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...

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...

Decline in snail abundance due to soil acidification causes eggshell defects in forest passerines.

PubMed

Graveland, J; van der Wal, R

1996-02-01

On poor soils in the Netherlands an increasing number of great tits, Parus major, and of other forest passerines produce eggs with defective shells and have low reproductive success as a result of calcium deficiency. A similar increase in eggshell defects has been observed in Germany and Sweden. Snail shells are the main calcium source for tits in forests where defective eggshells do not occur, but are very little taken in forests where tits often have eggshell defects. We investigated whether a decrease in snail abundance on poor soils could be responsible for the decline in eggshell quality, and if so, what caused this decrease. Snail density in forests where tits have eggshell defects was much lower than in forests where tits do not have such defects. Snail density correlated with the calcium content and to a lesser extent with pH of the litter layer. Liming of a calciumpoor forest soil with few snails resulted in snail densities comparable to those on calcium-rich soils after 4 years. Snail density has declined on calcium-poor soils over the last two decades, but not on calcium-rich soils. Acid deposition has caused a decline of soil calcium on poor soils. We conclude, therefore, that anthropogenic acidification has caused a decline in snail populations, resulting in an increase in eggshell defects in birds in forests on poor soils.

Disturbance, complexity, and succession of net ecosystem production in North America’s temperate deciduous forests

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

Gough, Christopher; Curtis, Peter; Hardiman, Brady

Century-old forests in the U.S. upper Midwest and Northeast power much of North Amer- ica’s terrestrial carbon (C) sink, but these forests’ production and C sequestration capacity are expected to soon decline as fast-growing early successional species die and are replaced by slower growing late successional species. But will this really happen? Here we marshal empirical data and ecological theory to argue that substantial declines in net ecosystem production (NEP) owing to reduced forest growth, or net primary production (NPP), are not imminent in regrown temperate deciduous forests over the next several decades. Forest age and production data for temperatemore » deciduous forests, synthesized from published literature, suggest slight declines in NEP and increasing or stable NPP during middle successional stages. We revisit long-held hypotheses by EP Odum and others that suggest low-severity, high-frequency disturbances occurring in the region’s aging forests will, against intuition, maintain NEP at higher-than- expected rates by increasing ecosystem complexity, sustaining or enhancing NPP to a level that largely o sets rising C losses as heterotrophic respiration increases. This theoretical model is also supported by biological evidence and observations from the Forest Accelerated Succession Experiment in Michigan, USA. Ecosystems that experience high-severity disturbances that simplify ecosystem complexity can exhibit substantial declines in production during middle stages of succession. However, observations from these ecosystems have exerted a disproportionate in uence on assumptions regarding the trajectory and magnitude of age-related declines in forest production. We conclude that there is a wide ecological space for forests to maintain NPP and, in doing so, lessens the declines in NEP, with signi cant implications for the future of the North American carbon sink. Our intellectual frameworks for understanding forest C cycle dynamics and resilience need to catch up to our more complex and nuanced understanding of ecological succession.« less

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...

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...

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...

Timber resource of Missouri's Prairie, 1972.

Treesearch

Jerold T. Hahn; Alexander Vasilevsky

1975-01-01

The third timber inventory of Missouri's Prairie Forest Survey Unit shows substantial declines in both growing-stock and sawtimber volumes between 1959 and 1972. Commercial forest area declined by one-fifth. Presents highlights and statistics on forest area and timber volume, growth, mortality, ownership, and use in 1972.

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-use dynamics.

From sink to source: Regional variation in U.S. forest carbon futures.

PubMed

Wear, David N; Coulston, John W

2015-11-12

The sequestration of atmospheric carbon (C) in forests has partially offset C emissions in the United States (US) and might reduce overall costs of achieving emission targets, especially while transportation and energy sectors are transitioning to lower-carbon technologies. Using detailed forest inventory data for the conterminous US, we estimate forests' current net sequestration of atmospheric C to be 173 Tg yr(-1), offsetting 9.7% of C emissions from transportation and energy sources. Accounting for multiple driving variables, we project a gradual decline in the forest C emission sink over the next 25 years (to 112 Tg yr(-1)) with regional differences. Sequestration in eastern regions declines gradually while sequestration in the Rocky Mountain region declines rapidly and could become a source of atmospheric C due to disturbances such as fire and insect epidemics. C sequestration in the Pacific Coast region stabilizes as forests harvested in previous decades regrow. Scenarios simulating climate-induced productivity enhancement and afforestation policies increase sequestration rates, but would not fully offset declines from aging and forest disturbances. Separating C transfers associated with land use changes from sequestration clarifies forests' role in reducing net emissions and demonstrates that retention of forest land is crucial for protecting or enhancing sink strength.

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 succession and intensive forest management have led to population declines of constituent species in the Pacific northwestern United States. Forest management treatments that maintain or restore even small amounts of broadleaf vegetation could mitigate further declines.

Twentieth-century shifts in forest structure in California: Denser forests, smaller trees, and increased dominance of oaks.

PubMed

McIntyre, Patrick J; Thorne, James H; Dolanc, Christopher R; Flint, Alan L; Flint, Lorraine E; Kelly, Maggi; Ackerly, David D

2015-02-03

We document changes in forest structure between historical (1930s) and contemporary (2000s) surveys of California vegetation through comparisons of tree abundance and size across the state and within several ecoregions. Across California, tree density in forested regions increased by 30% between the two time periods, whereas forest biomass in the same regions declined, as indicated by a 19% reduction in basal area. These changes reflect a demographic shift in forest structure: larger trees (>61 cm diameter at breast height) have declined, whereas smaller trees (<30 cm) have increased. Large tree declines were found in all surveyed regions of California, whereas small tree increases were found in every region except the south and central coast. Large tree declines were more severe in areas experiencing greater increases in climatic water deficit since the 1930s, based on a hydrologic model of water balance for historical climates through the 20th century. Forest composition in California in the last century has also shifted toward increased dominance by oaks relative to pines, a pattern consistent with warming and increased water stress, and also with paleohistoric shifts in vegetation in California over the last 150,000 y.

Twentieth-century shifts in forest structure in California: Denser forests, smaller trees, and increased dominance of oaks

USGS Publications Warehouse

McIntyre, Patrick J.; Thorne, James H.; Dolanc, Christopher R.; Flint, Alan L.; Flint, Lorraine E.; Kelly, Maggi; Ackerly, David D.

2015-01-01

We document changes in forest structure between historical(1930s) and contemporary (2000s) surveys of California vegetation through comparisons of tree abundance and size across the state and within several ecoregions. Across California, tree density in forested regions increased by 30% between the two time periods, whereas forest biomass in the same regions declined, as indicated by a 19% reduction in basal area. These changes reflect a demographic shift in forest structure: larger trees (>61 cm diameter at breast height) have declined, whereas smaller trees ( < 30 cm) have increased. Large tree declines were found in all surveyed regions of California, whereas small tree increases were found in every region except the south and central coast. Large tree declines were more severe in areas experiencing greater increases in climaticwater deficit since the 1930s, based on a hydrologicmodel of water balance for historical climates through the 20th century. Forest composition in California in the last century has also shifted toward increased dominance by oaks relative to pines, a pattern consistent with warming and increased water stress, and also with paleohistoric shifts in vegetation in California over the last 150,000 y.

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...

Population trends and management opportunities for neotropical migrants

Treesearch

Chandler S. Robbins; John. R. Sauer; Bruce G. Peterjohn

1993-01-01

The Breeding Bird Survey shows that certain Neotropical migrant songbird populations have been declining over the past 26 years. Among them are forest birds that require extensive forest on the breeding grounds and also forested habitats on tropical wintering grounds. Other species have shown significant declines only since the early 1980's. Birds with broader...

Timber resource of Missouri's Southwestern Ozarks, 1972.

Treesearch

Arnold J. Ostrom; Jerold T. Hahn

1974-01-01

The third timber inventory of Missouri's Southwestern Ozarks Forest Survey Unit shows a substantial decline in the volumes of both growing stock and sawtimber between 1959 and 1972. Commercial forest area also declined substantially during the same period. Presented are highlights and statistics on forest area and timber volume, growth, mortality, ownership, and...

Foliar chemistry of sugar maple: a regional view

Treesearch

Richard A. Hallett; Stephen B. Horsley; Robert P. Long; Scott W. Bailey; Thomas J. Hall

1999-01-01

Forest health and monitoring issues have become major focus of scientists and research institutions in Europe and North America during the last decade because of wide-spread forest decline symptoms in Europe, high elevation spruce/fir decline in eastern North America and sugar maple (Acer saccharum Marsh.) decline in Quebec, and the United States....

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...

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.

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

A century of changing flows: Forest management changed flow magnitudes and warming advanced the timing of flow in a southwestern US river

PubMed Central

2017-01-01

The continued provision of water from rivers in the southwestern United States to downstream cities, natural communities and species is at risk due to higher temperatures and drought conditions in recent decades. Snowpack and snowfall levels have declined, snowmelt and peak spring flows are arriving earlier, and summer flows have declined. Concurrent to climate change and variation, a century of fire suppression has resulted in dramatic changes to forest conditions, and yet, few studies have focused on determining the degree to which changing forests have altered flows. In this study, we evaluated changes in flow, climate, and forest conditions in the Salt River in central Arizona from 1914–2012 to compare and evaluate the effects of changing forest conditions and temperatures on flows. After using linear regression models to remove the influence of precipitation and temperature, we estimated that annual flows declined by 8–29% from 1914–1963, coincident with a 2-fold increase in basal area, a 2-3-fold increase in canopy cover, and at least a 10-fold increase in forest density within ponderosa pine forests. Streamflow volumes declined by 37–56% in summer and fall months during this period. Declines in climate-adjusted flows reversed at mid-century when spring and annual flows increased by 10–31% from 1964–2012, perhaps due to more winter rainfall. Additionally, peak spring flows occurred about 12 days earlier in this period than in the previous period, coincident with winter and spring temperatures that increased by 1–2°C. While uncertainties remain, this study adds to the knowledge gained in other regions that forest change has had effects on flow that were on par with climate variability and, in the case of mid-century declines, well before the influence of anthropogenic warming. Current large-scale forest restoration projects hold some promise of recovering seasonal flows. PMID:29176868

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-related disturbance rates reached as high as 8% per year in the western regions during the early-2000s. Although low compared to harvest and decline, fire disturbance rates also increased in the early- to mid-2000s. We segmented annual decline-related disturbance rates to distinguish between newly impacted areas and areas undergoing gradual but consistent decline over multiple years. We also translated Landsat reflectance change into tree canopy cover change information for greater relevance to ecosystem modelers and forest managers, who can derive better understanding of forest-climate interactions and better adapt management strategies to changing climate regimes. Similar studies could be carried out for other countries where there are sufficient Landsat data and historic temporal snapshots of high-resolution imagery.

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...

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...

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...

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,...

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,...

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.

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...

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,...

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.

Understanding the temporal dimension of the red-edge spectral region for forest decline detection using high-resolution hyperspectral and Sentinel-2a imagery

NASA Astrophysics Data System (ADS)

Zarco-Tejada, P. J.; Hornero, A.; Hernández-Clemente, R.; Beck, P. S. A.

2018-03-01

The operational monitoring of forest decline requires the development of remote sensing methods that are sensitive to the spatiotemporal variations of pigment degradation and canopy defoliation. In this context, the red-edge spectral region (RESR) was proposed in the past due to its combined sensitivity to chlorophyll content and leaf area variation. In this study, the temporal dimension of the RESR was evaluated as a function of forest decline using a radiative transfer method with the PROSPECT and 3D FLIGHT models. These models were used to generate synthetic pine stands simulating decline and recovery processes over time and explore the temporal rate of change of the red-edge chlorophyll index (CI) as compared to the trajectories obtained for the structure-related Normalized Difference Vegetation Index (NDVI). The temporal trend method proposed here consisted of using synthetic spectra to calculate the theoretical boundaries of the subspace for healthy and declining pine trees in the temporal domain, defined by CItime=n/CItime=n+1 vs. NDVItime=n/NDVItime=n+1. Within these boundaries, trees undergoing decline and recovery processes showed different trajectories through this subspace. The method was then validated using three high-resolution airborne hyperspectral images acquired at 40 cm resolution and 260 spectral bands of 6.5 nm full-width half-maximum (FWHM) over a forest with widespread tree decline, along with field-based monitoring of chlorosis and defoliation (i.e., 'decline' status) in 663 trees between the years 2015 and 2016. The temporal rate of change of chlorophyll vs. structural indices, based on reflectance spectra extracted from the hyperspectral images, was different for trees undergoing decline, and aligned towards the decline baseline established using the radiative transfer models. By contrast, healthy trees over time aligned towards the theoretically obtained healthy baseline. The applicability of this temporal trend method to the red-edge bands of the MultiSpectral Imager (MSI) instrument on board Sentinel-2a for operational forest status monitoring was also explored by comparing the temporal rate of change of the Sentinel-2-derived CI over areas with declining and healthy trees. Results demonstrated that the Sentinel-2a red-edge region was sensitive to the temporal dimension of forest condition, as the relationships obtained for pixels in healthy condition deviated from those of pixels undergoing decline.

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.

From sink to source: Regional variation in U.S. forest carbon futures

PubMed Central

Wear, David N.; Coulston, John W.

2015-01-01

The sequestration of atmospheric carbon (C) in forests has partially offset C emissions in the United States (US) and might reduce overall costs of achieving emission targets, especially while transportation and energy sectors are transitioning to lower-carbon technologies. Using detailed forest inventory data for the conterminous US, we estimate forests’ current net sequestration of atmospheric C to be 173 Tg yr−1, offsetting 9.7% of C emissions from transportation and energy sources. Accounting for multiple driving variables, we project a gradual decline in the forest C emission sink over the next 25 years (to 112 Tg yr−1) with regional differences. Sequestration in eastern regions declines gradually while sequestration in the Rocky Mountain region declines rapidly and could become a source of atmospheric C due to disturbances such as fire and insect epidemics. C sequestration in the Pacific Coast region stabilizes as forests harvested in previous decades regrow. Scenarios simulating climate-induced productivity enhancement and afforestation policies increase sequestration rates, but would not fully offset declines from aging and forest disturbances. Separating C transfers associated with land use changes from sequestration clarifies forests’ role in reducing net emissions and demonstrates that retention of forest land is crucial for protecting or enhancing sink strength. PMID:26558439

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)...

Avian population consequences of climate change are most severe for long-distance migrants in seasonal habitats.

PubMed

Both, Christiaan; Van Turnhout, Chris A M; Bijlsma, Rob G; Siepel, Henk; Van Strien, Arco J; Foppen, Ruud P B

2010-04-22

One consequence of climate change is an increasing mismatch between timing of food requirements and food availability. Such a mismatch is primarily expected in avian long-distance migrants because of their complex annual cycle, and in habitats with a seasonal food peak. Here we show that insectivorous long-distance migrant species in The Netherlands declined strongly (1984-2004) in forests, a habitat characterized by a short spring food peak, but that they did not decline in less seasonal marshes. Also, within generalist long-distance migrant species, populations declined more strongly in forests than in marshes. Forest-inhabiting migrant species arriving latest in spring declined most sharply, probably because their mismatch with the peak in food supply is greatest. Residents and short-distance migrants had non-declining populations in both habitats, suggesting that habitat quality did not deteriorate. Habitat-related differences in trends were most probably caused by climate change because at a European scale, long-distance migrants in forests declined more severely in western Europe, where springs have become considerably warmer, when compared with northern Europe, where temperatures during spring arrival and breeding have increased less. Our results suggest that trophic mismatches may have become a major cause for population declines in long-distance migrants in highly seasonal habitats.

Group clearfell harvest can promote regeneration of aspen forests affected by sudden aspen decline in western Colorado

Treesearch

Wayne D. Shepperd; Frederick W. Smith; Kristen A. Pelz

2015-01-01

An experimental assessment of the use of clearfell harvesting to initiate a regeneration response in commercially managed aspen forests affected by sudden aspen decline (SAD) was conducted in western Colorado in cooperation with the USDA Forest Service. Nine pure commercial quality aspen stands, with three levels of mortality attributed to SAD, were selected (...

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...

Forest restoration as a strategy to mitigate climate impacts on wildfire, vegetation, and water in semiarid forests.

PubMed

O'Donnell, Frances C; Flatley, William T; Springer, Abraham E; Fulé, Peter Z

2018-06-25

Climate change and wildfire are interacting to drive vegetation change and potentially reduce water quantity and quality in the southwestern United States, Forest restoration is a management approach that could mitigate some of these negative outcomes. However, little information exists on how restoration combined with climate change might influence hydrology across large forest landscapes that incorporate multiple vegetation types and complex fire regimes. We combined spatially explicit vegetation and fire modeling with statistical water and sediment yield models for a large forested landscape (335,000 ha) on the Kaibab Plateau in northern Arizona, USA. Our objective was to assess the impacts of climate change and forest restoration on the future fire regime, forest vegetation, and watershed outputs. Our model results predict that the combination of climate change and high-severity fire will drive forest turnover, biomass declines, and compositional change in future forests. Restoration treatments may reduce the area burned in high-severity fires and reduce conversions from forested to non-forested conditions. Even though mid-elevation forests are the targets of restoration, the treatments are expected to delay the decline of high-elevation spruce-fir, aspen, and mixed conifer forests by reducing the occurrence of high-severity fires that may spread across ecoregions. We estimate that climate-induced vegetation changes will result in annual runoff declines of up to 10%, while restoration reduced or reversed this decline. The hydrologic model suggests that mid-elevation forests, which are the targets of restoration treatments, provide around 80% of runoff in this system and the conservation of mid- to high-elevation forests types provides the greatest benefit in terms of water conservation. We also predict that restoration treatments will conserve water quality by reducing patches of high-severity fire that are associated with high sediment yield. Restoration treatments are a management strategy that may reduce undesirable outcomes for multiple ecosystem services. © 2018 by the Ecological Society of America.

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.

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

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...

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...

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 poorer crown...

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.,...

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...

Assessing Oak Decline Incidence and Distribution in the Southern U.S. Using Forest Inventory and Analysis Data

Treesearch

Steven W. Oak; James R. Steinman; Dale A. Starkey; Edwin K. Yockey

2004-01-01

Forest Inventory and Analysis data for twelve southern states were used to evaluate regional oak decline status. Total host type, vulnerable host type, and affected areas were determined. The attributes used for classification were forest type, predominant stem size class, oak basal area percent, and dieback damage coding. Host type totaled 104.7 million acres in the...

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...

Bird community composition

USGS Publications Warehouse

Antrobus, T.J.; Guilfoyle, M.P.; Barrow, W.C.; Hamel, P.B.; Wakeley, J.S.

2000-01-01

Neotropical migrants are birds that breed in North America and winter primarily in Central and South America. Long-term population studies of birds in the Eastern United States indicated declines of some forest-dwelling birds, many of which winter in the Neotropics (Peterjohn and others 1995). These declines were attributed to loss of wintering and breeding habitat due to deforestation and fragmentation, respectively. Many species of Nearctic migrants--birds that breed in the northern regions of North America and winter in the Southern United States--are also experiencing population declines. Because large areas of undistrubed, older, bottomland hardwood forests oftern contain large numbers of habitat specialists, including forest-interior neotropical migrants and wintering Nearctic migrants, these forests may be critical in maintaining avian diversity. This study had two primary objectivs: (1) to create a baseline data set that can be used as a standard against which other bottomland hardwood forests can be compared, and (2) to establish long-term monitoring stations during both breeding and wintering seasons to discern population trends of avian species using bottomland hardwood forests.

Degraded lands worth protecting: the biological importance of Southeast Asia's repeatedly logged forests

PubMed Central

Edwards, David P.; Larsen, Trond H.; Docherty, Teegan D. S.; Ansell, Felicity A.; Hsu, Wayne W.; Derhé, Mia A.; Hamer, Keith C.; Wilcove, David S.

2011-01-01

Southeast Asia is a hotspot of imperilled biodiversity, owing to extensive logging and forest conversion to oil palm agriculture. The degraded forests that remain after multiple rounds of intensive logging are often assumed to be of little conservation value; consequently, there has been no concerted effort to prevent them from being converted to oil palm. However, no study has quantified the biodiversity of repeatedly logged forests. We compare the species richness and composition of birds and dung beetles within unlogged (primary), once-logged and twice-logged forests in Sabah, Borneo. Logging had little effect on the overall richness of birds. Dung beetle richness declined following once-logging but did not decline further after twice-logging. The species composition of bird and dung beetle communities was altered, particularly after the second logging rotation, but globally imperilled bird species (IUCN Red List) did not decline further after twice-logging. Remarkably, over 75 per cent of bird and dung beetle species found in unlogged forest persisted within twice-logged forest. Although twice-logged forests have less biological value than primary and once-logged forests, they clearly provide important habitat for numerous bird and dung beetle species. Preventing these degraded forests from being converted to oil palm should be a priority of policy-makers and conservationists. PMID:20685713

Rapid regional recovery from sulfate and nitrate pollution in streams of the western Czech Republic - Comparison to other recovering areas

USGS Publications Warehouse

Majer, V.; Kram, P.; Shanley, J.B.

2005-01-01

Hydrochemical changes between 1991 and 2001 were assessed based on two synoptic stream surveys from the 820-km2 region of the Slavkov Forest and surrounding area, western Czech Republic. Marked declines of sulfate, nitrate, chloride, calcium and magnesium in surface waters were compared with other areas of Europe and North America recovering from acidification. Declines of sulfate concentration in the Slavkov Forest (-30 ??eq L-1 yr-1) were more dramatic than declines reported from other sites. However, these dramatic declines of strong acid anions did not generate a widespread increase of stream water pH in the Slavkov Forest. Only the most acidic streams experienced a slight increase of pH by 0.5 unit. An unexpected decline of stream water pH occurred in slightly alkaline streams. ?? 2004 Elsevier Ltd. All rights reserved.

Difficulties in tracking the long-term global trend in tropical forest area.

PubMed

Grainger, Alan

2008-01-15

The long-term trend in tropical forest area receives less scrutiny than the tropical deforestation rate. We show that constructing a reliable trend is difficult and evidence for decline is unclear, within the limits of errors involved in making global estimates. A time series for all tropical forest area, using data from Forest Resources Assessments (FRAs) of the United Nations Food and Agriculture Organization, is dominated by three successively corrected declining trends. Inconsistencies between these trends raise questions about their reliability, especially because differences seem to result as much from errors as from changes in statistical design and use of new data. A second time series for tropical moist forest area shows no apparent decline. The latter may be masked by the errors involved, but a "forest return" effect may also be operating, in which forest regeneration in some areas offsets deforestation (but not biodiversity loss) elsewhere. A better monitoring program is needed to give a more reliable trend. Scientists who use FRA data should check how the accuracy of their findings depends on errors in the data.

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.

Indiana's forests 1999-2003 (Part A)

Treesearch

Christopher Woodall; Dan Johnson; Joey Gallion; Charles Perry; Brett Butler; Ron Piva; Ed Jepsen; Dave Nowak; Phil Marshall

2005-01-01

The first completed annual inventory of Indiana's forests reports more than 4.5 million acres of forest land with a diverse array of forest types, substantial growth of economically valuable tree species, and future forest health concerns such as invasive species, forest fragmentation, and oak forest decline.

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.

Understanding the temporal dimension of the red-edge spectral region for forest decline detection using high-resolution hyperspectral and Sentinel-2a imagery.

PubMed

Zarco-Tejada, P J; Hornero, A; Hernández-Clemente, R; Beck, P S A

2018-03-01

The operational monitoring of forest decline requires the development of remote sensing methods that are sensitive to the spatiotemporal variations of pigment degradation and canopy defoliation. In this context, the red-edge spectral region (RESR) was proposed in the past due to its combined sensitivity to chlorophyll content and leaf area variation. In this study, the temporal dimension of the RESR was evaluated as a function of forest decline using a radiative transfer method with the PROSPECT and 3D FLIGHT models. These models were used to generate synthetic pine stands simulating decline and recovery processes over time and explore the temporal rate of change of the red-edge chlorophyll index (CI) as compared to the trajectories obtained for the structure-related Normalized Difference Vegetation Index (NDVI). The temporal trend method proposed here consisted of using synthetic spectra to calculate the theoretical boundaries of the subspace for healthy and declining pine trees in the temporal domain, defined by CI time=n /CI time=n+1 vs. NDVI time=n /NDVI time=n+1 . Within these boundaries, trees undergoing decline and recovery processes showed different trajectories through this subspace. The method was then validated using three high-resolution airborne hyperspectral images acquired at 40 cm resolution and 260 spectral bands of 6.5 nm full-width half-maximum (FWHM) over a forest with widespread tree decline, along with field-based monitoring of chlorosis and defoliation (i.e., 'decline' status) in 663 trees between the years 2015 and 2016. The temporal rate of change of chlorophyll vs. structural indices, based on reflectance spectra extracted from the hyperspectral images, was different for trees undergoing decline, and aligned towards the decline baseline established using the radiative transfer models. By contrast, healthy trees over time aligned towards the theoretically obtained healthy baseline . The applicability of this temporal trend method to the red-edge bands of the MultiSpectral Imager (MSI) instrument on board Sentinel-2a for operational forest status monitoring was also explored by comparing the temporal rate of change of the Sentinel-2-derived CI over areas with declining and healthy trees. Results demonstrated that the Sentinel-2a red-edge region was sensitive to the temporal dimension of forest condition, as the relationships obtained for pixels in healthy condition deviated from those of pixels undergoing decline.

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.

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...

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...

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...

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.

Quantifying the Detrimental Impacts of Land-Use and Management Change on European Forest Bird Populations

PubMed Central

Wade, Amy S. I.; Barov, Boris; Burfield, Ian J.; Gregory, Richard D.; Norris, Ken; Butler, Simon J.

2013-01-01

The ecological impacts of changing forest management practices in Europe are poorly understood despite European forests being highly managed. Furthermore, the effects of potential drivers of forest biodiversity decline are rarely considered in concert, thus limiting effective conservation or sustainable forest management. We present a trait-based framework that we use to assess the detrimental impact of multiple land-use and management changes in forests on bird populations across Europe. Major changes to forest habitats occurring in recent decades, and their impact on resource availability for birds were identified. Risk associated with these changes for 52 species of forest birds, defined as the proportion of each species' key resources detrimentally affected through changes in abundance and/or availability, was quantified and compared to their pan-European population growth rates between 1980 and 2009. Relationships between risk and population growth were found to be significantly negative, indicating that resource loss in European forests is an important driver of decline for both resident and migrant birds. Our results demonstrate that coarse quantification of resource use and ecological change can be valuable in understanding causes of biodiversity decline, and thus in informing conservation strategy and policy. Such an approach has good potential to be extended for predictive use in assessing the impact of possible future changes to forest management and to develop more precise indicators of forest health. PMID:23704997

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. However, the functionally realistic mechanisms beneath the pervasively climate-induced forest decline/dieback still remain unclear. Network-based long-term surveys and experiment studies are urgently needed for further understandings regarding the responses of forest/tree growth to climate warming/variations.

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.

Influence of eastern hemlock (Tsuga canadensis) forests on aquatic invertebrate assemblages in headwater streams

USGS Publications Warehouse

Snyder, C.D.; Young, J.A.; Lemarie, D.P.; Smith, D.R.

2002-01-01

We conducted a comparative study in the Delaware Water Gap National Recreation Area to determine the potential long-term impacts of hemlock forest decline on stream benthic macroinvertebrate assemblages. Hemlock forests throughout eastern North America have been declining because of the hemlock woolly adelgid, an exotic insect pest. We found aquatic invertebrate community structure to be strongly correlated with forest composition. Streams draining hemlock forests supported significantly more total taxa than streams draining mixed hardwood forests, and over 8% of the taxa were strongly associated with hemlock. In addition, invertebrate taxa were more evenly distributed (i.e., higher Simpson's evenness values) in hemlock-drained streams. In contrast, the number of rare species and total densities were significantly lower in streams draining hemlock, suggesting that diversity differences observed between forest types were not related to stochastic factors associated with sampling and that streams draining mixed hardwood forests may be more productive. Analysis of stream habitat data indicated that streams draining hemlock forests had more stable thermal and hydrologic regimes. Our findings suggest that hemlock decline may result in long-term changes in headwater ecosystems leading to reductions in both within-stream (i.e., alpha) and park-wide (i.e., gamma) benthic community diversity.

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.

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...

Creation of forest edges has a global impact on forest vertebrates

PubMed Central

Peres, CA; Banks-Leite, C; Wearn, OR; Marsh, CJ; Butchart, SHM; Arroyo-Rodríguez, V; Barlow, J; Cerezo, A; Cisneros, L; D’Cruze, N; Faria, D; Hadley, A; Harris, S; Klingbeil, BT; Kormann, U; Lens, L; Medina-Rangel, GF; Morante-Filho, JC; Olivier, P; Peters, SL; Pidgeon, A; Ribeiro, DB; Scherber, C; Schneider-Maunory, L; Struebig, M; Urbina-Cardona, N; Watling, JI; Willig, MR; Wood, EM; Ewers, RM

2017-01-01

Summary Forest edges influence more than half the world’s forests and contribute to worldwide declines in biodiversity and ecosystem functions. However, predicting these declines is challenging in heterogeneous fragmented landscapes. We assembled an unmatched global dataset on species responses to fragmentation and developed a new statistical approach for quantifying edge impacts in heterogeneous landscapes to quantify edge-determined changes in abundance of 1673 vertebrate species. We show that 85% of species’ abundances are affected, either positively or negatively, by forest edges. Forest core species, which were more likely to be listed as threatened by the IUCN, only reached peak abundances at sites farther than 200-400 m from sharp high-contrast forest edges. Smaller-bodied amphibians, larger reptiles and medium-sized non-volant mammals experienced a larger reduction in suitable habitat than other forest core species. Our results highlight the pervasive ability of forest edges to restructure ecological communities on a global scale. PMID:29088701

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...

Are ungulates in forests concerns or key species for conservation and biodiversity? Reply to Boulanger et al. (DOI: 10.1111/gcb.13899).

PubMed

Fløjgaard, Camilla; Bruun, Hans Henrik; Hansen, Morten D D; Heilmann-Clausen, Jacob; Svenning, Jens-Christian; Ejrnaes, Rasmus

2018-03-01

Increasing species richness of light demanding species in forests may not be a conservation concern if we accept a macroecological and evolutionary baseline for biodiversity. Most of the current biodiversity in Europe has evolved in the Pleistocene or earlier, and in ecosystems markedly influenced by dynamic natural processes, including grazing. Many threatened species are associated with high-light forest environments such as forest glades and edges, as these have strongly declined at least partially due to the decline of large herbivores in European forests. Hence, moderate grazing in forests should be an ecological baseline and conservation target rather than a concern. © 2017 John Wiley & Sons Ltd.

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.

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.

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

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.

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...

Creation of forest edges has a global impact on forest vertebrates.

PubMed

Pfeifer, M; Lefebvre, V; Peres, C A; Banks-Leite, C; Wearn, O R; Marsh, C J; Butchart, S H M; Arroyo-Rodríguez, V; Barlow, J; Cerezo, A; Cisneros, L; D'Cruze, N; Faria, D; Hadley, A; Harris, S M; Klingbeil, B T; Kormann, U; Lens, L; Medina-Rangel, G F; Morante-Filho, J C; Olivier, P; Peters, S L; Pidgeon, A; Ribeiro, D B; Scherber, C; Schneider-Maunoury, L; Struebig, M; Urbina-Cardona, N; Watling, J I; Willig, M R; Wood, E M; Ewers, R M

2017-11-09

Forest edges influence more than half of the world's forests and contribute to worldwide declines in biodiversity and ecosystem functions. However, predicting these declines is challenging in heterogeneous fragmented landscapes. Here we assembled a global dataset on species responses to fragmentation and developed a statistical approach for quantifying edge impacts in heterogeneous landscapes to quantify edge-determined changes in abundance of 1,673 vertebrate species. We show that the abundances of 85% of species are affected, either positively or negatively, by forest edges. Species that live in the centre of the forest (forest core), that were more likely to be listed as threatened by the International Union for Conservation of Nature (IUCN), reached peak abundances only at sites farther than 200-400 m from sharp high-contrast forest edges. Smaller-bodied amphibians, larger reptiles and medium-sized non-volant mammals experienced a larger reduction in suitable habitat than other forest-core species. Our results highlight the pervasive ability of forest edges to restructure ecological communities on a global scale.

Creation of forest edges has a global impact on forest vertebrates

NASA Astrophysics Data System (ADS)

Pfeifer, M.; Lefebvre, V.; Peres, C. A.; Banks-Leite, C.; Wearn, O. R.; Marsh, C. J.; Butchart, S. H. M.; Arroyo-Rodríguez, V.; Barlow, J.; Cerezo, A.; Cisneros, L.; D'Cruze, N.; Faria, D.; Hadley, A.; Harris, S. M.; Klingbeil, B. T.; Kormann, U.; Lens, L.; Medina-Rangel, G. F.; Morante-Filho, J. C.; Olivier, P.; Peters, S. L.; Pidgeon, A.; Ribeiro, D. B.; Scherber, C.; Schneider-Maunoury, L.; Struebig, M.; Urbina-Cardona, N.; Watling, J. I.; Willig, M. R.; Wood, E. M.; Ewers, R. M.

2017-11-01

Forest edges influence more than half of the world’s forests and contribute to worldwide declines in biodiversity and ecosystem functions. However, predicting these declines is challenging in heterogeneous fragmented landscapes. Here we assembled a global dataset on species responses to fragmentation and developed a statistical approach for quantifying edge impacts in heterogeneous landscapes to quantify edge-determined changes in abundance of 1,673 vertebrate species. We show that the abundances of 85% of species are affected, either positively or negatively, by forest edges. Species that live in the centre of the forest (forest core), that were more likely to be listed as threatened by the International Union for Conservation of Nature (IUCN), reached peak abundances only at sites farther than 200-400 m from sharp high-contrast forest edges. Smaller-bodied amphibians, larger reptiles and medium-sized non-volant mammals experienced a larger reduction in suitable habitat than other forest-core species. Our results highlight the pervasive ability of forest edges to restructure ecological communities on a global scale.

78 FR 46312 - Spruce Beetle Epidemic and Aspen Decline Management Response; Grand Mesa, Uncompahgre and...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-07-31

... providing for human safety. Treatments would be carried out on National Forest System (NFS) Lands within the scope of direction provided in the GMUG Revised Land and Resource Management Plan. DATES: To be most... DEPARTMENT OF AGRICULTURE Forest Service Spruce Beetle Epidemic and Aspen Decline Management...

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,...

Calcium status of the forest floor in red spruce forests of the northeastern U.S. - past, present and future

Treesearch

Mark B. David; Gregory B. Lawrence; Walter C. Shortle; Scott W. Bailey

1996-01-01

Dieback and growth decline of red spruce (Picea rubens) in the eastern U.S. coincides with the period of acidic deposition, and has led to much speculation as to whether this decline is caused by decreased root-available Ca in the soil.

Quantification of Lewis's Woodpecker habitat using Forest Inventory and Analysis data

Treesearch

Chris Witt

2009-01-01

The Utah Department of Natural Resources' Division of Wildlife Resources (UDWR) placed Lewis's Woodpecker (Melanerpes lewis) on their Sensitive Species Tier II list due to declining populations and suspected local extirpations throughout the state. It is thought that the decline in burned coniferous forest has reduced the amount of suitable...

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...

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

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...

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

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.

A second look a North Dakota's timber lands, 1980.

Treesearch

Pamela J. Jakes; W. Brad Smith

1982-01-01

The second inventory of North Dakota forest resources shows a decline in commercial forest area between 1954 and 1980. 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 forest resources. A forest type map is included.

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.

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.

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

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).

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.

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...

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?

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.

Medium density fiberboards from plantation grown Eucalyptus saligna

Treesearch

Andrzej Krzysik; John A. Youngquist; James H. Muehl; Fabio Spina Franca

1999-01-01

The production of industrial wood from natural forests is predicted to decline in the future. Factors that will contribute to this decline include changes in land use patterns, depletion of resources in some parts of the world, and the withdrawal of forest areas from industrial production in order to provide for environmental, recreational, and other social needs....

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...

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.

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...

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...

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...

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...

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...

China: changing wood products markets

Treesearch

Daowei Zhang; Junchang Liu; James Granskog; Jianbang Gan

1998-01-01

In the 1980's, China emerged as the world's second largest importer of forest products and the second largest importer of U.S. forest products. However, U.S. wood products exports to China declined nearly 93 percent from 1988 to 1996, from >/=448 million to >/=33 million. Little is known about the reasons that caused this decline. Less is probably known...

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.

Long-term effects of different forest regeneration methods on mature forest birds

Treesearch

Roger W. Perry; Julianna M.A. Jenkins; Ronald E. Thill; Frank R. Thompson

2018-01-01

Changes in forest structure that result from silviculture, including timber harvest, can positively or negatively affect bird species that use forests. Because many bird species associated with mature forests are facing population declines, managers need to know how timber harvesting affects species of birds that rely on mature trees or forests for breeding, foraging,...

