基于优化MaxEnt模型的原麝生境适宜性评价

为了解原麝(Moschus moschiferus)适宜生境的空间分布及生境需求,对其栖息地管理和保护提供科学依据,以陕西宜川原麝省级自然保护区为研究区域,应用GIS结合保护区红外相机、野外实测原麝分布点数据,利用R语言对MaxEnt模型优化后建模,对保护区原麝栖息地适宜性进行评价并分析各变量因子的权重值。结果表明:模型预测结果良好,保护区内原麝适宜栖息地面积约为61.36 km²,占保护区总面积的30.75%;次适宜栖息地面积约为100.32 km²,占保护区总面积的50.28%;不适宜栖息地面积约为37.86 km²,占保护区总面积的18.97%。植被类型、海拔、坡度和距河流距离是贡献率排前4的环境因子。保护区内人为因素干扰比较小,原麝在针阔混交林、海拔1 200～1 500 m和坡度20°以上的生境中出现概率较高,建议根据生境适宜性调整保护区范围(尤其是实验区范围),并在山体之间建立廊道,加强对原麝及其生境的保护。     

基于MaxEnt模型的天峻县大型野生草食动物生境适宜性评价

生境适宜性评价对大型野生草食动物与家畜栖息地分布及其食物竞争状况研究具有重要意义。为了解青海省天峻县大型野生草食动物的生境状况,利用ENMTools对环境数据进行相关性分析,筛选出9个主要环境因子用于建立模型,通过MaxEnt模型对天峻县的野牦牛(Bos mutus)、藏野驴(Equus kiang)、藏原羚(Procapra picticaudata)、岩羊(Pseudois nayaur)、鹅喉羚(Gazella subgutturosa)和盘羊(Ovis ammon)6个物种进行适宜性评价。结果表明,影响6种大型野生草食动物的主要环境因子为平均气温日较差和海拔;天峻县6种大型野生草食动物适宜生境面积约为12 607 km²,占天峻县面积的48.51%,适宜生境主要分布在西北部;各物种训练集(Training)与验证集(Tes data)AUC值分别为藏原羚0.936,0.915;鹅喉羚0.903,0.874;野牦牛0.934,0.911;岩羊0.946,0.821;藏野驴0.918,0.906;盘羊0.930,0.920,均达到了优秀水平。     

鹅喉羚种群生存力分析

采用VORTEX7．3软件对鹅喉羚的种群生存力进行了分析。研究结果显示：鹅喉羚集合种群在100年内的种群动态变化接近于根据野外工作得到的种群动态。种群在100年内的灭绝概率为零，在25年种群数量最大440，25～65年间鹅喉羚的种群数量呈下降趋势，65年时鹅喉羚的灭绝概率最大32%，种群数量约减少20％，之后种群数量处于稳定下降趋势。已经处于濒危状态，需妻保护。鹅喉羚死亡率的变化对它们种群生存力的影响要大于环境变化；逐步使鹅喉羚生境良性发展有利于鹅喉羚种群的良性发展；通过鹅喉羚种群闯进行个体交换有利于保持它们的进化潜力。     

基于MaxEnt模型的福建省台湾青枣种植潜力预测及适宜性区划

明确台湾青枣在福建省的种植潜力预测及其适宜性区划,为台湾青枣引扩种合理布局提供理论参考。基于MaxEnt模型预测台湾青枣在福建省种植潜力预测,通过存在概率确定台湾青枣种植分布气象指标与不同等级适宜性分布。结果表明：影响台湾青枣分布的主导气象因子为最冷季平均最低气温、≥10℃年活动积温、年日照时数和4月平均最低气温,适宜种植的区域气象条件为最冷季平均最低气温高于9.3℃,≥10℃年活动积温高于7173℃,年日照时数在1720h以上,4月平均最低气温高于15.1℃,适宜及以上等级区域主要分布在漳州各区县、龙岩东部南部、三明东部局部、泉州和福州大部地区以及厦门、莆田等市县。     

