Estimating population size in the subdesert mesite (Monias benschi): new methods and implications for conservation

The subdesert mesite, a terrestrial non-passerine bird endemic to the Mikea Forest of southwest Madagascar, is currently classified as globally threatened (category: Vulnerable). However, accurate assessment of threat in accordance with the IUCN Red List criteria (A, B and C) requires data on effective population size, area of habitat occupied and rate of decline, none of which is available for this species. Here we present the first empirical estimates of its population size using five complementary methods, three incorporating data on territory size and two using data gathered during call-playback surveys conducted throughout its entire global range. Estimates vary from 98,000 to 152,000 individuals, with the most reliable possibly being that generated by distance sampling (115,000). This figure is more than an order of magnitude greater than the only published estimate of <10,000 individuals. By analysing data on forest cover change, we estimate the population of the subdesert mesite to have declined by, at most, 10% in three generations. Although the rate of deforestation in 1994-1999 is double that calculated for 1962-1994, it is deemed unlikely that the population will decline by 20% over the next three generations. As such the species fails to meet criterion A. Although the subdesert mesite's range and area of occupancy are small, they are not fragmented and do not comprise fewer than 10 locations. Consequently, this species does not meet criterion B. Further, the species fails to meet criterion C, for which a maximum of 10,000 mature adults is required. According to IUCN (2000 Red List of Threatened Species) this species should therefore be downlisted in status. We discuss why it still warrants conservation attention and suggest the need for modifications to the criteria thresholds in relation to basic information about the ecology and taxonomic distinctness of species.     

Freshwater crabs and the biodiversity crisis: Importance, threats, status, and conservation challenges

Freshwater ecosystems in the tropics host a diverse endemic fauna including freshwater crabs, but the rapid loss and deterioration of habitat means that many species are now under imminent threat. Studies on freshwater fish and amphibians suggest a third to half of the species in some tropical freshwaters is either extinct or endangered, but the status of the freshwater crabs is not known. Freshwater crabs, with 1280 species, represent one-fifth of all the World’s brachyurans. We therefore undertook a comprehensive IUCN Red List assessment of the freshwater crabs, which was the first time that such a study had been attempted on a global scale for any group of freshwater invertebrates. The conservation status of all known species from the Americas, Africa, Europe, Asia, and Australasia revealed unexpectedly high threat levels. Here we show that about one-sixth of all freshwater crab species have an elevated risk of extinction, only one-third are not at-risk, and although none are actually extinct, almost half are too poorly known to assess. Out of 122 countries that have populations of freshwater crabs, 43 have species in need of protection. The majority of threatened species are restricted-range semi-terrestrial endemics living in habitats subjected to deforestation, alteration of drainage patterns, and pollution. This is illustrated with a case study of one such species found in Singapore. This underlines the need to prioritize and develop conservation measures before species decline to levels from which they cannot recover. The proportion of freshwater crabs threatened with extinction is equal to that of reef-building corals, and exceeds that of all other groups that have been assessed except for amphibians. These results represent a baseline that can be used to design strategies to save the World’s threatened freshwater crab species.     

Using remote sensing to inform conservation status assessment: Estimates of recent deforestation rates on New Britain and the impacts upon endemic birds

Remote sensing is increasingly used by policy-makers and conservationists to identify conservation priorities and changes in land cover. This is particularly important in the biodiverse tropics, where there are often few field data. Conservation action is often directed towards areas containing globally threatened species, but there have been few attempts to improve assessments of species’ extinction risk through remote sensing. Here, in a novel approach we use deforestation estimates, measured through satellite imagery, to assess the conservation status of an entire endemic avifauna, based on IUCN Red List criteria. The island of New Britain, east of New Guinea, is of very high global conservation importance, and home to 37 endemic or restricted-range bird species. Analysis suggests 12% of forest cover was lost between 1989 and 2000, including over 20% of forest under 100 m altitude, with substantial areas cleared for commercial oil palm plantations. Application of the IUCN Red List criteria to these new data on area of remaining forest and rates of deforestation indicates that many species are more threatened than previously realised, with the total number of threatened or near threatened species increasing from 12 to 21. Thus, this study highlights the urgency of establishing and effectively managing protected areas in suitable lowland forests of New Britain. More broadly, it demonstrates another potential of remote sensing to assist strategic conservation decisions.     

Seed germination and conservation of endangered species from the Italian Alps: Physoplexis comosa and Primula glaucescens

Physoplexis comosa and Primula glaucescens, endemic to calcareous grasslands of the Lombardy Prealps, northern Italy, are protected under Annex IV of European Community Directive 92/43/EEC. Seed germination dynamics of these species were studied with the aim of producing appropriate germination protocols for use in ex situ conservation. Seeds were collected from Monte Barro (922 m a.s.l.) and for Primula glaucescens from three additional sites in a more central part of its range (1217-2521 m a.s.l.). Physoplexis comosa germinated only in sterile in vitro conditions, in which germination percentages were extremely low without a supply of gibberellic acid (GA3; 1.7%); the optimum GA3 concentration was 100 mg l⁻¹ (> 90% germination), with lower germination at higher doses of 250-500 mg l⁻¹. Primula glaucescens germinated in both sterile and non-sterile conditions and, although total germination was not affected by GA3 concentration, doses of 10-500 mg l⁻¹ acted equally to prompt earlier and more rapid germination. Primula glaucescens from Monte Barro was characterised by slower and poorer germination than from central sites.     

