大沙鼠和子午沙鼠的种群生态位

大沙鼠(Ｒｈｏｍｂｏｍｙｓｏｐｉｍｕｓ)和子午沙鼠(Ｍｅｒｉｏｎｅｓｍｅｒｉｄｉａｎｕｓ)均为荒漠、半荒漠的典型鼠种,为群栖性鼠类,只是子午沙鼠不像大沙鼠那样形成很大的集群。在沙质荒漠生境,大沙鼠和子午沙鼠常混居于沙丘坡地上部,成为这些地区自然群落中的优势种。对于大沙鼠和子午沙鼠种群之间的关系,在空间分布格局方面的研究已有报道[1]。作者于1995年9～10月、1996年4～5月、9～10月和1999年10月在内蒙古包头市达尔罕茂名安联合旗北部的腾格淖尔地区,对大沙鼠和子午沙鼠种群生态位进行了研究,并就它们对资源的利用和分配以及两…     

大沙鼠种群密度与降水量的关系

大沙鼠（Rhombomys opimus）是中亚荒漠、半荒漠草原的典型鼠种,在荒漠草原多呈不连续的岛状分布,多集居于白刺（Nitraria sibirica）、盐爪爪（Kalidium foliatum）丛生的沙地或风成沙丘上的灌丛之间,是农、林、牧以及卫生防疫的重要害鼠。对其种群数量动态目前只有黄健和张大铭（2004）采用Leslie矩阵进行了研究。本文探讨了大沙鼠种群密度与降水量的关系,为其种群动态提供基础资料。     

大沙鼠的年龄鉴定与种群年龄组成

在鼠类生态学的研究中 ,对鼠类年龄的鉴定是一项重要的工作。年龄组成是种群的重要特征之一 ,它有助于了解种群的年龄结构以及种群数量变动的规律。大沙鼠 (Ｒｈｏｍｂｏｍｙｓｏｐｉｍｕｓ)是中亚地区荒漠及半荒漠草原的重要害鼠之一 ,在内蒙古西部的梭梭 (Ｈａｌｏｘｙｌｏｎａｍｍｏｄｅｎｄｒｏｎ)林区 ,由于大沙鼠的啃咬 ,影响了该地区梭梭林的正常结实 ,从而降低了结实量[1 ] 。同时 ,大沙鼠又是鼠疫和皮肤利什曼病的重要宿主。对大沙鼠的年龄鉴定与种群年龄组成进行研究 ,将有助于了解其种群数量变动的规律 ,从而为有效防治大沙鼠鼠…     

河西荒漠子午沙鼠的生态学初步观察

子午沙鼠Meriones meridanus Pallas是一种荒漠、半荒漠地区的小型啮齿动物。研究子午沙鼠生态学对这些地区的开发利用和防治鼠害具有很大意义。1961年4月—6月,在甘肃酒泉黑山湖地区进行了子午沙鼠生态调查,结果如下:一、不同栖息地的分布与数量剖检从各种不同栖息地捕获的子午沙鼠36只,发现每只鼠胃内食物平均重3.1克,(1.5克～7克),一般为2.5～3.5克。鼠胃的内容物中黄色食糜(枸杞叶)占44.7%,绿色(盐爪爪的叶和茎的表皮、东蔷叶)占30.4%,白色和褐色及其他(主要是东蔷种子,部分为其根、茎的韧皮部)分别占8.5%和16.4%。在剖检鼠胃的过程中…     

内蒙古半荒漠区啮齿动物群落分类及其多样性研究

自1988～1993年在内蒙古半荒漠区约11万km2的调查区域内共设置259个样方,布放有效夹日131109个,捕获啮齿动物19种。在此基础上,用其捕获率作为分类量纲,以样方-种的捕获率组成259×19的原始数据矩阵,应用快速聚类法进行鼠类群落划分,根据分类结果,并结合调查区域内各种地带性植被的特点将该地区啮齿动物划分为9个不同的鼠类群落。即群落:戈壁五趾跳鼠 五趾跳鼠 长爪沙鼠群落,群落生境为半荒漠区内典型的高平原、丘陵荒漠草原;群落:三趾跳鼠 子午沙鼠 小毛足鼠群落,群落生境为沙地,主要分布于阴山北麓的覆沙地带;群落;草原黄鼠 五趾跳鼠 长爪鼠群落,群落生境为半荒漠区内平原丘陵典型草原和山地典型草原;群落:赤颊黄鼠 黑线毛足鼠 五趾跳鼠群落,群落生境为戈壁针茅-隐子草草原;群落:戈壁五趾跳鼠 三趾跳鼠 蒙古羽尾跳鼠群落,群落生境为草原化荒漠,主要以强旱生灌木和半灌木组成;群落:黑线仓鼠 长爪沙鼠 小毛足鼠群落,群落生境为人工草地及阴山北麓山顶种植荞麦和莜麦的农田;群落:小毛足鼠 三趾跳鼠 长爪沙鼠群落,群落生境为典型荒漠草原重度退化的短花针茅冷蒿草场;群落:长尾仓鼠 大林姬鼠 棕背群落,群落生境为阴山山脉中段的次生林地如五当召、大桦背及蛮汉山;群落:五趾跳鼠 草原黄鼠 黑线毛足鼠群落     

