莱州湾南岸滨海湿地的生物多样性特征分析

通过2005年、2006年的实地调查和整理相关文献资料分析了莱州湾南岸滨海湿地的生物多样性总体特征,湿地维管束植物和水禽的区系组成特点,并与黄河三角洲滨海湿地的生物多样性特征进行了对比。莱州湾南岸滨海湿地维管束植物区系科的分化程度较低,属的分化程度较高,湿生植物、水生植物在区系中占据重要地位;从生活型角度分析,区系中草本植物、地下芽植物和一年生植物占据优势;从维管束植物区系的地理分布成分看,以温带分布属和世界分布属为主;莱州湾南岸滨海湿地水禽区系的居留型构成以旅鸟和候鸟为主,地理分布成分构成以古北界种为主。莱州湾南岸滨海湿地的维管束植物和水禽种类都明显少于相邻的黄河三角洲滨海湿地。

临沂湿地生物多样性研究及特征分析

为了更好地保护临沂湿地资源,通过实地调查、查阅文献和比较分析的方法,探讨临沂湿地生物多样性现状及其总体特征。结果表明,临沂湿地有浮游植物33科75属195种,维管束植物64科166属272种,浮游动物36科60属128种,鸟类46科101属195种,鱼类12科41属53种,底栖动物12科18属18种,两栖动物2科3属7种,爬行动物6科8属10种,哺乳类5科10属10种,昆虫103科317属452种,其中水生昆虫28科81属113种。临沂湿地具有生物多样性丰富、生物的生态适应类型复杂多样、生物区系分布有一定规律性、湿地资源性动植物和国家重点保护物种较多、湿地入侵物种逐年增多等特点。

大熊猫主食竹种及其生物多样性

现代大熊猫分布在四川西部37个县市区、陕西南部5个县和甘肃南部1个县,栖息地面积约200,000 km2,竹林面积约600,000 hm2,竹子蓄积量约18,000,000 t。分布范围在λ（E）102°00′-108°11,′ψ（N）27°53′-33°55,′常年活动在海拔（1 200）2 000 m-3 000（3 600）m之间。从南到北长度直线距离约750 km,东西宽约50 km-180km,处于我国地形第一级阶梯青藏高原向第二级阶梯高原山地盆地过渡地带上,呈狭长状弧形分布外貌,但并不连续而是作岛状的间断分布。大熊猫主食竹种在其分布范围内,分隶于竹亚科仅有的箣竹超族和北美箭竹超族2个超族中,前者含5属19种,后者含6属45种,一共采食11属64种竹子。其中除箣竹属的孝顺竹、硬头黄竹,慈竹属的慈竹及苦竹属的斑苦竹为栽培外,其余8属51种均为野生竹种,并有大面积的天然竹林。慈竹属、刚竹属、筇竹属、巴山木竹属和箬竹属等5属为我国特产,占大熊猫主食竹属的45%。筇竹属、镰序竹属、方竹属、箭竹属、玉山竹属和巴山木竹属等90%以上的种类产于我国西南部山区,而且大熊猫分布区也是该6属的分化中心和现代分布中心之一。大熊猫分布区的植物区系起源古老,成分复杂。在大熊猫天然采食的64种竹种中,除峨眉箬竹分布区域小和数量零星,不足以形成独立的群系外,其余63种竹子均可在竹林植被型中形成独立的群系。中国大熊猫栖息地主要是针叶林和阔叶林两个植被型组,有时偶见活动于灌丛植被型组区域。在针叶林植被型组共有5个植被型中的寒温性针叶林、温凉性针叶林、温凉性针阔叶混交林和暖性针叶林等4个植被型及以竹子为次优势层片的59个以上植物群丛组,阔叶林植被型组的落叶阔叶林、常绿落叶阔叶混交林和常绿阔叶林等3个植被型及以竹子为次优势层片的56个以上植物群丛组,总计针、阔叶林有7个植被型及115个以上植物群丛组是大熊猫的栖息地。其中温凉性针阔叶混交林又是大熊猫的最主要栖息地,周年四季都有活动足迹和采食其林下竹种。大熊猫栖息在有竹子为次优势层片的森林植物群落中,不但有食物的保障,而且有复杂的森林生态系统和良好的生活环境,使大熊猫得以长期延续生存繁衍和不断发展。

