Showing papers by "Julia A. Klein published in 2014"
University of Minnesota1, University of Maryland, College Park2, Iowa State University3, University of Oldenburg4, Utah State University5, Spanish National Research Council6, Wake Forest University7, University of Washington8, United States Department of Agriculture9, Colorado State University10, Michigan State University11, Trinity College, Dublin12, University of Queensland13, University of Toronto14, Lanzhou University15, University of California, San Diego16, Imperial College London17, University of Wisconsin-Madison18, University of Colorado Boulder19, United States Geological Survey20, Queensland University of Technology21, University of North Carolina at Chapel Hill22, University of Oxford23, University of Nebraska–Lincoln24, University of California, Berkeley25, University of Illinois at Urbana–Champaign26, University of Guelph27, University of Kentucky28, University of Melbourne29, Oregon State University30, Commonwealth Scientific and Industrial Research Organisation31, Swiss Federal Institute for Forest, Snow and Landscape Research32, Lancaster University33, Duke University34, University of California, Davis35
TL;DR: Testing the hypothesis that herbaceous plant species losses caused by eutrophication may be offset by increased light availability due to herbivory demonstrates that nutrients and herbivores can serve as counteracting forces to control local plant diversity through light limitation, independent of site productivity, soil nitrogen, herbivore type and climate.
Abstract: Human alterations to nutrient cycles and herbivore communities are affecting global biodiversity dramatically. Ecological theory predicts these changes should be strongly counteractive: nutrient addition drives plant species loss through intensified competition for light, whereas herbivores prevent competitive exclusion by increasing ground-level light, particularly in productive systems. Here we use experimental data spanning a globally relevant range of conditions to test the hypothesis that herbaceous plant species losses caused by eutrophication may be offset by increased light availability due to herbivory. This experiment, replicated in 40 grasslands on 6 continents, demonstrates that nutrients and herbivores can serve as counteracting forces to control local plant diversity through light limitation, independent of site productivity, soil nitrogen, herbivore type and climate. Nutrient addition consistently reduced local diversity through light limitation, and herbivory rescued diversity at sites where it alleviated light limitation. Thus, species loss from anthropogenic eutrophication can be ameliorated in grasslands where herbivory increases ground-level light.
639 citations
University of Minnesota1, Utah State University2, Iowa State University3, University of Oldenburg4, University of Guelph5, Lancaster University6, University of Washington7, University of Queensland8, Lanzhou University9, University of New Mexico10, Spanish National Research Council11, University of Wisconsin-Madison12, University of Colorado Boulder13, United States Department of Agriculture14, Queensland University of Technology15, University of Maryland, College Park16, Colorado State University17, University of Nebraska–Lincoln18, University of California, Berkeley19, Southwest Forestry University20, University of Kentucky21, University of Melbourne22, Oregon State University23, Commonwealth Scientific and Industrial Research Organisation24, Swiss Federal Institute for Forest, Snow and Landscape Research25, National Centre for Biological Sciences26, University of Oxford27
TL;DR: This paper analyzed diversity-stability relationships from 41 grasslands on five continents and examined how these relationships are affected by chronic fertilization, one of the strongest drivers of species loss globally.
Abstract: Studies of experimental grassland communities have demonstrated that plant diversity can stabilize productivity through species asynchrony, in which decreases in the biomass of some species are compensated for by increases in others. However, it remains unknown whether these findings are relevant to natural ecosystems, especially those for which species diversity is threatened by anthropogenic global change. Here we analyse diversity-stability relationships from 41 grasslands on five continents and examine how these relationships are affected by chronic fertilization, one of the strongest drivers of species loss globally. Unmanipulated communities with more species had greater species asynchrony, resulting in more stable biomass production, generalizing a result from biodiversity experiments to real-world grasslands. However, fertilization weakened the positive effect of diversity on stability. Contrary to expectations, this was not due to species loss after eutrophication but rather to an increase in the temporal variation of productivity in combination with a decrease in species asynchrony in diverse communities. Our results demonstrate separate and synergistic effects of diversity and eutrophication on stability, emphasizing the need to understand how drivers of global change interactively affect the reliable provisioning of ecosystem services in real-world systems.
369 citations
TL;DR: In this article, the authors present local ecological knowledge of climate and ecological change in central Tibet to support the finding of delayed summer on the Tibetan Plateau, a finding that has been subject to vigorous, ongoing debate based on Western scientific data.
