长山列岛发现黄嘴白鹭的繁殖种群

:1 999年 6～ 8月 ,在辽宁省长海县石城乡形人岛 (N30°31′,E1 2 3°0 2′)发现了目前已知国内最大的黄嘴白鹭繁殖种群 ,约 4 0 0余只。黄嘴白鹭于 4月份迁至该岛繁殖 ,巢材由蒿子杆构成 ,每窝产 4～ 6枚卵 ,卵为淡青色。 1 4枚卵平均大小为 4 8 5( 46 0～ 50 5)mm× 34 0 ( 31 0～ 36 5)mm ,平均重量为 2 8 3( 2 7 5～ 2 9 0 ) g。孵化期 2 1～ 2 3天     

Bone cadmium and lead in the ancient population from El Hierro, Canary Islands

This study was performed to determine the levels of lead (Pb) and cadmium (Cd) in 63 bone samples of the prehispanic population of the island El Hierro, comparing them with the values obtained on 98 prehispanic samples from Tenerife, Fuerteventura, Gran Canaria, and La Palma, all of them in the Canary Islands, and with eight modern samples who served as controls. Prehispanic individuals from El Hierro showed the lowest bone Pb values of all the archipelago (0.72±1.01 mg/kg), significantly different (F=6.9, p<0.001) from the values obtained for the population of other islands such as Tenerife (4.87±5.36 mg/kg) or Fuerteventura (4.45±7.85 mg/kg) and also from those of the modern population (30.53±14.62 mg/kg). On the other hand, bone Cd, although slightly lower in the ancient population groups, was not significantly different when compared with the modern one. In addition, no differences were observed in bone Cd among the ancient population of the different islands. Bone lead—but not cadmium—kept an inverse significant relationship with the distance of the burial site both to south Spain (r=−0.31) and Atlantic Morocco (r=−0.28, p<0.001 in both cases).     

Species richness, environmental heterogeneity and area: a case study based on land snails in Skyros archipelago (Aegean Sea, Greece)

Aim To test the performance of the choros model in an archipelago using two measures of environmental heterogeneity. The choros model is a simple, easy‐to‐use mathematical relationship which approaches species richness as a combined function of area and environmental heterogeneity. Location The archipelago of Skyros in the central Aegean Sea (Greece). Methods We surveyed land snails on 12 islands of the archipelago. We informed the choros model with habitat data based on natural history information from the land snail species assemblage. We contrast this with habitat information taken from traditional vegetation classification to study the behaviour of choros with different measures of environmental heterogeneity. R² values and Akaike's information criterion (AIC) were used to compare the choros model and the Arrhenius species–area model. Path analysis was used to evaluate the variance in species richness explained by area and habitat diversity. Results Forty‐two land snail species were recorded, living in 33 different habitat types. The choros model with habitat types had more explanatory power than the classic species–area model and the choros model using vegetation types. This was true for all islands of the archipelago, as well as for the small islands alone. Combined effects of area and habitat diversity primarily explain species richness in the archipelago, but there is a decline when only small islands are considered. The effects of area are very low both for all the islands of the archipelago, and for the small islands alone. The variance explained by habitat diversity is low for the island group as a whole, but significantly increases for the small islands. Main conclusions The choros model is effective in describing species‐richness patterns of land snails in the Skyros Archipelago, incorporating ecologically relevant information on habitat occupancy and area. The choros model is more effective in explaining richness patterns on small islands. When using traditional vegetation types, the choros model performs worse than the classic species–area relationship, indicating that use of proxies for habitat diversity may be problematic. The slopes for choros and Arrhenius models both assert that, for land snails, the Skyros Archipelago is a portion of a larger biogeographical province. The choros model, informed by ecologically relevant habitat measures, in conjunction with path analysis points to the importance of habitat diversity in island species richness.     

Distribution and sediment production of large benthic foraminifers on reef flats of the Majuro Atoll,Marshall Islands

