| 摘要: |
| 【目的】探究混交对林分生长的影响，为混交林营造和科学经营提供参考。【方法】收集整理了246篇文献617条数据进行Meta分析，通过亚组分析探讨不同混交树种类型（阔叶混交、针灌混交、针阔混交、针叶混交和竹针混交）、混交比例（指目的树种株数占混交林总株数的比例，分为≥0.1～＜0.2、≥0.2～＜0.4、≥0.4～＜0.6、≥0.6～＜0.8和≥0.8～＜0.9）、林龄（≤9 a、10～19 a、20～29 a、30～39 a和≥40 a）和海拔梯度（＜400 m、≥400～＜800 m、≥800～＜1 200 m、≥1 200～＜1 600 m和≥1 600～＜2 000 m）对混交林中目的树种胸径、树高、林分蓄积量及生物量生长的影响。【结果】混交对目的树种的胸径、树高、林分蓄积量以及生物量累积均有一定的促进作用。不同树种类型的混交林对林分生长的影响差异显著，其中针灌混交效益最大；不同混交比例对林分生长的影响差异显著，其中混交比例≥0.1～＜0.8时显著促进林分生长，而混交比例≥0.8～＜0.9时对树高生长、林分蓄积量和生物量的积累有一定抑制作用；混交对不同林龄林分的影响差异显著，随着林龄增大，混交对目的树种胸径生长和林分生物量累积的促进作用呈现先增后降的趋势，这与林木连年生长量变化特征一致，但混交对目的树种树高生长和林分蓄积量的促进作用随林龄增长呈现上升趋势；不同海拔梯度下，混交对林分生长的影响差异显著，随海拔上升，混交对林分生长的促进作用呈现先增加后降低的趋势，在海拔≥1 200～＜1 600 m时促进作用最大。【结论】混交对林分生长有促进作用，不同的混交树种类型、混交比例、林龄及海拔对混交效应的影响均差异显著。 |
| 关键词: 混交林 Meta分析 树种类型 混交比例 |
| DOI： |
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| 基金项目:国家重点研发计划项目（2016YFD0600304）；国家“973”计划项目（2010CB950602） |
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| Effects of mixing on forest growth:a meta-analysis |
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WANG Huirong,GUAN Mengran,ZHANG Shasha,et al
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| Abstract: |
| 【Objective】This study investigated the impact of mixing on growth of stands to provide reference for scientific construction and management of mixed forest.【Method】Meta analysis was conducted based on a dataset of 617 records from 246 literatures.The effects of mixing on DBH,tree height,stand volume and biomass growth under different tree types (broad-leaved tree mixture,conifer and shrub mixture,coniferous and broad leaved tree mixture,coniferous tree mixture and bamboo and coniferous tree mixture),mixed proportions (referring to the ratio of number of target tree species to total number of mixed forests including ≥0.1-<0.2,≥0.2-<0.4,≥0.4-<0.6,≥0.6-<0.8 and ≥0.8-<0.9),forest ages (≤9 a,10-19 a,20-29 a,30-39 a and ≥40 a) and altitudes (<400 m,≥400-<800 m,≥800-<1 200 m,≥1 200-<1 600 m and ≥1 600-<2 000 m) were discussed through subgroup analysis.【Result】Mixing promoted average DBH and tree height of target tree species,stand volume and biomass accumulations.The effects of different tree species on stand growth were significantly different,with the largest effect from conifer-shrub mixtures. Under different mixing proportions,the effect on stand growth had significant dissimilarity.The mixing proportion of ≥0.1-<0.8 significantly promoted stand growth, while the mixing ratio of ≥0.8-<0.9 depressed tree height growth,stand volume and biomass accumulations.The effects of mixture varied significantly with forest ages.With the increase of forest age,mixing benefited DBH growth of target tree species,while biomass accumulation firstly increased and then decreased.This was consistent with the traits of current annual increment of forest trees.The mixing benefit on target tree height and stand volume showed an increase with stand age.This was correlated to the biological characteristics of forest trees.The effect of mixing on stand growth was significantly different along altitude gradient.With the increase of altitude,stand growth showed a trend of increasing first and then decreasing.The largest promotion effect was at the altitude of ≥1 200-<1 600 m.【Conclusion】Mixing can promote growth of forest stands.The effects of tree types,proportions,age of forest,and altitude conditions on mixing effect were significantly different. |
| Key words: mixture Meta-analysis mixed tree type mixed proportion |