Abstract: Knowledge of climate change and its impacts can facilitate adaptation efforts. However, complex system dynamics, data scarcity, and heterogeneity often generate both contradictory findings and unexpected climate change impacts. Here we present local ecological knowledge of climate and ecological change in central Tibet to support the finding of delayed summer on the Tibetan Plateau, a finding that has been subject to vigorous, ongoing debate based on Western scientific data. Tibetans who actively herd on a daily basis and are located at higher elevations were most likely to notice changes in seasonality, reported as later start of summer and green-up, and as delayed and shortened livestock milking season. Local meteorological data, indigenous observations of higher snowlines and long-term animal number data suggest that a regional warming trend, rather than land use change, may underlie the delayed phenology trends. We demonstrate that local ecological knowledge can reveal counter-intuitive outcomes and help resolve apparent contradictions through its strengths in situations of high variability, ability to integrate over a range of variables and time scales, and operation outside of Western scientific logic. This suggests local knowledge does not exist to be confirmed or disproved by Western science, but rather can also advance Western science and help contribute to its debates. It is precisely points of apparent contradiction within and between knowledge systems that are most productive for more extensive inquiry. Future research on climate change, and climate adaptation policy-making, will benefit from careful, contextual dialog with local observations, focusing on observable biophysical phenomena that are affected by temperature and precipitation and that are important to livelihoods.
108 citations
TL;DR: In this paper, a political ecology approach to Tibetan pastoralists' vulnerability to climate change by qualitatively analyzing how the efficacy of strategies of mobility, communal pooling, storage, and covering and sheltering livestock have been transformed over time in Nagchu, Tibet.
Abstract: Severe snowstorms on the Tibetan Plateau, which lead to large-scale loss of livestock, are projected to increase in intensity and frequency with climate change. At the same time, political-economic and institutional changes from the 1950s to the present have altered pastoralists’ ability to use various coping strategies. We take a political ecology approach to Tibetan pastoralists’ vulnerability to climate change by qualitatively analyzing how the efficacy of strategies of mobility, communal pooling, storage, and covering and sheltering livestock have been transformed over time in Nagchu, Tibet. Recent government projects have focused on emergency aid and providing shelters. However, these are less effective than mobility and less important than the availability of labor power. Mobility and labor power have been reduced by development and environmental policies, as well as by larger political-economic transformations. These transformations have shifted herders’ coping strategies from internal to external, increasing their reliance upon the state.
79 citations
TL;DR: The authors explored how plant community properties varied along gradients of elevation, soil moisture, grazing intensity, solar radiation, ground surface roughness (ground concavity), and pika abundance in an alpine meadow ecosystem in central Tibet.
Abstract: Plant community properties such as species richness, evenness, and composition vary along environmental gradients. Arid and semi-arid ecosystems, such as the central Tibetan Plateau, are thought to be sensitive to changes in temperature and water availability, and also influenced by a long history of herbivore grazing. We used linear mixed effect models and Canonical Correspondence Analysis to explore how plant community properties varied along gradients of elevation, soil moisture, grazing intensity, solar radiation, ground surface roughness (ground concavity), and pika abundance in an alpine meadow ecosystem in central Tibet. We found that species richness increased with elevation. Species evenness increased with soil moisture at lower elevation, but decreased with soil moisture at higher elevation. Species composition was significantly associated with all environmental variables except solar radiation. The abundance of the dominant plant species, K. pygmaea, which is driven primarily by soil m...
55 citations
TL;DR: This article developed a cooperative jigsaw activity to encourage students to explore the complexities of joint decision making when taking into account multiple perspectives, and found that undergraduate science students were engaged, drew on a variety of types of evidence to support claims about managing rangelands impacted by climate change, and referenced both complex social and natural systems in their post-assessment.
Abstract: To meet the sustainability challenges of the future, we need leaders who are trained to work well in diverse, multidisciplinary teams and a populace that understands the biophysical and socioeconomic challenges facing humanity and how to meet the needs of its diverse stakeholders. With a goal of increasing climate literacy amongst college students, we developed a cooperative jigsaw activity to encourage students to explore the complexities of joint decision making when taking into account multiple perspectives. We found that undergraduate science (natural science and natural resources) students were engaged, drew on a variety of types of evidence to support claims about managing rangelands impacted by climate change, and referenced both complex social and natural systems in their postassessment. 2014 National Association of Geoscience Teachers. [DOI: 10.5408/13-070.1]
10 citations
6 citations