A conceptual model and framework for addressing the unaddressed issue of invasive plants in conservation linkages

Background/Question/Methods

Ecologists have frequently touted the merits of increased landscape connectivity, usually focusing on the efficacy of conservation linkages for maintaining viable populations of target species. An often-mentioned but still greatly understudied concern is that increased landscape connectivity via linkages may also aid the movement of undesired species (e.g., invasive plants) or events (e.g., fire or spread of disease). This paper directly addresses one of those major gaps: the issue of invasive plants in conservation linkages. It represents the first attempt to create an integrated research approach that will aid managers in identifying and prioritizing appropriate research and management actions, given their particular focal conservation linkage and invasive plant species. In order to guide research goals and methods, I developed a conceptual model describing the ways that invasive plants can exist in and move into, through, and out of landscape linkages, i.e. the classes of interactions between invasive plants and linkages. Each class of interaction within the model has three main components: the linkage, matrix, and focal species.

Results/Conclusions

I detail eight classes of interactions in my conceptual model, illustrating with results from my own research on invasive plant patterns in small and large-scale linkages in two different ecosystems. Conservation linkages can function as a) barriers, b) habitats (partial or complete), c) conduits (two types), and d) sources (two types) for invasive plant species. Central topics of the three components within each class of interaction include a) differentiating appropriately between matrix types, b) understanding edge effects within the linkages, and c) incorporating relevant invasive species’ ecology (primarily dispersal ecology). By focusing on landscape-scale patterns in real-world systems, this research will enhance landscape-level knowledge of invasion ecology and aid land managers in choosing, designing, and/or managing conservation linkages.