珍稀濒危植物金丝李的生境特征及致濒原因分析

采取查阅资料、走访和实地调查相结合的方法,调查了金丝李(Garcinia paucinervis)的地理分布、生境和资源现状,对其分布区气候特征、土壤营养状况和群落植被等进行分析;采用主成分分析法,找出影响金丝李分布的主要环境因子与群落特征因子,并探讨金丝李的致濒原因,为金丝李种质资源的有效保护、引种驯化等提供科学依据。结果表明,(1)金丝李主要分布在广西西北部、西南部、南部和云南东南部的石灰岩岩溶地貌山地上,跨越北纬22°27′58″~25°9′10″、东经103°55′58″~108°40′3″,海拔在194~830 m之间,其中海拔200~400 m分布较为常见。大多分布点位于山体的中、下部,坡度多为35~45°,分布较集中,且多为生境保持良好之地,种群内个体一般不到100株,大树和有结实的植株极少。(2)金丝李多分布在年均温20~22℃范围地区内,性喜暖热、雨量充沛的环境,喜疏松、湿润的中性或微碱性石灰土,肥力中等以上。(3)金丝李群落植被状况良好,植物种类多样,桂西北的群落有亚热带性质;桂西南、桂南和滇东南的群落则富有热带性质。(4)金丝李在资源的竞争中难以取得优势地位;群落植被遭到破坏,生境受人为干扰严重;各种群在不同年龄层次断层,种子萌发率低,种群天然更新能力弱等为金丝李濒危的主要原因。     

江西三清山东亚-北美间断分布属植物缺萼枫香群落研究

通过对三清山缺萼枫香林群落的野外调查和分析,其结果表明,(1)该群落乔木分层明显,其中第1层高达20～25m,最高可达35m。年龄结构显示,主要优势种缺萼枫香处于衰退状态。(2)群落生活型以高位芽植物占绝对优势(75.38%),地上芽植物较多(21.54%),反映出该群落具有山顶群落特征。(3)重要值计算表明,各优势种的重要值比例为缺萼枫香(52.08%)、细叶青冈(34.14%)、猴头杜鹃(31.01%)、多脉青冈(24.95%)和红花油茶(20.63%),其相应的科所占比例为壳斗科(21.9%)、金缕梅科(17.36%)、山茶科(14.86%)及杜鹃花科(12.96%),在科属地理分布区类型上群落具有从热带向温带过渡的特征,热带性科占57.84%,温带性科占42.16%。(4)多样性指数以及频度分析表明,以Shannon-Wiener公式计算,其多样性指数为4.46,介于广东鼎湖山常绿阔叶林与江西中亚热带常绿阔叶林之间;频度值分析为A>B>CE,与Raunkiaer频度定律有一定差异。整体分析表明缺萼枫香群落是中亚热带地区典型的山地常绿落叶阔叶林群落。     

上海海湾国家森林公园1 hm2样地群落结构特征及其动态监测意义

运用生态系统定位监测方法,于2011年在上海市奉贤区海湾国家森林公园内设置面积为100 m×100 m的样地,记录样地内的所有植物种类,定位调查高于1.3m的木本植物,分析其种类组成、区系成分、垂直结构和水平结构.结果表明,1 hm2样地内共记录有维管束植物31科68属73种,其中温带区系成分占总属数的51.8％,热带区系成分占46.4％.高于1.3m的木本植株3 094株,其中常绿树种6种,共1 670株,重要值占48.0％;落叶树种7种,共1 424株,重要值占52.0％.女贞(Ligustrum lucidum)、喜树(Camptotheca acuminata)、椤木石楠(Photinia davidsoniae)、乌桕(Sapium sebiferum)、黄山栾树(Koelreuteria integrifoliola)和香樟(Cinnamomum camphora)的重要值位居前6位,在垂直空间上呈分层结构.在0～50 m尺度范围内,女贞种群均呈集群分布,喜树种群呈均匀-随机-集群分布,椤木石楠和乌桕种群表现为集群-随机-均匀分布,黄山栾树和香樟种群表现为随机-集群-随机分布.从群落结构特征看,样地为以北温带成分、泛热带成分为主的常绿落叶阔叶混交林,表征了该地区自然植被的结构特征.建立长期固定样地可为长三角城市化地区平原地貌上城市森林的发生、发展和演替规律提供长期的数据基础.     