基于MaxEnt模型评价紫花苜蓿在锡林郭勒盟的分布适宜性及主导因子

采用最大熵(MaxEnt)物种分布模型,结合紫花苜蓿(Medicago sativa)已有的地理分布记录,选取影响紫花苜蓿生长的10个变量,包括7个气候变量(年均降水量、年总辐射量、年最低温度、年均温度、5月最低温度、8月平均温度、8月空气湿度)和3个土壤变量(土壤pH、土壤厚度、土壤有机质含量)。采用最大熵模型的Jackknife检验,计算各变量对紫花苜蓿适宜性的重要性,筛选出影响紫花苜蓿适宜性分布的主导因子。结果表明,最大熵模型的训练子集和测试子集的AUC分别为0.913、0.889,均达到“很准确”水平,说明模型能准确地模拟紫花苜蓿在锡林郭勒盟的地理分布,紫花苜蓿的适宜种植区(P＞0.50)主要分布于锡林郭勒盟南部和东南部,面积为0.98万km2,占研究区总面积的7.7%。影响紫花苜蓿适宜性分布的主导因子为年均降水量、年最低温度、5月最低温度和8月湿度。     

河南新乡黄河湿地鸟类国家级自然保护区生境适宜性评价研究

河南新乡黄河湿地国家级自然保护区是中原地区重要的鸟类自然保护区,本文以河南新乡黄河湿地国家级自然保护区为研究区域,对该保护区进行了越冬水鸟生境的专项调查。通过定量化分析越冬水鸟生境的影响因子,结合1990年,2000年和2014年保护区的景观类型图,采用生境适宜性模型(HSI)对新乡黄河湿地保护区水鸟生境适宜性的时空变化格局进行了预测和分析。     

基于MaxEnt模型的天峻县放牧家畜生境适宜区估计

天峻县是青海省海西州唯一的纯牧业县,预估放牧家畜在天峻县的生境适宜区,对合理放牧和保护大型野生草食动物栖息地具有重要意义。利用MaxEnt模型和地理空间分析技术,结合放牧家畜分布数据和主要环境数据,预测了天峻县放牧家畜(牦牛、绵羊、马)适宜区分布及其生态特征。结果表明,距居民点的距离和距道路的距离两个变量对放牧家畜生境适宜区分布影响最为显著;天峻县牦牛的适宜区面积18 857.22 km²,占天峻县总面积的79.89%,主要分布在苏里乡、龙门乡、木里镇;绵羊的适宜区面积18 908.73 km²,占天峻县总面积的80.11%,主要分布在苏里乡、龙门乡、木里镇、舟群乡、阳康乡;马的适宜区面积13 690.18 km²,占天峻县总面积的58.00%,主要分布在龙门乡、舟群乡、木里镇。     

甘肃兴隆山国家级自然保护区马麝夏季种群分布与生境适宜性的关系

掌握自然保护区马麝(Moschus chrysogaster)的分布、种群大小及与生境适宜性的关系是对濒危马麝开展可持续就地保护的前提和基础。2021年7月1日—8月25日,采用样线法和粪堆计数法对兴隆山国家级自然保护区的马麝种群进行调查,分析马麝的分布和种群大小与保护区夏季生境适宜性的关系。结果表明：保护区分布有马麝922～1 480头,主要分布在适宜生境内,平均种群密度为(4.00±0.93)头/km²;随夏季生境适宜性的增加,马麝的种群密度也呈上升趋势,高适宜区生境种群密度可达(18.01±1.36)头/km²。兴隆山保护区可通过生境保育提升其非适宜区的生境质量,扩大马麝的分布范围,促进种群增长。     

基于MaxEnt模型青藏高原老芒麦适生区模拟预测

本研究以青藏高原地区老芒麦(Elymus sibiricus L.)为研究对象,通过MaxEnt模型模拟预测其在青藏高原的分布格局,利用刀切法(Jackknife)筛选出影响老芒麦分布的主导环境因子,运用ArcGis软件对不同时期的老芒麦进行适生等级划分以及适生面积的计算.结果表明:老芒麦主要分布在青藏高原的东部地区....     

