安徽水生维管植物的多样性

通过实地调查并参考相关文献,对安徽水生维管植物的多样性进行了研究。结果表明:安徽共有水生维管植物142种、3亚种、6变种,隶属于76属,41科;具有4种生活型,组成了18个主要的植物群丛,其中挺水植物所占比例最高(56.7%),漂浮植物比例最低(7.3%)。分析安徽水生维管植物受威胁的原因,主要是湿地生境的破坏与恶化及外来种入侵等,因此,在加快湿地保护与建设的同时,应保护和利用湿地及水生植物的多样性。     

生物入侵--我国环境面临的巨大威胁

生物入侵现象近年来引起人们普遍关注,文章分析了我国生物入侵现状及其对环境的危害,并对其产生原因和对策做相应探讨,希望能引起大家重视,共同防范生物入侵。     

遵义市城区行道树组成结构分析

在采用抽样调查方法对遵义市区行道树进行调查的基础上,分析遵义城区行道树的分布格局及其树种多样性特点,并提出合理的管理措施建议。结果表明:(1)遵义城区行道树共有23种,其中桂花、女贞、杨树、广玉兰、悬铃木、柑橘等6个树种株数占总数的85.54%,总树种多样性指数为0.924;(2)行道树平均胸径偏低,胸径<10cm的树木占47%;(3)行道树总生物量约为1500t,相当于18.9hm2的森林,总叶面积为1018.67×103m2。     

Diversity and taxonomy of intertidal Bryozoa (Cheilostomata) at Akkeshi Bay,Hokkaido, Japan

We found 39 cheilostome species among more than 7000 specimens collected at 10 intertidal sites in rocky habitats along the shore of Akkeshi Bay, eastern Hokkaido Island, Japan. These species are herein described in detail and illustrated by scanning electron microscopy. Nine species (23% of total) are described as new (Electra asiatica, Callopora sarae, Conopeum nakanosum, Cauloramphus cryptoarmatus, Cauloramphus multispinosus, Cauloramphus niger, Stomachetosella decorata, Microporella luellae, and Celleporina minima), and 21 species (54%) are reported for the first time from Japan. Species richness ranged from eight to 29 species per study site. A TWINSPAN analysis showed the species fell into nine groups defined by the local pattern of distribution. A cluster analysis of study sites based on similarity of species composition showed three faunistic groups distributed geographically: in Akkeshi Lake, along the eastern‐central shore of the bay, and at the mouth of the bay. Species richness in estuarine Akkeshi Lake was low, with a species composition very different from the outer bay. Most cheilostomes were found on rock and shell substrata, but uncommonly occurred on concrete walls, algae, hydroids, tubes of polychaetes, other bryozoans, and anthropogenic debris. Of the 39 species found, 33 (85%) contained embryos during the collecting periods, 2–7 June and 3–6 July 2004. The biogeographical composition of intertidal cheilostomes at Akkeshi Bay included species with Arctic‐Boreal (28%), Boreal (59%), and Boreal‐Subtropical (13%) distributions. The overall species richness of intertidal cheilostomes was two‐thirds that documented intertidally in a comparable study at Kodiak, Alaska, a locality 15° higher in latitude. We attribute the lower richness at Akkeshi to differences in the nearshore marine environment between the two localities.     

基于净初级生产力的广西喀斯特区生物多样性维护功能评价

采用MODIS-NDVI数据、气象数据、土地覆被数据,利用光能利用率模型,估算2000～2017年的广西喀斯特区的植被净初级生产力（NPP）,分析广西喀斯特区植被NPP时空演变特征;运用气候方程法,构建广西喀斯特区气候资源空间分析模型,分析广西喀斯特区气候资源时空分布特征;在此基础上,结合地形因子,构建基于 NPP的广西喀斯特区生物多样性维护功能定量评价模型,分析广西喀斯特区生物多样性维护功能空间分布特征。结果表明：广西喀斯特区大部分为生物多样性维护功能重要区,以植被生态系统类型为空间尺度,生物多样性维护功能重要性特征表现为,灌丛＞农田植被＞草丛＞其他;以市县为空间尺度,生物多样性维护功能重要性特征表现为,由南向北、由东向西逐步递增趋势,重要、极重要区占50.6%,主要分布在百色、河池、崇左等国家级、市级山地自然保护区,一般重要区只占24.5%,主要分布贵港、玉林、桂林、贺州、来宾等地市自然灾害发生频繁、人类活动干扰频繁地区。基于较高空间分辨率的NPP,采用“3S”技术开展生物多样性维护功能定量评价,可以为区域生态保护空间精准定位提供技术支撑。