Science.gov

Sample records for pollution-induced forest decline

  1. Forest decline from air pollution

    SciTech Connect

    Hileman, B.

    1984-01-01

    Scientists in West Germany and the USA are involved in intensive efforts to ascertain the cause or causes of the declines in their forests. Ongoing research was discussed at an October 1983 symposium on air pollution and forest productivity, held in Washington, D.C., and sponsored by the Izaak Walton League of America and Pennsylvania State University. The dieback of spruce in the Northeast is relatively well-known. It was revealed at the symposium, however, that forests in other areas of the U.S. may be showing signs of stress and damage and that species other than spruce are affected. Samuel B. McLaughlin of Oak Ridge National Laboratory (ORNL) pointed out that red spruce, shortleaf pine, hickory, yellow birch, pitch pine, hemlock, and Fraser fir are declining in East Tennessee. He noted that these decline together with those in New England suggest that decreased productivity in several tree species has been occurring over a broad scale during the past two decades. One commonly held view is that acid deposition is causing the decline of forests in both Europe and the U.S. At the symposium, a number of different opinions about possible causes were expressed, ranging from drought to ozone to combinations of pollutants, including acid deposition, ozone and trace metals. Possible causes that were not subjects of active inquiry were disease and insects. Most researchers in the field believe there is little evidence that one of these is the primary damaging agent.

  2. [Forest degradation/decline: research and practice].

    PubMed

    Zhu, Jiao-Jun; Li, Feng-Qin

    2007-07-01

    As one of the most critical environmental problems in the 21st century, forest degradation has been facing worldwide. There are many definitions about forest degradation, but its common features are the permanent loss of forests, stand structure destructed, forest quality decreased, and forest functions lowered. Forest decline or tree decline in fact is one of the causes of forest degradation, which includes the general reduction of trees in vigor, low level growth of trees in productivity, death of trees, and even, decline of soil fertility. Many researches indicated that deforestation is the permanent loss of forests in area, which is shifted to other land uses. Deforestation is the product of the interactions between environmental, social, economic, cultural, and political forces at work in any given country/region, and thus, more and more attention is focused on the negative socioeconomic and environmental effects after forest degradation, especially on the reduction of forest area induced by deforestation. The effects of any decisions or policies in national and international levels on forest degradation induced by deforestation have been paid attention as well. How to make efforts and strengthen the worldwide cooperation to combat the forest degradation induced by deforestation must be challenged to find appropriate solutions. There are many researches on forest decline, because of its complexity and uncertainties. The major causes of forest decline include: 1) pollution from both industry and agriculture, 2) stress factors, e.g., desiccation, 3) changes in stand dynamics, 4) decline disease of forest or diseases of complex etiology, 5) degradation of productivity and/or soil fertility in pure plantation forests. Forest degradation in China is similar to that all over the world, but with the characteristics in forest components, i.e., 1) secondary forests are the major forest resources, 2) China has the most plantation forests in the world, some of which have

  3. Decline of Ohia Lehua forests in Hawaii

    Treesearch

    Robert E. Burgan; Robert E. Nelson

    1972-01-01

    Thousands of acres of ohia lehua (Metrosidems collina) forests on the island of Hawaii have died, and tree death is progressing rapidly into healthy forests. Most of the losses are on State-owned lands. All of the "ohia decline" cannot be attributed to the same agent. Some of the earlier decline was attributed to frost and sulphur dioxide....

  4. Forest declines in response to environmental change

    Treesearch

    Philip M. Wargo; Allan N.D. Auclair

    2000-01-01

    Decline diseases are intimately linked to stress and environmental change. There is strong evidence that, as a category, decline diseases have increased significantly in response to the climate, air chemistry, and other changes documented in the northeastern United States over the past century, and particularly the last two decades. No other forest response to...

  5. Characteristics of Declining Forest Stands on the Allegheny National Forest

    Treesearch

    William H. McWilliams; Robert White; Stanford L. Arner; Christopher, A. Nowak; Susan L. Stout; Susan L. Stout

    1996-01-01

    Forest stands with advanced symptoms of forest decline located on the Allegheny National Forest in northwestern Pennsylvania were studied to describe contemporary stand structure and composition, and the status of regeneration. Across all 340 stands, 12 percent of the total basal area per acre was in dead trees and 16 percent was in trees at high risk of mortality. For...

  6. Aspen decline on the Coconino National Forest

    Treesearch

    Mary Lou Fairweather; Brian W. Geils; Mike Manthei

    2008-01-01

    An accelerated decline of aspen occurred across the Coconino National Forest, in northern Arizona, following a frost event in June 1999, and a long-term drought that included an extremely dry and warm period from 2001 through 2002, and bouts of defoliation by the western tent caterpillar in 2004, 2005, and 2007. From 2003 to 2007, we monitored aspen mortality and...

  7. Comparison of in situ and airborne spectral measurements of the blue shift associated with forest decline

    NASA Technical Reports Server (NTRS)

    Rock, B. N.; Hoshizaki, T.; Miller, J. R.

    1988-01-01

    Visible IR Intelligent Spectrometer (VIRIS) reflectance data have been found to have similar features that are related to air-pollution-induced forest decline and visible damage in both the red spruce of Vermont and the Norway spruce of Baden-Wuerttemberg; the similarity suggests a common source of damage. Spectra of both species include a 5-nm blueshifting of the red-edge inflection point, while pigment data for both species indicate a loss of total chlorophylls. The blue shift of the chlorophyll absorption maximum, as well as the increased red radiance and decreased near-IR radiance of the damaged spruce, may be used to delineate and map damage areas.

  8. Potential streamflow changes from forest decline due to air pollution

    Treesearch

    R. M. Rice; J. Lewis

    1988-01-01

    In recent years, serious die-back of forest trees has been reported in western Europe and eastern North America. One presumed cause of the forest decline is air pollution and acid deposition. Concern has been expressed that adverse hydrologic responses might occur in forested watersheds as the result of reduced evapotranspiration and increased discharge. According...

  9. Ohia forest decline: its spread and severity in Hawaii

    Treesearch

    Edwin Q. P. Petteys; Robert E. Burgan; Robert E. Nelson

    1975-01-01

    Ohia forest decline–its severity and rate of spread–was studied by aerial photographic techniques on a 197,000-acre (80,000-ha) portion of the island of Hawaii. In 1954, only 300 acres (121 ha) showed signs of severe decline; by 1972, the acreage of severely affected forest had increased to 85,200 acres (34,480 ha). Rate of decline and current severity were related to...

  10. POPULATION DECLINES OF THE PUERTO RICAN VIREO IN GUANICA FOREST.

    Treesearch

    JOHN FAABORG; KATE M. DUGGER; WAYNE J. ARENDT; BETHANY L. WOODWORTH; MICHAEL E. BALTZ

    1997-01-01

    Abundance of the Puerto Rican Vireo (Vireo Zutimeri) in Guanica Forest, Puerto Rico, has declined gradually over the period 1973-1996 as determined by constant effort mist netting. Concurrent studies of breeding vireos show low nesting success, primarily due to parasitism by Shiny Cowbirds (Molothrus bonariensis). This decline may reflect the rather recent entry of the...

  11. Do improvement harvests mitigate oak decline in Missouri Ozark forests?

    Treesearch

    John P. Dwyer; John M. Kabrick; James Wetteroff

    2007-01-01

    Since the 1970s, oak decline has been a chronic problem throughout the oak-dominated forests of the Missouri Ozarks. Prior research indicates that environmental stress, particularly drought, leads to the onset of oak decline. Consequently, some scientists and managers have advocated thinning and intermediate harvesting to maintain or improve tree vigor and growth,...

  12. Drought-induced forest decline: causes, scope and implications

    PubMed Central

    Martínez-Vilalta, Jordi; Lloret, Francisco; Breshears, David D.

    2012-01-01

    A large number of episodes of forest mortality associated with drought and heat stress have been detected worldwide in recent decades, suggesting that some of the world's forested ecosystems may be already responding to climate change. Here, we summarize a special session titled ‘Drought-induced forest decline: causes, scope and implications’ within the 12th European Ecological Federation Congress, held in Ávila (Spain) from 25 to 29 September 2011. The session focused on the interacting causes and impacts of die-off episodes at the community and ecosystem levels, and highlighted recent events of drought- and heat-related tree decline, advances in understanding mechanisms and in predicting mortality events, and diverse consequences of forest decline. Talks and subsequent discussion noted a potentially important role of carbon that may be interrelated with plant hydraulics in the multi-faceted process leading to drought-induced mortality; a substantial and yet understudied capacity of many forests to cope with extreme climatic events; and the difficulty of separating climate effects from other anthropogenic changes currently shaping forest dynamics in many regions of the Earth. The need for standard protocols and multi-level monitoring programmes to track the spatio-temporal scope of forest decline globally was emphasized as critical for addressing this emerging environmental issue. PMID:22171020

  13. An Investigation of the Afternoon Decline in Tropical Forest Photosynthesis

    NASA Astrophysics Data System (ADS)

    Doughty, C.; Goulden, M. L.; Miller, S. D.; Menton, M. C.; da Rocha, H.; Freitas, H.; Figueira, M. A.; da Sousa, C. A.; Maia, A.

    2002-12-01

    The recent use of eddy covariance to measure the net exchange of CO2 between the atmosphere and a tropical forest in Santarem Para, Brazil, has indicated a substantial decline in forest photosynthesis in the afternoon, even after taking light differences into account. Afternoon declines in leaf-level gas exchange have been reported for many ecosystems, including tropical forests. Potential causes for this decline include stomatal responses to VPD, low leaf water potential, changes in biochemistry due to elevated temperature, photoinhibition, photorespiration, or intrinsic circadian rhythm. This study attempts to understand this decline by using leaf gas exchange to measure photosynthesis while canopy leaves are kept under constant light, humidity, and temperature conditions for 24 to 36 hours hours.At constant light levels of 100 PAR æmol~m-2s-1, 7 of 12 species tested showed a substantial decline photosynthesis at night, and a subsequent recovery in photosynthesis during the next day. In most cases, the internal CO2 of these plants increased at night, indicating that this diel cycle was not simply an effect of a circadian rhythm in stomatal conductance. Rather, the photosynthesis of a significant fraction of the plants surveyed appears to be under the direct control of a circadian oscillator.

  14. Devastating decline of forest elephants in central Africa.

    PubMed

    Maisels, Fiona; Strindberg, Samantha; Blake, Stephen; Wittemyer, George; Hart, John; Williamson, Elizabeth A; Aba'a, Rostand; Abitsi, Gaspard; Ambahe, Ruffin D; Amsini, Fidèl; Bakabana, Parfait C; Hicks, Thurston Cleveland; Bayogo, Rosine E; Bechem, Martha; Beyers, Rene L; Bezangoye, Anicet N; Boundja, Patrick; Bout, Nicolas; Akou, Marc Ella; Bene, Lambert Bene; Fosso, Bernard; Greengrass, Elizabeth; Grossmann, Falk; Ikamba-Nkulu, Clement; Ilambu, Omari; Inogwabini, Bila-Isia; Iyenguet, Fortune; Kiminou, Franck; Kokangoye, Max; Kujirakwinja, Deo; Latour, Stephanie; Liengola, Innocent; Mackaya, Quevain; Madidi, Jacob; Madzoke, Bola; Makoumbou, Calixte; Malanda, Guy-Aimé; Malonga, Richard; Mbani, Olivier; Mbendzo, Valentin A; Ambassa, Edgar; Ekinde, Albert; Mihindou, Yves; Morgan, Bethan J; Motsaba, Prosper; Moukala, Gabin; Mounguengui, Anselme; Mowawa, Brice S; Ndzai, Christian; Nixon, Stuart; Nkumu, Pele; Nzolani, Fabian; Pintea, Lilian; Plumptre, Andrew; Rainey, Hugo; de Semboli, Bruno Bokoto; Serckx, Adeline; Stokes, Emma; Turkalo, Andrea; Vanleeuwe, Hilde; Vosper, Ashley; Warren, Ymke

    2013-01-01

    African forest elephants- taxonomically and functionally unique-are being poached at accelerating rates, but we lack range-wide information on the repercussions. Analysis of the largest survey dataset ever assembled for forest elephants (80 foot-surveys; covering 13,000 km; 91,600 person-days of fieldwork) revealed that population size declined by ca. 62% between 2002-2011, and the taxon lost 30% of its geographical range. The population is now less than 10% of its potential size, occupying less than 25% of its potential range. High human population density, hunting intensity, absence of law enforcement, poor governance, and proximity to expanding infrastructure are the strongest predictors of decline. To save the remaining African forest elephants, illegal poaching for ivory and encroachment into core elephant habitat must be stopped. In addition, the international demand for ivory, which fuels illegal trade, must be dramatically reduced.

  15. Devastating Decline of Forest Elephants in Central Africa

    PubMed Central

    Blake, Stephen; Wittemyer, George; Hart, John; Williamson, Elizabeth A.; Aba’a, Rostand; Abitsi, Gaspard; Ambahe, Ruffin D.; Amsini, Fidèl; Bakabana, Parfait C.; Hicks, Thurston Cleveland; Bayogo, Rosine E.; Bechem, Martha; Beyers, Rene L.; Bezangoye, Anicet N.; Boundja, Patrick; Bout, Nicolas; Akou, Marc Ella; Bene, Lambert Bene; Fosso, Bernard; Greengrass, Elizabeth; Grossmann, Falk; Ikamba-Nkulu, Clement; Ilambu, Omari; Inogwabini, Bila-Isia; Iyenguet, Fortune; Kiminou, Franck; Kokangoye, Max; Kujirakwinja, Deo; Latour, Stephanie; Liengola, Innocent; Mackaya, Quevain; Madidi, Jacob; Madzoke, Bola; Makoumbou, Calixte; Malanda, Guy-Aimé; Malonga, Richard; Mbani, Olivier; Mbendzo, Valentin A.; Ambassa, Edgar; Ekinde, Albert; Mihindou, Yves; Morgan, Bethan J.; Motsaba, Prosper; Moukala, Gabin; Mounguengui, Anselme; Mowawa, Brice S.; Ndzai, Christian; Nixon, Stuart; Nkumu, Pele; Nzolani, Fabian; Pintea, Lilian; Plumptre, Andrew; Rainey, Hugo; de Semboli, Bruno Bokoto; Serckx, Adeline; Stokes, Emma; Turkalo, Andrea; Vanleeuwe, Hilde; Vosper, Ashley; Warren, Ymke

    2013-01-01

    African forest elephants– taxonomically and functionally unique–are being poached at accelerating rates, but we lack range-wide information on the repercussions. Analysis of the largest survey dataset ever assembled for forest elephants (80 foot-surveys; covering 13,000 km; 91,600 person-days of fieldwork) revealed that population size declined by ca. 62% between 2002–2011, and the taxon lost 30% of its geographical range. The population is now less than 10% of its potential size, occupying less than 25% of its potential range. High human population density, hunting intensity, absence of law enforcement, poor governance, and proximity to expanding infrastructure are the strongest predictors of decline. To save the remaining African forest elephants, illegal poaching for ivory and encroachment into core elephant habitat must be stopped. In addition, the international demand for ivory, which fuels illegal trade, must be dramatically reduced. PMID:23469289

  16. An experimental test of the causes of forest growth decline with stand age.

    Treesearch

    Michael G. Ryan; Dan Binkley; James H. Fownes; Christian Giardina; Randy S. Senock

    2004-01-01

    The decline in aboveground wood production after canopy closure in even-aged forest stands is a common pattern in forests, but clear evidence for the mechanism causing the decline is lacking. The problem is fundamental to forest biology, commercial forestry (the decline sets the rotation age), and to carbon storage in forests. We tested three hypotheses...

  17. Steeper declines in forest photosynthesis than respiration explain age-driven decreases in forest growth.

    PubMed

    Tang, Jianwu; Luyssaert, Sebastiaan; Richardson, Andrew D; Kutsch, Werner; Janssens, Ivan A

    2014-06-17

    The traditional view of forest dynamics originated by Kira and Shidei [Kira T, Shidei T (1967) Jap J Ecol 17:70-87] and Odum [Odum EP (1969) Science 164(3877):262-270] suggests a decline in net primary productivity (NPP) in aging forests due to stabilized gross primary productivity (GPP) and continuously increased autotrophic respiration (Ra). The validity of these trends in GPP and Ra is, however, very difficult to test because of the lack of long-term ecosystem-scale field observations of both GPP and Ra. Ryan and colleagues [Ryan MG, Binkley D, Fownes JH (1997) Ad Ecol Res 27:213-262] have proposed an alternative hypothesis drawn from site-specific results that aboveground respiration and belowground allocation decreased in aging forests. Here, we analyzed data from a recently assembled global database of carbon fluxes and show that the classical view of the mechanisms underlying the age-driven decline in forest NPP is incorrect and thus support Ryan's alternative hypothesis. Our results substantiate the age-driven decline in NPP, but in contrast to the traditional view, both GPP and Ra decline in aging boreal and temperate forests. We find that the decline in NPP in aging forests is primarily driven by GPP, which decreases more rapidly with increasing age than Ra does, but the ratio of NPP/GPP remains approximately constant within a biome. Our analytical models describing forest succession suggest that dynamic forest ecosystem models that follow the traditional paradigm need to be revisited.

  18. Evidence of forest declines in the eastern United States

    SciTech Connect

    Bruck, R.I.

    1996-11-01

    The evidence of forest declines in the eastern US has accumulated principally over the past 15 years. Several researchers have reported significant decreases in annual ring width growth of several tree species in nonurbanized parts of the eastern US. The identification of existing or abnormal growth trends is difficult because long-term data on natural variations in these ecosystems are lacking. Influences of previous natural and human disturbances are often ignored or difficult to determine. Tree ring data collected at any point in time represent a biased account of forest dynamics because only the survivors are present, and therefore past episodes of lethal stress are inherently underrepresented.

  19. Using Forest Service forest inventory and analysis data to estimate regional oak decline and oak mortality

    Treesearch

    Kathryn W. Kromroy; Jennifer Juzwik; Paul Castillo; Mark H. Hansen

    2008-01-01

    Damage and mortality data are collected as part of the US Forest Service, Forest Inventory and Analysis (FIA) ongoing assessments of the nation's timberlands. The usefulness and value of FIA tree data in assessing historical levels of oak decline and oak mortality were investigated for seven Midwestern states. The data were collected during two periodic...

  20. Air pollution and forest decline near Mexico City.

    PubMed

    Tovar, D C

    1989-04-01

    The forests of Abies religiosa Schl. et Cham. in the north and the northeast slopes of the mountains of the southwestern region of the Valley of Mexico are in an acute process of decline, particularly the fir forest of the Cultural and Recreational Park Desierto de los Leones. The mortality of the trees began in 1981, and by 1987 30% of the trees of the Park had died; the mortality continues. The surviving trees are in a very poor crown condition, having thin crowns with many dead branches. in the light of current knowledge air pollution, in particular the oxidant gases (ozone), are the primary cause of decline, but other conditions or agents (age of the trees and diseases) could be contributing factors in the dying of the trees.

  1. Advances of Air Pollution Science: From Forest Decline to Multiple-Stress Effects on Forest Ecosystem Services

    Treesearch

    E. Paoletti; M. Schaub; R. Matyssek; G. Wieser; A. Augustaitis; A. M. Bastrup-Birk; A. Bytnerowicz; M. S. Gunthardt-Goerg; G. Muller-Starck; Y. Serengil

    2010-01-01

    Over the past 20 years, the focus of forest science on air pollution has moved from forest decline to a holistic framework of forest health, and from the effects on forest production to the ecosystem services provided by forest ecosystems. Hence, future research should focus on the interacting factorial impacts and resulting antagonistic and synergistic responses of...

  2. Assessing forest decline in coniferous forests of Vermont using NS-001 Thematic Mapper Simulator data

    NASA Technical Reports Server (NTRS)

    Vogelmann, J. E.; Rock, B. N.

    1986-01-01

    This study evaluates the potential of measuring/mapping forest decline in spruce-fir forests using airborne NS-001 TMS data. Using field instruments, it was found that ratios of 1.65/1.23 and 1.65/0.83-micron reflectance discriminated between spruce samples of low and high-damage sites. Using TMS data, band ratios were found to be strongly correlated with ground-based measurements of forest damage. Ratio colo-density slice images using these band ratios, and images using 0.56 and 1.65-micron bands with either of these band ratios in a false-color composite, provide accurate means of detecting, quantifying and mapping levels of forest decline.

  3. Net aboveground biomass declines of four major forest types with forest ageing and climate change in western Canada's boreal forests.

    PubMed

    Chen, Han Y H; Luo, Yong

    2015-10-01

    Biomass change of the world's forests is critical to the global carbon cycle. Despite storing nearly half of global forest carbon, the boreal biome of diverse forest types and ages is a poorly understood component of the carbon cycle. Using data from 871 permanent plots in the western boreal forest of Canada, we examined net annual aboveground biomass change (ΔAGB) of four major forest types between 1958 and 2011. We found that ΔAGB was higher for deciduous broadleaf (DEC) (1.44 Mg ha(-1)  year(-1) , 95% Bayesian confidence interval (CI), 1.22-1.68) and early-successional coniferous forests (ESC) (1.42, CI, 1.30-1.56) than mixed forests (MIX) (0.80, CI, 0.50-1.11) and late-successional coniferous (LSC) forests (0.62, CI, 0.39-0.88). ΔAGB declined with forest age as well as calendar year. After accounting for the effects of forest age, ΔAGB declined by 0.035, 0.021, 0.032 and 0.069 Mg ha(-1)  year(-1) per calendar year in DEC, ESC, MIX and LSC forests, respectively. The ΔAGB declines resulted from increased tree mortality and reduced growth in all forest types except DEC, in which a large biomass loss from mortality was accompanied with a small increase in growth. With every degree of annual temperature increase, ΔAGB decreased by 1.00, 0.20, 0.55 and 1.07 Mg ha(-1)  year(-1) in DEC, ESC, MIX and LSC forests, respectively. With every cm decrease of annual climatic moisture availability, ΔAGB decreased 0.030, 0.045 and 0.17 Mg ha(-1)  year(-1) in ESC, MIX and LSC forests, but changed little in DEC forests. Our results suggest that persistent warming and decreasing water availability have profound negative effects on forest biomass in the boreal forests of western Canada. Furthermore, our results indicate that forest responses to climate change are strongly dependent on forest composition with late-successional coniferous forests being most vulnerable to climate changes in terms of aboveground biomass. © 2015 John Wiley & Sons Ltd.

  4. Air pollution, forest condition and forest decline in Southern Europe: an overview.

    PubMed

    Bussotti, F; Ferretti, M

    1998-01-01

    Over the last decades much of the work on the impact of air pollution on forests in Europe has concentrated on central and northern countries. The southern part of Europe has received far less attention, although air pollutants-especially the photochemical ones-can reach concentrations likely to have adverse effects on forest vegetation. Although international forest condition surveys present serious problems where data consistency is concerned, they reveal considerable year-by-year species-specific fluctuations rather than a large-scale forest decline. Cases of obvious decline related to environmental factors are well circumscribed: (1) the deterioration of some coastal forests due to the action of polluted seaspray; (2) the deterioration of reforestation projects, especially conifers, mainly due to the poor ecological compatibility between species and site; and (3) the decline of deciduous oaks in southern Italy and of evergreen oaks in the Iberian peninsula apparently due to the interaction of climate stresses and pests and diseases. However, besides obvious deterioration, changes in environmental factors can provoke situations of more subtle stress. The most sensitive stands are Mediterranean conifer forests and mesophile forests of the Mediterranean-montane plane growing at the edges of the natural ecological distribution. Evergreen sclerophyllous forests appear less sensitive to variations in climatic parameters, since they can adapt quite well to both drought and the action of UV-B rays. Several experiments were carried out to test the sensitivity of Mediterranean forest species to air pollutants. Most of those experiments used seedlings of different species treated with pollutant concentrations too high to be realistic, so it is difficult to derive adequate information on the response of adult trees in field conditions. Ozone has been proved to cause foliar injury in a variety of native forest species in different Southern European countries, while the

  5. Have changing forests conditions contributed to pollinator decline in the southeastern United States?

    Treesearch

    James L. Hanula; Scott Horn; Joseph J. O' Brien

    2015-01-01

    Two conservation goals of the early 20th century, extensive reforestation and reduced wildfire through fire exclusion, may have contributed to declining pollinator abundance as forests became denser and shrub covered. To examine how forest structure affects bees we selected 5 stands in each of 7 forest types including: cleared forest; dense young pines; thinned young...

  6. Survival analysis for a large scale forest health issue: Missouri oak decline

    Treesearch

    C.W. Woodall; P.L. Grambsch; W. Thomas; W.K. Moser

    2005-01-01

    Survival analysis methodologies provide novel approaches for forest mortality analysis that may aid in detecting, monitoring, and mitigating of large-scale forest health issues. This study examined survivor analysis for evaluating a regional forest health issue - Missouri oak decline. With a statewide Missouri forest inventory, log-rank tests of the effects of...

  7. Decline of forest interior conditions in the conterminous United States

    EPA Science Inventory

    Forest fragmentation threatens the sustainability of forest interior environments, thereby endangering subordinate ecological attributes and functions. We analyzed the spatial patterns of forest disturbance and recovery for the conterminous United States from 2001 to 2006 to det...

  8. Decline of forest interior conditions in the conterminous United States

    Treesearch

    Kurt H. Riitters; James D. Wickham

    2012-01-01

    Forest fragmentation threatens the sustainability of forest interior environments, thereby endangering subordinate ecological attributes and functions. We analyzed the spatial patterns of forest loss and gain for the conterminous United States from 2001 to 2006 to determine whether forest interior environments were maintained at five spatial scales. A 1.1% net loss of...

  9. Twentieth-century warming and the dendroclimatology of declining yellow-cedar forests in southeastern Alaska

    Treesearch

    Colin M. Beier; Scott E. Sink; Paul E. Hennon; David V. D' Amore; Glenn P. Juday

    2008-01-01

    Decline of yellow-cedar (Chamaecyparis nootkatensis((D. Don) Spach) has occurred on 200 000 ha of temperate rainforests across southeastern Alaska. Because declining forests appeared soon after the Little Ice Age and are limited mostly to low elevations (whereas higher elevation forests remain healthy), recent studies have hypothesized a climatic...

  10. Twentieth-century warming and the dendroclimatology of declining yellow-cedar forests in southeastern Alaska

    Treesearch

    Colin M. Beier; Scot E. Sink; Paul E. Hennon; David V. D' amore; Glenn P. Juday

    2008-01-01

    Decline of yellow-cedar (Chamaecyparis nootkatensis D. Don) Spach) has occurred on 200 000 ha of temperate rainforests across southeastern Alaska. Because declining forests appeared soon after the Little Ice Age and are limited mostly to low elevations (whereas higher elevation forests remain healthy), recent studies have hypothesized a climatic...

  11. Yellow-cedar decline in the North Coast Forest District of British Columbia.

    Treesearch

    Paul E. Hennon; David V. D' Amore; Stefan Zeglan; Mike. Grainger

    2005-01-01

    The distribution of a forest decline of yellow-cedar (Callitropsis nootkatensis (D. Don) Örsted) has been documented in southeast Alaska, but its occurrence in British Columbia was previously unknown. We conducted an aerial survey in the Prince Rupert area in September 2004 to determine if yellow-cedar forests in the North Coast Forest District of...

  12. An ecohydrological framework for water yield changes of forested catchments due to forest decline and soil acidification

    SciTech Connect

    Caspary, H.J. )

    1990-06-01

    The effect of forest decline on water resources is not well described, for there have been no long-term measurements on catchments with declining forests. The precipitation/runoff relationship of the declining forests of the Eyach catchment in the Northern Black Forest/Federal Republic of Germany is analyzed. The uninhabited catchment is subdivided into four subcatchments (7, 10, 30, 52 km{sup 2}) and is totally covered with coniferous forest, mostly Norway spruce. Long-term monitoring from 1973 to 1986 indicates a significant increase in water yield and the runoff coefficient for the growing season, although there has been no extensive cutting in the catchment. An ecohydrological systems model was developed by the incorporation of field data and plant physiological processes to describe the increase in water yield. Field data include hydrological, hydrogeological, geological, soil-physical, soil-chemical, water-chemical, air-chemical, pollutant deposition, forest inventory, and forest decline field measurements from the Eyach catchment and comparable neighboring regions. The model indicates that the observed increase in water yield is likely to be caused by a reduction of forest transpiration. This change in water yield is linked to forest decline and soil acidification caused by anthropogenic sources of air pollution.

  13. On the decline of ground lichen forests in the Swedish boreal landscape: Implications for reindeer husbandry and sustainable forest management.

    PubMed

    Sandström, Per; Cory, Neil; Svensson, Johan; Hedenås, Henrik; Jougda, Leif; Borchert, Nanna

    2016-05-01

    Lichens are a bottleneck resource for circumpolar populations of reindeer, and as such, for reindeer husbandry as an indigenous Sami land-use tradition in northern Sweden. This study uses ground lichen data and forest information collected within the Swedish National Forest Inventory since 1953, on the scale of northern Sweden. We found a 71 % decline in the area of lichen-abundant forests over the last 60 years. A decline was observed in all regions and age classes and especially coincided with a decrease of >60 year old, open pine forests, which was the primary explanatory factor in our model. The effects of reindeer numbers were inconclusive in explaining the decrease in lichen-abundant forest. The role that forestry has played in causing this decline can be debated, but forestry can have a significant role in reversing the trend and improving ground lichen conditions.

  14. Modeling the Effects of Harvest Alternatives on Mitigating Oak Decline in a Central Hardwood Forest Landscape.

    PubMed

    Wang, Wen J; He, Hong S; Spetich, Martin A; Shifley, Stephen R; Thompson Iii, Frank R; Fraser, Jacob S

    2013-01-01

    Oak decline is a process induced by complex interactions of predisposing factors, inciting factors, and contributing factors operating at tree, stand, and landscape scales. It has greatly altered species composition and stand structure in affected areas. Thinning, clearcutting, and group selection are widely adopted harvest alternatives for reducing forest vulnerability to oak decline by removing susceptible species and declining trees. However, the long-term, landscape-scale effects of these different harvest alternatives are not well studied because of the limited availability of experimental data. In this study, we applied a forest landscape model in combination with field studies to evaluate the effects of the three harvest alternatives on mitigating oak decline in a Central Hardwood Forest landscape. Results showed that the potential oak decline in high risk sites decreased strongly in the next five decades irrespective of harvest alternatives. This is because oak decline is a natural process and forest succession (e.g., high tree mortality resulting from intense competition) would eventually lead to the decrease in oak decline in this area. However, forest harvesting did play a role in mitigating oak decline and the effectiveness varied among the three harvest alternatives. The group selection and clearcutting alternatives were most effective in mitigating oak decline in the short and medium terms, respectively. The long-term effects of the three harvest alternatives on mitigating oak decline became less discernible as the role of succession increased. The thinning alternative had the highest biomass retention over time, followed by the group selection and clearcutting alternatives. The group selection alternative that balanced treatment effects and retaining biomass was the most viable alternative for managing oak decline. Insights from this study may be useful in developing effective and informed forest harvesting plans for managing oak decline.

  15. Comprehensive methods for earlier detection and monitoring of forest decline

    Treesearch

    Jennifer Pontius; Richard Hallett

    2014-01-01

    Forested ecosystems are threatened by invasive pests, pathogens, and unusual climatic events brought about by climate change. Earlier detection of incipient forest health problems and a quantitatively rigorous assessment method is increasingly important. Here, we describe a method that is adaptable across tree species and stress agents and practical for use in the...

  16. Advances of air pollution science: from forest decline to multiple-stress effects on forest ecosystem services.

    PubMed

    Paoletti, E; Schaub, M; Matyssek, R; Wieser, G; Augustaitis, A; Bastrup-Birk, A M; Bytnerowicz, A; Günthardt-Goerg, M S; Müller-Starck, G; Serengil, Y

    2010-06-01

    Over the past 20 years, the focus of forest science on air pollution has moved from forest decline to a holistic framework of forest health, and from the effects on forest production to the ecosystem services provided by forest ecosystems. Hence, future research should focus on the interacting factorial impacts and resulting antagonistic and synergistic responses of forest trees and ecosystems. The synergistic effects of air pollution and climatic changes, in particular elevated ozone, altered nitrogen, carbon and water availability, must be key issues for research. Present evidence suggests air pollution will become increasingly harmful to forests under climate change, which requires integration amongst various stressors (abiotic and biotic factors, including competition, parasites and fire), effects on forest services (production, biodiversity protection, soil protection, sustained water balance, socio-economical relevance) and assessment approaches (research, monitoring, modeling) to be fostered. Copyright 2009 Elsevier Ltd. All rights reserved.

  17. Drought-Caused Forest Decline In The Trans-Baikal Lake Area

    NASA Astrophysics Data System (ADS)

    Ranson, J.; Kharuk, V.; Oscorbin, P.; Im, S.

    2011-12-01

    One of the important consequences of observed and predicted climate change is regional desertification and conversion of forest lands into steppes. We documented progressive forest decline in the trans-Baikal Lake mountains (center point coordinates ~ 51°30'N/116°30'E). This area has a sever continental climate and is a transition area between the Siberian taiga and Mongolian steppes and deserts. Forests are dominated by birch and occupy north-facing mountains slopes (with elevations up to 1200 m). Southern facing slopes are typically covered by grass communities. Analysis of field measurements and satellite temporal data showed an increasing forest decline during the last decades (i.e, 1990-2010). The typical pattern of forest decline was ring-like with the forest die-back starting in the boundary area around the outside of the stand within the forest-grass transition zone. This decline was likely, caused by decreases in precipitation and soil water content. During the last two decades summer precipitation decrease was > 10% (P>0.05), and is now 270 ±30 mm/yr. Similarly, hydrothermal index value decreased to about 12% (P>0.05). Satellite-derived forest decline correlates with precipitation and hydrothermal index decreases. Soil studies showed highest water content values within soils of healthy stands, with minimum values within the dead stand areas, and intermediate within the transition zone. Satellite - based estimates of the total area with drought-caused forest decline was about 106 ha. Along with the observed decline of birch stands, two others climate-caused phenomena were noted within the study and adjacent areas during the last decades: a significant increase of fire frequency and decrease of lake surface area.

  18. Losing a jewel-Rapid declines in Myanmar's intact forests from 2002-2014.

    PubMed

    Bhagwat, Tejas; Hess, Andrea; Horning, Ned; Khaing, Thiri; Thein, Zaw Min; Aung, Kyaw Moe; Aung, Kyaw Htet; Phyo, Paing; Tun, Ye Lin; Oo, Aung Htat; Neil, Anthony; Thu, Win Myo; Songer, Melissa; LaJeunesse Connette, Katherine; Bernd, Asja; Huang, Qiongyu; Connette, Grant; Leimgruber, Peter

    2017-01-01

    New and rapid political and economic changes in Myanmar are increasing the pressures on the country's forests. Yet, little is known about the past and current condition of these forests and how fast they are declining. We mapped forest cover in Myanmar through a consortium of international organizations and environmental non-governmental groups, using freely-available public domain data and open source software tools. We used Landsat satellite imagery to assess the condition and spatial distribution of Myanmar's intact and degraded forests with special focus on changes in intact forest between 2002 and 2014. We found that forests cover 42,365,729 ha or 63% of Myanmar, making it one of the most forested countries in the region. However, severe logging, expanding plantations, and degradation pose increasing threats. Only 38% of the country's forests can be considered intact with canopy cover >80%. Between 2002 and 2014, intact forests declined at a rate of 0.94% annually, totaling more than 2 million ha forest loss. Losses can be extremely high locally and we identified 9 townships as forest conversion hotspots. We also delineated 13 large (>100,000 ha) and contiguous intact forest landscapes, which are dispersed across Myanmar. The Northern Forest Complex supports four of these landscapes, totaling over 6.1 million ha of intact forest, followed by the Southern Forest Complex with three landscapes, comprising 1.5 million ha. These remaining contiguous forest landscape should have high priority for protection. Our project demonstrates how open source data and software can be used to develop and share critical information on forests when such data are not readily available elsewhere. We provide all data, code, and outputs freely via the internet at (for scripts: https://bitbucket.org/rsbiodiv/; for the data: http://geonode.themimu.info/layers/geonode%3Amyan_lvl2_smoothed_dec2015_resamp).

  19. Losing a jewel—Rapid declines in Myanmar’s intact forests from 2002-2014

    PubMed Central

    Horning, Ned; Khaing, Thiri; Thein, Zaw Min; Aung, Kyaw Moe; Aung, Kyaw Htet; Phyo, Paing; Tun, Ye Lin; Oo, Aung Htat; Neil, Anthony; Thu, Win Myo; Songer, Melissa; Huang, Qiongyu; Connette, Grant; Leimgruber, Peter

    2017-01-01

    New and rapid political and economic changes in Myanmar are increasing the pressures on the country’s forests. Yet, little is known about the past and current condition of these forests and how fast they are declining. We mapped forest cover in Myanmar through a consortium of international organizations and environmental non-governmental groups, using freely-available public domain data and open source software tools. We used Landsat satellite imagery to assess the condition and spatial distribution of Myanmar’s intact and degraded forests with special focus on changes in intact forest between 2002 and 2014. We found that forests cover 42,365,729 ha or 63% of Myanmar, making it one of the most forested countries in the region. However, severe logging, expanding plantations, and degradation pose increasing threats. Only 38% of the country’s forests can be considered intact with canopy cover >80%. Between 2002 and 2014, intact forests declined at a rate of 0.94% annually, totaling more than 2 million ha forest loss. Losses can be extremely high locally and we identified 9 townships as forest conversion hotspots. We also delineated 13 large (>100,000 ha) and contiguous intact forest landscapes, which are dispersed across Myanmar. The Northern Forest Complex supports four of these landscapes, totaling over 6.1 million ha of intact forest, followed by the Southern Forest Complex with three landscapes, comprising 1.5 million ha. These remaining contiguous forest landscape should have high priority for protection. Our project demonstrates how open source data and software can be used to develop and share critical information on forests when such data are not readily available elsewhere. We provide all data, code, and outputs freely via the internet at (for scripts: https://bitbucket.org/rsbiodiv/; for the data: http://geonode.themimu.info/layers/geonode%3Amyan_lvl2_smoothed_dec2015_resamp) PMID:28520726

  20. Health of eastern North American sugar maple forests and factors affecting decline

    Treesearch

    Stephen B. Horsley; Robert P. Long; Scott W. Bailey; Richard A. Hallett; Philip M. Wargo

    2002-01-01

    Sugar maple (Acer saccharum) is a keystone species in the forests of the northeastern and Midwestern United States and eastern Canada. Its sustained health is an important issue in both managed and unmanaged forests. While sugar maple generally is healthy throughout its range, decline disease of sugar maple has occurred sporadically during the past...

  1. Has Virginia pine declined? The use of Forest Health Monitoring and other information in the determination

    Treesearch

    William G. Burkman; William A. Bechtold

    2000-01-01

    This paper examines the current status of Virginia pine, focusing on Forest Health Monitoring (FHM) results and using Forest Inventory and Analysis (FIA) information to determine if Virginia pine is showing a decline. An examination of crown condition data from live trees in the FHM program from 1991 through 1997 showed that Virginia pine had significantly...

  2. Changes in forest structure associated with oak decline in severely impacted areas of northern Arkansas

    Treesearch

    Eric Heitzman; Adrian Grell; Martin Spetich; Dale Starkey

    2007-01-01

    Four mature northern red oak (Quercus rubra L.)–white oak (Quercus alba L.) stands in the Boston Mountains of northern Arkansas were studied to describe the vegetation dynamics of forests heavily impacted by oak decline. Northern red oak was the species most susceptible to decline. Across the four stands, 51–75% of red oak density...

  3. Decline of sacred fir (Abies religiosa) in a forest park south of Mexico City.

    PubMed

    Alvarado R, D; De Bauer, L I; Galindo A, J

    1993-01-01

    Decline of sacred fir (Abies religiosa) trees in the high elevation forest park, Desierto de los Leones, located south of Mexico City, is described. Trees located in the windward zone (exposed to air masses from Mexico City) were the most severely affected, especially trees at the distal ends of ravines. Examination of tree growth rings indicated decreases in ring widths for the past 30 years. Polluted air from Mexico City may be an important causal factor in fir decline. Drought, due to excessive removal of soil water, insects, mites and pathogens, and poor forest management are possible contributing and interactive factors in fir decline.

  4. Forest Disturbance Across the Conterminous United States from 1985-2012: The Emerging Dominance of Forest Decline

    NASA Technical Reports Server (NTRS)

    Cohen, Warren B.; Yang, Zhiqiang; Stehman, Stephen; Schroeder, Todd; Bell, David M.; Masek, Jeffrey; Huang, Chengquan; Meigs, Garrett W.

    2015-01-01

    Evidence of shifting dominance among major forest disturbance agent classes regionally to globally has been emerging in the literature. For example, climate-related stress and secondary stressors on forests (e.g., insect and disease, fire) have dramatically increased since the turn of the century globally, while harvest rates in the western US and elsewhere have declined. For shifts to be quantified, accurate historical forest disturbance estimates are required as a baseline for examining current trends. We report annual disturbance rates (with uncertainties) in the aggregate and by major change causal agent class for the conterminous US and five geographic subregions between 1985 and 2012. Results are based on human interpretations of Landsat time series from a probability sample of 7200 plots (30 m) distributed throughout the study area. Forest disturbance information was recorded with a Landsat time series visualization and data collection tool that incorporates ancillary high-resolution data. National rates of disturbance varied between 1.5% and 4.5% of forest area per year, with trends being strongly affected by shifting dominance among specific disturbance agent influences at the regional scale. Throughout the time series, national harvest disturbance rates varied between one and two percent, and were largely a function of harvest in the more heavily forested regions of the US (Mountain West, Northeast, and Southeast). During the first part of the time series, national disturbance rates largely reflected trends in harvest disturbance. Beginning in the mid-90s, forest decline-related disturbances associated with diminishing forest health (e.g., physiological stress leading to tree canopy cover loss, increases in tree mortality above background levels), especially in the Mountain West and Lowland West regions of the US, increased dramatically. Consequently, national disturbance rates greatly increased by 2000, and remained high for much of the decade. Decline

  5. Forest stand structure, productivity, and age mediate climatic effects on aspen decline

    USGS Publications Warehouse

    Bell, David M.; Bradford, John B.; Lauenroth, William K.

    2014-01-01

    Because forest stand structure, age, and productivity can mediate the impacts of climate on quaking aspen (Populus tremuloides) mortality, ignoring stand-scale factors limits inference on the drivers of recent sudden aspen decline. Using the proportion of aspen trees that were dead as an index of recent mortality at 841 forest inventory plots, we examined the relationship of this mortality index to forest structure and climate in the Rocky Mountains and Intermountain Western United States. We found that forest structure explained most of the patterns in mortality indices, but that variation in growing-season vapor pressure deficit and winter precipitation over the last 20 years was important. Mortality index sensitivity to precipitation was highest in forests where aspen exhibited high densities, relative basal areas, quadratic mean diameters, and productivities, whereas sensitivity to vapor pressure deficit was highest in young forest stands. These results indicate that the effects of drought on mortality may be mediated by forest stand development, competition with encroaching conifers, and physiological vulnerabilities of large trees to drought. By examining mortality index responses to both forest structure and climate, we show that forest succession cannot be ignored in studies attempting to understand the causes and consequences of sudden aspen decline.

  6. Forest stand structure, productivity, and age mediate climatic effects on aspen decline.

    PubMed

    Bell, David M; Bradford, John B; Lauenroth, William K

    2014-08-01

    Because forest stand structure, age, and productivity can mediate the impacts of climate on quaking aspen (Populus tremuloides) mortality, ignoring stand-scale factors limits inference on the drivers of recent sudden aspen decline. Using the proportion of aspen trees that were dead as an index of recent mortality at 841 forest inventory plots, we examined the relationship of this mortality index to forest structure and climate in the Rocky Mountains and Intermountain Western United States. We found that forest structure explained most of the patterns in mortality indices, but that variation in growing-season vapor pressure deficit and winter precipitation over the last 20 years was important. Mortality index sensitivity to precipitation was highest in forests where aspen exhibited high densities, relative basal areas, quadratic mean diameters, and productivities, whereas sensitivity to vapor pressure deficit was highest in young forest stands. These results indicate that the effects of drought on mortality may be mediated by forest stand development, competition with encroaching conifers, and physiological vulnerabilities of large trees to drought. By examining mortality index responses to both forest structure and climate, we show that forest succession cannot be ignored in studies attempting to understand the causes and consequences of sudden aspen decline.

  7. Growth decline linked to warming-induced water limitation in hemi-boreal forests.

    PubMed

    Wu, Xiuchen; Liu, Hongyan; Guo, Dali; Anenkhonov, Oleg A; Badmaeva, Natalya K; Sandanov, Denis V

    2012-01-01

    Hemi-boreal forests, which make up the transition from temperate deciduous forests to boreal forests in southern Siberia, have experienced significant warming without any accompanying increase in precipitation during the last 80 years. This climatic change could have a profound impact on tree growth and on the stability of forest ecosystems in this region, but at present evidence for these impacts is lacking. In this study, we report a recent dramatic decline in the growth of hemi-boreal forests, based on ring width measurements from three dominant tree-species (Pinus sylvestris, Larix sibirica and Larix gmelinii), sampled from eight sites in the region. We found that regional tree growth has become increasingly limited by low soil water content in the pre- and early-growing season (from October of the previous year to July of the current year) over the past 80 years. A warming-induced reduction in soil water content has also increased the climate sensitivity of these three tree species. Beginning in the mid-1980s, a clear decline in growth is evident for both the pine forests and the larch forests, although there are increasing trends in the proxy of soil water use efficiencies. Our findings are consistent with those from other parts of the world and provide valuable insights into the regional carbon cycle and vegetation dynamics, and should be useful for devising adaptive forest management strategies.

  8. The importance of age-related decline in forest NPP for modeling regional carbon balances.

    PubMed

    Zaehle, Sönke; Sitch, Stephen; Prentice, I Colin; Liski, Jari; Cramer, Wolfgang; Erhard, Markus; Hickler, Thomas; Smith, Benjamin

    2006-08-01

    We show the implications of the commonly observed age-related decline in aboveground productivity of forests, and hence forest age structure, on the carbon dynamics of European forests in response to historical changes in environmental conditions. Size-dependent carbon allocation in trees to counteract increasing hydraulic resistance with tree height has been hypothesized to be responsible for this decline. Incorporated into a global terrestrial biosphere model (the Lund-Potsdam-Jena model, LPJ), this hypothesis improves the simulated increase in biomass with stand age. Application of the advanced model, including a generic representation of forest management in even-aged stands, for 77 European provinces shows that model-based estimates of biomass development with age compare favorably with inventory-based estimates for different tree species. Model estimates of biomass densities on province and country levels, and trends in growth increment along an annual mean temperature gradient are in broad agreement with inventory data. However, the level of agreement between modeled and inventory-based estimates varies markedly between countries and provinces. The model is able to reproduce the present-day age structure of forests and the ratio of biomass removals to increment on a European scale based on observed changes in climate, atmospheric CO2 concentration, forest area, and wood demand between 1948 and 2000. Vegetation in European forests is modeled to sequester carbon at a rate of 100 Tg C/yr, which corresponds well to forest inventory-based estimates.

  9. Growth Decline Linked to Warming-Induced Water Limitation in Hemi-Boreal Forests

    PubMed Central

    Wu, Xiuchen; Liu, Hongyan; Guo, Dali; Anenkhonov, Oleg A.; Badmaeva, Natalya K.; Sandanov, Denis V.

    2012-01-01

    Hemi-boreal forests, which make up the transition from temperate deciduous forests to boreal forests in southern Siberia, have experienced significant warming without any accompanying increase in precipitation during the last 80 years. This climatic change could have a profound impact on tree growth and on the stability of forest ecosystems in this region, but at present evidence for these impacts is lacking. In this study, we report a recent dramatic decline in the growth of hemi-boreal forests, based on ring width measurements from three dominant tree-species (Pinus sylvestris, Larix sibirica and Larix gmelinii), sampled from eight sites in the region. We found that regional tree growth has become increasingly limited by low soil water content in the pre- and early-growing season (from October of the previous year to July of the current year) over the past 80 years. A warming-induced reduction in soil water content has also increased the climate sensitivity of these three tree species. Beginning in the mid-1980s, a clear decline in growth is evident for both the pine forests and the larch forests, although there are increasing trends in the proxy of soil water use efficiencies. Our findings are consistent with those from other parts of the world and provide valuable insights into the regional carbon cycle and vegetation dynamics, and should be useful for devising adaptive forest management strategies. PMID:22916142

  10. Rapid warming accelerates tree growth decline in semi-arid forests of Inner Asia.

    PubMed

    Liu, Hongyan; Park Williams, A; Allen, Craig D; Guo, Dali; Wu, Xiuchen; Anenkhonov, Oleg A; Liang, Eryuan; Sandanov, Denis V; Yin, Yi; Qi, Zhaohuan; Badmaeva, Natalya K

    2013-08-01

    Forests around the world are subject to risk of high rates of tree growth decline and increased tree mortality from combinations of climate warming and drought, notably in semi-arid settings. Here, we assess how climate warming has affected tree growth in one of the world's most extensive zones of semi-arid forests, in Inner Asia, a region where lack of data limits our understanding of how climate change may impact forests. We show that pervasive tree growth declines since 1994 in Inner Asia have been confined to semi-arid forests, where growing season water stress has been rising due to warming-induced increases in atmospheric moisture demand. A causal link between increasing drought and declining growth at semi-arid sites is corroborated by correlation analyses comparing annual climate data to records of tree-ring widths. These ring-width records tend to be substantially more sensitive to drought variability at semi-arid sites than at semi-humid sites. Fire occurrence and insect/pathogen attacks have increased in tandem with the most recent (2007-2009) documented episode of tree mortality. If warming in Inner Asia continues, further increases in forest stress and tree mortality could be expected, potentially driving the eventual regional loss of current semi-arid forests. © 2013 John Wiley & Sons Ltd.

  11. Tennessee's forest land area was stable 1999-2005 but early successional forest area declined

    Treesearch

    Christopher M. Oswalt

    2008-01-01

    A new analysis of the most recent (2005) annualized moving average data for Tennessee indicates that the area of forest land in the State remained stable between 1999 and 2005. Although trends in forest land area vary from region to region within the State, Tennessee neither lost nor gained forest land between 1999 and 2005. However, Tennessee had more than 2.5 times...

  12. Sudden Oak Death in redwood forests: vegetation dynamics in the wake of tanoak decline

    Treesearch

    Benjamin Ramage; Kevin O’Hara

    2010-01-01

    Numerous lines of inquiry have concluded that tanoak (Lithocarpus densiflorus) will continue to experience drastic population declines and may even disappear entirely from redwood (Sequoia sempervirens) forests as a result of the exotic disease sudden oak death (SOD) (Maloney and others 2005, McPherson and others 2005,...

  13. Role of the wolf in a deer decline in the Superior National Forest

    USGS Publications Warehouse

    Mech, L.D.; Karns, P.D.

    1977-01-01

    White-tailed deer (Odocoileus virginianus) declined in the Superior National Forest of Minnesota between 1968 and 1974. In a 3,000 sq km area of the poorest habitat, deer were decimated. Contributing factors were severe winters, deteriorating habitat, and wolves. Wolves killed older deer, but insufficient fawns were available to replace them.

  14. Impacts of Oak Decline on Forest Structure in Arkansas and Oklahoma: Preliminary Results

    Treesearch

    Eric Heitzman; James M. Guldin

    2004-01-01

    We established field plots in the Ouachita and Ozark Mountains of Arkansas and Oklahoma to quantify the impacts of oak decline on forest structure. Plots were identified as either high risk (red oak basal area > 20 square feet per acre) or low risk (red oak basal area

  15. Role of the wolf in a deer decline in the Superior National Forest.

    Treesearch

    L. David Mech; Patrick D. Karns

    1977-01-01

    White-tailed deer (Odocoileus virginianus) declined in the Superior National Forest of Minnesota between 1968 and 1974. In a 3,000 km2 area of the poorest habitat, deer were decimated. Contributing factors were severe winters, deteriorating habitat, and wolves. Wolves killed older deer, but insufficient fawns were available to replace them.

  16. Modeling the effects of harvest alternatives on mitigating oak decline in a Central Hardwood Forest landscape

    Treesearch

    Wen J. Wang; Hong S. He; Martin A. Spetich; Stephen R. Shifley; Frank R. III Thompson; Jacob S. Fraser

    2013-01-01

    Oak decline is a process induced by complex interactions of predisposing factors, inciting factors, and contributing factors operating at tree, stand, and landscape scales. It has greatly altered species composition and stand structure in affected areas. Thinning, clearcutting, and group selection are widely adopted harvest alternatives for reducing forest...

  17. DETECTING FOREST STRESS AND DECLINE IN RESPONSE TO INCREASING RIVER FLOW IN SOUTHWEST FLORIDA, USA

    EPA Science Inventory

    Forest stress and decline resulting from increased river flows were investigated in Myakka River State Park (MRSP), Florida, USA. Since 1977, land-use changes around the upper Myakka River watershed have resulted in significant increases in water entering the river, which have...

  18. DETECTING FOREST STRESS AND DECLINE IN RESPONSE TO INCREASING RIVER FLOW IN SOUTHWEST FLORIDA, USA

    EPA Science Inventory

    Forest stress and decline resulting from increased river flows were investigated in Myakka River State Park (MRSP), Florida, USA. Since 1977, land-use changes around the upper Myakka River watershed have resulted in significant increases in water entering the river, which have...

  19. Population growth and the decline of natural Southern yellow pine forests

    Treesearch

    David B. South; Edward R. Buckner

    2004-01-01

    Population growth has created social and economic pressures that affect the sustainability of naturally regenerated southern yellow pine forests. Major causes of this decline include (1) a shift in public attitudes regarding woods burning (from one favoring it to one that favors fire suppression) and (2) an increase in land values (especially near urban centers). The...

  20. Decline of birds in a human modified coastal dune forest landscape in South Africa.

    PubMed

    Trimble, Morgan J; van Aarde, Rudi J

    2011-01-13

    Previous studies demonstrate that old-growth forest remnants and vegetation regenerating after anthropogenic disturbance provide habitat for birds in a human modified coastal dune forest landscape in northern KwaZulu-Natal, South Africa. However, occurrence does not ensure persistence. Based on a 13-year monitoring database we calculated population trends for 37 bird species and general trends in overall bird density in different vegetation types. We evaluated species' characteristics as covariates of population trend and assessed changes in rainfall and proportional area and survey coverage per vegetation type. 76% of species assessed have declined, 57% significantly so at an average rate of 13.9% per year. Overall, bird density has fallen at 12.2% per year across old-growth forest and woody regenerating vegetation types. Changes in proportional area and coverage per vegetation type may partly explain trends for a few species but are unlikely to account for most. Below average rainfall may have contributed to bird declines. However, other possibilities warrant further investigation. Species with larger range extents tended to decline more sharply than did others, and these species may be responding to environmental changes on a broader geographical scale. Our results cast doubt on the future persistence of birds in this human modified landscape. More research is needed to elucidate the mechanisms driving population decline in the study area and to investigate whether the declines identified here are more widespread across the region and perhaps the continent.

