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1.
The genus Prodontria (Scarabaeidae: Melolonthinae), which comprises 16 described species, is an endemic southern New Zealand genus occupying lowland and coastal habitats, inter-montane basins and alpine environments. Many of the species have a limited distribution and face potential threats from habitat change and predation. The only species to be formally protected is P. lewisii Broun, commonly known as the Cromwell Chafer, which is now restricted to a 81-ha reserve in Central Otago. One undescribed lowland species might be extinct as a result of habitat modification. The current status of Prodontria species, the known distribution of species and potential threats are discussed.  相似文献   

2.
The beetle genus Prodontria is of importance to New Zealand conservation programs. All Prodontria species are brachypterous (having reduced wings), and the genus presents some interesting evolutionary and biogeographic questions that are testable using phylogenetic reconstruction. A phylogeny was produced for 14 flightless Prodontria species, 2 macropterous (fully winged) Odontria species, and single representatives of 2 outgroup genera using sequence data from the mitochondrial COII gene. The data support probable conspecificity of the morphologically similar P. modesta and P. bicolorata but do not support their hypothesized sister-species relationship with the geographically proximate P. lewisi. The alpine P. capito is found to be a paraphyletic group, with the most eastern population diverging after the western populations made their appearance. Many interesting biogeographic disjunctions are here proposed to be anomalous and the result of morphological convergence. The data do not support the idea of a common flightless ancester for Prodontria, but suggest that brachyptery has evolved numerous times. In some instances, this appears to have led to contemporaneous speciation resulting in little resolution of phylogenetic relationships in some parts of the tree. These data allow for a new interpretation of the origin and diversification of the southern New Zealand flightless melolonthine fauna. Multiple speciation events involving wing reduction are suggested to involve at least one widespread flighted ancestor that has given rise to brachypterous forms.  相似文献   

3.
The genus Polianthes (Agavaceae) is endemic to Mexico and is important at the scientific, economical, and cultural level since prehispanic times. Habitat destruction is one of the main factors affecting populations of Polianthes species, yet little is known about the geographic distribution of this genus, and thus its vulnerability to habitat change. We compared three different approaches to measure the Polianthes species area of distribution to assess the risk of species extinction applying the MER (Method of Evaluation of Risk extinction of wild species for Mexico): area of occupancy, extent of occurrence, and ecological modeling. We also found the richness areas of distribution of this genus. We compared the species distributions with Terrestrial Protected Regions (TPR) and Natural Protected Areas (NPA). Although the three methods used to calculate the species area of distribution agree about the highly restricted nature of Polianthes species. The area of occupancy sub-estimate the species distribution, while the extent of occurrence over-estimate it for species with disjoint distribution. Thus, we recommend the use of ecological modeling to improve the assessment of the current species distribution area to apply the MER. Most Polianthes species are distributed in the Sierra Madre Occidental and Transvolcanic Belt. Three species do not occur in any of the NPA or TPR, one species has suitable habitat in three TPR but has not been recorded there, and one species, P. palustris, is likely extinct.  相似文献   

4.
The moist and cool cloud forests of East Africa represent a network of isolated habitats that are separated by dry and warm lowland savannah, offering an opportunity to investigate how strikingly different selective regimes affect species diversification. Here, we used the passerine genus Zosterops (white‐eyes) from this region as our model system. Species of the genus occur in contrasting distribution settings, with geographical mountain isolation driving diversification, and savannah interconnectivity preventing differentiation. We analyze (1) patterns of phenotypic and genetic differentiation in high‐ and lowland species (different distribution settings), (2) investigate the potential effects of natural selection and temporal and spatial isolation (evolutionary drivers), and (3) critically review the taxonomy of this species complex. We found strong phenotypic and genetic differentiation among and within the three focal species, both in the highland species complex and in the lowland taxa. Altitude was a stronger predictor of phenotypic patterns than the current taxonomic classification. We found longitudinal and latitudinal phenotypic gradients for all three species. Furthermore, wing length and body weight were significantly correlated with altitude and habitat type in the highland species Z. poliogaster. Genetic and phenotypic divergence showed contrasting inter‐ and intraspecific structures. We suggest that the evolution of phenotypic characters is mainly driven by natural selection due to differences in the two macro‐habitats, cloud forest and savannah. In contrast, patterns of neutral genetic variation appear to be rather driven by geographical isolation of the respective mountain massifs. Populations of the Z. poliogaster complex, as well as Z. senegalensis and Z. abyssinicus, are not monophyletic based on microsatellite data and have higher levels of intraspecific differentiation compared to the currently accepted species.  相似文献   