子午沙鼠种群繁殖特征分析

子午沙鼠（Ｍｅｒｉｏｎｅｓｍｅｒｉｄｉａｎｕｓ）是我国西北各省（区）荒漠草原的代表鼠种和优势鼠种。本文将１９９１～１９９６年在库布齐沙漠东段该鼠的繁殖调查资料报道如下。１材料与方法１１调查基点概况调查基点设在内蒙古伊克昭盟达拉特旗境内的中国农业科学...     

土壤非保护性有机碳对荒漠草原沙漠化的响应

沙化草地的恢复与重建是干旱半干旱区生态建设的重要内容,分析荒漠草原沙漠化过程中土壤非保护性有机碳分配比例的变异规律对于探讨沙化草地恢复机制具有重要的理论价值。以干旱、半干旱地区荒漠草原不同沙化阶段的土壤为研究对象,分析土壤粗颗粒有机碳、细颗粒有机碳、轻组有机碳含量和分配比例的分布特征、土壤非保护性有机碳转化为保护性有机碳的速率。结果表明:荒漠草原发生逆向演替后,土壤细颗粒有碳含量和分配比例表现为固定沙地荒漠草地半固定沙地流动沙地;粗颗粒有机碳含量表现为荒漠草地半固定沙地流动沙地固定沙地,粗颗粒有机碳分配比例表现为流动沙地半固定沙地荒漠草地固定沙地;轻组有机碳含量和分配比例递减。颗粒有机碳、轻组有机碳、土壤有机碳对草地沙漠化的敏感性不同,颗粒有机碳较轻组有机碳和土壤有机碳敏感性强,其中细颗粒有机碳较粗颗粒有机碳敏感性强。随着草地沙漠化程度的增强土壤非保护性有机碳分配比例呈下降趋势,表明草地沙漠化降低土壤质量。荒漠草地退化至流动沙地土壤非保护性有机碳转化为保护性有机碳的速率整体呈上升趋势。     

子午沙鼠的繁殖调查

子午沙鼠(Meriones meridianus Pallas)是西北各省荒漠草原的代表和优势鼠种,也是全国七种沙鼠中分布最广的种类。有关子午沙鼠的繁殖生物学,国内至今尚未见有报道。笔者于1979年4月—1980年3月在内蒙古四子王旗北部草原,通过逐月播铗捕打子午沙鼠,共获鼠470只,经对鼠体和睾丸进行测量、作副睾涂片检查精子、记录雌鼠的怀仔数及子宫内壁上的胎斑数等,了解其繁殖情况。现将调查结果初步总结于后。*8、9月份捕鼠数偏少,主要是由于连日暴雨,子午沙鼠的生境被淹,自然死亡增多和捕鼠条件比较困难的结果。一、性比在工作期间捕得的470只子午沙鼠…     

内蒙古达茂旗腾格淖尔地区大沙鼠种群繁殖习性的调查

鼠类繁殖生态学的研究是其种群生态学研究的一个重要方面 ,它不但为研究鼠类种群数量变动规律对种群数量进行预测预报提供重要的生态学基础资料 ,也为控制鼠害措施的制定提供依据 ,同时也具有重要的流行病学意义。大沙鼠 (Ｒｈｏｍｂｍｙｓｏｐｉｍｕｓ)广泛分布于中亚细亚、哈萨克斯坦、伊朗、阿富汗和蒙古国等地 ,在我国主要分布于内蒙古西部、甘肃北部和新疆 ,是荒漠—半荒漠地区的重要害鼠。我国对其生态学方面多注重于种群分布格局的研究[1～ 5] ,在繁殖方面的研究甚少[6] 。 1 979～1 980年和 1 995～ 1 996年对内蒙古包头市达尔罕茂…     

