Landscape Partnership Resources Library
Rebuilding Soils on Mined Land for Native Forests in Appalachia
The eastern U.S. Appalachian region supports the world’s most extensive temperate forests, but surface mining for coal has caused forest loss. New reclamation methods are being employed with the intent of restoring native forest on Appalachian mined lands. Mine soil construction is essential to the reforestation process. Here, we review scientific literature concerning selection of mining materials for mine soil construction where forest ecosystem restoration is the reclamation goal. Successful establishment and productive growth of native Appalachian trees has been documented on mine soils with coarse fragment contents as great as 60% but with low soluble salt levels and slightly to moderately acidic pHs, properties characteristic of the region’s native soils. Native tree productivity on some Appalachian mined lands where weathered rock spoils were used to reconstruct soils was found comparable to productivity on native forest sites. Weathered rock spoils, however, are lower in bioavailable N and P than native Appalachian soils and they lack live seed banks which native soils contain. The body of scientific research suggests use of salvaged native soils for mine soil construction when forest ecosystem restoration is the reclamation goal, and that weathered rock spoils are generally superior to unweathered rock spoils when constructing mine soils for this purpose.
Protected Areas as Frontiers for Human Migration
Causes of human population growth near protected areas have been much debated. We conducted 821 interviews in 16 villages around Budongo Forest Reserve, Masindi district, Uganda, to explore the causes of human migration to protected areas and to identify differences in forest use between migrant and nonmigrant communities. We asked subjects for information about birthplace, migration, household assets, household activities, and forest use. Interview subjects were categorized as nonmigrants (born in one of the interview villages), socioeconomic migrants (chose to emigrate for economic or social reasons) from within Masindi district (i.e., local migrants) and from outside the Masindi district (i.e., regional migrants), or forced migrants (i.e., refugees or internally displaced individuals who emigrated as a result of conflict, human rights abuses, or natural disaster). Only 198 respondents were born in interview villages, indicating high rates of migration between 1998 and 2008. Migrants were drawn to Budongo Forest because they thought land was available (268 individuals) or had family in the area (161 individuals). A greater number of regional migrants settled in villages near Lake Albert than did forced and local migrants. Migration category was also associated with differences in sources of livelihood. Of forced migrants 40.5% earned wages through labor, whereas 25.5% of local and 14.5% of regional migrants engaged in wage labor. Migrant groups appeared to have different effects on the environment. Of respondents that hunted, 72.7% were regional migrants. Principal component analyses indicated households of regional migrants were more likely to be associated with deforestation. Our results revealed gaps in current models of human population growth around protected areas. By highlighting the importance of social networks and livelihood choices, our results contribute to a more nuanced understanding of causes of migration and of the environmental effects of different migrant groups. Conservation Biology, Volume 26, No. 3, 547–556
Impact of terrestrial biosphere carbon exchanges on the anomalous CO2 increase in 2002–2003
Understanding the carbon dynamics of the terrestrial biosphere during climate fluctuations is a prerequisite for any reliable modeling of the climate-carbon cycle feedback. We drive a terrestrial vegetation model with observed climate data to show that most of the fluctuations in atmospheric CO2 are consistent with the modeled shift in the balance between carbon uptake by terrestrial plants and carbon loss through soil and plant respiration. Simulated anomalies of the Fraction of Absorbed Photosynthetically Active Radiation (FAPAR) during the last two El Nin˜o events also agree well with satellite observations. Our model results suggest that changes in net primary productivity (NPP) are mainly responsible for the observed anomalies in the atmospheric CO2 growth rate. Changes in heterotrophic respiration (Rh) mostly happen in the same direction, but with smaller amplitude. We attribute the unusual acceleration of the atmospheric CO2 growth rate during 2002–2003 to a coincidence of moderate El Nin˜o conditions in the tropics with a strong NPP decrease at northern mid latitudes, only partially compensated by decreased
Understanding Soil Time
Efforts to maintain soils in a sustainable manner are complicated by interactions among soil components that respond to perturbation at vastly different rates. VOL 321 SCIENCE
The influence of conversion of forest types on carbon sequestration and other ecosystem services in the South Central United States
This paper develops a forestland management model for the three states in the South Central United States (Arkansas, Louisiana, and Mississippi). Forest type and land-use shares are estimated to be a function of economic and physical variables. The results suggest that while historically pine plantations in this region have been established largely on old agricultural land, in the future pine plantations are likely to occur on converted hardwood-forest lands. This shift in the supply of land for plantations could have large effects on above-ground carbon storage and other ecosystem services. Subsidies of approximately $12–27 per ha per year would maintain the area of hardwood forests and reduce carbon emissions from the above-ground and product pool carbon stocks over the next 30 years. Across the several scenarios considered, results suggest that maintaining hardwoods could be an efficient carbon sequestration alternative.
