Citizen science did not add species richness—but it transformed the map of non-native molluscs
WHAT THE EVIDENCE SAYS
Across 1,190 occurrence records, natural-history collections held the broader taxonomic inventory and every species in the citizen-science dataset was already represented in collections. But citizen-science observations were disproportionately non-native and greatly expanded the number of occupied grid cells documented by the combined record.
WHY IT MATTERS / OUR READ
Different monitoring systems can be complementary even when one adds no species to the list. Opportunistic public observations may be particularly useful for detecting widespread, conspicuous or synanthropic invaders in places formal collections undersample.
CAVEATS / UNCERTAINTY
These are occurrence records, not abundance or impact estimates. Both datasets have strong and different sampling biases, and high representation of non-native species in citizen science does not itself measure invasion severity.
SOURCE
Tropical Ecology — primary occurrence-data study
View original evidence ↗
In Brazil’s Caatinga, museum and collection records captured more species overall, while citizen-science records disproportionately documented non-native molluscs and expanded spatial coverage.
Read the Wild Lands assessment →