  1. Decline of Birds in a Human Modified Coastal Dune Forest Landscape in South Africa

    PubMed Central

    Trimble, Morgan J.; van Aarde, Rudi J.

    2011-01-01

    Previous studies demonstrate that old-growth forest remnants and vegetation regenerating after anthropogenic disturbance provide habitat for birds in a human modified coastal dune forest landscape in northern KwaZulu-Natal, South Africa. However, occurrence does not ensure persistence. Based on a 13-year monitoring database we calculated population trends for 37 bird species and general trends in overall bird density in different vegetation types. We evaluated species' characteristics as covariates of population trend and assessed changes in rainfall and proportional area and survey coverage per vegetation type. 76% of species assessed have declined, 57% significantly so at an average rate of 13.9% per year. Overall, bird density has fallen at 12.2% per year across old-growth forest and woody regenerating vegetation types. Changes in proportional area and coverage per vegetation type may partly explain trends for a few species but are unlikely to account for most. Below average rainfall may have contributed to bird declines. However, other possibilities warrant further investigation. Species with larger range extents tended to decline more sharply than did others, and these species may be responding to environmental changes on a broader geographical scale. Our results cast doubt on the future persistence of birds in this human modified landscape. More research is needed to elucidate the mechanisms driving population decline in the study area and to investigate whether the declines identified here are more widespread across the region and perhaps the continent. PMID:21249203

  2. Impact of declining atmospheric deposition on forest soil solution chemistry in Flanders, Belgium

    NASA Astrophysics Data System (ADS)

    Verstraeten, Arne; Neirynck, Johan; Genouw, Gerrit; Cools, Nathalie; Roskams, Peter; Hens, Maarten

    2012-12-01

    Throughout Europe and the USA, forest ecosystem functioning has been impacted by long-term excessive deposition of acidifying compounds. In this study, we report on trends in stand deposition and soil solution fluxes of inorganic nitrogen (N) and sulphur (S) compounds over a 17-year period (1994-2010) in five ICP Forests monitoring plots in Flanders, northern Belgium. Deposition was dominated by N, and primarily NH4+. Deposition of SO42- and NH4+ declined by 56-68% and 40-59% respectively. Deposition of NO-3 decreased by 17-30% in deciduous forest plots, but remained stable in coniferous forest plots. The decrease of N and S deposition was parallelled by a simultaneous decline in base cation (BC = Ca2+ + K+ + Mg2+) deposition, resulting in a 45-74% decrease of potentially acidifying deposition. Trends in soil solution fluxes of NH4+, NO3-, SO42- and BC mirrored declining depositions. Nitrate losses below the rooting zone were eminent in both coniferous forest plots and in one deciduous forest plot, while net SO42- release was observed in two deciduous forest plots. Critical limits for BC/Al ratio were exceeded at the three plots on sandy soils with lower cation exchange capacity and base saturation. Soil solution acid neutralizing capacity increased but remained negative, indicating that soil acidification continued, as the start of recovery was delayed by a simultaneous decrease of BC depositions and short-term soil buffering processes. Despite substantial reductions, current N deposition levels still exceed 4-8 times the critical load for safeguarding sensitive lichen species, and are still 22-69% above the critical load for maintaining ground vegetation diversity.

  3. A Neighborhood Analysis of the Consequences of Quercus suber Decline for Regeneration Dynamics in Mediterranean Forests

    PubMed Central

    Ibáñez, Beatriz; Gómez-Aparicio, Lorena; Stoll, Peter; Ávila, José M.; Pérez-Ramos, Ignacio M.; Marañón, Teodoro

    2015-01-01

    In forests, the vulnerable seedling stage is largely influenced by the canopy, which modifies the surrounding environment. Consequently, any alteration in the characteristics of the canopy, such as those promoted by forest dieback, might impact regeneration dynamics. Our work analyzes the interaction between canopy neighbors and seedlings in Mediterranean forests affected by the decline of their dominant species (Quercus suber). Our objective was to understand how the impacts of neighbor trees and shrubs on recruitment could affect future dynamics of these declining forests. Seeds of the three dominant tree species (Quercus suber, Olea europaea and Quercus canariensis) were sown in six sites during two consecutive years. Using a spatially-explicit, neighborhood approach we developed models that explained the observed spatial variation in seedling emergence, survival, growth and photochemical efficiency as a function of the size, identity, health, abundance and distribution of adult trees and shrubs in the neighborhood. We found strong neighborhood effects for all the performance estimators, particularly seedling emergence and survival. Tree neighbors positively affected emergence, independently of species identity or health. Alternatively, seedling survival was much lower in neighborhoods dominated by defoliated and dead Q. suber trees than in neighborhoods dominated by healthy trees. For the two oak species, these negative effects were consistent over the three years of the experimental seedlings. These results indicate that ongoing changes in species’ relative abundance and canopy trees’ health might alter the successional trajectories of Mediterranean oak-forests through neighbor-specific impacts on seedlings. The recruitment failure of dominant late-successional oaks in the gaps opened after Q. suber death would indirectly favor the establishment of other coexisting woody species, such as drought-tolerant shrubs. This could lead current forests to shift

  4. A neighborhood analysis of the consequences of Quercus suber decline for regeneration dynamics in Mediterranean forests.

    PubMed

    Ibáñez, Beatriz; Gómez-Aparicio, Lorena; Stoll, Peter; Ávila, José M; Pérez-Ramos, Ignacio M; Marañón, Teodoro

    2015-01-01

    In forests, the vulnerable seedling stage is largely influenced by the canopy, which modifies the surrounding environment. Consequently, any alteration in the characteristics of the canopy, such as those promoted by forest dieback, might impact regeneration dynamics. Our work analyzes the interaction between canopy neighbors and seedlings in Mediterranean forests affected by the decline of their dominant species (Quercus suber). Our objective was to understand how the impacts of neighbor trees and shrubs on recruitment could affect future dynamics of these declining forests. Seeds of the three dominant tree species (Quercus suber, Olea europaea and Quercus canariensis) were sown in six sites during two consecutive years. Using a spatially-explicit, neighborhood approach we developed models that explained the observed spatial variation in seedling emergence, survival, growth and photochemical efficiency as a function of the size, identity, health, abundance and distribution of adult trees and shrubs in the neighborhood. We found strong neighborhood effects for all the performance estimators, particularly seedling emergence and survival. Tree neighbors positively affected emergence, independently of species identity or health. Alternatively, seedling survival was much lower in neighborhoods dominated by defoliated and dead Q. suber trees than in neighborhoods dominated by healthy trees. For the two oak species, these negative effects were consistent over the three years of the experimental seedlings. These results indicate that ongoing changes in species' relative abundance and canopy trees' health might alter the successional trajectories of Mediterranean oak-forests through neighbor-specific impacts on seedlings. The recruitment failure of dominant late-successional oaks in the gaps opened after Q. suber death would indirectly favor the establishment of other coexisting woody species, such as drought-tolerant shrubs. This could lead current forests to shift into

  5. Defying the decline: Carbon storage resistance to moderate disturbance in a temperate forest

    NASA Astrophysics Data System (ADS)

    Gough, C. M.; Hardiman, B. S.; Nave, L. E.; Bohrer, G.; Maurer, K.; Vogel, C.; Nadelhoffer, K. J.; Curtis, P.

    2012-12-01

    Carbon (C) storage rates in many forests are sustained, or decline only briefly, following disturbances that cause partial canopy defoliation. The mechanisms supporting such functional resistance to moderate forest disturbance are largely unknown. We used a large-scale experiment, in which >6,700 canopy dominant Populus (aspen) and Betula (birch) trees were stem girdled within a 39 ha area, to identify mechanisms sustaining C storage through partial canopy defoliation. The Forest Accelerated Succession ExperimenT (FASET) in northern Michigan, USA employs a suite of C cycling measurements within paired treatment and control meteorological flux tower footprints. We observed peak declines in leaf area index (LAI) of 44 % three years following disturbance without an associated reduction in C storage, quantified as net ecosystem production and (NEP) net primary production (NPP). The treatment forest resisted C storage declines by sustaining canopy light-use efficiency and light absorption during this period of low LAI. In the year following peak defoliation, complete reallocation of nitrogen (N) in the treatment forest from the foliage of senescent early successional aspen and birch to ungirdled later successional species facilitated the full recovery of total LAI to pre-disturbance levels. Sustained canopy physiological competency and light absorption following moderate disturbance coincided with upper canopy gap formation and a rise in structural complexity as the canopy became more multi-layered. Stability of canopy processes central to sustaining C storage during defoliation suggests a rapid shift in structure-function occurred in which the photosynthetic contribution of subcanopy vegetation increased to compensate for defoliation of canopy dominant trees. We conclude that C storage resistance to moderate disturbance depends not only on replacement of lost leaf area, but also on shifts in forest structure that sustain physiological functioning of the canopy during

  6. Plant-soil feedbacks in declining forests: implications for species coexistence.

    PubMed

    Gómez-Aparicio, Lorena; Domínguez-Begines, Jara; Kardol, Paul; Ávila, José M; Ibáñez, Beatriz; García, Luis V

    2017-07-01

    Plant-soil feedbacks (PSFs) play a relevant role as drivers of species abundance, coexistence, and succession in plant communities. However, the potential contribution of PSFs to community dynamics in changing forest ecosystems affected by global change drivers is still largely unexplored. We measured the direction, strength and nature (biological vs. chemical) of PSFs experienced by coexisting tree species in two types of declining Quercus suber forests of southwestern Spain (open woodland vs. closed forest) invaded by the exotic soil pathogen Phytophthora cinnamomi. To test PSFs in a realistic community context, we focused not only on individual PSFs (i.e., comparing the growth of a tree species on conspecific vs. heterospecific soil) but also calculated net-pairwise PSFs by comparing performance of coexisting tree species on their own and each other's soils. We hypothesized that the decline and death of Q. suber would alter the direction and strength of individual and net-pairwise PSFs due to the associated changes in soil nutrients and microbial communities, with implications for recruitment dynamics and species coexistence. In support of our hypothesis, we found that the decline of Q. suber translated into substantial alterations of individual and net-pairwise PSFs, which shifted from mostly neutral to significantly positive or negative, depending on the forest type. In both cases however the identified PSFs benefited other species more than Q. suber (i.e., heterospecific positive PSF in the open woodland, conspecific negative PSF in the closed forest). Our results supported PSFs driven by changes in chemical soil properties (mainly phosphorus) and arbuscular mycorrhizal fungi, but not in pathogen abundance. Overall, our study suggests that PSFs might reinforce the loss of dominance of Q. suber in declining forests invaded by P. cinnamomi by promoting the relative performance of non-declining coexisting species. More generally, our results indicate an

  7. Declining water yield from forested mountain watersheds in response to climate change and forest mesophication

    Treesearch

    Peter V. Caldwell; Chelcy F. Miniat; Katherine J. Elliott; Wayne. T. Swank; Steven T. Brantley; Stephanie H. Laseter

    2016-01-01

    Climate change and forest disturbances are threatening the ability of forested mountain watersheds to provide the clean, reliable, and abundant fresh water necessary to support aquatic ecosystems and a growing human population. Here we used 76 years of water yield, climate, and field plot vegetation measurements in six unmanaged, reference watersheds in the southern...

  8. Nonconsumptive effects of a generalist ungulate herbivore drive decline of unpalatable forest herbs.

    PubMed

    Heckel, Christopher D; Bourg, Norman A; McShea, William J; Kalisz, Susan

    2010-02-01

    High herbivore pressure is expected to benefit unpalatable species that co-occur with palatable browsed species. However, for five unpalatable understory species we found no evidence of benefit from deer browse. Detailed studies of one species in natural populations, Arisaema triphyllum, revealed surprising changes in its population structure and demography: deer browse level on a palatable species significantly correlates with reduced plant size and seed rain and male-biased sex ratios of co-occurring Arisaema populations. Analyses of individual size in five unpalatable forest plant species in long-term experimental paired deer exclosure/deer access plots corroborate the natural site results; all five species were smaller in deer access plots. Analyses of abiotic variables in natural and experimental sites suggest one potential mechanism for indirect effects of deer. Deer-mediated soil quality declines included increased soil penetration resistance and decreased leaf litter depth, which are known to hinder plant growth. Our results are likely applicable to other unpalatable forest species and have clear consequences for understory biodiversity. Unpalatable plant species in forests experiencing high deer numbers may be in decline along with their palatable neighbors. Our study implicates deer overabundance in the cascade of forest species decline and the urgency of this conservation issue in North America.

  9. Deer herbivory alters forest response to canopy decline caused by an exotic insect pest.

    PubMed

    Eschtruth, Anne K; Battles, John J

    2008-03-01

    Hemlock woolly adelgid (HWA; Adelges tsugae) infestations have resulted in the continuing decline of eastern hemlock (Tsuga canadensis) throughout much of the eastern United States. While the initial impacts of HWA infestations have been documented, our understanding of forest response to this disturbance remains incomplete. HWA infestation is not occurring in isolation but within a complex ecological context. The role of potentially important interacting factors, such as elevated levels of white-tailed deer herbivory, is poorly understood. Despite the potential for herbivory to alter forest successional trajectories following a canopy disturbance, little is known about herbivory-disturbance interactions, and herbivory is rarely considered in assessing forest response to a co-occurring disturbance. We used repeated censuses of deer exclosures and paired controls (400 paired plots) to quantify the impact of deer herbivory on tree seedling species abundance in 10 eastern hemlock ravines that span a gradient in HWA-induced canopy decline severity. Use of a maximum likelihood estimation framework and information theoretics allowed us to quantify the strength of evidence for alternative models developed to estimate the impacts of herbivory on tree seedling abundance as a function of varying herbivore density and canopy decline severity. The exclusion of deer herbivory had marked impacts on the abundance of the studied seedling species: Acer rubrum, Acer saccharum, Betula lenta, Nyssa sylvatica, Quercus montana, and Tsuga canadensis. For all six species, the relationship between seedling abundance and deer density was either exponential or saturating. Although the functional form of the response varied among seedling species, the inclusion of both deer density and canopy decline severity measures consistently resulted in models with substantially greater support. Canopy decline resulted in higher proportional herbivory impacts and altered the ranking of herbivory impacts

  10. Novel forest decline triggered by multiple interactions among climate, an introduced pathogen and bark beetles.

    PubMed

    Wong, Carmen M; Daniels, Lori D

    2017-05-01

    Novel forest decline is increasing due to global environmental change, yet the causal factors and their interactions remain poorly understood. Using tree ring analyses, we show how climate and multiple biotic factors caused the decline of whitebark pine (Pinus albicaulis) in 16 stands in the southern Canadian Rockies. In our study area, 72% of whitebark pines were dead and 18% had partially dead crowns. Tree mortality peaked in the 1970s; however, the annual basal area increment of disturbed trees began to decline significantly in the late 1940s. Growth decline persisted up to 30 years before trees died from mountain pine beetle (Dendroctonus ponderosae), Ips spp. bark beetles or non-native blister rust pathogen (Cronartium ribicola). Climate-growth relations varied over time and differed among the healthy and disturbed subpopulations of whitebark pine. Prior to the 1940s, cool temperatures limited the growth of all subpopulations. Growth of live, healthy trees became limited by drought during the cool phase (1947 -1976) of the Pacific Decadal Oscillation (PDO) and then reverted to positive correlations with temperature during the subsequent warm PDO phase. In the 1940s, the climate-growth relations of the disturbed subpopulations diverged from the live, healthy trees with trees ultimately killed by mountain pine beetle diverging the most. We propose that multiple factors interacted over several decades to cause unprecedented rates of whitebark pine mortality. Climatic variation during the cool PDO phase caused drought stress that may have predisposed trees to blister rust. Subsequent decline in snowpack and warming temperatures likely incited further climatic stress and with blister rust reduced tree resistance to bark beetles. Ultimately, bark beetles and blister rust contributed to tree death. Our findings suggest the complexity of whitebark pine decline and the importance of considering multiway drought-disease-insect interactions over various timescales when

  11. Declining water yield from forested mountain watersheds in response to climate change and forest mesophication.

    PubMed

    Caldwell, Peter V; Miniat, Chelcy F; Elliott, Katherine J; Swank, Wayne T; Brantley, Steven T; Laseter, Stephanie H

    2016-09-01

    Climate change and forest disturbances are threatening the ability of forested mountain watersheds to provide the clean, reliable, and abundant fresh water necessary to support aquatic ecosystems and a growing human population. Here, we used 76 years of water yield, climate, and field plot vegetation measurements in six unmanaged, reference watersheds in the southern Appalachian Mountains of North Carolina, USA to determine whether water yield has changed over time, and to examine and attribute the causal mechanisms of change. We found that annual water yield increased in some watersheds from 1938 to the mid-1970s by as much as 55%, but this was followed by decreases up to 22% by 2013. Changes in forest evapotranspiration were consistent with, but opposite in direction to the changes in water yield, with decreases in evapotranspiration up to 31% by the mid-1970s followed by increases up to 29% until 2013. Vegetation survey data showed commensurate reductions in forest basal area until the mid-1970s and increases since that time accompanied by a shift in dominance from xerophytic oak and hickory species to several mesophytic species (i.e., mesophication) that use relatively more water. These changes in forest structure and species composition may have decreased water yield by as much as 18% in a given year since the mid-1970s after accounting for climate. Our results suggest that changes in climate and forest structure and species composition in unmanaged forests brought about by disturbance and natural community dynamics over time can result in large changes in water supply.

  12. Forests in decline: yellow-cedar research yields prototype for climate change adaptation planning

    Treesearch

    Marie Oliver; Paul Hennon; David D' Amore

    2013-01-01

    Yellow-cedar has been dying across 600 miles of North Pacific coastal rain forest—from Alaska to British Columbia—since about 1880. Thirty years ago, a small group of pathologists began investigating possible biotic causes of the decline. When no biotic cause could be found, the scope broadened into a research program that eventually encompassed the fields of ecology,...

  13. Declining plant nitrogen supply and carbon accumulation in ageing primary boreal forest ecosystems

    NASA Astrophysics Data System (ADS)

    Högberg, Mona N.; Yarwood, Stephanie A.; Trumbore, Susan; Högberg, Peter

    2016-04-01

    Boreal forest soils are commonly characterized by a low plant nitrogen (N) supply. A high tree below-ground allocation of carbon (C) to roots and soil microorganisms in response to the shortage of N may lead to high microbial immobilisation of N, thus aggravating the N limitation. We studied the N supply at a Swedish boreal forest ecosystem chronosequence created by new land rising out of the sea due to iso-static rebound. The youngest soils develop with meadows by the coast, followed by a zone of dinitrogen fixing alder trees, and primary boreal conifer forest on ground up to 560 years old. With increasing ecosystem age, the proportion of microbial C out of the total soil C pool from the youngest to the oldest coniferous ecosystem was constant (c. 1-1.5%), whereas immobilised N (microbial N out of total soil N) increased and approached the levels commonly observed in similar boreal coniferous forests (c. 6-7 %), whereas gross N mineralization declined. Simultaneously, plant foliar N % decreased and the natural abundance of N-15 in the soil increased. More specifically, the difference in N-15 between plant foliage and soil increased, which is related to greater retention of N-15 relative to N-14 by ectomycorrhizal fungi as N is taken up from the soil and some N is transferred to the plant host. In the conifer forest, where these changes were greatest, we found increased fungal biomass in the F- and H-horizons of the mor-layer, in which ectomycorrhizal fungi are known to dominate (the uppermost horizon with litter and moss is dominated by saprotrophic fungi). Hence, we propose that the decreasing N supply to the plants and the subsequent decline in plant production in ageing boreal forests is linked to high tree belowground C allocation to C limited ectomycorrhizal fungi (and other soil microorganisms), a strong sink for available soil N. Data on organic matter C-14 suggested that the largest input of recently fixed plant C occurred in the younger coniferous forest

  14. Are orchid bees at risk? First comparative survey suggests declining populations of forest-dependent species.

    PubMed

    Nemésio, A

    2013-05-01

    The two largest Atlantic Forest remnants in the state of Espírito Santo, eastern Brazil, namely 'Reserva Biológica de Sooretama' (REBIO Sooretama) and 'Reserva Natural Vale' (RNV), were surveyed for their orchid-bee faunas. Seventeen scent baits were used to attract orchid-bee males. Three-thousand, two hundred and twenty-five males belonging to 24 species were actively collected with insect nets during 100 hours in March, April and December, 2009. In comparison with a previous study in the same area twelve years before, it is evident that the abundance of all forest-dependent orchid bees analysed declined around 50%, and it was statistically significant (P = 0.022) for Euglossa marianae Nemésio, 2011, the most sensitive to anthropogenic disturbances of all Atlantic Forest orchid bees. On the other hand, the abundance of populations of species tolerant to open or disturbed areas rose. Possible explanations are discussed.

  15. Ecosystem properties and forest decline in contrasting long-term chronosequences.

    PubMed

    Wardle, David A; Walker, Lawrence R; Bardgett, Richard D

    2004-07-23

    During succession, ecosystem development occurs; but in the long-term absence of catastrophic disturbance, a decline phase eventually follows. We studied six long-term chronosequences, in Australia, Sweden, Alaska, Hawaii, and New Zealand; for each, the decline phase was associated with a reduction in tree basal area and an increase in the substrate nitrogen-to-phosphorus ratio, indicating increasing phosphorus limitation over time. These changes were often associated with reductions in litter decomposition rates, phosphorus release from litter, and biomass and activity of decomposer microbes. Our findings suggest that the maximal biomass phase reached during succession cannot be maintained in the long-term absence of major disturbance, and that similar patterns of decline occur in forested ecosystems spanning the tropical, temperate, and boreal zones.

  16. Are Forest Songbirds Declining? Status Assessment from the Southern Appalachians and Northeastern Forests

    Treesearch

    Kathleen E. Franzreb; Kenneth V. Rosenberg

    1997-01-01

    Reported declines in populations of migratory songbirds in the eastern United States (Robbins et al. 1989, Askins et al. 1990, Hagan and Johnston 1992) have created a great deal of concern among researchers, land managers and conservationists, resulting in the formation of the large bird-conservation consortium, Partners In Flight. Among the causes implicated in these...

  17. Effect of root strength and soil saturation on hillslope stability in forests with natural cedar decline in headwater regions of SE Alaska.

    Treesearch

    Adelaide C. Johnson; Peter. Wilcock

    1998-01-01

    A natural decline in the population of yellow-cedar (Chamaecyparis nootkatensis) is occurring in pristine southeast Alaska forests and may be the most significant forest decline in the western United States. The frequency of landslides in cedar decline areas is three times larger than in areas of healthy forest. Three regions are investigated in...

  18. Declining summer flows of Rocky Mountain rivers: Changing seasonal hydrology and probable impacts on floodplain forests

    NASA Astrophysics Data System (ADS)

    Rood, Stewart B.; Pan, Jason; Gill, Karen M.; Franks, Carmen G.; Samuelson, Glenda M.; Shepherd, Anita

    2008-02-01

    SummaryIn analyzing hydrologic consequences of climate change, we previously found declining annual discharges of rivers that drain the hydrographic apex of North America, the Rocky Mountain headwaters region for adjacent streams flowing to the Arctic, Atlantic and Pacific oceans. In this study we investigated historic changes in seasonal patterns of streamflows, by comparing mean monthly flows and analyzing cumulative hydrographs over the periods of record of about a century. We tested predictions of change due to winter and spring warming that would increase the proportion of rain versus snow, and alter snow accumulation and melt. We analyzed records from 14 free-flowing, snow-melt dominated rivers that drained relatively pristine parks and protected areas, thus avoiding the effects of river damming, flow regulation, or watershed development. The collective results indicated that: (1) winter flows (especially March) were often slightly increased, (2) spring run-off and (3) peak flows occurred earlier, and most substantially, (4) summer and early autumn flows (July-October) were considerably reduced. The greatest changes were observed for the rivers draining the east-slope of the Rocky Mountains toward the northern prairies and Hudson Bay, with late summer flow decline rates of about 0.2%/year. This would have considerable ecological impact since this is the warm and dry period when evaporative demand is maximal and reduced instream flows would reduce riparian groundwater recharge, imposing drought stress on floodplain forests. In combination with the decline in annual discharge, earlier peaks and reduced summer flows would provide chronic stress on riparian cottonwoods and willows and especially restrict seedling recruitment. We predict a loss of floodplain forests along some river reaches, the narrowing of forest bands along other reaches, and increased vulnerability of these ecosystems to other impacts including livestock grazing, encroachment of upland

  19. Soil Respiration Declines Following Beetle - Induced Forest Mortality in a Lodgepole Pine Forest

    NASA Astrophysics Data System (ADS)

    Borkhuu, B.; Peckham, S. D.; Norton, U.; Ewers, B. E.; Pendall, E.

    2014-12-01

    Lodgepole pine (Pinus contorta var. latifolia) forests in northern Colorado and southeast Wyoming have been undergoing a major mortality event owing to mountain pine beetle (Dendroctonus ponderosae) infestation since 2007. We studied biotic and abiotic drivers of growing season soil respiration in four mature stands experiencing different levels of mortality between 2008 and 2012 in the Medicine Bow Mountains, southeastern Wyoming, USA. For five years, beetle infestation significantly altered forest structure. Stand mortality was 30% and more than 80% in stands with the lowest and highest mortality, respectively. Understory vegetation cover increased by 50% for five years following beetle infestation. Needlefall was increased by more than 50% during first two years of beetle infestation compared to the pre-disturbance period. We did not observe an immediate increase in soil respiration following beetle infestation as suggested by some researchers. Soil respiration rates in midsummer ranged from 1.4 ± 0.1 μmol m-2 s-1 in stands with highest mortality to 3.1 ± 0.2 μmol m-2s-1 in uninfested stand. Live tree basal area was the dominant factor controlling soil respiration, explaining more than 60% of the interannual and spatial variations in response to the disturbance. In addition, soil respiration was significantly correlated with fine root biomass, which explained 55% of variations, providing strong evidence that autotrophic respiration dominated the forest soil respiration flux. Furthermore, the seasonality of soil respiration was controlled mainly by mean monthly precipitation and mid-day photosynthetically active radiation. Each factor predicted from 30% to 50% of seasonal soil respiration variability with the highest correlation coefficients in stand with the lowest mortality. Our results clearly indicate that the reduction of photosynthesis in trees over the infestation period significantly reduced soil respiration. The remaining activity in dead stands may

  20. Long-term declines in stream and river inorganic nitrogen (N) export correspond to forest change.

    PubMed

    Lucas, Richard W; Sponseller, Ryan A; Gundale, Michael J; Stendahl, Johan; Fridman, Jonas; Högberg, Peter; Laudon, Hjalmar

    2016-03-01

    Human activities have exerted a powerful influence on the biogeochemical cycles of nitrogen (N) and carbon (C) and drive changes that can be a challenge to predict given the influence of multiple environmental stressors. This study focused on understanding how land management and climate change have together influenced terrestrial N storage and watershed inorganic N export across boreal and sub-arctic landscapes in northern Sweden. Using long-term discharge and nutrient concentration data that have been collected continuously for over three decades, we calculated the hydrologic inorganic N export from nine watersheds in this region. We found a consistent decline in inorganic N export from 1985 to 2011 over the entire region from both small and large watersheds, despite the absence of any long-term trend in river discharge during this period. The steepest declines in inorganic N export were observed during the growing season, consistent with the hypothesis that observed changes are biologically mediated and are not the result of changes in long-term hydrology. Concurrent with the decrease in inorganic N export, we report sustained increases in terrestrial N accumulation in forest biomass and soils across northern Sweden. Given the close communication of nutrient and energy stores between plants, soils, and waters, our results indicate a regional tightening of the N cycle in an already N-limited environment as a result of changes in forest management and climate-mediated growth increases. Our results are consistent with declining inorganic N efflux previously reported from small headwater streams in other ecosystems and shed new light on the mechanisms controlling these patterns by identifying corresponding shifts in the terrestrial N balance, which have been altered by a combination of management activities and climate change.

  1. Primates Decline Rapidly in Unprotected Forests: Evidence from a Monitoring Program with Data Constraints

    PubMed Central

    Rovero, Francesco; Mtui, Arafat; Kitegile, Amani; Jacob, Philipo; Araldi, Alessandro; Tenan, Simone

    2015-01-01

    Growing threats to primates in tropical forests make robust and long-term population abundance assessments increasingly important for conservation. Concomitantly, monitoring becomes particularly relevant in countries with primate habitat. Yet monitoring schemes in these countries often suffer from logistic constraints and/or poor rigor in data collection, and a lack of consideration of sources of bias in analysis. To address the need for feasible monitoring schemes and flexible analytical tools for robust trend estimates, we analyzed data collected by local technicians on abundance of three species of arboreal monkey in the Udzungwa Mountains of Tanzania (two Colobus species and one Cercopithecus), an area of international importance for primate endemism and conservation. We counted primate social groups along eight line transects in two forest blocks in the area, one protected and one unprotected, over a span of 11 years. We applied a recently proposed open metapopulation model to estimate abundance trends while controlling for confounding effects of observer, site, and season. Primate populations were stable in the protected forest, while the colobines, including the endemic Udzungwa red colobus, declined severely in the unprotected forest. Targeted hunting pressure at this second site is the most plausible explanation for the trend observed. The unexplained variability in detection probability among transects was greater than the variability due to observers, indicating consistency in data collection among observers. There were no significant differences in both primate abundance and detectability between wet and dry seasons, supporting the choice of sampling during the dry season only based on minimizing practical constraints. Results show that simple monitoring routines implemented by trained local technicians can effectively detect changes in primate populations in tropical countries. The hierarchical Bayesian model formulation adopted provides a flexible

  2. Unusual forest growth decline in boreal North America covaries with the retreat of Arctic sea ice.

    PubMed

    Girardin, Martin P; Guo, Xiao Jing; De Jong, Rogier; Kinnard, Christophe; Bernier, Pierre; Raulier, Frédéric

    2014-03-01

    The 20th century was a pivotal period at high northern latitudes as it marked the onset of rapid climatic warming brought on by major anthropogenic changes in global atmospheric composition. In parallel, Arctic sea ice extent has been decreasing over the period of available satellite data records. Here, we document how these changes influenced vegetation productivity in adjacent eastern boreal North America. To do this, we used normalized difference vegetation index (NDVI) data, model simulations of net primary productivity (NPP) and tree-ring width measurements covering the last 300 years. Climatic and proxy-climatic data sets were used to explore the relationships between vegetation productivity and Arctic sea ice concentration and extent, and temperatures. Results indicate that an unusually large number of black spruce (Picea mariana) trees entered into a period of growth decline during the late-20th century (62% of sampled trees; n = 724 cross sections of age >70 years). This finding is coherent with evidence encoded in NDVI and simulated NPP data. Analyses of climatic and vegetation productivity relationships indicate that the influence of recent climatic changes in the studied forests has been via the enhanced moisture stress (i.e. greater water demands) and autotrophic respiration amplified by the declining sea ice concentration in Hudson Bay and Hudson Strait. The recent decline strongly contrasts with other growth reduction events that occurred during the 19th century, which were associated with cooling and high sea ice severity. The recent decline of vegetation productivity is the first one to occur under circumstances related to excess heat in a 300-year period, and further culminates with an intensifying wildfire regime in the region. Our results concur with observations from other forest ecosystems about intensifying temperature-driven drought stress and tree mortality with ongoing climatic changes. © 2013 Her Majesty the Queen in Right of Canada

  3. Parallel declines in species and genetic diversity in tropical forest fragments.

    PubMed

    Struebig, Matthew J; Kingston, Tigga; Petit, Eric J; Le Comber, Steven C; Zubaid, Akbar; Mohd-Adnan, Adura; Rossiter, Stephen J

    2011-06-01

    The potential for parallel impacts of habitat change on multiple biodiversity levels has important conservation implications. We report on the first empirical test of the 'species-genetic diversity correlation' across co-distributed taxa with contrasting ecological traits in the context of habitat fragmentation. In a rainforest landscape undergoing conversion to oil palm, we show that depauperate species richness in fragments is mirrored by concomitant declines in population genetic diversity in the taxon predicted to be most susceptible to fragmentation. This association, not seen in the other species, relates to fragment area rather than isolation. While highlighting the over-simplification of extrapolating across taxa, we show that fragmentation presents a double jeopardy for some species. For these, conserving genetic diversity at levels of pristine forest could require sites 15-fold larger than those needed to safeguard species numbers. Importantly, however, each fragment contributes to regional species richness, with larger ones tending to contain more species.

  4. Comparison of in situ measurements of forest decline symptoms in Vermont (USA) and the Schwarzwald (FRG)

    NASA Technical Reports Server (NTRS)

    Rock, B. N.; Hoshizaki, T.; Lichtenthaler, H.; Schmuck, G.

    1986-01-01

    Field analyses were conducted at spruce/fir sites in the U.S. and Germany undergoing forest decline. Data gathered from common branch samples included reflectance curves, fluorescence measurements, and pigment concentrations. Similar reflectance signatures are seen for specimens from all sites. Reflectance spectra from specimens collected from high damage sites in both countries show a characteristic reflectance drop in the near infrared and a shift (5 nm) of the red edge to shorter wavelengths. Fluorescence data suggest altered state of health of photosynthetic pigments only in specimens from German high damage sites, and pigment extraction and analysis indicate a reduction in total chlorophyll, a decrease in chlorophyll b when compared with chlorophyll a, and a relative increase in carotenoids.

  5. Comparison of in situ measurements of forest decline symptoms in Vermont (USA) and the Schwarzwald (FRG)

    NASA Technical Reports Server (NTRS)

    Rock, B. N.; Hoshizaki, T.; Lichtenthaler, H.; Schmuck, G.

    1986-01-01

    Field analyses were conducted at spruce/fir sites in the U.S. and Germany undergoing forest decline. Data gathered from common branch samples included reflectance curves, fluorescence measurements, and pigment concentrations. Similar reflectance signatures are seen for specimens from all sites. Reflectance spectra from specimens collected from high damage sites in both countries show a characteristic reflectance drop in the near infrared and a shift (5 nm) of the red edge to shorter wavelengths. Fluorescence data suggest altered state of health of photosynthetic pigments only in specimens from German high damage sites, and pigment extraction and analysis indicate a reduction in total chlorophyll, a decrease in chlorophyll b when compared with chlorophyll a, and a relative increase in carotenoids.

  6. What are the functional mechanisms underlying forest decline? A case study on a European beech (Fagus sylvatica L.) stand.

    NASA Astrophysics Data System (ADS)

    Delaporte, Alice; Bazot, Stéphane; Fresneau, Chantal; Damesin, Claire

    2013-04-01

    The ongoing climate change is altering the precipitation patterns (abundance and frequency) of most parts of the world. The consequences of these changes on forests are already visible through frequent declines. A lot of them can be linked to the occurrence of long and/or repeated drought periods. Although forest decline could severely impact the nutrient and water cycles, their underlying functional causes are not well understood. Two main hypotheses have been proposed to explain the mechanisms of decline at the tree level: • Carbon reserves deficit ("carbon starvation") • Loss of water transport ( "hydraulic failure") Although hydraulic failure has been observed in a wetland species decline (poplar), our understanding of forest decline is still lacking in many species. Our study concerns a widespread species, European beech (Fagus sylvatica L.). A severely declining mature beech plot in the Fontainebleau state forest (France) was followed. This decline can be related to repeated droughts, enhanced by unfavorable soil conditions (sandy soil with very low extractible soil water). For the first time to our knowledge, an integrative in situ functional approach coupling both hydraulic and carbon, but also nitrogen functioning was developed. More precisely, pre-dawn and midday water potentials, "native" embolism, and embolism vulnerability of branches, radial tree growth, carbon and nitrogen reserves concentrations, were measured on healthy and declining trees. Our results showed that under normal climatic conditions (summer 2012), pre-dawn and midday water potentials were the same for healthy and declining trees throughout the season. Their losses of hydraulic conductivity ("native" embolism) were not significantly different, even at the end of the summer. Moreover, the embolism vulnerability curves also showed no significant difference (50% loss of hydraulic conductivity at around - 3MPa). Concerning C and N reserves concentrations, we showed that seasonal

  7. Decline in the pulp and paper industry: Effects on backward-linked forest industries and local economies

    Treesearch

    Consuelo Brandeis; Zhimei Guo

    2016-01-01

    Pulp, paper, and paperboard mills consume close to 52 percent of southern roundwood, providing a  significant market to southern forest landowners. Declining numbers of pulpwood-using mills and downward trends in mill  capacity, however, present a growing challenge to the southern forest sector. Shrinking mill  capacity affects rural communities that depend on mill...

  8. [Book review] Role of the wolf in a deer decline in the Superior National Forest, by L. David Mech and Patrick D. Karns

    USGS Publications Warehouse

    Greenwood, R.J.

    1979-01-01

    Review of: Role of the Wolf in a Deer Decline in the Superior National Forest. Volume 148 of USDA Forest Service Research Paper. L. David Mech and Patrick D. Karns. North Central Forest Experiment Station, Forest Service, United States Department of Agriculture, 1977. 23 pages.

  9. Demography of Symbiotic Nitrogen-Fixing Trees Explains Their Rarity and Successional Decline in Temperate Forests in the United States.

    PubMed

    Liao, Wenying; Menge, Duncan N L

    2016-01-01

    Symbiotic nitrogen (N) fixation is the major N input to many ecosystems. Although temperate forests are commonly N limited, symbiotic N-fixing trees ("N fixers") are rare and decline in abundance as succession proceeds-a challenging paradox that remains unexplained. Understanding demographic processes that underlie N fixers' rarity and successional decline would provide a proximate answer to the paradox. Do N fixers grow slower, die more frequently, or recruit less in temperate forests? We quantified demographic rates of N-fixing and non-fixing trees across succession using U.S. forest inventory data. We used an individual-based model to evaluate the relative contribution of each demographic process to community dynamics. Compared to non-fixers, N fixers had lower growth rates, higher mortality rates, and lower recruitment rates throughout succession. The mortality effect contributed more than the growth effect to N fixers' successional decline. Canopy and understory N fixers experienced these demographic disadvantages, indicating that factors in addition to light limitation likely contribute to N fixers' successional decline. We show that the rarity and successional decline of N-fixing trees in temperate forests is due more to their survival disadvantage than their growth disadvantage, and a recruitment disadvantage might also play a large role.

  10. Demography of Symbiotic Nitrogen-Fixing Trees Explains Their Rarity and Successional Decline in Temperate Forests in the United States

    PubMed Central

    Liao, Wenying; Menge, Duncan N. L.

    2016-01-01

    Symbiotic nitrogen (N) fixation is the major N input to many ecosystems. Although temperate forests are commonly N limited, symbiotic N-fixing trees (“N fixers”) are rare and decline in abundance as succession proceeds–a challenging paradox that remains unexplained. Understanding demographic processes that underlie N fixers’ rarity and successional decline would provide a proximate answer to the paradox. Do N fixers grow slower, die more frequently, or recruit less in temperate forests? We quantified demographic rates of N-fixing and non-fixing trees across succession using U.S. forest inventory data. We used an individual-based model to evaluate the relative contribution of each demographic process to community dynamics. Compared to non-fixers, N fixers had lower growth rates, higher mortality rates, and lower recruitment rates throughout succession. The mortality effect contributed more than the growth effect to N fixers’ successional decline. Canopy and understory N fixers experienced these demographic disadvantages, indicating that factors in addition to light limitation likely contribute to N fixers’ successional decline. We show that the rarity and successional decline of N-fixing trees in temperate forests is due more to their survival disadvantage than their growth disadvantage, and a recruitment disadvantage might also play a large role. PMID:27780268

  11. Shifting baselines on a tropical forest frontier: extirpations drive declines in local ecological knowledge.

    PubMed

    Kai, Zhang; Woan, Teoh Shu; Jie, Li; Goodale, Eben; Kitajima, Kaoru; Bagchi, Robert; Harrison, Rhett D

    2014-01-01

    The value of local ecological knowledge (LEK) to conservation is increasingly recognised, but LEK is being rapidly lost as indigenous livelihoods change. Biodiversity loss is also a driver of the loss of LEK, but quantitative study is lacking. In our study landscape in SW China, a large proportion of species have been extirpated. Hence, we were interested to understand whether species extirpation might have led to an erosion of LEK and the implications this might have for conservation. So we investigated peoples' ability to name a selection of birds and mammals in their local language from pictures. Age was correlated to frequency of forest visits as a teenager and is likely to be closely correlated to other known drivers of the loss of LEK, such as declining forest dependence. We found men were better at identifying birds overall and that older people were better able to identify birds to the species as compared to group levels (approximately equivalent to genus). The effect of age was also stronger among women. However, after controlling for these factors, species abundance was by far the most important parameter in determining peoples' ability to name birds. People were unable to name any locally extirpated birds at the species level. However, contrary to expectations, people were better able to identify extirpated mammals at the species level than extant ones. However, extirpated mammals tend to be more charismatic species and several respondents indicated they were only familiar with them through TV documentaries. Younger people today cannot experience the sights and sounds of forest animals that their parents grew up with and, consequently, knowledge of these species is passing from cultural memory. We suggest that engaging older members of the community and linking the preservation of LEK to biodiversity conservation may help generate support for conservation.

  12. Shifting Baselines on a Tropical Forest Frontier: Extirpations Drive Declines in Local Ecological Knowledge

    PubMed Central

    Kai, Zhang; Woan, Teoh Shu; Jie, Li; Goodale, Eben; Kitajima, Kaoru; Bagchi, Robert; Harrison, Rhett D.

    2014-01-01

    The value of local ecological knowledge (LEK) to conservation is increasingly recognised, but LEK is being rapidly lost as indigenous livelihoods change. Biodiversity loss is also a driver of the loss of LEK, but quantitative study is lacking. In our study landscape in SW China, a large proportion of species have been extirpated. Hence, we were interested to understand whether species extirpation might have led to an erosion of LEK and the implications this might have for conservation. So we investigated peoples' ability to name a selection of birds and mammals in their local language from pictures. Age was correlated to frequency of forest visits as a teenager and is likely to be closely correlated to other known drivers of the loss of LEK, such as declining forest dependence. We found men were better at identifying birds overall and that older people were better able to identify birds to the species as compared to group levels (approximately equivalent to genus). The effect of age was also stronger among women. However, after controlling for these factors, species abundance was by far the most important parameter in determining peoples' ability to name birds. People were unable to name any locally extirpated birds at the species level. However, contrary to expectations, people were better able to identify extirpated mammals at the species level than extant ones. However, extirpated mammals tend to be more charismatic species and several respondents indicated they were only familiar with them through TV documentaries. Younger people today cannot experience the sights and sounds of forest animals that their parents grew up with and, consequently, knowledge of these species is passing from cultural memory. We suggest that engaging older members of the community and linking the preservation of LEK to biodiversity conservation may help generate support for conservation. PMID:24466163

  13. Long-term growth decline in Toona ciliata in a moist tropical forest in Bangladesh: Impact of global warming

    NASA Astrophysics Data System (ADS)

    Rahman, Mizanur; Islam, Rofiqul; Islam, Mahmuda

    2017-04-01

    Tropical forests are carbon rich ecosystems and small changes in tropical forest tree growth substantially influence the global carbon cycle. Forest monitoring studies report inconsistent growth changes in tropical forest trees over the past decades. Most of the studies highlighted changes in the forest level carbon gain, neglecting the species-specific growth changes which ultimately determine community-level responses. Tree-ring analysis can provide historical data on species-specific tree growth with annual resolution. Such studies are inadequate in Bangladesh, which is one of the most climate sensitive regions in the tropics. In this study, we investigated long-term growth rates of Toona ciliata in a moist tropical forest of Bangladesh by using tree-ring analysis. We sampled 50 trees of varying size, obtained increment cores from these trees and measured tree-ring width. Analyses of growth patterns revealed size-dependent growth increments. After correcting for the effect of tree size on tree growth (ontogenetic changes) by two different methods we found declining growth rates in T. ciliata from 1960 to 2013. Standardized ring-width index (RWI) was strongly negatively correlated with annual mean and maximum temperatures suggesting that rising temperature might cause the observed growth decline in T. ciliata. Assuming that global temperatures will rise at the current rate, the observed growth decline is assumed to continue. The analysis of stable carbon and oxygen isotopes may reveal more insight on the physiological response of this species to future climatic changes.

  14. Discrimination between acute and chronic decline of Central European forests using map algebra of the growth condition and forest biomass fuzzy sets: A case study.

    PubMed

    Samec, Pavel; Caha, Jan; Zapletal, Miloš; Tuček, Pavel; Cudlín, Pavel; Kučera, Miloš

    2017-12-01

    Forest decline is either caused by damage or else by vulnerability due to unfavourable growth conditions or due to unnatural silvicultural systems. Here, we assess forest decline in the Czech Republic (Central Europe) using fuzzy functions, fuzzy sets and fuzzy rating of ecosystem properties over a 1×1km grid. The model was divided into fuzzy functions of the abiotic predictors of growth conditions (Fpred including temperature, precipitation, acid deposition, soil data and relative site insolation) and forest biomass receptors (Frec including remote sensing data, density and volume of aboveground biomass, and surface humus chemical data). Fuzzy functions were designed at the limits of unfavourable, undetermined or favourable effects on the forest ecosystem health status. Fuzzy sets were distinguished through similarity in a particular membership of the properties at the limits of the forest status margins. Fuzzy rating was obtained from the least difference of Fpred-Frec. Unfavourable Fpred within unfavourable Frec indicated chronic damage, favourable Fpred within unfavourable Frec indicated acute damage, and unfavourable Fpred within favourable Frec indicated vulnerability. The model in the 1×1km grid was validated through spatial intersection with a point field of uniform forest stands. Favourable status was characterised by soil base saturation (BS)>50%, BCC/Al>1, Corg>1%, MgO>6g/kg, and nitrogen deposition<1200mol(H(+))/ha·year. Vulnerable forests had BShumus 46-60%, BCC/Al 9-20 and NDVI≈0.42. Chronic forest damage occurs in areas with low temperatures, high nitrogen deposition, and low soil BS and Corg levels. In the Czech Republic, 10% of forests were considered non-damaged and 77% vulnerable, with damage considered acute in 7% of forests and chronic in 5%. The fuzzy model used suggests that improvement in forest health will depend on decreasing environmental load and restoration concordance between growth conditions and tree species composition

  15. Drought as a driver of declining boreal forest growth: Integrating forest inventory measurements with models to gain insight into underlying mechanisms

    NASA Astrophysics Data System (ADS)

    Trugman, A. T.; Medvigy, D.; Anderegg, W.; Caspersen, J.; Zeng, H.; Pacala, S. W.

    2016-12-01

    Boreal forests contain over 30% of Earth's terrestrial carbon and are an important component of the land carbon sink. However, the future ability of the boreal forest to maintain a net carbon sink is uncertain and depends on potentially compensating interactions of CO2 fertilization, warmer temperatures, and hotter drought conditions. Observational studies have attributed drought as a major driver of recent declines in growth and increases in mortality in many parts of the North American boreal forest. Yet, most vegetation models have a simplistic representation of vegetation water stress and fail to capture drought-associated growth and mortality trends, impacting our ability to accurately forecast the effects of climate change on the boreal forest. Here, we show additional evidence for widespread declines in boreal tree growth and increasing insect-related mortality in aspen trees based on a mixed model analysis of the Cooperative Alaska Forest Inventory. Our findings indicate that the growth decline is controlled by high midsummer potential evapotranspiration that overpowers any CO2 fertilization signal. We also observe a possible shift in the distribution of angiosperm and gymnosperm, a biological transition that could impact long-term local carbon dynamics. Using insight gained from our mixed model analysis, we perform a regional-scale model evaluation using the boreal forest version of Ecosystem Demography model 2 that includes a dynamic soil organic layer, 7 boreal-specific plant functional types, and a fully mechanistic plant hydraulic scheme. We then use both the Alaskan and Canadian Forest Inventories to constrain our hypotheses and assess whether drought related growth declines can be better attributed to tree drought response from (1) carbon starvation, (2) permanent damage of hydraulic machinery, or (3) delayed recovery of hydraulic machinery. Under each of these scenarios we forecast how drought potentially impacts decadal-scale boreal carbon dynamics.

  16. Survival rates of female white-tailed deer on an industrial forest following a decline in population density

    Treesearch

    Shawn M. Crimmins; John W. Edwards; Patrick D. Keyser; James M. Crum; W. Mark Ford; Brad F. Miller; Tyler A. Campbell; Karl V. Miller

    2013-01-01

    With white-tailed deer (Odocoileus virginianus) populations at historically high levels throughout many North American forests, many current management activities are aimed at reducing deer populations. However, very little information exists on the ecology of low-density white-tailed deer populations or populations that have declined in density. We...

  17. Hemlock declines rapidly with hemlock woolly adelgid infestation: impacts on the carbon cycle of the Southern Appalachian forests

    Treesearch

    April E. Nuckolls; Nina Wurzburger; Chelcy R. Ford; Ronald L. Hendrick; James M. Vose; Brian D. Kloeppel

    2008-01-01

    The recent infestation of southern Appalachian eastern hemlock stands by hemlock woolly adelgid (HWA) is expected to have dramatic and lasting effects on forest structure and function. We studied the short-term changes to the carbon cycle in a mixed stand of hemlock and hardwoods, where hemlock was declining due to either girdling or HWA infestation. We expected that...

  18. Developing a stand hazard index for oak decline in upland Oak forests of the Ozark Highlands, Missouri

    Treesearch

    Fan Zhaofei; Fan Xiuli; Martin A. Spetich; Stephen R. Shifley; W. Keith Moser; Randy G. Jensen; John M. Kabrick

    2011-01-01

    Black oak (Quercus velutina Lam.) and scarlet oak (Quercus coccinea Muenchh.)--two major components (44% of total stand basal area) of upland oak forests--are suffering severe decline and mortality in the Ozark Highlands, Missouri. However, factors influencing their survival (mortality) are not well understood. In this study we...

  19. Looking for age-related growth decline in natural forests: unexpected biomass patterns from tree rings and simulated mortality

    USGS Publications Warehouse

    Foster, Jane R.; D'Amato, Anthony W.; Bradford, John B.

    2014-01-01

    Forest biomass growth is almost universally assumed to peak early in stand development, near canopy closure, after which it will plateau or decline. The chronosequence and plot remeasurement approaches used to establish the decline pattern suffer from limitations and coarse temporal detail. We combined annual tree ring measurements and mortality models to address two questions: first, how do assumptions about tree growth and mortality influence reconstructions of biomass growth? Second, under what circumstances does biomass production follow the model that peaks early, then declines? We integrated three stochastic mortality models with a census tree-ring data set from eight temperate forest types to reconstruct stand-level biomass increments (in Minnesota, USA). We compared growth patterns among mortality models, forest types and stands. Timing of peak biomass growth varied significantly among mortality models, peaking 20–30 years earlier when mortality was random with respect to tree growth and size, than when mortality favored slow-growing individuals. Random or u-shaped mortality (highest in small or large trees) produced peak growth 25–30 % higher than the surviving tree sample alone. Growth trends for even-aged, monospecific Pinus banksiana or Acer saccharum forests were similar to the early peak and decline expectation. However, we observed continually increasing biomass growth in older, low-productivity forests of Quercus rubra, Fraxinus nigra, and Thuja occidentalis. Tree-ring reconstructions estimated annual changes in live biomass growth and identified more diverse development patterns than previous methods. These detailed, long-term patterns of biomass development are crucial for detecting recent growth responses to global change and modeling future forest dynamics.

  20. Looking for age-related growth decline in natural forests: unexpected biomass patterns from tree rings and simulated mortality.

    PubMed

    Foster, Jane R; D'Amato, Anthony W; Bradford, John B

    2014-05-01

    Forest biomass growth is almost universally assumed to peak early in stand development, near canopy closure, after which it will plateau or decline. The chronosequence and plot remeasurement approaches used to establish the decline pattern suffer from limitations and coarse temporal detail. We combined annual tree ring measurements and mortality models to address two questions: first, how do assumptions about tree growth and mortality influence reconstructions of biomass growth? Second, under what circumstances does biomass production follow the model that peaks early, then declines? We integrated three stochastic mortality models with a census tree-ring data set from eight temperate forest types to reconstruct stand-level biomass increments (in Minnesota, USA). We compared growth patterns among mortality models, forest types and stands. Timing of peak biomass growth varied significantly among mortality models, peaking 20-30 years earlier when mortality was random with respect to tree growth and size, than when mortality favored slow-growing individuals. Random or u-shaped mortality (highest in small or large trees) produced peak growth 25-30% higher than the surviving tree sample alone. Growth trends for even-aged, monospecific Pinus banksiana or Acer saccharum forests were similar to the early peak and decline expectation. However, we observed continually increasing biomass growth in older, low-productivity forests of Quercus rubra, Fraxinus nigra, and Thuja occidentalis. Tree-ring reconstructions estimated annual changes in live biomass growth and identified more diverse development patterns than previous methods. These detailed, long-term patterns of biomass development are crucial for detecting recent growth responses to global change and modeling future forest dynamics.

  1. Drought drove forest decline and dune building in eastern upper Michigan, USA, as the upper Great Lakes became closed basins

    USGS Publications Warehouse

    Loope, Walter L.; Loope, Henry M.; Goble, Ronald J.; Fisher, Timothy G.; Lytle, David E.; Legg, Robert J.; Wysocki, Douglas A.; Hanson, Paul R.; Young, Aaron R.

    2012-01-01

    Current models of landscape response to Holocene climate change in midcontinent North America largely reconcile Earth orbital and atmospheric climate forcing with pollen-based forest histories on the east and eolian chronologies in Great Plains grasslands on the west. However, thousands of sand dunes spread across 12,000 km2 in eastern upper Michigan (EUM), more than 500 km east of the present forest-prairie ecotone, present a challenge to such models. We use 65 optically stimulated luminescence (OSL) ages on quartz sand deposited in silt caps (n = 8) and dunes (n = 57) to document eolian activity in EUM. Dune building was widespread ca. 10–8 ka, indicating a sharp, sustained decline in forest cover during that period. This decline was roughly coincident with hydrologic closure of the upper Great Lakes, but temporally inconsistent with most pollen-based models that imply canopy closure throughout the Holocene. Early Holocene forest openings are rarely recognized in pollen sums from EUM because faint signatures of non-arboreal pollen are largely obscured by abundant and highly mobile pine pollen. Early Holocene spikes in nonarboreal pollen are recorded in cores from small ponds, but suggest only a modest extent of forest openings. OSL dating of dune emplacement provides a direct, spatially explicit archive of greatly diminished forest cover during a very dry climate in eastern midcontinent North America ca. 10–8 ka.

