Department of Forestry and Environmental Science
UNIVERSITY OF SRI JAYEWARDENPURA, SRI LANKA ../
FORESTRY AND ENVIRONMENT SYMPOSIUM
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|FORESTRY SYMPOSIUM 1996|
Height growth and survival of ten species common to dry zone are compared. Twenty, one year old seedlings were measured and the number of leaves counted. All the seedlings of the species studied were sampled for seedling survival and the observations were recorded at the end of each month.
The greater mean height growth between Chukrasia tabularis ( 14.89 +/- 3.23) and Phyllanthus indicus (7.52 +/- 1.25) was shown.). There was no significant difference between the mean height growths of these two species(alpha=0.05).The rank order of mean height growth among all the species studied was Chukrasia tabularis with the highest, followed by Phyllanthus indicus, Bridelia retusa ( 7.03 +/- 1.04), Pleurostylia opposita (5.65 +/- 0.81), Vitex altissima (5.59 +/- 0.67), Drypetes sepiaria ( 5.13 +/- 1.15), Syzygium cumini ( 5.03 +/- 0.65), Chloroxylon swietenia ( 4.86 +/- 1.07 ), Madhuca longifolia ( 4.16 +/- 0.90) and Manilkara hexandra (3.96 +/- 0.60). The mean annual height growth for the all these species was 5.76 cm yr-1. The leaf number per seedling in each of these species, with the exception of A. indica, Drypetes sepiaria and Madhuca longifolia showed a decline with the extended south-west drought.
Amongst these species, Manilkara hexandra (88.5%: n=87) exhibited the greatest percentage survival. Chukrasia tabularis, Vitex altissima, Pleurostylia opposita, Bridelia retusa, Drypetes sepiaria and Azadirachta indica consistently grouped together as those with medium survival percentage (50% - 70%). Madhuca longifolia, Chloroxylon swietenia and Phyllanthus inducus had the least survial percentage (< 50%).
Department of Forestry and Environmental Science,