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...

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.

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 ecosystems, whereas the soil C accumulation rate declined as N supply to the plants declined.

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...

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...

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.

Passive restoration following ungulate removal in a highly disturbed tropical wet forest devoid of native seed dispersers

USGS Publications Warehouse

Nafus, Melia; Savidge, Julie A.; Yackel Adams, Amy A.; Christy, Michelle T.; Reed, Robert

2018-01-01

Overabundant ungulate populations can alter forests. Concurrently, global declines of seed dispersers may threaten native forest structure and function. On an island largely devoid of native vertebrate seed dispersers, we monitored forest succession for 7 years following ungulate exclusion from a 5-ha area and adjacent plots with ungulates still present. We observed succession from open scrub to forest and understory cover by non-native plants declined. Two trees, native Hibiscus tiliaceus and non-native Leucaena leucocephala, accounted for most forest regeneration, with the latter dominant. Neither species is dependent on animal dispersers nor was there strong evidence that plants dependent on dispersers migrated into the 5-ha study area. Passive restoration following ungulate removal may facilitate restoration, but did not show promise for fully restoring native forest on Guam. Restoration of native forest plants in bird depopulated areas will likely require active outplanting of native seedlings, control of factors resulting in bird loss, and reintroduction of seed dispersers.

Predicting Impacts of Climate Change on the Aboveground Carbon Sequestration Rate of a Temperate Forest in Northeastern China

PubMed Central

Ma, Jun; Hu, Yuanman; Bu, Rencang; Chang, Yu; Deng, Huawei; Qin, Qin

2014-01-01

The aboveground carbon sequestration rate (ACSR) reflects the influence of climate change on forest dynamics. To reveal the long-term effects of climate change on forest succession and carbon sequestration, a forest landscape succession and disturbance model (LANDIS Pro7.0) was used to simulate the ACSR of a temperate forest at the community and species levels in northeastern China based on both current and predicted climatic data. On the community level, the ACSR of mixed Korean pine hardwood forests and mixed larch hardwood forests, fluctuated during the entire simulation, while a large decline of ACSR emerged in interim of simulation in spruce-fir forest and aspen-white birch forests, respectively. On the species level, the ACSR of all conifers declined greatly around 2070s except for Korean pine. The ACSR of dominant hardwoods in the Lesser Khingan Mountains area, such as Manchurian ash, Amur cork, black elm, and ribbed birch fluctuated with broad ranges, respectively. Pioneer species experienced a sharp decline around 2080s, and they would finally disappear in the simulation. The differences of the ACSR among various climates were mainly identified in mixed Korean pine hardwood forests, in all conifers, and in a few hardwoods in the last quarter of simulation. These results indicate that climate warming can influence the ACSR in the Lesser Khingan Mountains area, and the largest impact commonly emerged in the A2 scenario. The ACSR of coniferous species experienced higher impact by climate change than that of deciduous species. PMID:24763409

Predicting impacts of climate change on the aboveground carbon sequestration rate of a temperate forest in northeastern China.

PubMed

Ma, Jun; Hu, Yuanman; Bu, Rencang; Chang, Yu; Deng, Huawei; Qin, Qin

2014-01-01

The aboveground carbon sequestration rate (ACSR) reflects the influence of climate change on forest dynamics. To reveal the long-term effects of climate change on forest succession and carbon sequestration, a forest landscape succession and disturbance model (LANDIS Pro7.0) was used to simulate the ACSR of a temperate forest at the community and species levels in northeastern China based on both current and predicted climatic data. On the community level, the ACSR of mixed Korean pine hardwood forests and mixed larch hardwood forests, fluctuated during the entire simulation, while a large decline of ACSR emerged in interim of simulation in spruce-fir forest and aspen-white birch forests, respectively. On the species level, the ACSR of all conifers declined greatly around 2070s except for Korean pine. The ACSR of dominant hardwoods in the Lesser Khingan Mountains area, such as Manchurian ash, Amur cork, black elm, and ribbed birch fluctuated with broad ranges, respectively. Pioneer species experienced a sharp decline around 2080s, and they would finally disappear in the simulation. The differences of the ACSR among various climates were mainly identified in mixed Korean pine hardwood forests, in all conifers, and in a few hardwoods in the last quarter of simulation. These results indicate that climate warming can influence the ACSR in the Lesser Khingan Mountains area, and the largest impact commonly emerged in the A2 scenario. The ACSR of coniferous species experienced higher impact by climate change than that of deciduous species.

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...

Analysis of changes in eastern national forest timber sales between 1985 and 1997

Treesearch

William G. Luppold; John E. Baumgras

2000-01-01

Since the mid-1980s, the volume of sawtimber sold by eastern national forests has declined by 55 percent. Factors contributing to this decline include increased recreational demands, political pressures from environmentalists and the adoption of ecosystem management techniques. This paper examines the changes in the sales of roundwood products from 1985 to 1997 for...

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...

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...

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...

Effect of forest opening characteristics, prey abundance, and environmental factors on bat activity in the southern Appalachians

Treesearch

Jonathan D. Brooks; Susan C. Loeb; Patrick D. Gerard

2017-01-01

<>Early successional habitat (ESH) is important for many wildlife species. Over the past century, land use changes have caused ESH to decline in hardwood forests of the eastern United States. Because of the decline of ESH and ESH dependent wildlife, ESH has recently received increased attention from land managers and scientists. Bats, which...

Development, succession, and stand dynamics of upland oak forests in the Wisconsin Driftless Area: Implications for oak regeneration and management

Treesearch

Megan L. Buchanan; Kurt F. Kipfmueller; Anthony W. D' Amato

2017-01-01

Throughout the deciduous forests of the eastern United States, oak (Quercus) regeneration has declined in stands historically dominated by oak species. In the Wisconsin Driftless Area, the level of decline in oak regeneration is variable and influenced by stand structural development, historical disturbance regime, abiotic site characteristics, and...

Declining Radial Growth Response of Coastal Forests to Hurricanes and Nor'easters

NASA Astrophysics Data System (ADS)

Fernandes, Arnold; Rollinson, Christine R.; Kearney, William S.; Dietze, Michael C.; Fagherazzi, Sergio

2018-03-01

The Mid-Atlantic coastal forests in Virginia are stressed by episodic disturbance from hurricanes and nor'easters. Using annual tree ring data, we adopt a dendroclimatic and statistical modeling approach to understand the response and resilience of a coastal pine forest to extreme storm events, over the past few decades. Results indicate that radial growth of trees in the study area is influenced by age, regional climate trends, and individual tree effects but dominated periodically by growth disturbance due to storms. We evaluated seven local extreme storm events to understand the effect of nor'easters and hurricanes on radial growth. A general decline in radial growth was observed in the year of the extreme storm and 3 years following it, after which the radial growth started recovering. The decline in radial growth showed a statistically significant correlation with the magnitude of the extreme storm (storm surge height and wind speed). This study contributes to understanding declining tree growth response and resilience of coastal forests to past disturbances. Given the potential increase in hurricanes and storm surge severity in the region, this can help predict vegetation response patterns to similar disturbances in the future.

Land changes and their driving forces in the Southeastern United States

USGS Publications Warehouse

Napton, Darrell E.; Auch, Roger F.; Headley, Rachel; Taylor, Janis

2010-01-01

The ecoregions of the Middle Atlantic Coastal Plain, Southeastern Plains, Piedmont, and Blue Ridge provide a continuum of land cover from the Atlantic Ocean to the highest mountains in the East. From 1973 to 2000, each ecoregion had a unique mosaic of land covers and land cover changes. The forests of the Blue Ridge Mountains provided amenity lands. The Piedmont forested area declined, while the developed area increased. The Southeastern Plains became a commercial forest region, and most agricultural lands that changed became forested. Forests in the Middle Atlantic Coastal Plain declined, and development related to recreation and retirement increased. The most important drivers of land conversion were associated with commercial forestry, competition between forest and agriculture, and economic and population growth. These and other drivers were modified by each ecoregion’s unique suitability and land use legacies with the result that the same drivers often produced different land changes in different ecoregions.

Threshold responses of songbirds to long-term timber management on an active industrial forest

USGS Publications Warehouse

Becker, Douglas A.; Wood, Petra Bohall; Keyser, Patrick D.; Wigley, T. Bently; Dellinger, Rachel; Weakland, Cathy A.

2011-01-01

Forest managers often seek to balance economic benefits from timber harvesting with maintenance of habitat for wildlife, ecosystem function, and human uses. Most research on the relationship between avian abundance and active timber management has been short-term, lasting one to two years, creating the need to investigate long-term avian responses and to identify harvest thresholds when a small change in habitat results in a disproportionate response in relative abundance and nest success. Our objectives were to identify trends in relative abundance and nest success and to identify landscape-scale disturbance thresholds for avian species and habitat guilds in response to a variety of harvest treatments (clear-cuts, heavy and light partial harvests) over 14 years. We conducted point counts and monitored nests at an industrial forest in the central Appalachians of West Virginia during 1996–1998, 2001–2003, and 2007–2009. Early successional species increased in relative abundance across all three time periods, whereas interior-edge and forest-interior guilds peaked in relative abundance mid-study after which the forest-interior guild declined. Of 41 species with >10 detections, four (10%) declined significantly, 13 (32%) increased significantly (only three species among all periods), and 9 (22%) peaked in abundance mid-study (over the entire study period, four species had no significant change in abundance, four declined, and one increased). Based on piecewise linear models, forest-interior and interior-edge guilds’ relative abundance harvest thresholds were 28% total harvests (all harvests combined), 10% clear-cut harvests, and 18% light partial harvests, after which abundances declined. Harvest thresholds for the early successional guild were 42% total harvests, 11% clear-cut harvest, and 10% light partial harvests, and relative abundances increased after surpassing thresholds albeit at a reduced rate of increase after the clear-cut threshold. Threshold confidence intervals for individual species overlapped their guild threshold intervals 91% of the time. Even though relative abundance of most species (80%) did not decline as the area affected by timber management increased, implementing management at or below our approximate forest-interior and interior-edge harvest thresholds would reduce the number of declining species by half, maintain higher relative abundances of four species with a net decline in abundance but that peaked in abundance mid-study, and maintain higher relative abundances of ten additional species. In contrast, this management strategy also would prevent the increase in relative abundance of seven species and limit the increase in abundance of three species that increased throughout the study.

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)

Natural and anthropogenic drivers of calcium depletion in a northern forest during the last millennium.

PubMed

Leys, Bérangère A; Likens, Gene E; Johnson, Chris E; Craine, Joseph M; Lacroix, Brice; McLauchlan, Kendra K

2016-06-21

The pace and degree of nutrient limitation are among the most critical uncertainties in predicting terrestrial ecosystem responses to global change. In the northeastern United States, forest growth has recently declined along with decreased soil calcium (Ca) availability, suggesting that acid rain has depleted soil Ca to the point where it may be a limiting nutrient. However, it is unknown whether the past 60 y of changes in Ca availability are strictly anthropogenic or partly a natural consequence of long-term ecosystem development. Here, we report a high-resolution millennial-scale record of Ca and 16 other elements from the sediments of Mirror Lake, a 15-ha lake in the White Mountains of New Hampshire surrounded by northern hardwood forest. We found that sedimentary Ca concentrations had been declining steadily for 900 y before regional Euro-American settlement. This Ca decline was not a result of serial episodic disturbances but instead the gradual weathering of soils and soil Ca availability. As Ca availability was declining, nitrogen availability concurrently was increasing. These data indicate that nutrient availability on base-poor, parent materials is sensitive to acidifying processes on millennial timescales. Forest harvesting and acid rain in the postsettlement period mobilized significant amounts of Ca from watershed soils, but these effects were exacerbated by the long-term pattern. Shifting nutrient limitation can potentially occur within 10,000 y of ecosystem development, which alters our assessments of the speed and trajectory of nutrient limitation in forests, and could require reformulation of global models of forest productivity.

Natural and anthropogenic drivers of calcium depletion in a northern forest during the last millennium

PubMed Central

Leys, Bérangère A.; Likens, Gene E.; Craine, Joseph M.; Lacroix, Brice; McLauchlan, Kendra K.

2016-01-01

The pace and degree of nutrient limitation are among the most critical uncertainties in predicting terrestrial ecosystem responses to global change. In the northeastern United States, forest growth has recently declined along with decreased soil calcium (Ca) availability, suggesting that acid rain has depleted soil Ca to the point where it may be a limiting nutrient. However, it is unknown whether the past 60 y of changes in Ca availability are strictly anthropogenic or partly a natural consequence of long-term ecosystem development. Here, we report a high-resolution millennial-scale record of Ca and 16 other elements from the sediments of Mirror Lake, a 15-ha lake in the White Mountains of New Hampshire surrounded by northern hardwood forest. We found that sedimentary Ca concentrations had been declining steadily for 900 y before regional Euro-American settlement. This Ca decline was not a result of serial episodic disturbances but instead the gradual weathering of soils and soil Ca availability. As Ca availability was declining, nitrogen availability concurrently was increasing. These data indicate that nutrient availability on base-poor, parent materials is sensitive to acidifying processes on millennial timescales. Forest harvesting and acid rain in the postsettlement period mobilized significant amounts of Ca from watershed soils, but these effects were exacerbated by the long-term pattern. Shifting nutrient limitation can potentially occur within 10,000 y of ecosystem development, which alters our assessments of the speed and trajectory of nutrient limitation in forests, and could require reformulation of global models of forest productivity. PMID:27298361

The global position of the U S forest products industry

Treesearch

Jeffrey P. Prestemon; David N. Wear; Michaela O. Foster

2015-01-01

The United States’ share of global industrial roundwood production has declined since the 1990s. We reviewed data from 1961-2013 to evaluate the extent of this decline for industrial roundwood and derived secondary forest products compared to other major producing countries. We find that the U.S. global share of industrial roundwood peaked at 28 percent in 1999 but...

Northwest Forest Plan—the first 10 years (1994–2003): status and trends of northern spotted owl populations and habitat.

Treesearch

Joseph Lint

2005-01-01

This report presents results from monitoring spotted owl (Strix occidentalis caurina) populations and habitat during the first 10 years of implementation of the Northwest Forest Plan (the Plan). Estimated population decline ranged from 0 to 10 percent across study areas (weighted average of 3.4 percent) annually. The average annual rate of decline...

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...

Early human impact in the forest ecotone of southern High Asia (Hindu Kush, Himalaya)

NASA Astrophysics Data System (ADS)

Miehe, Georg; Miehe, Sabine; Schlütz, Frank

2009-05-01

The vegetation of the treeline ecotone of the southern declivity of arid High Asia (Hindu Kush, northern areas of Pakistan; Himalaya, northern central Nepal) is dominated by hedgehog-like open dwarf shrublands of thorny cushions. Since climatically sensitive ecotones are always also sensitive to human impact, the question arises whether the current lack of forests is a result of the Subboreal climate decline or of human impact. Due to inadequate knowledge of the pollen flora and of ecological indicator values of the plants, pollen analyses in High Asia have mainly been limited to the regional verification of globally known climatic impulses. However, the role of human impact on regional vegetation patterns has been widely neglected. We postulate that today's open dwarf shrublands replace woodlands and forests. Isolated vigorous juniper trees and successful reforestation appear to confirm our hypothesis. An abrupt decline of Pinus forests before 5700 and 5400 ka cal yr BP can be demonstrated. As the first indicator pollen of human impact appeared at both sites synchronous with the forest pollen decline, we infer human impact to be a more decisive cause for this environment change superimposing the effects of a climatic deterioration. The forests were displaced by open dwarf shrublands.

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 open systems with lower tree cover. Adult canopy decline would therefore represent an additional factor threatening the recruitment of Quercus forests worldwide.

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...

Spatial characteristics of early successional habitat across the Upper Great Lakes states

Treesearch

Brian G. Tavernia; Mark D. Nelson; James D. Garner; Charles H. (Hobie) Perry

2016-01-01

Creation and management of early successional forest (ESF) is needed to halt and reverse declines of bird species dependent on pioneering plant species or young forests. ESF-dependent bird species require specific structural forest classes and are sensitive to forest age (a surrogate for forest structure), patch size, proximity to patch edges, and the juxtaposition of...

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...

Centennial-scale reductions in nitrogen availability in temperate forests of the United States

USGS Publications Warehouse

McLauchlan, Kendra K.; Gerhart, Laci M.; Battles, John J.; Craine, Joseph M.; Elmore, Andrew J.; Higuera, Phil E.; Mack, Michelle M; McNeil, Brendan E.; Nelson, David M.; Pederson, Neil; Perakis, Steven

2017-01-01

Forests cover 30% of the terrestrial Earth surface and are a major component of the global carbon (C) cycle. Humans have doubled the amount of global reactive nitrogen (N), increasing deposition of N onto forests worldwide. However, other global changes—especially climate change and elevated atmospheric carbon dioxide concentrations—are increasing demand for N, the element limiting primary productivity in temperate forests, which could be reducing N availability. To determine the long-term, integrated effects of global changes on forest N cycling, we measured stable N isotopes in wood, a proxy for N supply relative to demand, on large spatial and temporal scales across the continental U.S.A. Here, we show that forest N availability has generally declined across much of the U.S. since at least 1850 C.E. with cool, wet forests demonstrating the greatest declines. Across sites, recent trajectories of N availability were independent of recent atmospheric N deposition rates, implying a minor role for modern N deposition on the trajectory of N status of North American forests. Our results demonstrate that current trends of global changes are likely to be consistent with forest oligotrophication into the foreseeable future, further constraining forest C fixation and potentially storage.

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...

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.

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...

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

PubMed

Randolph, KaDonna C

2013-06-01

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, US National Vegetation Survey, Canadian Acid Rain National Early Warning System, and joint US-Canadian North American Sugar Maple Decline Project laid the groundwork for the development of the US Forest Service crown-condition indicator. The crown-condition assessment protocols were selected and refined through literature review, peer review, and field studies in several different forest types during the late 1980s and early 1990s. Between 1980 and 2011, 126 publications relating specifically to the crown-condition indicator were added to the literature. The majority of the articles were published by the US Department of Agriculture, Forest Service or other State or Federal government agency, and more than half were published after 2004.

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...

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...

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,...

Height-related trends in leaf xylem anatomy and shoot hydraulic characteristics in a tall conifer: safety versus efficiency in water transport

Treesearch

D.R. Woodruff; F.C. Meinzer; B. Lachenbruch

2008-01-01

Growth and aboveground biomass accumulation follow a common pattern as tree size increases, with productivity peaking when leaf area reaches its maximum and then declining as tree age and size increase. Age- and size-related declines in forest productivity are major considerations in setting the rotational age of commercial forests, and relate to issues of carbon...

Land-use change in Missouri, 1959-1972.

Treesearch

Pamela J. Jakes; John S. Jr. Spencer; Burton L. Essex

1978-01-01

Missouri's third Forest Survey showed an 11% decline in commercial forest area between 1959 and 1972. Most of this land was converted to nonforest uses, primarily pasture. Of the land that remained classified as commercial forest, 75% underwent little or no treatment between surveys.

Mesohabitat use of threatened hemlock forests by breeding birds of the Delaware River basin in northeastern United States

USGS Publications Warehouse

Ross, R.M.; Redell, L.A.; Bennett, R.M.; Young, J.A.

2004-01-01

Avian biodiversity may be at risk in eastern parks and forests due to continued expansion of the hemlock woolly adelgid (Adelges tsugae), an exotic homopteran insect native to East Asia. To assess avian biodiversity, mesohabitat relations, and the risk of species loss with declining hemlock forests in Appalachian park lands, 80 randomly distributed fixed-radius plots were established in which territories of breeding birds were estimated on four forest-terrain types (hemlock and hardwood benches and ravines) in the Delaware Water Gap National Recreation Area. Both species richness and number of territories were higher in hardwood than hemlock forest types and in bench than ravine terrain types. Four insectivorous species, Acadian flycatcher (Empidonax virescens), blue-headed vireo (Vireo solitarius), black-throated green warbler (Dendroica virens), and Blackburnian warbler (Dendroica fusca), showed high affinity for hemlock forest type and exhibited significantly greater numbers of territories in hemlock than hardwood sites. These species are hemlock-associated species at risk from continued hemlock decline in the Delaware River valley and similar forests of the mid-Atlantic east slope. Two of these species, the blue-headed vireo and Blackburnian warbler, appeared to specialize on ravine mesohabitats of hemlock stands, the vireo a low-to-mid canopy species, the warbler a mid-to-upper canopy forager. Unchecked expansion of the exotic adelgid and subsequent hemlock decline could negatively impact 3,600 pairs from the park and several million pairs from northeastern United States hemlock forests due to elimination of preferred habitat.

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.

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. © The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

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...

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,...

Changes in the Carbon Cycle of Amazon Ecosystems During the 2010 Drought

NASA Technical Reports Server (NTRS)

Potter, Christophera; Klooster, Steven; Hiatt, Cyrus; Genovese, Vanessa; Castilla-Rubino, Juan Carlos

2011-01-01

Satellite remote sensing was combined with the NASA-CASA carbon cycle simulation model to evaluate the impact of the 2010 drought (July through September) throughout tropical South America. Results indicated that net primary production (NPP) in Amazon forest areas declined by an average of 7% in 2010 compared to 2008. This represented a loss of vegetation CO2 uptake and potential Amazon rainforest growth of nearly 0.5 Pg C in 2010. The largest overall decline in ecosystem carbon gains by land cover type was predicted for closed broadleaf forest areas of the Amazon River basin, including a large fraction of regularly flooded forest areas. Model results support the hypothesis that soil and dead wood carbon decomposition fluxes of CO2 to the atmosphere were elevated during the drought period of 2010 in periodically flooded forest areas, compared to forests outside the main river floodplains.

Changes in forest productivity across Alaska consistent with biome shift.

PubMed

Beck, Pieter S A; Juday, Glenn P; Alix, Claire; Barber, Valerie A; Winslow, Stephen E; Sousa, Emily E; Heiser, Patricia; Herriges, James D; Goetz, Scott J

2011-04-01

Global vegetation models predict that boreal forests are particularly sensitive to a biome shift during the 21st century. This shift would manifest itself first at the biome's margins, with evergreen forest expanding into current tundra while being replaced by grasslands or temperate forest at the biome's southern edge. We evaluated changes in forest productivity since 1982 across boreal Alaska by linking satellite estimates of primary productivity and a large tree-ring data set. Trends in both records show consistent growth increases at the boreal-tundra ecotones that contrast with drought-induced productivity declines throughout interior Alaska. These patterns support the hypothesized effects of an initiating biome shift. Ultimately, tree dispersal rates, habitat availability and the rate of future climate change, and how it changes disturbance regimes, are expected to determine where the boreal biome will undergo a gradual geographic range shift, and where a more rapid decline. © 2011 Blackwell Publishing Ltd/CNRS.

Basal area growth of sugar maple in relation to acid deposition, stand health, and soil nutrients.

PubMed

Duchesne, Louis; Ouimet, Rock; Houle, Daniel

2002-01-01

Previous studies have shown in noncalcareous soils that acid deposition may have increased soil leaching of basic cations above the input rate from soil weathering and atmospheric depositions. This phenomenon may have increased soil acidity levels, and, as a consequence, may have reduced the availability of these essential nutrients for forest growth. Fourteen plots of the Forest Ecosystem Research and Monitoring Network in Québec were used to examine the relation between post-industrial growth trends of sugar maple (Acer saccharum Marsh.) and acid deposition (N and S), stand decline rate, and soil exchangeable nutrient concentrations. Atmospheric N and S deposition and soil exchangeable acidity were positively associated with stand decline rate, and negatively with the average tree basal area increment trend. The growth rate reduction reached on average 17% in declining stands compared with healthy ones. The results showed a significant sugar maple growth rate reduction since 1960 on acid soils. The appearance of the forest decline phenomenon in Québec can be attributed, at least partially, to soil acidification and acid deposition levels.

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...

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...

Breeding bird populations in Missouri Ozark forests with and without clearcutting

Treesearch

Frank R., III Thompson; William D. Dijak; Thomas G. Kulowiec; David A. Hamilton

1992-01-01

Concern has arisen that forest management practices that create edge (such as clearcutting) are contributing to regional declines in neotropical migrant birds that inhabit forest interiors. Consequently, we studied breeding bird populations in an extensively forested region of southern Missouri to determine if the numbers of breeding birds differed between areas (n = 9...

Use of fragmented landscapes by Marbled Murrelets for nesting in Southern Oregon

Treesearch

C.B. Meyer; S.L. Miller

2002-01-01

As oldgrowth forest becomes more fragmented in the Pacific Northwest (U.S.A.), species dependent on large patches of oldgrowth forest may be at greater risk of extinction. The Marbled Murrelet (Brachyramphus marmoratus), a seabird whose populations are declining in North America, nests in such old-growth forests or forests with large remnant trees....

Restoration seed reserves for assisted gene flow within seed orchards

Treesearch

C.S. Echt; B.S. Crane

2017-01-01

Changing climate and declining forest populations imperil the future of certain forest tree species. To complement forest management and genetic conservation plans, we propose a new paradigm for seedling seed orchards: foster genetic mixing among a variety of seed sources to increase genetic diversity and adaptive potential of seed supplies used for forest restoration...

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...

21st Century drought-related fires counteract the decline of Amazon deforestation carbon emissions.

PubMed

Aragão, Luiz E O C; Anderson, Liana O; Fonseca, Marisa G; Rosan, Thais M; Vedovato, Laura B; Wagner, Fabien H; Silva, Camila V J; Silva Junior, Celso H L; Arai, Egidio; Aguiar, Ana P; Barlow, Jos; Berenguer, Erika; Deeter, Merritt N; Domingues, Lucas G; Gatti, Luciana; Gloor, Manuel; Malhi, Yadvinder; Marengo, Jose A; Miller, John B; Phillips, Oliver L; Saatchi, Sassan

2018-02-13

Tropical carbon emissions are largely derived from direct forest clearing processes. Yet, emissions from drought-induced forest fires are, usually, not included in national-level carbon emission inventories. Here we examine Brazilian Amazon drought impacts on fire incidence and associated forest fire carbon emissions over the period 2003-2015. We show that despite a 76% decline in deforestation rates over the past 13 years, fire incidence increased by 36% during the 2015 drought compared to the preceding 12 years. The 2015 drought had the largest ever ratio of active fire counts to deforestation, with active fires occurring over an area of 799,293 km 2 . Gross emissions from forest fires (989 ± 504 Tg CO 2 year -1 ) alone are more than half as great as those from old-growth forest deforestation during drought years. We conclude that carbon emission inventories intended for accounting and developing policies need to take account of substantial forest fire emissions not associated to the deforestation process.

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...

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...

Dynamics and pattern of a managed coniferous forest landscape in Oregon

NASA Technical Reports Server (NTRS)

Spies, Thomas A.; Ripple, William J.; Bradshaw, G. A.

1995-01-01

We examined the process of fragmentation in a managed forest landscape by comparing rates and patterns of disturbance (primarily clear-cutting) and regrowth between 1972 and 1988 using Landsat imagery. A 2589-km(exp 2) managed forest landscape in western Oregon was classified into two forest types, closed-canopy conifer forest (CF) (typically, greater than 60% conifer cover) and other forest and nonforest types (OT) (typically, less than 40 yr old or deciduous forest). The percentage of CF declined from 71 to 58% between 1972 and 1988. Declines were greatest on private land, least in wilderness, and intermediate in public nonwilderness. High elevations (greater than 914 m) maintained a greater percentage of CF than lower elevations (less than 914 m). The percentage of the area at the edge of the two cover types increased on all ownerships and in both elevational zones, whereas the amount of interior habitat (defined as CF at least 100 m from OT) decreased on all ownerships and elevational zones. By 1988 public lands contained approximately 45% interior habitat while private lands had 12% interior habitat. Mean interior patch area declined from 160 to 62 ha. The annual rate of disturbance (primarily clear-cutting) for the entire area including the wilderness was 1.19%, which corresponds to a cutting rotation of 84 yr. The forest landscape was not in a steady state or regulated condition which is not projected to occur for at least 40 yr under current forest plans. Variability in cutting rates within ownerships was higher on private land than on nonreserve public land. However, despite the use of dispersed cutting patterns on public land, spatial patterns of cutting and remnant forest patches were nonuniform across the entire public ownership. Large remaining patches (less than 5000 ha) of contiguous interior forest were restricted to public lands designated for uses other than timber production such as wilderness areas and research natural areas.

Response of bird communities to natural disturbance

Treesearch

Michael P. Guilfoyle; Wylie C. Barrow; Paul B. Hamel; James S. Wakeley; Sammy L. King; Teny J. Antrobus

2000-01-01

In addition to providing numerous important ecological functions, bottomland hardwoods provide important habitat for many wildlife species (Harris 1989), particularly many forest interior birds (Hamel and others 1996). National monitoring efforts showed nationwide declines for many forest bird species, including forest-dependent neotropical migrants (Johnston and Hagan...

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...

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.

Hydraulics play an important role in causing low growth rate and dieback of aging Pinus sylvestris var. mongolica trees in plantations of Northeast China.

PubMed

Liu, Yan-Yan; Wang, Ai-Ying; An, Yu-Ning; Lian, Pei-Yong; Wu, De-Dong; Zhu, Jiao-Jun; Meinzer, Frederick C; Hao, Guang-You

2018-07-01

The frequently observed forest decline in water-limited regions may be associated with impaired tree hydraulics, but the precise physiological mechanisms remain poorly understood. We compared hydraulic architecture of Mongolian pine (Pinus sylvestris var. mongolica) trees of different size classes from a plantation and a natural forest site to test whether greater hydraulic limitation with increasing size plays an important role in tree decline observed in the more water-limited plantation site. We found that trees from plantations overall showed significantly lower stem hydraulic efficiency. More importantly, plantation-grown trees showed significant declines in stem hydraulic conductivity and hydraulic safety margins as well as syndromes of stronger drought stress with increasing size, whereas no such trends were observed at the natural forest site. Most notably, the leaf to sapwood area ratio (LA/SA) showed a strong linear decline with increasing tree size at the plantation site. Although compensatory adjustments in LA/SA may mitigate the effect of increased water stress in larger trees, they may result in greater risk of carbon imbalance, eventually limiting tree growth at the plantation site. Our results provide a potential mechanistic explanation for the widespread decline of Mongolian pine trees in plantations of Northern China. © 2018 John Wiley & Sons Ltd.

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...

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...

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...

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...

Abundance, distribution, trends, and ownership patterns of early successional forests in the northeastern United States

Treesearch

Robert T. Brooks

2003-01-01

Early-successional forests are ephemeral and distinct forest communities, maintained by disturbance and dominated by small-sized trees and shrubs. These structural and compositional conditions form a unique habitat that is preferred by many wildlife species. Various sources have indicated that there have been declines in early-successional forest area and in the...

History and results of the Northern Forest Health Monitoring Program

Treesearch

Charles J. Barnett

2000-01-01

Forest Health Monitoring (FHM) Program was established because of a concern that the forests in the United States were declining. The program was established to monitor the state of and changes in forest conditions across the nation. This report looks at the distributions of trees into various rating categories for three variables collected on the FHM plots from 1991...

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...

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...

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...

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...

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)...

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...

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...

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...

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 (F pred including temperature, precipitation, acid deposition, soil data and relative site insolation) and forest biomass receptors (F rec 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 F pred -F rec . Unfavourable F pred within unfavourable F rec indicated chronic damage, favourable F pred within unfavourable F rec indicated acute damage, and unfavourable F pred within favourable F rec 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, C org >1%, MgO>6g/kg, and nitrogen deposition<1200mol(H + )/ha·year. Vulnerable forests had BS humus 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 C org 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. Copyright © 2017 Elsevier B.V. All rights reserved.

Timber in Missouri, 1972.

Treesearch

John S. Jr. Spencer; Burton L. Essex

1976-01-01

The third inventory of Missouri's timber resource shows a small gain in growing-stock volume and a somewhat larger gain in sawtimber volume since 1959. Area of commercial forest declined sharply between surveys. Presented are text and statistics on forest area and timber volume, growth, mortality, ownership, stocking, future timber supply, and forest management...

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

EPA Science Inventory

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

Timber resource of Missouri's Riverborder, 1972.

Treesearch

John S. Jr. Spencer; Arnold J. Ostrom

1975-01-01

The third timber inventory of Missouri's Riverborder Forest Survey Unit shows that neither the total volume of growing stock nor of sawtimber changed significantly between 1959 and 1972. Area of commercial forest land declined slightly. Presents statistics on forest area and timber volume, growth, mortality, ownership and use in 1972.

Predicting Metapopulation Responses to Conservation in Human-Dominated Landscapes

Treesearch

Zachary S. Ladin; Vincent D' Amico; Jan M. Baetens; Roland R. Roth; W. Gregory Shriver

2016-01-01

Loss of habitat to urbanization is a primary cause of population declines as human-dominated landscapes expand at increasing rates. Understanding how the relative effects of different conservation strategies is important to slow population declines for species in urban landscapes. We studied the wood thrush Hylocichla mustelina, a declining forest-...

Effect of scale on trait predictors of species responses to agriculture.

PubMed

Gilroy, James J; Medina Uribe, Claudia A; Haugaasen, Torbjørn; Edwards, David P

2015-04-01

Species persistence in human-altered landscapes can depend on factors operating at multiple spatial scales. To understand anthropogenic impacts on biodiversity, it is useful to examine relationships between species traits and their responses to land-use change. A key knowledge gap concerns whether these relationships vary depending on the scale of response under consideration. We examined how local- and large-scale habitat variables influence the occupancy dynamics of a bird community in cloud forest zones in the Colombian Chocó-Andes. Using data collected across a continuum of forest and agriculture, we examined which traits best predict species responses to local variation in farmland and which traits best predict species responses to isolation from contiguous forest. Global range size was a strong predictor of species responses to agriculture at both scales; widespread species were less likely to decline as local habitat cover decreased and as distance from forest increased. Habitat specialization was a strong predictor of species responses only at the local scale. Open-habitat species were particularly likely to increase as pasture increased, but they were relatively insensitive to variation in distance to forest. Foraging plasticity and flocking behavior were strong predictors of species responses to distance from forest, but not their responses to local habitat. Species with lower plasticity in foraging behaviors and obligate flock-following species were more likely to decline as distance from contiguous forest increased. For species exhibiting these latter traits, persistence in tropical landscapes may depend on the protection of larger contiguous blocks of forest, rather than the integration of smaller-scale woodland areas within farmland. Species listed as threatened or near threatened on the International Union for Conservation of Nature Red List were also more likely to decline in response to both local habitat quality and isolation from forest relative to least-concern species, underlining the importance of contiguous forests for threatened taxa. © 2014 Society for Conservation Biology.

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.

Seed dispersal by wind, birds, and bats between Philippine montane rainforest and successional vegetation.

PubMed

Ingle, Nina M R

2003-01-01

In the moist Neotropics, vertebrate frugivores have a much greater role in the dispersal of forest and successional woody plants than wind, and bats rather than birds play the dominant role in dispersing early successional species. I investigated whether these patterns also occurred in a Philippine montane rainforest and adjacent successional vegetation. I also asked whether seed mass was related to probability of dispersal between habitats. A greater number of woody species and stems in the forest produced vertebrate-dispersed seeds than wind-dispersed seeds. Although input of forest seeds into the successional area was dominated by vertebrate-dispersed seeds in terms of species richness, wind-dispersed seeds landed in densities 15 times higher. Frugivorous birds dispersed more forest seeds and species into the successional area than bats, and more successional seeds and species into the forest. As expected, seed input declined with distance from source habitat. Low input of forest seeds into the successional area at the farthest distance sampled, 40 m from forest edge, particularly for vertebrate-dispersed seeds, suggests very limited dispersal out of forest even into a habitat in which woody successional vegetation provides perches and fruit resources. For species of vertebrate-dispersed successional seeds, probability of dispersal into forest declined significantly with seed mass.

Floodplain forest loss and changes in forest community composition and structure in the upper Mississippi River: a wildlife habitat at risk

USGS Publications Warehouse

Knutson, M.G.; Klaas, E.E.

1998-01-01

Large floodplain forests represent a threatened and endangered type of ecosystem in the United States. Estimates of cumulative losses of floodplain forest range from 57% to 95% at different locations within the continental United Stales. Floodplain forests of the Upper Mississippi River (UMR) have significantly declined in extent due to agriculture, lock and dam construction, and urban development since European settlement. We collected data on shrubs, herbs, and trees from 56 floodplain forest plots in 1992 and compared our results with a previous analysis of historical tree data from the same area recorded by the General Land Office Survey in the 1840s. Acer saccharinum strongly dominates among mature trees and its relative dominance has increased over time. Salix spp. And Betula nigra have declined in relative dominance. Tree sizes are similar to those of presettlement forests, but present forests have fewer trees. The lack of early successional tree species and a trend toward an increasing monoculture of A. Saccharinum in the mature stages indicate problems with regeneration. Because floodplain forests represent a rare habitat type, losses and changes in habitat quality could pose serious problems for wildlife that depend upon these habitats, especially birds.

