Evaluation of the Applicability of Competition Indices for the Relationship between Competition and Individual Tree Growth of Taiwania (Taiwania cryptomerioides) Plantations in the Huisun Forest Area

• Main Authors: Li-Wen Ruan, 阮立雯
• Other Authors: 顏添明
• Format: Others
• Language: zh-TW
• Published: 2018
• Online Access: http://ndltd.ncl.edu.tw/handle/5jy7hg

碩士 === 國立中興大學 === 森林學系所 === 106 === The purpose of this study was to explore the relationship between competition and individual growth of Taiwania cryptomerioides plantations in the Huisun forest area. The study site was at the 3rd compartment of the Huisun forest area, National Chung Hsing University. Taiwania planted next to the International Conference Center in 1974. The total of the 35 target trees were carried out to analyze, which were divided into 2 classed based on diameter at breast height (DBH), namely DBH class I and II. We used the fixed and unfixed search radius as approaches to select competitors. Moreover, distance independent competition indices (DI) and distance dependent competition indices (DD) were used to the present study. The correlation analysis of tree characteristics, correlation analysis between tree’s growing space and tree characteristics, correlation analysis between competition indices and trees increment, individual trees competition-growth model were studied. The results showed that tree characteristics were highly significantly related to DBH in the target trees and DBH class II. The tree characteristics were highly significantly related to growing space in the target trees and DBH class II. The horizontal growth of DBH class I was effect by neighborhoods competition. In relative space, the crown competition of target tree, DBH class I and DBH class II were obviously. In correlation analysis betweeen competition indices and trees increment, the correlation coefficient between DD and basal area increment (BAI) was slightly higher to DI. The competition indices presenting in bigger fixed search radius were high significantly correlated with BAI. In addition, the competition indices could predict individual trees basal area growth. DI performed as well as DD. DI1-SF4 performed well in DI, DD13-O1 performed well in DD. However, no competition indices could predict well in target trees, DBH class I and DBH class II at the same time. Therefore, we just used target tree to follow-up analysis. When stand was uniform, we can used border zone to correct for plot edge bias, the result was similar to buffer. Including all trees in the plot as competitors, DI1 also performed well in the growth model.The results of this study will provide foundational information for forest management of Taiwania cryptomerioides plantation in the Huisun forest area.