物种保护的理论基础——从岛屿生物地理学理论到集合种群理论

全球面临着生境破碎化的危机,物种保护已成为人类面临的重大课题,并不是所有的人对岛屿生物地理学理论的产生及其关注的海洋岛屿都很熟悉,但是越来越多生物赖以生存的自然栖息地的丧失和破碎化都是有目共睹的,岛屿生物地理学和集合种群理论是目前物种保护的两个基本理论,物种迁入率和绝灭率的动态变化决策岛屿上的物种丰富度是岛屿生物地理学理论的核心内容,而集合种群理论关注的是局部种群之间个体迁移的动态以及物种的续存条件,在概述两个理论形成、发展及其核心内容的基础上,着重比较它们的异同点以及在生态学理论和实践中的应用,并论述物种保护理论范式从岛屿生物地理学向集合种群理论转变的基本背景和原因。     

岛屿生物地理学理论：模型与应用

前言岛屿有许多显著特征,如地理隔离,生物类群简单。这些特点为重复性研究和统计学分析奠定了基础,从而有利于许多深入而细致的生物学研究。因此,岛屿为发展和检验自然选择、物种形成及演化,以及生物地理学和生态学诸领域的理论和假设,提供了重要的自然实验室。岛屿生物地理学理论(MacArthurwilson学说)即为岛屿生物学研究中所产生的著名理论之一。该理论发展之     

Evaluation of terrestrial plants extracts for uranium sorption and characterization of potent phytoconstituents

Sorption capacity of four plants (Funaria hygrometrica, Musa acuminata, Brassica juncea and Helianthus annuus) extracts/fractions for uranium, a radionuclide was investigated by EDXRF and tracer studies. The maximum sorption capacity, i.e., 100% (complete sorption) was observed in case of Musa acuminata extract and fractions. Carbohydrate, proteins, phenolics and flavonoids contents in the active fraction (having maximum sorption capacity) were also determined. Further purification of the most active fraction provided three pure molecules, mannitol, sorbitol and oxo-linked potassium oxalate. The characterization of isolated molecules was achieved by using FTIR, NMR, GC-MS, MS-MS, and by single crystal-XRD analysis. Of three molecules, oxo-linked potassium oxalate was observed to have 100% sorption activity. Possible binding mechanism of active molecule with the uranyl cation has been purposed.     

Diversity of non-native terrestrial arthropods on woody plants in Canada

A list of non-native phytophagous insects and mites on woody plants (trees, shrubs, vines) in Canada was compiled using information from literature and input from taxonomists. The 419 recorded species include Hemiptera (53% of species), Lepidoptera (22%), Coleoptera (13%) and Hymenoptera (9%). Almost all species originate from the Palearctic, especially Europe, reflecting historical trade patterns. About 41% of species were directly introduced to Canada from countries of origin, and the remainder spread from the United States of America (USA) after initial establishment there. Major ports on the east and west coasts, on Lake Erie and Lake Ontario are the main points of entry for exotic species directly introduced, and southern British Columbia (BC), Ontario (ON) and Quebec (QC) are the major points of entry for species spreading from the USA. Consequently, BC, ON, QC and Nova Scotia have the highest diversity of non-native species, and the prairie provinces and northern territories have the lowest. The extent of the distribution of individual species is related to length of time in Canada, number of introductions and dispersal abilities. Almost all native woody plant genera in Canada have been invaded by exotic phytophages. The large majority of phytophages occur on angiosperms. Woody plant genera with the largest distribution, highest species diversity and highest local abundances tend to host the greatest number of non-native species, including Picea, Pinus, Malus, Prunus, Salix, Betula, Quercus, Pyrus and Populus. The arrival rate of species in Canada increased from the late nineteenth century until about 1960, and declined rapidly thereafter. Quarantine legislation enacted in the USA in 1912 and in Canada in 1976 seems to have reduced the rate of insect invasion. Electronic supplementary material  The online version of this article (doi:) contains supplementary material, which is available to authorized users.     

