舟山及其邻近岛屿獐种群的初步研究

舟山海岛上的獐(Hydropotes inermis),定海县志(1923)已有简要记录。作者在1978年调查时发现,舟山岛及其邻近较大的岛屿上普遍有獐,1976年海岛獐单位面积产量,5倍于浙江大陆邻近10个县的产量(盛和林,1981)。为进一步合理利用和发展獐资源,继而对舟山岛獐的种群结构繁殖和种群增长等问题进行研究,同时又对邻近10多个岛屿进行了访问调查,兹将初步结果报道如下。     

浙江沿海地区舟山新木姜子群落及种群结构特征分析

采用立木级结构代替年龄结构的方法,对浙江沿海地区(包括嵊泗县大戢山岛、定海区大猫岛、普陀区朱家尖岛、鄞州区瞻岐镇、北仑区春晓镇和宁海市力洋镇)的舟山新木姜子也Neolitsea sericea ( Bl.) Koidz.页群落的物种组成和垂直结构及其种群的年龄结构、静态生命表和分布格局进行了分析。结果表明：这6个舟山新木姜子天然群落共有维管束植物52科76属92种(含6变种),以木本植物为主,其中常绿木本植物34种,落叶木本植物31种。各群落的物种多样性指数差异较大,其中位于普陀区朱家尖岛的群落乔木层Shannon-Wiener指数( H忆)最高,位于定海区大猫岛的群落灌木层和草本层的H忆值均最高;且存在灌木层的H忆值大于乔木层和草本层的规律。种群个体年龄结构存在差异,但6个种群均为增长型种群,幼苗储备丰富,其他龄级的个体数量总体上随径级增大而减少。6个种群的分布格局均为显著的聚集分布,其中位于北仑区春晓镇的种群聚集强度最高,位于定海区大猫岛的种群聚集强度最低。从静态生命表看,舟山新木姜子岛屿类型种群的个体死亡率在径级玉( DBH<5 cm)和径级Ⅳ(15 cm≤DBH<20 cm)较高,大陆类型种群的个体死亡率在径级玉较高。研究结果显示：浙江沿海地区舟山新木姜子群落主要为常绿阔叶林,群落间的物种多样性差异明显源于人类活动的干扰;总体上看舟山新木姜子种群具有很强的更新能力。根据研究结果,对浙江沿海地区舟山新木姜子种群的保护提出了一些建议。     

北草蜥种群间生活史变异的成因分析:热环境、食物可利用性和体温的岛屿间差异

比较浙江温州北麂岛与洞头岛的热环境、食物可利用性以及动物体温,以辨析北草蜥岛屿种群间生活史特征差异中环境因子的作用。通过测定岛屿上北草蜥栖息地植被和环境温度,比较岛屿热环境的差异。野外测定活动蜥蜴的体温、环境温度和活动规律,实验室温梯板中测定动物喜好体温。用陷阱法测定无脊椎动物多样性和丰度,以比较岛屿蜥蜴种群的食物可利用性。岛屿植被存在差异导致热环境的差异。洞头岛植被高于北麂岛,地表层光线透入率则低于北麂岛。因而,洞头岛郁闭地表的平均温度和最高温度显著低于北麂岛,但两岛裸露地面的温度无显著差异。热环境的岛屿间差异进而影响北草蜥的野外体温。在春季,洞头岛的野外有效温度和基底温度显著大于北麂岛,而两岛北草蜥的体温无显著差异;在夏季,洞头岛的北草蜥体温、有效温度和基质温度均显著高于北麂岛;到秋季,北麂岛蜥蜴体温和环境温度高于洞头岛。地面无脊椎动物多样性和丰度的岛屿间差异表明北麂岛食物可利用性大于洞头岛。岛屿间北草蜥日活动规律和喜好体温无显著差异。本研究表明:(1)温度和食物可利用性存在岛屿间差异,岛屿种群间生活史特征差异可能与之有关;(2)两岛屿北草蜥主要采取行为调节对策来适应自然界的热环境变化,尚未发现热生理学特征的进化性漂移[动物学报51(5):797-805,2005]。     

