Observations on re-sprouting as regeneration strategy in Pterocarpus santalinus (Red sanders) - an endemic tree in dry deciduous forests of Sri Lankamalleswara wild life sanctuary, southern Eastern Ghats

摘要

Re-sprouting from roots and cut stumps as multiple sprouts after disturbance as an important regeneration mode is studied in Pterocarpus santalinus, an endemic tree of kadapa hill ranges of southern Eastern Ghats. The study was carried out in dry deciduous forests of Sri Lankamalleswara wildlife sanctuary. The inventory of different regeneration life stages seedling, sapling, regenerating trees was undertaken in two sites namely site 1 and site 2 of one hectare each by laying transects of 10 x 100 size. The inventory has yielded a range of 198-240 seedlings ha(-1), 45-58 saplings ha(-1) and 38-74 regenerating plants ha-1. Among them 47% of seedlings, 71% of saplings and 7% of regenerating trees comprised of multiple shoots. It reveals that the re-sprouting of stems after a disturbance helps the plant to progress from seedling to sapling and then successfully to a regenerating tree stage. Re-sprouting was observed in both the transects affected by fire and animal browsing, but a higher level of deaths occurred due to the later disturbance. Thus, animal browsing seems to be major factor than fire that affects the seedling survival. A negative relationship between the cut-stump size class and proportion of stumps with sprouts was observed. The 51-70 cm gbh class of cut stumps has registered higher percentage of cut stumps with sprouts as well as mean sprouts per stump. Majority of fruits comprised of two locules with only one seed, the abort of one seed may be helpful to have a better dispersal advantage.