Non-native plant species richness and influence of greenhouses and human populations in the conterminous United States  

作　　者：Brice B.Hanberry 

机构地区：[1]USDA Forest Service,Rocky Mountain Research Station,Rapid City,SD 57702,USA

出　　处：《Ecological Processes》2023年第1期388-401,共14页生态过程（英文）

基　　金：supported by the USDA Forest Service,Rocky Mountain Research Station.

摘　　要：Background One issue in invasive plant ecology is identification of the factors related to the invasion process that increase number of non-native species.When invasion by non-native species increases,so does the probability that some non-native species will become harmful,or classified as invasive species,which disrupt natural ecosystems with attendant economic and social costs.I quantified patterns of how non-native species richness varied with vegetation types and human populations.To evaluate the relative importance of different predictor variables for invasion pathways in the conterminous United States,I modeled non-native plant species richness by county compared to current and historical human populations;greenhouses and nurseries;railroads,pipelines,transmission lines,and oil and gas wells;and land covers of impervious surface,development intensity categories,agriculture,and vegetation types.I also modeled these variables within vegetation types,excluding vegetation variables.Results To summarize patterns,non-native plant species richness increased from 72 to 200 with increasing human population density classes.Forests and forest land use mosaics had the greatest mean number of non-native plant species,ranging from 121 to 166,whereas grasslands and grassland mosaics had the least number of non-native plant species,about 70.For modeling variable importance,all combined variables had R^(2)values of 56%(random forests regressor)and 54%(cubist regressor)for predictions of withheld observations of non-native plant species rich-ness,with greenhouse density and percent forestlands as most influential variables.Single variables of greenhouses(R^(2)=29%),historical and current human populations(R^(2)=27%and 23%),impervious surface(25%),and medium intensity development(23%)were most associated with non-native plant species richness.For vegetation types,greenhouse and historical human population densities were influential variables particularly in forestlands,shrublands,and wetlands.Conclusions Based on these models

关 键 词：Agriculture Energy Forest GRASSLAND INVASIVE PROPAGULE RURAL Transport Urban 

分 类 号：Q948[生物学—植物学]