Belize-Guatemala Border

NASA Image and Video Library

2017-08-29

The border between Belize and Guatemala illustrates striking differences in land use practices. In a study of deforestation published in 2016, Chicas and co-authors found that in their study area between 1991 and 2014, on the Guatemalan side of the border forested land declined 32%; in Belize, forested area declined 11%. In part of their study area shown in this image, the difference is more dramatic: near-pristine forest in Belize on the right, and agricultural fields in Guatemala on the left. The image was acquired May 10, 2016, covers an area of 27 by 41 km, and is located at 16.7 degrees north, 89.2 degrees west. https://photojournal.jpl.nasa.gov/catalog/PIA21826

Deforestation contributed to droughts that influenced Maya decline

NASA Astrophysics Data System (ADS)

Balcerak, Ernie

2011-12-01

New studies show that deforestation throughout much of southern Mexico in pre-Columbian times contributed to droughts that led to the decline of the Maya and Aztec civilizations. Significant droughts are known to have affected these civilizations between about 800 and 950 C.E.; it has been debated whether solar forcing, random natural variability, or clearing of rain forests to create pasture or farmlands primarily caused these droughts. Reconstructions of past land cover can be made based on population estimates. Central America was significantly deforested by Maya and Aztec societies before Europeans arrived about 1500 C.E. Forest then recovered as native populations declined, although more deforestation has been taking place in recent years.

Ground truth assessments of forests affected by oak decline and red oak borer in the interior highlands of Arkansas, Oklahoma, and Missouri: preliminary results from overstory analysis

Treesearch

James M. Guldin; Edward A. Poole; Eric Heitzman; John M. Kabrick; Rose-Marie Muzika

2006-01-01

Forests of the Interior Highlands of Arkansas, Oklahoma, and Missouri are being affected by oak decline and an unprecedented outbreak of a native beetle called the red oak borer. On average, Interior Highlands stands contained 236 trees per acre, of which 32 trees per acre (13.4 percent) were dead or dying. Stands averaged 97 square feet per acre of basal area, of...

Large-scale patterns of insect and disease activity in the conterminous United States and Alaska from the National Insect and Disease Detection Survey Database, 2010

Treesearch

Kevin M. Potter; Jeanine L. Paschke

2013-01-01

Analyzing patterns of forest pest infestations, diseases occurrences, forest declines and related biotic stress factors is necessary to monitor the health of forested ecosystems and their potential impacts on forest structure, composition, biodiversity, and species distributions (Castello and others 1995). Introduced nonnative insects and diseases, in particular, can...

Large-scale patterns of insect and disease activity in the conterminous United States and Alaska from the national insect and disease detection survey, 2009

Treesearch

Kevin M. Potter

2013-01-01

Analyzing patterns of forest pest infestation, disease occurrences, forest declines, and related biotic stress factors is necessary to monitor the health of forested ecosystems and their potential impacts on forest structure, composition, biodiversity, and species distributions (Castello and others 1995). Introduced nonnative insects and diseases, in particular, can...

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...

A preview of Maryland's forest resource

Treesearch

Douglas S. Powell; Teresa M. Bowers

1978-01-01

The 1976 forest survey of Maryland shows that the State has 2.5 million acres of commercial forest land, a decline of 13 percent since 1964. Ninety percent of it is in private ownership; 56 percent in sawtimber stands; 46 percent in the oak-hickory forest type. Timber volume has increased to 3.5 billion cubic feet of growing stock and 8.2 billion board feet of...

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...

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...

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...

Combined effects of thinning and decline on fine root dynamics in a Quercus robur L. forest adjoining the Italian Pre-Alps.

PubMed

Mosca, E; Montecchio, L; Barion, G; Dal Cortivo, C; Vamerali, T

2017-05-01

Oak decline is a complex phenomenon, characterized by symptoms of canopy transparency, bark cracks and root biomass reduction. Root health status is one of the first stress indicators, and root turnover is a key process in plant adaptation to unfavourable conditions. In this study, the combined effects of decline and thinning were evaluated on fine root dynamics in an oak forest adjoining the Italian Pre-Alps by comparison of acute declining trees with non-declining trees, both with and without thinning treatment of surrounding trees. Dynamics of volumetric root length density (RLD V ) and tip density (RTD V ), root tip density per unit length of root (RTD L ), diameter, branching index (BI) and mycorrhizal colonization were monitored by soil coring over 2 years as possible descriptors of decline. At the beginning of the experiment, the relationship between canopy transparency and root status was weak, declining trees having slightly lower RLD V (-20 %) and RTD V (-11 %). After a 1 year lag, during which the parameters were almost unaffected, BI and RLD V , together with tip density, tip vitality and mycorrhizal colonization, became the descriptors most representative of both decline class and thinning. Thinning of declining trees increased RLD V (+12 %) and RTD V (+32 %), but reduced tip mycorrhizal colonization and vitality over time compared with non-thinned trees, whereas the opposite occurred in healthy trees, together with a marked decrease in branching. After thinning, there was an initial reduction in the structure of the ectomycorrhizal community, although recovery occurred about 10 months later, regardless of decline severity. Decline causes losses of fine root length, and a moderate recovery can be achieved by thinning, allowing better soil exploration by oak roots. The close correlation between root vitality and mycorrhizal colonization and their deterioration after thinning indicates that decline does not benefit from reduced root competition, excluding the hypothesis of limited water and nutrient availability as a possible cause of the syndrome in this forest. © The Author 2017. Published by Oxford University Press on behalf of the Annals of Botany Company. All rights reserved. For Permissions, please email: journals.permissions@oup.com

Combined effects of thinning and decline on fine root dynamics in a Quercus robur L. forest adjoining the Italian Pre-Alps

PubMed Central

Montecchio, L.; Barion, G.; Dal Cortivo, C.; Vamerali, T.

2017-01-01

Abstract Aims Oak decline is a complex phenomenon, characterized by symptoms of canopy transparency, bark cracks and root biomass reduction. Root health status is one of the first stress indicators, and root turnover is a key process in plant adaptation to unfavourable conditions. In this study, the combined effects of decline and thinning were evaluated on fine root dynamics in an oak forest adjoining the Italian Pre-Alps by comparison of acute declining trees with non-declining trees, both with and without thinning treatment of surrounding trees. Methods Dynamics of volumetric root length density (RLDV) and tip density (RTDV), root tip density per unit length of root (RTDL), diameter, branching index (BI) and mycorrhizal colonization were monitored by soil coring over 2 years as possible descriptors of decline. Key Results At the beginning of the experiment, the relationship between canopy transparency and root status was weak, declining trees having slightly lower RLDV (–20 %) and RTDV (–11 %). After a 1 year lag, during which the parameters were almost unaffected, BI and RLDV, together with tip density, tip vitality and mycorrhizal colonization, became the descriptors most representative of both decline class and thinning. Thinning of declining trees increased RLDV (+12 %) and RTDV (+32 %), but reduced tip mycorrhizal colonization and vitality over time compared with non-thinned trees, whereas the opposite occurred in healthy trees, together with a marked decrease in branching. After thinning, there was an initial reduction in the structure of the ectomycorrhizal community, although recovery occurred about 10 months later, regardless of decline severity. Conclusions Decline causes losses of fine root length, and a moderate recovery can be achieved by thinning, allowing better soil exploration by oak roots. The close correlation between root vitality and mycorrhizal colonization and their deterioration after thinning indicates that decline does not benefit from reduced root competition, excluding the hypothesis of limited water and nutrient availability as a possible cause of the syndrome in this forest. PMID:28334145

Extreme mid-winter drought weakens tree hydraulic-carbohydrate systems and slows growth.

PubMed

Earles, J Mason; Stevens, Jens T; Sperling, Or; Orozco, Jessica; North, Malcolm P; Zwieniecki, Maciej A

2018-07-01

Rising temperatures and extended periods of drought compromise tree hydraulic and carbohydrate systems, threatening forest health globally. Despite winter's biological significance to many forests, the effects of warmer and dryer winters on tree hydraulic and carbohydrate status have largely been overlooked. Here we report a sharp and previously unknown decline in stem water content of three conifer species during California's anomalous 2015 mid-winter drought that was followed by dampened spring starch accumulation. Recent precipitation and seasonal vapor pressure deficit (VPD) anomaly, not absolute VPD, best predicted the hydraulic patterns observed. By linking relative water content and hydraulic conductivity (K h ), we estimated that stand-level K h declined by 52% during California's 2015 mid-winter drought, followed by a 50% reduction in spring starch accumulation. Further examination of tree increment records indicated a concurrent decline of growth with rising mid-winter, but not summer, VPD anomaly. Thus, our findings suggest a seasonality to tree hydraulic and carbohydrate declines, with consequences for annual growth rates, raising novel physiological and ecological questions about how rising winter temperatures will affect forest vitality as climate changes. © 2018 The Authors. New Phytologist © 2018 New Phytologist Trust.

Disturbance severity and net primary production resilience of a Great Lakes forest ecosystem

NASA Astrophysics Data System (ADS)

Goodrich-Stuart, E. J.; Fahey, R.; De La Cruz, A.; Gough, C. M.

2013-12-01

As many Eastern deciduous forests of North America transition from early to mid-succession, the future of regional terrestrial carbon (C) storage is uncertain. The gradual, patchy senescence of early-successional trees accompanying this transition is comparable in severity to moderate disturbances such as silvicultural thinnings or insect outbreaks. While stand-replacing disturbance causes forests to temporarily become C sources, more moderate disturbances may inflict little to no decline in C sequestration. Identifying the disturbance severity at which net primary production (NPP) declines and the underlying mechanisms that drive forest C storage resistance to disturbance is increasingly important as moderate disturbances increase in frequency and extent across the region. The Forest Accelerated Succession ExperimenT (FASET) at the University of Michigan Biological Station subjected 39 ha of forest to moderate disturbance in 2008 by advancing age-related tree mortality through the stem girdling of early successional aspen and birch. Stand-scale disturbance severity, expressed as relative basal area of girdled aspen and birch, was 39% but plot-scale severity varied substantially within the experimental area (9 to 66% in 0.1 ha plots) because of the heterogeneous distribution of aspen and birch. We used this disturbance severity gradient to examine: 1) the relationship between NPP resilience and disturbance severity; 2) the disturbance severity at which NPP resilience prompts a shift in dominance from canopy to subcanopy vegetation; 3) how NPP resilience relates to disturbance-driven changes in resource-use efficiency, and 4) how disturbance severity shapes emerging forest communities We found that NPP is highly resilient to low to moderate levels of disturbance, but that production declines once a higher disturbance threshold is exceeded. Several complementary mechanisms, including canopy structural reorganization and the reallocation of growth-limiting light and nitrogen resources, appear to maintain NPP up to the disturbance severity threshold. Our results suggest that both canopy and subcanopy trees reacted rapidly to compensate for canopy tree mortality, but at higher disturbance severities, subcanopy trees provided an important buffer in support of NPP resilience. Our data also suggests a larger increase in the growth rate of red maples (Acer rubrum) following disturbance than subcanopy red oak (Quercus rubra) and white pine (Pinus strobus), as well as a greater contribution to overall plot-level production in more severely disturbed plots. These findings demonstrate that some forests can tolerate substantial disturbance without a reduction in NPP, suggesting that the relationship between disturbance severity and declining production may be non-linear. This result has important implications for the region's C cycle, suggesting that moderate disturbances may not cause a decline in forest C sequestration but may actually stimulate new growth to maintain NPP.

Factors influencing avian habitat selection between oak-hickory and mesic forests in southern Illinois

Treesearch

Kevin P. Sierzega; Michael W. Eichholz

2014-01-01

Oak (Quercus spp.) regeneration has declined drastically over the past century in eastern deciduous forests predominantly because of decreased disturbance (i.e., fire). Many forests are undergoing mesophication, a positive feedback system that occurs within closed-canopy systems wherein shade-tolerant, late successional, mesic species such as maples...

The growing timber resource of Michigan, 1966.

Treesearch

Clarence D. Chase; Ray E. Pfeifer; John S. Spencer

1969-01-01

The third (1966) Forest Survey of Michigan shows sizable gains in growing-stock and sawtimber volumes since 1955, despite a small decline in the commercial forest area. Presented are statistics on forest area and timber volume, growth, mortality, ownership, stocking, and use. Also presented is a projection of timber growth, removals, and inventory to 1996.

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,...

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...

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...

Soil properties and aspen development five years after compaction and forest floor removal

Treesearch

Douglas M. Stone; John D. Elioff

1998-01-01

Forest management activities that decrease soil porosity and remove organic matter have been associated with declines in site productivity. In the northern Lake States region, research is in progress in the aspen (Populus tremuloides Michx. and P. grandidentata Michx.) forest type to determine effects of soil compaction and organic...

Area of old-growth forests in California, Oregon, and Washington.

Treesearch

Charles L. Bolsinger; Karen L. Waddell

1993-01-01

Area of old-growth forests in California, Oregon, and Washington has declined significantly in the second half of the 20th century. This 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.

Timber resource of Missouri's Northwestern Ozarks, 1972.

Treesearch

Alexander Vasilevsky; Burton L. Essex

1974-01-01

The third timber inventory of Missouri's Northwestern Ozarks Forest Survey Unit shows substantial gains in both growing-stock and sawtimber volumes between 1959 and 1972. The area of commercial forests declined during the same period. Presented are highlights and statistics on forest area and timer volume, growth, mortality, ownership and use in 1972.

Ten Years of Forest Cover Change in the Sierra Nevada Detected Using Landsat Satellite Image Analysis

NASA Technical Reports Server (NTRS)

Potter, Christopher S.

2014-01-01

The Landsat Ecosystem Disturbance Adaptive Processing System (LEDAPS) methodology was applied to detected changes in forest vegetation cover for areas burned by wildfires in the Sierra Nevada Mountains of California between the periods of 1975- 79 and 1995-1999. Results for areas burned by wildfire between 1995 and 1999 confirmed the importance of regrowing forest vegetation over 17% of the combined burned areas. A notable fraction (12%) of the entire 5-km (unburned) buffer area outside the 1995-199 fires perimeters showed decline in forest cover, and not nearly as many regrowing forest areas, covering only 3% of all the 1995-1999 buffer areas combined. Areas burned by wildfire between 1975 and 1979 confirmed the importance of disturbed (or declining evergreen) vegetation covering 13% of the combined 1975- 1979 burned areas. Based on comparison of these results to ground-based survey data, the LEDAPS methodology should be capable of fulfilling much of the need for consistent, low-cost monitoring of changes due to climate and biological factors in western forest regrowth following stand-replacing disturbances.

Persistent effects of a severe drought on Amazonian forest canopy.

PubMed

Saatchi, Sassan; Asefi-Najafabady, Salvi; Malhi, Yadvinder; Aragão, Luiz E O C; Anderson, Liana O; Myneni, Ranga B; Nemani, Ramakrishna

2013-01-08

Recent Amazonian droughts have drawn attention to the vulnerability of tropical forests to climate perturbations. Satellite and in situ observations have shown an increase in fire occurrence during drought years and tree mortality following severe droughts, but to date there has been no assessment of long-term impacts of these droughts across landscapes in Amazonia. Here, we use satellite microwave observations of rainfall and canopy backscatter to show that more than 70 million hectares of forest in western Amazonia experienced a strong water deficit during the dry season of 2005 and a closely corresponding decline in canopy structure and moisture. Remarkably, and despite the gradual recovery in total rainfall in subsequent years, the decrease in canopy backscatter persisted until the next major drought, in 2010. The decline in backscatter is attributed to changes in structure and water content associated with the forest upper canopy. The persistence of low backscatter supports the slow recovery (>4 y) of forest canopy structure after the severe drought in 2005. The result suggests that the occurrence of droughts in Amazonia at 5-10 y frequency may lead to persistent alteration of the forest canopy.

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...

Assessment of black ash (Fraxinus nigra) decline in Minnesota

Treesearch

Kathleen Ward; Michael Ostry; Robert Venette; Brian Palik; Mark Hansen; Mark Hatfield

2009-01-01

Black ash (Fraxinus nigra) is an important component of wetland forests throughout the Upper Midwest and northeastern United States and is highly valued for paneling, furniture, and basketry. Decline of black ash has been noted with increasing frequency, although no detailed studies of the pattern of decline across the region have been done. From...

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...

Sugar maple ecology and health: proceedings of an international symposium

Treesearch

Stephen B. Horsley; Robert P. Long; eds.

1999-01-01

Contains 28 papers and abstracts on sugar maple history and ecology; recent sugar maple declines; nutrient and belowground dynamics in northeastern forests; and interactions of forest health with biotic and abiotic stressors.

Impacts of forest age on water use in Mountain ash forests

USGS Publications Warehouse

Wood, Stephen A.; Beringer, Jason; Hutley, Lindsay B.; McGuire, A. David; Van Dijk, Albert; Kilinc, Musa

2008-01-01

Runoff from mountain ash (Eucalyptus regnans F.Muell.) forested catchments has been shown to decline significantly in the few decades following fire returning to pre-fire levels in the following centuries owing to changes in ecosystem water use with stand age in a relationship known as Kuczera's model. We examined this relationship between catchment runoff and stand age by measuring whole-ecosystem exchanges of water using an eddy covariance system measuring forest evapotranspiration (ET) combined with sap-flow measurements of tree water use, with measurements made across a chronosequence of three sites (24, 80 and 296 years since fire). At the 296-year old site eddy covariance systems were installed above the E. regnans overstorey and above the distinct rainforest understorey. Contrary to predictions from the Kuczera curve, we found that measurements of whole-forest ET decreased by far less across stand age between 24 and 296 years. Although the overstorey tree water use declined by 1.8mmday-1 with increasing forest age (an annual decrease of 657mm) the understorey ET contributed between 1.2 and 1.5mmday-1, 45% of the total ET (3mmday-1) at the old growth forest.

Impacts of fire on forest age and runoff in mountain ash forests

USGS Publications Warehouse

Wood, S.A.; Beringer, J.; Hutley, L.B.; McGuire, A.D.; Van Dijk, A.; Kilinc, M.

2008-01-01

Runoff from mountain ash (Eucalyptus regnans F.Muell.) forested catchments has been shown to decline significantly in the few decades following fire - returning to pre-fire levels in the following centuries - owing to changes in ecosystem water use with stand age in a relationship known as Kuczera's model. We examined this relationship between catchment runoff and stand age by measuring whole-ecosystem exchanges of water using an eddy covariance system measuring forest evapotranspiration (ET) combined with sap-flow measurements of tree water use, with measurements made across a chronosequence of three sites (24, 80 and 296 years since fire). At the 296-year old site eddy covariance systems were installed above the E. regnans overstorey and above the distinct rainforest understorey. Contrary to predictions from the Kuczera curve, we found that measurements of whole-forest ET decreased by far less across stand age between 24 and 296 years. Although the overstorey tree water use declined by 1.8 mm day-1 with increasing forest age (an annual decrease of 657 mm) the understorey ET contributed between 1.2 and 1.5 mm day-1, 45% of the total ET (3 mm day-1) at the old growth forest. ?? CSIRO 2008.

Competition amplifies drought stress in forests across broad climatic and compositional gradients

USGS Publications Warehouse

Gleason, Kelly; Bradford, John B.; Bottero, Alessandra; D'Amato, Tony; Fraver, Shawn; Palik, Brian J.; Battaglia, Michael; Iverson, Louis R.; Kenefic, Laura; Kern, Christel C.

2017-01-01

Forests around the world are experiencing increasingly severe droughts and elevated competitive intensity due to increased tree density. However, the influence of interactions between drought and competition on forest growth remains poorly understood. Using a unique dataset of stand-scale dendrochronology sampled from 6405 trees, we quantified how annual growth of entire tree populations responds to drought and competition in eight, long-term (multi-decadal), experiments with replicated levels of density (e.g., competitive intensity) arrayed across a broad climatic and compositional gradient. Forest growth (cumulative individual tree growth within a stand) declined during drought, especially during more severe drought in drier climates. Forest growth declines were exacerbated by high density at all sites but one, particularly during periods of more severe drought. Surprisingly, the influence of forest density was persistent overall, but these density impacts were greater in the humid sites than in more arid sites. Significant density impacts occurred during periods of more extreme drought, and during warmer temperatures in the semi-arid sites but during periods of cooler temperatures in the humid sites. Because competition has a consistent influence over growth response to drought, maintaining forests at lower density may enhance resilience to drought in all climates.

Assessment and monitoring of long-term forest cover changes in Odisha, India using remote sensing and GIS.

PubMed

Reddy, C Sudhakar; Jha, C S; Dadhwal, V K

2013-05-01

Deforestation and fragmentation are important concerns in managing and conserving tropical forests and have global significance. In the Indian context, in the last one century, the forests have undergone significant changes due to several policies undertaken by government as well as increased population pressure. The present study has brought out spatiotemporal changes in forest cover and variation in forest type in the state of Odisha (Orissa), India, during the last 75 years period. The mapping for the period of 1924-1935, 1975, 1985, 1995 and 2010 indicates that the forest cover accounts for 81,785.6 km(2) (52.5 %), 56,661.1 km(2) (36.4 %), 51,642.3 km(2) (33.2 %), 49,773 km(2) (32 %) and 48,669.4 km(2) (31.3 %) of the study area, respectively. The study found the net forest cover decline as 40.5 % of the total forest and mean annual rate of deforestation as 0.69 % year(-1) during 1935 to 2010. There is a decline in annual rate of deforestation during 1995 to 2010 which was estimated as 0.15 %. Forest type-wise quantitative loss of forest cover reveals large scale deforestation of dry deciduous forests. The landscape analysis shows that the number of forest patches (per 1,000) are 2.463 in 1935, 10.390 in 1975, 11.899 in 1985, 12.193 in 1995 and 15.102 in 2010, which indicates high anthropogenic pressure on the forests. The mean patch size (km(2)) of forest decreased from 33.2 in 1935 to 5.5 in 1975 and reached to 3.2 by 2010. The study demonstrated that monitoring of long term forest changes, quantitative loss of forest types and landscape metrics provides critical inputs for management of forest resources.

Late Holocene forest dynamics in the Gulf of Gaeta (central Mediterranean) in relation to NAO variability and human impact

NASA Astrophysics Data System (ADS)

Di Rita, Federico; Lirer, Fabrizio; Bonomo, Sergio; Cascella, Antonio; Ferraro, Luciana; Florindo, Fabio; Insinga, Donatella Domenica; Lurcock, Pontus Conrad; Margaritelli, Giulia; Petrosino, Paola; Rettori, Roberto; Vallefuoco, Mattia; Magri, Donatella

2018-01-01

A new high-resolution pollen record, spanning the last five millennia, is presented from the Gulf of Gaeta (Tyrrhenian Sea, central Italy), with the aim of verifying if any vegetation change occurred in the central Mediterranean region in relation to specific well-known global and/or regional climate events, including the 4.2 ka event, the Medieval Climate Anomaly (MCA) and the Little Ice Age (LIA), and to detect possible vegetation changes related to still under-investigated climate signals, for example the so-called "Bond 2" cold event around 2.8 ka BP. The vegetation dynamics of the Gaeta record shows a recurrent pattern of forest increase and decline punctuating the mid- and late Holocene. When the timing of these patterns is compared with the climate proxy data available from the same core (planktonic foraminifera assemblages and oxygen stable isotope record) and with the NAO (North Atlantic Oscillation) index, it clearly appears that the main driver for the forest fluctuations is climate, which may even overshadow the effects of human activity. We have found a clear correspondence between phases with negative NAO index and forest declines. In particular, around 4200 cal BP, a drop in AP (Arboreal Pollen) confirms the clearance recorded in many sites in Italy south of 43°N. Around 2800 cal BP, a vegetation change towards open conditions is found at a time when the NAO index clearly shows negative values. Between 800 and 1000 AD, a remarkable forest decline, coeval with a decrease in the frequencies of both Castanea and Olea, matches a shift in the oxygen isotope record towards positive values, indicating cooler temperatures, and a negative NAO. Between 1400-1850 AD, in the time period chronologically corresponding to the LIA (Little Ice Age), the Gaeta record shows a clear decline of the forest cover, particularly evident after 1550 AD, once again in correspondence with negative NAO index.

Using Landsat and a Bayesian hard classifier to study forest change in the Salmon Creek Watershed area from 1972-2013

NASA Astrophysics Data System (ADS)

Mullis, David Stone

The Salmon Creek Watershed in Sonoma County, California, USA, is home to a variety of wildlife, and many of its residents are mindful of their place in its ecology. In the past half century, several of its native and rare species have become threatened, endangered, or extinct, most notably the once common Coho salmon and Chinook salmon. The cause of this decline is believed to be a combination of global climate change, local land use, and land cover change. More specifically, the clearing of forested land to create vineyards, as well as other agricultural and residential uses, has led to a decline in biodiversity and habitat structure. I studied sub-scenes of Landsat data from 1972 to 2013 for the Salmon Creek Watershed area to estimate forest cover over this period. I used a maximum likelihood hard classifier to determine forest area, a Mahalanobis distance soft classifier to show the software's uncertainty in classification, and manually digitized forest cover to test and compare results for the 2013 30 m image. Because the earliest images were lower spatial resolution, I also tested the effects of resolution on these statistics. The images before 1985 are at 60 m spatial resolution while the later images are at 30 m resolution. Each image was processed individually and the training data were based on knowledge of the area and a mosaic of aerial photography. Each sub-scene was classified into five categories: water, forest, pasture, vineyard/orchard, and developed/barren. The research shows a decline in forest area from 1972 to around the mid-1990s, then an increase in forest area from the mid-1990s to present. The forest statistics can be helpful for conservation and restoration purposes, while the study on resolution can be helpful for landscape analysis on many levels.

Do food availability, parasitism, and stress have synergistic effects on red colobus populations living in forest fragments?

PubMed

Chapman, Colin A; Wasserman, Michael D; Gillespie, Thomas R; Speirs, Michaela L; Lawes, Michael J; Saj, Tania L; Ziegler, Toni E

2006-12-01

Identifying factors that influence animal density is a fundamental goal in ecology that has taken on new importance with the need to develop informed management plans. This is particularly the case for primates as the tropical forest that supports many species is being rapidly converted. We use a system of forest fragments adjacent to Kibale National Park, Uganda, to examine if food availability and parasite infections have synergistic affects on red colobus (Piliocolobus tephrosceles) abundance. Given that the size of primate populations can often respond slowly to environmental changes, we also examined how these factors influenced cortisol levels. To meet these objectives, we monitored gastrointestinal parasites, evaluated fecal cortisol levels, and determined changes in food availability by conducting complete tree inventories in eight fragments in 2000 and 2003. Red colobus populations declined by an average of 21% among the fragments; however, population change ranged from a 25% increase to a 57% decline. The cumulative basal area of food trees declined by an average of 29.5%; however, forest change was highly variable (a 2% gain to a 71% decline). We found that nematode prevalence averaged 58% among fragments (range 29-83%). The change in colobus population size was correlated both with food availability and a number of indices of parasite infections. A path analysis suggests that change in food availability has a strong direct effect on population size, but it also has an indirect effect via parasite infections. 2006 Wiley-Liss, Inc.

Declines in low-elevation subalpine tree populations outpace growth in high-elevation populations with warming

USGS Publications Warehouse

Conlisk, Erin; Castanha, Cristina; Germino, Matthew J.; Veblen, Thomas T; Smith, Jeremy M.; Kueppers, Lara M.

2017-01-01

Species distribution shifts in response to climate change require that recruitment increase beyond current range boundaries. For trees with long life spans, the importance of climate-sensitive seedling establishment to the pace of range shifts has not been demonstrated quantitatively.Using spatially explicit, stochastic population models combined with data from long-term forest surveys, we explored whether the climate-sensitivity of recruitment observed in climate manipulation experiments was sufficient to alter populations and elevation ranges of two widely distributed, high-elevation North American conifers.Empirically observed, warming-driven declines in recruitment led to rapid modelled population declines at the low-elevation, ‘warm edge’ of subalpine forest and slow emergence of populations beyond the high-elevation, ‘cool edge’. Because population declines in the forest occurred much faster than population emergence in the alpine, we observed range contraction for both species. For Engelmann spruce, this contraction was permanent over the modelled time horizon, even in the presence of increased moisture. For limber pine, lower sensitivity to warming may facilitate persistence at low elevations – especially in the presence of increased moisture – and rapid establishment above tree line, and, ultimately, expansion into the alpine.Synthesis. Assuming 21st century warming and no additional moisture, population dynamics in high-elevation forests led to transient range contractions for limber pine and potentially permanent range contractions for Engelmann spruce. Thus, limitations to seedling recruitment with warming can constrain the pace of subalpine tree range shifts.

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

Treesearch

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...

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...

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...

Recent drought-induced decline of forests along a water-balance tipping point for ecosystems in western Canada

NASA Astrophysics Data System (ADS)

Hess, N. J.; Tfaily, M. M.; Heredia-Langnar, A.; Rodriguez, L.; Purvine, E.; Todd-Brown, K. E.

2016-12-01

In western Canada, the forest-prairie boundary corresponds to a hydrologically-defined ecosystem "tipping point" where long-term precipitation is barely sufficient to meet the water use requirements of healthy, closed-canopy forests. In the province of Alberta, the severe subcontinental drought of 2001-2002 heralded the beginning of a 15-year dry period, representing a northward incursion of prairie-like climates into boreal and cordilleran forests. This poses a significant concern for ecosystem functioning of these forests, given GCM projections for continued warming and drying under anthropogenic climate change during this century. Through a multi-scale monitoring approach, we have examined the regional-scale impacts of recent droughts and associated climatic drying on the productivity and health of two important boreal tree species: aspen (Populus tremuloides) and white spruce (Picea glauca). For aspen, the 2016 re-measurement of a regional network of 150 ground plots revealed that tree mortality has escalated, especially in stands exposed to the combined impacts of multi-year drought and insect defoliation. On average, mortality losses exceeded growth gains during 2000-2016 for the 54 aspen plots in Alberta, leading to a net multi-year decline in the aboveground biomass of these stands. For white spruce, tree-ring analysis of 40 stands across Alberta revealed that the prolonged dry period led to a 38% decline in average, tree-level growth in aboveground biomass. In both species, stand age was not a significant factor affecting forest sensitivity to drought and climatic drying, suggesting that these forests are at risk if the trend toward more frequent, severe drought continues in the region.

Recent drought-induced decline of forests along a water-balance tipping point for ecosystems in western Canada

NASA Astrophysics Data System (ADS)

Hogg, E. H.; Michaelian, M.

2017-12-01

In western Canada, the forest-prairie boundary corresponds to a hydrologically-defined ecosystem "tipping point" where long-term precipitation is barely sufficient to meet the water use requirements of healthy, closed-canopy forests. In the province of Alberta, the severe subcontinental drought of 2001-2002 heralded the beginning of a 15-year dry period, representing a northward incursion of prairie-like climates into boreal and cordilleran forests. This poses a significant concern for ecosystem functioning of these forests, given GCM projections for continued warming and drying under anthropogenic climate change during this century. Through a multi-scale monitoring approach, we have examined the regional-scale impacts of recent droughts and associated climatic drying on the productivity and health of two important boreal tree species: aspen (Populus tremuloides) and white spruce (Picea glauca). For aspen, the 2016 re-measurement of a regional network of 150 ground plots revealed that tree mortality has escalated, especially in stands exposed to the combined impacts of multi-year drought and insect defoliation. On average, mortality losses exceeded growth gains during 2000-2016 for the 54 aspen plots in Alberta, leading to a net multi-year decline in the aboveground biomass of these stands. For white spruce, tree-ring analysis of 40 stands across Alberta revealed that the prolonged dry period led to a 38% decline in average, tree-level growth in aboveground biomass. In both species, stand age was not a significant factor affecting forest sensitivity to drought and climatic drying, suggesting that these forests are at risk if the trend toward more frequent, severe drought continues in the region.

Effects of forest management on California Spotted Owls: implications for reducing wildfire risk in fire‐prone forests.

PubMed

Tempel, Douglas J; Gutiérrez, R J; Whitmore, Sheila A; Reetz, Matthew J; Stoelting, Ricka E; Berigan, William J; Seamans, Mark E; Zachariah Peery, M

Management of many North American forests is challenged by the need to balance the potentially competing objectives of reducing risks posed by high-severity wildfires and protecting threatened species. In the Sierra Nevada, California, concern about high-severity fires has increased in recent decades but uncertainty exists over the effects of fuel-reduction treatments on species associated with older forests, such as the California Spotted Owl (Strix occidentalis occidentalis). Here, we assessed the effects of forest conditions, fuel reductions, and wildfire on a declining population of Spotted Owls in the central Sierra Nevada using 20 years of demographic data collected at 74 Spotted Owl territories. Adult survival and territory colonization probabilities were relatively high, while territory extinction probability was relatively low, especially in territories that had relatively large amounts of high canopy cover (≥70%) forest. Reproduction was negatively associated with the area of medium-intensity timber harvests characteristic of proposed fuel treatments. Our results also suggested that the amount of edge between older forests and shrub/sapling vegetation and increased habitat heterogeneity may positively influence demographic rates of Spotted Owls. Finally, high-severity fire negatively influenced the probability of territory colonization. Despite correlations between owl demographic rates and several habitat variables, life stage simulation (sensitivity) analyses indicated that the amount of forest with high canopy cover was the primary driver of population growth and equilibrium occupancy at the scale of individual territories. Greater than 90% of medium-intensity harvests converted high-canopy-cover forests into lower-canopy-cover vegetation classes, suggesting that landscape-scale fuel treatments in such stands could have short-term negative impacts on populations of California Spotted Owls. Moreover, high-canopy-cover forests declined by an average of 7.4% across territories during our study, suggesting that habitat loss could have contributed to declines in abundance and territory occupancy. We recommend that managers consider the existing amount and spatial distribution of high-canopy forest before implementing fuel treatments within an owl territory, and that treatments be accompanied by a rigorous monitoring program.

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

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.

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...

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...

Alabama forests: Trends and prospects

Treesearch

Paul A. Murphy

1973-01-01

Between 1963 and 1972, forest area in Alabama declined 2 percent to 21.3 million acres. Softwood volume increased 30 percent and hardwood 15 percent. Volumes increased in all tree-size classes, but increases were greatest in small trees.

Red-cockaded woodpecker colony status and trends on the Angelina, Davy Crockett and Sabine national forests

Treesearch

Richard N. Conner; D. Craig Rudolph

1989-01-01

Abundant hardwood midstory, colony isolation, and habitat fragmentation are believed to be the causes for severe population declines of red-cockaded woodpeckers on three national forests in eastern Texas.

Synergistic Ecoclimate Teleconnections from Forest Loss in Different Regions Structure Global Ecological Responses.

PubMed

Garcia, Elizabeth S; Swann, Abigail L S; Villegas, Juan C; Breshears, David D; Law, Darin J; Saleska, Scott R; Stark, Scott C

2016-01-01

Forest loss in hotspots around the world impacts not only local climate where loss occurs, but also influences climate and vegetation in remote parts of the globe through ecoclimate teleconnections. The magnitude and mechanism of remote impacts likely depends on the location and distribution of forest loss hotspots, but the nature of these dependencies has not been investigated. We use global climate model simulations to estimate the distribution of ecologically-relevant climate changes resulting from forest loss in two hotspot regions: western North America (wNA), which is experiencing accelerated dieoff, and the Amazon basin, which is subject to high rates of deforestation. The remote climatic and ecological net effects of simultaneous forest loss in both regions differed from the combined effects of loss from the two regions simulated separately, as evident in three impacted areas. Eastern South American Gross Primary Productivity (GPP) increased due to changes in seasonal rainfall associated with Amazon forest loss and changes in temperature related to wNA forest loss. Eurasia's GPP declined with wNA forest loss due to cooling temperatures increasing soil ice volume. Southeastern North American productivity increased with simultaneous forest loss, but declined with only wNA forest loss due to changes in VPD. Our results illustrate the need for a new generation of local-to-global scale analyses to identify potential ecoclimate teleconnections, their underlying mechanisms, and most importantly, their synergistic interactions, to predict the responses to increasing forest loss under future land use change and climate change.

Ecological consequences of forest elephant declines for Afrotropical forests.

