中国红壤坡地不同林地养分动态变化与模拟研究

在中国科学院红壤生态试验站对红壤坡地不同林地进行6a（1991-1996）定位观测，对N、P、K养分动态循环进行了系统分析，建立了养分循环的分室模型。结果表明：不同林地N、P、K贮量绝大部分存在土壤分室中占97％以上，6年生阔叶林、针叶林N、P、K年总净积累量为正，分别为36．51kg hm^-2、29．70kg hm^-2，系统养分盈余，另外N、P、K各分量积累量均为正，表现为各营养元素系统内盈余；对照（自然荒坡）N、P、K年净积累总量为-9．59kg hm^-2，为养分流失状态，N、P、K各分量也为流失状态。同时对有林坡地和荒坡地进行了0—10a的系统N、P、K在各分室的运转状态模拟，模拟结果表明：N、P、K在阔叶林和针叶林系统均表现盈余，植株地上部分累积量较大，土壤分室N轻微流失，而P、K盈余，自然荒坡土壤养分有轻微流失。

NUTRIENT DYNAMICS OF FORESTS ON RED SOIL SLOPES AND SIMULATION

In the Ecological Experimental Station of Red Soil of Chinese Academy of Sciences, a six-year (1991~1996) stationary experiment had been carried out on a red soil slope land with different forests to study systematically dynamic circulation of N, P and K and establish a compartment model of nutrient circulation. The results indicate that a major part of N, P and K was stored in the soil compartment in different forest lands, amounting to above 97%. The annual total net accumulation of N, P and K was positive for six-year old broadleaf forest and conifer forest, being 36.51 kg hm^-2 and 29.70 kg hm^-2, respectively. The entire system was gaining in nutrient reserve, and N, P and K were all accumulating, showing surplus in the system. As a contrast, the annual total net accumulation of N, P, K in control (nature wild slope) was -9.59 kg hm^-2, suggesting an out flow of nutrients, N, P and K from the system. Meanwhile, simulation of N, P, K circulation in different compartments of the forest slope land and wild slope land within 0~10 years was described. The results indicate that N, P and K were in surplus in the broadleaf forest and conifer forest systems, and their accumulation in the ground parts of the plants was significant, but, in the soil compartment N was losing, and P and K were gaining. The results also show that nutrients in the soil compartment on the nature wild slope suffered slight loss.