台湾岛和海南岛兰科植物区系特征比较

为探明台湾岛和海南岛兰科( Orchidaceae)植物区系特征,在充分查阅相关资料的基础上,对2个岛屿兰科植物的物种组成、生活型和分布区类型进行分析,并对这2个岛屿与大陆陆地和周边国家兰科植物的分布特征进行比较和分析。结果表明：2个岛屿的兰科植物共有146属639种,其中,台湾岛有107属446种,海南岛有96属302种。2个岛屿树兰亚科( Subfam. Epidendroideae)的属和种比例均最高;原始的拟兰亚科( Subfam. Apostasioideae)在台湾岛无分布,而在海南岛分布有2属4种。从属和种的数量看,含1种和2~5种的属比例较高,分别占台湾岛兰科植物总属数的43.9%和36.4%,占海南岛兰科植物总属数的45.8%和40.6%;且包含种数多的属的比例较低。从生活型看,2个岛屿地生兰和附生兰的比例较高,分别占台湾岛兰科植物总种数的52.7%和34.3%,占海南岛兰科植物总种数的37.1%和55.3%。从分布区类型看,台湾岛和海南岛的兰科植物分别可划分为11和10个分布区类型,且均以热带亚洲至热带大洋洲分布型属和种的比例最高,热带亚洲分布型属和种的比例也较高。从热带成分与温带成分的数量比(R/T)看,台湾岛和海南岛兰科植物属的R/T值分别为3.6和3.3,种的R/T值分别为10.9和11.9,说明2个岛屿的兰科植物均以热带成分为主,台湾岛还包含一定的温带成分。从共有属和共有种看,2个岛屿与大陆陆地的兰科植物共有属均约占各自兰科植物总属数的90.7%,其中,三地共有属有66属;台湾岛与大陆陆地的兰科植物共有种比例较低(46.2%),而海南岛与大陆陆地的兰科植物共有种比例较高(74.9%),说明2个岛屿与大陆陆地兰科植物属的同源性较高,且海南岛兰科植物的大陆性特征更明显。与周边国家相比,2个岛屿与越南的兰科植物共有种比例较高,分别占台湾岛和海南岛兰科植物总种数的33.9%和75.2%。综合分析结果显示：台湾岛和海南岛的兰科植物种类丰富,生活型齐全,且具有明显的热带性质,但台湾岛的兰科植物还表现出一定的温带性质;2个岛屿与大陆陆地兰科植物的亲缘关系较近,但台湾岛兰科植物的特有性更明显。     

千岛湖片段化生境中木本植物种子雨基本特征及其影响因子

为探究片段化生境中木本植物种子雨的基本特征,该研究根据2015—2020年(研究期间)在千岛湖样岛上的植物群落长期监测样地内每月收集的种子雨数据,采用Kruskal-Wallis检验对木本植物的种子雨密度进行年际差异分析,对不同传播方式物种的种子雨密度进行月份间差异性分析,并利用线性混合效应模型,探究岛屿空间特征(岛屿面积、距最近岛屿的距离、距大陆的距离)以及气候因子(0 ℃以上积温、降水量)对木本植物以及不同传播方式物种的种子雨密度的影响。结果表明:(1)2015—2020年6年间,在29个样岛用240个收集器共收集到877 178粒木本植物的成熟种子,属于26科40属52种。(2)动物传播是木本植物主要的种子传播方式,不同传播方式物种的种子雨时间动态存在较大差异。(3)木本植物的种子雨年密度与岛屿面积和年积温呈显著正相关,与年降水量呈显著负相关。(4)自主传播物种的种子雨月密度与距最近岛屿的距离呈显著正相关,而动物传播物种的种子雨月密度则与距大陆的距离呈显著正相关,风力传播物种的种子雨月密度与月积温呈极显著正相关。综上表明,生境片段化通过岛屿空间特征影响了木本植物种子雨的时间动态。     

封面图说

<正>东海舟山海域——舟山位于长江口以南、杭州湾以东的浙江省北部,属东海海域。其陆地面积12410公顷,大小岛屿有1300多个,其中舟山本岛面积为4720公顷,占陆地总面积的38%,为中国第四大岛。舟山群岛岛礁众多,星罗棋布,约相当于中国海岛总数的20%。舟山不仅是我国最大的渔场,也是世界著名四大渔场之一。舟山的黄鱼、带     

