Proportion of protected areas with conservation activities between 1990 and 1999 across different African regions.

<p>The number of protected areas with available information on presence and absence of any conservation activity (research, tourism and law enforcement guards) over the considered period were in total 105.</p

Influence of tourism activities and PA size on threat level in 83 PAs.

<p>In bold are highlighted significant values (p <i><0.05</i>). See abbreviations in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0114154#pone-0114154-t002" target="_blank">Tab 2</a>. AIC, Akaike's Information Criterion; AICw, Akaike Information Criterion weight; Rank, model rank from the smallest to the largest AIC value; k, number of variables including the intercept.</p><p>Influence of tourism activities and PA size on threat level in 83 PAs.</p

Influence of law enforcement activities and PA size on threat levels in 90 PAs.

<p>In bold are highlighted significant values (p <i><0.05</i>). See abbreviations in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0114154#pone-0114154-t002" target="_blank">Tab 2</a>. AIC, Akaike's Information Criterion; AICw, Akaike Information Criterion weight; Rank, model rank from the smallest to the largest AIC value; k, number of variables including the intercept.</p><p>Influence of law enforcement activities and PA size on threat levels in 90 PAs.</p

Threats impact levels to 98 tropical African protected areas at a continental and regional scale.

<p>Clockwise from top: Africa (a), Central Africa (b), East Africa (c) and West Africa (d).</p

Regional distribution of the protected areas (PAs) in tropical Africa considered in the analyses.

<p>The regions are coloured in different grey scale colours. Light grey represents West Africa, including 54 protected areas; medium grey represents Central Africa, including 31 protected areas; dark grey represents East Africa, including 14 protected areas. On the left-side bottom corner a MODIS NDVI image of Africa, with a red quadrant highlighting the tropical area considered in the study.</p

Influence of research activities and PA size on threat level in 92 PAs.

<p>In bold are highlighted significant values (p <i><0.05</i>). See abbreviations in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0114154#pone-0114154-t002" target="_blank">Tab 2</a>. AIC, Akaike's Information Criterion; AICw, Akaike Information Criterion weight; Rank, model rank from the smallest to the largest AIC value; k, number of variables including the intercept.</p><p>Influence of research activities and PA size on threat level in 92 PAs.</p

Symmetric matrix with Spearman's correlation between all threat impact levels recorded in 98 protected areas.

<p>In bold are highlighted significant correlations (<i>p</i><0.0001) following post hoc test Bonferroni correction (<i>p</i> = 0.05/78). Abbreviations: coh, commercial hunting; suh, subsistence hunting; agr, agriculture; fuw, fuel wood; inf, infrastructure; has, human settlement around; his, human settlement inside; war, war; dis, disease; fir, fire; min, mining; log, logging.</p><p>Symmetric matrix with Spearman's correlation between all threat impact levels recorded in 98 protected areas.</p