Abstract:
Pinus caribaea has a variety of negative effects on local ecosystems. One of the issues
related to P. caribaea plantations is the low rate of leaf litter decomposition and suppression
of undergrowth regeneration. There are studies carried out to discover the causes for
this in many countries. However, the number of studies conducted in Sri Lanka is low.
The leaf litter decomposition is governed by different factors including microclimate,
litter quality, nutrient availability, soil conditions and decomposer community. This
study was designed to identify fungal microbial community inhabiting ground litter in
P. caribaea plantations and determine the effect on undergrowth by comparison with
adjacent native vegetation at two locations in Belihuloya. The methodology followed
was dilution series prepared by the collected soil samples. Each solution of different
concentrations was cultured in Potato Dextrose Agar media and incubated at 28°C. The
resulted fungal species were sub cultured under the same temperature. The diversity of
fungal species was determined by macroscopic colony culture characteristics. Overall, 16
different fungal species were isolated and identified based on the macroscopic morphological
characteristics. Three species were identified as the most abundant species in both
vegetation types in both locations. Four species were common to both Pinus plantation
and adjacent native vegetation. Three species were exclusively identified in the first
Pinus plantation and two species in the second Pinus plantation. The first adjacent
native vegetation recorded two species and five species were observed in the second
adjacent vegetation. The measured pH values in two vegetation types were acidic which
favor a fungal decomposer community. Similarly, soil temperature of both vegetation
types ranged between 22°-25°C exerting a positive impact on fungal inhabitation on
ground litter. Overall, a considerable diversity of fungal species was observed during
the study.
