中国后生耳蕨组和新生耳蕨组（耳蕨属）的叶表皮解剖研究

利用光学显微镜对国产耳蕨属后生耳蕨组和新生耳蕨组３１个种４０个样品成熟叶表皮的细胞的形态特征的研究结果表明，后生耳蕨组和新生耳蕨组植物的气孔均分布在叶片下表皮，为气孔多形型，气孔基本类型有四细胞型和极型两种；气孔的类型、大小、气孔指数、表皮细胞形状等有一定的稳定性，可以作为后生耳蕨组和新生耳蕨组植物系统与分类研究的依据之一．     

濒危植物邢氏水蕨和海南岛水蕨叶绿体序列rbcL比较及隐种分析

2021年,水蕨属（Ceratopteris）所有植物包括邢氏水蕨（C. shingii）、水蕨（C. thalictroides）和粗梗水蕨（C. pteridoides）被列为国家二级重点保护野生植物。水蕨属植物是研究植物性别决定、配子体形态建成以及遗传学、细胞生物学和生物化学等学科的模式植物之一,也是中国重要的野生水生植物种质资源。隐种（Cryptic species）问题已经成为系统分类研究、物种形成机制、生物进化和基于保护目的的种群遗传研究及保护计划共同关注的重要问题。基于叶绿体rbcL序列评价邢氏水蕨和海南岛陵水黎族自治县白水岭（BSL）、陵水黎族自治县木号镇（BJC）、海口城西镇（SPSK）等3个新发现的水蕨种群叶绿体序列rbcL的差异及系统发育关系,分析新发现尚未被评价的3个水蕨种群的隐种类型,为水蕨属不同物种和隐种的保护及利用提供科学依据。结果表明,邢氏水蕨和3个种群水蕨的rbcL序列长度为1 227 bp,邢氏水蕨有2个变异位点,分别在783 bp处和1 164 bp处。采用邻近法（NJ）构建了水蕨属叶绿体rbcL系统发育树。系统发育树显示BSL、BJC、SPSK等...     

乌毛蕨凝集素的部分性质

乌毛蕨的叶片经PBS抽提和硫酸铵沉淀，得到的粗蛋白经活性碳柱处理后，在分子筛层析柱Sephadex G-100上纯化得到一种凝集素(Blechnum Orientale Lectin，简称BOL)，BOL的比活性比粗提液提高了32倍，活力回收率达75％，在PAGE上显示一条蛋白染色带，而在SDS-PAGE上显示BOL由两个不同的亚基组成，亚基分子量分别为16600和22910．BOL是一种糖蛋白，其中性糖含量为20．06％．其分子中含有Mg和Ca两种金属元素，含量分别为0．08％和0．70％．BOL对温度变化敏感，其凝血活性能被N-乙酰葡萄糖胺所抑制，用滤纸圆片法检测，BOL在测试的8种菌中对大肠杆菌和玉米大斑病菌的生长有抑制作用，图4表5参13     

新记录的水蕨种群特征和群落的物种多样性

近几十年来,由于人类活动的影响,水蕨在我国的分布范围和种群数量正日趋减少,濒临灭绝,现被列为国家二级重点保护野生植物.根据标本记载和相关研究资料,于2003年8月至2006年10月,对分布在我国热带和亚热带的濒危植物水蕨进行广泛的野外调查.在每一调查点,用全球定位系统(GPS)测定了各样点的经纬度,记录了其生境特征和种群的生长状况,采集和鉴定水蕨及其主要伴生种,研究了其群落的结构特征.结果发现濒危植物水蕨的7个分布新记录.它们分别位于云南勐腊县郊区和勐仑、广东英德和阳春、浙江临安、海南三亚以及湖南郴州.新发现的水蕨种群主要生长在稻田或废弃稻田、水沟、菜地、旅游区.与水蕨相伴生的物种主要有11科15属17种,分别隶属于7个群丛.人类活动是导致水蕨濒危的主要原因.凭证标本均保存于武汉大学植物标本馆.     

