Steep slopes promote downhill dispersal of Quercus crispula seeds and weaken the fine-scale genetic structure of seedling populations Takafumi Ohsawa, Yoshiaki Tsuda, Yoko Saito, Haruo Sawada and Yuji IdeAnn. For. Sci., 64 4 (2007) 405-412DOI: https://doi.org/10.1051/forest:2007017