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Experimental climate change weakens the insurance effect of biodiversity: Ecosystems are simultaneously affected by biodiversity loss and climate change, but we know little about how these factors interact. We predicted that climate warming and CO2-enrichment should strengthen trophic cascades by reducing the relative efficiency of predation-resistant herbivores, if herbivore consumption rate trades off with predation resistance. This weakens the insurance effect of herbivore diversity. We tested this prediction using experimental ocean warming and acidification in seagrass mesocosms. Metaanalyses of published experiments first indicated that consumption rate trades off with predation resistance. The experiment then showed that three common herbivores together controlled macroalgae and facilitated seagrass dominance, regardless of climate change. When the predation-vulnerable herbivore was excluded in normal conditions, the two resistant herbivores maintained top-down control. Under warming, however, increased algal growth outstripped control by herbivores and the system became algal-dominated. Consequently, climate change can reduce the relative efficiency of resistant herbivores and weaken the insurance effect of biodiversity.

TOP PREDATORS AS CONSERVATION TOOLS: We review the ecological rationale behind the potential compatibility between top predators and biodiversity conservation, and examine their effectiveness as surrogate species. Evidence suggests that top predators promote species richness or are spatio-temporally associated with it for six causative or noncausative reasons: resource facilitation, trophic cascades, dependence on ecosystem productivity, sensitivity to dysfunctions, selection of heterogeneous sites and links to multiple ecosystem components. Therefore, predator-centered conservation may deliver certain biodiversity goals. To this aim, predators have been employed in conservation as keystone, umbrella, sentinel, flagship, and indicator species. However, quantitative tests of their surrogate-efficacy have been astonishingly few. Evidence suggests they may function as structuring agents and biodiversity indicators in some ecosystems but not others, and that they perform poorly as umbrella species; more consensus exists for their efficacy as sentinel and flagship species. Conservation biologists need to use apex predators more cautiously, as part of wider, context- dependent mixed strategies.

Negative density-dependent dispersal in the American black bear (Ursus americanus) revealed by noninvasive sampling and genotyping: Although the dispersal of animals is influenced by a variety of factors, few studies have used a condition-dependent approach to assess it. The mechanisms underlying dispersal are thus poorly known in many species, especially in large mammals. We used 10 microsatellite loci to examine population density effects on sex-specific dispersal behavior in the American black bear, Ursus americanus. We tested whether dispersal increases with population density in both sexes. Fine-scale genetic struc- ture was investigated in each of four sampling areas using Mantel tests and spatial autocorrelation analyses. Our results revealed male-biased dispersal pattern in low- density areas. As population density increased, females appeared to exhibit philopa- try at smaller scales. Fine-scale genetic structure for males at higher densities may indicate reduced dispersal distances and delayed dispersal by subadults.

Climate change hotspots in the United States: We use a multi-model, multi-scenario climate model ensemble to identify climate change hotspots in the continental United States. Our ensemble consists of the CMIP3 atmosphere-ocean general circulation models, along with a high-resolution nested climate modeling system. We test both high (A2) and low (B1) greenhouse gas emissions trajectories, as well as two different statistical metrics for identifying regional climate change hotspots. We find that the pattern of peak responsiveness in the CMIP3 ensemble is persistent across variations in GHG concentration, GHG trajectory, and identification method. Areas of the southwestern United States and northern Mexico are the most persistent hotspots. The high-resolution climate modeling system produces highly localized hotspots within the basic GCM structure, but with a higher sensitivity to the identification method. Across the ensemble, the pattern of relative climate change hotspots is shaped primarily by changes in interannual variability of the contributing variables rather than by changes in the long-term mean

Public land, timber harvests, and climate mitigation: Quantifying carbon sequestration potential on U.S. public timberlands: Scientists and policy makers have long recognized the role that forests can play in countering the atmospheric buildup of carbon dioxide (CO2), a greenhouse gas (GHG). In the United States, terrestrial carbon sequestration in private and public forests offsets approximately 11% of all GHG emissions from all sectors of the economy on an annual basis. Although much of the attention on forest carbon sequestration strategy in the United States has been on the role of private lands, public forests in the United States represent approximately 20% of the U.S. timberland area and also hold a significantly large share (30%) of the U.S. timber volume. With such a large standing timber inventory, these forested lands have considerable impact on the U.S. forest carbon balance. To help decision makers understand the carbon implications of potential changes in public timberland management, we compared a baseline timber harvest scenario with two alternative harvest scenarios and estimated annual carbon stock changes associated with each. Our analysis found that a ‘‘no timber harvest’’ scenario eliminating harvests on public lands would result in an annual increase of 17–29 million metric tonnes of carbon (MMTC) per year between 2010 and 2050—as much as a 43% increase over current sequestration levels on public timberlands and would offset up to 1.5% of total U.S. GHG emissions. In contrast, moving to a more intense harvesting policy similar to that which prevailed in the 1980s may result in annual carbon losses of 27–35 MMTC per year between 2010 and 2050. These losses would represent a significant decline (50–80%) in anticipated carbon sequestration associated with the existing timber harvest policies. If carbon sequestration were valued in the marketplace as part of a GHG offset program, the economic value of sequestered carbon on public lands could be substantial relative to timber harvest revenues. Public timberland; Forestry; Climate change; Carbon sequestration