EDTA对波士顿蕨吸收Hg的影响及其光合响应

采用水培实验方法研究EDTA对波士顿蕨吸收和转移Hg的影响,以及波士顿蕨对Hg及Hg和EDTA胁迫下光合系统II(PSII)的响应.结果显示:波斯顿蕨的根部能富集Hg,加入EDTA可以提高Hg从其根部转移到地上部分.单独Hg处理略微抑制了叶绿素的合成,Hg或Hg与EDTA处理对叶绿素的合成没有明显的影响.Hg或Hg与EDTA对植物的光合作用产生一定程度的胁迫作用.Hg单独处理或Hg与EDTA一起处理都导致了植物光合效能指数下降,干扰光系统II中的能量转移,将部分反应中心被转化为能耗中心,在一定程度上抑制了光系统II中的电子传递.     

低浓度二噁英抑制青鳉幼鱼耳泡生成与SOX9b相关联

2,3,7,8-四氯二苯并对二恶英(2,3,7,8-Tetrachlorodibenzo-p-Dioxin,TCDD)是一种持久性环境有机污染物质,它在有机体内的蓄积性引起研究人员的重视。以青鳉胚胎作为实验动物模型,使用原位杂交和定量聚合酶链锁反应(Polymerase Chain Reaction,PCR)技术从分子水平探讨了TCDD对胚胎耳泡的发育及其毒性作用机制。结果表明,TCDD造成青鳉幼鱼耳泡生成障碍。通过原位杂交和q PCR分析表明,TCDD引起软骨发育的变化与SOX9b表达降低有密切的关联。研究认为青鳉胚胎是一种非常敏感的TCDD模式动物,其耳泡软骨发育以及SOX9b基因表达可能是一种二恶英发育毒性的效应标记物。     

退耕还林后圪针耳流域的土地承载力

山西省中阳县圪针耳流域土地承载力计算结果表明 ,流域内 1 5°以上坡地应全部退耕还林 ,人均基本口粮田不能低于 0 .0 66hm2 ;退耕还林后流域内极限土地承载力为 2 80 2人 ,大于预测人口数量。退耕还林后宜农地生产能保证粮食安全 ,并能使退耕地退得下、稳得住     

不同海拔高度短穗兔耳草克隆生长及克隆繁殖特征

研究了青藏铁路和青藏公路沿线 5个不同海拔高度样地中短穗兔耳草克隆生长和克隆繁殖的特征.结果表明,不同海拔高度短穗兔耳草匍匐茎数量、匍匐茎长度、基株干重、匍匐茎干重和无性系分株干重等均存在极显著差异(P<0. 01);匍匐茎数量与海拔高度之间存在明显的负线性相关性(P=0. 046 4);匍匐茎长度、基株干重、匍匐茎干重、单位长度上匍匐茎干重、无性系分株干重和匍匐茎分株总干重 /基株干重比值均与海拔高度之间存在极显著的二次多项式相关性(P<0. 01),但匍匐茎长度、匍匐茎分株总干重 /基株干重随海拔高度的变化趋势与基株干重、匍匐茎干重、单位长度上匍匐茎干重、无性系分株干重随海拔高度的变化趋势相反.在短穗兔耳草分布的海拔范围内,其克隆繁殖和克隆生长有一个“最佳”海拔高度,远离这一高度,其克隆繁殖和克隆生长会受到一定限制. 图 6表 2参 18     

书讯

青藏高原蕨麻李军乔著科学出版社出版(2011年8月)978-7-03-032119-0$75.00 B5开本平装内容简介本书针对青藏高原野生资源植物——蕨麻的资源地理分布、民间应用历史、自然资源概况、生物学及生态学特性、栽培技术、品种选育、生态价值、经济价值、商品标准等进行了系统、全面的试验研究,提出了蕨麻综合开发的途径,从而为资源植物合理高效的开发提供了理论依据。     

淮河水系淮南段椎实螺类(Lymnaeidae)生态学研究

于2004年春季（4月）和秋季（9月），分别对淮河水系淮南段不同环境条件下的10个站点椎实螺类的种类和分布特征进行了调查，共鉴定出椎实螺类5种，其中萝卜螺属4种，土蜗属1种，耳萝卜螺为优势种；全流域平均密度和生物量，春季为227．7Ind.／m^2。和175．50g／m^2，秋季为100．2Ind．／m^2和88．85g／m^2．工业污染较重的站点（D、F、I）椎实螺类的群落结构趋于简化，而流域底质生境异质性的站点（E、H）螺类种数呈现多样性．图1表2参16     

Microsite-limited recruitment controls fern colonization of post-agricultural forests

