Biodiversity loss threatens human well-being.

The diversity of life on Earth is dramatically affected by Human alterations of ecosystems. Compelling evidence now shows that the reverse is also true: biodiversity in the broad snsse affects the properties of ecosystem and, therefore, the benefits that humans obtain from them. In this article, we provide a synthesis of the most crucial messages emerging from the latest scientific literature and international assessments of the role of biodiversity in ecosystem services and human well- being. Human societies have beeb built on biodiversity. Many activities indispensable for human subsistence lead to biodiversity loss, and this trend is ikely to continue in the future. We clearly benefit from the diversity of organisms that we have learned to use for medicines, food, fibers, and other renwable resources. In addition, biodiversity has always been an integral part of the human experience and there are many moral reasons to preserve it for its own sake. What has been less recognized is that biodiversity also influences human well- being, including the access to water and basic materials for a satifactory life, and security in the face of environmental change, through its effects on the ecosystem processes that lie at the core of the Earth´s most vital life support system.Fil: Díaz, Sandra Myrna. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto Multidisciplinario de Biología Vegetal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto Multidisciplinario de Biología Vegetal; ArgentinaFil: Fargione, Joseph. Universidad Nacional de Córdoba; Argentina. University Of New Mexico; Estados UnidosFil: Chapin III, Francis Stuart. University Of Alaska; Estados UnidosFil: Tilman, David. University of Minnesota; Estados Unido

Going beyond 'it depends:' the role of context in shaping participation in natural resource management

Public participation is increasingly advocated in natural resource management to meet a spectrum of instrumental to normative goals. However, the success of participation in achieving these goals is highly variable, depending on both societal and institutional contexts. Whether participation realises its benefits or succumbs to its pitfalls is shaped by dynamic interactions operating among three contextual dimensions: participatory rationales (instrumental to normative), institutional fit of different levels (types) of participation (information delivery to partnership to delegation), and social structures (such as cultural context, social capital and power distribution). Some levels of participation may support the existing power hierarchy, others benefit organized stakeholder groups and special interests, and still others foster deliberative democratic outcomes. We argue that wise choice of levels of participation in particular contexts shapes the balance of participation’s benefits and pitfalls

Interactions between changing climate and biodiversity: Shaping humanity's future

Scientists have known for more than a century aboutpotential human impacts on climate (1). In the last 30 y,estimates of these impacts have been confirmed andrefined through increasingly precise climate assess-ments (2). Other global-scale human impacts, includingland use change, overharvesting, air and water pollu-tion, and increased disease risk from antibiotic resis-tance, have risen to critical levels, seriously jeopardizingthe prospects that future generations can thrive (3–5).Earth has entered a stage characterized by humandomination of critical Earth system processes (6–8).Although the basic trajectories of these changes arewell known, many of the likely consequences areshrouded in uncertainty because of poorly understoodinteractions among these drivers of change and there-fore their effects on ecosystems and societies.Fil: Stuart Chapin III, F.. University of Alaska; Estados UnidosFil: Díaz, Sandra Myrna. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto Multidisciplinario de Biología Vegetal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto Multidisciplinario de Biología Vegetal; Argentin

Changes in the surface energy budget after fire in boreal ecosystems of interior Alaska: An annual perspective

Understanding links between the disturbance regime and regional climate in boreal regions requires observations of the surface energy budget from ecosystems in various stages of secondary succession. While several studies have characterized fire‐induced differences in surface energy fluxes from boreal ecosystems during summer months, much less is known about these differences over the full annual cycle. Here we measured components of the surface energy budget (including both radiative and turbulent fluxes) at three sites from a fire chronosequence in interior Alaska for a 1‐year period. Our sites consisted of large burn scars resulting from fires in 1999, 1987, and ∼1920 (hereinafter referred to as the 3‐, 15‐, and 80‐year sites, respectively). Vegetation cover consisted primarily of bunch grasses at the 3‐year site, aspen and willow at the 15‐year site, and black spruce at the 80‐year site. Annual net radiation declined by 31% (17 W m^(−2)) for both the 3‐ and the 15‐year sites as compared with the 80‐year site (which had an annual mean of 55 W m^(−2)). Annual sensible heat fluxes were reduced by an even greater amount, by 55% at the 3‐year site and by 52% at the 15‐year site as compared with the 80‐year site (which had an annual mean of 21 W m^(−2)). Absolute differences between the postfire ecosystems and the mature black spruce forest for both net radiation and sensible heat fluxes were greatest during spring (because of differences in snow cover and surface albedo), substantial during summer and winter, and relatively small during fall. Fire‐induced disturbance also initially reduced annual evapotranspiration (ET). Annual ET decreased by 33% (99 mm yr^(−1)) at the 3‐year site as compared with the 80‐year site (which had an annual flux of 301 mm yr^(−1)). Annual ET at the 15‐year site (283 mm yr^(−1)) was approximately the same as that from the 80‐year site, even though the 15‐year site had substantially higher ET during July. Our study suggests that differences in annual ET between deciduous and conifer stands may be smaller than that inferred solely from summer observations. This study provides a direct means to validate land surface processes in global climate models attempting to capture vegetation‐climate feedbacks in northern terrestrial regions

