Zur Keimungsphysiologie des Wildhafers (Avena fatua L.)

The density of the phytophagous curculionid weevil complex belonging to one family and four subfamilies was determined in three different ecotypes including date‐palm, vegetable and natural (fallow) habitats in Western Saudi Arabia. Different densities were observed in the three habitats during 1996–1997. However, the date palm habitat showed high number of curculionid weevils. This may be attributed to the availability of food source, vegetational cover and shaded environment in the available niche. Chi square test showed that there were significant differences in density numbers between the three habitats. Three peaks were observed in the date‐palm habitat during December, March and May.     

The resurgence in resource nationalism and private protected areas: Through the lens of Save Valley Conservancy's indigenisation

It has been observed that the resurgence in resource nationalism in the past decade worldwide has profound implications for all economic sectors including protected areas. However, a review of the international protected area literature reveals a paucity of studies that make use of the construct of resource nationalism as an analytical framework. This paper addresses this gap by bringing to the fore how Zimbabwe's ZANU PF (the political party that brought the country's independence in 1980) has deployed and extended this construct from the 2000 land reform programme to one of the world's largest private wildlife sanctuaries, namely the Save Valley Conservancy (SVC). In doing so, the paper relies extensively on the narratives, debates and legitimations of the ruling elite and other stakeholders around the recent ‘indigenisation’ of the SVC. It was found that a range of actors attempted to use resource nationalism as a ‘resource’ to further their own private economic and political interests whilst others resorted to the conservation discourse. One of the main conclusions of this paper is that managers of protected areas need to be sensitive to the resurgence in resource nationalism. In this connection, it is argued that the ability to negotiate the resurgence in resource nationalism will determine the fate of some private protected areas. The study suggests possible solutions around the indigenisation of SVC and points to future research priorities.     

Responses to drought stress among sex morphs of Oxyria sinensis (Polygonaceae), a subdioecious perennial herb native to the East Himalayas

It is generally accepted that dioecious plants occur more frequently in dry and nutrient‐poor habitats, suggesting that abiotic stress factors could contribute to evolution of dioecy from hermaphrodite. Therefore, experimental investigations on the responses of subdioecious species, a special sexual system comprising male, female, and hermaphrodite plants, to abiotic stress factors could quantify the contribution of selective pressure on the evolution of dioecy. In this study, we evaluated the physiological responses of different sex morphs of Oxyria sinensis Hemsley, a perennial herb native to the East Himalayas, to drought stress. Male, female, and hermaphrodite plants of O. sinensis were subjected to low, moderate, and high drought stress conditions in a glasshouse. Generally, with increasing water stress, the values of most measured variables slightly decreased, whereas water‐use efficiency slightly increased. Furthermore, there were no significant differences in most of the measured parameters among the sex morphs under each drought stress treatment, indicating that O. sinensis might be well‐adapted to drought stress conditions as its typical habitat is the dry and hot habitats of xerothermic river valleys. However, nitrogen‐use efficiency was significantly higher in male and female plants than in hermaphrodite plants under high drought stress conditions, suggesting that that nitrogen‐use efficiency under conditions of drought stress might have contributed to the evolution of dioecy from the hermaphrodite to some degree.     

秦岭田峪河流域植被研究

田峪河流域位于秦岭北坡 ,北纬 33°47′～ 34°0 5′,东经 1 0 8°1 5′～ 1 0 8°2 7′。根据田峪河流域植物群落的外貌特征、种类组成及其构成特点 ,将该流域的植被分成 5个类型 : .次生灌丛 ; .落叶阔叶林 ; .针阔叶混交林 ; .针叶林 ; .亚高山灌丛。它与秦岭北坡的植被类型基本一致     

基于SHAW模型对拉萨河谷冬小麦农田生态系统水分传输特征的模拟研究

以青藏高原的拉萨河谷下游的农田为研究对象,利用中国科学院拉萨高原生态试验站的观测数据,通过模型模拟的方法分析了高原冬小麦农田生态系统水分传输的主要特征并结合当地的气象条件和灌溉情况对当地制定适宜的冬小麦农田灌溉制度进行了初步探讨.采用2004年5～10月的土壤水分观测数据对SHAW模型进行参数率定,然后,利用2004年10月～2005年10月的土壤水分观测数据对率定的参数进行验证并评价SHAW模型的在该地区的模拟性能.通过分析2004～2005年冬小麦农田水分传输过程的模拟结果,得出该地区农田生态系统水分传输的主要特征:①拔节-灌浆期是冬小麦耗水旺期,水分主要在土壤-植物间传输.②冬小麦生长期间耗水量为826mm,是华北平原的1.7～1.9倍,其中土壤蒸发占了37.5%.③冬小麦根系吸水主要集中于10～40cm土层,在浅层土壤水分供应不足时,冬小麦才倾向于利用深层土壤水分(40cm以下).④整个冬小麦生长期间农田的总深层渗漏量达到约占总灌溉量的50%.其中,播种-返青期间灌溉量的72%渗漏到70cm土层以下.最后,基于研究得出的冬小麦农田生态系统水分传输特征,对该地区适宜的灌溉制度进行了分析探讨.     