微囊藻毒素对陆生植物的污染途径及累积研究进展

微囊藻毒素(Microcystins,MCs)是全世界范围内普遍存在、且随着水体污染的加剧而在自然环境中大量积聚的蓝藻毒素之一,对多种生物有着严重的毒性作用.MCs在生物体内富集并通过食物链传递,对人类健康造成威胁.近些年,MCs对陆生植物的毒害作用及累积研究尤为引人关注,取得了一批重要的研究成果.MC-LR(L为亮氨酸)和MC-RR(R为精氨酸)是淡水水体中普遍存在且危害较大的两种MCs异构体.针对这两种毒素,重点介绍其对陆生植物的污染途径、毒性作用及其在作物体内的累积量,对今后的研究进行了展望.     

温州沿海小型海岛植物丰富度和β多样性及其影响因子

于2012-2015年调查了温州沿海20个小型无居民海岛的植物组成,共记录到维管束植物366种,隶属于95科244属,其中草本植物226种木本植物140种。拟合了5个种-面积关系模型,采用赤池信息量AIC对模型进行选择,发现种-面积-生境类型关系模型SAH_nR权重系数最大,为40.26%,两种断点回归种-面积关系模型BR-SAR权重系数分别仅为6.94%和0.43%,表明基于这20个海岛拟合的种-面积关系不存在小岛屿效应。岛屿植物物种丰富度主要受面积A影响,离大陆距离,I_m对丰富度无显著作用;偏相关分析表明除A外,周长/面积比PAR和岛屿生境多样性指数H_d显著影响了植物丰富度,其逐步回归方程分别为:植物总丰富度S=76.714+1.696A-0.046PAR,R~2=0.839;木本植物丰富度S_(-woody)=6.525+0.455A+24.544H_d,R~2=0.697;草本植物丰富度S_(-herbaceous)=66.899+1.285A-0.04PAR-23.434H_d,R~2=0.865。偏最小二乘回归PLS分析中岛屿空间特征参数对岛屿物种相似性指数重要性排序为:I_m(0.61)I_i(0.56)PAR(0.49)A(0.20)岸线长度Per(0.14)生境类型H(0.072)岛屿高程E(0.065)岛屿形状指数SI(0.05)。由此可见,近岸的小型海岛植物丰富度并不总是由岛屿面积来决定;隔离度对岛屿植物β多样性影响较大。     

Allometric scaling of maximum population density: a common rule for marine phytoplankton and terrestrial plants

A primary goal of macroecology is to identify principles that apply across varied ecosystems and taxonomic groups. Here we show that the allometric relationship observed between maximum abundance and body size for terrestrial plants can be extended to predict maximum population densities of marine phytoplankton. These results imply that the abundance of primary producers is similarly constrained in terrestrial and marine systems by rates of energy supply as dictated by a common allometric scaling law. They also highlight the existence of general mechanisms linking rates of individual metabolism to emergent properties of ecosystems.     

Alternative causes for range limits: a metapopulation perspective

All species have limited distributions at broad geographical scales. At local scales, the distribution of many species is influenced by the interplay of the three factors of habitat availability, local extinctions and colonization dynamics. We use the standard Levins metapopulation model to illustrate how gradients in these three factors can generate species' range limits. We suggest that the three routes to range limits have radically different evolutionary implications. Because the Levins model makes simplifying assumptions about the spatial coupling of local populations, we present numerical studies of spatially explicit metapopulation models that complement the analytical model. The three routes to range limits give rise to distinct spatiotemporal patterns. Range limits in one species can also arise because of environmental gradients impinging upon other species. We briefly discuss a predator–prey example, which illustrates indirect routes to range limits in a metacommunity context.     

A niche for biology in species distribution models

Why species are found where they are is a central question in biogeography. The most widely used tool for understanding the controls on distribution is species distribution modelling. Species distribution modelling is now a well‐established method in both the theoretical and applied ecological literature. In this special issue we examine the current state of the art in species distribution modelling and explore avenues for including more biological processes in such models. In particular we focus on physiological, demographic, dispersal, competitive and ecological‐modulation processes. This overview highlights opportunities for new species distribution model concepts and developments, as well as a statistical agenda for implementing such models.     