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

    NASA Astrophysics Data System (ADS)

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

    2013-11-01

    Dynamic fluvial processes strongly influence ecological communities and ecosystem health in riverine and riparian ecosystems, particularly in drought-prone regions. In these systems, there is a need to develop tools to measure impacts from local and regional hydrogeomorphic changes on the key biological and physical processes that sustain riparian ecosystem health and potential recovery. We used dendrochronology of Populus nigra, a riparian tree that is vulnerable to changes in local hydrology, to analyze ecosystem response following channel incision due to gravel mining along the Drôme River, a Mediterranean Basin stream in southern France. We cored 55 trees at seven floodplain sites, measured ring widths, and calculated basal area growth to compare the severity and timing of local growth decline along the river. Current basal area increment (BAI) growth per tree ranged almost 10-fold among sites (7.7 ± 1.3 to 63.9 ± 15.2 cm2 year- 1, mean ± SE) and these differences were significant. Mean BAI was correlated positively with the proportion of healthy trees at a site, and negatively with proportion of dead canopy area. Regime shift analysis of the tree-ring series indicates that tree growth declined significantly at four sites since 1978, coincident with documented channel incision. In addition, patterns of low growth and crown dieback are consistent with stress due to reduced water supply. The most impaired sites were not directly adjacent to local mining pits visible on aerial photographs, nor did the sequence of growth regime shifts suggest a pattern of channel incision progressing from these areas. The initiation of site growth declines was most typically associated with drought years, and the most impaired sites were spatially distributed to suggest the influence of local bedrock controls on soil depth. Climate in the Drôme basin and in the Mediterranean region is trending significantly toward hotter growing seasons with a decrease in summer river

  3. Oak Decline

    Treesearch

    Vernon Ammon; T. Evan Nebeker; Ted H. Filer; Francis I. McCracken; J. D. Solomon; H. E. Kennedy

    1989-01-01

    Occurrence of decline and mortality in this nation's hardwood forests has been documented in reports for the past 130 years. From 1856 through 1981, more than 26 decline events were reported from eight eastern states affecting almost all species of oaks. Fourteen factors have been implicated as either primary or secondary agents responsible for decline and...

  4. Enigmatic declines in bird numbers in lowland forest of eastern Ecuador may be a consequence of climate change

    PubMed Central

    Loiselle, Bette A.

    2015-01-01

    Bird populations have declined in many parts of the world but most of those declines can be attributed to effects of human activities (e.g., habitat fragmentation); declines in areas unaffected by human activities are not common. We have been sampling bird populations at an undisturbed site in lowland forest of eastern Ecuador annually since 2001 using a combination of mist nets and direct observations on two 100-ha plots. Bird numbers fluctuated on both plots during the first 8 years but did not show a consistent pattern of change. Since about 2008, numbers of birds on both plots have declined; capture rates in 2014 were ∼40% less than at the start of the study and observation rates were ∼50% less. Both understory and canopy species declined in abundance. Overall, insectivores showed the most pronounced declines but declines varied among trophic groups. The period from 2008 onward also was a period of stronger La Niña events which, at this study site, are associated with increased rainfall. The mechanism for the declines is not known but likely reflects a combination of reduced reproductive success coupled with reduced survival associated with changing climate. PMID:26339554

  5. Enigmatic declines in bird numbers in lowland forest of eastern Ecuador may be a consequence of climate change.

    PubMed

    Blake, John G; Loiselle, Bette A

    2015-01-01

    Bird populations have declined in many parts of the world but most of those declines can be attributed to effects of human activities (e.g., habitat fragmentation); declines in areas unaffected by human activities are not common. We have been sampling bird populations at an undisturbed site in lowland forest of eastern Ecuador annually since 2001 using a combination of mist nets and direct observations on two 100-ha plots. Bird numbers fluctuated on both plots during the first 8 years but did not show a consistent pattern of change. Since about 2008, numbers of birds on both plots have declined; capture rates in 2014 were ∼40% less than at the start of the study and observation rates were ∼50% less. Both understory and canopy species declined in abundance. Overall, insectivores showed the most pronounced declines but declines varied among trophic groups. The period from 2008 onward also was a period of stronger La Niña events which, at this study site, are associated with increased rainfall. The mechanism for the declines is not known but likely reflects a combination of reduced reproductive success coupled with reduced survival associated with changing climate.

  6. Amphibian populations in the terrestrial environment: Is there evidence of declines of terrestrial forest amphibians in northwestern California?

    USGS Publications Warehouse

    Welsh, H.H.; Fellers, G.M.; Lind, A.J.

    2007-01-01

    Amphibian declines have been documented worldwide; however the vast majority are species associated with aquatic habitats. Information on the status and trends of terrestrial amphibians is almost entirely lacking. Here we use data collected across a 12-yr period (sampling from 1984-86 and from 1993-95) to address the question of whether evidence exists for declines among terrestrial amphibians in northwestern California forests. The majority of amphibians, both species and relative numbers, in these forests are direct-developing salamanders of the family Plethodontidae. We examined amphibian richness and evenness, and the relative abundances of the four most common species of plethodontid salamanders. We examined evidence of differences between years in two ecological provinces (coastal and interior) and across young, mature, and late seral forests and with reference to a moisture gradient from xeric to hydric within late seral forests. We found evidence of declines in species richness across years on late seral mesic stands and in the coastal ecological province, but these differences appeared to be caused by differences in the detection of rarer species, rather than evidence of an overall pattern. We also found differences among specific years in numbers of individuals of the most abundant species, Ensatina eschscholtzii, but these differences also failed to reflect a consistent pattern of declines between the two decadal sample periods. Results showing differences in richness, evenness, and relative abundances along both the seral and moisture continua were consistent with previous research. Overall, we found no compelling evidence of a downward trend in terrestrial plethodontid salamanders. We believe that continued monitoring of terrestrial salamander populations is important to understanding mechanisms of population declines in amphibian species. Copyright 2007 Society for the Study of Amphibians and Reptiles.

  7. European Holocene landscape change: a comparison of pollen-based approaches to reconstructing land use shifts and forest decline

    NASA Astrophysics Data System (ADS)

    Woodbridge, Jessie; Roberts, Neil; Fyfe, Ralph; Gaillard, Marie-José; Trondman, Anna-Kari; Davis, Basil; Kaplan, Jed

    2016-04-01

    Europe's primaeval forests have been progressively cleared and fragmented since the first appearance of Neolithic farming activities around 6000 years ago. Understanding spatial and temporal changes in forest cover is valuable to researchers interested in past human-environment interactions. Here we present a comparison of reconstructed Holocene forest cover across Europe from three different transformed fossil pollen-based datasets, an extensive modern surface pollen data set, and modern forest cover from remote sensing. The REVEALS approach (Trondman et al., 2015) provides a quantified and validated reconstruction of vegetation incorporating plant productivity estimates, but is currently only available for a limited number of grid cells in mid-latitude and northern Europe for a limited number of time windows. The pseudobiomization (PBM) (Fyfe et al., 2015) and plant functional type (PFT) (Davis et al., 2015) based approaches provide continuous semi-quantitative records of land use change for temperate and Northern Europe spanning the Holocene, but do not provide truly quantified vegetation reconstructions. Estimated modern forest cover based on the various approaches ranges between ~29 and 54%. However, the Holocene estimates of vegetation change show broadly similar trends, with a forest maximum from ~8.2 to ~6 ka BP, and a decline in forest cover after 6 ka BP, accelerating after ~1.2 ka BP. The reconstructions, when broadly disaggregated into northern and mid-latitude Europe, confirm that mid-latitude forest cover has declined more than that in northern Europe over the last 6 ka. The continuous record provided by the PBM has been used to establish a 'half forest loss' date for each grid cell in temperate and northern Europe, which has identified that the timing of forest loss varied spatially with certain regions remaining forested for longer. References Davis BAS, Collins PM, Kaplan JO (2015) The age and post-glacial development of the modern European

  8. Comparison of FVS projection of oak decline on the Mark Twain National Forest to actual growth and mortality as measured over three FIA inventory cycles

    Treesearch

    Don Vandendriesche; Linda Haugen

    2008-01-01

    Oak decline has been recorded on oak forests throughout the Ozark Plateau of Missouri since the 1970s, but severe drought in the late 1990s, combined with the advancing age of the Ozark forests, has intensified the levels of crown dieback and mortality beyond historical levels. The purpose of this project was to determine whether the Forest Vegetation Simulator (FVS)...

  9. Declining snowpack and forest productivity in a montane ecosystem in the Northern Rocky Mountains

    NASA Astrophysics Data System (ADS)

    Hu, J.; Clute, T.; Simpson, T.; Hoylman, Z. H.; Jencso, K. G.

    2016-12-01

    Across the western U.S., declining snowpacks have increased drought, leading to reduced productivity rates in high elevation forests. As climate projections predict decreases in the ratio of snow/rainfall by the end of the century, this shift in the mode of precipitation could potentially lead to further decreases in forest productivity. However, different tree species across the montane ecosystem might respond differently to these shifts; while some tree species might experience decreased growth rates, other species might capitalize on the extra rainfall and increase growth rates. Furthermore, the landscape topography will also play an important role by modulating the sensitivity of different trees to these changing precipitation regimes. In this study, we examined the long-term patterns of plant water source use across an elevational gradient in western Montana. Because snow and rain have distinct oxygen isotopic values, we analyzed the δ18O of cellulose from tree rings at annual time scales to track changes in source water in two main species: Pseudotsuga menziezii and Pinus Ponderosa at both high and low elevation. We also used the same cores to link growth rate with the dominant source water. We first compared the annual changes in δ18O of cellulose with available SNOTEL and Snow Course data. We found poor agreement between snowpack depth and δ18O of cellulose prior to 1980. However, after 1980, we found a strong negative relationship; small snowpack years resulted in enriched δ18O of cellulose values while large snowpack years resulted in depleted δ18O of cellulose values. We then used the Craig-Gordon model along with our input of δ18O of cellulose to back calculate source water and found strong agreement between modeled versus measured values. Since the δ18O of cellulose also captures the atmospheric conditions, we then tested the sensitivity of the Craig-Gordon model to changes in relative humidity versus source water. These preliminary results a

  10. Forecasting long-term acorn production with and without oak decline using forest inventory data

    Treesearch

    Cathryn H. Greenberg; Chad E. Keyser; Leah C. Rathburn; Anita K. Rose; Todd M. Fearer; Henry W. McNab

    2013-01-01

    Acorns are important as wildlife food and for oak regeneration, but production is highly variable, posing a challenge to forest managers targeting acorn production levels. Forest managers need tools to predict acorn production capability tailored to individual landscapes and forest management scenarios, adjusting for oak mortality and stand development over time. We...

  11. US forests are showing increased rates of decline in response to a changing climate

    Treesearch

    Warren B. Cohen; Zhiqiang Yang; David M. Bell; Stephen V. Stehman

    2015-01-01

    How vulnerable are US forest to a changing climate? We answer this question using Landsat time series data and a unique interpretation approach, TimeSync, a plot-based Landsat visualization and data collection tool. Original analyses were based on a stratified two-stage cluster sample design that included interpretation of 3858 forested plots. From these data, we...

  12. An evaluation of bur oak (Quercus macrocarpa) decline in the urban forest of Winnipeg, Manitoba, Canada

    USGS Publications Warehouse

    Catton, H.A.; St., George; Remphrey, W.R.

    2007-01-01

    Winnipeg, Manitoba, Canada, has a large, indigenous population of bur oak (Quercus macrocarpa Michx.). In the 1980s, many of these trees were showing signs of decline, a disease caused by a complex of abiotic and secondary biotic stressing agents. Potential causal factors were investigated by comparing various aspects of 120 bur oaks visually rated as healthy or declined based on crown dieback levels. The results indicated that many selected bur oak trees predated surrounding urban development and that declined trees were significantly older with more severe stem wounds and competition from surrounding trees than healthy specimens. Average annual growth ring widths of healthy and declined trees were similar in the early part of the 20th century. However, decline actually began decades before symptoms were noticed, coinciding with a period of in tense city-wide urban development, as growth of declined trees was slower than that of healthy trees beginning sporadically in the 1940s and consistently from 1974 to 2001. During the early years of decline, the year-by-year separation in ring width between the two categories was significantly positively related to precipitation levels. This suggested that in wet years, declined trees may have been surrounded by unfavorable water-logged soils, possibly as a result of natural drainage patterns being impeded by urban development. ?? 2007 International Society of Arboriculture.

  13. Oak decline in central hardwood forests: frequency, spatial extent, and scale

    Treesearch

    Steven W Oak; Marty Spetich; Randall S. Morin

    2015-01-01

    Oak decline is a widely distributed disease that results from an interacting set of factors in the Central Hardwood Region. Episodes of decline have been reported since before the turn of the twentieth century and from every state in the region. It is a stress-mediated disease that results from the interactions of physiologically mature trees, abiotic and biotic...

  14. Reassessment of Loblolly Pine Decline on the Oakmulgee Ranger District, Talladega National Forest, Alabama

    Treesearch

    Nolan J. Hess; William J. Otroana; John P. Jones; Arthur J. Goddard; Charles H. Walkinshaw

    1999-01-01

    Loblolly pine (Pinus taeda L.) decline has been a management concern on the Oakmulgee Ranger District since the 1960's. The symptoms include sparse crowns, reduced radial growth, deterioration of fine roots, decline, and mortality of loblolly pine by age 50.

  15. Use of TMS/TM data for mapping of forest decline damage in the northeastern United States. [Thematic Mapper Simulator (TMS) Thematic Mapper (TM)

    NASA Technical Reports Server (NTRS)

    Rock, B. N.; Vogelmann, J. E.

    1986-01-01

    Remote sensing systems were used to monitor forest decline damage suspected of being due to air pollution. Field activities and aircraft overflights were centered on montane spruce/fir forest sites. Using aircraft data acquired with the Thematic Mapper Simulator (TMS) and LANDSAT Thematic Mapper (TM) during the growing season, extensive areas of forest decline damage were accurately mapped. Seven levels of decline damage are discrininated and mapped and the levels of discriminated damage agree well (rsq-0.94) with visual assessment conducted on the ground. New areas of high damage were discovered. A band ratio (TM5/TM4) is most useful in discriminating and quantifying the various levels of forest decline damage.

  16. Macrofossil and Tree-Ring Evidence for a Long-Term Forest Succession and Mid-Holocene Hemlock Decline

    NASA Astrophysics Data System (ADS)

    Filion, Louise; Quinty, François

    1993-07-01

    Paludified dune fields in southern Québec provided a unique opportunity to analyze a mid-Holocene forest succession, ranging from xero-mesophilous forests to treed peatlands, which registered the hemlock decline, a major biostratigraphic event in eastern North America. Our fossil-tree chronology established from 66 radiocarbon dates of tree stems indicates that white pine and hemlock were present at the study site about 6000-5700 yr B.P. Hemlock reached a maximum 4900-4800 yr B.P. and then declined between 4600 and 3800 yr B.P.; the species recovered around 3700 yr B.P. and then decreased when white pine and eastern latch dominated the site after 3000 yr B.P. and between 2600 and 2200 yr B.P., respectively. Tree-ring signatures of fossil hemlocks suggest the continuous influence of biotic factors, possibly insect defoliators, throughout the record, as shown by recurrent suppressed-growth pattern. Microscopic examination of the hemlock fossil stems disclosed no evidence of fungal disease. The hemlock decline was probably caused by regional posthypsithermal climatic changes, toward moister conditions.

  17. Viewing forests from below: fine root mass declines relative to leaf area in aging lodgepole pine stands.

    PubMed

    Schoonmaker, A S; Lieffers, V J; Landhäusser, S M

    2016-07-01

    In the continued quest to explain the decline in productivity and vigor with aging forest stands, the most poorly studied area relates to root system change in time. This paper measures the wood production, root and leaf area (and mass) in a chronosequence of fire-origin lodgepole pine (Pinus contorta Loudon) stands consisting of four age classes (12, 21, 53, and ≥100 years), each replicated ~ five times. Wood productivity was greatest in the 53-year-old stands and then declined in the ≥100-year-old stands. Growth efficiency, the quantity of wood produced per unit leaf mass, steadily declined with age. Leaf mass and fine root mass plateaued between the 53- and ≥100-year-old stands, but leaf area index actually increased in the older stands. An increase in the leaf area index:fine root area ratio supports the idea that older stand are potentially limited by soil resources. Other factors contributing to slower growth in older stands might be lower soil temperatures and increased self-shading due to the clumped nature of crowns. Collectively, the proportionally greater reduction in fine roots in older stands might be the variable that predisposes these forests to be at a potentially greater risk of stress-induced mortality.

  18. Grass invasion of a hardwood forest is associated with declines in belowground carbon pools

    Treesearch

    Michael S. Strickland; Jayna L. Devore; John C. Maerz; Mark A. Bradford

    2010-01-01

    Invasive plant species affect a range of ecosystem processes but their impact on belowground carbon (C) pools is relatively unexplored. This is particularly true for grass invasions of forested ecosystems. Such invasions may alter both the quantity and quality of forest floor inputs. Dependent on both, two theories, ‘priming’ and ‘preferential substrate utilization’,...

  19. The Decline of Austrocedrus Forests in Patagonia (Mal del Ciprés): Another Phytophthora-Caused Forest Disease

    Treesearch

    Alina Greslebin; Everett Hansen

    2009-01-01

    Austrocedrus chilensis, an indigenous Cupressaceae of the Patagonian Andes forests, is suffering a disease that has been called "Mal del Ciprés" (MDC). This disease was first reported more than 50 years ago but, in spite of many studies, its causes remained unclear until recently. The disease begins in the root system, the distribution...

  20. Drying of Floodplain Forests Associated with Water-Level Decline in the Apalachicola River, Florida - Interim Results, 2006

    USGS Publications Warehouse

    Darst, Melanie R.; Light, Helen M.

    2007-01-01

    Floodplain forests of the Apalachicola River, Florida, are drier in composition today (2006) than they were before 1954, and drying is expected to continue for at least the next 50 years. Drier forest composition is probably caused by water-level declines that occurred as a result of physical changes in the main channel after 1954 and decreased flows in spring and summer months since the 1970s. Forest plots sampled from 2004 to 2006 were compared to forests sampled in the late 1970s (1976-79) using a Floodplain Index (FI) based on species dominance weighted by the Floodplain Species Category, a value that represents the tolerance of tree species to inundation and saturation in the floodplain and consequently, the typical historic floodplain habitat for that species. Two types of analyses were used to determine forest changes over time: replicate plot analysis comparing present (2004-06) canopy composition to late 1970s canopy composition at the same locations, and analyses comparing the composition of size classes of trees on plots in late 1970s and in present forests. An example of a size class analysis would be a comparison of the composition of the entire canopy (all trees greater than 7.5 cm (centimeter) diameter at breast height (dbh)) to the composition of the large canopy tree size class (greater than or equal to 25 cm dbh) at one location. The entire canopy, which has a mixture of both young and old trees, is probably indicative of more recent hydrologic conditions than the large canopy, which is assumed to have fewer young trees. Change in forest composition from the pre-1954 period to approximately 2050 was estimated by combining results from three analyses. The composition of pre-1954 forests was represented by the large canopy size class sampled in the late 1970s. The average FI for canopy trees was 3.0 percent drier than the average FI for the large canopy tree size class, indicating that the late 1970s forests were 3.0 percent drier than pre-1954

  1. Influence of forest canopy and snow on microclimate in a declining yellow-cedar forest of southeast Alaska

    Treesearch

    Paul E. Hennon; David V. D' Amore; Dustin T. Witter; Melinda B. Lamb

    2010-01-01

    Site factors predispose yellow-cedar (Chamaecyparis nootkatensis D. Don (Spach)) to a widespread climate-induced mortality in southeast Alaska. We investigated the influence of canopy cover and snow on microclimate at two small watersheds across a range of declining yellow-cedar stands on Baranof and Chichagof Islands in southeast Alaska. Two...

  2. Mutualism-disrupting allelopathic invader drives carbon stress and vital rate decline in a forest perennial herb

    PubMed Central

    Brouwer, Nathan L.; Hale, Alison N.; Kalisz, Susan

    2015-01-01

    Invasive plants can negatively affect belowground processes and alter soil microbial communities. For native plants that depend on soil resources from root fungal symbionts (RFS), invasion could compromise their resource status and subsequent ability to manufacture and store carbohydrates. Herbaceous perennials that depend on RFS-derived resources dominate eastern North American forest understories. Therefore, we predict that forest invasion by Alliaria petiolata, an allelopathic species that produces chemicals that are toxic to RFS, will diminish plant carbon storage and fitness. Over a single growing season, the loss of RFS could reduce a plant's photosynthetic physiology and carbon storage. If maintained over multiple growing seasons, this could create a condition of carbon stress and declines in plant vital rates. Here we characterize the signals of carbon stress over a short timeframe and explore the long-term consequence of Alliaria invasion using Maianthemum racemosum, an RFS-dependent forest understory perennial. First, in a greenhouse experiment, we treated the soil of potted Maianthemum with fresh leaf tissue from either Alliaria or Hesperis matronalis (control) for a single growing season. Alliaria-treated plants exhibit significant overall reductions in total non-structural carbohydrates and have 17 % less storage carbohydrates relative to controls. Second, we monitored Maianthemum vital rates in paired experimental plots where we either removed emerging Alliaria seedlings each spring or left Alliaria at ambient levels for 7 years. Where Alliaria is removed, Maianthemum size and vital rates improve significantly: flowering probability increases, while the probability of plants regressing to non-flowering stages or entering prolonged dormancy are reduced. Together, our results are consistent with the hypothesis that disruption of a ubiquitous mutualism following species invasion creates symptoms of carbon stress for species dependent on RFS. Disruption

  3. Declines in Soil pH due to Anthropogenic Nitrogen Inputs Alter Buffering and Exchange Reactions in Tropical Forest Soils

    NASA Astrophysics Data System (ADS)

    Lohse, K. A.

    2003-12-01

    Anthropogenic nitrogen (N) inputs may alter tropical soil buffering and exchange reactions that have important implications for nutrient cycling, forest productivity, and downstream ecosystems. In contrast to relatively young temperate soils that are typically buffered from N inputs by base cation reactions, aluminum reactions may serve to buffer highly weathered tropical soils and result in immediate increases in aluminum mobility and toxicity. Increased nitrate losses due to chronic N inputs may also deplete residual base cations in already weathered base cation-poor soils, further acidify soils, and thereby reduce nitrate mobility through pH-dependent anion exchange reactions. To test these hypotheses, I determined soil pH and cation and anion exchange capacity (CEC and AEC) and measured base cation and aluminum soil solution losses following first-time and long-term experimental N additions from two Hawaiian tropical forest soils, a 300 year old Andisol and a 4.1 million year old Oxisol. I found that elevated base cation losses accompanied increased nitrate losses after first time N additions to the young Andisol whereas immediate and large aluminum losses were associated with increased nitrate losses from the Oxisol. In the long-term, base cation and aluminum losses increased in proportion to nitrate losses. Long-term N additions at both sites resulted in significant declines in soil pH, decreased CEC and increased AEC. These results suggest that even chronic N inputs resulting in small but elevated nitrate losses may deplete residual base cations, increase mobility and toxicity of aluminum, and potentially lead to declines in forest productivity and acidification of downstream ecosystems. These findings also suggest that AEC may provide a long-term mechanism to delay nitrate losses in tropical forests with significant variable charge that are experiencing chronic anthropogenic N inputs.

  4. [Relationship between decline disease of exotic pines(Pinus taeda and P. eliottii) and forest stand and environmental factors].

    PubMed

    Shu, Q; Zou, Y; Yang, G; Zhu, Q; Huang, C

    2001-06-01

    The relationship between decline disease of exotic pines(Pinus taeda and P. eliottii) plantations in Anhui Province and forest stand status and environmental factors was quantitatively analyzed. Among 18 variable factors from 4 types of factors(climate, soil, stand status, and other diseases and insect pests), 10 factors contributed greatly to the state of illness. These were tree age, stand density, resin-tapping, rainfall, temperature, clay soil, stone soil, soil depth, water-logging, and other diseases and insect pests. Of them soil depth and rainfall negatively, and others positively related with the severity of disease. Accordingly, a linear multiple regression model was derived, which might predict the developmental level of decline disease at any given conditions of exotic pine plantation. In addition, the spiral chart of decline disease was mapped based on the action size and time order of various nosogenetic factors during the incidence of decline disease, which was used to visually describe and quantitatively analyze the disease with complicated causes.

  5. Stand Dynamics of Coast Redwood/Tanoak Forests Following Tanoak Decline

    Treesearch

    Kristen M. Waring; Kevin L. O' Hara

    2007-01-01

    Current threats to North American forests increasingly include exotic tree pathogens that cause extensive mortality. In California, tanoak (Lithocarpus densiflorus) mortality has increased rapidly since 1995, due to Phytophthora ramorum, believed to be an introduced pathogen. Tanoak frequently grows as a major component of redwood...

  6. Decline in American marten occupancy rates at Sagehen Experimental Forest, California

    Treesearch

    Katie M. Moriarty; William J. Zielinski; Eric D. Forsman

    2011-01-01

    We compared the distribution and frequency of American marten (Martes americana) detections during historic surveys and a recent survey on the Sagehen Experimental Forest (SEF) in the Sierra Nevada Mountains, California. This area has been the location of 9 previous marten surveys during 1980–1993, each involving a systematic detection/non-...

  7. Eastern hemlock transpiration: patterns, controls, and implications for its decline in southern Appalachian forests

    Treesearch

    Chelcy R. Ford; James M. Vose

    2006-01-01

    Eastern hemlock, a principal riparian and cove canopy species in the southern Appalachian mountains, is facing potential widespread mortality due to the hemlock adelgid (HWA). To estimate the impact that the loss of this species will have on forest transpiration (E1) we quantified whole-tree (Ec) and leaf-level (E

  8. Occupancy patterns of regionally declining grassland sparrow populations in a forested Pennsylvania landscape.

    PubMed

    Hill, Jason M; Diefenbach, Duane R

    2014-06-01

    Organisms can be affected by processes in the surrounding landscape outside the boundary of habitat areas and by local vegetation characteristics. There is substantial interest in understanding how these processes affect populations of grassland birds, which have experienced substantial population declines. Much of our knowledge regarding patterns of occupancy and density stem from prairie systems, whereas relatively little is known regarding how occurrence and abundance of grassland birds vary in reclaimed surface mine grasslands. Using distance sampling and single-season occupancy models, we investigated how the occupancy probability of Grasshopper (Ammodramus savannarum) and Henslow's Sparrows (A. henslowii) on 61 surface mine grasslands (1591 ha) in Pennsylvania changed from 2002 through 2011 in response to landscape, grassland, and local vegetation characteristics . A subset (n = 23; 784 ha) of those grasslands were surveyed in 2002, and we estimated changes in sparrow density and vegetation across 10 years. Grasshopper and Henslow's Sparrow populations declined 72% and 49%, respectively from 2002 to 2011, whereas overall woody vegetation density increased 2.6 fold. Henslow's Sparrows avoided grasslands with perimeter-area ratios ≥0.141 km/ha and woody shrub densities ≥0.04 shrubs/m(2). Both species occupied grasslands ≤13 ha, but occupancy probability declined with increasing grassland perimeter-area ratio and woody shrub density. Grassland size, proximity to nearest neighboring grassland (x = 0.2 km), and surrounding landscape composition at 0.5, 1.5, and 3.0 km were not parsimonious predictors of occupancy probability for either species. Our results suggest that reclaimed surface mine grasslands, without management intervention, are ephemeral habitats for Grasshopper and Henslow's Sparrows. Given the forecasted decline in surface coal production for Pennsylvania, it is likely that both species will continue to decline in our study region for the

  9. Occupancy patterns of regionally declining grassland sparrow populations in a forested Pennsylvania landscape

    USGS Publications Warehouse

    Hill, Jason M.; Diefenbach, Duane R.

    2014-01-01

    Organisms can be affected by processes in the surrounding landscape outside the boundary of habitat areas and by local vegetation characteristics. There is substantial interest in understanding how these processes affect populations of grassland birds, which have experienced substantial population declines. Much of our knowledge regarding patterns of occupancy and density stem from prairie systems, whereas relatively little is known regarding how occurrence and abundance of grassland birds vary in reclaimed surface mine grasslands. Using distance sampling and single-season occupancy models, we investigated how the occupancy probability of Grasshopper (Ammodramus savannarum) and Henslow's Sparrows (A. henslowii) on 61 surface mine grasslands (1591 ha) in Pennsylvania changed from 2002 through 2011 in response to landscape, grassland, and local vegetation characteristics . A subset (n = 23; 784 ha) of those grasslands were surveyed in 2002, and we estimated changes in sparrow density and vegetation across 10 years. Grasshopper and Henslow's Sparrow populations declined 72% and 49%, respectively from 2002 to 2011, whereas overall woody vegetation density increased 2.6 fold. Henslow's Sparrows avoided grasslands with perimeter–area ratios ≥0.141 km/ha and woody shrub densities ≥0.04 shrubs/m2. Both species occupied grasslands ≤13 ha, but occupancy probability declined with increasing grassland perimeter–area ratio and woody shrub density. Grassland size, proximity to nearest neighboring grassland ( = 0.2 km), and surrounding landscape composition at 0.5, 1.5, and 3.0 km were not parsimonious predictors of occupancy probability for either species. Our results suggest that reclaimed surface mine grasslands, without management intervention, are ephemeral habitats for Grasshopper and Henslow's Sparrows. Given the forecasted decline in surface coal production for Pennsylvania, it is likely that both species will continue to decline in our study region for the

  10. Reproductive Performance of a Declining Forest Passerine in Relation to Environmental and Social Factors: Implications for Species Conservation

    PubMed Central

    Grendelmeier, Alex; Arlettaz, Raphaël; Gerber, Michael; Pasinelli, Gilberto

    2015-01-01

    Identifying factors influencing a species' ecological niche and demography is a prerequisite for species conservation. However, our understanding of the interplay between demographic rates and biotic/abiotic factors is still poor for most species of conservation concern. We evaluated relevance of eight hypotheses relating to timing of breeding, temporal nest exposure, nest concealment, topography, tree structure, predation risk and disturbance, density dependence and weather for explaining variation in reproductive performance of the declining wood warbler Phylloscopus sibilatrix in northern Switzerland. Reproductive performance was monitored with cameras at 136 nests from 2010 to 2012 and was associated to temporal exposure, timing of breeding and concealment of nests. Daily nest survival was positively related to the number of grass and sedge tussocks, nest concealment and nest age. Clutch size and number of fledglings decreased, the later in the season a nest was initiated. Nest survival over an average nesting period of 31 days was 46.9 ± 0.07% (mean ± SE), daily nest survival rate was 0.976 ± 0.002. As for many ground-breeding birds, nest predation was the principal cause of nest failure, accounting for 79% of all nest losses. Conservation measures should aim at increasing the area of relatively homogenous forest stands featuring suitable habitats characterized by abundant and accessible grass and sedge tussocks. In managed forests, such conditions can be found in stands of middle age (i.e. pole wood) with little to no shrub layer. PMID:26172954

  11. Remote sensing of forest decline and Enaphalodes rufulus outbreak in the Arkansas Ozarks, U.S.A

    NASA Astrophysics Data System (ADS)

    Riggins, John Joseph

    A widespread oak decline event was reported in the Arkansas Ozarks during the late 1990's. Ground-based monitoring attempts have been successful at recording the progression of this event, but are extremely laborious and as a result are only possible in a few locations. Remote sensing technologies offer the ability to substantially decrease labor and time required to collect large-scale forest biophysical data. Remote sensors allow continuous samples to be acquired across large tracts of land that would only be represented by a few widely spaced sampling points in traditional terrestrial sampling schemes. Remotely sensed data from large study areas can be acquired in minutes or hours, which greatly reduces cost compared to long-term field sampling activities. Additionally, changes of biophysical variables ongoing during long-term data collection can be avoided. Sampling bias caused by multiple individuals collecting field data is also reduced. Geographically-referenced digital remote sensor data from the Arkansas Ozarks have been acquired using two fundamentally different remote sensor systems: a hand held spectroradiometer, and aerial LIDAR (Light Detection and Ranging). Spectroradiometer data were used to identify the spectral signatures of northern red oak decline, and methods for applying this information to aerial imagery were described. LIDAR data were used to estimate total aboveground biomass. Biomass estimates will allow subsequent remote sensing and hazard modeling to estimate quantifiable changes in biomass at the landscape level.

  12. Air pollutant deposition at declining forest sites of the Tanzawa Mountains, Japan

    NASA Astrophysics Data System (ADS)

    Igawa, Manabu; Kojima, Kyosuke; Yoshimoto, Osamu; Nanzai, Ben

    2015-01-01

    Fir and beech trees have been dying in the Tanzawa Mountains, which are located southwest of the Kanto Plain. We have observed fog characteristics since 1988 in Mt. Oyama, which is isolated from others, located southeast of the Mountains. Acid fog has been frequently observed there. The annual mean pH of the fog has remained roughly constant, but the pH distribution of fog has shifted to higher pH recently, which corresponds closely with the improvement of air pollution at the base of Mt. Oyama. Acid fog is still formed, and it may have affected tree species such as fir and beech, which are sensitive to air pollution. We observed rainy periods and foggy periods using a visibility meter at the mountain top. The canopies at the high altitude are confirmed to be wetted for a long period, which might enhance the air pollutant deposition. We also observed air pollution and wet deposition at Mt. Nabewari, located southwest of the Tanzawa Mountains. The acid gas concentrations are about the same level in the two mountains and are in the order of SO2 > HNO3 > HCl. Comparison of wet deposition at the summit of Mt. Nabewari to that of Mt. Oyama also revealed that they were of similar levels. In the Tanzawa Mountains, fir trees and beech trees are declining by the damage of acid fog, although the high concentration ozone and the other factors may have also affected them.

  13. Signature of a Pre-Human Population Decline in the Critically Endangered Reunion Island Endemic Forest Bird Coracina newtoni

    PubMed Central

    Salmona, Jordi; Salamolard, Marc; Fouillot, Damien; Ghestemme, Thomas; Larose, Jerry; Centon, Jean-François; Sousa, Vitor; Dawson, Deborah A.; Thebaud, Christophe; Chikhi, Lounès

    2012-01-01

    The exceptional biodiversity of Reunion Island is threatened by anthropogenic landscape changes that took place during the 350 years of human colonization. During this period the human population size increased dramatically from 250 to 800,000. The arrival of humans together with the development of agriculture, invasive species such as rats and cats, and deforestation has lead to the extinction of more than half of the original vertebrate species of the island. For the remaining species, significant work is being carried out to identify threats and conservation status, but little genetic work has been carried on some of the most endangered species. In the last decade theoretical studies have shown the ability of neutral genetic markers to infer the demographic history of endangered species and identify and date past population size changes (expansions or bottlenecks). In this study we provide the first genetic data on the critically endangered species the Reunion cuckoo-shrike Coracina newtoni. The Reunion cuckoo-shrike is a rare endemic forest bird surviving in a restricted 12-km2 area of forested uplands and mountains. The total known population consists of less than one hundred individuals out of which 45 were genotyped using seventeen polymorphic microsatellite loci. We found a limited level of genetic variability and weak population structure, probably due to the limited geographic distribution. Using Bayesian methods, we identified a strong decline in population size during the Holocene, most likely caused by an ancient climatic or volcanic event around 5000 years ago. This result was surprising as it appeared in apparent contradiction with the accepted theory of recent population collapse due to deforestation and predator introduction. These results suggest that new methods allowing for more complex demographic models are necessary to reconstruct the demographic history of populations. PMID:22916272

  14. Signature of a pre-human population decline in the critically endangered Reunion Island endemic forest bird Coracina newtoni.

    PubMed

    Salmona, Jordi; Salamolard, Marc; Fouillot, Damien; Ghestemme, Thomas; Larose, Jerry; Centon, Jean-François; Sousa, Vitor; Dawson, Deborah A; Thebaud, Christophe; Chikhi, Lounès

    2012-01-01

    The exceptional biodiversity of Reunion Island is threatened by anthropogenic landscape changes that took place during the 350 years of human colonization. During this period the human population size increased dramatically from 250 to 800,000. The arrival of humans together with the development of agriculture, invasive species such as rats and cats, and deforestation has lead to the extinction of more than half of the original vertebrate species of the island. For the remaining species, significant work is being carried out to identify threats and conservation status, but little genetic work has been carried on some of the most endangered species. In the last decade theoretical studies have shown the ability of neutral genetic markers to infer the demographic history of endangered species and identify and date past population size changes (expansions or bottlenecks). In this study we provide the first genetic data on the critically endangered species the Reunion cuckoo-shrike Coracina newtoni. The Reunion cuckoo-shrike is a rare endemic forest bird surviving in a restricted 12-km(2) area of forested uplands and mountains. The total known population consists of less than one hundred individuals out of which 45 were genotyped using seventeen polymorphic microsatellite loci. We found a limited level of genetic variability and weak population structure, probably due to the limited geographic distribution. Using Bayesian methods, we identified a strong decline in population size during the Holocene, most likely caused by an ancient climatic or volcanic event around 5000 years ago. This result was surprising as it appeared in apparent contradiction with the accepted theory of recent population collapse due to deforestation and predator introduction. These results suggest that new methods allowing for more complex demographic models are necessary to reconstruct the demographic history of populations.

  15. The Declining Cocoa Economy and the Atlantic Forest of Southern Bahia, Brazil: Conservation Attitudes of Cocoa Planters.

    ERIC Educational Resources Information Center

    Alger, Keith; Caldas, Marcellus

    1994-01-01

    Causes of the degradation of Brazilian Atlantic Forest in the southeastern cocoa region of the State of Bahia are investigated by means of a survey on cocoa planter's forest conservation attitudes. Policies encouraging private forest conservation, and development of forest-conserving agricultural alternatives for landless poor are recommended. (LZ)

  16. The Declining Cocoa Economy and the Atlantic Forest of Southern Bahia, Brazil: Conservation Attitudes of Cocoa Planters.

    ERIC Educational Resources Information Center

    Alger, Keith; Caldas, Marcellus

    1994-01-01

    Causes of the degradation of Brazilian Atlantic Forest in the southeastern cocoa region of the State of Bahia are investigated by means of a survey on cocoa planter's forest conservation attitudes. Policies encouraging private forest conservation, and development of forest-conserving agricultural alternatives for landless poor are recommended. (LZ)

  17. Oak decline and red oak borer outbreak: impact in upland oak-hickory forests of Arkansas, USA

    Treesearch

    Laurel J. Haavik; Joshua S. Jones; Larry D. Galligan; James M. Guldin; Fred M. Stephen

    2012-01-01

    Oak-hickory forests in the Ozark and Ouachita Mountains of Arkansas recently experienced an episode of oak mortality in concert with an outbreak of the red oak borer (Enaphalodes rufulus (Haldeman) (Coleoptera: Cerambycidae)). We utilized data from the Forest Inventory and Analysis (FIA) program of the USDA Forest Service to explore changes in percent red oak (Quercus...

  18. Climatic sensitivity, water-use efficiency, and growth decline in boreal jack pine (Pinus banksiana) forests in Northern Ontario

    NASA Astrophysics Data System (ADS)

    Dietrich, Rachel; Bell, F. Wayne; Silva, Lucas C. R.; Cecile, Alice; Horwath, William R.; Anand, Madhur

    2016-10-01

    Rises in atmospheric carbon dioxide (atmCO2) levels are known to stimulate photosynthesis and increase intrinsic water-use efficiency (iWUE) in trees. Stand-level increases in iWUE depend on the physiological response of dominant species to increases in atmCO2, while tree-level response to increasing atmCO2 depends on the balance between the direct effects of atmCO2 on photosynthetic rate and the indirect effects of atmCO2 on drought conditions. The aim of this study was to characterize the response of boreal jack pine (Pinus banksiana) stands in Northern Ontario to changes in atmCO2 and associated climatic change over the past 100 years. The impact of changes in growing season length, temperature, and precipitation, as well as atmCO2 on tree growth, was determined using stable carbon isotopes and dendrochronological analysis. Jack pine stands in this study were shown to be in progressive decline. As expected, iWUE was found to increase in association with rising atmCO2. However, increases in iWUE were not directly coupled with atmCO2, suggesting that the degree of iWUE improvement is limited by alternative factors. Water-use efficiency was negatively associated with tree growth, suggesting that warming- and drought-induced stomatal closure has likely led to deviations from expected atmCO2-enhanced growth. This finding corroborates that boreal forest stands are likely to face continued stress under future climatic warming.

  19. Diagnosing injury to eastern forest trees

    Treesearch

    John M. Skelly; Donald D. Davis; William Merrill; E. Alan Cameron; H. Daniel Brown; David B. Drummond; Leon S., eds. Dochinger

    1987-01-01

    The purpose of this manual is to assist members of the National Vegetation Survey in recognizing air pollutant-induced injury and in identifying disease and insect damage that may be confused with air pollutant-induced injury to forest vegetation in the eastern United States. Ozone, sulfur dioxide, and, to a limited geographic extent, hydrogen fluoride, are all...

  20. How fast will trees die? A transition matrix model of ash decline in forest stands infested by emerald ash borer

    Treesearch

    Kathleen S. Knight; Robert P. Long; Joanne Rebbeck; Annemarie Smith; Kamal Gandhi; Daniel A. Herms

    2008-01-01

    We recorded Fraxinus spp. tree health and other forest stand characteristics for 68 plots in 21 EAB-infested forest stands in Michigan and Ohio in 2005 and 2007. Fraxinus spp. were a dominant component of these stands, with more than 900 ash trees (including Fraxinus americana, Fraxinus pennsylvanica, Fraxinus profunda...

  1. Preliminary assessment of airborne imaging spectrometer and airborne thematic mapper data acquired for forest decline areas in the Federal Republic of Germany

    NASA Technical Reports Server (NTRS)

    Herrmann, Karin; Ammer, Ulrich; Rock, Barrett; Paley, Helen N.

    1988-01-01

    This study evaluated the utility of data collected by the high-spectral resolution airborne imaging spectrometer (AIS-2, tree mode, spectral range 0.8-2.2 microns) and the broad-band Daedalus airborne thematic mapper (ATM, spectral range 0.42-13.0 micron) in assessing forest decline damage at a predominantly Scotch pine forest in the FRG. Analysis of spectral radiance values from the ATM and raw digital number values from AIS-2 showed that higher reflectance in the near infrared was characteristic of high damage (heavy chlorosis, limited needle loss) in Scotch pine canopies. A classification image of a portion of the AIS-2 flight line agreed very well with a damage assessment map produced by standard aerial photointerpretation techniques.

  2. Preliminary assessment of airborne imaging spectrometer and airborne thematic mapper data acquired for forest decline areas in the Federal Republic of Germany

    NASA Technical Reports Server (NTRS)

    Herrmann, Karin; Ammer, Ulrich; Rock, Barrett; Paley, Helen N.

    1988-01-01

    This study evaluated the utility of data collected by the high-spectral resolution airborne imaging spectrometer (AIS-2, tree mode, spectral range 0.8-2.2 microns) and the broad-band Daedalus airborne thematic mapper (ATM, spectral range 0.42-13.0 micron) in assessing forest decline damage at a predominantly Scotch pine forest in the FRG. Analysis of spectral radiance values from the ATM and raw digital number values from AIS-2 showed that higher reflectance in the near infrared was characteristic of high damage (heavy chlorosis, limited needle loss) in Scotch pine canopies. A classification image of a portion of the AIS-2 flight line agreed very well with a damage assessment map produced by standard aerial photointerpretation techniques.

  3. The Role of Forest Tent Caterpillar Defoliations and Partial Harvest in the Decline and Death of Sugar Maple

    PubMed Central

    Hartmann, Henrik; Messier, Christian

    2008-01-01

    Background and Aims Natural and anthropogenic disturbances can act as stresses on tree vigour. According to Manion's conceptual model of tree disease, the initial vigour of trees decreases as a result of predisposing factors that render these trees more vulnerable to severe inciting stresses, stresses that can then cause final vigour decline and subsequent tree death. This tree disease model was tested in sugar maple (Acer saccharum) by assessing the roles of natural and anthropogenic disturbances in tree decline and death. Methods Radial growth data from 377 sugar maple trees that had undergone both defoliations by insects and partial harvest were used to estimate longitudinal survival probabilities as a proxy for tree vigour. Radial growth rates and survival probabilities were compared among trees subjected to different levels of above- and below-ground disturbances, between periods of defoliation and harvest, and between live and dead trees. Key Results Manion's tree disease model correctly accounts for vigour decline and tree death in sugar maple; tree growth and vigour were negatively affected by a first defoliation, predisposing these trees to death later during the study period due to a second insect outbreak that initiated a final vigour decline. This decline was accelerated by the partial harvest disturbance in 1993. Even the most severe anthropogenic disturbances from partial harvest did not cause, unlike insect defoliation, any growth or vigour declines in live sugar maple. Conclusions Natural disturbances acted as predisposing and inciting stresses in tree sugar maple decline and death. Anthropogenic disturbances from a partial harvest at worst accelerated a decline in trees that were already weakened by predisposing and inciting stresses (i.e. repeated insect defoliations). Favourable climatic conditions just before and after the partial harvest may have alleviated possible negative effects on growth resulting from harvesting. PMID:18660493

  4. Amphibian populations in the terrestrial environment: Is there evidence of declines of terrestrial forest amphibians in northwestern California?

    Treesearch

    Hartwell H. Welsh Jr.; Gary M. Fellers; Amy J. Lind

    2007-01-01

    Amphibian declines have been documented worldwide; however the vast majority are species associated with aquatic habitats. Information on the status and trends of terrestrial amphibians is almost entirely lacking. Here we use data collected across a 12-yr period (sampling from 1984–86 and from 1993–95) to address the question of whether evidence exists for declines...

  5. The role of forest tent caterpillar defoliations and partial harvest in the decline and death of sugar maple.

    PubMed

    Hartmann, Henrik; Messier, Christian

    2008-09-01

    Natural and anthropogenic disturbances can act as stresses on tree vigour. According to Manion's conceptual model of tree disease, the initial vigour of trees decreases as a result of predisposing factors that render these trees more vulnerable to severe inciting stresses, stresses that can then cause final vigour decline and subsequent tree death. This tree disease model was tested in sugar maple (Acer saccharum) by assessing the roles of natural and anthropogenic disturbances in tree decline and death. Radial growth data from 377 sugar maple trees that had undergone both defoliations by insects and partial harvest were used to estimate longitudinal survival probabilities as a proxy for tree vigour. Radial growth rates and survival probabilities were compared among trees subjected to different levels of above- and below-ground disturbances, between periods of defoliation and harvest, and between live and dead trees. Manion's tree disease model correctly accounts for vigour decline and tree death in sugar maple; tree growth and vigour were negatively affected by a first defoliation, predisposing these trees to death later during the study period due to a second insect outbreak that initiated a final vigour decline. This decline was accelerated by the partial harvest disturbance in 1993. Even the most severe anthropogenic disturbances from partial harvest did not cause, unlike insect defoliation, any growth or vigour declines in live sugar maple. Natural disturbances acted as predisposing and inciting stresses in tree sugar maple decline and death. Anthropogenic disturbances from a partial harvest at worst accelerated a decline in trees that were already weakened by predisposing and inciting stresses (i.e. repeated insect defoliations). Favourable climatic conditions just before and after the partial harvest may have alleviated possible negative effects on growth resulting from harvesting.

  6. Characterization of Extreme Deposition of Air Pollutants in MT. Mitchell State Park: Potential for Forest Decline and Opportunity for Cloud Deacidification

    NASA Astrophysics Data System (ADS)

    Defelice, Thomas Peter

    The decline of forests has long been attributed to various natural (e.g. drought), man-made (e.g. logging), and perhaps, combinations of these (eg. fires caused by loggers) causes. A new type of forest decline (attributed to the deposition of air pollutants and other natural causes) has become apparent at high elevation sites in western Europe and North America; especially for above cloudbase forests like those in the Mt. Mitchell State Park. Investigations of air pollutant deposition are plentiful and laboratory studies have shown extreme deposition of these pollutants to be potentially harmful to forests. However, no field study has concentrated on these events. The primary objective of this study is to characterize (i.e., meterologically, microphysically, chemically) extreme episodes of air pollutant deposition. This study defines extreme aqueous events as having a pH < 3.1. pH's of this order are known to reduce laboratory tree growth depending on their age and species. On the average, one out of three aqueous events, sampled in the park during the 1986-1988 growing seasons (mid-May through mid-September), was extreme. Their occurrence over time may lead to the death of infant and 'old' trees, and to the reduced vigor of trees in their prime, as a result of triggering the decline mechanisms of these trees. These events usually last ~ 4.0 h, form during extended periods of high atmospheric pressure, have a liquid water content of ~ 0.10 gm^{-3}, and near typical cloud droplet sizes (~ 8.0 μm). Extreme aqueous events deposit most of their acid at their end. The deposition from the infrequent occurrences of very high ozone ( >=q100 ppb) and sulfur dioxide (>=q 5 ppb) concentrations in conjunction with these cloud events may be even more detrimental to the canopy, then that by extreme aqueous events alone. The physical characteristics of these combined events appear to include those of mature, precipitating clouds. Their occurrence may provide a clue as to how

  7. Forests

    Treesearch

    Louis R. Iverson; Mark W. Schwartz

    1994-01-01

    Originally diminished by development, forests are coming back: forest biomass is accumulating. Forests are repositories for many threatened species. Even with increased standing timber, however, biodiversity is threatened by increased forest fragmentation and by exotic species.

  8. Effects of calcite and magnesite application to a declining Masson pine forest on strongly acidified soil in Southwestern China.

    PubMed

    Huang, Yongmei; Kang, Ronghua; Ma, Xiaoxiao; Qi, Yu; Mulder, Jan; Duan, Lei

    2014-05-15

    Liming of strongly acidified soil under a Masson pine (Pinus massoniana Lamb.) forest was studied through a seven-year field manipulation experiment at Tieshanping, Chongqing in Southwestern China. To distinguish between the individual effects of Ca(2+) and Mg(2+) addition, we separately applied calcite (CaCO3) and magnesite (MgCO3), rather than using dolomite [CaMg(CO3)2]. Both calcite and magnesite additions caused a significant increase in pH and a decrease in dissolved inorganic monomeric aluminium (Ali) concentration of soil water. Ecological recovery included increases of herb biomass (both treatments) and Mg content in Masson pine needles (magnesite treatment only). However, the growth rate of Masson pine did not increase under either treatment, possibly because of nutrient imbalance due to phosphorus (P) deficiency or limited observation period. In China, acid deposition in forest ecosystems commonly coincides with large inputs of atmogenic Ca(2+), both enhancing Mg(2+) leaching. Calcite addition may further decrease the Mg(2+) availability in soil water, thereby exacerbating Mg(2+) deficiency in the acidified forest soils of southern and southwestern China. The effect of anthropogenic acidification of naturally acid forest soils on P availability needs further study. Copyright © 2014 Elsevier B.V. All rights reserved.

  9. Evaluating key landscape features of a climate- induced forest decline (Project WC-EM-07-01)

    Treesearch

    Paul Hennon; Dustin Wittwer

    2013-01-01

    Yellow-cedar is a culturally, economically, and ecologically important tree in coastal Alaska that has been experiencing a widespread mortality known as yellow-cedar decline for about 100 years. Mapping during annual aerial detection surveys has identified nearly the entire geographical distribution of the problem, which totals over 500,000 acres in Alaska (Lamb and...

  10. Growth decline and divergent tree ring isotopic composition (δ(13) C and δ(18) O) contradict predictions of CO2 stimulation in high altitudinal forests.

    PubMed

    Gómez-Guerrero, Armando; Silva, Lucas C R; Barrera-Reyes, Miguel; Kishchuk, Barbara; Velázquez-Martínez, Alejandro; Martínez-Trinidad, Tomás; Plascencia-Escalante, Francisca Ofelia; Horwath, William R

    2013-06-01

    Human-induced changes in atmospheric composition are expected to affect primary productivity across terrestrial biomes. Recent changes in productivity have been observed in many forest ecosystems, but low-latitude upper tree line forests remain to be investigated. Here, we use dendrochronological methods and isotopic analysis to examine changes in productivity, and their physiological basis, in Abies religiosa (Ar) and Pinus hartwegii (Ph) trees growing in high-elevation forests of central Mexico. Six sites were selected across a longitudinal transect (Transverse Volcanic Axis), from the Pacific Ocean toward the Gulf of Mexico, where mature dominant trees were sampled at altitudes ranging from 3200 to 4000 m asl. A total of 60 Ar and 84 Ph trees were analyzed to describe changes in growth (annual-resolution) and isotopic composition (decadal-resolution) since the early 1900s. Our results show an initial widespread increase in basal area increment (BAI) during the first half of the past century. However, BAI has decreased significantly since the 1950s with accentuated decline after the 1980s in both species and across sites. We found a consistent reduction in atmosphere to wood (13) C discrimination, resulting from increasing water use efficiency (20-60%), coinciding with rising atmospheric CO2 . Changes in (13) C discrimination were not followed, however, by shifts in tree ring δ(18) O, indicating site- and species-specific differences in water source or uptake strategy. Our results indicate that CO2 stimulation has not been enough to counteract warming-induced drought stress, but other stressors, such as progressive nutrient limitation, could also have contributed to growth decline. Future studies should explore the distinct role of resource limitation (water vs. nutrients) in modulating the response of high-elevation ecosystems to atmospheric change.

  11. Solar radiation and functional traits explain the decline of forest primary productivity along a tropical elevation gradient.

    PubMed

    Fyllas, Nikolaos M; Bentley, Lisa Patrick; Shenkin, Alexander; Asner, Gregory P; Atkin, Owen K; Díaz, Sandra; Enquist, Brian J; Farfan-Rios, William; Gloor, Emanuel; Guerrieri, Rossella; Huasco, Walter Huaraca; Ishida, Yoko; Martin, Roberta E; Meir, Patrick; Phillips, Oliver; Salinas, Norma; Silman, Miles; Weerasinghe, Lasantha K; Zaragoza-Castells, Joana; Malhi, Yadvinder

    2017-06-01

    One of the major challenges in ecology is to understand how ecosystems respond to changes in environmental conditions, and how taxonomic and functional diversity mediate these changes. In this study, we use a trait-spectra and individual-based model, to analyse variation in forest primary productivity along a 3.3 km elevation gradient in the Amazon-Andes. The model accurately predicted the magnitude and trends in forest productivity with elevation, with solar radiation and plant functional traits (leaf dry mass per area, leaf nitrogen and phosphorus concentration, and wood density) collectively accounting for productivity variation. Remarkably, explicit representation of temperature variation with elevation was not required to achieve accurate predictions of forest productivity, as trait variation driven by species turnover appears to capture the effect of temperature. Our semi-mechanistic model suggests that spatial variation in traits can potentially be used to estimate spatial variation in productivity at the landscape scale. © 2017 John Wiley & Sons Ltd/CNRS.

