Andrew T Tredennick

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Multiple stable states, bifurcations and thresholds are fashionable concepts in the ecological literature, a recognition that complex ecosystems may at times exhibit the interesting dynamic behaviours predicted by relatively simple biomathematical models. Recently, several papers in Global Ecology and Biogeography, Proceedings of the National Academy of(More)
Theoretical models of allometric scaling provide frameworks for understanding and predicting how and why the morphology and function of organisms vary with scale. It remains unclear, however, if the predictions of 'universal' scaling models for vascular plants hold across diverse species in variable environments. Phenomena such as competition and(More)
The potential relationship between climate change and conflict is intriguing and warrants rigorous study. However, the proposition by Burke et al. (1) that warming may be a directly causative factor in the risk of civil war in Sub-Saharan Africa seems unlikely. Theanalysis ofBurke et al. (1) suggests instead a tenuous historical association between warming(More)
Contemporary theory on the maintenance and stability of the savanna biome has focused extensively on how climate and disturbances interact to affect tree growth and demography. In particular, the role of fire in reducing tree cover from climatic maxima is now well appreciated, and in certain cases, herbivory also strongly affects tree cover. However, in(More)
Temporal stability of ecosystem functioning increases the predictability and reliability of ecosystem services, and understanding the drivers of stability across spatial scales is important for land management and policy decisions. We used species-level abundance data from 62 plant communities across five continents to assess mechanisms of temporal(More)
Temporal asynchrony among species helps diversity to stabilize ecosystem functioning, but identifying the mechanisms that determine synchrony remains a challenge. Here, we refine and test theory showing that synchrony depends on three factors: species responses to environmental variation, interspecific interactions, and demographic stochasticity. We then(More)
Theory relating species richness to ecosystem variability typically ignores the potential for environmental variability to promote species coexistence. Failure to account for fluctuation-dependent coexistence may explain deviations from the expected negative diversity-ecosystem variability relationship, and limits our ability to predict the consequences of(More)
Complex interactions among climate change and ecosystem processes (plant demographics, tree-grass interactions, grazers, browsers, fire and nitrogen) challenge our ability to predict future carbon stocks in Africa and other tropical regions. Recent work suggests Africa has a near zero decade-scale carbon balance, but that climate fluctuations induce(More)
Plant population models are powerful tools for predicting climate change impacts in one location, but are difficult to apply at landscape scales. We overcome this limitation by taking advantage of two recent advances: remotely sensed, speciesspecific estimates of plant cover and statistical models developed for spatiotemporal dynamics of animal populations.(More)
1Department of Wildland Resources and the Ecology Center, 5230 Old Main Hill, Utah State University, 4 Logan, Utah 84322, USA; 2U.S. Geological Survey, Colorado Cooperative Fish and Wildlife Research Unit, 5 Fort Collins, CO 80523, USA; 3Department of Fish, Wildlife, and Conservation Biology, Colorado State 6 University, Fort Collins, CO 80523 USA;(More)