A review on the relationships between plant genetic diversity and ecosystem functioning

The loss of genetic diversity is accelerating due to habitat loss and population reduction caused by global change and anthropologenic activities. For species-poor ecosystems, the effect of genetic diversity on ecosystem functioning may not be smaller than that of species diversity. Therefore, understanding the relationship between genetic diversity and ecosystem functioning (GD-EF) and its underlying mechanisms is important for biodiversity conservation, responses of ecosystems to environmental change and ecological restoration. Here, we reviewed the studies on the effects of plant genetic diversity on ecosystem structures (community structure of the higher tropic level) and ecosystem functions (primary production, nutrient cycling and ecosystem stability), and the mechanisms underlying these relationships. We also discussed the influence of functional diversity on GD-EF, the comparison of effects of the genetic and species diversity on ecosystem functioning, and the application of GD-EF in the ecological restorations. We finally pointed out the limitations in current studies to provide references for the future: (1) further studies on the mechanisms of GD-EF are needed; (2) no study has evaluated the influence of genetic diversity on maltifunctinarity; (3) the impacts of different measurements of genetic diversity on ecosystem functioning are unclear; (4) there are lack of long-time GD-EF studies and GD-EF studies conducted at multidimensional scales; (5) the relative importance of genetic diversity and other factors on ecosystem functioning in the nature is unclear.