WHY FORESTS ARE PIVOTAL IN PLANNING FOR CLIMATE CHANGE: 17 slides show carbon-forest relationships including logging and carbon in US forests

Spatial relationship between climatologies and changes in global vegetation activity: Vegetation forms a main component of the terrestrial biosphere and plays a crucial role in land-cover and climate- related studies. Activity of vegetation systems is commonly quantified using remotely sensed vegetation indices (VI). Extensive reports on temporal trends over the past decades in time series of such indices can be found in literature. However, little remains known about the processes underlying these changes at large spatial scales. In this study, we aimed at quantifying the spatial relationship between changes in potential climatic growth constraints (i.e. temperature, precipitation and incident solar radiation) and changes in vegetation activity (1982–2008). We demonstrate an additive spatial model with 0.5° resolution, consisting of a regression component representing climate-associated effects and a spatially correlated field representing the combined influence of other factors, including land-use change. Little over 50% of the spatial variance could be attributed to changes in climatologies; conspicuously, many greening trends and browning hotspots in Argentina and Australia. The nonassociated model component may contain large- scale human interventions, feedback mechanisms or natural effects, which were not captured by the climatologies. Browning hotspots in this component were especially found in subequatorial Africa. On the scale of land-cover types, strongest relationships between climatologies and vegetation activity were found in forests, including indications for browning under warming conditions (analogous to the divergence issue discussed in dendroclimatology). Keywords: climate- and human-induced change, climatologies, Gaussian random field, growth constraints, regression, spatial additive model, vegetation-activity trends

Exponential Decline of Deep-Sea Ecosystem Functioning Linked to Benthic Biodiversity Loss: Here, we present a global-scale study based on 116 deep-sea sites that relates benthic biodiversity to several independent indicators of ecosystem functioning and efficiency. We show that deep-sea ecosystem functioning is exponentially related to deep-sea biodiversity and that ecosystem efficiency is also exponentially linked to functional biodiversity. These results suggest that a higher biodiversity supports higher rates of ecosystem processes and an increased efficiency with which these processes are performed. The exponential relationships presented here, being consistent across a wide range of deep-sea ecosystems, suggest that mutually positive functional interactions (ecological facilitation) can be common in the largest biome of our biosphere.Conclusions: Our results suggest that a biodiversity loss in deep-sea ecosystems might be associated with exponential reductions of their functions. Because the deep sea plays a key role in ecological and biogeochemical processes at a global scale, this study provides scientific evidence that the conservation of deep-sea biodiversity is a priority for a sustainable functioning of the worlds’ oceans.

DOES WOOD SLOW DOWN “SLUDGE DRAGONS?” THE INTERACTION BETWEEN RIPARIAN ZONES AND DEBRIS FLOWS IN MOUNTAIN LANDSCAPES: Conservation measures for aquatic species throughout the Pacific Northwest rely heavily on maintaining forested riparian zones. A key rationale for this strategy is that the presence of standing and downed trees next to streams will provide a continuous source of wood, which is an important structural component of aquatic habitat. Yet little is known about the interactions between wood and debris flows, which are an important way that wood enters streams.Researchers from the PNW Research Station and Oregon State University created a physics-based simulation of debris flow dynamics in a headwater basin within the Oregon Coast Range. They found that the presence of wood funda- mentally changes the behavior of debris flows by reducing the momentum and distance that they travel. Because debris flow deposits are primary storage sites for sediment within headwater catchments, a shift toward shorter flows means that more sediment is stored higher up in watersheds. In addition, they found that zones with high densities of wood and sediment are relatively fixed in space and do not migrate downstream. This suggests that management strategies could specifically target achieving habitat objectives within these high accumulation zones, and there may be multiple management pathways for achieving these objectives.

