共查询到20条相似文献,搜索用时 31 毫秒
1.
2.
3.
4.
5.
成都市外来入侵物种调查研究 总被引:3,自引:0,他引:3
对成都市外来入侵物种的种类、数量、分布和危害进行了调查,初步发现有蔗扁蛾(香蕉蛾)Opogona sacchari(Bojer)、大瓶螺(福寿螺、苹果螺、雪螺)Pomacea canaliculata Spix、空心莲子草(水花生、喜旱莲子草)Altertian-thera philoxeroides(Mart.)Griseb、凤眼莲(水葫芦、凤眼蓝)Eichhornia crassipes (Mart.)Solms、牛蛙Rana cntesbei-ana Shaw等.提出了引入扩散原因及危害分析、防除方法,近期可能入侵成都市的外来物种,防治外来入侵物种工作存在的问题. 相似文献
6.
7.
Genetic modification leads to several important moral issues. Up until now they have mainly been discussed from the viewpoint that only individual living beings, above all animals, are morally considerable. The standpoint that also collective entities such as species belong to the moral sphere have seldom been taken into account in a more thorough way, although it is advocated by several important environmental ethicists. The main purpose of this article is to analyze in more detail than often has been done what the practical consequences of this ethical position would be for the use of genetic engineering on animals and plants. The practical consequences of the holistic standpoint (focused on collective entities) of Holmes Rolston, III, is compared with the practical consequences of the individualistic standpoints (focused on individual living beings) of Bernard E. Rollin and Philipp Balzer, Klaus Peter Rippe, and Peter Schaber, respectively. The article also discusses whether the claim that species are morally considerable is tenable as a foundation for policy decisions on genetic engineering. 相似文献
8.
Often ecologists and natural resource managers can easily access data on invasive species occurrence across a region. Yet,
collecting species abundance data over a large area is arguably more important for decision making, but inherently costly,
so methods which can provide robust information at low-cost are particularly valuable. Studies of species distribution often
use occurrence data to build models of the environmental niche. Environmental suitability derived from such models may be
used to predict the potential distributions of species. The ability of such models to predict spatial patterns in abundance
have recently been demonstrated. Here we tested the relationship of environmental suitability with local abundance of an aquatic
invasive species, olive hymenachne (Hymenachne amplexicaulis) in the Wet Tropics of Australia. Ordinary least squares and quantile regressions revealed a positive relationship between
environmental suitability and local abundance of olive hymenachne. We expand on this and use the relationship between environmental
suitability and local abundance to quantify the effectiveness of management (reduction in local abundance) under four different
management investments. We show that the upper limit of abundance can be used to evaluate management effectiveness based on
varying investments, and that ongoing management is the most effective at reducing local abundance. We discuss implications
of this in addressing important problems in invasive species management. 相似文献
9.
Knegtering E Drees JM Geertsema P Huitema HJ Uiterkamp AJ 《Environmental management》2005,36(6):862-871
Environmental Impact Assessments (EIAs) should ideally help minimize adverse effects on biological diversity by considering
impacts of projects on wide ranges of species. This paper investigates how recent Dutch EIAs included the species comprising
animal diversity. We present results of two studies on fauna data used in the EIAs. Objectives were to determine for different
taxa (a) the relative representation of species in Environmental Impact Statements (EISs); (b) the extent to which EISs referred
to specific species and the accuracy of survey data referred to; and (c) apparent roles of different EIA actors in species
inclusion. EIAs were found to use data on various taxa but on limited numbers of species. The frequency with which taxa were
included varied significantly. Birds were most frequently included, followed by mammals, amphibians, and other species groups.
The quality of data on birds exceeded that regarding other vertebrates. Our results indicate that (a) EIA working groups of
independent experts were the most influential in determining the data to be used; (b) on average, proponents included data
more often than required by guidelines; and (c) in 30 to 40% of the EIAs, the participation of nongovernmental organizations
prompted use of data. Despite the key role of experts in data inclusion, the taxon rankings found in the EIAs showed little
deviation from those observed in studies on people’s preferences for species. Given the limited ranges of species considered,
it is doubtful that the EIAs examined effectively contributed to conserving animal species diversity.
