COS 86-2 - A conceptual classification scheme to navigate current knowledge in invasion science

Abstract: Non-native and invasive species are on the rise, along with their global impacts on ecosystems, economies, and human health. Invasion science is critical to mitigate these impacts, but due to the increasing volume of data and information in this area, it has become difficult to acquire and maintain an overview of the relevant evidence. As biological invasions have become a major topic in research and management, available knowledge has to be transparently organized and made accessible to everyone. We aim to address these challenges by developing an interactive atlas of invasion science based on a structured conceptual network.

Our work is based on the hierarchy-of-hypotheses approach, which assumes that hypotheses and concepts are often structured hierarchically and can be used to classify and organize current knowledge in research fields like invasion science. We designed a conceptual scheme to classify 39 major invasion hypotheses and studies addressing them. We applied two complementary approaches: First, using a top-down approach, a group of invasion biologists formulated how the hypotheses are related to overarching themes and research questions in the field. This was first done individually by experts based on their knowledge, followed by an iterative consensus approach to reach a single classification. Second, we used a bottom-up approach based on manually classifying >1100 published studies according to hypotheses, research questions and themes.

We identified four overarching themes in invasion science: Impacts of invasions, Invasion success (establishment and spread) and invasibility, Pathways and conditions of introduction, and Management of biological invasions. Most of the hypotheses (31/39) focus on a single theme. However, seven hypotheses are related to two different themes, and one hypothesis is related to three themes. Furthermore, we identified nine major questions guiding research in invasion science.

The online portal (a first prototype is available at https://hi-knowledge.org) will employ novel methods for knowledge synthesis. It will be an evolving knowledge resource, where users can get an overview of the major themes, questions and hypotheses in invasion science and discover related studies. We hope that this tool will contribute to the community from students to practitioners and be used as a bridge between the different users. We will outline our approach and discuss ideas for complementary initiatives in other disciplines.