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Nick Isaac, Tom August & Gary Powney
Trends in British Biodiversity since 1970
@drnickisaac
Target 12By 2020 the extinction of known threatened species has been prevented and their conservation status, particularly of those most in decline, has been improved and sustained.
• Population time-series• Annual estimates of status• Taxonomically restricted
How do we know if the targets have been met?
• Red List indices• Many species• Temporally-imprecise
Botham et al (2011) UK Butterfly Monitoring Scheme Annual Report 2011.
Biological records: the third way
• Volunteer citizen scientists have been recording biodiversity for centuries
• A rich source of data for measuring change
• But the data are biased in space and time
Biodiversity change using atlases
Thomas, JA et al. (2004). Comparative losses of British butterflies, birds, and plants and the global extinction crisis. Science, 303 1879–81
Estimating trends from biological records
http://figshare.com/articles/Extracting_trends_from_citizen_science_data_BES_version_/778699
MethodData Trends
Trends in British Biodiversity since 1970
• What proportion of species are declining?
• What are the net changes in biodiversity?
• Which taxa are doing best/worst?
• Are common or rare species faring best?
Vertebrates
Plants
Other Invertebrates
Insects
0 500 1000 1500 2000 2500
Number of species
Quantitative trends for >5000 species
No bird or mammals!
Status of British Biodiversity since 1970
• More species show significant increases (19%) than declines(14%)
Significance = Power
• More significant trends are apparent in groups with most data
Dragonflies & Damselflies
Moths
Long-hornbeetles
Soldier Beetles
Hoverflies
Vascular Plants
Trends in British Biodiversity 1990-2000
• Good news: Median change +2.4%; Net change +4%• Bad news: >1000 species would qualify as VU or worse
Median
Comparative patterns among taxa
Below the line: Rare species are doing better than common (& vice versa)
Median % change
Net
% c
hang
e
Conclusions
• Mixed news about the UK biodiversity• More increases than declines• Many species in steep decline
• Big losses among some groups, especially ladybirds & centipedes
• Substantial biotic homogenisation
• We can report against CBD targets for a much greater range of taxa than previously possible
https://github.com/BiologicalRecordsCentrehttp://bit.ly/18wTrrK