Effects of competition on growth of Amur linden plantation

Abstract

Competition is the common ecological phenomenon that exists in a stand after canopy closure. The effect of competition on DBH, height, crown diameter and crown area of individual amur linden trees was examined. We used two plots data, from amur linden (Tilia amurensis) plantation, 14 years old, in Liaoning province, to analyze the correlations among DBH, total height, crown diameer and crown area, and used the size-ratio of competiting tree DBHs to subject tree DBH to calculate distance-dependent competition index. The results show that DBH has the largest variation comparing with standard deviations and coeficeints. DBH and crown factors have higher correlations. Competition index is an important factor in tree growth. The best fitting models are exponent, for Cl vs height and Cl vs crown factors, and power, for Cl vs DBH. The more closed correlation model is Cl vs DBH (R^2=0.7028), which performed 16.32%-18.86% better than other models. These reflect that DBH is an important indicator to display stand competition for amur linden.