文献类型：期刊文献

英文题名：The effect of the calculation method, plot size, and stand density on the top height estimation in natural spruce-fir-broadleaf mixed forests

作者：Zhou, Mengli[1] Lei, Xiangdong[1] Duan, Guangshuang[2] Lu, Jun[1] Zhang, Huiru[1]

第一作者：Zhou, Mengli

通信作者：Lei, XD[1]

机构：[1]Chinese Acad Forestry, Inst Forest Resource Informat Tech, Key Lab Forest Management & Growth Modelling Stat, Beijing 100091, Peoples R China;[2]Xinyang Normal Univ, Xinyang 464000, Henan, Peoples R China

年份：2019

卷号：453

外文期刊名：FOREST ECOLOGY AND MANAGEMENT

收录：;EI(收录号：20193607407004);Scopus(收录号：2-s2.0-85071723477);WOS:【SCI-EXPANDED(收录号:WOS:000496607200006)】；

基金：We would like to thank all people contributing to sample plot survey for this study, and Mrs Lingxia Hong, from the Institute of Forest Resource Information Techniques, Chinese Academy of Forestry, for her guidance on the coding. Our appreciation is also extended to: Prof. Oscar Garca, from the University of Northern British Columbia, for sharing his code about the U-estimator methods; and to Prof. Wojciech Ochal, from University of Agriculture in Krakow, for the discussion about random sample plot selection. The study was funded by National Key R&D Program of China (Grant No. 2017YFC0504101) and Special Fund for Forest Scientific Research in the Public Welfare (Grant No. 201504303).

语种：英文

外文关键词：Stand top height; Stand density effect; Plot size effect; Uncertainty; Natural mixed forest

摘要：Stand dominant height or top height (TH) is a crucial variable for the measurement of potential site productivity, forest growth and yield projection, biomass estimation, structure stratification, and determination of development stages. There are variable definitions of TH, and it is affected by calculation method and stand characteristics. These issues have been examined for pure forests, but there is a knowledge gap on the estimation of TH for natural mixed forests with heterogenous and complex structure. We examined the effect of the calculation method, plot size, and stand density on the TH estimation in natural spruce-fir-broadleaf mixed forests in northeast China. The data were from 12 one-hectare plots with 10,195 height measurements. There were 14 calculation methods derived from the combination of four TH estimation methods (Conventional estimate; Adjusted largest trees; U-estimator, Sub-plot estimation) and four optional tree selection strategies with the consideration of tree species and tree size. Sample plots, with an area ranging from 0.01 ha to 0.50 ha with the interval of 0.01 ha, were randomly selected, and repeated 200 times with a bootstrapping method. In total there were 120,000 subplots generated from the 12 one-hectare plots. Results revealed that there was a strong correlation among the estimate methods, but the TH estimates were significantly different with the difference ranging from 0.02 m to 9.49 m. A threshold of plot size for stabilizing the TH estimate ranged from 0.05 ha to 0.1 ha. Stand density had complicated effects on TH estimations. The uncertainty for plot area and stand density was quantified. There were weak correlations between TH and stand volume, biomass and the periodic basal area increment, but moderate and high correlations with stand arithmetic and weighted mean height, respectively. We recommend the adjusted tallest trees method irrespective of tree species as the optimum for practical application for mixed forests.