荒漠草地土壤微生物生物量和微生物熵对沙漠化的响应

采用空间序列代替时间演替的方法,分析宁夏中北部盐池县荒漠草地不同沙漠化阶段(荒漠草地、固定沙地、半固定沙地和流动沙地)土壤微生物生物量(SMB)和微生物熵(qMB)的变化特征及其影响因子.结果表明:从荒漠草地到流动沙地,土壤微生物生物量碳、氮、磷分别降低46.1%、80.8%和30.0%.随着荒漠草地沙漠化程度的加剧,土壤微生物熵碳(qMBC)、土壤微生物熵氮(qMBN)、土壤微生物熵磷(qMBP)均表现为荒漠草地>固定沙地>半固定沙地>流动沙地,而土壤-微生物化学计量不平衡性(C∶Nimb、C∶Pimb、N∶Pimb)基本呈增加趋势.土壤微生物生物量氮与C∶Nimb呈显著正相关,与N∶Pimb呈显著负相关;土壤微生物生物量磷与C∶Pimb呈显著正相关.冗余分析(RDA)显示,土壤生态化学计量(C∶N、C∶P)对微生物熵碳的负效应最明显.荒漠草地沙漠化显著影响土壤微生物生物量和微生物熵.     

从文献看种群、种群生态及种群行为研究

通过维普中文期刊网和英文ScienceDirect数据库有关种群、种群生态和种群行为文献的查询,发现文献的发表量很不平衡,种群研究文献的年增长率远大于种群生态和种群行为。英文文献中关于种群行为研究的文献增长率高于种群生态,而中文文献正好相反。     

Modelling the effectiveness of contraception for controlling introduced populations of elephant in South Africa

Re‐introduced African elephant (Loxodonta africana Blumenbach) populations are growing at very high rates in many of southern Africa’s reserves, have attained densities higher than previously thought possible and may be exhibiting irruptive growth. Active management of such populations is necessary to prevent the potentially negative effects on habitat and biodiversity that are associated with elephant overpopulation. One potentially feasible method of elephant management is immunocontraception, but very little is known about the long‐term effectiveness of this method. Using demographic data from three South African elephant populations, we made model projections of the effects of contraception on population growth rates to determine whether contraception may be a feasible management tool for elephant. In comparison with noncontracepted populations, realistic reductions in population growth rate after 20 years of contraception were projected to be up to c. 64%, with 50% being a very feasible target. Through its ability to reduce population growth rates, immunocontraception should be an effective tool for preventing or minimizing irruption in elephants and, perhaps, other introduced ungulate species.     

Predator–vole interactions in northern Europe: the role of small mustelids revised

The cyclic population dynamics of vole and predator communities is a key phenomenon in northern ecosystems, and it appears to be influenced by climate change. Reports of collapsing rodent cycles have attributed the changes to warmer winters, which weaken the interaction between voles and their specialist subnivean predators. Using population data collected throughout Finland during 1986–2011, we analyse the spatio-temporal variation in the interactions between populations of voles and specialist, generalist and avian predators, and investigate by simulations the roles of the different predators in the vole cycle. We test the hypothesis that vole population cyclicity is dependent on predator–prey interactions during winter. Our results support the importance of the small mustelids for the vole cycle. However, weakening specialist predation during winters, or an increase in generalist predation, was not associated with the loss of cyclicity. Strengthening of delayed density dependence coincided with strengthening small mustelid influence on the summer population growth rates of voles. In conclusion, a strong impact of small mustelids during summers appears highly influential to vole population dynamics, and deteriorating winter conditions are not a viable explanation for collapsing small mammal population cycles.     

MAXIMUM-LIKELIHOOD ESTIMATION OF POPULATION DIVERGENCE TIMES AND POPULATION PHYLOGENY IN MODELS WITHOUT MUTATION

In this paper we present a method for estimating population divergence times by maximum likelihood in models without mutation. The maximum-likelihood estimator is compared to a commonly applied estimator based on Wright's F_ST statistic. Simulations suggest that the maximum-likelihood estimator is less biased and has a lower variance than the F_ST-based estimator. The maximum-likelihood estimator provides a statistical framework for the analysis of population history given genetic data. We demonstrate how maximum-likelihood estimates of the branching pattern of divergence of multiple populations may be obtained. We also describe how the method may be applied to test hypotheses such as whether populations have maintained equal population sizes. We illustrate the method by applying it to two previously published sets of human restriction fragment length polymorphism (RFLP) data.     

GPS collars have an apparent positive effect on the survival of a large carnivore

Are instrumented animals representative of the population, given the potential bias caused by selective sampling and the influence of capture, handling and wearing bio-loggers? The answer is elusive owing to the challenges of obtaining comparable data from individuals with and without bio-loggers. Using non-invasive genetic data of a large carnivore, the wolverine (Gulo gulo) in Scandinavia, and an open-population spatial capture–recapture model, we found a 16 (credible interval: 4–30) percentage points lower mortality probability for GPS-collared individuals compared with individuals without GPS collars. While the risk of dying from legal culling was comparable for collared and non-collared wolverines, the former experienced lower probability of mortality due to causes other than legal culling. The aforementioned effect was pronounced despite a potentially lower age—and therefore likely higher natural mortality—of collared individuals. Reports of positive effects of bio-loggers on the survival of individuals are uncommon and we argue that GPS collars could shield animals from poaching. Our results highlight the challenges of drawing population-level inferences for populations subjected to poaching when using data from instrumented individuals.     

