Long-Term Ecological Research (LTER)/NTL001: Physical Limnology of North Temperate Lakes Primary Study Lakes

LTER - Long-Term Ecological Research Program/North Temperate Lakes (NTL)

LTER/NTL001 [Summary adapted from the LTER Core Data Set Catalog]:

Parameters characterizing the physical limnology of the seven primary lakes (Allequash, Big Muskellunge, Crystal, Sparkling, and Trout lakes and unnamed lakes 27-02, and 12-15) are measured at one station in the deepest part of each lake at 0.25-m to 1-m depth intervals depending on the lake.

Parameters include lake level (measured at the shoreline), water temperature, vertical penetration of photosynthetically active radiation (PAR), secchi disk depth, dissolved oxygen, ice thickness, and snow depth on lake. Additional derived parameters include PAR extinction coefficients for the water column and the epilimnion, and percent oxygen saturation. Auxiliary data include time of day, air temperature, wave height, cloud cover, and wind speed and direction.

Special Comments: These measurements are made concurrently with parameters listed in chemical (NTL002) and plankton (NTL003) databases. Derived data sets containing epilimnetic averages and hypsometrically weighted averages over depths are also available.

The North Temperate Lakes (NTL) site is affiliated with the Center for Limnology at the University of Wisconsin, Madison. The NTL site focuses its research on north temperate lake ecosystems in the Northern Highland Lakes District of Wisconsin. The Northern Highland Lakes District, has an area of approximately 10,000 sq. km. and has one of the highest concentrations of lakes in the world. Lakes range in size from 0.1 to 1,500 ha, in depth from 1 to 33 m, and in fertility from oligotrophic to eutrophic. Other representative limnological conditions include: rainwater dominated, groundwater dominated and drainage lakes; dystrophic lakes; lakes with varved sediments, winterkill lakes, temporary and permanent forest ponds, and reservoirs. Lakes are influenced by strong seasonality and are usually ice covered from late November to late April. Lakes within the Northern Highland exhibit near-natural water quality conditions. Nearly 80% of the land area and two-thirds of the lake frontage are protected.

NTL LTER research topics include physical, chemical, and biological limnology; hydrology and geochemistry; climate forcing; producer and consumer ecology; ecology of invasions; ecosystem variability; lakescape and landscape ecology. Information about LTER is also available at 'http://lternet.edu/'