Assessing the relative roles of dispersal limitation and environmental effects in population dynamics and community assembly is fundamental to understanding patterns of species distribution and diversity. In forests growing on abandoned agricultural lands, both legacies of vegetation disturbance and changes in the abiotic environment shape the diversity and composition of recovering communities. Here I specify how interactions among historical, environmental, and biological factors influence species distributions, focusing on three fern species with contrasting distributions across forests of different history in central New York, USA: Dryopteris carthusiana, Dryopteris intermedia, and Polystichum acrostichoides. Using population surveys, spore-trap and spore-bank studies, and a three-year field experiment, I compare demographic rates among species and between forest types to determine which life history stages limit colonization and which traits explain species distributions. Adult plants of all three species were larger and more likely to produce spores in post-agricultural forests than in adjacent, uncleared stands. Though lower population densities led to fewer spores in post-agricultural soils, spore availability still exceeded recruitment by four to five orders of magnitude. Sowing additional spores had relatively little effect, while microhabitat conditions had the greatest impact on establishment rates. Given similar microsites, the two forest types had equal rates of establishment, but some forest-floor features preferentially occupied by juvenile plants were less frequent in post-agricultural stands. The availability of suitable sites for establishment, created by small-scale heterogeneity on forest floors, thus limits both the growth of fern populations and the colonization of new habitats. In fact, reduced microtopographic variation in post-agricultural forests may represent a greater hindrance to plant establishment than changes in mean environmental conditions. Among the three fern species, establishment rates differed as species distributions would predict, with the strongest colonizer consistently having the highest rates and the slowest colonizer the lowest. Rather than random or trait-mediated dispersal, the different distributions of these species reflect life history traits that determine establishment rates and thus colonization ability. This case study demonstrates that ecological interactions based on the unique life histories of individual species can override dispersal in determining species distributions.     

Assessing the Value of the Umbrella‐Species Concept for Conservation Planning with Meta‐Analysis

Abstract: The umbrella‐species concept, which suggests that conservation strategies designed for one species may benefit co‐occurring species, has been promoted as a framework for conservation planning. Nevertheless, there has been considerable variation in the outcome of empirical tests of this concept that has led researchers to question its value, so we used data from 15 published studies in a meta‐analysis to evaluate whether conservation of putative umbrella species also conserves co‐occurring species. We tested the effectiveness of putative umbrella species categorized by taxonomic group, taxonomic similarity to co‐occurring species, body size, generality of resource use, and trophic level to evaluate criteria proposed to guide the selection of umbrella species. We compared species richness and number of individuals (by species and higher taxonomic group) between sites with and without putative umbrella species to test whether more co‐occurring species were present in greater abundances when the area or resource needs of umbrella species were met. Species richness and abundance of co‐occurring species were consistently higher in sites where umbrella species were present than where they were not and for conservation schemes with avian than with mammalian umbrella species. There were no differences in species richness or species abundance with resource generalist or specialist umbrella species or based on taxonomic similarity of umbrella and co‐occurring species. Taxonomic group abundance was higher in across‐taxonomic umbrella species schemes than when umbrella species were of the same taxon as co‐occurring species. Co‐occurring species had similar, or higher, species richness with small‐bodied umbrella species relative to larger‐bodied umbrella species. The only significant difference among umbrella species categorized by trophic level was that species richness was higher with omnivorous than it was with carnivorous avian umbrella species. Our results suggest there is merit to the umbrella‐species concept for conservation, but they do not support the use of the criteria we used to identify umbrella species.     

An island biogeography approach for understanding changes in compositional similarity at present scenario of biotic homogenization

Local extinction of native species and colonization of non-native species are commonly invoked as responsible for changes in species similarity among biotas of different regions. In this study we used a model of species similarity between islands to assess the emergent, and unexplored, effects of changes in colonization by native species, extinction of non-native species, and propagule pressure on species similarity among insular communities. The model predicts that extinction probability of endemic species has a positive but asymptotic effect on species similarity, which is exacerbated by increasing colonization and reducing extinction of non-native species. Species similarity tends to increase with increasing colonization probability by non-native species, however this effect may be reduced, or even reverted, when the islands are exposed to an elevated number of non-native species that are prone to extinction, high levels of endemic species loss, and an initially large number of native species shared between islands. Species similarity was positively affected by the propagule pressure rate of non-native species only when their colonization and extinction probabilities were large and small enough, respectively. A negative effect of propagule pressure rate can be caused by an increase in the pool size of non-native species, which involves the introduction of different species into different islands, promoting biotic differentiation between islands. Our results indicate that the interactions between colonization, extinction and species pool lead to nonlinear responses and unexpected scenarios of biotic change. In order to validate model predictions, future research programs should focus on understanding the dynamics on such complex meta-communities where coexist native, non-native and endemic species.     