基于MaxEnt分析我国羊草分布区的生物气候特征

羊草（Leymus chinensis）是欧亚大陆草原区东部草甸草原及干旱草原上的重要建群种之一。利用生物气候数据分析我国羊草的适生气候特征,客观反映我国羊草的地理分布范围及主导其分布的生物气候因子,能为我国羊草的分布潜力提供科学依据。本研究从我国数字植物标本馆获取204个羊草标本记录数据,并从WorldClim获取生物气候数据（1950-2000年）,用最大熵模型（MaxEnt）模拟羊草的地理分布,检测其生物气候主导因子及其适宜值。结果表明,冷季降雨量（bio19）对羊草分布的增益最大,干季降雨量（bio17）和最干月降水量（bio14）依次次之。同时羊草分布概率分别与冷季降雨量（bio19）,干季降雨量（bio17）和最干月降水量（bio14）为单峰响应关系。较纬度和海拔因子,经度是影响我国羊草分布格局的主要因子。     

Genetic Diversity of Gazella subgutturosa Based on Mitochondrial DNA D-Loop Sequence in Xinjiang Ebinur Lake

To investigate the genetic diversity and genetic data of Gazella subgutturosa from Xinjiang Ebinur lake National Wetland Nature Reserves, the Ebinur lake goose antelope 35 feces samples were analyzed.Using noninvasive DNA technology, the mitochondrial DNA D-Loop 878 bp fragment was successfully amplified.Sequences results for GenBank database BLAST comparison and Clustal W and DNASP software analysis.The results showed that the sequences of the above fragments were successfully amplified, total 55 polymorphic loci were detected, which were not found insert and deficiency.This study found 15 variable sites, including 14 transversion sites and 1 top transposition.The average A, T, C and G contents in D-Loop were 28.03%, 31.57%, 24.84% and 15.56%, respectively.The contents of A+T (59.6%) were higher than G+C (40.4%).In addition, a total of 16 mtDNA haploid type were detected, haploid type polymorphism (h) was 0.886 ±0.037, nucleotide diversity degree (π) was 0.037±0.01528.The results showed that Ebinur lake Gazelle subgutturosa maintained high variation in mitochondrial D-Loop sequences.     

A three-dimensional pelvimetric assessment on pelvic cavity of gazelle (Gazella subgutturosa) by computed tomography

The gazelles (Gazella subgutturosa), which are at the risk of extinction and are legally protected, have a cultural and aesthetic value in Turkey. It becomes incredibly important to increase their numbers in order to ensure their survival. In this context, it is required to examine thoroughly the pelvic cavity which contains reproductive organs and is used as the birth canal, as well. This study was conducted to determine the pelvimetric data of the gazelles by scanning their pelvic cavity via a multidetector computed tomography (MDCT) and preparing three-dimensional models of the pelvic cavity. Twelve adult (6 females, 6 males) gazelle carcasses were used in the study. After the pelvic cavity was scanned using the MDCT device with 64 detectors at 80 kV, 200 mA, 639 mGY and 0.625 mm cross-section thickness, the MDCT images were obtained. The three-dimensional models of the images obtained using MIMICS 20.1 (The Materialise Group, Leuven, Belgium) program were prepared. Pelvimetric measurements of the pelvic cavity were taken using these models. It was determined based on the pelvimetric examinations that there was a significant difference between the female and male gazelles in terms of conjugate diameter, vertical diameter, intermediate traversal diameter, and cranial and medial transverse diameter data at p < .05. Also, there was a significant difference in their data related to caudal transverse diameter and ischial arch at p < .01. Consequently, it is thought that the use of pelvimetric values belonging to the pelvic cavity of gazelles would reveal the sexual dimorphism of the species and its differences with other species and would contribute to clinical sciences.     

Three-dimensional modelling of computed tomography images of limb bones in gazelles (Gazella subgutturosa)