基于线粒体16S rRNA基因的舟山群岛碧蛾蜡蝉种群遗传多样性分析

【目的】揭示岛屿隔离效应对舟山群岛及邻近大陆碧蛾蜡蝉Geisha distinctissima种群遗传多样性的影响。【方法】依据本研究获取的舟山群岛(11个岛屿)及邻近大陆15个种群共247头碧蛾蜡蝉样本的16S rRNA基因序列,对该地区种群进行遗传多样性评估;采用贝叶斯推断法构建系统发育树并绘制单倍型网络图,以解析种群间的遗传结构;通过中性检验、错配分布分析和贝叶斯天空线(Bayesian skyline plot, BSP)分析,探讨该地区碧蛾蜡蝉的种群历史动态。【结果】贝叶斯系统树及单倍型网络图均没有解析出舟山群岛碧蛾蜡蝉种群明显的遗传结构。且分子方差分析发现,遗传变异主要集中在种群内部(种群内变异占68.26%),种群间没有明显的遗传分化,显示了该地区碧蛾蜡蝉种群遗传多样性的均质化。不同种群间的单倍型多态性和核苷酸多态性与大陆-岛屿距离及岛屿隔离时间不相关。中性检验分析检测到Tajima’s D和Fu’s Fs均呈显著的负值,且错配分布分析呈现出典型的单峰,表明该地区碧蛾蜡蝉种群发生了近期的种群扩张事件。BSP分析表明,这种扩张事件发生在大约0.5～3.5千年前。【结论】岛屿隔离效应可能不足以驱使舟山群岛及邻近大陆的碧蛾蜡蝉种群遗传多样性产生明显的差异。     

舟山岛中国小鲵种群数量和分布的研究

舟山岛自１９８５ 年发现有中国小鲵分布后, 作者于每年１２ 月至翌年５ 月小鲵繁殖期间, 对岛上中国小鲵的种群数量和分布情况开展全面调查, 表明其种群密度大, 分布广泛, 资源丰富。     

舟山岛中国小鲵种数量和分布的研究

舟山岛自１９８５年发现有中国小鲵分布后,作者于每年１２月至翌年５月小鲵繁殖期间,对岛上中国小鲵的种群数量和分布情况开展全面调查,表明其种群密度大,分布广泛、资源丰富。     

岛屿特有种全缘冬青遗传多样性的ISSR分析

全缘冬青(Ilex integra)为岛屿特有植物,主要分布于浙江舟山群岛,被列为浙江省珍稀濒危植物。作者运用ISSR分子标记对舟山群岛的6个全缘冬青种群(5个自然种群和1个栽培种群)共57个个体进行了遗传多样性分析。采用9条随机引物扩增出78条清晰谱带,其中45条为多态性条带,多态位点百分比(PPL)为57.7%。经POPGENE软件分析,全缘冬青种群平均多态位点百分比(PPL)为42.1%,Nei’s基因多样度(HE)为0.153,较其他海岛植物的遗传多样性偏低。5个自然种群遗传分化系数Gst=0.316,AMOVA测度Fst=0.295,Shannon多样性分化系数S=0.304,遗传分化程度较高。全缘冬青种群间地理距离与遗传距离具有正相关性(r=0.649,P<0.05),岛屿间地理隔离对种群间遗传分化产生了较为显著的影响。UPGMA聚类分析显示,朱家尖岛与普陀岛种群亲缘关系较近,而舟山岛栽培种群是由桃花岛自然种群移植而来。针对全缘冬青种群遗传多样性较低及遗传分化程度较高的现状,应加强现有自然种群的就地保护,促进种群自然更新;建立种质资源库,收集不同岛屿的种源进行混合繁殖,促进基因交流。     

舟山群岛獐的分布

1999 年7 月至2000 年6 月采用访问和样线法对浙江舟山群岛25 个岛上的獐的分布进行调查。结果显示獐在该地区主要分布在北纬30°26′以南, 东经122°24′以西, 且集中在西南诸岛上。较大岛屿獐的分布比例较高, 10 km²以上的岛屿81.25 %有獐分布。并且其周围小岛獐的分布比例也较高。所调查的5 个距离舟山本岛3 km范围内的小岛均有獐分布。獐所分布的岛屿随着离大陆和本岛距离的增加而减少。獐主要栖息在山丘上, 但夜里常到农田觅食。21.47 %有人居住岛上有獐分布。对獐分布影响较大的因素是离本岛和大陆的距离及岛屿面积; 其次是人类活动, 主要是偷猎; 淡水水源影响不大; 分布与岛屿形状无关。獐可以在岛屿之间迁游, 从而影响分布。獐在舟山地区可能是原有分布的, 几次地质变化可能对其产生一定影响。     

Insular shifts and trade-offs in life-history traits in pond frogs in the Zhoushan Archipelago, China

