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811.
Predation on native fauna by non‐native invasive mammals is widely documented, but effects of predation at the population level are rarely measured. Eradication of invasive mammals from islands has led to recovery of native biota, but the benefits of controlling invasive mammal populations in settings where eradication is not feasible are less understood. We used various combinations of aerially delivered toxic bait and control measures on the ground to reduce abundances of invasive rats (Rattus rattus) to low levels over large areas on mainland New Zealand and then monitored the abundance of invertebrates on replicated treatment sites to compare with abundances on similar nontreatment sites. We also assessed rat diet by examining stomach contents. Abundance of the rats’ most‐consumed invertebrate prey item, the large‐bodied Auckland tree weta (Hemideina thoracica), increased 3‐fold on treatment sites where we maintained rats at <4/ha for approximately 3 years, compared with the nontreatment sites. Auckland tree weta also increased in abundance on sites where rats were controlled with a single aerial‐poisoning operation, but rat abundance subsequently increased on these sites and tree weta abundance then declined. Nevertheless, our data suggest that biennial reduction of rat abundances may be sufficient to allow increases in tree weta populations. Other invertebrates that were consumed less often (cave weta [Rhaphidophoridae], spiders [Araneae], and cockroaches [Blattodea]) showed no systematic changes in abundance following rat control. Our results suggest that the significant threat to recruitment and individual survival that predation by rats poses for tree weta can be mitigated by wide‐scale aerial pest control. Efectos del Control Extensivo Espacial de Ratas Invasoras sobre la Abundancia de Invertebrados Nativos en Bosques de Nueva Zelanda  相似文献   
812.
在我国经济发展中,地热资源为我国社会经济的发展起到了重要支持作用,地热资源来自于地球内部,其在工业、农业领域中已经成为一种重要的生态型能源。对地热能源的特性及其可持续开发利用模式进行全面的认识,是推动我国经济快速发展与保护自然生态环境的热门课题。鉴于此,本文对地热资源的概念及分类进行探讨,并论述了其主要特性,在此基础上深入解析了地热资源的可持续开发利用模式。  相似文献   
813.
高义和  徐良 《环境工程》2010,28(6):47-49
针对利淮钢铁公司80t电炉在冶炼过程中产生的大量高温烟气,在优化原有除尘系统的同时,增加了余热回收系统,使整个系统在运行中既满足了环保要求又节约了大量能源;简要叙述了余热回收系统的工艺流程及西门子PLC在余热回收系统中的应用。  相似文献   
814.
Conservation of carnivores in an increasingly changing environment is greatly helped by understanding the decision-making processes underlying habitat patch choice. Foraging theory may give us insight into spatio-temporal search patterns and consequent foraging decisions that carnivores make in heterogeneous and fluctuating environments. Constraints placed on central-place foragers in particular are likely to influence both foraging decisions and related spatio-temporal movement patterns. We used discrete choice models to investigate the spatio-temporal ranging behaviour of GPS collared female wolverines (Gulo gulo) with dependent cubs in south-central Norway. Activity patterns, home range use and selection for elevation were analyzed in relation to spatial and temporal covariates (daily and seasonal) and related to different foraging behaviours. In spring, wolverines showed restricted movement patterns around rendezvous sites at high elevations by day, whereas during the night animals were active at lower elevations. Over the summer, this daily pattern in intensity of use diminished and their overall selectiveness for elevation decreased as cubs grow more mobile and independent. At the onset of autumn, wolverines showed intensive use of the profitable forest-alpine tundra ecotone. We argue that reproducing wolverines deployed a foraging strategy attuned to altering their movement patterns throughout the summer to address a continuous, but diminishing, trade-off between providing both food and shelter for their offspring. Incorporating spatially and temporally explicit activity patterns and home range use in discrete choice resource selection models thus enhances the understanding of the motives behind wolverine resource utilization in space and time. Such knowledge may provide guidance to managers designing regional-scale zoning, in order to facilitate carnivore recovery and to minimize conflicts with human activities.  相似文献   
815.
