The Shortgrass Steppe (SGS) LTER project studies an ecosystem that has persisted under a regime of semi-arid extremes, with high inter- and intra-annual variability in precipitation and temperature. The 340 mm of annual precipitation falls primarily during spring rainstorms over several days as well as during a period of summer rains from more localized thunderstorms. Further, the system is well-adapted both to grazing by large herbivores and to smaller-scale disturbances caused by animals like prairie dogs.

Most ecosystem services that affect our quality of life are not bought and sold in the market, and thus we do not know what people would be willing to pay for them. What are the economic benefits of a decrease in air pollution? What are the economic costs of a Eurasian water-milfoil invasion? Environmental economists have honed several techniques to estimate such values, including Contingent Valuation (CV), hedonic price analysis, and the travel-cost method.

The KBS LTER site is in a diverse, rural-to-semirural landscape typical of the U.S. Great Lakes and upper Midwest regions. Research at KBS asks how diverse plants, animals, and microbes in agricultural landscapes can contribute to farm productivity, environmental performance, and profitability. We study annual and perennial crops including corn, soybean, and wheat rotations, forage crops such as alfalfa, and biofuel crops such as poplars, switchgrass, and native successional communities.

Two major foundations of ecosystem science are comparative analyses and long-term studies. Here, we explore the capacity of long-term and comparative data to predict lake characteristics (LCs). We ask if a variable is best explained by neighboring lakes (NL; comparative data), lake history (LH; temporal data), or by some combination of the two.

Tropical environments are changing fast due to deforestation and regrowth, urbanization, climate change, and other forces. The consequences are immense for the whole array of ecosystem services people require. The Luquillo Long-Term Ecological Research Program (LUQ) is tackling these issues in Puerto Rico. LUQ began in 1988 and focused on natural disturbances (hurricanes, landslides, droughts, floods) and ecosystem response. That work revealed patterns of resistance and resilience to cycles of natural disturbance.

The Konza Prairie LTER Program (KNZ) is a comprehensive, interdisciplinary research program designed to provide a mechanistic and predictive understanding of ecological processes in mesic grasslands, and contribute to synthesis and conceptual advances in ecology. Konza LTER also offers education and training at all levels (K-12 to postgraduate) as well as public outreach, and contributes ecological knowledge essential for addressing land-use and management issues in grasslands.

Rusty crayfish (Orconectes rusticus) are invasive in the upper Midwest United States. They often reach high densities and negatively affect native crayfish species, aquatic macrophytes, benthic invertebrates, and some fish populations. However, in some lakes rusty crayfish do not achieve high densities and do not negatively affect native biota. We conducted a whole-lake experiment designed to remove rusty crayfish from Sparkling Lake, a part of the North Temperate Lakes LTER site in Vilas County, Wisconsin.

    Turbulent mixing in lakes plays a crucial role in nutrient transport (e.g. phosphorus) and thus influences the water quality within the lake. Field experiments were conducted in Lake Mendota in the summer 2008 to determine the interior and boundary mixing. The interior mixing is generally several orders of magnitude smaller than the boundary mixing because the thermal stratification inhibits vertical mixing through the metalimnion.

The vision for North Temperate Lakes (NTL) LTER is to gain a predictive understanding of lakes and lake districts at longer and broader scales than has been traditional in limnology. We employ long-term observations, comparisons, experimental manipulations, and diverse modeling and statistical tools to understand change in social-ecological systems. Here, we highlight four ongoing initiatives that demonstrate our multifaceted, interdisciplinary approach to research.