人工林生产力和生物量的动态模拟

Simulation of plantation productivity and biomass dynamics

为了评价栽植方式对人工林生产力及其碳汇功能的影响,利用基于个体的空间明晰模型,模拟分析了不同栽植密度、植株空间分布格局和幼苗大小不整齐性影响下的生产力、累积生物量、现存生物量和碳储量动态及其种群的存活曲线特征.结果表明:密度、分布格局及幼苗大小不整齐性对人工林植株的生长和竞争有着显著的影响,从而导致人工林生产力、生物量和碳储量的变化.均匀分布下的最大生产力、累积生物量、最大现存生物量和碳储量较随机分布的有更高的值;均匀分布下,这四个变量均随栽植密度的增大、幼苗大小不整齐性减小而增加,却延迟了人工林达到生产力峰值和最大现存生物量的时间.因此人工林应选用大小不整齐性适中的植株幼苗,以中等密度均匀分布格局的方式栽植.

In order to evaluate the influence of planting methods on the productivity and carbon sequestration in plantation, the productivity, accumulated biomass, standing biomass, carbon storage and surivival curves of the population were examined under different planting density, plant spatial distribution and seeding size inequality by using an individual-based and spatially explicit model. The model results showed that density, spatial distribution pattern and seeding size inequality had significant impact on the growth and competition of plants, thus resulting in altering the productivity, biomass and carbon storage of the plants. The maximum productivity, accumulated biomass, maximum of standing biomass and carbon storage under uniform distribution were larger than under random distribution, and this four variables increased when the planting density increased and the seeding size inequality was reduced, but the time to reach peak productivity and the maximum of standing biomass of plantation under uniform distribution was delayed. Therefore, the seeding of moderate seeding size inequality should be used in plantation with intermediate density and uniform planting.