Abstract:

The Sawtooth oak (Quercus acutissima)forest community was measured by quarter point and quadrat methods. New patchness index has been suggested:

Mathematical express of L index is the covariance of the probability of plant population density disposing in i resource axis’ j resource state and theoretical probability in i axis’ j state when the population is regularly disposed, (j=l,2,…’n; n=number of resource states). Dominant species in the shrub layer and herb layer were put in four axes–light level (k axis), relative soil water content (Rw axis), soil fertility score (F axis) and soil nitrogen content (N axis) and studied. Each species’ patchness index, niche breadth, niche overlap with other species have been analysed in the four axes. Shannon-Wiener diversity index (D) increases with the increase in abundance of resource, H’ (Homogeneity) decreases with the increase in abundance of resource, their regression equation:

D=0.4040–0.0211 R+0.0248 F H’=1.112–0.1400 Ln Rw+0.00064N Biomass (W) regression equation:

Herb layer: W= –12.30+4.07OLnRw

Shrub layer: W= –16.70–0.0735k+2.080Rw–0.4400F

Quercus acutissima’ seedling: W= –35.25+20.88LnN

or W= 2.476 – 0.0371Rw