5.
The Australo‐Papuan catbird genus Ailuroedus has a complex distribution and a contested taxonomy. Here, we integrate phylogenetic analysis of DNA data and morphology to study the group's biogeography and to re‐examine its taxonomy. We couple phylogeographic and abiotic data to examine differences between the major groups defined in our phylogenetic analysis. Our results are consistent with Ailuroedus catbirds being divided into two species complexes, one distributed in humid forests in the lowlands on New Guinea and another in comparably drier and colder forests mainly in mid‐mountains on New Guinea and Australia. Vicariant events during the Pliocene are surmised to have been the major force in shaping the contemporary phylogeographical signature of this genus. Several previously suggested vicariant events, such as fragmentation of xeric forests in Australia and the uplift of the central mountain range on New Guinea, are reinforced as important Pliocene barriers for tropical forest taxa in this region. Interaction between Pleistocene climatic fluctuations and differences in habitat requirements may explain a higher and more recent population structures in the mid‐mountain catbird complex and the lack of representatives from the lowland clade in the comparably drier Australia. Phylogeographical patterns in both catbird complexes, respectively, both comply and deviate from other lowland and mid‐mountain taxa in the region. This highlights that taxon‐specific properties, such as their historical spatial and ecological distributions, capacity to disperse and tolerance to habitat changes, affect the phylogeographical histories of organisms. Within both species complexes, the genetic differentiation between several geographically isolated populations was found to exceed those commonly observed for avian sister species. As these genetically distinct taxa also were found to be morphological diagnosable, we suggest a revised classification of the genus Ailuroedus, where we recognize three species within the lowland complex and seven species within the mid‐mountain complex.  相似文献   

6.
双花木属植物潜在分布区模拟与分析   总被引:1,自引:0,他引:1  
孟艺宏  徐璕  姜小龙  徐刚标 《生态学报》2019,39(8):2816-2825
气候变化直接影响着物种的分布范围。了解气候变化对濒危物种分布区的影响,是开展保护生物学研究的基础。双花木属(Disanthus Maxim.) 1种1变种,隶属金缕梅科(Hamamelidaceae),为东亚特有濒危物种和典型的中-日间断分布成分,在研究东亚植物区系地理演化方面具有重要的科学价值。本研究基于双花木属植物19个当前居群分布点的气候变量,运用MaxEnt模型预测双花木属植物在末次盛冰期(约22000年前)、当前(1950—2000年)和未来(2060—2080年)气候情景下的潜在分布区的结果显示,受试者工作特征曲线下的面积(AUC=0.9999±0.0001)接近于1,表明MaxEnt模型的预测准确度极高;气候变量贡献率和Jackknife检验评估的结果显示,制约双花木属植物分布的主导气候变量是最湿月降水量和最干月降水量。采用ArcGIS 10.0中的ArcToolbox空间分析工具定量分析比较双花木属的分布动态,基于生境稳定性(N_(stab))、当前与其他时期分布区面积比(N_a)和扩张/收缩程度(N_e)的分析结果揭示,在双花木属植物进化过程中,分布范围经历了收缩过程;未来的温室气体排放量升高程度不同,其适生区呈现不同程度(30%—65%)收缩,特别是RCP 8.5气候情景下,我国武夷山山脉的潜在分布区有可能会丧失。探讨双花木属植物对不同时期气候变化的响应,重建冰期以来该属植物地理分布的变迁历史,分析限制其潜在地理分布的主导气候变量,可为双花木属植物保育措施的制定和东亚地区植物区系物种形成演化的研究提供理论参考。  相似文献   

