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1.
异噻唑啉酮类杀菌剂1,2-苯并异噻唑-3-酮(BIT)和甲基异噻唑啉酮(MIT)虽已在多种行业中广泛使用,但目前有关其毒性尤其对水体中生物毒性的数据还较少。鉴于BIT和 MIT在水体中普遍存在,本文研究了这两种污染物对两栖动物黑斑蛙胚胎和蝌蚪的急性毒性。黑斑蛙胚胎和蝌蚪分别暴露系列浓度的BIT和 MIT,观察化学品对其生长、发育和运动的影响,计算96小时半数致死浓度(96 h-LC50)和96小时半数致畸浓度(96 h-TC50),确定最小生长抑制浓度(MCIG)。结果发现,BIT对黑斑蛙胚胎的96 h-LC50和96 h-TC50分别为2.99 mg?L-1和0.60 mg?L-1,MCIG小于0.40 mg?L-1,对蝌蚪的96 h-LC50为6.44 mg?L-1。MIT对黑斑蛙胚胎的96 h-LC50和96 h-TC50分别为5.30 mg?L-1和2.36 mg?L-1,MCIG为2.59 mg?L-1,对蝌蚪的96 h-LC50为7.58 mg?L-1。根据《化学农药环境安全评价准则报批稿》中两栖动物蝌蚪急性毒性的分级标准,判定BIT和MIT的毒性等级为中等。该毒性数据为异噻唑啉酮类杀菌剂的环境管理提供参考。  相似文献   

2.
异噻唑啉酮类杀菌剂1,2-苯并异噻唑-3-酮(BIT)和甲基异噻唑啉酮(MIT)虽已在多种行业中广泛使用,但目前有关其毒性尤其对水体中生物毒性的数据还较少。鉴于BIT和 MIT在水体中普遍存在,本文研究了这两种污染物对两栖动物黑斑蛙胚胎和蝌蚪的急性毒性。黑斑蛙胚胎和蝌蚪分别暴露系列浓度的BIT和 MIT,观察化学品对其生长、发育和运动的影响,计算96小时半数致死浓度(96 h-LC50)和96小时半数致畸浓度(96 h-TC50),确定最小生长抑制浓度(MCIG)。结果发现,BIT对黑斑蛙胚胎的96 h-LC50和96 h-TC50分别为2.99 mg?L-1和0.60 mg?L-1,MCIG小于0.40 mg?L-1,对蝌蚪的96 h-LC50为6.44 mg?L-1。MIT对黑斑蛙胚胎的96 h-LC50和96 h-TC50分别为5.30 mg?L-1和2.36 mg?L-1,MCIG为2.59 mg?L-1,对蝌蚪的96 h-LC50为7.58 mg?L-1。根据《化学农药环境安全评价准则报批稿》中两栖动物蝌蚪急性毒性的分级标准,判定BIT和MIT的毒性等级为中等。该毒性数据为异噻唑啉酮类杀菌剂的环境管理提供参考。  相似文献   

3.
双酚F(BPF)和双酚S(BPS)作为双酚A(BPA)替代品广泛使用,然而有关BPF和BPS的毒性数据非常有限。采用系列浓度的BPA、BPF、BPS溶液,暴露黑斑蛙胚胎和蝌蚪96 h,通过半致死浓度(LC50)、最小生长抑制浓度(MCIG)和致畸率等指标比较3种化合物的急性毒性。结果显示:100 mg·L-1BPS未导致黑斑蛙胚胎及蝌蚪畸形和死亡。BPA和BPF对黑斑蛙胚胎的96h-LC50分别为7.68 mg·L-1和7.99 mg·L-1,MCIG分别为4.47 mg·L-1和4.77 mg·L-1,最大致畸率为33.33%;对蝌蚪的96 h-LC50分别为9.00 mg·L-1和9.52 mg·L-1。依据《化学农药环境安全评价准则》的毒性分级标准,判定BPA和BPF的毒性等级为中毒,BPS的毒性等级为低毒。表明BPF急性毒性与BPA相当,BPS急性毒性低于BPA。本研究数据可为BPF、BPS作为BPA替代品的生产和使用以及相应的环境管理提供毒理学参考。  相似文献   

