Scale Expansion of Community Investigations and Integration of the Effects of Abiotic and Biotic Processes on Maintenance of Species Diversity

Table 5

The regression relationship between 𝑙𝑛𝑌 and, respectively, plant density, herb above-ground biomass, and successional stages at the plot level.

Process impacting filter	Regression model^a	𝑛	𝑅^2	𝐹-value	𝑃 value
Plant density (stem·ha^−1)	𝑦=8.80𝐸−006𝑥^2−0.008𝑥+3.619 (tree layer)	15	0.506	6.157	0.014
	𝑦=0.015𝑥^2−0.231𝑥+3.216 (shrub layer)	60	0.340	14.456	0.000
	𝑦=4.63𝐸−006𝑥^2−0.003𝑥+3.805 (herb layer)	60	0.325	10.602	0.000
Above-ground biomass (g·m^−2)	𝑦=1.07𝐸−005𝑥^2−0.003𝑥+3.608 (herb layer)	60	0.135	3.347	0.045
Successional stages	𝑦=−0.4569𝑥+3.7729 (tree layer)	15	0.5664	16.994	0.001
	𝑦=−0.2632𝑥+1.7585 (shrub layer)	60	0.033	1.531	0.222
	𝑦=0.0439𝑥^2−0.1889𝑥+2.8064 (herb layer)	60	0.0913	2.209	0.122

^a𝑦 = ln𝑌, 𝑥 =a process impacting filter.