我国3个桉树人工林种植区生产力影响因素

Factors influencing the productivity of three Eucalyptus plantation areas in China

研究影响桉树人工林生产力的主要因素,对于提高桉树人工林生产力以及经营水平和合理利用树种都具有重要的意义。收集我国3个桉树人工林种植区(广东省、广西壮族自治区、云南省)关于生物量与生产力研究中的相关数据,对海拔、林分密度、林龄、年均温和年降水量与乔木层生物量进行了主成分分析与混合模型分析,探究各因素对我国桉树人工林生物量与生产力的影响。结果显示:年均温、年降水量、林龄、海拔和林分密度均是影响广东、广西、云南这3个省(区)桉树人工林生物量的主要因素,其中年降水量对这3个地区桉树人工林的生物量影响极其显著(P<0.01),林龄和林分密度对桉树人工林的生物量影响显著(P<0.05)。这是因为这3个地区都位于亚热带,温度都属于桉树生长的适宜温度,而这3个地区存在明显的干湿季,降水量在季节和地域上分布不均匀,导致这3个地区年降水量存在较明显的差异。因此,年降水量成为影响这3个地区桉树人工林生物量的关键因素。

Understanding the main factors that affect the productivity of Eucalyptus plantations is important for promoting productivity. To this end, we collected density, age, altitude, mean annual temperature mean annual precipitation, and tree biomass data from Eucalyptus plantations in the three Eucalyptus plantation areas in China, which are Guangdong Province, Guangxi Province, and Yunnan Province. Principal component analysis and mixed-effects modeling were then used to explore the influences of various factors on the productivity of the Eucalyptus plantations. Mean annual temperature, mean annual precipitation, age, altitude and density were the main factors that affected the biomass of Eucalyptus plantations in the three provinces which mean annual precipitation （P〈0.01）, forest age, and density （P〈0.05） had significant effects, due to the three provinces were located in a subtropical region. The temperature of all three areas is suitable for Eucalyptus growth. However, the areas are also subject to distinct dry and wet seasons, which means that the distribution of precipitation is uneven, both spatially and temporally, which subsequently causes significant differences in the Eucalyptus biomass of the three provinces. Therefore, mean annual precipitation is a key factor in Eucalyptus biomass in China.