The distributions and population densities of large benthic foraminifers (LBFs) were investigated on reef flats of the Majuro Atoll, Marshall Islands. Annual sediment production by foraminifers was estimated based on population density data. Predominant LBFs were Calcarina and Amphistegina, and the population densities of these foraminifers varied with location and substratum type on reef flats. Both foraminifers primarily attached to macrophytes, particularly turf-forming algae, and were most abundant on an ocean reef flat (ORF) and in an inter-island channel near windward, sparsely populated islands. Calcarina density was higher on windward compared to leeward sides of ORFs, whereas Amphistegina density was similar on both sides of ORFs. These foraminifers were more common on the ocean side relative to the lagoon side of reef flats around a windward reef island, and both were rare or absent in nearshore zones around reef islands and on an ORF near windward, densely populated islands. Foraminiferal production rates varied with the degree to which habitats were subject to water motion and human influences. Highly productive sites (>10³ g CaCO₃ m⁻² year⁻¹) included an ORF and an inter-island channel near windward, sparsely populated islands, and a seaward area of a reef flat with no reef islands. Low-productivity sites (<10 g CaCO₃ m⁻² year⁻¹) included generally nearshore zones of lagoonal reef flats, leeward ORFs, and a windward ORF near densely populated islands. These results suggest that the distribution and production of LBFs were largely influenced by a combination of natural environmental factors, including water motion, water depth, elevation relative to the lowest tidal level at spring tide, and the distribution of suitable substratum. The presence of reef islands may limit the distribution and production of foraminifers by altering water circulation in nearshore environments. Furthermore, increased anthropogenic factors (population and activities) may adversely affect foraminiferal distribution and production.     

Cospeciation of figs and fig-wasps: a case study of endemic species pairs in the Ogasawara Islands

The interactions between figs (Ficus, Moraceae) and fig-wasps (Agaonidae, Chalcidoidea, Hymenoptera) are special plant-pollinator relationships that are highly species-specific, in that each fig species is pollinated by a single fig-wasp species that can breed only in that particular fig species. This study examined the degree of pre-mating isolation and genetic differentiation for three fig/fig-wasp pairs endemic to the Ogasawara Islands. Simple Y-tube tests revealed that fig-wasps from Ficus nishimurae and Higashidaira type chose their own host figs significantly more often, while fig-wasps from F. boninsimae did not. Based on RAPD markers, the genetic differentiation among the fig species was low, but F. boninsimae formed a cluster within the F. nishimurae cluster. The Higashidaira type has been derived from a subpopulation of F. nishimurae. Five mitochondrial DNA haplotypes were found in the fig-wasps and each haplotype correlated well with the fig species on their island of origin. These results led to a three-step hypothesis on the cospeciation process: (1) spatial separation of fig/fig-wasp populations arises; (2) gene flow is restricted and character differentiation of fig-wasps occurs; (3) there is further restriction of gene flow and genetic and character differentiation of figs.     

西沙群岛主要岛屿鸟类和小型兽类群落调查研究

对海岛动物资源的本底调查和研究,可为更好地保护海洋和海岛生态系统提供重要的依据。2018年4月-2019年12月,利用样线法、铗夜法等对西沙群岛东岛、永兴岛等岛屿的鸟类、小型兽类资源进行了4次调查,结合历史记录数据对其物种组成和多样性变化进行了分析。调查共记录到小型兽类3种,臭鼩（Suncus murinus）见于林灌丛,褐家鼠（Rattus norvegicus）和黄胸鼠（R.flavipectus）见于房舍区;共记录到鸟类13目26科65种,其中国家Ⅱ级重点保护动物4种,新记录到鸟类29种;广布型鸟类34种,古北界鸟类20种,东洋界鸟类11种;冬候鸟28种,留鸟23种,旅鸟6种,夏候鸟5种,迷鸟3种;东岛鸟类物种数高于永兴岛,但多样性和均匀度均较低;雨季物种丰富度、多样性和均匀度均高于旱季;东岛为国家Ⅱ级重点保护动物红脚鲣鸟（Sula sula）中国唯一的繁殖地,应加强保护。与1974年和2005年报道的数据对比,本次调查记录的鸟类物种丰富度最高,留鸟物种数最多。结果反映西沙群岛小型兽类种类较少,主要分布在房舍区及其附近的林灌从;暗示小型兽类带入、扩散等可能与人为活动相关,其生态效应予以重视和长期监测。西沙群岛鸟类物种有丰富度较高、候鸟占比高、季节和年份间差异明显、留鸟物种数有所增加、为红脚鲣鸟唯一的繁殖地等特点。西沙群岛生态系统的完整性,对候鸟和留鸟的保护,尤其是红脚鲣鸟的保护十分重要,应予以重视。     