Changing Forests in a Warming World

Severe fires can dramatically alter the future growth of a spruce forest. A severe fire is likely to change the forest to one dominated by broadleaf deciduous trees, especially in drier places.York's Knowledge Mobilization Unit provides services and funding for faculty, graduate students, and community organizations seeking to maximize the impact of academic research and expertise on public policy, social programming, and professional practice. It is supported by SSHRC and CIHR grants, and by the Office of the Vice-President Research & Innovation. [email protected] www.researchimpact.c

Changing Daily Wind Speeds on Alaska’s North Slope: Implications for Rural Hunting Opportunities

Because of their reliance on the harvest of fish and game, Alaskan rural communities have experienced a variety of impacts from climate change, the effects of which are amplified at high latitudes. We collaborated with hunters from the coastal community of Wainwright, Alaska, to document their observations of environmental change (e.g., sea ice, wind, temperature) and the implications of those changes for opportunities to hunt bowhead whale (Balaena mysticetus) during spring and caribou (Rangifer tarandus) during summer. We integrated hunter observations on wind with statistical analysis of daily wind speed data collected in the nearby community of Barrow, Alaska, between 1971 and 2010 to characterize changes in the number of days with suitable hunting conditions. Hunters in Wainwright currently observe fewer days than in previous decades with wind conditions suitable for safely hunting bowhead whales and caribou. The statistical analysis of wind speed data supported these conclusions and suggested that the annual windows of opportunity for hunting each species have decreased by up to seven days since 1971. This study demonstrates the potential power of collaboration between local communities and researchers to characterize the societal impacts of climate change. Continued collaborative research with residents of rural northern Alaskan communities could produce knowledge and develop tools to help rural Alaskans adapt to novel social-ecological conditions.Les collectivités rurales de l’Alaska dépendent de la récolte du poisson et du gibier et à ce titre, elles sont assujetties à une panoplie d’incidences découlant du changement climatique, dont les effets sont amplifiés en haute altitude. Grâce à l’aide des chasseurs de la collectivité côtière de Wainwright, en Alaska, nous avons consigné les observations de ces chasseurs relativement à l’évolution de l’environnement (en ce qui a trait, par exemple, à la glace de mer, au vent et aux températures) de même que les incidences de cette évolution sur les possibilités de chasse de la baleine boréale (Balaena mysticetus) au printemps, et du caribou (Rangifer tarandus) à l’été. Nous avons intégré les observations des chasseurs au sujet du vent à l’analyse statistique des données de la vitesse quotidienne du vent, données recueillies dans la localité avoisinante de Barrow, en Alaska, entre 1971 et 2010, afin de caractériser les changements quant au nombre de jours où les conditions de chasse sont convenables. Comparativement aux décennies précédentes, les chasseurs de Wainwright observent un moins grand nombre de jours, à l’heure actuelle, qu’au cours des décennies précédentes pendant lesquels le régime des vents se prête à la chasse sécuritaire de la baleine boréale et du caribou. L’analyse statistique des données de la vitesse du vent permet de soutenir ces conclusions et suggère qu’annuellement, la période pendant laquelle chacune de ces espèces peut faire l’objet de la chasse a diminué dans une mesure allant jusqu’à sept jours depuis 1971. Cette étude témoigne du pouvoir de collaboration qui pourrait exister entre les collectivités de la région et les chercheurs dans le but de caractériser les incidences du changement climatique sur la société. Les travaux de recherche en collaboration continue avec les habitants des collectivités rurales du nord de l’Alaska pourraient permettre de produire des connaissances et d’élaborer des outils qui aideraient les Alaskiens à s’adapter aux nouvelles conditions socioécologiques

Role of Boreal Vegetation in Controlling Ecosystem Processes and Feedbacks to Climate