PubMed

Poulsen, John R; Rosin, Cooper; Meier, Amelia; Mills, Emily; Nuñez, Chase L; Koerner, Sally E; Blanchard, Emily; Callejas, Jennifer; Moore, Sarah; Sowers, Mark

2018-06-01

Poaching is rapidly extirpating African forest elephants (Loxodonta cyclotis) from most of their historical range, leaving vast areas of elephant-free tropical forest. Elephants are ecological engineers that create and maintain forest habitat; thus, their loss will have large consequences for the composition and structure of Afrotropical forests. Through a comprehensive literature review, we evaluated the roles of forest elephants in seed dispersal, nutrient recycling, and herbivory and physical damage to predict the cascading ecological effects of their population declines. Loss of seed dispersal by elephants will favor tree species dispersed abiotically and by smaller dispersal agents, and tree species composition will depend on the downstream effects of changes in elephant nutrient cycling and browsing. Loss of trampling and herbivory of seedlings and saplings will result in high tree density with release from browsing pressures. Diminished seed dispersal by elephants and high stem density are likely to reduce the recruitment of large trees and thus increase homogeneity of forest structure and decrease carbon stocks. The loss of ecological services by forest elephants likely means Central African forests will be more like Neotropical forests, from which megafauna were extirpated thousands of years ago. Without intervention, as much as 96% of Central African forests will have modified species composition and structure as elephants are compressed into remaining protected areas. Stopping elephant poaching is an urgent first step to mitigating these effects, but long-term conservation will require land-use planning that incorporates elephant habitat into forested landscapes that are being rapidly transformed by industrial agriculture and logging. © 2017 Society for Conservation Biology.

EAB induced tree mortality impacts ecosystem respiration and tree water use in an experimental forest

Treesearch

Charles E. Flower; Douglas J. Lynch; Kathleen S. Knight; Miquel A. Gonzales-Meler

2011-01-01

The invasive emerald ash borer (Agrilus planipennis Fairmaire, EAB) has been spreading across the forest landscape of the Midwest resulting in the rapid decline of ash trees (Fraxinus spp.). Ash trees represent a dominant riparian species in temperate deciduous forests of the Eastern United States (USDA FIA Database). Prior...

Needs and Opportunities for Longleaf Pine Ecosystem Restoration in Florida

Treesearch

Kenneth W. Outcalt

1997-01-01

Data from permanent plots measured periodically by Forest Inventory and Analyses of the Southern Research Station, USDA Forest Service shows a continuing decline in the longleaf pine (Pinus pulustris Mill,) ecosystem in Florida from 1987 to 1995. Conversion to some other forest type resulted in a net loss of 58,000 ha natural stands of longleaf pine...

Options for managing early-successional forest and shrubland bird habitats in the northeastern United States

Treesearch

Richard M. DeGraaf; Mariko Yamasaki

2003-01-01

Historically, forests in the northeastern United States were disturbed by fire, wind, Native American agriculture, flooding, and beavers (Castor canadensis). Of these, wind and beavers are now the only sources of natural disturbance. Most disturbance-dependent species, especially birds, are declining throughout the region whereas species affiliated with mature forests...

Effect of stand width and adjacent habitat on breeding bird communities in bottomland hardwoods

Treesearch

John C. Kilgo; Robert A. Sargent

1998-01-01

Bottomland hardwood forests support an abundant and diverse avifauna, but area of this forest type has been reduced, and current projections indicate continued declines. The authors compared breeding bird abundance indices and species richness among bottomland hardwood stands ranging in width from 1,000 m and enclosed by forested habitat. They also...

Loss of foundation species: consequences for the structure and dynamics of forested ecosystems

Treesearch

Aaron M. Ellison; Michael S. Bank; Barton D. Clinton; Elizabeth A. Colburn; Katherine Elliott; Chelcy Rae Ford; David R. Foster; Brian D. Kloeppel; Jennifer D. Knoepp; Gary M. Lovett; Jacqueline Mohan; David A. Orwig; Nicholas L. Rodenhouse; William V. Sobczak; Kristina A. Stinson; Jeffrey K. Stone; Christopher M. Swan; Jill Thompson; Betsy Von Holle; Jackson R. Webster

2005-01-01

In many forested ecosystems, the architecture and functional ecology of certain tree species define forest structure and their species-specific traits control ecosystem dynamics. Such foundation tree species are declining throughout the world due to introductions and outbreaks of pests and pathogens, selective removal of individual taxa, and over-harvesting. Through a...

25+ year changes in forest structure and tree-ring patterns in three old-growth red spruce stands in West Virginia

Treesearch

Eric Heitzman; Sean Doughterty; James Rentch; Steve Adams; Steve. Stephenson

2010-01-01

The extent of red spruce (Picea rubens) forests in West Virginia has dramatically declined from an estimated 1.5 million acres in 1865 to 30,000 acres today because of widespread logging and forest fires during the late 1800s and early 1900s.

Mangroves among the most carbon-rich forests in the tropics

Treesearch

Daniel. C. Donato; J. Boone Kauffman; Daniel Murdiyarso; Sofyan Kurnianto; Melanie Stidham; Markku Kanninen

2011-01-01

Mangrove forests occur along ocean coastlines throughout the tropics, and support numerous ecosystem services, including fisheries production and nutrient cycling. However, the areal extent of mangrove forests has declined by 30–50% over the past half century as a result of coastal development, aquaculture expansion and over-harvesting. Carbon emissions resulting from...

Small-diameter success stories III.

Treesearch

Jean Livingston

2008-01-01

More than 73 million acres of our national forests and millions more in public and private forestlands are in need of some form of restoration. Our forests are declining in health because of major changes over the years in forest structure and composition. However, restoration of these overstocked stands is extremely expensive. If new, economical, and value-added uses...

An Afforestation System for Restoring Bottomland Hardwood Forests: Biomass Accumulation of Nuttall Oak Seedlings Interplanted Beneath Eastern Cottonwood

Treesearch

Emile S. Gardiner; John A. Stanturf; Callie J. Schweitzer

2004-01-01

Bottomland hardwood forests of the southeastern United States have declined in extent since European settlement. Forest restoration activities over the past decade, however, have driven recent changes in land use through an intensified afforestation effort on former agricultural land. This intense afforestation effort, particularly in the Lower Mississippi Alluvial...

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...

Simulated nitrogen deposition affects community structure of arbuscular mycorrhizal fungi in northern hardwood forests

Treesearch

Linda T.A. Van Diepen; Erik Lilleskov; Kurt S. Pregitzer

2011-01-01

Our previous investigation found elevated nitrogen deposition caused declines in abundance of arbuscular mycorrhizal fungi (AMF) associated with forest trees, but little is known about how nitrogen affects the AMF community composition and structure within forest ecosystems. We hypothesized that N deposition would lead to significant changes in the AMF community...

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...

Opportunities for conservation-based development of nontimber forest products in the Pacific Northwest.

Treesearch

Bettina von Hagen; Roger D. Fight

1999-01-01

Declines in timber harvests on public lands and new market opportunities have rekindled an interest in nontimber forest products. Such products as edible mushrooms, medicinal plants, and floral and holiday greens provide alternative sources of revenue and employment for rural communities. This paper describes and analyzes the contribution of the nontimber forest...

Urban forest sustainability in the United States

Treesearch

David J. Nowak

2017-01-01

Urban forests in the United States provide numerous ecosystem services that vary in magnitude across the country and are valued in the billions of dollars per year. Urban tree cover has been on the decline in recent years. Numerous forces for change will continue to alter urban forests in the coming years (i.e., development, climate change, insects and diseases,...

Risk of genetic maladaptation due to climate change in three major European tree species

Treesearch

Aline Frank; Glenn T. Howe; Christoph Sperisen; Peter Brang; Brad St. Clair; Dirk R. Schmatz; Caroline Heiri

2017-01-01

Tree populations usually show adaptations to their local environments as a result of natural selection. As climates change, populations can become locally maladapted and decline in fitness. Evaluating the expected degree of genetic maladaptation due to climate change will allow forest managers to assess forest vulnerability, and develop strategies to preserve forest...

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…

Relationships between forest songbird populations and managed forests in Idaho

Treesearch

Diane M. Evans; Deborah M. Finch

1994-01-01

Many species of songbirds have experienced population declines. In the eastern U.S. in recent years, but conclusive data on population trends and factors affecting populations in the West are lacking. Few studies have evaluated the importance of surrounding land configuration to songbird abundances. In 1992, we initiated a study in mixed conifer forest in west-central...

Evaluating the Impact of Forest Schools: A Collaboration between a University and a Primary School

ERIC Educational Resources Information Center

Slade, Melanie; Lowery, Claire; Bland, Ken

2013-01-01

The Forest School movement, an important part of education in Scandinavia, has gained momentum in the UK in recent years. Within the context of declining access to, and engagement with, the natural environment Forest Schools can provide invaluable life experiences for our children. In 2012 the University of Northampton investigated opportunities…

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...

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...

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...

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...

Forest aging, disturbance and the carbon cycle.

PubMed

Curtis, Peter S; Gough, Christopher M

2018-05-16

Contents Summary I. Introduction II. Forest aging and carbon storage III. Successional trends of NEP in northern deciduous forests IV. Mechanisms sustaining NEP in aging deciduous forests Acknowledgements References SUMMARY: Large areas of forestland in temperate North America, as well as in other parts of the world, are growing older and will soon transition into middle and then late successional stages exceeding 100 yr in age. These ecosystems have been important regional carbon sinks as they recovered from prior anthropogenic and natural disturbance, but their future sink strength, or annual rate of carbon storage, is in question. Ecosystem development theory predicts a steady decline in annual carbon storage as forests age, but newly available, direct measurements of forest net CO 2 exchange challenge that prediction. In temperate deciduous forests, where moderate severity disturbance regimes now often prevail, there is little evidence for any marked decline in carbon storage rate during mid-succession. Rather, an increase in physical and biological complexity under these disturbance regimes may drive increases in resource-use efficiency and resource availability that help to maintain significant carbon storage in these forests well past the century mark. Conservation of aging deciduous forests may therefore sustain the terrestrial carbon sink, whilst providing other goods and services afforded by these biologically and structurally complex ecosystems. © 2018 The Authors. New Phytologist © 2018 New Phytologist Trust.

Tracking forest cover change of Margalla Hills over a period of two decades (1992-2011): A remote sensing perspective

NASA Astrophysics Data System (ADS)

Khalid, Noora; Ullah, Saleem

2016-07-01

Forests play a critical role in balancing the ecological soundness of a region and in the facilitation of essential forest resources. Depletion of forest cover is a serious environmental problem throughout the world including Pakistan where a striking degradation of forest reserves has been an ecological concern for quite some time. Remote sensing techniques have been used to monitor land use and forest cover changes. The present study aims at exploring the potential impacts of climate change in the decline of forest reserves on Margalla Hills National Park (MHNP), since it remains the primary culprit behind this depletion. Landsat images for 1992, 2000 and 2011 were manipulated for the spatial and temporal analysis, interpretation and computation of the change and shift that has occurred over the past two decades. The analysis revealed a great increase in the built-up area, barren soil and agricultural land. Though other classes such as water body, lower vegetation, scrub and conifer forest showed a diminishing trend. The rise in temperature and relative humidity, the depletion in annual precipitation, frequent wild fires and the boost in urbanization and agricultural practices are the climatic conditions and causative agents chiefly responsible for the decline shown by the vegetation of the area. The degrading condition of the forest is below par and requires conservation practices to be carried out in order to avoid ecological disturbances.

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.

Forest nutrient and carbon pools at Walker Branch watershed: changes during a 21-year period

Treesearch

Carl C. Trettin; D.W. Johnson; D.E. Todd

1999-01-01

A 21-yr perspective on changes in nutrient and C pools on undisturbed upland forest sites is provided. Plots originally representing four cover types have been sampled three times. On each plot, forest biomass, forest floor, and soil, to a depth of 60 cm, were measured, sampled, and analyzed for Ca, Mg, C, N, and P. Exchangeable soil Ca and Mg have declined in most...

Status of oak seedlings and saplings in the northern United States: implications for sustainability of oak forests

Treesearch

Chris W. Woodall; Randall S. Morin; Jim R. Steinman; Charles H. Perry

2008-01-01

Oak species are a substantial component of forest ecosystems in a 24-state region spanning the northern U.S. During recent decades, it has been documented that the health of oak forests has been experiencing large-scale decline. To further evaluate the sustainability of oak forests in nearly half the states of the U.S., the current status of oak seedlings and saplings...

Progressive Decline in Photosynthetic Uptake Capacity in a Hemlock Stand Infested by Hemlock Woolly Adelgid

NASA Astrophysics Data System (ADS)

Munger, J. W.; David, O.; Barker Plotkin, A.; Schaaf, C.

2017-12-01

Hemlock Woolly Adelgid (HWA) is an invasive insect pest infesting eastern hemlock. Affected hemlock trees typically die within 4-10 years. Black birch seedlings thrive as a thinning canopy allows additional light to reach the forest floor. HWA invasion is a unique disturbance where decline and recovery are occuring simultaneously over an extended period. Although the overall vegetation dynamics associated with HWA disturbance have been well studied, the instantaneous carbon balance at the ecosystem scale has not been closely observed. At the Harvard Forest in central MA we have measured CO2, water and energy eddy flux since 2004. HWA has been present at Harvard Forest since 2002, but defoliation was insignificant prior to 2010. Since 2010 defoliation among trees near the Hemlock tower has increased dramatically and tree mortality is increasing. The pace of HWA attack has been monitored by periodic surveys and stand structure has been observed by 3-d lidar scans. In order to quantify changes in ecosystem metabolism without biasing the results from data filling we evaluate mean ecosystem function derived from a simple model that relates CO2 flux to temperature and light response. The mean carbon uptake efficiency during summer growing season has declined about 13% from before 2010 (pre-HWA) to after 2010 (post-HWA). Ecosystem respiration averaged over these intervals has not changed noticeably over this period. However, annual mean Reco in the summer peaks in 2014 and then declines over subsequent years. Mean uptake coefficients declined from 26 to 14 μmol-C m-2s-1 per μmol-photon m-2s-1 between 2010 and 2015, with some recovery in 2016. Taken together, results show that despite an accelerating forest mortality, ecosystem carbon stock in this infested hemlock stand has not been destabilized and that rates of carbon metabolism are changing more slowly than the decline in hemlock biomass. The ecosystem can partially compensate for loss of foliage as more light reaches previously shaded needles and new seedlings emerge in open gaps. However, we anticipate a shift in carbon uptake phenology as the fraction of deciduous vegetation increases. Ongoing mortality will add to the large carbon stock in the forest floor, but as yet there has not been a detectable change in rates of whole-ecosystem respiration.

Habitat Effects on the Breeding Performance of Three Forest-Dwelling Hawks.

PubMed

Björklund, Heidi; Valkama, Jari; Tomppo, Erkki; Laaksonen, Toni

2015-01-01

Habitat loss causes population declines, but the mechanisms are rarely known. In the European Boreal Zone, loss of old forest due to intensive forestry is suspected to cause declines in forest-dwelling raptors by reducing their breeding performance. We studied the boreal breeding habitat and habitat-associated breeding performance of the northern goshawk (Accipiter gentilis), common buzzard (Buteo buteo) and European honey buzzard (Pernis apivorus). We combined long-term Finnish bird-of-prey data with multi-source national forest inventory data at various distances (100-4000 m) around the hawk nests. We found that breeding success of the goshawk was best explained by the habitat within a 2000-m radius around the nests; breeding was more successful with increasing proportions of old spruce forest and water, and decreasing proportions of young thinning forest. None of the habitat variables affected significantly the breeding success of the common buzzard or the honey buzzard, or the brood size of any of the species. The amount of old spruce forest decreased both around goshawk and common buzzard nests and throughout southern Finland in 1992-2010. In contrast, the area of young forest increased in southern Finland but not around hawk nests. We emphasize the importance of studying habitats at several spatial and temporal scales to determine the relevant species-specific scale and to detect environmental changes. Further effort is needed to reconcile the socioeconomic and ecological functions of forests and habitat requirements of old forest specialists.

The variation of productivity and its allocation along a tropical elevation gradient: a whole carbon budget perspective.

PubMed

Malhi, Yadvinder; Girardin, Cécile A J; Goldsmith, Gregory R; Doughty, Christopher E; Salinas, Norma; Metcalfe, Daniel B; Huaraca Huasco, Walter; Silva-Espejo, Javier E; Del Aguilla-Pasquell, Jhon; Farfán Amézquita, Filio; Aragão, Luiz E O C; Guerrieri, Rossella; Ishida, Françoise Yoko; Bahar, Nur H A; Farfan-Rios, William; Phillips, Oliver L; Meir, Patrick; Silman, Miles

2017-05-01

Why do forest productivity and biomass decline with elevation? To address this question, research to date generally has focused on correlative approaches describing changes in woody growth and biomass with elevation. We present a novel, mechanistic approach to this question by quantifying the autotrophic carbon budget in 16 forest plots along a 3300 m elevation transect in Peru. Low growth rates at high elevations appear primarily driven by low gross primary productivity (GPP), with little shift in either carbon use efficiency (CUE) or allocation of net primary productivity (NPP) between wood, fine roots and canopy. The lack of trend in CUE implies that the proportion of photosynthate allocated to autotrophic respiration is not sensitive to temperature. Rather than a gradual linear decline in productivity, there is some limited but nonconclusive evidence of a sharp transition in NPP between submontane and montane forests, which may be caused by cloud immersion effects within the cloud forest zone. Leaf-level photosynthetic parameters do not decline with elevation, implying that nutrient limitation does not restrict photosynthesis at high elevations. Our data demonstrate the potential of whole carbon budget perspectives to provide a deeper understanding of controls on ecosystem functioning and carbon cycling. © 2016 The Authors. New Phytologist © 2016 New Phytologist Trust.

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.

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.

Medium density fiberboard made from Eucalyptus saligna

Treesearch

Andrzej M. Krzysik; James H. Muehl; John A. Youngquist; Fabio Spina Franca

2001-01-01

The production of industrial wood from natural forests is predicted to decline in the future. Factors that will contribute to this decline include changes in land use patterns, depletion of resources in some parts of the world, and the withdrawal of...

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 management of forest carbon, changing climate and species biodiversity. PMID:28225787

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 management of forest carbon, changing climate and species biodiversity.

Emerald ash borer aftermath forests: The dynamics of ash mortality and the responses of other plant species

Treesearch

Kathleen S. Knight; Daniel A. Herms; John Cardina; Robert Long; Joanne Rebbeck; Kamal J.K. Gandhi; Annemarie Smith; Wendy S. Klooster; Catherine P. Herms; Alejandro A. Royo

2010-01-01

The effects of emerald ash borer (EAB) (Agrilus planipennis) on forest ecosystems are being studied through a collaborative research program involving the U.S. Forest Service's Northern Research Station and The Ohio State University. We are monitoring the decline and mortality of >4,500 ash trees and saplings, EAB population density, changes...

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...

Ectomycorrhizal fungal succession coincides with shifts in organic nitrogen availability and canopy closure in post-wildfire jack pine forests

Treesearch

Stephen D. LeDuc; Erik A. Lilleskov; Thomas R. Horton; David E. Rothstein

2013-01-01

Successional changes in belowground ectomycorrhizal fungal (EMF) communities have been observed with increasing forest stand age; however, mechanisms behind this change remain unclear. It has been hypothesized that declines of inorganic nitrogen (N) and increases of organic N influence changes in EMF taxa over forest development. In a post-wildfire chronosequence of...

Ecosystem transformation by emerging infectious disease: loss of large tanoak from California forests

Treesearch

Richard C. Cobb; Joao A.N. Filipe; Ross K. Meentemeyer; Christopher A. Gilligan; David M. Rizzo

2012-01-01

1. Few pathogens are the sole or primary cause of species extinctions, but forest disease has caused spectacular declines in North American overstorey trees and restructured forest ecosystems at large spatial scales over the past 100 years. These events threaten biodiversity associated with impacted host trees and other resources valued by human societies even when...

Changes in early-successional hardwood forest area in four bird conservation regions across four decades

Treesearch

Sonja N. Oswalt; Kathleen E. Franzreb; David A. Buehler

2012-01-01

Early successional hardwood forests constitute important breeding habitat for many migratory songbirds. Declines in populations of these species suggest changes in habitat availability either on the species’ wintering grounds or on their early successional breeding grounds. We used Forest Inventory and Analysis data from 11 states across four decades to examine changes...

Biodiversity conservation in the face of dramatic forest disease: an integrated conservation strategy for tanoak (Notholithocarpus densiflorus) threatened by sudden oak death

Treesearch

Richard C. Cobb; David M. Rizzo; Katherine J. Hayden; Matteo Garbelotto; A.N. Filipe João; Christopher A. Gilligan; Whalen W. Dillon; Ross K. Meentemeyer; Yana S. Vlachovic; Ellen Goheen; Tedmund J. Swiecki; Everett M. Hansen; Susan J. Frankel

2013-01-01

Non-native diseases of dominant tree species have diminished North American forest biodiversity, structure, and ecosystem function over the last 150 years. Since the mid-1990s, coastal California forests have suffered extensive decline of the endemic overstory tree tanoak, Notholithocarpus densiflorus (Hook. & Arn.) Manos, Cannon & S. H. Oh...

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...

Seventy years of understory development by elevation class in a New Hampshire mixed forest: management implications

Treesearch

William B. Leak

2009-01-01

New England forest managers are faced with numerous environmental issues, such as global warming, nutrient depletion, and species declines that could influence the choice of appropriate silvicultural techniques and objectives. On the Bartlett Experimental Forest, New Hampshire, 70 years of change on more than 400 remeasured cruise plots by elevation classes ranging...

Developing and managing sustainable forest ecosystems for spotted owls in the Sierra Nevada

Treesearch

J. Verner; K.S. McKelvey

1994-01-01

Studies of the California spotted owl have revealed significant selection for habitats with large, old trees; relatively high basal areas of snags; and relatively high biomass in large, downed logs. Based on planning documents for national forests in the Sierra Nevada, we projected declining amounts of older-forest attributes. Region 5 has adopted measures to retain...

The cost of acquiring public hunting access on family forests lands

Treesearch

Michael A. Kilgore; Stephanie A. Snyder; Joesph M. Schertz; Steven J. Taff

2008-01-01

To address the issue of declining access to private forest land in the United States for hunting, over 1,000 Minnesota family forest owners were surveyed to estimate the cost of acquiring non-exclusive public hunting access rights. The results indicate landowner interest in selling access rights is extremely modest. Using binary logistic regression, the mean annual...

Productivity of early successional shrubland birds in clearcuts and groupcuts in an eastern deciduous forest

Treesearch

David I. King; Richard M. DeGraaf; Curtice R. Griffin

2001-01-01

Uneven-aged forest management has been advocated as a silvicultural practice because of concerns about the negative effects of even-aged management on birds that dwell in mature forests. Recent evidence, however, indicates that in the northeastern United States, bird species that inhabit early successional habitats may be experiencing more widespread declines than...

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...

An Interim Old-Growth Definition for Cypress-Tupelo Communities in the Southeast

Treesearch

Margaret S. Devall

1998-01-01

Forested wetlands [cypress-tupelo (Taxodium spp.-llryssa spp.)] as well as some bottomland hardwood forests, are of increasing interest in the South. They are important in water management, wildlife conservation, habitat diversity, and high quality timber (Ewe1 and Odom 1984). The acreage of such forests in the region has declined dramatically; for example, at the time...

Spruce-fir forest changes during a 30-year nitrogen saturation experiment

Treesearch

Steven G. McNulty; Johnny L. Boggs; John D. Aber; Lindsey E. Rustad

2017-01-01

A field experiment was established in a high elevation red spruce (Picea rubens Sarg.) – balsam fir (Abies balsamea) forest on Mount Ascutney Vermont, USA in 1988 to test the nitrogen (N) saturation hypothesis, and to better understand the mechanisms causing forest decline at the time. The study established replicate control, lowand high dose nitrogen addition plots (i...

Ecophysiology of seedling establishment in contrasting spruce-fir forests of southern Appalachian and Rocky Mountain ecotones, USA

Treesearch

William K. Smith; Keith N.C. Reinhardt; Daniel M. Johnson

2010-01-01

Fraser fir (Abies fraseri [Pursh] Poiret) and red spruce (Picea rubens Sarg.) occur as codominant trees in six relic, mountain-top populations that make up the high-elevation forests of the Southern Appalachian Mountains (SA). These two relic species of the former boreal forest have experienced a significant decline over the past...

Trends in snag populations in Northern Arizona mixed-conifer and ponderosa pine forests, 1997-2012

Treesearch

J. L. Ganey; S. C. Vojta

2014-01-01

We monitored snag populations in drought-stressed mixed-conifer and ponderosa pine (Pinus ponderosa) forests, northern Arizona, at 5-yr intervals from 1997-2012. Snag density increased from 1997-2007 in both forest types, with accelerated change due to drought-related tree mortality during the period 2002-2007. Snag density declined non-significantly from 2007-2012,...

Persistent effects of a severe drought on Amazonian forest canopy

PubMed Central

Saatchi, Sassan; Asefi-Najafabady, Salvi; Malhi, Yadvinder; Aragão, Luiz E. O. C.; Anderson, Liana O.; Myneni, Ranga B.; Nemani, Ramakrishna

2013-01-01

Recent Amazonian droughts have drawn attention to the vulnerability of tropical forests to climate perturbations. Satellite and in situ observations have shown an increase in fire occurrence during drought years and tree mortality following severe droughts, but to date there has been no assessment of long-term impacts of these droughts across landscapes in Amazonia. Here, we use satellite microwave observations of rainfall and canopy backscatter to show that more than 70 million hectares of forest in western Amazonia experienced a strong water deficit during the dry season of 2005 and a closely corresponding decline in canopy structure and moisture. Remarkably, and despite the gradual recovery in total rainfall in subsequent years, the decrease in canopy backscatter persisted until the next major drought, in 2010. The decline in backscatter is attributed to changes in structure and water content associated with the forest upper canopy. The persistence of low backscatter supports the slow recovery (>4 y) of forest canopy structure after the severe drought in 2005. The result suggests that the occurrence of droughts in Amazonia at 5–10 y frequency may lead to persistent alteration of the forest canopy. PMID:23267086

Mathematical model of forest succession and land use for the North Carolina Piedmont

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

Johnson, W.C.

1977-01-01

A linear, constant-coefficient compartment model was constructed to simulate temporal changes in the areal extent of major forest types in the North Carolina Piedmont. Model structure and transfer coefficients were derived from published ecological literature and available USDA Forest Service statistical summaries. The results show the importance of old-field abandonment to the perpetuation of extensive loblolly pine (Pinus taeda) forests in the Piedmont. Should abandonment cease, post-harvest treatment and planting of loblolly pine would have to be increased considerably over current levels to maintain an extensive loblolly pine forest type. Extrapolation of current rates of change forward 250 years wouldmore » result in a sizeable increase in the area of loblolly pine and loblolly pine-oak types, a slight increase in oak-hickory, a sizeable decline in shortleaf and Virginia pine (Pinus echinata, Pinus virginiana, resp.) types and a slight decline for other mixed pine-hardwood and lowland and dry upland hardwood categories compared to current conditions. The technique can be a useful tool either to assess some long-term effects of present management and use trends or to suggest strategies necessary to obtain a desired regional mixture of forest types.« less

Long-term trends in breeding birds in an old-growth Adirondack forest and the surrounding region

USGS Publications Warehouse

McNulty, S.A.; Droege, S.; Masters, R.D.

2008-01-01

Breeding bird populations were sampled between 1954 and 1963, and 1990 and 2000 in an old-growth forest, the Natural Area of Huntington Wildlife Forest (HWF), in the Adirondack Mountains of New York. Trends were compared with data from regional North American Breeding Bird Surveys (BBS) and from a forest plot at Hubbard Brook Experimental Forest, New Hampshire. Trends for 22 species in the HWF Natural Area were negative, eight were positive, and one was zero; 20 were significant. Fifteen of 17 long-distance migrants declined, whereas 7 of 14 short-distance migrants and permanent residents declined. Most (74%) HWF Natural Area species, despite differences in sampling periods and local habitat features, matched in sign of trend when compared to Adirondack BBS routes, 61% matched northeastern BBS routes, and 71% matched eastern United States BBS routes, while 66% matched Hubbard Brook species. The agreement in population trends suggests that forest interior birds, especially long-distance migrants, are affected more by regional than local factors. The analysis indicated that bird trends generated from BBS routes may not be as biased toward roads as previously suggested.

Avian malaria Plasmodium relictum in native Hawaiian forest birds: epizootiology and demographic impacts on ‵apapane Himatione sanguinea

USGS Publications Warehouse

Atkinson, Carter T.; Samuel, Michael D.

2010-01-01

The role of introduced avian malaria Plasmodium relictum in the decline and extinction of native Hawaiian forest birds has become a classic example of the potential effect of invasive diseases on biological diversity of naïve populations. However, empirical evidence describing the impact of avian malaria on fitness of Hawai‵i's endemic forest birds is limited, making it difficult to determine the importance of disease among the suite of potential limiting factors affecting the distribution and abundance of this threatened avifauna. We combined epidemiological force-of-infection with multistate capture––recapture models to evaluate a 7-year longitudinal study of avian malaria in ‵apapane, a relatively common native honeycreeper within mid-elevation Hawaiian forests. We found that malaria transmission was seasonal in this mid-elevation forest; transmission peaked during fall and during some years produced epizootic mortality events. Estimated annual mortality of hatch-year birds typically exceeded 50% and mortality of adults exceeded 25% during epizootics. The substantial impact of avian malaria on this relatively common native species demonstrates the key role this disease has played in the decline and extinction of Hawaiian forest birds.

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...

Sugarberry Dieback and Mortality in Southern Louisiana: Cause, Impact, and Prognosis

Treesearch

J.D. Solomon; A. Dan Wilson; Theodor D. Leininger; D.G. Lester; C.S. McCasland; S. Clarke; C. Affeltranger

1997-01-01

A sudden widespread decline of sugarberry trees (Celfis laevigufu) was observed in southern Louisiana during the period between the early fall of 1988 and spring of 1990. Approximately 3 million acres or 5,000 square miles of forested lands were affected by the decline. In addition, sporadic reports of sugarberry decline also were reported at numerous locations in...

Temperature and rainfall interact to control carbon cycling in tropical forests.

PubMed

Taylor, Philip G; Cleveland, Cory C; Wieder, William R; Sullivan, Benjamin W; Doughty, Christopher E; Dobrowski, Solomon Z; Townsend, Alan R

2017-06-01

Tropical forests dominate global terrestrial carbon (C) exchange, and recent droughts in the Amazon Basin have contributed to short-term declines in terrestrial carbon dioxide uptake and storage. However, the effects of longer-term climate variability on tropical forest carbon dynamics are still not well understood. We synthesised field data from more than 150 tropical forest sites to explore how climate regulates tropical forest aboveground net primary productivity (ANPP) and organic matter decomposition, and combined those data with two existing databases to explore climate - C relationships globally. While previous analyses have focused on the effects of either temperature or rainfall on ANPP, our results highlight the importance of interactions between temperature and rainfall on the C cycle. In cool forests (< 20 °C), high rainfall slowed rates of C cycling, but in warm tropical forests (> 20 °C) it consistently enhanced both ANPP and decomposition. At the global scale, our analysis showed an increase in ANPP with rainfall in relatively warm sites, inconsistent with declines in ANPP with rainfall reported previously. Overall, our results alter our understanding of climate - C cycle relationships, with high precipitation accelerating rates of C exchange with the atmosphere in the most productive biome on earth. © 2017 John Wiley & Sons Ltd/CNRS.

Forest age-induced changes in evapotranspiration and water yield in a eucalypt forest

NASA Astrophysics Data System (ADS)

Cornish, P. M.; Vertessy, R. A.

2001-02-01

Water yields in a regrowth eucalypt forest were found to increase initially and then to decline below pre-treatment levels during the 16-year period which followed the logging of a moist old-growth eucalypt forest in Eastern Australia. Both regrowth and old-growth stands were dominated by Sydney Blue Gum ( Eucalyptus saligna Smith) and Silvertop Stringybark ( Eucalyptus laevopinea R. Baker). Using a paired-catchment approach we observed significant reductions in five of six gauged catchments, and were able to associate their magnitude with forest growth rate, canopy cover and soil depth. Regular yield declines were interrupted for a period in some catchments, possibly due to foliar insect attack. Yield reductions of up to a maximum 600 mm per year in logged and regenerated areas were in accord with water yield reductions observed in Mountain Ash ( Eucalyptus regnans F.J. Muell.) regeneration in Victoria. This study therefore represents the first confirmation of these Maroondah Mountain Ash results in another forest type that has also undergone eucalypt-to-eucalypt succession. Baseflow analysis indicated that baseflow and stormflow both increased after logging, with stormflow increases dominant in catchments with shallower soils. The lower runoff observed when the regenerating forest was aged 13-16 years was principally a consequence of lower baseflow.

Dependence of hydropower energy generation on forests in the Amazon Basin at local and regional scales.

PubMed

Stickler, Claudia M; Coe, Michael T; Costa, Marcos H; Nepstad, Daniel C; McGrath, David G; Dias, Livia C P; Rodrigues, Hermann O; Soares-Filho, Britaldo S

2013-06-04

Tropical rainforest regions have large hydropower generation potential that figures prominently in many nations' energy growth strategies. Feasibility studies of hydropower plants typically ignore the effect of future deforestation or assume that deforestation will have a positive effect on river discharge and energy generation resulting from declines in evapotranspiration (ET) associated with forest conversion. Forest loss can also reduce river discharge, however, by inhibiting rainfall. We used land use, hydrological, and climate models to examine the local "direct" effects (through changes in ET within the watershed) and the potential regional "indirect" effects (through changes in rainfall) of deforestation on river discharge and energy generation potential for the Belo Monte energy complex, one of the world's largest hydropower plants that is currently under construction on the Xingu River in the eastern Amazon. In the absence of indirect effects of deforestation, simulated deforestation of 20% and 40% within the Xingu River basin increased discharge by 4-8% and 10-12%, with similar increases in energy generation. When indirect effects were considered, deforestation of the Amazon region inhibited rainfall within the Xingu Basin, counterbalancing declines in ET and decreasing discharge by 6-36%. Under business-as-usual projections of forest loss for 2050 (40%), simulated power generation declined to only 25% of maximum plant output and 60% of the industry's own projections. Like other energy sources, hydropower plants present large social and environmental costs. Their reliability as energy sources, however, must take into account their dependence on forests.

What caused the population decline of the Bridled White-eye on Rota, Mariana Islands?

USGS Publications Warehouse

Fancy, Steven G.; Snetsinger, Thomas J.

2001-01-01

The Bridled White-eye (Zosterops conspicillatus rotensis) was Once thought to be common and widespread on Rota, Commonwealth of the Northern Mariana Islands, but is now restricted to several patches of native limestone forest in and adjacent to the Sabana region. Surveys conducted in 1990 indicated that the population had declined by 87% between 1982 and 1990 for unknown reasons. The low density and restricted habitat association of the Bridled White-eye on Rota contrasts with the situation on Saipan, Tinian, Agiguan, and formerly on Guam, where the Bridled White-eye is the most common forest bird and occurs at all elevations and in all habitat types. We surveyed the entire range of the Rota Bridled White-eye in 1996 to estimate its current numbers and distribution. We also reviewed existing information on the white-eye and evaluated potential causes of its decline, including predation by Black Drongos (Dicrurus macrocercus), rats (Rattus spp.), and the brown tree snake Boiga irregularis); pesticides; avian disease; and habitat loss and alteration. We found that 94% of the extant population of 1,165 white-eyes on Rota was restricted to four patches of old-growth, native limestone forest covering only 259 ha. We believe that the population decline and current localized distribution is primarily a result of habitat changes due to agricultural development and typhoons, but the absence of white-eyes from several stands of native forest above 200 m remains unexplained. The Rota white-eye may be a different species from white-eyes found on Saipan, Tinian, Agiguan, and Guam, with different habitat preferences.

Carbon in the Former Soviet Union: The Current Balance

NASA Technical Reports Server (NTRS)

Woodwell, G. M.; Stone, T. A.; Houghton, R. A.

1997-01-01

This work has been carried out in a period of great changes in Russia that have brought extreme hardships to the scientific community. We have been fortunate in establishing excellent relationships with the Russian scientific community and believe we have helped to retain coherence in circumstances where the continuation of research was in doubt. We have learned much and have been effective in advancing, even establishing, scholars and programs in Russia that might not otherwise have survived the transition. The vigor of the International Boreal Forest Research Association (IBFRA) is one sign of the value and success of these activities. Largely due to the current political and economic transitions in the former Soviet Union, the forests of much of the FSU are under reduced logging pressure. In addition, there is a decline in air pollution as heavy industry has waned, at least for now. Russian forestry statistics and our personal experience indicate a decline, perhaps as high as 60%, in forest harvesting over the last few years. But, new international market pressures on the forests exist in European Russia and in the Far East. The central government, still the "owner" of Russian forests, is having difficulty maintaining control over forest use and management particularly in the Far East and among the southern territories that have large, nonRussian ethnic populations. Extraordinarily large areas of mixed forest and grasslands, sparse or open forests, and mixed forests and tundra must be considered when calculating forest area It is insufficient to think of Russia as simply forest and nonforest Forest productivity, measured as growth of timber, appears to be in decline in all areas of Russia except in European Russia. Most information and publications on the recent history of these forests is heavily dependent on statistical data from the Soviet era. The interpretation of these data is very much open to debate. Anatoly Shwidenko, a long term collaborator and former senior scientist (mensuration) for the Soviet Committee on Forests, now a scholar at the International Institute of Applied Systems Analysis (IIASA), Vienna, has provided abundant contributions from the data available to him and from his experience. Forest stand carbon is concentrated in the Russian Far East (i.e. Primorski Kray), Central-Southern Siberia and European Russia But, soil carbon can be 10 times forest stand C. Our efforts in mapping the area and changes in area (as well as the internal structure) of forests have made major contributions to our joint understanding of the scale and status of these forests. To realize the importance of this contribution one needs only to recognize that any large scale Soviet-era maps of the area did not include latitude and longitude. Even today, there is great reluctance to provide these data, the basis of any GIS.