浙江古田山濒危植物香果树群落组成和结构特征

香果树(Emmenopterys henryi)为中国特有的孑遗植物,国家Ⅱ级保护植物。参照CTFS(Center for Tropical Forest Science)固定样地的调查方法,对古田山自然保护区香果树野生群落的生境特点、物种组成、群落外貌、垂直结构、生物量、物种多样性以及种群动态等进行调查。结果表明,古田山香果树群落主要分布于海拔600~850 m的沟谷地带,生长地岩石裸露度较高,部分群落盖度较高。样地内共有维管植物47科、71属、89种,植物种类较为丰富,科属组成较为分散,壳斗科、山茶科和樟科的种类相对较多;从属的地理成分看,热带分布的属与温带分布的属的比例分别为51.47%和44.12%,体现了亚热带森林的植物区系特点。群落垂直结构较为明显,可分为乔木层、灌木层和草本层,并有一定数量的层间植物;乔木层、灌木层和草本层的物种多样性大小为乔木层灌木层草本层。香果树种群的年龄结构属稳定型,但物种个体总数较少,仍需注意加强保护。该研究可为古田山香果树群落的发生、发展和演替的深入研究提供基础数据,为古田山自然保护区香果树群落濒危机制探讨、有效保护和生态系统管理提供理论支持。     

古田山国家自然保护区针阔叶混交林植物物种多样性特征

利用样方法进行野外群落调查.共调查了6个样地,每个样地大小为20m×20 m,研究古田山自然保护区针阔叶混交林植物物种多样性特征.结果表明:古田山针阔混交林的科、属、种组成多样性较高,植物种类丰富.组成复杂.群落的属种多样性>科属多样性>科种多样性.从灌木层、乔木层至草本层物种多样性依次递减,乔木层和灌木层的物种多样性指数明显大于草本层物种多样性指数.     

威海市区黑松林群落分析的研究

根据威海市区黑松林的调查结果,分析了该群落的组成和结构特征。在11500m2的样地里有维管束植物105种,它们隶属于39科89属,其中被子植物37科;裸子植物1科;蕨类植物1科。该群落以单种科和寡种科占绝大多数,单种属有75种,占总数的71%,种数大于2的有13科,占总数的33%。该群落分为乔木层、灌木层及草本层3个层次,乔木层主要以黑松Pinusthunbergli、麻栎QuercusacutissimaCarr.等种类组成,灌木层主要以麻栎组成,草本层种类较少,以禾本植物为主。该群落中、高位芽植物占优势,缺乏隐芽植物。叶型以中、小型叶为主,缺乏大型叶植物。TWINSPAN将115个样方分为11个群落类型。调查结果表明本地区黑松林群落结构简单,不同黑松林群落结构差异较小,且物种丰富度低,是人为干扰强烈所致。     

长江口近岸鱼类种类组成及其多样性

根据2004年8月、11月和2005年2月(Ⅰ年度),2005年8月、11月和2006年2月、5月(Ⅱ年度),2007年8月、11月和2008年2月、5月(Ⅲ年度)共3个水文年对长江口近岸水域(121°32.08′～122°11.65′E,31°19.58′～31°38′N)15个取样站点11个航次的底拖网调查样品,对该水域的鱼类种类组成、生物量、丰度、优势种、生物多样性的时间和空间动态变化进行了分析.结果表明:调查水域共出现鱼类13目24科39属42种,鲈形目种类(18种)最多,其次为鲱形目(5种)和鲤形目(4种),种类组成有明显的季节变化,夏季种类数最多,冬季最少;生物量和丰度年度和季节变化明显,平均值分别为8.10 g(100 m2)-1和1.25 ind(100 m2)-1,鱼类生物量和丰度均呈显著下降趋势(Ⅲ年度Ⅱ年度Ⅰ年度),季节变化趋势为夏季春季秋季冬季;生物多样性指数以夏季最高,春季最低,且有下降的趋势;优势种的种类与优势度季节和年度间有较大的变化,造成这种趋势的主要原因可能是与棘头梅童鱼(Collichthys lucidus)和凤鲚(Coilia mystus)的繁殖和索饵洄游有关.     

