SEED BANK DYNAMICS OF KEKILLA FERN LANDS AND ABANDONED CHENA UNDER PARTIAL SHADE AND FULL SUN CONDITIONS

Abstract

Seed bank dynamics can be considered an important component of the regeneration ofindividual plant populations and communities. Soil seed bank dynamics in Kekillafernlands and abandoned chena need to be studied as possible sources of regeneration forforest restoration of degraded lands.

This study was done to understand regeneration dynamics of soil seed banks with referenceto two light regimes in Kekil1a fernlands and abandoned chena in the periphery ofSinharaja World Heritage Site.

Sinharaja World Heritage Site is one of the least disturbed and biologically unique lowlandrain forests now remaining in Sri Lanka. Today some areas of the periphery of Sinharajaare covered with secondary scrub and Kekilla (Dicranopteris linearis) fernlands. Threesites of Kekilla fernlands and three sites of abandoned chena were selected for the study.

Four soil samples were purposively collected from four different locations in each site.These four samples were pooled and mixed in a polythene bag. Eight trays were preparedusing one mixture of soil from one site. Four trays from each site were placed underpartial shade (750J.! mol m-2 S-1 ) and others were placed under full sunlight (2000J.! mol m-2S-I). Seeds inside the soils were allowed to germinate. Newly germinated seeds wererecorded every fifth day. All germinated seeds that were able to be identified wereremoved and counted once a month.

Seedlings of 45 taxa were identified during the period of study. Among the countedseedlings a larger proportion was recruited under the partial shade treatment than full suntreatment. Results indicate that the number of species germinated from abandoned chenawas greater than that of Kekilla femlands. Finding suggest that in all treatments onlypioneer species germinated. Climax species were not represented in any of the sites orlight treatments.