Understanding movement of plants, and the consequences of that movement, is critical to understanding the responses of plant communities to a changing climate. Most considerations of plant movement in response to climate change focus on long distance dispersal (LDD) and the dispersal kernel, in particular whether the tail of the dispersal curve is sufficiently “long” to keep up with the moving climate envelope. However, simply focusing on static dispersal kernels is likely to be very misleading because it ignores the extreme complexity of the seed dispersal process and its outcomes. Further, this approach ignores local dispersal, which is also expected to change in important ways in response to climate change.
Results/Conclusions
In this talk, I will not answer the question posed in the title, but will instead illustrate how complex the question is, how complex the answer is likely to be, and develop a framework for developing a better understanding of plant movement in a changing climate. A starting point is the seed dispersal effectiveness (SDE) framework, where SDE is a function of the quantity of seeds dispersed and the quality of dispersal provided individual seeds. Climate change can affect both the quantity of seeds dispersed (e.g. altered disperser assemblages, phenological mismatches, climate-induced reductions in crop size) and the quality of dispersal (e.g. changes in the net strength of facilitation). Secondly, we need to consider both local, within population seed dispersal (Local SDE) and the LDD needed for migration (Migration SDE). If climate change reduces the effectiveness of local dispersal it can reduce source strength and thus the number of LDD events. In addition, both Local SDE and Migration SDE will likely respond in complex ways to climate change. As a simple example, a static dispersal kernel is irrelevant if it extends the tail into a habitat unsuitable for the disperser, limiting seed arrival and seedling establishment.