Analysis On Spatial Structure Based On Multi-function Management Of Aerial Seeding Pinus Massoniana Plantations

The areas in south of Jiangxi Province is an important ecological barrier, which is also the national strategic reserve timber production base. Aerial seeding Pinus massoniana plantation is one of the main forest resource of Jiangxi and comprehensively promoting its quality of stand plays a decisive role in Jiangxi ecological economic construction. Based on the methods of sample investigation and sample determination this paper took aerial seeding Pinus massoniana plantations of Xingguo County as the research object in south of Jiangxi Province, analyzed the stand carbon sequestration, water conservation, biodiversity conservation, timber production function and the stand spatial structure, discussed the effect of stand spatial structure on functions of stand and set up the spatial structure optimization models of multi-function management which was taken single function as the leading factor, taken the ecology function as the leading factor and the optimal overall function to provide the scientific evidence for management of aerial seeding Pinus massoniana plantations in south of Jiangxi Province. The main results were as follows:(1) The average carbon stock of stands was 85.18 t/hm2 and showed that: tree layer > soil layer > herb layer > litter layer > shrub layer; Average water conservation of stands was 553.10 t/hm2 and characterized by soil layer > forest canopy > litter layer; Average plant Shannon-Wiener index of stands was 0.84 and showed the shrub layer > herb layer > tree layer; Average volume of stands was 79.80 m3/hm2.(2) Through analysis spatial structure of 30 typical sample plots, concluded that average neighborhood comparison of stands was 0.50 which belonged to intermediate; Average open degree of stands was 0.23 and the growth space of trees was insufficient; Average mingling degree of stands was 0.27 which belonged to moderate mixed state; Average uniform angle index was 0.52 which belonged to the aggregate distribution; Average spatial density of stands was 0.43 which belonged to medium density.(3) The correlation order of the space structure indexes whose effect on carbon stock, water conservation, plant diversity, volume respectively were showed that spatial density > mingling degree > neighborhood comparison > open degree > spatial density, mingling degree > spatial density > open degree > uniform angle index> neighborhood comparison, spatial density > uniform angle index > mingling degree> open degree > neighborhood comparison, spatial density > uniform angle index > mingling degree > open degree > neighborhood comparison; The influence of neighborhood comparison to carbon stock reached a significant level(P<0.05), the mingling degree had significant influence on carbon stock, water conservation, plant diversity(P<0.05), the effect of open degree on carbon stock, volume were also significant(P<0.05), spatial density had a significant impact on the water conservation, plant diversity, volume(P<0.05), non-significant relationship was found between uniform angle index and all functions(P>0.05).(4) Through setting up the spatial structure optimization models of multi-function management which was taken single function as the leading factor, taken the ecology function as the leading factor and the optimal overall function, concluded that the ideal model of spatial structure and spatial structure composite index. The ideal spatial structure composite index of taking carbon sequestration function, water conservation, the biodiversity protection and timber production function as the leading factor respectively were 0.78、0.78、0.90、0.68, the ideal spatial structure composite index of taking the ecology function as the leading factor was 0.97, the ideal spatial structure composite index of optimal overall function was 0.93.