An integrative analysis of threats affecting protected areas in a biodiversity stronghold in Southeast Mexico

Protected areas (PAs) are one of the main strategies to preserve tropical biodiversity. However, their viability is compromised by the impacts of a variety of threats. To gain a more integrated view of how different threats affect them, individually and in combination, we analyzed the spatial distribution of forest loss (2010–2015), human density, incidence of fires, and mining activities in four PAs (Cordon Pico Loro-Paxtal: CPL, El Triunfo Biosphere Reserve: ETBR, La Sepultura Biosphere Reserve: SEBR and La Frailescana: LF) located in the biodiversity stronghold of the Sierra Madre de Chiapas (SMC), Mexico. We integrated these threats in a Human Pressure Index (HPI, ranging from 0 to 1, where 1 is the highest human pressure). We found that the SEBR and LF were affected mainly by forest loss (13.43% and 11.67% forest area lost, respectively) and fire incidence (between 0.02-0.73 and 0–0.81 fire hotspots/km2, respectively). On the other hand, the ETBR and CPL had lower forest loss and fire incidence but higher mining presence (16.2% and 84.8% of their area involving this activity, respectively), and population density (on average 0.6 and 8.6 inhabitants/km2, respectively). The highest HPI values (>0.6) occurred in the northern and the southern extremes of the study area encompassing 42.6%, 54.5% and 54.1% of the extent of the SEBR, LF, and CPL, respectively, putting in high risk important areas to maintain landscape connectivity. Despite occurring in the same region (SMC) focal PAs are affected differently by the assessed threats. A nonintegrated analysis of threats affecting PAs in biodiversity strongholds such as the SMC risks producing a biased view of their intensity, reducing the possibility to planning more effective conservation strategies.