桉树、相思、湿地松生物量估算系数差异特征及其影响因素

Differences in Biomass Estimation Coefficients of Eucalyptus spp., Acacia spp. and Pinus elliottii and Their Key Influencing Factors

对已出版或发表的我国不同地点的桉树(主要包括尾巨桉、巨尾桉、尾叶桉和尾细桉等)、相思(主要包括马占相思、黑木相思、大叶相思、台湾相思和肯氏相思等)和湿地松生物量数据进行收集、整理和筛选,分析不同人工林生物量3个常见估算系数(生物量转换与扩展系数BCEF、生物量扩展系数BEF和根茎比R)的差异特征以及与林分结构特征(林龄、胸径、树高、林分密度、林分蓄积量)、气候因子(年均气温、年均降水量)和地形因子(海拔)的关系。结果表明:桉树、相思、湿地松人工林的BCEF平均值分别为0.66 Mg·m^(-3)、0.98 Mg·m^(-3)、0.69 Mg·m^(-3),BCEF平均值分别为1.26、1.61、1.66,R平均值分别为0.19、0.23、0.22。桉树林生物量估算系数的主要影响因子为树高和林分密度,相思林生物量估算系数主要受胸径和蓄积量影响。湿地松林生物量估算系数受林分结构特征影响不大,主要受到气候因子(年均温度、年均降水量)和地形因子(海拔)影响。因此,在估算区域尺度人工林生物量时应考虑林分结构特征及气候和地形因子引起的生物量估算系数差异。

Data from published literature on biomass measurements of Eucalyptus spp.(including E.urophylla×E.grandis,E.grandis×E.urophylla,E.urophylla×E.tereticornis and E.urophylla),Acacia spp.(including A.mangium,A.melanoxylon,A.auriculiformis,A.confusa and A.trinervata)and Pinus elliottii forests in different locations in China were collected and analyzed.The characteristics of three common estimation coefficients of biomass(biomass conversion and expansion factor BCEF,biomass expansion factor BEF,and root/shoot ratio R)in different forests and the relationship with stand structure characteristics(stand age,mean DBH,mean tree height,stand density,and standing volume),climatic factors(annual average temperature and annual average precipitation)and topographic factors(elevation)were summarized and differences examined.The results showed that the mean BCEF values of Eucalyptus spp.,Acacia spp.,and P.elliottii forests averaged 0.66 Mg·m^(−3),0.98 Mg·m^(−3) and 0.69 Mg·m^(−3),respectively,the mean BEF values were 1.26,1.61 and 1.66 respectively,and the mean R values were 0.19,0.23 and 0.22 respectively.The main factors influencing the biomass estimation coefficients of Eucalyptus forests were tree height and stand density,while the biomass estimation coefficients of Acacia forests were mainly affected by DBH and stocking volume.Estimated biomass coefficients for P.elliottii forests were not significantly influenced by stand structural characteristics,but mainly by climatic factors (mean annual temperature, mean annual precipitation) and topographic factors (elevation). Therefore, differences in biomass estimation coefficients due to stand structure characteristics and climatic and topographic factors should be taken into account when estimating biomass of planted forests at the regional scale.