  12. History of sugar maple decline

    Treesearch

    David R. Houston

    1999-01-01

    Only a few episodes of sugar maple dieback or decline were recorded during the first half of the 20th Century. In contrast, the last 50 years have provided numerous reports of both urban and forest dieback/decline. In the late 1950s, a defoliation-triggered decline, termed maple blight, that occurred in Wisconsin prompted the first comprehensive, multidisciplinary...

  13. Arkansas forests

    Treesearch

    William W.S. van Hees

    1980-01-01

    The 1978 Arkansas Forest survey shows a 9 percent reduction in forest land area since 1969. Presently 16.6 million acres, 50 percent of the total State area, are forested. Diversions of forest land to agriculture, particularly to soybean fields in the Delta and to pasture in the Ozarks, account for most of the decline.

  14. Desiccation by Foliar Deposition of Hygroscopic Aerosols may link Air Pollution to Forest Decline and Tree Mortality associated with Global-Change-Type Drought

    NASA Astrophysics Data System (ADS)

    Burkhardt, J.; Grantz, D. A.; Hunsche, M.; Pariyar, S.; Sutton, M. A.; Zinsmeister, D.

    2016-12-01

    Leaf surfaces are a major sink for atmospheric aerosol deposition. Plants benefit from aerosol associated nutrients and are able to increase deposition by leaf surface micromorphology. Recent studies have shown that deposited hygroscopic aerosols can also influence plant water relations. This might be an important issue even for remote forest ecosystems, given the strong anthropogenic influence on aerosol production and efficient atmospheric transport. We study processes of aerosol deposition to plant surfaces and their impact on water relations and drought tolerance, both for experimental particle amendment and for aerosol exclusion in filtered air (FA). FA plants experience an environment with < 10% concentration of hygroscopic aerosols compared to ambient air (AA), but no difference in trace gases. Increasing particle concentration leads to decreasing water use efficiency and increasing minimum epidermal conductance (gmin; a measure of uncontrolled water loss inversely related to drought tolerance). After particle amendment, anisohydric beech seedlings increased transpiration and maintained photosynthesis, while isohydric pine seedlings maintained transpiration and tended to reduce photosynthesis. FA seedlings of pine, oak, and fir showed lower gmin than corresponding AA seedlings. The results support the concept of hydraulic activation of stomata (HAS) and an associated wick action caused by leaf surface particles. Concentrated salt solutions formed by hygroscopicity even in unsaturated air may create a thin liquid film that penetrates the stomatal pore, allowing evaporation of liquid water at the leaf surface. Increased gmin suggests the significance of this process under ambient conditions. The direct impact of air pollution on plant drought tolerance is poorly integrated in current scenarios of forest decline and tree mortality, but might represent an important component.

  15. Nutritional factors associated with decline in Canada

    Treesearch

    Benoit Cote

    1999-01-01

    Forest decline in eastern Canada was particuiarly severe in the early 1980's and is still prevalent in some areas (Bowers and Hopkin 1997). Early public and scientific opinions on the causes of forest decline were often not based on sound scientific knowledge. Factors such as acidic precipitation and ozone were rnost often mentioned as direct causes of forest...

  16. You can hide but you can’t run: apparent competition, predator responses and the decline of Arctic ground squirrels in boreal forests of the southwest Yukon

    PubMed Central

    Gillis, Elizabeth A.; Boonstra, Rudy; Krebs, Charles J.

    2016-01-01

    Throughout much of North America’s boreal forest, the cyclical fluctuations of snowshoe hare populations (Lepus americanus) may cause other herbivores to become entrained in similar cycles. Alternating apparent competition via prey switching followed by positive indirect effects are the mechanisms behind this interaction. Our purpose is to document a change in the role of indirect interactions between sympatric populations of hares and arctic ground squirrels (Urocitellus parryii plesius), and to emphasize the influence of predation for controlling ground squirrel numbers. We used mark-recapture to estimate the population densities of both species over a 25-year period that covered two snowshoe hare cycles. We analysed the strength of association between snowshoe hare and ground squirrel numbers, and the changes to the seasonal and annual population growth rates of ground squirrels over time. A hyperbolic curve best describes the per capita rate of increase of ground squirrels relative to their population size, with a single stable equilibrium and a lower critical threshold below which populations drift to extinction. The crossing of this unstable boundary resulted in the subsequent uncoupling of ground squirrel and hare populations following the decline phase of their cycles in 1998. The implications are that this sustained Type II predator response led to the local extinction of ground squirrels. When few individuals are left in a colony, arctic ground squirrels may also have exhibited an Allee effect caused by the disruption of social signalling of approaching predators. PMID:27635312

  17. SAYANI'91 - A joint United States/Commonwealth of Independent States field campaign to investigate forest decline damage in the Krasnoyarsk region of southcentral Siberia

    NASA Technical Reports Server (NTRS)

    Williams, D. L.; Kharuk, V. I.; Zhirin, V. M.; Rock, B. N.; Ranson, K. J.; Wessman, C. A.; Curtiss, B.

    1992-01-01

    The field experiment described took place in the Sayani Mountains of Siberia. The purpose of the joint field campaign was to observe and exchange methodologies with Russian scientists with regard to the development of remote sensing techniques for the early detection and assessment of forest decline damage believed to be associated with atmospheric deposition and/or insect and disease infestations. Several types of passive and active remote sensing measurements were made in conjunction with biophysical measurements on vegetative samples collected from four study sites representing a strong elevational gradient. Relatively cloud-free SPOT data were also acquired over the study area. Moderate canopy damage was recorded at the mid-elevation site (3400 ft/1037 m). The lowest levels of damage were recorded at the lowest elevation site (2300 ft/701 m.) At all sites, east versus west flagging of the canopy was noted (i.e., full canopy on the west-facing side of the canopy, significantly less foliage on the east-facing side).

  18. SAYANI'91 - A joint United States/Commonwealth of Independent States field campaign to investigate forest decline damage in the Krasnoyarsk region of southcentral Siberia

    NASA Technical Reports Server (NTRS)

    Williams, D. L.; Kharuk, V. I.; Zhirin, V. M.; Rock, B. N.; Ranson, K. J.; Wessman, C. A.; Curtiss, B.

    1992-01-01

    The field experiment described took place in the Sayani Mountains of Siberia. The purpose of the joint field campaign was to observe and exchange methodologies with Russian scientists with regard to the development of remote sensing techniques for the early detection and assessment of forest decline damage believed to be associated with atmospheric deposition and/or insect and disease infestations. Several types of passive and active remote sensing measurements were made in conjunction with biophysical measurements on vegetative samples collected from four study sites representing a strong elevational gradient. Relatively cloud-free SPOT data were also acquired over the study area. Moderate canopy damage was recorded at the mid-elevation site (3400 ft/1037 m). The lowest levels of damage were recorded at the lowest elevation site (2300 ft/701 m.) At all sites, east versus west flagging of the canopy was noted (i.e., full canopy on the west-facing side of the canopy, significantly less foliage on the east-facing side).

  19. You can hide but you can't run: apparent competition, predator responses and the decline of Arctic ground squirrels in boreal forests of the southwest Yukon.

    PubMed

    Werner, Jeffery R; Gillis, Elizabeth A; Boonstra, Rudy; Krebs, Charles J

    2016-01-01

    Throughout much of North America's boreal forest, the cyclical fluctuations of snowshoe hare populations (Lepus americanus) may cause other herbivores to become entrained in similar cycles. Alternating apparent competition via prey switching followed by positive indirect effects are the mechanisms behind this interaction. Our purpose is to document a change in the role of indirect interactions between sympatric populations of hares and arctic ground squirrels (Urocitellus parryii plesius), and to emphasize the influence of predation for controlling ground squirrel numbers. We used mark-recapture to estimate the population densities of both species over a 25-year period that covered two snowshoe hare cycles. We analysed the strength of association between snowshoe hare and ground squirrel numbers, and the changes to the seasonal and annual population growth rates of ground squirrels over time. A hyperbolic curve best describes the per capita rate of increase of ground squirrels relative to their population size, with a single stable equilibrium and a lower critical threshold below which populations drift to extinction. The crossing of this unstable boundary resulted in the subsequent uncoupling of ground squirrel and hare populations following the decline phase of their cycles in 1998. The implications are that this sustained Type II predator response led to the local extinction of ground squirrels. When few individuals are left in a colony, arctic ground squirrels may also have exhibited an Allee effect caused by the disruption of social signalling of approaching predators.

  20. Oak Decline

    Treesearch

    Philip M. Wargo; David R. Houston; Leon A. LaMadeleine

    1983-01-01

    Periodic occurrences of decline and death of oaks over widespread areas have been recorded since 1900. These outbreaks, variously named oak decline, oak dieback, or oak mortality, are caused by a complex interaction of environmental stresses and pests and given the name oak decline.

  1. Mountain pine beetle infestations and Sudden Aspen Decline in Colorado: Can the Forest Inventory and Analysis annual inventory system address the issues?

    Treesearch

    Michael T. Thompson

    2009-01-01

    There are two events occurring in Colorado that are concerning forest managers in Colorado. There is severe and widespread mortality of lodgepole pine due to the mountain pine beetle and aspen forests in some areas of the state have experienced widespread, severe, and rapid crown deterioration leading to mortality. Implementation of the Forest Inventory and Analysis...

  2. Hickory decline and mortality: Update on hickory decline research

    Treesearch

    Jennifer Juzwik; Ji-Huyn Park; Linda Haugen

    2010-01-01

    Research continued through the 2010 field season on the etiology of hickory decline that is characterized by thinning crowns with small, yellow leaves and hickory bark beetle attack on the upper main stem. This research is part of a larger project initiated in 2006 to assess the distribution and determine the cause(s) of Forest Health Monitoring reported decline and...

  3. Recognizing and preventing maple decline

    Treesearch

    James W. Walters

    1992-01-01

    Maple decline (i.e. maple blight, maple dieback) has periodically caused significant losses of sugar maple in northern hardwood forests. The first major outbreak of maple decline was reported in northeastern Wisconsin and upper Michigan in the late 1950's. The disease reappeared in the same general area during the late 1970's and early 1980's.

  4. Intellectual Decline.

    ERIC Educational Resources Information Center

    Guilford, J.P.

    In investigations of decline of intellectual status with age, cross-sectional and longitudinal studies give divergent results--the former show almost universal declines in test performances among older groups while the latter often show gains. Although few structure-of-intellect (SI) factors have been explored in relation to adult ages, two kinds…

  5. Intellectual Decline.

    ERIC Educational Resources Information Center

    Guilford, J.P.

    In investigations of decline of intellectual status with age, cross-sectional and longitudinal studies give divergent results--the former show almost universal declines in test performances among older groups while the latter often show gains. Although few structure-of-intellect (SI) factors have been explored in relation to adult ages, two kinds…

  6. Long-term changes in forest composition and diversity following early logging (1919-1923) and the decline of American chestnut (Castanea dentata)

    Treesearch

    Katherine J. Elliott; Wayne T. Swank

    2008-01-01

    Chestnut blight fungus (Endothia parasitica [Murr.] P.I. And. & H.W. And. is a classic example of an invasive species, which severely damaged populations of its host, Castanea dentata, and had widespread and long-term impacts on eastern North American forests. Concurrently, forests were further disturbed by lumbering, which was common across the...

  7. Evaluation of autophagy as a mechanism involved in air pollutant-induced pulmonary injury

    EPA Science Inventory

    Evaluation of autophagy as a mechanism involved in air pollutant-induced pulmonary injuryHenriquez, A.1, Snow, S.2, Miller, D1.,Schladweiler, M.2 and Kodavanti, U2.1 Curriculum in Toxicology, UNC, Chapel Hill, NC. 2 EPHD/NHEERL, US EPA, RTP, Durham, NC. ...

  8. Evaluation of autophagy as a mechanism involved in air pollutant-induced pulmonary injury

    EPA Science Inventory

    Evaluation of autophagy as a mechanism involved in air pollutant-induced pulmonary injuryHenriquez, A.1, Snow, S.2, Miller, D1.,Schladweiler, M.2 and Kodavanti, U2.1 Curriculum in Toxicology, UNC, Chapel Hill, NC. 2 EPHD/NHEERL, US EPA, RTP, Durham, NC. ...

  9. NOVEL INSIGHTS INTO THE MECHANISM OF SUBCHRONIC AIR POLLUTANT-INDUCED CARDIOVASCULAR IMPAIRMENT

    EPA Science Inventory

    The mechanisms by which air pollutants induce cardiovascular mortality are unknown. We hypothesized that blood vessels are the target of injury by circulating oxidation by-products following pollutant exposure. We exposed male Wistar Kyoto rats (12-15 wks old), nose-only to air, ...

  10. NOVEL INSIGHTS INTO THE MECHANISM OF SUBCHRONIC AIR POLLUTANT-INDUCED CARDIOVASCULAR IMPAIRMENT

    EPA Science Inventory

    The mechanisms by which air pollutants induce cardiovascular mortality are unknown. We hypothesized that blood vessels are the target of injury by circulating oxidation by-products following pollutant exposure. We exposed male Wistar Kyoto rats (12-15 wks old), nose-only to air, ...

  11. Declining Enrollments.

    ERIC Educational Resources Information Center

    Wakefield, Howard E.; Donnelly, Richard A.

    The five sections in this loose-leaf binder are intended to provide Wisconsin school board members with information necessary for decision-making on the problem of declining enrollment. Section 1 contains information about the extent of the problem and summarizes recent trends in population and school enrollments in the nation and the state.…

  12. Growth declines in red spruce

    SciTech Connect

    Zedaker, S.M.; Hyink, D.M.; Smith, D.W.

    1987-01-01

    Over the past two decades second-growth red spruce stands in the Northeast have demonstrated declines in radial increment. Some observers are implicating air pollution as a primary cause of the declines, based on recently acquired increment cores from dominant trees. Various forms of air pollution (O/sub 3/, NO/sub x/, SO/sub 2/, and trace metals) are known to reduce growth and development of tree species, but few studies have provided concrete evidence of regional pollution-caused declines in forest ecosystems. Recently published evidence of a synchronous, consistent, and unprecedented regional decline in red spruce should be weighed against the realization that radial increment in red spruce declines naturally as stands age. Separating anthropogenic stress-caused growth patterns from natural stand dynamics requires an in-depth knowledge of forest growth and yield, tree silvics, and forest ecosystem processes. Detailed analyses of growth by stand characteristics - site index, density, elevation, stand history - will be necessary to implicate air pollution as a primary cause of red spruce decline.

  13. Simulated nitrogen deposition causes a decline of intra- and extraradical abundance of arbuscular mycorrhizal fungi and changes in microbial community structure in northern hardwood forests

    Treesearch

    Linda T.A. van Diepen; Erik A. Lilleskov; Kurt S. Pregitzer; R. Michael. Miller

    2010-01-01

    Increased nitrogen (N) deposition caused by human activities has altered ecosystem functioning and biodiversity. To understand the effects of altered N availability, we measured the abundance of arbuscular mycorrhizal fungi (AMF) and the microbial community in northern hardwood forests exposed to long-term (12 years) simulated N deposition (30 kg N ha-1...

  14. Louisiana forests

    Treesearch

    Herbert S. Sternitzke

    1965-01-01

    The total amount of forest land in Louisiana is virtually the same today as it was a decade ago. But its distribution has changed noticeably. In the Delta, for example, forest acreage is still declining; between 1954 and 1964, it dropped some 7 percent, thus closely paralleling trends in the Delta sections of neighboring Arkansas and Mississippi. Outside the Delta,...

  15. Satellite-derived estimates of forest leaf area index in southwest Western Australia are not tightly coupled to interannual variations in rainfall: implications for groundwater decline in a drying climate.

    PubMed

    Smettem, Keith R J; Waring, Richard H; Callow, John N; Wilson, Melissa; Mu, Qiaozhen

    2013-08-01

    There is increasing concern that widespread forest decline could occur in regions of the world where droughts are predicted to increase in frequency and severity as a result of climate change. The average annual leaf area index (LAI) is an indicator of canopy cover and the difference between the annual maximum and minimum LAI is an indicator of annual leaf turnover. In this study, we analyzed satellite-derived estimates of monthly LAI across forested coastal catchments of southwest Western Australia over a 12 year period (2000-2011) that included the driest year on record for the last 60 years. We observed that over the 12 year study period, the spatial pattern of average annual satellite-derived LAI values was linearly related to mean annual rainfall. However, interannual changes to LAI in response to changes in annual rainfall were far less than expected from the long-term LAI-rainfall trend. This buffered response was investigated using a physiological growth model and attributed to availability of deep soil moisture and/or groundwater storage. The maintenance of high LAIs may be linked to a long-term decline in areal average underground water storage and diminished summer flows, with an emerging trend toward more ephemeral flow regimes. © 2013 John Wiley & Sons Ltd.

  16. North Carolina's forests, 2002

    Treesearch

    Mark J. Brown; Barry D. New; Sonja N. Oswalt; Tony G. Johnson; Victor A. Rudis

    2006-01-01

    In 2002, forests covered 18.3 million acres in North Carolina, of which 17.7 million were classified as timberland. Hardwood forest types prevailed on 72 percent of timberland and planted pine stands occupied 15 percent. Nonindustrial private forest landowners controlled 78 percent of timberland, forest industry holdings declined to 8 percent, and publicly owned...

  17. Iowa's forest resources, 1974.

    Treesearch

    John S. Jr. Spencer; Pamela J. Jakes

    1980-01-01

    The second inventory of Iowa's forest resources shows big declines in commercial forest area and in growing-stock and sawtimber volumes between 1954 and 1974. Presented are text and statistics on forest area and timber volume, growth, mortality, ownership, stocking, future timber supply, timber use, forest management opportunities, and nontimber resources.

  18. Long-term changes in the acidity of a dekalb forest soil in the mid-region of the Susquehanna River Watershed

    Treesearch

    Joy R. Robert; William E. Sharpe

    1996-01-01

    Forest soil acidification has been reported to result in reduced forest productivity and forest decline. Soil acidification and forest decline may trigger changes in nutrient cycling in forest ecosystems with important consequences for drainage water chemistry and aquatic biota.

  19. Mapping young forest in Wisconsin

    Treesearch

    Mark Nelson; Kirk Stueve; Charles Perry; Dale Gormanson; Chengquan Huang; Sean. Healey

    2012-01-01

    Population declines of early successional forest-associated wildlife species have been linked to declines in habitat abundance. Forest Inventory and Analysis (FIA) data can be used to estimate composition and change in 'young' forest, but such information typically lacks spatial specificity for determining landscape patterns that also affect habitat...

  20. Arkansas forest resource patterns

    Treesearch

    Charles C. Van Sickle

    1970-01-01

    A new forest survey of Arkansas reveals that forests cover 55 percent of the land in the State. In all, 18.2 million acres are available for and capable of growing industrial timber. Substantial change has occurred in the timber resource. In the 10 years preceding the new survey, forest area declined by one-eighth . Clearing for cropland and pasture claimed...

  1. Seasonal and pollution-induced variations in biomarkers of transplanted mussels within the Beagle Channel.

    PubMed

    Giarratano, Erica; Gil, Mónica N; Malanga, Gabriela

    2011-06-01

    The occurrence of biomarker variations linked to environmental factors makes it difficult to distinguish the effect of pollution. In an attempt to evaluate spatial and seasonal effects of environmental parameters on biomarker responses, mussels Mytilus edulis chilensis coming from an aquaculture farm were transplanted to several points within Ushuaia Bay (Beagle Channel) for 6 weeks in summer and winter. Activities of superoxide dismutase, catalase, glutathione-S-transferase and levels of lipid peroxidation were measured in gills and digestive gland. Cu, Zn, Fe, Cd and Pb concentrations were also assessed. Results indicated a significant effect of seasons on biological responses as well as in metal bioaccumulation showing the influence of natural factors such as dissolved oxygen, temperature and food availability. The interdependence of those environmental factors is important for the homeostasis of thermoconformers, especially regarding their oxidative metabolism and should also be taken into consideration to distinguish natural from pollution-induced variations.

  2. Linking pollution induced community tolerance (PICT) and microbial community structure in chronically metal polluted estuarine sediments.

    PubMed

    Ogilvie, Lesley A; Grant, Alistair

    2008-03-01

    We tested the ability of pollution induced community tolerance (PICT) to detect the effects of chronic metal pollution on estuarine sediment microbial communities, along a gradient spanning two orders of magnitude in metal concentrations. In tandem, we investigated the associated microbial community structure using terminal restriction fragment length polymorphism (T-RFLP). Tolerance of microbes to Cu, measured as IC50 (inhibitory concentration 50%), was strongly correlated with pore water Cu concentration (r(2)=0.842). No strong correlation existed for other metals tested, highlighting the ability of PICT to identify the pollutant causing a toxic effect. There was no correlation between microbial community structure and community tolerance to metals tested, but analysis of community structure did provide some information on reasons for observed PICT response. PICT methodology used here provided a greater strength and consistency of association with pollutant concentration compared to microbial community structure and can be recommended as a sensitive indicator of metal pollution on estuarine sediment microbial communities.

  3. Decline as a disease category: Is it helpful?

    Treesearch

    M.E. Ostry; R.C. Venette; J. Juzwik

    2011-01-01

    Many, but not all, forest pathologists use "decline" to describe forest tree diseases of complex etiology. We contend that this distinction from abiotic or biotic diseases is completely arbitrary, has caused undue confusion, and provides no practical insights for forest managers. All diseases are complex and can be characterized within the conceptual...

  4. DO ACUTE PHASE PROTEINS REFLECT SEVERITY OF INFLAMMATION IN RAT MODELS OF POLLUTANT-INDUCED LUNG INJURY?

    EPA Science Inventory

    Title: DO ACUTE PHASE PROTEINS REFLECT THE SEVERITY OF INFLAMMATION IN RAT MODELS OF POLLUTANT-INDUCED LUNG INJURY?

    M. C. Schladweiler, BS 1, P. S. Gilmour, PhD 2, D. L. Andrews, BS 1, D. L. Costa, ScD 1, A. D. Ledbetter, BS 1, K. E. Pinkerton, PhD 3 and U. P. Kodavanti, ...

  5. DO ACUTE PHASE PROTEINS REFLECT SEVERITY OF INFLAMMATION IN RAT MODELS OF POLLUTANT-INDUCED LUNG INJURY?

    EPA Science Inventory

    Title: DO ACUTE PHASE PROTEINS REFLECT THE SEVERITY OF INFLAMMATION IN RAT MODELS OF POLLUTANT-INDUCED LUNG INJURY?

    M. C. Schladweiler, BS 1, P. S. Gilmour, PhD 2, D. L. Andrews, BS 1, D. L. Costa, ScD 1, A. D. Ledbetter, BS 1, K. E. Pinkerton, PhD 3 and U. P. Kodavanti, ...

  6. Oak decline risk rating for the southeastern United States

    Treesearch

    S. Oak; F. Tainter; J. Williams; D. Starkey

    1996-01-01

    Oak decline risk rating models were developed for upland hardwood forests in the southeastern United States using data gathered during regional oak decline surveys. Stepwise discriminant analyses were used to relate 12 stand and site variables with major oak decline incidence for each of three subregions plus one incorporating all subregions. The best model for the...

  7. Oak Decline in Missouri: History Revisited

    Treesearch

    Jay R. Law; Ross Melick; Charly Studyvin; James R. Steinman

    2004-01-01

    In the 1980s, following extreme winters in the late 1970s and severe droughts in 1976, 1980, and 1983, dead and dying scarlet and black oaks were found on 185,000 acres of the Mark Twain National Forest. That decline event was linked to environmental stresses (Law and Gott 1987). Severe oak decline is now affecting an estimated 500,000 acres on the Mark Twain. High-...

  8. Rapid method for assessing pollution-induced community tolerance in contaminated soil

    SciTech Connect

    Rutgers, M.; Verlaat, I.M. van`t; Wind, B.; Posthuma, L.; Breure, A.M.

    1998-11-01

    Using the pollution-induced community tolerance (PICT) concept, this article presents a rapid method for detecting toxic effects of contaminated soil on soil microbial communities and for elucidating the causal relationship between exposure history and toxic effects in exposed microbial communities. The method is based on the use of multiwell plates (Biolog{reg_sign}) for producing concentration versus effect relationships for (maximally) 95 different microbial metabolic activities. For this, artificial exposure in the multiwell plate is established to the contaminant supposedly causing toxic effects in the field. The method was tested in a gradient of zinc-contaminated field plots by studying community tolerance to zinc. For most substrates the metabolic activities showed an increased community tolerance for zinc with increased zinc concentration in the field. Consequently, PICT has evolved after 2.5 years of zinc exposure under field conditions. The perspectives for future use of the PICT concept in combination with the multiwell technique for demonstrating ecotoxicological effects of contaminated sites is exemplified by the comparison of Dutch soil quality criteria for zinc with the collected data. This comparison showed that the evolution of microbial-PICT for zinc has occurred at environmental concentrations near the Dutch intervention value, a quality criterion linked to remediation urgency.

  9. Pollution-Induced Community Tolerance To Diagnose Hazardous Chemicals in Multiple Contaminated Aquatic Systems.

    PubMed

    Rotter, Stefanie; Gunold, Roman; Mothes, Sibylle; Paschke, Albrecht; Brack, Werner; Altenburger, Rolf; Schmitt-Jansen, Mechthild

    2015-08-18

    Aquatic ecosystems are often contaminated with large numbers of chemicals, which cannot be sufficiently addressed by chemical target analyses. Effect-directed analysis (EDA) enables the identification of toxicants in complex contaminated environmental samples. This study suggests pollution-induced community tolerance (PICT) as a confirmation tool for EDA to identify contaminants which actually impact on local communities. The effects of three phytotoxic compounds local periphyton communities, cultivated at a reference (R-site) and a polluted site (P-site), were assessed to confirm the findings of a former EDA study on sediments. The sensitivities of R- and P-communities to prometryn, tributyltin (TBT) and N-phenyl-2-naphthylamine (PNA) were quantified in short-term toxicity tests and exposure concentrations were determined. Prometryn and PNA concentrations were significantly higher at the P-site, whereas TBT concentrations were in the same range at both sites. Periphyton communities differed in biomass, but algal class composition and diatom diversity were similar. Community tolerance of P-communities was significantly enhanced for prometryn, but not for PNA and TBT, confirming site-specific effects on local periphyton for prometryn only. Thus, PICT enables in situ effect confirmation of phytotoxic compounds at the community level and seems to be suitable to support confirmation and enhance ecological realism of EDA.

  10. Mechanisms of pollution induced community tolerance in a soil microbial community exposed to Cu.

    PubMed

    Wakelin, Steven; Gerard, Emily; Black, Amanda; Hamonts, Kelly; Condron, Leo; Yuan, Tong; van Nostrand, Joy; Zhou, Jizhong; O'Callaghan, Maureen

    2014-07-01

    Pollution induced community tolerance (PICT) to Cu(2+), and co-tolerance to nanoparticulate Cu, ionic silver (Ag(+)), and vancomycin were measured in field soils treated with Cu(2+) 15 years previously. EC50 values were determined using substrate induced respiration and correlations made against soil physicochemical properties, microbial community structure, physiological status (qCO2; metabolic quotient), and abundances of genes associated with metal and antibiotic resistance. Previous level of exposure to copper was directly (P < 0.05) associated with tolerance to addition of new Cu(2+), and also of nanoparticle Cu. However, Cu-exposed communities had no co-tolerance to Ag(+) and had increased susceptibly to vancomycin. Increased tolerance to both Cu correlated (P < 0.05) with increased metabolic quotient, potentially indicating that the community directed more energy towards cellular maintenance rather than biomass production. Neither bacterial or fungal community composition nor changes in the abundance of genes involved with metal resistance were related to PICT or co-tolerance mechanisms.

  11. The Management of Decline

    ERIC Educational Resources Information Center

    Boulding, Kenneth E.

    1975-01-01

    With the probability of declining enrollments education needs, according to the author, to develop administrators skilled in adjusting to decline. He notes what educators can learn from the decline of agriculture and railroads and points up the need to get out from under the grants economy. (JT)

  12. The Dilemma of Decline.

    ERIC Educational Resources Information Center

    Abramowitz, Susan

    This paper, one of two related documents, examines the impact of declining enrollments on educational expenditures. It highlights population and social changes that have contributed to the decline and discusses the general financing of schools. Finally, the paper discusses strategies state policymakers can use to manage decline, including…

  13. Adolescence Intellectual Decline.

    ERIC Educational Resources Information Center

    Campbell, Patricia B.

    The purposes of this study were to investigate adolescent intellectual decline, and to attempt to determine some of the sexual differences possibly inherent in the phenomenon. It was hypothesized that (1) girls would decline in greater numbers and to a greater degree than boys; and (2) areas and amounts of sex differences of the decliners would…

  14. Butternut Decline (Pest Alert)

    Treesearch

    USDA Forest Service; Northeastern Area, State and Private Forestry

    A decline of butternut has been noted in Wisconsin, Minnesota, Iowa, and Illinois for the past several years. The causes are being investigated and we need additional information on the occurrence of the problem. We also need to know if the problem is found on walnut. Symptoms of decline include trunk and branch cankers with subsequent dieback of the crown. Decline...

  15. Remote Sensing of Forest Health Indicators for Assessing Change in Forest Health

    Treesearch

    Michael K. Crosby; Zhaofei Fan; Martin A. Spetich; Theodor D. Leininger

    2012-01-01

    Oak decline poses a substantial threat to forest health in the Ozark Highlands of northern Arkansas and southern Missouri, where coupled with diseases and insect infestations, it has damaged large tracts of forest lands. Forest Health Monitoring (FHM) crown health indicators (e.g. crown dieback, etc.), collected by the U.S. Forest Service’s Forest Inventory and...

  16. Global Forest Area Trends Underestimate Threats from Forest Fragmentation

    EPA Science Inventory

    Forest loss and fragmentation of the remainder threaten the ecological attributes and functions which depend upon forests1. Forest interior area is particularly valued because it is relatively remote from human influence2, 3, 4, 5. Recent global assessments report declines in t...

  17. Global Forest Area Trends Underestimate Threats from Forest Fragmentation

    EPA Science Inventory

    Forest loss and fragmentation of the remainder threaten the ecological attributes and functions which depend upon forests1. Forest interior area is particularly valued because it is relatively remote from human influence2, 3, 4, 5. Recent global assessments report declines in t...

  18. East Oklahoma forests

    Treesearch

    Herbert S. Sternitzke; Charles C. van Sickle

    1968-01-01

    The 17 counties designated as east Oklahoma in this report encompass the main belt of commercial timberland in the State (fig. 1). Forests occupy 5.5 million acres or some 57 percent of the total land area. During the decade that elapsed between the 1956 and 1966 surveys, the acreage of forest land declined about 5 percent. The modest drop in forest area was largely...

  19. Assessing the threat that anthropogenic calcium depletion poses to forest health and productivity

    Treesearch

    Paul G. Schaberg; Eric K. Miller; Christopher. Eagar

    2010-01-01

    Growing evidence from around the globe indicates that anthropogenic factors including pollution-induced acidification, associated aluminum mobility, and nitrogen saturation are disrupting natural nutrient cycles and depleting base cations from forest ecosystems. Although cation depletion can have varied and interacting influences on ecosystem function, it is the loss...

  20. What is forest landscape restoration?

    Treesearch

    David Lamb; John Stanturf; Palle Madsen

    2012-01-01

    The extent and distribution of global forests is a matter of considerable concern. The overall rate of deforestation remains high although recent reports suggest it is fi nally beginning to decline (FAO 2011 ) . But this hides regional differences. In temperate regions net forest cover is increasing because of afforestation and natural expansion of forests. By contrast...

  1. Assessment of Loblolly Pine Decline in Central Alabama

    Treesearch

    Nolan J. Hess; William J. Otrosina; Emily A. Carter; Jim R. Steinman; John P. Jones; Lori G. Eckhardt; Ann M. Weber; Charles H. Walkinshaw

    2002-01-01

    Loblolly pine (Pinus taeda L.) decline has been prevalent on upland sites of central Alabama since the 1960's. The purpose of this study was to compare Forest Health Monitoring (FHM) standards and protocols with root health evaluations relative to crown, stem, and site measurements. Thirty-nine 1/6 acre plots were established on loblolly decline...

  2. Decline of Ohia (Metrosideros polymorpha) in Hawaii: a review

    Treesearch

    Charles S. Hodges; Ken T. Adee; John D. Stein; Hulton B. Wood; Robert D. Doty

    1986-01-01

    Portions of the ohia (Metrosideros polymorpha) forests on the windward slopes of Mauna Loa and Mauna Kea on the island of Hawaii began dying in 1952. Little mortality has occurred since 1972. About 50,000 ha are affected by the decline. Individual trees exhibit several symptoms, from slow progressive dieback to rapid death. Seven types of decline...

  3. State of pine decline in the southeastern United States

    Treesearch

    Lori Eckhardt; Mary Anne Sword Sayer; Don Imm

    2010-01-01

    Pine decline is an emerging forest health issue in the southeastern United States. Observations suggest pine decline is caused by environmental stress arising from competition, weather, insects and fungi, anthropogenic disturbances, and previous management. The problem is most severe for loblolly pine on sites that historically supported longleaf pine, are highly...

  4. Forest Sustainability in the Northern United States

    Treesearch

    Sherri Wormstead

    2006-01-01

    Are populations of songbirds declining? Are we harvesting more timber than we grow? How healthy and productive are our forests? What will happen to our forests if current rates of development continue? How will forest fragmentation and loss impact water and air quality, recreation, and our country?s forest related economy?

  5. Forest Area in North Dakota, 1980

    Treesearch

    Ronald L. Hackett

    1982-01-01

    In 1980 North Dakota's forest resources covered 518,100 acres of land, a slight decline from 572,400 acres reported in 1954. The area of commercial forest land also dropped from 398,400 acres to 343,200 acres. The aspen forest type makes up 41 percent of the commercial forest area.

  6. Forest Area in Eastern South Dakota, 1980

    Treesearch

    Thomas L. Castonguay

    1982-01-01

    In 1980 eastern South Dakota's forest resources covered 266,300 acres of land, a slight decline from the 296,600 acres reported in 1965. The area of commercial forest land also dropped from 165,400 acres to 113,600 acres. The elm-ash-locust forest type covers 40 percent of the commercial forest area.

  7. Declining Enrollment. Research Report.

    ERIC Educational Resources Information Center

    National School Boards Association, Washington, DC.

    Population growth in the United States has declined since the early 1970s. As a result of the lower birth rate and changing migration patterns, approximately one-third of the school districts in the country have experienced some drop in enrollment. Smaller districts are the hardest hit by enrollment decline, since they are less able to absorb the…

  8. Diagnosing School Decline

    ERIC Educational Resources Information Center

    Duke, Daniel L.

    2008-01-01

    One of the most important strategies for stopping school decline is recognizing its signs early on and promptly applying appropriate interventions. In this article, the author identifies 11 indicators of school decline that are associated with inadequate and inappropriate responses to the challenges of budget cuts, state and federal mandates, loss…

  9. Diagnosing School Decline

    ERIC Educational Resources Information Center

    Duke, Daniel L.

    2008-01-01

    One of the most important strategies for stopping school decline is recognizing its signs early on and promptly applying appropriate interventions. In this article, the author identifies 11 indicators of school decline that are associated with inadequate and inappropriate responses to the challenges of budget cuts, state and federal mandates, loss…

  10. Disruption of calcium nutrition at Hubbard Brook Experimental Forest (New Hampshire) alters the health and productivity of red spruce and sugar maple trees and provides lessons pertinent to other sites and regions

    Treesearch

    Paul G. Schaberg; Gary J. Hawley

    2010-01-01

    Pollution-induced acidification and other anthropogenic factors are leaching calcium (Ca) and mobilizing aluminum (Al) in many forest soils. Because Ca is an essential nutrient and Al is a potential toxin, resulting depletions of Ca and increases in available Al may significantly alter the health and productivity of forest trees. Controlled experiments on red spruce (...

  11. Emergent insects, pathogens and drought shape changing patterns in oak decline in North America and Europe

    Treesearch

    Laurel J. Haavik; Sharon A. Billings; James M. Guldin; Fred M. Stephen

    2015-01-01

    Forest declines are well-studied phenomena. However, recent patterns suggest that the traditional sequence of events and factors involved in forest decline are changing. Several reports in recent decades involve emergent mortality agents, many of which are native insects and diseases. In addition, changing climate and weather patterns place increasing emphasis on root...

  12. Oak decline across the Ozark Highlands- from stand to landscape and regional scale processes

    Treesearch

    Marty Spetich; Zhaofei Fan; Hong S. He; Wen J. Wang; Michael K. Crosby; Stephen R. Shifley

    2016-01-01

    Oak decline has been a problem in forests of the Ozark Highlands (OzH) for decades. It has impacted upland oak-hickory forests, particularly species in the red oak group (Quercus section Lobatae) across the Ozark Highlands of Missouri, Arkansas, and Oklahoma. The oak decline complex is often described in terms of predisposing...

  13. The status of forest management research in the United States.

    Treesearch

    Donald G. Hodges; Pamela J. Jakes; Frederick W. Cubbage

    1988-01-01

    In 1985, the USDA Forest Service invested nearly $30 million in forest management research, forest industry invested $19 million, and universities invested at least $17 million. Investments in this research have been declining since then. Forest Service data indicate that the public sector is the largest beneficiary of forest management research.

  14. ForestCrowns: a transparency estimation tool for digital photographs of forest canopies

    Treesearch

    Matthew Winn; Jeff Palmer; S.-M. Lee; Philip Araman

    2016-01-01

    ForestCrowns is a Windows®-based computer program that calculates forest canopy transparency (light transmittance) using ground-based digital photographs taken with standard or hemispherical camera lenses. The software can be used by forest managers and researchers to monitor growth/decline of forest canopies; provide input for leaf area index estimation; measure light...

  15. Forest health and global change.

    PubMed

    Trumbore, S; Brando, P; Hartmann, H

    2015-08-21

    Humans rely on healthy forests to supply energy, building materials, and food and to provide services such as storing carbon, hosting biodiversity, and regulating climate. Defining forest health integrates utilitarian and ecosystem measures of forest condition and function, implemented across a range of spatial scales. Although native forests are adapted to some level of disturbance, all forests now face novel stresses in the form of climate change, air pollution, and invasive pests. Detecting how intensification of these stresses will affect the trajectory of forests is a major scientific challenge that requires developing systems to assess the health of global forests. It is particularly critical to identify thresholds for rapid forest decline, because it can take many decades for forests to restore the services that they provide. Copyright © 2015, American Association for the Advancement of Science.

  16. Declining fertility in Nepal.

    PubMed

    Das Dangol, B; Retherford, R D; Thapa, S

    1997-03-01

    This article relies on data from the 1991 Nepal Fertility, Family Planning, and Health Survey (NFFPHS) and the 1996 Nepal Living Standards Survey (NLSS) to assess trends in fertility in Nepal. The NFFPHS shows heaping at ages 5, 8, 10, and 12 years and a larger proportion of infants. The NLSS shows a different pattern of misreporting of youth and a stronger but similar pattern of age heaping as the NFFPHS for adults. Children ever born by maternal age indicates a degree of completeness and the deletion by older women of deceased children and married children living outside the household. Findings suggest less complete reporting in the NLSS. Age-specific fertility rates are calculated based on birth histories (BH) and the own-children (OC) method based on life tables. Findings indicate that BH and OC estimates of the cumulative fertility rate (CFR) derived from the NLSS and the NFFPHS were comparable for estimating trends in the total fertility rate (TFR). The trends from the two data sets overlapped fairly well during 1983-89. Fertility trends by single years of age showed considerably annual fluctuations due to age misreporting. The CFR and TFR for aggregated time periods showed little or no decline for the earlier 5-year period, a steeper decline in the second period, and variations in trends by data set for the third period from 1983 to 1989. One curve showed no decline and the other showed fertility decline. Fitting a straight line to the trend for 1977-91 shows that CFR declined by 1.61 children from 5.29 children in 1977 to 3.68 children in 1991. TFR declined by 1.90 children from 6.68 children in 1977 to 4.78 children in 1991. The author cautions that the point of fertility decline was not determined exactly, but data suggest that decline occurred around 1980, and the rate was fast thereafter. TFR declined by 2.70 children in urban areas and 1.83 children in rural areas.

  17. Urban Decline and Durable Housing.

    ERIC Educational Resources Information Center

    Glaeser, Edward L.; Gyourko, Joseph

    2005-01-01

    Urban decline is not the mirror image of growth, and durable housing is the primary reason the nature of decline is so different. This paper presents a model of urban decline with durable housing and verifies these implications of the model: (1) city growth rates are skewed so that cities grow more quickly than they decline; (2) urban decline is…

  18. Pollutant-induced cell death and reactive oxygen species accumulation in the aerial roots of Chinese banyan (Ficus microcarpa)

    PubMed Central

    Liu, Nan; Cao, Ce; Sun, Zhongyu; Lin, Zhifang; Deng, Rufang

    2016-01-01

    Industrial pollutants induce the production of toxic reactive oxygen species (ROS) such as O2.−, H2O2, and ·OH in plants, but they have not been well quantified or localized in tissues and cells. This study evaluated the pollutant- (HSO3−, NH4NO3, Al3+, Zn2+, and Fe2+) induced toxic effects of ROS on the aerial roots of Chinese banyan (Ficus microcarpa). Root cell viability was greatly reduced by treatment with 20 mM NaHSO3, 20 mM NH4NO3, 0.2 mM AlCl3, 0.2 mM ZnSO4, or 0.2 mM FeSO4. Biochemical assay and histochemical localization showed that O2.− accumulated in roots in response to pollutants, except that the staining of O2.− under NaHSO3 treatment was not detective. Cytochemical localization further indicated that the generated O2.− was present mainly in the root cortex, and pith cells, especially in NH4NO3- and FeSO4-treated roots. The pollutants also caused greatly accumulated H2O2 and ·OH in aerial roots, which finally resulted in lipid peroxidation as indicated by increased malondialdehyde contents. We conclude that the F. microcarpa aerial roots are sensitive to pollutant-induced ROS and that the histochemical localization of O2.− via nitrotetrazolium blue chloride staining is not effective for detecting the effects of HSO3− treatment because of the treatment’s bleaching effect. PMID:27805029

  19. Pollutant-induced cell death and reactive oxygen species accumulation in the aerial roots of Chinese banyan (Ficus microcarpa).

    PubMed

    Liu, Nan; Cao, Ce; Sun, Zhongyu; Lin, Zhifang; Deng, Rufang

    2016-11-02

    Industrial pollutants induce the production of toxic reactive oxygen species (ROS) such as O2(.-), H2O2, and (·)OH in plants, but they have not been well quantified or localized in tissues and cells. This study evaluated the pollutant- (HSO3(-), NH4NO3, Al(3+), Zn(2+), and Fe(2+)) induced toxic effects of ROS on the aerial roots of Chinese banyan (Ficus microcarpa). Root cell viability was greatly reduced by treatment with 20 mM NaHSO3, 20 mM NH4NO3, 0.2 mM AlCl3, 0.2 mM ZnSO4, or 0.2 mM FeSO4. Biochemical assay and histochemical localization showed that O2(.-) accumulated in roots in response to pollutants, except that the staining of O2(.-) under NaHSO3 treatment was not detective. Cytochemical localization further indicated that the generated O2(.-) was present mainly in the root cortex, and pith cells, especially in NH4NO3- and FeSO4-treated roots. The pollutants also caused greatly accumulated H2O2 and (·)OH in aerial roots, which finally resulted in lipid peroxidation as indicated by increased malondialdehyde contents. We conclude that the F. microcarpa aerial roots are sensitive to pollutant-induced ROS and that the histochemical localization of O2(.-) via nitrotetrazolium blue chloride staining is not effective for detecting the effects of HSO3(-) treatment because of the treatment's bleaching effect.

  20. Pollutant-induced cell death and reactive oxygen species accumulation in the aerial roots of Chinese banyan (Ficus microcarpa)

    NASA Astrophysics Data System (ADS)

    Liu, Nan; Cao, Ce; Sun, Zhongyu; Lin, Zhifang; Deng, Rufang

    2016-11-01

    Industrial pollutants induce the production of toxic reactive oxygen species (ROS) such as O2.‑, H2O2, and ·OH in plants, but they have not been well quantified or localized in tissues and cells. This study evaluated the pollutant- (HSO3‑, NH4NO3, Al3+, Zn2+, and Fe2+) induced toxic effects of ROS on the aerial roots of Chinese banyan (Ficus microcarpa). Root cell viability was greatly reduced by treatment with 20 mM NaHSO3, 20 mM NH4NO3, 0.2 mM AlCl3, 0.2 mM ZnSO4, or 0.2 mM FeSO4. Biochemical assay and histochemical localization showed that O2.‑ accumulated in roots in response to pollutants, except that the staining of O2.‑ under NaHSO3 treatment was not detective. Cytochemical localization further indicated that the generated O2.‑ was present mainly in the root cortex, and pith cells, especially in NH4NO3- and FeSO4-treated roots. The pollutants also caused greatly accumulated H2O2 and ·OH in aerial roots, which finally resulted in lipid peroxidation as indicated by increased malondialdehyde contents. We conclude that the F. microcarpa aerial roots are sensitive to pollutant-induced ROS and that the histochemical localization of O2.‑ via nitrotetrazolium blue chloride staining is not effective for detecting the effects of HSO3‑ treatment because of the treatment’s bleaching effect.

  1. The role of environmental factors in oak decline and mortality in the Ozark Highlands

    Treesearch

    John M. Kabrick; Daniel C. Dey; Randy G. Jensen; Michael Wallendorf

    2008-01-01

    Oak decline is a chronic problem in Missouri Ozark forests. Red oak group species are most susceptible and decline is reportedly more severe on droughty, nutrient-poor sites. However, it was not clear whether greater decline severity was caused by poor site conditions or is simply due to the greater abundance of red oak group species found on poorer sites. We conducted...

  2. Widespread decline of Congo rainforest greenness in the past decade.

    PubMed

    Zhou, Liming; Tian, Yuhong; Myneni, Ranga B; Ciais, Philippe; Saatchi, Sassan; Liu, Yi Y; Piao, Shilong; Chen, Haishan; Vermote, Eric F; Song, Conghe; Hwang, Taehee

    2014-05-01

    Tropical forests are global epicentres of biodiversity and important modulators of climate change, and are mainly constrained by rainfall patterns. The severe short-term droughts that occurred recently in Amazonia have drawn attention to the vulnerability of tropical forests to climatic disturbances. The central African rainforests, the second-largest on Earth, have experienced a long-term drying trend whose impacts on vegetation dynamics remain mostly unknown because in situ observations are very limited. The Congolese forest, with its drier conditions and higher percentage of semi-evergreen trees, may be more tolerant to short-term rainfall reduction than are wetter tropical forests, but for a long-term drought there may be critical thresholds of water availability below which higher-biomass, closed-canopy forests transition to more open, lower-biomass forests. Here we present observational evidence for a widespread decline in forest greenness over the past decade based on analyses of satellite data (optical, thermal, microwave and gravity) from several independent sensors over the Congo basin. This decline in vegetation greenness, particularly in the northern Congolese forest, is generally consistent with decreases in rainfall, terrestrial water storage, water content in aboveground woody and leaf biomass, and the canopy backscatter anomaly caused by changes in structure and moisture in upper forest layers. It is also consistent with increases in photosynthetically active radiation and land surface temperature. These multiple lines of evidence indicate that this large-scale vegetation browning, or loss of photosynthetic capacity, may be partially attributable to the long-term drying trend. Our results suggest that a continued gradual decline of photosynthetic capacity and moisture content driven by the persistent drying trend could alter the composition and structure of the Congolese forest to favour the spread of drought-tolerant species.

  3. Widespread decline of Congo rainforest greenness in the past decade

    NASA Astrophysics Data System (ADS)

    Zhou, Liming; Tian, Yuhong; Myneni, Ranga B.; Ciais, Philippe; Saatchi, Sassan; Liu, Yi Y.; Piao, Shilong; Chen, Haishan; Vermote, Eric F.; Song, Conghe; Hwang, Taehee

    2014-05-01

    Tropical forests are global epicentres of biodiversity and important modulators of climate change, and are mainly constrained by rainfall patterns. The severe short-term droughts that occurred recently in Amazonia have drawn attention to the vulnerability of tropical forests to climatic disturbances. The central African rainforests, the second-largest on Earth, have experienced a long-term drying trend whose impacts on vegetation dynamics remain mostly unknown because in situ observations are very limited. The Congolese forest, with its drier conditions and higher percentage of semi-evergreen trees, may be more tolerant to short-term rainfall reduction than are wetter tropical forests, but for a long-term drought there may be critical thresholds of water availability below which higher-biomass, closed-canopy forests transition to more open, lower-biomass forests. Here we present observational evidence for a widespread decline in forest greenness over the past decade based on analyses of satellite data (optical, thermal, microwave and gravity) from several independent sensors over the Congo basin. This decline in vegetation greenness, particularly in the northern Congolese forest, is generally consistent with decreases in rainfall, terrestrial water storage, water content in aboveground woody and leaf biomass, and the canopy backscatter anomaly caused by changes in structure and moisture in upper forest layers. It is also consistent with increases in photosynthetically active radiation and land surface temperature. These multiple lines of evidence indicate that this large-scale vegetation browning, or loss of photosynthetic capacity, may be partially attributable to the long-term drying trend. Our results suggest that a continued gradual decline of photosynthetic capacity and moisture content driven by the persistent drying trend could alter the composition and structure of the Congolese forest to favour the spread of drought-tolerant species.

  4. Declining School Enrollments.

    ERIC Educational Resources Information Center

    Fowler, Delbert H.

    Declining enrollment means that school districts must engage in thoughtful, thorough planning to cope with this trend, according to the author. His paper outlines a process for school closing, including ways to involve the community in the decision-making process, thereby reducing the likelihood of community conflict and preserving the school…

  5. Declining Black Employment.

    ERIC Educational Resources Information Center

    Vedder, Richard; Gallaway, Lowell

    1993-01-01

    Explores income inequality during declining African-American employment, examines current welfare systems, and suggests ways to improve the economic disadvantages of minority groups. Letting markets work can improve the economic status of African Americans. The present dual African-American economy, a market economy and an entitlement economy, is…

  6. Fraternities in Decline.

    ERIC Educational Resources Information Center

    Reisberg, Leo

    2000-01-01

    Reports on a decline in fraternity membership, which is ascribed to changing demographics, bad publicity about alcohol abuse and hazing incidents, and changing student values. Graphs illustrate fraternity membership trends at six universities, including 10-year comparisons in membership, academic performance, and pledges; and average number of men…

  7. Declining Resources, Targeted Strategies

    ERIC Educational Resources Information Center

    Levenson, Nathan

    2011-01-01

    As resources shrink, the need to do more with less becomes critical. As a business CEO turned superintendent, this author has seen firsthand that many options exist, but none are fun, easy, or politically rewarding. He contends that the challenge of managing declining resources is not the choice between doing less for children or discovering new…

  8. Fraternities in Decline.

    ERIC Educational Resources Information Center

    Reisberg, Leo

    2000-01-01

    Reports on a decline in fraternity membership, which is ascribed to changing demographics, bad publicity about alcohol abuse and hazing incidents, and changing student values. Graphs illustrate fraternity membership trends at six universities, including 10-year comparisons in membership, academic performance, and pledges; and average number of men…

  9. Forest survey results for higher grade hardwood sawtimber

    Treesearch

    Roy C. Beltz

    1991-01-01

    The 1987 Forest Survey of Mississippi shows a slight increase in forest area and a substantial gain in hardwood inventory. Hardwood gains, appearing in all diameter classes, suggest an increase in quality but hardwood users generally believe quality is declining. By our analysis, volume of top quality hardwood declined while volume in other grades increased. Forest...

  10. [Fertility decline in Spain].

    PubMed

    Arango, J

    1987-01-01

    The historical processes of secular fertility decline in Spain and Portugal are not well understood. Very few microdemographic studies of small geographic regions or particular social strata have been done. A contribution by David Reher to the First Spanish-Portuguese-Italian Historical Demography Conference on the fertility decline in the interior province of Cuenca, Spain, uses the own-children method to analyze changes in marital fertility in the 19th and 20th centuries. Reher discovered a slight fertility decline of perhaps 15% which occurred between the end of the 18th century and 1860-75. The fertility decline did not resume until after the Spanish Civil War, and then it was a very gradual and continuous process. When instead of the total female population, women aged 35-39 were studied, unequivocal signs of fertility control appeared. Conscious fertility control thus appears to have begun among older women limiting rather than spacing births. Reher's analysis by social groups demonstrates that fertility declined first and more rapidly in the nonagricultural and urban populations and among the higher income groups. The fertility decline in Cuenca was certainly not identical to that in most of Spain, but may have been fairly typical of a large part of the interior. Another contribution to the Historical Demography Conference, by Anna Cabre and Isabel Pujadas, analyzes fertility trends and cyclical fluctuations in 20th century Cataluna, arguing that they must be placed in historical perspective if recent changes are to be understood and plausible projections made. Their work demonstrates the value of selecting a relatively homogeneous geographic unit for analysis. The contribution of Margarita Delgado to the conference analyzed interregional fertility differences in contemporary Spain. The high legitimate fertility of the south of Spain is accentuated by high nuptiality rates. In central Spain, the combination of high legitimate fertility rates and low

  11. USE OF REPEATED BRONCHOALVEOLAR LAVAGE IN RABBITS TO ASSESS POLLUTANT-INDUCED LUNG CHANGES IN AN ANIMAL MODEL OF CARDIOVASCULAR (CV) DISEASE.

    EPA Science Inventory

    Animal models of coronary heart disease (e.g., hyperlipidemic rabbits) are being used to investigate epidemiologic associations between higher levels of air pollution and adverse CV consequences. Mechanisms by which pollutant-induced lung or systemic inflammation leads to acute C...

  12. USE OF REPEATED BRONCHOALVEOLAR LAVAGE IN RABBITS TO ASSESS POLLUTANT-INDUCED LUNG CHANGES IN AN ANIMAL MODEL OF CARDIOVASCULAR (CV) DISEASE.

    EPA Science Inventory

    Animal models of coronary heart disease (e.g., hyperlipidemic rabbits) are being used to investigate epidemiologic associations between higher levels of air pollution and adverse CV consequences. Mechanisms by which pollutant-induced lung or systemic inflammation leads to acute C...