4.
甲基异噻唑啉酮(methylisothiazolinone,MIT)作为防腐剂,广泛用于个人护理品、日用品和涂料中。MIT随着污水进入地表水循环,普遍存在于水体中,但目前关于MIT对水生生物毒性的研究还比较少。本文以模式生物斑马鱼的胚胎作为受试对象,评价MIT对斑马鱼胚胎的毒性。将受精后3 h的健康斑马鱼胚胎暴露于梯度浓度的MIT下,观察其对胚胎生长发育的影响,用吖啶橙(AO)染色检测细胞凋亡情况。结果发现,48 h暴露浓度大于1.0 mg·L-1的胚胎孵化被显著抑制,72 h浓度大于1.52 mg·L-1的幼鱼心率显著降低,统计96 h幼鱼死亡和畸形数,并重复验证和计算得到96 h半致死浓度(96 h 50%lethal concentration,96 h-LC50)为6.15 mg·L-1,96 h半致畸浓度(96 h 50%teratogenesis concentration,96 h-TC50)为3.89 mg·L-1,测量96 h胚胎体长,分析最小生长抑制浓度(minimum concentration to inhibit growth,MCIG)为2.31 mg·L-1,AO染色显示72 h胚胎的凋亡细胞主要集中在脑部和尾部。不同时期下镜检观察到,胚胎出现的畸形主要包括尾部发育不良,脊柱弯曲,卵黄囊水肿和心包水肿。此外,高浓度处理组24 h胚胎自主抽动次数增加,72 h和96 h活动能力减弱,触碰反应迟钝。因此,推断MIT对斑马鱼胚胎的发育有较大影响,同时有一定的神经毒性。根据《危险化学品鱼类急性毒性分级试验方法》,判定MIT对斑马鱼胚胎为高毒,该毒性实验结果可为MIT在工业生产和环境中的风险管理提供依据。  相似文献   

5.
PFOS及其4种替代品对两栖动物非洲爪蟾和黑斑蛙蝌蚪的急性毒性结果为:用调聚法合成的织物三防整理剂对非洲爪蟾蝌蚪和黑斑蛙蝌蚪的96h-LC50分别为8和21mg·L-1,而PFOS对两种蝌蚪的96h-LC50分别为92和81mg·L-1。此实验结果说明织物三防整理剂的急性毒性高于PFOS。用电解氟化法合成的C4、C6织物三防整理剂和50%的全氟丁基有机铵盐阳离子表面活性剂浓度在100mg·L-1时,对两种蝌蚪都没有毒性。这说明,从急性毒性的角度,C4、C6织物三防整理剂和表面活性剂可作为PFOS的替代品使用,但是织物三防整理剂的急性毒性比PFOS大,作为替代品使用应慎重考虑。另外,PFOS和织物三防整理剂对黑斑蛙蝌蚪的急性毒性与对非洲爪蟾蝌蚪的急性毒性存在差异。出于保护我国本土两栖动物的目的,使用黑斑蛙开展毒性评价比使用非洲爪蟾更有现实意义。  相似文献   

