Protected areas are one of the primary conservation tools used worldwide. However, they are often embedded in a landscape that is intensely used by people, such as for agriculture or urban development. The proximity of these land-use types to protected areas can potentially affect the ecological effectiveness (or conservation effectiveness) of protected areas. In this article, we examine to what degree adjacent agricultural and urban land uses affect the ecological effectiveness of protected areas over the greater Gauteng region of South Africa. We selected 198 common, resident bird species, and analysed detection/non-detection data for these species collected over regular grid cells (approximately 61 km2 in area). For each species, we estimated abundance per grid cell with the Royle-Nichols model in relation to the proportion of protected area as a covariate. Our study focused on how this relationship between proportion of protected area and abundance (which we term the ‘protection–abundance relationship’) changed as a function of other land-use types in the grid cell. Specifically, we examined the interaction effects between protected area and both urban and agricultural land-use type per grid cell on bird abundance. We assigned each species to one of seven guilds, namely: frugivores, gleaners, granivores, ground-feeders, hawkers, predators and vegivores, and examined how the protection–abundance relationship varied across guilds in relation to agriculture and urban area. As urban area within a grid cell increased, the protection–abundance relationship became more positive for 58% of all species. At the level of guilds, the protection–abundance relationship became more positive for two guilds (granivores and ground-feeders), more negative for frugivores, and remained unchanged for the other four guilds (gleaners, hawkers, predators and vegivores). As agricultural area within a grid cell increased, the protection–abundance relationship became more positive for 49% of all species. At the guild level, the protection–abundance relationship became more positive for six guilds (frugivores, gleaners, ground-feeders, hawkers, predators and vegivores) and remained unchanged for the granivores. Our results show land-use type near protected areas modified the effect protected areas had on bird abundances, and hence the ecological effectiveness of protected areas. Our results suggest that protected areas should be viewed as constituents within the landscape, rather than islands of protection.

中文翻译：

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为什么景观很重要：附近的城市和农业用地会影响保护区的鸟类数量

保护区是世界范围内使用的主要保护工具之一。然而，它们通常嵌入人们频繁使用的景观中，例如用于农业或城市发展。这些土地利用类型与保护区的接近程度可能会影响保护区的生态有效性（或保护有效性）。在本文中，我们研究了相邻的农业和城市土地利用在多大程度上影响了南非大豪登地区保护区的生态效益。我们选择了 198 种常见的常驻鸟类，并分析了通过常规网格单元（面积约 61 平方公里）收集的这些物种的检测/非检测数据。对于每个物种，我们使用 Royle-Nichols 模型估计每个网格单元的丰度，并将保护区的比例作为协变量。我们的研究重点关注保护区比例与丰度（我们称之为“保护-丰度关系”）之间的这种关系如何随着网格单元中其他土地利用类型的变化而变化。具体而言，我们研究了保护区与每个网格单元的城市和农业土地利用类型之间对鸟类丰度的相互作用影响。我们将每个物种分配到七个行会之一，即：食果动物、拾荒者、食谷动物、地面饲养者、小贩、捕食者和食肉动物，并研究了与农业和城市地区相关的行会之间的保护-丰富关系如何变化。随着网格单元内城市面积的增加，58% 的物种的保护-丰度关系变得更加积极。在公会层面，两个公会（食粮动物和地面食肉动物）的保护-丰度关系变得更加积极，对食果动物更加负面，而其他四个公会（拾荒者、小贩、掠食者和食肉动物）则保持不变。随着网格单元内农业面积的增加，所有物种中 49% 的保护-丰度关系变得更加积极。在公会层面，六个公会（食果动物、拾荒者、地食者、小贩、掠食者和食肉动物）的保护-丰富关系变得更加积极，而食粮动物则保持不变。我们的结果表明保护区附近的土地利用类型改变了保护区对鸟类丰度的影响，从而改变了保护区的生态效益。