保持中度生长势成为建筑外表面绿化的选择策略

针对建筑外表面绿化的特殊性提出了中度生长势概念,分析了生长势和绿化寿命的影响因素并提出了概念模型,进一步结合实验探讨了中度生长势的判定.研究结果将补充和丰富城市特殊生境绿化条件下的植物栽培养护理念,为实现节约、可持续的栽培养护模式,延长绿化生命周期提供指导.     

Microhabitat selection in the sand recluse spider (Sicarius thomisoides): the effect of rock size and temperature

In spiders, temperature is considered an important environmental variable for microhabitat selection. In this study, we evaluated the effect of temperature and rock size on the presence of the sand recluse spider Sicarius thomisoides and the degree of selectivity in different locations. This species is a large spider that lives under rocks in desert and semi-desert climates and is particularly active during the summer. In Chile, these spiders can be found at both coastal and inland locations under different thermal conditions, where usually the temperatures are lower near the coast. If large-scale climatic conditions are important for this species, they may be expected to select lower rock temperatures on the coast than at inland locations. In addition, we would expect that the spiders would choose larger rocks in inland compared to coast locations, which reduce the effect of high temperatures. We found that the probability of finding individuals of this species increased according to rock temperature and rock size in the field. Our results suggest that S. thomisoides prefers larger and warmer rocks to shelter under during the day, this selectivity being similar at both coastal and inland locations. Thus, this species tends to select rocks with the same thermal and structural conditions, independent of the climatic conditions.     

Specialist and generalist species in habitat use: implications for conservation assessment in snakes

Habitat specialization is recorded as one of the central factors that make species vulnerable to extinction. Among snakes, there is considerable variation in this trait, as some species are specialists and others are generalists in habitat use. We have quantified habitat specialization in the snakes of the southern Iberian Peninsula, and compared it with their abundance and IUCN categories. All data were combined for a principal components analysis that discriminated two main groups: three generalist species that live in all types of habitat, and five specialist species that ranged from rather scarce to extremely rare and are found only in unaltered habitats. The three generalist snakes are not threatened and their IUCN category is Least Concern. Three out of the five specialist species are categorized as Near Threatened, Vulnerable, and Endangered at regional or national levels. The other two species are currently considered Not Threatened and we discuss whether they are incorrectly classified. The conservation status of snakes is difficult to evaluate because of their secretive habits and low population densities. We suggest that quantifying habitat specialization may be a useful tool for assessing the conservation status of secretive organisms such as snakes.     

基于GIS图谱法的中药资源生境恢复研究——以云南楚雄州彝药资源研究为例

为了对我国中药资源数字化的深入研究提供基础,提出利用现代GIS技术与地学图谱叠加相结合的方法进行生境恢复研究,建立了生境恢复的评价指标体系,并以云南楚雄州为研究区域,进行了彝药资源的生境恢复研究案例.结果表明: 1)生境恢复研究是实现我国中药资源可持续发展和利用的重要途径;2)GIS图谱法是进行生境恢复研究的科学有效技术方法.     

白腹锦鸡雌鸟繁殖期的活动区和栖息地选择

2006年3-9月,利用无线电遥测技术和系统搜索法对四川省石棉县栗子坪自然保护区白腹锦鸡雌鸟的繁殖期活动区和栖息地选择进行了研究.对遥测时间超过4个月的3只雌性个体的研究表明:白腹锦鸡雌鸟的繁殖期活动区面积为(31.16±26.02) hm2,核心区面积为(10.06±8.47) hm2;繁殖鸟的活动区在产卵前后有明显变化,算术中心距离超过300 m,未繁殖鸟不明显.白腹锦鸡雌鸟主要选择较稀疏、稍矮、盖度较大、倒木数少的乔木环境和较密而盖度较大的灌木、草本植物的环境.     