Edo Knegtering produced this work in his personal capacity 相似文献
10.
Spartina pectinata (prairie cordgrass) was grown under five hydroperiods (wet–dry cycles) to determine its potential for use in stormwater wetlands,
particularly as an alternative to the highly invasive Phalaris arundinacea (an exotic grass). Rhizomes planted in outdoor microcosms grew vigorously in all treatments, namely, weekly flooding in early
summer, weekly flooding in late summer, flooding every three weeks throughout the summer, weekly flooding throughout the summer,
and no flooding. Neither the timing nor frequency of 24-hour floods (10–20 cm deep) affected total stem length (grand mean
1003 ± 188.8 cm per pot, n = 140) or above-ground biomass (46.5 ± 8.3 g per pot, equivalent to ∼360 g/m2). However, by late summer, fewer new tillers were found in unflooded microcosms, indicating that vegetative expansion is
drought-sensitive.
The growth of Spartina plants was further assessed with and without Glyceria striata (a native grass) and Phalaris arundinacea. Glyceria growth was not affected by hydrologic treatment. Glyceria reduced Spartina growth by approximately 11%, suggesting potential as a cover crop that might reduce establishment and growth of Phalaris seedlings. Seeds of Phalaris did not germinate, but branch fragments established where soil was moist from flooding, regardless of the presence of Glyceria. The ability of Spartina to establish vegetatively and grow well under variable water levels leads us to recommend further testing in stormwater wetlands,
along with early planting of Glyceria to reduce weed invasions. 相似文献
11.
Ragwort (Senecio jacobaea and S. aquaticus) causes major losses to agricultural revenue and induces livestock morbidity throughout parts of Europe, North America, and
Australasia. The introduction of legislation in the U.K. and Australia has meant that landowners can be prosecuted if the
plant spreads to adjacent land, which has led to an increase in activities attempting to control these species. Commonly used
interventions include natural enemies, herbicide applications, manual and mechanical removal. Through the use of explicit
systematic methodology involving comprehensive searches and detailed inclusion criteria, data from primary research are collated
for each type of intervention. Meta-analyses show that 2,4-D, Asulam, Clopyralid, and MCPA are effective at reducing ragwort
densities. However, when the datasets were analysed for their effectiveness against individual species, 2,4-D and MCPA were
only effective against S. jacobaea, while Asulam was only effective against S. aquaticus. Natural enemies Longitarsus jacobaeae and a combination of L. jacobaeae and Tyria jacobaeae appear to have the potential to reduce S. jacobaea densities. Only applying T. jacobaeae does not appear to significantly reduce S. jacobaea densities, but does reduce the number of capitula per plant, seeds per capitula, viability of seeds, and dry weight of the
plants. There is insufficient experimental evidence available to assess other interventions such as manual or mechanical removal.
Further research into these types of interventions is recommended, as well as more detailed reporting of site characteristics
and experimental design to allow full investigation of each intervention to explain possible reasons for variations in their
effectiveness. 相似文献
12.
13.
外来物种入侵及其环境法律调控准则 总被引:12,自引:0,他引:12
随着世界经济、贸易和交通高度发达的影响,外来物种入侵活动且益加剧,已尼成为威胁我国生物多样性与生态环境的重要因素之一,对我国的一些地区造成了巨大的生态和经济损失。有关外来入侵物种管理的立法应贯彻风险预防原则。 相似文献
14.
