1 Graduate School of Human and Environmental Studies,
Kyoto University, Kyoto 606- 8501, Japan,
2 Faculty of Science, Kagoshima University, Kagoshima
890-0065, Japan
3 Research Institute for Humanity and Nature, Kyoto 603-8047,
Japan
4 Faculty of Agriculture, Ehime University, Matsuyama 790-8566,
Japan
a Present address: Graduate School of Life Sciences, Tohoku
University, Sendai 980- 8578, Japan.
Abstract: We examined the effects of slash-and-burn deforestation
on the properties of the ant-associated mutualistic interactions
with plants and hemipterans in and around a lowland tropical
rainforest in Borneo. We compared the frequency of occurrence
and composition of the involved species among primary and
secondary forest plots of different stand ages (time since
last slash-and-burn event). For ants attending both extrafloral
nectaries (EFNs) and hemipterans, for trees bearing EFNs,
and for trees with hemipteranattending ants, the number of
species was higher in primary than in secondary forest, and
less than 20% of species observed in the primary forest plots
were also recorded in the secondary forest. For Macaranga
myrmecophytes, both the number of species and the frequency
of occurrence were higher in primary than in secondary forest,
and the species observed in secondary forest comprised approximately
one-third of the species occurring in primary forest. In contrast
the weaver ant Oecophylla smaragdina, which tended
to exclude other arboreal ant species, was significantly more
abundant in secondary than in primary forest. These results
suggest that slash-and-burn deforestation drastically decreases
the diversity of species involved in mutualistic interactions
between ants and plants and between ants and hemipterans.
Keywords: human disturbance through slash-and-burn; ant-plant
interaction; anthemipteran trophobioses; Macaranga
myrmecophytes; Oecophylla smaragdina; EFNbearing
plants