  13. Back to the forest: exploring forest transitions in Candelaria Loxicha, Mexico.

    PubMed

    Aguilar-Støen, Mariel; Angelsen, Arild; Moe, Stein R

    2011-01-01

    Declining profitability of agriculture and/or higher prices of forest products and services typically drive an increase in forest cover. This article examines changes in forest cover in Candelaria Loxicha, Mexico. Forest cover increased in the area as a result of coffee cultivation in coffee forest-garden systems. Dependence on forest products and services, and not prices of forest products, drive the process in our study site. Low international coffee prices and high labor demand outside the community might pull farmers out of agriculture, but they do not completely abandon the lands. A diversification in income sources prevents land abandonment and contributes to maintaining rural populations and coffee forest gardens.

  14. Louisiana forests: Status and outlook

    Treesearch

    Paul A. Murphy

    1975-01-01

    Between 1964 and 1974, forest area in Louisiana declined 9 percent to 14.5 million acres. Softwood volume increased 31 percent to 9 billion cubic feet, and hardwood declined 7 percent to 7.7 billion. All softwood size classes had increases in volume, and all hardwood size classes had decreases.

  15. Incidence and impact of oak decline in Western Virginia, 1986

    Treesearch

    Steven W. Oak; Cindy M. Huber; Raymond M. Sheffield

    1991-01-01

    Data collected in consecutive forest surveys of Virginia show that losses to oak decline from 1977-1986 were between 7.4 and 13.5 million cubic feet per year in the Northern Piedmont and Mountain Survey Units. Losses were greatest in the Northern Mountain Unit. The ratio of site index/age appears promising as a predictor of oak decline occurrence after severe stress...

  16. 75 FR 6539 - Healthy Forests Reserve Program

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-02-10

    ..., sequesters carbon, and helps purify the air. However, some forest ecosystems have had their ecological... population declines. Active management and protection of forest ecosystems can also increase carbon sequestration and improve air quality. Many forest ecosystems are located on private lands and provide habitat...

  17. Forest Land In Indiana Counties, 1967

    Treesearch

    Burton L. Essex

    1968-01-01

    Commercial forest land has declined slightly from 4.1 million acres in 1950 to 3.9 million acres in 1967. The more heavily forested counties are in the southern half of the State where forest land has been increasing

  18. Midsouth's Changing Hardwood Forests

    Treesearch

    Herbert S. Sternitzke; Robert L. Johnson

    1979-01-01

    Significant changes have occurred in the Midsouth's hardwood resources over the past quarter century. Prime hardwood acreage has declined alarmingly in some areas due to expansion of soybean cropland. Selective cutting and lack of forest management have diminished the overall quality of available hardwood, too.

  19. North Carolina's forests, 1990

    Treesearch

    Mark J. Brown

    1990-01-01

    Since 1984, area of timberland in North Carolina declined by less than 1 percent and currently totals 18.7 million acres. Nonindustrial private forest landowners control 76 percent of the State's timberland. Volume of softwood growing stock increased 4 percent, and hardwood growing-stock volume also increased 4 percent. Softwood net annual growth rose 18 percent...

  20. Nebraska's second forest inventory.

    Treesearch

    Gerhard K. Raile

    1986-01-01

    The second inventory of the timber resource of Nebraska shows a 25% decline in commercial forest area and a 23% gain in growing-stock volume between 1955 and 1983. Text and statistics are presented on area, volume, growth, mortality, removals, utilization, biomass, and future timber supply.

  1. Georgia's forests, 1997

    Treesearch

    Michael T. Thompson; Larry W. Thompson

    2002-01-01

    Since 1989, area of timberland in Georgia increased by less than 1 percent and in 1997 totaled 23.8 million acres. Nonindustrial private forest owners controlled 72 percent of the State's timberland. Volume of softwood growing stock declined 3 percent, whereas hardwood growing-stock volume increased 7 percent to 16.5 billion cubic feet. Net annual growth for...

  2. Michigan forest statistics, 1980.

    Treesearch

    Gerhard K. Raile; W. Brad Smith

    1983-01-01

    The fourth inventory of the timber resource of Michigan shows a 7% decline in commercial forest area and a 27% gain in growing-stock volume between 1966 and 1980. Highlights and statistics are presented on area, volume, growth, mortality, removals, utilization, and biomass.

  3. No long-term persistence of bacterial pollution-induced community tolerance in tylosin-polluted soil.

    PubMed

    Demoling, Louise Aldén; Bååth, Erland

    2008-09-15

    Pollution-induced community tolerance (PICT) of soil bacteria to the antibiotic tylosin was studied over 95 days. Tylosin was added at increasing concentrations, together with different amounts of alfalfa to study the effects of substrate addition on PICT and bacterial growth in soil. The leucine incorporation technique was used to estimate bacterial growth and as a detection method in the PICT concept. Direct inhibition of the bacterial growth rates, resulting in a dose-response curve, was found above 50 mg of tylosin kg(-1) of soil two days after tylosin addition (IC50 value of 960 mg tylosin kg(-1)). After 10 days of exposure to at least 50 mg of tylosin kg(-1), the PICT was observed and correlated to inhibition of bacterial growth by tylosin. A return of the PICT to control levels was found over time, and after 95 days at 1500 mg of tylosin kg(-1), essentially no PICT was found, as compared to the unpolluted control soil. The return of PICT to pre-exposure levels was not totally reflected in the recovery of bacterial growth. Alfalfa addition did not affect the inhibitory effect of tylosin on bacterial growth rates; neither did it alter the PICT. Since tylosin is relatively rapidly degraded in soil, our results indicate that the PICT will return to prepollution levels when the selective pressure of the toxicant is removed and will thus be a useful technique for monitoring remediation measures.

  4. In situ spatio-temporal changes in pollution-induced community tolerance to zinc in autotrophic and heterotrophic biofilm communities.

    PubMed

    Tlili, Ahmed; Corcoll, Natalia; Bonet, Berta; Morin, Soizic; Montuelle, Bernard; Bérard, Annette; Guasch, Helena

    2011-11-01

    Pollution-induced community tolerance (PICT) uses increased tolerance in populations at contaminated sites as an indicator of contaminant effects. However, given the broad structural and functional complexity that characterizes biological communities, the acquisition of PICT could vary with (i) target community, (ii) intensity of toxicant exposure, (iii) the species succession stage, and (iv) the physicochemical characteristics of the studied site. To assess the spatio-temporal changes of zinc-induced tolerance in fluvial biofilm communities, we conducted an in situ study in Osor River (North-East Catalonia, Spain), which has zinc contamination. Biofilms were developed for 5 weeks in a non-metal-polluted site, and were then transferred to different sites in Osor River with different levels of zinc contamination. The spatio-temporal changes of biofilm PICT to zinc was determined using photosynthetic activity bioassays and respiration-induced aerobic bioassays at T(0), and at 1, 3 and 5 weeks of exposure. We also performed physicochemical characterization of the sites, taxonomic analysis of diatoms, bacterial and fungal diversity and profiled pigments of phototrophic communities. We used multivariate ordination to analyze results. In addition to natural species succession, the intensity of metal pollution exerted structural pressure by selecting the most metal-tolerant species, but differently depending on the type of biofilm. Zn-tolerance values indicated that exposure to high levels of zinc had effects that were similar to a longer exposure to lower levels of zinc.

  5. Use of the MicroResp™ method to assess pollution-induced community tolerance to metals for lotic biofilms.

    PubMed

    Tlili, Ahmed; Marechal, Marjorie; Montuelle, Bernard; Volat, Bernadette; Dorigo, Ursula; Bérard, Annette

    2011-01-01

    Understanding the ecological status of aquatic ecosystems and the impact of anthropogenic contamination requires correlating exposure to toxicants with impact on biological communities. Several tools exist for assessing the ecotoxicity of substances, but there is still a need for new tools that are ecologically relevant and easy to use. We have developed a protocol based on the substrate-induced respiration of a river biofilm community, using the MicroResp™ technique, in a pollution-induced community tolerance approach. The results show that MicroResp™ can be used in bioassays to assess the toxicity toward biofilm communities of a wide range of metals (Cu, Zn, Cd, Ag, Ni, Fe, Co, Al and As). Moreover, a community-level physiological profile based on the mineralization of different carbon substrates was established. Finally, the utility of MicroResp™ was confirmed in an in-situ study showing gradient of tolerance to copper correlated to a contamination gradient of this metal in a small river.

  6. Regional Forest Fragmentation and the Nesting Success of Migratory Birds

    Treesearch

    Scott K. Robinson; Frank R. Thompson III; Therese M. Donovan; Donald R. Whitehead; John Faaborg

    1995-01-01

    Forest fragmentation, the disruption in the continuity of forest habitat, is hypothesized to be a major cause of population decline for, some species of forest birds because fragmentation reduces nesting (reproductive) success. Nest predation and parasitism by cowbirds increased with forest fragmentation in nine midwestern (United States)landscapes that varied from 6...

  7. Decline of red spruce in the Adirondacks, New York

    SciTech Connect

    Scott, J.T.; Siccama, T.G.; Johnson, A.H.; Breisch, A.R.

    1984-01-01

    Thirty-two stands in the spruce-fir forests of Whiteface Mountain in the Adirondacks, originally sampled from 1964-66, were resurveyed in 1982. From 10-25 Bitterlich points were used in each stand in 1982 to obtain an estimate of basal area per hectare. Data were summarized for low elevation (<900m) and high elevation (> or = 900m) forests. Red spruce declined by 40-60% in basal area for the low elevation forests and by 60-70% above 900m. Balsam fir decreased by 35% at high elevations, due to natural disturbance in several of the stands, but was unchanged when only undisturbed stands were considered. The decline of red spruce accounted for about three quarters of the total decrease in basal area for both the high- and low-elevation forests. Spruce seedling frequency for the high-elevation sample decreased by 80%, but was unchanged below 900m. The pattern of spruce decline in the Adirondacks is similar to findings for New England. The cause of the decline is speculative at the time.

  8. A review of southern pine decline in North America

    Treesearch

    David R. Coyle; Kier D. Klepzig; Frank H. Koch; Lawrence A. Morris; John T. Nowak; Steven W. Oak; William J. Otrosina; William D. Smith; Kamal J.K. Gandhi

    2015-01-01

    The southeastern United States is among the most productive forested areas in the world. Four endemic southern pine species – loblolly, longleaf, shortleaf, and slash - contribute significantly to the economic and ecological values in the region. A recently described phenomenon known as Southern Pine Decline (SPD) has been reported as having widespread impact in the...

  9. Oak wilt and oak decline in the upper midwest USA

    Treesearch

    Jennifer Juzwik; Thomas L. Schmidt

    2000-01-01

    Oaks are a significant component of the hardwood forests of the Upper Midwest USA. Numerous species occur over vast areas in the region and are highly valued for a variety of reasons. Oak wilt caused by C. fagacearum, and oak decline associated with several factors are the major causes of the species, deterioration and death in the region....

  10. Forest statistics for Central Florida - 1970

    Treesearch

    Nolan L. Snyder; Herbert A. Knight

    1970-01-01

    Since 1959, area of commercial forest in Central Florida has declined from 3.2 to 2.7 million acres, or 16 percent, excluding the reclassification of 1.7 million acres from non-stocked forest to natural rangeland. Some 589,400 acres were actually diverted from commercial forest to other land uses, while only 56,400 acres of new forest were added. Volume of softwood...

  11. Air pollutants effects on forest ecosystems

    SciTech Connect

    Not Available

    1985-01-01

    This book presents the papers given at a conference on the effects of acid rain on forests. The conference was sponsored by the National Acid Precipitation Assessment Program (NAPAP). Topics considered at the conference included the status of US research on acid deposition and its effects contributing factors to the decline of forests, evidence for effects on ecosystems, the effects of air pollutants on forest ecosystems in North America and Europe, forest management, and future scientific research programs and management approaches.

  12. Acid-base status of upper rooting zone soil in declining and non-declining sugar maple (Acer saccharum Marsh) stands in Pennsylvania

    Treesearch

    William E. Sharpe; Troy L. Sunderland

    1995-01-01

    Sugar maple (Acer saccharum Marsh) is an important commercial tree species of the central hardwood region which is valued for its wood and maple sugar products. High elevation sugar maple stands in northcentral Pennsylvania have been in serious decline for about the last 15 years with more than 1,200 hectares of maple forest affected. The decline...

  13. Habitat split and the global decline of amphibians.

    PubMed

    Becker, Carlos Guilherme; Fonseca, Carlos Roberto; Haddad, Célio Fernando Baptista; Batista, Rômulo Fernandes; Prado, Paulo Inácio

    2007-12-14

    The worldwide decline in amphibians has been attributed to several causes, especially habitat loss and disease. We identified a further factor, namely "habitat split"-defined as human-induced disconnection between habitats used by different life history stages of a species-which forces forest-associated amphibians with aquatic larvae to make risky breeding migrations between suitable aquatic and terrestrial habitats. In the Brazilian Atlantic Forest, we found that habitat split negatively affects the richness of species with aquatic larvae but not the richness of species with terrestrial development (the latter can complete their life cycle inside forest remnants). This mechanism helps to explain why species with aquatic larvae have the highest incidence of population decline. These findings reinforce the need for the conservation and restoration of riparian vegetation.

  14. Oak decline around the world

    Treesearch

    Kurt W. Gottschalk; Philip M. Wargo

    1997-01-01

    Oak (Quercus spp.) decline is a malady related to the consequences of stress and successful attack of stressed trees by opportunistic (secondary) organisms (Wargo et al. 1983). It is a progressive process where trees decline in health for several years before they die. Houston (1981) developed a model of declines that is presented in Figure 1. So...

  15. Pollution-induced community tolerance and functional redundancy in a decomposer food web in metal-stressed soil.

    PubMed

    Salminen, J; van Gestel, C A; Oksanen, J

    2001-10-01

    Pollution may lead to the development of pollution-induced community tolerance (PICT) in a stressed community. We studied the presence of PICT in soil food webs using soil microcosms. Soil microcosms containing soil invertebrates and microbes were collected from polluted and unpolluted areas and exposed to a range of soil zinc concentrations. A pine seedling was planted in each microcosm to measure the effects of the origin of the community and Zn pollution on above-ground plant production. The effects of the treatments on nutrient content in the soil were also measured. The diversity of soil microarthropods and the soil's mineral nutrient content were low at the Zn-polluted site. We did not observe an increasing Zn tolerance among the soil organisms in the polluted soil. However, low population growth rates of soil invertebrates from the polluted site may indicate the deleterious effects on fitness of long-lasting pollution. In the soil from the nonpolluted site, Zn additions caused changes in the invertebrate food web structure. These changes were explained by the good physiological condition of the animals and their insensitivity to Zn. The fact that the food web structure in soil from the polluted site did not change can be used as a rough indicator of PICT. Structural stability is presumed by the lack of Zn-sensitive species at this site and the inability of populations to acclimate by altering their growth or reproduction patterns in response to changing soil conditions. Although microbial-based soil decomposer systems may have a high functional redundancy, our results indicate that metal stress at the polluted site exceeds the tolerance limits of the system. As a consequence, ecosystem function at this site is endangered. This study also shows that the evolution of metal tolerance by soil decomposer organisms may not be a common reaction to soil pollution, although changes of population and community structure indicated severe metal stress on organisms.

  16. Pollution-induced community tolerance (PICT) and seasonal variations in the sensitivity of phytoplankton to atrazine in nanocosms.

    PubMed

    Bérard, A; Benninghoff, C

    2001-11-01

    Algae communities exposed to a herbicide like atrazine (PS II inhibitor) are expected to be selected and to be more tolerant to the herbicide than unexposed communities (pollution-induced community tolerance, PICT). The PICT may be an ecotoxicological tool for detecting this selective action of chronic pollution, and this method has been applied to several toxicants in experimental systems and in field studies. But the detection of PICT with PS II inhibitors has sometimes been variable. This work was done to study the long-term effects of exposure to atrazine (10 microg/l) and the PICT responses of phytoplankton communities in repeated outdoor nanocosms. Phytoplankton communities were sampled in Lake Geneva at different periods of the year and the effects of atrazine were analysed by studying community structure, biomass and primary production, and by measuring tolerance to atrazine in a short-term physiological test based on 14C incorporation. We find that PICT is a sensitive method for measuring effects. Even atrazine concentrations causing little restructuring induced tolerance in most of our experiments. But the short- and long-term responses of phytoplankton to atrazine varied between experiments, probably due to the initial compositions of the communities and environmental factors associated with seasonal parameters. The selection and detection steps of PICT to atrazine thus vary greatly with environmental conditions and the physiological adaptations of algae to the herbicide. To monitor risk assessment in aquatic systems, PICT studies applied to algae, must be investigated in the light of seasonal contaminations and seasonal events and successions.

  17. Forest Management.

    ERIC Educational Resources Information Center

    Weicherding, Patrick J.; And Others

    This bulletin deals with forest management and provides an overview of forestry for the non-professional. The bulletin is divided into six sections: (1) What Is Forestry Management?; (2) How Is the Forest Measured?; (3) What Is Forest Protection?; (4) How Is the Forest Harvested?; (5) What Is Forest Regeneration?; and (6) What Is Forest…

  18. Urban Forests

    Treesearch

    David Nowak

    2016-01-01

    Urban forests (and trees) constitute the second forest resource considered in this report. We specifically emphasize the fact that agricultural and urban forests exist on a continuum defined by their relationship (and interrelationship) with a given landscape. These two forest types generally serve different purposes, however. Whereas agricultural forests are...

  19. Forest pathology in Hawaii

    USGS Publications Warehouse

    Gardner, D.E.

    2003-01-01

    Native Hawaiian forests are characterised by a high degree of endemism, including pathogens as well as their hosts. With the exceptions of koa (Acacia koa Gray), possibly maile (Alyxia oliviformis Gaud.), and, in the past, sandalwood (Santalum spp.), forest species are of little commercial value. On the other hand, these forests are immensely important from a cultural, ecological, and evolutionary standpoint. Forest disease research was lacking during the mid-twentieth century, but increased markedly with the recognition of ohia (Metrosideros polymorpha Gaud.) decline in the 1970s. Because many pathogens are themselves endemic, or are assumed to be, having evolved with their hosts, research emphasis in natural areas is on understanding host-parasite interactions and evolutionary influences, rather than disease control. Aside from management of native forests, attempts at establishing a commercial forest industry have included importation of several species of pine, Araucaria, and Eucalyptus as timber crops, and of numerous ornamentals. Diseases of these species have been introduced with their hosts. The attacking of native species by introduced pathogens is problematic - for example, Armillaria mellea (Vahl ex Fr.) Que??l. on koa and mamane (Sophora chrysophylla (Salisb.) Seem.). Much work remains to be done in both native and commercial aspects of Hawaiian forest pathology.

  20. The effects of site factors on the rate of hemlock decline: a case study in New Jersey

    Treesearch

    Denise Royle; Richard Lathrop

    2000-01-01

    The rate of decline of hemlock (Tsuga canadensis) trees infested with hemlock woolly adelgid (Adelges tsugae) appears to be highly variable and site dependent. Rates of hemlock forest decline have not been quantified at the landscape scale and reasons for observed variations in the rate of decline remain unknown. Others have...

  1. Fungi associated with stem cankers and coincidental scolytid beetles on declining hickory in the upper midwest

    Treesearch

    Jennifer Juzwik; Linda Haugen; Ji-Hyun Park; Melanie Moore

    2008-01-01

    Higher than expected levels of hickory decline and mortality have recently been reported by Forest Health Monitoring, USDA Forest Service, on Carya spp. in Iowa, Maryland, Missouri, New York, Pennsylvania, and West Virginia. Widespread mortality of hickory has historically been attributed to outbreaks of the hickory bark beetle (Scolytus...

  2. Recent population decline of the Marbled Murrelet in the Pacific Northwest

    Treesearch

    Sherri L. Miller; Martin G. Raphael; Gary A. Falxa; Craig Strong; Jim Baldwin; Thomas Bloxton; Beth M. Galleher; Monique Lance; Deanna Lynch; Scott F. Pearson; C. John Ralph; Richard D. Young

    2012-01-01

    We document here a decline of nearly 30% in the Marbled Murrelet (Brachyramphus marmoratus) population of Washington, Oregon, and northern California between 2000 and 2010. The Northwest Forest Plan is an ecosystem-management plan for federal forest lands in the Pacific Northwest of the United States that incorporates monitoring to determine if...

  3. Clonal xenobiotic resistance during pollution-induced toxic injury and hepatocellular carcinogenesis in liver of female flounder (Platichthys flesus (L.)).

    PubMed

    Koehler, Angela; Alpermann, Tilmann; Lauritzen, Bjarne; Van Noorden, Cornelis J F

    2004-01-01

    Juvenile and adult female flounder (Platichthys flesus (L.)) were caught either in the estuary of the most polluted European river, the Elbe, or as controls in a reference site to study pollution-induced xenobiotic resistance in their livers in relation to pathological alterations. In juvenile fish, livers displayed reversible and irreversible degenerative toxipathic lesion types but never showed (pre)neoplastic changes. Tumour frequencies up to 70% were found macroscopically in livers of adult female flounder which had progressed to adenomas and carcinomas in the most polluted site. Because male adult flounder show only up to 50% of livers containing early preneoplastic foci but never malignancies, we focussed our study on female individuals. (Pre)neoplastic changes ranged from early eosinophilic foci to basophilic foci, adenomas and hepatocellular carcinomas. Adenomas were generally eosinophilic whereas carcinomas were mainly basophilic. These phenotypical sequential changes strongly resemble those found in chemically-induced liver carcinogenesis in mammals. Characteristic mutations known from mammalian cancers have not been found so far in these flounder livers. Therefore, we investigated whether epigenetic events had induced a metabolic "resistant phenotype" of (pre)malignant cancer cells during hepatocellular carcinogenesis. With a quantitative immunohistochemical approach, we studied expression of P-glycoprotein (P-gp)-mediated multixenobiotic resistance (MXR), cytochrome P4501A1, glutathione-S-transferase-A which are key proteins in xenobiotic metabolism and elimination. Glucose-6-phosphate dehydrogenase (G6PDH) activity, the major source of the reducing power NADPH which is needed for biotransformation, oxyradical scavenging and biosynthesis, was detected as well. We observed upregulation of G6PDH activity already in early preneoplastic eosinophilic foci and subsequent further upregulation in basophilic foci and carcinomas. P-gp started to become

  4. Tree squirrel habitat selection and predispersal seed predation in a declining subalpine conifer

    Treesearch

    Shawn T. McKinney; Carl E. Fiedler

    2009-01-01

    Differential responses by species to modern perturbations in forest ecosystems may have undesirable impacts on plant-animal interactions. If such disruptions cause declines in a plant species without corresponding declines in a primary seed predator, the effects on the plant could be exacerbated. We examined one such interaction between Pinus...

  5. Long-term decline of a winter-resident bird community in Puerto Rico

    Treesearch

    J. Faaborg; W. J. Arendt; J. D. Toms; K. M. Dugger; W. A. Cox; M. Canals Mora

    2013-01-01

    Despite concern expressed two decades ago, there has been little recent discussion about continuing declines of migrant bird populations. Monitoring efforts have been focused almost exclusively on the breeding grounds. We describe the long-term decline of a winter-resident bird population in Guanica Commonwealth Forest, Puerto Rico, one of the last remaining tracts of...

  6. Oak decline in the Boston Mountains, Arkansas, USA: Spatial and temporal patterns under two fire regimes

    Treesearch

    Martin A. Spetich; Hong S. He

    2008-01-01

    A spatially explicit forest succession and disturbance model is used to delineate the extent and dispersion of oak decline under two fire regimes over a 150-year period. The objectives of this study are to delineate potential current and future oak decline areas using species composition and age structure data in combination with ecological land types, and to...

  7. Site factors influencing oak decline in the interior highlands of Arkansas, Missouri, and Oklahoma

    Treesearch

    Edward A. Poole; Eric Heitzman; James M. Guldin

    2006-01-01

    Oak decline is affecting the forests in the Interior Highlands of Arkansas, Missouri, and Oklahoma. In 2002 and 2003, field plots were established throughout the region to evaluate the influence of topographic position and aspect on oak decline. Density and basal area of dead and dying oaks did not significantly differ by either topographic position or aspect. Lack of...

  8. East Texas forests: Status and trends

    Treesearch

    Paul A. Murphy

    1976-01-01

    The softwood inventory in east Texas has grown 24 percent durring the 1965-1975 time period; hardwood volume has gained 13 percent. Forest area declined slightly, a trend that is expected to continue into the future.

  9. Decomposing the seasonal fitness decline.

    PubMed

    Öberg, Meit; Pärt, Tomas; Arlt, Debora; Laugen, Ane T; Low, Matthew

    2014-01-01

    Seasonal fitness declines are common, but the relative contribution of different reproductive components to the seasonal change in the production of reproductive young, and the component-specific drivers of this change is generally poorly known. We used long-term data (17 years) on breeding time (i.e. date of first egg laid) in northern wheatears (Oenanthe oenanthe) to investigate seasonal reproductive patterns and estimate the relative contributions of reproductive components to the overall decline in reproduction, while accounting for factors potentially linked to seasonal declines, i.e. individual and habitat quality. All reproductive components-nest success (reflecting nest predation rate), clutch size, fledging success and recruitment success-showed a clear decline with breeding time whereas subsequent adult survival did not. A non-linear increase in nest predation rate caused nest success to decline rapidly early in the season and level off at ~80% success late in the breeding season. The combined seasonal decline in all reproductive components caused the mean production of recruits per nest to drop from around 0.7-0.2; with the relative contribution greatest for recruitment success which accounted for ~50% of the decline. Our data suggest that changing environmental conditions together with effects of nest predation have strong effects on the seasonal decline in fitness. Our demonstration of the combined effects of all reproductive components and their relative contribution shows that omitting data from later stages of breeding (recruitment) can greatly underestimate seasonal fitness declines.

  10. Disturbance and Forest Health in Oregon and Washington.

    Treesearch

    Sally Campbell; Leon Liegel

    1996-01-01

    The scope and intensity of disturbance by such agents as fire, insects, diseases, air pollution, and weather in Pacific Northwest forests suggests that forest health has declined in recent years in many areas. The most significant disturbances and causes of tree mortality or decline in Oregon and Washington are presented and illustrated. We discuss the interrelations...

  11. Recent Widespread Tree Growth Decline Despite Increasing Atmospheric CO2

    PubMed Central

    Silva, Lucas C. R.; Anand, Madhur; Leithead, Mark D.

    2010-01-01

    Background The synergetic effects of recent rising atmospheric CO2 and temperature are expected to favor tree growth in boreal and temperate forests. However, recent dendrochronological studies have shown site-specific unprecedented growth enhancements or declines. The question of whether either of these trends is caused by changes in the atmosphere remains unanswered because dendrochronology alone has not been able to clarify the physiological basis of such trends. Methodology/Principal Findings Here we combined standard dendrochronological methods with carbon isotopic analysis to investigate whether atmospheric changes enhanced water use efficiency (WUE) and growth of two deciduous and two coniferous tree species along a 9° latitudinal gradient across temperate and boreal forests in Ontario, Canada. Our results show that although trees have had around 53% increases in WUE over the past century, growth decline (measured as a decrease in basal area increment – BAI) has been the prevalent response in recent decades irrespective of species identity and latitude. Since the 1950s, tree BAI was predominantly negatively correlated with warmer climates and/or positively correlated with precipitation, suggesting warming induced water stress. However, where growth declines were not explained by climate, WUE and BAI were linearly and positively correlated, showing that declines are not always attributable to warming induced stress and additional stressors may exist. Conclusions Our results show an unexpected widespread tree growth decline in temperate and boreal forests due to warming induced stress but are also suggestive of additional stressors. Rising atmospheric CO2 levels during the past century resulted in consistent increases in water use efficiency, but this did not prevent growth decline. These findings challenge current predictions of increasing terrestrial carbon stocks under climate change scenarios. PMID:20657763

  12. Recent widespread tree growth decline despite increasing atmospheric CO2.

    PubMed

    Silva, Lucas C R; Anand, Madhur; Leithead, Mark D

    2010-07-21

    The synergetic effects of recent rising atmospheric CO(2) and temperature are expected to favor tree growth in boreal and temperate forests. However, recent dendrochronological studies have shown site-specific unprecedented growth enhancements or declines. The question of whether either of these trends is caused by changes in the atmosphere remains unanswered because dendrochronology alone has not been able to clarify the physiological basis of such trends. Here we combined standard dendrochronological methods with carbon isotopic analysis to investigate whether atmospheric changes enhanced water use efficiency (WUE) and growth of two deciduous and two coniferous tree species along a 9 degrees latitudinal gradient across temperate and boreal forests in Ontario, Canada. Our results show that although trees have had around 53% increases in WUE over the past century, growth decline (measured as a decrease in basal area increment--BAI) has been the prevalent response in recent decades irrespective of species identity and latitude. Since the 1950s, tree BAI was predominantly negatively correlated with warmer climates and/or positively correlated with precipitation, suggesting warming induced water stress. However, where growth declines were not explained by climate, WUE and BAI were linearly and positively correlated, showing that declines are not always attributable to warming induced stress and additional stressors may exist. Our results show an unexpected widespread tree growth decline in temperate and boreal forests due to warming induced stress but are also suggestive of additional stressors. Rising atmospheric CO2 levels during the past century resulted in consistent increases in water use efficiency, but this did not prevent growth decline. These findings challenge current predictions of increasing terrestrial carbon stocks under climate change scenarios.

  13. Potential causes for amphibian declines in Puerto Rico

    USGS Publications Warehouse

    Burrowes, P.A.; Joglar, R.L.; Green, David E.

    2004-01-01

    We monitored 11 populations of eight species of Eleutherodactylus in Puerto Rico from 1989 through 2001. We determined relative abundance of active frogs along transects established in the Caribbean National Forest (El Yunque), Carite Forest, San Lorenzo, and in the vicinity of San Juan. Three species (Eleutherodactylus karlschmidti, E. jasperi, and E. eneidae) are presumed to be extinct and eight populations of six different species of endemic Eleutherodactylus are significantly declining at elevations above 400 m. Of the many suspected causes of amphibian declines around the world, we focused on climate change and disease. Temperature and precipitation data from 1970a??2000 were analyzed to determine the general pattern of oscillations and deviations that could be correlated with amphibian declines. We examined a total of 106 tissues taken from museum specimens collected from 1961a??1978 and from live frogs in 2000. We found chytrid fungi in two species collected at El Yunque as early as 1976, this is the first report of chytrid fungus in the Caribbean. Analysis of weather data indicates a significant warming trend and an association between years with extended periods of drought and the decline of amphibians in Puerto Rico. The 1970's and 1990's, which represent the periods of amphibian extirpations and declines, were significantly drier than average. We suggest a possible synergistic interaction between drought and the pathological effect of the chytrid fungus on amphibian populations.

  14. Global biodiversity: indicators of recent declines.

    PubMed

    Butchart, Stuart H M; Walpole, Matt; Collen, Ben; van Strien, Arco; Scharlemann, Jörn P W; Almond, Rosamunde E A; Baillie, Jonathan E M; Bomhard, Bastian; Brown, Claire; Bruno, John; Carpenter, Kent E; Carr, Geneviève M; Chanson, Janice; Chenery, Anna M; Csirke, Jorge; Davidson, Nick C; Dentener, Frank; Foster, Matt; Galli, Alessandro; Galloway, James N; Genovesi, Piero; Gregory, Richard D; Hockings, Marc; Kapos, Valerie; Lamarque, Jean-Francois; Leverington, Fiona; Loh, Jonathan; McGeoch, Melodie A; McRae, Louise; Minasyan, Anahit; Hernández Morcillo, Monica; Oldfield, Thomasina E E; Pauly, Daniel; Quader, Suhel; Revenga, Carmen; Sauer, John R; Skolnik, Benjamin; Spear, Dian; Stanwell-Smith, Damon; Stuart, Simon N; Symes, Andy; Tierney, Megan; Tyrrell, Tristan D; Vié, Jean-Christophe; Watson, Reg

    2010-05-28

    In 2002, world leaders committed, through the Convention on Biological Diversity, to achieve a significant reduction in the rate of biodiversity loss by 2010. We compiled 31 indicators to report on progress toward this target. Most indicators of the state of biodiversity (covering species' population trends, extinction risk, habitat extent and condition, and community composition) showed declines, with no significant recent reductions in rate, whereas indicators of pressures on biodiversity (including resource consumption, invasive alien species, nitrogen pollution, overexploitation, and climate change impacts) showed increases. Despite some local successes and increasing responses (including extent and biodiversity coverage of protected areas, sustainable forest management, policy responses to invasive alien species, and biodiversity-related aid), the rate of biodiversity loss does not appear to be slowing.

  15. Global biodiversity: indicators of recent declines

    USGS Publications Warehouse

    Butchart, Stuart H.M.; Walpole, Matt; Collen, Ben; Van Strien, Arco; Scharlemann, Jorn P.W.; Almond, Rosamunde E.A.; Baillie, Jonathan E.M.; Bomhard, Bastian; Brown, Claire; Bruno, John; Carpenter, Kent E.; Carr, Genevieve M.; Chanson, Janice; Chenery, Anna M.; Csirke, Jorge; Davidson, Nick C.; Dentener, Frank; Foster, Matt; Galli, Alessandro; Galloway, James N.; Genovesi, Piero; Gregory, Richard D.; Hockings, Marc; Kapos, Valerie; Lamarque, Jean-Francois; Leverington, Fiona; Loh, Jonathan; McGeoch, Melodie A.; McRae, Louise; Minasyan, Anahit; Morcillo, Monica Hernandez; Oldfield, Thomasina E.E.; Pauly, Daniel; Quader, Suhel; Revenga, Carmen; Sauer, John R.; Skolnik, Benjamin; Spear, Dian; Stanwell-Smith, Damon; Stuart, Simon N.; Symes, Andy; Tierney, Megan; Tyrrell, Tristan D.; Vie, Jean-Christophe; Watson, Reg

    2011-01-01

    In 2002, world leaders committed, through the Convention on Biological Diversity, to achieve a significant reduction in the rate of biodiversity loss by 2010. We compiled 31 indicators to report on progress toward this target. Most indicators of the state of biodiversity (covering species' population trends, extinction risk, habitat extent and condition, and community composition) showed declines, with no significant recent reductions in rate, whereas indicators of pressures on biodiversity (including resource consumption, invasive alien species, nitrogen pollution, overexploitation, and climate change impacts) showed increases. Despite some local successes and increasing responses (including extent and biodiversity coverage of protected areas, sustainable forest management, policy responses to invasive alien species, and biodiversity-related aid), the rate of biodiversity loss does not appear to be slowing.

  16. Additional pest surveyed: hickory decline

    Treesearch

    Jennifer Juzwik; Ji-Hyun. Park

    2011-01-01

    A five year investigation of the cause of rapid crown decline and mortality of bitternut hickory was concluded in September 2011. Results of a series of related studies found that multiple cankers and xylem (the water conducting tissue) dysfunction caused by Ceratocystis smalleyi are correlated with rapid crown decline typical of a limited vascular...

  17. Mobility decline in old age.

    PubMed

    Rantakokko, Merja; Mänty, Minna; Rantanen, Taina

    2013-01-01

    Mobility is important for community independence. With increasing age, underlying pathologies, genetic vulnerabilities, physiological and sensory impairments, and environmental barriers increase the risk for mobility decline. Understanding how mobility declines is paramount to finding ways to promote mobility in old age.

  18. Feminine Intellectual Decline During Adolescence.

    ERIC Educational Resources Information Center

    Campbell, Patricia B.

    The purpose of this study was to investigate further the relationship between sex and a decline of intellectual abilities during adolescence and to examine some personality differences between young women who declined in intellectual abilities during adolescence and those who did not. Differences examined were: need to be included, need to be…

  19. Disturbance and forest health in Oregon and Washington. Forest Service general technical report

    SciTech Connect

    Brookes, M.H.; Campbell, S.; Liegel, L.

    1996-10-01

    The scope and intensity of disturbance by such agents as fire, insects, diseases, air pollution, and weather in the Pacific Northwest forests suggest that forest health has declined in recent years in many areas. The most significant disturbances and causes of tree mortality or decline in Oregon and Washington are presented and illustrated. We discuss the interrelations of disturbance with forest management activities and the effect on native trees and suggest some solutions for reducing the severity of disturbance. One chapter reports on forest health monitoring pilot project.

  20. A comparison of forest dynamics at two sites in the Southeastern Ozark Mountains of Missouri

    Treesearch

    Michael A. Jenkins; Stephen G. Pallardy

    1993-01-01

    Changes in tree species composition and regeneration patterns were studied in 53 permanent vegetation plots located at two sites (Pioneer Forest and University State Forest) in oak-hickory forests of southeastern Missouri where mortality and decline of red oak species have been identified. The two sites also exhibited differing levels of decline and mortality. Between...

  1. Population declines in North American birds that migrate to the neotropics

    USGS Publications Warehouse

    Robbins, C.S.; Sauer, J.R.; Greenberg, R.S.; Droege, S.

    1989-01-01

    Using data from the North American Breeding Bird Survey, we determined that most neotropical migrant bird species that breed in forests of the eastern United States and Canada have recently (1978-1987) declined in abundance after a period of stable or increasing populations. Most permanent residents and temperate-zone migrants did not show a general pattern of decrease during this period. Field data from Mexico were used to classify a subset of the neotropical migrants as using forest or scrub habitats during winter. Population declines during 1978-1987 were significantly greater among the forest-wintering species, while populations of scrub-wintering species increased. The same subset of neotropical migrants also showed overall declines in forest-breeding species, but no significant differences existed between species breeding in forest and scrub habitats. Neotropical migrant species that primarily use forested habitats in either wintering or breeding areas are declining, but a statistically significant association between habitat and population declines was detected only in the tropics.

  2. Forest hydrology

    Treesearch

    Ge Sun; Devendra Amatya; Steve McNulty

    2016-01-01

    Forest hydrology studies the distribution, storage, movement, and quality of water and the hydrological processes in forest-dominated ecosystems. Forest hydrological science is regarded as the foundation of modern integrated water¬shed management. This chapter provides an overview of the history of forest hydrology and basic principles of this unique branch of...

  3. Forest Management

    Treesearch

    S. Hummel; K. L. O' Hara

    2008-01-01

    Global variation in forests and in human cultures means that a single method for managing forests is not possible. However, forest management everywhere shares some common principles because it is rooted in physical and biological sciences like chemistry and genetics. Ecological forest management is an approach that combines an understanding of universal processes with...

  4. Forest soils

    Treesearch

    Charles H. (Hobie) Perry; Michael C. Amacher

    2009-01-01

    Productive soils are the foundation of sustainable forests throughout the United States. Forest soils are generally subjected to fewer disturbances than agricultural soils, particularly those that are tilled, so forest soils tend to have better preserved A-horizons than agricultural soils. Another major contrast between forest and agricultural soils is the addition of...

  5. Alaska forest products: using resources well.

    Treesearch

    Valerie. Rapp

    2003-01-01

    Despite abundant forest resources in the state, the Alaska forest products industry declined throughout the 1990s and early 21st century. In a state with lots of trees, mills are going out of business and most finished lumber used in the state is imported from the lower 48 United States and Canada. The Alaska Wood Utilization Research and Development Center (Wood...

  6. Forest carbon uptake in North America's aging temperate deciduous forests: A data-theory-model mismatch?

    NASA Astrophysics Data System (ADS)

    Gough, C. M.; Curtis, P.; Bond-Lamberty, B. P.; Hardiman, B. S.; Scheuermann, C. M.; Nave, L. E.; Nadelhoffer, K. J.

    2015-12-01

    Century-old temperate deciduous forests in the US upper Midwest and Northeast power much of North America's terrestrial carbon sink, but these forests' carbon uptake capacity is expected to soon decline. But will this really happen? We marshal empirical data and ecological theory to show that declines in carbon uptake are not imminent in regrown temperate deciduous forests during coming decades, despite long-held assumptions and modeling results that predict declining carbon uptake during middle stages of ecosystem development. Age and production data for temperate deciduous forests, synthesized from published literature, do not provide evidence for declining net primary and ecosystem production (NPP and NEP, respectively) within the age-range most regional forests will occupy over the next half-century. Ecological theory suggests a mechanism for sustained carbon uptake in the region's aging forests in which high-frequency, low-severity disturbances maintain NPP and NEP by increasing ecosystem complexity. This theoretical model is supported by observations from the Forest Accelerated Succession Experiment in Michigan, USA, but such mechanisms sustaining production in old forests are not broadly represented in ecosystem models. Ecosystems experiencing low-frequency, high-severity disturbances that simplify ecosystem complexity do exhibit declining production during middle stages of succession, but we suggest that such scenarios have exerted a disproportionate influence on prevailing modeling and ecological assumptions regarding age-related declines in forest production. We conclude that there is wide ecological space for forests to sustain high rates of carbon uptake during middle stages of ecosystem development, and that advancing mechanistic understanding of long-term forest carbon cycle dynamics is essential to modeling the continent's future carbon sink strength.

  7. Catastrophic ape decline in western equatorial Africa.

    PubMed

    Walsh, Peter D; Abernethy, Kate A; Bermejo, Magdalena; Beyers, Rene; De Wachter, Pauwel; Akou, Marc Ella; Huijbregts, Bas; Mambounga, Daniel Idiata; Toham, Andre Kamdem; Kilbourn, Annelisa M; Lahm, Sally A; Latour, Stefanie; Maisels, Fiona; Mbina, Christian; Mihindou, Yves; Obiang, Sosthène Ndong; Effa, Ernestine Ntsame; Starkey, Malcolm P; Telfer, Paul; Thibault, Marc; Tutin, Caroline E G; White, Lee J T; Wilkie, David S

    2003-04-10

    Because rapidly expanding human populations have devastated gorilla (Gorilla gorilla) and common chimpanzee (Pan troglodytes) habitats in East and West Africa, the relatively intact forests of western equatorial Africa have been viewed as the last stronghold of African apes. Gabon and the Republic of Congo alone are thought to hold roughly 80% of the world's gorillas and most of the common chimpanzees. Here we present survey results conservatively indicating that ape populations in Gabon declined by more than half between 1983 and 2000. The primary cause of the decline in ape numbers during this period was commercial hunting, facilitated by the rapid expansion of mechanized logging. Furthermore, Ebola haemorrhagic fever is currently spreading through ape populations in Gabon and Congo and now rivals hunting as a threat to apes. Gorillas and common chimpanzees should be elevated immediately to 'critically endangered' status. Without aggressive investments in law enforcement, protected area management and Ebola prevention, the next decade will see our closest relatives pushed to the brink of extinction.

  8. The state of South Carolina's forests, 2001

    Treesearch

    Roger C. Conner; Tim Adams; Brett J. Butler; William A. Bechtold; Tony G. Johnson; Sonja N. Oswalt; Gretchen Smith; Susan Will-Wolf; Christopher W. Woodall

    2004-01-01

    Forest land area in South Carolina amounted to 12.4 million acres, including 12.2 million acres of timberland. Nonindustrial-private timberland amounted to 8.9 million acres, a decline of less than 1 percent since 1993. Family forest owners dominate the private ownership group with 357,000 landowners who collectively control 7.1 million acres of forest land in the...

  9. Rapid decline of the volcanically threatened Montserrat oriole.

    Treesearch

    Geoff M. Hilton; Phil W. Atkinson; Gerard A.L. Gray; Wayne J. Arendt; David W. Gibbons

    2003-01-01

    Prior to 1995, the Montserrat oriole (Icterus oberi) was confined to ca. 30 km2 of hill forest on the Lesser Antillean island of Montserrat, but was not listed as globally threatened. Since then, the eruption of the Soufriere Hills volcano has destroyed more than half of the species’ range. Recent intensive monitoring has indicated that the species has also declined...

  10. Alternative forest resource use - outdoor recreation and rural economics

    Treesearch

    Ellene Kebede; John Schelhas; Janet Haslerig

    2008-01-01

    Since the 1980s demand for outdoor recreation has been increasing in the United States. Growing income and change in lifestyles have been cited as factors contributing to the increase in demand. This period also coincided with a decline in timber prices and loss of income to forest land owners. Forest-based recreation has intensified as a part of forest management...

  11. A national assessment of physical activity on US national forests

    Treesearch

    Jeffrey D. Kline; Randall S. Rosenberger; Eric M. White

    2011-01-01

    In an era of declining timber harvests on federal lands, the US Forest Service has sought to better describe the public benefits associated with the nation's continued investment in managing the national forests. We considered how national forests contribute to public health by providing significant outdoor recreation opportunities. Physical inactivity has become...

  12. Chapter 36: Status of Forest Habitat of the Marbled Murrelet

    Treesearch

    David A. Perry

    1995-01-01

    Marbled Murrelets (Brachyramphus marmoratus) have been shown to be dependant upon old-growth forests for nesting habitat. These forests have declined over the last century as they are cut for human use. This paper reviews the current status of old-growth forests along the west coast, in both the United States and Canada.

  13. Intraguild Predation and Native Lady Beetle Decline

    PubMed Central

    Gardiner, Mary M.; O'Neal, Matthew E.; Landis, Douglas A.

    2011-01-01

    Coccinellid communities across North America have experienced significant changes in recent decades, with declines in several native species reported. One potential mechanism for these declines is interference competition via intraguild predation; specifically, increased predation of native coccinellid eggs and larvae following the introduction of exotic coccinellids. Our previous studies have shown that agricultural fields in Michigan support a higher diversity and abundance of exotic coccinellids than similar fields in Iowa, and that the landscape surrounding agricultural fields across the north central U.S. influences the abundance and activity of coccinellid species. The goal of this study was to quantify the amount of egg predation experienced by a native coccinellid within Michigan and Iowa soybean fields and explore the influence of local and large-scale landscape structure. Using the native lady beetle Coleomegilla maculata as a model, we found that sentinel egg masses were subject to intense predation within both Michigan and Iowa soybean fields, with 60.7% of egg masses attacked and 43.0% of available eggs consumed within 48 h. In Michigan, the exotic coccinellids Coccinella septempunctata and Harmonia axyridis were the most abundant predators found in soybean fields whereas in Iowa, native species including C. maculata, Hippodamia parenthesis and the soft-winged flower beetle Collops nigriceps dominated the predator community. Predator abundance was greater in soybean fields within diverse landscapes, yet variation in predator numbers did not influence the intensity of egg predation observed. In contrast, the strongest predictor of native coccinellid egg predation was the composition of edge habitats bordering specific fields. Field sites surrounded by semi-natural habitats including forests, restored prairies, old fields, and pasturelands experienced greater egg predation than fields surrounded by other croplands. This study shows that intraguild

  14. Decline of ectomycorrhizal fungi following a mountain pine beetle epidemic.

    PubMed

    Treu, Roland; Karst, Justine; Randall, Morgan; Pec, Gregory J; Cigan, Paul W; Simard, Suzanne W; Cooke, Janice E K; Erbilgin, Nadir; Cahill, James F

    2014-04-01

    Forest die-off caused by mountain pine beetle (MPB; Dendroctonus ponderosa) is rapidly transforming western North American landscapes. The rapid and widespread death of lodgepole pine (Pinus contorta) will likely have cascading effects on biodiversity. One group particularly prone to such declines associated with MPB are ectomycorrhizal fungi, symbiotic organisms that can depend on pine for their survival, and are critical for stand regeneration. We evaluated the indirect effects of MPB on above- (community composition of epigeous sporocarps) and belowground (hyphal abundance) occurrences of ectomycorrhizal fungi across 11 forest stands. Along a gradient of mortality (0-82% pine killed), macromycete community composition changed; this shift was driven by a decrease in the species richness of ectomycorrhizal fungi. Both the proportion of species that were ectomycorrhizal and hyphal length in the soil declined with increased MPB-caused pine mortality; < 10% of sporocarp species were ectomycorrhizal in stands with high pine mortality compared with > 70% in stands without MPB attacks. The rapid range expansion of a native insect results not only in the widespread mortality of an ecologically and economically important pine species, but the effect of MPB may also be exacerbated by the concomitant decline of fungi crucial for recovery of these forests.

  15. The use of biomarkers in biomonitoring: a 2-tier approach assessing the level of pollutant-induced stress syndrome in sentinel organisms.

    PubMed

    Viarengo, A; Lowe, D; Bolognesi, C; Fabbri, E; Koehler, A

    2007-09-01

    The paper outlines a 2-tier approach for wide-scale biomonitoring programmes. To obtain a high level of standardization, we suggest the use of caged organisms (mussels or fish). An "early warning", highly sensitive, low-cost biomarker is employed in tier 1 (i.e. lysosomal membrane stability (LMS) and survival rate, a marker for highly polluted sites). Tier 2 is used only for animals sampled at sites in which LMS changes are evident and there is no mortality, with a complete battery of biomarkers assessing the levels of pollutant-induced stress syndrome. Possible approaches for integrating biomarker data in a synthetic index are discussed, along with our proposal to use a recently developed Expert System. The latter system allows a correct selection of biomarkers at different levels of biological organisation (molecular/cellular/tissue/organism) taking into account trends in pollutant-induced biomarker changes (increasing, decreasing, bell-shape). A selection of biomarkers of stress, genotoxicity and exposure usually employed in biomonitoring programmes is presented, together with a brief overview of new biomolecular approaches.

  16. Acid phosphatase activity in liver macrophage aggregates as a marker for pollution-induced immunomodulation of the non-specific immune response in fish

    NASA Astrophysics Data System (ADS)

    Broeg, Katja

    2003-10-01

    The activity of acid phosphatase in liver macrophage aggregates (MA-AP) of different fish species was used as a marker for a pollution-induced modulation of the digestive capacity of phagocytes, since functions of the non-specific immune response play a central role in the maintenance of animals' health. Based upon the investigation of more than 900 individual flounders (Platichthys flesus) and mullets (Liza aurata), natural variations, gender-specific differences and pollution-induced alterations in AP activity are demonstrated in this study. MA-AP activity was dependent on temperature and season but, nevertheless, distinctions between differently polluted areas were visible in all sampling campaigns with lowest MA-AP activity in fish from the polluted areas of the German Bight and the Israeli coast of the Mediterranean Sea. For organochlorine contaminants, as well as for mercury and copper, a significant correlation could be observed between residue concentrations in fish tissues and MA-AP activity. In all cases, except mercury which showed a positive correlation, AP activity was suppressed in animals with a high contaminant burden. MA-AP activity turned out to give reliable and consistent results for a quantification of immunomodulation in both fish species.

  17. Historical amphibian declines and extinctions in Brazil linked to chytridiomycosis.

    PubMed

    Carvalho, Tamilie; Becker, C Guilherme; Toledo, Luís Felipe

    2017-02-08

    The recent increase in emerging fungal diseases is causing unprecedented threats to biodiversity. The origin of spread of the frog-killing fungus Batrachochytrium dendrobatidis (Bd) is a matter of continued debate. To date, the historical amphibian declines in Brazil could not be attributed to chytridiomycosis; the high diversity of hosts coupled with the presence of several Bd lineages predating the reported declines raised the hypothesis that a hypervirulent Bd genotype spread from Brazil to other continents causing the recent global amphibian crisis. We tested for a spatio-temporal overlap between Bd and areas of historical amphibian population declines and extinctions in Brazil. A spatio-temporal convergence between Bd and declines would support the hypothesis that Brazilian amphibians were not adapted to Bd prior to the reported declines, thus weakening the hypothesis that Brazil was the global origin of Bd emergence. Alternatively, a lack of spatio-temporal association between Bd and frog declines would indicate an evolution of host resistance in Brazilian frogs predating Bd's global emergence, further supporting Brazil as the potential origin of the Bd panzootic. Here, we Bd-screened over 30 000 museum-preserved tadpoles collected in Brazil between 1930 and 2015 and overlaid spatio-temporal Bd data with areas of historical amphibian declines. We detected an increase in the proportion of Bd-infected tadpoles during the peak of amphibian declines (1979-1987). We also found that clusters of Bd-positive samples spatio-temporally overlapped with most records of amphibian declines in Brazil's Atlantic Forest. Our findings indicate that Brazil is post epizootic for chytridiomycosis and provide another piece to the puzzle to explain the origin of Bd globally. © 2017 The Author(s).

  18. Development history and bibliography of the US Forest Service crown-condition indicator for forest health monitoring

    Treesearch

    KaDonna Randolph

    2013-01-01

    Comprehensive assessment of individual-tree crown condition by the US Department of Agriculture, Forest Service, Forest Inventory and Analysis (FIA) Program has its origins in the concerns about widespread forest decline in Europe and North America that developed in the late 1970s and early 1980s. Programs such as the US National Acid Precipitation Assessment Program,...

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

    Treesearch

    Sharon M. Hood; Stephen Baker; Anna Sala

    2016-01-01

    Fire frequency in low-elevation coniferous forests in western North America has greatly declined since the late 1800s. In many areas, this has increased tree density and the proportion of shade-tolerant species, reduced resource availability, and increased forest susceptibility to forest insect pests and high-severity wildfire. In response, treatments are...

  20. Spatio-Temporal Trends of Oak Decline and Mortality under Periodic Regional Drought in the Ozark Highlands of Arkansas and Missouri

    Treesearch

    Zhaofei Fan; Xiuli Fan; Michael K. Crosby; W. Keith Moser; Hong He; Martin A. Spetich; Stephen R. Shifley

    2012-01-01

    At the forest landscape/region level, based on annual Forest Inventory and Analysis plot data from 1999 to 2010, oak decline and mortality trends for major oak species (groups) were examined in the Ozark Highlands of Arkansas and Missouri. Oak decline has elevated cumulative mortality of red oak species to between 11 and 15 percent in terms of relative density and...

  1. Changing national forest values: A content analysis. Forest Service research paper

    SciTech Connect

    Bengston, D.N.; Xu, Z.

    1995-11-01

    This evolution of forest values is currently being widely discussed and debated in the forestry community. It is often claimed that a fundamental shift in forest values has taken place in recent decades. Gordon argued that a shift in public values is part of the explanation for the declining influence of the multiple-use sustained-yield paradigm of forest management. It is increasingly recognized that the values people hold about forest ecosystems are an important part of the social underpinning of ecosystem management, the emerging forest management paradigm. In either case, values play a critical role in identifying ecosystem management goals, setting the context for decisionmaking, and guiding our choices.

  2. [A review on disturbance ecology of forest].

