Livestock grazing, plateau pikas and the conservation of avian biodiversity on the Tibetan plateau

On the Qinghai-Tibet plateau increased livestock numbers have resulted in degradation of the grasslands with potential impacts on native biodiversity. Concurrently, perceived increases in populations of native small mammals such as plateau pikas (Ochotona curzoniae) have led to poisoning programs, with uncertain impacts on species such as ground-nesting birds. We explored the relationships between the local seasonal abundance of small birds and (1) the density of pika burrows; (2) livestock grazing practices; and (3) local poisoning of pikas. Around Naqu prefecture, central Tibet, we used a nested experimental design to collect data from areas rested from grazing over summer, nearby areas with year-round grazing and areas subjected to pika poisoning. Additional data were collected from a site where grazing had not occurred for at least 4 years prior to the study. Poisoning pikas in spring had no detectable effect on the local abundance of birds the following autumn. However, two ground-nesting species, white-rumped and rufous-necked snowfinches, showed positive associations with the density of pika burrows, indicating that long-term 'pika poisoning could reduce the density of these species by reducing the density of pika burrows. Rufous-necked snowfinches and non ground-nesting species including horned larks and common hoopoes showed positive responses to reduced grazing pressure from livestock, particularly in the long-rested site, indicating current grazing levels could be having a negative impact on these species. Conservation of small passerine biodiversity in this system will require changed management practices for livestock and pikas that consider the complex three-way interaction between livestock grazing, pikas and small birds. (C) 2008 Elsevier Ltd. All rights reserved.

Genetic diversity and conservation of endangered animal species

The loss of biodiversity resulting from extinctions is receiving increasing attention. Over several thousands of animal species have been evaluated and recognized as endangered species. Inbreeding depression has been demonstrated in many wild animal speci

Bird and mammal conservation in Gaoligongshan Region and Jingdong County, Yunnan, China: patterns of species richness and nature reserves

Elevational and latitudinal patterns of species richness for birds and mammals were compared with human population density in relation to nature reserve designation in two areas of Yunnan Province, China. Results suggest that species richness is not the same for the two areas. In Gaoligongshan Region, species richness is inversely correlated with elevation and altitude, while reserve designation is positively correlated with elevation and latitude. In Jingdong County, reserve designations are positively correlated with elevation, but species richness shows no clear trends. In general, the present situation is strongly influenced by human activities. It appears that reserve designation is mismatched with species richness in Gaoligongshan Region, while there is a better fit between the two in Jingdong County. In both areas, however, it appeared that reserves were located primarily in order to reduce conflict with humans rather than to maximize conservation of biodiversity, probably because humans were responsible for forest-especially primary forest-destruction and degradation in the low-lying areas.

Population status, threats and conservation of the Yangtze finless porpoise

The Yangtze finless porpoise (Neophocaena phocaenoides asiaeorientalis) is currently limited to the middle and lower reaches of the Yangtze River from Yichang to Shanghai, China, and the adjoining Poyang and Dongting Lakes. Its population size has decreased remarkably during the last several decades due to the heavy impact of human activities, including overfishing of prey species, water development projects that cause attendant habitat loss and degradation, water pollution, and accidental deaths caused by harmful fishing gear and collisions with motorized vessels. It was estimated that the number of remaining individuals was down to approximately 1800 in 2006, a number that is decreasing at a rate as high as 5% per year. Three conservation measures - in situ and ex situ conservation and captive breeding have been applied to the protection of this unique porpoise since the early 1990s. Seven natural and two "semi-natural" reserves have so far been established. Since 1996, a small group of finless porpoises has been successfully reared in a facility at the Institute of Hydrobiology of the Chinese Academy of Sciences; three babies were born in captivity on July 5, 2005, June 2, 2007 and July 5, 2008. These are the first freshwater cetaceans ever born in captivity in the world. Several groups of these porpoises caught in the main stream of the Yangtze River, or rescued, have been introduced into the Tian'e-Zhou Semi-natural Reserve since 1990. These efforts have proven that, not only can these animals survive in the area, they are also to reproduce naturally and successfully. More than 30 calves had been born in the reserve since then, with one to three born each year. Taking deaths and transfers into account, there were approximately 30 individuals living in the reserve as of the end of 2007. Among eight mature females captured in April 2008, five were confirmed pregnant. This effort represents the first successful attempt at off-site protection of a cetacean species in the world, and establishes a solid base for conservation of the Yangtze finless porpoise. A lesson must be drawn from the tragedy of Chinese River Dolphin (Lipotes vexillifer), which has already been declared likely extinct. Strong, effective and appropriate protective measures must be carried out quickly to prevent the Yangtze finless porpoise from becoming a second Chinese River Dolphin, and save the biodiversity of the Yangtze River as a whole.