The prehistory and biogeography of terrestrial vertebrates on Guam, Mariana Islands

Aim By establishing a prehistoric fossil record for the vertebrate fauna of Guam, we can document the composition of the island’s fauna prior to Western contact. It will also complement the extensive prehistoric fossil data already known from the nearby islands of Rota, Tinian and Aguiguan, and improve our understanding of natural distributional patterns through a chronologically deeper view of the biogeography of the Mariana Islands. Location Northern Guam, Mariana Islands, Micronesia. Methods Fossil‐bearing sediment was removed from karst features with vertically and horizontally controlled excavation methods. Age determinations of the fossils were estimated by radiocarbon dating associated wood charcoal samples. Results The 3314 bones (fossils) of terrestrial vertebrates date to the past two millennia and represent 34 species. Among 12 species of squamate reptiles, one is extinct (a gekkonid lizard) and another, the monitor lizard, Varanus indicus, was introduced to Guam no later than about 1600 years ago. The 17 species of birds feature five that are extinct. Two others not recorded previously on Guam are extirpated. Eight others were lost on Guam in historic times. We also recovered bones of two species of indigenous bats, (Pteropus sp., extirpated; Emballonura semicaudata, probably extirpated), and non‐native rodents, (Rattus spp.). Main conclusions Guam’s contemporary faunal losses have been well documented since invasion of the Brown Treesnake (Boiga irregularis) during or shortly after WWII. Other exotics, as well as habitat deterioration, have abetted this snake’s deleterious presence. Our data further show that human impact led to declines or losses of vertebrate populations by late prehistoric times. Numerous anthropogenic extirpations would not be evident without studying fossils. Our chrono‐stratigraphic evidence argues for the arrival of non‐native rats (Rattus sp.) only about 1000 years ago, which helps to explain why a flightless rail survived on Guam into modern times, unlike on most other islands in Oceania.     

江苏海岸带陆生盐土植物矿质元素含量的特点及生物循环

陆生盐土植物在生长过程中吸收积累了大量的Cl和Na;从海向陆随着土壤和植被的生态演替,植物中Cl和Na的浓度逐渐降低;N与Cl、Na有相似的水平分布规律;植物种类是影响元素吸收积累的主要因素。在盐地碱蓬中N、P、K、Ca、Mg、Na、Cl、Mn和Zn的含量均是生长前期较高,随着其生长老化逐渐降低,大穗结缕草、白茅与盐地碱蓬相比,Ca的含量前期低后期高,Na、Mn、Cu和Zn的季节变化不明显。参加盐地碱蓬系统生物循环的元素中,Cl和Na的比例最大,在大穗结缕草和白茅生态系统中比例较小;由于白茅被收割利用,一些元素从此生态系统中流失。     

Using niche-based modelling to assess the impact of climate change on tree functional diversity in Europe

Rapid anthropogenic climate change is already affecting species distributions and ecosystem functioning worldwide. We applied niche-based models to analyse the impact of climate change on tree species and functional diversity in Europe. Present-day climate was used to predict the distributions of 122 tree species from different functional types (FT). We then explored projections of future distributions under one climate scenario for 2080, considering two alternative dispersal assumptions: no dispersal and unlimited dispersal. The species-rich broadleaved deciduous group appeared to play a key role in the future of different European regions. Temperate areas were projected to lose both species richness and functional diversity due to the loss of broadleaved deciduous trees. These were projected to migrate to boreal forests, thereby increasing their species richness and functional diversity. Atlantic areas provided an intermediate case, with a predicted reduction in the numbers of species and occasional predicted gains in functional diversity. This resulted from a loss in species within the broadleaved deciduous FT, but overall maintenance of the group. Our results illustrate the fact that both species-specific predictions and functional patterns should be examined separately in order to assess the impacts of climate change on biodiversity and gain insights into future ecosystem functioning.     

Nestedness and migratory status of avian assemblages in North America and Europe

We examine patterns of nestedness and species incidence for the resident and migrant components of avifaunas in North America and Europe. While all assemblages were significantly nested, there were no significant differences between North American and European avifaunas overall in nestedness or incidence. Residents did not differ from migrants in their adherence to a nested distribution, but did exhibit significantly higher incidences when continental affiliation was ignored.¶We develop a new nestedness index that examines each species' relative contribution to an assemblage's overall pattern of nestedness. The relative nestedness index exhibits a quadratic relationship with incidence such that species with low incidences and species with high incidences generally increase the overall level of nestedness, while species with intermediate incidence tend to decrease nestedness.     

