滨豇豆的生态生物学特征

为探究滨豇豆(Vignamarina)的生态生物学特性及其对热带珊瑚岛的适应性,对西沙群岛野生滨豇豆的叶片形态解剖结构、生理特征和营养成分进行了分析。结果表明,滨豇豆具有叶片厚、比叶面积小、栅栏组织发达、气孔密度大、气孔面积指数大等形态特征,对减少蒸腾、保持水分起到重要作用。滨豇豆叶片的SOD活性和脯氨酸(Pro)含量高,丙二醛(MDA)含量低,表明抗氧化能力较强;滨豇豆叶片养分含量适中但其生境土壤养分含量很低,说明其对养分有着良好的吸收利用能力,利于适应贫瘠的环境。因此,滨豇豆具有能够较好地适应珊瑚岛礁高温、干旱、贫瘠生境的形态解剖结构和生理特征,加之其具有良好的固氮和养分利用能力,可作为热带珊瑚岛植被恢复的工具种。     

崇明东滩南部河口盐沼植物群落种间关系的数量分析

对崇明东滩南部盐沼植物群落样方进行调查,基于现有17种高等植物,特别是8种常见植物的2×2联列表和植被盖度值,利用方差比率法、χ²检验以及Spearman秩相关分析对物种关联性和相关性进行分析.结果表明: 方差比率(VR=0.61)的检验统计量W=48.61,落在 χ² 2个临界值区间之外,因此该区域盐沼植物群落内植物整体关联度表现为显著负相关;依据各优势植物对环境的适应方式和生境的主导因素,参考Spearman秩相关分析的结果,将它们划分为4个生态种组: 芦苇、糙叶苔草-藨草-水莎草、互花米草-海三棱藨草、白茅-稗草.崇明东滩南部盐沼植物群落种间关系复杂,群落表现极不稳定,植物对于环境影响较为敏感.在明确物种之间关系的基础上,针对海三棱藨草的分布现状提出了相应种群的保护措施和建议.     

Seedling interactions in a tropical forest in Panama

Competition is believed to be a central force limiting local diversity and controlling the structure of plant communities. However, it has been proposed that the stressed understory environment limits total understory plant density to such low levels that competitive exclusion cannot be an important factor limiting the local diversity of understory plants. To evaluate the importance of inter-seedling competition, we performed a seedling competition experiment with five shade-tolerant species in a tropical moist forest in Panama. Three-month-old seedlings were transplanted into the forest singly or with their roots intertwined with a single conspecific or heterospecific seedling in all pairwise species combinations. If competition is important, performance (survival, stem height, and number of leaves after one and six years) would be expected to be lowest with a conspecific neighbor and greatest without a neighbor. The experiment was replicated in five 0.24-m² plots at each of 20 sites in tall secondary forest. To test whether seedling performance differed among treatments we fitted linear mixed models (LMM) and generalized linear mixed models (GLMM), treating species identity and microsite (site and plot) as random effects. The five shade-tolerant study species all experienced good establishment with relatively high survival and growth rates. The neighbor treatment consistently affected seedling performance, but the effect was always very small, both in absolute terms and relative to the much stronger species and microsite effects. Seedlings with a conspecific neighbor consistently performed worse than seedlings with a heterospecific neighbor, but having no neighbor generally did not cause superior performance relative to the other treatments. We conclude that direct competitive interactions are relatively unimportant among understory plants in humid tropical forests.     

中国大陆青冈分布区东缘大金山岛种群种子形态变异

在大陆青冈分布区东缘的大金山岛种群中按不同坡向取样,旨在揭示相对均一条件下青冈种子的形态变异及变异的来源,以从不同侧面研究环境对形态变异的作用。大金山岛种群青冈种子的长度、直径和重量分别为1.557±0.128cm、1.175±0.112cm、1.321±0.310g,处于青冈种子正常分布范围内。单颗种子的长度、直径符合正态分布,而重量则明显偏离正态分布。不同坡向青冈种子间差异很小,表明微地形的影响较小;种群变异的来源株内和株间约各占一半,说明种子表型具有一定的可塑性,主要由于种子处于植株不同部位的缘故。     

Field Anesthesia and Health Assessment of Free-ranging <Emphasis Type="Italic">Cebus capucinus</Emphasis> in Panama

Health and disease are critical factors for understanding primate evolution and for developing effective conservation and management strategies. However, comprehensive health assessments of wild primate populations are rare, in part because of the difficulty and risk of chemically immobilizing subjects to obtain the necessary biological samples. We report here the results of a health assessment, as well as the methods and drug dosages used to capture white-faced capuchins (Cebus capucinus) on Barro Colorado Island, Panama. We captured and measured 24 capuchins as part of an ongoing radiotelemetry study, and collected biological samples from 9 of them for a comprehensive health survey. Telazol® was very effective for immobilizing and capturing capuchins, although the doses we used were higher than those recommended for captive capuchins. High Telazol doses immobilized individuals quickly, ensuring that we were able to find and recover the sedated monkeys. The capuchins were generally in good condition, and had few ecto-, hemo-, or intestinal parasites. However, all but 1 of the adults had substantial dental abnormalities. In addition, 1 juvenile had indeterminate genitalia that we believe to be the result of hypospadias. Seven of the capuchins tested positive for exposure to Herpesvirus tamarinus and all individuals tested positive for exposure to Cebus cytomegalovirus. Hematology, serum chemistry, and plasma mineral levels from the wild individuals were, for the most part, comparable to those recorded for captive Cebus capucinus, and contribute to establishing baseline health values for the species.     