6.
选择合适的尤其是本土生物种进行化学品生态毒性评估,对于各国化学品的环境管理十分重要.本文选择我国本土两栖种黑斑蛙的胚胎为试验生物,以半数致死浓度LC50、半数致畸浓度TC50、致畸指数TI及最小抑制生长浓度MCIG为终点指标,建立了黑斑蛙胚胎发育毒性试验方法.以五氯酚、视磺酸、氯化镉、重铬酸钾为测试物研究了方法的敏感性,并以五氯酚为测试物研究了方法的可重复性.结果显示:五氯酚、视磺酸、氯化镉和重铬酸钾对黑斑蛙胚胎的LC50分别为572.3 μg·L-1、54.8 μg·L-1、6.8 mg·L-1和97.5 mg· L-1.五氯酚、视磺酸和氯化镉对黑斑蛙胚胎的TC50分别为246.5 μg·L-1、18.7 μg· L-1和3.4 mg·L-1,TI分别为2.3、2.9和2.0,MCIG分别为160.0 μg· L-1、10.1 μg·L-1和2.4 mg·L-1.重复性试验发现,五氯酚的LC50、TC50、TI及MCIG的变异系数分别为12.6%、18.0%、23.0%和18.6%.与文献中非洲爪蟾胚胎试验的数据比较,这些数据显示黑斑蛙胚胎与非洲爪蟾胚胎对测试物的敏感性存在一定的差异,各个终点指标的变异系数相当.因此,本文建立的黑斑蛙胚胎发育毒性试验可以用于化学品的发育毒性评价,为我国化学品环境管理提供技术支持.  相似文献   

7.
三氯生(TCS)和三氯卡班(TCC)是个人护理品中常用抗菌剂,在水体中普遍存在,但目前其对两栖动物的毒性研究仍较少。本研究以黑斑蛙蝌蚪和非洲爪蛙蝌蚪为受试生物,研究TCS和TCC对蝌蚪的急性毒性。将处于第一个蝌蚪发育期的黑斑蛙蝌蚪(Gosner 26期)和非洲爪蛙蝌蚪(NF 46期)分别暴露于系列浓度的TCS和TCC,测定其对蝌蚪的半数致死浓度(96 hLC_(50))。结果发现,TCS对黑斑蛙蝌蚪和非洲爪蛙蝌蚪的96 h-LC_(50)分别为441μg·L~(-1)和280μg·L~(-1);TCC对黑斑蛙蝌蚪和非洲爪蛙蝌蚪的96 h-LC_(50)为252μg·L~(-1)和217μg·L~(-1)。这些数据显示TCS和TCC对两种蝌蚪的毒性较高,且对非洲爪蛙蝌蚪毒性均略高于对黑斑蛙蝌蚪的毒性,整体来看TCC的毒性略高于TCS。  相似文献   

8.
为评估Cu2+,Hg2+,Cr6+,Cd2+,Li+,Al3+和Co2+7种金属离子对中国林蛙(Rana Chensinensis)和中华大蟾蜍(Bufo gargarizans)蝌蚪的急性毒性效应,采用生物毒性试验方法对中国林蛙和中华大蟾蜍36期蝌蚪,进行上述7种金属离子的急性毒性试验,分别测定了这7种金属离子对中国林蛙蝌蚪和中华大蟾蜍蝌蚪的半数致死浓度(LC50)。此外,分析了中国林蛙和中华大蟾蜍36期蝌蚪的肥满度、肝指数等形态指标。结果显示,Cu2+、Hg2+、Cr6+、Cd2+、Li1+、Al3+、Co2+对中国林蛙蝌蚪的96h-LC50分别为0.270 mg·L-1、0.803 mg·L-1、2.375 mg·L-1、7.351 mg·L-1、11.273 mg·L-1、17.265 mg·L-1和20.973 mg·L-1。对中华大蟾蜍蝌蚪的96 h-LC50分别0.593 mg·L-1、0.593 mg·L-1、2.827 mg·L-1、2.592 mg·L-1、12.656 mg·L-1、14.020 mg·L-1和57.435 mg·L-1。中国林蛙蝌蚪对Cu2+、Cr6+、Li+、Co6+4种金属离子的敏感性相对较高,而中华大蟾蜍蝌蚪对Hg2+、Cd2+、Al3+3种金属离子的敏感性相对较高。形态指标的差异是中国林蛙与中华大蟾蜍蝌蚪对同一金属离子敏感性差异的原因之一。  相似文献   