天津新港区潮间带沉积物细菌群落结构

利用PCR-DGGE技术对天津新港潮间带(东经117°45′11.4"～45′12.4",北纬39°2′42.8"～3′14.6")沉积物中的细菌群落组成和优势菌群进行了调查,通过Quantity One软件分析不同样品的DGGE图谱,发现9个站位的细菌种类、数量和多样性都存在明显差别,表明该潮间带细菌群落的空间异质性...     

浙江古田山自然保护区青冈林植物物种多样性研究

分析了浙江古田山自然保护区青冈林的植物区系组成和群落物种多样性。结果表明，8个样地中共有维管束植物147种(含变种)，隶属51科92属。其中蕨类植物5科7属14种，裸子植物1科1属1种，被子植物45科84属132种。青冈林植物区系成分复杂，具有较高的热带成分比例。群落科、属、种组成多样性较高，植物种类丰富，组成复杂。群落垂直结构中，物种多样性依灌木层→乔木层→草本层的次序递减，乔木层、灌木层的物种多样性指数明显大于草本层。     

西双版纳勐养山地雨林群落生态学研究

依据5个25m×20m样地的调查,对西双版纳勐养热带山地雨林的群落结构、种类组成、生活型构成、多样性、种面积关系等进行了研究.结果显示,勐养山地雨林主要由茜草科、桃金娘科、肉豆蔻科、樟科、大戟科等植物种类组成,以黄棉木(Metadina trichotoma)、华夏蒲桃(Syzygium cathayense)、假广子(Knema erratica)及山桂花(Paramicheliabaillonii)为乔木优势种;群落乔木层以中叶、全缘、革质、尾尖、常绿植物占优势,灌草层植物则以中叶、全缘、纸质叶植物为主;藤本植物中以木质藤本占优势,板根和茎花现象少见.各种性质表明该群落是西双版纳较为典型的山地雨林群落类型,可命名为黄棉木-华夏蒲桃林.图1表5参22     

Achieving Open Access to Conservation Science

Conservation science is a crisis discipline in which the results of scientific enquiry must be made available quickly to those implementing management. We assessed the extent to which scientific research published since the year 2000 in 20 conservation science journals is publicly available. Of the 19,207 papers published, 1,667 (8.68%) are freely downloadable from an official repository. Moreover, only 938 papers (4.88%) meet the standard definition of open access in which material can be freely reused providing attribution to the authors is given. This compares poorly with a comparable set of 20 evolutionary biology journals, where 31.93% of papers are freely downloadable and 7.49% are open access. Seventeen of the 20 conservation journals offer an open access option, but fewer than 5% of the papers are available through open access. The cost of accessing the full body of conservation science runs into tens of thousands of dollars per year for institutional subscribers, and many conservation practitioners cannot access pay‐per‐view science through their workplace. However, important initiatives such as Research4Life are making science available to organizations in developing countries. We urge authors of conservation science to pay for open access on a per‐article basis or to choose publication in open access journals, taking care to ensure the license allows reuse for any purpose providing attribution is given. Currently, it would cost $51 million to make all conservation science published since 2000 freely available by paying the open access fees currently levied to authors. Publishers of conservation journals might consider more cost effective models for open access and conservation‐oriented organizations running journals could consider a broader range of options for open access to nonmembers such as sponsorship of open access via membership fees. Obtención de Acceso Abierto a la Ciencia de la Conservación     

Some polyphagous Homoptera gain protection from their natural enemies by feeding on the toxic plantsSpartium junceum andErythrina corallodendrum (Leguminosae)