梅江流域鸟类群落结构及其多样性

采用固定样带法和样点法对梅江流域的鸟类群落进行了研究,共记录到201种,隶属16目49科127属,其中留鸟81种、冬候鸟67种、夏候鸟40种、旅鸟13种,分别占40．1％、33．3％、19．9％、6．7％;古北界种类95种（占47．3％）,东洋界种类64种（占31．8％）,广布型种类42种（占20．9％）;国家I级保护种类1种,国家II级保护种类21种（占10％）;《国际湿地公约》指定种类24种（占12％）,《中澳候鸟保护协议》指定种类22种（占11％）,《中日候鸟保护协议》指定种类76种（占38％）,《濒危野生动植物种国际贸易公约》（CITES）指定种类19种（占9％）,有益的、有重要经济价值的、有重要科学研究价值的物种155种（占77％）。该流域的鸟类群落多样性指数3．7617,均匀度指数0．7093。     

Effectiveness of management zoning designed for flagship species in protecting sympatric species

Flagship species have been used widely as umbrella species (i.e., species with large home range whose protection often provides protection for sympatric species) in the management of China's nature reserves. This conflation of flagship and umbrella species is best represented by the giant panda (Ailuropoda melanoleuca) and other large, endangered mammals designated as conservation targets in site selection and planning of reserves. Few empirical studies have tested the effectiveness of flagship species as surrogates for a broader range of sympatric species. Using extensive camera-trap data, we examined the effectiveness of management zones designated to protect flagship (target) species in conserving sympatric species in 4 wildlife reserves (Gutianshan, Changqing, Laohegou, and Wolong). We tested whether the progression from peripheral to core zones was associated with an increasing habitat association for both target and sympatric species. The distribution patterns of the study species across the zones in each reserve indicated a disparity between management zones and the species’ habitat requirements. Management zone was included in the final model for all target species, and most of them had higher occurrence in core zones relative to less-protected zones, but zone was not a predictor for most of the sympatric species. When management zone was associated with the occurrence of sympatric species, threatened species generally had higher detections in core zones, whereas common species had higher detections outside of the core zone. Our results suggested that reserve planning based on flagship species does not adequately protect sympatric species due to their specialized habitat requirements. We recommend re-examining the effectiveness of management zoning and urge a multispecies and reserve-wide monitoring plan to improve protection of China's wildlife.     

An Empirical Assessment of the Focal Species Hypothesis

Biodiversity surrogates and indicators are commonly used in conservation management. The focal species approach (FSA) is one method for identifying biodiversity surrogates, and it is underpinned by the hypothesis that management aimed at a particular focal species will confer protection on co‐occurring species. This concept has been the subject of much debate, in part because the validity of the FSA has not been subject to detailed empirical assessment of the extent to which a given focal species actually co‐occurs with other species in an assemblage. To address this knowledge gap, we used large‐scale, long‐term data sets of temperate woodland birds to select focal species associated with threatening processes such as habitat isolation and loss of key vegetation attributes. We quantified co‐occurrence patterns among focal species, species in the wider bird assemblage, and species of conservation concern. Some, but not all, focal species were associated with high levels of species richness. One of our selected focal species was negatively associated with the occurrence of other species (i.e., it was an antisurrogate)—a previously undescribed property of nominated focal species. Furthermore, combinations of focal species were not associated with substantially elevated levels of bird species richness, relative to levels associated with individual species. Our results suggest that although there is some merit to the underpinning concept of the FSA, there is also a need to ensure that actions are sufficiently flexible because management tightly focused on a given focal species may not benefit some other species, including species of conservation concern, such of which might not occur in species‐rich assemblages. Una Evaluación Empírica de la Hipótesis de Especie Focal     

Are ecological groups of species optimal for forest dynamics modelling?