In the field, dark respiration rates are greatest in cores from more northerly locations. This is due in part to greater amounts of dwarf shrub biomass in the more northerly cores, but also to differences in soil organic matter quality. Laboratory incubations of these soils under common conditions show some evidence for greater pools of available carbon in soils from more northerly tundra sites, although the most northerly site does not fit this pattern for reasons which are unclear at this time. While field measurements of cores transplanted among different vegetation types at the same location (Toolik Lake) show relatively small differences in whole ecosystem carbon flux, laboratory incubation of these same soils shows that there are large differences in soil respiration rates under common conditions. This is presumably due to differences in organic matter quality. Microenvironmental site factors (temperature, soil moisture, degree of anaerobiosis, etc.) may be responsible for evening out these differences in the field. These site factors, which differ with slope, aspect, and drainage within a given location along the latitudinal gradient, appear to exert at least as strong a control over carbon fluxes as do macroclimatic factors among sites across the latitudinal gradient. While our field measurements indicate that, in the short term, warming will tend to increase ecosystem losses Of CO2 via respiration more than they will increase plant gross assimilation, the degree to which different topographically-defined plant communities will respond is likely to vary

Climate and species affect fine root production with long-term fertilization in acidic tussock tundra near Toolik Lake, Alaska

Author Posting. © The Author(s), 2007. This is the author's version of the work. It is posted here by permission of Springer for personal use, not for redistribution. The definitive version was published in Oecologia 153 (2007): 643-652, doi:10.1007/s00442-007-0753-8.Long-term fertilization of acidic tussock tundra has led to changes in plant species composition, increases in aboveground production and biomass and substantial losses of soil organic carbon (SOC). Root litter is an important input to SOC pools, though little is known about fine root demography in tussock tundra. In this study, we examined the response of fine root production and live standing fine root biomass to short- and long-term fertilization, as changes in fine root demography may contribute to observed declines in SOC. Live standing fine root biomass increased with long-term fertilization, while fine root production declined, reflecting replacement of the annual fine root system of Eriophorum vaginatum, with the long-lived fine roots of Betula nana. Fine root production increased in fertilized plots during an unusually warm growing season, but remained unchanged in control plots, consistent with observations that B. nana shows a positive response to climate warming. Calculations based on a few simple assumptions suggest changes in fine root demography with long-term fertilization and species replacement could account for between 20 and 39% of observed declines in SOC stocks.This project was supported by National Science Foundation research grants 9810222, 9911681, 0221606 and 0528748

Changes in the surface energy budget after fire in boreal ecosystems of interior Alaska: An annual perspective

Understanding links between the disturbance regime and regional climate in boreal regions requires observations of the surface energy budget from ecosystems in various stages of secondary succession. While several studies have characterized fire‐induced differences in surface energy fluxes from boreal ecosystems during summer months, much less is known about these differences over the full annual cycle. Here we measured components of the surface energy budget (including both radiative and turbulent fluxes) at three sites from a fire chronosequence in interior Alaska for a 1‐year period. Our sites consisted of large burn scars resulting from fires in 1999, 1987, and ∼1920 (hereinafter referred to as the 3‐, 15‐, and 80‐year sites, respectively). Vegetation cover consisted primarily of bunch grasses at the 3‐year site, aspen and willow at the 15‐year site, and black spruce at the 80‐year site. Annual net radiation declined by 31% (17 W m^(−2)) for both the 3‐ and the 15‐year sites as compared with the 80‐year site (which had an annual mean of 55 W m^(−2)). Annual sensible heat fluxes were reduced by an even greater amount, by 55% at the 3‐year site and by 52% at the 15‐year site as compared with the 80‐year site (which had an annual mean of 21 W m^(−2)). Absolute differences between the postfire ecosystems and the mature black spruce forest for both net radiation and sensible heat fluxes were greatest during spring (because of differences in snow cover and surface albedo), substantial during summer and winter, and relatively small during fall. Fire‐induced disturbance also initially reduced annual evapotranspiration (ET). Annual ET decreased by 33% (99 mm yr^(−1)) at the 3‐year site as compared with the 80‐year site (which had an annual flux of 301 mm yr^(−1)). Annual ET at the 15‐year site (283 mm yr^(−1)) was approximately the same as that from the 80‐year site, even though the 15‐year site had substantially higher ET during July. Our study suggests that differences in annual ET between deciduous and conifer stands may be smaller than that inferred solely from summer observations. This study provides a direct means to validate land surface processes in global climate models attempting to capture vegetation‐climate feedbacks in northern terrestrial regions