9.
为探究并比较淡水鱼种日本青鳉早期发育阶段对Cu2和Cd2等重金属胁迫的响应,在实验室通过半静态方式,对日本青鳉受精卵和仔稚鱼分别进行了48 h和96 h急性毒性实验.结果表明:Cu2对日本青鳉胚胎24、48 h-LC50分别为8.164 mg·L-1和6.965 mg·L-1;Cd2+对日本青鳝胚胎24、48 h-LC50分别为63.084 mg· L-1和53.093 mg ·L-1;较低浓度组Cu2+(≤1.97 mg ·L-1)时日本青鳉胚胎的发育速率快于对照组,而较高浓度组(≥3.87 mg·L-1)胚胎的发育速率则慢于对照组;与Cu2略有不同,无论浓度高低Cd2对胚胎的孵化速率均产生抑制作用;Cu2+和Cd2质量浓度分别高于1.97 mg·Lq和19.68 mg· L-1时,两种重金属离子均显著降低胚胎的孵化率(P<0.05).Cu2对日本青鳉初孵仔鱼24、48、72和96 h-LC50分别为5361 mg·L-1、2.844 mg·L-1、2.020 mg·L-1和1352 mg·L-1;Cd2+对日本青鳉初孵仔鱼24、48、72和96 h-LC50分别为15.907 mg·L-1、10550 mg·L-1、7.986 mg· L-1和6346 mg·L-1;Cu2+对日本青鳉稚鱼24、48、72和96 h-LC50分别为5.732 mg·L-1、4.037 mg· L-1、2A98 mg·L-1和1.955 mg·L-1;Cd2+对日本青鳉稚鱼的24、48、72和96 h-LC50分别为16A19 mg·L、11.745 mg· L-1、8516 mg·L-1和6.776 mg· L-1.与其它淡水水生生物相比,日本青鳉仔稚鱼对铜和镉离子较为敏感.  相似文献   

10.
两栖动物蝌蚪急性毒性试验是评价化学品急性毒性的一种方法。以毒死蜱、乙草胺、重铬酸钾和全氟辛烷磺酸盐(PFOS)为测试物,比较了我国本土黑斑蛙(Rana nigromaculata)与国际通用种非洲爪蟾(Xenopus laevis)在蝌蚪急性毒性试验中的敏感性。结果发现:2类蝌蚪分别进行的11次试验中,空白对照组黑斑蛙蝌蚪死亡率(0.9%)远低于非洲爪蟾蝌蚪的死亡率(5.8%);重铬酸钾和PFOS对黑斑蛙蝌蚪的96 h-LC50分别为34.0 mg·L-1和81.0 mg·L-1,而对非洲爪蟾蝌蚪的96 h-LC50分别为51.6 mg·L-1和92.1 mg·L-1,显示黑斑蛙蝌蚪对这2种化学品的敏感性略高于非洲爪蟾蝌蚪;毒死蜱和乙草胺对黑斑蛙蝌蚪的96 h-LC50分别为0.41 mg·L-1和4.1 mg·L-1,而对非洲爪蟾蝌蚪的96 h-LC50分别为0.12 mg·L-1和3.1 mg·L-1,显示黑斑蛙蝌蚪对这2种化学品的敏感性略低于非洲爪蟾。鉴于2类蝌蚪对化学品的敏感性存在差异,且黑斑蛙蝌蚪的自然死亡率低,材料更易获得,笔者认为黑斑蛙蝌蚪比非洲爪蟾更适合作为蝌蚪急性毒性试验的材料,用于我国化学品环境管理中的毒性评价。  相似文献   

