摘要
叶面积指数(Leaf area index)是描述叶片生长过程的重要参数之一。为探讨我国帽儿山地区落叶阔叶林长时间序列叶面积指数变化规律,利用LAI-2200对帽儿山林场老爷岭试验站12块样地生长季叶面积指数进行测量,使用生长方程对离散LAI值进行拟合,计算不同时间的叶面积指数生长速率和生长季累积叶面积指数,分析不同立地条件下不同林分叶面积指数生长情况,对其动态变化规律进行研究。研究表明:生长季4月到8月,12块落叶阔叶林叶面积指数均随时间呈单峰变化。以杨树有优势树种的样地用Mitscherlich生长方程拟合其LAI效果最优,以色木和白桦为优势树种的样地采用logistic生长方程拟合效果最优,其它样地Gompertz生长方程拟合最优,各样地生长方程拟合R2均高于0.962。杨树林叶面积指数增速最快,胡桃楸林增速缓慢,6月初到8月中下旬为冠层LAI生长速度趋于平稳。空间位置相近的阴阳坡样地叶面积指数生长规律差别较大,最高累计叶面积指数相差17.6%。此研究结果为帽儿山地区阔叶林叶面积指数动态变化规律提供数据基础,为该地区林冠植被的空间异质性及其造成影响,以及提升日步长碳循环、水循环生态机理模型精度提供更为准确的数据支持。
Leaf area index（ LAI） is one of the most important structural parameters to describe leaf growth process. To explore the seasonal variation rules of leaf area index for long time sequence in Maoer Mountain of China,this paper measured the LAI in 12 sample plots and monitored the seasonal dynamics by using LAI- 2200. Four growth equations were used to fit the scattered LAI- values and calculate the growth rate of LAI and the cumulative LAI- values,and the seasonal variation rules of leaf area index under different site conditions were analyzed. The results showed that the LAI of 12 sites of deciduous broad- leaved forest in the growth season from April to August was in a single peak curve. Mitscherlich growth equation was the best fitting model for the plots dominated by poplar tree species. Logistic growth equation was the best for the plots dominated by Betula platyphylla and Acer mono species. Gompertz growth equation can be used to fit the other sites. The R2 value in all kinds of growth equation were larger than 0. 962. The LAI increment of poplar sites was the largest,and that of Juglans mandshurica sites were relatively slower. Between early June and late August,LAI- values tended to be stabilized. The differences of LAI growth were larger in different slopes of the same spatial location and the highest difference of cumulative leaf area index was 17. 6%. The results of dynamic variation rules of forest leaf area index can provide a basis for future study in the spatial heterogeneity of vegetation and its impact,carbon modeling,water cycling from stands to landscape levels.
出处
《森林工程》
2016年第4期1-6,共6页
Forest Engineering
基金
"十二五"国家科技支撑计划项目(2011BAD37B01)
中央高校基本科研业务费专项资金项目(DL11BA19)