    PubMed

    Zhu, Jiaojun; Liu, Zugen

    2004-10-01

    More than 80% of terrestrial ecosystems have been influenced by natural disasters, human activities and the combination of both natural and human disturbances. Forest ecosystem, as one of the most important terrestrial ecosystems, has also been disturbed without exception. Under the disturbance from natural disasters and human activities, particularly from the unreasonable activities of human beings, forest decline or forest degradation has become more and more severe. For this reason, sustaining or recovering forest service functions is one of the current purposes for managing forest ecosystems. In recent decades, the studies on disturbed ecosystems have been carried out frequently, especially on their ecological processes and their responses to the disturbances. These studies play a very important role in the projects of natural forest conservation and the construction of ecological environment in China. Based on a wide range of literatures collection on forest disturbance research, this paper discussed the fundamental concepts of disturbance ecology, the relationships between forest management and disturbance, and the study contents of forest disturbance ecology. The major research topics of forest disturbance ecology may include: 1) the basic characteristics of disturbed forests; 2) the processes of natural and human disturbances; 3) the responses of forests ecosystem to the disturbances; 4) the main ecological processes or the consequential results of disturbed forests, including the change of biodiversity, soil nutrient and water cycle, eco-physiology and carbon cycle, regeneration mechanism of disturbed forests and so on; 5) the relationships between disturbances and forest management; and 6) the principles and techniques for the management of disturbed forests. This review may be helpful to the management of disturbed forest ecosystem, and to the projects of natural forest conservation in China.

  3. Shrinking tropical forests, human agents of change, and conservation policy.

    PubMed

    Rudel, Thomas K

    2006-12-01

    Human agents of landscape transformation in the tropics affect forests differently as the forests decline in size. Five agents of change--road builders, corporate concession holders, community forest managers, park advocates, and urban consumers--have different effects on large forests in remote tropical regions than they do on remnant forests in settled agricultural regions. Because forests vary so much in size across tropical regions, these differences in the effects of agents on forests have important implications for regional conservation efforts. To make these implications explicit, I compared the effects of the five agents in regions with large forests with their effects in regions with small forests. The comparisons indicated that, as forests declined in size, new roads no longer destroyed forests, corporate loggers left the forests, community forest managers became more effective, parks became less feasible as a means of conservation, and urban consumers initiated tree planting. My results suggest that awareness about the changing effects of humans on landscapes with shrinking forests can serve as a useful tool in formulating regionally appropriate policies for conserving tropical forests.

  4. Forest Plantations

    Treesearch

    D. Zhang; J.A. Stanturf

    2008-01-01

    Between the extremes of afforestation and unaided naturalregeneration of natural forests, there is a range offorest conditions in which human intervention occurs.Previously, forest plantations were defined as...

  5. Forest Resources

    SciTech Connect

    2016-06-01

    Forest biomass is an abundant biomass feedstock that complements the conventional forest use of wood for paper and wood materials. It may be utilized for bioenergy production, such as heat and electricity, as well as for biofuels and a variety of bioproducts, such as industrial chemicals, textiles, and other renewable materials. The resources within the 2016 Billion-Ton Report include primary forest resources, which are taken directly from timberland-only forests, removed from the land, and taken to the roadside.

  6. The role of old forests and big trees in forest carbon sequestration in the Pacific Northwest

    Treesearch

    Andrew N. Gray

    2015-01-01

    Forest ecosystems are an important component of the global carbon (C) cycle. Recent research has indicated that large trees in general, and old-growth forests in particular, sequester substantial amounts of C annually. C sequestration rates are thought to peak and decline with stand age but the timing and controls are not well-understood. The objectives of this study...

  7. Using silviculture to sustain upland oak forests under stress on the Daniel Boone National Forest, Kentucky

    Treesearch

    Callie Jo Schweitzer; Kurt W. Gottschalk; Jeff W. Stringer; Stacy L. Clark; David L. Loftis

    2011-01-01

    We used a large-scale silvicultural assessment designed to examine the efficacy of five stand-level prescriptions in reducing the potential impacts of gypsy moth infestations and oak decline on upland hardwood forests in Kentucky's Daniel Boone National Forest. Prescriptions involved a mix of intermediate stand treatments aimed at increasing residual tree vigor...

  8. Area of old-growth forests in California, Oregon, and Washington. Forest Service research bulletin

    SciTech Connect

    Bolsinger, C.L.; Waddell, K.L.

    1993-12-01

    An area of old-growth forests in California, Oregon, and Washington has declined significantly in the second half of the 20th century. The report summarizes available information on old-growth forest area by ownership in California, Oregon, and Washington. Old-growth definitions used by the various owners and agencies are provided.

  9. Threats to at-risk species in America's private forests: a Forests on the Edge report

    Treesearch

    Susan M. Stein; Mary A. Carr; Ronald E. McRoberts; Lisa G. Mahal; Sara J. Comas

    2010-01-01

    More than 4,600 native animal and plant species associated with private forests in the United States are at risk of decline or extinction. This report identifies areas across the conterminous United States where at-risk species habitats in rural private forests are most likely to decrease because of increases in housing density from 2000 to 2030. We also identify areas...

  10. Georgia's forests

    Treesearch

    Raymond M. Sheffield; Herbert A. Knight

    1984-01-01

    In accordance with the Forest and rangeland renewable resources planning act(RPA) of 1974, the fifth inventory of Georgia’s forest was expanded to accommodate nontimber as well as timber resources. This report presents the principal findings concerning the extent of condition of forest lands, associated timber volumes, and rates of growth and removals. Nontimber...

  11. Forest ecology

    Treesearch

    Malcolm North

    2014-01-01

    Building on information summaries in two previous general technical reports (PSW-GTR-220 and PSW-GTR-237), this chapter focuses on four topics raised by forest managers and stakeholders as relevant to current forest management issues. Recent studies suggest that the gap size in lower and mid-elevation historical forests with active fire regimes was often about 0.12 to...

  12. Growth declines in red spruce

    SciTech Connect

    McLaughlin, S.B. ); Adams, H.S. )

    1987-10-01

    In this letter, the authors take issue with Zedaker, Hyink, and Smith who have indicated that observed red spruce growth declines can be expected based on growth trends for even-aged stands of red spruce as documented in Meyer (1929). Recently, an examination was made of stand stocking levels at 750 sites where red spruce were cored and neither the rate of growth decline nor the extent of mortality were found to be related to stand stocking levels or previous disturbance history. The authors conclude that the Meyer data do not represent an appropriate model for stand dynamics of old-growth, high-elevation stands and no not adequately explain the growth declines observed at many of those sites.

  13. Forest turnover rates follow global and regional patterns of productivity

    USGS Publications Warehouse

    Stephenson, N.L.; van Mantgem, P.J.

    2005-01-01

    Using a global database, we found that forest turnover rates (the average of tree mortality and recruitment rates) parallel broad-scale patterns of net primary productivity. First, forest turnover was higher in tropical than in temperate forests. Second, as recently demonstrated by others, Amazonian forest turnover was higher on fertile than infertile soils. Third, within temperate latitudes, turnover was highest in angiosperm forests, intermediate in mixed forests, and lowest in gymnosperm forests. Finally, within a single forest physiognomic type, turnover declined sharply with elevation (hence with temperature). These patterns of turnover in populations of trees are broadly similar to the patterns of turnover in populations of plant organs (leaves and roots) found in other studies. Our findings suggest a link between forest mass balance and the population dynamics of trees, and have implications for understanding and predicting the effects of environmental changes on forest structure and terrestrial carbon dynamics. ??2005 Blackwell Publishing Ltd/CNRS.

  14. Health of North American forests: Stress and risk assessment

    SciTech Connect

    Smith, W.H. )

    1990-01-01

    The 1980s will be remembered by forest professionals as a decade of intense and widespread societal concern for the vitality and integrity of forest systems. Daily reports of tropical deforestation and temperate forest decline have heightened social consciousness of forest health. It is therefore appropriate, as we enter the 1990s, to assess the health of our forests and propose new initiatives in this critically important area. Making generalizations about the health of North American forests is difficult because of the extraordinary diversity of forests, management regimes, and stress factors. This overview article summarizes forest health fundamentals, significant health risks, and priorities in future forest health management for temperate forests of the United States.

  15. Pollution-induced community tolerance to non-steroidal anti-inflammatory drugs (NSAIDs) in fluvial biofilm communities affected by WWTP effluents.

    PubMed

    Corcoll, Natàlia; Acuña, Vicenç; Barceló, Damià; Casellas, Maria; Guasch, Helena; Huerta, Belinda; Petrovic, Mira; Ponsatí, Lidia; Rodríguez-Mozaz, Sara; Sabater, Sergi

    2014-10-01

    We assessed the tolerance acquired by stream biofilms to two non-steroidal anti-inflammatory-drugs (NSAIDs), ibuprofen and diclofenac. Biofilms came from a stream system receiving the effluent of a wastewater treatment plant (WWTP). The response of biofilms from a non-polluted site (upstream the WWTP) was compared to that of others downstream with relevant and decreasing levels of NSAIDs. Experiments performed in the laboratory following the pollution-induced community tolerance (PICT) approach determined that both algae and microbial communities from biofilms of the sites exposed at the highest concentrations of ibuprofen and diclofenac acquired tolerance to the mixture of these NSAIDs occurring at the sites. It was also observed that the chronic pollution by the WWTP effluent affected the microbial metabolic profile, as well as the structure of the algal community. The low (at ng L(-1) level) but chronic inputs of pharmaceuticals to the river ecosystem result in tolerant communities of lower diversity and altered microbial metabolism.

  16. Recent Honey Bee Colony Declines

    DTIC Science & Technology

    2007-03-26

    Population Losses . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 Symptoms of Colony Collapse Disorder...MAAREC), which represents beekeeping associations in New Jersey, Maryland, Delaware, Pennsylvania, and West Virginia. Past Honey Bee Population Losses... population losses due to bee pests, parasites, pathogens, and disease. Most notable are declines due to two parasitic mites, the Varroa destructor and the

  17. Functional decline in old age

    PubMed Central

    Hébert, R

    1997-01-01

    Functional decline is a common condition, occurring each year in nearly 12% of Canadians 75 years of age and older. The model of functional health proposed by the World Health Organization (WHO) represents a useful theoretical framework and is the basis for the SMAF (Système de measure de l'autonomie fonctionelle or Functional Autonomy Measurement System), an instrument that measures functional autonomy. The functional decline syndrome, in which functional autonomy is diminished or lost, may present as an acute condition, i.e., a medical emergency for which the patient must be admitted to a geriatric assessment unit. The subacute form is a more insidious condition in which the patient requires comprehensive assessment and a rehabilitation program. A preventive approach based on screening of those at risk and early intervention should prevent or delay the appearance of functional decline or diminish its consequences. Effective strategies for the prevention of or rehabilitation from functional decline will help reduce the incidence of disabilities and the period of dependence near the end of life. These strategies are absolute prerequisites for controlling sociohealth expenses and, most importantly, for allowing people to live independently in old age. PMID:9347774

  18. Declining Enrollment--A Blessing.

    ERIC Educational Resources Information Center

    Imhof, Howard E.

    This report describes how a New York school district took advantage of a decline in elementary school enrollment to restructure the district's educational program, reduce staff requirements, and eliminate double shifting at the district's junior high and high school. The district's plan involved closing one of the three elementary schools and…

  19. Impact of Declining Rural Infrastructure.

    ERIC Educational Resources Information Center

    McKenzie, Fiona Haslem

    A study investigated the impact of declining rural community infrastructure on social, environmental, and economic well-being in Western Australia's central wheatbelt. Questionnaires were completed by 398 residents of the central wheatbelt, on-farm interviews were conducted with 68 respondents, and 4 focus groups were held in area towns.…

  20. The Decline of the Audience.

    ERIC Educational Resources Information Center

    Jensen, Marvin D.

    The decline of manners prevalent in American audiences can be reversed only by finding and addressing the causes for poor behavior. One theory suggests that social stresses have a ripple effect, eroding generosity and spawning a meanness of spirit that is eventually reflected in audience behavior. A related theory suggests that audience rudeness…

  1. Declining Sunshine for Phoenix Lander

    NASA Image and Video Library

    2008-09-30

    The yellow line on this graphic indicates the number of hours of sunlight each sol, or Martian day, beginning with the entire Martian day about 24 hours and 40 minutes for the first 90 sols, then declining to no sunlight by about sol 300.

  2. Spatial relationships between sugar maple (Acer saccharum Marsh), sugar maple decline, slope, aspect, and atmospheric deposition in northern Pennsylvania

    Treesearch

    Patrick Drohan; Susan Stout; Gary Peterson

    1999-01-01

    Sugar maple decline began to affect Allegheny Plateau forests in the early to mid-1980s. The forests of the region were exposed to several stresses In the period frorn 1985- 1996, including droughts during 1988, 1991, and 1995. Additionally, both native and exotic insects reached epidemic levels during this period (see, for example, Rhoads, 1993). Other documented...

  3. Chinese culture and fertility decline.

    PubMed

    Wu, C; Jia, S

    1992-01-01

    Coale has suggested that cultural factors exert a significant influence on fertility reduction; countries in the "Chinese cultural circle" would be the first to show fertility decline. In China, the view was that traditional Chinese culture contributed to increased population. This paper examines the nature of the relationship between Chinese culture and fertility. Attention was directed to a comparison of fertility rates of developing countries with strong Chinese cultural influence and of fertility within different regions of China. Discussion was followed by an explanation of the theoretical impact of Chinese culture on fertility and direct and indirect beliefs and practices that might either enhance or hinder fertility decline. Emigration to neighboring countries occurred after the Qing dynasty. Fertility after the 1950s declined markedly in Japan, Singapore, Hong Kong, South Korea, Taiwan, and mainland China: all countries within the Chinese cultural circle. Other countries within the Chinese circle which have higher fertility, yet lower fertility than other non-Chinese cultural countries, are Malaysia, Thailand, and Indonesia. Within China, regions with similar fertility patterns are identified as coastal regions, central plains, and mountainous and plateau regions. The Han ethnic group has lower fertility than that of ethnic minorities; regions with large Han populations have lower fertility. Overseas Chinese in East Asian countries also tend to have lower fertility than their host populations. Chinese culture consisted of the assimilation of other cultures over 5000 years. Fertility decline was dependent on the population's desire to limit reproduction, favorable social mechanisms, and availability of contraception: all factors related to economic development. Chinese culture affects fertility reduction by affecting reproductive views and social mechanisms directly, and indirectly through economics. Confucianism emphasizes collectivism, self

  4. Predicting Succession under Conditions of Enrollment Decline.

    ERIC Educational Resources Information Center

    Berger, Michael A.

    1984-01-01

    Using 56 school districts that experienced enrollment declines, this study describes the variables in superintendent succession amidst declining enrollments and locates the strongest predictors of succession. (JW)

  5. Impact of community-based forest management on forest protection: evidence from an aid-funded project in Ethiopia.

    PubMed

    Takahashi, Ryo; Todo, Yasuyuki

    2012-09-01

    Many African countries have adopted community-based forest management (CBFM) to prevent deforestation. However, empirical studies have not reached a consensus on the effectiveness of CBFM. The purpose of this study is to examine the impact of the establishment of participatory forest management associations in Ethiopia. We used remote sensing data to gauge the change in forest area and employed a two-stage least squares model to correct for possible biases. The results indicate that the forest area managed by forest associations declines more in the year of establishment than forest areas with no association. This finding suggests that villagers may engage in "last-minute" logging. However, 1 year after the establishment of the forest associations, the forest area of the associations increased substantially, most likely because the associations monitor illegal logging, enabling the regeneration of open areas within the registered forest area. On average, the forest area of the forest associations increased by 1.5 % in the first 2 years, whereas forest areas not managed as part of an association declined by 3.3 %. The cumulative impact over 2 years yields a net increase in the rate of change of 4.8 %. These results demonstrate that it is important to improve the monitoring of forest areas during the initial establishment of participatory forest management associations to maximize the effects of association establishment.

  6. Risk factors of oak decline and regional mortality patterns in the Ozark Highlands of Arkansas and Missouri

    Treesearch

    Martin A. Spetich; Zhaofei Fan; Xiuli Fan; Hong He; Stephen R. Shifley; W. Keith Moser

    2011-01-01

    Since the late 1970s, oak decline and mortality have plagued Midwestern-upland oak-hickory forests, particularly species in the red oak group (Quercus Section Lobatae) across the Ozark Highlands of Missouri, Arkansas, and Oklahoma (Dwyer and others 1995). Drought is a common inciting factor in oak decline, while advanced tree age is considered a...

  7. A remote sensing-assisted risk rating study to predict oak decline and recovery in the Missouri Ozark Highlands, USA

    Treesearch

    Cuizhen Wang; Hong S. He; John M. Kabrick

    2008-01-01

    Forests in the Ozark Highlands underwent widespread oak decline affected by severe droughts in 1999-2000. In this study, the differential normalized difference water index was calculated to detect crown dieback. A multi-factor risk rating system was built to map risk levels of stands. As a quick response to drought, decline in 2000 mostly occurred in stands at low to...

  8. Why do forest products become less available?A pan-tropical comparison of drivers of forest-resource degradation

    NASA Astrophysics Data System (ADS)

    Hermans-Neumann, Kathleen; Gerstner, Katharina; Geijzendorffer, Ilse R.; Herold, Martin; Seppelt, Ralf; Wunder, Sven

    2016-12-01

    Forest products provide an important source of income and wellbeing for rural smallholder communities across the tropics. Although tropical forest products frequently become over-exploited, only few studies explicitly address the dynamics of degradation in response to socio-economic drivers. Our study addresses this gap by analyzing the factors driving changes in tropical forest products in the perception of rural smallholder communities. Using the poverty and environment network global dataset, we studied recently perceived trends of forest product availability considering firewood, charcoal, timber, food, medicine, forage and other forest products. We looked at a pan-tropical sample of 233 villages with forest access. Our results show that 90% of the villages experienced declining availability of forest resources over the last five years according to the informants. Timber and fuelwood together with forest foods were featured as the most strongly affected, though with marked differences across continents. In contrast, availability of at least one main forest product was perceived to increase in only 39% of the villages. Furthermore, the growing local use of forest resources is seen as the main culprit for the decline. In villages with both growing forest resource use and immigration—vividly illustrating demographic pressures—the strongest forest resources degradation was observed. Conversely, villages with little or no population growth and a decreased use of forest resources were most likely to see significant forest-resource increases. Further, villages are less likely to perceive resource declines when local communities own a significant share of forest area. Our results thus suggest that perceived resource declines have only exceptionally triggered adaptations in local resource-use and management patterns that would effectively deal with scarcity. Hence, at the margin this supports neo-Malthusian over neo-Boserupian explanations of local resource

  9. Early changes in physical tree characteristics during an oak decline event in the Ozark highlands

    Treesearch

    Martin A. Spetich

    2006-01-01

    An oak decline event is severely affecting up to 120 000 ha in the Ozark National Forest of Arkansas. Results of early changes in physical tree characteristics during that event are presented. In the fall and winter of 1999 and 2000, we established research plots on a site that would become a center of severe oak decline. In August 2000, standing trees > 14 cm in...

  10. Predicting rarity and decline in animals, plants, and mushrooms based on species attributes and indicator groups

    PubMed Central

    Musters, C J M; Kalkman, Vincent; van Strien, Arco

    2013-01-01

    In decisions on nature conservation measures, we depend largely on knowledge of the relationship between threats and environmental factors for a very limited number of species groups, with relevant environmental factors often being deduced from the relationship between threat and species traits. But can relationships between traits and levels of threats be identified across species from completely different taxonomic groups; and how accurately do well-known taxonomic groups indicate levels of threat in other species groups? To answer these questions, we first made a list of 152 species attributes of morphological and demographic traits and habitat requirements. Based on these attributes we then grew random forests of decision trees for 1183 species in the 18 different taxonomic groups for which we had Red Lists available in the Netherlands, using these to classify animals, plants, and mushrooms according to their rarity and decline. Finally, we grew random forests for four species groups often used as indicator groups to study how well the relationship between attribute and decline within these groups reflected that relationship within the larger taxonomic group to which these groups belong. Correct classification of rarity based on all attributes was as high as 88% in animals, 85% in plants, and 94% in mushrooms and correct classification of decline was 78% in animals, 69% in plants, and 70% in mushrooms. Vertebrates indicated decline in all animals well, as did birds for all vertebrates and vascular plants for all plants. However, butterflies poorly indicated decline in all insects. Random forests are a useful tool to relate rarity and decline to species attributes thereby making it possible to generalize rarity and decline to a wider set of species groups. Random forests can be used to estimate the level of threat to complete faunas and floras of countries or regions. In regions like the Netherlands, conservation policy based on attributes known to be relevant

  11. White ash decline in Massachusetts: The role of site and climate factors

    SciTech Connect

    Woodcock, H.

    1993-01-01

    White ash increased in basal area between 1962 to 1979 on continuous forest inventory (CFI) plots in Massachusetts, but 20% of 82 ash plots (>10% basal area ash) were classified as decline (from growth and mortality rates). Reclassification of 18 plots on the basis of % crown dieback in 1991 validated the decline classification system and indicated little change in plot decline status in the past decade. Mortality of dominant and co-dominant trees was associated with sites characterized by a high landscape position and soils shallow to bedrock (R[sup 2] = 0.6926, p = 0.0007). Ephemeral streams were common; these sites would be prone to fluctuations in moisture supply. Similar relationships were identified on three 2 ha intensive study sites. Distribution of decline-prone microsite types and decline of ash was highly heterogeneous on the study sites (but not on the CFI plots). Tree-ring analysis showed that trees growing on [open quote]decline-prone[close quote] sites were sensitive to drought (measured by growing year Palmer Drought Severity Index) and indicated that the present episode of decline on these sites began in the 1960s, the most severe drought period since 1836. Ash yellows was identified on one and possibly the second of the two study sites with ash decline, and on two of the three decline CFI plots resampled in 1991. Sites with a SI > 80 supported healthy trees in 1991. For sites with a SI < 80, a decline index estimated from landscape position and soil moisture predicted the distribution of decline on the two intensive study sites on which ash decline was present and shows promise as a method of evaluating sites for their potential for ash decline. The relationship between decline and site factors was unique to white ash among several species tested (i.e. it was species-specific). On ash decline sites, red oak and sugar maple increased in relative importance.

  12. Responses of riparian cottonwoods to alluvial water table declines

    USGS Publications Warehouse

    Scott, M.L.; Shafroth, P.B.; Auble, G.T.

    1999-01-01

    extent of morphological responses and mortality of Populus to the rate, depth, and duration of water table declines can assist in the design of management prescriptions to minimize impacts of alluvial groundwater depletion on existing riparian Populus forests.

  13. The future of tropical forests.

    PubMed

    Wright, S Joseph

    2010-05-01

    Five anthropogenic drivers--land use change, wood extraction, hunting, atmospheric change, climate change--will largely determine the future of tropical forests. The geographic scope and intensity of these five drivers are in flux. Contemporary land use change includes deforestation (approximately 64,000 km(2) yr(-1) for the entire tropical forest biome) and natural forests regenerating on abandoned land (approximately 21,500 km(2) yr(-1) with just 29% of the biome evaluated). Commercial logging is shifting rapidly from Southeast Asia to Africa and South America, but local fuelwood consumption continues to constitute 71% of all wood production. Pantropical rates of net deforestation are declining even as secondary and logged forests increasingly replace old-growth forests. Hunters reduce frugivore, granivore and browser abundances in most forests. This alters seed dispersal, seed and seedling survival, and hence the species composition and spatial template of plant regeneration. Tropical governments have responded to these local threats by protecting 7% of all land for the strict conservation of nature--a commitment that is only matched poleward of 40 degrees S and 70 degrees N. Protected status often fails to stop hunters and is impotent against atmospheric and climate change. There are increasing reports of stark changes in the structure and dynamics of protected tropical forests. Four broad classes of mechanisms might contribute to these changes. Predictions are developed to distinguish among these mechanisms.

  14. Decline of the oil cartel

    SciTech Connect

    Fieleke, N.S.

    1986-07-01

    A review of the development that led to the current decline in oil prices concludes that sharp relative price changes have been a major source of world economic instability for the past 13 years. The results for oil-importing countries have been cycles of inflation and contraction followed by inflation and rapid growth. Some see the recent price decline as an effort by OPEC to regain enough power to bring about an eventual price rise. Although past price and production relationships indicate that OPEC has operated as a cartel, the author sees current efforts to persuade non-OPEC producers to lower their production as an indication of weakness. The Strategic Petroleum Reserve could help the US cope with any future supply disruption. 7 figures, 3 tables.

  15. Normal cognitive decline or dementia?

    PubMed

    Ebmeier, Klaus P

    2010-01-01

    Cognitive speed, inhibitory function, and memory decline with age while crystallised, particularly verbal, abilities remain largely intact. Poor health, fewer years of education, lower activity, the presence of the APOE E4 allele, and high BP appear to predict faster cognitive decline. Dementia is diagnosed in the presence of objective cognitive impairment, both long- and short-term memory, plus at least one additional (cortical) cognitive deficit, such as dysphasia, dyspraxia, agnosia, or disturbance in executive functioning. In addition, patients have to show significant impairment in social or occupational functioning and a significant decline from previous levels. Both smoking and diabetes increase the risk of all types of dementia, not smoking or even stopping smoking reduces this risk, but better control of type 2 diabetes does not appear to have a measurable effect. Drinking small to moderate amounts of alcohol appears to confer some benefit in ameliorating cognitive decline. There is some evidence that HRT, DHEA, BP lowering in patients without prior cerebrovascular disease, statins, vitamin B6 and procaine are NOT helpful. There is insufficient evidence to establish or refute a beneficial effect for exercise, treatment of type 2 diabetes, omega-3 fatty acids, folic acid with/without vitamin B12, antioxidant vitamins, or ginkgo biloba. Depressive symptoms are more prevalent than dementia. Clinical (major) depression can present with cognitive deterioration, often associated with subjective complaints. Patients with subjective or objective memory impairment, but without functional deterioration, can be referred to the local memory clinic, while demented patients eligible for acetylcholinesterase inhibitor treatment, patients whose diagnosis is unclear and who may need some specific investigations, as well as patients who may benefit from a combined approach with psychotropic drugs and behavioural support should be referred to the local mental health team.

  16. Intracerebral haemorrhage and cognitive decline.

    PubMed

    Murao, K; Rossi, C; Cordonnier, C

    2013-10-01

    Relationships between intracerebral hemorrhage (ICH) and dementia might be of interest since some causes of ICH such as cerebral amyloid angiopathy are strongly linked with dementia, especially Alzheimer's disease. The aim of this narrative review was to highlight the interesting relationship of ICH lesions and cognitive decline leading to dementia. We considered the whole spectrum of hemorrhagic lesions in the brain parenchyma, namely spontaneous ICH and brain microbleeds. Copyright © 2013. Published by Elsevier Masson SAS.

  17. Declining interstitial transsudation in man

    NASA Technical Reports Server (NTRS)

    Demarchin, P.; Lagneaux, D.; Lecomte, J.

    1980-01-01

    Results and methodology of experimentation dealing with declining interstitial transsudation are discussed. Concepts of the formation of interstitial fluids are in agreement with measurements of calf volume in normal young women, in horizontal recumbency or after horizontal immersion. The volume of the calf is reduced when the hydrostatic pressure of the blood column is diminished under the phlebostatic level and when the external pressure is increased by the hydrostatic pressure of a water bath.

  18. National forests

    Treesearch

    Linda A. Joyce; Geoffry M. Blate; Jeremy S. Littell; Steven G. McNulty; Constance I. Millar; Susanne C. Moser; Ronald P. Neilson; Kathy O' Halloran; David L. Peterson

    2008-01-01

    The National Forest System (NFS) is composed of 155 national forests (NFs) and 20 national grasslands (NGs), which encompass a wide range of ecosystems, harbor much of the nation’s biodiversity, and provide myriad goods and services. The mission of the U.S. Forest Service (USFS), which manages the NFS, has broadened from water and timber to sustaining ecosystem health...

  19. Acceleration of oxygen decline in the tropical Pacific over the past decades by aerosol pollutants

    NASA Astrophysics Data System (ADS)

    Ito, T.; Nenes, A.; Johnson, M. S.; Meskhidze, N.; Deutsch, C.

    2016-06-01

    Dissolved oxygen in the mid-depth tropical Pacific Ocean has declined in the past several decades. The resulting expansion of the oxygen minimum zone has consequences for the region's ecosystem and biogeochemical cycles, but the causes of the oxygen decline are not yet fully understood. Here we combine models of atmospheric chemistry, ocean circulation and biogeochemical cycling to test the hypothesis that atmospheric pollution over the Pacific Ocean contributed to the redistribution of oxygen in deeper waters. We simulate the pollution-induced enhancement of atmospheric soluble iron and fixed nitrogen deposition, as well as its impacts on ocean productivity and biogeochemical cycling for the late twentieth century. The model reproduces the magnitude and large-scale pattern of the observed oxygen changes from the 1970s to the 1990s, and the sensitivity experiments reveal the reinforcing effects of pollution-enhanced iron deposition and natural climate variability. Despite the aerosol deposition being the largest in mid-latitudes, its effect on oceanic oxygen is most pronounced in the tropics, where ocean circulation transports added iron to the tropics, leading to an increased regional productivity, respiration and subsurface oxygen depletion. These results suggest that anthropogenic pollution can interact and amplify climate-driven impacts on ocean biogeochemistry, even in remote ocean biomes.

  20. Cognitive decline in Parkinson disease.

    PubMed

    Aarsland, Dag; Creese, Byron; Politis, Marios; Chaudhuri, K Ray; Ffytche, Dominic H; Weintraub, Daniel; Ballard, Clive

    2017-04-01

    Dementia is a frequent problem encountered in advanced stages of Parkinson disease (PD). In recent years, research has focused on the pre-dementia stages of cognitive impairment in PD, including mild cognitive impairment (MCI). Several longitudinal studies have shown that MCI is a harbinger of dementia in PD, although the course is variable, and stabilization of cognition - or even reversal to normal cognition - is not uncommon. In addition to limbic and cortical spread of Lewy pathology, several other mechanisms are likely to contribute to cognitive decline in PD, and a variety of biomarker studies, some using novel structural and functional imaging techniques, have documented in vivo brain changes associated with cognitive impairment. The evidence consistently suggests that low cerebrospinal fluid levels of amyloid-β42, a marker of comorbid Alzheimer disease (AD), predict future cognitive decline and dementia in PD. Emerging genetic evidence indicates that in addition to the APOE*ε4 allele (an established risk factor for AD), GBA mutations and SCNA mutations and triplications are associated with cognitive decline in PD, whereas the findings are mixed for MAPT polymorphisms. Cognitive enhancing medications have some effect in PD dementia, but no convincing evidence that progression from MCI to dementia can be delayed or prevented is available, although cognitive training has shown promising results.

  1. Warming delays autumn declines in photosynthetic capacity in a boreal conifer, Norway spruce (Picea abies).

    PubMed

    Stinziano, Joseph R; Hüner, Norman P A; Way, Danielle A

    2015-12-01

    Climate change, via warmer springs and autumns, may lengthen the carbon uptake period of boreal tree species, increasing the potential for carbon sequestration in boreal forests, which could help slow climate change. However, if other seasonal cues such as photoperiod dictate when photosynthetic capacity declines, warmer autumn temperatures may have little effect on when carbon uptake capacity decreases in these species. We investigated whether autumn warming would delay photosynthetic decline in Norway spruce (Picea abies (L.) H. Karst.) by growing seedlings under declining weekly photoperiods and weekly temperatures either at ambient temperature or a warming treatment 4 °C above ambient. Photosynthetic capacity was relatively constant in both treatments when weekly temperatures were >8 °C, but declined rapidly at lower temperatures, leading to a delay in the autumn decline in photosynthetic capacity in the warming treatment. The decline in photosynthetic capacity was not related to changes in leaf nitrogen or chlorophyll concentrations, but was correlated with a decrease in the apparent fraction of leaf nitrogen invested in Rubisco, implicating a shift in nitrogen allocation away from the Calvin cycle at low autumn growing temperatures. Our data suggest that as the climate warms, the period of net carbon uptake will be extended in the autumn for boreal forests dominated by Norway spruce, which could increase total carbon uptake in these forests.

  2. Landscape dynamics in Mediterranean oak forests under global change: understanding the role of anthropogenic and environmental drivers across forest types.

    PubMed

    Acácio, Vanda; Dias, Filipe S; Catry, Filipe X; Rocha, Marta; Moreira, Francisco

    2017-03-01

    The Mediterranean region is projected to be extremely vulnerable to global change, which will affect the distribution of typical forest types such as native oak forests. However, our understanding of Mediterranean oak forest responses to future conditions is still very limited by the lack of knowledge on oak forest dynamics and species-specific responses to multiple drivers. We compared the long-term (1966-2006) forest persistence and land cover change among evergreen (cork oak and holm oak) and deciduous oak forests and evaluated the importance of anthropogenic and environmental drivers on observed changes for Portugal. We used National Forest Inventories to quantify the changes in oak forests and explored the drivers of change using multinomial logistic regression analysis and an information theoretical approach. We found distinct trends among oak forest types, reflecting the differences in oak economic value, protection status and management schemes: cork oak forests were the most persistent (62%), changing mostly to pines and eucalypt; holm oak forests were less persistent (53.2%), changing mostly to agriculture; and deciduous oak forests were the least persistent (45.7%), changing mostly to shrublands. Drivers of change had distinct importance across oak forest types, but drivers from anthropogenic origin (wildfires, population density, and land accessibility) were always among the most important. Climatic extremes were also important predictors of oak forest changes, namely extreme temperatures for evergreen oak forests and deficit of precipitation for deciduous oak forests. Our results indicate that under increasing human pressure and forecasted climate change, evergreen oak forests will continue declining and deciduous oak forests will be replaced by forests dominated by more xeric species. In the long run, multiple disturbances may change competitive dominance from oak forests to pyrophytic shrublands. A better understanding of forest dynamics and the

  3. Initinal and secondary decline of transport of radionuclides in Fukushima in the terrestrial environment

    NASA Astrophysics Data System (ADS)

    Onda, Yuichi; Taniguchi, Keisuke; Wakiyama, Yoshifumi; Yoshimura, Kazuya; Smith, Hugh; Brake, Will; Iwagami, Sho; Kato, Hiroaki

    2017-04-01

    The Fukushima Daiichi Nuclear Power Plant accident has released massive amount of radiocesium into the terrestrial environment, and the radiocecium have been moved through rainfall and erosional processes. Especially, radiocesium (Cs-137) transfer and flux through river network is important to understand the redistribution of radiocesium in terrestrial environment. An intensive field monitoring campaign has been started including mapping project, immediately after the Fukushima NPP accident including detailed monitoring site in upstream (Yamakiya site), and 30 monitoring sites in downstream river sites. In this presentation, I will present the initial and secondary decline of summary of environmental transfer studies after the Fukushima NPP accident The processes includes forest canopy to ground soil and aquifers, transfer to river and marine. The activity concentration of radiocesium of suspended sediment declining rapidly in rivers until about 1 year after the fallout, then decline slowly, but the tendency of rate of decline differs between rivers. The rate of decline in paddy field and headwater stream is quicker in initial decline followed by slower decline. However, the slow decline of activity concentration of suspend sediment in cropland and decline steadily. We will analyse the difference in initial and secondary decline between rivers using upstream land use and runoff characteristics.

  4. Declining Use of Wild Resources by Indigenous Peoples of the Ecuadorian Amazon.

    PubMed

    Gray, Clark L; Bozigar, Matthew; Bilsborrow, Richard E

    2015-02-01

    Wild product harvesting by forest-dwelling peoples, including hunting, fishing, forest product collection and timber harvesting, is believed to be a major threat to the biodiversity of tropical forests worldwide. Despite this threat, few studies have attempted to quantify these activities across time or across large spatial scales. We use a unique longitudinal household survey (n = 480) to describe changes in these activities over time in 32 indigenous communities from five ethnicities in the northern Ecuadorian Amazon. To provide insight into the drivers of these changes, we also estimate multilevel statistical models of these activities as a function of household and community characteristics. These analyses reveal that participation in hunting, fishing, and forest product collection is high but declining across time and across ethnicities, with no evidence for a parallel decline in resource quality. However, participation in timber harvesting did not significantly decline and there is evidence of a decline in resource quality. Multilevel statistical models additionally reveal that household and community characteristics such as ethnicity, demographic characteristics, wealth, livelihood diversification, access to forest, participation in conservation programs and exposure to external markets are significant predictors of wild product harvesting. These characteristics have changed over time but cannot account for declining participation in resource harvesting. This finding suggests that participation is declining due to changes in the regional-scale social and economic context, including urbanization and the expansion of government infrastructure and services. The lesson for conservationists is that macro-scale social and economic conditions can drive reductions in wild product harvesting even in the absence of successful conservation interventions.

  5. Declining Use of Wild Resources by Indigenous Peoples of the Ecuadorian Amazon

    PubMed Central

    Gray, Clark L.; Bozigar, Matthew; Bilsborrow, Richard E.

    2015-01-01

    Wild product harvesting by forest-dwelling peoples, including hunting, fishing, forest product collection and timber harvesting, is believed to be a major threat to the biodiversity of tropical forests worldwide. Despite this threat, few studies have attempted to quantify these activities across time or across large spatial scales. We use a unique longitudinal household survey (n = 480) to describe changes in these activities over time in 32 indigenous communities from five ethnicities in the northern Ecuadorian Amazon. To provide insight into the drivers of these changes, we also estimate multilevel statistical models of these activities as a function of household and community characteristics. These analyses reveal that participation in hunting, fishing, and forest product collection is high but declining across time and across ethnicities, with no evidence for a parallel decline in resource quality. However, participation in timber harvesting did not significantly decline and there is evidence of a decline in resource quality. Multilevel statistical models additionally reveal that household and community characteristics such as ethnicity, demographic characteristics, wealth, livelihood diversification, access to forest, participation in conservation programs and exposure to external markets are significant predictors of wild product harvesting. These characteristics have changed over time but cannot account for declining participation in resource harvesting. This finding suggests that participation is declining due to changes in the regional-scale social and economic context, including urbanization and the expansion of government infrastructure and services. The lesson for conservationists is that macro-scale social and economic conditions can drive reductions in wild product harvesting even in the absence of successful conservation interventions. PMID:25620805

  6. Reconciling divergent interpretations of quaking aspen decline on the northern Colorado Front Range.

    PubMed

    Kashian, Daniel M; Romme, William H; Regan, Claudia M

    2007-07-01

    Ecologists have debated over the past 65 years whether quaking aspen (Populus tremuloides Michx.) has or has not declined in abundance, vigor, or regeneration in western North America. Many studies have provided divergent interpretations of the condition of aspen forests, leading to difficulty in translating this ecological information into management recommendations. To reconcile these contrasting conclusions and to test the hypothesis that multiple types of aspen decline and persistence occur simultaneously on heterogeneous landscapes, we assessed 91 aspen stands across the northern Colorado Front Range to determine the range of ecological conditions that underlie aspen decline or persistence. Approximately 15% of aspen forest area in our sample exhibited dieback of mature stems coupled with a lack of young trees indicative of declining stands, most often at lower elevations where elk browsing is heavy and chronic, and where effects of fire exclusion have been most significant. However, 52% of the area sampled had multiple cohorts indicative of self-replacing or persistent stands. Conifer dominance was increasing in over 33% of all aspen forest area sampled, most often at high elevations among lodgepole pine (Pinus contorta var. latifolia Englem. ex Wats.) forests. Reconstructions of relative basal area and density of aspen and lodgepole pine in these stands suggest cyclical dominance of these species, where conifers gradually replace aspen over long fire intervals, and aspen vigorously re-establish following stand-replacing fires. The diversity of ecological contexts across the northern Colorado Front Range creates a variety of aspen dynamics leading to decline or persistence, and no single trend describes the general condition of aspen forests in appropriate detail for managers. Active management may be useful in preserving individual stands at fine scales, but management prescriptions should reflect specific drivers of decline in these stands.

  7. Restoration of three forest herbs in the Liliaceae family by manipulating deer herbivory and overstorey and understorey vegetation

    Treesearch

    Cynthia D. Huebner; Kurt W. Gottschalk; Gary W. Miller; Patrick H. Brose

    2010-01-01

    Research on herbaceous vegetation restoration in forests characterised by overstorey tree harvests, excessive deer herbivory, and a dominant fern understorey is lacking. Most of the plant diversity found in Eastern hardwood forests in the United States is found in the herbaceous understorey layer. Loss of forest herbaceous species is an indicator of declining forest...

  8. Texas' forests, 2008

    Treesearch

    James W. Bentley; Consuelo Brandeis; Jason A. Cooper; Christopher M. Oswalt; Sonja N. Oswalt; KaDonna Randolph

    2014-01-01

    This bulletin describes forest resources of the State of Texas at the time of the 2008 forest inventory. This bulletin addresses forest area, volume, growth, removals, mortality, forest health, timber product output, and the economy of the forest sector.

  9. Florida's Forest

    Treesearch

    William A. Bechtold; Herbert A. Knight

    1982-01-01

    In accordance with the Forest and Rangeland renewable Resources planning act (RPA) of 1974, the fifth inventory of Florida’s forests was expanded to accommodate both timber and nontimber evaluations. This report presents the principal findings of the timber evaluation. The nontimber evaluations will be published separately.

  10. Urban forests

    Treesearch

    David J. Nowak; Eric J. Greenfield

    2016-01-01

    Trees and forests are resources that significantly affect the health and well-being of people who live in urban areas where more than 80 percent of the U.S. population resides. These trees within our cities and communities provide many ecosystem services and values to both urban and rural populations. Healthy urban and rural forests are critical for sustaining quality...

  11. The fertility decline in Kenya.

    PubMed

    Robinson, W C; Harbison, S F

    1995-01-01

    In Sub-Saharan Africa Kenya is a prime example of a country experiencing a rapid decline in fertility and greater contraceptive prevalence. These changes have occurred since 1980 when fertility was high at 8.0 children per woman. In 1993 the total fertility rate (TFR) was 5.4, and the growth rate declined to about 2.0%. This transition is swifter than any country in contemporary Asia or historical Europe. The likely projection for Kenya is attainment of replacement level fertility during the 2020s and a leveling of population at about 100 million persons. Fertility has declined the most in urban areas and central and eastern regions. Bongaarts' proximate determinants (TFR, total marital fertility rate, total natural marital fertility rate, and total fecundity) are reduced to the proportion of currently married women using contraception, the proportion in lactational nonfecund status, and the proportion currently married. Actual fertility change is accounted for by total fertility change of 3.0 children. Lactational infecundability accounts for 0.5 potential births, and changes in marital fertility account for 1.0 reduced births per woman. About 70% of fertility reduction is accounted for by contraception and abortion. During 1977-78 80% of fertility control was due to lactational nonfecundity, 10% to nonmarriage, and 10% to contraception. In 1993 lactational nonfecundity accounted for 50% of the reduction, nonmarriage for 20%, and abortion about 30%. Future fertility is expected to be dependent on contraceptive prevalence. Kenya has experienced the Coale paradigm of preconditions necessary for demographic transition (willing, ready, and able). High fertility in Africa is not intractable. Creating the change in attitudes that leads to readiness is linked to education, health, and exposure to modernizing media and urban lifestyles. The public sector family planning program in Kenya has created the opportunity for access and availability of contraception. The key

  12. Forest resources of the Lincoln National Forest

    Treesearch

    John D. Shaw

    2006-01-01

    The Interior West Forest Inventory and Analysis (IWFIA) program of the USDA Forest Service, Rocky Mountain Research Station, as part of its national Forest Inventory and Analysis (FIA) duties, conducted forest resource inventories of the Southwestern Region (Region 3) National Forests. This report presents highlights of the Lincoln National Forest 1997 inventory...

  13. Forest resources of the Tonto National Forest

    Treesearch

    John D. Shaw

    2004-01-01

    The Interior West Forest Inventory and Analysis (IWFIA) program of the USDA Forest Service, Rocky Mountain Research Station, as part of its national Forest Inventory and Analysis (FIA) duties, conducted forest resource inventories of the Southwestern Region (Region 3) National Forests. This report presents highlights of the Tonto National Forest 1996 inventory...

  14. Forest resources of the Gila National Forest

    Treesearch

    John D. Shaw

    2008-01-01

    The Interior West Forest Inventory and Analysis (IWFIA) program of the USDA Forest Service, Rocky Mountain Research Station, as part of its national Forest Inventory and Analysis (FIA) duties, conducted forest resource inventories of the Southwestern Region (Region 3) National Forests. This report presents highlights of the Gila National Forest 1994 inventory including...

  15. Forest health assessment for eastern hardwood forests

    Treesearch

    Daniel B. Twardus

    1995-01-01

    Information presented here, was obtained generally from 3 sources: the Cooperative Forest Health Protection Program, the Forest Inventory and Analysis Program and the National Forest Health Monitoring Program. The Cooperative Forest Health Protection Program is a joint State-Federal effort responsible for forest-wide surveys of forest damage. From these surveys, we...

  16. Forest resources of the Prescott National Forest

    Treesearch

    Paul Rogers

    2003-01-01

    The Interior West Forest Inventory and Analysis (IWFIA) program of the USDA Forest Service, Rocky Mountain Research Station, as part of its national Forest Inventory and Analysis (FIA) duties, conducted forest resource inventories of the Southwestern Region (Region 3) National Forests. This report presents highlights of the Prescott National Forest 1996...

  17. Analysis of the interaction between timber markets and the forest resources of Maine

    Treesearch

    William G. Luppold; Paul E. Sendak

    2004-01-01

    The abundant timber resources of Maine are critical to the State's timber economy; thus, when the 1995 forest inventory indicated a 20% decline in softwood growing stock, there was great concern by industry and government. Furthermore, declining near-term softwood growing stock levels were forecast. To better understand what was occurring in Maine's forest,...

  18. Forest Management Policy and Community Well-Being in the Pacific Northwest

    Treesearch

    Susan Charnley; Ellen M. Donoghue; Cassandra Moseley

    2008-01-01

    This study uses a multiscale, multimethods approach to examine the effects of declining timber harvests on the well-being of forest communities in the Pacific Northwest as a result of the Northwest Forest Plan (the Plan). We found that the effects of declining timber harvests were variable and depended on the importance of the timber sector in a community in the late...

  19. Forest management policy and community well-being in the Pacific Northwest

    Treesearch

    Susan Charnley; Ellen M. Donoghue; Cassandra Moseley

    2008-01-01

    This study uses a multiscale, multimethods approach to examine the effects of declining timber harvests on the well-being of forest communities in the Pacific Northwest as a result of the Northwest Forest Plan (the Plan). We found that the effects of declining timber harvests were variable and depended on the importance of the timber sector in a community in the late...

  20. Analysis of the Interaction Between Timber Markets and the Forest Resources of Maine

    Treesearch

    William G. Luppold

    2004-01-01

    The abundant timber resources of Maine are critical to the State's timber economy; thus, when the 1995 forest inventory indicated a 20% decline in softwood growing stock, there was great concern by industry and government. Furthermore, declining near-term softwood growing stock levels were forecast. To better understand what was occurring in Maine's forest,...

  1. Dietary Factors and Cognitive Decline.

    PubMed

    Smith, P J; Blumenthal, J A

    2016-03-01

    Cognitive decline is an increasingly important public health problem, with more than 100 million adults worldwide projected to develop dementia by 2050. Accordingly, there has been an increased interest in preventive strategies that diminish this risk. It has been recognized that lifestyle factors including dietary patterns, may be important in the prevention of cognitive decline and dementia in later life. Several dietary components have been examined, including antioxidants, fatty acids, and B vitamins. In addition, whole dietary eating plans, including the Mediterranean diet (MeDi), and the Dietary Approaches to Stop Hypertension (DASH) diet, with and without weight loss, have become areas of increasing interest. Although prospective epidemiological studies have observed that antioxidants, fatty acids, and B vitamins are associated with better cognitive functioning, randomized clinical trials have generally failed to confirm the value of any specific dietary component in improving neurocognition. Several randomized trials have examined the impact of changing 'whole' diets on cognitive outcomes. The MeDi and DASH diets offer promising preliminary results, but data are limited and more research in this area is needed.

  2. Dietary Factors and Cognitive Decline

    PubMed Central

    Smith, P.J.; Blumenthal, J.A.

    2015-01-01

    Cognitive decline is an increasingly important public health problem, with more than 100 million adults worldwide projected to develop dementia by 2050. Accordingly, there has been an increased interest in preventive strategies that diminish this risk. It has been recognized that lifestyle factors including dietary patterns, may be important in the prevention of cognitive decline and dementia in later life. Several dietary components have been examined, including antioxidants, fatty acids, and B vitamins. In addition, whole dietary eating plans, including the Mediterranean diet (MeDi), and the Dietary Approaches to Stop Hypertension (DASH) diet, with and without weight loss, have become areas of increasing interest. Although prospective epidemiological studies have observed that antioxidants, fatty acids, and B vitamins are associated with better cognitive functioning, randomized clinical trials have generally failed to confirm the value of any specific dietary component in improving neurocognition. Several randomized trials have examined the impact of changing ‘whole’ diets on cognitive outcomes. The MeDi and DASH diets offer promising preliminary results, but data are limited and more research in this area is needed. PMID:26900574

  3. Forest statistics for North Carolina, 1990

    Treesearch

    Tony G. Johnson

    1991-01-01

    Since 1984, area of timberland in North Carolina declined almost 78,000 acres to 18.7 million acres. Nonindustrial private forest landowners control 76 percent of the State's timberland. Area classified as a pine type declined 3 percent to 6.3 million acres. Nearly 295,000 acres were harvested annually, while 357,000 per year were regenerated both by artificial...

  4. Forest statistics for Florida, 1987

    Treesearch

    Mark J. Brown; Michael T. Thompson

    1988-01-01

    Since 1980, area of timberland in Florida was decreased by 4 percent to less than 15.0 million acres. Area of nonindustrial private forest land has declined 12 percent to 7.1 million acres. Area harvested and retained in timberland averaged 296,000 acres annually. An average of 272,000 acres regenerated annually. 72 percent of which occurred through artificial methods...

  5. Timber rattlesnakes and Louisiana pine snakes of the West Gulf Coastal Plain: hypotheses of decline

    Treesearch

    D. Craig Rudolph; Shirley J. Burgdorf

    1997-01-01

    Timber rattlesnakes (Croatlus horridus) and Louisiana pine snakes (Pituophis melanoleucus ruthveni) are large-bodies snakes occurring on the West Gulf Coastal Plain. Both species are thoguht to be declining due to increasing habitat alteration. Timber rattlesnakes occur in closed canopy hardwood and pine-hardwood forests, and...

  6. Three-year progression of emerald ash borer-induced decline and mortality in southeastern Michigan

    Treesearch

    Kamal J.K. Gandhi; Annemarie Smith; Robert P. Long; Robin A.J. Taylor; Daniel A. Herms

    2008-01-01

    We monitored the progression of ash (Fraxinus spp.) decline and mortality due to emerald ash borer (EAB), Agrilus planipennis, in 38 forest stands in the upper Huron River watershed region of southeastern Michigan from 2004-2007. Black ash (F. nigra), green ash (F. pennsylvanica), and white ash...

  7. Seasonal change in tropical habitat quality and body condition for a declining migratory songbird.

    PubMed

    McKinnon, Emily A; Rotenberg, James A; Stutchbury, Bridget J M

    2015-10-01

    Many migratory songbirds spend their non-breeding season in tropical humid forests, where climate change is predicted to increase the severity and frequency of droughts and decrease rainfall. For conservation of these songbirds, it is critical to understand how resources during the non-breeding season are affected by seasonal patterns of drying, and thereby predict potential long-term effects of climate change. We studied habitat quality for a declining tropical forest-dwelling songbird, the wood thrush (Hylocichla mustelina), and tested the hypothesis that habitat moisture and arthropod abundance are drivers of body condition during the overwintering period. We examined habitat moisture, abundance of arthropods and fruit, and condition of individual birds (n = 418) in three habitat types--mature forest, mature forest with increased presence of human activity, and riparian scrub--from October to April. We found a strong pattern of habitat drying from October (wet season) to March (prior to spring migration) in all habitats, with concurrent declines in arthropod and fruit abundance. Body condition of birds also declined (estimated ~5 % decline over the wintering period), with no significant difference by habitat. Relatively poor condition (low body condition index, low fat and pectoral muscles scores) was equally apparent in all habitat types in March. Climate change is predicted to increase the severity of dry seasons in Central America, and our results suggest that this could negatively affect the condition of individual wood thrushes.

  8. Effects of low-density thinning in a declining white pine stand in Maine

    Treesearch

    William B. Leak; Mariko. Yamasaki

    2013-01-01

    Low-density (32 ft2/acre residual basal area) and medium-low density (60 ft2/acre residual basal area) thinnings were studied over a 4-year period in a declining white pine stand on the Massabesic Experimental Forest in southern Maine. Gross basal area growth at 60 ft2 was about three-fourths the rate...

  9. Association of Phytophthora cinnamomi with white oak decline in southern Ohio

    Treesearch

    Annemarie M. Nagle; Robert P. Long; Laurence V. Madden; Pierluigi. Bonello

    2010-01-01

    A decline syndrome and widespread mortality of mature white oak tree (Quercus alba) associated with wet and low-lying areas has been recently observed in southern Ohio forests. Previous studies have isolated Phytophthora cinnamomi from white oak rhizospheres. In 2008 and 2009, P. cinnamomi population densities in...

  10. Host-environment mismatches associated with subalpine fir decline in Colorado

    Treesearch

    Robin M. Reich; John E. Lundquist; Kristina Hughes

    2016-01-01

    Subalpine fir decline (SFD) has killed more trees in Colorado’s high elevation forests than any other insect or disease problem. The widespread nature of this disorder suggests that the cause involves climatic factors. We examined the influence of varying combinations of average annual temperature and precipitation on the incidence and distribution of SFD. Climatic...

  11. Red oak decline and mortality by ecological land type in the Missouri ozarks

    Treesearch

    John M. Fan Kabrick; Stephen R. Shifley

    2007-01-01

    Oak decline, the precipitous mortality of mature oak trees, has been a chronic problem in xeric oak ecosystems and is reaching unprecedented levels in red oak group (Quercus section Lobatae) species in the Ozark Highlands. The high rates of mortality are leading to rapid changes in species composition, forest structure, and related changes in fire...

  12. Involvement of Phythophthora species in white oak (Quercus alba) decline in southern Ohio

    Treesearch

    Y. Balci; R.P. Long; M. Mansfield; D. Balser; W.L. MacDonald

    2010-01-01

    This study was initiated to investigate the possible role of Phytophthora species in white oak decline (Quercus alba) in southern Ohio at Scioto Trail State Forest. Surveys demonstrated the presence of four species of Phytophthora including one novel species. By far, the most common species was P....

  13. Declining atmospheric sulfate deposition in a small agricultural watershed in central Pennsylvania, USA

    USDA-ARS?s Scientific Manuscript database

    Sulfur emissions in the northeastern USA are only 20% of what they once were due the enactment of the Clean Air Act. While there are numerous reports of aquatic and forested ecosystems recovering as a result of the decline in sulfur deposition, there is little information describing such effects in ...