无居民海岛开发生态损害评估——以象山县大羊屿岛为例

无居民海岛独特的生态系统和地理位置决定了受损后的修复成本极高、开发难度极大,其保护与开发已经成为国内外学界关注的重点。基于海岛生态系统服务价值理论构建了无居民海岛开发的生态损害评估模型,以我国首个公开拍卖使用权的大羊屿岛为例验证模型的科学性和可行性,并与2018年调整后的无居民海岛使用金征收标准中生态损害成本额度进行对比分析。研究结果表明：（1）大羊屿岛开发的生态损害补偿金为1644.82万元。其中,陆域开发行为所需的生态损害补偿金为890.19万元,高于海洋开发行为所造成的生态损害补偿金;（2）通过本文计算的海岛陆域生态损害补偿金高出现行海岛使用金标准中的生态损害成本371.90万元,2018年旅游用岛使用金征收标准仍有上调空间。对无居民海岛开发的生态损害评估可以增强政府和企业对于海岛资源的保护意识,重新权衡无居民海岛开发的利弊,避免对海岛资源过度和盲目的开发。     

Differential representation of human skeletal remains in eroded and redeposited coastal deposits: A case study from the Marshall Islands

A historical cemetery on Majuro Atoll, Republic of the Marshall Islands, was partially washed away during an exceptional seasonal high tide. The osteological analysis of the human remains washed out by the tides showed that the anatomical representation of the bones found on the shoreline is distinctly skewed, caused by the erosion of the graves by wave action and the differential transport of bones by waves and currents. The two major factors involved in the observed differential preservation of skeletal elements appear to be (i) the overall weight of the bone and (ii) its ability to float. Light-weighted bones, such as the phalanges, or heavily spongiotic bones, such as vertebrae and patellae, float easily and — by wave and tidal action — can be carried out to sea, leaving the heavier bones, such as femora, tibiae, or non-floating bones, such as the crania and mandibles, behind.     

The population ecology of Rattus exulans on Tiritiri Matangi Island,and a model of comparative population dynamics in New Zealand

Abstract

On Tiritiri, a small predator-free island in northern New Zealand, kiore (Rattus exulans) were live and snap trapped in grassland and forest. In both habitats, kiore abundance peaked in late summer/autumn. The increase followed a 3 month breeding season during which females produced two to three litters, each averaging 7 young. During the population decline in autumn and winter, animals lost weight. Few bred in the breeding season of their birth and none lived to breed in a second breeding season, so the population consisted of distinct age cohorts. These patterns may relate to a highly seasonal food supply.

Kiore elsewhere in New Zealand show seasonal breeding, but the length of breeding, sexual maturation, and litter size vary. Other studies of kiore in the Pacific show less marked seasonal fluctuations, longer breeding seasons, and smaller litters. We propose a model to explain the variation in rodent demography in New Zealand. The model is based on the seasonal availability of food, along with the modifying influences of predation and dispersal.     

High Islands Versus Low Islands: A Comparison of Fish Faunal Composition of the Palau Islands

High islands, with potentially greater habitat diversity, are expected to have greater species richness and diversity compared to low islands, typically atolls and coral islands of lower habitat diversity, within the same geographical area. Patterns of species similarity, richness, and diversity were compared among coral reef fishes between the low island of the Southwest Palau Islands (SWPI), and the low and high islands of the Main Palauan Archipelago (MPA). Data from diurnal visual transects accounted for approximately 64% and 69% of the shorefish faunas known from the SWPI and MPA, respectively. Two distinct fish faunas were representative of low and high islands. The first was confined to the coral islands of the SWPI. The second was partitioned into both low and high islands of the MPA, and Helen Reef, a large atoll in the SWPI. The second type was clustered into atolls, low islands with atoll-like barrier reef systems, a coral island, and three high island systems, one with an extensive barrier reef system. Contrary to the prediction that high islands, with relatively greater habitat diversity, would have greater species richness and diversity, species richness and diversity were greatest at Kossol, a large atoll-like low island locality at the northern end of a high island in the MPA, followed by two atolls, Kayangel (MPA, north of Kossol) and Helen Reef. In contrast, species richness and diversity were lower at high island localities and lowest at small coral islands. These results suggest that habitat diversity for reef fishes increases as a function of increasing area regardless of whether the locality is a high or low island.     

Bacterial Genomic Islands: Organization,Function, and Evolutionary Role

Data on the structural organization and evolutionary role of specific bacterial DNA regions known as genomic islands are reviewed. Emphasis is placed on the most extensively studied genomic islands, pathogenicity islands (PAIs), which are present in the chromosome of Gram-negative and Gram-positive pathogenic bacteria and absent from related nonpathogenic strains. PAIs are long DNA regions that harbor virulence genes and often differ in GC content from the remainder of the bacterial genome. Many PAI occur in the tRNA gene loci, which provide a convenient target for foreign gene insertion. Some PAI are highly homologous to each other and contain sequences similar to ISs, phage att sites, and plasmid ori sites, along with functional or defective integrase and transposase genes, suggesting horizontal transfer of PAI among bacteria.     

