Temperature and livestock grazing trigger transcriptome responses in bumblebees along an elevational gradient

It is assumed that climate and land-use changes cause increasing stress to pollinators, which play pivotal roles in almost all terrestrial ecosystems, with consequences on population growth, diversity and ecosystem functions. While these responses to global change drivers are well located, the molecular pathways triggering the response are poorly understood. We analysed the transcriptomic response of Bombus lucorum workers in their systematic responses to temperature and livestock grazing, sampled along an elevational gradient from 650 – 1930 m.a.s.l., and from differently managed grassland sites (livestock grazing vs. unmanaged) in and around the National Park Berchtesgaden (German Alps). Overall design: In total, 81 B. lucorum workers (Lowlands: 30; mid-elevation: 25; highlands: 26) were collected via sweep nets on 16 different study sites (lowlands: 6 study sites from 641-987 m a.s.l.; mid-elevations: 5 study sites from 1140-1420 m a.s.l; highlands: 5 study sites from 1579-1930 m a.s.l.) between end of July and mid of August 2019 between 9 am and 7 pm. We collected 5 workers per study site except for the highest site, where on one site less individuals were found, therefore on another site more individuals were captured.