Anagenetic evolution in island plants

Aim  Plants in islands have often evolved through adaptive radiation, providing the classical model of evolution of closely related species each with strikingly different morphological and ecological features and with low levels of genetic divergence. We emphasize the importance of an alternative (anagenetic) model of evolution, whereby a single island endemic evolves from a progenitor and slowly builds up genetic variation through time.
Location  Continental and oceanic islands.
Methods  We surveyed 2640 endemic angiosperm species in 13 island systems of the world, both oceanic and continental, for anagenetic and cladogenetic patterns of speciation. Genetic data were evaluated from a progenitor and derivative species pair in Ullung Island, Korea, and Japan.
Results  We show that the anagenetic model of evolution is much more important in oceanic islands than previously believed, accounting for levels of endemic specific diversity from 7% in the Hawaiian Islands to 88% in Ullung Island, Korea, with a mean for all islands of 25%. Examination of an anagenetically derived endemic species in Ullung Island reveals genetic (amplified fragment length polymorphism) variation equal or nearly equal to that of its continental progenitor.
Main conclusions  We hypothesize that, during anagenetic speciation, initial founder populations proliferate, and then accumulate genetic variation slowly through time by mutation and recombination in a relatively uniform environment, with drift and/or selection yielding genetic and morphological divergence sufficient for the recognition of new species. Low-elevation islands with low habitat heterogeneity are highly correlated with high levels of anagenetic evolution, allowing prediction of levels of the two models of evolution from these data alone. Both anagenetic and adaptive radiation models of speciation are needed to explain the observed levels of specific and genetic diversity in oceanic islands.     

Vulnerability of terrestrial island vertebrates to projected sea‐level rise

Sea‐level rise (SLR) from global warming may have severe consequences for biodiversity; however, a baseline, broad‐scale assessment of the potential consequences of SLR for island biodiversity is lacking. Here, we quantify area loss for over 12 900 islands and over 3000 terrestrial vertebrates in the Pacific and Southeast Asia under three different SLR scenarios (1 m, 3 m and 6 m). We used very fine‐grained elevation information, which offered >100 times greater spatial detail than previous analyses and allowed us to evaluate thousands of hitherto not assessed small islands. Depending on the SLR scenario, we estimate that 15–62% of islands in our study region will be completely inundated and 19–24% will lose 50–99% of their area. Overall, we project that between 1% and 9% of the total island area in our study region may be lost. We find that Pacific species are 2–3 times more vulnerable than those in the Indomalayan or Australasian region and risk losing 4–22% of range area (1–6 m SLR). Species already listed as threatened by IUCN are particularly vulnerable compared with non‐threatened species. Under a simple area loss–species loss proportionality assumption, we estimate that 37 island group endemic species in this region risk complete inundation of their current global distribution in the 1 m SLR scenario that is widely anticipated for this century (and 118 species under 3 m SLR). Our analysis provides a first, broad‐scale estimate of the potential consequences of SLR for island biodiversity and our findings confirm that islands are extremely vulnerable to sea‐level rise even within this century.     

Persistence, extinction and different species pools within the flora of lake islands in western Ireland

The vascular flora on twenty-nine lake islands in Lough Corrib, western Ireland was surveyed in 1992–93. Thirteen of these islands had been surveyed by the author in 1974 (Roden, 1979). Data on species–area curves and species turnover between 1974 and 1992 are presented. Species numbers on each island did not change greatly in the 18-year interval and extinctions were most common on smaller islands. It is known that six of the islands surveyed are less than 150 years old and their flora must have immigrated over open water during that period. It is shown that this group of species has a different log species/log area regression than the remaining flora, with a much shallower slope (low Z value). The proportion of less widespread species was greatest on islands nearest to the mainland. The implication of different slopes in different species groups and the restriction of turnover to rare species is discussed with reference to the island Theory of Biogeography.     

A note on simplifying likelihoods for site occupancy models

We show how a simple reparameterization can reduce the number of parameters that need to be estimated by numerical maximum likelihood in site occupancy models. Three examples are provided.