Late Chachapoya population structure prior to Inka conquest

Archaeological and ethnohistorical documents suggest that the Chachapoya region was inhabited by a number of distinct sociopolitical groups that only united in the face of their common enemy, the Inka. The purpose of this research is to quantify the amount of internal genetic differentiation and levels of extraregional gene flow during the Late Chachapoya period, in order to obtain a better understanding of the genetic relationship between these presumed ethnic groups. Craniometric data were collected from three Late Chachapoya samples (Laguna Huayabamba, Kuelap, and Laguna de los Cóndores), in order to understand the genetic relationships between the groups and facilitate our understanding of Late Chachapoya population structure. Genetic differentiation among these series ranged from 0.047 (heritability = 1.0) to 0.090 (heritability = 0.55). The Relethford-Blangero residuals indicate that the Laguna Huayabamba and Laguna de los Cóndores populations were receiving greater than average external gene flow, while Kuelap was receiving less than average external gene flow. The correspondence between biological and archaeological data in the investigation of prehistoric ethnic identity is discussed.     

竹类植物种群生态学研究进展与展望

综述了竹类种群生理生态学、种群动态、繁殖特性、无性系种群特征等几个方面的研究进展,概括了群落水平上竹类种群对森林更新的影响。并从竹类种群克隆多样性与微进化、生长适应机理、开花机制,以及竹类种群与林窗更新等四个方面展望未来竹类种群生态学研究的重点和主要趋势。     

福建南北泥蚶种内分化的RAPD分析

采用随机扩增多态性DNA(RAPD)技术,对泥蚶在福建以南(广东汕头和湛江)和福建以北(浙江温岭和韩国)种群(分别合称南方类群和北方类群)做了遗传分化研究。由筛选出的20个随机引物共获得103个清晰可辨的RAPD标记,扩增片段长度在250—2500bp。汕头种群与湛江种群,韩国种群与温岭种群之间的最小遗传距离分别为0．0612和0．0692,而南、北类群间的遗传距离却在0．3261-0．4511。类群间近交系数也大于类群内。NJ和UPGMA法构建的系统树均显示汕头种群、湛江种群首先聚在一起,再与温岭种群和韩国种群聚合,说明两个类群发生了较明显的遗传分化,估计与地理隔离有关。     

种群生存力分析（PVA）的方法与应用

随着人们对资源的加速利用,生境丧失和破碎化导致物种濒危问题日益严重.以岛屿生物地理学为理论起源的种群生存力分析（PVA）,通过分析和模拟种群动态过程并建立灭绝概率与种群数量之间的关系,为濒危物种保护提供了重要的理论依据和研究途径.在过去的几十年中,种群生存力分析已成为保护生物学中一项重要的研究内容.目前种群生存力分析发展稳定,但对其实际预测能力和准确性尚存质疑,应用方面也有待进一步发展.种群生存力分析的进一步完善还需要在理论和方法上的创新,特别是籍于景观生态学和可持续性科学的理念,将空间分析手段、经济社会因素纳入到物种和种群的预测和管理上,从而使其 具有更完整的理论基础和更高的实用价值.为此,本文对种群生存力分析的历史、基本概念、研究方法、模型应用和准确性进行了综述,并提出了有关的研究展望.     

北京东灵山海拔梯度上辽东栎种群结构和空间分布

种群年龄结构和空间分布格局是种群生态学的核心研究内容.为了阐明辽东栎种群海拔梯度分布特点,在北京东灵山地区辽东栎海拔分布范围(1000～1800m)内调查10条样带,研究种群大小级结构和空间分布的变异.种群的平均胸径在海拔梯度上表现出两段式的分布特征,海拔1480m为两段分布的分界点,在每一段内随海拔增加平均胸径也增加, 这反映了海拔梯度上种群的不同发育历史.种群密度、种群的聚集程度、种群的结构在海拔梯度上的分布特征都与平均胸径分布相似,种群密度和聚集程度与平均胸径为负相关系,其分布趋势与平均胸径相反.总体上,东灵山海拔梯度上辽东栎种群还是比较稳定的.辽东栎种群结构和空间分布在海拔梯度上的分布特征是种群发育历史、物种特性、环境、干扰等因素在海拔梯度上综合作用的结果.