Phylogenetic trees and the future of mammalian biodiversity: Phylogenies describe the origins and history of species. However, they can also help to predict species’ fates and so can be useful tools for managing the future of biodiversity. This article starts by sketching how phylogenetic, geographic, and trait information can be combined to elucidate present mammalian diversity patterns and how they arose. Recent diversification rates and standing diversity show different geographic patterns, indicating that cra- dles of diversity have moved over time. Patterns in extinction risk reflect both biological differences among mammalian lineages and differences in threat intensity among regions. Phylogenetic com- parative analyses indicate that for small-bodied mammals, extinc- tion risk is governed mostly by where the species live and the intensity of the threats, whereas for large-bodied mammals, eco- logical differences also play an important role. This modeling approach identifies species whose intrinsic biology renders them particularly vulnerable to increased human pressure. We outline how the approach might be extended to consider future trends in anthropogenic drivers, to identify likely future battlegrounds of mammalian conservation, and the likely casualties. This framework could help to highlight consequences of choosing among different future climatic and socioeconomic scenarios. We end by discussing priority-setting, showing how alternative currencies for diversity can suggest very different priorities. We argue that aiming to maximize long-term evolutionary responses is inappropriate, that conservation planning needs to consider costs as well as benefits, and that proactive conservation of largely intact systems should be part of a balanced strategy. extinction risk 􏰧 latent risk 􏰧 mammals

Variability, contingency and rapid change in recent subarctic alpine tree line dynamics: Summary 1 Boundaries between forest and tundra ecosystems, tree lines, are expected to advance in altitude and latitude in response to climate warming. However, varied responses to 20th century warming suggest that in addition to temperature, tree line dynamics are mediated by species-specific traits and environmental conditions at landscape and local scales. 2 We examined recent tree line dynamics at six topographically different, but climatic- ally similar, sites in south-west Yukon, Canada. Dendroecological techniques were used to reconstruct changes in density of the dominant tree species, white spruce (Picea glauca), and to construct static age distributions of willow (Salix spp.), one of two dominant shrub genera. Data were analysed to identify periods and rates of establish- ment and mortality and to relate these to past climate. 3 Tree line elevation and stand density increased significantly during the early to mid 20th century. However, this change was not uniform across sites. Spruce advanced rapidly on south-facing slopes and tree line rose 65 – 85 m in elevation. Tree line did not advance on north-facing slopes, but stand density increased 40–65%. Differences observed between aspects were due primarily to the differential presence of permafrost. Additional variability among sites was related to slope and vegetation type. Results were less conclusive for willow, but evidence for an advance was found at two sites. 4 Increases in stand density were strongly correlated with summer temperatures. The period of rapid change coincided with a 30-year period of above average temperatures, beginning in 1920. The highest correlations were obtained using a forward average of 30 – 50 years, supporting the hypothesis that tree line dynamics are controlled more by conditions influencing recruitment than by establishment alone. 5 The changes observed at several sites are suggestive of a threshold response and challenge the notion that tree lines respond gradually to climate warming. Overall, the results provide further evidence to support the idea that the pattern and timing of change is contingent on local, landscape, and regional-scale factors, as well as species’ biology. Key-words: climate change, dendroecology, ecotones, forest-tundra, non-linearity, Picea glauca, Salix glauca, stand dynamics, timberline, Yukon

Climatic variability and episodic Pinus ponderosa establishment along the forest-grassland ecotones of Colorado: The primary objective of this study was the detection of possible climatic influences on the recent (i.e., past c. 40 years) establishment of ponderosa pine (Pinus ponderosa) at or near forest-grassland ecotones in the northern Front Range of Colorado. Germination dates were precisely determined for >500 juvenile ponderosa pine collected in six widely dispersed sample areas. All sites sampled were open areas lacking an overstory tree cover but located near seed sources. To evaluate the effects of recent climatic variation on recruitment and survival patterns, three types of climate data were used: (1) instrumental climate records from nearby local weather stations; (2) a multivariate index of El Nino/Southern Oscillation (ENSO); and (3) a regional, ponderosa pine tree-ring index sensitive to moisture variation. There is a strong association between episodic recruitment of ponderosa pine and years in which spring and fall moisture availability is high in the instrumental climate record. During the past 40 years, tree establishment was highly episodic and concentrated mainly in four years—1973, 1979, 1983, and 1990. These years are also associated with large-scale warming of sea-surface temperatures in the eastern tropical Pacific (i.e., El Nin ̃o events). These years of abundant seedling establishment also coincide with years of above average radial growth in mature ponderosa pine. Thus, at open sites suitable for the survival of shade-intolerant ponderosa pine, successful establishment of seedlings is highly episodic depending on local moisture availability related to broad-scale climatic variation. This study demonstrates the climatic sensitivity of ponderosa pine recruitment at low elevation sites along forest-grassland ecotones in the northern Colorado Front Range.

