Native diversity buffers against severity of non-native tree invasions

Abstract

Determining the drivers of non-native plant invasions is critical for managing native ecosystems and limiting the spread of invasive species1,2. Tree invasions in particular have been relatively overlooked, even though they have the potential to transform ecosystems and economies3,4. Here, leveraging global tree databases5–7, we explore how the phylogenetic and functional diversity of native tree communities, human pressure and the environment influence the establishment of non-native tree species and the subsequent invasion severity. We find that anthropogenic factors are key to predicting whether a location is invaded, but that invasion severity is underpinned by native diversity, with higher diversity predicting lower invasion severity. Temperature and precipitation emerge as strong predictors of invasion strategy, with non-native species invading successfully when they are similar to the native community in cold or dry extremes. Yet, despite the influence of these ecological forces in determining invasion strategy, we find evidence that these patterns can be obscured by human activity, with lower ecological signal in areas with higher proximity to shipping ports. Our global perspective of non-native tree invasion highlights that human drivers influence non-native tree presence, and that native phylogenetic and functional diversity have a critical role in the establishment and spread of subsequent invasions.

The role of the plant microbiome for forestry, agriculture and urban greenspace in times of environmental change

“…proximity of ports), but also an influence of abiotic factors such as mean annual temperature and level of precipitation. The authors of this study proposed that increased temperature impacts on the resource availability in the topsoil by changing the belowground microorganism composition (Delavaux et al., 2023 ). Such a hypothesis raises a number of questions.…”

Reversing functional extinction: successful restoration of eradicated oyster reefs

“…After approximately 6 months, the three-dimensional habitat of oysters appeared to suppress the turf algae, limiting it to fragmented patches (note that on another reef restoration, misaligning construction and oyster recruitment enabled algae turf to maintain spatial dominance; McAfee et al 2021b). Additionally, this high native biodiversity, which is shown to buffer the impacts of invasive plants in terrestrial systems (Delavaux et al 2023), may serve to limit the success of invasive species accessing the reef. To date, no invasive species have been observed in the restoration, yet this remains a constant threat to be monitored.…”

Biodiversity increases resistance of grasslands against plant invasions under multiple environmental changes

“…There are many factors that affect the likelihood of species invasions, including background climatic conditions, the magnitude and type of anthropogenic environmental change, and biotic features of the community (e.g. the types and diversity of native species), all of which can interact 6 , 7 . Among the many hypotheses in invasion biology addressing these factors 8 , much attention has been paid to the biotic resistance hypothesis 9 , 10 , which predicts that more diverse communities should be more resistant to species invasions.…”

“…Empirical support for the biotic resistance hypothesis has been mixed. While some large-scale observational studies show compelling evidence for negative relationships between native diversity and invasion 7 , 11 , these observational studies have limited ability to infer causality. This is because both native residents and invaders respond to variation in the environment and to each other 12 , 13 .…”