STUDY ON RESIDUES OF ~（14）C－FENITROTHION IN MODEL RICE－FISH ECOSYSTEM AND FIELD RICE－FISH ECOSYSTEM

ＳＴＵＤＹＯＮＲＥＳＩＤＵＥＳＯＦ~（１４）Ｃ－ＦＥＮＩＴＲＯＴＨＩＯＮＩＮＭＯＤＥＬＲＩＣＥ－ＦＩＳＨＥＣＯＳＹＳＴＥＭＡＮＤＦＩＥＬＤＲＩＣＥ－ＦＩＳＨＥＣＯＳＹＳＴＥＭＺｈａｎｇＺｈｏｎｇｌｉａｎｇ（张仲良）；ＷａｎｇＨｕａｘｉｎ（王化新）；Ｇ?..     

生态系统服务功能损害调查与价值量化方法研究

随着国家对生态环境保护的大力推进,开展生态系统服务功能损害鉴定评估,可以切实打击环境污染和生态破坏行为,提升污染环境和破坏生态者的违法成本.主要通过对各种生态系统提供的服务功能进行整理,依据中国现行的生态环境损害鉴定评估相关技术规范和方法对生态系统服务功能的调查和评价进行了程序、内容、方法上的研究分析,同时选取森林生态...     

商业生态系统的扩展性研究

提出一个两层的商业生态系统模型,上层网络中的用户进行商业活动,构成一个生态系统;下层网络由多个查询服务器组成,构成分布式查询系统,供上层用户注册其服务代理以及查找服务.上层和下层网络随时间不断演化且相互影响.在该模型的基础上,研究下层分布式系统的可扩展性.实验表明,该系统是可扩展的,并通过比较得出影响可扩展性的因素.     

The Study of Telecommunicati on Industry Based on the Ecosystem

1IntroductionIn the long evolution, many life-forms in the naturalecosystem have formed very perfect and exact system,which has uncommon capability to adapt the change ofthe environment and can use the substance andthe ener-gy efficiently. Moreover ,the telecommunicationindus-trylooks like the natural ecosystem. Every telecommu-nication enterprise can be regarded as an ani mated life-form,competing and cooperating with others ,adjustingitself gradually to adapt the environment that changeswith…     

我国近海水生生态系统的退化与修复

近年来,由于我国海洋生态资源的过度开发,环境污染不断加剧,使我国海洋水生生态系统受损严重,局部海域生态失衡,生物多样性锐减.目前,海水生态系统的退化已经引起国家政府部门的重视,并开始探索、研究、试验和实验水生生态系统的修复工作.这对我国近海生态系统的发展起着协调、促进的作用.     

城市生态文明建设视角下水土保持措施的应用

水土资源是国家经济发展与生态文明建设的重要支持。现阶段我国的水土保持中对城市生态文明建设的重视程度不足,存在诸多限制性因素。本文在城市生态文明建设的视角下,分析水土保持措施的应用。     

尼洋河流域水电梯级开发对生态环境质量影响的分析评价

结合尼洋河流域实际情况选取了8个环境影响因子,利用灰色GM(1,1)模型分别对有无梯级水电开发流域生态环境变化进行了预测和综合评价,得到尼洋河水电梯级开发对生态环境可能影响的结论为:梯级水电开发对流域生态环境状况有一定影响;流域梯级水电开发,使年平均流量相对于无梯级开发时减少,对森林面积的影响较小;对鱼类资源数量的影响是有利的;梯级水电开发对保护鱼类种类的影响是不利的;年输沙量明显减少。     

ECOSYSTEM ENGINEERS MODULATE EXOTIC INVASIONS IN RIPARIAN PLANT COMMUNITIES BY MODIFYING HYDROGEOMORPHIC CONNECTIVITY

Patterns of native and exotic plant species richness and cover were examined in relation with ecosystem engineer effects of pioneer vegetation within the Mediterranean gravel bed river Tech, South France. The floristic composition was characterized according to two distinct vegetation types corresponding to two habitats with contrasted conditions: (i) open and exposed alluvial bars dominated by herbaceous communities; and (ii) islands and river margins disconnected from annual hydrogeomorphic disturbances and covered by woody vegetation. A significant positive correlation between exotic and native plant species richness and cover was observed for both vegetation types. However, significant differences in native and exotic species richness and cover were found between these two vegetation types. Higher values of total species richness and Shannon diversity were attained within the herbaceous vegetation type than within the woody type. These differences are most likely related to changes in local exposure to hydrogeomorphic disturbances driven by woody engineer plant species and to vegetation succession. A lower exotic species cover within the woody vegetation type than within the herbaceous type suggested an increase of resistance to invasion by exotic species during the biogeomorphic succession. The engineer effects of woody vegetation through landform construction resulted in a decrease of alpha (α) diversity at the patch scale but, in parallel, caused an increase in gamma (γ) diversity at the scale of the studied river segment. Our study corroborates recent investigations that support the theory of biotic acceptance of exotic species by native species at the local scale (generally <10 m²) within heterogeneous and disturbed environments. Furthermore, we suggest that in riparian contexts such as the River Tech exotic species trapp sediment at the same time as native species and thus contribute to the increase in ecosystem resistance during the biogeomorphic succession. Copyright © 2012 John Wiley & Sons, Ltd.     

Effect of a policy intervention on handset subsidies on the intention to change handsets and households’ expenses in mobile telecommunications

This study examined effect of a policy intervention that provides an upper limit for handset subsidies on users’ intention to change handset and households’ expenses on mobile telecommunications. The Korean government has prohibited mobile network providers from providing excessive subsidies for mobile handsets to attract subscribers since Nov. 2014 according to the mobile act. Using the exogenous variation, we estimate the impact of the policy on the intention to change handsets and expenses on handset installment, total mobile communications, and online content. The longitudinal data are from the 2014 to 2015 waves of the Korea Media Panel Survey. The mobile act lowered the predicted probability of switching handsets by 0.4% points. Moreover, the mobile act increased the predicted probability of any expense on handset installment by 7.5% points and had a significant impact on the amount of expenses on handset installment, with an increase of 7.8%. The mobile act lowered users’ willingness to switch handsets and increased spending on handset installment. This increased burden in handset installment might shrink the online content market, which has a large need for government support, as well as decrease consumers’ welfare. We assert that the policy intervention on handset subsidies is questionable with regard to both consumer welfare and the healthiness of the ICT ecosystem.