Effects of Prescribed Burning on Andropogon scoparius in Postagricultural Grasslands in Connecticut

Abstract

-Since 1968 postagricultural Andropogon scoparius grasslands have been subjected to annual and biennial burning. After 17 years of burning, Andropogon standing crop has increased averaging 364 g/m2 compared to 252 g/m2 when unburned. Baptisia tinctoria, a fire increaser and nitrogen fixer, increased in density 2and 3.5-fold with annual and biennial burning, respectively. Woody growth was stem-killed, but resurged following each burn. Clonal species such as Gaylussacia baccata and Comptonia peregrina increased 3and 4-fold, respectively, after more than a decade of burning. Where nonclonal woody species were present in burn plots, there was little change in woody cover; unburned plots have become dominated by woody growth. A multifactor, qualitative working model involving increases in light, soil moisture and temperature, mineralization, nitrogen-fixing species and ash is proposed to explain why Andropogon standing crop increases with burning. The use of fire favors perpetuation of a native eastern prairie grassland somewhat similar to that which previously existed in the Hempstead Plains of Long Island, New York. The use of prescribed burning has considerable potential in wildlife management and ecosystem restoration and in maintaining graminoiddominated landscapes within this oak forest region.