The question of why some species are rare while others are common is enduring and has important implications for ecological theory, rare species conservation, and overall biodiversity. As part of a broad research agenda to help address this question, we are using network analysis – a computational tool that uses mathematical graph theory to link different concepts as a visual map – to characterize the body of research comparing rare and common plant species, an area that has not been comprehensively reviewed in ~15 years. Our aims are to 1) explore the integration of ecological and evolutionary concepts in this body of research, 2) identify overall strengths and gaps in research foci, and 3) reveal shifts in research foci through time. We began with keywords associated with 18 ecological and evolutionary concepts modeled after a previous study that used network analysis to explore research on invasive plant species. Relevant papers were searched for keywords and results were used to generate connectivity values. Gephi open-source software was then used to define and weight connections between concepts. Our preliminary use of network analysis focused on the 54 studies included in a 2002 review of research comparing rare and common plant species.
Results/Conclusions
Our analysis revealed a clear centralized hub within the network connecting the majority of ecological concepts explored, which included biotic, abiotic, and anthropogenic influences. This hub sharply contrasted with an evident disconnect between ecological and evolutionary concepts, such as adaptation, genetic diversity, and gene flow, revealing that research integrating these concepts was relatively limited. Overall, the least explored concept was epigenetics, which was not connected to any other concepts in the network, suggesting that research focus in this area was especially lacking. In our comprehensive review of literature published since the 2002 review, we have identified ~200 additional studies that describe research comparing rare and common plant species. We are continuing to refine network concepts and apply text analytics to facilitate keyword searches for a comprehensive and updated network analysis that includes all published research in this area, as well as networks specific to consecutive time intervals of research activity to explore how research on plant species’ rarity has evolved through time. These activities will help to frame our concurrent empirical investigations of the potential ability of congeneric rare and common plant species to adapt and acclimate to environmental change within the broader context of rarity research.