| 要旨トップ | 目次 | | 日本生態学会第60回全国大会 (2013年3月,静岡) 講演要旨 ESJ60 Abstract |
一般講演(ポスター発表) P1-202 (Poster presentation)
How human disturbance influences community trophic dynamics have rarely been studied in open terrestrial ecosystems. We conducted such a study in a tropical dry forest in Madagascar, focusing 10 species of lizard: Blaesodactylus ambonihazo, Furcifer oustaleti, Furcifer rhinoceratus, Geckolepis maculata, Hemidactylus frenatus, Lygodactylus tolampyae, Oplurus cuvieri, Phelsuma kochi, Uroplatus guentheri, and Zonosaurus laticaudatus. We used stable isotope ratios of carbon and nitrogen to describe the trophic position of each species, and compared them between disturbed and undisturbed sites within a small area (3 X 1.5km). We further documented details of community trophic dynamics between the sites using community-wise metrics. We found that the trophic positions of some species shifted dramatically while others are relatively stable. Our results also suggest a possible relaxation of ecological species packing in disturbed areas, possibly due to utilization of novel human-introduced carbon sources by some species such as Z. laticaudatus and H. frenatus. Thus, some species may play different ecological role in different habitat, and human disturbance can cause ecological shifts over a small geographic scale.