The Historical Dynamics of Socio-ecological Traps
Environmental degradation is a typical unintended outcome of collective human behavior. Hardin’s metaphor of the ‘‘tragedy of the commons’’ has become a conceived wisdom that captures the social dynamics leading to environmental degradation. Recently, ‘‘traps’’ has gained currency as an alternative concept to explain the rigidity of social and ecological processes that produce environmental degradation and livelihood impoverishment. The trap metaphor is, however, a great deal more complex compared to Hardin’s insight. This paper takes stock of studies using the trap metaphor. It argues that the concept includes time and history in the analysis, but only as background conditions and not as a factor of causality. From a historical–sociological perspective this is remarkable since social–ecological traps are clearly path-dependent processes, which are causally produced through a conjunction of events. To prove this point the paper conceptualizes social–ecological traps as a process instead of a condition, and systematically compares history and timing in one classic and three recent studies of social– ecological traps. Based on this comparison it concludes that conjunction of social and environmental events contributes profoundly to the production of trap processes. The paper further discusses the implications of this conclusion for policy intervention and outlines how future research might generalize insights from historical–sociological studies of traps.
Impact of disturbed desert soils on duration of mountain snow cover
Snow cover duration in a seasonally snow covered mountain range (San Juan Mountains, USA) was found to be shortened by 18 to 35 days during ablation through surface shortwave radiative forcing by deposition of disturbed desert dust. Frequency of dust deposition and radiative forcing doubled when the Colorado Plateau, the dust source region, experienced intense drought (8 events and 39–59 Watts per square meter in 2006) versus a year with near normal precipitation (4 events and 17–34 Watts per square meter in 2005). It is likely that the current duration of snow cover and surface radiation budget represent a dramatic change from those before the widespread soil disturbance of the western US in the late 1800s that resulted in enhanced dust emission. Moreover, the projected increases in drought intensity and frequency and associated increases in dust emission from the desert southwest US may further reduce snow cover duration
Linking climate change to lemming cycles
The population cycles of rodents at northern latitudes have puzzled people for centuries1,2 , and their impact is manifest throughout the alpine ecosystem2,3 . Climate change is known to be able to drive animal population dynamics between stable and cyclic phases 4,5 , and has been suggested to cause the recent changesin cyclic dynamics of rodents and their predators 3,6–9 . But although predator–rodent interactions are commonly argued to be the cause of the Fennoscandian rodent cycles 1,10–13 , the role of the environment in the modulation of such dynamics is often poorly understood in natural systems 8,9,14 . Hence, quantitative links between climatedriven processes and rodent dynamics have so far been lacking. Here we show that winter weather and snow conditions, together with density dependence in the net population growth rate, account for the observed population dynamics of the rodent community dominated by lemmings (Lemmus lemmus) in an alpine Norwegian core habitat between 1970 and 1997, and predictthe observed absence of rodent peak years after 1994. These local rodent dynamics are coherentwith alpine bird dynamics both locally and over all ofsouthern Norway, consistent with the influence of large-scale fluctuations in winter conditions. The relationship between commonly available meteorological data and snow conditions indicates that changes in temperature and humidity, and thus conditions in the subnivean space, seem to markedly affect the dynamics of alpine rodents and their linked groups. The pattern of less regular rodent peaks, and corresponding changes in the overall dynamics of the alpine ecosystem, thusseemslikely to prevail over a growing area under projected climate change.