  14. Growing hickories (Carya spp.) for roost trees: A method to support conservation of declining bat populations

    Treesearch

    Tara Luna; Daniel L. Lindner; R. Kasten Dumroese

    2014-01-01

    Bats (Vespertilionidae and Phyllostomidae) are a critically important component of North American ecosystems. These insectivorous mammals provide largely unrecognized ecosystem services to agriculture and forest health and sustain bat-dependent native plant populations. The decline of North American bat populations reflects the recent emergence of the fungal disease...

  15. Fire as a tool in restoring and maintaining beetle diversity in boreal forests: preliminary results from a large-scale field experiment

    Treesearch

    E. Hyvarinen; H. Lappalainen; P. Martikainen; J. Kouki

    2003-01-01

    During the 1900s, the amount of dead and decaying wood has declined drastically in boreal forests in Finland because of intensive forest management. As a result, species requiring such resources have also declined or have even gone extinct. Recently it has been observed that in addition to old-growth forests, natural, early successional phases are also important for...

  16. Evaluation of the leucine incorporation technique for detection of pollution-induced community tolerance to copper in a long-term agricultural field trial with urban waste fertilizers.

    PubMed

    Lekfeldt, Jonas Duus Stevens; Magid, Jakob; Holm, Peter E; Nybroe, Ole; Brandt, Kristian Koefoed

    2014-11-01

    Copper (Cu) is known to accumulate in agricultural soils receiving urban waste products as fertilizers. We here report the use of the leucine incorporation technique to determine pollution-induced community tolerance (Leu-PICT) to Cu in a long-term agricultural field trial. A significantly increased bacterial community tolerance to Cu was observed for soils amended with organic waste fertilizers and was positively correlated with total soil Cu. However, metal speciation and whole-cell bacterial biosensor analysis demonstrated that the observed PICT responses could be explained entirely by Cu speciation and bioavailability artifacts during Leu-PICT detection. Hence, the agricultural application of urban wastes (sewage sludge or composted municipal waste) simulating more than 100 years of use did not result in sufficient accumulation of Cu to select for Cu resistance. Our findings also have implications for previously published PICT field studies and demonstrate that stringent PICT detection criteria are needed for field identification of specific toxicants. Copyright © 2014 Elsevier Ltd. All rights reserved.

  17. Comparison of aerobic and anaerobic [3H]leucine incorporation assays for determining pollution-induced bacterial community tolerance in copper-polluted, irrigated soils.

    PubMed

    Aaen, Karoline Nolsø; Holm, Peter E; Priemé, Anders; Hung, Ngoc Ngo; Brandt, Kristian Koefoed

    2011-03-01

    Pollution-induced community tolerance (PICT) constitutes a sensitive and ecologically relevant impact parameter in ecotoxicology. We report the development and application of a novel anaerobic [(3) H]leucine incorporation assay and its comparison with the conventional aerobic [(3) H]leucine incorporation assay for PICT detection in soil bacterial communities. Selection of bacterial communities was performed over 42 d in bulk soil microcosms (no plants) and in rice (Oryza sativa) rhizosphere soil mesocosms. The following experimental treatments were imposed using a full factorial design: two soil types, two soil water regimes, and four Cu application rates (0, 30, 120, or 280 µg g(-1)). Bacterial communities in bulk soil microcosms exhibited similar Cu tolerance patterns when assessed by aerobic and anaerobic PICT assays, whereas aerobic microorganisms tended to be more strongly selected for Cu tolerance than anaerobic microorganisms in rhizosphere soil. Despite similar levels of water-extractable Cu, bacterial Cu tolerance was significantly higher in acid sulfate soil than in alluvial soil. Copper amendment selected for significant PICT development in soils subjected to alternate wetting and drying, but not in continuously flooded soils. Our results demonstrate that soil bacterial communities subjected to alternate wetting and drying may be more affected by Cu than bacterial communities subjected to continuous flooding. We conclude that the parallel use of anaerobic and aerobic [(3) H]leucine PICT assays constitutes a valuable improvement over existing procedures for PICT detection in irrigated soils and other redox gradient environments such as sediments and wetlands. Copyright © 2010 SETAC.

  18. Pollution-induced tolerance to copper of nematode communities in the severely contaminated Restronguet Creek and adjacent estuaries, Cornwall, United Kingdom

    SciTech Connect

    Millward, R.N.; Grant, A.

    2000-02-01

    Pollution-induced community tolerance (PICT) has been proposed as an indicator of the deleterious effects of pollutants on communities in the field. Nematode assemblages were sampled at 10 estuarine sites that ranged from uncontaminated to grossly contaminated with metals. Relative tolerance of these assemblages to Cu was quantified using acute toxicity tests. There were large differences between sites in tolerance to Cu, and copper tolerance was strongly correlated with severity of contamination. Enhanced Cu tolerance occurred at two sites where Cu concentration in sediment was around 180 {micro}g/g but not at a third site, where Cu concentration was 214 {micro}g/g. This implies a threshold of effects on these nematode communities at {approximately}200 {micro}g/g Cu. Comparison with studies of nematode community composition in these same estuaries indicates that PICT is at least as sensitive as the best available ecological monitoring methods. It is, however, faster to carry out and requires much less taxonomic expertise. The PICT appears to be a sensitive indicator of ecological effects of pollution and has considerable promise as a monitoring tool.

  19. Pollution-induced community tolerance (PICT) as a tool for monitoring Lake Geneva long-term in situ ecotoxic restoration from herbicide contamination.

    PubMed

    Larras, Floriane; Rimet, Frédéric; Gregorio, Vincent; Bérard, Annette; Leboulanger, Christophe; Montuelle, Bernard; Bouchez, Agnès

    2016-03-01

    Chemical monitoring revealed a regular decrease in herbicide concentration in Lake Geneva since last decades that may be linked to an ecotoxic restoration of nontarget phytoplanktonic communities. The Pollution-induced community tolerance (PICT) approach was tested as a tool to monitor the ecotoxic restoration of Lake Geneva for herbicides from 1999 to 2011. We conducted monthly assessments in 1999 and in 2011 for the tolerance of the phytoplankton communities to two herbicides (atrazine and copper), using PICT bioassays. The taxonomical composition of the communities was determined on the same collecting dates. The herbicide concentration decrease during the 12 years significantly influenced the composition of communities. The PICT monitoring indicated that a significant tolerance decrease in the community to both herbicides accompanied the herbicide concentration decrease. PICT measurements for atrazine and copper also changed at the intra-annual level. These variations were mainly due to community composition shifts linked to seasonal phosphorus and temperature changes. PICT monitoring on a seasonal basis is required to monitor the mean tolerance of communities. PICT appeared to be a powerful tool that reflected the toxic effects on environmental communities and to monitor ecotoxic ecosystem restoration.

  20. Conifer Decline and Mortality in Siberia

    NASA Astrophysics Data System (ADS)

    Kharuk, V.; Im, S.; Ranson, K.

    2015-12-01

    "Dark needle conifer" (DNC: Abies sibirica, Pinus sibirica and Picea obovata) decline and mortality increase were documented in Russia during recent decades. Here we analyzed causes and scale of Siberian pine and fir mortality in Altai-Sayan and Baikal Lake Regions and West Siberian Plane based on in situdata and remote sensing (QuickBird, Landsat, GRACE). Geographically, mortality began on the margins of the DNC range (i.e., within the forest-steppe and conifer-broadleaf ecotones) and on terrain features with maximal water stress risk (narrow-shaped hilltops, convex steep south facing slopes, shallow well-drained soils). Within ridges, mortality occurred mainly along mountain passes, where stands faced drying winds. Regularly mortality was observed to decrease with elevation increase with the exception of Baikal Lake Mountains, where it was minimal near the lake shore and increased with elevation (up to about 1000 m a.s.l.). Siberian pine and fir mortality followed a drying trend with consecutive droughts since the 1980s. Dendrochronology analysis showed that mortality was correlated with vapor pressure deficit increase, drought index, soil moisture decrease and occurrence of late frosts. In Baikal region Siberian pine mortality correlated with Baikal watershed meteorological variables. An impact of previous year climate conditions on the current growth was found (r2 = 0.6). Thus, water-stressed trees became sensitive to bark beetles and fungi impact (including Polygraphus proximus and Heterobasidion annosum). At present, an increase in mortality is observed within the majority of DNC range. Results obtained also showed a primary role of water stress in that phenomenon with a secondary role of bark beetles and fungi attacks. In future climate with increased drought severity and frequency Siberian pine and fir will partly disappear from its current range, and will be substituted by drought-tolerant species (e.g., Pinus silvestris, Larix sibirica).

  1. Forest dynamics in the U.S. indicate disproportionate attrition in western forests, rural areas and public lands

    PubMed Central

    2017-01-01

    Forests are experiencing significant changes; studying geographic patterns in forests is critical in understanding the impact of forest dynamics to biodiversity, soil erosion, water chemistry and climate. Few studies have examined forest geographic pattern changes other than fragmentation; however, other spatial processes of forest dynamics are of equal importance. Here, we study forest attrition, the complete removal of forest patches, that can result in complete habitat loss, severe decline of population sizes and species richness, and shifts of local and regional environmental conditions. We aim to develop a simple yet insightful proximity-based spatial indicator capturing forest attrition that is independent of spatial scale and boundaries with worldwide application potential. Using this proximity indicator, we evaluate forest attrition across ecoregions, land ownership and urbanization stratifications across continental United States of America. Nationally, the total forest cover loss was approximately 90,400 km2, roughly the size of the state of Maine, constituting a decline of 2.96%. Examining the spatial arrangement of this change the average FAD was 3674m in 1992 and increased by 514m or 14.0% in 2001. Simulations of forest cover loss indicate only a 10m FAD increase suggesting that the observed FAD increase was more than an order of magnitude higher than expected. Furthermore, forest attrition is considerably higher in the western United States, in rural areas and in public lands. Our mathematical model (R2 = 0.93) supports estimation of attrition for a given forest cover. The FAD metric quantifies forest attrition across spatial scales and geographic boundaries and assesses unambiguously changes over time. The metric is applicable to any landscape and offers a new complementary insight on forest landscape patterns from local to global scales, improving future exploration of drivers and repercussions of forest cover changes and supporting more informative

  2. Forest dynamics in the U.S. indicate disproportionate attrition in western forests, rural areas and public lands.

    PubMed

    Yang, Sheng; Mountrakis, Giorgos

    2017-01-01

    Forests are experiencing significant changes; studying geographic patterns in forests is critical in understanding the impact of forest dynamics to biodiversity, soil erosion, water chemistry and climate. Few studies have examined forest geographic pattern changes other than fragmentation; however, other spatial processes of forest dynamics are of equal importance. Here, we study forest attrition, the complete removal of forest patches, that can result in complete habitat loss, severe decline of population sizes and species richness, and shifts of local and regional environmental conditions. We aim to develop a simple yet insightful proximity-based spatial indicator capturing forest attrition that is independent of spatial scale and boundaries with worldwide application potential. Using this proximity indicator, we evaluate forest attrition across ecoregions, land ownership and urbanization stratifications across continental United States of America. Nationally, the total forest cover loss was approximately 90,400 km2, roughly the size of the state of Maine, constituting a decline of 2.96%. Examining the spatial arrangement of this change the average FAD was 3674m in 1992 and increased by 514m or 14.0% in 2001. Simulations of forest cover loss indicate only a 10m FAD increase suggesting that the observed FAD increase was more than an order of magnitude higher than expected. Furthermore, forest attrition is considerably higher in the western United States, in rural areas and in public lands. Our mathematical model (R2 = 0.93) supports estimation of attrition for a given forest cover. The FAD metric quantifies forest attrition across spatial scales and geographic boundaries and assesses unambiguously changes over time. The metric is applicable to any landscape and offers a new complementary insight on forest landscape patterns from local to global scales, improving future exploration of drivers and repercussions of forest cover changes and supporting more informative

  3. Prospective Scope of Forest Management Education at James Madison's Montpelier

    ERIC Educational Resources Information Center

    Munsell, John F.; Hamilton, Rachel; Downing, Adam K.

    2009-01-01

    Urban sprawl and intergenerational transfers are fostering a new period of family forest ownership in the United States typified by larger numbers of younger owners with smaller parcels that are interested in managing their forests but often lacking requisite knowledge. At the same time, there is a general decline in the public's connection to…

  4. Condition varies with habitat choice in postbreeding forest birds

    Treesearch

    Scott H. Stoleson

    2013-01-01

    Many birds that are experiencing population declines require extensive tracts of mature forest habitat for breeding. Recent work suggests that at least some may shift their habitat use to early-successional areas after nesting but before migration. I used constant-effort mist netting in regenerating clearcuts (4-8 years postcut) and dense mature-forest understories to...

  5. Prospective Scope of Forest Management Education at James Madison's Montpelier

    ERIC Educational Resources Information Center

    Munsell, John F.; Hamilton, Rachel; Downing, Adam K.

    2009-01-01

    Urban sprawl and intergenerational transfers are fostering a new period of family forest ownership in the United States typified by larger numbers of younger owners with smaller parcels that are interested in managing their forests but often lacking requisite knowledge. At the same time, there is a general decline in the public's connection to…

  6. 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...

  7. Ways of Dealing with Enrollment Decline

    ERIC Educational Resources Information Center

    Phi Delta Kappan, 1978

    1978-01-01

    Two consultants and superintendents from Livonia (Michigan), New Orleans, Salt Lake City, and Seattle discuss the impact of declining enrollments on the schools and some of the actions school districts are taking to cope with the decline. (IRT)

  8. Declining Sunshine for Phoenix Lander

    NASA Technical Reports Server (NTRS)

    2008-01-01

    The yellow line on this graphic indicates the number of hours of sunlight each sol, or Martian day, at the Phoenix landing site's far-northern latitude, beginning with the entire Martian day (about 24 hours and 40 minutes) for the first 90 sols, then declining to no sunlight by about sol 300. The blue tick mark indicates that on Sol 124 (Sept. 29, 2008), the sun is above the horizon for about 20 hours.

    The brown vertical bar represents the period from Nov. 18 to Dec. 24, 2008, around the 'solar conjunction,' when the sun is close to the line between Mars and Earth, affecting communications.

    The green vertical rectangle represents the period from February to November 2009 when the Phoenix lander is expected to be encased in carbon-dioxide ice.

  9. [Functional decline in older people].

    PubMed

    Wada, Taizo

    2013-10-01

    World Health Organization(WHO) proposed to be used as an index of the health of elderly independence of functioning. Basic activities of daily living (BADL), such as bathing, dressing, toileting, transferring, continence, and feeding are well known as the functioning of the elderly. However, not only BADL, there are a variety of levels, such as the ability to play a social role, intellectual activities and instrumental activities of daily living (IADL), which are components of the Tokyo Metropolitan Institute of Gerontology Index of Competence(TMIG-IC). Functional decline in older people is associated with age, gender, depression, up and go test and manual dexterity. Smoking, body-mass index, and exercise patterns in midlife and late adulthood are predictors of subsequent disability.

  10. Declining Sunshine for Phoenix Lander

    NASA Technical Reports Server (NTRS)

    2008-01-01

    The yellow line on this graphic indicates the number of hours of sunlight each sol, or Martian day, at the Phoenix landing site's far-northern latitude, beginning with the entire Martian day (about 24 hours and 40 minutes) for the first 90 sols, then declining to no sunlight by about sol 300. The blue tick mark indicates that on Sol 124 (Sept. 29, 2008), the sun is above the horizon for about 20 hours.

    The brown vertical bar represents the period from Nov. 18 to Dec. 24, 2008, around the 'solar conjunction,' when the sun is close to the line between Mars and Earth, affecting communications.

    The green vertical rectangle represents the period from February to November 2009 when the Phoenix lander is expected to be encased in carbon-dioxide ice.

  11. Adult attachment and declining birthrates.

    PubMed

    Draper, Thomas W; Holman, Thomas B; White, Whitney; Grandy, Shannon

    2007-02-01

    Attachment scores for 658 young adults living in the U.S.A. were obtained using the Experiences in Close Relationships scale. The participants came from a subsample of the RELATE data set, who had also filled out the adult attachment measure. Those young adults living in Utah County, Utah, an area of the country with a higher than normal birthrate (88% members of the Church of Jesus Christ of Latter-day Saints), also had higher than average adult attachment scores. While the methodology was not sufficient to assess causal direction nor eliminate the possibility of unidentified influences, an undiscussed psychological factor, adult attachment, may play a role in the numerical declines observed among nonimmigrant communities in the USA and Europe.

  12. Tree squirrel habitat selection and predispersal seed predation in a declining subalpine conifer.

    PubMed

    McKinney, Shawn T; Fiedler, Carl E

    2010-03-01

    Differential responses by species to modern perturbations in forest ecosystems may have undesirable impacts on plant-animal interactions. If such disruptions cause declines in a plant species without corresponding declines in a primary seed predator, the effects on the plant could be exacerbated. We examined one such interaction between Pinus albicaulis (whitebark pine), a bird-dispersed, subalpine forest species experiencing severe population declines in the northern part of its range, and Tamiasciurus hudsonicus (red squirrel), an efficient conifer seed predator, at 20 sites in two distinct ecosystems. Hypotheses about squirrel habitat preferences were tested to determine how changes in forest conditions influence habitat use and subsequent levels of predispersal cone predation. We performed habitat selection modeling and variable ranking based on Akaike's information criterion; compared the level and variance of habitat use between two forest types (P. albicaulis dominant and mixed conifer); and modeled the relationship between P. albicaulis relative abundance and predispersal cone predation. T. hudsonicus did not demonstrate strong habitat preference for P. albicaulis, and thus, declines in the pine were not met with proportional declines in squirrel habitat use. P. albicaulis habitat variables were the least important in squirrel habitat selection. Squirrel habitat use was lower and varied more in P. albicaulis-dominant forests, and predispersal cone predation decreased linearly with increasing P. albicaulis relative abundance. In Northern Rocky Mountain sites, where P. albicaulis mortality was higher and abundance lower, squirrel predation was greater than in Central Rocky Mountain sites. In ecosystems with reduced P. albicaulis abundance, altered interactions between the squirrel and pine may lead to a lower proportion of P. albicaulis contributing to population recruitment because of reduced seed availability. Reducing the abundance of competing conifers

  13. Breeding season concerns and response to forest management: Can forest management produce more breeding birds? Ornitologia Neotropical

    Treesearch

    J.L. Larkin; P.B. Wood; T.J. Boves; J. Sheehan; D.A. Buehler

    2012-01-01

    Cerulean Warblers (Setophaga cerulea), one of the fastest declining avian species in North America, are associated with heterogeneous canopies in mature hardwood forests. However, the age of most second and third-growth forests in eastern North American is not sufficient for natural tree mortality to maintain structurally diverse canopies. Previous research suggests...

  14. Predictors of Organizational Responses to Decline.

    ERIC Educational Resources Information Center

    Parker, Barbara; Zammuto, Raymond F.

    Results of research on predictors of organizational responses to declining enrollments at 56 small to medium-sized colleges and universities are discussed. Decline was experienced from 1978-1979 to 1981-1982. Severity of decline was selected as an objective predictor of organizational response, while internal agreement on mission and attributions…

  15. 31 CFR 240.7 - Declination protest.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 31 Money and Finance:Treasury 2 2011-07-01 2011-07-01 false Declination protest. 240.7 Section 240... STATES TREASURY General Provisions § 240.7 Declination protest. (a) Who may protest. Only a presenting bank may protest the declination of a check that it has presented to a Federal Reserve Bank for payment...

  16. 31 CFR 240.7 - Declination protest.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 31 Money and Finance:Treasury 2 2013-07-01 2013-07-01 false Declination protest. 240.7 Section 240... STATES TREASURY General Provisions § 240.7 Declination protest. (a) Who may protest. Only a presenting bank may protest the declination of a check that it has presented to a Federal Reserve Bank for payment...

  17. 31 CFR 240.7 - Declination protest.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 31 Money and Finance:Treasury 2 2012-07-01 2012-07-01 false Declination protest. 240.7 Section 240... STATES TREASURY General Provisions § 240.7 Declination protest. (a) Who may protest. Only a presenting bank may protest the declination of a check that it has presented to a Federal Reserve Bank for payment...

  18. 31 CFR 240.7 - Declination protest.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 31 Money and Finance: Treasury 2 2010-07-01 2010-07-01 false Declination protest. 240.7 Section... STATES TREASURY General Provisions § 240.7 Declination protest. (a) Who may protest. Only a presenting bank may protest the declination of a check that it has presented to a Federal Reserve Bank for payment...

  19. 31 CFR 240.7 - Declination protest.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 31 Money and Finance: Treasury 2 2014-07-01 2014-07-01 false Declination protest. 240.7 Section... STATES TREASURY General Provisions § 240.7 Declination protest. (a) Who may protest. Only a presenting bank may protest the declination of a check that it has presented to a Federal Reserve Bank for payment...

  20. Targeted reforestation could reverse declines in connectivity for understory birds in a tropical habitat corridor.

    PubMed

    Fagan, Matthew E; DeFries, Ruth S; Sesnie, Steven E; Arroyo-Mora, J Pablo; Chazdon, Robin L

    2016-07-01

    Re-establishing connectivity between protected areas isolated by habitat clearing is a key conservation goal in the humid tropics. In northeastern Costa Rica, payments for environmental services (PES) and a government ban on deforestation have subsidized forest protection and reforestation in the San Juan-La Selva Biological Corridor (SJLSBC), resulting in a decline in mature forest loss and the expansion of tree plantations. We use field studies and graph models to assess how conservation efforts have altered functional connectivity over the last 25 years for four species of insectivorous understory birds. Field playback studies assessed how reforestation habitat quality affected the willingness of Myrmeciza exsul, Henicorhina leucosticta, Thamnophilus atrinucha, and Glyphorynchus spirurus to travel outside forest habitat for territorial defense. Observed travel distances were greatest in nonnative and native tree plantations with high understory stem density, regardless of overstory composition. In contrast, tree plantations with low stem density had travel responses comparable to open pasture for three of the four bird species. We modeled landscape connectivity for each species using graph models based on varying possible travel distances in tree plantations, gallery forests, and pastures. From 1986 to 2011, connectivity for all species declined in the SJLSBC landscape (5825 km(2) ) by 14% to 21% despite only a 4.9% net loss in forest area and the rapid expansion of tree plantations over 2% of the landscape. Plantation placement in the landscape limited their potential facilitation of connectivity because they were located either far from forest cover or within already contiguous forest areas. We mapped current connectivity bottlenecks and identified priority areas for future reforestation. We estimate that reforestation of priority areas could improve connectivity by 2% with only a 1% gain in forest cover, an impressive gain given the small area reforested

  1. Forest restoration and forest communities: have local communities benefited from forest service contracting of ecosystem management?

    PubMed

    Moseley, Cassandra; Reyes, Yolanda E

    2008-08-01

    Conservation-based development programs have sought to create economic opportunities for people negatively impacted by biological diversity protection. The USDA Forest Service, for example, developed policies and programs to create contracting opportunities for local communities to restore public lands to replace jobs lost from reduced timber harvest. This article examines 12 years of Forest Service land management contracting in western Oregon, Washington, and northern California to evaluate if contractors located in communities near national forests have been awarded more land management contracts and contract value over time. We find that land management contracting spending has declined dramatically and, once we control for intervening factors, we find that local contractors have received a smaller proportion of land management contracts over time.

  2. Forest Restoration and Forest Communities: Have Local Communities Benefited from Forest Service Contracting of Ecosystem Management?

    NASA Astrophysics Data System (ADS)

    Moseley, Cassandra; Reyes, Yolanda E.

    2008-08-01

    Conservation-based development programs have sought to create economic opportunities for people negatively impacted by biological diversity protection. The USDA Forest Service, for example, developed policies and programs to create contracting opportunities for local communities to restore public lands to replace jobs lost from reduced timber harvest. This article examines 12 years of Forest Service land management contracting in western Oregon, Washington, and northern California to evaluate if contractors located in communities near national forests have been awarded more land management contracts and contract value over time. We find that land management contracting spending has declined dramatically and, once we control for intervening factors, we find that local contractors have received a smaller proportion of land management contracts over time.

  3. Protected forests in Europe approaches-harmonising the definitions for international comparison and forest policy making.

    PubMed

    Parviainen, Jari; Frank, Georg

    2003-01-01

    Comparison of forest protection between regions in Europe is extremely difficult, because there is such wide variation of strategies, procedures and constraints; the way forests have been used historically and their present closeness to nature also varies, and furthermore so does the definition of what constitutes a forest. For the European Ministerial Conference on the Protection of Forests in Europe (MCPFE) in 2003, forest protection has been harmonised into three categories for the sake of comparison: protection to safeguard biodiversity, protection of landscape and specific natural features, and protective forest functions. There is no single, uniform and universal model and no internationally agreed target with respect to the percentage of forests which should be protected. What is more important than a fixed percentage level of forested area (e.g. 5 or 10%) is that the protection network should be biogeographically and ecologically representative and accordingly distributed on a regional basis. Long-term practical experience and research have proved that conservation of different species of organisms can be assured by appropriate silvicultural management of multifunctional production forests. Consequently, the focus of debate in Europe appears to shift more and more from total protection in segregated areas to 'precision protection' and to combining protection and timber production in the holistic, integrated concept of modern management of forest areas.Advances in regional ecological planning and the growing adoption of naturalistic forest management practices have slowed the decline of the biological diversity in the multifunctional production forests. However, this fact is not yet widely and sufficiently acknowledged and appreciated. There is consequently a political and scientific need for continued study of the effects of naturalistic silvicultural management on the biodiversity of forests. Information from such research is crucially needed before new

  4. Status of the Longleaf Pine Forests of the West Gulf Coastal Plain

    Treesearch

    Kenneth W. Outcalt

    1997-01-01

    Datafrom the USDA Forest Service, forest inventory and analyses permanent field plot were used to track changes in longleaf pine (Pinuspalustris Mill.) communities in Texas and Louisiana between 1985 and 1995. The decline of longleaf forest has continued in Louisiana. Texas had much less longleaf type in 1985, but unlike Louisiana there has been a small increase in the...

  5. Aboveground biomass variability across intact and degraded forests in the Brazilian Amazon

    Treesearch

    Marcos Longo; Michael Keller; Maiza N. dos-Santos; Veronika Leitold; Ekena R. Pinagé; Alessandro Baccini; Sassan Saatchi; Euler M. Nogueira; Mateus Batistella; Douglas C. Morton

    2016-01-01

    Deforestation rates have declined in the Brazilian Amazon since 2005, yet degradation from logging, fire, and fragmentation has continued in frontier forests. In this study we quantified the aboveground carbon density (ACD) in intact and degraded forests using the largest data set of integrated forest inventory plots (n = 359) and airborne lidar data (18,000 ha)...

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

    Treesearch

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

    1993-01-01

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

  7. Short-term response of breeding birds to oak regeneration treatments in upland hardwood forest.

    Treesearch

    Katie Greenberg; Kathleen Franzreb; Tara Keyser; Stan Zarnoch; Dean Simon; Gordon Warburton

    2015-01-01

    Population declines of several successional-scrub bird species are partly associated with deceased habitat availability as abandoned farmlands return to forest and recently harvested forests regrow. Restoration of mixed-oak (Quercus spp.) forest is also a concern because of widespread oak regeneration failure, especially on moist, productive sites where competition...

  8. FUEL CONDITIONS ASSOCIATED WITH NATIVE AND EXOTIC GRASSES IN A SUBTROPICAL DRY FOREST IN PUERTO RICO

    Treesearch

    Jarrod M. Thaxton; Skip J. Van Bloem; Stefanie Whitmire

    2012-01-01

    Exotic grasses capable of increasing frequency and intensity of anthropogenic fire have invaded subtropical and tropical dry forests worldwide. Since many dry forest trees are susceptible to fire, this can result in decline of native species and loss of forest cover. While the contribution of exotic grasses to altered fire regimes has been well documented, the role of...

  9. Forest fragmentation and its effects on birds

    USGS Publications Warehouse

    Robbins, C.S.; Johnson, James E.

    1988-01-01

    Fragmentation of forest land, whether by suburban development, highways, transmission lines, or poorly planned cutting regimes, seriously affects reproduction by the large numbers of obligate forest interior birds. Many of our warblers, vireos, thrushes, tanagers, and flycatchers are highly migratory insectivorous birds that spend more than half the year in the neotropics, but migrate north to the United States and Canada to rear their young. These tropical visitors are especially vulnerable to predation and cowbird parasitism and are unable to maintain their populations within 100-200 m of forest edge. Habitats for these declining species can be provided by managing forest lands in large blocks so as to maintain at all times extensive contiguous areas of successional stages as well as of mature forest. Avoiding scattered small cuts will also help by reducing edge, road construction, and other disturbance.

  10. Forest resources of the Clearwater National Forest

    Treesearch

    Ryan P. Hughes

    2011-01-01

    The Interior West Forest Inventory and Analysis (IWFIA) Program of the USDA Forest Service, Rocky Mountain Research Station, as part of our National Forest System cooperative inventories, conducted a forest resource inventory on the Clearwater National Forest using a nationally standardized mapped-plot design (for more details see section "Inventory methods...

  11. Declining scaup populations: A retrospective analysis of long-term population and harvest survey data

    USGS Publications Warehouse

    Afton, A.D.; Anderson, M.G.

    2001-01-01

    We examined long-term databases concerning population status of scaup (lesser [Aythya affinis] and greater scaup [A. marila] combined) and harvest statistics of lesser scaup to identify factors potentially limiting population growth. Specifically, we explored evidence for and against the general hypotheses that scaup populations have declined in association with declining recruitment and/or female survival. We examined geographic heterogeneity in scaup demographic patterns that could yield evidence about potential limiting factors. Several biases exist in survey methodology used to estimate scaup populations and harvest statistics; however, none of these biases likely accounted for our major findings that (1) the continental scaup breeding population has declined over the last 20 years, with widespread and consistent declines within surveyed areas of the Canadian western boreal forest where most lesser scaup breed; (2) sex ratios of lesser scaup in the U.S. harvest have increased (more males now relative to females); and (3) age ratios of lesser scaup in the U.S. harvest have declined (fewer immatures now relative to adults), especially in the midcontinent region. We interpreted these major findings as evidence that (1) recruitment of lesser scaup has declined over the last 20 years, particularly in the Canadian western boreal forest; and (2) survival of female lesser scaup has declined relative to that of males. We found little evidence that harvest was associated with the scaup population decline. Our findings underscore the need for both improvements and changes to population survey procedures and new research to discriminate among various hypotheses explaining the recent scaup population decline.

  12. Forest resources of Puerto Rico, 1990. Forest Service Resource Bulletin

    SciTech Connect

    Franco, P.A.; Weaver, P.L.; Eggen-McIntosh, S.

    1997-10-01

    The prinicipal findings of the second forest survey of Puerto Rico (1990) and changes that have occurred since the survey was established in 1980 are presented. The forest inventory estimates describe the timber resource found within the potential commercial region designated in the first survey. The timber resource addressed consists primarily of regrown areas on abandoned pastures and cropland, including coffee production areas. The status and trends of the timber resource are presented for the two Life Zones occurring in the commercial region, as well as for various forest classes, which are based on stand history and origin. Topics dicussed include forest area, timberland area, basal area, species composition, timber volume, growing-stock volume, and sawtimber volume. results of the 1990 survey are promising, showing inceases in numbers of trees across all diamater classes and substantial increases in volume. These trends offer evidence that Puerto Rico`s forests are continuing to recover following a dramatic decline of the late 19th and early 20th centuries.

  13. Mortality rates decline in Malaysia.

    PubMed

    1991-11-01

    Experiencing remarkable decreases in mortality rates over the past 3 decades, Malaysia currently has one of the lowest mortality rates among developing countries, a rate that compares favorably with those of developed countries. Between 1957 and 1989, the crude death rate dropped from 12.4/1000 population to 4.6. Over the same period, Malaysia recorded even greater decreases in the infant mortality rate, from 75.5/1000 births to 15.2. The Maternal mortality rate also declined from 1.48 in 1970 to 0.24 in 1988. The data indicates that mortality rates vary from state to state, and that rural areas have a higher mortality than urban areas. According to a study by the National Population and Family Development Board, the use of maternal and child health services has played an important role in reducing neonatal, perinatal, infant, child, and maternal mortality rates. Nearly all women in Malaysia receive antenatal services. While the country has achieved great gains on mortality rates, programs focusing on specific age and socioeconomic groups could lead to even greater reductions. The Minister for National Unity and Social Development, Dato Napsiah Omar, has called for the development of programs designed to improve the population's quality of life.

  14. Forest statistics for North Alabama counties - 1990

    Treesearch

    William H. McWilliams; K.L. Duncan; John S. Vissage

    1990-01-01

    The 1990 forest inventory of North Alabama revealed the following:Timberland area is 2,105.1 thousand acres, a decrease of 4 percent.The distribution of live-tree volume shows that the large increases that too place in all but the 6-inch class between 1972 and 1982 have abated. Past declines in the 6-inch class have continued...

  15. The browning of Alaska's boreal forest

    Treesearch

    Mary Beth Parent; David. Verbyla

    2010-01-01

    We used twelve Landsat scenes from the 1980s-2009 and regional 2000-2009 MODIS data to examine the long-term trend in the normalized difference vegetation index (NDVI) within unburned areas of the Alaskan boreal forest. Our analysis shows that there has been a declining trend in NDVI in this region, with the strongest "browning trend" occurring in eastern...

  16. Forest products harvested in Hawaii - 1967

    Treesearch

    Herbert L. Wick

    1968-01-01

    A survey of the primary forest products harvested in Hawaii in 1967 showed a total value of $334,000, a 24 percent increase over the value in the 1958 survey. Compared with the earlier survey, the volume of sawlogs and treefern harvested has gone up while the volume of fuelwood and posts harvested has declined.

  17. Air pollution: worldwide effects on mountain forests

    Treesearch

    Anne M. Rosenthal; Andrzej Featured: Bytnerowicz

    2004-01-01

    Widespread forest decline in remote areas of the Carpathian Mountains has been linked to air pollution from urban and industrial regions. Besides injuring plant tissues directly, pollutants may deposit to soils and water, drastically changing susceptible ecosystems. Researcher Andrzej Bytnerowicz has developed effective methods for assessing air quality over wildlands...

  18. Early successional forest habitats and water resources

    Treesearch

    James Vose; Chelcy Ford

    2011-01-01

    Tree harvests that create early successional habitats have direct and indirect impacts on water resources in forests of the Central Hardwood Region. Streamflow increases substantially immediately after timber harvest, but increases decline as leaf area recovers and biomass aggrades. Post-harvest increases in stormflow of 10–20%, generally do not contribute to...

  19. The contribution of atmospheric deposition and forest harvesting to forest soil acidification in China since 1980

    NASA Astrophysics Data System (ADS)

    Zhu, Qichao; De Vries, Wim; Liu, Xuejun; Zeng, Mufan; Hao, Tianxiang; Du, Enzai; Zhang, Fusuo; Shen, Jianbo

    2016-12-01

    Soils below croplands and grasslands have acidified significantly in China since the 1980s in terms of pH decline in response to acid inputs caused by intensified fertilizer application and/or acid deposition. However, it is unclear what the rate is of pH decline of forest soils in China in response to enhanced acid deposition and wood production over the same period. We therefore gathered soil pH data from the Second National Soil Inventory of China and publications from the China National Knowledge Infrastructure (CNKI) database in 1981-1985 and 2006-2010, respectively, to evaluate the long-term change of pH values in forest soils. We found that soil pH decreased on average by 0.36 units in the period 1981-1985 to 2006-2010., with most serious pH decline occurring in southwest China (0.63 pH units). The soil type with the strongest pH decline was the semi-Luvisol (0.44 pH units). The decrease in pH was significantly correlated with the acid input induced by atmospheric deposition and forest harvesting. On average, the contribution of atmospheric deposition to the total acid input was estimated at 84% whereas element uptake (due to forest wood growth and harvest) contributed 16% only. Atmospheric deposition is thus the major driver for the significant forest soil acidification across China.

  20. Investigating the Dynamics of Wandoo Crown Decline with Time Series Landsat Imagery

    NASA Astrophysics Data System (ADS)

    Zdunic, K.; Behn, G.; van Dongen, R.

    2012-08-01

    In the forests of south west Western Australia dramatic declines in tree health have been observed in recent years. The species Eucalyptus wando has exhibited loss of crown foliage in increasing stages of severity; this condition is referred to as wandoo crown decline and can lead to death. Determining the extent and timing of these declines is difficult on the ground due to the large distribution of E. wandoo and the observation of tree declines at a range of locations and dates over the last 40 years. Understanding the distribution, severity and timing of these declines is essential to the identification of the causes of these impacts. Investigation of time series Landsat imagery can inform on locations of crown foliage loss and the time periods these losses occurred in. Applying a vegetation index to a 20 year sequence of imagery enabled periods of decline to be identified. Employment of trend analysis of four date time series demonstrated the dynamics of wandoo crown cover. Comparisons of periods of decline with the variations of cover density over the entire image sequence facilitated the identification of possible locations and timing of wandoo crown decline impacts. Changes in crown cover observed by the imagery analysis were compared to field surveys.

  1. Water yield following forest-grass-forest transitions

    NASA Astrophysics Data System (ADS)

    Elliott, Katherine J.; Caldwell, Peter V.; Brantley, Steven T.; Miniat, Chelcy F.; Vose, James M.; Swank, Wayne T.

    2017-02-01

    Many currently forested areas in the southern Appalachians were harvested in the early 1900s and cleared for agriculture or pasture, but have since been abandoned and reverted to forest (old-field succession). Land-use and land-cover changes such as these may have altered the timing and quantity of water yield (Q). We examined 80 years of streamflow and vegetation data in an experimental watershed that underwent forest-grass-forest conversion (i.e., old-field succession treatment). We hypothesized that changes in forest species composition and water use would largely explain long-term changes in Q. Aboveground biomass was comparable among watersheds before the treatment (208.3 Mg ha-1), and again after 45 years of forest regeneration (217.9 Mg ha-1). However, management practices in the treatment watershed altered resulting species composition compared to the reference watershed. Evapotranspiration (ET) and Q in the treatment watershed recovered to pretreatment levels after 9 years of abandonment, then Q became less (averaging 5.4 % less) and ET more (averaging 4.5 % more) than expected after the 10th year up to the present day. We demonstrate that the decline in Q and corresponding increase in ET could be explained by the shift in major forest species from predominantly Quercus and Carya before treatment to predominantly Liriodendron and Acer through old-field succession. The annual change in Q can be attributed to changes in seasonal Q. The greatest management effect on monthly Q occurred during the wettest (i.e., above median Q) growing-season months, when Q was significantly lower than expected. In the dormant season, monthly Q was higher than expected during the wettest months.

  2. [Concentration or decline in Puebla?].

    PubMed

    Cabrera Becerra, V

    1993-04-01

    Some doubts have been expressed over whether the slowing pace of urbanization suggested by the 1990 census of Mexico was an accurate reflection of changing conditions, or whether it resulted from some intentional or unintended bias. Comparison of data from succeeding censuses indicates that the growth rate of the city of Puebla declined from 6.32% in 1980 to 2.63% in 1990. This work argues that, in Puebla, a trend to deconcentration of the population within the city of Puebla during the 1980s was accompanied by rapid growth in smaller and medium sized nearby cities, resulting in increased overall concentration in Puebla's metropolitan area. The absolute population of the city of Puebla increased from 772,908 in 1980 to 1,007,170 in 1990. The central area of the state of Puebla, which surrounds the city, increased its share of the state population from 51.67% in 1980 to 52.21% in 1990. The number of places with over 5000 inhabitants in the area surrounding the city of Puebla increased from 27 in 1980 to 39 in 1990. Construction of the Puebla-Atlixco highway will undoubtedly attract growth to the area southwest of Puebla. Small cities to the east of Puebla have shown significant growth although their region remains strongly rural. The same process of deconcentration of population in Puebla and concentration in its surrounding metropolitan regions can probably also be detected in patterns of investment of public funds. The trend is likely to continue through the 1990s.

  3. Forest dieback in Russia: Causes, distribution and implications for the future

    SciTech Connect

    Krankina, O.N. . Dept. of Forest Science); Dixon, R.K. . Environmental Research Lab.); Shvidenko, A.Z. ); Selikhovkin, A.V. )

    1994-12-01

    The Russian Federation with its great expanse of forest land plays a prominent role in the global environment. Over 20% of the world's forest resources and about one-half of boreal forest are located on Russian territory. Forest dieback following natural or anthropogenic disturbance is a significant factor in boreal forest dynamics. The leading causes of dieback are forest fires and adverse weather conditions. Although natural disturbance accounts for the greater part of dieback, anthropogenic factors are significant in increasing susceptibility of forests to stress natural agents. In industrially developed regions air pollution, harvesting, major constructions, and mining are directly responsible for forest dieback. Since factors of forest dieback are closely interrelated a single cause of dieback is often impossible to establish. In 1991 the largest proportion of forest dieback occurred in the southern part of Europe-Urals and West Siberia as well as in the Far East. Data on forest dieback is available only for monitored forest, which constitutes 60% of the total forest land in Russia, so, these values should be regarded as fairly conservative. Decline of forests is estimated to affect additionally about 2 [times] 10[sup 6] ha per year. Projected global climate change is likely to dramatically increase forest decline and dieback.

  4. Long-term decline and short-term crash of the once abundant Rusty Blackbird

    USGS Publications Warehouse

    Greenberg, R.; Blancher, P.; Niven, D.; Droege, S.

    2008-01-01

    The Rusty Blackbird (Euphagus carolinus), a formerly common breeding species of boreal wetlands, has exhibited the most marked decline of any North American landbird. North American Breeding Bird Survey (BBS) trends in abundance are estimated to be -12.5% / yr over the last 40 years, which is tantamount to a >95% cumulative decline. Trends in abundance calculated from Christmas Bird Counts (CBC) for a similar period indicate a range-wide decline of -5.6% / yr. Qualitative analyses of ornithological accounts suggest the species has been declining for over a century before the period covered by the estimated declines. Several studies document range retraction in the southern boreal forest, whereas limited data suggest that abundance may be more stable in more northerly areas. This pattern is both supported and contradicted by winter declines based in CBC data. The lower estimates of decline in the CBC data compared to BBS is consistent with the idea that the coverage of BBS is biased towards the southern boreal whereas CBC covers the entire winter range. However, the CBC declines are similar between the South Atlantic coast (with populations derived from the southeastern boreal) and the Mississippi Valley (populations from the northwest boreal). The major hypotheses for the decline include degradation of boreal habitats from logging and agricultural agricultural development, mercury contamination, and wetland desiccation resulting from global warming. Other likely reasons for decline include loss or degradation of wooded wetlands of the southeastern U.S and mortality associated with abatement efforts targeting nuisance blackbirds. We present a matrix of hypotheses and predictions that test them based on the geography of decline and more detailed indicators of population health which should form the strategic basis of future research.

  5. Illinois' Forests 2005

    Treesearch

    Susan J. Crocker; Gary J. Brand; Brett J. Butler; David E. Haugen; Dick C. Little; Dacia M. Meneguzzo; Charles H. Perry; Ronald J. Piva; Barry T. Wilson; Christopher W. Woodall

    2009-01-01

    The first full, annualized inventory of Illinois' forests reports more than 4.5 million acres of forest land with an average of 459 trees per acre. Forest land is dominated by oak/hickory forest types, which occupy 65 percent of total forest land area. Seventy-two percent of forest land consists of sawtimber, 20 percent contains poletimber, and 8 percent contains...

  6. Minnesota's Forests 2008

    Treesearch

    Patrick D. Miles; David Heinzen; Manfred E. Mielke; Christopher W. Woodall; Brett J. Butler; Ron J. Piva; Dacia M. Meneguzzo; Charles H. Perry; Dale D. Gormanson; Charles J. Barnett

    2011-01-01

    The second full annual inventory of Minnesota's forests reports 17 million acres of forest land with an average volume of more than 1,000 cubic feet per acre. Forest land is dominated by the aspen forest type, which occupies nearly 30 percent of the total forest land area. Twenty-eight percent of forest land consists of sawtimber, 35 percent poletimber, 35 percent...

  7. Midsouth forest area trends

    Treesearch

    Richard A. Birdsey; William H. McWilliams

    1986-01-01

    The forest inventory and analysis unit of the southern forest experiment stations (Forest Survey) conducts periodic inventories at approximately 10-year intervals of the forest resources of the Midsouth States (fig. 1). This report contains a summary of forest acreage estimates made between 1950 and 1985. The statistics are based on published forest survey reports and...

  8. Georgia's forests, 2004

    Treesearch

    Richard A. Harper; Nathan D. McClure; Tony G. Johnson; J. Frank Green; James K. Johnson; David B. Dickinson; James L. Chamerlain; KaDonna C. Randolph; Sonja N. Oswalt

    2009-01-01

    Between 1997 and 2004, the Forest Service, Forest Inventory and Analysis Program conducted the eighth inventory of Georgia forests. Forest land area remained stable at 24.8 million acres, and covered about two-thirds of the land area in Georgia. About 24.2 million acres of forest land was considered timberland and 92 percent of that was privately owned. Family forest...

  9. Nebraska's forests, 2005

    Treesearch

    Dacia M. Meneguzzo; Brett J. Butler; Susan J. Crocker; David E. Haugen; W. Keith Moser; Charles H. Perry; Barry T. Wilson; Christopher W. Woodall

    2008-01-01

    Results of the first annual inventory of Nebraska's forests (2001-05) show an estimated 1.24 million acres of forest land; 1.17 million acres meet the definition of timberland. Softwood forest types account for one-third of all forest land area, with ponderosa pine being the most prevalent type. Hardwood forest types comprise 58 percent of Nebraska's forest...

  10. Effects of rapid urban sprawl on urban forest carbon stocks: integrating remotely sensed, GIS and forest inventory data.

    PubMed

    Ren, Yin; Yan, Jing; Wei, Xiaohua; Wang, Yajun; Yang, Yusheng; Hua, Lizhong; Xiong, Yongzhu; Niu, Xiang; Song, Xiaodong

    2012-12-30

    Research on the effects of urban sprawl on carbon stocks within urban forests can help support policy for sustainable urban design. This is particularly important given climate change and environmental deterioration as a result of rapid urbanization. The purpose of this study was to quantify the effects of urban sprawl on dynamics of forest carbon stock and density in Xiamen, a typical city experiencing rapid urbanization in China. Forest resource inventory data collected from 32,898 patches in 4 years (1972, 1988, 1996 and 2006), together with remotely sensed data (from 1988, 1996 and 2006), were used to investigate vegetation carbon densities and stocks in Xiamen, China. We classified the forests into four groups: (1) forest patches connected to construction land; (2) forest patches connected to farmland; (3) forest patches connected to both construction land and farmland and (4) close forest patches. Carbon stocks and densities of four different types of forest patches during different urbanization periods in three zones (urban core, suburb and exurb) were compared to assess the impact of human disturbance on forest carbon. In the urban core, the carbon stock and carbon density in all four forest patch types declined over the study period. In the suburbs, different urbanization processes influenced forest carbon density and carbon stock in all four forest patch types. Urban sprawl negatively affected the surrounding forests. In the exurbs, the carbon stock and carbon density in all four forest patch types tended to increase over the study period. The results revealed that human disturbance played the dominant role in influencing the carbon stock and density of forest patches close to the locations of human activities. In forest patches far away from the locations of human activities, natural forest regrowth was the dominant factor affecting carbon stock and density.

  11. Why health care workers decline influenza vaccination.

    PubMed

    Moore, Brenda S

    2009-11-01

    Influenza vaccine is essential to preventing influenza among health care workers and their patients. Therefore, the staff of the employee health clinic worked diligently to provide an opportunity for all employees to receive influenza vaccinations. Despite these efforts, a significant percentage of employees declined the vaccine. During the 2007-2008 influenza season, employees were instructed to either receive the influenza vaccine or decline in writing. The vaccination rate for all staff members and direct caregivers, during the 2007-2008 vaccination season, was 52%, with 35% declining and 13% not participating. In response to the 35% declining, data were analyzed to develop an effective educational tool focused on reasons for declination. This article presents an overview of the study, the reasons employees declined influenza vaccine, and strategies for improving vaccination rates. Copyright 2009, SLACK Incorporated.

  12. Declines in woodland salamander abundance associated with non-native earthworm and plant invasions.

    PubMed

    Maerz, John C; Nuzzo, Victoria A; Blossey, Bernd

    2009-08-01

    Factors that negatively affect the quality of wildlife habitat are a major concern for conservation. Non-native species invasions, in particular, are perceived as a global threat to the quality of wildlife habitat. Recent evidence indicates that some changes to understory plant communities in northern temperate forests of North America, including invasions by 3 non-native plant species, are facilitated by non-native earthworm invasion. Furthermore, non-native earthworm invasions cause a reduction in leaf litter on the forest floor, and the loss of forest leaf litter is commonly associated with declines in forest fauna, including amphibians. We conducted a mark-recapture study of woodland salamander abundance across plant invasion fronts at 10 sites to determine whether earthworm or plant invasions were associated with reduced salamander abundance. Salamander abundance declined exponentially with decreasing leaf litter volume. There was no significant relationship between invasive plant cover and salamander abundance, independent of the effects of leaf litter loss due to earthworm invasion. An analysis of selected salamander prey abundance (excluding earthworms) at 4 sites showed that prey abundance declined with declining leaf litter. The loss of leaf litter layers due to non-native earthworm invasions appears to be negatively affecting woodland salamander abundance, in part, because of declines in the abundance of small arthropods that are a stable resource for salamanders. Our results demonstrate that earthworm invasions pose a significant threat to woodland amphibian fauna in the northeastern United States, and that plant invasions are symptomatic of degraded amphibian habitat but are not necessarily drivers of habitat degradation.

  13. Declining brown-headed cowbird (Molothrus ater) populations are associated with landscape-specific reductions in brood parasitism and increases in songbird productivity

    Treesearch

    W. Andrew Cox; Frank R., III Thompson; Brian Root; John Faaborg; Csaba. Moskat

    2012-01-01

    Many songbird species have experienced significant population declines, partly because of brood parasitism by the Brown-headed Cowbird (Molothrus ater), which is positively associated with increasing landscape forest cover in the midwestern United States. However, cowbirds are also experiencing long-term population declines, which should reduce...

  14. Cognitive Issues: Decline, Delirium, Depression, Dementia.

    PubMed

    Harris, Melodee

    2017-09-01

    Cognitive decline in older persons can be pathologic or occur as a part of the normal aging process. Delirium, depression, and dementia are geriatric syndromes and neurocognitive disorders that are the result of cognitive decline associated with pathology. This overview is a brief guide on cognitive decline and how to identify, manage, and treat associated neurocognitive disorders, including delirium, depression, and dementia. Copyright © 2017 Elsevier Inc. All rights reserved.

  15. The National Audubon Society's eastern forest conservation initiative: examining opportunities for bird conservation at a regional scale

    Treesearch

    Curtis Smalling; Mary. Elfner

    2010-01-01

    The forests of the east are under tremendous pressure from a variety of sources, including increasing development and fragmentation, declining air quality, declining water quality, and global climate change. Many priority bird species depend on these forested habitats, including a high percentage (75 percent) of neotropical migrant breeding species.

  16. An assessment of the downturn in the forest products sector in the northern region of the United States

    Treesearch

    C.W. Woodall; W.G. Luppold; P.J. Ince; R.J. Piva; K.E. Skog

    2012-01-01

    The forest industry within the northern region of the U.S. has declined notably in employment, mill numbers, wood consumption, and forest harvests since 2000…a downturn exacerbated by the recession of 2007 to 2009. Longer term industrial decline (since 2000) has been evidenced by reductions in secondary products (e.g., furniture) and print paper manufacturing which can...

  17. Effects of the "great recession" on the forest products sector in the northern region of the United States

    Treesearch

    Christopher W. Woodall; William G. Luppold; Peter J. Ince; Ronald J. Piva; Kenneth E. Skog

    2012-01-01

    The forest industry within the northern region of the United States has demonstrated a notable decline in terms of employment, number of mills, wood consumption, and forest harvests since 2000--a downturn exacerbated by the "Great Recession" of 2007-2009. Longer term industrial decline (since 2000) has been evidenced by reductions in secondary product (e.g.,...

  18. Habitat split as a cause of local population declines of amphibians with aquatic larvae.

    PubMed

    Becker, C Guilherme; Fonseca, Carlos R; Haddad, Célio F B; Prado, Paulo I

    2010-02-01

    Most amphibian species have biphasic life histories and undergo an ontogenetic shift from aquatic to terrestrial habitats. In deforested landscapes, streams and forest fragments are frequently disjunct, jeopardizing the life cycle of forest-associated amphibians with aquatic larvae. We tested the impact of habitat split--defined as human-induced disconnection between habitats used by different life-history stages of a species--on four forest-associated amphibian species in a severely fragmented landscape of the Brazilian Atlantic Forest. We surveyed amphibians in forest fragments with and without streams (referred to as wet and dry fragments, respectively), including the adjacent grass-field matrix. Our comparison of capture rates in dry fragments and nearby streams in the matrix allowed us to evaluate the number of individuals that engaged in high-risk migrations through nonforested habitats. Adult amphibians moved from dry fragments to matrix streams at the beginning of the rainy season, reproduced, and returned at the end of the breeding period. Juveniles of the year moved to dry fragments along with adults. These risky reproductive migrations through nonforested habitats that expose individuals to dehydration, predation, and other hazards may cause population declines in dry fragments. Indeed, capture rates were significantly lower in dry fragments compared with wet fragments. Declining amphibians would strongly benefit from investments in the conservation and restoration of riparian vegetation and corridors linking breeding and nonbreeding areas.

  19. Forests & Trees.

    ERIC Educational Resources Information Center

    Gage, Susan

    1989-01-01

    This newsletter discusses the disappearance of the world's forests and the resulting environmental problems of erosion and flooding; loss of genetic diversity; climatic changes such as less rainfall, and intensifying of the greenhouse effect; and displacement and destruction of indigenous cultures. The articles, lessons, and activities are…

  20. Montane forests

    Treesearch

    Malcolm North; Brandon M. Collins; Hugh Safford; Nathan L. Stephenson

    2016-01-01

    California’s montane forests include some of the most productive and diverse temperate ecosystems in the world, containing the largest single stem tree (the 1487 m3 General Sherman giant sequoia [Sequoiadendron giganteum]) (Van Pelt 2001) and highest conifer diversity (30 plus species in the Klamath-Siskiyou mountain range) (Sawyer 2006)....

  1. Subalpine forests

    Treesearch

    C.I. Millar; P.W. Rundel

    2016-01-01

    The subalpine forests of California comprise the highest elevation ecosystems that are dominated by upright trees. They are defined as a zone influenced primarily by abiotic controls, including persistent snowpack, desiccating winds, acute and chronic extreme temperatures, soil moisture and evapotranspirative stresses, and short growing seasons. Bounded at the...

