RATTAN DIVERSITY AND BROAD EDAPHIC NICHES IN A TROPICAL RAINFOREST OF BUTON, SULAWESI, INDONESIA
ABSTRACT: Rattan diversity and
broad edaphic niches in a tropical rainforest of Buton, Sulawesi, Indonesia.
Reinwardtia 15(2): 99 – 110. — This paper attempts to answer the question: how
can at least 20 species of rattan palms in the genus Calamus (family Palmae
(Arecaceae)) co -exist in a rainforest? A survey of rattans was made in
Lambusango Forest on Buton, an island close to south east Sulawesi, in
Indonesia. Rattan species and numbers were recorded in 87 quadrats of 30 × 10
m, laid out along linear transects in habitats with a variety of soils.
Evidence for edaphic (soil) niches was sought. Different rattan species were found
to be adapted to soils with different conductivity and pH values. Standardised
mean difference (d) scores were calculated for pairs of species based on their
response to soil pH. Of the 66 pairs tested, 61 were found to be significantly
different statistically. Such differences suggest, but do not prove, that many
species occupy different edaphic niches. It was found that species which show a
preference for soils with intermediate pH values (5.0 to 6.5) can grow in soils
with a wide range of pH values, implying broad edaphic niches and that competition
between these species is weak. Correspondence analysis shows that many species
do not distinguish greatly between many soils with intermediate pH values. It
is concluded that rattan species show evidence for having different edaphic
niches, although the niches for many species are broad. It is speculated that
many rattan species may be ecologically equivalent and that a weak version of
ecological neutrality theory may apply.
Author: ROSIE PRITCHETT
Journal Code: jpbiologigg160010