Habitat-induced reciprocal transformation in the root phenotype of Oriental ginseng is associated with alteration in DNA methylation

Oriental ginseng is an important medicinal plant that grows in 2 major forms or ecotypes, wild and domesticated. Each form differs conspicuously in root phenotype, but can be converted from one type to another by habitat. Here we show that the habitat-induced transformation of ginseng root phenotype was accompanied by alteration in cytosine methylation at a large number of 5′-CCGG-3′ sites detected by the methylation-sensitive polymorphism (MSAP) marker. The collective CG and CHG methylation levels of all 4 landraces of the domesticated form were significantly lower than those of the wild form. Interestingly, artificially transplanted ginseng plants recreated in both directions the methylation levels (at least in CHG) of their natural counterparts. The methylation differences between the 2 ginseng ecotypes were validated at 2 isolated MSAP loci bearing homology to a 5S rRNA gene or a copia retrotransposon. Our results implicate a link between epigenetic variation and habitat-induced phenotypic flexibility in Oriental ginseng.     

广西元宝山自然保护区黑熊春季觅食生境特征

在广西元宝山自然保护区野外设置了82个20 m×20 m样方,初步分析黑熊春季觅食地生境特征,对16个生态因子进行主成分分析和单因子适合度检验。结果表明：黑熊觅食地生境特征的主要影响因子为水源距离、海拔和灌木密度;次要因子为食物丰富度因子(树径、乔木密度、乔木距离、灌木距离)、地理性因子(坡向、坡位、坡度)、干扰性因子(树桩密度、树桩距离、倒木距离、人为干扰距离)和微生境因子(避风性、郁闭度)。对黑熊的生境喜好程度分析发现：水源丰富、一定海拔、避风性适中、植物茂盛(乔木密度、灌木密度、乔木距离、灌木距离)、坡向向阳、郁闭度好(30 %～80 %)、坡度较大的山嵴和山坡位为其最适生境。由于人类活动增加,干扰因子(树桩密度、树桩距离、倒木距离、人为干扰距离)成为影响黑熊生境选择的重要因素。     

陕西黄龙山自然保护区褐马鸡秋季觅食地选择

2006年10～11月,在陕西黄龙山自然保护区对褐马鸡觅食地选择进行研究.分析表明:褐马鸡喜欢生活在针阔混交林;海拔1 200～1 400 m;小于10°的平缓坡;中坡位;山沟;乔木盖度50%～80%,乔木高度小于10 m,乔木密度小于0.10个/m2;灌丛盖度小于30%,灌丛高度大于1.5 m,灌丛密度小于1个/m2;草本盖度小于30%,草本高度小于16 cm;隐蔽级小于10%;水源距离小于300 m;林边距离小于100 m;人为干扰距离100～300 m的环境.主成分分析表明,褐马鸡觅食地选择的主要因子有4种,依次为:地形及草本植物因子(海拔、地理性、坡位、草本盖度和高度)、隐蔽因子(灌丛盖度、密度和高度以及隐蔽级)、干扰因子(水源距离、人为干扰距离、林边距离和植被类型)、食物因子(乔木直径、高度、密度和盖度).     

Factors influencing anuran distribution in coastal dune wetlands in southern Brazil

We investigated the potential role of hydroperiod and habitat structural complexity as explanatory factors defining richness, abundance and spatial and temporal distribution of anurans in wetlands of coastal dunes. This survey was performed in 15 wetlands along the Atlantic coastal zone of southern Brazil. We identified 10 anuran species (nine in the adult and eight in the tadpole stage) distributed in seven genera from five families. The adult richness and abundance varied among the hydroperiod classes, but without temporal variations. Both tadpole richness and abundance varied temporally and both were influenced by hydroperiod. Adult anuran composition was associated with dry months and wetland area, whereas tadpole composition was associated with emergent and floating macrophytes, wetland area and vegetation cover. This study identified the importance of habitat structural complexity and hydroperiod in spatial–temporal distribution models of anurans.