Primary Production

What is it? Plant growth in most ecosystems forms the base or primary component of the food web, and produces food for other organisms.

Konza Prairie LTER scientist measures productivity in the tallgrass prairie.

Primary Productivity Research in LTER

	The Konza Prairie LTER Site is located in the tallgrass prairie grassland of eastern Kansas.

At Konza Prairie LTER scientists study the ANPP of the tallgrass prairie as well as several important factors that affect ANPP, including grazing by bison and the frequency of fire.

Scientists gather baseline data by measuring primary production for several years to find out how much plant growth there is every year in the absence of grazing or fire. Once the natural variations of primary production are determined, scientists have a good idea of the average amount of plant growth in that environment, and can then conduct experiments.

Here are two questions LTER scientists are trying to answer:
How do Bison affect ANPP? American Bison (Bison bison), which make their living by eating prairie grasses, are traditional residents of the tallgrass prairie, and were re-introduced to the study site in 1998. Scientists continue to measure primary production to find out what effect Bison have on plant growth.

	American Bison (Bison bison) were re-introduced to the Konza Prairie LTER study site in 1998.

How does fire affect ANPP? To study the effects of fire on ANPP, scientists divide the study site into areas that remain unburned and areas that are burned at different time intervals (for example burned every year or every other year). Primary production is measured in the burned and unburned areas over time to find out if there is a change in ANPP based on the frequency of burning.

Experimentation with controlled burns is an imporant part of resarch at the Konza Prairie LTER site, Flint Hills, Kansas.