北京地区油松、侧柏人工林叶面积指数变化规律

Change patterns of leaf area index(LAI) of Pinus tabulaeformis and Platycladus orientalis plantations in Beijing

叶面积指数（LAI）是群体结构的重要参数．也是衡量林分质量的重要指标。通过光学测量方法和遥感技术等手段测量的大范围LAI需要进一步的地面实测验证。以北京十三陵林场为研究区，利用CI-110植冠分析仪和野外实测的69个油松和侧柏林分LAI为基础，分析了有效叶面积指数（LAIe）与实测叶面积指数（LAIa）的关系。结果表明，油松林的LAIe／IAIa之值在35．52％～36．36％；侧柏林的LAIe／LAIa之值在14．60％～16．72％。由于测定的油松、侧柏林分郁闭度在0．5～0．8，符合生态公益林的经营要求，因此油松、侧柏林的LAI是合适的，可以作为油松、侧柏林林分质量调控的一个重要依据。

Leaf area index （LAI） is an important parameter in plant population structure research, and of significance in the estimation of stand quality. The large scope LAI obtained by optical measurement and remote sensing needs to be validated by actual survey. With Pinus tabulaeformis and Platycladus orientalis plantations in the State Shisanling Forest Farm of Belling as test objects, and using the LAI data obtained by Digital Plant Canopy Imager （CI-110） and field survey, this paper analyzed the relationship between effective LAI （LAIe） and actual LAI （LAIa）. The results showed that the LAIe/LAIa ratio of P. tabulaeformis plantation was 35.52 % - 36.36 %, and that of P. orientalis plantation was 14.60 % - 16.72 %. Because the canopy openness of test plantations ranged from 0.5 to 0.8, which accorded with the requirement of non-commercial forest management, the LAI of P. tabulaeformis and P. orientalis plantations was appropriate to be used as an important gist in their quality control.