杉木幼林生态系统N、P、K循环及模拟研究

STUDY ON THE CYCLE OF N、P、K IN CHINESE FIR YOUNG PLANTATION ECOSYSTEM AND ITS SIMULATION

在尤溪杉木人工林生态站７年定位观测基础上，进行杉木幼林生态系统养分循环研究，建立了养分循环的分室模型。结果表明：７年生杉木幼林生态系统Ｎ、Ｐ、Ｋ贮量分别为；７３０８．４６、２０２２．９６、１３０２９０．１４ｋｇ／ｎｍ２，其中９９．７３％存在于土壤分室中。杉木幼林Ｎ、Ｐ、Ｋ年吸收量５２．２０ｋｇ／ｈｍ２，年存留量２２．６２ｋｇ／ｈｍ２，年归还量２９．５８ｋｇ／ｈｍ２，系统每年通过水文学途径获得Ｎ、Ｐ、Ｋ为１５．９２ｋｇ／ｈｍ２，径流输出９．２３ｋｇ／ｈｍ２，系统中年净积累６．６９ｋｇ／ｈｍ２。同时通过计算模拟，定量地描述了０—１０年内系统Ｎ、Ｐ、Ｋ在各分室的运转状态及施肥效果，并计算了Ｎ、Ｐ、Ｋ达到稳定状态时的平衡点。

On the basis of seven year fixed position observation in Youxi Ecosystem Experimental Station, the nutrient cycle in Chinese fir young plantation ecosystem was studied and the compartment models of N 、P 、K cycle were established. The results were as follows: The total quantities of N、 P、K accumalated in a 7 year old Chinese fir plantation ecosystem were 7308.46, 2022. 96 and 130290. 14kg/hm2 respectively, in which about 99. 73% was stored in the soil compartment. The annual absorption of N、P、 K was 52. 2kg/hm2 with 22. 62kg/hm2 of them ratained, 29. 58kg/hm2 of them returned. The input through hydrologic way into the ecosystem and the output through runoff out of the ecosystem were 15. 92kg/hm2 and 9. 23kg/hm'2 respectively. And thus, the net accumulation of ecosystem was 6. 69kg/hm2.The transformations of N 、P、K and results of fertilization in four compartments of ecosystem within 0-10 years were diseribed quantitatively and the balance points at the time when they reach a stable state were calculated.