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1.
《植物生态学报》2018,42(9):946
模拟物种的潜在分布区是保护管理受威胁物种的重要手段。该研究对海南岛石灰岩特有种、濒危植物——海南凤仙花(Impatiens hainanensis)的潜在适宜生境分布进行预测, 旨在为海南凤仙花的有效保护及重引入工作提供基础的科学依据。研究基于海南凤仙花8个种群分布点和12个环境变量, 利用最大熵模型(MaxEnt)和GIS技术构建海南凤仙花适宜生境预测模型, 模拟了当前时期海南凤仙花在海南岛的潜在分布区; 同时基于5个实际分布数据和5个不存在数据, 采用受试者工作特征曲线下的面积(AUC)、Kappa系数、真实技巧统计值(TSS)及总体精度4个评估指标综合评价模型的预测精度。研究结果表明: 4个评估指标值均在0.9以上, 说明MaxEnt模型能够很好地预测海南凤仙花潜在适宜生境的分布。限制其分布的主要环境因子为坡度、最干季降水量、降水量季节性变异系数。当前, 海南凤仙花的最适宜生境占海南岛总面积的1.8%, 主要分布于白沙西部与南部、昌江中部和南部、东方东部、乐东东北部。海南凤仙花潜在适宜生境分布狭窄, 且破碎化严重, 迫切需要保护。因此建议: 收集海南凤仙花各种群种子, 建立种质资源库; 将东方天安乡、江边乡及乐东东北部(佳西保护区)等可能存在最适宜生境的地区, 作为今后野外深入调查的首选区域和重引入的重点区域。  相似文献   

2.
海南岛石灰岩特有植物的初步研究   总被引:8,自引:1,他引:8  
特有植物是了解一个地区植物区系的起源与演化规律的关键。对海南岛石灰岩特有植物的地理分布特征和分类的初步研究表明:本区共有石灰岩特有植物63种,隶属于37科52属,其中热带性的属占的比例较高;属于海南石灰岩专性种的有18种,一些种类对生长基质的要求相当严格。与其它地区比较,石灰岩山地的特有化发展在海南不很明显。从特有植物的分布来看昌江是海南一个重要的石灰岩植物分化中心。对海南石灰岩特有种比例较低的原因和保育进行了探讨。  相似文献   

3.
为探明华石斛(Dendrobium sinense)潜在适宜分布范围,运用地理信息系统GIS技术和MaxEnt模型,基于25个野外调查的分布数据,以气候变量和地形变量为环境预测因子,对华石斛当前及未来时期的适宜生境进行预测。结果表明,华石斛在海南岛内的潜在适宜生境面积约为403.4 km2,占海南岛总面积的1.1%,主要分布于海南热带雨林国家公园霸王岭分局、鹦哥岭分局、尖峰岭分局、吊罗山分局以及五指山分局管辖区域,零星分布于黎母山分局管辖区、五指山市南部、琼中县、万宁市、保亭县和三亚市等地。华石斛适宜分布区域极其狭窄,适宜生境斑块化,呈现较为严重的破碎化。海拔、降水量季节性变异系数、最湿季降水量及最暖月最高温是影响华石斛种群分布格局的主要环境因子,华石斛的最适宜生境条件为海拔1 070~1 600 m,降水量季节性变异系数0.80~0.88,最湿季降水量1 700~2 266 mm,最暖月最高温18℃~25℃。相比于当前,2050年在RCP4.5、RCP8.5气候情景下,华石斛的潜在适宜生境分别减少19.1%和19.5%,2070年减少19.7%和19.8%。预测模型的3个评估指标(A...  相似文献   

