Influence of Cattle Stocking Rate on Browsing of Norway Spruce in Subalpine Wood Pastures

In the Swiss Alps, 15% of Swiss mountain forests are grazed during summer, mainly by cattle. The forest laws of various Swiss cantons characterise forest grazing as a detrimental form of land use and stipulate that this grazing practice should be restricted. However, little is known about tree damage actually caused by cattle. Seven subalpine ranges in the Swiss Canton Grisons, grazed by cattle at different stocking rates, were investigated. The condition of naturally regenerated young trees (Picea abies (L.) Karst.) was assessed before and after the cattle grazing period. In order to characterise the influence of wild ungulates on the young trees during winter, the assessment of tree condition was repeated in the proximate spring. In total, 4% of the young trees were browsed on the apical shoot, 10% were browsed on lateral shoots, 13% of the trees showed other damage. The variation among ranges could almost completely be explained by the cattle stocking rate (livestock units per hectare). During winter, wild ungulates browsed 3 times as many young trees as the cattle during summer. The results suggest that cattle stocking rates on subalpine wood pastures should not exceed one livestock unit per hectare in order to avoid intensive browsing and other damage by cattle on young Norway spruces.     

西昆仑地区野生有蹄类动物种群及其影响因子研究

采用样线法对新疆西昆仑地区野生有蹄类的种群分布和数量进行了调查,并运用Distance软件对调查数据进行了分析。结果显示：该地区的岩羊（Pseudois nayaur）种群密度为3.075头/km2,北山羊（Capraibex）的种群密度为1.27头/km2。在设定的3个调查区域：矿区、公路区、低干扰区内,岩羊的种群密度依次为：2.55头/km2、3.17头/km2和4.38头/km2;北山羊在3个调查区域的种群密度依次为：0头/km2、2.28头/km2、0.16头/km2。对动物群的行为进行了观察和分析,结果表明：公路的对动物行为有一定程度的影响,而矿点分布对动物的分布和行为未表现出显著的相关性。     

Competitor densities,habitat, and weather: effects on interspecific interactions between wild deer species

There is a growing interest on the potential interplay between weather, habitat, and interspecific competition on population dynamics of wild herbivores. Favorable environmental conditions may buffer the negative effects of competition; conversely, competition may be expected to be stronger under harsh environmental conditions. We investigated relationships between competitor abundance, weather, and habitat cover on density and local distribution of a medium-sized herbivore, the roe deer Capreolus capreolus, as well as its spatial overlap with fallow deer Dama dama in a Mediterranean protected area. Over 11 years (2007–2017), roe deer density was not affected by spring–summer rainfall in the previous year and decreased with increasing density of fallow deer in the previous year. Hence, over the considered temporal scale, results supported a major role of competition over weather in influencing population trends of roe deer. At a finer spatial scale, roe deer occupancy was negatively affected by local abundance of fallow deer, especially in “poorer” habitats. We found a slight support for a positive effect of fallow deer density on interspecific spatial overlap. Moreover, fine-scale spatial overlap between deer species increased with decreasing rainfall in spring–summer. Fallow deer were introduced to our study area in historical times and their role as superior competitors over roe deer has been found also in other study areas. We suggest a potential role of harsh weather conditions during the growing season of vegetation (i.e. scarce rainfall) in triggering the potential for ecological overlap, emphasizing the negative effects of interspecific competition.     

云南白马雪山自然保护区有蹄类动物活动节律及影响因素初步研究

动物活动节律是了解动物生存策略和科学管护的基础,为探究白马雪山保护区有蹄类活动节律及影响因素,于2020年6月—2022年6月在云南白马雪山国家级自然保护区布控74台红外相机,对比分析白马雪山保护区德钦叶日、维西塔城片区有蹄类动物的活动节律及人为活动影响。为掌握白马雪山保护区有蹄类动物日活动节律及科学制定生物多样性保护措施提供科学数据支持。