文献类型：期刊文献

英文题名：Soil available phosphorus and pH are key factors affecting the site index of Larix kaempferi plantations in China

作者：Wei, Hongyang[1] Chen, Dongsheng[1] Wu, Chunyan[1] Sun, Xiaomei[1] Zhang, Shougong[1]

第一作者：Wei, Hongyang

通信作者：Sun, XM[1];Zhang, SG[1]

机构：[1]Chinese Acad Forestry, Res Inst Forestry, State Key Lab Tree Genet & Breeding, Key Lab Tree Breeding & Cultivat,Natl Forestry & G, Beijing, Peoples R China

年份：2024

卷号：7

外文期刊名：FRONTIERS IN FORESTS AND GLOBAL CHANGE

收录：;Scopus(收录号：2-s2.0-85207029024);WOS:【SCI-EXPANDED(收录号:WOS:001340019500001)】；

基金：The author(s) declare financial support was received for the research, authorship, and/or publication of this article. Site collection and field data collection was funded by the National Key Research and Development Program of China (2023YFD2200801). Lab work was funded by the Fundamental Research Funds for the Central Non-profit Research Institution of CAF (CAFYBB2022ZC001, LYSZX202002) and the National Key Research and Development Program of China (2022YFD2200103).

语种：英文

外文关键词：Larix kaempferi; site index; environmental variables; climate; topography

摘要：Assessing the quality of forest sites is crucial for evaluating the potential productivity of forests and formulating effective management strategies. Therefore, it is essential to understand how environmental variables affect the site quality. This study focuses on quantifying the effects of 44 different environmental variables including climate, topography, and soil properties on the site index of Larix kaempferi plantations in three different climate regions in China, utilizing the random forest algorithm. L. kaempferi site index was determined from stem analysis data by felling dominant trees from 51 even-aged stands. The results indicated that the proposed random forest model explained similar to 59.47% of site index variations. Among many environmental variables, available phosphorus, pH, degree-days above 5 degrees C (DD5), and spring mean maximum temperature (Tmax_MAM) had significant effects on the site index (P < 0.05), and the importance of soil chemical properties generally exhibits relatively larger effects on the site index than climate variables and topography variables. The partial dependence analysis revealed that the L. kaempferi plantations had maximum values at similar to 30 mg/kg of available phosphorus in the first soil layers, 30 mg/kg of available phosphorus in the second soil layers, 20 mg/kg of available phosphorus in the third soil layers, the DD5 between 2,600and 3,000 degrees C, and Tmax_MAM similar to 15 degrees C. Our findings attempt to provide a better understanding of the site-growth relationship.