凉水自然保护区松鼠巢址选择的特征

2006 年6 月11 日至9 月27 日和2007 年8 月14 日至9 月21 日采用样线法,并结合定位观察的方法在凉水国家级自然保护区对松鼠的巢址选择进行了定量研究,共获取107 个巢样方和230 个对照样方。对每个样方分别测定了12 个巢树参数和7 个环境参数。统计分析结果表明,松鼠仅在针叶树上营巢,59.8 ± 4. 7% 的巢建于红松上,但对枝叶比红松更为浓密的云杉和臭冷杉有显著的选择性,而且显著倾向于在以云杉、臭冷杉为优势树种的生境中营巢。松鼠选择比较高大(树高21.5 ± 0.4 m)、活动通道比较多(3.6 ±0.1)的树营巢,巢树周围的树木密度(169 ± 4 株/ hm² )和多样性(辛普森指数0.51 ± 0.01)显著高于对照样方。巢址生境多位于南向的中、下坡位。巢址高12.4 ± 0.4 m,紧贴树干,多朝南。红松树上的巢多建于树冠的中下部,云杉和臭冷杉树上的巢多建于树冠的上部。松鼠巢对包括道路在内的林隙没有显著的回避。     

The effects of hoarding habitat selection of Eurasian red squirrels (Sciurus vulgaris) on natural regeneration of the Korean pines

Cone-cores discarded by Eurasian red squirrels were used to study the habitat selection of Korean pine-seeds hoarding, in forest patch Nos. 16 and 19 in Liangshui Nature Reserve, China. Ten transects with a total length of 15 km were uniformly set, and data from 343 valid samples were collected in a 369 hm² area. One hundred and eighty four were hoarding samples which were determined according to the cluster analysis based on the number of the cone-cores, while the other 159 were control samples. The principal component analysis, using 11 habitat factors, suggested that the distance from Korean pine forest, forest type, number of Korean pine seedlings, density and type of bush significantly influenced the habitat selection of hoarding by Eurasian red squirrels. The results of Bailey’s method indicated that the squirrels showed (1) preference for natural coniferous forest, natural fir and spruce forest and planted spruce forest; (2) avoidance of planted Korean pine forest and planted larch forest; and (3) random use of natural Korean pine forest. Moreover the distance from the Korean pines in the range of 150–600 m showed no effect on the habitat selection of hoarding by the Eurasian red squirrels. More than 50% of the cone-cores were discarded in either fringe or gap of the Korean pine forest with more cone-cores found at <300 m than at 300 m away (One-Way ANOVA; df = 3, 183, F = 5.76, p = 0.0009). This demonstrated that the Eurasian red squirrels could take the cone-cores out of the Korean pine forest. The density of bushes in samples of hoarding area was significantly lower than that in control samples (Kruskal–Wallis test; df = 1, χ² = 83.99, p < 0.0001). The number of the Korean pine seedlings in samples of hoarding area was significantly higher than that in the control samples (Kruskal–Wallis test; df = 1, χ² = 104.13, p < 0.0001). This illustrated that the hoarding habitat favoured the germination of the Korean pine seedlings. In conclusion the behavior of hoarding Korean pine seeds by the Eurasian red squirrels can promote the regeneration and dispersal of the Korean pines.     

The effect of landscape structure on dispersal distances of the Eurasian red squirrel

Landscape structure can affect dispersal and gene flow in a species. In urban areas, buildings, roads, and small habitat patches make the landscape highly fragmented and can inhibit movement and affect dispersal behavior. Similarly, in rural forested areas, large open areas, such as fields, may act as barriers to movement. We studied how landscape structure affects natal dispersal distances of Eurasian red squirrels (Sciurus vulgaris) in an urban area and a rural area in Finland, by monitoring juvenile red squirrels with radio telemetry. We observed extremely long dispersal distances—up to 16 km—in the rural study area, but shorter distances—on average only half a kilometer—in the urban study area. The landscape structure affected the eventual dispersal paths; in the rural landscape, dispersers favored spruce dominated areas and avoided fields along their dispersal route, although they occasionally even crossed wide fields. In the urban landscape, squirrels preferred areas with deciduous or coniferous trees. The movement steps made by dispersers were longer in the more hostile landscape compared to forested areas. Despite these effects on movement path, the landscape structure only had a minor effect on straight line dispersal distances moved from the natal nest. In other words, individuals moved longer distances and were likely to circumvent barriers in their path, but this did not affect how far they settled from their natal home. This result indicates that, although landscape structure has obvious effects on movement, it still may have only a small effect on other aspects of the population, for example, gene flow.     

