Oil exploitation drives environmentally- and trait-mediated diversity of non-native plants in the Yungas forest in Argentina

Abstract

Anthropogenic disturbances profoundly affect forest ecosystems worldwide. Oil exploitation is one of the major stressors driving the high co-occurrence of different non-native plant species in the Yungas forest of Calilegua National Park, Argentina. Using a dataset of records collected from 2010 to 2020, we evaluated environmental drivers and oil exploitation activity shaping the occurrence and diversity of non-native plant species in 18 study sites.To do so, we first compared species richness and diversity at different levels of anthropogenic disturbance. Then, we used regression models to investigate species-environment relationships. Lastly, a fourth corner analysis was applied to investigate how the interaction between explanatory variables and plant functional traits shapes the occurrence of the studied non-native plant species.We found that oil exploitation activities promoted the diversity of non-native plants in the protected area. Presence of the three most widespread non-native plant species was influenced by the topographic slope and organic matter content. The fourth corner analysis further showed that the positive interaction between plant N-fixation capacity with either close proximity to oil boreholes, a low organic matter content or a high coverage of herbs positively affected the presence of non-native plant species.To our knowledge, this is the first time that trait-environment relationships under a gradient of anthropogenic disturbance were investigated to explain the occurrence and diversity of non-native plant species. Given that abundant non-native plant species have partially overlapping niches in the Yungas transition forests, it is advisable that future restoration actions focus on groups of non-native plants rather than single species. Additionally, non-native plant species of concern, which are able to successfully establish in both disturbed and undisturbed areas require adapted eradication measures.