Data from: Additive and interactive effects of pollination and biological pest control on crop yield

1. Insect pollination and biological pest control simultaneously influence
crop yield, but are often investigated individually. This can lead to
under- or over-estimation of the importance of individual services when
they interact to affect yield. Recent, limited evidence from field studies
showed contrasting results with both additive and non-additive positive
and negative effects. 2. To disentangle the mechanisms underlying these
responses, we conducted a greenhouse experiment and a field study. We
tested the potential and realised contribution of insect pollination to
cotton boll retention and yield under various pest pressures and
biocontrol levels. 3. We found both additive and interactive effects of
insect pollination and biocontrol within a single crop system depending on
the level of pest pressure. In the greenhouse experiment, pollination did
not contribute to cotton boll retention and final yield at low pest
pressure. At high pest abundances boll retention and final yield were
higher when pollinators were present. In the field study, pollination was
sufficient to alter the negative effect of pests on boll retention. Thus,
interactive effect between the two ecosystem services on boll retention
was present at high pest pressure in the greenhouse and at natural levels
of pest pressure in the field, but not at lower pest abundances in
controlled conditions. 4. Although cotton plants partly compensated for
bolls shedding by increasing their weight in the greenhouse experiment,
this effect was not detected in the field study, likely due to higher
environmental variation. Similarly, interactive effect of pollination and
biocontrol on the final yield was present only in the greenhouse study. 5.
Synthesis and applications: We conclude that the contrasting findings of
additive versus non-additive effects between ecosystem services may be due
to the levels of services and disservices tested and environmental
variation. Further, this study shows that even when an ecosystem service
does not appear to limit crop yield it can make a substantial contribution
to yield depending on another service. For achieving food and fibre
security, it is essential that future studies test interactive effects
between these ecosystem services in different systems and environmental
conditions.22-Jul-2019