韩国与中国东北地区松鼠线粒体DNA控制区的序列变异

为了研究松鼠东北亚种(Sciurus vulgaris manchuricusThomas)不同种群的序列变异水平并进一步确定分类地位,我们分析了韩国5个地点和中国东北2个地点的松鼠标本的线粒体DNA控制区的全序列(1 058 bp)。39个韩国松鼠标本显示出21种单倍型,这些单倍型间的平均Tamura-Nei距离为1·0%; 24个中国松鼠标本显示21种单倍型,单倍型间的平均Tamura-Nei距离为1·4% (1 058 bp的全序列中发生变异的位点有119个,占11·2%)。韩国松鼠和中国松鼠间的平均距离为1·3%。并且韩国和中国松鼠的所有42个单倍型形成了一个单系分支,Fst值为0·04,表明在两个国家的松鼠间没有发生遗传分化。因此,序列分析的分子生物学的结果支持现行的分类,即来自韩国的朝鲜亚种(S·v·coreae)是中国北部地区松鼠东北亚种(S·v·manchuricus)的同物异名。这还需要进一步对北朝鲜和中国东北其它地区更多标本的分子和形态学分析来验证这一结论。     

Geographical distance and physical barriers shape the genetic structure of Eurasian red squirrels (Sciurus vulgaris) in the Italian Alps

Red squirrels (Sciurus vulgaris) are widely distributed throughout Eurasia, occurring in many types of coniferous and mixed-deciduous forests. In fragmented landscapes, small and partly isolated populations with low immigration rates show reduced genetic diversity, but reforestation can increase gene flow and restore levels of genetic variation in a few decades. No studies have so far investigated the genetic structure of red squirrel in large, continuous forests. The Italian Alps are presently characterized by almost continuous, recently reconnected forest habitats, that were affected by deep landscape changes during last glaciations but remained mostly unchanged between 10 000 and 200 years bp, when forest cover was heavily reduced. In this study we analyse patterns of genetic variability of red squirrels in and between seven sites distributed over 250 km of Alpine habitat, using mitochondrial DNA (mtDNA) and microsatellites. We use isolation-by-distance (IBD) models to investigate the relative importance that past (Pleistocene glaciations) and recent (fragmentation, bottlenecks) events had on the present genetic situation. Both nuclear and mtDNA data indicate a significant differentiation among study sites and a significant correlation between genetic and geographical distance only over a large scale. No recent bottlenecks are recorded through microsatellites and demographic models strongly support equilibrium between gene flow and drift; however, mtDNA suggests that there may have been local demographic crashes, probably in correspondence with the 19th-century forest fragmentation. These findings indicate that local landscape factors other than geographical distance per se, such as barriers of unsuitable habitat, affect gene flow and determine differentiation.     

The effects of hoarding habitat selection of Eurasian red squirrels (Sciurus vulgaris) on natural regeneration of the Korean pines

Cone-cores discarded by Eurasian red squirrels were used to study the habitat selection of Korean pine-seeds hoarding, in forest patch Nos. 16 and 19 in Liangshui Nature Reserve, China. Ten transects with a total length of 15 km were uniformly set, and data from 343 valid samples were collected in a 369 hm² area. One hundred and eighty four were hoarding samples which were determined according to the cluster analysis based on the number of the cone-cores, while the other 159 were control samples. The principal component analysis, using 11 habitat factors, suggested that the distance from Korean pine forest, forest type, number of Korean pine seedlings, density and type of bush significantly influenced the habitat selection of hoarding by Eurasian red squirrels. The results of Bailey’s method indicated that the squirrels showed (1) preference for natural coniferous forest, natural fir and spruce forest and planted spruce forest; (2) avoidance of planted Korean pine forest and planted larch forest; and (3) random use of natural Korean pine forest. Moreover the distance from the Korean pines in the range of 150–600 m showed no effect on the habitat selection of hoarding by the Eurasian red squirrels. More than 50% of the cone-cores were discarded in either fringe or gap of the Korean pine forest with more cone-cores found at <300 m than at 300 m away (One-Way ANOVA; df = 3, 183, F = 5.76, p = 0.0009). This demonstrated that the Eurasian red squirrels could take the cone-cores out of the Korean pine forest. The density of bushes in samples of hoarding area was significantly lower than that in control samples (Kruskal–Wallis test; df = 1, χ² = 83.99, p < 0.0001). The number of the Korean pine seedlings in samples of hoarding area was significantly higher than that in the control samples (Kruskal–Wallis test; df = 1, χ² = 104.13, p < 0.0001). This illustrated that the hoarding habitat favoured the germination of the Korean pine seedlings. In conclusion the behavior of hoarding Korean pine seeds by the Eurasian red squirrels can promote the regeneration and dispersal of the Korean pines.     

