昆明北郊圣诞树人工林营养元素的积累与循环

对地处滇中的昆明北郊水源保护区红壤山地１０年生圣诞树人工林营养元素的吸收、分布及其生物循环作了系统研究。结果表明：营养元素在该林分植物体中的贮量约为１８０４ｋｇ／ｈｍ￣２，其中各器官积累量的排序为干＞叶＞枝＞根，各元素的积累量以Ｎ＞Ｃａ＞Ｋ＞Ｍｇ＞Ｐ为序。土壤中营养元素贮量５３８２０ｋｇ／ｈｍ￣２，其中Ｃａ，Ｋ和Ｎ较多，Ｍｇ，Ｐ较少，该人工林对各营养元素的年吸收量为：Ｎ１６３．４０ｋｇ／ｈｍ￣２，Ｐ５．５８ｋｇ／ｈｍ￣２，Ｋ１５３．７３ｋｇ／ｈｍ￣２，Ｃａ１３９．４０ｋｇ／ｈｍ￣２和Ｍｇ３０．２７ｋｇ／ｈｍ￣２；年存留量和年归还量分别为：Ｎ７７．５９ｋｇ／ｈｍ￣２和８５．７１ｋｇ／ｈｍ￣２，Ｐ２．８３ｋｇ／ｈｍ￣２和２．７５ｋｇ／ｈｍ￣２，Ｋ４３．９６ｋｇ／ｈｍ￣２和１０９．７６ｋｇ／ｈｍ￣２，Ｃａ４８．７１ｋｇ／ｈｍ￣２和９０．６９ｋｇ／ｈｍ￣２以及Ｍｇ７．２２ｋｇ／ｈｍ￣２和２２．５５ｋｇ／ｈｍ￣２；富集率分别为１．７４，１．９０，１．６８，１．５７和２．０５；循环系数分０．５３，０．４９，０．７１，０．６５和０．７５；周转期分别为１１ａ，１３ａ，１４ａ，１２ａ和８ａ。

Study on Accumulation and biological Cycle of Nutrients in Acacia dealbata Plantaion in Redsoil Mountain Region in Central Yunnan Province

The absorption , distribution and biological cycles of nutrient elements(N,P,K,Ca and Mg) in 10 years old A,dealbata plantation in red soil mountain region in the pro-tected ditricts of water sources in the north Kunming are studied.The results show that theamount of nutrient elements accumulated in stand crop in the plantation is about 1804 kg/hm￣2 while is 53 820kg/hm￣2 in the soil pool.The accumulation of nutrient elements in theplantation gradualy declines from trunks,leaves,branches to roots and decreases in the or-der of N>Ca>K>Mg>P,The annual absorption of N,P,K, Ca and Mg are 163.40kg/hm￣2,5.58kg/hm￣2,153.738kg/hm￣2,139.408kg/hm￣2 and 30.278kg/hm￣2,respectively, in whichthe annual retention are 77.598kg/hm￣2 for N,2.838kg/hm￣2 for P,43.968kg/hm￣2 for K, 48.718kg/hm￣2 for Ca and 7.728kg/hm￣2 for Mg, and the annual return are 85.818kg/hm￣2 for N,2.758kg/hm￣2 for P,109.768kg/hm￣2 for K, 90.698kg/hm￣2 for Ca,22.558kg/hm￣2 for Mg tively,The enrichment ratios of the elements and the speed of turnover period(yr)in theplantation are 1.74,1.90,1.68,1. 57,2. 05 and 11,13,14,12,8,respevtvely.