Context-Dependency of Enemy Impact on Plant Communities in a Changing World

Global environmental change is strongly altering biodiversity and ecosystem functioning. Antagonistic biotic interactions affect the diversity and functioning of plant communities but are notoriously context dependent and are therefore likely to be altered by global change drivers. Global change can directly affect biotic interactions and can also indirectly alter the abundance, diversity and composition of plant enemy communities, via changes to plant productivity, diversity and functional composition. Changes in the enemy community feedback to alter the plant community. However, we lack predictions for how different global change drivers may alter enemy communities and their impact on plant communities. In this review we summarize current knowledge on the impact of invertebrate herbivores and fungal pathogens on plant productivity, diversity and community composition, and outline theory and expectations on how important global change drivers – nitrogen enrichment, warming and elevated CO², as well as the loss of plant and insect diversity, may affect the impact of plant-enemies on plant communities.