Summary Interactions were studied among alkaloid-containing legumes (Erythrina corallodendrum andSpartium junceum) and non-toxic plants (Citrus sinensis, Cucurbita moschata andEuphorbia tirucalli), several polyphagous homopterans,Aphis craccivora (Aphididae),Icerya purchasi, I. aegyptiaca (Margarodidae),Lepidosaphes ulmi (Diaspididae) andPlanococcus citri (Pseudococcidae), and some major natural enemies of these homopterans. Significant reductions in survival due to negative effects of alkaloid containing as compared with non-alkaloidal plants were recorded for the predatorsRodolia cardinalis andChilocorus bipustulatus, but not forCryptolaemus montrouzieri (Coleoptera: Coccinellidae),Chrysoperla carnea (Neuroptera: Chrysopidae) andSympherobius sanctus (Neuroptera: Sympherobiidae). The development time of the larvae or pupae ofR. cardinalis, C. carnea andS. sanctus was longer on the toxic plants than on the non-toxic ones. The percentage of parasitism ofA. craccivora collected from the non-alkaloidal plantsVicia palaestina andMelilotus albus was much higher than that onS. junceum. The parasitoid complexes ofA. craccivora differed between both plant groups. The nutritive value of honeydew ofI. purchasi andA. craccivora, as expressed by the life span ofEncyrtus infelix (Hymenoptera: Encyrtidae) adults, was also investigated. Life spans were significantly longer when the wasps fed on honeydew produced on non-alkaloidal plants (C. sinensis andPittosporum tobira) than on alkaloid containing plants whenI. purchasi — but notA. craccivora — was the producer. It is suggested that the chemical defense ofE. corallodendrum andS. junceum is exploited by polyphagous phytophages to reduce predation. In nature, population growth and density of four of the investigated homopterans are conspicuously high when they developed on the alkaloid containing plant species, and very low on non-alkaloid plants. The efficiency of their natural enemies may be reduced by sequestration of alkaloids (or other toxic plant compounds) or their transfer into excreted honeydew. Therefore it is assumed that a generalist phytophagous homopteran may be protected from its natural enemies, although at different rates of efficiency, if it can safely sequester the host allelochemical when it develops on toxic species within its host range.     

Rapid,recurring, structured survey versus bioblitz for generating biodiversity data and analysis with a multispecies abundance model

A bioblitz inexpensively and quickly generates biodiversity data, but bioblitzes are often conducted with haphazard, unreplicated sampling. Results tend to be taxonomically, geographically, or temporally biased, lack metadata, and consist of lists of observed taxa that do not enable further analyses or correction for imperfect detection. A rapid, recurring, structured survey (RRSS) uses a structured sampling design and temporal and spatial replication to survey randomly selected sites on a conservation property. We participated in a loosely structured bioblitz and a subsequent RRSS at Big Canoe Creek Nature Preserve in Springville (St. Clair County), Alabama (USA) to compare observed richness derived from the 2 survey approaches. The RRSS data structure enabled us to fit models that accounted for imperfect detection to estimate abundances, occupancy probabilities, and habitat associations. The loosely structured bioblitz data could not be used in such models. We present a new integrated multispecies abundance model that we applied to avian RRSS data. Our model extension enables estimation for the community, employs data augmentation to estimate the number of undetected species, and incorporates covariates. The RRSS generated a more comprehensive and less biased list of observed taxonomic richness than the loosely structured bioblitz (e.g., 73 vs. 45 bird species and 104 vs. 63 insect families from the RRSS vs. loosely structured bioblitz, respectively). Models fit to the RRSS data identified seasonal patterns in avian community composition and allowed for estimation of habitat–occupancy relationships for insect taxa. The RRSS protocol has potential for broad transferability as a standardized, quick, and inexpensive way to inventory biodiversity and estimate ecological parameters while providing an outreach opportunity.     

Compliance with and ecosystem function of biodiversity offsets in North American and European freshwaters

Land-use change via human development is a major driver of biodiversity loss. To reduce these impacts, billions of dollars are spent on biodiversity offsets. However, studies evaluating offset project effectiveness that examine components such as the overall compliance and function of projects remain rare. We reviewed 577 offsetting projects in freshwater ecosystems that included the metrics project size, type of aquatic system (e.g., wetland and creek), offsetting measure (e.g., enhancement, restoration, and creation), and an assessment of the projects’ compliance and functional success. Project information was obtained from scientific and government databases and gray literature. Despite considerable investment in offsetting projects, crucial problems persisted. Although compliance and function were related to each other, a high level of compliance did not guarantee a high degree of function. However, large projects relative to area had better function than small projects. Function improved when projects targeted productivity or specific ecosystem features and when multiple complementary management targets were in place. Restorative measures were more likely to achieve targets than creating entirely new ecosystems. Altogether the relationships we found highlight specific ecological processes that may help improve offsetting outcomes.     