Drought in the United States: Causes and Issues for Congress: Drought is a natural hazard with often significant societal, economic, and environmental consequences. Public policy issues related to drought range from how to identify and measure drought to how best to prepare for, mitigate, and respond to drought impacts, and who should bear associated costs. Severe drought in 2011 and 2012 fueled congressional interest in near-term issues, such as current (and recently expired) federal programs and their funding, and long-term issues, such as drought forecasting and various federal drought relief and mitigation actions. Continuing drought conditions throughout the country contribute to ongoing interest in federal drought policies and responses. As of April 2013, drought has persisted across approximately two-thirds of the United States and is threatening agricultural production and other sectors. More than 1,180 counties so far have been designated as disaster areas for the 2013 crop season, including 286 counties contiguous to primary drought counties. In comparison, in August 2012, more than 1,400 counties in 33 states had been designated as disaster counties by the U.S. Secretary of Agriculture. Most attention in the 112th Congress focused on the extension of expired disaster assistance programs in separate versions of a 2012 farm bill. Attention in the 113th Congress again is expected to focus on farm bill legislation; however, other bills addressing different aspects of drought policy and response have also been introduced. (For information regarding drought disaster assistance for agricultural producers, see CRS Report RS21212, Agricultural Disaster Assistance. For information on the 2012 bill, see CRS Report R42552, The 2012 Farm Bill: A Comparison of Senate-Passed S. 3240 and the House Agriculture Committee’s H.R. 6083 with Current Law.) Although agricultural losses typically dominate drought impacts, federal drought activities are not limited to agriculture. For example, the 2012 drought raised congressional interest in whether and to what extent other federal agencies have and are using authorities to address drought. Similarly, the President in August 2012 convened the White House Rural Council to assess executive branch agencies’ responses to the ongoing drought. The Administration shortly thereafter announced several new administrative actions to address the drought. While numerous federal programs address different aspects of drought, no comprehensive national drought policy exists. A 2000 National Drought Policy Commission noted the patchwork nature of drought programs, and that despite a major federal role in responding to drought, no single federal agency leads or coordinates drought programs—instead, the federal role is more of “crisis management.” Congress may opt to revisit the commission’s recommendations. Congress also may consider proposals to manage drought impacts, such as authorizing new assistance to develop or augment water supplies for localities, industries, and agriculture—or providing funding for such activities where authorities already exist. Congress also may address how the two major federal water management agencies, the U.S. Army Corps of Engineers and the Bureau of Reclamation, plan for and respond to drought. This report describes the physical causes of drought, drought history in the United States, and policy challenges related to drought. It also provides examples of recurrent regional drought conditions. For information on federal agricultural disaster assistance and related legislation, see the CRS reports noted above.

Renewable Energy and Energy Efficiency Incentives: A Summary of Federal Programs: Summary Energy is crucial to the operation of a modern industrial and services economy. Recently, there have been growing concerns about the availability and cost of energy and about environmental impacts of fossil energy use. Those concerns have rekindled interest in energy efficiency, energy conservation, and the development and commercialization of renewable energy technologies. Many of the existing energy efficiency and renewable energy programs have authorizations tracing back to the 1970s. Many of the programs have been reauthorized and redesigned repeatedly to meet changing economic factors. The programs apply broadly to sectors ranging from industry to academia, and from state and local governments to rural communities. Since 2005, Congress has enacted several major energy laws: the Energy Policy Act of 2005 (EPACT 2005; P.L. 109-58); the Energy Independence and Security Act of 2007 (EISA; P.L. 110- 140); the Energy Improvement and Extension Act (EIEA), enacted as Division B of the Emergency Economic Stabilization Act (EESA; P.L. 110-343); and the American Reinvestment and Recovery Act (ARRA; P.L. 111-5). Each of those laws established, expanded, or modified energy efficiency and renewable energy research, development, demonstration, and deployment (RDD&D) programs. The Department of Energy (DOE) operates the greatest number of efficiency and renewable energy incentive programs. The Department of the Treasury and the Department of Agriculture (USDA) operate several programs. A few programs can also be found among the Departments of Interior (DOI), Labor (DOL), Housing and Urban Development (HUD), Veterans Affairs (VA), and the Small Business Administration (SBA). This report describes federal programs that provide grants, loans, loan guarantees, and other direct or indirect incentives for energy efficiency, energy conservation, and renewable energy. For each program, the report provides the administering agency, authorizing statute(s), annual funding, and the program expiration date. The appendixes provide summary information in a tabular format and also list recently expired programs.

