基于多功能经营的赣南飞播马尾松林空间结构模式研究

The region of southern Jiangxi is an important ecological barrier in southern China, which is also the national timber strategic reserve production base. Aerial seeding Pinus massoniana plantation is one of the main forest resources in south Jiangxi covering 21.4% of forestland area, however, this type of stand is generally existing the problem of poor function making it is hard to meet the requirements of timber production and ecological functions at present. Therefore, how to realize multi-function management through regulation is the main issues needed to be solved. From the viewpoint of system theory, stand structure affects its functions significantly. As stand spatial structure is more vital than non-spatial structure, the influences of spatial structure on stand functions will be considered in this research. Aerial seeding Pinus massoniana plantation in Xingguo Country of south Jiangxi is chosen as the research subject. According to stand structure factors, plots are set by theory and methods of forest management, ecology and mathematics. Plots investigation and sample determination will be used to collect data for analyzing the timber production, water conservation, carbon sequestration and biodiversity of the stand, as well as the stand's spatial structure, exposing the coupling mechanism between the stand function and its spatial structure. Mathematical statistics principles and data mining technology as well as multi-objective programming will be used to set up the spatial structure model of stand multi-function management. The stand regulation technology proposed in this research will provide a scientific basis and decision-making reference for the multi-function management of aerial seeding Pinus massoniana plantation in southern Jiangxi.

赣南是我国南方地区重要的生态屏障，也是全国木材战略储备生产基地。飞播马尾松林是赣南主要森林资源之一，面积占有林地总面积的21.4%，但其普遍存在林分整体功能较低的问题，针对其难以满足木材生产和生态功能多重需求现状，如何通过调控实现多功能经营是当前亟待解决的科学问题。从系统论结构决定功能观点出发，林分结构对功能有重要影响，且林分空间结构比非空间结构更为重要。本项目以赣南兴国县的飞播马尾松林为研究对象，集成森林经理学、生态学、数学等理论与手段，综合考虑林分结构因子设置样地，通过样地调查与样品测定，明确林分木材生产、涵养水源、固碳和生物多样性功能，揭示林分空间结构特征，探明林分功能与林分空间结构的耦合机理；应用数理统计原理和数据挖掘技术，以多功能经营空间结构为目标，采用多目标规划方法，建立林分多功能经营空间结构模式，提出林分多功能经营调控技术，为赣南飞播马尾松林多功能经营提供科学依据和决策参考。

赣南是我国南方地区重要的生态屏障，也是全国木材战略储备生产基地。飞播马尾松林是赣南主要森林资源之一，但普遍存在林分整体功能较低的问题，难以满足木材生产和生态功能多重需求，如何实现多功能经营是当前亟待解决的科学问题。项目以赣南兴国县的飞播马尾松林为研究对象，探讨林分木材生产、水源涵养、固碳和生物多样性功能，揭示林分空间结构特征，探明林分功能与空间结构的耦合机理；建立林分多功能经营空间结构模式并提出调控技术。重要结果有：株数密度1500-2100株•hm-2有利于林下植被生长发育、提高土壤持水性能及林分固碳功能；补植阔叶树有利提高土壤养分及水源涵养、固碳和生物多样性功能。林分碳密度为98.29 t•hm-2，且土壤层（0-100 cm）＞乔木层＞林下植被层＞凋落物层，株数密度、平均胸径、土层厚度、坡位、林龄、郁闭度是影响林分碳密度的主要因子；林分水源涵养量为553.10 t•hm-2，为土壤层>林冠层>枯落物层，林下植被为芒萁类的林地表层水文效应优于灌木类和禾草类；林分植物多样性指数为0.84，且灌木层>草本层>乔木层，生物因子、非生物因子对物种多样性的单独解释率分别为34.8%和7.5%；林分蓄积量为79.80 m3•hm-2，木材生产功能较低。林分空间结构的大小比数为0.50，处于中庸状态；开敞度为0.23，林木生长空间不足；混交度为0.27，属中度混交；角尺度为0.52，属聚集分布；空间密度为0.43，属中等密度。大小比数对碳储量影响显著，混交度对碳储量、水源涵养量、植物多样性的影响均达显著水平，开敞度对碳储量、蓄积量具有显著影响，空间密度对水源涵养量、植物多样性、林分蓄积量影响显著，角尺度对各功能影响均未达显著水平。以固碳、水源涵养、生物多样性保护、木材生产等4个单项功能为主导及以生态功能为主导、整体功能最优6种多功能经营模式的理想空间结构综合指数分别为0.78、0.78、0.90、0.68、0.97、0.93，并提出了其相应的空间结构模式与技术。研究成果可为提高飞播马尾松林相关功能及以不同主导功能的多功能经营空间结构调控提供科学依据和决策参考。