首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到16条相似文献,搜索用时 0 毫秒
1.
Polycladus gayi is a colourful and easily recognizable land planarian native to the temperate to cold rainforests of the west coast of southern South America, in Chile and Argentina; however, its ecology is poorly understood. Here, we describe the first records of P. gayi preying on a black snail Macrocyclis peruvianus in the wild. Two events were recorded, the first in a healthy forest in Llancahue Alto, Panguipulli, Chile, during the austral summer of 2023, and the second in a mature evergreen forest in the coastal range of La Union, Chile. These records expand our knowledge of the feeding habits and behaviour of P. gayi and add M. peruvianus to its prey list.  相似文献   

2.
In April 2009 two specimens of a terrestrial flatworm were collected from under a rock in an orchard at Ciutadella de Menorca on the easternmost Balearic island of Menorca (Spain). Their external morphology suggested that both specimens belonged to the invasive blue planarian Caenoplana coerulea, a species which is native to eastern Australia. Sequence data of a fragment of the mitochondrial cytochrome c oxidase subunit I (COI) and of the entire 18S ribosomal RNA confirm its identification. This is one of the first records of the species in Europe where it has only been found in one locality in the United Kingdom, France and NE Spain.  相似文献   

3.
【目的】为预测和分析大豆蚜Aphis glycines的全球潜在地理分布,研究大豆蚜分布与环境变量之间的联系。【方法】利用最大熵法生态位模型(maximum entropy niche-based modeling, MaxEnt)和地理信息系统软件ArcGIS,根据收集的大豆蚜已知分布点和环境变量,预测大豆蚜的全球潜在地理分布区,推测环境变量对大豆蚜分布的影响。【结果】结果表明,大豆蚜适生区主要分布在低海拔地区,高 度适生区集中在25°~50°N的中国、日本、韩国、朝鲜、加拿大、美国、意大利和格鲁吉亚。决定大豆蚜分布地点的关键环境变量为最暖季度降水量、最暖季度平均温度、最湿季度平均温度、最干月降水量、月平均昼夜温差和温度季节性变化标准差。【结论】大豆蚜潜在地理分布区域广泛,应在各国大豆农产品贸易时做好检验检疫工作,以防止大豆蚜的扩散。  相似文献   

4.
Libellula angelina is an endangered dragonfly species that is native to East Asia. Recently, their population has become severely reduced through habitat loss. To protect L. angelina populations, we need to understand which factors determine their distribution and how their potential habitats will change in the future. In this study, the habitat preference of L. angelina was identified through field surveys, and the potential distribution of L. angelina and the impact of integrated climate–land cover changes were simulated using the MaxEnt model. Furthermore, the wetland loss scenario was applied to areas where the current trend in wetland loss will continue in the future. The field survey identified that L. angelina prefers small inland wetlands: permanent freshwater, ponds; permanent rivers, ponds; irrigated land; and estuarine waters. From the MaxEnt results, altitude was the variable with the greatest contribution and distance from wetlands was the most unique variable. MaxEnt described the geographic pattern of occurrences under the current climate well, with few areas requiring any further survey. In the future projection, the potential habitat area was increased by up to 48.8% and 30.6% in the 2050s and 2080s, respectively. However, potential habitat loss was expected if wetlands continue to decline as they have done in the last 20 years. The wetland loss scenario resulted in potential habitat losses of 1.9%–2.3% and 4.5%–6.1% in the 2050s and 2080s, respectively. Therefore, to protect L. angelina populations we must minimize the loss of current populations, secure wetlands and strengthen the connectivity between wetlands.  相似文献   