Island and mainland populations of animal species often differ strikingly in life-history traits such as clutch size, egg size, total reproductive effort and body size. However, despite widespread recognition of insular shifts in these life-history traits in birds, mammals and reptiles, there have been no reports of such life-history shifts in amphibians. Furthermore, most studies have focused on one specific life-history trait without explicit consideration of coordinated evolution among these intimately linked life-history traits, and thus the relationships among these traits are poorly studied. Here we provide the first evidence of insular shifts and trade-offs in a coordinated suite of life-history traits for an amphibian species, the pond frog Rana nigromaculata . Life-history data were collected from eight islands in the Zhoushan Archipelago and neighboring mainland China. We found consistent, significant shifts in all life-history traits between mainland and island populations. Island populations had smaller clutch sizes, larger egg sizes, larger female body size and invested less in total reproductive effort than mainland populations. Significant negative relationships were found between egg size and clutch size and between egg size and total reproductive effort among frog populations after controlling for the effects of body size. Therefore, decreased reproductive effort and clutch size, larger egg size and body size in pond frogs on islands were selected through trade-offs as an overall life-history strategy. Our findings contribute to the formation of a broad, repeatable ecological generality for insular shifts in life-history traits across a range of terrestrial vertebrate taxa.     

Insular shifts in body size of rice frogs in the Zhoushan Archipelago, China

1. Differences in body size between mainland and island populations have been reported for reptiles, birds and mammals. Despite widespread recognition of insular shifts in body size in these taxa, there have been no reports of such body size shifts in amphibians. 2. We provide the first evidence of an insular shift in body size for an amphibian species, the rice frog Rana limnocharis. We found significant increases in body size of rice frogs on most sampled islands in the Zhoushan archipelago when compared with neighbouring mainland China. 3. Large body size in rice frogs on islands was significantly related to increased population density, in both breeding and non-breeding seasons. Increases in rice frog density were significantly related to higher resource availability on islands. Increased resource availability on islands has led to higher carrying capacities, which has subsequently facilitated higher densities and individual growth rates, resulting in larger body size in rice frogs. We also suggest that large body size has evolved on islands, as larger individuals are competitively superior under conditions of harsh intraspecific competition at high densities. 4. Increases in body size in rice frogs were not related to several factors that have been implicated previously in insular shifts in body size in other taxa. We found no significant relationships between body size of rice frogs and prey size, number of larger or smaller frog species, island area or distance of islands from the mainland. 5. Our findings contribute to the formation of a broad, repeatable ecological generality for insular shifts in body size across a range of terrestrial vertebrate taxa, and provide support for recent theoretical work concerning the importance of resource availability for insular shifts in body size.     

The terrestrial vertebrates of the Bazaruto Archipelago,Mozambique: a biogeographical perspective

Abstract. Data on the birds, amphibians, reptiles and mammalian species of the Bazaruto Archipelago, Mozambique are presented. Species diversity was compared to island size and with data for other East African Islands. There was a low degree of endemism and the different faunas (particularly for mammals and the herpetofauna) were mainland in origin and a nested subset of that on the mainland. Several mammal and bird families were absent from the islands suggesting a process of relaxation on these relatively young islands with little colonization. Reasons for the observed diversity are discussed.     

Factors determining the number of land bird species on Islands around South-Western Australia

Summary New evidence from the passerine faunas of islands off Southwestern Australia agrees with the hypothesis that the passerine faunas of Australian and New Zealand islands are impoverished because most passerine species are poor colonizers. Dispersal of landbirds onto Carnac Island near Perth was infrequent, and many of those species that arrived were represented by single birds. Comparison of similarly structured island and mainland habitats showed that island habitats still have fewer passerine bird species than mainland habitats. Island bird faunas are more stable over short periods of time than over long periods; this is contrary to island avifaunas in the Northern Hemisphere.The following features typify the avifaunas of Australian islands: immigration of species of land birds occurs infrequently; (natural) extinction is rare; and the degree of saturation of the avifaunas is low. Without more direct evidence, competitive interactions should not be invoked to account for the species poverty of these insular avifaunas.     

Factors influencing vascular plant diversity on 22 islands off the coast of eastern North America

