Seed Germination and Seedling Survival Percentage of Shorea robusta Gaertn.f. in Buffer Areas of Similipal Biosphere Reserve, Odisha, India

Abstract

Seed germination and seedling survival percentage of Shorea robusta was studied in Similipal Biosphere Reserve (SBR) from 2010 to 2011. During the investigation period it was found that larger seeds (12 to 14 mm diameter) exhibited higher germination percentage (70 ± 6.5%) and all the seedlings survived. On the other hand, smaller seeds showed a very low percentage of germination (25 ± 4.24%) and none of the seedlings survived. It was also noticed from the study that the growth phase of the parent tree has a prominent effect on the germination potential of seeds. Juvenile trees with Girth at Breast Height (GBH) 75 to 80 cm as well as over mature (GBH: 91 to105 cm) or senile trees (GBH: 106 to 150 cm) produce seeds with a lesser germination capacity. However, young trees (GBH: 81 to 90 cm) produce seeds with a higher germination potential. Not only these aspects but also the orientation of seeds showed a peculiar phenomenon during natural germination. Maximum percentage (85 ± 12.75%) of seed germination was marked in case of seeds fallen on the forest floor in inverted position in comparison to other seed orientation types i.e. upright and horizontal. The uprightly falling seeds on the forest floor exhibited the minimum percentage (32 ± 6.84%) of germination, while horizontally falling seeds showed an intermediate range of germination percentage. Percentage survival of seedlings also followed the same pattern.