4.
通过2014-2015年两次冬季野外调查, 将收集的79处马鹿(Cervus elaphus)出现信息作为分布点数据, 选取地形、景观类型、植被特征和人类干扰4类19种因子作为环境变量, 利用最大熵(maximum entropy, MaxEnt)模型, 分析了小兴安岭铁力林业局辖区马鹿种群冬季潜在适宜生境分布特征和主要环境因子对马鹿分布的影响。结果显示: 模型预测精度较高, 训练集与验证集的平均AUC(area under the curve, 受试工作者曲线下面积)值分别为0.949和0.958; Jackknife检验结果表明: 景观类型因子对马鹿生境选择的影响较大; 坡向、距大路距离、距混交林距离、距灌草地距离和距农田距离是影响马鹿生境分布的主要环境因子, 其综合贡献值依次为27.8%、23.9%、19.5%、15.3%和10.4%; 距小路距离对马鹿分布影响较小。我们依据MaxEnt模型最大约登指数, 找到最佳中断点0.22作为阈值将马鹿冬季栖息地划分为适宜和不适宜两个等级, 其面积分别为663.49 km2和1,378.85 km2, 分别占研究区总面积的32%和68%。马鹿的适宜生境主要分布在铁力林业局辖区的东部山地和中部林地等区域; 南部地区接近铁力市区, 人类活动频繁, 不适宜马鹿栖息。对马鹿种群的保护管理措施提出3点建议: 控制人为干扰; 构建多样性景观; 优先保护马鹿的潜在适宜生境分布区。  相似文献   

5.
中华穿山甲(Manis pentadactyla)属于全球极度濒危物种,也是我国一级保护动物。对中华穿山甲的非法捕杀曾导致其种群数量锐减。但是,近年来相关研究报道较少,穿山甲分布状况不明,极大地制约了对该物种的有效保护。搜集了近年来国内中华穿山甲的救护记录和救护新闻,甄别出67个记录分布点,利用最大熵模型软件(MaxEnt)进行因子筛选,结果表明最冷季度降水量、人口密度、年降水量、坡度、坡向、海拔等6个环境变量是与中华穿山甲分布显著相关的影响因子。基于6个主导环境变量构建的MaxEnt模型AUC平均值为0.961±0.014,预测结果达到极好标准。刀切法(Jackknife)表明,其中最冷季度降水量、年降水量、人口密度和海拔是影响中华穿山甲分布的主要因素。中华穿山甲适宜生境(出现概率大于0.498)具有以下特点:最冷季度降水量141.22-439.46 mm,年降水量1471.67-2386.56 mm,人口密度≥390人/km2,海拔<316.98 m。该模型预测中华穿山甲在我国的潜在分布适宜区主要位于我国长江以南地区,总面积约为74.27×104 km2,占国土面积的7.73%,主要集中在江西、广东、湖南和广西省,面积分别占该区域的97.58%,89.65%,76.90%和73.08%;其次是浙江、福建、台湾和安徽省。湖北、江苏、四川、云南、贵州等省份也有中华穿山甲的零星分布。湖北东南部、江苏南部、浙江西南部和福建西北部等与江西接壤的区域也是中华穿山甲的重要潜在分布适宜区。明确中华穿山甲的潜在分布适宜区,可为该物种的种群保护和栖息地管理提供科技支撑。  相似文献   

6.
生境适宜性评价对野生动物的保护与管理具有重要意义。为了解陕西秦岭地区斑羚(Naemorhedus griseus)的生境状况,利用2011—2013年间在秦岭地区采集的斑羚分布点数据,通过MaxEnt模型对陕西秦岭地区的斑羚生境进行适宜性评价。结果表明,陕西秦岭地区的斑羚适宜生境面积约为9800 km~2,占秦岭山地面积的17%,主要位于秦岭中西部区域;次适宜生境面积约为6940 km~2,占秦岭面积的12%,主要位于适宜生境的周边区域。海拔、月均昼夜温差和年降雨量是影响陕西秦岭地区斑羚生境适宜性的主要环境变量,而人类干扰对生境适宜性的影响较小。陕西秦岭地区的斑羚偏好于选择1800—3000 m的中高海拔区间、年降水量为750—850 mm、月均昼夜温差8℃左右的环境。明确了斑羚适宜生境在秦岭的分布状况及关键环境影响因子,可为下一步制定濒危动物保护和生境管理提供理论依据。  相似文献   

