Data from: Landscape complexity promotes hoverflies across different types of semi-natural habitats in farmland

1. Semi-natural habitats (SNH) provide essential resources for many
organisms in agricultural landscapes and can increase biodiversity at the
local and landscape scale. For the management of ecosystem services, it is
crucial to understand how local characteristics of SNH and the surrounding
landscape complexity affect beneficial species. 2. We investigated this
for hoverflies (Diptera: Syrphidae), an important functional group
providing both pest control and pollination services, in a total of 138
SNH in 35 agricultural landscapes in Switzerland and Germany. SNH differed
in type (woody, herbaceous), shape (areal, linear) and availability of
food resources (floral resources and aphids). They were located along a
gradient of landscape complexity (1-75 % SNH in a 1 km radius). 3. In
total 9,030 hoverflies belonging to 89 species were collected. In both
countries, hoverfly community composition was mainly driven by SNH type
and SNH shape, and in Switzerland additionally by landscape complexity.
Species richness of hoverflies increased with increasing amounts of SNH at
the landscape scale. However, the ubiquitous and dominant aphidophagous
species Episyrphus balteatus was indifferent to landscape composition. 4.
Species richness of total and aphidophagous hoverflies was higher in woody
than herbaceous SNH. Hoverfly species richness was similar in linear and
areal SNH, but non-aphidophagous hoverflies were more vulnerable to
landscape simplification in linear than areal SNH. Effects of the SNH type
partly differed between the two countries: In Germany, the dominant
aphidophagous species E. balteatus preferred woody over herbaceous SNH,
while no such difference was found in Switzerland. 5. Surprisingly, local
richness and abundance of floral resources were poor predictors for
hoverfly abundance, richness or community composition. 6. Synthesis and
applications: Large-scale conservation and restoration of complex
agricultural landscapes with a high proportion of different SNH types is
key for the conservation of hoverfly diversity, and thus likely promote
pest control and pollination services provided by them. Local improvement
of SNH to promote hoverflies has to consider regional differences in
habitat characteristics.07-Dec-2017