Skip to main content
Advanced Search

Filters: Tags: Ecosystems (X) > partyWithName: John Wesley Powell Center for Earth System Analysis and Synthesis (X) > Types: Raster (X)

7 results (30ms)   

View Results as: JSON ATOM CSV
thumbnail
Advancing our mechanistic understanding of ecosystem responses to climate change is critical to improve ecological theories, develop predictive models to simulate ecosystem processes, and inform sound policies to manage ecosystems and human activities. Manipulation of temperature in the field, or the “ecosystem warming experiment,” has proved to be a powerful tool to understand ecosystem responses to changes in temperature. No comprehensive synthesis has been conducted since the last one more than 10 years ago. A new synthetic analysis is critically needed to advance our understanding of ecosystem responses to warming, to highlight experimental artifacts and appropriate interpretations, and to guide development...
thumbnail
Tropical forests contain > 50% of the world’s known species (Heywood 1995), 55% of global forest biomass (Pan et al. 2011), and exchange more carbon (C), water and energy with the atmosphere than any other ecosystem type (e.g., Saugier et al. 2001). Despite their importance, there is more uncertainty associated with predictions of how tropical forests will respond to warming than for any other biome (Randerson et al. 2009). This uncertainty is of global concern due to the large quantity of C cycled by these forests and the high potential for biodiversity loss. Given the importance of tropical forests, decision makers and land managers around the globe need increased predictive capacity regarding how tropical forests...
thumbnail
Geographically Isolated Wetlands (GIWs) occur along gradients of hydrologic and ecological connectivity and isolation, even within wetland types (e.g., forested, emergent marshes) and functional classes (e.g., ephemeral systems, permanent systems, etc.). Within a given watershed, the relative positions of wetlands and open-waters along these gradients influence the type and magnitude of their chemical, physical, and biological effects on downgradient waters. In addition, the ways in which GIWs connect to the broader hydrological landscape, and the effects of such connectivity on downgradient waters, depends largely upon climate, geology, and relief, the heterogeneity of which expands with increasing scale. Developing...
thumbnail
Fibrous erionite, a zeolite mineral, has been designated as a human carcinogen by the World Health Organization and is believed to be the cause of extraordinarily high rates of malignant mesothelioma and other asbestos - related diseases in several villages in Central Turkey. A recent study by the University of Hawaii in collaboration with the U. S. Environmental Protection Agency in Dunn County, North Dakota has demonstrated similar human exposures to fibrous erionite as those in found in Turkey. The source of these exposures is an erionite - bearing volcanic tuff that has been mined, crushed, and used to gravel hundreds of miles of roads. While elevated rates of mesothelioma are not yet apparent in North Dakota,...
thumbnail
Mercury (Hg) is a serious environmental problem that is impacting ecological and human health on a global scale. However, local and regional processes are largely responsible for producing methylmercury, which drives ecological risk. This is particularly true in western North America where the combination of diverse landscapes, habitat types, climates, and Hg sources may disproportionally impact the region relative to other areas in North America. Even with decades of regional Hg research and monitoring, there is still no holistic synthesis of the spatiotemporal patterns of Hg in abiotic and biotic resources across the region, nor has there been a formal, simultaneous analysis of the landscape, ecological and climatological...
thumbnail
Current land use practices have affected ecosystem structure and processes in ways that have degraded delivery of key ecosystem services controlling exchanges of carbon and nitrogen with the atmosphere and surface and groundwater systems. These impacts are observed in the emissions of greenhouse gases (GHG) and N pollution in our nation’s water systems and coastal areas. Improvements in databases of climate, soils, and land use practices in the north central Great Plains (i.e., NCGP: Colorado, Kansas, Wyoming, Nebraska, Montana, South Dakota, and North Dakota) provide a unique opportunity for integration and synthesis of this information on the exchanges of C and N affecting our environmental resources. In addition,...
thumbnail
The timing of breeding is constrained in Arctic ecosystems and small temporal differences in when individuals breed can have large effects on fitness. Arctic ecosystems are generally warming more rapidly than other ecosystems which, for migratory species, can cause an imbalance, or mismatch, between when they have evolved to breed versus when it is optimal to breed environmentally. Geese are abundant herbivores summering in tundra ecosystems, and whose presence has important feedbacks on ecosystem processes. Some goose populations have already exhibited signs that spring vegetation phenology is occurring earlier than individuals are able to breed, with a consequent effect on their reproductive fitness. The magnitude...