7.
在有人为干扰的森林景观中开展鹿科动物适宜生境分布研究,对于解决大尺度生境保护与小面积森林经营的矛盾问题有着重要的参考意义,也符合我国林区的现实需求.2013—2015年冬季进行的多次野外调查收集196处鹿科动物出现点信息,将这些点作为分布点数据,选取地形、景观类型、植被特征和人类干扰4类17种因子作为环境变量,利用最大熵模型方法,分析4种林下经营面积情景下小兴安岭铁力林业局马鹿和狍的潜在适宜生境分布特征及其对环境因子的响应.结果表明:模型预测精度达到优秀水平,稳定性好,鹿科动物的适宜生境主要集中在东部区域;不同情景下,两种鹿科动物的主要环境影响因子相似,均为距农田距离、距居民点距离、距河流距离、距营林区距离和海拔因子,其中,距营林区距离因子的贡献率稳定在4%~6%;两种鹿科动物躲避人类经营活动干扰的距离(1200~1300 m)较为接近.在无林下经营情景中,鹿科动物的适宜生境分布较广、面积较大;随着经营面积的增大,适宜生境面积减少;当经营面积扩大到现实情况的2~3倍时,鹿科动物栖息地面积缩减较为严重.  相似文献   

8.
杨彪  张全建  王彬  龚旭  段晨松  张远彬 《生态学报》2020,40(17):6077-6085
雅砻江冬麻豆(Salweenia bouffordiana)是近年发现的西南特有冬麻豆属新濒危种,主要分布于四川新龙县的雅砻江河谷。开展其生境适宜性评价及其影响因素分析是对其有效保护的前提和基础。基于2015年8月在雅砻江河谷调查获得的55个分布点,结合24个环境变量数据,利用最大熵模型分析影响雅砻江冬麻豆生境的主要环境因子及其适宜生境预测。结果表明:(1)AUC(曲线下面积)值高于0.9,模型具有较高的准确度,适宜于雅砻江冬麻豆的生境适宜性预测和评估;(2)年均温、最湿月降水、昼夜温差月均值和距河流距离是影响雅砻江冬麻豆生境的最主要环境变量,其最适生境环境变量组合为年均温7.9℃、最湿月降水120-124 mm、昼夜温差月均值13.8℃以及距河流距离33 m;(3)雅砻江冬麻豆的潜在适宜和次适宜生境面积分别约为4.83×103 hm2和2.37×104 hm2,但仅约7.56×102 hm2的潜在适宜生境和3.28×103 hm2的潜在次适宜生境位于现有自然保护区管辖范围内。雅砻江冬麻豆的潜在适生区主要沿雅砻江河谷呈狭长的条带状分布,现存区受人类活动影响大,未有生物学地位定级,应尽快确定其生物学保护地位,建立保护小区或社区保护地进行就地保护。  相似文献   

9.
为明确国家二级保护树种—云南榧树(Torreya yunnanensis)的潜在生境分布区和保护现状,利用50个云南榧树的存在记录点和7个对其分布影响较高的主导环境因子(最冷季平均降水量、降水季节性变异系数、年温差范围、土壤容重、土壤类型、坡向和下层土壤中的百分比粘土)运用最大熵模型(MaxEnt)和地理信息系统(ArcGIS 10.2)模拟其在云南省的潜在生境的分布状况,并将其模拟结果与现有的云南省自然保护区的范围进行叠加分析。研究结果显示:(1)MaxEnt模型对云南榧树潜在生境的模拟的结果所表现出的精度高(AUC=0.977)。(2)云南榧树在云南省的潜在分布区主要集中在三江并流区,云南榧树潜在生境在云南省自然保护区内主要分布在高黎贡山(2364.35 km~2, 58.35%)、白马雪山(846.46 km~2, 31.66%)和云岭(625.55 km~2, 82.42%)自然保护区。(3)最冷季平均降水量(>75.58 mm)、降水季节性变异系数(<64.28)、年温差(24.08—26.40℃)是影响云南榧树在云南省潜在生境分布的主要气候因子。(4)金沙江可能...  相似文献   