Soil Temperature following Logging-Debris Manipulation and Aspen Regrowth in Minnesota: Implications for Sampling Depth and Alteration of Soil Processes
Soil temperature is a fundamental controller of processes influencing the transformation and flux of soil C and nutrients following forest harvest. Soil temperature response to harvesting is influenced by the amount of logging debris (biomass) removal that occurs, but the duration, magnitude, and depth of influence is unclear. Logging debris manipulations (none, moderate, and heavy amounts) were applied following clearcut harvesting at four aspendominated (Populus tremuloides Michx.) sites in northeastern Minnesota, and temperature was measured at 10-, 30-, and 50-cm depths for two growing seasons. Across sites, soil temperature was significantly greater at all sample depths relative to uncut forest in some periods of each year, but the increase was reduced with increasing logging-debris retention. When logging debris was removed compared to when it was retained in the first growing season, mean growing season soil temperatures were 0.9, 1.0, and 0.8°C greater at 10-, 30-, and 50-cm depths, respectively. These patterns were also observed early in the second growing season, but there was no discernible difference among treatments later in the growing season due to the modifying effect of rapid aspen regrowth. Where vegetation establishment and growth occurs quickly, effects of logging debris removal on soil temperature and the processes influenced by it will likely be short-lived. The significant increase in soil temperature that occurred in deep soil for at least 2 yr after harvest supports an argument for deeper soil sampling than commonly occurs in experimental studies.
Illuminating the Modern Dance of Climate and CO2
Records of Earth’s past climate imply higher atmospheric carbon dioxide concentrations in the future 19 SEPTEMBER 2008 VOL 321 SCIENCE
Prolonged suppression of ecosystem carbon dioxide uptake after an anomalously warm year
Terrestrial ecosystems control carbon dioxide fluxes to and from the atmosphere1,2 through photosynthesis and respiration, a balance between net primary productivity and heterotrophic respiration, that determines whether an ecosystem issequestering carbon or releasing it to the atmosphere. Global1,3–5 and site-specific6 data sets have demonstrated that climate and climate variability influence biogeochemical processes that determine net ecosystem carbon dioxide exchange (NEE) at multiple timescales. Experimental data necessary to quantify impacts of a single climate variable, such as temperature anomalies, on NEE and carbon sequestration of ecosystems at interannual timescales have been lacking. This derives from an inability of field studies to avoid the confounding effects of natural intra-annual and interannual variability in temperature and precipitation. Here we present results from a fouryear study using replicate 12,000-kg intact tallgrass prairie monoliths located in four 184-m3 enclosed lysimeters7 . We exposed 6 of 12 monoliths to an anomalously warm year in the second year of the study8 and continuously quantified rates of ecosystem processes, including NEE. We find that warming decreases NEE in both the extreme year and the following year by inducing drought that suppresses net primary productivity in the extreme year and by stimulating heterotrophic respiration of soil biota in the subsequent year. Our data indicate thattwo years are required for NEE in the previously warmed experimental ecosystems to recover to levels measured in the control ecosystems. Thistime lag caused net ecosystem carbon sequestration in previously warmed ecosystems to be decreased threefold over the study period, compared with control ecosystems. Our findings suggest that more frequent anomalously warm years9 , a possible consequence of increasing anthropogenic carbon dioxide levels10, may lead to a sustained decrease in carbon dioxide uptake by terrestrial ecosystems. Vol 455| 18 September 2008
Politics for the day after tomorrow: The logic of apocalypse in global climate politics
The recent global climate change discourse is a prominent example of a securitization of environmental issues. While the problem is often framed in the language of existentialism, crisis or even apocalypse, climate discourses rarely result in exceptional or extraordinary measures, but rather put forth a governmental scheme of piecemeal and technocratic solutions often associated with risk management. This article argues that this seeming paradox is no accident but follows from a politics of apocalypse that combines two logics – those of security and risk – which in critical security studies are often treated as two different animals. Drawing on the hegemony theory of Ernesto Laclau and Chantal Mouffe, however, this article shows that the two are inherently connected. In the same way as the Christian pastorate could not do without apocalyptic imageries, today’s micro-politics of risk depends on a series of macro-securitizations that enable and legitimize the governmental machinery. This claim is backed up by an inquiry into current global discourses of global climate change regarding mitigation, adaptation and security implications. Although these discourses are often framed through the use of apocalyptic images, they rarely result in exceptional or extraordinary measures, but rather advance a governmental scheme of risk management. Tracing the relationship between security and risk in these discourses, we use the case of climate change to highlight the relevance of our theoretical argument.
