Increasing atmospheric CO₂ will likely affect both the hydrologic cycle and ecosystem productivity. Current assumptions that increasing CO₂ will lead to increased ecosystem productivity and plant water use efficiency (WUE) are driving optimistic predictions of higher crop yields as well as greater availability of freshwater resources due to a decrease in evapotranspiration.

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.

The California Current System is a coastal upwelling biome, as found along the eastern margins of all major ocean basins. These are among the more productive ecosystems in the world ocean. The California Current Ecosystem (CCE) LTER site (centered on 32.9° N, 120.3° W) is investigating nonlinear transitions in the California Current coastal pelagic ecosystem, with particular attention to long-term forcing by a secular warming trend, multi-decadal oscillations (e.g., PDO and NPGO), and ENSO in altering the structure and dynamics of the pelagic ecosystem.

 Experimental studies of phytoplankton growth and grazing processes were conducted in the California Current Ecosystem off Point Conception, California to test the hypothesis that growth and grazing losses determine, to first order, the local dynamics of phytoplankton in the upwelling circulation.

If long-term responses of plant photosynthesis to rising atmospheric carbon dioxide (CO₂) levels are similar or predictably different among species, functional types, and ecosystem types, general global models of CO₂ fertilization effects can effectively be developed. To address this issue we measured gas exchange rates of 13 perennial grassland species from four functional groups exposed to eleven years of long-term free-air CO₂ enrichment (eCO₂, +180 ppm above ambient CO₂, BioCON).

The goal of the Arctic LTER is to predict the future ecological characteristics of Arctic Alaska based upon our knowledge of the controls of ecosystem structure and function as exerted by physical setting and geologic factors, climatic factors, biotic factors, and the changes in fluxes of water and materials from land to water.

The vast majority of biodiversity on Earth lives in the soil; to what degree are this diversity and the ecosystem functions they perform regulated by climate and plant productivity? In this study, we seek to determine the relationship between climate/Net Primary Productivity (NPP) and soil food web structure. Research sites, each consisting of a forest and paired grassland, are located along east-west transects in Oregon; these transects encompass climates producing the greatest productivity and nearly the least productivity on the continent.

Accurate habitat mapping in salt marshes is important for both management and conservation goals, as it provides information essential for identifying sensitive areas and documenting changes over time as the result of sea level rise or human perturbations. The goal of this study is to characterize patterns of marsh plant distribution in the salt marshes surrounding back barrier islands (hammocks) within the Georgia Coastal Ecosystems LTER. In the summer of 2007 the GCE LTER surveyed over 50 hammocks of different origin and size.

The hydraulic architecture of parallel veined monocots is fundamentally different from the branched networks of dicot leaves. The functional significance of this difference on leaf level gas exchange is not well understood. In order to investigate how the hydraulic architecture of monocots affect gas exchange we measured the axial hydraulic conductivity and leaf level gas exchange from the base to tip of 7 grass species. Stomatal conductance (g_s) and photosynthesis (A) increased but hydraulic conductivity (K_h) declined along the length of the blade.