The period gene: High conservation of the region coding for Thr-Gly dipeptides in the Drosophila nasuta species subgroup

In this study, the region corresponding to the Thr-Gly region of the period (per) gene in the Drosophila nasuta subgroup of species was sequenced. The results showed, that this region was highly conserved in the D. nasuta subgroup. There were only nine variable sites found in this 300-bp-long region, all located in two small regions highly variable among Drosophila species. No length variation was observed either within this subgroup or in the Yunnan (YN) population of D. albomicans. The deduced amino acid sequences were identical for all 14 taxa in the D. nasuta subgroup, and a stretch of alternating Thr-Gly pairs was not observed in this subgroup. A phylogenetic tree was constructed. The clustering of some species was in general agreement with previous works, but it also raised some question on the phylogenetic relationship between the nasuta species. The data did not implicate the Thr-Gly region playing a role in behavioral isolation in this subgroup of Drosophila.

Evolutionary Conservation of Dazl Genomic Organization and its Continuous and Dynamic Distribution Throughout Germline Development in Gynogenetic Gibel Carp

To investigate germline development and germ cell specification, we identified a Dazl homolog (CagDazl) from gynogenetic gibel carp (Carassius auratus gibelio). Its cDNA sequence and BAC clone sequence analyses revealed the genomic organization conservation and conserved synteny of the Dazl family members and their neighborhood genes among vertebrates, especially in fish. Moreover, a polyclonal antibody specific to CagDazl was produced and used to examine its expression and distribution throughout germline development at protein level. Firstly, ovary-specific expression pattern of CagDazl was confirmed in adult tissues by RT-PCR and Western blot. In addition, in situ hybridization and immunofluorescence localization demonstrated its specific expression in germ cells, and both its transcript and protein were localized to germ plasm. Then, co-localization of CagDazl and mitochondrial cloud was found, confirming that CagDazl transcript and its protein are germ plasm component and move via METRO pathway during oogenesis. Furthermore, the CagDazl is abundant and continuous throughout germline development and germ cell specification including primordial germ cell (PGC) formation, oogonium differentiation, oocyte development, and embryogenesis, and the dynamic distribution occurs at different development stages. The data suggest that maternal CagDazl might play an important role in gibel carp PGC formation. Therefore, CagDazl is a useful and specific marker for tracing germ plasm and germ cell development in the gynogenetic gibel carp. In addition, in comparison with previous studies in sexual reproduction species, the continuous and dynamic distribution of CagDazl protein in the germ plasm throughout the life cycle seems to have significant implication in sex evolution of vertebrates. J. Exp. Zool. (Mol. Deu. Euol.) 312B:855-871, 2009. (C) 2009 Wiley-Liss, Inc.

