Host-parasitoid dynamics in a fragmented landscape: Holly trees, holly leaf miners and their parasitoids

Many species inhabit fragmented landscapes, where units of resource have a patchy spatial distribution. While numerous studies have investigated how the incidence and dynamics of individual species are affected by the spatial configuration and landscape context of habitat patches, fewer studies have...

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Main Authors: Klapwijk, M, Lewis, O
Format: Journal article
Language:English
Published: 2012
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author Klapwijk, M
Lewis, O
author_facet Klapwijk, M
Lewis, O
author_sort Klapwijk, M
collection OXFORD
description Many species inhabit fragmented landscapes, where units of resource have a patchy spatial distribution. While numerous studies have investigated how the incidence and dynamics of individual species are affected by the spatial configuration and landscape context of habitat patches, fewer studies have investigated the dynamics of multiple interacting resource and consumer species in patchy landscapes. We describe a model system for investigating host-parasitoid dynamics in a patchy landscape: a network of 166 holly trees, a specialised herbivore of holly (the leaf miner, Phytomyza ilicis (Curtis, 1948)), and its suite of parasitoids. We documented patch occupancy by P. ilicis, its density within patches, and levels of parasitism over a 6-year period, and manipulated patch occupancy by creating artificially vacant habitat patches. Essentially all patches were occupied by the herbivore in each year, suggesting that metapopulation dynamics are unlikely to occur in this system. The main determinants of densities for P. ilicis and its parasitoids were resource availability (patch size and host density, respectively). While P. ilicis is apparently not restricted by the spatial distribution of resources, densities of its parasitoids showed a weaker positive relationship with host density in more isolated patches. In patches where local extinctions were generated experimentally, P. ilicis densities and levels of parasitism recovered to pre-manipulation levels within a single generation. Furthermore, patch isolation did not significantly affect re-colonisation by hosts or parasitoids. Analysing the data at a variety of spatial scales indicates that the balance between local demography and dispersal may vary depending on the scale at which patches are defined. Taken together, our results suggest that the host and its parasitoids have dispersal abilities that exceed typical inter-patch distances. Patch dynamics are thus largely governed by dispersal rather than within-patch demography, although the role of demography is higher in larger patches. © 2011 Gesellschaft für ökologie.
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spelling oxford-uuid:740b8302-f3ed-400e-975c-e76fe2109d412022-03-26T20:00:15ZHost-parasitoid dynamics in a fragmented landscape: Holly trees, holly leaf miners and their parasitoidsJournal articlehttp://purl.org/coar/resource_type/c_dcae04bcuuid:740b8302-f3ed-400e-975c-e76fe2109d41EnglishSymplectic Elements at Oxford2012Klapwijk, MLewis, OMany species inhabit fragmented landscapes, where units of resource have a patchy spatial distribution. While numerous studies have investigated how the incidence and dynamics of individual species are affected by the spatial configuration and landscape context of habitat patches, fewer studies have investigated the dynamics of multiple interacting resource and consumer species in patchy landscapes. We describe a model system for investigating host-parasitoid dynamics in a patchy landscape: a network of 166 holly trees, a specialised herbivore of holly (the leaf miner, Phytomyza ilicis (Curtis, 1948)), and its suite of parasitoids. We documented patch occupancy by P. ilicis, its density within patches, and levels of parasitism over a 6-year period, and manipulated patch occupancy by creating artificially vacant habitat patches. Essentially all patches were occupied by the herbivore in each year, suggesting that metapopulation dynamics are unlikely to occur in this system. The main determinants of densities for P. ilicis and its parasitoids were resource availability (patch size and host density, respectively). While P. ilicis is apparently not restricted by the spatial distribution of resources, densities of its parasitoids showed a weaker positive relationship with host density in more isolated patches. In patches where local extinctions were generated experimentally, P. ilicis densities and levels of parasitism recovered to pre-manipulation levels within a single generation. Furthermore, patch isolation did not significantly affect re-colonisation by hosts or parasitoids. Analysing the data at a variety of spatial scales indicates that the balance between local demography and dispersal may vary depending on the scale at which patches are defined. Taken together, our results suggest that the host and its parasitoids have dispersal abilities that exceed typical inter-patch distances. Patch dynamics are thus largely governed by dispersal rather than within-patch demography, although the role of demography is higher in larger patches. © 2011 Gesellschaft für ökologie.
spellingShingle Klapwijk, M
Lewis, O
Host-parasitoid dynamics in a fragmented landscape: Holly trees, holly leaf miners and their parasitoids
title Host-parasitoid dynamics in a fragmented landscape: Holly trees, holly leaf miners and their parasitoids
title_full Host-parasitoid dynamics in a fragmented landscape: Holly trees, holly leaf miners and their parasitoids
title_fullStr Host-parasitoid dynamics in a fragmented landscape: Holly trees, holly leaf miners and their parasitoids
title_full_unstemmed Host-parasitoid dynamics in a fragmented landscape: Holly trees, holly leaf miners and their parasitoids
title_short Host-parasitoid dynamics in a fragmented landscape: Holly trees, holly leaf miners and their parasitoids
title_sort host parasitoid dynamics in a fragmented landscape holly trees holly leaf miners and their parasitoids
work_keys_str_mv AT klapwijkm hostparasitoiddynamicsinafragmentedlandscapehollytreeshollyleafminersandtheirparasitoids
AT lewiso hostparasitoiddynamicsinafragmentedlandscapehollytreeshollyleafminersandtheirparasitoids