The rich generally get richer, but there are exceptions: Correlations between species richness of native plant species and alien weeds in Mexico

摘要: Studies on the resistance of communities to plant invasions at different spatial scales have yielded contradictory results that been attributed scale-dependent factors. Some these studies argue either for or against Elton's notion biotic through diversity. We studied correlation between alien weeds and native species, dividing latter group into weedy non-weedy integrating various factors influence diversity an analysis scale federal states Mexico. The resulting multiple-regression models weed species are robust (adjusted R2 = 0.87 R2 = 0.69, respectively) show a strong partial number (native alien) with non-weed species. These agree showing positive larger scales. Both also include human population density as important predictor variable, but this is more (β = 0.62) than (β = 0.32). In regression model richness, non-cultivated (fallow) area (β = 0.24) correlated positively richness. richness was variable (β = −0.51), negative (rpart = −0.4). This result consistent hypothesis, suggesting independent may be masked by other both non-weeds.