Developing and ranking a national red list of Saudi Arabian plants through meta-analysis

Methods aimed at ranking species considered important for conservation at the national level are usually applied to countries with a long history of botanical surveys and comprehensive spatial coverage. Here we propose a simple, objective and transferable method for areas for which botanical knowledge is still highly sporadic. What makes our method unique is that it does not require the use of detailed field surveys as we show how data can be obtained using freely available international open data sources to complement national data. This reduction in reliance on national surveys makes it internationally applicable. Nevertheless, the choice of criteria cannot be standardized across nations as this is dependent on data availability. Yet our approach has in built flexibility to accommodate these limitations by allowing users to select their own criteria. Applying the method to Saudi Arabia, a total of 266 taxa were selected to make up its National Red List (NRL) of plants. Taxa were ranked in order of importance on the basis of 12 criteria according to threat, range, taxonomic rarity and conservation importance. Evaluating the ten highest scoring plants reveals that not all enjoy in situ protection or are the focus of detailed management plans, and there are still disagreements relating to species taxonomy. Nevertheless, the method proposed in this paper provides a vital starting point for species-based conservation in areas of low data coverage and availability. • Method proposed for determining National Red Lists of Threatened plants; • Analytical hierarchical process with strong emphasis on open source data; • Particularly useful to countries with incomplete survey history; • Applied to Saudi Arabia as an example; • 266 of most important Saudi plant taxa for conservation ranked.