SaudiVeg ecoinformatics: Aims,current status and perspectives

During the last decade many electronic databases of vegetation plots were established in many countries around the world. These databases contain valuable phytosociological information assisting both governmental and NGO (Non-governmental organizations) agencies to formulate strategies and on-ground plans to manage and protect nature resources. This paper provides an account on aims, current status and perspectives of building of a vegetation database for the Central Region (Najd) of Saudi Arabia – the founding element of the Saudi Vegetation Database (SVD). The data stored by the database are sample plots (vegetation relevés) collected according to the field techniques of the Braun-Blanquet approach (lists of taxa accompanied by semi-quantitative cover assessment), and are accompanied by general vegetation characteristics such as vegetation layering and cover, information on life-form of the recorded species, geographical coordinates, altitude, soil typology, topography and many more. More than 2900 vegetation-plot records (relevés) have so far been collected in the Najd region; of these more than 2000 have already been stored using the Turboveg database platform. These field records cover many habitats such as depressions, wadis (dry river beds), agricultural lands, sand dunes, sabkhas, and ruderal habitats. The ecological information collected in the database is currently the largest set of vegetation data collated into a database in the Middle East. These data are of great importance for biodiversity studies in Saudi Arabia, since the region is recording a loss of biodiversity at a fast rate due to environmental problems such as global warming and land-use changes. We envisage that this database would catalyze further data collection on vegetation of the entire Arabian Peninsula, and shall serve as one of the most important datasets for classification and mapping of the vegetation of the Kingdom of Saudi Arabia.     

浙江天台山甜槠群落研究

以分布在浙江省天台山的甜储群落为对象,分析了群落的特征和性质。甜储群落中,甜储的优势突出,呈单优势群落。群落垂直结构复杂,可分为乔木层、灌木层、草本层,亦有一定数量的层间植物。乔木层的物种多样性指数偏低,这与特定生境所形成的单优势群落有关。各样地间的植物种类具有较高的相似性,群落内种类组成相对一致。群落内优势种群甜储、木荷的年龄结构属稳定型或增长型,它们在各样地的分布格局均呈集群分布。     

新疆卡拉麦里山有蹄类野生动物自然保护区啮齿动物群落多样性及其与环境因子的关系

啮齿动物的群落结构受生态环境特征影响,并能反映环境变化规律。为探讨啮齿动物群落多样性及其与环境因子间的关系,利用铗捕法获得了新疆卡拉麦里山有蹄类野生动物自然保护区9种生境类型的环境因子及啮齿动物群落结构数据。2019-2020年春、夏季,共布设样地291块,有效铗日55269个,调查总面积176.875 km²,记录了啮齿类分布的12个环境因子。捕获啮齿动物419只,分属1目4科10属12种,优势种为三趾跳鼠（Dipus sagitta）和五趾跳鼠（Allactaga sibirica）,分别占捕获总个体数的34.13%和27.68%。分析结果显示,卡山自然保护区啮齿类捕获率最高的生境类型为沙漠（2.18%）;捕获鼠种的主要分布型为耐旱型（98.09%）。12个环境因子在9个生境类型中均呈极显著差异（P<0.01）,说明该保护区啮齿动物分布的生境异质性高。冗余分析表明,海拔高度、植被种类、灌木盖度和灌木高度是决定啮齿动物群落结构最主要的4个环境因子,其中植被种数与啮齿类群落多样性呈正相关,随着植被种数数值的增加,除优势度指数外,其它多样性指数随之增加。     