Forest carbon emissions from cropland expansion in the Brazilian Cerrado biome

NASA Astrophysics Data System (ADS)

Noojipady, Praveen; Morton, C. Douglas; Macedo, N. Marcia; Victoria, C. Daniel; Huang, Chengquan; Gibbs, K. Holly; Edson Bolfe, L.

2017-02-01

Land use, land use change, and forestry accounted for two-thirds of Brazil’s greenhouse gas emissions profile in 2005. Amazon deforestation has declined by more than 80% over the past decade, yet Brazil’s forests extend beyond the Amazon biome. Rapid expansion of cropland in the neighboring Cerrado biome has the potential to undermine climate mitigation efforts if emissions from dry forest and woodland conversion negate some of the benefits of avoided Amazon deforestation. Here, we used satellite data on cropland expansion, forest cover, and vegetation carbon stocks to estimate annual gross forest carbon emissions from cropland expansion in the Cerrado biome. Nearly half of the Cerrado met Brazil’s definition of forest cover in 2000 (≥0.5 ha with ≥10% canopy cover). In areas of established crop production, conversion of both forest and non-forest Cerrado formations for cropland declined during 2003-2013. However, forest carbon emissions from cropland expansion increased over the past decade in Matopiba, a new frontier of agricultural production that includes portions of Maranhão, Tocantins, Piauí, and Bahia states. Gross carbon emissions from cropland expansion in the Cerrado averaged 16.28 Tg C yr-1 between 2003 and 2013, with forest-to-cropland conversion accounting for 29% of emissions. The fraction of forest carbon emissions from Matopiba was much higher; between 2010-2013, large-scale cropland conversion in Matopiba contributed 45% of total Cerrado forest carbon emissions. Carbon emissions from Cerrado-to-cropland transitions offset 5%-7% of the avoided emissions from reduced Amazon deforestation rates during 2011-2013. Comprehensive national estimates of forest carbon fluxes, including all biomes, are critical to detect cross-biome leakage within countries and achieve climate mitigation targets to reduce emissions from land use, land use change, and forestry.

Suggestions for Forest Conservation Policy under Climate Change

NASA Astrophysics Data System (ADS)

Choe, H.; Thorne, J. H.; Lee, D. K.; Seo, C.

2015-12-01

Climate change and the destruction of natural habitats by land-use change are two main factors in decreasing terrestrial biodiversity. Studying land-use and climate change and their impact under different scenarios can help suggest policy directions for future events. This study explores the spatial results of different land use and climate models on the extent of species rich areas in South Korea. We built land use models of forest conversion and created four 2050 scenarios: (1) a loss trend following current levels, resulting in 15.5% lost; (2) similar loss, but with forest conservation in areas with suitable future climates; (3) a reduction of forest loss by 50%; and (4) a combination of preservation of forest climate refugia and overall reduction of loss by 50%. Forest climate refugia were identified through the use of species distribution models run on 1,031 forest plant species to project current and 2050 distributions. We calculated change in species richness under four climate projections, permitting an assessment of forest refugia zones. We then crossed the four land use models with the climate-driven change in species richness. Forest areas predominantly convert to agricultural areas, while climate-suitable extents for forest plants decline and move northward, especially to higher elevations. Scenario 2, that has the higher level of deforestation but protects future species rich areas, conserves nearly as much future biodiversity as scenario 3, which reduced deforestation rates by 50%. This points to the importance of including biogeographic climate dynamics in forest policy. Scenario 4 was the most effective at conserving forest biodiversity. We suggest conserving forest areas with suitable climates for biodiversity conservation and the establishment of monoculture plantations targeted to areas where species richness will decline based on our results.

Long-term monitoring reveals an avian species credit in secondary forest patches of Costa Rica

PubMed Central

Brouwer, Nathan L.; Olivieri, Alison; Girard-Woolley, Julie; Richardson, Judy F.

2017-01-01

Degraded and secondary forests comprise approximately 50% of remaining tropical forest. Bird community characteristics and population trends in secondary forests are infrequently studied, but secondary forest may serve as a “safety net” for tropical biodiversity. Less understood is the occurrence of time-delayed, community-level dynamics such as an extinction debt of specialist species or a species credit resulting from the recolonization of forest patches by extirpated species. We sought to elucidate patterns and magnitudes of temporal change in avian communities in secondary forest patches in Southern Costa Rica biannually over a 10 year period during the late breeding season and mid-winter. We classified birds caught in mist nets or recorded in point counts by residency status, and further grouped them based on preferred habitat, sensitivity to disturbance, conservation priority, foraging guild, and foraging strata. Using hierarchical, mixed-effects models we tested for trends among species that share traits. We found that permanent-resident species increased over time relative to migrants. In both seasons, primary forest species generally increased while species typical of secondary forest, scrub, or edge declined. Species relatively sensitive to habitat disturbance increased significantly over time, whereas birds less sensitive to disturbance decreased. Similarly, generalists with higher habitat breadth scores declined. Because, we found very few changes in vegetation characteristics in secondary forest patches, shifts in the avian community toward primary forest species represent a species credit and are likely related to vegetation changes in the broader landscape. We suggest that natural regeneration and maturation of secondary forests should be recognized as a positive conservation development of potential benefit even to species typical of primary forest. PMID:28674671

Synergistic Ecoclimate Teleconnections from Forest Loss in Different Regions Structure Global Ecological Responses

PubMed Central

Garcia, Elizabeth S.; Swann, Abigail L. S.; Villegas, Juan C.; Breshears, David D.; Law, Darin J.; Saleska, Scott R.; Stark, Scott C.

2016-01-01

Forest loss in hotspots around the world impacts not only local climate where loss occurs, but also influences climate and vegetation in remote parts of the globe through ecoclimate teleconnections. The magnitude and mechanism of remote impacts likely depends on the location and distribution of forest loss hotspots, but the nature of these dependencies has not been investigated. We use global climate model simulations to estimate the distribution of ecologically-relevant climate changes resulting from forest loss in two hotspot regions: western North America (wNA), which is experiencing accelerated dieoff, and the Amazon basin, which is subject to high rates of deforestation. The remote climatic and ecological net effects of simultaneous forest loss in both regions differed from the combined effects of loss from the two regions simulated separately, as evident in three impacted areas. Eastern South American Gross Primary Productivity (GPP) increased due to changes in seasonal rainfall associated with Amazon forest loss and changes in temperature related to wNA forest loss. Eurasia’s GPP declined with wNA forest loss due to cooling temperatures increasing soil ice volume. Southeastern North American productivity increased with simultaneous forest loss, but declined with only wNA forest loss due to changes in VPD. Our results illustrate the need for a new generation of local-to-global scale analyses to identify potential ecoclimate teleconnections, their underlying mechanisms, and most importantly, their synergistic interactions, to predict the responses to increasing forest loss under future land use change and climate change. PMID:27851740

Synergistic Ecoclimate Teleconnections from Forest Loss in Different Regions Structure Global Ecological Responses

DOE PAGES

Garcia, Elizabeth S.; Swann, Abigail L. S.; Villegas, Juan C.; ...

2016-11-16

Forest loss in hotspots around the world impacts not only local climate where loss occurs, but also influences climate and vegetation in remote parts of the globe through ecoclimate teleconnections. The magnitude and mechanism of remote impacts likely depends on the location and distribution of forest loss hotspots, but the nature of these dependencies has not been investigated. We use global climate model simulations to estimate the distribution of ecologically-relevant climate changes resulting from forest loss in two hotspot regions: western North America (wNA), which is experiencing accelerated dieoff, and the Amazon basin, which is subject to high rates ofmore » deforestation. The remote climatic and ecological net effects of simultaneous forest loss in both regions differed from the combined effects of loss from the two regions simulated separately, as evident in three impacted areas. Eastern South American Gross Primary Productivity (GPP) increased due to changes in seasonal rainfall associated with Amazon forest loss and changes in temperature related to wNA forest loss. Eurasia's GPP declined with wNA forest loss due to cooling temperatures increasing soil ice volume. Southeastern North American productivity increased with simultaneous forest loss, but declined with only wNA forest loss due to changes in VPD. In conclusion, our results illustrate the need for a new generation of local-to-global scale analyses to identify potential ecoclimate teleconnections, their underlying mechanisms, and most importantly, their synergistic interactions, to predict the responses to increasing forest loss under future land use change and climate change.« less

Synergistic Ecoclimate Teleconnections from Forest Loss in Different Regions Structure Global Ecological Responses

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

Garcia, Elizabeth S.; Swann, Abigail L. S.; Villegas, Juan C.

Forest loss in hotspots around the world impacts not only local climate where loss occurs, but also influences climate and vegetation in remote parts of the globe through ecoclimate teleconnections. The magnitude and mechanism of remote impacts likely depends on the location and distribution of forest loss hotspots, but the nature of these dependencies has not been investigated. We use global climate model simulations to estimate the distribution of ecologically-relevant climate changes resulting from forest loss in two hotspot regions: western North America (wNA), which is experiencing accelerated dieoff, and the Amazon basin, which is subject to high rates ofmore » deforestation. The remote climatic and ecological net effects of simultaneous forest loss in both regions differed from the combined effects of loss from the two regions simulated separately, as evident in three impacted areas. Eastern South American Gross Primary Productivity (GPP) increased due to changes in seasonal rainfall associated with Amazon forest loss and changes in temperature related to wNA forest loss. Eurasia's GPP declined with wNA forest loss due to cooling temperatures increasing soil ice volume. Southeastern North American productivity increased with simultaneous forest loss, but declined with only wNA forest loss due to changes in VPD. In conclusion, our results illustrate the need for a new generation of local-to-global scale analyses to identify potential ecoclimate teleconnections, their underlying mechanisms, and most importantly, their synergistic interactions, to predict the responses to increasing forest loss under future land use change and climate change.« less

Biology of amphibians and reptiles in old-growth forests in the Pacific northwest. Forest Service general technical report

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

Blaustein, A.R.; Beatty, J.J.; Olson, D.H.

1995-03-01

The amphibian and reptile fauna of older forest ecosystems in the Pacific Northwest includes several endemic species, species with unique behavioral and ecological characteristics, and species whose populations have been in decline in recent years. The authors review the biology of these species and include information on their distinguishing characteristics, behavior, and ecology. Herpetofaunal associations with forest characteristic and the impact of habitat loss are addressed.

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.

The biodiversity cost of carbon sequestration in tropical savanna.

PubMed

Abreu, Rodolfo C R; Hoffmann, William A; Vasconcelos, Heraldo L; Pilon, Natashi A; Rossatto, Davi R; Durigan, Giselda

2017-08-01

Tropical savannas have been increasingly viewed as an opportunity for carbon sequestration through fire suppression and afforestation, but insufficient attention has been given to the consequences for biodiversity. To evaluate the biodiversity costs of increasing carbon sequestration, we quantified changes in ecosystem carbon stocks and the associated changes in communities of plants and ants resulting from fire suppression in savannas of the Brazilian Cerrado, a global biodiversity hotspot. Fire suppression resulted in increased carbon stocks of 1.2 Mg ha -1 year -1 since 1986 but was associated with acute species loss. In sites fully encroached by forest, plant species richness declined by 27%, and ant richness declined by 35%. Richness of savanna specialists, the species most at risk of local extinction due to forest encroachment, declined by 67% for plants and 86% for ants. This loss highlights the important role of fire in maintaining biodiversity in tropical savannas, a role that is not reflected in current policies of fire suppression throughout the Brazilian Cerrado. In tropical grasslands and savannas throughout the tropics, carbon mitigation programs that promote forest cover cannot be assumed to provide net benefits for conservation.

Ecosystem-based management in the whitebark pine zone

Treesearch

Robert E. Keane; Stephen F. Arno; Catherine A. Stewart

2000-01-01

Declining whitebark pine (Pinus albicaulis) forests have necessitated development of innovative methods to restore these ecologically valuable, high elevation ecosystems. We have began an extensive restoration study using prescribed fire and silvicultural cuttings to return native ecological processes to degenerating whitebark pine forests....

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.

Understanding landowner intentions to create early successional forest habitat in the northeastern United States

USGS Publications Warehouse

Dayer, Ashley A.; Stedman, Richard C.; Allred, Shorna B.; Rosenberg, Kenneth V.; Fuller, Angela K.

2016-01-01

Early successional forest habitat (ESH) and associated wildlife species in the northeastern United States are in decline. One way to help create early successional forest conditions is engaging private forest landowners in even-aged forest management because their limited participation may have contributed to declines in ESH for wildlife species of high conservation concern. We applied the reasoned action approach from social psychology to predict intentions of landowners in the 13-county Southern Tier of New York State, USA, to conduct patch-cuts, which is a type of even-aged forest management. We tested the predictive ability of the model using data from a mail survey of landowners conducted from November 2010 to January 2011. Landowner intention to conduct patch-cuts was high (55% of respondents), with attitude being the strongest direct predictor of behavioral intention. Our results suggest that patch-cutting intentions are most likely expressed by landowners who think the behavior is good for their land and wildlife, believe in positive outcomes of land and wildlife management, belong to a game wildlife organization, and have conducted patch-cuts in the past. Strategies to engage more landowners in ESH management will have the highest likelihood of success if outreach efforts focus on influencing behavioral beliefs and subsequently attitudes, possibly working with game wildlife organizations to communicate a unified message for habitat conservation, including the importance of maintaining and creating ESH. Our results demonstrate the importance of social science research to increase the likelihood that conservation targets for declining wildlife species are met. Published 2015. This article is a U.S. Government work and is in the public domain in the USA.

Simulating secondary succession of elk forage values in a managed forest landscape, western Washington

USGS Publications Warehouse

Jenkins, Kurt J.; Starkey, Edward E.

1996-01-01

Modern timber management practices often influence forage production for elk (Cervus elaphus) on broad temporal and spatial scales in forested landscapes. We incorporated site-specific information on postharvesting forest succession and forage characteristics in a simulation model to evaluate past and future influences of forest management practices on forage values for elk in a commercially managed Douglas fir (Pseudotsuga menziesii, PSME)-western hemlock (Tsuga heterophylla, TSHE) forest in western Washington. We evaluated future effects of: (1) clear-cut logging 0, 20, and 40% of harvestable stands every five years; (2) thinning 20-year-old Douglas fir forests; and (3) reducing the harvesting cycle from 60 to 45 years. Reconstruction of historical patterns of vegetation succession indicated that forage values peaked in the 1960s and declined from the 1970s to the present, but recent values still were higher than may have existed in the unmanaged landscape in 1945. Increased forest harvesting rates had little short-term influence on forage trends because harvestable stands were scarce. Simulations of forest thinning also produced negligible benefits because thinning did not improve forage productivity appreciably at the stand level. Simulations of reduced harvesting cycles shortened the duration of declining forage values from approximately 30 to 15 years. We concluded that simulation models are useful tools for examining landscape responses of forage production to forest management strategies, but the options examined provided little potential for improving elk forages in the immediate future.

Modelling Associations between Public Understanding, Engagement and Forest Conditions in the Inland Northwest, USA

PubMed Central

Hartter, Joel; Stevens, Forrest R.; Hamilton, Lawrence C.; Congalton, Russell G.; Ducey, Mark J.; Oester, Paul T.

2015-01-01

Opinions about public lands and the actions of private non-industrial forest owners in the western United States play important roles in forested landscape management as both public and private forests face increasing risks from large wildfires, pests and disease. This work presents the responses from two surveys, a random-sample telephone survey of more than 1500 residents and a mail survey targeting owners of parcels with 10 or more acres of forest. These surveys were conducted in three counties (Wallowa, Union, and Baker) in northeast Oregon, USA. We analyze these survey data using structural equation models in order to assess how individual characteristics and understanding of forest management issues affect perceptions about forest conditions and risks associated with declining forest health on public lands. We test whether forest understanding is informed by background, beliefs, and experiences, and whether as an intervening variable it is associated with views about forest conditions on publicly managed forests. Individual background characteristics such as age, gender and county of residence have significant direct or indirect effects on our measurement of understanding. Controlling for background factors, we found that forest owners with higher self-assessed understanding, and more education about forest management, tend to hold more pessimistic views about forest conditions. Based on our results we argue that self-assessed understanding, interest in learning, and willingness to engage in extension activities together have leverage to affect perceptions about the risks posed by declining forest conditions on public lands, influence land owner actions, and affect support for public policies. These results also have broader implications for management of forested landscapes on public and private lands amidst changing demographics in rural communities across the Inland Northwest where migration may significantly alter the composition of forest owner goals, understanding, and support for various management actions. PMID:25671619

Promoting and maintaining diversity in contemporary hardwood forests: Confronting contemporary drivers of change and the loss of ecological memory

Treesearch

Christopher R. Webster; Yvette L. Dickinson; Julia I. Burton; Lee E. Frelich; Michael A. Jenkins; Christel C. Kern; Patricia Raymond; Michael R. Saunders; Michael B. Walters; John L. Willis

2018-01-01

Declines in the diversity of herbaceous and woody plant species in the understory of eastern North American hardwood forests are increasingly common. Forest managers are tasked with maintaining and/or promoting species diversity and resilience; however, the success of these efforts depends on a robust understanding of past and future system dynamics and identification...

Saproxylic beetles in a Swedish boreal forest landscape managed according to 'new forestry'

Treesearch

Stig Larsson; Barbara Ekbom; L. Martin Schroeder; Melodie A. McGeoch

2006-01-01

A major threat to biodiversity in Swedish forests is the decline of Coarse Woody Debris (CWD), which is an essential resource for many organisms and plays an essential role for the structure and function of boreal forests. Removal of CWD in commercial forestry has depleted important resources for many rare wood-living (saproxylic) beetles. Replenishment of CWD has been...

Monitoring oak-hickory forest change during an unprecedented red oak borer outbreak in the Ozark Mountains: 1990 to 2006

Treesearch

Joshua S. Jones; Jason A. Tullis; Laurel J. Haavik; James M. Guldin; Fred M. Stephen

2014-01-01

Upland oak-hickory forests in Arkansas, Missouri, and Oklahoma experienced oak decline in the late 1990s and early 2000s during an unprecedented outbreak of a native beetle, the red oak borer (ROB), Enaphalodes rufulus (Haldeman). Although remote sensing supports frequent monitoring of continuously changing forests, comparable in situ observations are critical for...

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...

Carbon stocks and accumulation rates in Pacific Northwest forests: role of stand age, plant community, and productivity

Treesearch

Andrew N. Gray; Thomas R. Whittier; Mark E. Harmon

2016-01-01

Forest ecosystems are removing significant amounts of carbon from the atmosphere. Both abiotic resource availability and biotic interactions during forest succession affect C accumulation rates and maximum C stocks. However, the timing and controls on the peak and decline in C accumulation rates as stands age, trees increase in size, and canopy gaps become prevalent...

Comparing Basal Area Growth Rates in Repeated Inventories: Simpson's Paradox in Forestry

Treesearch

Charles E. Thomas; Bernard R. Parresol

1989-01-01

Recent analyses of radial growth rates in southern commercial forests have shown that current rates are lower than past rates when compared diameter class by diameter class. These results have been interpreted as an indication that the growth rate of the forest is declining. In this paper, growth rates of forest populations in Alabama are studied. Basal area growth (a...

Forest Area in Wisconsin Counties, 1968

Treesearch

Burton L. Essex

1972-01-01

In 1968 Wisconsin''s forests covered 14.9 million acres of land, a slight decline from the 15.2 million acres reported in 1956. The area of commercial forest land also dropped slightly to 14.5 million acres; increases in the eastern part of the State of 50,000 acres were more than offset by losses of 381,000 acres in the west and central sections.

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...

Total belowground carbon flux in subalpine forests is related to leaf area index, soil nitrogen, and tree height

Treesearch

E. Berryman; Michael Ryan; J. B. Bradford; T. J. Hawbaker; R. Birdsey

2016-01-01

In forests, total belowground carbon (C) flux (TBCF) is a large component of the C budget and represents a critical pathway for delivery of plant C to soil. Reducing uncertainty around regional estimates of forest C cycling may be aided by incorporating knowledge of controls over soil respiration and TBCF. Photosynthesis, and presumably TBCF, declines with...

Status and Trends for the U.S. Forest Products Sector: A Technical Document Supporting the Forest Service 2010 RPA Assessment

Treesearch

Kenneth E. Skog; David B. McKeever; Peter J. Ince; James L. Howard; Henry N. Spelter; Albert T. Schuler

2012-01-01

Forest products sector products and income help sustain the social, economic, and ecological benefits of forestry in the United States. Solidwood products consumption increased with population between 1965 and 2008 and varied with housing starts. Lumber's share declined from 83% to 70%, and structural panels' share increased from 9% to 17%. Paper and...

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. Results indicate key locations where spatial targeting of PES within the SJLSBC study region would protect existing forest connectivity and enhance the connectivity benefits of reforestation. © 2016 by the Ecological Society of America.

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...

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-...

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...

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...

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...

Changes in Carbon Storage and Net Carbon Exchange After a Shelterwood Harvest at Howland Forest, Maine

NASA Astrophysics Data System (ADS)

Scott, N. A.; Rodrigues, C. A.; Hughes, H.; Lee, J. T.; Davidson, E. A.; Dail, D. B.; Goltz, S. M.; Malerba, P.; Hollinger, D. Y.

2003-12-01

While many forests are actively sequestering carbon, little research has examined the direct effects of forest management practices on carbon sequestration. This is a critical issue in North America, where a large proportion of forests are managed. At the Howland Forest in Maine, we are using eddy covariance, biometric techniques and modeling to evaluate changes in carbon storage following a shelterwood cut that removed just under 30% of aboveground biomass. This management regime is becoming increasingly common throughout the region. Prior to harvest, the stand contained about 76 Mg C ha-1 (30 m2ha-1 basal area) in above- and below-ground live biomass. Harvesting removed about 15 Mg C ha-1 (SEM=2.1), and created about 5.3 Mg C ha-1 (SEM=1.1) of aboveground and 5.2 Mg C ha-1 (SEM=0.7) of root/stump detritus. Leaf-area index and litterfall declined by about 40% with harvest. Approximately half of the harvested wood was used for paper products (half-life of 3.5 years) and half for longer-lived wood products (half-life of 45 years). In a nearby, unharvested stand, eddy covariance measurements indicated that net ecosystem exchange (NEE) averages about 1.8 Mg C ha-1 y-1. A comparison of NEE at unharvested and harvested stands, both pre- and post-harvest, indicated that NEE declined following the harvest by about 18%, which is less than expected based on basal area and LAI changes. Both daily uptake and nocturnal respiration declined after harvest. Soil respiration declined slightly with harvest, suggesting no major soil C loss after harvest; harvesting had little effect on soil moisture and temperature. When decay of paper and wood products is included in a preliminary carbon budget, we predict that the forest will be a net C source to the atmosphere for at least 5 years, assuming pre-harvest growth rates of trees. How quickly the carbon balance becomes positive will depend largely on whether post-harvest tree growth rates increase.

NITROGEN FLUX FROM WEST CASCADE RANGE HEADWATER STREAMS DRAINING FORESTS ALONG A SUCCESSIONAL GRADIENT

EPA Science Inventory

Conceptual models predict that unpolluted, aggrading forest ecosystems tightly retain available nitrogen (N) until declining productivity by mature trees reduces the demand for essential nutrients and export increases to equal N inputs. Short-term nitrate loss following disturban...

Monarch butterfly population decline in North America: identifying the threatening processes

USGS Publications Warehouse

Thogmartin, Wayne E.; Wiederholt, Ruscena; Oberhauser, Karen; Drum, Ryan G.; Diffendorfer, Jay E.; Altizer, Sonia; Taylor, Orley R.; Pleasants, John M.; Semmens, Darius J.; Semmens, Brice X.; Erickson, Richard A.; Libby, Kaitlin; Lopez-Hoffman, Laura

2017-01-01

The monarch butterfly (Danaus plexippus) population in North America has sharply declined over the last two decades. Despite rising concern over the monarch butterfly's status, no comprehensive study of the factors driving this decline has been conducted. Using partial least-squares regressions and time-series analysis, we investigated climatic and habitat-related factors influencing monarch population size from 1993 to 2014. Potential threats included climatic factors, habitat loss (milkweed and overwinter forest), disease and agricultural insecticide use (neonicotinoids). While climatic factors, principally breeding season temperature, were important determinants of annual variation in abundance, our results indicated strong negative relationships between population size and habitat loss variables, principally glyphosate use, but also weaker negative effects from the loss of overwinter forest and breeding season use of neonicotinoids. Further declines in population size because of glyphosate application are not expected. Thus, if remaining threats to habitat are mitigated we expect climate-induced stochastic variation of the eastern migratory population of monarch butterfly around a relatively stationary population size.

Integrating inter- and intra-annual tree-ring width, carbon isotopes and anatomy: responses to climate variability in a temperate oak forest

NASA Astrophysics Data System (ADS)

Granda, Elena; Bazot, Stéphane; Fresneau, Chantal; Boura, Anaïs; Faccioni, Georgia; Damesin, Claire

2015-04-01

While many forests are experiencing strong tree declines due to climate change in temperate ecosystems, others nearby to those declining show no apparent signs of decline. This could be due to particular microsite conditions or, for instance, to a higher plasticity of given traits that allow a better performance under stressful conditions. We studied oak functional mechanisms (Quercus petraea) leading to the apparently healthy status of the forest and their relation to the observed climatic variability. This study was conducted in the Barbeau Forest (northern France), where cores from mature trees were collected. Three types of functional traits (secondary growth, physiological variables - δ13C and derived Δ13C and iWUE- and several anatomical ones -e.g. vessel area, density-) were recorded for each ring for the 1991-2011 period, distinguishing EW from LW in all measured traits. Among the three types of functional traits, those related to growth experienced the highest variability both between years and between individuals, followed by anatomical and physiological ones. Secondary growth maintained a constant trend during the study period. Instead, ring, EW and LW δ13C slightly declined from 1991 to 2011. Additional intra-ring δ13C analyses allowed for a more detailed understanding of the seasonal dynamics within each year. In particular, the year 2007 (an especially favorable climatic year during the growing season) showed the lowest δ13C values during the EW-LW transition for the whole study period. Inter-annual anatomical traits varied in their responses, but in general, no temporal trends were found. The results from structural equation modeling (SEM) showed direct relationships of seasonal climate and growth, as well as indirect relationships mediated by anatomical and physiological traits. We further discuss the implications of these results on future forest responses to ongoing climate changes.

The consequences of poaching and anthropogenic change for forest elephants.

PubMed

Breuer, Thomas; Maisels, Fiona; Fishlock, Vicki

2016-10-01

Poaching has devastated forest elephant populations (Loxodonta cyclotis), and their habitat is dramatically changing. The long-term effects of poaching and other anthropogenic threats have been well studied in savannah elephants (Loxodonta africana), but the impacts of these changes for Central Africa's forest elephants have not been discussed. We examined potential repercussions of these threats and the related consequences for forest elephants in Central Africa by summarizing the lessons learned from savannah elephants and small forest elephant populations in West Africa. Forest elephant social organization is less known than the social organization of savannah elephants, but the close evolutionary history of these species suggests that they will respond to anthropogenic threats in broadly similar ways. The loss of older, experienced individuals in an elephant population disrupts ecological, social, and population parameters. Severe reduction of elephant abundance within Central Africa's forests can alter plant communities and ecosystem functions. Poaching, habitat alterations, and human population increase are probably compressing forest elephants into protected areas and increasing human-elephant conflict, which negatively affects their conservation. We encourage conservationists to look beyond documenting forest elephant population decline and address the causes of these declines when developing conversation strategies. We suggest assessing the effectiveness of the existing protected-area networks for landscape connectivity in light of current industrial and infrastructure development. Longitudinal assessments of the effects of landscape changes on forest elephant sociality and behavior are also needed. Finally, lessons learned from West African elephant population loss and habitat fragmentation should be used to inform strategies for land-use planning and managing human-elephant interactions. © 2016 Society for Conservation Biology.

Long-term change of protective forest during the past four decades at Dongshan Island, southeastern China

NASA Astrophysics Data System (ADS)

Zhang, Caiyun; Yan, Jing; Shang, Shaoling

2017-02-01

The Dongshan Island is a typical protective forest area of the southeastern coastal region of China. In this work, we extract the variation of the Dongshan Island’s protective forest area since the 1970s from the remote sensing data of the LandSAT and the Chinese HJ 1A/B satellites, and we examined the possible reasons for the variation. The results showed that the maximum likelihood classification of the extracted remote sensing data of the Dongshan Island coastal protective forest had a total accuracy of 92.6%. In the last 40 years, the area of the Dongshan Island coastal protective forest experienced a waving variation of decrease (1973-1984), increase (1984-1999) and decrease (1999-2008), in which human activity was the predominant impact factor for this fluctuation pattern. Since the early 1960s to the 1980s, due to the Cultural Revolution and the later deforestation and land reclamation activities, the protective forest of Dongshan Island was severely damaged. The total area declined sharply from 2134.4 ha in 1964 to 1515.74 ha in 1984, and the northern area of the island had the most significant decrease. After 1988, the Fujian Province began to aggressively establish the coastal protective forest system, and the protective forest acreage increased significantly to 3370.22 ha in 1999, an increase of nearly 1.2 times based on the figure of 1984. In the past five years, the area of protective forest declined slightly again, mainly because of the natural aging of the protective forest ecosystem, tourism development and the booming aquaculture industry.

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.

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.

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 vegetation: a plant functional approach based on pollen data. Vegetation History and Archaeobotany. 24, 303-317. Fyfe RM, Woodbridge J and Roberts N (2015) From forest to farmland: pollen-inferred land cover change across Europe using the pseudobiomization approach. Global Change Biology 20, 1197-1212. Trondman A-K, Gaillard M-J, Sugita S et al. (2015) Pollen-based land-cover reconstructions for the study of past vegetation-climate interactions in NW Europe at 0.2 k, 0.5 k, 3 k and 6 k years before present. Global Change Biology. 21, 676-697.

Vertical distribution and temporal dynamics of dissolved 137Cs concentrations in soil water after the Fukushima Dai-ichi Nuclear Power Plant accident.

PubMed

Iwagami, Sho; Onda, Yuichi; Tsujimura, Maki; Hada, Manami; Pun, Ishwar

2017-11-01

Radiocesium ( 137 Cs) migration from headwater forested areas to downstream rivers has been investigated in many studies since the Fukushima Dai-ichi Nuclear Power Plant (FDNPP) accident, which was triggered by a catastrophic earthquake and tsunami on 11 March 2011. The accident resulted in the release of a huge amount of radioactivity and its subsequent deposition in the environment. A large part of the radiocesium released has been shown to remain in the forest. The dissolved 137 Cs concentration and its temporal dynamics in river water, stream water, and groundwater have been reported, but reports of dissolved 137 Cs concentration in soil water remain sparse. In this study, soil water was sampled, and the dissolved 137 Cs concentrations were measured at five locations with different land-use types (mature/young cedar forest, broadleaf forest, meadow land, and pasture land) in Yamakiya District, located 35 km northwest of FDNPP from July 2011 to October 2012. Soil water samples were collected by suction lysimeters installed at three different depths at each site. Dissolved 137 Cs concentrations were analyzed using a germanium gamma ray detector. The dissolved 137 Cs concentrations in soil water were high, with a maximum value of 2.5 Bq/L in July 2011, and declined to less than 0.32 Bq/L by 2012. The declining trend of dissolved 137 Cs concentrations in soil water was fitted to a two-component exponential model. The rate of decline in dissolved 137 Cs concentrations in soil water (k 1 ) showed a good correlation with the radiocesium interception potential (RIP) of topsoil (0-5 cm) at the same site. Accounting for the difference of 137 Cs deposition density, we found that normalized dissolved 137 Cs concentrations of soil water in forest (mature/young cedar forest and broadleaf forest) were higher than those in grassland (meadow land and pasture land). Copyright © 2017 Elsevier Ltd. All rights reserved.

Evidence of montane spruce-fir forest recovery on the high peaks and ridges of the black mountains, North Carolina: recent trends, 1986-2003

Treesearch

Todd Allen Bowers; Robert I. Bruck

2010-01-01

Decline in high elevation red spruce (Picea rubens Sarg.) and Fraser fir (Abies fraseri (Pursh) Poir.) forests throughout the southern Appalachians was shown following extensive surveys conducted during the 1980s.

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...

Land use change in Ohio, 1952 to 1979

Treesearch

Thomas W. Birch; Wharton Eric H.; Wharton Eric H.

1982-01-01

An analytical report on trends of major land uses in Ohio from 1952 to 1979. The relationship between the decline in farm area and increase in forest land is emphasized. The losses of wood fiber attributable to clearing forest land between 1968 and 1979 are also estimated.

Forest Loss and the Biodiversity Threshold: An Evaluation Considering Species Habitat Requirements and the Use of Matrix Habitats

PubMed Central

Estavillo, Candelaria; Pardini, Renata; da Rocha, Pedro Luís Bernardo

2013-01-01

Habitat loss is the main driver of the current biodiversity crisis, a landscape-scale process that affects the survival of spatially-structured populations. Although it is well-established that species responses to habitat loss can be abrupt, the existence of a biodiversity threshold is still the cause of much controversy in the literature and would require that most species respond similarly to the loss of native vegetation. Here we test the existence of a biodiversity threshold, i.e. an abrupt decline in species richness, with habitat loss. We draw on a spatially-replicated dataset on Atlantic forest small mammals, consisting of 16 sampling sites divided between forests and matrix habitats in each of five 3600-ha landscapes (varying from 5% to 45% forest cover), and on an a priori classification of species into habitat requirement categories (forest specialists, habitat generalists and open-area specialists). Forest specialists declined abruptly below 30% of forest cover, and spillover to the matrix occurred only in more forested landscapes. Generalists responded positively to landscape heterogeneity, peaking at intermediary levels of forest cover. Open area specialists dominated the matrix and did not spillover to forests. As a result of these distinct responses, we observed a biodiversity threshold for the small mammal community below 30% forest cover, and a peak in species richness just above this threshold. Our results highlight that cross habitat spillover may be asymmetrical and contingent on landscape context, occurring mainly from forests to the matrix and only in more forested landscapes. Moreover, they indicate the potential for biodiversity thresholds in human-modified landscapes, and the importance of landscape heterogeneity to biodiversity. Since forest loss affected not only the conservation value of forest patches, but also the potential for biodiversity-mediated services in anthropogenic habitats, our work indicates the importance of proactive measures to avoid human-modified landscapes to cross this threshold. PMID:24324776

Influence of hiking trails on montane birds

Treesearch

William V. Deluca; David I. King

2014-01-01

Montane forests contribute significantly to regional biodiversity. Long-term monitoring data, often located along hiking trails, suggests that several indicator species of this ecosystem have declined in recent decades. Declining montane bird populations have been attributed to anthropogenic stressors such as climate change and atmospheric deposition. Several studies...

Land use and carbon dynamics in the southeastern United States from 1992 to 2050

USGS Publications Warehouse

Zhao, Shuqing; Liu, Shuguang; Sohl, Terry L.; Young, Claudia; Werner, Jeremy M.

2013-01-01

Land use and land cover change (LUCC) plays an important role in determining the spatial distribution, magnitude, and temporal change of terrestrial carbon sources and sinks. However, the impacts of LUCC are not well understood and quantified over large areas. The goal of this study was to quantify the spatial and temporal patterns of carbon dynamics in various terrestrial ecosystems in the southeastern United States from 1992 to 2050 using a process-based modeling system and then to investigate the impacts of LUCC. Spatial LUCC information was reconstructed and projected using the FOREcasting SCEnarios of future land cover (FORE-SCE) model according to information derived from Landsat observations and other sources. Results indicated that urban expansion (from 3.7% in 1992 to 9.2% in 2050) was expected to be the primary driver for other land cover changes in the region, leading to various declines in forest, cropland, and hay/pasture. The region was projected to be a carbon sink of 60.4 gC m−2 yr−1 on average during the study period, primarily due to the legacy impacts of large-scale conversion of cropland to forest that happened since the 1950s. Nevertheless, the regional carbon sequestration rate was expected to decline because of the slowing down of carbon accumulation in aging forests and the decline of forest area.

