Resource connectivity for beneficial insects in landscapes dominated by monoculture tree crop plantations

Abstract

Homogenization of agricultural landscapes affects ecological processes and biodiversity and can affect the community composition of ecosystem service providers. These effects can have particular impact in landscapes dominated by monocultures of pollinator-dependent tree crop plantations, which create both spatial and temporal homogeneity at the landscape scale. I looked for associations between the proportion of nearby unmanaged vegetation and potential wild pollinator groups collected within flowering almond orchards in two types of landscape. In the Complex landscape, characterized by a heterogeneous mosaic of multiple crops, semi-natural grassland and natural woodland, insect pollinator groups were not associated with unmanaged vegetation. In the Simple landscape, dominated by monoculture almond plantations, most pollinator groups showed positive relationships with the two unmanaged vegetation types (grassland and woodland). In particular, all wild bee and all but one hoverfly individual were found in remnant native vegetation patches within almond plantations, rather than within rows of almond trees. More research is necessary to identify how structural differences created in monoculture landscapes, between crops and the native vegetation they encroach on, influence ecological communities and the provision of ecosystem services.

Keywords:

• monoculture
• broadacre
• functional connectivity
• almond plantation
• orchard
• wild pollinators

Acknowledgements

Select Harvests and Manna Farms provided access to their orchards; J. Abell and K. Lumb provided field assistance; G. Luck, M. Mayfield and G. Gurr provided valuable comments on the study design and earlier versions of the manuscript. S. McDonald prepared images used in Figure 1.

Disclosure statement

No potential conflict of interest was reported by the author.

Funding

The work was supported by the Institute for Land Water and Society under a postgraduate research scholarship.

Supplemental data

Supplemental data for this paper can be accessed at 10.1080/14735903.2015.1025496.