Temperature control of larval dispersal and the implications for marine ecology, evolution, and conservation
Temperature controls the rate of fundamental biochemical processes and thereby regulates organismal attributes including development rate and survival. The increase in metabolic rate with temperature explains substantial among-species variation in lifehistory traits, population dynamics, and ecosystem processes. Temperature can also cause variability in metabolic rate within species. Here, we compare the effect of temperature on a key component of marine life cycles among a geographically and taxonomically diverse group of marine fish and invertebrates. Although innumerable lab studies document the negative effect of temperature on larval development time, little is known about the generality versus taxon-dependence of this relationship. We present a unified, parameterized model for the temperature dependence of larval development in marine animals. Because the duration of the larval period is known to influence larval dispersal distance and survival, changes in ocean temperature could have a direct and predictable influence on population connectivity, community structure, and regional-to-global scale patterns of biodiversity.
The Role of Local Governance and Institutions in Livelihoods Adaptation to Climate Change
The most important implications of climate change from the perspective of the World Bank concern its potentially disastrous impacts on the prospects for development, especially for poorer populations in the global South. Earlier writings on climate change had tended to focus more on its links with biodiversity loss, spread of pathogens and diseases, land use planning, ecosystem change, and insurance markets, rather than its connections with development (Easterling and Apps 2005, Harvell et al. 2002, Tompkins and Adger 2004). But as the Social Development Department of the World Bank recently noted, “Climate change is the defining development challenge of our generation” (SDV, 2007: 2). These words echo the World Bank President Robert Zoellick’s statement at the United Nations Climate Change Conference in 2007 in Bali where he called climate change a “development, economic, and investment challenge.” Indeed, understanding the relationship between climate change, the human responses it necessitates, and how institutions shape such responses is an increasingly urgent need. This report directs attention towards a subset of such relationships, focusing on rural institutions and poor populations in the context of climate variability and change-induced adaptations.
Tangled Trends for Temperate Rain Forests as Temperatures Tick Up
Climate change is altering growing conditions in the temperate rain forest region that extends from northern California to the Gulf of Alaska. Longer, warmer growing seasons are generally increasing the overall potential for forest growth in the region. However, species differ in their ability to adapt to changing conditions. For example, researchers with Pacific Northwest Research Station examined forest trends for southeastern and southcentral Alaska and found that, in 13 years, western redcedar showed a 4.2-percent increase in live-tree biomass, while shore pine showed a 4.6-percent decrease. In general, the researchers found that the amount of live-tree biomass in extensive areas of unmanaged, higher elevation forest in southern Alaska increased by as much as 8 percent over the 13-year period, contributing to significant carbon storage. Hemlock dwarf mistletoe is another species expected to fare well under warmer conditions in Alaska. Model projections indicate that habitat for this parasitic species could increase 374 to 757 percent over the next 100 years. This could temper the prospects for western hemlock—a tree species otherwise expected to do well under future climate conditions projected for southern Alaska. In coastal forests of Washington and Oregon, water availability may be a limiting factor in future productivity, with gains at higher elevations but declines at lower elevations.
Looking at the Big Picture: The Importance of Landbase Interactions Among Forests, Agriculture, and Climate Mitigation Policies
Land use change is a key part of global change. Deforestation, urban sprawl, agriculture, and other human influences have substantially altered natural ecosystems and fragmented the global landscape. Slowing down deforestation and afforesting environmentally sensitive agricultural land are important steps for mitigating climate change. Because no policy operates in a vacuum, however, it’s important to consider how separate climate mitigation policies might interact with each other. Ralph Alig, a scientist with the Pacific Northwest Research Station, and his colleagues evaluated the potential impacts of policy instruments available for climate change mitigation. By using the Forest and Agriculture Sector Optimization Greenhouse Gases model, the researchers analyzed how land might shift between forestry and agriculture and to more developed uses depending on different land use policies and several carbon pricing scenarios. They also examined the likely effects on timber, crop prices, and bioenergy production if landowners were paid to sequester carbon on their land. The researchers found that projected competition for raw materials is greatest in the short term, over the first 25 years of the 50-year projections. Climate change is occurring within a matrix of other changes. By 2050, an additional 3 billion people are expected to be living on Earth, needing food, clean water, and places to live. Incentives for landowners to maintain undeveloped land will be vital to sequestering carbon and providing other services of intact ecosystems
Managing Wildfire Risk in Fire-Prone Landscapes: How Are Private Landowners Contributing?
