PARENT SESSION
Poster Session 24: Agro-Ecology
Wednesday, August 10, 5:00 PM - 6:30 PM, Exhibit Hall 220 A-E, Level 2, Palais des congrès de Montréal
Spider assemblages in apple orchards: how adjacent habitat structure influences potential source populations.
Sackett, Tara*,1, 2, Buddle, Chris1, Vincent, Charles2, 1 McGill University, Ste. Anne de Bellevue, Quebec, Canada2 Agriculture and Agri-Food Canada, Saint-Jean-sur-Richelieu, Quebec, Canada
ABSTRACT- In agricultural systems the manipulation of adjacent habitats can enhance natural enemy populations in the agroecosystem, as adjacent habitats provide a source of generalist predators for periodic recolonization as well as supplying overwintering sites and alternative resources. For spiders, the pattern between species assemblages found in agroecosystems and flowering strips or non-structurally similar adjacent habitats has been studied in some detail and the results have been variable; in some cases it appears that there is low spider community similarity and exchange from one habitat to another because of structural dissimilarity between the habitats. An understanding of how vegetation structure in adjacent habitats affects spider communities is important when considering appropriate landscape manipulations as source habitat for nearby agroecosystems. In this study we compared spider assemblages in apple tree foliage in three orchards to assemblages in adjacent habitats with either similar physiognomic structure (adjacent deciduous forest) or dissimilar structure (field, low vegetation beside forest). We found that spider assemblages in the foliage of apple trees were more similar in species composition and diversity to assemblages found in the foliage of adjacent forest than to assemblages found in adjacent fields or the ground vegetation at the forest edge. These results suggest that adjacent habitats with vegetation physiognomically similar to plant structure in the agroecosystem will be better source habitats for spiders than adjacent habitats with different structures.
Key words: spiders, agriculture, habitat, diversity