民勤沙区几种荒漠植物群落的现实生态位研究

民勤沙区属于典型的干旱荒漠气候,植被以灌木荒漠为主,盖度一般只有5%~15%.植物群落内生态位宽度悬殊,植物种之间的生态位相似比例很小.生态位宽度和生态位相似比例小是受制于干旱荒漠生境条件的结果,是干旱荒漠生态环境中稀疏荒漠植物的主要特征之一.植物的现实生态位宽度与年际降水量关系密切,在地貌、土壤颗粒、土壤水分、土壤养分等影响因子中,土壤水分是主导因子.当地地下水位深20 m左右,植物无法利用,植物种之间对资源的竞争主要表现为对水分资源的竞争,降水资源是植物种之间竞争的关键资源.同一种植物在不同群落中的生态位宽度变幅较大,不同群落内部植物种竞争关系的差异是由物种的生态位和由相对稳定的地貌、土壤条件以及随年际变动的降水条件共同作用的结果.群落中的优势种植物的生态位最宽,当优势种生态位减小时,一年生短命植物往往会进入群落中.荒漠植物的冠层单一,以冠幅占样方面积比作为植物的特征值计算其生态位特征值比较准确可靠.     

Danaea (Marattiaceae) revisited: biodiversity,a new classification and ten new species of a neotropical fern genus

Revision of the Neotropical fern genus Danaea (Marattiaceae) has resulted in the recognition of ten new species, which are here for the first time presented to the scientific audience. Morphological and molecular data suggest that the genus consists of three monophyletic subgenera that are circumscribed here. A key is provided to aid species identification. The geographical ranges of the species are summarized and discussed with regard to speciation. © 2010 The Linnean Society of London, Botanical Journal of the Linnean Society, 2010, 163 , 360–385.     

The systematic importance of anatomical data in Gagea (Liliaceae) from the Flora Iranica area

Anatomical features of basal leaves, pedicels and tepals of 22 species of Gagea belonging to four sections (Platyspermum, Plecostigma, Gagea and Didymobulbos) are investigated. Anatomical characters are mapped onto a molecular phylogenetic tree and their evolution is evaluated. The systematic importance of the anatomical characters is discussed. Anatomical characters are more systematically useful in the Irano‐Turanian taxa than in Euro‐Siberian taxa. The presence of collenchyma and/or sclerenchyma and the pentagonal outline of the transverse section of the basal leaf is found in Irano‐Turanian taxa of section Platyspermum and is mostly absent in Euro‐Siberian taxa. A diagnostic key based on combined anatomical characters is provided. The level of variation in anatomical characters is greater in the basal leaf than the pedicel and lowest in the tepals. Convergent evolution in anatomical characters is associated with ecological shifts between sunny, open, dry habitats and closed, humid habitats. © 2010 The Linnean Society of London, Botanical Journal of the Linnean Society, 2010, 164 , 155–177.     

山西省重点保护野生植物就地保护现状

建立自然保护区是生物多样性保护最为直接和有效的方法。开展重要保护物种的科学考察和研究, 评价其就地保护现状, 对区域内实施科学合理的保护与管理具有重要的意义。本文基于文献资料和野外调查, 分析了山西省重点保护野生植物的地理分布及就地保护现状, 结果显示: (1)山西省重点保护野生植物共57种, 其中有49种分布在自然保护区内, 就地保护率为86%; (2)在地理分布上, 晋城、运城、临汾和阳泉4个市的保护区内分布的保护植物种类最多; (3)采用“累计筛选法”共鉴别出6个保护贡献率最高的保护区, 其累计保护贡献率达到86%; (4)总体来说, 山西省重点保护野生植物受到较全面的就地保护, 但仍存在一些保护空缺, 这些保护空缺地的鉴别将为山西省自然保护区的进一步规划提供科学参考。     

Three new species of the subgenus Parapenthecia from the Oriental Region (Diptera: Drosophilidae: Apenthecia)

Three new species of the subgenus Parapenthecia of the genus Apenthecia are reported from the Oriental Region: A. (P.) heterochaeta Chen and Toda, sp. nov. from Indonesia, and A. (P.) hispida Chen and Toda, sp. nov. and A. (P.) litongi Cao and Chen, sp. nov. from south China. Interestingly, the last species lacks a very peculiar character, the swollen or scale‐like orbital setae, which are commonly seen in all other species of the genus Apenthecia. A key to all species of the subgenus Parapenthecia is provided.     

