Maturity Of Ground Covers Increases The Resilience And Presence Of Natural Enemies In The Trophic Network Of Olive Canopy

The quality of a habitat is related to its lifetime (age) and the disturbances to which it has been exposed. Natural enemies and their interactions in trophic networks can be affected by the maturity of the systems they inhabit. The positive effects of ground covers and adjacent vegetation on natural enemies have been demonstrated in olive groves; however, the effect of the quality of such habitats has been largely neglected. In the present study, we assessed the effects of matureness of ground covers on the arthropod community of the olive canopy, specially the natural enemies. Sampling was made in an organic olive orchard at two periods of time separated by more than 10 years. We analyzed the differences in abundance and richness of arthropods in the olive canopy and their interactions with ground cover and adjacent vegetation using trophic networks. Our results suggest that the establishment and maturity of the ground cover inside the olive orchard affected the structure and complexity of the trophic network. The taxa of herbivores, omnivores, and parasitoids did not change drastically while there was an increase in predator taxa between both periods, which subsequently produced an increase in the vulnerability of herbivores. In essence, the taxa of predators increased twice their number maintaining the same proportion of preys per taxon. According to our analysis, a mature ground cover could provide the trophic network of the olive trees with new efficient taxa to enhance the biological control of pests.