11.
A bioblitz inexpensively and quickly generates biodiversity data, but bioblitzes are often conducted with haphazard, unreplicated sampling. Results tend to be taxonomically, geographically, or temporally biased, lack metadata, and consist of lists of observed taxa that do not enable further analyses or correction for imperfect detection. A rapid, recurring, structured survey (RRSS) uses a structured sampling design and temporal and spatial replication to survey randomly selected sites on a conservation property. We participated in a loosely structured bioblitz and a subsequent RRSS at Big Canoe Creek Nature Preserve in Springville (St. Clair County), Alabama (USA) to compare observed richness derived from the 2 survey approaches. The RRSS data structure enabled us to fit models that accounted for imperfect detection to estimate abundances, occupancy probabilities, and habitat associations. The loosely structured bioblitz data could not be used in such models. We present a new integrated multispecies abundance model that we applied to avian RRSS data. Our model extension enables estimation for the community, employs data augmentation to estimate the number of undetected species, and incorporates covariates. The RRSS generated a more comprehensive and less biased list of observed taxonomic richness than the loosely structured bioblitz (e.g., 73 vs. 45 bird species and 104 vs. 63 insect families from the RRSS vs. loosely structured bioblitz, respectively). Models fit to the RRSS data identified seasonal patterns in avian community composition and allowed for estimation of habitat–occupancy relationships for insect taxa. The RRSS protocol has potential for broad transferability as a standardized, quick, and inexpensive way to inventory biodiversity and estimate ecological parameters while providing an outreach opportunity.  相似文献   

12.
Land-use change via human development is a major driver of biodiversity loss. To reduce these impacts, billions of dollars are spent on biodiversity offsets. However, studies evaluating offset project effectiveness that examine components such as the overall compliance and function of projects remain rare. We reviewed 577 offsetting projects in freshwater ecosystems that included the metrics project size, type of aquatic system (e.g., wetland and creek), offsetting measure (e.g., enhancement, restoration, and creation), and an assessment of the projects’ compliance and functional success. Project information was obtained from scientific and government databases and gray literature. Despite considerable investment in offsetting projects, crucial problems persisted. Although compliance and function were related to each other, a high level of compliance did not guarantee a high degree of function. However, large projects relative to area had better function than small projects. Function improved when projects targeted productivity or specific ecosystem features and when multiple complementary management targets were in place. Restorative measures were more likely to achieve targets than creating entirely new ecosystems. Altogether the relationships we found highlight specific ecological processes that may help improve offsetting outcomes.  相似文献   

13.
Protected areas (PAs) are often implemented without consideration of already existing PAs, which is likely to cause an overrepresentation of certain biophysical conditions. We assessed the representativeness of the current PA network with regard to the world's biophysical conditions to highlight which conditions are underprotected and where these conditions are located. We overlaid terrestrial and marine PAs with information on biophysical conditions (e.g., temperature, precipitation, and elevation) and then quantified the percentage of area covered by the PA network. For 1 variable at a time in the terrestrial realm, high temperature, low precipitation, and medium and very high elevation were underrepresented. For the marine realm, low and medium sea surface temperature (SST), medium and high sea surface salinity (SSS), and the deep sea were underrepresented. Overall, protection was evenly distributed for elevation across the terrestrial realm and SST across the marine realm. For 2 variables at a time, cold and very dry terrestrial environments had mostly low protection, which was also the case for low SST and low and medium SSS across most depths for marine environments. Low protection occurred mostly in the Sahara and the Arabian Peninsula for the terrestrial realm and along the Tropic of Capricorn and toward the poles for the marine realm. Although biodiversity measures are of prime importance for the design of PA networks, highlighting biophysical gaps in current PAs adds a frequently overlooked perspective. These gaps may weaken the potential of PAs to conserve biodiversity. Thus, our results may provide useful insights for researchers, practitioners, and policy makers to establish a more comprehensive global PA network.  相似文献   

14.
Summary The adaptation of defensive secretions to their target organisms was examined for the abdominal gland secretions ofBledius furcatus, B. spectabilis andB. arenarius. Therefore the target organisms of the secretion of theseBledius species (i.e. their predators) had to be identified. At the collection sites examined these were the earwigLabidura riparia, the antCataglyphis bicolor, the flyLispe candicans, different carabids of the generaPogonus, Dichirotrichus, Dyschirius, Bembidion andCalathus and the wading birdsHaematopus ostralegus andCalidris alba. The secretion of the abdominal glands contains the toxin ptoluquinone dissolved in either-dodecalactone and 1-undecene (B. furcatus andB. spectabilis) or in octanoic acid and octyloctanoate (B. arenarius). The ratio of these solvents is species-specific. Application experiments using some of the natural insect predators (L. riparia, C. bicolor, Pogonus, Di. gustavii, Dyschirius) revealed that these solvent ratios provided a more effective deterrent than other possible ratios. Thus by combining the solvents in certain ratios, the capability of cuticular penetration and therefore the effectiveness of the defensive secretions are adapted to their natural targets.  相似文献   

