Environmental changes such as global warming and habitat degradation are altering the composition of animal and plant communities around the world. Understanding these changes, and how to mitigate them requires knowledge of how species interact as their populations vary in time and space. We study structured communities in natural, disturbed and agricultural settings, with an emphasis on (but not limited to!) parasitoid wasps, their butterfly hosts, plants the butterflies feed on, and their diseases and microbial symbionts.
We have a long term study of the parasitoids of the The Glanville fritillary butterfly metapopulation in Åland, Finland. The host metapopulation is made up of local populations that are dynamic and differ in size, connectivity and age. This is the context experienced by the parasitoids and hyperparasitoids of the butterfly, and natural variation within this system can be used to test predictions of (meta)community structure.
van Nouhuys, S., Hanski, I. 2005 Metacommunities of butterflies and their parasitoids. In Metacommunities: Spatial Dynamics and Ecological Communities (M. Leibold, R. Holt and M. Holyoak eds.). University of Chicago Press. pp. 99-121
Tscharntke, T., R. Bommarco, Y. Clough, T. Crist, D. Kleijn, T. Rand, J. Tylianakis, S. van Nouhuys, S.Vidal 2007. Conservation biological control and enemy diversity on a landscape scale.(authors alphabetical after Tscharntke). Biological Control, 43: 294-309 PDF
Food chain length and contrasting spatial scales of parasitoid populations
One important prediction of metacommunity structure is that food chain length decreases with habitat fragmentation. That is, the negative affect of habitat fragmentation increase with trophic level. We approach this idea several ways using the plant-butterfly-parasitoid-hyperparasitoid food chains in Åland.
Wang, S., Brose, U., van Nouhuys S., Holt R. D., Loreau, M. 2021
Metapopulation capacity determines food chain length in fragmented landscapes. PNAS, 118 (34) e2102733118
van Nouhuys, S. 2005. Effects of habitat fragmentation at different trophic levels in insect communities. Annales Zoologici Fennici, 42: 433–447
van Nouhuys, S. & Hanski, I. 2002. Multitrophic interactions in space: metacommunity dynamics in fragmented landscapes. In Multitrophic level interactions (T. Tscharntke & B. A. Hawkins eds.) Cambridge University Press. pp. 124-147
Indirect interactions in the metacommunity
Species interact indirectly through shared enemies (apparent competition), or through intermediate species, such as an herbivore that is experienced by both its food plants and its parasitoids (Multitrophic interactions). These indirect interactions vary spatially, and can influence the large scale population dynamics of species and community structure.
Wang, S., Brose, U., van Nouhuys S., Holt R. D., Loreau, M. 2021. Metapopulation capacity determines food chain length in fragmented landscapes. PNAS, 118 (34) e2102733118
Opedal OH, Ovaskainen O, Saastamoinen M, Laine AL, van Nouhuys S. 2020. Host-plant availability drives the spatiotemporal dynamics of interacting metapopulations across a fragmented landscape. Ecology 101: e03186
Nieminen, M. and van Nouhuys, S. 2017. The roles of trophic interactions, competition and landscape in determining metacommunity structure of a seed-feeding weevil and its parasitoids. Ann. Zool. Fennici, 54: 83-96
van Nouhuys, S. and Kraft, T. S. 2012. Indirect interaction between butterflies meditated by a shared pupal parasitoid. Population Ecology, 54: 251-260
van Nouhuys, S. & I. Hanski 2000. Apparent competition between parasitoids mediated by a shared hyperparasitoid. Ecology Letters, 3: 82-84
van Nouhuys, S. & I. Hanski 2002. Multitrophic interactions in space: metacommunity dynamics in fragmented landscapes. In Multitrophic level interactions (T. Tscharntke & B. A. Hawkins eds.) Cambridge University Press. pp. 124-147