Sequestration of cucurbitacin analogs by New and Old World chrysomelid leaf beetles in the tribe Luperini

Summary Two South American polyphagous leaf beetles,Diabrotica speciosa andCerotoma arcuata, selectively accumulated the bitter tasting compound 23,24-dihydrocucurbitacin D in their body after ingesting root tissues of cucurbit plants. Similarly, three Asian Cucurbitaceae-feeding specialists in the genusAulacophora were found to sequester the same compound. Cucurbitacin analogs were shown to deter feeding by a bird predator, indicating an allomonal role for these compounds in cucurbitacin-associated chrysomelid leaf beetles both of New and Old Worlds. The strong affinity to cucurbitacins, selective sequestration of the analogs and consequent protection from predators suggested an ecological adaptation mechanism developed in common among these two geographically isolated subtribes in the Luperini.     

Effects of Controlled Fire and Livestock Grazing on Bird Communities in East African Savannas

Abstract: In East Africa fire and grazing by wild and domestic ungulates maintain savannas, and pastoralists historically set fires and herded livestock through the use of temporary corrals called bomas. In recent decades traditional pastoral practices have declined, and this may be affecting biodiversity. We investigated the effects of prescribed fires and bomas on savanna bird communities in East Africa during the first and second dry seasons of the year (respectively before and after the rains that mark the onset of breeding for most birds). We compared abundance, richness, and community composition on 9‐ha burned plots, recently abandoned bomas, and control plots in the undisturbed matrix habitat over a 3‐year period. Generally, recently burned areas and abandoned bomas attracted greater densities of birds and had different community assemblages than the surrounding matrix. The effects of disturbances were influenced by interactions between primary productivity, represented by the normalized difference vegetation index, and time. Bird densities were highest and a greater proportion of species was observed on burned plots in the months following the fires. Drought conditions equalized bird densities across treatments within 1 year, and individuals from a greater proportion of species were more commonly observed on abandoned bomas. Yearly fluctuations in abundance were less pronounced on bomas than on burns, which indicate that although fire may benefit birds in the short term, bomas may have a more‐lasting positive effect and provide resources during droughts. Several Palearctic migrants were attracted to burned plots regardless of rainfall, which indicates continued fire suppression may threaten their already‐declining populations. Most notably, the paucity of birds observed on the controls suggests that the current structure of the matrix developed as a result of fire suppression. Traditional pastoralism appears critical to the maintenance of avian diversity in these savannas.     

A palaeo-hydrogeological model for arsenic contamination in southern and south-east Asia

An argument is presented in which areas of natural arsenic contamination of modern groundwaters throughout Asia have a common origin. Arsenic originally accumulated in oceanic ferro-manganoan sediments of the eastern Palaeo-Tethys. This was further concentrated through oceanic crustal extinction in what later became the south-east Chinese accreted mineralised terrain. Proto-Himalayan uplift of this area created the palaeo-drainage systems of the Ganges – Brahmaputra, Irrawaddy, Mekong, and Red Rivers, with consequent headwater erosion of arsenic-rich sediments. Their downstream deposition as immature and easily redistributed Neogene sandstones, silts, and iron-rich clays has created secondary and tertiary reservoirs of adsorbed and authigenic arsenic, from which the current arsenic-rich groundwaters have evolved. Considering river basins within the above palaeo-hydrogeological framework provides a basis for assessing the risk of arsenic in groundwater basins of south and south-eastern Asia.     