Black Truffle Harvesting in Spanish Forests: Trends, Current Policies and Practices, and Implications on its Sustainability

NASA Astrophysics Data System (ADS)

Garcia-Barreda, Sergi; Forcadell, Ricardo; Sánchez, Sergio; Martín-Santafé, María; Marco, Pedro; Camarero, J. Julio; Reyna, Santiago

2018-04-01

The European black truffle is a mycorrhizal fungus native to Spanish Mediterranean forests. In most Spanish regions it was originally commercially harvested in the second half of the 20th century. Experts agree that wild truffle yields suffered a sharp decline during the 1970s and 1980s. However, official statistics for Spanish harvest are scarce and seemingly conflicting, and little attention has been paid to the regime for the exploitation of truffle-producing forests and its implications on the sustainability of this resource. Trends in harvest from 1969 to 2013 and current harvesting practices were analyzed as a case study, taking into account that Spain is a major truffle producer worldwide, but at the same time truffles have only recently been exploited. The available statistical sources, which include an increasing proportion of cultivated truffles since the mid-1990s, were explored, with estimates from Truffle Harvesters Federation showing higher consistency. Statistical sources were then compared with proxies for wild harvest (rents from truffle leases in public forests) to corroborate time trends in wild harvesting. Results suggest that black truffle production is recovering in recent years thanks to plantations, whereas wild harvest is still declining. The implications of Spanish legal and institutional framework on sustainability of wild truffle use are reviewed. In the current scenario, the decline of wild harvest is likely to continue and eventually make commercial harvesting economically unattractive, thus aggravating sustainability issues. Strengthening of property rights, rationalization of harvesting pressure, forest planning and involvement of public stakeholders are proposed as corrective measures.

[Effects of mulching management of Phyllostachys heterocycla forests on the characteristics of soil infiltration and biometrics in southwest Zhejiang Province, China].

PubMed

Wang, Yi Kun; Jin, Ai Wu; Fang, Sheng Zuo

2017-05-18

Soil infiltration, soil physical and chemical properties, root length density and soil fauna diversity were studied in Phyllostachys heterocycla forests with different mulching times in southwest Zhejiang Province, China. Significant differences of soil infiltration capability were found among the forests with different mulching times and among soil layers. Soil infiltration capability generally declined in the deeper soil layers. With mulching management, soil infiltration capability increased under the first mulching, and then declined with the increase of mulching times. The Kostiakov model was suitable for simulating soil infiltration process. With the extending of mulching times (4 to 6 years), soil pH and total/non-capillary porosity decreased, while soil bulk density, soil orga-nic matter and total nitrogen contents increased significantly. Soil initial, steady, and average infiltration rates as well as the cumulative infiltration amount correlated closely with the length density of roots with diameter from 0.5 mm to 5.0 mm, showing a decreasing tendency with the decrease in root length density. Soil fauna density was highest in the forest under the first mulching, and was lowest after third mulching. The decreased numbers of large and meso-arthropods, including Symphyla, Chilopoda, Diplopoda, Hymenoptera and pseudoscorpions, and the micro-arthropods, including Oribatida, Mesostigmata, Onychiuridae, Neanuridae, Cyphoderidae, and Entomobryidae, showed negative effects on soil infiltration. In conclusion, long-term mulching changed soil physical and chemical properties, decreased soil infiltration capability, and suppressed the development of soil fauna, which might cause the decline ofP. heterocycla forests.

Dependence of hydropower energy generation on forests in the Amazon Basin at local and regional scales

PubMed Central

Stickler, Claudia M.; Coe, Michael T.; Costa, Marcos H.; Nepstad, Daniel C.; McGrath, David G.; Dias, Livia C. P.; Rodrigues, Hermann O.; Soares-Filho, Britaldo S.

2013-01-01

Tropical rainforest regions have large hydropower generation potential that figures prominently in many nations’ energy growth strategies. Feasibility studies of hydropower plants typically ignore the effect of future deforestation or assume that deforestation will have a positive effect on river discharge and energy generation resulting from declines in evapotranspiration (ET) associated with forest conversion. Forest loss can also reduce river discharge, however, by inhibiting rainfall. We used land use, hydrological, and climate models to examine the local “direct” effects (through changes in ET within the watershed) and the potential regional “indirect” effects (through changes in rainfall) of deforestation on river discharge and energy generation potential for the Belo Monte energy complex, one of the world’s largest hydropower plants that is currently under construction on the Xingu River in the eastern Amazon. In the absence of indirect effects of deforestation, simulated deforestation of 20% and 40% within the Xingu River basin increased discharge by 4–8% and 10–12%, with similar increases in energy generation. When indirect effects were considered, deforestation of the Amazon region inhibited rainfall within the Xingu Basin, counterbalancing declines in ET and decreasing discharge by 6–36%. Under business-as-usual projections of forest loss for 2050 (40%), simulated power generation declined to only 25% of maximum plant output and 60% of the industry’s own projections. Like other energy sources, hydropower plants present large social and environmental costs. Their reliability as energy sources, however, must take into account their dependence on forests. PMID:23671098

Long-term change in limnology and invertebrates in Alaskan boreal wetlands

USGS Publications Warehouse

Corcoran, R.M.; Lovvorn, J.R.; Heglund, P.J.

2009-01-01

Climate change is more pronounced at high northern latitudes, and may be affecting the physical, chemical, and biological attributes of the abundant wetlands in boreal forests. On the Yukon Flats, located in the boreal forest of northeast Alaska, wetlands originally sampled during 1985-1989 were re-sampled for water chemistry and macroinvertebrates in summer 2001-2003. Wetlands sampled lost on average 19% surface water area between these periods. Total nitrogen and most metal cations (Na, Mg, and Ca, but not K) increased between these periods, whereas total phosphorus and chlorophyll a (Chl a) declined. These changes were greater in wetlands that had experienced more drying (decreased surface area). Compared with 1985-1989, densities of cladocerans, copepods, and ostracods in both June and August were much higher in 2002-2003, whereas densities of amphipods, gastropods, and chironomid larvae were generally lower. In comparisons among wetlands in 2002-2003 only, amphipod biomass was lower in wetlands with lower Chl a, which might help explain the decline of amphipods since the late 1980s when Chl a was higher. The decline in Chl a corresponded to greatly increased zooplankton density in June, suggesting a shift in carbon flow from scrapers and deposit-feeders to water-column grazers. Declines in benthic and epibenthic deposit-feeding invertebrates suggest important food web effects of climate change in otherwise pristine wetlands of the boreal forest. ?? 2008 Springer Science+Business Media B.V.

Vegetation dynamics and rainfall sensitivity of the Amazon.

PubMed

Hilker, Thomas; Lyapustin, Alexei I; Tucker, Compton J; Hall, Forrest G; Myneni, Ranga B; Wang, Yujie; Bi, Jian; Mendes de Moura, Yhasmin; Sellers, Piers J

2014-11-11

We show that the vegetation canopy of the Amazon rainforest is highly sensitive to changes in precipitation patterns and that reduction in rainfall since 2000 has diminished vegetation greenness across large parts of Amazonia. Large-scale directional declines in vegetation greenness may indicate decreases in carbon uptake and substantial changes in the energy balance of the Amazon. We use improved estimates of surface reflectance from satellite data to show a close link between reductions in annual precipitation, El Niño southern oscillation events, and photosynthetic activity across tropical and subtropical Amazonia. We report that, since the year 2000, precipitation has declined across 69% of the tropical evergreen forest (5.4 million km(2)) and across 80% of the subtropical grasslands (3.3 million km(2)). These reductions, which coincided with a decline in terrestrial water storage, account for about 55% of a satellite-observed widespread decline in the normalized difference vegetation index (NDVI). During El Niño events, NDVI was reduced about 16.6% across an area of up to 1.6 million km(2) compared with average conditions. Several global circulation models suggest that a rise in equatorial sea surface temperature and related displacement of the intertropical convergence zone could lead to considerable drying of tropical forests in the 21st century. Our results provide evidence that persistent drying could degrade Amazonian forest canopies, which would have cascading effects on global carbon and climate dynamics.

Vegetation Dynamics and Rainfall Sensitivity of the Amazon

NASA Technical Reports Server (NTRS)

Hilker, Thomas; Lyapustin, Alexei I.; Tucker, Compton J.; Hall, Forrest G.; Myneni, Ranga B.; Wang, Yujie; Bi, Jian; Mendes de Moura, Yhasmin; Sellers, Piers J.

2014-01-01

We show that the vegetation canopy of the Amazon rainforest is highly sensitive to changes in precipitation patterns and that reduction in rainfall since 2000 has diminished vegetation greenness across large parts of Amazonia. Large-scale directional declines in vegetation greenness may indicate decreases in carbon uptake and substantial changes in the energy balance of the Amazon. We use improved estimates of surface reflectance from satellite data to show a close link between reductions in annual precipitation, El Nino southern oscillation events, and photosynthetic activity across tropical and subtropical Amazonia. We report that, since the year 2000, precipitation has declined across 69% of the tropical evergreen forest (5.4 million sq km) and across 80% of the subtropical grasslands (3.3 million sq km). These reductions, which coincided with a decline in terrestrial water storage, account for about 55% of a satellite-observed widespread decline in the normalized difference vegetation index (NDVI). During El Nino events, NDVI was reduced about 16.6% across an area of up to 1.6 million sq km compared with average conditions. Several global circulation models suggest that a rise in equatorial sea surface temperature and related displacement of the intertropical convergence zone could lead to considerable drying of tropical forests in the 21st century. Our results provide evidence that persistent drying could degrade Amazonian forest canopies, which would have cascading effects on global carbon and climate dynamics.

Mangrove forest distributions and dynamics in Madagascar (1975-2005)

USGS Publications Warehouse

Giri, C.; Muhlhausen, J.

2008-01-01

Mangrove forests of Madagascar are declining, albeit at a much slower rate than the global average. The forests are declining due to conversion to other land uses and forest degradation. However, accurate and reliable information on their present distribution and their rates, causes, and consequences of change have not been available. Earlier studies used remotely sensed data to map and, in some cases, to monitor mangrove forests at a local scale. Nonetheless, a comprehensive national assessment and synthesis was lacking. We interpreted time-series satellite data of 1975, 1990, 2000, and 2005 using a hybrid supervised and unsupervised classification approach. Landsat data were geometrically corrected to an accuracy of ?? one-half pixel, an accuracy necessary for change analysis. We used a postclassification change detection approach. Our results showed that Madagascar lost 7% of mangrove forests from 1975 to 2005, to a present extent of ???2,797 km2. Deforestation rates and causes varied both spatially and temporally. The forests increased by 5.6% (212 km2) from 1975 to 1990, decreased by 14.3% (455 km 2) from 1990 to 2000, and decreased by 2.6% (73 km2) from 2000 to 2005. Similarly, major changes occurred in Bombekota Bay, Mahajamba Bay, the coast of Ambanja, the Tsiribihina River, and Cap St Vincent. The main factors responsible for mangrove deforestation include conversion to agriculture (35%), logging (16%), conversion to aquaculture (3%), and urban development (1%). ?? 2008 by MDPI.

Long-term effects of prescribed fire on mixed conifer forest structure in the Sierra Nevada, California

USGS Publications Warehouse

van Mantgem, Phillip J.; Stephenson, Nathan L.; Knapp, Eric; Keeley, Jon E.

2011-01-01

The capacity of prescribed fire to restore forest conditions is often judged by changes in forest structure within a few years following burning. However, prescribed fire might have longer-term effects on forest structure, potentially changing treatment assessments. We examined annual changes in forest structure in five 1 ha old-growth plots immediately before prescribed fire and up to eight years after fire at Sequoia National Park, California. Fire-induced declines in stem density (67% average decrease at eight years post-fire) were nonlinear, taking up to eight years to reach a presumed asymptote. Declines in live stem biomass were also nonlinear, but smaller in magnitude (32% average decrease at eight years post-fire) as most large trees survived the fires. The preferential survival of large trees following fire resulted in significant shifts in stem diameter distributions. Mortality rates remained significantly above background rates up to six years after the fires. Prescribed fire did not have a large influence on the representation of dominant species. Fire-caused mortality appeared to be spatially random, and therefore did not generally alter heterogeneous tree spatial patterns. Our results suggest that prescribed fire can bring about substantial changes to forest structure in old-growth mixed conifer forests in the Sierra Nevada, but that long-term observations are needed to fully describe some measures of fire effects.

An assessment of forest cover and impervious surface area on family forests in the New York City Watershed

Treesearch

Nathaniel M. Anderson; Rene H. Germain; Myrna H. Hall

2012-01-01

Between 1984 and 2000, the parcelization of family forests in the New York City Watershed caused a decline in average parcel size from 19 to 16 ac. However, little is known about the timing and intensity of development on subdivided parcels, which has the potential to negatively affect water quality by increasing nonpoint source pollution associated with nutrient...

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’,...

Population decline of the Elfin-woods Warbler Setophaga angelae in eastern Puerto Rico

Treesearch

W.J. Arendt; S.S. Qian; K. Mineard

2013-01-01

We estimated the population density of the globally threatened Elfin-woods Warbler Setophaga angelae within two forest types at different elevations in the Luquillo Experimental Forest in north-eastern Puerto Rico. Population densities ranged from 0.01 to 0.02 individuals/ha in elfin woodland and 0.06–0.26 individuals/ha in palo colorado forest in 2006, with average...

Pasture age effects on N[sub 2]O, NO and CH[sub 4] emissions in the Atlantic Lowlands of Costa Rica

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

Keller, M.; Reiners, W.A.; Veldkamp, E.

A study conducted in Brazil indicated that N[sub 2]O emissions increased following forest conversion to pasture. Our first study in Costa Rica indicated the reverse. To explore this contradiction, we measured N[sub 2]O, NO, and CH[sub 4] emissions in a chronosequence of 8 sites comprising forest and derive pastures of ayes 2 to 25 years, all on the same soil type in the Atlantic Lowlands of Costa Rica. We found large differences through the chronosequence in the fluxes of these three gases. Flux changes were related to changes in available nitrogen, organic matter, moisture content, and bulk density in themore » soil. N[sub 2]O emissions from the 2-year pasture were much greater than from the forest. Emissions declined with pasture age so that 25-year pasture had much smaller emissions than the forest. NO emissions from young pastures were similar to forest emissions, then declined sharply with pasture age. Forest soils consumed CH[sub 4]. Pasture soils mainly produced CH[sub 4]. Prediction of the effects of land use change on trace gas fluxes in the tropics will require an assessment of the history and soil condition of individual land units.« less

US forest products in the global economy

Treesearch

Dave N Wear; Jeff Prestemon; Michaela O. Foster

2015-01-01

The United States’ shares of global industrial roundwood production and derivative products have declined precipitously since the 1990s. We evaluate the extent of these declines compared with those of major producing countries from 1961 to 2013. We find that the US global share of industrial roundwood peaked at 28% in 1999 but by 2013 was at 17%, with the decline...

Midsouth veneer industry

Treesearch

Dennis M. May; John S. Vissage

1990-01-01

The USDA Forest Service, Southern Forest Experiment Station's latest survey of the Midsouth veneer industry shows the softwood veneer industry continuing its dominance as the hardwood veneer industry has continued to decline. The number of softwood mills has stabilized after years of growth, while both commercial and container hardwood mills have decreased in...

Timber resource of Minnesota's Central Hardwood Unit, 1977.

Treesearch

Alexander Vasilevsky; Ronald L. Hackett

1980-01-01

The fourth inventory of Minnesota's Central Hardwood Unit shows large gains in growing-stock and sawtimber volumes but a 17% decline in commercial forest area between 1962 and 1977. This report gives statistical highlights and contains detailed tables of forest area as well as timber volume, growth, mortality, ownership, and use.

Historical trends in rusty blackbird nonbreeding habitat in forested wetlands

Treesearch

Paul B. Hamel; Diane De Steven; Ted Leininger; Randy. Wilson

2009-01-01

Rusty Blackbird (Euphagus carolinus) populations have declined perhaps 95% in the recent past, creating legitimate concern that the species may become endangered. During the nonbreeding period the species occurs predominantly in southern U.S. forested wetland habitats, with concentrations in the Mississippi Alluvial Valley and in the southeastern...

Timber resource of Minnesota's Aspen-Birch Unit, 1977.

Treesearch

John S. Jr. Spencer; Arnold J. Ostrom

1979-01-01

The fourth inventory of Minnesota's Aspen-Birch Unit shows solid gains in growing-stock and sawtimber volumes between 1962 and 1977, but a 13% decline in commercial forest area. This report gives statistical highlights and contains detailed tables of forest area a well as timber volume, growth, mortality, ownership, and use.

Reproductive success of migratory birds in habitat sources and sinks

Treesearch

Therese M. Donovan; Frank R. , III Thompson; John Faaborg; John R. Probst

1995-01-01

Fragmentation of breeding habitat in North America has been implicated in the decline of forest-nesting, Neotropical migrant birds. We used a comparative approach to examine the effects of fragmentation on three forest-nesting migrants: Ovenbird (Seiurus aurocapillus), Red-eyed Vireo (Vireo ofivaceus), and Wood Thrush (...

Red-cockaded woodpecker population trends and management on Texas national forests

Treesearch

Richard N. Conner; D. Craig Rudolph

1994-01-01

Red-cockaded Woodpecker (Picoides borealis) population trends and concurrent management on four national forests in eastern Texas were evaluated from 1983 through 1993. Following years of decline, populations stabilized and began to increase after intensive management efforts were initiated. Management activities included control of hardwood midstory and understory,...

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...

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...

Climatic water deficit, tree species ranges, and climate change in Yosemite National Park

Treesearch

James A. Lutz; Jan W. van Wagtendonk; Jerry F. Franklin

2010-01-01

Modelled changes in climate water deficit between past, present and future climate scenarios suggest that recent past changes in forest structure and composition may accelerate in the future, with species responding individualistically to further declines in water availability. Declining water availability may disproportionately affect Pinus monticola...

Assessing aspen using remote sensing

Treesearch

Randy Hamilton; Kevin Megown; Jeff DiBenedetto; Dale Bartos; Anne Mileck

2009-01-01

Large areas of aspen (Populus tremuloides) have disappeared and continue to disappear from western forests due to successional decline and sudden aspen decline (SAD). This loss of aspen ecosystems negatively impacts watersheds, wildlife, plants, and recreation. Much can still be done to restore aspen if timely and appropriate action is taken. However, land managers...

Delineating Contaminants and Transport Pathways Within a Coastal Watershed in Southeast Puerto Rico

USDA-ARS?s Scientific Manuscript database

Coastal water quality decline due to point and non-point source pollution from terrestrial sources is a serious concern throughout the Caribbean basin and worldwide. Toxic and noxious algal blooms, declines in mangrove forests and seagrass meadows, depletion of fishery stocks, coral reef die-off, pu...

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.

Effects of experimental removal of Barred Owls on population demography of Northern Spotted Owls in Washington and Oregon—2017 progress report

USGS Publications Warehouse

Wiens, J. David; Dugger, Katie M.; Lesmeister, Damon B.; Dilione, Krista E.; Simon, David C.

2018-05-21

Populations of Northern Spotted Owls (Strix occidentalis caurina; hereinafter referred to as Spotted Owl) are declining throughout this subspecies’ geographic range. Evidence indicates that competition with invading populations of Barred Owls (S. varia) has contributed significantly to those declines. A pilot study in California showed that localized removal of Barred Owls coupled with conservation of suitable forest conditions can slow or even reverse population declines of Spotted Owls. It remains unknown, however, whether similar results can be obtained in areas with different forest conditions, greater densities of Barred Owls, and fewer remaining Spotted Owls. During 2015–17, we initiated a before-after-control-impact (BACI) experiment at three study areas in Oregon and Washington to determine if removal of Barred Owls can improve population trends of Spotted Owls. Each study area had at least 20 years of pre-treatment demographic data on Spotted Owls, and represented different forest conditions occupied by the two owl species in the Pacific Northwest. This report describes research accomplishments and preliminary results from the first 2.5 years (March 2015–August 2017) of the planned 5-year experiment.

The biodiversity cost of carbon sequestration in tropical savanna

PubMed Central

Abreu, Rodolfo C. R.; Hoffmann, William A.; Vasconcelos, Heraldo L.; Pilon, Natashi A.; Rossatto, Davi R.; Durigan, Giselda

2017-01-01

Tropical savannas have been increasingly viewed as an opportunity for carbon sequestration through fire suppression and afforestation, but insufficient attention has been given to the consequences for biodiversity. To evaluate the biodiversity costs of increasing carbon sequestration, we quantified changes in ecosystem carbon stocks and the associated changes in communities of plants and ants resulting from fire suppression in savannas of the Brazilian Cerrado, a global biodiversity hotspot. Fire suppression resulted in increased carbon stocks of 1.2 Mg ha−1 year−1 since 1986 but was associated with acute species loss. In sites fully encroached by forest, plant species richness declined by 27%, and ant richness declined by 35%. Richness of savanna specialists, the species most at risk of local extinction due to forest encroachment, declined by 67% for plants and 86% for ants. This loss highlights the important role of fire in maintaining biodiversity in tropical savannas, a role that is not reflected in current policies of fire suppression throughout the Brazilian Cerrado. In tropical grasslands and savannas throughout the tropics, carbon mitigation programs that promote forest cover cannot be assumed to provide net benefits for conservation. PMID:28875172

Drier Forest Composition Associated with Hydrologic Change in the Apalachicola River, Florida

USGS Publications Warehouse

Darst, Melanie R.; Light, Helen M.

2008-01-01

Forests of the Apalachicola River floodplain had shorter flood durations, were drier in composition, and had 17 percent fewer trees in 2004 than in 1976. The change to drier forest composition is expected to continue for at least 80 more years. Floodplain drying was caused by large declines in river levels resulting from erosion of the river channel after 1954 and from decreased flows in spring and summer months since the 1970s. Water-level declines have been greatest at low and medium flows, which are the most common flows (occurring about 80 percent of the time). Water levels have remained relatively unchanged during large floods which continue to occur about three times per decade. A study conducted by the U.S. Geological Survey compared temporal changes in hydrologic conditions, forest composition, forest characteristics, and individual species of trees, as well as estimated the potential for change in composition of floodplain forests in the nontidal reach of the Apalachicola River. The study was conducted with the cooperation of the Florida Department of Environmental Protection and the Northwest Florida Water Management District. Forest composition and field observations from studies conducted in 1976-1984 (termed '1976 data') were used as baseline data for comparison with data from plots sampled in 2004-2006 ('2004 data'). Flood durations were shorter in all periods subsequent to 1923-1976. The periods of record used to calculate flood durations for forest data were subsets of the complete record available (1923-2004). At sampled plots in all forest types and reaches combined, flood durations changed an average of more than 70 percent toward the baseline flood duration of the next drier forest type. For all forest types, changes in flood durations toward the next drier type were greatest in the upper reach (95.9 percent) and least in the lower reach (42.0 percent). All forests are expected to be 38.2 percent drier in species composition by 2085, the year when the median age of surviving 2004 subcanopy trees will reach the median age (99 years) of the 2004 large canopy trees. The change will be greatest for forests in the upper reach (45.0 percent). Forest composition changes from pre-1954 to 2085 were calculated using Floodplain Indices from 1976 and 2004 tree-size classes and replicate plots. Species composition in high bottomland hardwood forests is expected to continue to change, and some low bottomland hardwood forests are expected to become high bottomland hardwood forests. Organisms associated with floodplain forests will be affected by the changes in tree species, which will alter the timing of leaf-out, fruiting, and leaf-drop, the types of fruit and debris produced, and soil chemistry. Swamps will contain more bottomland hardwood species, but will also have an overall loss of tree density. The density of trees in swamps significantly decreased by 37 percent from 1976 to 2004. Of the estimated 4.3 million (17 percent) fewer trees that existed in the nontidal floodplain in 2004 than in 1976, 3.3 million trees belonged to four swamp species: popash, Ogeechee tupelo, water tupelo, and bald cypress. Water tupelo, the most important tree in the nontidal floodplain in terms of basal area and density, has declined in number of trees by nearly 20 percent since 1976. Ogeechee tupelo, the species valuable to the tupelo honey industry, has declined in number of trees by at least 44 percent. Greater hydrologic variability in recent years may be the reason swamps have had a large decrease in tree density. Drier conditions are detrimental for the growth of swamp species, and periodic large floods kill invading bottomland hardwood trees. The loss of canopy density in swamps may result in the swamp floor being exposed to more light with an increase in the amount of ground cover present, which in turn, would reduce tree replacement. The microclimate of the swamp floor would become wa

Successional changes of Collembola and soil microbiota during forest rotation.

PubMed

Chauvat, Matthieu; Zaitsev, Andrei S; Wolters, Volkmar

2003-10-01

Dynamic approaches to forest ecosystems are surprisingly rare. Here we report about successional changes in collembolan community structure and microbial performances during forest rotation. The study was carried out in a chronosequence of four spruce forest stands (5-, 25-, 45-, and 95 years old; Tharandter forest, Germany). CO2 release significantly increased after clear-cutting and the amount of C stored in the organic layer subsequently declined. The early phase of forest rotation was characterized by a very active decomposer microflora, stimulation of both fungi and bacteria as well as by a high abundance of surface-oriented Collembola. In addition, collembolan species turnover was accelerated. While the biomass of fungi further increased at intermediate stages of forest rotation, the metabolic activity of the microflora was low, the functional diversity of bacteria declined and the collembolan community became impoverished. Euedaphic species dominated during this stage of forest development. These changes can be explained by both reduction in microhabitat diversity and depletion of food sources associated with an accumulation of recalcitrant soil organic matter. Results of the General Regression Model procedure indicate a shift from specific associations between collembolan functional groups and microbiota at the early stage of forest rotation to a more diffuse pattern at intermediate stages. Though the hypothesis that Collembola are relatively responsive to changes in environmental conditions is confirmed, consistently high community similarity suggests a remarkable persistence of some components of microarthropod assemblages. Our study provides evidence for substantial ecosystem-level implications of changes in the soil food web during forest rotation. Moreover, correlations between bacterial parameters and Collembola point to the overarching impact of differences in the composition of the microbial community on microarthropods.

Soil bacterial communities of a calcium-supplemented and a reference watershed at the Hubbard Brook Experimental Forest (HBEF), New Hampshire, USA

Treesearch

Ganapathi Sridevi; Rakesh Minocha; Swathi A. Turlapati; Katherine C. Goldfarb; Eoin L. Brodie; Louis S. Tisa; Subhash C. Minocha

2012-01-01

Soil Ca depletion because of acidic deposition-related soil chemistry changes has led to the decline of forest productivity and carbon sequestration in the northeastern USA. In 1999, acidic watershed (WS) 1 at the Hubbard Brook Experimental Forest (HBEF), NH, USA was amended with Ca silicate to restore soil Ca pools. In 2006, soil samples were collected from the Ca-...

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.

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...

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...

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...

Land-use history as a major driver for long-term forest dynamics in the Sierra de Guadarrama National Park (central Spain) during the last millennia: implications for forest conservation and management

NASA Astrophysics Data System (ADS)

Morales-Molino, César; Colombaroli, Daniele; Valbuena-Carabaña, María; Tinner, Willy; Salomón, Roberto L.; Carrión, José S.; Gil, Luis

2017-05-01

In the Mediterranean Basin, long-lasting human activities have largely resulted in forest degradation or destruction. Consequently, conservation efforts aimed at preserving and restoring Mediterranean forests often lack well-defined targets when using current forest composition and structure as a reference. In the Iberian mountains, the still widespread Pinus sylvestris and Quercus pyrenaica woodlands have been heavily impacted by land-use. To assess future developments and as a baseline for planning, forest managers are interested in understanding the origins of present ecosystems to disclose effects on forest composition that may influence future vegetation trajectories. Quantification of land-use change is particularly interesting to understand vegetation responses. Here we use three well-dated multi-proxy palaeoecological sequences from the Guadarrama Mountains (central Spain) to quantitatively reconstruct changes occurred in P. sylvestris forests and the P. sylvestris-Q. pyrenaica ecotone at multi-decadal to millennial timescales, and assess the driving factors. Our results show millennial stability of P. sylvestris forests under varying fire and climate conditions, with few transient declines caused by the combined effects of fire and grazing. The high value of pine timber in the past would account for long-lasting pine forest preservation and partly for the degradation of native riparian vegetation (mostly composed of Betula and Corylus). Pine forests further spread after planned forest management started at 1890 CE. In contrast, intensive coppicing and grazing caused Q. pyrenaica decline some centuries ago (ca. 1500-1650 CE), with unprecedented grazing during the last decades seriously compromising today's oak regeneration. Thus, land-use history played a major role in determining vegetation changes. Finally, we must highlight that the involvement of forest managers in this work has guaranteed a practical use of palaeoecological data in conservation and management practice.

Early Forest Soils and Their Role in Devonian Global Change

PubMed

Retallack

1997-04-25

A paleosol in the Middle Devonian Aztec Siltstone of Victoria Land, Antarctica, is the most ancient known soil of well-drained forest ecosystems. Clay enrichment and chemical weathering of subsurface horizons in this and other Devonian forested paleosols culminate a long-term increase initiated during the Silurian. From Silurian into Devonian time, red clayey calcareous paleosols show a greater volume of roots and a concomitant decline in the density of animal burrows. These trends parallel the decline in atmospheric carbon dioxide determined from isotopic records of pedogenic carbonate in these same paleosols. The drawdown of carbon dioxide began well before the Devonian appearance of coals, large logs, and diverse terrestrial plants and animals, and it did not correlate with temporal variation in volcanic or metamorphic activity. The early Paleozoic greenhouse may have been curbed by the evolution of rhizospheres with an increased ratio of primary to secondary production and by more effective silicate weathering during Silurian time.

Detection of forest decline in Monchegorsk area

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

Hagner, O.; Rigina, O.

1998-01-01

Forests on the Kola Peninsula in Northern Russia are growing close to the limits of the northern tree line. They are subjected to both natural (low temperatures and a short period of biochemical activity) and anthropogenic stress factors. The metallurgic industry complex Severo-nickel close to the city of Monchegorsk in the central Russian Kola Peninsula is one of the major sources of sulfur dioxide (SO{sub 2}), nickel, and copper emissions in the region. The environmental impact on the surrounding area is dramatic. In this study multispectral changes observed in Landsat-MSS satellite image data from 1978, 1986, and 1992 are usedmore » to evaluate the relevance of a mathematical model of SO{sub 2} concentration in ambient air as a component for assessment of forest decline. The multispectral changes detected were found to have a statistically significant correspondence to the modeled (SO{sub 2}) concentration levels in ambient air.« less

Global sustainable timber supply and demand

Treesearch

Peter J. Ince

2010-01-01

Industrial timber use has provided timber revenue that has helped make timber supply and demand more sustainable in the leading timber producing regions of the world. Sustainable development implies not consuming more resources today than we can replace tomorrow, but sustainable forest management implies more than merely a non-declining supply of timber. Forests as a...

Factors affecting bee communities in forest openings and adjacent mature forest

Treesearch

H. Patrick Roberts; David I. King; Joan Milam

2017-01-01

Anthropogenic disturbance of habitat is considered a contributing factor of pollinator declines, but some disturbances such as silviculture, may have positive implications for pollinator communities. Silviculture is a key source of disturbance in the eastern USA and thus, developing a better understanding of its ramifications for these keystone species is important for...

Timber resource of Missouri's Eastern Ozarks, 1972.

Treesearch

Burton L. Essex; John S. Jr. Spencer

1974-01-01

The third timber inventory of Missouri's Eastern Ozarks Forest Survey Unit shows that there was a substantial gain in the volume of growing stock and smaller but sizable gain in the volume of sawtimber between 1959 and 1972; however, the area of commercial forest land declined slightly. This report gives statistical highlights and tables presenting detailed...

Wisconsin's 1968 timber resource--a perspective.

Treesearch

John S. Jr. Spencer; Harry W. Thorne

1972-01-01

The third inventory of Wisconsin's timber resource shows substantial gains in growing-stock and sawtimber volumes since 1956, in spite of a small decline in area of commercial forest land. Presented are text and statistics on forest area and timber volume, growth, mortality, ownership, stocking, and use in 1968. Two 30-year projections of timber growth, removals...

Area requirements and landscape-level factors influencing shrubland birds

Treesearch

H. Patrick Roberts; David I. King

2017-01-01

Declines in populations of birds that breed in disturbance-dependent early-successional forest have largely been ascribed to habitat loss. Clearcutting is an efficient and effective means for creating earlysuccessional vegetation; however, negative public perceptions of clearcutting and the small parcel size typical of private forested land in much of the eastern...

Aspen, climate, and sudden decline in western USA

Treesearch

Gerald E. Rehfeldt; Dennis E. Ferguson; Nicholas L. Crookston

2009-01-01

A bioclimate model predicting the presence or absence of aspen, Populus tremuloides, in western USA from climate variables was developed by using the Random Forests classification tree on Forest Inventory data from about 118,000 permanent sample plots. A reasonably parsimonious model used eight predictors to describe aspen's climate profile. Classification errors...

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...

More than Just Trees: Assessing Reforestation Success in Tropical Developing Countries

ERIC Educational Resources Information Center

Le, Hai Dinh; Smith, Carl; Herbohn, John; Harrison, Stephen

2012-01-01

Rural communities in many parts of the tropics are dependent of forests for their livelihoods and for environmental services. Forest resources in the tropics have declined rapidly over the past century and therefore many developing countries in the tropics have reforestation programs. Although reforestation is a long-term process with long-term…

Spatial models reveal the microclimatic buffering capacity of old-growth forests

Treesearch

Sarah J. K. Frey; Adam S. Hadley; Sherri L. Johnson; Mark Schulze; Julia A. Jones; Matthew. G. Betts

2016-01-01

Climate change is predicted to cause widespread declines in biodiversity, but these predictions are derived from coarse-resolution climate models applied at global scales. Such models lack the capacity to incorporate microclimate variability, which is critical to biodiversity microrefugia. In forested montane regions, microclimate is thought to be influenced by...

Songbird use of regenerating forest, glade, and edge habitat types

Treesearch

Alix D. Fink; Frank R., III Thompson; April A. Tudor

2006-01-01

Population numbers of many bird species associated with early-successional or disturbance-dependent habitat types are declining. We used an information-theoretic approach to evaluate hypotheses concerning factors affecting breeding bird densities in different early-successional habitat types. We studied shrubland bird communities in 3- to 5-year-old regenerating forest...

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.

Managing an oak decline crisis in Oakville, Ontario: lessons learned

Treesearch

Peter A. Williams; John W. McNeil; Kurt W. Gottschalk; Robert A. Haack

2013-01-01

The town of Oakville, Ontario, is located along the north shore of Lake Ontario between Toronto and Hamilton. In the fall of 2002, significant oak (Quercus spp.) mortality was observed at Oakville's Iroquois Shoreline Woods Park, an environmentally significant forest remnant noted for its oak-dominated forests. Investigations suggested that oak...

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...

Conservation of genetic diversity in slippery elm (Ulmus rubra) in Wisconsin despite the devastating impact of Dutch elm disease

USDA-ARS?s Scientific Manuscript database

Forest trees tend to be genetically diverse, a condition related to their longevity, outcrossing mating system and extensive gene flow that maintains high levels of genetic diversity within populations. Forest pest epidemics are responsible for many historic and contemporary population declines repo...

Altered species interactions and implications for natural regeneration in whitebark pine communities

Treesearch

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

2011-01-01

Whitebark pine (Pinus albicaulis) decline has altered trophic interactions and led to changes in community dynamics in many Rocky Mountain subalpine forests (McKinney and Tomback 2007). Here we discuss how altered species interactions, driven by disproportionate whitebark pine mortality, constrain the capability of whitebark pine forests to contribute genetic material...

Mitigating budget constraints on visitation volume surveys: the case of U.S. National forests

Treesearch

Ashley E. Askew; Donald B.K. English; Stanley J. Zarnoch; Neelam C. Poudyal; J.M. Bowker

2014-01-01

Stratified random sampling (SRS) provides a scientifically based estimate of a population comprising mutually exclusive, homogenous subgroups. In the National Visitor Use Monitoring (NVUM) program, SRS is used to estimate recreation visitation and visitor characteristics across activities on National forests. However, with rising costs and declining budgets, carrying...

Population ecology, habitat requirements, and conservation of neotropical migratory birds

Treesearch

Deborah M. Finch

1991-01-01

This report was prepared in support of the National Fish and Wildlife Foundation's Neotropical Migratory Bird Conservation Program and the USDA Forest Service's role in the program. Recent analyses of data on forest-dwelling species, many of which are neotropical migrants, show population declines in many North American areas. The literature review summarizes...

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...

Breeding bird communities of the hardwood ecosystem experiment

Treesearch

Melissa C. Malloy; John B. Dunning

2013-01-01

Declining population trends of breeding birds associated with mature forests of the eastern and central United States have been a major concern for conservationists and land managers. As a landscape-scale, long-term, manipulative experiment, the Hardwood Ecosystem Experiment (HEE) in Indiana may provide important insights into factors associated with these declines....

Amphibians and wildfire in the U.S. Northwest

Treesearch

Blake R. Hossack

2006-01-01

Recent evidence of amphibian declines along with outbreaks of large wildfires in western North American conifer forests has underscored our lack of knowledge about effects of fire on amphibians in these ecosystems. Understanding the connection between amphibian declines and wildfire is proving complex in some areas because the past century of fire suppression and other...