金佛山亚热带常绿阔叶林地表土壤动物群落特征及其影响因素

为探讨小尺度下不同微生境的土壤动物群落特征及其与环境因子之间的关系,于2018年10月在金佛山西坡亚热带常绿阔叶林样带内,对其凋落物层及腐殖质层两类微生境的土壤动物群落进行调查及相应环境因子的测定。此次调查共捕获地表土壤动物12381头,隶属于3门9纲22目。其中优势类群为蜱螨目和长角虫兆目,个体数占比为75.24%;常见类群为原虫兆目、愈腹虫兆目、短角虫兆目、双翅目、鞘翅目和膜翅目,个体数占比为21.23%。同时,土壤动物的密度（M）、Shannon-Wiener多样性指数（H）、Simpson优势度指数（D）及Pielou均匀度指数（E）均表现为腐殖质层极显著高于凋落物层（P<0.01）。根据回归分析及冗余分析结果发现,两类微生境的土壤动物群落特征与环境因子的关系存在一定差异;影响凋落物层土壤动物群落特征的重要环境因子为凋落物的总有机碳、碳氮比、湿度及pH,而影响腐殖质层土壤动物群落特征的重要环境因子为腐殖质的干重、总氮、总磷、湿度、pH及微生物生物量氮。研究表明,常绿阔叶林生态系统的不同微生境间土壤动物多样性特征存在显著差异,小尺度下环境因子对土壤动物群落特征具有重要影响。     

Effects of Temperature on Bud-Sprouting and Early Growth of Cyperus esculentus in the Dark

Cyperus esculentus tubers and early growth of their sprouts. Percent sprouting increased with increasing temperature within the range of 12 to 38 C, while no sprouting occurred at 10 C and few tubers sprouted at 42 C. The rate of sprouting also increased with temperature up to 35 C. A base temperature of 11.4 C was determined for bud-sprouting of tubers in this species. Higher temperatures led to larger sprouts and greater survival rate. In particular, increased temperature favored root growth, and hence resulted in high root: shoot ratio of the sprouts. Larger tubers produced larger sprouts as a consequence of mobilizing a greater amount of their reserves, but they tended to utilize a smaller proportion of their reserves. The efficiency of reserve utilization significantly differed among the incubation temperatures, and its relation with temperature followed a quadratic pattern. This pattern is different from that documented for the bud-sprouting of rhizomes and stolons of other perennials. Our results demonstrate that temperature is crucial to the successful establishment of C. esculentus. Received 24 June 1999/ Accepted in revised form 14 December 1999     

Woody vegetation composition and diversity in woodlands inside and outside a Forest Reserve in Jos,Nigeria

Protected areas such as forest reserves are often assumed to be best ways to conserve biodiversity and maintain intact ecosystems. We examined woody plant composition and diversity in the gallery forest and savannah woodland habitats of Amurum Forest Reserve and areas immediately surrounding it in Jos, Nigeria. A total of 100 10 × 10 m sample plots were established inside and outside the reserve. All woody plants ≥1 cm diameter at breast height (dbh) were identified and measured. A total of 7,564 individual plants categorized as 134 species from 44 families were recorded. Overall species diversity was significantly higher in the Forest Reserve than outside the reserve, although more species were encountered outside the reserve. Our findings suggest that, protected areas and the areas surrounding them are important for the conservation of biodiversity as the areas outside protected areas also contain species of conservation value. The continuous degrading areas outside protected areas isolates them and poses a serious threat to the long‐term viability of wildlife populations, so it is important that biodiversity in protected areas and their surrounding areas be conserved.     

不同时间和空间尺度上台湾水青冈群落谱系结构动态变化

群落谱系结构是了解群落聚群过程的一个基础研究内容。但是现有大部分研究内容集中在群落组成和结构的时空差异,对谱系结构的动态变化研究较少。以浙江省清凉峰国家级自然保护区的国家二级保护植物台湾水青冈(Fagus hayatae)林为研究对象,利用2006年、2011年、2016年3次群落动态调查数据,从10、20、50m的3个空间尺度上研究该群落在10a间的谱系结构动态变化,分析时空尺度对台湾水青冈群落谱系结构的影响,探究调控台湾水青冈群落动态变化的主要因子,为后期台湾水青冈林的保护提供理论基础。研究发现(1)在10a森林动态变化过程中,群落的MPD指数下降,MNTD指数增加。NRI和NTI指数在大尺度上随时间显著增加,但在小尺度上无显著变化。(2)随着空间尺度的增加,上述指数的动态变化趋势均不断增强。以上结果表明,2006—2016年间台湾水青冈群落总体谱系结构表现出不断聚集的趋势,而近缘种的谱系关系则不断疏远;群落谱系结构的聚集趋势随空间尺度的增加而增强。大尺度上的环境过滤和小尺度上的随机过程和种间竞争作用可能是导致该地区台湾水青冈群落谱系结构动态变化的主要生态学过程。     

