The distinct fruit size and physical defense promote divergent secondary seed dispersal strategies of three oak species

7 S.

e-journal

200211176

Variations in fruit properties including fruit size, physical defense and chemical composition influence seed foraging and secondary dispersal, but the details remain unclear. Here, we focused on three common nutbearing tree species (Quercus aliena Blume, Q. dentata Thunb., and Q. variabilis Blume), which often co-occur in mixed deciduous forest in northern China. We estimated their acorn properties and evaluated their effects on the secondary dispersal patterns. We found similar chemical profiles but different acorn sizes and physical defense among these three species. Moreover, we detected distinct secondary seed dispersal strategies in relation to their acorn properties: Q. dentata produced the smallest-sized acorns with the lowest physical defense, which had shorter dispersal range but the highest survival rate; Q. variabilis generated the largest-sized acorns with the highest physical defense, which suffered the lowest survival rate but benefited from the longer dispersal range; and an intermediate survival rate existed in Q. alienawith the intermediate-sized acorns. In addition, P`ere David’s rock squirrel (Sciurotamias davidianus Milne-Edwards, Sciuridae) and brown rat (Rattus norvegicus Berkenhout, Muridae) are secondary seed dispersal agents for three oak species.