Dominant species of mid-elevation grasslands of the uKhahlamba-Drakensberg Park are predicted to be largely immune to climate change  

作　　者：Debbie JEWITT Craig D.MORRIS Tim G.O’CONNOR Michelle J.TEDDER 

机构地区：[1]Ezemvelo KZN Wildlife,Scientific Services,PO Box 13053,Cascades 3202,South Africa [2]School of Animal,Plant and Environmental Sciences,University of the Witwatersrand,Johannesburg,Private Bag X3,WITS 2050,South Africa [3]Agricultural Research Council-Animal Production(ARC-AP),℅School of Life Sciences University of KwaZulu-Natal,Private Bag X01,Scottsville 3209,Pietermaritzburg,South Africa [4]School of Life Sciences,University of KwaZulu-Natal,Private Bag X01,Scottsville 3209,Pietermaritzburg,South Africa

出　　处：《Journal of Mountain Science》2023年第9期2468-2486,共19页山地科学学报（英文）

摘　　要：Anticipating global change impact on natural vegetation,especially in poorly researched systems,requires an understanding of the environmental factors that most strongly influence the organisation of plant communities at different scales.The environmental relations of plant communities in the Drakensberg mountains of South Africa remain poorly researched.This study investigated the influence of selected environmental determinants on the dominant species of plant community organisation in this area.In order to provide an overview of the influence of the environment on botanical composition and plant diversity,this study,conducted as four discrete exercises,investigated the interplay of altitude,aspect and slope on the abundance of selected species,and to examine the influence of latitude,geological substrate and local topography on species composition.Plant diversity showed no pattern of response to investigated environmental variables.Species composition was related to temperature and solarradiation variables.High altitude sites facing east were distinct for non-graminoid species.Altitude and latitude exerted a pronounced effect on species composition,confounded by longitude and precipitation gradients.Geological substrate,in concert with slope steepness and orientation,influenced composition,restricting the abundance but not distribution of some grasses.Highly individualistic responses were found for C_3,C_4,and non-graminoid species in relation to altitude,slope and aspect.Slope and aspect mediate the effects of altitude and hence temperature for some species.This study has demonstrated the complexity of drivers influencing species and compositional distribution in the Drakensberg and permits a preliminary consideration of potential changes in the composition and dominance structure of mid-elevation grasslands in response to climate change.The dominant grass species were widespread across environmental gradients,occupying currently warm,cool,moist and dry habitats.Hence,we predict that these midelevation C_4 gr

关 键 词：Drakensberg Environmental gradients Grasslands Mountain biodiversity Vegetation 

分 类 号：S812[农业科学—草业科学]