Lukhele Sifiso M, Shapiro Julie Teresa, Mahlaba Themb'alilahlwa A M, Sibiya Muzi D, McCleery Robert A, Fletcher Robert J, Monadjem Ara
Department of Biological Sciences, University of Eswatini, Private Bag 4, Kwaluseni, Eswatini.
Department of Biological Sciences, University of Cyprus, P O Box 20537, Nicosia, 1678, Cyprus.
Heliyon. 2021 Mar 24;7(3):e06563. doi: 10.1016/j.heliyon.2021.e06563. eCollection 2021 Mar.
Agricultural intensification is a threat to terrestrial ecosystems around the world. Agricultural areas, especially monocultures, create homogenous landscapes for wildlife. However, certain crops, such as sugarcane, are harvested in phases, creating a mosaic of fields in different stages of growth. We investigated changes in avian communities across four different sugarcane growth stages: emerging, short, medium and tall sugarcane, as well as control sites that represented native savanna habitat in northeast Eswatini prior to conversion to agriculture. In total, we sampled nine sites in sugarcane fields (at different growth stages) and three in native savanna. We conducted bird counts at 5-week intervals along 200m line transects over both the breeding and non-breeding seasons. We recorded a total of 124 bird species belonging to 58 families. Bird species richness and diversity were higher in savannas compared to any stages of growth in sugarcane. In contrast, functional beta diversity and uniqueness were higher in sugarcane than in savanna. Community composition was also different between the two land-uses. While there was overlap in bird species composition between different sugarcane growth stages, there was high beta diversity and high turnover between sites, indicative of the high temporal and spatial variability in bird communities in sugarcane fields. We demonstrated that the spatial and temporal variability created by the different growth stages of sugarcane promotes the occurrence of species with different traits, which may contribute to ecosystem functioning and promote the conservation of bird species as sugarcane fields can provide resource complementation for species with different needs.
农业集约化对全球陆地生态系统构成威胁。农业区域，尤其是单一栽培区，为野生动物创造了同质化的景观。然而，某些作物，如甘蔗，是分阶段收割的，形成了处于不同生长阶段的田地镶嵌景观。我们调查了鸟类群落在甘蔗四个不同生长阶段的变化：甘蔗出苗期、矮株期、中株期和高株期，以及代表斯威士兰东北部在转为农业用地之前的原生稀树草原栖息地的对照地点。我们总共在甘蔗田（处于不同生长阶段）中选取了9个地点，在原生稀树草原选取了3个地点。在繁殖季节和非繁殖季节，我们沿着200米的直线样带每隔5周进行一次鸟类数量统计。我们总共记录了属于58个科的124种鸟类。与甘蔗的任何生长阶段相比，稀树草原的鸟类物种丰富度和多样性更高。相反，甘蔗地的功能β多样性和独特性比稀树草原更高。两种土地利用类型的群落组成也不同。虽然不同甘蔗生长阶段的鸟类物种组成存在重叠，但地点之间的β多样性很高且周转率很高，这表明甘蔗田鸟类群落具有很高的时间和空间变异性。我们证明，甘蔗不同生长阶段产生的时空变异性促进了具有不同特征的物种的出现，这可能有助于生态系统功能，并促进鸟类物种的保护，因为甘蔗田可以为具有不同需求的物种提供资源互补。
