Impact of Livestock Grazing on Ecosystem Services in a Mediterranean Ecosystem

ecosystem services;livestock grazing;mediterranean heathlands;Natural Resources and Environemnt

Cheng, Wan-ChihSchueller, Sheila ;

University of Michigan

关键词: ecosystem services;    livestock grazing;    mediterranean heathlands;    Natural Resources and Environemnt;   

Others  :  https://deepblue.lib.umich.edu/bitstream/handle/2027.42/116125/wan-chih%20cheng%20thesis2015.pdf?sequence=1&isAllowed=y

瑞士|英语

来源: The Illinois Digital Environment for Access to Learning and Scholarship

【 摘 要 】

Livestock husbandry is one of the most important human activities in arid regions ofthe planet and is the predominant driver of environmental degradation inMediterranean ecosystems. Nonetheless, despite the very long history of animalhusbandry in this region, relatively little is known on the relationship betweenlivestock grazing and the provisioning of ecosystem services in a Mediterraneansetting.Methods. This study focuses on mediterranean heathlands (;;phrygana’), aspecies-rich plant community that is widespread over large areas of the MediterraneanBasin, and a habitat subjected to goat and sheep grazing for almost 10,000 years. Weevaluate multiple trophic levels of this community (including vegetation conditionand structure, floral resources, as well as populations of primary and secondaryconsumers), across a spectrum of livestock grazing intensities in island ecosystems inthe Aegean Sea (Greece). We also evaluated some of the important ecosystemservices provided by phryganic habitats to local human communities, includingvegetation productivity, erosion protection, pollination services, disease dilution, andmaintenance of biodiversity.Results. Results show that all measured aspects of vegetation condition and structure(vegetation biomass, canopy cover, basal cover, plant species richness and plantdiversity) decline monotonically with rising levels of livestock grazing. Furthermore,while increasingly higher herbivore stocking rates result in diminished floralresources, the effects on pollinator populations and diversity are more equivocal.Secondary consumers (Podarcis wall lizards) appear to benefit the most fromintermediate levels of grazing intensity. However, foraging rates by honey bees (Apismellifera), an economically important species in the region, decline as livestockherbivory rates rise, suggesting that there are direct tradeoffs between livestockhusbandry and apiculture in these landscapes.Conclusions. Impacts of livestock husbandry on local ecosystems depend on stockingrates used. While at low stocking rates, grazing appears to have either equivocal orboth positive and negative effects on different ecosystem services, at higher stockingrates these effects become mostly negative. While there is no specific stocking ratethat is likely to minimize all impacts, our results suggest that intensive grazing hasclear negative ecological consequences in terms of lost ecosystem services.