spring/summer and fall/winter seasons, respectively, during the final measured year prior to coppice. However, the post-coppice efficacy was higher than the efficacy observed during the first three years following establishment of the cover. While additional longer-term studies are recommended, this project demonstrated that woody ET covers could potentially produce harvestable biomass while still effectively managing aerial moisture.

  12. New Biotechnological Tools for the Genetic Improvement of Major Woody Fruit Species

    PubMed Central

    Limera, Cecilia; Sabbadini, Silvia; Sweet, Jeremy B.; Mezzetti, Bruno

    2017-01-01

    The improvement of woody fruit species by traditional plant breeding techniques has several limitations mainly caused by their high degree of heterozygosity, the length of their juvenile phase and auto-incompatibility. The development of new biotechnological tools (NBTs), such as RNA interference (RNAi), trans-grafting, cisgenesis/intragenesis, and genome editing tools, like zinc-finger and CRISPR/Cas9, has introduced the possibility of more precise and faster genetic modifications of plants. This aspect is of particular importance for the introduction or modification of specific traits in woody fruit species while maintaining unchanged general characteristics of a selected cultivar. Moreover, some of these new tools give the possibility to obtain transgene-free modified fruit tree genomes, which should increase consumer's acceptance. Over the decades biotechnological tools have undergone rapid development and there is a continuous addition of new and valuable techniques for plant breeders. This makes it possible to create desirable woody fruit varieties in a fast and more efficient way to meet the demand for sustainable agricultural productivity. Although, NBTs have a common goal i.e., precise, fast, and efficient crop improvement, individually they are markedly different in approach and characteristics from each other. In this review we describe in detail their mechanisms and applications for the improvement of fruit trees and consider the relationship between these biotechnological tools and the EU biosafety regulations applied to the plants and products obtained through these techniques. PMID:28861099

  13. Hydraulic conductivity, photosynthesis and leaf water balance in six evergreen woody species from fall to winter.

    PubMed

    Taneda, Haruhiko; Tateno, Masaki

    2005-03-01

    To confirm that freeze-thaw embolism is a primary stress for evergreen woody species in winter, hydraulic conductivity, photosynthesis and leaf water potential were measured during fall and winter in trees growing in a cool temperate zone (Nikko) and in a warm temperate zone (Tokyo). We examined two evergreen conifers that naturally occur in the cool temperate zone (Abies firma Siebold & Zucc. and Abies homolepis Siebold & Zucc.), and four evergreen broad-leaved woody species that are restricted to the warm temperate zone (Camellia japonica L., Cinnamomum camphora (L.) J. Presl, Ilex crenata Thunb. and Quercus myrsinaefolia Blume). In Tokyo, where no freeze-thaw cycles of xylem sap occurred, hydraulic conductivity, photosynthesis and water balance remained constant during the experimental period. In Nikko, where there were 38 daily freeze-thaw cycles by February, neither of the tracheid-bearing evergreen conifers showed xylem embolism or leaf water deficits. Similarly, the broad-leaved evergreen trees with small-diameter vessels did not exhibit severe embolism or water deficits and maintained CO(2) assimilation even in January. In contrast, the two broad-leaved evergreen trees with large-diameter vessels showed significantly reduced hydraulic conductivity and shoot die-back in winter. We conclude that freeze-thaw embolism restricts evergreen woody species with large-diameter vessels to the warm temperate zone, whereas other stresses limit the distribution of broad-leaved trees, that have small-diameter vessels, but which are restricted to the warm temperate zone.

