Effects of forest fragmentation to hybridization of dipterocarp trees

2015 Fiscal Year Final Research Report

• Project/Area Number: 24688017
• Research Category: Grant-in-Aid for Young Scientists (A)
• Allocation Type: Partial Multi-year Fund
• Research Field: Forest science
• Research Institution: Forestry and Forest Products Research Institute
• Principal Investigator: Tanaka Kenzo 国立研究開発法人 森林総合研究所, 植物生態研究領域, 主任研究員 (30414486)
• Research Collaborator: ICHIE Tomoaki ; KAMIYA Koichi ; NANAMI Satoshi
• Project Period (FY): 2012-04-01 – 2016-03-31
• Keywords: 熱帯林 / 東南アジア / フタバガキ / 雑種 / 光合成 / Shorea / 浸透交雑 / 断片化

Outline of Final Research Achievements

Although natural hybridisation between dipterocarp trees is considered rare, we found many putative dipterocarp hybrids (genus Shorea spp.) in a forest fragment in Singapore. We analysed seedling survival and growth rates in relation to environmental variables for S. curtisii, S. leprosula and hybrids of the two species. Hybrids were more frequent at the seedling stage than at the mature stage. F1 individuals had growth and survival rates comparable to their parent species, with the exception of higher growth rates in S. leprosula. Our results showed that hybrid F1 seedlings lacked obvious heterosis, and might therefore have similar fitness to that of parent species for the present forest environment. We also found more frequent interspecific hybridization in fragmented forests than non-disturbed forests with large area. This indicates that forest fragmentation may accelerate hybridization between dipterocarps tree species.

Free Research Field

樹木生理生態学