Laboratory of Tropical Ecology
Our team at the Laboratory of tropical ecology studies all aspects of tropical biodiversity, particularly its evolutionary origins and ecological mechanisms shaping present day ecosystems. Our studies combine extensive field inventories of species and their interactions in tropical ecosystems, particularly rainforests, with manipulative experiments and molecular analysis. We focus particularly on the ecology of plant-insect food webs, tropical forest dynamics, and large-scale distribution of tropical biodiversity. Most of our studies are based in Papua New Guinea, at the New Guinea Binatang Research Center (www.entu.cas.cz/png).
Plant-insect food webs in tropical rainforests
This study examines extremely complex plant-insect food webs in tropical forests, particularly in Papua New Guinea, and ecological and phylogenetic determinants of their structure. In particular, we examine species richness and host specificity of herbivorous insects from multiple guilds on plant species selected across entire plant phylogeny. Further, we study associated parasitoids and predators, particularly ants, spiders and also birds. Our analytical approaches include the study of plant phylogenetic relationships and their signal in insect trophic interactions, as well as manipulative experiments investigating the importance of predators on herbivores and, by extension, on plants. Key publications: Novotny et al. (2002, Nature 416: 841-4), Weiblen et al. (2006, Ecology 87: S62-75), Novotny et al. (2010, J. Anim. Ecol. in press).
Large-scale patterns of insect diversity in tropical rainforests
We study changes in species composition (beta diversity) and food web structure on large geographical scales (across hundreds of kms), both within relatively homogeneous lowland rainforest habitats and along major environmental gradients, including altitudinal. Our studies documented low beta diversity of insect herbivores within large areas of tropical lowland forests in New Guinea, while our ongoing study along a complete rainforest altitudinal gradient (from 200 to 3700 m asl.) indicates large species turnover with altitude of several insect taxa. This study is also paralelled by molecular analyses of differentiation among conspecific populations of insects with distance. Key papers: Novotny et al. (2007, Nature 448, 692-5), Craft et al. (2010, PNAS 107, 5041-6).
Forest dynamics in a tropical rainforest
We are in the middle of the first survey of our 50-ha permanent forest dynamics plot in lowland rainforest near Wanang Village in Papua New Guinea. We will map, tag and identify all stems more than 1 cm in diameter, approximately 270,000 stems in total. This plot (surveyed in collaboration with G. Weiblen, University of Minnesota) is a part of the global network of forest dynamics plot coordinated by the Center for Tropical Forest Science. It is so far the only such plot east of Wallace's line