15.
The politics of development includes subtexts of choice, as underpinned by community consensus (or lack of it), against the larger backdrop of a liberal democracy, with its intricate power structures that influence the choice of concepts and often lead to complicity rather than consent. A dilemma exists between the understanding of field-level practitioners and that of academics, whose understandings of progress differ. Progress can (and often does) imply long-term change across generations whereas development is often more a matter of crisis management and delivering tangible results to end-users. This makes it a bone of contention across political systems, irrespective of local or global dynamics. Development can emerge as a tool to be wielded for power and further political mileage at the expense of progress. Progress cannot be studied as a counterpoint to development as the sense of history is often missing in development interventions. Development tends to be piecemeal as its very logic often stems from the rationale of power. This is not to suggest, however, that development is only about politics; it is definitely more than the politics of everyday life and involves all of civil society that requires its critical and immediate attention. In this sense, it has become a priority for politicians with an underlying agenda designed to out-manouevre dissent and all statements of protest.  相似文献   

16.
An argument is presented in which areas of natural arsenic contamination of modern groundwaters throughout Asia have a common origin. Arsenic originally accumulated in oceanic ferro-manganoan sediments of the eastern Palaeo-Tethys. This was further concentrated through oceanic crustal extinction in what later became the south-east Chinese accreted mineralised terrain. Proto-Himalayan uplift of this area created the palaeo-drainage systems of the Ganges – Brahmaputra, Irrawaddy, Mekong, and Red Rivers, with consequent headwater erosion of arsenic-rich sediments. Their downstream deposition as immature and easily redistributed Neogene sandstones, silts, and iron-rich clays has created secondary and tertiary reservoirs of adsorbed and authigenic arsenic, from which the current arsenic-rich groundwaters have evolved. Considering river basins within the above palaeo-hydrogeological framework provides a basis for assessing the risk of arsenic in groundwater basins of south and south-eastern Asia.  相似文献   

17.
As landscapes continue to fall under human influence through habitat loss and fragmentation, fencing is increasingly being used to mitigate anthropogenic threats and enhance the commercial value of wildlife. Subsequent intensification of management potentially erodes wildness by disembodying populations from landscape-level processes, thereby disconnecting species from natural selection. Tools are needed to measure the degree to which populations of large vertebrate species in formally protected and privately owned wildlife areas are self-sustaining and free to adapt. We devised a framework to measure such wildness based on 6 attributes relating to the evolutionary and ecological dynamics of vertebrates (space, disease and parasite resistance, exposure to predation, exposure to limitations and fluctuations of food and water supply, and reproduction). For each attribute, we set empirical, species-specific thresholds between 5 wildness states based on quantifiable management interventions. We analysed data from 205 private wildlife properties with management objectives spanning ecotourism to consumptive utilization to test the framework on 6 herbivore species representing a range of conservation statuses and commercial values. Wildness scores among species differed significantly, and the proportion of populations identified as wild ranged from 12% to 84%, which indicates the tool detected site-scale differences both among populations of different species and populations of the same species under different management regimes. By quantifying wildness, this framework provides practitioners with standardized measurement units that link biodiversity with the sustainable use of wildlife. Applications include informing species management plans at local scales; standardizing the inclusion of managed populations in red-list assessments; and providing a platform for certification and regulation of wildlife-based economies. Applying this framework may help embed wildness as a normative value in policy and mitigate the shifting baseline of what it means to truly conserve a species.  相似文献   