7.
Effective Solutions for Howler Conservation   总被引:2,自引:0,他引:2  
All species of howlers are at risk due to habitat destruction. I review the three most serious threats to howler survival—agricultural disturbance, logging disturbance, and hunting—both in a general context and in species accounts. Withal, the adaptability of howlers has allowed them to be a widespread genus throughout Central and South America. Alouatta is especially adaptable due to its generalized folivorous diet. I discuss how this adaptability relates to survival in situations of habitat destruction. In addition, I examine howler preference for riverine habitats and their ability to capitalize on secondary forests and secondary growth. I take a practical approach, suggesting some solutions for species survival, which include habitat management and reintroductions. Successful conservation models highlighted are the Community Baboon Sanctuary in Belize, in which villagers manage their lands for the benefit of the black howler and for their own economic benefit from ecotourism, and a village-sustainable logging system in Quintana Roo, Mexico, which has reduced levels of deforestation while benefiting both villagers and howlers, as well as other wildlife. A successful translocation of black howlers in Belize in order to reestablish a viable population is also described. The paper concludes with further suggestions to encourage howler conservation.  相似文献   

8.
Poorly known species may be cryptically endangered, especially when they inhabit fragmented and threatened habitats. Heart‐tongued frogs (genus Phyllodytes, family Hylidae, Lophyohylinae) comprise 17 species of poorly known frogs that have obligatory associations with tank bromeliads. The distributions of all species are restricted to a small, extremely fragmented, region of Atlantic Forest in eastern Brazil. We model climate and tank bromeliad distributions to better understand frog distribution limits. Using records from several sources for frogs and bromeliads with climate data from WorldClim, we modelled the distribution of Phyllodytes using maximum entropy. We compared climate and altitude within the distribution and nearby to test how climate may limit distribution. Climate together with bromeliad distributions provided the best model and predicted the smallest suitable area for Phyllodytes that was larger than that occupied, from the state of Paraíba in the north to Rio Grande do Sul in the south. Phyllodytes occurs in lower elevations that are warmer, wetter and less variable than the surrounding regions where it does not occur, and dispersal is apparently limited by the surrounding, inhospitable, region. Dispersal limitation and habitat fragmentation have relegated Phyllodytes to many very small habitat fragments. With many species in this genus being known from a single or few samples, this unfortunate combination of limitation and fragmentation suggests that some or all species of Phyllodytes may be threatened with extinction, especially if habitat fragmentation continues at its present pace in eastern Brazil.  相似文献   

9.
10.
A powdery mildew fungus on leaves of Dalbergia cultrata var. cultrata (Fabaceae) collected at the Queen Sirikit Botanical Garden in northern Thailand is proven to be a new species of the genus Brasiliomyces and is described as B. chiangmaiensis sp. nov. with light and SEM micrographs. Differences in known Brasiliomyces species are discussed, and a key to species of this genus is provided.  相似文献   

11.
Conservation status, identification, distribution, habitat and ecology, reproduction, threats, conservation actions and recommendations of a critically endangered fish, Hucho bleekeri Kimura, which is endemic to China, was introduced.  相似文献   

