4.3 Synthesis and applications
Our findings show that newly established grasslands can increase ant
species richness, abundance and pest control in agroecosystems, but also
indicate that it takes longer than three years to maintain biodiversity
level functions that are comparable to old semi-natural grasslands. To
counteract the loss of important biodiversity functions, agricultural
management should take into account key strategies for ecological
enhancement
(Bommarco,
Kleijn, & Potts, 2013; Perović et al., 2018) and consider the
replacement of harmful measures.
Our findings illustrate that new grasslands should be integrated into a
long-term management strategy for the promotion and resilience of
yield-enhancing ecosystem services provided by ants. Firstly, a turnover
of newly established grasslands back into crop fields inevitably
destroys initiated ant colonies, disrupts ant community succession and
dramatically reduces arthropod populations that deliver key biocontrol
services
(Ganser,
Knop, & Albrecht, 2019). Secondly, a long-term establishment of new
grasslands is paramount to promote not only ubiquitous ant species in
their abundance but also habitat specialists with longer colonization
times
(Dauber
& Wolters, 2005), in account of the fact that only a broad diversity of
functional insurance species can guarantee the resilience of biological
control services in European agroecosystems
(Tscharntke
et al., 2005). Our findings suggest that newly established grasslands
represent a promising measure for enhancing agricultural landscapes, but
must be preserved in the longer term to allow comprehensive immigration
of ant species into habitats that support agricultural biodiversity and
functionality.