Changes in the bee fauna of a German botanical garden between 1997 and 2017, attributable to climate warming, not other parameters

More than 75 percent decline over 27 years in total flying insect biomass in protected areas

(2017) Caspar A. Hallmann et al.   PLoS One

DNA barcoding largely supports 250 years of classical taxonomy: identifications for Central European bees (Hymenoptera, Apoideapartim)

(2015) Stefan Schmidt et al.   Molecular Ecology Resources

Bee declines driven by combined stress from parasites, pesticides, and lack of flowers

(2015) D. Goulson et al.   SCIENCE

Common garden comparison of the leaf-out phenology of woody species from different native climates, combined with herbarium records, forecasts long-term change

(2014) Constantin M. Zohner et al.   ECOLOGY LETTERS

Global pollinator declines: trends, impacts and drivers

(2010) Simon G. Potts et al.   TRENDS IN ECOLOGY & EVOLUTION

The role of botanical gardens in climate change research

(2009) Richard B. Primack et al.   NEW PHYTOLOGIST

Decline and Conservation of Bumble Bees

(2007) D. Goulson et al.   Annual Review of Entomology