A simple method for isolation of microsatellites from the Japanese squirrel,Sciurus lis,without constructing a genomic library

We developed a simple and easy method to isolate microsatellites without screening genomic libraries by hybridization. The method requires only three basic techniques: polymerase chain reaction, DNA cloning and sequencing. We applied this method to develop microsatellite markers for the Japanese squirrel and isolated 45 clones that contained repetitive sequences. Among the 22 clones that we tested further, we found 11 diagnostic microsatellite loci that are applicable to the molecular ecological study of Japanese squirrels.     

Release of treated effluent into streams: A global review of ecological impacts with a consideration of its potential use for environmental flows

1. Worldwide, the addition of treated wastewater (i.e. effluent) to streams is becoming more common as urban populations grow and developing countries increase their use of wastewater treatment plants. Release of treated effluent can impair water quality and ecological communities, but also could help restore flow and maintain aquatic habitat in water-stressed regions. To assess this range of potential outcomes, we conducted a global review of studies from effluent-fed streams to examine the impacts of effluent on water quality and aquatic and riparian biota.
2. We identified 147 quantitative studies of effluent-fed streams, most of which were from the U.S.A. and Europe. Over 85% of the studies identified water quality as a primary study focus, including basic physical and chemical parameters, as well as trace organic contaminants. Nearly 60% of the studies had at least some focus on aquatic or riparian biota, primarily fish, aquatic invertebrates, and basal resources (e.g. algae).
3. Effluent inputs generally impaired water quality near discharge points, mainly through increased water temperature, nutrients, and concentrations of trace organic contaminants, but also via decreased dissolved oxygen levels. The majority of ecological studies found that basal resources, aquatic invertebrates, and fish were negatively affected in a variety of ways (e.g. biodiversity losses, replacement of sensitive with tolerant species). However, several studies showed the importance of effluent in providing environmental flows to streams that had been dewatered by anthropogenic water withdrawals, especially in semi-arid and arid regions.
4. Knowledge gaps identified include the abiotic impacts of effluent, such as changes in channel morphology and hydrology (e.g. how nutrient-rich and warmer effluent affects infiltration rates or interactions with groundwater), the effects of effluent on plants and vertebrates (e.g. amphibians, birds), and the impact of effluent-induced perennialisation on naturally intermittent or ephemeral streams.
5. Although effluent-fed streams often exhibit signs of ecological impairment, there is great potential for these systems to serve as refuges of aquatic biodiversity and corridors of ecological connectivity when wastewater treatment standards are high, especially in semi-arid and arid regions where natural streams have been dewatered.

     

Fractal analysis provides new insights into the complexity of marine mammal behavior: A review,two methods,their application to diving and surfacing patterns,and their relevance to marine mammal welfare assessment

Fractals have been applied to describe the complexity of behavioral displays in a range of organisms. Recent work suggests that they may represent a promising tool in the quantification of subtle behavioral responses in marine mammals under chronic exposure to disturbance. This paper aims at introducing the still seldom used fractals to the broader community of marine mammal scientists. We first briefly rehearse some of the fundamental principles behind fractal theory and review the previous uses of fractals in marine mammal science. We subsequently introduce two methods that may be used to assess the complexity of marine mammal diving patterns, and we apply them to the temporal dynamics of the diving patterns of killer whales in the presence and absence of sea kayaks, the sequential behavior of harbor and gray seals in environments with distinct levels of anthropogenic influence, and southern right whales with and without calves. We discuss the ecological relevance of identifying fractal properties in marine mammal behavior, and the potential strength of the fractal behavioral parameters in comparison to more standard behavioral metrics. We finally briefly address the relevance fractal methods may have for the design and implementation of management and conservation strategies.