  14. New Biotechnological Tools for the Genetic Improvement of Major Woody Fruit Species.

    PubMed

    Limera, Cecilia; Sabbadini, Silvia; Sweet, Jeremy B; Mezzetti, Bruno

    2017-01-01

    The improvement of woody fruit species by traditional plant breeding techniques has several limitations mainly caused by their high degree of heterozygosity, the length of their juvenile phase and auto-incompatibility. The development of new biotechnological tools (NBTs), such as RNA interference (RNAi), trans-grafting, cisgenesis/intragenesis, and genome editing tools, like zinc-finger and CRISPR/Cas9, has introduced the possibility of more precise and faster genetic modifications of plants. This aspect is of particular importance for the introduction or modification of specific traits in woody fruit species while maintaining unchanged general characteristics of a selected cultivar. Moreover, some of these new tools give the possibility to obtain transgene-free modified fruit tree genomes, which should increase consumer's acceptance. Over the decades biotechnological tools have undergone rapid development and there is a continuous addition of new and valuable techniques for plant breeders. This makes it possible to create desirable woody fruit varieties in a fast and more efficient way to meet the demand for sustainable agricultural productivity. Although, NBTs have a common goal i.e., precise, fast, and efficient crop improvement, individually they are markedly different in approach and characteristics from each other. In this review we describe in detail their mechanisms and applications for the improvement of fruit trees and consider the relationship between these biotechnological tools and the EU biosafety regulations applied to the plants and products obtained through these techniques.

  15. Biofuel Manufacturing from Woody Biomass: Effects of Sieve Size Used in Biomass Size Reduction

    PubMed Central

    Zhang, Meng; Song, Xiaoxu; Deines, T. W.; Pei, Z. J.; Wang, Donghai

    2012-01-01

    Size reduction is the first step for manufacturing biofuels from woody biomass. It is usually performed using milling machines and the particle size is controlled by the size of the sieve installed on a milling machine. There are reported studies about the effects of sieve size on energy consumption in milling of woody biomass. These studies show that energy consumption increased dramatically as sieve size became smaller. However, in these studies, the sugar yield (proportional to biofuel yield) in hydrolysis of the milled woody biomass was not measured. The lack of comprehensive studies about the effects of sieve size on energy consumption in biomass milling and sugar yield in hydrolysis process makes it difficult to decide which sieve size should be selected in order to minimize the energy consumption in size reduction and maximize the sugar yield in hydrolysis. The purpose of this paper is to fill this gap in the literature. In this paper, knife milling of poplar wood was conducted using sieves of three sizes (1, 2, and 4 mm). Results show that, as sieve size increased, energy consumption in knife milling decreased and sugar yield in hydrolysis increased in the tested range of particle sizes. PMID:22665985

  16. Woody encroachment and its consequences on hydrological processes in the savannah

    PubMed Central

    2016-01-01

    Woody encroachment due to changes in climate or in the disturbance regimes (fire and herbivory) has been observed throughout the savannah biome over the last century with ecological, hydrological and socioeconomic consequences. We assessed changes in tree density and basal area and estimated changes in rain interception by the canopies across a 5-year period over a biomass gradient in Cerrado vegetation protected from fire. We modelled throughfall, stemflow and net rainfall on the basis of tree basal area (TBA). Tree density increased by an average annual rate of 6.7%, basal area at 5.7% and rain interception by the canopies at 0.6% of the gross rainfall. Independent of the vegetation structure, we found a robust relationship of 0.9% less rainfall reaching the ground as TBA increases by 1 m2 ha−1. Increases in tree biomass with woody encroachment may potentially result in less water available for uptake by plants and to recharge rivers and groundwater reserves. Given that water is a seasonally scarce resource in all savannahs, woody encroachment may threaten the ecosystem services related to water resources. This article is part of the themed issue ‘Tropical grassy biomes: linking ecology, human use and conservation’. PMID:27502378

  17. Woody vegetation and land cover changes in the Sahel of Mali (1967-2011)

    NASA Astrophysics Data System (ADS)

    Spiekermann, Raphael; Brandt, Martin; Samimi, Cyrus

    2015-02-01

    In the past 50 years, the Sahel has experienced significant tree- and land cover changes accelerated by human expansion and prolonged droughts during the 1970s and 1980s. This study uses remote sensing techniques, supplemented by ground-truth data to compare pre-drought woody vegetation and land cover with the situation in 2011. High resolution panchromatic Corona imagery of 1967 and multi-spectral RapidEye imagery of 2011 form the basis of this regional scaled study, which is focused on the Dogon Plateau and the Seno Plain in the Sahel zone of Mali. Object-based feature extraction and classifications are used to analyze the datasets and map land cover and woody vegetation changes over 44 years. Interviews add information about changes in species compositions. Results show a significant increase of cultivated land, a reduction of dense natural vegetation as well as an increase of trees on farmer's fields. Mean woody cover decreased in the plains (-4%) but is stable on the plateau (+1%) although stark spatial discrepancies exist. Species decline and encroachment of degraded land are observed. However, the direction of change is not always negative and a variety of spatial variations are shown. Although the impact of climate is obvious, we demonstrate that anthropogenic activities have been the main drivers of change.

