Abstract:

Plant invasion potentially will be affected by increased extreme drought events and deposition of atmospheric N. However, results from previous research indicate that it is not clear as to how extreme drought, N deposition and their interaction affect alien plant invasion, in particular for the invasive woody legumes. We conducted a greenhouse experiment with three invasive and three native woody species of legumes (Fabaceae). We grew plants in extreme drought and in well-watered conditions combined with low and high levels of N and compared plant height, number of leaves and biomass production and allocation. Growth of native woody legumes was suppressed more by extreme drought than that of invasive woody legumes. Although an increase in soil N availability decreased the root mass fraction of plants of all species, it did not affect their overall performance. We found that invasive woody legumes can tolerate the adverse effects of the prolonged extreme drought better than native woody legumes. These results enhance our understanding of the effects of drought due to climate change on the invasion of alien woody legumes.

Key words: Fabaceae, global warming, N deposition, plant invasion, water availability