保存温度及时间对厌氧氨氧化污泥活性的影响   总被引:7,自引:2,他引:5       下载免费PDF全文
通过改变保存温度和时间,研究了厌氧氨氧化污泥活性的变化规律以及污泥活性恢复能力.结果表明,保存温度、时间对厌氧氨氧化污泥活性影响显著.常温(15±2)℃、低温(5±2)℃对厌氧氨氧化污泥活性影响较小,而中温(30±2)℃、冷冻(-20±2)℃都会使其活性大幅降低,甚至消失.在保存的前30d厌氧氨氧化污泥活性迅速下降,然后趋于缓慢.根据衰减指数模型推出常温状态下衰减指数为0.0324,相对于其他温度最小.并根据保存温度、时间对其影响的特点提出了合适的保存方法,使得厌氧氨氧化污泥的活性能够在较短时间内得到恢复.  相似文献   
816.
《Environmental Hazards》2013,12(4):361-377
This paper examines how and if the post-disaster distribution of housing assistance in two cities of Bam, in Iran, and Bhuj, in India, fulfilled the broad aim of enabling the stricken population to achieve housing recovery. Drawing on interviews with stricken households and officials as well as document review, the paper provides an account of the housing assistance distribution policies in these cities as they were formed, evolved, interpreted, and implemented as well as the ways they were experienced by disaster-stricken people. The paper investigates who did not receive assistance, who did not recover (yet) despite receiving assistance, and – in contrast to these groups – who recovered/accumulated new assets during the recovery process. While in both cities public policies of assistance distribution expanded the capacity of the majority of the stricken people to recover, they failed to provide a timely and appropriate support for the recovery of lower income groups, tenants, and squatters, in line with their needs and priorities.  相似文献   
817.
《Environmental Hazards》2013,12(4):298-312
Despite the fact that one of the main reasons for business discontinuity after the shock of a natural disaster is lifeline outages, individual preparedness and recovery efforts have been given priority. This paper focuses on the significance of lifeline services for business continuity in order to highlight the necessity for collective action to achieve community recovery. Post-disaster research was conducted on a sample of business survivors in the town of Adapazari, which was severely affected by an earthquake in 1999. The study looked into the dependence of businesses on various infrastructure systems and the effects on those businesses of lifeline outages. The findings of the study address the need for community-level actions that are beyond the capability of any individual firm and which will ensure the continuity of business.  相似文献   
818.
We integrate new challenges to thinking about resource markets and sustainable resource use policies in a general framework. The challenges, emerging from six papers that JEEM publishes in a special issue, are (i) demand uncertainty and stockpiling, (ii) international trade and resource dependence, (iii) deforestation, and (iv) intertemporal effects of climate change policies (“Green Paradox”). We discuss new insights and results on these issues by fitting them into the Hotelling model of non-renewable resource depletion.  相似文献   
819.
城市污水处理厂进行脱氮除磷工艺时,大量的磷从水体转入活性污泥中,如不能回收这部分磷,将造成磷的大量流失,这与磷矿稀缺的现状形成矛盾。通过建立污泥停留时间5 d和10 d的两个厌氧反应系统,对污泥中磷的释放规律进行研究,并采用鸟粪石法对上清液中的磷进行回收。研究结果表明,厌氧污泥上清液中的磷含量高达150 mg.L-1,SRT为5 d和10 d的系统,分别在4 d和2 d后磷的质量浓度由14 mg.L-1上升到100 mg.L-1,且基本上都以正磷酸盐的形式存在。将pH从8.3上升到9.0,磷的回收率可以从60%提升到90%,当pH达到8.8时,磷的回收率即可超过80%,表现出了较好的磷回收效果。研究还发现镁离子和磷酸根的摩尔比对磷的回收率的影响较小,在pH=8.8时,将镁磷比从1.43提升到1.83,磷的回收率仅从79.2%提升到85.5%;在pH=9.0时提高镁磷比对磷的回收基本没有影响。  相似文献   
820.
In this diary study, we aimed to examine the moderating effects of the following: (i) recovery efforts at work and (ii) detachment from work on the relationship between work‐related flow and energy after work. Specifically, we hypothesized that flow would be beneficial for energy after work when employees failed (versus managed) to recover during work breaks. Additionally, we predicted that when employees experience flow at work, they would be more vigorous (and less exhausted) at the end of the day when they detached from work in the evening compared with days when they failed to detach. The study tracked 83 participants who completed daily surveys over four consecutive days. Results of multilevel analyses indicated that some characteristics of flow, such as absorption and enjoyment, were significantly associated with energy after work. Recovery at work and detachment from work moderated the relationship between flow (specifically the enjoyment component) and after‐work energy. Copyright © 2011 John Wiley & Sons, Ltd.  相似文献   
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