采自哈纳斯的新疆新记录的地衣

报道了１９９６年７月在哈纳斯自然保护区及其附近所采到的新疆新记录地衣１２种，其中１种１属为地知地衣，另１１种隶属于１１个属，６科。     

地图衣的2个中国新记录种

地图衣主要分布于极地和温带高海拔地区,全世界约有200种。中国已经发现的地图衣仅有28种。该文报道了地图衣的2个中国新记录种(Rhizocarpon concentricum和R.geminatum),并提供了这2种地衣的详细特征照片。     

新疆哈纳斯自然保护区地衣群落的聚类分析

我们根据多年的实地调查结果并采用聚类分析方法对分布在哈纳斯国家级自然保护区的地衣群落进行了研究。结果表明分布在该地区的地衣种类有 10 3种 ,他们分别属于 2 0科 ,4 0属。地衣物种形成了 6种群落。同时发现该地区地衣对基物形成专一性 ,它们的基物包括 :树皮、藓丛、藓土、草地、石面、地面、土层、石浮土等。     

哈纳斯国家自然保护区地衣区系的基本特点

对哈纳斯自然保护区地衣区系的形成进行了研究，从地学的角度简明地阐述了地衣区系的形成条件、地理区系成分特点。笔者等于1985年以来几次在保护区进行实地考察和室内分析的基础上，对保护区自然地理条件，特别是对地衣植被有一些初步认识，并对该地区环境保护、旅游业的发展与生物资源和生物多样性研究提供参考。     

污染指示生物苔藓和蚂蚁中的重金属污染比较分析

采样测定并比较了城市不同区域两种指示生物苔藓和蚂蚁体内的Pb、Cu、Cr、Cd含量及分布特征，讨论了这两种指示生物的重金属累积率和土壤重金属浓度的关系。结果表明，苔藓对比有很强的富集能力，其体内的重金属浓度随土壤浓度的增大而增大，且比蚂蚁更易受到环境中重金属污染的影响；Pb和Cd是蚂蚁的环境敏感元素，但蚂蚁对重金属在体内的持续积累有一定的抑制机制，其体内Cu的浓度与土壤中浓度的相关性较Pb、Cd小，且Cd在较低浓度时和土壤浓度呈相关性，较高浓度时相关性受抑制。同时运用污染指数分析评估了城市环境的污染状况及重金属对指示生物的毒性。     

新疆乌鲁木齐南山八一林场地衣生态地理学特征

采用显色反应(CT)、微量结晶 (MCT)和薄层色谱 (TLC)等方法,分析乌鲁木齐南山八一林场地衣的物种组成及生态地理特征。结果表明：乌鲁木齐南山八一林场地衣资源较为丰富,共有7目、23科、51属、114种、9变型、9变种。含5种以上的大科共有7个,占总科数的30.43%,分别包括本地区50.98%的属和68.42%的种。地衣的地理成分可划分为12类, 包括欧亚-北美成分(39.47%) 、北半球广布成分(13.16%) 、中国特有成分(12.28%)和世界广布成分(10.53%)。该地区地衣种类与北美、欧洲等地在地衣区系上有一定的相似性,并具有明显的中国特有种类。     

Pyrosequencing Reveals Significant Changes in Microbial Communities Along the Ecological Succession of Biological Soil Crusts in the Tengger Desert of China

Biological soil crusts (BSCs) have important ecological functions in arid and semiarid lands, but they remain poorly understood in terms of the changes in microbial communities during BSC succession under in situ field conditions. Here, 454 pyrosequencing was used to assess the microbial community composition of four BSC types in the Tengger Desert of China: alga, lichen (cyanolichen and green alga-lichen), and moss crusts, representing early, middle, and final successional stages of BSCs, respectively. The results showed the highest diversity of microbial communities inhabiting lichen crusts, whereas the lowest diversity was observed in moss crusts. Five phyla, Proteobacteria, Actinobacteria, Cyanobacteria, Bacteroidetes, and Acidobacteria, accounted for about 72% to 87% of total prokaryotic sequences in different BSCs. The most abundant eukaryotic microorganism was Ascomycota, accounting for 47% to 93% of the total eukaryotic sequences. Along the succession of BSCs, the abundance of photoautotrophic Cyanobacteria, Chlorophyta, and Bacillariophyta declined, and that of heterotrophic microorganisms such as bacteria and fungi increased. Statistical analysis showed clear divergency of microbial taxa at the class level among the different successional stages of BSCs. The clustering results at class level showed that the moss crusts were the farthest from the rest in prokaryotic composition; the alga crusts were the most different in terms of eukaryotic microorganisms and the two kinds of lichen crusts were relatively closer in both compositions. Ordination analysis showed that the main variations of community structure among BSCs could be explained best by the abundance of Cyanobacteria and Ascomycota and by physiochemical properties of BSCs, including mechanical composition, moisture, and electrical conductivity. In conclusion, our results indicate that Cyanobacteria and Ascomycota likely play an important role in the evolution of BSC structure and functions and highlight the importance of environmental factors in shaping microbial community structures of BSCs in the Tengger Desert of China.     

Optimization of DTPA and calcium chloride extractants for assessing extractable metal fraction in polluted soils

Abstract

Metal availability in soils is often assessed by means of extraction with chemical solutions, among others the chelating agent DTPA (diethylenetriaminepentaacetic acid) and the non‐buffered salt calcium chloride (CaCl₂). The same procedures are used for polluted soils that were originally created to assess the nutrient status of arable soils. We studied the influence of various parameters (type of shaker, shaking time, soil to solution ratio, and concentration of chemical extractant) and modify the DTPA and CaCl₂ extraction procedures to make them suitable for the study of polluted soils. The chosen extraction ratio and extractant concentration were the followings: 8 g/20 mL of 0.1 MCaCl₂ and 2 g/20 mL of 0.005 M DTPA. The optimized procedures were applied to nine soil samples affected by different sources of pollution (mine works, vehicle emissions, and various industries). Cadmium (Cd) showed the highest extractability with both extractants. Depending on the soil, copper (Cu) and zinc (Zn) (using DPTA) and Cu and manganese (Mn) (using CaCl₂) were the followings in the extractable amounts. Cadmium, Cu, and Zn were highly correlated in both extractions and with total contents.     

提取地衣真菌总DNA的简便方法

利用液氮破碎地衣体的上下表皮层及藻层，再用氯化苄在弱碱条件下破坏真菌细胞壁，从而获得地衣真菌总ＤＮＡ．此方法简便、省时、价廉，获得的总ＤＮＡ蛋白质污染少，产量高，可进一步进行ＰＣＲ扩增．     

河北省地衣新记录属

报道了采自河北省地衣5新记录属:孔文衣属(Opegrapha Humb.)、袋衣属(Hypogymnia(Nyl.)Nyl.)、黄茶渍属(Candelariella Muell.Arg.)、黄烛衣属(Candelaria Massal.)和盾衣属(Peltula Nyl.)。文中对5属地衣的生境、识别特征和地理分布特点进行了简要概述。