Department of Agricultural, Forest and Food Sciences, University of Torino, Grugliasco, Italy.
PLoS One. 2021 Nov 3;16(11):e0259120. doi: 10.1371/journal.pone.0259120. eCollection 2021.
Regardless of the issue, most of the research carried out on summer pastures of European Alps had to consider the effects of grazing management, as it is an intrinsic component of alpine environment. The management intensity of grazing livestock is measured in terms of livestock stocking rate, but not always a direct measure of it is easily retrievable. Therefore, the aim of the research was to test the reliability of proxies easily retrievable from open data sources (i.e. slope and distance from buildings) in approximating the pastoral site-use intensity. To test the proxies' effectiveness two different approaches were used. With the first one, the proxies' reliability was assessed in a case-study conducted at farm scale by using the number of positions gathered with GPS collars, which are a reliable measure of livestock site-use intensity. With the second, the proxies' reliability was assessed by means of five Vegetation Ecological Groups (VEGs), used as a tool for indirect quantification of livestock site-use intensity at regional scale (thirty-two alpine valleys of the Western Italian Alps, Piedmont Region-Italy). At farm scale, distance from buildings and slope were both reliable predictors of the number of GPS locations as assessed with a Generalized Additive Model. Results of Generalized Linear Models at the regional scale showed that the values of both the slope and the distance from buildings were able to separate VEGs along the same site-use intensity gradient assessed by modelling the number of GPS locations at farm scale. By testing proxies' reliability both with a direct (i.e. GPS collar positions) and indirect (i.e. VEGs) measurement of livestock site-use intensity, results indicated that slope and distance from buildings can be considered effective surrogates of site-use intensity gradient in alpine grasslands managed under livestock grazing. Therefore, when the level of site-use intensity in research carried out in alpine summer pastures is not directly available, a reliable solution consists in the use of the terrain slope and the distance from buildings, which are also easily retrievable from open data sources or computable.
无论问题是什么，对阿尔卑斯山夏季牧场的大部分研究都必须考虑放牧管理的影响，因为它是高山环境的固有组成部分。放牧牲畜的管理强度用牲畜载畜率来衡量，但并非总是可以直接获取其度量值。因此，研究的目的是测试从公开数据源（即坡度和与建筑物的距离）中轻松检索到的代理的可靠性，以近似牧场使用强度。为了测试代理的有效性，使用了两种不同的方法。第一种方法是在农场规模的案例研究中评估代理的可靠性，使用 GPS 项圈收集的位置数量来评估，这是衡量牲畜使用强度的可靠指标。第二种方法是使用五个植被生态组（VEG）评估代理的可靠性，作为在区域尺度上间接量化牲畜使用强度的工具（意大利皮埃蒙特地区的三十二个意大利西部阿尔卑斯山的高山山谷）。在农场规模上，建筑物距离和坡度都是 GPS 位置数量的可靠预测因子，这是通过广义加性模型评估的。区域尺度上广义线性模型的结果表明，坡度和建筑物距离的值都能够沿着通过对农场规模上的 GPS 位置数量进行建模来评估的相同使用强度梯度来区分 VEG。通过使用直接（即 GPS 项圈位置）和间接（即 VEG）测量牲畜使用强度来测试代理的可靠性，结果表明，坡度和建筑物距离可以被认为是高山草地放牧管理下使用强度梯度的有效替代物。因此，当在高山夏季牧场进行的研究中无法直接获得使用强度水平时，一个可靠的解决方案是使用地形坡度和与建筑物的距离，这些也可以从公开数据源或可计算的来源中轻松检索到。