The objective of the present study was to model in 3D the detailed morphometric features of the thoracic and pelvic limb bones of the gazelle (Gazella subgutturosa), whose natural habitat is only in the Sanliurfa province, by using multidetector computerized tomography (MDCT) images. Materials from 14 (7 male and 7 female) dead gazelles were collected from the Harran University Veterinary Medicine Faculty clinics during or after treatment. MDCT images of the gazelles were taken and saved as DICOM (Digital Imaging and Communications in Medicine) files. MIMICS 20.1 software was used to generate a 3D reconstruction of the data, and morphological and morphometrical evaluation was performed. In respect of morphological features, the combined metacarpus (Mc) III and metacarpus Mc IV were the main weight-bearing metacarpal bone, while Mc II and Mc V were rudimentary. On the femur, the lateral condyle was bigger than the medial condyle at the caudodistal end and the medial wing of the trochlea femoris was larger than the lateral. As with the thoracic limb, the combined metatarsus (Mt) III and metatarsus Mt IV were the main weight-bearing metacarpal bone and they displayed a synostosis structure. There was no secondary metatarsus in the gazelles’ pelvic limb. Based on digital measurements, the tibia was the longest bone of the gazelles’ skeletal system, and there was a statistically significant sexual dimorphism throughout the skeleton at the levels of p < .05, p < .01 and p < .001. As a result, the present study's findings are useful as reference data for further studies on anatomy, surgery and archaezoology, while also being useful for classifying species and for forensic sciences.     

A serologic investigation of blue tongue virus (BTV) in cattle,sheep and gazella subgutturosa subgutturosa in southeastern turkey

Bluetongue virus (BTV) is a vector-borne disease of ruminants disseminated in the tropic and sub-tropic zone of the world. It is also an important problem in the Middle East. Three serotypes (4–9–16) of the virus have been isolated so far in Turkey. Gazella subgutturosa subgutturosa (Goitred Gazella) is native species of Anatolia. Due to risk of extinction, captured Gazelles have been taken under protection in a restricted area at Ceylanpinar state farm. In this study, the presence of Bluetongue virus (BTV) was investigated serologically in 82 Goitred Gazella, 684 sheep and 100 cattle. Seropositivity rates in Gazella, sheep and cattle were detected as 40.2%, 295% and 88%, respectively.     

气候变化对中国梅花鹿潜在栖息地影响

研究表明,气候变化将会使生物多样性降低甚至是物种灭绝。研究气候变化对物种栖息地的影响,对未来研究物种多样性和保护生态系统功能完整性提供实践意义。以梅花鹿(Cervus nippon)为研究对象,将23个环境因子通过去相关性后得到8个环境因子,利用最大熵(MaxEnt)模型模拟了梅花鹿基准气候条件下在中国潜在生境分布,并预测了ssp245和ssp585两种气候变化情景下2021—2040年(2030s)、2041—2060年(2050s)、2061—2080年(2070s)梅花鹿潜在分布。23个环境因子中,对3个不同的梅花鹿亚种,降水季节性、海拔、最干月降水量这3个因子是影响梅花鹿生境分布的主要因子。基准气候条件下,梅花鹿的潜在生境面积占总研究区域总面积的3.72%。随着时间的推移,研究区内梅花鹿东北亚种当前潜在生境面积明显增加,其中ssp585情景增加程度大于ssp245情景。在ssp585情景2050s阶段,总潜在生境面积将增加524.79%;梅花鹿华南亚种当前潜在生境面积明显减少,在ssp585情景下,梅花鹿适宜生境面积减小幅度将大于ssp245情景下梅花鹿适宜生境面积减小幅度,其在相应阶段分别减少77.61%、96.29%和93.62%。适宜生境逐渐消失。梅花鹿四川亚种在ssp245、ssp585两种情景下,适宜生境面积变动较小,并且都有5%—10%的新增适宜生境。     

MaxEnt模型对新疆盾糙璃眼蜱生境适应性预测

璃眼蜱属是我国部分区域的优势蜱种,可传播多种病原.为了解新疆地区盾糙璃眼蜱生境适应性,从文献中获取我国新疆地区盾糙璃眼蜱分布点信息,结合环境气候因子数据,运用MaxEnt最大熵模型,分析了19个环境气候因子对盾糙璃眼蜱分布的潜在影响,并分析和预测了当前和未来不同气候模式下盾糙璃眼蜱潜在的地理分布区,筛选出了4个相关的环...     

扎龙保护区苍鹭营巢最适生境选择模型

本文建立了扎龙国家自然保护区苍鹭营巢的最适生境选择指数模型。通过对影响苍鹭营巢的主要生境因子水源、植被种类、植被密度和植被高度等进行调查分析，分别建立了相应的选择指数，为苍鹭营巢的生境质量评价提供了一种建模思想。