Monitoring landscape-scale environmental changes with citizen scientists: Twenty years of land use change in Great Britain

Author(s): Martay, B., Pearce-Higgins, J.W., Harris, S.J. & Gillings, S.

Published: July 2018

Journal: Journal for Nature Conservation Volume: 44

Digital Identifier No. (DOI): 10.1016/j.jnc.2018.03.001

Citizen science is increasingly recognised as one of the most cost-effective means of achieving large-scale and long-term biodiversity monitoring. We’re quite familiar with this concept for birds and butterflies, but what about for habitat? Historically, changes in habitat or land cover in the UK have been recorded through two main approaches: professional field data collection and remote sensing using satellites. Both have major limitations: field surveys are costly and can only cover small areas, whereas remote sensing can cover the whole country but with less detail and greater uncertainties.

BTO scientists were keen to see if habitat data collected by volunteers for the Breeding Bird Survey (BBS) could contribute to understanding how habitats have changed. Over 2,500 BBS volunteers have recorded the habitats along their survey transects since 1994, from city centres to mountain tops.

These data were used to quantify change over time in the reporting of different habitats in the British countryside. Increases in woodland cover were detected, in particular, mixed woodland, and declines in farmland cover, particularly livestock farming were also found. Whilst the estimate of habitat area matched existing data well, estimates of habitat change did not.

These results are encouraging considering that habitat recording on BBS was not designed for the purpose of habitat monitoring. This work shows that volunteers can play a significant role in monitoring of habitats provided clear protocols are followed that have been designed with habitat monitoring in mind.

Abstract

Citizen science is increasingly recognised as one of the most cost-effective means of achieving large-scale and long-term biodiversity monitoring. Here we assess the potential for citizen scientists to contribute to the long-term monitoring of land cover, land use and habitat change through ongoing field data collection.

Land cover monitoring is most commonly carried out via remote sensing or professional surveys but these can be costly, low detail or spatiotemporally limited. We used ongoing habitat data collection by citizen scientists participating in a structured survey of breeding birds to assess whether there is the potential for citizen scientists more broadly to play a role in the long-term monitoring of habitat extent and condition. Categorical habitat data has been collected annually by over 2500 volunteers as part of the UK Breeding Bird Survey since 1994 and we used this to quantify temporal variation in the reporting of different habitats in the British countryside. Where possible we validated our estimates of habitat cover and change using independent estimates from professional surveys and other datasets.

We detected increases in woodland cover, in particular mixed woodland, and declines in farmland cover, particularly livestock farming. Our habitat cover estimates closely matched alternative land cover estimates but there was little correspondence in estimates of change between survey types and we discuss why discrepancies may occur.

Although the data we used were not initially designed for this purpose, our results suggest that there is considerable potential to use citizen science for cost-effective identification of temporal patterns in land use, habitat-type and management in ways that could complement other methods.

Staff Author(s)