Genetic study of the population of Tenerife (Canary Islands,Spain): Protein markers and review of classical polymorphisms

Data on six protein polymorphisms (19 alleles) from the human population of Tenerife are presented and discussed along with other classical markers in relation to the origin of the Canarians. Genetic influences from three population groups were considered: the Iberians, and the Berbers and non-Berbers (Arabs) from north Africa. The systems examined show the Tenerife population lies within the limits of variation described for various Iberian groups, with a slight tendency towards the characteristics of north African populations. When blood groups, red cell enzymes and serum protein data were considered, the similarity of the Canary population to Iberians seems strengthened (70% estimated contribution of Iberian peninsula genes to the present-day Canarian pool), while some relation with north African groups is shown. Genetic distances between Canarians and Arabs and Canarians and Berbers are lower than those between the two north African groups, indicating a relative and comparable contribution of each to the present-day gene pool of the Canarian population. The Arab contribution could be attributable to the slaves who were introduced to these islands after the conquest in the 15th century, while the Berber contribution could be the remnants of the extinct aboriginal peoples of the islands (Guanches) or a more recent immigration due to slavery. Genetic data do not allow us to distinguish between these two possibilities. Am. J. Phys. Anthropol. 102:337–349, 1997. © 1997 Wiley-Liss, Inc.     

Rodents and their predators in the eastern Bay of Islands

Abstract

Traps were set for rodents and mustelids on five islands (Motukiekie, Moturua, Okahu, Urupukapuka, and Waewaetorea) in the eastern Bay of Islands in March 1984. Kiore (Rattus exulans) were caught on Moturua Island and Norway rats (R. norvegicus) on all five islands, but no mustelids were caught or seen. Kiore on Moturua Island were very scarce compared with other northern offshore islands, perhaps because of competition from Norway rats and the presence of stoats and cats. Kiore were breeding and young matured in the season of their birth. Norway rats were scarce and found mainly near the shoreline on four of the islands. On Waewaetorea Island they were plentiful and widespread despite the possible presence of stoats. About a third of the mature females were visibly pregnant. Average litter size was 6.9 embryos, and 44% of the parous females had borne two or three litters. Females first ovulated at 180 ± 5 g weight and 356 ± 5 mm total length on average. Males first produced sperm at 189 ± 7 g weight and 364 ± 4 mm total length. Most rats matured before reaching a tooth-wear age index of 5.     

Island incidence and mainland population density: mammals from Mediterranean islands

Abstract. The reasons why some species are resistant to extinction or are better invaders of islands than others remain unexplained. In this study, we test the hypothesis that mammals living on the mainland at higher density than predicted by the density/body mass relationship have a much greater chance to colonize a small island successfully, and/or that they are less likely to become extinct when living on small islands. For this, we used data compiled on mammals from a number of Mediterranean islands. We show a nested pattern for mammals on western Mediterranean islands, which suggests that the distribution of mammals on these islands is not the result of a random process. Using two comparative methods, we show that mammal density on the mainland, corrected for body mass, is negatively correlated with island size. Mammals with a high density compared to the density/mass relationship are the best invaders and/or probably have less chance of going extinct on small islands when population size is small.     

大穗型小麦产量形成过程中光合特性的动态变化

在大田条件下,对8个大穗型小麦新品系和多穗型品种西农979(对照)的产量性状以及不同生育期叶片光合速率、叶绿素荧光参数、叶绿素含量(Chl)和叶面积指数(LAI)进行研究.结果表明：除单位面积穗数低于对照外,8个新品系的穗粒数、穗粒重和千粒重均显著高于对照,大穗型小麦新品系2036、2037、2038、2039和2040的产量显著高于对照;8个新品系的平均光合速率(P_n)与对照差异不显著,而PSⅡ最大光能转换效率、PSⅡ实际量子效率、光化学猝灭系数和PSⅡ反应中心活性均高于对照;品系2037、2040、2039、2038和2036的Chl比对照分别提高17.5%、19.1%、15.3%、13.9%和7.9%;大穗型小麦品系的LAI明显高于对照,且在生育后期下降缓慢.     