放牧方式对浑善达克沙地东缘草地植被特征影响

为探讨不同放牧方式下的草地植被组成变化,研究放牧方式对草地植物群落数量特征及生物多样性特征的影响,以浑善达克沙地东缘克什克腾旗为研究区域,通过对3种放牧方式的比较研究,结果表明:不同放牧方式在一定程度上改变了植被种群结构。自由放牧的优势种为羊草、落草,季节性放牧的优势种为羊草、碱蒿,划区轮牧的优势种为羊草和沙米;总体来说,划区轮牧下的植物种数、盖度、高度、生物量及多样性指数均高于季节性放牧和自由放牧。说明适宜的放牧方式可提高草地生态系统的稳定性和生产潜力。

Status of urban vegetation in Guangzhou City

According to a survey for the urban vegetation of Guangzhou, urban vegetation has a significantly difference from natural vegetation because of intense human impacts. The research was conducted in a synthetic survey for soil, species di-versity, roadside trees and ecological function of urban vegetation in Guangzhou City. The results showed that: (1) soil densi-ties of urban roadside and park forests were higher than mean density of natural forest soil. The pH values of soil in urban roadside were higher too, and the content of organic matter and the concentration of nitrogen were lower. (2) Species diversity of urban vegetation was lower. The most number of species was only 16 species in tree layers of urban forest. (3) Tree growth was limited by narrow space in high-density urban area, where the trees with defects and disorders were common. (4) Com-paring with mature natural forests, the productivity of urban vegetation was lower. The effect of urban vegetation on balance of carbon and oxygen were influenced by the low primary production of urban vegetation. Therefore, the growth condition for urban vegetation should be improved. Biodiversity, primary production and ecological function should be increased for urban vegetation in order to improve urban eco-environment.

Microbial Community Characteristics in a Degraded Wetland of the Yellow River Delta

Five different sites with a soluble salt gradient of 3.0-17.7 g kg^-1 dry soil from the coast to the inland were selected, and the microbial population size, activity and diversity in the rhizospheres of five common plant species and the adjacent bulk soils （non-rhizosphere） were compared in a degraded wetland of the Yellow River Delta, Shandong Province, China to study the effects of soil environment （salinity, seasonality, depth, and rhizosphere） on microbial communities and the wetland＇s ecological function, thus providing basic data for the bioremediation of degraded wetlands. There was a significant negative linear relationship between the salinity and the total number of microorganisms, overall microbial activity, or culturable microbial diversity. Salinity adversely affected the microbial community, and higher salinity levels resulted in smaller and less active microbial communities. Seasonal changes were observed in microbial activity but did not occur in the size and diversity. The microbial size, activity and diversity decreased with increasing soil depth. The size, activity and diversity of culturable microorganisms increased in the rhizospheres. All rhizospheres had positive effects on the microbial communities, and common seepweed had the highest rhizosphere effect. Three halophilic bacteria （Pseudomonas mendocina, Burkholderia glumae, and Acinetobacter johnsonii） were separated through BIOLOG identification, and common seepweed could be recommended for bioremediation of degraded wetlands in the Yellow River Delta.

Spatial Correlation and Ecological Characteristics Analysis of Man-agement Area for Biodiversity Conservation and Relevant Regionalization

Formulation of different ecological zone plans according to the corresponding protection targets and the necessity of proper conservation policy is one of the measures to achieve the goal of ecological conservation in China.In order to clarify the interrelation among key ecological zone plans,this paper carried out the research on spatial relation of priority areas of biodiversity conservation and three key ecological areas(key ecological function areas,key regions of ecological service function,national nature reserves)and the research on ecological conditions,based on multi-scale ecological spatial theme information,which incorporates elements like ecological quality and type,and by the aid of spatial information analysis and GIS modeling.The results showed a contrastively fine spatial consistency with 68.8%of priority areas of biodiversity conservation overlapping with three key ecological areas.Although the environment in priority areas of biodiversity conservation were in good conditions,protection pressure is also increasing,powerful supervision and protection should not be ignored.The environmental conditions in the overlapping areas,as a whole,were superior to those in the non-overlapping areas.Since two areas have different characteristics,targeted protection measures should be formulated based on this difference,which will be very important for biodiversity conservation in priority areas of biodiversity conservation.

