Determination of relationships between leaf area Index and Stand characteristics in anatolian black pine stands of kastamonu region, Türkiye

ABSTRACT Background: Leaf area index (LAI) is an important stand characteristic in terms of forest productivity and stand growth, and it shows significant correlations with other stand characteristics. In this study, it is aimed to reveal the relationships between LAI and some other stand characteristics, i.e. mean diameter, stand age, dominant height, site index, number of trees, stand basal area, stand density, total crown biomass and crown dimensions for Anatolian black pine (Pinus nigra J.F. Arnold subsp. pallasiana (Lamb.) Holmboe) stands in Kastamonu region, which is one of the economically important tree species in Türkiye, and to develop a regression model for LAI estimations by using these relationships. Results: The data obtained from 119 temporary sample plots were used in the study. According to the results, stand basal area, stand density, total crown biomass, dominant height, number of trees, mean diameter, and site index positively correlated with LAI. LAI values were significantly different in terms of stand density and site classes. Among the candidate models for LAI estimations, the model containing site index and stand density as independent variables was the most successful model with the adjusted coefficient of determination ( R adj 2) of 0,63 and the Akaike information criterion ( AIC) of -67,25. Conclusion: The LAI, which is difficult to measure directly in practice, of Anatolian black pine stands in Kastamonu region of Türkiye could be estimated accurately with the help of the equation developed.

摘要 背景：叶面积指数（Leaf Area Index, LAI）是关乎森林生产力与林分生长的重要林分特征，且与其他林分特征存在显著相关性。本研究旨在揭示土耳其经济重要树种之一的安纳托利亚黑松（Pinus nigra J.F. Arnold subsp. pallasiana (Lamb.) Holmboe）在卡斯塔莫努地区的林分中，叶面积指数与若干其他林分特征（即平均直径、林分年龄、优势木高、立地指数、林木株数、林分断面积、林分密度、总冠层生物量及冠层维度）之间的关联，并基于这些关系构建用于叶面积指数估算的回归模型。结果：本研究共使用119块临时样地的调查数据。结果显示，林分断面积、林分密度、总冠层生物量、优势木高、林木株数、平均直径及立地指数均与叶面积指数呈正相关。叶面积指数在林分密度和立地等级层面存在显著差异。在用于叶面积指数估算的候选模型中，以立地指数和林分密度作为自变量的模型表现最优，其调整决定系数（adjusted coefficient of determination, R adj²）为0.63，赤池信息准则（Akaike information criterion, AIC）为-67.25。结论：实践中难以直接测定的土耳其卡斯塔莫努地区安纳托利亚黑松林分的叶面积指数，可通过本研究构建的方程实现精准估算。