Threats to intact tropical peatlands and opportunities for their conservation

Large, intact areas of tropical peatland are highly threatened at a global scale by the expansion of commercial agriculture and other forms of economic development. Conserving peatlands on a landscape scale, with their hydrology intact, is of international conservation importance to preserve their distinctive biodiversity and ecosystem services and maintain their resilience to future environmental change. We explored threats to and opportunities for conserving remaining intact tropical peatlands; thus, we excluded peatlands of Indonesia and Malaysia, where extensive deforestation, drainage, and conversion to plantations means conservation in this region can protect only small fragments of the original ecosystem. We focused on a case study, the Pastaza‐Marañón Foreland Basin (PMFB) in Peru, which is among the largest known intact tropical peatland landscapes in the world and is representative of peatland vulnerability. Maintenance of the hydrological conditions critical for carbon storage and ecosystem function of peatlands is, in the PMFB, primarily threatened by expansion of commercial agriculture linked to new transport infrastructure that is facilitating access to remote areas. There remain opportunities in the PMFB and elsewhere to develop alternative, more sustainable land‐use practices. Although some of the peatlands in the PMFB fall within existing legally protected areas, this protection does not include the most carbon‐dense (domed pole forest) areas. New carbon‐based conservation instruments (e.g., REDD+, Green Climate Fund), developing markets for sustainable peatland products, transferring land title to local communities, and expanding protected areas offer pathways to increased protection for intact tropical peatlands in Amazonia and elsewhere, such as those in New Guinea and Central Africa which remain, for the moment, broadly beyond the frontier of commercial development.     

What Every Conservation Biologist Should Know about Economic Theory

Abstract: The last century has seen the ascendance of a core economic model, which we will refer to as Walrasian economics. This model is driven by the psychological assumptions that humans act only in a self‐referential and narrowly rational way and that production can be described as a self‐contained circular flow between firms and households. These assumptions have critical implications for the way economics is used to inform conservation biology. Yet the Walrasian model is inconsistent with a large body of empirical evidence about actual human behavior, and it violates a number of basic physical laws. Research in behavioral science and neuroscience shows that humans are uniquely social animals and not self‐centered rational economic beings. Economic production is subject to physical laws including the laws of thermodynamics and mass balance. In addition, some contemporary economic theory, spurred by exciting new research in human behavior and a wealth of data about the negative global impact of the human economy on natural systems, is moving toward a world view that places consumption and production squarely in its behavioral and biophysical context. We argue that abandoning the straightjacket of the Walrasian core is essential to further progress in understanding the complex, coupled interactions between the human economy and the natural world. We call for a new framework for economic theory and policy that is consistent with observed human behavior, recognizes the complex and frequently irreversible interaction between human and natural systems, and directly confronts the cumulative negative effects of the human economy on the Earth's life support systems. Biophysical economics and ecological economics are two emerging economic frameworks in this movement.     

Effects of Coffee Management on Deforestation Rates and Forest Integrity

Knowledge about how forest margins are utilized can be crucial for a general understanding of changes in forest cover, forest structure, and biodiversity across landscapes. We studied forest‐agriculture transitions in southwestern Ethiopia and hypothesized that the presence of coffee (Coffea arabica)decreases deforestation rates because of coffee's importance to local economies and its widespread occurrence in forests and forest margins. Using satellite images and elevation data, we compared changes in forest cover over 37 years (1973–2010) across elevations in 2 forest‐agriculture mosaic landscapes (1100 km² around Bonga and 3000 km² in Goma‐Gera). In the field in the Bonga area, we determined coffee cover and forest structure in 40 forest margins that differed in time since deforestation. Both the absolute and relative deforestation rates were lower at coffee‐growing elevations compared with at higher elevations (?10/20% vs. ?40/50% comparing relative rates at 1800 m asl and 2300–2500 m asl, respectively). Within the coffee‐growing elevation, the proportion of sites with high coffee cover (>20%) was significantly higher in stable margins (42% of sites that had been in the same location for the entire period) than in recently changed margins (0% of sites where expansion of annual crops had changed the margin). Disturbance level and forest structure did not differ between sites with 30% or 3% coffee. However, a growing body of literature on gradients of coffee management in Ethiopia reports coffee's negative effects on abundances of forest‐specialist species. Even if the presence of coffee slows down the conversion of forest to annual‐crop agriculture, there is a risk that an intensification of coffee management will still threaten forest biodiversity, including the genetic diversity of wild coffee. Conservation policy for Ethiopian forests thus needs to develop strategies that acknowledge that forests without coffee production may have higher deforestation risks than forests with coffee production and that forests with coffee production often have lower biodiversity value. Efectos de la Administración Cafetalera sobre las Tasas de Deforestación y la Integridad de los Bosques