The Niwot Ridge (NWT) LTER site was one of the five original LTER sites established in 1980. The LTER program is based at the University of Colorado-Boulder and is administered through the Institute of Arctic and Alpine Research (INSTAAR) and in cooperation with the Mountain Research Station, with special use permits from the US Forest Service.

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.

Background/Questions/Methods

Drought-related tree mortality occurs worldwide, including recent episodes in piñon-juniper woodlands of the American west. Although the physiological mechanisms of mortality are poorly understood, carbon starvation may occur in trees that limit transpiration (E) to avoid hydraulic failure.

Ecosystems in topographically complex (mountainous) terrain are responsible for a majority of land-atmosphere CO2 exchange (net ecosystem exchange; NEE) across the western United States due to high inputs of winter precipitation as snowfall. NEE in these regions has been historically difficult to quantify using the eddy covariance (EC) method, however, due to complexities in surface terrain that lead to irregularities in streamline air flow, particularly advective fluxes during periods of low turbulent mixing.

Environmental justice research seeks to understand the patterns and processes shaping the distribution of environmental burdens and amenities across society. While environmental justice research in the US has generally focused on toxics, urban design, hazard management, and segregation have reshaped patterns of risk associated with environmental processes, such as flooding, and the social patterns of exposure to those risks. In Baltimore, flood risks have been a major impetus behind the engineering of the hydrologic systems of the city.

A monthly and annual water budget has been created for the entire Shark River Slough (SRS) within the Everglades National Park (ENP) over 2002-2008. Inputs considered are surface water inflows (S12s and S333 canal structures) and rainfall, while outputs consist of discharge to the Gulf of Mexico (Lostman, Shark, Broad, Harney and North rivers) and evapotranspiration (ET).

In arid ecosystems, current year precipitation explains a low proportion of the annual aboveground net primary production (ANPP). There is evidence that precipitation that occurred in previous years is responsible for the observed difference between actual and expected ANPP, a concept called legacy. Here, we study the mechanisms that generate these legacies, thus we will able to better understand the controls of the global carbon cycle, and to forecast changes in ANPP with a changing climate.

Climate warming in western North America is expected to result in reduced snowpack, earlier melt, and increased evapotranspiration.  Consequently a shift toward a greater proportion of streamflow earlier in the water year with diminished spring and summer streamflows is anticipated.  However, few datasets exist of streamflow with associated climate and vegetation records adequate to interpret changes in climate, forest processes, and their consequences for streamflows.  This study examines trends in long-term streamflow records from three headwater catchments in old growth f