Testing the assumed worse population performance of threatened organisms with a citizen science program

Maria B. Garcia, Jose L Silva, Pablo Tejero and Iker Pardo, Pyrenean Institute of Ecology - CSIC, Zaragoza, Spain, Iker Pardo, University of the Basque Country, UPV/EHU, Leioa, Spain

Background/Question/Methods . Long-term monitoring of biodiversity is a fundamental part of the conservation strategy. Citizen Science programs of environmental monitoring are increasing exponentially, but most of them report on species records and cannot help in assessing local extinction risk. Here, we present results of the “Adopt a plant” program, a collaborative network that is currently monitoring more than 300 populations of 200 plants (threatened, common, rare, and habitat indicators) across a heterogeneous landscape in NE Spain. Coordinated by researchers, participants follow scientifically rigorous sampling methods to track plant abundances year after year in fixed representative areas within populations. Two standardized and easily interpretable indices are estimated from the structured data they gather annually: the overall trend (mean population abundance change, as percentage) and temporal fluctuations (standard deviation of annual changes).
Results/Conclusions . The analyses of populations monitored over up to 11 years evidence an important stability of plant abundance (average trend +0.14%), with threatened species having similar trends and lower temporal variability than non threatened ones. Regardless of the conservation status, small populations performed worse than large ones. Less than 10% of studied populations faced direct human threats. We advocate the expansion of the program to other areas with active participative networks, because it can increase the effectivity of conservation planning at regional scale, and allow general comparisons of the same threatened or functional indicators species across large extensions (e.g., species of interest of the Habitats Directive).