Conservation value of tropical forests: Distance to human settlements matters more than management in Central Africa

Abstract

Tropical forests in Central Africa host unique biodiversity threatened by human degradation of habitats and defaunation. Forests allocated to conservation, production and community management are expected to have different conservation values. Here, we aimed to identify the determinants of the conservation value of tropical forests in southeastern Cameroon, by disentangling the effects of forest allocations, proximity to human settlements, and local habitat. We inventoried two taxonomical groups: mammal species with camera traps (3464 independent detection events) and dung beetle species with pitfall traps (4475 individuals). We used an integrated analytical approach, examining both species richness and composition. For both mammals and dung beetles, species richness decreased from the protected area to the community forests, and the logging concession showed intermediate richness. Species richness of both groups was negatively correlated to the proximity to human settlements and disturbance, with a decreasing gradient of body mass and the loss of the most threatened species. The replacement (i.e., spatial turnover) of both mammal and dung beetle species among forest allocations suggest an integration of conservation initiatives to a large number of different sites, with a priority on protected and remote areas of high biodiversity. These results confirm the high conservation value of protected areas and their essential role in conservation strategies, ecologically connected with well-managed production forests with variable conservation value mainly depending on accessibility. Community forests located close to villages are much more degraded but not totally defaunated and still provide bushmeat to local populations.

Human disturbance and prey occupancy as predictors of carnivore richness and biomass in a Himalayan hotspot

“…Spatial avoidance of human‐dominated habitats by carnivores has been frequently reported (Dias et al , 2019; Heim et al , 2019; Lhoest et al , 2020), and may be explained by fear of humans (Frid & Dill, 2002; Miller & Schmitz, 2019; Suraci et al , 2019). Humans have presumed the role of ‘super predator’ in wildlife communities globally (Darimont et al , 2015).…”

Variation in behavioral traits of two frugivorous mammals may lead to differential responses to human disturbance

“…Body size is a key aspect in predator–prey interactions; large‐sized animals may have a higher perception of the risk of predation than smaller‐sized ones (Davidson et al, 2009; McGraw & Zuberbuhler, 2008; Preisser & Orrock, 2012; Zuberbühler, 2007). Evidence of the effects of body size on the response of mammal species to human disturbance was recently reported in south‐east Cameroon (Lhoest et al, 2019) and Gabon (Beirne et al, 2019), where there was a gradient of increasing body mass of mammals with increasing distance to villages. The effects of body size on the response of different species to predation risk is related to the fact that different species present different flight initiation distances, and the flight initiation distance increases as body size increases (Gotanda, Turgeon, & Kramer, 2009; Møller & Erritzøe, 2014).…”

“…The avoidance of human settlements or presence is often attributed to hunting; under such circumstances, animal species may find refuge where hunting intensity is low (Blom et al, 2005; Vanthomme et al, 2013). Although we did not measure hunting pressure in our analyses, the distance to human settlements was considered as a proxy for hunting pressure because the increasing distance to villages is likely to correspond to a decrease in hunting signs (Beirne et al, 2019; Koerner et al, 2017; Lhoest et al, 2019). Previous studies in our research site have shown that hunting signs, and not research activities, determined space use by gorillas and chimpanzees for nesting along transects (Tagg et al, 2018; Tagg & Willie, 2013).…”

“…More generalist species according to habitat types are more resilient to human disturbance than specialist species (Galan‐Acedo et al, 2019), which may be a consequence of the higher dispersal ability of generalist species (Kneitel, 2018). Body size may influence the response to predation; in this case, larger‐bodied animal species may respond negatively to the presence of predators compared to smaller‐bodied ones (Benitez‐Lopez, 2018; Davidson, Hamilton, Boyer, Brown, & Ceballos, 2009; Lhoest et al, 2019; Navarro‐Castilla, Barja, & Diaz, 2018; Preisser & Orrock, 2012). Also, the perceived risk of predation may be relatively higher in terrestrial than arboreal animal species (Wereszczuk & Zalewski, 2015).…”

Quantifying the Use of Forest Ecosystem Services by Local Populations in Southeastern Cameroon

“…It is also below the sustainability standard of the maximum production of wild meat roughly estimated between 150 and 200 kg/km 2 /year in tropical forests [76]. Even if bushmeat consumption in Eschiambor could then seem to be sustainable, inventories of mammal populations have shown that only small animals remain in these areas close to villages and roads due to past hunting pressure [87]. Indeed, a high and growing hunting pressure induces a decline in the biomass of forest vertebrates, with large-bodied preferred game species declining rapidly [88,89].…”