The distribution and ecology of Chirocephalus diaphanus Prévost (Branchiopoda: Anostraca) in Britain

The anostracan Chirocephalus diaphanus is at the northwestern limits of its range in Britain. Its distribution, based on records made since first reported nearly three centuries ago, is mapped. Aspects of its ecology and behaviour that have a bearing on its requirements, and therefore on the pattern of its distribution, are noted. It is an almost defenceless, opportunistic species, largely confined to temporary pools where it avoids predators. It occurs in those regions of Britain where a high winter water table is followed by a dry spring and early summer, and is essentially confined to the zone in which there is a deficit between precipitation and evapotranspiration during the six months April to September. Such conditions prevail in the south and southeast. Cooler, wetter, northern and western parts, with their more frequent rain-days and cloud cover, do not favour the formation of suitable temporary pools. The eurythermous nature of C. diaphanus, its ability to remain active at low temperatures, and its tolerance of a wide range of other conditions, enable it to exploit, and to reach maturity in, temporary pools before such predators as can colonize them have had the opportunity to do so. Dispersal and survival during ensuing periods of drought are effected by drought-resistant resting eggs. Possible genetic, reproductive and ecological constraints relevant to events that take place towards the edge of its range are noted.     

Tropical cyclones and reproductive ecology of Crocodylus acutus Cuvier, 1807 (Reptilia: Crocodilia: Crocodylidae) on a Caribbean atoll in Mexico

Crocodylus acutus, a coastal species nesting in sand beaches, could be affected by increasing tropical cyclone frequency. We studied key characteristics of C. acutus reproductive ecology on Banco Chinchorro atoll from 2006 to 2009, including the impact of two tropical cyclones. Hurricanes increased canopy openness causing earlier nesting the following year. Crocodiles nested at the beginning of the wet season with hatching in mid-wet season; this could represent a compromise between risking nest flooding and increasing freshwater availability for hatchlings. Tropical cyclones dramatically reduced nesting success by cooling and flooding clutches. Nursery sites were usually hypersaline, but heavy rainfall from tropical cyclones can likely benefit hatchling survival by decreasing salinity. While tropical cyclones have negative short-term impacts on crocodile nesting, they likely have an overall beneficial effect by creating and maintaining open sandy nesting areas used by C. acutus and they may explain its widespread distribution in Caribbean coastal areas.     

Habitat characterization and potential distribution of Tylototriton vietnamensis in northern Vietnam

The habitat preferences of the endemic Vietnam Crocodile Newt, Tylototriton vietnamensis were investigated on two scales: (1) at Yen Tu Nature Reserve, Bac Giang Province, Vietnam, while compiling information about pond occupancy and developing a qualitative comparison among breeding sites and (2) by developing a Species Distribution Model based on climate and land cover data identifying further suitable habitats in northern Vietnam. A factor analysis followed by a multiple linear regression showed 94% support for our occupancy ranking model. Our results suggest that T. vietnamensis preferentially inhabits small pools with long hydroperiod and pH above 4.3. Suitable areas for the species have higher incidence in northern regions, where undisturbed vegetation and temperature-related variables seem to make greater contributions. Additionally, these potentially suitable areas are strongly fragmented and only a few are under IUCN protection, increasing their vulnerability towards further degradation.     

微电影的媒介生态性研究

凭借数码摄像和互联网等外部技术的成熟和当代人片段化阅读习惯的深层需求，微电影迅速成为一种新兴的艺术形式和媒介。微电影的媒介生态位介于电视和电影之间，加上自身系统的开放性和互动性，微电影的媒介生态特征呈现出和谐健康的发展态势。     

地域生态中云南民族情感表达的符号化图式——建国以来云南歌曲创作评述

依托资料查询与口碑访谈,较为系统地考察了新中国云南歌曲创作的审美轨迹、梳理了云南作曲学科历经几代学人不懈努力、由此形成的既立足本土民族音乐素材又吸收作曲学科新的创作技法和新的艺术观念进行歌曲创作的优秀传统,并把这种文化精神的传承和学术的努力置于相关的社会背景中进行了纵向与横向的审视,在学理层面对建国后云南歌曲创作在国家政策的背景下、在云南民族音乐素材的养育下取得的累累成果进行了较为全面的学术性评述。     

Food spectrum analysis of the Asian toad,Duttaphrynus melanostictus (Schneider, 1799) (Anura: Bufonidae), from Timor Island,Wallacea

The Asian toad, Duttaphrynus melanostictus (Schneider, 1799), is widespread throughout tropical Asia and very abundant where it occurs. It was relatively recently introduced to Timor, the second largest island in the biogeographic region called Wallacea. Timor Island shows an exceptionally high level of endemism in a wide range of faunal groups and there are concerns that D. melanostictus may have a negative impact on this diversity, including vertebrates, through direct predation. To evaluate the impact the diet of D. melanostictus might have on the local fauna, gut contents of 83 preserved toad specimens from five habitat types in Timor-Leste, a country occupying the eastern half of Timor Island, were examined. We identified 5581 prey items, comprising the following animal groups: annelids; snails and slugs; spiders and harvestmen; woodlice; millipedes and centipedes; grasshoppers, crickets and earwigs; termites; thrips and true bugs; beetles; ants; hymenopterans other than ants; true flies; butterflies; unidentified insects; and insect larvae. Small eusocial insects (ants and termites) constituted the major part of the diet (61.6% and 23.4%, respectively). No vertebrate prey was recorded. Prey item composition did not differ between habitats. The wide prey spectrum well indicates that D. melanostictus is a generalist invertebrate feeder, as other studies, from regions where this species occurs naturally, have already shown. Although the Asian toad seems to not generally prey on vertebrates, vertebrate species that are morphologically similar to invertebrates in their overall appearance may be consumed. Hence, a negative effect on some taxa (e.g. blindsnakes) may be possible. We also present some limited data on intestinal parasites occurring in D. melanostictus.     

延平区上洋村“森林人家”可持续发展研究

"森林人家"是适应森林生态旅游需求的一种新型休闲健康旅游产品.以延平区上洋村"森林人家"为例,首先分析了"森林人家"发展的区位交通优势、资源优势与文化优势.在此基础上,指出了一些不可持续发展的现象与问题.最后,以可持续发展理念为指导,提出了延平区上洋村"森林人家"可持续发展的对策,希望能为上洋村及其他同类区域"森林人家"可持续发展提供一些有益的借鉴.     

人为干扰对城市近郊区森林植物多样性的影响——以贵阳市乌当区为例

该文研究了贵阳市乌当区马背山森林在弃耕地干扰、道路干扰、工程废弃物干扰和火干扰等4种人为干扰作用下,植物多样性的特征及其与环境因子之间的关系.结果表明:研究区域道路干扰类型的物种多样性指数最高,其次为弃耕地干扰和火干扰类型,工程废弃物干扰类型的物种多样性最低;工程废弃物干扰类型与道路干扰类型植物相似性最高,弃耕地干扰类型和工程废弃物干扰类型相似性最低.土壤结构对植物多样性的影响较大,土壤养分对植物多样性的影响不明显.各人为干扰的环境因素中,挖掘个数及面积、小路面积、岩石盖度与植物多样性和均匀度呈显著负相关,与生态优势度呈正相关.距林缘距离、枯落物盖度及高度、样地盖度等环境变量与植物多样性指数和均匀度指数呈正相关,与生态优势度呈负相关.