The huge diversity of tree species in tropical rain-forests makes the modelling of its dynamics a difficult task. One-way to deal with it is to define species groups. A classical approach for building species groups consists in grouping species with nearby characteristics, using cluster analysis. A group of species is then characterized by the same list of attributes as a single species, and it is incorporated in the model of forest dynamics in the same way as a single species. In this paper, a new approach for building species group is proposed. It relies on the discrepancy between model predictions when all species are considered separately, and model predictions when species groups are used. An aggregation error that quantifies the bias in model predictions that results from species grouping is thus defined. We then define the optimal species grouping as the one that minimizes the aggregation error. Using data from a tropical rain-forest in French Guiana and a toy model of forest dynamics, this new method for species grouping is confronted to the classical method based on cluster analysis of the species characteristics, and to a combined method based on a cluster analysis that uses the aggregation error as a dissimilarity between species. The optimal species grouping is quite different from the classical species grouping. The ecological interpretation of the optimal groups is difficult, as there is no direct linkage between the species characteristics and the way that they are grouped. The combined approach yields species groups that are closed to the optimal ones, with much less computations. The optimal species groups are thus specific to the model of forest dynamics and lack the generality of those of the classical method, that in turn are not optimal.     

两种人工林对工程建筑废弃地植被初始生态恢复的影响

以隔河岩水电工程建筑废弃地初始生态恢复中人工构建植被为研究对象,在样地调查的基础上,分析了废弃地退化生态系统植物多样性和植物群落组成与结构的恢复对种植植物种类的生态响应。通过与周围未治理废弃地及自然次生林群落组成与结构的比较,研究了该废弃地植被的生态恢复进程。结果显示,苗木种植促进了本地植物种类在废弃地的扩散和定居,初步形成了具一定组成与结构的群落类型,是一种及时有效的生态恢复技术。但不同的苗木种类对废弃地植被初始生态恢复的效果不同,通过比较圆柏(Sabinachinensis)和湿地松(Pinuselliottii)2种人工林的生物多样性及群落组成与结构,认为圆柏林的初始生态恢复效果比湿地松林好。     

Effects of Self-Compatibility on the Distribution Range of Invasive European Plants in North America

Abstract:  Many plant species have been introduced to new continents, but only a small subset of these have become invasive. It has been predicted that self-compatible species, particularly those that do not need the services of pollinators, are more likely to establish and spread after long-distance dispersal. We tested whether this hypothesis, commonly called Baker's law, applies to 361 species that have invaded the United States from Europe. Species capable of autonomous seed production occurred in significantly more states than species requiring a pollen vector. Moreover, of the species that are not capable of autonomous seed production, self-compatible species occurred in significantly more states than those that are not self-compatible. The positive effect of autonomous seed production on the range of invasion was larger for abiotically pollinated species than for biotically pollinated species and for monocarpic species than for polycarpic species. These results support Baker's law, and we recommend that screening protocols for predicting invasiveness of species considered for introduction should include assessment of their breeding system.     

Single Species as Indicators of Species Richness and Composition in California Coastal Sage Scrub Birds and Small Mammals

Abstract: Individual species may be useful as indicators of biodiversity if an association exists between the presence of a species and another component of biodiversity. We evaluated 40 species of birds and small mammals, including 11 species of conservation concern, as potential indicators of species richness and species composition in southern California coastal sage scrub habitats. This habitat, which is the target of large-scale conservation planning, has been greatly reduced by human development and supports many plants and animals of conservation concern. We asked whether there is an association between the presence of a potential indicator species and the species richness and composition of the bird or small-mammal community in which it is found. We used point counts and live-trapping to quantify the distribution of birds and small mammals, respectively, at 155 points in 16 sites located in three counties. Of the few species we found associated with species richness, some were associated with higher species richness and others with lower richness, and species of conservation concern were not more frequently associated with species richness than were common species. Ordination analysis revealed a geographic gradient in coastal sage scrub bird and small-mammal species composition across southern California, and 18 of the species we evaluated were associated with the composition of the bird and small-mammal community in which they were found. Our results suggest that efforts to conserve bird and small-mammal biodiversity in coastal sage scrub should not focus exclusively on rare species or on locations with the highest species richness, but instead should focus on a diverse suite of species that are representative of the range of variation in communities found in coastal sage scrub habitats.