A review of remote sensing methods for biodiversity assessment and bioindicator extraction

Biodiversity assessment constitutes a multivariate problem depending on several factors and consisting of various characteristics. In order to evaluate biodiversity and extract meaningful information about its trends, threats and dynamics, various biodiversity indicators or “bioindicators”, have been proposed and developed. The bioindicators adopted by the Conference of the Parties (COP) to the Convention on Biological Diversity (CBD) and the Streamlining European 2010 Biodiversity Indicators (SEBI2010) constitute two of the most widely adopted sets of indicators for biodiversity assessment. We review several recent methods based on remote sensing observations, derived either from satellite or airborne sensors, in an effort to approach biodiversity assessment from different perspectives, ranging from ecosystem fragmentation and habitat mapping to monitoring of species distribution and invasion of alien species. The discussed methods, extracting various biodiversity related characteristics, can be exploited for the direct or indirect extraction of bioindicators belonging to the CBD and SEBI2010 frameworks. We make the connection between those methods and the respective bioindicators that could potentially be calculated using the proposed methodologies, which is rarely explicitly mentioned in the literature.