10.
基于MAXENT模型的贺兰山岩羊生境适宜性评价   总被引:12,自引:0,他引:12  
刘振生  高惠  滕丽微  苏云  王晓勤  孔芳毅 《生态学报》2013,33(22):7243-7249
生境评价对物种保护具有非常重要的意义。本研究在GIS空间技术的支持下,于2010年到2011年间,在贺兰山岩羊分布区采集其地理分布点数据以及环境变量数据,并运用MAXENT模型对贺兰山区域岩羊的生境适宜性进行评价分析。模型的评价结果达到优秀水平,研究结果表明:岩羊生境选择的主要影响因子为矿区、坡度、海拔和道路,生境适宜区主要分布于贺兰山东坡(宁夏贺兰山国家级自然保护区)的西南部,而西坡(内蒙古贺兰山国家级自然保护区)有少量分布,适宜生境面积总和为1 006.9 km2,占研究区域面积的28%。岩羊偏爱于海拔1 500-2 300 m的山势陡峭地带,建议对矿区和道路这两种人为干扰因素采取相应的措施,以提高岩羊的生境质量,促进其种群发展。  相似文献   

11.
Aims Modelling potential distribution ranges of threatened species is of great significance for their conservation. In this paper, the distribution of potential suitable habitat of Impatiens hainanensis, a limestone-endemic and endangered plant in Hainan Island, was studied to provide scientific basis for their effective in situ conservation and re-introduction of I. hainanensis. Methods Based on eight occurrence sites and 12 environmental variables, the Maximum Entropy (MaxEnt) algorithm and GIS technology were used to create a model linking the distribution ranges of I. hainanensis with environments. With data on five actual distribution sites and five non-occurrence sites, four model evaluation metrics (area under the receiver operating characteristic curve (AUC), kappa coefficient, true skill statistic (TSS), overall accuracy) were used to evaluate the predictive performance and accuracy of this model. Important findings The results indicated that the indicative value of all four evaluation metrics were above 0.9, indicating that the MaxEnt model can effectively predict the potential suitable habitats of I. hainanensis. Slope, precipitation of the driest quarter and coefficients of precipitation variation were the three main environmental factors influencing the distribution of I. hainanensis. At present, the most suitable habitat includes western and southern parts of Baisha County, the central and southern parts of Changjiang County, the eastern part of the Dongfang City and northeastern Ledong County, accounting for 1.8% of land area on Hainan Island. Since the potential suitable habitat of I. hainanensis is rare and severely fragmented, the protection of this species is urgent. We suggest to collect the seeds of various geographic populations of I. hainanensis to establish a germplasm resource bank. The most suitable habitat of the species, including Tian’an Village and Jiangbian Village in Dongfang City, northeast of Ledong County (Jiaxi Reserve), should be selected as the priority places for future extensive field surveys and re-introduction. © Chinese Journal of Plant Ecology.  相似文献   

12.
刘璐  钱天陆  席唱白  迟瑶  王结臣 《生态学报》2021,41(14):5879-5887
识别动物的适宜生境对野生动物保护、区域生态保护以及自然保护区的规划等具有指导意义。以滇金丝猴生存区域为例,选取7个影响滇金丝猴生境适宜性的主要因子:植被类型、海拔、坡度、坡向、距水系距离、距居民点距离、距道路距离,基于GIS技术,构建阻力面,确定累积阻力阈值,计算可达面积并据此划分斑块,结合现有猴群的栖息地分布、保护区设立对划分结果进行分析讨论。结果表明,区域内滇金丝猴的适宜生境面积整体占比较低,猴群移动受到人类活动干扰或水系阻隔的影响,其生境受到了不同程度的破坏,且生境适宜度表现出中部最高,北部次之,南部最差的规律。划分生境适宜性等级的方法,考虑到了明显地物对动物移动的较强阻隔作用,顾及到了空间连续性和斑块完整性,实验结果可反映出不同区域的生境适宜性差异。  相似文献   