5.
Dinoflagellates of the genus Ceratium are predominantly found in marine environments, with a few species in inland waters. Over the last decades, the freshwater species Ceratium hirundinella and Ceratium furcoides have colonized and invaded several South American basins. The purpose of this study was to create a distribution model for the invasive dinoflagellate C. furcoides in South America in order to further investigate the basins at potential risk, as well as the environmental conditions that influence its expansion. This species is known to develop blooms due to its mobility, resistance to sedimentation, and optimized use of resources. Although nontoxic, blooms of the species cause many problems to both the natural ecosystems and water users. Potential distribution was predicted by using a maximum entropy algorithm (MaxEnt). Model was run with 101 occurrences obtained from the scientific literature, and climatic, hydrological and topographic variables. The developed model had a very good performance for the study area. The most susceptible areas identified were mainly concentrated in the basins between southeastern Brazil and northeastern Argentina. Besides already affected regions, new potentially suitable areas were identified in temperate regions of South America. The information generated here will be useful for authorities responsible for water and watershed management to monitor the spread of this species and address problems related to its establishment in new environments.  相似文献   

6.
7.
Abstract

Artioposthia triangulata was originally described from New Zealand in 1895 but was subsequently found to have spread to Northern Ireland in 1963 and Scotland and England in 1965. It is now widespread in both Ireland and Scotland, where it has been shown to reduce earthworm numbers to below detectable levels. Ecoclimatic data were used in the computer program CLIMEX to estimate the potential spread of A. triangulata to Europe and the rest of the world. Results indicated it could establish in agricultural land in most of north‐western Europe, and persist in domestic gardens throughout much of central Europe, east and west North America, Australia, southern South America, and South Africa. It is difficult to assess either the extent to which earthworm numbers and diversity would be decreased or how far the effect of their loss to soil structure, nutrient cycling, or wildlife would be detrimental in these areas.  相似文献   

8.
Roads have become one of the main corridors supporting the dispersal of alien plants and their penetration and integration into native vegetation communities in new areas. The aim of this study was to use data sampled in 1970, 1994, and 2010 in order to check for changes in the spread of alien species along roadsides in relation to the adjacent land use. The results show that nutrient influxes and mechanical disturbance associated with the onset of intensive farming had a significant impact on the spread of the plant species in this study. In general, a significant increase was documented in the spread of species of invasive status. A different trend in the spread of archaeophytes and neophytes was observed in cases in which a road was adjacent to the meadow. Most of the archaeophytes in these habitats spread significantly in the first 20 years, and the distribution of neophytes did not show an increasing tendency. The highest rate of expansion was observed for plants propagating only by seed and in the built-up area of municipalities. Plants exhibiting both seed and vegetative propagation prevailed in the vicinity of meadows and forest vegetation.  相似文献   

9.
徐春阳  刘秀嶶  贺春玲  高洁  彭艳琼 《昆虫学报》2021,64(11):1313-1327
【目的】当前全球气候变化、土地利用改变、人类活动加剧等正威胁着传粉昆虫的多样性及分布;蜜蜂是生态系统中重要的传粉昆虫类群,对气候、环境变化响应敏感。本研究以重要的传粉昆虫大蜜蜂Apis dorsata为对象,探讨全球变化格局下其潜在适生区变化以及影响其分布的关键因子。【方法】通过文献、馆藏和野外调查系统收集了全球范围内大蜜蜂的物种分布数据,使用13个环境变量通过MaxEnt模型模拟了大蜜蜂当前的潜在适生区;使用9个气候变量并结合公共地球系统模型(CCSM4)模拟了大蜜蜂过去、当前和未来的潜在适生区。【结果】AUC比率显示MaxEnt模型对大蜜蜂的潜在适生区模拟具有较高的准确性,模拟结果表明大蜜蜂的中高潜在适生区主要分布在南亚和东南亚湿润的热带雨林、热带季节性雨林和低地雨林。人类影响、温度季节性变化、等温性、最冷季均温和海拔是影响大蜜蜂潜在适生区的5个最主要因子;在人类影响下大蜜蜂的潜在适生区向山区和连片的湿润常绿森林区收缩,中高潜在适生区显著减少且呈破碎化趋势。基于9个气候变量和CCSM4气候模型对过去、当前和未来的模拟结果显示:在过去的末次冰盛期,东南亚地区可能是大蜜蜂的避难所;在未来,广布于热带地区的大蜜蜂适生区与当前的相近,且部分地区适生指数升高。【结论】基于气候的模拟结果显示大蜜蜂能积极应对未来气候变暖,但随人类活动的加剧及全球气候变化,大蜜蜂仍然面临较大的威胁,需要加强其在南亚和东南亚的中高潜在适生区的重视和保护。  相似文献   

