Site use of grazing cattle and sheep in a large-scale pasture landscape:: A GPS/GIS assessment
Site use of grazing cattle and sheep in a large-scale pasture landscape:: A GPS/GIS assessment
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DOI：
10.1016/j.applanim.2007.05.012
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发表时间：
2008-05-01
影响因子：
2.3
通讯作者：
Haerdtle, Wemer
中科院分区：
文献类型：
--
作者：
Putfarken, Dorothee;Dengler, Juergen;Haerdtle, Wemer
在大规模牧场系统中全年低密度混合物种放牧已成为一个流行的保护概念，因为它被认为是保持半开放文化景观的宝贵生物多样性。本研究旨在阐明哪些植被类型的优先放牧的牛和羊，以及是否放牧动物改变他们的喜好，通过季节，使全年放牧导致利用所有的栖息地。此外，我们想确定的主要因素的网站使用模式的动物。这项研究进行了180公顷的自然保护区和前军事训练区在北方德国从1月至10月。在该区域内，每5分钟使用全球定位系统（GPS）同时记录一个牛群和一个羊群的位置。为此，我们将一个GPS项圈交替地安装在三头不同的奶牛上，另一个安装在三只不同的绵羊上。如果有领动物的位置在5分钟内变化超过6米但小于100米，则假定放牧是基于通过直接观察验证这些阈值。使用地理信息系统，我们分析了位置数据方面的植被特征，海拔高度，距离围栏，水源，和羊棚。对于每个月，我们确定了Ivlev的选择性指数的草食动物物种在8个广泛的植被类型。我们使用多元线性回归建立模型，描述放牧频率的网格单元的区域取决于这些网格单元的参数和它们的空间位置。牛喜欢潮湿和生产性的栖息地，而绵羊喜欢干燥和营养不良的栖息地。只有当饲料供应极度短缺时，动物才会转向它们以前避免的地点。这两个物种的空间偏好的差异比季节变化更显着。牛羊的空间需求在很大程度上是互补的。放牧地点，更好的水的可用性（即较低的距离饮水槽和池塘）显着首选的牛。绵羊喜欢放牧地点靠近他们的shed.Our研究结果表明，只有不同的食草动物的组合保证了这样一个大的低强度牧场的所有栖息地放牧，从而保持在一个管理状态有利于保护。然而，饮水槽、围栏和畜棚的位置应仔细考虑，因为这些设施严重影响动物的场地使用。(C)2007 Elsevier B.V.保留所有权利。
Year-round mixed-species grazing at low densities in large-scale pasture systems has become a popular conservation concept as it is assumed to maintain the valuable biodiversity of semi-open cultural landscapes. This study aims to elucidate which vegetation types are preferentially grazed by cattle and sheep and whether the grazing animals change their preferences through the seasons so that year-round grazing leads to a utilization of all habitats. Additionally, we wanted to determine the main factors underlying the site use patterns of the animals.The study was conducted on 180 ha of a nature reserve and former military training area in northern Germany from January to October. Within this area, the positions of one cattle herd and one sheep flock were simultaneously recorded every 5 min using the global positioning system (GPS). For this purpose, we fitted one GPS collar alternately to three different cows and another to three different sheep. If the position of a collared animal had changed more than 6 m but less than 100 m within 5 min grazing was assumed based on a validation of these thresholds by direct observation. Using a geographic information system, we analysed the location data with regard to vegetation characteristics, altitude, and distance from fences, water sources, and a sheep shed. For each month, we determined Ivlev's electivity index of both herbivore species in relation to eight broad vegetation types. We used multiple linear regression to create models that describe the grazing frequencies in the grid cells of the area depending on parameters of those grid cells and their spatial position.Cattle preferred moist and productive habitats, whereas sheep preferred dry and nutrient-poor habitats. Only when feed was in extremely short supply, the animals switched to sites they had previously avoided. Differences in the spatial preferences of the two species were more marked than seasonal changes. Spatial demands of cattle and sheep were largely complementary. Grazing sites with better water availability (i.e. lower distance from the drinking trough and ponds) were significantly preferred by cattle. The sheep preferred grazing sites close to their shed.Our results show that only a combination of different herbivores guarantees that all habitats of such a large low-intensity pasture are grazed and thus are kept in a management status favourable to conservation. However, the positioning of drinking troughs, fences, and sheds should be carefully considered as these facilities seriously influence the site use of the animals. (C) 2007 Elsevier B.V. All rights reserved.