13.
Species mapping is a useful conservation tool for predicting patterns of biological diversity, or identifying geographical areas of conservation significance. Mapping can also improve our understanding of the appropriateness of habitat areas for individual species. We outline a computer-based methodology, PREDICT, for the analysis of the habitat requirements of species in a combined GIS-statistical programming environment. The paper details the statistical background to the approach adopted, the program structure and input file information and then applies these techniques to bird data from Bioko Island, West Africa. It produces images and statistics that assess the potential of unstudied areas for wildlife for which presence/absence data and basic habitat information are available. Suitability for target species is determined within surveyed and non-surveyed squares by a form of weights of evidence. The program measures the degree of association between habitat factors and presence/absence of target species by means of 2 tests. The overall suitability weighting of each square, as the sum of all individual habitat factor weightings, is finally displayed in maps depicting areas of highly suitable, suitable, unsuitable and highly unsuitable habitat. Statistical relations between vegetation, rainfall and landscape features on Bioko Island and the location of 9 endemic bird taxa are presented herein. Final confirmation of the accuracy of predictions of the studied bird taxa will ensue from future field observations. However, in a series of misclassification tests of the program, actual distribution detection rate was in excess of 90%. The use of PREDICT can guide investigations of little known species in remote areas and provide a practical solution to identify areas of high rare species diversity in need of conservation.  相似文献   

14.

Aim

Citizen science is a cost-effective potential source of invasive species occurrence data. However, data quality issues due to unstructured sampling approaches may discourage the use of these observations by science and conservation professionals. This study explored the utility of low-structure iNaturalist citizen science data in invasive plant monitoring. We first examined the prevalence of invasive taxa in iNaturalist plant observations and sampling biases associated with these data. Using four invasive species as examples, we then compared iNaturalist and professional agency observations and used the two datasets to model suitable habitat for each species.

Location

Hawai'i, USA.

Methods

To estimate the prevalence of invasive plant data, we compared the number of species and observations recorded in iNaturalist to botanical checklists for Hawai'i. Sampling bias was quantified along gradients of site accessibility, protective status and vegetation disturbance using a bias index. Habitat suitability for four invasive species was modelled in Maxent, using observations from iNaturalist, professional agencies and stratified subsets of iNaturalist data.

Results

iNaturalist plant observations were biased towards invasive species, which were frequently recorded in areas with higher road/trail density and vegetation disturbance. Professional observations of four example invasive species tended to occur in less accessible, native-dominated sites. Habitat suitability models based on iNaturalist versus professional data showed moderate overlap and different distributions of suitable habitat across vegetation disturbance classes. Stratifying iNaturalist observations had little effect on how suitable habitat was distributed for the species modelled in this study.

Main Conclusions

Opportunistic iNaturalist observations have the potential to complement and expand professional invasive plant monitoring, which we found was often affected by inverse sampling biases. Invasive species represented a high proportion of iNaturalist plant observations, and were recorded in environments that were not captured by professional surveys. Combining the datasets thus led to more comprehensive estimates of suitable habitat.  相似文献   

15.
有前景的模式植物小立碗藓的研究新进展   总被引:1,自引:0,他引:1  
刘艳  曹同  陈静文   《广西植物》2007,27(1):90-94
小立碗藓是在分子生物学研究方面有广阔应用前景的模式植物。该文主要综述了有关小立碗藓在功能基因组学、进化和适应性及植物生理等方面最新的研究进展。  相似文献   

16.
The loss of wetlands and semi-natural grasslands throughout much of Europe has led to a historic decline of species associated with these habitats. The reinstatement of these habitats, however, requires spatially explicit predictions of the most suitable sites for restoration, to maximize the ecological benefit per unit effort. One species that demonstrates such declines is the white stork Ciconia ciconia , and the restoration of habitat for this flagship species is likely to benefit a suite of other wetland and grassland biota. Storks are also being reintroduced into southern Sweden and elsewhere, and the a priori identification of suitable sites for reintroduction will greatly improve the success of such programmes. Here a simple predictive habitat-use model was developed, where only a small but reliable presence-only dataset was available. The model is based on the extent and relative soil moisture of semi-natural pastures, the extent of wetlands and the extent of hayfields in southern Sweden. Here the model was used to predict the current extent of stork habitat that is suitable for successful breeding, and the extent of habitat that would become suitable with moderate habitat restoration. The habitat model identifies all 10 occupied nesting sites where breeding is currently successful. It also identifies ∼300 km2 of habitat that is predicted to be suitable stork habitat, but that is presently unused; these sites were identified as potential areas for stork reintroduction. The model also identifies over 100 areas where moderate habitat restoration is predicted to have a disproportionate effect (relative to the restoration effort) on the area of suitable habitat for storks; these sites were identified as priorities for habitat restoration. By identifying areas for reintroduction and restoration, such habitat suitability models have the potential to maximize the effectiveness of such conservation programmes.  相似文献   

