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高敬 《农业图书情报学刊》2006,18(5):125-127
以文献计量学方法,统计分析了1989~2005年间清华同方光盘股份有限公司的《中国期刊全文数据库》与重庆维普资讯有限公司的《中文科技期刊数据库》中收录的人工湿地研究文献,以期为人工湿地研究者提供参考。共检索到文献495篇,其中署名文献482篇,这些文章分布在全国210种期刊中。第一作者共339人,其中核心作者(发表文章不低于4篇者)21人,他们发表文章占文献总量的20%。 相似文献
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对西藏当雄县3种不同放牧管理模式(冬季放牧、冬春季放牧和全年放牧)下的高寒沼泽的植物群落结构和土壤碳氮进行了调查。调查发现,3种放牧管理模式下的高寒沼泽植物群落总盖度差异不显著,而优势物种藏嵩草的高度和盖度差异显著;放牧管理对沼泽群落结构和物种多样性影响较大,随着放牧强度的增加,物种丰富度增加;放牧利用显著降低了高寒沼泽湿地群落优势物种藏嵩草的高度和盖度,其优势度也显著降低,使得高寒沼泽逐渐退化。冬季放牧、冬春季放牧和全年放牧沼泽地上生物量和地下生物量依次降低。同时,随着放牧强度的增加,高寒沼泽表层土壤有机碳氮的含量也显著降低,且高寒沼泽表层土壤碳氮与地上和地下生物量显著正相关。通过对比分析,冬季放牧是当前西藏高寒沼泽较好的放牧管理模式。 相似文献
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Mark Everard 《水产资源保护:海洋与淡水生态系统》2008,18(6):1052-1061
- 1. To assess the efficacy of environmental management policies and practices, there is a progressive transition from monitoring of activities towards assessment of their outcomes for the environment.
- 2. Population trends of key taxonomic groups can serve as useful indicators of broader environmental integrity and health. Several necessary and desirable criteria for selecting meaningful and suitable indicators are discussed. The attributes of a range of taxa and survey methods used for their assessment are discussed with reference to these criteria.
- 3. Survey methods, data holdings and analytical methods for populations of wild birds at present provide a good basis for developing indicators of the quality of fresh waters at a landscape scale. Other taxa are not necessarily any less appropriate; however, survey design and data representativeness are often limiting factors to the use of other taxa for assessing geographic and temporal trends.
- 4. Taxonomic science and ecological monitoring are necessary for determining society' progress with sustainable development and for informing appropriate enhancements to policy and management practice, particularly so for fresh waters.
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新疆博斯腾湖湿地生态质量的定量评价 总被引:3,自引:1,他引:3
定量评价湿地的生态质量,对保护湿地生态环境具有重要意义。以湿地生态系统服务功能、生态环境保护功能、湿地资源评价为综合评价层,以12个生态评价因子为指标层,构建博斯腾湖湿地生态质量定量评价指标体系,采用层次分析法(AHP)以及专家评议的方法,计算出各生态评价因子的权重,使用问卷调查法得出各因子的得分,最终通过综合评价指数(CEI)来表达湿地的生态环境质量。分析结果表明:博斯腾湖湿地当前生态质量级别为一般。在此基础上,进一步分析了湿地退化的原因,提出了维持湿地可持续发展的保护措施。通过博斯腾湖湿地生态质量的定量评价,对掌握现阶段博斯腾湖的生态环境状况,维持湿地的可持续发展有着极为重要的指导意义。 相似文献
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Quantifying the nitrogen retention capacity of natural wetlands in the large-scale drainage basin of the Baltic Sea 总被引:3,自引:0,他引:3
We estimate the nitrogen retention capacity of natural wetlands in the 1.7 million km2 Baltic Sea drainage basin, using a wetland GIS data base. There are approximately 138,000 km2 of wetlands (bogs and fens) in the Baltic Sea drainage basin, corresponding to 8% of the area. The input of nitrogen to natural wetlands from atmospheric deposition was estimated to 55,000–161,000 ton y1. A map of the deposition of both wet and dry nitrogen is presented. The input from the human population was estimated to 255,000 ton y1 in terms of excretory release in processed sewage water. There may also be leakage from forests and agricultural land into the wetlands. Due to lack of data on hydrology and topography, such potential nitrogen sources are not accounted for here. The capacity of the wetlands to retain the atmospheric deposition of nitrogen was estimated to 34,000–99,000 ton y1. The potential retention by wetlands was estimated to 57,000–145,000 ton y1 when the nitrogen input from the human population was added. If drained wetlands were to be restored and their area added to the present wetland area, the nitrogen retention capacity was estimated to increase to 196,000–261,000 ton y1. Our results indicate that existing natural wetlands in the Baltic Sea drainage basin annually can retain an amount of nitrogen which corresponds to about 5–13% of annual total (natural and anthropogenic) nitrogen emissions entering the Baltic Sea. The ecosystem retention service performed by wetlands accounts for a substantial nitrogen removal, thereby reducing the eutrophication of the Baltic Sea. 相似文献
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We investigated the abundance and genetic heterogeneity of bacterial nitrite reductase genes (nir) and soil structural properties in created and natural freshwater wetlands in the Virginia piedmont. Soil attributes included soil organic matter (SOM), total organic carbon (TOC), total nitrogen (TN), pH, gravimetric soil moisture (GSM), and bulk density (Db). A subset of soil attributes were analyzed across the sites, using euclidean cluster analysis, resulting in three soil condition (SC) groups of increasing wetland soil development (i.e., SC1 < SC2 < SC3; less to more developed or matured) as measured by accumulation of TOC, TN, the increase of GSM, and the decrease of Db. There were no difference found in the bacterial community diversity between the groups (p = 0.4). NirK gene copies detected ranged between 3.6 × 104 and 3.4 × 107 copies g−1 soil and were significantly higher in the most developed soil group, SC3, than in the least developed soil group, SC1. However, the gene copies were lowest in SC2 that had a significantly higher soil pH (~6.6) than the other two SC groups (~5.3). The same pattern was found in denitrifying enzyme activity (DEA) on a companion study where DEA was found negatively correlated with soil pH. Gene fragments were amplified and products were screened by terminal restriction fragment length polymorphism (T-RFLP) analysis. Among 146 different T-RFs identified, fourteen were dominant and together made up more than 65% of all detected fragments. While SC groups did not relate to whole nirK communities, most soil properties that identified SC groups did significantly correlate to dominant members of the community. 相似文献
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A comparison of Riley encased methodology and traditional techniques for planting red mangroves (Rhizophora mangle) 总被引:2,自引:0,他引:2
The effectiveness of encasement and traditional techniques for planting red mangroves (Rhizophora mangle) in moderate to high wave energy environments was assessed. The three encasement types were the halflength PVC pipes, fulllength PVC pipes, and bamboo pipes. Plantings were conducted in August, 1997 at two locations in the Indian River Lagoon, Florida: Sebastian and Rocky Point. Furthermore, plantings were conducted in November, 1997 using fulllength encasements and conventional planting. Results indicate that seedlings planted within fulllength PVC encasements had the highest survivorship and growth because of their protection from waves and currents. Failure of seedlings within bamboo encasements seemed to be caused by insufficient light exposure. When comparing the two locations, a significantly greater growth was observed at the Sebastian location than at the Rocky Point location for the planting conducted in November, but not for those planted in August. No significant difference was observed in seedling survival when comparing those planted in August and November. However, there was a significantly greater growth in mangroves planted in August. With the exception of width of surf zone, there was no significant difference in the selected environmental parameters between the two locations. 相似文献