A review of more than 230 "citizen science" projects says the involvement of volunteers offers "high value to research, policy and practice".
It added that such schemes had the potential to help meet the demands of monitoring the UK's environment.
The review's authors also produced a guide offering advice on how to get the most out of citizen science projects.
The review and guide was commissioned by the UK Environmental Observation Framework (UK-EOF).
The authors, from Nerc Centre for Ecology and Hydrology (CEH) and the Natural History Museum, London, reviewed 234 projects - ranging from small one-off local surveys to large-scale long-term programmes.