The Tagliamento River: A model ecosystem of European importance   总被引：5，自引：0，他引：5  

Klement?TocknerEmail author  James?V.?Ward  David?B.?Arscott  Peter?J.?Edwards  Johannes?Kollmann  Angela?M.?Gurnell  Geoffrey?E.?Petts  Bruno?Maiolini 《Aquatic Sciences - Research Across Boundaries》2003,65(3):239-253

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“3S”技术在沿河生态环境建设中的应用     

杨炜  张加仁 《贵州地质》2003,20(4):253-259

以卫星遥感(RS)为主要信息源、以地理信息系统(GIS)为技术支撑,全球定位系统(GPs)为辅助,集县农业资源区划多年研究成果,建立县域一级农业资源生态环境遥感及信息系统。运用ETM卫星遥感信息源,提取8大类土地信息,并以新景河流域为例,应用该信息系统对其生态环境进行模拟分析、评价,提出科学决策意见。  相似文献   

海洋生态系统动力学模型及其研究进展   总被引：11，自引：0，他引：11  

刘桂梅  孙松  王辉 《地球科学进展》2003,18(3):427-432

海洋生态系统动力学研究是当前多学科交叉研究的热门领域，依据国内外研究进展，分别就人们在模型研究中所采用的过程模型、个体模型、种群模型、种间模型及生态系统模型进行了介绍，并概述了当前国际上的研究热点全球变化与海洋生态系统动力学研究，总结了我国的海洋生态系统动力学研究现状以及进一步研究中存在的问题和发展趋势。  相似文献   

Contrasting Recolonization Strategies in Multi-Species Seagrass Meadows     

Rene N. Rollon  Erik D. De Ruyter Van Steveninck  Wim Van Vierssen  Miguel D. Fortes 《Marine pollution bulletin》1999,37(8-12):450-459

This study shows that in a multi-species seagrass meadow in a shallow and clear-water site, all the former seagrass species were able to recolonize in the artificially created gaps of 0.25 m² in size within ca. 2 yr. Extrapolation of the recolonization curves of the different species predicted a full recovery within 10 yr post-disturbance. Fitted curves for the dominant species Enhalus acoroides and Thalassia hemprichii showed contrasting strategies, the latter having a comparatively high intrinsic rate, achieving full recovery within ca. 2 yr post-disturbance. E. acoroides was the latest species to establish and the projected full-recovery time was among the longest (ca. 10 yr). The effect of timing of gap creation was generally not significant (except for Syringodium isoetifolium) neither was the temporal variation in density of most species outside the gaps. As recolonization by sexual propagules was found to be low, increasing the gap size would most probably require a much longer recovery period. A crude estimate for E. acoroides would be >10 yr for 1 m² of gap. Further, since the densities of most seagrass species vary significantly between sites, and colonization rates depend on adjacent seagrass densities, the recovery curves would also be different across sites.  相似文献   

桂林岩溶洼地生态系统中大气CO2动态及环境意义   总被引：17，自引：1，他引：16  

曹建华  潘根兴 《地质论评》1999,45(1):105-111

对桂林岩溶试验场岩溶洼地生态系统中大气ＣＯ２动态的昼夜观测结果说明,岩溶洼地对大气ＣＯ２具有一定的调蓄作用,并促进岩溶发育;植被的光合呼吸作用是制约大气ＣＯ２日动态直接的因素,而土壤ＣＯ２向大气的排放居次要地位。  相似文献   

Modeling N_2O Emissions from Agricultural Fields in Southeast China     

勾继  郑循华  王明星  李长生 《大气科学进展》1999,(4)

l.Intr0ductionWiththedevelopmentofeconomy,theenvironmentalproblemsarebec0mingincreasinglyserious.Am0ngthem,theenhancementofgreenh0useeffectsandglobalwarm-ingaretwoimPOrtantonesthathavear0usedwideattention.Nitrousoxide(N,O)isanim-POrtantgreenhousegasandplayingagreatroleinthesetwoprocesses.SincetheIndustrialRevolution,theatmosphericN2Oconcentrationhasincreasedbyaboutl5%(IPCC,l995).Inthelast4Oyears,itincreasedrapidlyatarateof0.2%ro.3%yr-'(IPCC,l99O).Ifitin-creasesatthisrate,theatmospheri…  相似文献   

退化山地生态系统恢复和重建问题的探讨   总被引：59，自引：10，他引：49  

包维楷  陈庆恒 《山地学报》1999,17(1):22-27

结合近１５年来在岷江上游退化山地系统开展恢复与重建研究的理论和实践,讨论和提出了退化山地生态系统恢复和重建的恰当空间尺度,合理目标,恢复和重建的策略,途径及应采取的措施。  相似文献   

(火用)(Exergy)在湖泊生态系统建模中的应用     

张永泽  刘玉生  郑丙辉 《湖泊科学》1997,9(1):75-81

基于达尔文"适者生存"理论的热力学表述,本文把热力学概念"(火用)(Exergy)"作为一些重要模型参数的目标函数引入湖泊生态动力学模型.应用拥控制下的参数组合模拟程序实现了参数随时间的变化,并通过变化的模型参数来反映湖泊生态系统中物种组成和生态结构随时间的变化.这一改进克服了以往模型刚性较强、适应性差和生态系统特性考虑少的缺陷,该改进的湖泊生态动力学模型被成功用于滇池生态系统的模拟.  相似文献   

Vertical transferring process of rare elements in coral reef lagoons of Nansha Islands, South China Sea     

Jinming Song  Pengcheng Li 《中国科学D辑(英文版)》1998,41(1):42-48

The vertical fluxes and vertical transferring forms of 18 rare elements were studied for the first time in the coral reef ecosystem of Nansha Islands, South China Sea, by deploying sediment traps. The results showed that the vertical transferring flux of most of the measured rare elements in Yongshu lagoon were higher than that in Zhubi lagoon. The vertical transferring forms of rare elements were mainly in the carbonate form, but Ta, As, Th mainly in the ion-exchange form, Ag in iron-manganese oxide form and Sb in the organic matter+sulphide form. None of the 18 rare elements was transferred mainly in the form of detritus silicate to sea floor. This proved that rare elements originating from the earth’s crust were redistributed in sinking particulates after they were brought into ocean. The relation between the fluxes and surface seawater temperature (STT) was also studied. The sensitivity of rare elements to SST was in order:Rb>V>As>Ti>U>Zn>Sb>Hf>Ag>Cs. Project supported by the National Natural Science Foundation of China (Grant No. 49576291).  相似文献   

条件价值评估法的发展与应用   总被引：115，自引：2，他引：115  

张志强  徐中民  程国栋 《地球科学进展》2003,18(3):454-463

环境物品或生态系统服务的经济价值评估是国际上生态经济学、环境经济学研究的前沿领域。由于绝大多数环境物品或生态系统服务的公共物品特性，其经济价值的评估需要运用非市场的价值评估技术。条件价值评估法（CVM）是非市场价值评估技术中应用最广、影响最大的一种方法。详细介绍了国际上CVM及其发展与应用研究的现状，分析了CVM在环境价值评估技术中的地位及其理论基础，总结了最大支付意愿（WTP）的各种引导技术，全面归纳了CVM研究中可能出现的各种偏差及其相应的解决方法，简要介绍了最大支付意愿的数据统计分析方法。  相似文献