  18. A dynamic leaf gas-exchange strategy is conserved in woody ...

    EPA Pesticide Factsheets

    Rising atmospheric [CO2], ca, is expected to affect stomatal regulation of leaf gas-exchange of woody plants, thus influencing energy fluxes as well as carbon (C), water and nutrient cycling of forests. Researchers have reported that stomata regulate leaf gas-exchange around “set points” that include a constant leaf internal [CO2], ci, a constant drawdown in CO2 (ca - ci), and a constant ci/ca. Because these set points can result in drastically different consequences for leaf gas-exchange, it will be essential for the accuracy of Earth systems models that generalizable patterns in leaf gas-exchange responses to ca be identified if any do exist. We hypothesized that the concept of optimal stomatal behavior, exemplified by woody plants shifting along a continuum of these set point strategies, would provide a unifying framework for understanding leaf gas-exchange responses to ca. We analyzed studies reporting C stable isotope ratio (δ13C) or photosynthetic discrimination (∆13C) from woody plant taxa that grew across ca spanning at least 100 ppm for each species investigated. From these data we calculated ci, and in combination with known or estimated ca, leaf gas-exchange regulation strategies were assessed. Overall, our analyses does not support the hypothesis that trees are canalized towards any of the proposed set points, particularly so for a constant ci. Rather, the results are consistent with the hypothesis that stomatal optimization regulates leaf gas

  19. Scaling Chromosomes for an Evolutionary Karyotype: A Chromosomal Tradeoff between Size and Number across Woody Species.

    PubMed

    Liang, Guolu; Chen, Hong

    2015-01-01

    This study aims to examine the expected scaling relationships between chromosome size and number across woody species and to clarify the importance of the scaling for the maintenance of chromosome diversity by analyzing the scaling at the inter- & intra-chromosomal level. To achieve for the goals, chromosome trait data were extracted for 191 woody species (including 56 evergreen species and 135 deciduous species) from the available literature. Cross-species analyses revealed a tradeoff among chromosomes between chromosome size and number, demonstrating there is selective mechanism crossing chromosomes among woody species. And the explanations for the result were presented from intra- to inter-chromosome contexts that the scaling may be compromises among scale symmetry, mechanical requirements, and resource allocation across chromosomes. Therein, a 3/4 scaling pattern was observed between total chromosomes and m-chromosomes within nucleus which may imply total chromosomes may evolve from more to less. In addition, the primary evolutionary trend of karyotype and the role of m-chromosomes in the process of karyotype evolution were also discussed.

  20. Modeling aboveground tree woody biomass using national-scale allometric methods and airborne lidar

    NASA Astrophysics Data System (ADS)

    Chen, Qi

    2015-08-01

    Estimating tree aboveground biomass (AGB) and carbon (C) stocks using remote sensing is a critical component for understanding the global C cycle and mitigating climate change. However, the importance of allometry for remote sensing of AGB has not been recognized until recently. The overarching goals of this study are to understand the differences and relationships among three national-scale allometric methods (CRM, Jenkins, and the regional models) of the Forest Inventory and Analysis (FIA) program in the U.S. and to examine the impacts of using alternative allometry on the fitting statistics of remote sensing-based woody AGB models. Airborne lidar data from three study sites in the Pacific Northwest, USA were used to predict woody AGB estimated from the different allometric methods. It was found that the CRM and Jenkins estimates of woody AGB are related via the CRM adjustment factor. In terms of lidar-biomass modeling, CRM had the smallest model errors, while the Jenkins method had the largest ones and the regional method was between. The best model fitting from CRM is attributed to its inclusion of tree height in calculating merchantable stem volume and the strong dependence of non-merchantable stem biomass on merchantable stem biomass. This study also argues that it is important to characterize the allometric model errors for gaining a complete understanding of the remotely-sensed AGB prediction errors.