The fire-prone landscapes of the West include both public and private lands. Wildfire burns indiscriminately across property boundaries, which means that the way potential fuels are managed on one piece of property can affect wildfire risk on neighboring lands. Paige Fischer and Susan Charnley, social scientists with the Pacific Northwest Research Station, surveyed private landowners in eastern Oregon to learn how they perceive fire risk on their land and what they do, if anything, to reduce that risk. The scientists found that owners who live on a forested parcel are much more likely to reduce fuels than are those who live elsewhere. Private forest owners are aware of fire risk and knowledgeable about methods for reducing fuels, but are constrained by the costs and technical challenges of protecting large acreages of forested land. Despite the collective benefits of working cooperatively, most of these owners reduce hazardous fuels on their land independently, primarily because of their distrust about working with others, and because of social norms associated with private property ownership. These results provide guidance for developing more effective fuel reduction programs that accommodate the needs and preferences of private forest landowners. The findings also indicate the potential benefits of bringing landowners into collective units to work cooperatively, raising awareness about landscape-scale fire risk, and promoting strategies for an “alllands” approach to reducing wildfire risk
Forests in Decline: Yellow-Cedar Research Yields Prototype for Climate Change Adaptation Planning
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, soils, hydrology, ecophysiology, dendrochronology, climatology, and landscape analysis. Combined studies ultimately revealed that the loss of this culturally, economically, and ecologically valuable tree is caused by a warming climate, reduced snowpack, poor soil drainage, and the species’ shallow roots. These factors lead to fine-root freezing, which eventually kills the trees. The considerable knowledge gained while researchers sought the cause of widespread yellow-cedar mortality forms the basis for a conservation and adaptive management strategy. A new approach to mapping that overlays topography, cedar populations, soil drainage, and snow enables land managers to pinpoint locations where yellowcedar habitat is expected to be suitable or threatened in the future, thereby bringing climate change predictions into management scenarios. The research program serves as a prototype for evaluating the effects of climate change in other landscapes. It shows the value of long-term, multidisciplinary research that encourages scientists and land managers to work together toward developing adaptive management strategies
Tangled Trends for Temperate Rain Forests as Temperatures Tick Up
Climate change is altering growing conditions in the temperate rain forest region that extends from northern California to the Gulf of Alaska. Longer, warmer growing seasons are generally increasing the overall potential for forest growth in the region. However, species differ in their ability to adapt to changing conditions. For example, researchers with Pacific Northwest Research Station examined forest trends for southeastern and southcentral Alaska and found that, in 13 years, western redcedar showed a 4.2-percent increase in live-tree biomass, while shore pine showed a 4.6-percent decrease. In general, the researchers found that the amount of live-tree biomass in extensive areas of unmanaged, higher elevation forest in southern Alaska increased by as much as 8 percent over the 13-year period, contributing to significant carbon storage. Hemlock dwarf mistletoe is another species expected to fare well under warmer conditions in Alaska. Model projections indicate that habitat for this parasitic species could increase 374 to 757 percent over the next 100 years. This could temper the prospects for western hemlock—a tree species otherwise expected to do well under future climate conditions projected for southern Alaska. In coastal forests of Washington and Oregon, water availability may be a limiting factor in future productivity, with gains at higher elevations but declines at lower elevations
Logging Debris Matters: Better Soil, Fewer Invasive Plants
The logging debris that remains after timber harvest traditionally has been seen as a nuisance. It can make subsequent tree planting more difficult and become fuel for wildfire. It is commonly piled, burned, or taken off site. Logging debris, however, contains significant amounts of carbon and nitrogen—elements critical to soil productivity. Its physical presence in the regenerating forest creates microclimates that influence a broad range of soil and plant processes. Researchers Tim Harrington of the Pacific Northwest Research Station; Robert Slesak, a soil scientist with the Minnesota Forest Resources Council; and Stephen Schoenholtz, a professor of forest hydrology and soils at Virginia Tech, conducted a five-year study at two sites in Washington and Oregon to see how retaining logging debris affected the soil and other growing conditions at each locale. They found that keeping logging debris in place improved soil fertility, especially in areas with coarse-textured, nutrient-poor soils. Soil nitrogen and other nutrients important to tree growth increased, and soil water availability increased due to the debris’ mulching effect. The debris cooled the soil, which slowed the breakdown and release of soil carbon into the atmosphere. It also helped prevent invasive species such as Scotch broom and trailing blackberry from dominating the sites. Forest managers are using this information to help maximize the land’s productivity while reducing their costs associated with debris disposal.
