Pollinator declines create many concerns
Pollinator declines create many concerns, though data in many cases are lacking.
For northeastern North America, a literature review (doi: 10.12688/f1000research.2-146.v1) has shown a relationship of declines on different geographical scales.
Though species providing crop pollination seemed to be favoured by human environment, the importance of ecosystem services in natural environment must be considered.
For lots of information on the topic for Europe look the STEP homepage: http://www.step-project.net/?P=20