同域分布的珍稀野生动物对放牧的行为响应策略

保护区内放牧活动对野生动物保护存在负面影响,明确不同物种对放牧干扰的行为响应对制定更有针对性的保护管理政策具有重要意义。使用红外相机研究卧龙自然保护区放牧活动对多种珍稀野生动物的影响,分析放牧激励政策实施前后大熊猫(Ailuropoda melanoleuca)及其同域分布的小熊猫(Ailurus fulgens)、川金丝猴(Rhinopithecus roxellana)、水鹿(Rusa unicolor) 4种珍稀野生动物的照片数、空间分布以及活动模式的变化,探讨这4种动物对放牧的行为响应策略。结果表明:(1)一期(2012—2013),2012年10月实施了禁马政策,同年12月实施放牧(牛羊)激励政策)家畜照片数量很少,4种野生动物照片数相对较多。二期(2014—2015)家畜的照片数显著增加(P0.01),小熊猫(P0.05)与川金丝猴(P0.01)的照片数均显著减少,大熊猫、水鹿的照片数也呈减少趋势;到三期(2016—2017),大熊猫、小熊猫及水鹿3种关注野生动物的照片数基本回升到激励政策实施前的水平,无川金丝猴照片记录。(2)一期,4种野生动物在研究区域有较广的分布;二期,大熊猫、小熊猫的空间分布范围均缩小,无川金丝猴空间分布信息,而家畜、水鹿的空间分布范围有所增加;到三期,大熊猫、小熊猫的空间分布基本恢复到放牧激励政策实施前的区域,无川金丝猴的空间分布信息。(3)放牧激励政策实施前后,大熊猫、小熊猫及川金丝猴活动模式无明显变化,但水鹿的活动更加集中于傍晚,以避开人类与家畜的活动高峰。同域分布的不同的野生动物对人类活动(如放牧)的行为响应策略不同,各保护区在制定相关保护政策时应综合考虑人类干扰对多个物种的影响,增加决策的科学性与合理性。     

盐城国家级自然保护区景观格局变化及其驱动力

利用RS、GIS手段研究分析了盐城新洋港—新港闸段国家级自然保护区内景观格局的时空变化及其驱动力因子,结果表明:1992—2008年间,在景观面积变化方面,全区内景观主体由自然景观变成了人工景观;核心区内自然景观面积变化不大,仍以自然景观为主;缓冲区和试验区内的自然景观面积都不断减少,分别减少了约30%和75%。在景观破碎度方面,全区内景观的密度指数增加1倍,景观破碎化程度加剧;核心区内斑块密度指数呈现略减,各景观类型的平均斑块的面积增大,景观破碎化程度略增但不显著;缓冲区和试验区破碎化程度加剧。在景观多样性方面,全区内景观格局由简单变得复杂化,多样性指数增大,异质化程度增加;核心区内景观多样性呈现略增但不显著;缓冲区内景观多样性显著增加;实验区内多样性指数减小,景观异质化程度降低;整个研究区内的景观格局向均衡化方向发展,核心区和缓冲区变化与全区一致,而试验区景观格局朝单一化方向发展。由于引起景观格局变化的外界干扰不断加深,盐城国家级自然保护区内的景观生态环境保护与经济开发之间的矛盾亦将愈发突出。     

广东象头山国家级自然保护区珍稀野生花卉资源

对广东象头山国家级自然保护区珍稀野生花卉资源调查结果表明,本区内有52科68属88种,其中蕨类植物11科11属13种;被子植物41科57属75种,并对其基本组成、多样性等进行分析。根据本区珍稀野生花卉的现状与特点,划分出生活类型,提出园林配置方式,对资源保护和开发利用提出建议。