水蜜桃种质资源的RAPD分析

利用RAPD技术,采用从200个随机引物中筛选的22个随机引物对48个水蜜桃品种的基因组I)NA进行扩增。通过180个扩增位点谱带的聚类,分析供试水蜜桃的系统发育;并运用特殊谱带,建立了水蜜桃的分子检索表;提出了重点保存的水蜜桃种质有冈山白、Spring time、Rebin、白凤、霞晖2号、早艳、奉化玉露。     

基于主导生态功能价值核算的生态补偿研究——以若尔盖重要生态功能区为例

重要生态功能区是指在保持流域、区域生态平衡,防止和减轻自然灾害,确保国家和地区生态安全方面具有重要作用的区域。我国重要生态功能区生态破坏形势十分严峻,严重阻碍了区域社会经济的可持续发展。为此,国家非常重视重要生态功能区的环境保护和生态建设,提出通过建立生态补偿机制,加强对重要生态功能区的保护。重要生态功能区的主导生态功能不仅是保护的主要对象,而且通常还是区外受益区经济利益的关切点,以主导生态功能价值作为生态补偿标准的参考依据,更具有现实性和可操作性。本文以若尔盖重要生态功能区为例进行了研究,对主导生态功能进行了分析和价值评价,从理论核算价值上,提出了若尔盖重要生态功能区生态补偿的参考标准。     

麦双尾蚜的龄期鉴别

麦双尾蚜Diuraphis noxia (Mordvilko)无翅孤雌蚜的体长、体宽、头宽、腹管宽、上尾片长、尾片长和触角节Ⅲ长等7个形态指标,在各龄期间差异显著。根据麦双尾蚜的翅、翅芽、触角节数、尾片形状、上尾片长与宽比值等特征作为龄期鉴别的主要指标,编制了麦双尾蚜龄期鉴定检索表。     

On New Findings of a Rare Sea Snake <Emphasis Type="Italic">Leioselasma czeblukovi</Emphasis> Kharin, 1984, with Remarks on Species Composition and Taxonomical Position of the Genus <Emphasis Type="Italic">Leioselasma</Emphasis> Lacepede, 1804, (Serpentes: Hydrophiidae)

Information is presented about a finding of two specimens of a rare sea snake Leioselasma czeblukovi, which was known until now only from the holotype and a paratype, and also about the taxonomical position of the genus Leioselasma within the group of genera Hydrophis sensu lato and the species composition of the latter. An identification key for species is presented.     

Plant growth forms: an ecological and evolutionary perspective

Trees, shrubs, lianas and herbs have widely different mechanical architectures, which can also vary phenotypically with the environment. This review investigates how environmental effects, particularly mechanical perturbation, can influence biomechanical development in self-supporting and climbing growth forms. The bifacial vascular cambium is discussed in terms of its significance to growth form variation, ecology and evolution among extant plants, and during its appearance and early evolution. A key aspect of this developmental innovation concerned its potential for architectural and mechanical variation in response to environmental effects as well as optimizing hydraulic supply before the appearance of laminate leaves. Growth form diversity and its importance to past and present ecosystems are discussed in relation to both evolutionary constraints and ecological factors such as climatic change and atmospheric CO2 concentrations. We discuss how widely ranging growth forms such as climbers show a large range of developmental and phenotypic variation that has much to offer in understanding how the environment can modify plant development, particularly in terms of the bifacial vascular cambium. The broad approach we propose would benefit a wide range of studies from research into wood development to long-term ecological censuses of today's potentially changing ecosystems.