Core scientists in biodiversity research.

<p><b>(A)</b> Global distribution of identified core scientists in biodiversity research, with PhD (green) and current (red) affiliation. The size of a circle represents the number of core scientists. The lines represent the movement of each individual scientist from the PhD location to the current affiliation. The map focuses on North America and Europe, as 142 out of 156 core scientists in biodiversity research (91%) were affiliated to institutions in these two continents. The map was generated using QGIS version 2.12.0 [<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0199327#pone.0199327.ref020" target="_blank">20</a>]. <b>(B)</b> Core scientists’ network during different time periods. Colors represent modularity clusters. Node size represents degree (centrality), i.e. how many publications one core scientist published with other core scientists. The network was generated using Gephi version 0.8.2 [<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0199327#pone.0199327.ref022" target="_blank">22</a>].</p

Network statistics describing the collaboration among identified core scientists working on biodiversity during different time periods.

<p>Network statistics describing the collaboration among identified core scientists working on biodiversity during different time periods.</p

Correlations of GDP, number of threatened species, number of ecoregions and total size of protected areas (each for all 8 regions) with the number of publications for each continental region based on authors’ affiliation and on study site.

<p>Significant correlations are highlighted in bold.</p

Cartograms showing ratios between biodiversity-related research effort and biodiversity quantifiers.

<p>In <b>(A)</b> the size of each country represents the number of threatened species (based on the IUCN Red List); the color represents the ratio between publication count and number of threatened species. In <b>(B)</b> the size of each country represents the number of ecoregions (based on the WWF List of Ecoregions); the color represents the ratio between publication count and number of ecoregions. In both (A) and (B), red countries have fewer studies per threatened species or per ecoregion and thus exhibit a relative biodiversity research deficit. The cartograms were generated using QGIS version 2.12.0 [<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0199327#pone.0199327.ref020" target="_blank">20</a>].</p

Sankey diagram quantifying research flows from the region of author affiliation to the region of research conductance.

<p>Vertical bars: GDP, the number of threatened species, the number of ecoregions and protected land surface area in each region (relative values; n = 49,932).</p

S1 File -

The diversity of life sensu lato comprises both biological and cultural diversity, described as “biocultural diversity.” Similar to plant and animal species, cultures and languages are threatened by extinction. Since drylands are pivotal systems for nature and people alike, we use oases in the Sahara Desert as model systems for examining spatial patterns and trends of biocultural diversity. We identify both the underlying drivers of biodiversity and the potential proxies that are fundamental for understanding reciprocal linkages between biological and cultural diversity in oases. Using oases in Algeria as an example we test current indices describing and quantifying biocultural diversity and identify their limitations. Finally, we discuss follow-up research questions to better understand the underlying mechanisms that control the coupling and decoupling of biological and cultural diversity in oases.</div

Relationships between similarity in biocultural diversity.

Relationships between similarity in biological and cultural diversity between individual oases in Algeria (different proxies given on y-axes) and their geographic distances (x-axes). Pearson correlation coefficients (r) and significance values (p) are shown.</p

Correlations between (i) area, human population, and distance and (ii) biological and cultural diversity proxies on the level of (A) individual oases and (B) oasis groups in Algeria.

Correlations between (i) area, human population, and distance and (ii) biological and cultural diversity proxies on the level of (A) individual oases and (B) oasis groups in Algeria.</p

Oases (palm tree) and different trade routes in the Sahara Desert.

Individual oasis settlements are grouped based on their location in the same valley, depression, or region (compare S1 File: Table S1). The trade routes represent the pathways between stop-over sites (trade nodes, such as marketplaces). Trade routes are used for the transport of cargo and provide a link between producers and buyers (based on Old World Trade Routes Project: http://www.ciolek.com/owtrad.html [58]). The map shows that oases are often located along trade routes and form important trade nodes along these routes.</p

Schematic presentation of drivers and describing proxies of biocultural diversity.

Proxy groups are listed for both biological and cultural diversity (see section: Proxies for biocultural diversity in oases). Temporal change plays an overarching role as it affects environmental factors (e.g.,. climate and size of oasis), degree of connectivity, and human influences.</p