Restoring whitebark pine ecosystems in the face of climate change

Treesearch

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

2017-01-01

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

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....

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 ...

Red-cockaded woodpecker recovery: An integrated strategy

Treesearch

D. Craig Rudolph; Richard N. Conner; Jeffrey R. Walters

2004-01-01

Populations of the red-cockaded woodpecker (Picoides borealis) have experienced massive declines since European colonization of North America. This is due to extensive habitat loss and alteration. Logging of old-growth pine forests and alteration of the fire regime throughout the historic range of the species were the primary causes of population decline. Listing of...

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...

Bird community composition

Treesearch

T.J. Antrobus; M.P. Guilfoyle; W.C. Barrow; Paul B. Hamel; J.S. Wakeley

2000-01-01

Neotropical migrants are birds that breed in North America and winter primarily in Central and South America. Longterm population studies of birds in the Eastern United States indicated declines of some forest-dwelling birds, many of which winter in the Neotropics (Peterjohn and others 1995). These declines were attributed to loss of wintering and breeding habitat due...

The changing science of forest health

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

Gray, G.; Clark, L.

In many western states, forest health is an immediate and growing concern. The pattern of historic use and management has altered the natural conditions of their ecosystems, making the forests much more susceptible to drought stresses, insects, and deseases. Scientists, resource managers, and policymakers are asking how healthy conditions can be restored, how further forest decline can be prevented, and how losses can be reduced. The general ecosystem approach is described, along with how science can be translated into action in a Sustaining Ecological Systems (SES) approach. The Blue Mountains in Oregon are highlighted as the specific example. An strategymore » for action on overall forest health is described.« less

Predicting impacts of future human population growth and development on occupancy rates of forest-dependent birds

USGS Publications Warehouse

Brown, Michelle L.; Donovan, Therese; Schwenk, W. Scott; Theobald, David M.

2014-01-01

Forest loss and fragmentation are among the largest threats to forest-dwelling wildlife species today, and projected increases in human population growth are expected to increase these threats in the next century. We combined spatially-explicit growth models with wildlife distribution models to predict the effects of human development on 5 forest-dependent bird species in Vermont, New Hampshire, and Massachusetts, USA. We used single-species occupancy models to derive the probability of occupancy for each species across the study area in the years 2000 and 2050. Over half a million new housing units were predicted to be added to the landscape. The maximum change in housing density was nearly 30 houses per hectare; however, 30% of the towns in the study area were projected to add less than 1 housing unit per hectare. In the face of predicted human growth, the overall occupancy of each species decreased by as much as 38% (ranging from 19% to 38% declines in the worst-case scenario) in the year 2050. These declines were greater outside of protected areas than within protected lands. Ninety-seven percent of towns experienced some decline in species occupancy within their borders, highlighting the value of spatially-explicit models. The mean decrease in occupancy probability within towns ranged from 3% for hairy woodpecker to 8% for ovenbird and hermit thrush. Reductions in occupancy probability occurred on the perimeters of cities and towns where exurban development is predicted to increase in the study area. This spatial approach to wildlife planning provides data to evaluate trade-offs between development scenarios and forest-dependent wildlife species.

Climate Induced Birch Mortality in Trans-Baikal Lake Region, Siberia

NASA Technical Reports Server (NTRS)

Kharuk, V. I.; Ranson, K. J.; Oskorbin, P. A.; Im, S. T.; Dvinskaya, M. L.

2013-01-01

The Trans-Baikal (or Zabailkal'e) region includes the forest-steppe ecotones south and east of Lake Baikal in Russia and has experienced drought for several years. The decline and mortality of birch (Betula pendula) stands within the forest-steppe ecotone Trans-Baikal region was studied based on a temporal series of satellite data, ground measurements, and tree ring analysis. During the first decade of the 21st century birch stands decline and mortality were observed on )about 5% of the total area of stands within our 1250 km(exp 2 study area. Birch forest decline and mortality occurs mainly at the margins of stands, within the forest-steppe ecotone on slopes with direct insolation. During the first decade of the 21st century summer (June-August) precipitation was about 25% below normal. Soil water content measurements were lowest within dead stands and highest within healthy stands and intermediate within damaged stands. Drought impact on stands was amplified by an increase in summer air temperatures (+0.9 C) in comparison with the previous decade. Tree ring data of ''surviving'' and ''dead'' tree groups showed a positive correlation with summer/annual precipitation and negative correlation with summer air temperatures. Temperature and precipitation extreme anomalies tend to occur in the region with a period of about 27 years. The observed anomaly was the most severe since the beginning of meteorological observations in the year 1900. Data for the other sites showed a positive climate impact on the growth and expansion of Siberian forests. That is, the same species (B. pendula) showed considerable increase (1.4 times both in height and stem volume) during 20th-21st centuries as temperature increased but precipitation remained at adequate levels.

Standardized Assessment of Biodiversity Trends in Tropical Forest Protected Areas: The End Is Not in Sight.

PubMed

Beaudrot, Lydia; Ahumada, Jorge A; O'Brien, Timothy; Alvarez-Loayza, Patricia; Boekee, Kelly; Campos-Arceiz, Ahimsa; Eichberg, David; Espinosa, Santiago; Fegraus, Eric; Fletcher, Christine; Gajapersad, Krisna; Hallam, Chris; Hurtado, Johanna; Jansen, Patrick A; Kumar, Amit; Larney, Eileen; Lima, Marcela Guimarães Moreira; Mahony, Colin; Martin, Emanuel H; McWilliam, Alex; Mugerwa, Badru; Ndoundou-Hockemba, Mireille; Razafimahaimodison, Jean Claude; Romero-Saltos, Hugo; Rovero, Francesco; Salvador, Julia; Santos, Fernanda; Sheil, Douglas; Spironello, Wilson R; Willig, Michael R; Winarni, Nurul L; Zvoleff, Alex; Andelman, Sandy J

2016-01-01

Extinction rates in the Anthropocene are three orders of magnitude higher than background and disproportionately occur in the tropics, home of half the world's species. Despite global efforts to combat tropical species extinctions, lack of high-quality, objective information on tropical biodiversity has hampered quantitative evaluation of conservation strategies. In particular, the scarcity of population-level monitoring in tropical forests has stymied assessment of biodiversity outcomes, such as the status and trends of animal populations in protected areas. Here, we evaluate occupancy trends for 511 populations of terrestrial mammals and birds, representing 244 species from 15 tropical forest protected areas on three continents. For the first time to our knowledge, we use annual surveys from tropical forests worldwide that employ a standardized camera trapping protocol, and we compute data analytics that correct for imperfect detection. We found that occupancy declined in 22%, increased in 17%, and exhibited no change in 22% of populations during the last 3-8 years, while 39% of populations were detected too infrequently to assess occupancy changes. Despite extensive variability in occupancy trends, these 15 tropical protected areas have not exhibited systematic declines in biodiversity (i.e., occupancy, richness, or evenness) at the community level. Our results differ from reports of widespread biodiversity declines based on aggregated secondary data and expert opinion and suggest less extreme deterioration in tropical forest protected areas. We simultaneously fill an important conservation data gap and demonstrate the value of large-scale monitoring infrastructure and powerful analytics, which can be scaled to incorporate additional sites, ecosystems, and monitoring methods. In an era of catastrophic biodiversity loss, robust indicators produced from standardized monitoring infrastructure are critical to accurately assess population outcomes and identify conservation strategies that can avert biodiversity collapse.

Effect of Experimentally Manipulated Fire Regimes on the Response of Forests to Drought

NASA Astrophysics Data System (ADS)

Refsland, T. K.; Knapp, B.; Fraterrigo, J.

2017-12-01

Climate change is expected to increase drought stress in many forests and alter fire regimes. Fire can reduce tree density and thus competition for limited water, but the effects of changing fire regimes on forest productivity during drought remain poorly understood. We measured the annual ring-widths of adult oak (Quercus spp.) trees in Mark Twain National Forest, Missouri USA that experienced unburned, annual or periodic (every 4 years) surface fire treatments from 1951 - 2015. Severe drought events were identified using the BILJOU water balance model. We determined the effect of fire treatment on stand-level annual growth rates as well as stand-level resistance and resilience to drought, defined as the drought-induced reduction in growth and post-drought recovery in growth, respectively. During favorable wet years, annual and periodic fire treatments reduced annual growth rates by approximately 10-15% relative to unburned controls (P < 0.001). Stand-level growth rates declined 22-40% during drought events (P < 0.001), but fire-driven changes to stand basal area had no effect on the resistance or resilience of trees to drought. The decline in annual growth rates of burned stands during favorable wet years was likely caused by increased nitrogen (N) limitation in burned plots. After 60 years of treatment, burned plots experienced 30% declines in total soil N relative to unburned plots. Our finding that drought resistance and resilience were similar across all treatments suggest that fire-driven reductions in stand density may have negligible effects on soil moisture availability during drought. Our results highlight that climate-fire interactions can have important long-term effects on forest productivity.

Tipping point of a conifer forest ecosystem under severe drought

NASA Astrophysics Data System (ADS)

Huang, Kaicheng; Yi, Chuixiang; Wu, Donghai; Zhou, Tao; Zhao, Xiang; Blanford, William J.; Wei, Suhua; Wu, Hao; Ling, Du; Li, Zheng

2015-02-01

Drought-induced tree mortality has recently received considerable attention. Questions have arisen over the necessary intensity and duration thresholds of droughts that are sufficient to trigger rapid forest declines. The values of such tipping points leading to forest declines due to drought are presently unknown. In this study, we have evaluated the potential relationship between the level of tree growth and concurrent drought conditions with data of the tree growth-related ring width index (RWI) of the two dominant conifer species (Pinus edulis and Pinus ponderosa) in the Southwestern United States (SWUS) and the meteorological drought-related standardized precipitation evapotranspiration index (SPEI). In this effort, we determined the binned averages of RWI and the 11 month SPEI within the month of July within each bin of 30 of RWI in the range of 0-3000. We found a significant correlation between the binned averages of RWI and SPEI at the regional-scale under dryer conditions. The tipping point of forest declines to drought is predicted by the regression model as SPEItp = -1.64 and RWItp = 0, that is, persistence of the water deficit (11 month) with intensity of -1.64 leading to negligible growth for the conifer species. When climate conditions are wetter, the correlation between the binned averages of RWI and SPEI is weaker which we believe is most likely due to soil water and atmospheric moisture levels no longer being the dominant factor limiting tree growth. We also illustrate a potential application of the derived tipping point (SPEItp = -1.64) through an examination of the 2002 extreme drought event in the SWUS conifer forest regions. Distinguished differences in remote-sensing based NDVI anomalies were found between the two regions partitioned by the derived tipping point.

Standardized Assessment of Biodiversity Trends in Tropical Forest Protected Areas: The End Is Not in Sight

PubMed Central

O'Brien, Timothy; Alvarez-Loayza, Patricia; Boekee, Kelly; Campos-Arceiz, Ahimsa; Eichberg, David; Espinosa, Santiago; Fegraus, Eric; Fletcher, Christine; Gajapersad, Krisna; Hallam, Chris; Hurtado, Johanna; Jansen, Patrick A.; Kumar, Amit; Larney, Eileen; Lima, Marcela Guimarães Moreira; Mahony, Colin; Martin, Emanuel H.; McWilliam, Alex; Mugerwa, Badru; Ndoundou-Hockemba, Mireille; Razafimahaimodison, Jean Claude; Romero-Saltos, Hugo; Rovero, Francesco; Salvador, Julia; Santos, Fernanda; Sheil, Douglas; Spironello, Wilson R.; Willig, Michael R.; Winarni, Nurul L.; Zvoleff, Alex; Andelman, Sandy J.

2016-01-01

Extinction rates in the Anthropocene are three orders of magnitude higher than background and disproportionately occur in the tropics, home of half the world’s species. Despite global efforts to combat tropical species extinctions, lack of high-quality, objective information on tropical biodiversity has hampered quantitative evaluation of conservation strategies. In particular, the scarcity of population-level monitoring in tropical forests has stymied assessment of biodiversity outcomes, such as the status and trends of animal populations in protected areas. Here, we evaluate occupancy trends for 511 populations of terrestrial mammals and birds, representing 244 species from 15 tropical forest protected areas on three continents. For the first time to our knowledge, we use annual surveys from tropical forests worldwide that employ a standardized camera trapping protocol, and we compute data analytics that correct for imperfect detection. We found that occupancy declined in 22%, increased in 17%, and exhibited no change in 22% of populations during the last 3–8 years, while 39% of populations were detected too infrequently to assess occupancy changes. Despite extensive variability in occupancy trends, these 15 tropical protected areas have not exhibited systematic declines in biodiversity (i.e., occupancy, richness, or evenness) at the community level. Our results differ from reports of widespread biodiversity declines based on aggregated secondary data and expert opinion and suggest less extreme deterioration in tropical forest protected areas. We simultaneously fill an important conservation data gap and demonstrate the value of large-scale monitoring infrastructure and powerful analytics, which can be scaled to incorporate additional sites, ecosystems, and monitoring methods. In an era of catastrophic biodiversity loss, robust indicators produced from standardized monitoring infrastructure are critical to accurately assess population outcomes and identify conservation strategies that can avert biodiversity collapse. PMID:26785119

Shifting Patterns of Boreal Forest Succession and Browning Over the Last 30 Years

NASA Astrophysics Data System (ADS)

Goulden, M.; Czimczik, C. I.; Randerson, J. T.

2017-12-01

Climate and fire largely control the productivity ("greenness") and biodiversity of boreal forests in North America. Our research focuses on better understanding: 1) the patterns of, controls on, and recent changes in North American Boreal Forest "Browning" and the declining Normalized Difference Vegetation Index (NDVI) observed in satellite records, and 2) the patterns of, controls on, and recent changes in North American Boreal Forest fire recovery and succession. Much of our effort has used the Landsat archive to analyze the patterns of wildfire and forest recovery along a transect cutting across central Canada; this study areas covers 3 Landsat rows x 25 paths with 2500 summer images. Key findings include: 1) Most (80-90%) of the recent NDVI trends in our study area are attributable to wildfire (areas that burned after 1995 and also before 1975 show browning; areas that burned in 1975-1995 show greening). 2) There are a significant number of non-fire related patches that show either browning or greening; some of these patches are related to fires or human disturbances that aren't in our disturbance database, but others occur in wetter areas, where there is a general tendency toward browning with many specific cases of greening. 3) Various remote sensing metrics yield complementary information providing a clearer sense of the biophysical trends during succession. 4) We see evidence of accelerating succession from 1985-1995 to 2005-2015. This acceleration isn't dramatic, just 1-3 years during early recovery and more during later succession, but it is a consistent feature of the analysis. We are not seeing a systematic decline in old-stand LAI. While NDVI declines in old stands with the loss of deciduous trees, we are not seeing a systematic decrease in old stand LAI or wide spread mortality.

A casualty of climate change? Loss of freshwater forest islands on Florida's Gulf Coast.

PubMed

Langston, Amy K; Kaplan, David A; Putz, Francis E

2017-12-01

Sea level rise elicits short- and long-term changes in coastal plant communities by altering the physical conditions that affect ecosystem processes and species distributions. While the effects of sea level rise on salt marshes and mangroves are well studied, we focus on its effects on coastal islands of freshwater forest in Florida's Big Bend region, extending a dataset initiated in 1992. In 2014-2015, we evaluated tree survival, regeneration, and understory composition in 13 previously established plots located along a tidal creek; 10 plots are on forest islands surrounded by salt marsh, and three are in continuous forest. Earlier studies found that salt stress from increased tidal flooding prevented tree regeneration in frequently flooded forest islands. Between 1992 and 2014, tidal flooding of forest islands increased by 22%-117%, corresponding with declines in tree species richness, regeneration, and survival of the dominant tree species, Sabal palmetto (cabbage palm) and Juniperus virginiana (southern red cedar). Rates of S. palmetto and J. virginiana mortality increased nonlinearly over time on the six most frequently flooded islands, while salt marsh herbs and shrubs replaced forest understory vegetation along a tidal flooding gradient. Frequencies of tidal flooding, rates of tree mortality, and understory composition in continuous forest stands remained relatively stable, but tree regeneration substantially declined. Long-term trends identified in this study demonstrate the effect of sea level rise on spatial and temporal community reassembly trajectories that are dynamically re-shaping the unique coastal landscape of the Big Bend. © 2017 John Wiley & Sons Ltd.

Declines in low-elevation subalpine tree populations outpace growth in high-elevation populations with warming

DOE PAGES

Conlisk, Erin; Castanha, Cristina; Germino, Matthew J.; ...

2017-02-08

Species distribution shifts in response to climate change require that recruitment increase beyond current range boundaries. For trees with long life spans, the importance of climate-sensitive seedling establishment to the pace of range shifts has not been demonstrated quantitatively. Using spatially explicit, stochastic population models combined with data from long-term forest surveys, we explored whether the climate-sensitivity of recruitment observed in climate manipulation experiments was sufficient to alter populations and elevation ranges of two widely distributed, high-elevation North American conifers. Empirically observed, warming-driven declines in recruitment led to rapid modelled population declines at the low-elevation, ‘warm edge’ of subalpine forestmore » and slow emergence of populations beyond the high-elevation, ‘cool edge’. Because population declines in the forest occurred much faster than population emergence in the alpine, we observed range contraction for both species. For Engelmann spruce, this contraction was permanent over the modelled time horizon, even in the presence of increased moisture. For limber pine, lower sensitivity to warming may facilitate persistence at low elevations – especially in the presence of increased moisture – and rapid establishment above tree line, and, ultimately, expansion into the alpine. Synthesis. Assuming 21st century warming and no additional moisture, population dynamics in high-elevation forests led to transient range contractions for limber pine and potentially permanent range contractions for Engelmann spruce. Thus, limitations to seedling recruitment with warming can constrain the pace of subalpine tree range shifts.« less

Declines in low-elevation subalpine tree populations outpace growth in high-elevation populations with warming

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

Conlisk, Erin; Castanha, Cristina; Germino, Matthew J.

Species distribution shifts in response to climate change require that recruitment increase beyond current range boundaries. For trees with long life spans, the importance of climate-sensitive seedling establishment to the pace of range shifts has not been demonstrated quantitatively. Using spatially explicit, stochastic population models combined with data from long-term forest surveys, we explored whether the climate-sensitivity of recruitment observed in climate manipulation experiments was sufficient to alter populations and elevation ranges of two widely distributed, high-elevation North American conifers. Empirically observed, warming-driven declines in recruitment led to rapid modelled population declines at the low-elevation, ‘warm edge’ of subalpine forestmore » and slow emergence of populations beyond the high-elevation, ‘cool edge’. Because population declines in the forest occurred much faster than population emergence in the alpine, we observed range contraction for both species. For Engelmann spruce, this contraction was permanent over the modelled time horizon, even in the presence of increased moisture. For limber pine, lower sensitivity to warming may facilitate persistence at low elevations – especially in the presence of increased moisture – and rapid establishment above tree line, and, ultimately, expansion into the alpine. Synthesis. Assuming 21st century warming and no additional moisture, population dynamics in high-elevation forests led to transient range contractions for limber pine and potentially permanent range contractions for Engelmann spruce. Thus, limitations to seedling recruitment with warming can constrain the pace of subalpine tree range shifts.« less

Vegetation dynamics and rainfall sensitivity of the Amazon

PubMed Central

Hilker, Thomas; Lyapustin, Alexei I.; Tucker, Compton J.; Hall, Forrest G.; Myneni, Ranga B.; Wang, Yujie; Bi, Jian; Mendes de Moura, Yhasmin; Sellers, Piers J.

2014-01-01

We show that the vegetation canopy of the Amazon rainforest is highly sensitive to changes in precipitation patterns and that reduction in rainfall since 2000 has diminished vegetation greenness across large parts of Amazonia. Large-scale directional declines in vegetation greenness may indicate decreases in carbon uptake and substantial changes in the energy balance of the Amazon. We use improved estimates of surface reflectance from satellite data to show a close link between reductions in annual precipitation, El Niño southern oscillation events, and photosynthetic activity across tropical and subtropical Amazonia. We report that, since the year 2000, precipitation has declined across 69% of the tropical evergreen forest (5.4 million km2) and across 80% of the subtropical grasslands (3.3 million km2). These reductions, which coincided with a decline in terrestrial water storage, account for about 55% of a satellite-observed widespread decline in the normalized difference vegetation index (NDVI). During El Niño events, NDVI was reduced about 16.6% across an area of up to 1.6 million km2 compared with average conditions. Several global circulation models suggest that a rise in equatorial sea surface temperature and related displacement of the intertropical convergence zone could lead to considerable drying of tropical forests in the 21st century. Our results provide evidence that persistent drying could degrade Amazonian forest canopies, which would have cascading effects on global carbon and climate dynamics. PMID:25349419

Forest investigations by polarimetric AIRSAR data in the Harz mountains

NASA Technical Reports Server (NTRS)

Keil, M.; Poll, D.; Raupenstrauch, J.; Tares, T.; Winter, R.

1993-01-01

The Harz Mountains in the North of Germany have been a study site for several remote sensing investigations since 1985, as the mountainous area is one of the forest regions in Germany heavily affected by forest decline, especially in the high altitudes above 800 m. In a research program at the University of Berlin, methods are developed for improving remote sensing assessment of forest structure and forest state by additional GIS information, using several datasets for establishing a forest information system. The Harz has been defined as a test site for the SIR-C/X-SAR mission which is going to deliver multifrequency and multipolarizational SAR data from orbit. In a pilot project let by DLR-DFD, these data are to be investigated for forestry and ecology purposes. In preparing a flight campaign to the SIR-C / X-SAR mission, 'MAC EUROPE 1991', performed by NASA/JPL, an area of about 12 km in the Northern Harz was covered with multipolarizational AIRSAR data in the C-, L- and P-band, including the Brocken, the highest mountain of the Harz, with an altitude of 1142 m. The multiparameter AIRSAR data are investigated for their information content on the forest state, regarding the following questions: (1) information on forest stand parameters like forest types, age classes and crown density, especially for the separation of deciduous and coniferous forest; (2) information on the storm damages (since 1972) and the status of regeneration; (3) information on the status of forest destruction because of forest decline; and (4) influence of topography, local incidence angle and soil moisture on the SAR data. Within the project various methods and tools have been developed for the investigation of multipolarimetric radar backscatter responses and for discrimination purposes, in order to use the multipolarization information of the compressed Stokes matrix delivered by JPL.

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 very low pH clouds might be deacidified. That is, base gases (eg. ammonia) locally introduced into such clouds at the proper time may render them harmless upon impact with the forest canopy, and beneficial to regional water supply users.

Urbanization impacts on mammals across urban-forest edges and a predictive model of edge effects.

PubMed

Villaseñor, Nélida R; Driscoll, Don A; Escobar, Martín A H; Gibbons, Philip; Lindenmayer, David B

2014-01-01

With accelerating rates of urbanization worldwide, a better understanding of ecological processes at the wildland-urban interface is critical to conserve biodiversity. We explored the effects of high and low-density housing developments on forest-dwelling mammals. Based on habitat characteristics, we expected a gradual decline in species abundance across forest-urban edges and an increased decline rate in higher contrast edges. We surveyed arboreal mammals in sites of high and low housing density along 600 m transects that spanned urban areas and areas turn on adjacent native forest. We also surveyed forest controls to test whether edge effects extended beyond our edge transects. We fitted models describing richness, total abundance and individual species abundance. Low-density housing developments provided suitable habitat for most arboreal mammals. In contrast, high-density housing developments had lower species richness, total abundance and individual species abundance, but supported the highest abundances of an urban adapter (Trichosurus vulpecula). We did not find the predicted gradual decline in species abundance. Of four species analysed, three exhibited no response to the proximity of urban boundaries, but spilled over into adjacent urban habitat to differing extents. One species (Petaurus australis) had an extended negative response to urban boundaries, suggesting that urban development has impacts beyond 300 m into adjacent forest. Our empirical work demonstrates that high-density housing developments have negative effects on both community and species level responses, except for one urban adapter. We developed a new predictive model of edge effects based on our results and the literature. To predict animal responses across edges, our framework integrates for first time: (1) habitat quality/preference, (2) species response with the proximity to the adjacent habitat, and (3) spillover extent/sensitivity to adjacent habitat boundaries. This framework will allow scientists, managers and planners better understand and predict both species responses across edges and impacts of development in mosaic landscapes.

Urbanization Impacts on Mammals across Urban-Forest Edges and a Predictive Model of Edge Effects

PubMed Central

Villaseñor, Nélida R.; Driscoll, Don A.; Escobar, Martín A. H.; Gibbons, Philip; Lindenmayer, David B.

2014-01-01

With accelerating rates of urbanization worldwide, a better understanding of ecological processes at the wildland-urban interface is critical to conserve biodiversity. We explored the effects of high and low-density housing developments on forest-dwelling mammals. Based on habitat characteristics, we expected a gradual decline in species abundance across forest-urban edges and an increased decline rate in higher contrast edges. We surveyed arboreal mammals in sites of high and low housing density along 600 m transects that spanned urban areas and areas turn on adjacent native forest. We also surveyed forest controls to test whether edge effects extended beyond our edge transects. We fitted models describing richness, total abundance and individual species abundance. Low-density housing developments provided suitable habitat for most arboreal mammals. In contrast, high-density housing developments had lower species richness, total abundance and individual species abundance, but supported the highest abundances of an urban adapter (Trichosurus vulpecula). We did not find the predicted gradual decline in species abundance. Of four species analysed, three exhibited no response to the proximity of urban boundaries, but spilled over into adjacent urban habitat to differing extents. One species (Petaurus australis) had an extended negative response to urban boundaries, suggesting that urban development has impacts beyond 300 m into adjacent forest. Our empirical work demonstrates that high-density housing developments have negative effects on both community and species level responses, except for one urban adapter. We developed a new predictive model of edge effects based on our results and the literature. To predict animal responses across edges, our framework integrates for first time: (1) habitat quality/preference, (2) species response with the proximity to the adjacent habitat, and (3) spillover extent/sensitivity to adjacent habitat boundaries. This framework will allow scientists, managers and planners better understand and predict both species responses across edges and impacts of development in mosaic landscapes. PMID:24810286

Changes in turnover rather than production regulate biomass of ectomycorrhizal fungal mycelium across a Pinus sylvestris chronosequence.

PubMed

Hagenbo, Andreas; Clemmensen, Karina E; Finlay, Roger D; Kyaschenko, Julia; Lindahl, Björn D; Fransson, Petra; Ekblad, Alf

2017-04-01

In boreal forest soils, ectomycorrhizal fungi are fundamentally important for carbon (C) dynamics and nutrient cycling. Although their extraradical mycelium (ERM) is pivotal for processes such as soil organic matter build-up and nitrogen cycling, very little is known about its dynamics and regulation. In this study, we quantified ERM production and turnover, and examined how these two processes together regulated standing ERM biomass in seven sites forming a chronosequence of 12- to 100-yr-old managed Pinus sylvestris forests. This was done by determining ERM biomass, using ergosterol as a proxy, in sequentially harvested in-growth mesh bags and by applying mathematical models. Although ERM production declined with increasing forest age from 1.2 to 0.5 kg ha -1  d -1 , the standing biomass increased from 50 to 112 kg ha -1 . This was explained by a drastic decline in mycelial turnover from seven times to one time per year with increasing forest age, corresponding to mean residence times from 25 d up to 1 yr. Our results demonstrate that ERM turnover is the main factor regulating biomass across differently aged forest stands. Explicit inclusion of ERM parameters in forest ecosystem C models may significantly improve their capacity to predict responses of mycorrhiza-mediated processes to management and environmental changes. © 2016 The Authors. New Phytologist © 2016 New Phytologist Trust.

Effects of timber harvests and silvicultural edges on terrestrial salamanders.

PubMed

MacNeil, Jami E; Williams, Rod N

2014-01-01

Balancing timber production and conservation in forest management requires an understanding of how timber harvests affect wildlife species. Terrestrial salamanders are useful indicators of mature forest ecosystem health due to their importance to ecosystem processes and sensitivity to environmental change. However, the effects of timber harvests on salamanders, though often researched, are still not well understood. To further this understanding, we used artificial cover objects to monitor the relative abundance of terrestrial salamanders for two seasons (fall and spring) pre-harvest and five seasons post-harvest in six forest management treatments, and for three seasons post-harvest across the edge gradients of six recent clearcuts. In total, we recorded 19,048 encounters representing nine species of salamanders. We observed declines in mean encounters of eastern red-backed salamanders (Plethodon cinereus) and northern slimy salamanders (P. glutinosus) from pre- to post-harvest in group selection cuts and in clearcuts. However, we found no evidence of salamander declines at shelterwoods and forested sites adjacent to harvests. Edge effects induced by recent clearcuts influenced salamanders for approximately 20 m into the forest, but edge influence varied by slope orientation. Temperature, soil moisture, and canopy cover were all correlated with salamander counts. Our results suggest silvicultural techniques that remove the forest canopy negatively affect salamander relative abundance on the local scale during the years immediately following harvest, and that the depth of edge influence of clearcuts on terrestrial salamanders is relatively shallow (<20 m). Small harvests (<4 ha) and techniques that leave the forest canopy intact may be compatible with maintaining terrestrial salamander populations across a forested landscape. Our results demonstrate the importance of examining species-specific responses and monitoring salamanders across multiple seasons and years. Long-term monitoring will be necessary to understand the full impacts of forest management on terrestrial salamanders.

Soil Carbon Stocks Decrease following Conversion of Secondary Forests to Rubber (Hevea brasiliensis) Plantations

PubMed Central

de Blécourt, Marleen; Brumme, Rainer; Xu, Jianchu; Corre, Marife D.; Veldkamp, Edzo

2013-01-01

Forest-to-rubber plantation conversion is an important land-use change in the tropical region, for which the impacts on soil carbon stocks have hardly been studied. In montane mainland southeast Asia, monoculture rubber plantations cover 1.5 million ha and the conversion from secondary forests to rubber plantations is predicted to cause a fourfold expansion by 2050. Our study, conducted in southern Yunnan province, China, aimed to quantify the changes in soil carbon stocks following the conversion from secondary forests to rubber plantations. We sampled 11 rubber plantations ranging in age from 5 to 46 years and seven secondary forest plots using a space-for-time substitution approach. We found that forest-to-rubber plantation conversion resulted in losses of soil carbon stocks by an average of 37.4±4.7 (SE) Mg C ha−1 in the entire 1.2-m depth over a time period of 46 years, which was equal to 19.3±2.7% of the initial soil carbon stocks in the secondary forests. This decline in soil carbon stocks was much larger than differences between published aboveground carbon stocks of rubber plantations and secondary forests, which range from a loss of 18 Mg C ha−1 to an increase of 8 Mg C ha−1. In the topsoil, carbon stocks declined exponentially with years since deforestation and reached a steady state at around 20 years. Although the IPCC tier 1 method assumes that soil carbon changes from forest-to-rubber plantation conversions are zero, our findings show that they need to be included to avoid errors in estimating overall ecosystem carbon fluxes. PMID:23894456

Effects of Timber Harvests and Silvicultural Edges on Terrestrial Salamanders

PubMed Central

MacNeil, Jami E.; Williams, Rod N.

2014-01-01

Balancing timber production and conservation in forest management requires an understanding of how timber harvests affect wildlife species. Terrestrial salamanders are useful indicators of mature forest ecosystem health due to their importance to ecosystem processes and sensitivity to environmental change. However, the effects of timber harvests on salamanders, though often researched, are still not well understood. To further this understanding, we used artificial cover objects to monitor the relative abundance of terrestrial salamanders for two seasons (fall and spring) pre-harvest and five seasons post-harvest in six forest management treatments, and for three seasons post-harvest across the edge gradients of six recent clearcuts. In total, we recorded 19,048 encounters representing nine species of salamanders. We observed declines in mean encounters of eastern red-backed salamanders (Plethodon cinereus) and northern slimy salamanders (P. glutinosus) from pre- to post-harvest in group selection cuts and in clearcuts. However, we found no evidence of salamander declines at shelterwoods and forested sites adjacent to harvests. Edge effects induced by recent clearcuts influenced salamanders for approximately 20 m into the forest, but edge influence varied by slope orientation. Temperature, soil moisture, and canopy cover were all correlated with salamander counts. Our results suggest silvicultural techniques that remove the forest canopy negatively affect salamander relative abundance on the local scale during the years immediately following harvest, and that the depth of edge influence of clearcuts on terrestrial salamanders is relatively shallow (<20 m). Small harvests (<4 ha) and techniques that leave the forest canopy intact may be compatible with maintaining terrestrial salamander populations across a forested landscape. Our results demonstrate the importance of examining species-specific responses and monitoring salamanders across multiple seasons and years. Long-term monitoring will be necessary to understand the full impacts of forest management on terrestrial salamanders. PMID:25517409

Seasonal changes in needle water content and needle ABA concentration of Japanese red pine, Pinus densiflora, in declining forests on Mt. Gokurakuji, Hiroshima prefecture, Japan.

PubMed

Kume, Atsushi; Hanba, Yuko T; Nakane, Kaneyuki; Sakurai, Naoki; Sakugawa, Hiroshi

2006-05-01

To evaluate the effects of air pollution on the decline of Pinus densiflora forests, various research has been conducted around Mt. Gokurakuji (34 degrees 23'N, 132 degrees 19'E, 693 m a.s.l.) north of the Seto Inland Sea, west Japan. To investigate the mechanisms responsible for decreases in photosynthesis (Pn) and stomatal conductance (gl), delta13C of needles and seasonal changes in the water content (WC) and abscisic acid concentration (ABA) of needles were measured in various stands. The delta13C values were less negative in declining stands and younger needles. ABA and WC were not correlated with each other. WC decreased consistently with needle age while the ABA showed a minimum in August and a smaller content in older needles. Monthly precipitation and the daily maximum vapor pressure were not correlated with ABA and WC. In declining stands, WC and ABA tended to be higher and lower, respectively, than in nondeclining stands. These results suggest that the trees in declining stands received less water stress than those in nondeclining stands and the differences in gl and delta13C are not caused by the difference in water stress. The possibilities of the effects of air pollution and the infection of pine-wood nematode on the physiological decline on the pine needles are discussed.

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.

Twentieth-century decline of large-diameter trees in Yosemite National Park, California, USA

USGS Publications Warehouse

Lutz, J.A.; van Wagtendonk, J.W.; Franklin, J.F.

2009-01-01

Studies of forest change in western North America often focus on increased densities of small-diameter trees rather than on changes in the large tree component. Large trees generally have lower rates of mortality than small trees and are more resilient to climate change, but these assumptions have rarely been examined in long-term studies. We combined data from 655 historical (1932-1936) and 210 modern (1988-1999) vegetation plots to examine changes in density of large-diameter trees in Yosemite National Park (3027 km2). We tested the assumption of stability for large-diameter trees, as both individual species and communities of large-diameter trees. Between the 1930s and 1990s, large-diameter tree density in Yosemite declined 24%. Although the decrease was apparent in all forest types, declines were greatest in subalpine and upper montane forests (57.0% of park area), and least in lower montane forests (15.3% of park area). Large-diameter tree densities of 11 species declined while only 3 species increased. Four general patterns emerged: (1) Pinus albicaulis, Quercus chrysolepis, and Quercus kelloggii had increases in density of large-diameter trees occur throughout their ranges; (2) Pinus jeffreyi, Pinus lambertiana, and Pinus ponderosa, had disproportionately larger decreases in large-diameter tree densities in lower-elevation portions of their ranges; (3) Abies concolor and Pinus contorta, had approximately uniform decreases in large-diameter trees throughout their elevational ranges; and (4) Abies magnifica, Calocedrus decurrens, Juniperus occidentalis, Pinus monticola, Pseudotsuga menziesii, and Tsuga mertensiana displayed little or no change in large-diameter tree densities. In Pinus ponderosa-Calocedrus decurrens forests, modern large-diameter tree densities were equivalent whether or not plots had burned since 1936. However, in unburned plots, the large-diameter trees were predominantly A. concolor, C. decurrens, and Q. chrysolepis, whereas P. ponderosa dominated the large-diameter component of burned plots. Densities of large-diameter P. ponderosa were 8.1 trees ha-1 in plots that had experienced fire, but only 0.5 trees ha-1 in plots that remained unburned. ?? 2009 Elsevier B.V. All rights reserved.

Impacts of climate and insect defoliators on productivity and function of trembling aspen (Populus tremuloides) in Alaskan boreal forests

NASA Astrophysics Data System (ADS)

Boyd, M. A.; Walker, X. J.; Rogers, B. M.; Goetz, S. J.; Wagner, D.; Mack, M. C.