12.
1. Freshwater crayfish of the genus Astacoides are endemic to the highlands of eastern Madagascar. Very little is known about their ecology and how this affects their vulnerability to threats. Working in the Fianarantsoa forest corridor, we used a combination of ecological research (>29 000 crayfish caught and released) and interviews (>130 interviews in 38 villages) to investigate the ecology and status of four of the seven described species. 2. Astacoides species studied showed very slow growth, with growth rates of Astacoides granulimanus and Astacoides crosnieri among the slowest known in any species of crayfish. We found individuals of all three species for which we had growth data which we estimate at more than 20‐years old. The size at which females became ovigerous varied among species. Astacoides betsileoensis withheld reproduction until a large size (only 30% of females were gravid at 60‐mm carapace length, compared with 90% for A. granulimanus). This is likely to make A. betsileoensis particularly vulnerable to overexploitation and we found that only 10% of individuals measured in a market (n = 909) would have reproduced before being caught compared with 35% of the more common A. granulimanus (n = 30 561). 3. Habitat loss is a serious threat to the genus; even A. granulimanus, the most widespread species, was only found in rivers or streams flanked by natural vegetation. Astacoides caldwelli, the rarest species in this study, was found only at low altitudes (<800 m) in rivers draining forested catchments. Habitat loss is particularly rapid in low elevation forest. A. crosnieri was restricted to swampy land that is rapidly being converted to rice fields. Introduced Asian snakehead fish (Channa maculata) may pose a hitherto unrecognised threat to some species, particularly A. betsileoensis. 4. Madagascar's freshwater habitats have great significance for global biodiversity yet conservation effort, as in much of the world, has focused on terrestrial ecosystems. Until recently almost nothing was known about the ecology of Astacoides crayfish, a diverse and economically important genus. Here, we show that members of the genus vary markedly in their reproductive biology, growth rates, habitat requirements and the threats they face. We suggest that habitat loss is an urgent threat, especially to A. caldwelli and A. crosnieri, while overharvesting is probably the most immediate threat to the larger A. betsileoensis. We call for more attention to be paid to Madagascar's exceptional, yet understudied, freshwater biodiversity.  相似文献   

13.
The Perote deer mouse Peromyscus bullatus is a rare species known only from a few specimens. It is endemic to the plains surrounding the Oriental Basin in the states of Veracruz and Puebla, Mexico, in the area where the Sierra Madre Oriental and the eastern end of the Transverse Volcanic Range merge. In past studies, a small area within the basin provided the only known habitat. During two recent surveys adjacent to this area, in habitats that matched the area in the state of Puebla where P. bullatus was previously found, we made new surveys. This mouse is differentiable from other species of the genus, mainly in the large of the auditory and the size of the ear. Intrinsic factors are highly discriminating in choice of habitat, low densities, and has restricted distribution, as well as the extrinsic factor of habitat deterioration, indicates a serious conservation problem.  相似文献   

14.
Greater bamboo lemurs (Prolemur simus) are endemic to Madagascar and are the only recognized species within their genus. The IUCN lists the species as critically endangered, with very few confirmed distribution records and <200 individuals known in the wild. With the aim of contributing to its conservation, we attempted to find previously unknown sites containing the species. Working closely with local communities, and basing our methodology on the gathering of local knowledge, we surveyed 44 sites in and around the Ankeniheny-Zahamena Corridor. We found evidence of the presence of Prolemur simus at 18 sites. We made direct sightings at 6 sites, of a total of 65 confirmed individuals, and identified their characteristic feeding remains at the other sites. Twelve of the sites are located in midaltitude rain forest within the corridor, and 6 lie in isolated and degraded lowland areas outside the corridor. These discoveries more than double the number of sites where the species is known to occur, and extend its known range 85 km further north. We identified numerous threats to the newly discovered sites, including hunting pressure, habitat destruction, habitat disturbance, and habitat fragmentation. Demographic factors related to small population sizes and population isolation may also impact the viability of the populations. Our results illustrate the benefits of systematic gathering of local knowledge when searching for rare or secretive primates.  相似文献   

