Journal Article Research Support, Non-U.S. Gov't competition Soil beta diversity functional diversity hypervolumes parasitism soil nematodes Antarctic plants Conyza canadensis Diversidad beta Research Support, U.S. Gov't, Non-P.H.S. antagonistic plant-plant interactions beneficiary feedback effect beta多样性、功能多样性、同质化、超体积、土壤动物、土壤线虫 biogeography community feedbacks context dependence cost and benefit of facilitation cross-continental experiment diversidad funcional facilitation fauna del suelo functional homogenization hipervolúmenes homogenización homogenization impact invasion ecology