Aim The influence of physiographic and historical factors on species richness of native and non‐native vascular plants on 22 coastal islands was examined. Location Islands off the coast of north‐eastern USA and south‐eastern Canada between 41° and 45° N latitude were studied. Island size ranges from 3 to 26,668 ha. All islands were deglaciated between 15,000 and 11,000 yr bp ; all but the four New Brunswick islands were attached to the mainland until rising sea level isolated them between 14,000 and 3800 yr bp . Methods Island species richness was determined from floras compiled or revised since 1969. Simple and multiple regression and rank correlation analysis were employed to assess the relative influence of independent variables on species richness. Potential predictors included island area, latitude, elevation, distance from the mainland, distance from the nearest larger island, number of soil types, years since isolation, years since deglaciation, and human population density. Results Native vascular plant species richness for the 22 islands in this study is influenced most strongly by island area, latitude, and distance from the nearest larger island; richness increases with island area, but decreases with latitude and distance from the nearest larger island as hypothesized. That a similar model employing distance from the mainland does not meet the critical value of P confirms the importance of the stepping‐stone effect. Habitat diversity as measured by number of soil types is also an important predictor of native plant species richness, but at least half of its influence can be attributed to island area, with which it is correlated. Two historical factors, years since deglaciation and years since isolation, also appear to be highly correlated with native species richness, but their influence cannot be separated from that of latitude for the present sample size. Non‐native vascular plant species richness is influenced primarily by island area and present‐day human population density, although human population density may be a surrogate for the cumulative effect of several centuries of anthropogenic impacts related to agriculture, hunting, fishing, whaling, tourism, and residential development. Very high densities of ground‐nesting pelagic birds may account for the high percentage of non‐native species on several small northern islands. Main conclusions Many of the principles of island biogeography that have been applied to oceanic islands apply equally to the 22 islands in this study. Native vascular plant species richness for these islands is strongly influenced by physiographic factors. Influence of two historical factors, years since deglaciation and years since isolation, cannot be assessed with the present sample size. Non‐native vascular plant species richness is influenced by island area as well as by human population density; human population density may be a surrogate for other anthropogenic impacts.     

Nested distribution of amphibians in the Zhoushan archipelago, China: can selective extinction cause nested subsets of species?

Because of their poor dispersal ability, amphibians are well suited for testing the selective extinction theory on islands. Amphibian fauna in the Zhoushan archipelago, China, exhibit a high level of nestedness (C = 0.893), and the species number is lower on islands than on similar sized areas on the mainland. No correlation was found between island-specific species richness and the nearest distance from a larger island, distance from the mainland or density of human population. These results suggest that no amphibian colonisation has occurred in the archipelago since island isolation 7000–9000 years ago. Furthermore, the results imply that selective extinction contributes to the nestedness of amphibians in the Zhoushan archipelago. The incidence of a species on the islands is significantly correlated with log area of the smallest island occupied by the species and the number of provinces on the Chinese mainland in which the species occur. However, there is no correlation with average body length of adults and island occurrence. It is concluded that (1) the area of the smallest island occupied by a species is a good estimate of the minimum area for a viable population of the species and a good predictor of species incidence on islands, (2) species with a restricted distribution range are more vulnerable to extinction from islands than those with a wide distribution range and (3) the effect of body size on occurrence on the islands is uncertain, and may be specific to the archipelago and taxa studied. The observed nestedness of amphibian assemblages has two implications for conservation: (1) not only can all the species found in several small reserves be found on a large reserve of the same total size, but additional species can be found on the single large reserve; (2) for a reserve to maintain viable populations of all species in a region it should be at least as large as the smallest island occupied by the most vulnerable species. Received: 16 December 1996 / Accepted: 22 September 1997     

Phylogeography of the Japanese pipistrelle bat,Pipistrellus abramus,in China: the impact of ancient and recent events on population genetic structure

The influence of Pleistocene climatic oscillations on shaping the genetic structure of Asian biota is poorly known. The Japanese pipistrelle bat occurs over a wide range in eastern Asia, from Siberia to Japan. To test the relative impact of ancient and more recent events on genetic structure in this species, we combined mitochondrial (cytochrome b) and microsatellite markers to reconstruct its phylogeographic and demographic history on continental China and its offshore islands, Hainan Island and the Zhoushan Archipelago. Our mitochondrial DNA tree recovered two divergent geographical clades, indicating multiple glacial refugia in the region. The first clade was mainly confined to Hainan Island, indicating that gene flow between this population and the continent has been restricted, despite being repeatedly connected to the mainland during repeated glacial episodes. By contrast, haplotypes sampled on the Zhoushan Archipelago were mixed with those from the mainland, suggesting a recent shared history of expansion. Although microsatellite allele frequencies showed clear discontinuities across the sampling range, supporting the current isolation of both Hainan Island and the Zhoushan Archipelago, we also found clear evidence of more recent back colonization, probably via post‐glacial expansion or, in the latter case, occasional long distance dispersal. The results obtained highlight the importance of using multiple sets of markers for teasing apart the roles of ancient and more recent events on population genetic structure. © 2010 The Linnean Society of London, Biological Journal of the Linnean Society, 2010, 99 , 582–594.