DOI: 10.5061/dryad.61dh0rs
title: Data from: Associations between plant and pollinator communities under grassland restoration respond mainly to landscape connectivity

description: 1. Land use change can disrupt associations between different trophic
 groups, but it is unclear if habitat restoration can recover these
 associations. In Sweden, restoration efforts have been applied to increase
 areas of semi-natural grassland previously remaining as small fragments
 due to abandonment. We assessed how the associations between plant and
 pollinator communities can be modified by grassland abandonment and
 restoration, together with landscape connectivity. 2. We surveyed plant,
 hoverfly and bee communities in 10 abandoned, 18 restored and 10 intact
 grasslands in south-central Sweden, distributed along a gradient of
 isolation from other species-rich grasslands. We assessed the effects of
 management history and connectivity on the relationships between several
 measures of the composition of plant and pollinator communities as well as
 between plant community composition and pollinator guilds. 3. The
 composition of the local flowering plant community was an important
 determinant of both hoverfly and bee communities. However,
 plant-pollinator associations were modulated by landscape connectivity
 and, to some extent, by grassland management history. Abundance, species
 richness and functional richness of bees and species richness of
 hoverflies were positively associated with local plant communities in
 isolated grasslands, but these associations weakened in well-connected
 grasslands. In contrast, hoverfly abundance correlated positively with
 plant communities in well-connected grasslands. 4. The response of
 pollinator feeding guilds was consistent with overall pollinator
 communities. However, abundance of bees adapted to foraging on particular
 plants (long-tongued and short-tongued) responded positively to specific
 host plant species abundance. 5. Synthesis and applications. Our results
 show how land use and landscape context can significantly affect
 interactions between different trophic levels. Land use and landscape
 context should therefore be recognised in grassland restoration
 guidelines. Enhancement of both functional-rich and species-rich plant
 communities, as well as increasing abundance and species and functional
 richness of host plants for specialist pollinators will amend pollinator
 diversity. Restoration actions should consider the spatial configuration
 of the landscape to improve its outcome. Efforts in more isolated
 grasslands should focus on promoting local habitat quality while, in more
 connected grasslands, the priority should be maintaining connectivity to
 well-preserved grasslands.
description: Plant-pollinator
 diversity indices per study siteData table with the
 information associated to each study site: name, coordinates, grassland
 category (abandoned, restored or continuously grazed), landscape
 connectivity index, flowering plant diversity variables (abundance,
 species richness, species evennes, functional richness and functional
 evenness) and bee and hoverfly diversity variables (abundance, species
 richness, species evennes, functional richness and functional
 evenness).Rotches-Ribalta_Plant-pollinator diversity indices per study site.xlsx