侧柏人工林冠层特性对不同森林经营方式的响应

摘要

为深入认识不同森林经营方式下林木冠层结构变化及适应特性,以九龙山区侧柏人工林为对象,设置结构化经营(A)、全面割灌(B)、对照(C,不实施任何经营措施)、结构化经营+全面割灌(D)4种处理,利用Hem-iView数字植物冠层分析仪测定林分冠层特性.结果表明:侧柏人工林的截获直接辐射、叶面积指数、叶倾角在不同经营方式下均发生显著变化,截获散射辐射和总辐射无显著变化.其中,叶面积指数为(2.04±0.54)～(2.32±0.48),4种处理间的差异表现为C处理最小,显著低于A、B和D,且A、B和D间差异不显著.叶倾角则与叶面积指数呈相反趋势,表现为C处理最大,显著高于其它3种处理.截获直接辐射为(11373.0±383.4)～(11872.0±2924.)MJ·m-2·a-1,D处理显著高于C处理,与A和B无显著差异.综合以上结果可知,割灌和结构森林化经营措施对侧柏人工林的冠层结构特性变化能产生显著影响,二者的有效结合对发挥冠层作用具更大潜能.%In order to find out more about the change and adapted characteristic of canopy structure under different management measures, we studied the Platycladus orientalis plantation lied on Jiulong Mountain.Four types of management forests were designed, structure-based forest management (A), cutting bush (B), control (C, without any management), structure-based forest management+cutting bush ( D). The characteristic of canopy of P.Orientalis plantation was investigated by using HemiView data plant canopy analyzer.The results showed that fractional interception of direct radiation (IDR), leaf area index ( LAI) , and mean leaf angle ( MLA) all changed significantly, however there was no different fractional interception of scattered radiation (ISR) and interception of total radiation (ITD) in P.orienat lis plantation.LAI was 2.04±0.54-2.32±0.48, which change trend was in C much lower than that was in the others, whereas there was no significantly different between A, B and D.MLA was 45.7°±5.5°in C, much higher than that in A, B and D. In addition, IDR was 11373.0±383.4-11872.0±292.4 MJ· m-2 · a-1 in the P.orientalis plantation.IDRin D was much higher than that in C, but there was no significant difference between A and B.These results collectively suggest that both cutting bush and structure-based forest management have significantly effect to canopy structure characteristic of P.orientalis plantation, and they would play grea-ter potential if they are effectively combined.