金沙江支流普渡河、小江干热河谷的丛枝菌根

调查具有不同植物群落的金沙江支流普渡河、小江干热河谷中91种常见植物的丛枝菌根真菌的侵染率及孢子密度。普渡河样地调查了56种植物,其中54种(96%)植物能形成典型的丛枝菌根,其平均孢子密度为1423±175/100g土;小江样地35种植物中有34种(97%)植物能形成典型的丛枝菌根,其平均孢子密度为601±103/100g土。单因素方差分析表明两个样地植物的AMF总感染率差异不显著,但其根际土壤中AMF孢子密度却存在显著差异,小江样地的AMF孢子密度明显低于普渡河样地。相关性分析表明,干热河谷植物的AMF感染率与其根际土壤中的AMF孢子密度之间不存在相关性。此外,调查还发现91种植物中,有61种植物(67%)在形成AM的同时,也被黑色有隔内生菌感染。     

怒江中游西藏境内干旱河谷荒漠植被特征

基于实地调查资料,对西藏境内怒江中游河谷的特殊荒漠型植被进行了研究。结果表明：（1）22个样方中有85种维管植物,其种子植物属的分布区类型以泛热带分布为主,占21．6％;种以中国特有分布中的西南特有成分为主,占53．2％;（2）生活型谱以矮高位芽植物为主,占41．2％,地面芽植物占40．0％;（3）采用Raunkiaer频度分析,出现在10个以上样方中的物种有白刺花、垫状卷柏、芸香草和阔盖中国蕨等,频度分别是68．2％、50．0％、50．0％、45．5％;（4）根据该河谷区域的气候特点、干旱程度、群落的生态外貌特征和生活型等,并结合《中国植被》对灌丛和荒漠的划分,认为该河谷区域的植被盖度极低,不属于灌丛类型,而是非地带性的干旱河谷型荒漠植被。     

Evaluating the stick-gap method in a Mexican tropical dryland: Effect of stick length and sample size

The degradation of drylands by human activities is a serious problem in many developing countries. Monitoring in these countries therefore is basic to prevent or mitigate land degradation. The stick-gap method is one graphical approach that has been used to monitor rangelands in eastern Africa. This method collects data on vegetation cover and structure with a 1-m-long stick at 20 locations per site. These data are then used to calculate land health indicators. Because the stick-gap method is easy to implement and to understand, it is suitable for monitoring drylands in other developing countries. However, the effect of stick length and sample size on the estimation of indicators such as basal gaps should be first evaluated. In this study, we measured basal gaps with 1-m- and 0.5-m-long sticks at 20 and 100 locations per site in two mesquite shrublands with different vegetation structure within a Mexican tropical dryland area. We correlated the basal gaps estimated using different stick lengths and sample sizes with the basal gaps estimated using one standard tape method. The correlations between these estimates were not significant considering 20 locations per site, independent of whether 1-m- or 0.5-m-long sticks were used. However, the correlations between these estimates were significant considering 100 locations per site. Also, the correlations between these methods were slightly higher when 0.5-m-long sticks were used in comparison to 1-m-long sticks. These results were similar in mesquite shrublands with either open or closed canopies. We conclude that increasing sample size to 100 locations per site and decreasing stick length to 0.5 m would be sufficient for estimating the proportion of basal gaps in both open- and closed-canopy mesquite shrublands.     

Les percuteurs en pierre du site du Paléolithique moyen de Ketrosy,couche 3

The Middle Palaeolithic site Ketrosy (Middle Dniester valley) has been found and investigated by N.K. Anisyutkin in 1974–1979. He excavated 3 different complexes. The most interesting complex is the area № 1. It has the one (third) cultural layers in fair preservation, which had been dated appr. 100,000 years ago, by buried soils investigations. In the obtained collection, the hammerstones are represented by 19 pebbles with the traces of pecking. By its metrics, tools from Ketrosy fit within the framework of variability of the Middle – Upper Paleolithic hammerstones. But the location of the impact-marcs does not look ordinary and we suppose the transverse grip of the tools, conditioned, perhaps, by the anatomy of the inhabitants of the Ketrosy site. Low intensity of wear indicates “ad-hoc” mode of pebbles use as hammers. Spatial analysis of stone artifacts and bone remains (in particular – the context of hammers findings) confirm the short occupation and well-defined objects of cultural layer.     

晋江流域水质污染与浮游动物四季群落结构的关系

报道了2003年2、4、6、8、10和12月在福建晋江流域15个样点进行浮游动物群落生态学调查研究的结果。采用种类组成、种群数量、优势种群、Margalef和Shannon-Wiener多样性指数等参数,初步比较了流域中各不同河段的水质状况,结果显示,流域受污染程度的顺序为东、西溪〈晋江干流〈南、北干渠。东溪、西溪上过度开发的梯级水电站对浮游动物群落结构和水质有明显的影响,加速了水体富营养化进程。