A5053835120- Ecology and Vegetation Dynamics Studies
- Wildlife Ecology and Conservation
- Plant and animal studies
- Animal Ecology and Behavior Studies
- Rangeland and Wildlife Management
- Rangeland Management and Livestock Ecology
- Fire effects on ecosystems
- Soil Carbon and Nitrogen Dynamics
- Mycorrhizal Fungi and Plant Interactions
- Land Use and Ecosystem Services
- Forest Ecology and Biodiversity Studies
- Marine and coastal ecosystems
- Plant Parasitism and Resistance
- Peatlands and Wetlands Ecology
- Marine Biology and Ecology Research
- Species Distribution and Climate Change
- Isotope Analysis in Ecology
- Botany and Plant Ecology Studies
- Animal Behavior and Reproduction
- Bat Biology and Ecology Studies
- Fish Ecology and Management Studies
- Fungal Biology and Applications
- Bioenergy crop production and management
- Agriculture and Rural Development Research
- Coral and Marine Ecosystems Studies
Syracuse University
2015-2024
Utah State University
1995-2024
Institute of Ecology and Biodiversity
2014-2015
Smithsonian Tropical Research Institute
2014-2015
University of Florida
2006-2015
University of Arizona
2014-2015
Santa Fe Institute
2014-2015
Macquarie University
2014-2015
Read Jones Christoffersen (Canada)
2014
Pontificia Universidad Católica de Chile
2014
Humans are modifying both the identities and numbers of species in ecosystems, but impacts such changes on ecosystem processes controversial. Plant diversity, functional composition were experimentally varied grassland plots. Each factor by itself had significant effects many processes, diversity principal factors explaining plant productivity, percent nitrogen, total light penetration. Thus, habitat modifications management practices that change likely to have large processes.
Declining biodiversity represents one of the most dramatic and irreversible aspects anthropogenic global change, yet ecological implications this change are poorly understood. Recent studies have shown that loss basal species, such as autotrophs or plants, affects fundamental ecosystem processes nutrient dynamics autotrophic production. Ecological theory predicts changes induced by at base an should impact entire system. Here we show experimental reductions in grassland plant richness...
Because a diversity of resources should support consumers, most models predict that increasing plant increases animal diversity. We report results direct experimental test the dependence on sampled arthropods in well‐replicated grassland experiment which species richness and functional were directly manipulated. In simple regressions, both number planted ($$\mathrm{log}\,_{2}$$ transformed) groups significantly increased arthropod but not abundance. However, was only significant predictor...
Herbivores can often control plant dynamics by mediating positive feedbacks in species' influence on nutrient cycling. In a 7-yr field experiment nitrogen-limited Minnesota oak savanna, we tested whether herbivores accelerated or decelerated nitrogen (N) cycling through their effects plants. We measured of excluding insect (primarily Orthoptera and Homoptera) mammalian white-tailed deer, Odocoileus virginianus) above- belowground biomass, species composition, tissue concentration, available...
We experimentally separated the effects of two components plant diversity-plant species richness and functional group richness-on insect communities. Plant had contrasting on abundances, a result we attributed to three factors. First, lower abundances at higher were explained by sampling effect, which was caused increasing likelihood that one low-quality group, C4 grasses, would be present reduce average 25%. Second, biomass, positively related richness, strong, positive effect abundances....
Tree cover is a fundamental structural characteristic and driver of ecosystem processes in terrestrial ecosystems, trees are major global carbon (C) sink. Fire herbivores have been hypothesized to play dominant roles regulating African savannas, but the evidence for this conflicting. Moving up trophic scale, factors that regulate fire occurrence herbivores, such as disease predation, poorly understood any given ecosystem. We used Bayesian state-space model show wildebeest population eruption...
We argue for expanding the role of theory in ecology to accelerate scientific progress, enhance ability address environmental challenges, foster development synthesis and unification, improve design experiments large-scale environmental-monitoring programs. To achieve these goals, it is essential what we call efficient theories, which have several key attributes. Efficient theories are grounded first principles, usually expressed language mathematics, make few assumptions generate a large...
Protected areas provide major benefits for humans in the form of ecosystem services, but landscape degradation by human activity at their edges may compromise ecological functioning. Using multiple lines evidence from 40 years research Serengeti-Mara ecosystem, we find that such edge has effectively "squeezed" wildlife into core protected area and altered ecosystem's dynamics even within this 40,000-square-kilometer ecosystem. This spatial cascade reduced resilience was mediated movement...
Abstract Whole‐genome duplication (polyploidy) occurs frequently and repeatedly within species, often forming new lineages that contribute to biodiversity, particularly in plants. Establishment persistence of polyploids may be thwarted by competition with surrounding diploids; however, climatic niche shifts, where occupy different niches than diploid progenitors, help overcome this challenge. We tested for shifts between cytotypes using a ordination approach an unprecedentedly large data set...
Ecology Letters (2010) 13: 959–968 Abstract Grazing occurs over a third of the earth’s land surface and may potentially influence storage 10 9 Mg year −1 greenhouse gases as soil C. Displacement native herbivores by high densities livestock has often led to overgrazing C loss. However, it remains unknown whether matching those can yield equivalent sequestration. In Trans‐Himalayas we found that, despite comparable grazing intensities, watersheds converted pastoralism had 49% lower than which...
Mechanistic explanations of herbivore spatial distribution have focused largely on either resource-related (bottom-up) or predation-related (top-down) factors. We studied direct and indirect influences the distributions Serengeti hotspots, defined as temporally stable areas inhabited by mixed herds resident grazers. Remote sensing variation in landscape features were first used to create a map which was tested for accuracy against an independent data set observations. Subsequently, we...
Summary Given the role of fire in shaping ecosystems, especially grasslands and savannas, it is important to understand its broader impact on these systems. Post‐fire stimulation plant nutrients thought benefit grazing mammals explain their preference for burned areas. However, also reduces vegetation height increases visibility, thereby potentially reducing predation risk. Consequently, may be more beneficial smaller herbivores, with higher nutritional needs greater risks predation. We...
Rapid environmental changes have fostered debates and motivated research on how to effectively preserve or restore ecosystem processes. One such debate deals with the effects of biodiversity, loss thereof, Recent studies demonstrate that resource-use complementarity, now known as "niche-differentiation effect," presence a competitive species strong processes, "sampling can explain why productivity nutrient retention are sometimes enhanced increasing richness. In well-replicated outdoor...
Plant resources, predators, and abiotic conditions represent three major factors that potentially influence insect herbivore abundance in terrestrial ecosystems. In nitrogen (N)-limited environments the potential for bottom-up (plant resource) control is strong because plant quality may limit abundance. However, extremes conditions, such as temperature moisture, can mask effects. I tested these hypotheses an 8-yr field experiment measured responses of plants grasshoppers (Orthoptera) to N...
We measured legume abundance following 13— and 5—yr experiments testing for the effects of mammalian herbivores, nutrients, climate on plant communities in an old field a savanna east central Minnesota. Total was significantly greater plots with herbivores excluded. Within herbivore exclosures, legumes were more abundant to which P, K, S, Mg, Mn, Ca, Na, trace minerals had been added. Legumes than field. Lathyrus venosus, rapidly growing early—maturing species, largely responsible these...
Because the goal of ecology is to understand causes patterns observed in natural world, studies that document novel ecosystems are central importance. The report "The influence island area on ecosystem properties" by David A. Wardle et al. (29 Aug., p. 1296) such a study. Some interpretations data made illustrate difficulty ascribing causation basis observation. In particular, their assertions "that process rates were lowest those islands with greatest diversity" and "this finding direct...