15.
Macrophyte communities of European streams with altered physical habitat   总被引:2,自引:2,他引:0  
The impact of altering hydro-morphology on three macrophyte community types was investigated at 107 European stream sites. Sites were surveyed using standard macrophyte and habitat survey techniques (Mean Trophic Rank Methodology and River Habitat Survey respectively). Principal Components Analysis shows the macrophyte community of upland streams live in a more structurally diverse physical habitat than lowland communities. Variables representing the homogeneity and diversity of the physical environment were used to successfully separate un-impacted from impacted sites, e.g. homogeneity of depth and substrate increased with decreasing quality class for lowland sites (ANOVA p < 0.05). Macrophyte attribute groups and structural metrics such as species richness were successfully linked to hydro-morphological variables indicative of impact. Most links were specific to each macrophyte community type, e.g., the attribute group liverworts, mosses and lichens decreased in abundance with increasing homogeneity of depth and decreasing substrate size at lowland sites but not at upland sites. Elodea canadensis, Sparganium emersum and Potamogeton crispus were indicative of impacted lowland sites. Many of the indicator species are also known to be tolerant to other forms of impact. The potential for a macrophyte tool indicative of hydro-morphological impact is discussed. It is concluded one could be constructed by combining indicator species and metrics such as species richness and evenness.  相似文献   

16.
The Gove Crow butterfly, Euploea alcathoe enastri Fenner, 1991, is restricted to Gove Peninsula of north-eastern Arnhem Land, a remote area of northern Australia. The subspecies has been listed as an Endangered taxon under federal and Northern Territory legislation, and represents one of only a few cases in the Australian Region in which a tropical butterfly has been targeted for species-orientated conservation. However, accurate status evaluation and conservation management have been hampered by lack of detailed information on spatial distribution, critical habitat, and the extent and severity of threatening processes. Surveys carried out during 2006–2008 indicate that the subspecies has a limited geographical range (extent of occurrence approximately 6,700 km2) within which it is recorded from 11 locations or subpopulations embracing a total of 21 sites. Most sites comprise discrete habitat patches that are relatively small in area (<10 ha) within which adults are localised and occur in low abundance (<15 h−1). Of the four major habitat types in which E. alcathoe enastri was detected, only mixed paperbark tall open forest with rainforest elements in the understorey and rainforest edge (i.e. the ecotone between evergreen monsoon vine-forest and eucalypt/paperbark woodland) comprise breeding habitats. These habitat patches were always associated with permanent creeks or perennial groundwater seepages or springs that form swamplands, usually along drainage lines or flood plains in coastal or near coastal lowland areas. Major threats identified at the site level are habitat modification through altered fire regime and habitat disturbance by feral animals (buffalo, pig); potential threats at the landscape level include habitat loss through invasive species (grassy weeds, tramp ants) and global climate change. However, since critical breeding areas are subject to natural disturbance by both fire and flood, and occasionally cyclonic events, an optimal balance in disturbance regime is probably required to sustain breeding populations. Although E. alcathoe enastri is a narrow-range endemic that is ecologically specialised, there is no evidence of decline. Accordingly, the conservation status of the subspecies should be regarded as Near Threatened (‘Conservation Dependent’) under IUCN criteria. Components for an effective long-term conservation management plan of the butterfly and its habitat, which largely depend on the cooperation of traditional landowners and involvement of local indigenous ranger groups, are briefly discussed.  相似文献   

17.
The copepod genus Eurytemora occupies a wide range of habitat types throughout the Northern Hemisphere, with among the broadest salinity ranges of any known copepod. The epicenter of diversity for this genus lies along coastal Alaska, where several species are endemic. Systematic analysis has been difficult, however, because of a tendency toward morphological stasis in this genus, despite large genetic divergences among populations and species. The goals of this study were to (1) analyze patterns of morphological variation and divergence within this genus, focusing on Eurytemora species that occur in North America, and (2) determine patterns of geographic and salinity distribution of Eurytemora species within the ancestral range in Alaska. We applied a comparative multivariate morphological analysis using 16–26 characters from 125 specimens from 20 newly collected sites in Alaska and 15 existing samples predominantly from North America. Results from principal component and hierarchical cluster analyses identified seven distinct morphological species of Eurytemora in North America (E. affinis, E. americana, E. canadensis, E. composita, E. herdmani, E. pacifica, and E. raboti), and identified diagnostic characters that distinguish the species (forming the basis for a new identification key). Several previously named species were regarded as synonyms. The sites we sampled in Alaska were remarkable in the high levels of sympatry of Eurytemora species, to a degree not seen outside of Alaska. Future studies of Eurytemora should shed light on patterns of habitat invasions and physiological evolution within the genus, and yield insights into mechanisms leading to its remarkably broad geographic and habitat range.  相似文献   