18.
Abstract: In the United States, as elsewhere, a growing debate pits national energy policy and homeland security against biological conservation. In rural communities the extraction of fossil fuels is often encouraged because of the employment opportunities it offers, although the concomitant itinerant workforce is often associated with increased wildlife poaching. We explored possible positive and negative factors associated with energy extraction in the Greater Yellowstone Ecosystem (GYE), an area known for its national parks, intact biological diversity, and some of the New World's longest terrestrial migrations. Specifically, we asked whether counties with different economies—recreation (ski), agrarian (ranching or farming), and energy extractive (petroleum)—differed in healthcare (gauged by the abundance of hospital beds) and in the frequency of sexual predators. The absolute and relative frequency of registered sex offenders grew approximately two to three times faster in areas reliant on energy extraction. Healthcare among counties did not differ. The strong conflation of community dishevel, as reflected by in‐migrant sexual predators, and ecological decay in Greater Yellowstone is consistent with patterns seen in similar systems from Ecuador to northern Canada, where social and environmental disarray exist around energy boomtowns. In our case, that groups (albeit with different aims) mobilized campaigns to help maintain the quality of rural livelihoods by protecting open space is a positive sign that conservation can matter, especially in the face of rampant and poorly executed energy extraction projects. Our findings further suggest that the public and industry need stronger regulatory action to instill greater vigilance when and where social factors and land conversion impact biological systems.  相似文献   

19.
How should managers choose among conservation options when resources are scarce and there is uncertainty regarding the effectiveness of actions? Well‐developed tools exist for prioritizing areas for one‐time and binary actions (e.g., protect vs. not protect), but methods for prioritizing incremental or ongoing actions (such as habitat creation and maintenance) remain uncommon. We devised an approach that combines metapopulation viability and cost‐effectiveness analyses to select among alternative conservation actions while accounting for uncertainty. In our study, cost‐effectiveness is the ratio between the benefit of an action and its economic cost, where benefit is the change in metapopulation viability. We applied the approach to the case of the endangered growling grass frog (Litoria raniformis), which is threatened by urban development. We extended a Bayesian model to predict metapopulation viability under 9 urbanization and management scenarios and incorporated the full probability distribution of possible outcomes for each scenario into the cost‐effectiveness analysis. This allowed us to discern between cost‐effective alternatives that were robust to uncertainty and those with a relatively high risk of failure. We found a relatively high risk of extinction following urbanization if the only action was reservation of core habitat; habitat creation actions performed better than enhancement actions; and cost‐effectiveness ranking changed depending on the consideration of uncertainty. Our results suggest that creation and maintenance of wetlands dedicated to L. raniformis is the only cost‐effective action likely to result in a sufficiently low risk of extinction. To our knowledge we are the first study to use Bayesian metapopulation viability analysis to explicitly incorporate parametric and demographic uncertainty into a cost‐effective evaluation of conservation actions. The approach offers guidance to decision makers aiming to achieve cost‐effective conservation under uncertainty.  相似文献   

20.
Summary Acanthoscelides obtectus (Say) is one of the most damaging pests of kidney beans,Phaseolus vulgaris L. worldwide. However, aromatic plants from the families Lamiaceae, Lauraceae, Myrtaceae and Poaceae can protect kidney beans by direct or delayed insecticidal effect, through increased adult mortality and inhibition of beetle reproduction (both oviposition and adult emergence). The efficiency of hydrodistillated and intact plants fromThymus vulgaris andT. serpyllum, Mentha piperata, Rosmarinus officinalis, Satureia hortensis, Eucalyptus globulus, Laurus nobilis, Origanum vulgare, andCymbopogon nardus was compared. For both extracts,Origanum vulgare had the best effect. The insecticidal effect was induced by more than the essential oils because no significant difference was noticed between distilled and intact plants extract. Inhibition of reproduction was particularly important. These results suggest that lipidic as well as non lipidic, allelochemicals, such as phenolics, or non-protein amino-acids, or flavonoids may be involved in the toxicity of aromatic plants to this beetle.  相似文献   

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