Dynamic genetic features of eukaryotic plankton diversity in the Nakdong River estuary of Korea

Estuaries are environments where freshwater and seawater mix and they display various salinity profiles.The construction of river barrages and dams has rapidly changed these environments and has had a wide range of impacts on plankton communities.To understand the dynamics of such communities,researchers need accurate and rapid techniques for detecting plankton species.We evaluated the diversity of eukaryotic plankton over a salinity gradient by applying a metagenomics tool at the Nakdong River estuary in Korea.Environmental samples were collected on three dates during summer and autumn of 2011 at the Eulsukdo Bridge at the mouth of that river.Amplifying the 18 S rDNA allowed us to analyze 456 clones and 122 phylotypes.Metagenomic sequences revealed various taxonomic groups and cryptic genetic variations at the intra-and inter-specific levels.By analyzing the same station at each sampling date,we observed that the phylotypes presented a salinity-related pattern of diversity in assemblages.The variety of species within freshwater samples reflected the rapid environmental changes caused by freshwater inputs.Dinophyceae phylotypes accounted for the highest proportion of overall diversity in the seawater samples.Euryhaline diatoms and dinoflagellates were observed in the freshwater,brackish and seawater samples.The biological data for species composition demonstrate the transitional state between freshwater and seawater.Therefore,this metagenomics information can serve as a biological indicator for tracking changes in aquatic environments.

Seasonal Effect of Geomorphological Chronosequence Features on Soil Biota Dynamics

Numerous studies have been devoted to the physical-chemical weathering processes leading to the creation of unique soil formations having their own history that induce soil-biotic diversity.However,the extent to which unique geomorphic formations influence soil biotic seasonal variation is not clear.Our aim was to define seasonal variations of soil biota in soils of different-aged terraces of the Makhtesh Ramon anticline erosional cirque in southern Israel.The strong effect of Makhtesh Ramon (Ramon crater) erosional fluvial terrace age initiated by climatic changes during the Late Pleistocene- Early Holocene period on seasonal variations in both soil properties and the abundance and composition of soil biota were demonstrated.However,age dependence was not constant and values for observed soil properties and microbial activity were negligible between younger and older terraces for certain seasons,while free-living nematodes along with bacterial-feeding group were strongly dependent on the geomorphic features of the ages throughout the study period.

Impact of grazing on germination trait selection in an alpine grassland on the Tibet Plateau

Previous studies indicated that grazing can cause significant changes in abiotic and biotic environment in grassland.However,how these changes impact germination trait selection in grassland has not been well studied.Thus,we aimed to explore whether grazing can significantly change germination trait diversity and composition of grasslands community.We measured the germination traits of species in the laboratory,and compared their performance in grazed and nongrazed grasslands.Then,we compared the community-weighted means of germination traits and functional diversity of grazed and nongrazed grasslands based on these germination traits to know whether grazed and nongrazed grasslands differed in their germination trait structures.At the species level,we found that the changes of abundance in grazed and nongrazed grasslands were not related to species’germination traits.However,at the community level,compared with nongrazed grasslands,species in the grazed grasslands generally exhibited a higher seed germination percentage.Moreover,seed germination response in grazed grasslands was more positively related to alternating temperature than in nongrazed grasslands,and breadth of the germination temperature niche was narrower in grazed than in nongrazed grasslands.Compared with nongrazed grasslands,seed germination trait diversity was increased and germination trait evenness decreased in grazed grasslands.Grazing can change microhabitat conditions,thereby changing germination trait selection by environmental filtering,resulting in a significant difference in germinate trait composition at the community level.

Research on structural characteristics of large-scale CdS thin films deposited by CBD under low ammonia condition

Cadmium sulfide(Cd S) buffer layers with the scale of 10 cm×10 cm are deposited by chemical bath deposition(CBD) with different temperatures and thiourea concentrations under low ammonia condition.There are obvious hexagonal phases and cubic phases in Cd S thin films under the conditions of low temperature and high thiourea concentration.The main reason is that the heterogeneous reaction is dominant for homogeneous reaction.At low temperature,Cd S thin films with good uniformity and high transmittance are deposited by adjusting the thiourea concentration,and there is almost no precipitation in reaction solution.In addition,the low temperature is desired in assembly line.The transmittance and the band gap of Cd S thin films are above 80% and about 2.4 e V,respectively.These films are suitable for the buffer layers of large-scale Cu(In,Ga)Se2(CIGS) solar cells.