Biodiversity policies in the European Union (EU) are mainly implemented through the Birds and Habitats Directives as well
as the establishment of Natura 2000, a network of protected areas throughout the EU. Considerable resources must be allocated
for fulfilling the Directives and the question of optimal allocation is as important as it is difficult. In general, economic
evaluations of conservation targets at most consider the costs and seldom the welfare economic benefits. In the present study,
we use welfare economic benefit estimates concerning the willingness-to-pay for preserving endangered species and for the
aggregate area of heathland preserved in Denmark. Similarly, we obtain estimates of the welfare economic cost of habitat restoration
and maintenance. Combining these welfare economic measures with expected species coverage, we are able to estimate the potential
welfare economic contribution of a conservation network. We compare three simple nonprobabilistic strategies likely to be
used in day-to-day policy implementation: i) a maximum selected area strategy, ii) a hotspot selection strategy, and iii)
a minimizing cost strategy, and two more advanced and informed probabilistic strategies: i) a maximum expected coverage strategy
and ii) a strategy for maximum expected welfare economic gain. We show that the welfare economic performance of the strategies
differ considerably. The comparison between the expected coverage and expected welfare shows that for the case considered,
one may identify an optimal protection level above which additional coverage only comes at increasing welfare economic loss. 相似文献
15.
16.
植物在人工湿地中的作用及物种选择 总被引:13,自引:0,他引:13
本文主要阐述了植物在人工湿地中的作用和选取植物的一些原则,并分析了今后所研究的重点。植物在人工湿地中起着非常重要的作用,不但可以去除污染物质,而且具有生态美学和经济价值;选择植物应考虑植物的净化能力、适应性等因素。最后提出了植物研究需要加强的地方。 相似文献
17.
18.
Western European landscapes have drastically changed since the 1950s, with agricultural intensifications and the spread of
urban settlements considered the most important drivers of this land-use/land-cover change. Losses of habitat for fauna and
flora have been a direct consequence of this development. In the present study, we relate butterfly occurrence to land-use/land-cover
changes over five decades between 1951 and 2000. The study area covers the entire Swiss territory. The 10 explanatory variables
originate from agricultural statistics and censuses. Both state as well as rate was used as explanatory variables. Species
distribution data were obtained from natural history collections. We selected eight butterfly species: four species occur
on wetlands and four occur on dry grasslands. We used cluster analysis to track land-use/land-cover changes and to group communes
based on similar trajectories of change. Generalized linear models were applied to identify factors that were significantly
correlated with the persistence or disappearance of butterfly species. Results showed that decreasing agricultural areas and
densities of farms with more than 10 ha of cultivated land are significantly related with wetland species decline, and increasing
densities of livestock seem to have favored disappearance of dry grassland species. Moreover, we show that species declines
are not only dependent on land-use/land-cover states but also on the rates of change; that is, the higher the transformation rate from small to large farms, the higher the loss of dry grassland species.
We suggest that more attention should be paid to the rates of landscape change as feasible drivers of species change and derive
some management suggestions. 相似文献
19.
通过对重庆市主城区5个样点的蝴蝶调查,共采集蝴蝶1629只,隶属4总科8科31属49种。从整个研究区域来看,东方菜粉蝶(Pieris conidia)为优势种,青风蝶(Graphium sarpedon)、菜粉蝶(Pieris rapae)、蒙链荫眼蝶(Neope muirheadi)、矍眼蝶(Vpthima halda)、苎麻珍蝶(Acraea issoria)和酢浆灰蝶(Pseudozizeeria maha)为常见种。样点的多样性指数从高到低依次为:南山植物园〉歌乐山〉照母山植物园〉铁山坪〉重庆大学校园。其中,特有属和特有种的数量从高到低依次为:照母山植物园〉铁山坪〉歌乐山〉南山植物园〉重庆大学校园。不同样点蝴蝶种类的相似性系数在0.1304—0.3462之间,铁山坪跟南山植物园之间的相似性系数最大,相似性系数最小的两个地点为重庆大学校园与南山植物园。不同生境中蝴蝶的多样性指数从高到低依次为:灌丛森林〉灌丛草地〉草地森林〉森林灌丛〉草地农田〉森林〉农田〉草地。 相似文献
20.
新疆外来入侵种现状研究 总被引:1,自引:0,他引:1
通过对我国新疆9种已呈现出较大危害的外来入侵种的分布范围、生境类型、种群建立状况、起源、首次发现或引入的地点及时间、来源、引入路径、入侵途径、经济和生态影响等内容进行了研究,并深入分析了目前外来入侵种管理等方面存在的问题,提出了外来入侵物种预防、控制和管理措施。 相似文献