17.
植物多样性与植物竞争强度和生态位重叠度的关系会随环境发生变化。为探究上述关系在若尔盖地区的表现形式,于2021年8月对若尔盖地区典型的水生、湿生、湿生-中生和中生植物群落进行调查,构建了新的植物竞争强度(Competition intensity,CI)公式并进行测算,计算了植物群落的植物多样性指数(包括物种丰富度、Shannon-Weiner指数、Simpson指数和Pielou均匀度指数)和生态位重叠度(Niche overlap of species,NOS),分析了植物群落物种多样性指数与CI和NOS的关系。结果表明:1)从水生到中生生境,植物多样性指数均呈增加趋势(P<0.05);2)湿生-中生生境的CI显著高于湿生生境(P<0.05),湿生生境的NOS高于水生生境(P<0.05);CI与NOS无显著相关性,但在湿生生境中两者呈倒抛物线关系(P<0.05)。3)整体来看,植物群落的物种丰富度与CI呈抛物线关系(P<0.05),与NOS无显著关系(P>0.05);Shannon-Weiner指数、Simpson指数和Pielou均匀度指数均与NOS呈线性正相关(P<0.05),与CI无显著关系(P>0.05);从单个生境看,湿生-中生生境的Simpson指数、Shannon-Weiner指数和Pielou均匀度指数与CI呈线性负相关(P<0.05),其余生境的上述多样性指数与CI无显著关系(P>0.05);各生境的植物多样性指数均与NOS无显著相关性(P>0.05)。本研究表明,从水生到中生生境,若尔盖地区的植物多样性呈增加趋势,但植物多样性与物种竞争强度和生态位重叠度的关系较复杂。本研究结果有助于理解若尔盖高原植物多样性的形成机制。  相似文献   

18.
遥感与GIS支持下的崇明东滩迁徙鸟类生境适宜性分析   总被引:4,自引:2,他引:4  
崇明东滩鸟类自然保护区位于长江入海口,是国际迁徙鸟类重要的栖息地.受自然和社会因素影响,该地区鸟类栖息环境正处于快速变化.研究采用面向对象的图像分割方法提取鸟类生境适宜性多边形评价单元,根据近年来野外调查数据分析了影响迁徙鸟类生存的地类、植被、潮沟、底栖生物等关键环境因素,建立了鸟类与关键环境影响因素的定性定量关系.在此基础上利用GIS空间分析方法和技术,进行了崇明东滩鸟类保护区内主要四大鸟类种群雁鸭类、鸻鹬类、鹭类以及鸥类的生境适宜性分析.结果表明:(1)崇明东滩迁徙鸟类生境较适宜的面积占保护区总面积40%左右;(2)光滩区域、与光滩邻近的海三棱藨草带以及潮沟地带是鸟类生境适宜性较好的地理区域;(3)基于面向对象的遥感分析技术和GIS空间分析技术,能有效且简便地对生态环境处于快速动态变化中的物种生境适宜性进行快速、客观准确的分析评价,其结果可为崇明东滩鸟类种群及其生存环境规划、保护和管理提供基础科学依据.  相似文献   

19.
基于生境适宜性指数模型的俚岛海黍子生境层级分布   总被引:1,自引:0,他引:1  
为了深入了解海黍子生境,利用模型对山东俚岛海黍子生境进行适宜性分析,分别选取温度、盐度、水深、浊度、底质、无机氮浓度、磷酸盐浓度和距海藻床距离8种环境因子,通过层次分析法赋值因子权重,结合空间分析方法建立了海黍子HSI模型.利用该模型对山东俚岛近岸海域2018年春、秋两季的环境因子调查结果进行了海黍子生境分析.结果 表...  相似文献   

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