Prey density, prey detectability and food habits: the case of Bonelli’s eagle and the conservation measures

In the diet of raptors the presence of prey-species is influenced by their abundance and the ground-level vegetation in territories, this situation being analysed for the Bonelli’s eagle (Hieraaetus fasciatus) in south-eastern Spain. First, the minimum number of prey-items for the reliability of results was tested, obtaining between 15 and 30 prey-items depending of pair. Second, differences in prey frequency and productivity among pairs was analysed, finding an interpair shift in both variables, but there was no relationship between the frequency of prey-species in the diet and productivity. Third, it was found that the percentage of European wild rabbit in the diet was less correlated with its abundance in territories than with the surface of open land in the same. This suggests that accessibility to rabbits would be more important for the Bonelli’s eagle that the absolute abundance of this prey type. Thus, open land is the single variable selected by a multiple multiple-regression analysis explaining the frequency of rabbits in this raptor’s diet. Birds as prey complemented the diet when open-land scarcity in the territories implies low rabbit detectability and consumption. Conservation measures proposed concerning the increase of prey availability in this declining population should consider both the absolute prey density and prey detectability, avoiding extensive reforestation in territories and favouring vegetation structure suitable for prey detection by eagles.     

Geographic differentiation of morphological traits and isozymes in the Mediterranean island endemic Anchusa crispa: implications for the conservation of a protected species

Understanding population differentiation and genetic diversity within population is critical to the development of conservation programmes for threatened species. The protected species, Anchusa crispa Viv. occurs on coastal sand dunes in three disjunct geographical groups of populations: two populations on the east coast of Corsica, several populations around a single estuary on the west coast of Corsica and at a number of sites in north-west Sardinia, where two different subspecies occur. In this study we quantify differentiation of reproductive traits and isozymes among regions and populations on Corsica and between subspecies on Sardinia. No isozyme variation was detected within any of the studied populations nor among populations from a given geographic region. Two loci showed geographic differentiation between regions on Corsica. On Sardinia, the two subspecies showed no isozyme differentiation, and, depending on the loci examined, are similar to one or other of the two regions on Corsica. Reproductive traits show significant differentiation between geographic regions on Corsica, but little variation among populations within a region. In populations on the west coast of Corsica, flowers are small and have a stigma situated at the same level as the apex of the anthers whereas on the east coast, flowers are larger and have the stigma below the anthers. On Sardinia, A. crispa subsp. crispa has a floral morphology similar to the Corsican plants, whereas subspecies maritima has larger flowers with the stigma positioned above the anthers (approach-herkogamy). Quantitative variation in floral morphology thus agrees with the separation of two taxonomic entities on Sardinia and geographic variation in reproductive traits and isozymes has important ramifications for the sampling of populations for conservation programmes.     

中国科学院遗传与发育生物学研究所农业资源研究中心的研究热点与研究方向变化分析——基于文献计量学分析方法

采用中国知网(CNKI)和Web of Science核心合集(Wo S)两大数据库的文献计量分析工具,统计分析了中国科学院遗传与发育生物学研究所农业资源研究中心(以下简称"农业资源研究中心")创建40年来科技论文发表情况,从文献角度,分析农业资源研究中心的研究基础、研究热点和研究趋势的变化历程。共检索到论文2 052篇,中文文献1 467篇、英文文献585篇。论文发文总量呈逐年增长趋势,前20年以中文论文为主,2005年达到峰值,之后出现回落的趋势,但年发文量基本保持在50篇左右。2002年以后,英文论文呈快速增长态势,2003—2017年以26.85%的年均增长率增加。被CNKI引用≥50次的论文有118篇,被Wo S引用≥50次的论文有44篇。中文论文发表在235种期刊上,英文论文发表在237种期刊上;发文量前10的中文来源刊平均影响因子1.022,英文来源刊平均影响因子3.411。论文的资助基金主要来源是中国科学院知识创新工程基金、国家自然科学基金、国家重点基础研究发展计划(973计划)、国家高技术研究发展计划(863计划)、国家科技支撑计划等。国际合作基金项目呈逐年上升趋势,资助基金机构达到73个,出现频率较多的是中国科学院的国际合作项目、澳大利亚国际农业研究中心基金、国家留学基金和欧共体基金等。合作研究机构主要集中在河北、北京、山东、山西等地。与国外合作的研究单位主要集中在美国、日本、荷兰、澳大利亚、丹麦、巴基斯坦等国家。Cite Space关键词共现分析显示,创建初期农业资源研究中心的研究内容少且较分散,体现在关键词数量少、相互联系弱。之后,研究主题不断增多,2000年左右达到峰值,关键词之间联系逐渐紧密。研究作物以小麦、玉米为主,研究区域集中在华北平原。目前气候变化的大背景下,研究内容主要集中于作物栽培、育种与分子生物学,农业水资源及其利用,农田生态系统及其碳、氮循环,及盐碱地土壤、水和植物的利用等方面。总之,农业资源研究中心在过去40年的发展中,取得了显著的研究成果,研究水平不断提高,形成了鲜明的研究特色。     

福建旅游型海岛水土保持措施研究——以妈祖圣地湄洲岛为例

 旅游型海岛作为福建重要的旅游目的地,以独特旅游景观和旅游环境得到旅游者的青睐,但旅游开发不当引发的水土流失加剧影响了海岛旅游景观质量和环境质量,必须引起高度重视。以湄洲岛为例,分析湄洲岛水土流失现状及对旅游发展的影响,提出福建旅游型海岛水土保持原则和植物、工程、政策、技术等6方面具体的水土保持措施,努力实现"旅游促水保、水保促旅游"的良性循环。