Genetic structure and low-genetic diversity suggesting the necessity for conservation of the Chinese Longsnout catfish, Leiocassis longirostris (Pisces : Bagriidae)

Genetic variation and phylogenetic relationship of Leiocassis longirostris populations from the Yangtze River were investigated at mitochondrial DNA level. The samples were collected from the upstream and mid-downstream of the Yangtze River. Three mitochondrial DNA fragments, ND5/6, cytochrome b (Cyt b) and control region (D-loop), were amplified and then digested by 10 restriction endonucleases. Twenty-three D-loop fragments randomly selected were sequenced. Digestion patterns of ND5/6 by AluI and HaeIII, D-loop by HinfI and RsaI, and Cyt b by HaeIII were polymorphic. Ten and eighteen haplotypes were obtained from RFLP data and sequence data, respectively. The individuals from upstream and mid-downstream of the Yangtze River were apparently divided into two groups. The average genetic distance was 0.008 and 0.010 according to the two data. Low diversities and decreasing abundance indicated that Leiocassis longirostris may be in severe danger and reasonable measures of fishery management should be taken.

稀有植物太行花的保护生物学研究

悬崖代表着一个残遗的、较少受到干扰的古生境，悬崖也是生物多样性的避难所。这个特殊生境中分布种类丰富的稀有植物和特有植物，而这些稀有和特有植物又往往以悬崖为唯一的生境，在长期的演化历史进程中形成彼此相互适应的关系。这种分布在特殊生境中的稀有植物为保护研究提出了新的研究方向和问题。本文以蔷薇科的中国特有植物太行花（Taihangia rupestris Yü et Li）为对象，对这个仅分布在有限的地理范围内悬崖上的稀有物种进行了保护生物学的研究。 利用RAPD分子标记技术对太行花8个居群的遗传多样性和遗传结构进行了检测分析。结果表明太行花居群内维持着较高的遗传多样性水平，未显示遭受过严重遗传瓶颈的迹象。同时，居群间遗传分化显著，与居群间的地理距离相关，聚类分析得到的树系图与太行花种下两个变种（太行花原变种Taihangia rupestris var. rupestris和缘毛太行花Taihangia rupestris var. ciliate Yü et Li）的划分相符。 通过栽培实验，研究了太行花对光照和养分的反应，从生态学角度检测植物对环境因子变化的适应能力。结果表明光照处理显著影响太行花的气体交换参数，且显示出随季节不同而变化的趋势。在8月第一次测量时，光合速率随着光照水平的增加而增加;而在9月底第二次测量时，高光下植株的光合速率反低于中光条件下的植株。光合光反应曲线表明太行花对不同光照水平（高光、中光和低光）均显示出一定的光合适应性。 光照对太行花的生长反应、形态、解剖等指标均具有显著的作用。在收获时，高光下植物形成小而厚的叶片，更快的叶片形成速率足以弥补单叶面积上光合速率的下降，使植株维持最大的总生物量。中光条件下的植株具有更长的叶柄，更大的叶面积，大而薄的叶片，和更大的叶面积比，被认为是对较弱光照环境适应的表现。而光照对叶片的气孔指标（气孔密度、气孔指数和大小）没有作用，养分施加对太行花的影响也甚微。总体来说，太行花显示出对光照变化的生理适应性和形态可塑性，光照和养分这两个环境条件均非影响太行花局限分布的关键因素。 同时，我们采用扫描电镜手段跟踪观察了太行花的花的早期发育过程。太行花早期发育过程中苞片内残留的退化花痕迹表明，太行花的顶生单花其实是有限聚伞花序中其它花芽败育的结果，显示出从花序向单花演化的趋势。同时，雌蕊的发育在早期是正常的，未显示出退化痕迹。 根据以上结果表明，局限分布在特殊生境上的太行花并未显示出生理适应幅度的狭窄性和遗传多样性水平的降低，因此，太行花在长期的进化过程中形成了对特殊生境——悬崖的适应性，遗传衰退和缺乏适应性不是稀有植物太行花局限分布的原因。在对太行花的保护中应进一步加强对其生境的保护，并在进行迁地保护和回归引种时应兼顾不同变种和地理分布的居群，以实现对其遗传完整性的有效保护。