利用Biome-BGC模型模拟了19602013年太白山太白红杉林生态系统的净初级生产力(NPP),对其与太白红杉的径向生长关系进行了探讨,并分析了NPP值对气候变化的响应关系.结果表明: 19602013年太白山太白红杉林北坡NPP年均值为305.33g C m~(-2) a~(-1),南坡为320.71g C m~(-2) a~(-1),南北坡的NPP值均呈现出一定的上升趋势,北坡的上升速率(0.47g C m~(-2) a~(-1) )要小于南坡(1.29g C m~(-2) a~(-1) ),但是北坡太白红杉分布下限区NPP值波动浮动较大.且北坡太白红杉NPP值随着海拔高度的上升而逐渐下降,低海拔的变化振幅要大于高海拔地区,南坡无明显变化.多数采样点的模拟NPP值与树轮宽度指数年际变化趋势趋于一致,相关关系呈显著相关.太白红杉标准年表、模型模拟NPP值与气象因子的相关分析均表明太白红杉的生长与生长季气温的相关性显著高于降水,即生长季的气温是太白红杉生长的限制因子.气候的变化作为制约太白红杉生境的重要因素,影响了太白红杉树木的生长,进而对NPP的变化产生了影响.树木年轮很好的检验了Biome-BGC模型模拟结果.
英文摘要:
In this paper,the Biome-BGC model was used to simulate net primary productivity ( NPP) of the Larix chinensis forest ecosystem during 19602013. The relationship between the NPP value and climatic factors,as well as the response of Larix chinensis radial growth to climate change were analyzed. The results showed that the average NPP of Larix chinensis on the northern slope of Mt. Taibai was 305.33 g C m~(-2) a~(-1) and 320.71 g C m~(-2) a~(-1)on the southern slope during 19602013 years. The NPP values of both the northern and southern slopes increased. The rate increase of the northern slope ( 0.47 g C m~(-2) a~(-1) ) was lower than that of the southern slope ( 1.29 g C m~(-2) a~(-1) ). However,the range of NPP fluctuation was larger at the lower limit of the distribution of Larix chinensis. The NPP value of Larix chinensis on the northern slope decreased gradually with the increase in altitude. On the northern slope,the NPP amplitude at low altitude was higher than that at high altitude,whereas the southern slope showed no obvious change. The simulated NPP values for most sampling points were consistent with the interannual variation trend in the tree-ring width index,and the correlation was significant. The correlation between the simulated NPP and the meteorological factors showed that the connection between growth and temperature during the growing season was significantly higher than that of precipitation,indicating that temperature in the growing season was the major limiting factor for growth of Larix chinensis. As a result,the tree-ring data could be used to validate simulation results based on the Biome-BGC model.