Experimental evidence of multiple ecosystem services and disservices provided by ecological intensification in Mediterranean agro-ecosystems

1. Intensifying agricultural production in sustainable ways is pivotal to
increasing food production while reducing environmental impacts.
Ecological intensification is based on managing organisms that provide
services underlying crop production to simultaneously intensify
agricultural production and increase biodiversity. However, few studies
address the interactions and trade-offs between biodiversity, multiple
ecosystem services and crop production. 2. We experimentally quantified
the effect of uncultivated field margins, a prominent practice of
ecological intensification, on agricultural production, biodiversity, as
well as on multiple ecosystem services and disservices, in an intensive
Mediterranean agro-ecosystem. We used a split-plot design and sampled
butterflies, rodent and arthropod pests, arthropod natural enemies (both
parasitoids and predators), weeds, damage to crop and crop yield in
different distances into the field in three tomato and eleven wheat crops
along the growing season. 3. Field margins increased natural enemy
densities, reduced pest-damage to crop and consequently increased yield in
tomato crops. Notably, we found that pest control by one predator species
was dominant in the field centre, while parasitoid natural enemies were
confined to the field edges. Pest control was more prominent in the late
crop-stage compared to early season sampling and field margins increased
weed control in tomato crops by reducing weed cover. 4. Field margins
increased natural enemy densities in wheat at the beginning of the season,
but effects on arthropod pests were inconsistent. Field margins slightly
increased weed cover, but had no impact on rodent densities and total
yield. 5. Butterfly abundance, but not richness, was positively affected
by vegetated field margins. 6. Synthesis and applications: Our results
highlight the importance of a mechanistic and holistic approach to
promoting ecological intensification. Although field margins provided pest
and weed control in the highly intensive tomato crop, they increased weed
cover in wheat, which could potentially restrict yields at the field
scale. Farmers' guidelines should therefore consider the interactive
effects of multiple services on a variety of crops. Moreover, biodiversity
components that do not provide crop production services should be
independently targeted (e.g. by sowing plants that provide food
resources).