Multisensoral, object- and GIS-based classification of grassland habitats in the Bio sphere Reserve Schwäbische Alb

Insect Conserv Diversity

Biermann

Dieterich

et al. 2021

Scant floral resources are a major cause of declining pollinator populations in farmland. Measures to increase floral resources on arable land include agronomically non‐productive approaches, like flowering fields (seed mixture of flowering forbs sown on fallows) and production‐integrated approaches like organically farmed crops sustaining flowering arable wild plants. However, little is known about their relative efficacy for bumblebee conservation. We observed weight gain, foraging activity, worker body size, queen brood cell number and analysed stored pollen types of Bombus terrestris colonies experimentally sited adjacent to arable fields farmed under four crop‐use types: (i) cereal mono‐crops (winter wheat) under conventional farming, (ii) non‐productive conventional flowering fields, (iii) organic cereal mono‐crops (winter spelt) and (iv) organic legume mixed‐crops (lentil mixed‐crop). Additionally, we analysed the effects of flower cover in the surrounding landscape. Colonies located adjacent to organic winter spelt fields had higher foraging activity and larger body sizes, whereas other colony performance measures were unaffected by local crop‐use type. Phacelia tanacetifolia, which was only cultivated in flowering fields, accounted for about 50% of the total pollen amount irrespective of crop‐use type. This indicated a landscape‐wide attraction for B. terrestris to flowering fields. Flower cover in the surrounding landscape did not affect colony development, but negatively affected pollen diversity. We conclude that although the pollen supply of flowering fields in the surrounding landscape strongly attracts bumblebees, local bumblebee populations could still benefit from less intensive farming practices increasing flowering wild plant diversity, such as with flower‐rich organic winter cereals.

Section: Methodsmentioning

confidence: 99%

Organic winter cereals benefit bumblebee colonies in agricultural landscapes with mass‐flowering crops

Insect Conserv Diversity

Biermann

Dieterich

et al. 2021

“…We analysed land cover types using the Geographical Information System ArcGIS 10.2.2 (1999-2014 ESRI Inc.) and data from an areawide classification of habitat complexes of the Biosphere Reserve Swabian Alb (see Schlager et al, 2013). There was one study site outside the borders of the Biosphere Reserve Swabian Alb.…”

Section: Landscape Analysismentioning

confidence: 99%

Flowering fields, organic farming and edge habitats promote diversity of plants and arthropods on arable land

Journal of Applied Ecology

Berger

Dieterich

et al. 2021

Carabid functional diversity is enhanced by conventional flowering fields, organic winter cereals and edge habitats

Agriculture, Ecosystems & Environment

Löveï

Magura

et al. 2019

The continued decline in farmland biodiversity in Europe despite substantial funding for agrienvironment schemes (AES) has prompted calls for more effective biodiversity conservation measures. The current AES regime allows for both holistic measures, such as organic farming, that broadly target the agricultural environment and biodiversity-specific measures, but little is known of their relative efficacies. To address this gap, we studied carabids in 48 arable fields that presented four crop types under different management practices along a gradient of landscape complexity: (a) conventionally managed crop (winter wheat), (b) biodiversityspecific AES under conventional management (sown flowering field), (c) organically managed mono-crop (winter spelt) and (d) organically managed lentil-mixed crop (lentil intercropped with cereal or camelina). For these four crop-use types we compared functional diversity of carabid assemblages at the edge and center of the fields. Using pitfall traps, we collected more than 55,000 carabids of 95 species over two years. We characterized diversity using community weighted means and functional divergence of three ecological traitsbody size, feeding type, and flight ability. Conventional flowering fields and organic winter spelt, but not organic spring sown lentil-mixed-crop, increased the proportion of plant feeding carabids; moreover, trait characteristics and their divergences were most affected by field edges, with smaller, less carnivorous and more flight-enabled species found there than in the center. Distribution of body size and feeding type but not of flight ability was higher within carabid assemblages at the field edges than centres. Surrounding landscape complexity did not affect carabid traits. We conclude that future AES policy should avoid strict decisions between biodiversity specificand holistic measures. Instead, priority should be given to a diversity of different measures, targeting the enhancement of edge habitats as well as productive and non-productive measures.