18.
The Rhytidae (Mollusca; Gastropoda; Pulmonata) are a group of large carnivorous land snails distributed in the southern hemisphere, with a particularly rich fauna in New Zealand. The endemic genus Powelliphanta consists of at least 10 species and many more recognised subspecies, most of which are restricted to the western margin of South Island, New Zealand. Powelliphanta taxa tend to have restricted ecological and spatial ranges among the mountains of this region, with some species being limited to lowland forest and others to habitats at or above the treeline. Among recent discoveries is a population of snails occupying habitat on and around a peak called Mt Augustus, which is situated at the edge of a large and economically important coalfield. Since recognition of the potential biological significance of the Mt Augustus snails in 2004, almost all of their habitat has been destroyed by opencast mining revealing a direct conflict between economic and biodiversity prioritisation. Our analysis of mtDNA sequence data indicate Powelliphanta “Augustus” is a distinctive evolutionary lineage, more closely related to a nearby lowland species Powelliphanta lignaria than the spatial and ecological neighbour Powelliphanta patrickensis. Powelliphanta “Augustus” appears to be a specialised local endemic species. Despite a growing international awareness of the importance of biodiversity conservation, the demand for foreign earnings continues to take priority over the protection of our biota.  相似文献   

19.
不同气候情景下四子柳的亚洲潜在地理分布格局变化预测   总被引:1,自引:0,他引:1  
四子柳(Salix tetrasperma Roxb.)为杨柳科柳属为数不多的分布区扩展到热带的物种之一,广泛分布于华南和东南亚地区,但其生境破碎化较为严重。该物种具有较高的园林绿化价值和生态价值,预测不同气候情景下该物种的地理分布将为四子柳的资源开发和合理利用乃至柳属的起源和分化研究提供重要的科学依据。利用四子柳全面且精确的分布信息和高分辨率环境数据,基于Maxent模型和ArcGIS空间分析,构建其末次间冰期、末次盛冰期、当代以及未来(2050,2070)的潜在空间分布格局,评价环境因子对分布模型的重要性,定量确定未来受到威胁的适宜生境区域和面积。结果表明,四子柳目前的适宜生境面积为234.65×10~4 km~2,主要位于东亚、南亚和东南亚的热带地区,气温年较差和年均降水量是限制其分布的主要环境因子。总体而言,从冰期至未来,四子柳的分布中心有南北往返迁移的趋势。四子柳在末次盛冰期时向西北方向扩张并开始出现于热带地区,表明该物种开始适应热带气候,进入全新世中期以后种群收缩并退缩到云贵高原的河谷地区和印度尼西亚的平原区域。随着全球气候变暖,在不同二氧化碳浓度路径下2050年和2070年四子柳的潜在适生境有可能破碎化增加,建议对缅甸东部及中部成片减少的边缘群体进行实时监测。  相似文献   

20.
通过对中国产丝瓜藓属Pohlia(缺齿藓科Mielichhoferiaceae)植物系统地分类学研究,对本属一具有假根生念珠状排列的芽胞的种——念珠丝瓜藓的形态解剖学特征和地理分布进行了修订,并讨论了念珠丝瓜藓的生境,以及与其相近种泛生丝瓜藓、明齿丝瓜藓和黄丝瓜藓等进行了比较分析。根据标本信息,确定念珠丝瓜藓在中国的分布由原来的5省区扩大到10省区,并绘制了该种在中国的分布图。  相似文献   

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