2017-12-01

Climate change has increased tree mortality and growth decline in forested ecosystems worldwide. In response to warming and drying of the boreal forest, trembling aspen (Populus tremuloides) has experienced recent large-scale productivity declines. Although declines in productivity are thought to be primarily a result of moistures stress, infestation is another major driver of aspen decline and may interact strongly with climate. Throughout interior Alaska widespread and consistent foliar damage by the aspen epidermal leaf miner Phyllocnistis populiella has been observed concurrent with some of the warmest and driest growing seasons on record. Here we use tree ring measurements and remote sensing indices of vegetation productivity (NDVI) to study the influence of leaf miner and climate on aspen productivity and physiology in the Alaskan boreal forest, and assess if NDVI reflects variations in these ground-based measurements. We assessed ring width and tree ring stable carbon isotope (d13C) response of aspen to infestation and a climate moisture index (CMI) from 2004 - 2014. We found that when growth was negatively correlated to infestation, then it was no longer positively influenced by moisture availability during the growing season. Regardless of the radial growth response to leaf mining, tree ring d13C decreased with increasing infestation. We also found that NDVI was influenced by leaf mining and showed a positive correlation with tree ring d13C, which suggests that NDVI is reflective of changes in tree characteristics under leaf mining that influence tree ring d13C. This finding also reveals the prospect of using satellite data to monitor fluctuations in tree physiology during leaf miner infestation. Our results indicate that aspen productivity will be severely hindered during leaf miner infestation, and that infestation will inhibit the ability of aspen to respond to favorable climate conditions by increasing growth and potentially photosynthesis. This suggests that the productivity, reproduction, and health of aspen in boreal forests, and in turn any related biophysical or carbon sequestration benefits, may become limited under future warming if infestation by leaf miner continues or accelerates.

Group points to underlying causes of ecosystem, blodiversity loss

NASA Astrophysics Data System (ADS)

Showstack, Randy

Freshwater diversion, urban water pollution,and overfishing are leading to the decline of some of Pakistan's coastal mangrove ecosystems. In Mexico's Calakmul Biosphere Reserve, near the border of Guatemala, population growth and poverty are pushing forest clearing. Meanwhile, in Chilika Lake in southeast India, changes in economic policies and global markets have led to changes in commercial aquaculture that is partly responsible for the decline of local fisheries and the bird population.These are the conclusions of some of the 10 case studies contained in a World Wildlife Fund (WWF) report, issued on July 6, that examines forests, wetlands, steppes, mangroves, and other habitats to determine the underlying causes for biodiversity loss.

The vulnerability of Indo-Pacific mangrove forests to sea-level rise

USGS Publications Warehouse

Lovelock, Catherine E.; Cahoon, Donald R.; Friess, Daniel A.; Guntenspergen, Glenn R.; Krauss, Ken W.; Reef, Ruth; Rogers, Kerrylee; Saunders, Megan L.; Sidik, Frida; Swales, Andrew; Saintilan, Neil; Thuyen, Le Xuan; Triet, Tran

2015-01-01

Sea-level rise can threaten the long-term sustainability of coastal communities and valuable ecosystems such as coral reefs, salt marshes and mangroves. Mangrove forests have the capacity to keep pace with sea-level rise and to avoid inundation through vertical accretion of sediments, which allows them to maintain wetland soil elevations suitable for plant growth. The Indo-Pacific region holds most of the world’s mangrove forests, but sediment delivery in this region is declining, owing to anthropogenic activities such as damming of rivers. This decline is of particular concern because the Indo-Pacific region is expected to have variable, but high, rates of future sea-level rise. Here we analyse recent trends in mangrove surface elevation changes across the Indo-Pacific region using data from a network of surface elevation table instruments. We find that sediment availability can enable mangrove forests to maintain rates of soil-surface elevation gain that match or exceed that of sea-level rise, but for 69 per cent of our study sites the current rate of sea-level rise exceeded the soil surface elevation gain. We also present a model based on our field data, which suggests that mangrove forests at sites with low tidal range and low sediment supply could be submerged as early as 2070.

The vulnerability of Indo-Pacific mangrove forests to sea-level rise.

PubMed

Lovelock, Catherine E; Cahoon, Donald R; Friess, Daniel A; Guntenspergen, Glenn R; Krauss, Ken W; Reef, Ruth; Rogers, Kerrylee; Saunders, Megan L; Sidik, Frida; Swales, Andrew; Saintilan, Neil; Thuyen, Le Xuan; Triet, Tran

2015-10-22

Sea-level rise can threaten the long-term sustainability of coastal communities and valuable ecosystems such as coral reefs, salt marshes and mangroves. Mangrove forests have the capacity to keep pace with sea-level rise and to avoid inundation through vertical accretion of sediments, which allows them to maintain wetland soil elevations suitable for plant growth. The Indo-Pacific region holds most of the world's mangrove forests, but sediment delivery in this region is declining, owing to anthropogenic activities such as damming of rivers. This decline is of particular concern because the Indo-Pacific region is expected to have variable, but high, rates of future sea-level rise. Here we analyse recent trends in mangrove surface elevation changes across the Indo-Pacific region using data from a network of surface elevation table instruments. We find that sediment availability can enable mangrove forests to maintain rates of soil-surface elevation gain that match or exceed that of sea-level rise, but for 69 per cent of our study sites the current rate of sea-level rise exceeded the soil surface elevation gain. We also present a model based on our field data, which suggests that mangrove forests at sites with low tidal range and low sediment supply could be submerged as early as 2070.

Lessons about parks and poverty from a decade of forest loss and economic growth around Kibale National Park, Uganda.

PubMed

Naughton-Treves, Lisa; Alix-Garcia, Jennifer; Chapman, Colin A

2011-08-23

We use field data linked to satellite image analysis to examine the relationship between biodiversity loss, deforestation, and poverty around Kibale National Park (KNP) in western Uganda, 1996-2006. Over this decade, KNP generally maintained forest cover, tree species, and primate populations, whereas neighboring communal forest patches were reduced by half and showed substantial declines in tree species and primate populations. However, a bad decade for forest outside the park proved a prosperous one for most local residents. Panel data for 252 households show substantial improvement in welfare indicators (e.g., safer water, more durable roof material), with the greatest increases found among those with highest initial assets. A combination of regression analysis and matching estimators shows that although the poor tend to be located on the park perimeter, proximity to the park has no measureable effect on growth of productive assets. The risk for land loss among the poor was inversely correlated with proximity to the park, initial farm size, and decline in adjacent communal forests. We conclude the current disproportionate presence of poor households at the edge of the park does not signal that the park is a poverty trap. Rather, Kibale appears to provide protection against desperation sales and farm loss among those most vulnerable.

Lessons about parks and poverty from a decade of forest loss and economic growth around Kibale National Park, Uganda

PubMed Central

Naughton-Treves, Lisa; Alix-Garcia, Jennifer; Chapman, Colin A.

2011-01-01

We use field data linked to satellite image analysis to examine the relationship between biodiversity loss, deforestation, and poverty around Kibale National Park (KNP) in western Uganda, 1996–2006. Over this decade, KNP generally maintained forest cover, tree species, and primate populations, whereas neighboring communal forest patches were reduced by half and showed substantial declines in tree species and primate populations. However, a bad decade for forest outside the park proved a prosperous one for most local residents. Panel data for 252 households show substantial improvement in welfare indicators (e.g., safer water, more durable roof material), with the greatest increases found among those with highest initial assets. A combination of regression analysis and matching estimators shows that although the poor tend to be located on the park perimeter, proximity to the park has no measureable effect on growth of productive assets. The risk for land loss among the poor was inversely correlated with proximity to the park, initial farm size, and decline in adjacent communal forests. We conclude the current disproportionate presence of poor households at the edge of the park does not signal that the park is a poverty trap. Rather, Kibale appears to provide protection against desperation sales and farm loss among those most vulnerable. PMID:21873178

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

Quantifying density-independent mortality of temperate tree species

Treesearch

Heather E Lintz; Andrew N. Gray; Andrew Yost; Richard Sniezko; Chris Woodall; Matt Reilly; Karen Hutten; Mark Elliott

2016-01-01

Forest resilience to climate change is a topic of national concern as our standing assets and future forestsare important to our livelihood. Many tree species are predicted to decline or disappear while othersmay be able to adapt or migrate. Efforts to quantify and disseminate the current condition of forests areurgently needed to guide management and policy. Here, we...

Advancing the science of forest hydrology A challenge to agricultural and biological engineers

Treesearch

Devendra Amatya; Wayne Skaggs; Carl Trettin

2009-01-01

For more than a century, agricultural and biological engineers have provided major advances in science, engineering, and technology to increase food and fiber production to meet the demands of a rapidly growing global population. The land base for these technological advances has originated largely from forested lands, which have experienced dramatic declines over the...

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...

Monitoring the Health of Sugar Maple, "Acer Saccharum"

ERIC Educational Resources Information Center

Carlson, Martha

2013-01-01

The sugar maple, "Acer saccharum," is projected to decline and die in 88 to 100 percent of its current range in the United States. An iconic symbol of the northeastern temperate forest and a dominant species in this forest, the sugar maple is identified as the most sensitive tree in its ecosystem to rising temperatures and a warming…

Landslide initiation, runout, and deposition within clearcuts and old-growth forests of Alaska.

Treesearch

A.C. Johnson; D.N. Swanston; K.E. McGee

2000-01-01

More than 300 landslides and debris flows were triggered by an October 1993 storm on Prince of Wales Island, southeast Alaska. Initiation, runout, and deposition patterns of landslides that occurred within clearcuts, second-growth, and old-growth forests were examined. Blowdown and snags, associated with cedar decline and "normal" rates of mortality, were...

The paleoecology of fire and oaks in eastern forests

Treesearch

William A. III Patterson

2006-01-01

Oaks (Quercus spp.) currently dominate eastern deciduous forests, but are widely perceived as declining, with regeneration inadequate to perpetuate many stands. Most stands regenerated following fire in the 19th and early 20th centuries, and a lack of recent fire is viewed as contributing to the shortage of sapling and pole-size stands. But paleoecological studies...

Forest Field Trips among High School Science Teachers in the Southern Piedmont

ERIC Educational Resources Information Center

McCabe, Shannon M.; Munsell, John F.; Seiler, John R.

2014-01-01

Students benefit in many ways by taking field trips to forests. Improved academic performance, increased participation in outdoor recreation, and a better grasp of natural resources management are some of the advantages. However, trips are not easy for teachers to organize and lead. Declining budgets, on-campus schedules, and standards of learning…

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-...

Deriving habitat models for northern long-eared bats from historical detection data: a case study using the Fernow Experimental Forest

Treesearch

W. Mark Ford; Alexander Silvis; Jane L. Rodrigue; Andrew B. Kniowski; Joshua B. Johnson

2016-01-01

The listing of the northern long-eared bat (Myotis septentrionalis) as federally threatened under the Endangered Species Act following severe population declines from white-nose syndrome presents considerable challenges to natural resource managers. Because the northern long-eared bat is a forest habitat generalist, development of effective...

Relationships among North American songbird trends, habitat fragmentation, and landscape occupancy

Treesearch

Therese M. Donovan; Curtis H. Flather

2002-01-01

Fragmentation of breeding habitat has been hypothesized as a cause of population declines in forest-nesting migratory birds. Negative correlations between the degree of fragmentation and bird density or fecundity at local or regional scales support the fragmentation hypothesis. Yet, in spite of reduced fecundity and densities in fragmented systems, many forest-nesting...

Some effects of forest preservation

Treesearch

William B. Leak

1974-01-01

Long-term preservation (no cutting) of a deciduous forest stand in New Hampshire is leading toward stable populations of beech, sugar maple, striped maple, mountain maple, and hobblebush, coupled with a decline or complete disappearance of other woody species. The humus has stabilized at a depth no greater than that of cut stands. Nitrate discharge in the streams is...

The biology of amphibians and reptiles in old-growth forests in the Pacific Northwest.

Treesearch

A.P. Blaustein; J.J. Beatty; D.H. Olson; R.M. Storm

1995-01-01

The amphibian and reptile fauna of older forest ecosystems in the Pacific Northwest includes several endemic species, species with unique behavioral and ecological characteristics, and species whose populations have been in decline in recent years. We review the biology of these species and include information on their distinguishing characteristics, behavior, and...

Special forest products: an east-side perspective.

Treesearch

William E. Schlosser; Keith A. Blatner

1997-01-01

The special forest products industry has gained increasing attention, as timber harvest levels in the Pacific Northwest have declined, and has been heralded, at least by some, as a partial solution to the employment problems common throughout the rural areas of Washington, Oregon, Idaho, and Montana To date, relatively little work has been published on those portions...

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...

Elevational shifts in thermal suitability for mountain pine beetle population growth in a changing climate

Treesearch

Barbara J. Bentz; Jacob P. Duncan; James A. Powell

2016-01-01

Future forests are being shaped by changing climate and disturbances. Climate change is causing large-scale forest declines globally, in addition to distributional shifts of many tree species. Because environmental cues dictate insect seasonality and population success, climate change is also influencing tree-killing bark beetles. The mountain pine beetle,...

Monitoring environmental stress in forest trees using biochemical and physiological markers

Treesearch

R. Minocha; S.C. Minocha; S. Long

2003-01-01

Our objective was to determine the usefulness of polyamines, particularly putrescine, and amino acids such as arginine, as foliar indicators of abiotic stress in visually asymptomatic trees. An evaluation of apparently healthy trees is essential in developing risk assessment and stress remediation strategies for forest trees prior to the onset of obvious decline....

Western white pine growth relative to forest openings

Treesearch

Theresa B. Jain; Russell T. Graham; Penelope Morgan

2004-01-01

In northern Rocky Mountains moist forests, timber harvesting, fire exclusion, and an introduced stem disease have contributed to the decline in western white pine (Pinus monticola Dougl. ex D. Don) abundance (from 90% to 10% of the area). Relations between canopy openings (0.1-15 ha) and western white pine growth within different physical settings are identified....

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...

Marine habitat selection by marbled murrelets (Brachyramphus marmoratus) during the breeding season

Treesearch

Teresa J. Lorenz; Martin G. Raphael; Thomas D. Bloxton; Christian Andrew Hagen

2016-01-01

The marbled murrelet (Brachyramphus marmoratus) is a declining seabird that is wellknown for nesting in coastal old-growth forests in the Pacific Northwest. Most studies of habitat selection have focused on modeling terrestrial nesting habitat even though marine habitat is believed to be a major contributor to population declines in some regions....

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...

Use of stable isotope ratios for evaluating sulfur sources and losses at the Hubbard Brook Experimental Forest

Treesearch

M.J. Mitchell; B. Mayer; S.W. Bailey; J.W. Hornbeck; C. Alewell; C.T. Driscoll; G.E. Likens

2001-01-01

Anthropogenic S emissions have been declining in eastern North America since the early 1970s. Declines in atmospheric S deposition have resulted in decreases in concentrations and fluxes of SO42-) in precipitation and drainage waters. Recent S mass balance studies have shown that the outflow of SO4...

Forest statistics for Georgia, 1989

Treesearch

Michael T. Thompson

1989-01-01

Since 1982, area of timberland in Georgia has declined by about 102,000 acres to 23.6 million acres. Nonindustrial private owners control 68 percent of the State's timberland. New pine stands established by artificial and natural means exceeded the area of pine harvested by over 3 percent. Number of softwood stems declined in all diameter classes through the 14-...

An evaluation of powerline rights-of-way as habitat for early-successional shrubland birds

Treesearch

David I. King; Bruce E. Byers

2002-01-01

Recent population declines among bird species that breed in early-successional shrubland habitats in the eastern United States have been associated with declines in habitat availability. Forest succession has eliminated shrublands in many locations, but powerline rights-of-way constitute a potential reservoir of shrubland habitat for birds. We studied 2 populations of...

Biology and Sampling of Red Oak Borer Populations in the Ozark Mountains of Arkansas

Treesearch

Damon Crook; Fred Stephen; Melissa Fierke; Dana Kinney; Vaughn Silisbury

2004-01-01

A complex interaction of multiple factors has resulted in >75 percent mortality/decline of more than 1 million acres of red oak (Quercus, subgenus Erythrobalanus) on the Ozark-St. Francis National Forests. The most striking feature of this oak decline event is an unprecedented outbreak of red oak borer. A visual stand assessment...

HOW to Identify and Manage Ash Yellows in Forest Stands and Home Landscapes

Treesearch

Steven Katovich; Wayne A. Sinclair

1994-01-01

Ash yellows is a recently discovered disease that causes slow growth and decline of ash (Fraxinus) species. Ash yellows went undetected until the 1980's because its symptoms were not differentiated from those of decline caused by adverse environmental factors such as drought, shallow soils, flooding, or parasitism by opportunistic fungi. Current knowledge supports...

Assessing land ownership as a driver of change in the distribution, structure, and composition of California's forests.

NASA Astrophysics Data System (ADS)

Easterday, K.; Kelly, M.; McIntyre, P. J.

2015-12-01

Climate change is forecasted to have considerable influence on the distribution, structure, and function of California's forests. However, human interactions with forested landscapes (e.g. fire suppression, resource extraction and etc.) have complicated scientific understanding of the relative contributions of climate change and anthropogenic land management practices as drivers of change. Observed changes in forest structure towards smaller, denser forests across California have been attributed to both climate change (e.g. increased temperatures and declining water availability) and management practices (e.g. fire suppression and logging). Disentangling how these drivers of change act both together and apart is important to developing sustainable policy and land management practices as well as enhancing knowledge of human and natural system interactions. To that end, a comprehensive historical dataset - the Vegetation Type Mapping project (VTM) - and a modern forest inventory dataset (FIA) are used to analyze how spatial variations in vegetation composition and structure over a ~100 year period can be explained by land ownership.Climate change is forecasted to have considerable influence on the distribution, structure, and function of California's forests. However, human interactions with forested landscapes (e.g. fire suppression, resource extraction and etc.) have complicated scientific understanding of the relative contributions of climate change and anthropogenic land management practices as drivers of change. Observed changes in forest structure towards smaller, denser forests across California have been attributed to both climate change (e.g. increased temperatures and declining water availability) and management practices (e.g. fire suppression and logging). Disentangling how these drivers of change act both together and apart is important to developing sustainable policy and land management practices as well as enhancing knowledge of human and natural system interactions. To that end, a comprehensive historical dataset - the Vegetation Type Mapping project (VTM) - and a modern forest inventory dataset (FIA) are used to analyze how spatial variations in vegetation composition and structure over a ~100 year period can be explained by land ownership.

Effects of Climate Variability and Accelerated Forest Thinning on Watershed-Scale Runoff in Southwestern USA Ponderosa Pine Forests

PubMed Central

Robles, Marcos D.; Marshall, Robert M.; O'Donnell, Frances; Smith, Edward B.; Haney, Jeanmarie A.; Gori, David F.

2014-01-01

The recent mortality of up to 20% of forests and woodlands in the southwestern United States, along with declining stream flows and projected future water shortages, heightens the need to understand how management practices can enhance forest resilience and functioning under unprecedented scales of drought and wildfire. To address this challenge, a combination of mechanical thinning and fire treatments are planned for 238,000 hectares (588,000 acres) of ponderosa pine (Pinus ponderosa) forests across central Arizona, USA. Mechanical thinning can increase runoff at fine scales, as well as reduce fire risk and tree water stress during drought, but the effects of this practice have not been studied at scales commensurate with recent forest disturbances or under a highly variable climate. Modifying a historical runoff model, we constructed scenarios to estimate increases in runoff from thinning ponderosa pine at the landscape and watershed scales based on driving variables: pace, extent and intensity of forest treatments and variability in winter precipitation. We found that runoff on thinned forests was about 20% greater than unthinned forests, regardless of whether treatments occurred in a drought or pluvial period. The magnitude of this increase is similar to observed declines in snowpack for the region, suggesting that accelerated thinning may lessen runoff losses due to warming effects. Gains in runoff were temporary (six years after treatment) and modest when compared to mean annual runoff from the study watersheds (0–3%). Nonetheless gains observed during drought periods could play a role in augmenting river flows on a seasonal basis, improving conditions for water-dependent natural resources, as well as benefit water supplies for downstream communities. Results of this study and others suggest that accelerated forest thinning at large scales could improve the water balance and resilience of forests and sustain the ecosystem services they provide. PMID:25337823

Effects of climate variability and accelerated forest thinning on watershed-scale runoff in southwestern USA ponderosa pine forests.

PubMed

Robles, Marcos D; Marshall, Robert M; O'Donnell, Frances; Smith, Edward B; Haney, Jeanmarie A; Gori, David F

2014-01-01

The recent mortality of up to 20% of forests and woodlands in the southwestern United States, along with declining stream flows and projected future water shortages, heightens the need to understand how management practices can enhance forest resilience and functioning under unprecedented scales of drought and wildfire. To address this challenge, a combination of mechanical thinning and fire treatments are planned for 238,000 hectares (588,000 acres) of ponderosa pine (Pinus ponderosa) forests across central Arizona, USA. Mechanical thinning can increase runoff at fine scales, as well as reduce fire risk and tree water stress during drought, but the effects of this practice have not been studied at scales commensurate with recent forest disturbances or under a highly variable climate. Modifying a historical runoff model, we constructed scenarios to estimate increases in runoff from thinning ponderosa pine at the landscape and watershed scales based on driving variables: pace, extent and intensity of forest treatments and variability in winter precipitation. We found that runoff on thinned forests was about 20% greater than unthinned forests, regardless of whether treatments occurred in a drought or pluvial period. The magnitude of this increase is similar to observed declines in snowpack for the region, suggesting that accelerated thinning may lessen runoff losses due to warming effects. Gains in runoff were temporary (six years after treatment) and modest when compared to mean annual runoff from the study watersheds (0-3%). Nonetheless gains observed during drought periods could play a role in augmenting river flows on a seasonal basis, improving conditions for water-dependent natural resources, as well as benefit water supplies for downstream communities. Results of this study and others suggest that accelerated forest thinning at large scales could improve the water balance and resilience of forests and sustain the ecosystem services they provide.

Approaches to restoration of oak forests on farmed lowlands of the Mississippi river and its tributaries (Avances en la restauración de bosques de roble en tierras bajas agrícolas del Río Mississippi y sus tributaries)

Treesearch

E.S. Gardiner; D.C. Dey; John Stanturf; B.R. Lockhart

2010-01-01

The lowlands associated with the Mississippi River and its tributaries historically supported extensive broadleaf forests that were particularly rich in oak (Quercus spp.) species. Beginning in the 1700s, deforestation for agriculture substantially reduced the extent of the original forest, and fragmented the remainder into small parcels. More recently, declines in...

Selective logging: do rates of forest turnover in stems, species composition and functional traits decrease with time since disturbance? – A 45 year perspective

PubMed Central

Osazuwa-Peters, Oyomoare L.; Jiménez, Iván; Oberle, Brad; Chapman, Colin A.; Zanne, Amy E.

2015-01-01

Selective logging, the targeted harvesting of timber trees in a single cutting cycle, is globally rising in extent and intensity. Short-term impacts of selective logging on tropical forests have been widely investigated, but long-term effects on temporal dynamics of forest structure and composition are largely unknown. Understanding these long-term dynamics will help determine whether tropical forests are resilient to selective logging and inform choices between competing demands of anthropogenic use versus conservation of tropical forests. Forest dynamics can be studied within the framework of succession theory, which predicts that temporal turnover rates should decline with time since disturbance. Here, we investigated the temporal dynamics of a tropical forest in Kibale National Park, Uganda over 45 years following selective logging. We estimated turnover rates in stems, species composition, and functional traits (wood density and diameter at breast height), using observations from four censuses in 1989, 1999, 2006, and 2013, of stems ≥ 10 cm diameter within 17 unlogged and 9 logged 200 × 10 m vegetation plots. We used null models to account for interdependencies among turnover rates in stems, species composition, and functional traits. We tested predictions that turnover rates should be higher and decrease with increasing time since the selective logging event in logged forest, but should be less temporally variable in unlogged forest. Overall, we found higher turnover rates in logged forest for all three attributes, but turnover rates did not decline through time in logged forest and was not less temporally variable in unlogged forest. These results indicate that successional models that assume recovery to pre-disturbance conditions are inadequate for predicting the effects of selective logging on the dynamics of the tropical forest in Kibale. Selective logging resulted in persistently higher turnover rates, which may compromise the carbon storage capacity of Kibale’s forest. Selective logging effects may also interact with effects from other global trends, potentially causing major long-term shifts in the dynamics of tropical forests. Similar studies in tropical forests elsewhere will help determine the generality of these conclusions. Ultimately, the view that selective logging is a benign approach to the management of tropical forests should be reconsidered in the light of studies of the effects of this practice on long-term forest dynamics. PMID:26339115

Selective logging: do rates of forest turnover in stems, species composition and functional traits decrease with time since disturbance? - A 45 year perspective.

PubMed

Osazuwa-Peters, Oyomoare L; Jiménez, Iván; Oberle, Brad; Chapman, Colin A; Zanne, Amy E

2015-12-01

Selective logging, the targeted harvesting of timber trees in a single cutting cycle, is globally rising in extent and intensity. Short-term impacts of selective logging on tropical forests have been widely investigated, but long-term effects on temporal dynamics of forest structure and composition are largely unknown. Understanding these long-term dynamics will help determine whether tropical forests are resilient to selective logging and inform choices between competing demands of anthropogenic use versus conservation of tropical forests. Forest dynamics can be studied within the framework of succession theory, which predicts that temporal turnover rates should decline with time since disturbance. Here, we investigated the temporal dynamics of a tropical forest in Kibale National Park, Uganda over 45 years following selective logging. We estimated turnover rates in stems, species composition, and functional traits (wood density and diameter at breast height), using observations from four censuses in 1989, 1999, 2006, and 2013, of stems ≥ 10 cm diameter within 17 unlogged and 9 logged 200 × 10 m vegetation plots. We used null models to account for interdependencies among turnover rates in stems, species composition, and functional traits. We tested predictions that turnover rates should be higher and decrease with increasing time since the selective logging event in logged forest, but should be less temporally variable in unlogged forest. Overall, we found higher turnover rates in logged forest for all three attributes, but turnover rates did not decline through time in logged forest and was not less temporally variable in unlogged forest. These results indicate that successional models that assume recovery to pre-disturbance conditions are inadequate for predicting the effects of selective logging on the dynamics of the tropical forest in Kibale. Selective logging resulted in persistently higher turnover rates, which may compromise the carbon storage capacity of Kibale's forest. Selective logging effects may also interact with effects from other global trends, potentially causing major long-term shifts in the dynamics of tropical forests. Similar studies in tropical forests elsewhere will help determine the generality of these conclusions. Ultimately, the view that selective logging is a benign approach to the management of tropical forests should be reconsidered in the light of studies of the effects of this practice on long-term forest dynamics.

Drought drives rapid shifts in soil biogeochemistry and greenhouse gas emissions in a wet tropical forest

NASA Astrophysics Data System (ADS)

O'Connell, C.; Silver, W. L.; Ruan, L.

2016-12-01

Global circulation models suggest that climate change will increase the frequency and severity of drought in the humid tropics (Neelin et al., 2006). There is considerable uncertainty about the effects of drought on biogeochemical cycling in these ecosystems (Chambers et al., 2012), which play a key role in global carbon (C) and nitrogen (N) budgets (Vitousek & Sanford, 1986; Wright, 2005; Le Quéré et al., 2009). We used an automated sensor array to determine the effects of a recent severe drought on soil moisture, oxygen (O2), greenhouse gas emissions, and key nutrients across a wet tropical forest landscape. The onset of drought led to a rapid decline in soil moisture (46% drop in 21 days) and an associated rise in soil aeration. Drying also led to significant declines in inorganic P concentrations, an element commonly limiting to net primary productivity (NPP) in humid tropical forests (Cleveland et al. 2011). Drought increased soil carbon dioxide (CO2) emissions from slopes by 60% (from 3.79 ± 2.92 to 6.06 ± 4.26 µmol m-2 s-1) and valleys by 163% (from 0.57 ± 0.17 to 1.51 ± 0.75 µmol m-2 s-1). Methane (CH4) fluxes declined by 90% in valleys after the drought (from 17.43 ± 29.60 to 1.67 ± 4.09 nmol m-2 s-1) but increased above pre-drought baseline by tenfold and hundredfold in ridges and slopes, respectively, post-drought, offsetting the initial decline in soil CH4 emissions. Soil moisture and soil O2 concentrations were slow to recover after the onset of rains, effectively increasing the length of the drought effect by up to 65%. Results indicate that drought is likely to result in soil C losses and increased soil P limitation, potentially decreasing tropical forest C uptake and storage in the future.

Avian species richness in relation to intensive forest management practices in early seral tree plantations.

PubMed

Jones, Jay E; Kroll, Andrew J; Giovanini, Jack; Duke, Steven D; Ellis, Tana M; Betts, Matthew G

2012-01-01

Managers of landscapes dedicated to forest commodity production require information about how practices influence biological diversity. Individual species and communities may be threatened if management practices truncate or simplify forest age classes that are essential for reproduction and survival. For instance, the degradation and loss of complex diverse forest in young age classes have been associated with declines in forest-associated Neotropical migrant bird populations in the Pacific Northwest, USA. These declines may be exacerbated by intensive forest management practices that reduce hardwood and broadleaf shrub cover in order to promote growth of economically valuable tree species in plantations. We used a Bayesian hierarchical model to evaluate relationships between avian species richness and vegetation variables that reflect stand management intensity (primarily via herbicide application) on 212 tree plantations in the Coast Range, Oregon, USA. Specifically, we estimated the influence of broadleaf hardwood vegetation cover, which is reduced through herbicide applications, on bird species richness and individual species occupancy. Our model accounted for imperfect detection. We used average predictive comparisons to quantify the degree of association between vegetation variables and species richness. Both conifer and hardwood cover were positively associated with total species richness, suggesting that these components of forest stand composition may be important predictors of alpha diversity. Estimates of species richness were 35-80% lower when imperfect detection was ignored (depending on covariate values), a result that has critical implications for previous efforts that have examined relationships between forest composition and species richness. Our results revealed that individual and community responses were positively associated with both conifer and hardwood cover. In our system, patterns of bird community assembly appear to be associated with stand management strategies that retain or increase hardwood vegetation while simultaneously regenerating the conifer cover in commercial tree plantations.

Degradation of Root Community Traits as Indicator for Transformation of Tropical Lowland Rain Forests into Oil Palm and Rubber Plantations

PubMed Central

Edy, Nur; Meyer, Marike; Corre, Marife D.; Polle, Andrea

2015-01-01

Conversion of tropical forests into intensely managed plantations is a threat to ecosystem functions. On Sumatra, Indonesia, oil palm (Elaeis guineensis) plantations are rapidly expanding, displacing rain forests and extensively used rubber (Hevea brasiliensis) agro-forests. Here, we tested the influence of land use systems on root traits including chemical traits (carbon, nitrogen, mineral nutrients, potentially toxic elements [aluminium, iron] and performance traits (root mass, vitality, mycorrhizal colonization). Traits were measured as root community-weighed traits (RCWTs) in lowland rain forests, in rubber agro-forests mixed with rain forest trees, in rubber and oil palm plantations in two landscapes (Bukit Duabelas and Harapan, Sumatra). We hypothesized that RCWTs vary with land use system indicating increasing transformation intensity and loss of ecosystem functions. The main factors found to be related to increasing transformation intensity were declining root vitality and root sulfur, nitrogen, carbon, manganese concentrations and increasing root aluminium and iron concentrations as well as increasing spore densities of arbuscular mycorrhizas. Mycorrhizal abundance was high for arbuscular and low for ectomycorrhizas and unrelated to changes in RCWTs. The decline in RCWTs showed significant correlations with soil nitrogen, soil pH and litter carbon. Thus, our study uncovered a relationship between deteriorating root community traits and loss of ecosystem functionality and showed that increasing transformation intensity resulted in decreasing root nutrition and health. Based on these results we suggest that land management that improves root vitality may enhance the ecological functions of intense tropical production systems. PMID:26366576

Degradation of Root Community Traits as Indicator for Transformation of Tropical Lowland Rain Forests into Oil Palm and Rubber Plantations.

PubMed

Sahner, Josephine; Budi, Sri Wilarso; Barus, Henry; Edy, Nur; Meyer, Marike; Corre, Marife D; Polle, Andrea

2015-01-01

Conversion of tropical forests into intensely managed plantations is a threat to ecosystem functions. On Sumatra, Indonesia, oil palm (Elaeis guineensis) plantations are rapidly expanding, displacing rain forests and extensively used rubber (Hevea brasiliensis) agro-forests. Here, we tested the influence of land use systems on root traits including chemical traits (carbon, nitrogen, mineral nutrients, potentially toxic elements [aluminium, iron] and performance traits (root mass, vitality, mycorrhizal colonization). Traits were measured as root community-weighed traits (RCWTs) in lowland rain forests, in rubber agro-forests mixed with rain forest trees, in rubber and oil palm plantations in two landscapes (Bukit Duabelas and Harapan, Sumatra). We hypothesized that RCWTs vary with land use system indicating increasing transformation intensity and loss of ecosystem functions. The main factors found to be related to increasing transformation intensity were declining root vitality and root sulfur, nitrogen, carbon, manganese concentrations and increasing root aluminium and iron concentrations as well as increasing spore densities of arbuscular mycorrhizas. Mycorrhizal abundance was high for arbuscular and low for ectomycorrhizas and unrelated to changes in RCWTs. The decline in RCWTs showed significant correlations with soil nitrogen, soil pH and litter carbon. Thus, our study uncovered a relationship between deteriorating root community traits and loss of ecosystem functionality and showed that increasing transformation intensity resulted in decreasing root nutrition and health. Based on these results we suggest that land management that improves root vitality may enhance the ecological functions of intense tropical production systems.

Pervasive Rise of Small-scale Deforestation in Amazonia.

PubMed

Kalamandeen, Michelle; Gloor, Emanuel; Mitchard, Edward; Quincey, Duncan; Ziv, Guy; Spracklen, Dominick; Spracklen, Benedict; Adami, Marcos; Aragão, Luiz E O C; Galbraith, David

2018-01-25

Understanding forest loss patterns in Amazonia, the Earth's largest rainforest region, is critical for effective forest conservation and management. Following the most detailed analysis to date, spanning the entire Amazon and extending over a 14-year period (2001-2014), we reveal significant shifts in deforestation dynamics of Amazonian forests. Firstly, hotspots of Amazonian forest loss are moving away from the southern Brazilian Amazon to Peru and Bolivia. Secondly, while the number of new large forest clearings (>50 ha) has declined significantly over time (46%), the number of new small clearings (<1 ha) increased by 34% between 2001-2007 and 2008-2014. Thirdly, we find that small-scale low-density forest loss expanded markedly in geographical extent during 2008-2014. This shift presents an important and alarming new challenge for forest conservation, despite reductions in overall deforestation rates.

Relationships of three species of bats impacted by white-nose syndrome to forest condition and management

USGS Publications Warehouse

Silvis, Alexander; Perry, Roger W.; Ford, W. Mark

2016-01-01

Forest management activities can have substantial effects on forest structure and community composition and response of wildlife therein. Bats can be highly influenced by these structural changes, and understanding how forest management affects day-roost and foraging ecology of bats is currently a paramount conservation issue. With populations of many cave-hibernating bat species in eastern North America declining as a result of white-nose syndrome (WNS), it is increasingly critical to understand relationships among bats and forest-management activities. Herein, we provide a comprehensive literature review and synthesis of: (1) responses of northern long-eared (Myotis septentrionalis) and tri-colored (Perimyotis subflavus) bats—two species affected by WNS that use forests during summer—to forest management, and (2) an update to a previous review on the ecology of the endangered Indiana bat (Myotis sodalis).

Factors Contributing to the Decline of Traditional Practices in Communities from the Gwallek-Kedar area, Kailash Sacred Landscape, Nepal.

PubMed

Atreya, Kishor; Pyakurel, Dipesh; Thagunna, Krishna Singh; Bhatta, Laxmi Dutt; Uprety, Yadav; Chaudhary, Ram Prasad; Oli, Bishwa Nath; Rimal, Sagar Kumar

2018-05-01

Traditional knowledge and practices are increasingly recognized in the resource conservation and management practices, however are declining in many parts of the world including Nepal. Studies on the inventory of traditional knowledge are available, albeit limited, and empirical analysis of factors contributing to the decline of traditional knowledge are negligible in Nepal. We thus initiated this study in the Nepal part of the Kailash Sacred Landscape to (i) document traditional knowledge and practices on agriculture, forest-based herbal remedy, and genetic resource conservation; and (ii) identify factors contributing to the decline of traditional practices in the communities. Data was collected during September-December 2015 through key informant interviews, focus group discussions, and households survey. The household survey data was used in binary logistic regression analysis to identify factors contributing to the decline of six key traditional practices. The study documented 56 types of traditional practices. The regressions showed that the age of the respondent, distance to the nearest forest, distance to the nearest motorable road, family members' ill health, and seasonal migration of the household members for jobs significantly influencing to the decline of the particular traditional practices, however, their effects vary within a practice and among the practices. The use of modern medicine, increasing road linkages, decreasing trend of plant resource availability, and agriculture intensification are responsible for the decline of the particular traditional practices. We recommend to recognize their significance in the governing socio-ecological systems and to link the traditional and scientific knowledge systems through policy formulations.