林分环境对侧柏人工林结构化经营的响应机制研究

Platycladus orientalis, an endemic and main afforestation tree species of plantation in China, occupies a very important position in the vegetation restoration and has invaluable ecological, social and economic benefits. Structure-based forest management is widely adopted for sustainable management of natural and plantation forest, and many successful examples are achieved. However, the response mechanism of stand environment to the structure-based management is rarely reported. In this project, the plots of Platycladus orientalis plantation were established. The quantitative monitoring method for small scale was employed, and variation characteristics of stand environment factors, including microclimatic factor (eg. wind direction and speed, air temperature and humidity, illumination intensity, soil temperature and humidity), hydrology factor (eg. rainfall, interception, throughfall, stemflow, soil evaporation, soil moisure ), soil nutrition (eg. total nitrogen, total phosphorus, organic carbon) and soil microorganism (eg. biomass, number, species), were tested. The relationship between the forest spatial structure and microclimate, hydrological process, soil nutrition and soil microorganism was quantitatively analyzed. The effect of forest structure-based management on forest physical and biological environment was clarified. And then, the response mechanism of forest environment to the structure-based management in the Platycladus orientalis plantation was revealed. It provides the scientific basis for water management, nutrition management and structure optimization management of plantation.

侧柏为我国特有种，是我国人工林的主要造林树种之一，在植被恢复中占据着极其重要位置，发挥着不可估量的生态、社会和经济效益。结构化森林经营作为一种可持续经营方法，已被广泛应用于天然林与人工林的经营，并且取得了一系列成果。然而关于林分环境对结构化经营的响应机制研究鲜有报道。本研究以侧柏人工林为研究对象，采用小尺度定量监测方法，监测结构化经营影响下林分小气候因子（风速、风向、空气温湿度及光照、土壤温湿度），水文因子（降水、截留、穿透雨、树干茎流、土壤蒸发、表层土壤含水量），土壤养分（全氮、全磷、有机碳）和微生物（生物量、数量、种类）的变化特征，定量分析林分空间结构与小气候、水文过程、土壤养分和微生物的关系，阐明结构化经营对林分物理和生物环境的影响规律，进而揭示林分环境对结构化经营的响应机制，以期为人工林的水分、养分管理及结构优化经营提供理论基础和参考依据。

侧柏为我国特有种，是我国人工林的主要造林树种之一，在植被恢复中占据着极其重要位置，发挥着不可估量的生态、社会和经济效益。结构化森林经营作为一种可持续经营方法，已被广泛应用于天然林与人工林的经营，并且取得了一系列成果。然而关于林分环境对结构化经营的响应机制研究鲜有报道。本研究以侧柏人工林为研究对象，主要开展了：（1）结构化经营对小气候的影响研究；（2）结构化经营对水文效应的影响研究；（3）结构化经营对土壤养分和微生物的影响研究；（4）空间结构的定量分析及其与环境的关系研究。. 通过以上研究，取得了一系列成果：（1）结构化经营优化了林分空间结构，促进中、大径木的生长，提高了林分生产力和稳定性；（2）结构化经营通过改变冠层结构，降低昼夜温差、增强林内光照、增加林内通风度，进而提高林内舒适度；（3）结构化经营能促进降雨穿透林冠层，显著增加树干茎流量、显著减少林冠截留量；（4）枯落物截留量与林外降雨量、降雨持续时间、间隔时间、降雨强度、空气相对湿度存在显著相关关系，结构化经营可以增加枯落物截留量；（5）结构化经营降低土壤养分含量和化学计量比，显著降低土壤有机碳和全钾含量及C/N化学计量比；（6）采用非线性加权回归方法，研建了气候敏感的可变参数碳储量生长模型。研究结果可为人工林的水分、养分管理及结构优化经营提供理论基础和参考依据。