Spatial patterns of structures (e.g., nests and burrows) in animal populations can provide insight into underlying ecological processes. Banner-tailed kangaroo rats (Dipodomys spectabilis) and harvester ants (Pogonomyrmex rugosus) are the largest and most dominant granivores found in rodent and ant communities of the northern Chihuahuan Desert. Both species build conspicuous, above-ground structures and are highly territorial.
Long-Term Trends in Spatial Partitioning of Biodiversity: Considerations of Disturbance and Recovery
Patterns of biodiversity at large spatial scales (i.e., γ diversity) can be driven by either within-community (α) or among-community (β) components. The degree to which α or β components contribute to γ diversity may depend on the amount of environmental variation that exists in the spatial extents studied. However, few studies have assessed both spatial configuration and temporal changes in biodiversity, especially in systems that frequently experience large-scale disturbance.
Little information exists on how climate variation may interact with trophic controls on annual net primary production (ANPP), and even less is known about how these interactions will affect community structure. Understanding how communities respond to climate variation and grazing will be crucial for managing grasslands with abundant large herbivores. We conducted a simulated grazing experiment in the Rainfall Manipulation Plots (RaMPs) at Konza Prairie Biological Station, Kansas.
How will anticipated changes in climate interact with grassland plant community composition and diversity to affect the performance of seedlings? We ask this question for two reasons. 1) If plant species are to track spatial shifts in the locations of suitable climatic conditions, plant species must invade communities by means of seedling establishment; more diverse plant communities have been shown to be less invasible, but it is not known how warming will interact with diversity to affect invasion.
Resilience in a coral reef ecosystem: Initiation of a long-term experiment to determine the effects of multiple disturbances
Documenting the trajectories of ecological communities following a disturbance represents one of the five core research themes central to LTER network science. Quantifying degrees of resilience, here defined as the time needed for a community to return to a previous steady or quasi-steady state following a disturbance, can be especially challenging when ecosystems experience multiple perturbations that, in combination, can cause complex, non-linear community responses.
The Central Arizona–Phoenix Long-term Ecological Research (CAP LTER) project is based in the central Arizona and metropolitan Phoenix region, embedded in the Sonoran Desert. As the fifth-largest and, until recently, the fastest-growing city in the US, Phoenix is an excellent location for urban ecological research. Phoenix was established after the Civil War, initially one of several small towns surrounded by irrigated farmland. Continued agrarian expansion predated the explosive growth of housing in the second half of the 20th century.
The Sevilleta LTER is located at the intersection of several aridland ecosystem types. Although it is axiomatic that water is the key limiting resource in aridland ecosystems, most arid land soils are also chronically low in nutrients and organic matter. Resource availability is a function of the frequency and size of precipitation events as well as the time between events. As a consequence, NPP and organic matter decomposition are often decoupled in space and time, and soil nutrient supply rates may limit NPP during periods when soil moisture is sufficient for plant growth.
Interactions between hurricanes and the legacy of human disturbance, determine the future composition of the Luquillo Forest.
The Luquillo Forest Dynamics Plot (LFDP) is a 16-ha long-term study plot in subtropical wet forest in the Luquillo Mountains of Puerto Rico. It is part of the Luquillo LTER and the Center for Tropical Science (CTFS) network of large tropical forest plots. Forests are often subject to multiple, compounded disturbances, representing both natural and human-induced processes. Our goal is to understand forest structure, diversity and dynamics, and to predict long-term changes resulting from interactions of past human land use and intermittent hurricane damage.
Community responses of ground-dwelling beetles (Tenebrionidae) to a gradient of traditional and manipulated grazing in shortgrass steppe
Responses of plants to grazing are better understood, and more predictable, than those of consumers in grassland ecosystems of the North American Great Plains. In 2003, we began a large-scale, replicated experiment to examine the effects of grazing on ground-dwelling beetles (Tenebrionidae), an important consumer community in shortgrass steppe of north-central Colorado, USA. We sought to determine whether modifications of the intensity and seasonality of livestock grazing alter the structure and diversity of beetle communities compared to traditional grazing regimes.
The metacommunity framework integrates species-specific responses to environmental gradients to detect emergent patterns of species organization. More specifically, a metacommunity is a set of ecological communities that are potentially linked by dispersal, with each community being a group of species at a particular site.