Nutrient cycling characteristics of Quercus acutissima and Pinus massoniana mixed forest in the Three-Gorge Reservoir area, China

The cycling characteristics of nitrogen(N), phosphorus(P) and potassium(K) of the Quercus acutissima and Pinus massoniana mixed forest, which is the most common forest type in the Three Gorge Reservoir areas in China, were systematically analyzed. The results showed that N, P and K accumulated in the plant pool and in the litter pool, while total N, P, and K were deficient in the soil pool and in the forest systems. Contents of N in the soil of depth 20-40 cm were the key factor limiting growth of trees. The biological outside cycling coefficients were 8.78, 72.5 and 11.7 times of inside cycling coefficients of N, P and K, respectively. 33.92, 10.26 and 15.88 kg of N, P and K return to the litter pool from branches, leaves and throughfall per year, but, 14.31, 1.32 and 10.48 kg of N, P and K return to the soil from litter pool per year respectively. It is clear that 58% of N, 87% of P, and 34% of K are lost by surface runoff per year. 5.49%, 1.30%, and 8.34% of N, P and K withdraw from leaves to branches, 4.99%, 1.99% and 7.30% of N, P and K withdraw from branches to trunks per year,respectively.     

三峡水库地震孕震机理及蓄水地震活动分析

本文从三峡库区区域地质构造、活动断裂及库区水文地质特点建立三峡库区区域地震模型;根据蓄水后岩石的库水与地质相互作用对该区水文地质及构造影响,对该区水库诱发地震进行理论分析,浅释了三峡库区水库地震孕震机理;以三峡遥测台网测震资料及宜昌台地壳形变手段在蓄水前后的监测的地壳动态变化特征为基础,对三峡水库诱发地震作了初步探讨及趋势分析.     

东张水库环境污染现状及保护对策

根据“九五”期间以及2001年～2002年对东张水库的水质常规监测结果，对水质、水生生物及污染源进行综合评价，并提出保护对策．     

Nutrient cycling characteristics of Quercus acutissima and Pinus massoniana mixed forest in the Three Gorge Reservoir area, China

The cycling characteristics of nitrogen(N), phosphorus(P) and potassium(K) of the Quercus acutissima and Pinus massonianamixed forest which is the most common forest type in the Three Gorge Reservoir areas in China, were systematically analyzed. The results showed that N, P and K accumulated in the plant pool and in the litter pool, while total N, P, and K were deficient in the soil pool and in the forest systems. Contents of N in the soil of depth 20—40 cm were the key factor limiting growth of trees. The biological outside cycling coefficients were 8.78, 72.5 and 11.7 times of inside cycling coefficients of N, P and K, respectively. 33.92, 10.26 and 15.88 kg of N, P and K return to the litter pool from branches, leaves and throughfall per year, but, 14.31, 1.32 and 10.48 kg of N, P and K return to the soil from litter pool per year respectively. It is clear that 58% of N, 87% of P, and 34% of K are lost by surface runoff per year. 5.49%, 1.30%, and 8.34% of N, P and K withdraw from leaves to branches, 4.99%, 1.99% and 7.30% of N, P and K withdraw from branches to trunks per year, respectively.     

Development and application of a GIS database for the Miyun Reservoir water quality protection

１　Ｉｎｔｒｏｄｕｃｔｉｏｎ１．１　ＭｉｙｕｎＲｅｓｅｒｖｏｉｒａｎｄａｓｓｏｃｉａｔｅｄｓｔｕｄｉｅｓＴｈｅＭｉｙｕｎＲｅｓｅｒｖｏｉｒ（Ｆｉｇ．１），ｓｉｔｕａｔｅｄｉｎＭｉｙｕｎＣｏｕｎｔｙ，９０ｋｍｔｏｔｈｅｎｏｒｔｈｅａｓｔｏｆＢｅｉｊｉｎｇＣｉｔｙ，ｉｓｏｎｅｏｆｔｈｅｍｏｓｔｉｍｐｏｒｔａｎｔｒｅｓｅｒｖｏｉｒｓｉｎｔｈｅｓｕｂｕｒｂｓｏｆＢｅｉｊｉｎｇ，ｓｅｒｖｉｎｇａｓｔｈｅｓｏｕｒｃｅｏｆｄｒｉｎｋｉｎｇｗａｔｅｒｆｏｒｔｈｅｐｅｏｐｌｅｏｆｔｈｅｃａｐｉｔａｌ．Ｉｔｈａｓａ…     

闹得海水库营养状态分析及富营养化防治

结合9年来对闹得海水库水质监测及相关文献资料，评价闹得海水库营养状态，分析主要污染物变化趋势，对该水库营养状态进行分析，提出该水库富营养化防治对策。结果表明：闹得海水库9年来营养状态在中营养-中富营养之间，主要营养盐总氮、总磷及高锰酸盐指数9年间无显著变化，农业面源是该水库主要营养盐及有机物主要来源。     

东牙溪水库偏碱性污染的成因研究

每年的3-6月份，东牙溪水库表层水出现大面积的偏碱性污染的现象。调查发现水体中pH值与氨氮、溶解氧和水温等指标具有显著的相关性，其污染的规律性与浮游藻类强烈的光合作用特征十分一致。     

小塔山水库富营养化污染与控制

介绍小塔山水库富营养化污染的成因、对富营养化污染采取的防治措施及取得的成绩，得出了降低水库总氮、总磷的含量及控制氮磷比是治理水库富营养化污染的关键措施。     

泥沙沉降对长江水体富营养化相关因素的影响初探

针对三峡库区重庆段蓄水后,泥沙沉降对长江水体富营养化相关因素的影响进行了研究。三峡库区含沙量大,泥沙对水环境的影响不容忽视。为准确预测成库后三峡库区重庆段富营养化的发生,文章通过泥沙沉降对水质影响静态模拟试验,研究了长江原水的泥沙沉降对水体中叶绿素a、透明度、溶解性总磷、溶解性总氮、浊度等指标的影响。结果表明:三峡成库后泥沙更易沉降,引起水体浊度降低、透明度增大,这可能利于藻类的生长,导致叶绿素a的质量浓度增加,同时,泥沙沉降也使水体的溶解性氮磷比增大,对富营养化发生有抑制作用。     

重庆库区不同海拔段繁殖鸟类群落的物种多样性

1996~1997年,对三峡工程重庆库区的鸟类群落的物种组成和种群数量进行了调查,共调查记录库区繁殖鸟类12目40科170种,数量17326只,其中留鸟有104种,占繁殖鸟总数的61.2%,夏侯鸟66种,占38.8%.用秩-多度曲线对不同海拔段的繁殖鸟类群落进行多样性分析的结果显示:1)秩-多度曲线方法的结果比Shannon-Wiener等物种多样性指数更直观,能更全面地反映多样性状况,该曲线可以对不同群落或相同群落在不同时间的物种多样性进行比较,是分析生物多样性的一种最直观的方法;2)人类干扰是影响各海拔段繁殖鸟类群落物种多样性的主要因素,人类干扰越强烈,鸟类群落物种多样性越低.图2表3参20