Understanding lichen diversity on remote areas using parataxonomic units as a surrogate for species richness

Background/Question/Methods

Careful expert collection of specimens in the field and further determination of species is the most reliable method for determining species richness. However, either lack of access to experts or extended time lags between surveying and expert identifications may make this approach impractical, especially in remote areas as Antarctica, where fieldwork is logistically challenging. In order to accelerate assessments of local biodiversity levels, cost-effective survey methods and surrogate methods for the prediction of species richness are needed. We propose a combination of a photographic “citizen science” approach for the collection of data, and the use of parataxonomic units (PUs) richness as a possible alternative to efficiently collect preliminary information and build databases on ecosystems diversity. Lichen communities are useful indicators for the status of many different terrestrial ecosystems because they are notably sensitive to environmental stress. To test and calibrate our sampling protocol, five National Parks in the Washington DC area were photographically surveyed during the 2011 boreal summer. The sites chosen in each park correspond exactly with sites previously surveyed by the Lichen Biomonitoring Project (LBP, http://mason.gmu.edu/~jlawrey/CUE/). From the photographs, different lichen PUs were isolated in the lab, and cataloged as "specimens". We estimated the number of PUs and the number of species present in each park and using different methods, and we compared estimated PUs richness with estimated species richness from the LBP censuses.

Results/Conclusions

The number of specimens and PUs depended on the quality of the photographs and specimens, and varied across parks and plots. For most Parks, we found no significant differences between species richness estimated from expert sampling and our protocol. Even though the applicability of this protocol has a number of limitations, we show it can provide quick diversity estimates when expert sampling is not practical or available. We are now applying this technique to catalogue the lichen richness on one of the most remote areas of the world: the Antarctic Peninsula, where it is difficult to identify appropriate sites for conservation because comprehensive data on flora are not available for many areas. As part of the Antarctic Site Inventory Project (ASI), we are gathering photographic information and developing a database on lichen richness for sites that are frequently visited by tourists. These surveys will provide preliminary information useful for identifying areas for protection and priorities for future research.