尖峰岭自然保护区扩大区域植物多样性研究

尖峰岭自然保护区2002年由省级上升为国家级自然保护区, 面积由原来的7,762 hm²增加至20,170 hm²。为建立一个比较完善的国家级自然保护区管理体系, 海南大学于2003年10月通过路线调查与标准样方相结合的方法对保护区扩大区域展开了植被资源调查工作。本次调查共记录到43种尖峰岭地区新记录种, 其中黄毛马兜铃(Aristolochia fulvicoma)、海南地不容(Stephania hainanensis)、卵叶石笔木(Tutcheria ovalifolia)、蜜茱萸(Melicope patulinervia)和南烛(Lyonia ovalifolia)等5种为海南特有种。在本次调查的9,600 m²天然林标准样方中共记录到高1.5 m以上的立木3,466株398种, 隶属于69科161属。在扩大区域内共有国家级珍稀濒危和保护植物41种, 其中国家I级保护植物4种, 新记录到的尖峰岭地区国家级濒危植物2种, 即毛茶(Antirhea chinensis)和琼棕(Chuniophoenix hainanensis), 并基本确定了这些植物的垂直分布状况。扩大区域热带低地雨林、热带山地雨林、热带山顶矮林3种群落类型的物种多样性指数均较高, 且Simpson指数(D)及Shannon-Wiener指数(H＇)均是热带山地雨林>热带低地雨林>热带山顶矮林; 均匀度则是热带山地雨林>热带山顶矮林>热带低地雨林。表明经过多年封山育林及实施天然林保护工程, 扩大区域内曾经受过强烈干扰的热带低地雨林和山地雨林已经得到了很好的恢复。     

MORPHOLOGICAL VARIABILITY OF EUNOTIA PECTINALIS (BACILLARIOPHYCEAE) IN A SOFTWATER RHODE ISLAND STREAM AND IN CULTURE1

The diatom Eunotia pectinalis (O. F. Müll.?) Rabh. exhibited considerable morphological variability in samples collected over a 13-month period from a softwater Rhode Island stream. All observed morphotypes were classified into three main complexes based upon their valve configuration. These groupings were confirmed by discriminant analysis using quantitative valve characteristics and were named in accordance with their associated varieties: minor (Kütz.) Rabh., pectinalis and ventricosa Grun. Clonal cultures were subjected to a defined series of temperatures, agitation rates and light intensities in order to assess inherent morphological variability. Similar trends were evident for all complexes. Over time, valve length decreased, valve breadth enlarged, and striae number per 10 μm at valve center and apex increased. Morphological plasticity was evident in culture and appeared to be more a function of the clone genotype than the environmental conditions to which it was subjected. One clone originally identified as E. pectinalis var. minor assumed certain morphological features of E. vanheurckii Patr. after four months in culture.     

Feral cat diet and impact on sooty terns at Juan de Nova Island, Mozambique Channel

Feral cat Felis catus predation on seabirds has been well documented; however, details regarding shifts in feral cat diet in relation to seabird availability, seabird predation rate and impact on seabird population dynamics are scarce. Here, we present data documenting a seasonal shift in feral cat diet at Juan de Nova Island, Mozambique Channel. We also quantify sooty tern Sterna fuscata predation by feral cats and examine the impact on sooty terns over both the short term (by removing individual cats from sub-colonies) and over the longer term by highlighting their influence on population growth rate ( λ ) using a deterministic matrix model. Cat diet shifted dramatically from insects, rats and mice outside the tern breeding season to primarily terns when terns were breeding. The predation rate of sooty terns at Juan de Nova was estimated at 5.94 terns cat⁻¹ day⁻¹, with a proportion of these (22%) being killed without being consumed ('surplus kills'). When only one cat was removed from each sub-colony, tern predation declined tenfold in the short term. From our matrix model, the annual growth rate for sooty terns was 1.01 in the absence of cat predation. It remained above one until a predation impact equivalent to approximately three times the estimated cat density (12.04 per km²) was incorporated. Our results demonstrate that cats preferentially predate and have an impact on breeding sooty terns at Juan de Nova, and that an increase in cat density could lead to negative effects on population growth, despite the large breeding tern population.     

Phylogeography of the marine isopod Stenosoma nadejda (Rezig, 1989) in North African Atlantic and western Mediterranean coasts reveals complex differentiation patterns and a new species

The transition zone between the Mediterranean and Atlantic basins has been extensively addressed in phylogeographical studies of marine species. However, biases exist towards the analysis of highly dispersive species, and there is a higher sampling effort in European coasts compared to North Africa. This may be hindering a detailed understanding of the historical and contemporary processes that shaped patterns of population genetic structure in the region. In the present study, we investigated the phylogeographical and phylogenetic patterns of mitochondrial cytochrome c oxidase subunit I sequences from a species with direct development and low dispersal abilities, Stenosoma nadejda (Rezig, 1989). The study area included 13 localities along the Atlantic and Mediterranean North African coasts, as well as the Alboran Sea. A new Stenosoma species, from the coasts of Algeria and Alboran Island, was discovered. For S. nadejda, phylogeographical analyses revealed three distinct clades: one in the Iberian Atlantic plus the Alboran Sea, one in the western Mediterranean, and another in the Atlantic coast of Africa. Haplotypes from the Alboran Island were more related to those from the western Mediterranean coast (east of the Almeria–Oran Front). Given the strong differentiation, it is probable that this species survived in multiple glacial refugia during the Pleistocenic glaciations. © 2011 The Linnean Society of London, Biological Journal of the Linnean Society, 2011, 104 , 419–431.