Applying Landscape Ecology to Plant Integrated Pest Management
Special presentation by Dr. Julie-Éléonore Maisonhaute, Centre de recherche agroalimentaire de Mirabel (CRAM). Everyone is welcome to attend.
Landscape ecology, which aims to understand the relationship between spatial context and ecological processes, can be applied to many ecosystems including agroecosystems. The basics of landscape ecology include concepts such as spatiotemporal dynamics of landscapes, landscape composition (ex. heterogeneity), landscape configuration (ex. fragmentation), and landscape perturbations. For the past few decades, an increasing number of studies have applied landscape ecology concepts to agroecosystems, focusing on the effect of the spatial context on the population dynamics of pests or natural enemies. Landscape ecology applied to agroecosystems plays an important role in plant Integrated Pest Management (IPM), as it can help to model population dynamics of both pests and natural enemies (which landscape components have significant effects?), make predictions about future infestations (which landscape components are associated with lower/higher infestations?) or implement biological control programs (which landscape components are beneficial for natural enemies and associated with a more efficient control of pests?). For instance, managing agricultural landscape, such as conserving non-crop areas or implementing strip cropping, have been showed to have significant positive effects on natural enemies and conservative biological control. Scale is also an important parameter to take into account, since species of arthropods respond differently to landscape structure, from a very local/fine scale to a large/regional scale. How spatial context can affect arthropod communities in agroecosystems and how it can be used in plant IPM will be further discussed using examples of an invasive pest (the soybean aphid) and natural enemy communities (aphidophagous guild and ground beetles). For instance, studies have revealed that the effect of the spatial context on the soybean aphid highly depends on the invasion sequence, involving effects of summer host (soybean), overwintering host (buckthorn or woodland) or crop diversity, while studies on natural enemies in corn system have showed temporal variation of the effect of the spatial context, as well as variations between species and trophic groups. All of these effects of landscape context on pests and natural enemies should be taken into account when implementing plant IPM programs.