10.
【目的】未来数十年的气候变化预计会是造成很多物种生境丧失的一个重要因素。对适应能力相对脆弱的地方性物种,预测气候变化对其生境的影响将对生物多样性保护具有重要意义。【方法】本文基于最大熵模型,对珍稀蝉科中国特有种枯蝉Subpsaltria yangi在当前和未来气候条件下的生境适宜度进行了评估。【结果】结果表明,枯蝉主要局限分布于黄土高原及邻近地区。预计至2050年,即使在温和的气候变化情景下,枯蝉的生境面积也会明显减少。影响枯蝉栖息地分布的关键因素为年平均气温、最冷月的最低气温、最冷季的平均气温和最潮湿月份的降水量。枯蝉现存种群栖息地应当受到保护,甘肃天水和陕西延安地区应作为枯蝉分布的核心区予以保护,以应对气候变化对其生境带来的影响。【结论】本研究获得的枯蝉适宜生境分布图可以为该稀有物种的新种群发现、现生种群分布地土地规划管理以及有效的自然保护区设立提供重要信息。  相似文献   

11.
In September 2013, the walnut twig beetle (WTB) Pityophthorus juglandis Blackman, a species native to Mexico and south‐western USA, was recorded for the first time in Europe, in northern Italy. The collected adults were found to be vector of the fungus Geosmithia morbida Kola?ik, Freeland, Utley & Tisserat, an aggressive pathogen causing thousand cankers disease in walnut (Juglans spp.). To determine the geographical distribution of the WTB and the main aspects of biology, phenology and voltinism, an intensive survey of the main walnut plantations near the site of the first finding was conducted in 2014. The beetles began to fly with a mean air temperature of about 18°C (mid‐May) and continued until late October. Two partially overlapping generations occurred, with the second taking place in late September. The WTB was found in 14 of the 27 monitored walnut plantations. The infested sites were spread over four different non‐contiguous administrative provinces belonging to two regions (Veneto and Lombardy) of northern Italy. The most distant infested plantations were about 130 km apart along a west–east gradient, and about 70 km along a north–south gradient. In this respect, the distribution area of the WTB in northern Italy may be prudently estimated at about 4200 km2. Molecular analysis of the collected individuals showed no genetic differences among the six sampled P. juglandis populations, suggesting that a few individuals might have arrived in Italy through a single introduction event and then spread over the territory. Given the quick mortality of infested walnuts and the wide distribution area, eradication strategies appear unrealistic. Possible strategies of biological control or local chemical treatments must be investigated.  相似文献   

12.
The recently completed Odonata database for California consists of specimen records from the major entomology collections of the state, large Odonata collections outside of the state, previous literature, historical and recent field surveys, and from enthusiast group observations. The database includes 32,025 total records and 19,000 unique records for 106 species of dragonflies and damselflies, with records spanning 1879–2013. Records have been geographically referenced using the point-radius method to assign coordinates and an uncertainty radius to specimen locations. In addition to describing techniques used in data acquisition, georeferencing, and quality control, we present assessments of the temporal, spatial, and taxonomic distribution of records. We use this information to identify biases in the data, and to determine changes in species prevalence, latitudinal ranges, and elevation ranges when comparing records before 1976 and after 1979. The average latitude of where records occurred increased by 78 km over these time periods. While average elevation did not change significantly, the average minimum elevation across species declined by 108 m. Odonata distribution may be generally shifting northwards as temperature warms and to lower minimum elevations in response to increased summer water availability in low-elevation agricultural regions. The unexpected decline in elevation may also be partially the result of bias in recent collections towards centers of human population, which tend to occur at lower elevations. This study emphasizes the need to address temporal, spatial, and taxonomic biases in museum and observational records in order to produce reliable conclusions from such data.  相似文献   