Massive Forest Dieback SW US: Summary: • Tree death is an important ecological process, but we don’t know very much about it. • MFD (Massive Forest Dieback) is often driven by stress from extreme climate events, rather than equilibrial mean climate conditions. • MFD occurs naturally in many forest types. However, there are indications that emerging patterns of dieback in some montane areas are being amplified by global climate change, and predictions of more extreme climate events suggest risk of increases in associated forest dieback episodes. • We cannot accurately predict the effects of climate change on montane forest ecosystems without better field data and model incorporation of species-specific thresholds of stress-induced tree mortality, and the dynamics of amplifying disturbances like insect outbreaks and fire. • CIRMOUNT could help address these knowledge gaps by fostering regional networks for long-term monitoring and research on: 1) plot-based demographies of multiple tree species across landscape and regional gradients to get data on pulses of mortality and natality; 2) tree growth using straightforward dendrometer band methods; 3) feedbacks between forest dieback, other disturbances, and overall ecosystem patterns and processes; and 4) effectiveness of mitigation strategies (e.g., thinning, prescribed burning).

A Changing Climate for Prediction: Standard climate model projections, which have shown the significance of global warming, must be redesigned to inform climate change adaptation and mitigation policy.

Could climate change capitalism?: Economist Nicholas Stern’s latest book is a rare and masterly synthesis of climate-change science and economics. His ‘global deal’ could change capitalism for the better, says Robert Costanza.

THE COST OF LEAFING: Understanding the trade-offs involved for plants making leaves promises fresh insights on every scale from the plant to the planet, finds John Whitfield. Excerpt: One definition of economics is the study choice under the constraint of scarcity, and the narrowrangeofchoicesintheleafeconomics spectrum provides a vivid illus- tration of the various scarcities that dominate plants’ lives. The fact that all leaves lie fairly close to the axis of the spectrum shows that, despite the vast diversity of foliage produced over hundreds of millions of years of evolution, plants have little room for manoeuvre in how they build their leaves. “Most textbooks of ecology project the idea that there’s an almost infinite diversity of organisms,” says plant ecologist Philip Grime of the University of Sheffield, UK. “But if you look at the core biology of what organisms do with resources, you find severe constraints and trade-offs.”

The payoff of conservation investments in tropical countryside: The future of biodiversity and ecosystem services hinges on har- monizing agricultural production and conservation, yet there is no planning algorithm for predicting the efficacy of conservation investments in farmland. We present a conservation planning framework for countryside (working agricultural landscapes) that calculates the production and conservation benefits to the current baseline of incremental investments. Our framework is analogous to the use of reserve design algorithms. Unlike much countryside modeling, our framework is designed for application in data- limited contexts, which are prevalent. We apply our framework to quantify the payoff for Costa Rican birds of changing farm plot and border vegetation. We show that installing windbreaks of native vegetation enhances both bird diversity and farm income, espe- cially when complementing certain crop types. We make predic- tions that differ from those of approaches currently applied to agri-environment planning,: e.g., although habitat with trees has lower local species richness than farm plot habitats (1– 44% lower), replacing any plot habitat with trees should boost regional rich- ness considerably. Our planning framework reveals the small, targeted changes on farms that can make big differences for biodiversity. biodiversity 􏰧 conservation planning 􏰧 countryside biogeography 􏰧 ecological-economic models 􏰧 matrix

Reliability of Indicators of Decline in Abundance: Although there are many indicators of endangerment (i.e., whether populations or species meet criteria that justify conservation action), their reliability has rarely been tested. Such indicators may fail to identify that a population or species meets criteria for conservation action (false negative) or may incorrectly show that such criteria have been met (false positive). To quantify the rate of both types of error for 20 com- monly used indicators of declining abundance (threat indicators), we used receiver operating characteristic curves derived from historical (1938–2007) data for 18 sockeye salmon (Oncorhynchus nerka) populations in the Fraser River, British Columbia, Canada. We retrospectively determined each population’s yearly status (reflected by change in abundance over time) on the basis of each indicator. We then compared that popu- lation’s status in a given year with the status in subsequent years (determined by the magnitude of decline in abundance across those years). For each sockeye population, we calculated how often each indicator of past status matched subsequent status. No single threat indicator provided error-free estimates of status, but indicators that reflected the extent (i.e., magnitude) of past decline in abundance (through comparison of current abundance with some historical baseline abundance) tended to better reflect status in subsequent years than the rate of decline over the previous 3 generations (a widely used indicator). We recommend that when possible, the reliability of various threat indicators be evaluated with empirical analyses before such indicators are used to determine the need for conservation action. These indicators should include estimates from the entire data set to take into account a historical baseline.

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