Evaluation of sustainable land management in urban area: A case study of Shanghai,China

With the accelerating urbanization process, there is an increasing shortage of land resource. It leads to an increasingly serious conflicts between built-up areas and other types of land use. This will further hinder city sustainable development. To address the issue, this paper takes urban land management sustainability as the study object and puts forward an evaluation method on sustainable land management (SLM) in urban area. First, four aspects of sustainable land management are proposed, namely economic progress, social stability, urban improvement and ecological balance. Second, a system with fourteen indicators is built according to the aspects. Third, using the indicators, the sub-performance and the overall efficiency of SLM are evaluated with the technique for order preference by similarity to ideal solution (TOPSIS) based on entropy weight. After that, the proposed method is applied to a case study of Shanghai, China. The results show the time series changing of SLM performance from 2000 to 2011 and reveal an unbalanced development path among the four aspects of SLM. Accordingly, policy recommendations are proposed to improve the sustainable land management efficiency. Therefore, it demonstrates that the proposed evaluation method can be used to reveal to what extend the urban land use is reasonable and sustainable and provides guidance on government urban land planning and policy making. Consequently, it helps to improve the land use efficiency and ease the land use conflict.     

Life history and population dynamics of a tree species in tropical semi‐arid climate: A case study with Cordia oncocalyx

In semi‐arid climates, plant population dynamics are strongly influenced by the amount and temporal distribution of rainfall. We monitored a population of the tree species Cordia oncocalyx (Boraginaceae) for 24 months in the dry thorny woodland of semi‐arid northeastern Brazil, to investigate which life‐history traits allow this tree to be locally dominant. We used horizontal life tables and a Lefkovitch matrix and tested for relationships among demographic parameters of seedling, infant, juvenile, immature, virginile and reproductive ontogenetic stages with rainfall and canopy openness. Germination and recruitment occurred in the rainy months, and dry‐season mortality occurred only in seedlings (76% and 100%, first and second years, respectively) and infants (3% and 6%). Juveniles showed greater height growth under more open canopies (Spearman correlation coefficient = 0.24), suggesting that light availability influences growth. The population growth rate was λ = 1.0336, and the highest sensitivity occurred in the infant‐juvenile transition. Our results show light as a restrictive growth factor for plants in the juvenile stage and confirm the strong influence of rainfall on the dynamics of trees in a seasonally dry environment. The formation of a persistent seed bank with germination concentrated at the rainfall onset but spreading over the rainy season are strategies that hedge bets before establishment. The formation of a bank of infants, which can resume growth as soon as there is water, hedges bets after establishment. We attribute the positive population growth rate of Cordia oncocalyx to survival strategies allowing bet‐hedging both before and after establishment.     

基于空间扩张互侵过程的土地生态安全动态评价——以(中国)苏锡常地区为例

从景观单元水平过程出发,通过采用生态用地和建设用地两种不同源空间扩张互侵过程的方法,提出了以分区形式的土地生态安全动态评价方法。以快速城市化苏锡常地区为研究区域,分别以生态系统服务价值高的水域和林地及建设用地现状为扩张源,生态系统服务价值和生态风险值为阻力赋值依据,在模拟不同生态安全格局水平和城市发展模式的基础上测算互侵结果并进行区划。结果表明:1)不同城市发展模式下建设用地空间扩张随生态用地从底线到满意到理想水平变化呈空间集聚收敛趋势;生态用地呈似圈层状空间集聚趋势。2)城市发展模式对土地生态安全水平具有显著影响;高等级源优先发展模式下土地资源利用更集约。3)将研究区划分为生态核心区(面积占比35.27%)、生态安全区(29.07%)、缓冲区(7.76%)及建设区(27.90%),提出相应土地用途管制措施。探讨了新方法不足和未来研究方向。     

Genetic diversity and population size: island populations of the common shrew, Sorex araneus

Populations of many species are currently being fragmented and reduced by human interactions. These processes will tend to reduce genetic diversity within populations and reduce individual heterozygosities because of genetic drift, inbreeding and reduced migration. Conservation biologists need to know the effect of population size on genetic diversity, as this is likely to influence a population's ability to persist. Island populations represent an ideal natural experiment with which to study this problem. In a study of common shrews (Sorex araneus) on offshore Scottish islands, 497 individuals from 13 islands of different sizes and 6 regions on the mainland were trapped and genotyped at eight microsatellite loci. Previous genetic work had revealed that most of the islands in this study were highly genetically divergent from one another and the mainland. We found that most of the islands exhibited lower genetic diversity than the mainland populations. In the island populations, mean expected heterozygosity, mean observed heterozygosity and mean allelic richness were significantly positively correlated with log island size and log population size, which were estimated using habitat population density data and application of a Geographic Information System.