13.
入侵害虫蔗扁蛾在我国的潜在分布区   总被引:1,自引:0,他引:1  
【目的】蔗扁蛾是危害巴西木、甘蔗等园林植物和经济作物的重要入侵害虫。该虫于20世纪90年代初在我国被发现,现已分布在海南、广东和上海等19个省市,并有迅速扩散蔓延的趋势。对入侵害虫的潜在分布区进行预测,可为实施害虫监测和管理提供参考。【方法】根据蔗扁蛾已有分布点的记录,分别在4种地理区域构建Maxent生态位模型,并采用加权平均值法对其进行整合,进而分析蔗扁蛾在我国的潜在分布区。【结果】基于4种地理区域构建的Maxent模型对我国南部地区的预测结果基本一致,4种模型的预测差异主要在新疆北部和西南部、黑龙江东部和西部、吉林西部、山西中部等地区。整合模型显示,华东和华南地区以及东部沿海地区具有较大的分布可能性。【结论】蔗扁蛾在我国尤其是南方具有较大的潜在分布空间。这些地区应警惕蔗扁蛾的入侵,同时采取应对措施防止其进一步扩散。  相似文献   

14.
明确野生动植物的地理分布是基础生态学和应用生态学领域的一个基础但关键的步骤,为后续分析提供了重要的信息。而野生动植物分布调查是一项需要投入大量人力,精力和资金的工作,特别是稀有物种的调查。物种分布模型越来越受到广泛引用尤其是在生物保护方面。为了证明物种分布模型在野生生物调查中精确采样方法的可行性,以全球易危物种黑颈鹤和白头鹤的实际繁殖分布预测为例,使用随机森林(Random Forest)算法加以验证。比较发现物种分布模型预测实际调查分布点,随机样方法生成的随机点,系统样方法的规则点在空间相对出现概率具有显著差异(P0.001),实际分布点具有较高的相对出现概率。该结果表明若在物种分布相对出现概率较高区域设置样方能够减少实际调查区域,有效提高发现目标物种的概率,从而减少调查投入。基于物种分布模型的精确采样方法将有效地提高我们对稀有物种分布的了解,有利于野生动植物的保护规划。  相似文献   

15.
Current population genetic models fail to cope with genetic differentiation for species with large, contiguous and heterogeneous distribution. We show that in such a case, genetic differentiation can be predicted at equilibrium by circuit theory, where conductance corresponds to abundance in species distribution models (SDMs). Circuit‐SDM approach was used for the phylogeographic study of the lepidopteran cereal stemborer Busseola fuscaFüller (Noctuidae) across sub‐Saharan Africa. Species abundance was surveyed across its distribution range. SDMs were optimized and selected by cross‐validation. Relationship between observed matrices of genetic differentiation between individuals, and between matrices of resistance distance was assessed through Mantel tests and redundancy discriminant analyses (RDAs). A total of 628 individuals from 130 localities in 17 countries were genotyped at seven microsatellite loci. Six population clusters were found based on a Bayesian analysis. The eastern margin of Dahomey gap between East and West Africa was the main factor of genetic differentiation. The SDM projections at present, last interglacial and last glacial maximum periods were used for the estimation of circuit resistance between locations of genotyped individuals. For all periods of time, when using either all individuals or only East African individuals, partial Mantel r and RDA conditioning on geographic distance were found significant. Under future projections (year 2080), partial r and RDA significance were different. From this study, it is concluded that analytical solutions provided by circuit theory are useful for the evolutionary management of populations and for phylogeographic analysis when coalescence times are not accessible by approximate Bayesian simulations.  相似文献   

16.
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号