  2. Forest Phytophthoras

    Treesearch

    J. L. Parke

    2013-01-01

    Profiles are provided for 5 forest Phytopthora species: P. kernoviae, P. pinifolia, P.alni, P. cinnamomi, P.katsurae. Also presented are a "Host and Habitat Index for Phytophthora Species in Oregon" and "Histopathological Investigations of the Infection Process and Propagule Development of...

  3. Forest Imaging

    NASA Technical Reports Server (NTRS)

    1992-01-01

    NASA's Technology Applications Center, with other government and academic agencies, provided technology for improved resources management to the Cibola National Forest. Landsat satellite images enabled vegetation over a large area to be classified for purposes of timber analysis, wildlife habitat, range measurement and development of general vegetation maps.

  4. Feral Pigs, Introduced Mosquitoes, and the Decline of Hawai'i's Native Birds

    USGS Publications Warehouse

    LaPointe, Dennis A.

    2006-01-01

    The introduction of mosquitoes, avian pox, and avian malaria to the Hawaiian Islands has had a profound effect on the geographical distribution and population number of highly susceptible Hawaiian honeycreepers, and likely contributed to the extinction of several species. While the mosquito vector (disease-carrier) is most closely associated with human activity, in remote Hawaiian rain forests, feral pigs may be pivotally important to the disease system. Since 1991, USGS scientists have taken a leadership position in identifying the role these diseases continue to play in the decline and extinction of native Hawaiian forest birds and in finding ways to mitigate their impacts.

  5. Drivers of reforestation in human-dominated forests.

    PubMed

    Nagendra, Harini

    2007-09-25

    Tropical forest habitat continues to decline globally, with serious negative consequences for environmental sustainability. The small mountain country of Nepal provides an excellent context in which to examine trajectories of forest-cover change. Despite having experienced large-scale forest clearing in the past, significant reforestation has taken place in recent years. The range of biophysical and ecological environments and diversity of tenure arrangements provide us with a context with sufficient variation to be able to derive insight into the impact of a range of hypothesized drivers of forest change. This article draws on a dataset of 55 forests from the middle hills and Terai plains of Nepal to examine the factors associated with forest clearing or regeneration. Results affirm the central importance of tenure regimes and local monitoring for forest regrowth. In addition, user group size per unit of forest area is an important, independent explanator of forest change. These variables also can be associated with specific practices that further influence forest change such as the management of social conflict, adoption of new technologies to reduce pressure on the forest, and involvement of users in forest maintenance activities. Such large-N, comparative studies are essential if we are to derive more complex, nuanced, yet actionable frameworks that help us to plan better policies for the management of natural resources.

  6. Drivers of reforestation in human-dominated forests

    PubMed Central

    Nagendra, Harini

    2007-01-01

    Tropical forest habitat continues to decline globally, with serious negative consequences for environmental sustainability. The small mountain country of Nepal provides an excellent context in which to examine trajectories of forest-cover change. Despite having experienced large-scale forest clearing in the past, significant reforestation has taken place in recent years. The range of biophysical and ecological environments and diversity of tenure arrangements provide us with a context with sufficient variation to be able to derive insight into the impact of a range of hypothesized drivers of forest change. This article draws on a dataset of 55 forests from the middle hills and Terai plains of Nepal to examine the factors associated with forest clearing or regeneration. Results affirm the central importance of tenure regimes and local monitoring for forest regrowth. In addition, user group size per unit of forest area is an important, independent explanator of forest change. These variables also can be associated with specific practices that further influence forest change such as the management of social conflict, adoption of new technologies to reduce pressure on the forest, and involvement of users in forest maintenance activities. Such large-N, comparative studies are essential if we are to derive more complex, nuanced, yet actionable frameworks that help us to plan better policies for the management of natural resources. PMID:17881576

  7. Possible red spruce decline: Contributions of tree-ring analysis

    SciTech Connect

    Van Deusen, P.C. ); Reams, G.A. ); Cook, E.R. )

    1991-01-01

    Debate continues about the cause of apparent unprecedented decreases in ring width at all elevations, and increasing levels of mortality at high elevations, in red spruce (Picea rubens) stands in the northeastern United States. These growth and mortality trends are often used as evidence of red spruce decline, but the possibility remains that they may be occurring naturally. Two hypotheses are being used to explain the causes of red spruce growth reduction across its range and increased levels of standing dead at some high-elevation sites. This article summarizes the basic evidence used by advocates of these hypotheses and discusses the strengths of their arguments. The information presented is based primarily on tree-ring studies sponsored by the Forest Response Program, which is part of the National Acid Precipitation Assessment Program.

  8. Historical decline in coral reef growth after the Panama Canal.

    PubMed

    Guzman, Hector M; Cipriani, Roberto; Jackson, Jeremy B C

    2008-07-01

    The Panama Canal is near its vessel size and tonnage handling capacity, and Panamanians have decided to expand it. The expansion of the Canal may consider the historical long-lasting impacts on marine coastal habitats particularly on sensitive coral reefs. These potential impacts were discussed during the national referendum as were other equally important issues, such as its effects on forests, watersheds, and water supply. Coral growth rates provide a direct measure of coral fitness and past environmental conditions comparable to analyses of tree rings. We examined stable isotopes, metal geochemical tracers, and growth rates on a century-long (1880-1989) chronology based on 77 cores of the dominant reef-building coral Siderastrea siderea collected near the Caribbean entrance to the canal. Our results showed a gradual decline in coral growth unrelated to changes in sea surface temperature but linked to runoff and sedimentation to coastal areas resulting from the construction and operation of the Panama Canal.

  9. The Changes in China's Forests: An Analysis Using the Forest Identity

    PubMed Central

    Shi, Lei; Zhao, Shuqing; Tang, Zhiyao; Fang, Jingyun

    2011-01-01

    Changes in forest carbon stocks are a determinant of the regional carbon budget. In the past several decades, China has experienced a pronounced increase in forest area and density. However, few comprehensive analyses have been conducted. In this study, we employed the Forest Identity concept to evaluate the changing status of China's forests over the past three decades, using national forest inventory data of five periods (1977–1981, 1984–1988, 1989–1993, 1994–1998, and 1999–2003). The results showed that forest area and growing stock density increased by 0.51% and 0.44% annually over the past three decades, while the conversion ratio of forest biomass to growing stock declined by 0.10% annually. These developments resulted in a net annual increase of 0.85% in forest carbon sequestration, which is equivalent to a net biomass carbon uptake of 43.8 Tg per year (1 Tg = 1012 g). This increase can be attributed to the national reforestation/afforestation programs, environmentally enhanced forest growth and economic development as indicated by the average gross domestic product. PMID:21695254

  10. The changes in China's forests: an analysis using the Forest Identity.

    PubMed

    Shi, Lei; Zhao, Shuqing; Tang, Zhiyao; Fang, Jingyun

    2011-01-01

    Changes in forest carbon stocks are a determinant of the regional carbon budget. In the past several decades, China has experienced a pronounced increase in forest area and density. However, few comprehensive analyses have been conducted. In this study, we employed the Forest Identity concept to evaluate the changing status of China's forests over the past three decades, using national forest inventory data of five periods (1977-1981, 1984-1988, 1989-1993, 1994-1998, and 1999-2003). The results showed that forest area and growing stock density increased by 0.51% and 0.44% annually over the past three decades, while the conversion ratio of forest biomass to growing stock declined by 0.10% annually. These developments resulted in a net annual increase of 0.85% in forest carbon sequestration, which is equivalent to a net biomass carbon uptake of 43.8 Tg per year (1 Tg = 10(12) g). This increase can be attributed to the national reforestation/afforestation programs, environmentally enhanced forest growth and economic development as indicated by the average gross domestic product.

  11. Population trends of forest birds at Hakalau Forest National Wildlife Refuge, Hawai'i

    USGS Publications Warehouse

    Camp, Richard J.; Pratt, Thane K.; Gorresen, P. Marcos; Jeffrey, John J.; Woodworth, Bethany L.

    2010-01-01

    The Hakalau Forest National Wildlife Refuge was established to protect native Hawaiian forest birds, particularly endangered species. Management for forest restoration on the refuge has consisted mainly of removing feral ungulates, controlling invasive alien plants, and reforesting former pastures. To assess effects of this habitat improvement for forest birds, we estimated density annually by distance sampling and examined population trends for native and alien passerines over the 21 years since the refuge was established. We examined long-term trends and recent short-term trajectories in three study areas: (1) reforested pastureland, (2) heavily grazed open forest that was recovering, and (3) lightly grazed closed forest that was relatively intact. Three species of native birds and two species of alien birds had colonized the reforested pasture and were increasing. In the open forest, densities of all eight native species were either stable or increasing. Long-term trends for alien birds were also generally stable or increasing. Worryingly, however, during the most recent 9 years, in the open forest trajectories of native species were decreasing or inconclusive, but in the reforested pasture they generally increased. The closed forest was surveyed in only the most recent 9 years, and trajectories of native species there were mixed. Overall, long-term population trends in Hakalau are stable or increasing, contrasting with declines in most other areas of Hawai'i over the same period. However, more recent mixed results may indicate emergent problems for this important bird area.

  12. USDA Forest Service Experimental Forests and Ranges

    Treesearch

    Ralph H. Crawford

    2006-01-01

    Experimental Forests and Ranges (EF&Rs) have provided and continue to provide scientific information for the management of National Forests, industrial and private lands. In accordance with federal authority 4062.01 of the Forest Service Manual, section 4000 provisions of the Organic Administration Act of 1897 (16 USC 551), and the Forest and Rangeland Renewable...

  13. Forest ownership dynamics of southern forests

    Treesearch

    Brett J. Butler; David N. Wear

    2013-01-01

    Key FindingsPrivate landowners hold 86 percent of the forest area in the South; two-thirds of this area is owned by families or individuals.Fifty-nine percent of family forest owners own between 1 and 9 acres of forest land, but 60 percent of family-owned forests are in holdings of 100 acres or more.Two-...

  14. Virginia's Forests

    Treesearch

    William A. Bechtold; Mark J. Brown; John B. Tansey

    1987-01-01

    Between 1977 and 1986, area of timberland in Virginia declined from 16.0 to 15.4 million acres. Volume of softwood growing stock increased by 5 percent, and volume of hardwood growing stock increased by 11 percent. Softwood net annual growth decreased by 7 percent, and hardwood growing-stick growth decreased by 1 percent. Softwood removals remained almost unchanged...

  15. Declining Undergraduate Student Performance in Higher Education.

    ERIC Educational Resources Information Center

    Spinelli, Teri

    Factors contributing to declining academic performance of college students are considered, including: increased government intervention in education, declining faculty expectations and lowered standards, administrative policies, and changing student attitudes and expectations. One view is that government is largely responsible for the…

  16. Aging, Terminal Decline, and Terminal Drop

    ERIC Educational Resources Information Center

    Palmore, Erdman; Cleveland, William

    1976-01-01

    Data from a 20-year longitudinal study of persons over 60 were analyzed by step-wise multiple regression to test for declines in function with age, for terminal decline (linear relationship to time before death), and for terminal drop (curvilinear relationship to time before death). There were no substantial terminal drop effects. (Author)

  17. Reversing Africa's Decline. Worldwatch Paper 65.

    ERIC Educational Resources Information Center

    Brown, Lester R.; Wolf, Edward C.

    This paper highlights some of the themes that any successful strategy to reverse the decline of Africa must embrace. Africa is a continent experiencing a breakdown in the relationship between people and their natural support systems. Famine and the threat of famine are among the manifestations of this breakdown. This decline can be reversed. To do…

  18. Amphibian decline in Yellowstone National Park

    Treesearch

    Debra A. Patla; Charles R. Peterson; Paul Stephen Corn

    2009-01-01

    We conduct long-term amphibian monitoring in Yellowstone National Park (YNP) (1) and read McMenamin et al.'s article (2) with interest. This study documents decline in the extent of seasonal wetlands in the Lamar Valley of YNP during extended drought, but the conclusion, widely reported in the media, of "severe declines in 4 once-common amphibian species,...

  19. Is University Research on the Decline?

    ERIC Educational Resources Information Center

    Ferne, Georges

    1980-01-01

    Decline in research emphasis in universities is tied to a number of factors: defensive apathy in the university scientific community; weakening links between teaching and research; declining enrollments; problems in interdisciplinary work; employment stability and aging faculty, obsolete equipment, support staff reduction, and growing bureaucracy.…

  20. Novelty Seeking in Adulthood: Increases Accompany Decline

    ERIC Educational Resources Information Center

    Reio, Thomas G., Jr.; Choi, Namok

    2004-01-01

    Using stereotypes, researchers have predicted that novelty seeking declines in adulthood. Through this cross-sectional study, the authors revealed that only the external sensational type of novelty seeking declined, whereas the internal sensational and internal and external cognitive types remained stable or increased. A population of 233 adults…

  1. Tracking changes in the susceptibility of forest land infested with gypsy moth. Forest Service research paper (Final)

    SciTech Connect

    Gansner, D.A.; Quimby, J.W.; King, S.L.; Arner, S.L.; Drake, D.A.

    1994-08-01

    The report questions the forest land subject to intensive outbreaks of gypsy moth (Lymantria dispar L.) which become less susceptible to defoliation. A model for estimating the lifelihood of gypsy moth defoliation has been developed and validated. It was applied to forest-inventory plot data to quantity trends in the susceptibility of forest land in south-central Pennsylvania during a period of intensive infestation. Results show that even though susceptibility of the region's forest apparently has declined, the potential for future infestations remains relatively high.

  2. Fir Decline and Mortality in the Southern Siberian Mountains

    NASA Technical Reports Server (NTRS)

    Kharuk, Viacheslav I.; Im, Sergei T.; Petrov, Ilya A.; Dvinskaya, Mariya, L.; Fedotova, Elena V.; Ranson, Kenneth J.

    2016-01-01

    Increased dieback and mortality of dark needle conifer (DNC) stands (composed of fir (Abies sibirica),Siberian pine (Pinus sibirica) and spruce (Picea obovata))were documented in Russia during recent decades. Here we analyzed spatial and temporal patterns of fir decline and mortality in the southern Siberian Mountains based on satellite, in situ and dendrochronological data. The studied stands are located within the boundary between DNC taiga to the north and forest-steppe to the south. Fir decline and mortality were observed to originate where topographic features contributed to maximal water-stress risk, i.e., steep (1825),convex, south-facing slopes with a shallow well-drained root zone. Fir regeneration survived droughts and increased stem radial growth, while upper canopy trees died. Tree ring width(TRW) growth negatively correlated with vapor pressure deficit (VPD), drought index and occurrence of late frosts, and positively with soil water content. Previous year growth conditions (i.e., drought index, VPD, soil water anomalies)have a high impact on current TRW (r 0.600.74). Fir mortality was induced by increased water stress and severe droughts (as a primary factor) in synergy with bark-beetles and fungi attacks (as secondary factors). Dendrochronology data indicated that fir mortality is a periodic process. In a future climate with increased aridity and drought frequency, fir (and Siberian pine) may disappear from portions of its current range (primarily within the boundary with the forest steppe)and is likely to be replaced by drought-tolerant species such as Pinus sylvestris and Larix sibirica.

  3. Fir Decline and Mortality in the Southern Siberian Mountains

    NASA Technical Reports Server (NTRS)

    Kharuk, Viacheslav I.; Im, Sergei T.; Petrov, Ilya A.; Dvinskaya, Mariya, L.; Fedotova, Elena V.; Ranson, Kenneth J.

    2016-01-01

    Increased dieback and mortality of dark needle conifer (DNC) stands (composed of fir (Abies sibirica),Siberian pine (Pinus sibirica) and spruce (Picea obovata)) were documented in Russia during recent decades. Here we analyzed spatial and temporal patterns of fir decline and mortality in the southern Siberian Mountains based on satellite, in situ and dendrochronological data. The studied stands are located within the boundary between DNC taiga to the north and forest-steppe to the south. Fir decline and mortality were observed to originate where topographic features contributed to maximal water-stress risk, i.e., steep (18 deg to 25 deg), convex, south-facing slopes with a shallow well-drained root zone. Fir regeneration survived droughts and increased stem radial growth, while upper canopy trees died. Tree ring width (TRW) growth negatively correlated with vapor pressure deficit (VPD), drought index and occurrence of late frosts, and positively with soil water content. Previous year growth conditions (i.e., drought index, VPD, soil water anomalies) have a high impact on current TRW (r = 0.60 to 0.74). Fir mortality was induced by increased water stress and severe droughts (as a primary factor) in synergy with bark-beetles and fungi attacks (as secondary factors). Dendrochronology data indicated that fir mortality is a periodic process. In a future climate with increased aridity and drought frequency, fir (and Siberian pine) may disappear from portions of its current range (primarily within the boundary with the forest- steppe) and is likely to be replaced by drought-tolerant species such as Pinus sylvestris and Larix sibirica.

  4. Fir Decline and Mortality in the Southern Siberian Mountains

    NASA Technical Reports Server (NTRS)

    Kharuk, Viacheslav I.; Im, Sergei T.; Petrov, Ilya A.; Dvinskaya, Mariya, L.; Fedotova, Elena V.; Ranson, Kenneth J.

    2016-01-01

    Increased dieback and mortality of dark needle conifer (DNC) stands (composed of fir (Abies sibirica),Siberian pine (Pinus sibirica) and spruce (Picea obovata))were documented in Russia during recent decades. Here we analyzed spatial and temporal patterns of fir decline and mortality in the southern Siberian Mountains based on satellite, in situ and dendrochronological data. The studied stands are located within the boundary between DNC taiga to the north and forest-steppe to the south. Fir decline and mortality were observed to originate where topographic features contributed to maximal water-stress risk, i.e., steep (1825),convex, south-facing slopes with a shallow well-drained root zone. Fir regeneration survived droughts and increased stem radial growth, while upper canopy trees died. Tree ring width(TRW) growth negatively correlated with vapor pressure deficit (VPD), drought index and occurrence of late frosts, and positively with soil water content. Previous year growth conditions (i.e., drought index, VPD, soil water anomalies)have a high impact on current TRW (r 0.600.74). Fir mortality was induced by increased water stress and severe droughts (as a primary factor) in synergy with bark-beetles and fungi attacks (as secondary factors). Dendrochronology data indicated that fir mortality is a periodic process. In a future climate with increased aridity and drought frequency, fir (and Siberian pine) may disappear from portions of its current range (primarily within the boundary with the forest steppe)and is likely to be replaced by drought-tolerant species such as Pinus sylvestris and Larix sibirica.

  5. Fir Decline and Mortality in the Southern Siberian Mountains

    NASA Technical Reports Server (NTRS)

    Kharuk, Viacheslav I.; Im, Sergei T.; Petrov, Ilya A.; Dvinskaya, Mariya, L.; Fedotova, Elena V.; Ranson, Kenneth J.

    2016-01-01

    Increased dieback and mortality of dark needle conifer (DNC) stands (composed of fir (Abies sibirica),Siberian pine (Pinus sibirica) and spruce (Picea obovata)) were documented in Russia during recent decades. Here we analyzed spatial and temporal patterns of fir decline and mortality in the southern Siberian Mountains based on satellite, in situ and dendrochronological data. The studied stands are located within the boundary between DNC taiga to the north and forest-steppe to the south. Fir decline and mortality were observed to originate where topographic features contributed to maximal water-stress risk, i.e., steep (18 deg to 25 deg), convex, south-facing slopes with a shallow well-drained root zone. Fir regeneration survived droughts and increased stem radial growth, while upper canopy trees died. Tree ring width (TRW) growth negatively correlated with vapor pressure deficit (VPD), drought index and occurrence of late frosts, and positively with soil water content. Previous year growth conditions (i.e., drought index, VPD, soil water anomalies) have a high impact on current TRW (r = 0.60 to 0.74). Fir mortality was induced by increased water stress and severe droughts (as a primary factor) in synergy with bark-beetles and fungi attacks (as secondary factors). Dendrochronology data indicated that fir mortality is a periodic process. In a future climate with increased aridity and drought frequency, fir (and Siberian pine) may disappear from portions of its current range (primarily within the boundary with the forest- steppe) and is likely to be replaced by drought-tolerant species such as Pinus sylvestris and Larix sibirica.

  6. Virginia's forests, 2001

    Treesearch

    Anita K. Rose

    2007-01-01

    Between 1997 and 2001, the Forest Service’s Forest Inventory and Analysis (FIA) Program conducted the seventh inventory of the forests of Virginia. About 15,844,000 acres, or 62 percent, of Virginia was forested. The majority (12,102,000 acres) of Virginia’s forest land was in nonindustrial private forest ownership. Public ownership and forest industry ranked second...

  7. The perception of fundamental frequency declination.

    PubMed

    Pierrehumbert, J

    1979-08-01

    A series of experiments was carried out to investigate how fundamental frequency declination is perceived by speakers of English. Using linear predictor coded speech, nonsense sentences were constructed in which fundamental frequency on the last stressed syllable had been systematically varied. Listeners were asked to judge which stressed syllable was higher in pitch. Their judgments were found to reflect normalization for expected declination; in general, when two stressed syllables sounded equal in pitch, the second was actually lower. The pattern of normalization reflected certain major features of production patterns: A greater correction for declination was made for wide pitch range stimuli than for narrow pitch range stimuli. The slope of expected declination was less for longer stimuli than for shorter ones. Lastly, amplitude was found to have a significant effect on judgments, suggesting that the amplitude downdrift which normally accompanies fundamental frequency declination may have an important role in the perception of phrasing.

  8. Thresholds in forest bird occurrence as a function of the amount of early-seral broadleaf forest at landscape scales

    USGS Publications Warehouse

    Betts, M.G.; Hagar, J.C.; Rivers, J.W.; Alexander, J.D.; McGarigal, K.; McComb, B.C.

    2010-01-01

    Recent declines in broadleaf-dominated, early-seral forest globally as a function of intensive forest management and/or fire suppression have raised concern about the viability of populations dependent on such forest types. However, quantitative information about the strength and direction of species associations with broadleaf cover at landscape scales are rare. Uncovering such habitat relationships is essential for understanding the demography of species and in developing sound conservation strategies. It is particularly important to detect points in habitat reduction where rates of population decline may accelerate or the likelihood of species occurrence drops rapidly (i.e., thresholds). Here, we use a large avian point-count data set (N = 4375) from southwestern and northwestern Oregon along with segmented logistic regression to test for thresholds in forest bird occurrence as a function of broadleaf forest and early-seral broadleaf forest at local (150-m radius) and landscape (500–2000-m radius) scales. All 12 bird species examined showed positive responses to either broadleaf forest in general, and/or early-seral broadleaf forest. However, regional variation in species response to these conditions was high. We found considerable evidence for landscape thresholds in bird species occurrence as a function of broadleaf cover; threshold models received substantially greater support than linear models for eight of 12 species. Landscape thresholds in broadleaf forest ranged broadly from 1.35% to 24.55% mean canopy cover. Early-seral broadleaf thresholds tended to be much lower (0.22–1.87%). We found a strong negative relationship between the strength of species association with early-seral broadleaf forest and 42-year bird population trends; species most associated with this forest type have declined at the greatest rates. Taken together, these results provide the first support for the hypothesis that reductions in broadleaf-dominated early-seral forest due to

  9. Thresholds in forest bird occurrence as a function of the amount of early-seral broadleaf forest at landscape scales.

    PubMed

    Betts, M G; Hagar, J C; Rivers, J W; Alexander, J D; McGarigal, K; McComb, B C

    2010-12-01

    Recent declines in broadleaf-dominated, early-seral forest globally as a function of intensive forest management and/or fire suppression have raised concern about the viability of populations dependent on such forest types. However, quantitative information about the strength and direction of species associations with broadleaf cover at landscape scales are rare. Uncovering such habitat relationships is essential for understanding the demography of species and in developing sound conservation strategies. It is particularly important to detect points in habitat reduction where rates of population decline may accelerate or the likelihood of species occurrence drops rapidly (i.e., thresholds). Here, we use a large avian point-count data set (N = 4375) from southwestern and northwestern Oregon along with segmented logistic regression to test for thresholds in forest bird occurrence as a function of broadleaf forest and early-seral broadleaf forest at local (150-m radius) and landscape (500-2000-m radius) scales. All 12 bird species examined showed positive responses to either broadleaf forest in general, and/or early-seral broadleaf forest. However, regional variation in species response to these conditions was high. We found considerable evidence for landscape thresholds in bird species occurrence as a function of broadleaf cover; threshold models received substantially greater support than linear models for eight of 12 species. Landscape thresholds in broadleaf forest ranged broadly from 1.35% to 24.55% mean canopy cover. Early-seral broadleaf thresholds tended to be much lower (0.22-1.87%). We found a strong negative relationship between the strength of species association with early-seral broadleaf forest and 42-year bird population trends; species most associated with this forest type have declined at the greatest rates. Taken together, these results provide the first support for the hypothesis that reductions in broadleaf-dominated early-seral forest due to

  10. Using Forest Health Monitoring to assess aspen forest cover change in the southern Rockies ecoregion

    Treesearch

    Paul Rogers

    2002-01-01

    Long-term qualitative observations suggest a marked decline in quaking aspen (Populus tremuloides Michx.) primarily due to advancing succession and fire suppression. This study presents an ecoregional coarse-grid analysis of the current aspen situation using Forest Health Monitoring (FHM) data from Idaho, Wyoming, and Colorado. A...

  11. Biomass removal and its effect on productivity of an artificially regenerated forest stand in the Missouri ozarks

    Treesearch

    Flex Jr. Ponder

    2007-01-01

    Intensive harvesting, which removes a greater proportion of the forest biomass than conventional harvesting and the associated nutrients, may cause a decline in forest productivity. Planted seedling response to three biomass removal levels (1. removal of boles only=OM1, 2. all surface organic matter removed, forest floor not removed=OM2, and 3. removal of all surface...

  12. Potential significance of frost, topographic relief, and Acacia koa stands to restoration of mesic Hawaiian forests on abandoned rangeland

    Treesearch

    Paul G. Scowcroft; Jack. Jeffrey

    1999-01-01

    Beginning in the 1850s, logging, land clearing, and burning were used to convert high elevation Hawaiian forests to cattle pasture. Recently, declining pro®ts from ranching, the need to expand habitat for endangered species, and diminishing supplies of native saw-timber have prompted interest in restoring native forests. The Forest Service, in cooperation with the...

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

    Treesearch

    Dwight Scarbrough; Jennifer Juzwik

    2004-01-01

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

  14. Climate warming threatens semi-arid forests in Inner Asia

    NASA Astrophysics Data System (ADS)

    WU, X.

    2015-12-01

    A line of evidences reveal an increasing tree growth decline and tree mortality mainly attributable to climate warming and the warming-mediated changes in drought and other processes in many parts of world tropical, temperate and boreal forests. However, the growth responses to climate change of the widely distributed semi-arid forests are unclear. Here, we synthetically investigate the tree growth patterns during past decades and its interannual response to climate variations in Inner Asia combining the ground truth field survey and samplings, remote sensing observations and climate data. We identified a pervasive tree growth decline since mid-1990s in semi-arid forests in Inner Asia. The widely observed tree growth decline is dominantly attributable to warming-induced water stress during pre- and early growing season. Tree growth of semi-arid forests in Inner Asia is particularly susceptible to spring warming and has been suffering a prolonged growth limitation in recent decades due to spring warming-mediated water conditions. Additionally, we identified a much slower growth rate in younger trees and a lack of tree regeneration in these semi-arid forests. The widely observed forest growth reduction and lack of tree regeneration over semi-arid forests in Inner Asia could predictably exert great effects on forest structure, regionally/globally biophysical and biochemical processes and the feedbacks between biosphere and atmosphere. Notably, further increases in forest stress and tree mortality could be reasonably expected, especially in context of the increase frequency and severity of high temperature and heat waves and changes in forest disturbances, potentially driving the eventual regional loss of current semi-arid forests. Given the potential risks of climate induced forest dieback, increased management attention to adaptation options for enhancing forest resistance and resilience to projected climate stress can be expected. However, the functionally realistic

  15. Climate Warming Threatens Semi-arid Forests in Inner Asia

    NASA Astrophysics Data System (ADS)

    WU, X.; Liu, H.; Qi, Z.; Li, X.

    2014-12-01

    A line of evidences reveal an increasing tree growth decline and tree mortality mainly attributable to climate warming and the warming-mediated changes in drought and other processes (such as fire and insect dynamics) in many parts of world tropical, temperate and boreal forests. However, the growth responses to climate change of the widely distributed semi-arid forests are unclear. Here, we synthetically investigate the tree growth patterns during past decades and its interannual response to climate variations in Inner Asia combining the ground truth field survey and samplings, remote sensing observations and climate data. We identified a pervasive tree growth decline since mid-1990s in semi-arid forests in Inner Asia. The widely observed tree growth decline is dominantly attributable to warming-induced water stress during pre- and early growing season. Tree growth of semi-arid forests in Inner Asia is particularly susceptible to spring warming and has been suffering a prolonged growth limitation in recent decades due to spring warming-mediated water conditions. Additionally, we identified a much slower growth rate in younger trees and a lack of tree regeneration in these semi-arid forests. The widely observed forest growth reduction and lack of tree regeneration over semi-arid forests in Inner Asia could predictably exert great effects on forest structure, regionally/globally biophysical and biochemical processes and the feedbacks between biosphere and atmosphere. Notably, further increases in forest stress and tree mortality could be reasonably expected, especially in context of the increase frequency and severity of high temperature and heat waves and changes in forest disturbances, potentially driving the eventual regional loss of current semi-arid forests. Given the potential risks of climate induced forest dieback, increased management attention to adaptation options for enhancing forest resistance and resilience to projected climate stress can be expected

  16. Fire Regime and Stability of the West African Tropical Forest

    NASA Astrophysics Data System (ADS)

    Dwomoh, F. K.; Wimberly, M. C.

    2014-12-01

    Ecological discussions concerning alternative stable states theory suggest that tropical forest ecosystems could shift to qualitatively different alternative states upon catastrophic disturbances which exceed forest resilience. In this regard, it is expected that changes in the fire regime facilitated by climate and land use alterations could lead to rapid forest cover loss, creating conditions likely to push tropical forests to tipping points, beyond which forest resilience is lost. However, there is a dearth of empirical examples of fire-driven alternative stable states involving tropical forests. Key among the constraints for this scarcity are the requirements for large scale disturbances and long-term data, both of which are scarce. However, in the West African tropical forest (referred to as the Upper Guinean forest, UGF) a number of protected areas were impacted by large fire events during the 1980s El Niño-driven droughts, providing an opportunity for testing hypotheses concerning alternative stable states in tropical forest ecosystems. This paper aims to demonstrate fire-driven alternative stable states in the deciduous forest zone of the UGF by analyzing fire activity and forest recovery in fire-impacted forest reserves. We analyzed historical Landsat and MODIS imagery to map and quantify vegetation cover change, fire frequency and fire severity patterns. Our analyses suggest that the historic fires in the 1980s were catastrophic enough to remove forest canopy, thereby triggering a landscape-scale alternative stable states. Forest cover declined substantially becoming replaced by a novel ecosystem with low tree density. Our results also indicate the establishment of a positive fire-vegetation feedback effect, such that the new vegetation which displaced severely burned forests is more pyrogenic and maintained through frequent burns. This study expands our knowledge on the vulnerability of tropical forest ecosystems to state transitions in response to fire

  17. Generating a Positive Response to Declining Resources: 50 Tips for Success in a Declining School District.

    ERIC Educational Resources Information Center

    Lasher, Gaylord C.

    Based on the author's research and experience with organizational decline, this speech discusses research on managing declining schools and provides a framework for thinking about decline. The long period of abundance between World War II and the middle 1970s shaped American character and accustomed its leaders, including school administrators, to…

  18. Theoretical Analysis of Maximum Flow Declination Rate versus Maximum Area Declination Rate in Phonation

    ERIC Educational Resources Information Center

    Titze, Ingo R.

    2006-01-01

    Purpose: Maximum flow declination rate (MFDR) in the glottis is known to correlate strongly with vocal intensity in voicing. This declination, or negative slope on the glottal airflow waveform, is in part attributable to the maximum area declination rate (MADR) and in part to the overall inertia of the air column of the vocal tract (lungs to…

  19. Theoretical Analysis of Maximum Flow Declination Rate versus Maximum Area Declination Rate in Phonation

    ERIC Educational Resources Information Center

    Titze, Ingo R.

    2006-01-01

    Purpose: Maximum flow declination rate (MFDR) in the glottis is known to correlate strongly with vocal intensity in voicing. This declination, or negative slope on the glottal airflow waveform, is in part attributable to the maximum area declination rate (MADR) and in part to the overall inertia of the air column of the vocal tract (lungs to…

  20. Are forest disturbances amplifying or canceling out climate change-induced productivity changes in European forests?

    PubMed Central

    Reyer, Christopher P O; Bathgate, Stephen; Blennow, Kristina; Borges, Jose G; Bugmann, Harald; Delzon, Sylvain; Faias, Sonia P; Garcia-Gonzalo, Jordi; Gardiner, Barry; Gonzalez-Olabarria, Jose Ramon; Gracia, Carlos; Hernández, Juan Guerra; Kellomäki, Seppo; Kramer, Koen; Lexer, Manfred J; Lindner, Marcus; van der Maaten, Ernst; Maroschek, Michael; Muys, Bart; Nicoll, Bruce; Palahi, Marc; Palma, João HN; Paulo, Joana A; Peltola, Heli; Pukkala, Timo; Rammer, Werner; Ray, Duncan; Sabaté, Santiago; Schelhaas, Mart-Jan; Seidl, Rupert; Temperli, Christian; Tomé, Margarida; Yousefpour, Rasoul; Zimmermann, Niklaus E; Hanewinkel, Marc

    2017-01-01

    Recent studies projecting future climate change impacts on forests mainly consider either the effects of climate change on productivity or on disturbances. However, productivity and disturbances are intrinsically linked because 1) disturbances directly affect forest productivity (e.g. via a reduction in leaf area, growing stock or resource-use efficiency), and 2) disturbance susceptibility is often coupled to a certain development phase of the forest with productivity determining the time a forest is in this specific phase of susceptibility. The objective of this paper is to provide an overview of forest productivity changes in different forest regions in Europe under climate change, and partition these changes into effects induced by climate change alone and by climate change and disturbances. We present projections of climate change impacts on forest productivity from state-of-the-art forest models that dynamically simulate forest productivity and the effects of the main European disturbance agents (fire, storm, insects), driven by the same climate scenario in seven forest case studies along a large climatic gradient throughout Europe. Our study shows that, in most cases, including disturbances in the simulations exaggerate ongoing productivity declines or cancel out productivity gains in response to climate change. In fewer cases, disturbances also increase productivity or buffer climate-change induced productivity losses, e.g. because low severity fires can alleviate resource competition and increase fertilization. Even though our results cannot simply be extrapolated to other types of forests and disturbances, we argue that it is necessary to interpret climate change-induced productivity and disturbance changes jointly to capture the full range of climate change impacts on forests and to plan adaptation measures. PMID:28855959

  1. Are forest disturbances amplifying or canceling out climate change-induced productivity changes in European forests?

    PubMed

    Reyer, Christopher P O; Bathgate, Stephen; Blennow, Kristina; Borges, Jose G; Bugmann, Harald; Delzon, Sylvain; Faias, Sonia P; Garcia-Gonzalo, Jordi; Gardiner, Barry; Gonzalez-Olabarria, Jose Ramon; Gracia, Carlos; Hernández, Juan Guerra; Kellomäki, Seppo; Kramer, Koen; Lexer, Manfred J; Lindner, Marcus; van der Maaten, Ernst; Maroschek, Michael; Muys, Bart; Nicoll, Bruce; Palahi, Marc; Palma, João Hn; Paulo, Joana A; Peltola, Heli; Pukkala, Timo; Rammer, Werner; Ray, Duncan; Sabaté, Santiago; Schelhaas, Mart-Jan; Seidl, Rupert; Temperli, Christian; Tomé, Margarida; Yousefpour, Rasoul; Zimmermann, Niklaus E; Hanewinkel, Marc

    2017-03-16

    Recent studies projecting future climate change impacts on forests mainly consider either the effects of climate change on productivity or on disturbances. However, productivity and disturbances are intrinsically linked because 1) disturbances directly affect forest productivity (e.g. via a reduction in leaf area, growing stock or resource-use efficiency), and 2) disturbance susceptibility is often coupled to a certain development phase of the forest with productivity determining the time a forest is in this specific phase of susceptibility. The objective of this paper is to provide an overview of forest productivity changes in different forest regions in Europe under climate change, and partition these changes into effects induced by climate change alone and by climate change and disturbances. We present projections of climate change impacts on forest productivity from state-of-the-art forest models that dynamically simulate forest productivity and the effects of the main European disturbance agents (fire, storm, insects), driven by the same climate scenario in seven forest case studies along a large climatic gradient throughout Europe. Our study shows that, in most cases, including disturbances in the simulations exaggerate ongoing productivity declines or cancel out productivity gains in response to climate change. In fewer cases, disturbances also increase productivity or buffer climate-change induced productivity losses, e.g. because low severity fires can alleviate resource competition and increase fertilization. Even though our results cannot simply be extrapolated to other types of forests and disturbances, we argue that it is necessary to interpret climate change-induced productivity and disturbance changes jointly to capture the full range of climate change impacts on forests and to plan adaptation measures.

  2. Are forest disturbances amplifying or canceling out climate change-induced productivity changes in European forests?

    NASA Astrophysics Data System (ADS)

    Reyer, Christopher P. O.; Bathgate, Stephen; Blennow, Kristina; Borges, Jose G.; Bugmann, Harald; Delzon, Sylvain; Faias, Sonia P.; Garcia-Gonzalo, Jordi; Gardiner, Barry; Gonzalez-Olabarria, Jose Ramon; Gracia, Carlos; Guerra Hernández, Juan; Kellomäki, Seppo; Kramer, Koen; Lexer, Manfred J.; Lindner, Marcus; van der Maaten, Ernst; Maroschek, Michael; Muys, Bart; Nicoll, Bruce; Palahi, Marc; Palma, João HN; Paulo, Joana A.; Peltola, Heli; Pukkala, Timo; Rammer, Werner; Ray, Duncan; Sabaté, Santiago; Schelhaas, Mart-Jan; Seidl, Rupert; Temperli, Christian; Tomé, Margarida; Yousefpour, Rasoul; Zimmermann, Niklaus E.; Hanewinkel, Marc

    2017-03-01

    Recent studies projecting future climate change impacts on forests mainly consider either the effects of climate change on productivity or on disturbances. However, productivity and disturbances are intrinsically linked because 1) disturbances directly affect forest productivity (e.g. via a reduction in leaf area, growing stock or resource-use efficiency), and 2) disturbance susceptibility is often coupled to a certain development phase of the forest with productivity determining the time a forest is in this specific phase of susceptibility. The objective of this paper is to provide an overview of forest productivity changes in different forest regions in Europe under climate change, and partition these changes into effects induced by climate change alone and by climate change and disturbances. We present projections of climate change impacts on forest productivity from state-of-the-art forest models that dynamically simulate forest productivity and the effects of the main European disturbance agents (fire, storm, insects), driven by the same climate scenario in seven forest case studies along a large climatic gradient throughout Europe. Our study shows that, in most cases, including disturbances in the simulations exaggerate ongoing productivity declines or cancel out productivity gains in response to climate change. In fewer cases, disturbances also increase productivity or buffer climate-change induced productivity losses, e.g. because low severity fires can alleviate resource competition and increase fertilization. Even though our results cannot simply be extrapolated to other types of forests and disturbances, we argue that it is necessary to interpret climate change-induced productivity and disturbance changes jointly to capture the full range of climate change impacts on forests and to plan adaptation measures.

  3. Declining scaup populations: issues, hypotheses, and research needs

    USGS Publications Warehouse

    Austin, J.E.; Afton, A.D.; Anderson, M.G.; Clark, R.G.; Custer, Christine M.; Lawrence, J.S.; Pollard, J.B.; Ringelman, J.K.

    2000-01-01

    The population estimate for greater (Aythya marila) and lesser (Aythya affinis) scaup (combined) has declined dramatically since the early 1980s to record lows in 1998. The 1998 estimate of 3.47 million scaup is far below the goal of 6.3 million set in the North American Waterfowl Management Plan (NAWMP), causing concern among biologists and hunters. We summarize issuesof concern, hypotheses for factors contributing to the population decline, and research and management needs recommended by participants of the Scaup Workshop, held in September 1999. We believe that contaminants, lower female survival, and reduced recruitment due to changes in food resources or breedingground habitats are primary factors contributing to the decline. These factors are not mutually exclusive but likely interact across seasons. Workshop participants identified seven action items. We need to further delineate where declines in breeding populations have occurred, with a primary focus on the western Canadian boreal forest, where declines appear to be most pronounced. Productivity in various areas and habitats throughout the breeding range needs to be assessed by conducting retrospective analyses of existing data and by intensive field studies at broad and local scales. Annual and seasonal survival rates need to be determined in order to assess the role of harvest or natural mortality. Effects of contaminants on reproduction, female body condition, and behavior must be investigated. Use, distribution, and role of food resources relative to body condition and reproduction need to be examined to better understand seasonal dynamics of nutrient reserves and the role in reproductive success. Affiliations among breeding, migration, and wintering areas must be assessed in order to understand differential exposure to harvest or contaminants, and differential reproductive success and recruitment. Biologists and agencies need to gather and improve information needed to manage greater and lesser

  4. Long-term decline of the Amazon carbon sink.

    PubMed

    Brienen, R J W; Phillips, O L; Feldpausch, T R; Gloor, E; Baker, T R; Lloyd, J; Lopez-Gonzalez, G; Monteagudo-Mendoza, A; Malhi, Y; Lewis, S L; Vásquez Martinez, R; Alexiades, M; Álvarez Dávila, E; Alvarez-Loayza, P; Andrade, A; Aragão, L E O C; Araujo-Murakami, A; Arets, E J M M; Arroyo, L; Aymard C, G A; Bánki, O S; Baraloto, C; Barroso, J; Bonal, D; Boot, R G A; Camargo, J L C; Castilho, C V; Chama, V; Chao, K J; Chave, J; Comiskey, J A; Cornejo Valverde, F; da Costa, L; de Oliveira, E A; Di Fiore, A; Erwin, T L; Fauset, S; Forsthofer, M; Galbraith, D R; Grahame, E S; Groot, N; Hérault, B; Higuchi, N; Honorio Coronado, E N; Keeling, H; Killeen, T J; Laurance, W F; Laurance, S; Licona, J; Magnussen, W E; Marimon, B S; Marimon-Junior, B H; Mendoza, C; Neill, D A; Nogueira, E M; Núñez, P; Pallqui Camacho, N C; Parada, A; Pardo-Molina, G; Peacock, J; Peña-Claros, M; Pickavance, G C; Pitman, N C A; Poorter, L; Prieto, A; Quesada, C A; Ramírez, F; Ramírez-Angulo, H; Restrepo, Z; Roopsind, A; Rudas, A; Salomão, R P; Schwarz, M; Silva, N; Silva-Espejo, J E; Silveira, M; Stropp, J; Talbot, J; ter Steege, H; Teran-Aguilar, J; Terborgh, J; Thomas-Caesar, R; Toledo, M; Torello-Raventos, M; Umetsu, R K; van der Heijden, G M F; van der Hout, P; Guimarães Vieira, I C; Vieira, S A; Vilanova, E; Vos, V A; Zagt, R J

    2015-03-19

    Atmospheric carbon dioxide records indicate that the land surface has acted as a strong global carbon sink over recent decades, with a substantial fraction of this sink probably located in the tropics, particularly in the Amazon. Nevertheless, it is unclear how the terrestrial carbon sink will evolve as climate and atmospheric composition continue to change. Here we analyse the historical evolution of the biomass dynamics of the Amazon rainforest over three decades using a distributed network of 321 plots. While this analysis confirms that Amazon forests have acted as a long-term net biomass sink, we find a long-term decreasing trend of carbon accumulation. Rates of net increase in above-ground biomass declined by one-third during the past decade compared to the 1990s. This is a consequence of growth rate increases levelling off recently, while biomass mortality persistently increased throughout, leading to a shortening of carbon residence times. Potential drivers for the mortality increase include greater climate variability, and feedbacks of faster growth on mortality, resulting in shortened tree longevity. The observed decline of the Amazon sink diverges markedly from the recent increase in terrestrial carbon uptake at the global scale, and is contrary to expectations based on models.

  5. Asymmetric disassembly and robustness in declining networks

    PubMed Central

    Saavedra, Serguei; Reed-Tsochas, Felix; Uzzi, Brian

    2008-01-01

    Mechanisms that enable declining networks to avert structural collapse and performance degradation are not well understood. This knowledge gap reflects a shortage of data on declining networks and an emphasis on models of network growth. Analyzing >700,000 transactions between firms in the New York garment industry over 19 years, we tracked this network's decline and measured how its topology and global performance evolved. We find that favoring asymmetric (disassortative) links is key to preserving the topology and functionality of the declining network. Based on our findings, we tested a model of network decline that combines an asymmetric disassembly process for contraction with a preferential attachment process for regrowth. Our simulation results indicate that the model can explain robustness under decline even if the total population of nodes contracts by more than an order of magnitude, in line with our observations for the empirical network. These findings suggest that disassembly mechanisms are not simply assembly mechanisms in reverse and that our model is relevant to understanding the process of decline and collapse in a broad range of biological, technological, and financial networks. PMID:18936489

  6. Asymmetric disassembly and robustness in declining networks.

    PubMed

    Saavedra, Serguei; Reed-Tsochas, Felix; Uzzi, Brian

    2008-10-28

    Mechanisms that enable declining networks to avert structural collapse and performance degradation are not well understood. This knowledge gap reflects a shortage of data on declining networks and an emphasis on models of network growth. Analyzing >700,000 transactions between firms in the New York garment industry over 19 years, we tracked this network's decline and measured how its topology and global performance evolved. We find that favoring asymmetric (disassortative) links is key to preserving the topology and functionality of the declining network. Based on our findings, we tested a model of network decline that combines an asymmetric disassembly process for contraction with a preferential attachment process for regrowth. Our simulation results indicate that the model can explain robustness under decline even if the total population of nodes contracts by more than an order of magnitude, in line with our observations for the empirical network. These findings suggest that disassembly mechanisms are not simply assembly mechanisms in reverse and that our model is relevant to understanding the process of decline and collapse in a broad range of biological, technological, and financial networks.

  7. Maryland striped bass: recruitment declining below replacement

    SciTech Connect

    Goodyear, C.P.; Cohen, J.E.; Christensen, S.W.

    1985-01-01

    A mathematical technique was developed to examined interrelationships among first-year survival rates, adult fecundity, and adult survival of striped bass Morone saxatilis based on indices of year-class strength. Application of this technique to striped bass in Maryland waters of the Chesapeake Bay provided evidence for reduced survival in the life cycle. If adult fecundity and survival have remained constant, first-year survival declined significantly from 1969 to 1983, and averaged less than that needed for replacement for the last 10 years. Treatment of the individual spawning grounds separately indicated that the downward trend in survival for the pooled data was the result of declines in the upper bay and, to a lesser extent, in the Choptank River. Alternatively, if first-year survival and adult fecundity were assumed to have remained constant, an annual decline of about 1.9% in adult survival would have been required to produce the observed trend in the pooled year-class data. This would be consistent with increased fishing mortality and implies declining recruitment because of declining stock size. Continuing declines in first-year or adult survival would eliminate the Maryland striped bass stock and the fishery it supports. Conversely, an increase in adult survival could offset of the unknown factor or factors responsible for the apparent decline in first-year survival. 25 references, 1 figure, 1 table.

  8. Dispersal of forest insects

    NASA Technical Reports Server (NTRS)

    Mcmanus, M. L.

    1979-01-01

    Dispersal flights of selected species of forest insects which are associated with periodic outbreaks of pests that occur over large contiguous forested areas are discussed. Gypsy moths, spruce budworms, and forest tent caterpillars were studied for their massive migrations in forested areas. Results indicate that large dispersals into forested areas are due to the females, except in the case of the gypsy moth.

  9. Dispersal of forest insects

    NASA Technical Reports Server (NTRS)

    Mcmanus, M. L.

    1979-01-01

    Dispersal flights of selected species of forest insects which are associated with periodic outbreaks of pests that occur over large contiguous forested areas are discussed. Gypsy moths, spruce budworms, and forest tent caterpillars were studied for their massive migrations in forested areas. Results indicate that large dispersals into forested areas are due to the females, except in the case of the gypsy moth.

  10. Forest condition in Latvia

    Treesearch

    Madis Sipols

    1998-01-01

    Systematic assessment and observation (survey, inventory) of forests in Latvia has been underway since the 1700's. Latvia's forests are in the boreal/temperate forest zone and cover 44 percent of the country. Forest growing conditions are subdivided into five site class types: forests on dry mineral, wet mineral, wet peat, drained mineral, drained peat soils...

  11. Mississippi's forests, 2006

    Treesearch

    Sonja N. Oswalt; Tony G. Johnson; John W. Coulston; Christopher M. Oswalt

    2009-01-01

    Forest land covers 19.6 million acres in Mississippi, or about 65 percent of the land area. The majority of forests are classed as timberland. One hundred and thirty-seven tree species were measured on Mississippi forests in the 2006 inventory. Thirty six percent of Mississippi's forest land is classified as loblolly-shortleaf pine forest, 27 percent is classified...

  12. Mapping Forest Inventory and Analysis forest land use: timberland, reserved forest land, and other forest land

    Treesearch

    Mark D. Nelson; John Vissage

    2007-01-01

    The Forest Inventory and Analysis (FIA) program produces area estimates of forest land use within three subcategories: timberland, reserved forest land, and other forest land. Mapping these subcategories of forest land requires the ability to spatially distinguish productive from unproductive land, and reserved from nonreserved land. FIA field data were spatially...

  13. Wind River Experimental Forest.

    Treesearch

    Valerie. Rapp

    2003-01-01

    The Wind River Experimental Forest, known as the cradle of forest research in the Pacific Northwest, is a major center for ecological and silvicultural research in west-side Pacific Northwest forests. In the state of Washington, Wind River Experimental Forest is in the south-central area of the Gifford Pinchot National Forest, north of the Columbia River Gorge National...

  14. Forest statistics of Kentucky

    Treesearch

    The Forest Survey Organization. Central States Forest Experiment Station

    1952-01-01

    The Forest Survey is conducted in the various regions by the forest experiment stations of the Forest Service. In Kentucky the project is directed by the Central States Forest Experiment Station with headquarters in Columbus, Ohio. This Survey Release presents the more significant preliminary statistics on the forest area, timber volume, timber growth, and timber drain...

  15. Forest statistics of Indiana

    Treesearch

    The Forest Survey Organization. Central States Forest Experiment Station

    1953-01-01

    The Forest Survey is conducted in the various regions by the forest experiment stations of the Forest Service. In Indiana the project is directed by the Central States Forest Experiment Station with headquarters in Columbus, Ohio. This Survey Release presents the more significant preliminary statistics on the forest area timber volume, timber growth, and timber drain...

  16. Forest statistics for Alabama

    Treesearch

    Philip R. Wheeler

    1953-01-01

    This report summarizes data on forest acreage, timber volume, growth, and drain1/ collected by the Southern Forest Survey in Alabama, It is primarily the product of the new Forest Survey of the State, made between 1951 and 1953, but it also draws on the first Forest Survey of 1935-36 to show the changes in forest conditions during the intervening...

  17. South Dakota's Forests 2010

    Treesearch

    Ronald J. Piva; Brian F. Walters; Douglas D. Haugan; Gregory J. Josten; Brett J. Butler; Susan J. Crocker; Grant M. Domke; Mark A. Hatfield; Cassandra M. Kurtz; Andrew J. Lister; Tonya W. Lister; W. Keith Moser; Mark D. Nelson; Christopher W. Woodall

    2013-01-01

    The second completed annual inventory of South Dakota's forests reports 1.9 million acres of forest land. Softwood forests make up 68 percent of the total forest land area, with the ponderosa pine forest type by itself accounting for 60 percent of the total.

  18. South Dakota's forests 2005

    Treesearch

    Ronald J. Piva; W. Keith Moser; Douglas D. Haugan; Gregory J. Josten; Gary J. Brand; Brett J. Butler; Susan J. Crocker; Mark H. Hansen; Dacia M. Meneguzzo; Charles H. Perry; Christopher W. Woodall

    2009-01-01

    The first completed annual inventory of South Dakota's forests reports almost 1.7 million acres of forest land. Softwood forests make up 74 percent of the total forest land area; the ponderosa pine forest type by itself accounts for 69 percent of the total.

  19. Forest Statistics for Vermont

    Treesearch

    John R. McGuire; Robert D. Wray; Robert D. Wray

    1952-01-01

    This preliminary report is a product of the forest survey of the Northeast carried on by the Northeastern Forest Experiment Station as part of the nation-wide forest survey being made by the Forest Service, U.S. Department of Agriculture. A comprehensive report on the results of the forest survey in Vermont will be published later. NOTE: this document was scanned from...

  20. Quantifying widespread canopy cover decline through the course of a beetle kill epidemic in Colorado with remote sensing of snow

    NASA Astrophysics Data System (ADS)

    Baker, E. H.; Raleigh, M. S.; Molotch, N. P.

    2014-12-01

    Since the mid-1990s, outbreaks of aggressive bark beetle species have caused extensive forest morality across 600,000 km2 of North-American forests, killing over 17,800 km2 of forest in Colorado alone. This mortality has resulted in a widespread, spatially heterogeneous decline of forest canopies, which in turn exerts strong controls on the accumulation and melt of the snowpack. In the Western United States, where approximately 70-80% of total annual runoff originates as mountain snowmelt, it is important to monitor and quantify changes in forest canopy in snow-dominated catchments. To quantify annual values of forest canopy cover, this research develops a metric from time series of daily fractional snow covered area (FSCA) from NASA's Moderate Resolution Imaging Spectroradiometer (MODIS) snow covered area and grain size (MODSCAG) algorithm. In areas where soil and rock are completely snow-covered, a land pixel is composed only of forest canopy and snow. Following a snowfall event, FSCA initially rises rapidly, as snow is intercepted in the canopy, and then declines, as snow unloads from the canopy. The lower of these local minima form a threshold representative of snow-free canopy conditions, which serves as a spatially explicit metric of forest canopy. Investigation of a site in southern Colorado with over 40% spruce beetle mortality shows a statistically significant decrease of canopy cover, from 76 (±4)% pre-infestation to 55 (±8)% post-infestation (t=-5.1, p<0.01). Additionally, this yearly parameterization of forest canopy is well correlated (ρ=0.76, p<0.01) with an independent product of yearly crown mortality derived from U.S. Forest Service Aerial Detection Surveys. Future work will examine this relationship across varied ecologic settings and geographic locations, and incorporate field measurements of species-specific canopy change after beetle kill.