Beschta Robert L, Donahue Debra L, DellaSala Dominick A, Rhodes Jonathan J, Karr James R, O'Brien Mary H, Fleischner Thomas L, Williams Cindy Deacon
Department of Forest Ecosystems and Society, Oregon State University, Corvallis, OR, 97331, USA,
Environ Manage. 2014 Jun;53(6):1039-42. doi: 10.1007/s00267-014-0263-5. Epub 2014 Apr 1.
Svejcar et al. (Environ Manage, 2014) offered several perspectives regarding Beschta et al. (Environ Manage 51:474-491, 2013)--a publication that addressed the interacting ecological effects of climate change and domestic, wild, and feral ungulates on public lands in the western United States (US)--by largely focusing on three livestock grazing issues: (1) legacy versus current day impacts; (2) grazing as a fire reduction tool; and (3) the complexity of grazing. Regarding these issues, we indicate that (1) legacy effects to western ecosystems were indeed significant and contemporary livestock use on public lands generally maintains or exacerbates many of those effects; (2) livestock grazing has been a major factor affecting fire frequency, fire severity, and ecosystem trajectories in the western US for over a century; and (3) the removal or reduction of grazing impacts in these altered ecosystems is the most effective means of initiating ecological recovery. Svejcar et al. (Environ Manage, 2014) offer no evidence that livestock use is consistent with the timely recovery of grazing-degraded uplands, riparian areas, or stream systems. We thus conclude that public-land ecosystems can best persist or cope with a changing climate by significantly reducing ungulate grazing and related impacts.
斯韦卡尔等人(《环境管理》,2014年)针对贝施塔等人(《环境管理》51:474 - 491,2013年)的研究提出了几种观点——该研究探讨了气候变化以及家养、野生和野生有蹄类动物对美国西部公共土地的生态交互影响——主要聚焦于三个牲畜放牧问题:(1)遗留影响与当前影响;(2)放牧作为一种减少火灾的工具;(3)放牧的复杂性。关于这些问题,我们指出:(1)对西部生态系统的遗留影响确实显著,当前公共土地上的牲畜使用通常维持或加剧了其中许多影响;(2)一个多世纪以来,牲畜放牧一直是影响美国西部火灾频率、火灾严重程度和生态系统轨迹的主要因素;(3)在这些已改变的生态系统中消除或减少放牧影响是启动生态恢复的最有效手段。斯韦卡尔等人(《环境管理》,2014年)没有提供证据表明牲畜使用与放牧退化的高地、河岸地区或溪流系统的及时恢复相一致。因此,我们得出结论,公共土地生态系统要最好地持续存在或应对气候变化,就需要大幅减少有蹄类动物的放牧及相关影响。