云南哀牢山大气降雨过程中养分输入及输出变化的初步研究

本文以滇西南中山湿性常绿阔叶林为研究对象,分析了大气降雨对该森林生态系统养分输入和输出的影响。结果表明,该地区在大气降雨过程中养分输入：Ｎ以大气降雨为主；Ｐ、Ｋ、Ｍｇ以穿透雨为主,它们分别占总输入量的６９．８５％、７７．３３％、９８．１９％和８０．４０％；Ｃａ养分输入,大气降雨和穿透雨约各占总输入量的一半,分别是４５．３５％和５４．３８％。养分输出以地下土壤渗漏为主,Ｎ、Ｐ、Ｋ、Ｃａ、Ｍｇ分别占总输出量的９６．５２％、８６．７９％、６９．１３％、９８．１７％和９７．２１％。在养分循环中Ｎ、Ｐ、Ｋ、Ｃａ分别增加了１５．９４１ｋｇ／ｈａ．ａ、０．３５３ｋｇ／ｈａ,ａ、３．８３ｋｇ／ｈａ．ａ和１．２６４ｋｇ／ｈａ．ａ．,而Ｍｇ则减少了０．６５４ｋｇ／ｈａ．ａ。

A PRELIMINARY STUDY ON CHANGE OF NUTRIENT IMPORT AND EXPORT IN THE PROCESS OF RAINFALL IN THE AILAOMOUNTAINS REGION OF YUNNAN PROVINCE

In this paper, the effects of rainfall on nutrient import and export in the broad-leaved evergreen forest in southwest Yunnan Province have been observed. The results show that in the proress of rainfall the nutrient import in rainfall is mainly N and the major elements of nutrient import in throughrain are P,K and Mg. They orcupy 69.85%, 77.33%, 98.19%,and 80.40% of the total nutrient import respectively. Ca occupies about half of the total nutrient import in rainfall and throughrain and the percentages are 45.35% and 54. 38%respectively. The major form of nutrient export is soil percolation. N, P, K, Ca and Mg occupy 96. 52%, 86.79%, 69.13%, 98.17% and 97.21% of the total nutrient export respectively. In nutrient cycle,N, P, K and Ca increase 15. 94kg/ha. a, 0. 353kg/ha. a,3. 83kg/ha. a, 1. 26 kg/ha. a. respectively,but Mg reduces 0. 654 kg/ha. a.