Inconsistent outcomes of heterogeneity-basedmanagement underscore importance of matchingevaluation to conservation objectives
Inconsistent outcomes of heterogeneity-basedmanagement underscore importance of matchingevaluation to conservation objectives
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基于异质性的管理的不一致结果强调了将评估与保护目标相匹配的重要性
DOI：
10.1016/j.envsci.2013.03.005
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发表时间：
2013
期刊：
影响因子：
5.5
通讯作者：
D. Debinski
中科院分区：
文献类型：
--
作者：
D. McGranahan;D. Engle;S. Fuhlendorf;S. L. Winter;James R. Miller;D. Debinski
保护政策通常激励受人类影响地区的管理者创造景观异质性，以最大限度地提高生物多样性。在牧场，斑块干扰制度创建景观异质性（斑块对比度），但基于异质性的管理成果很少测试的普遍反应。我们分析了四个生境变量-植被结构，植物功能群组成，凋落物覆盖，和裸露的地面-从五个实验牧场在俄克拉荷马州和爱荷华州，美国。我们测试了不同地点和地点内对基于异质性的管理的响应一致性。我们计算了每个变量的效应大小，以比较异质性管理的牧场（补丁烧放牧）和同质性管理的牧场（放牧与同质火制度）的补丁对比。不同地点和同一地点的影响差异很大。异质性为基础的管理的影响是积极的所有变量只有三个五个实验牧场的位置。没有一个地点在所有四个变量中显示出一致的积极影响模式，尽管有一个地点对任何变量都没有影响。在另一个位置，我们发现了一个积极的影响，基于异质性的管理凋落物覆盖和裸露的地面，但没有影响植被结构和植物功能群组成。我们讨论影响的变化和如何火放牧相互作用适用于牧场管理和保护。虽然它是公认的做法，使用异质性为基础的管理，以增加牧场栖息地的多样性，管理人员还应确认，评估指标符合预期的保护成果。
Conservation policy often incentivizes managers of human-impacted areas to create landscape heterogeneity to maximize biodiversity. In rangeland, patchy disturbance regimes create landscape heterogeneity (patch contrast), but outcomes of heterogeneity-based management are rarely tested for a universal response. We analyzed four habitat variables – vegetation structure, plant functional group composition, litter cover, and bare ground – from five experimental rangelands in Oklahoma and Iowa, USA. We tested for response consistency to heterogeneity-based management across and within locations. We calculated effect sizes for each variable to compare patch contrast on pastures managed for heterogeneity (patch burn-grazing) and pastures managed for homogeneity (grazing with homogeneous fire regimes). Effects varied considerably across and within locations. Effects of heterogeneity-based management were positive for all variables at only three of five experimental rangeland locations. No location showed a consistent pattern of positive effect across all four variables, although one location showed no effect for any variable. At another location, we found a positive effect of heterogeneity-based management on litter cover and bare ground, but no effect on vegetation structure and plant functional group composition. We discuss effect variability and how the fire–grazing interaction applies to rangeland management and conservation. Although it is accepted practice to use heterogeneity-based management to increase rangeland habitat diversity, managers should also confirm that evaluation metrics match desired conservation outcomes.