When a plant is introduced (accidentally or intentionally, but usually by humans) into a new region, many factors can influence the ability for that species to become established. One major factor at play is the different set of species it will interact with in this new environment—will they work with it or against it? We naturally tend to focus on the negatives; like whether there are enemies like pathogens, predators or other competitors that will control it.
What has received less attention is how positive interactions are affecting the spread of non-native species. For example, we know that the availability of pollinators is important for many plant species. So when a species moves, it doesn’t just leave its enemies behind, it also leaves its friends, its beneficial partnerships.
And it appears that for symbiotic legumes, these beneficial partners matter a lot. Their associated rhizobia matter so much that we can see their impacts on legume species spread at a global scale, across multiple continents and islands.
Plant species diversity doesn’t improve soil
The above quote was left as a reply to a comment I’d left on a big ag research and education industry video talking about cover crops ages ago. It still irks me that these people are so ignorant.
Today I read the following study on plant species diversity’s impact on soil ecosystems, albeit in a conservation and restoration context that ends up restoring degraded agricultural lands these people create:
Restoring and managing for more diverse plant communities can improve recovery of belowground biology and functioning in predictable ways. Specifically, we found greater accumulation of roots, more predictable recovery of soil microorganisms (bacteria and fungal biomass), more rapid improvement in soil structure (less compaction), and less nitrogen available for loss from the system in prairie restored and managed for high plant diversity (>30 species) relative to the low diversity (<10 species) grassland plantings. Thus, the hypothesis that biodiversity promotes ecosystem functioning is relevant to large-scale conservation and restoration practices on the landscape.