Threat of land-cover change in Cameroon 887
TABLE 1 Proportions of various land-cover types in the effective study area (8,915.4 km2 cloud-free of the 13,845 km2 total study area) in the Littoral Region of Cameroon in 1975 and 2017.
1975
Land use/land cover
Water
Urban area Cleared land
Disturbed vegetation
Natural forest
Mapped area (%)
3.0 0.1 0.2
31.0 63.0
Estimated area (%)
0.5 0.2 0.5
16.0 72.0
Confidence interval (%)
−0.1–1.6 −0.1–0.01 −0.2–0.2
−0.1–0.3 2017
Mapped area (%)
2.7 5.0 2.2
−2.0–2.0
37.0 53.1
Estimated area (%)
3.0 5.0 3.0
38.0 51.0
Confidence interval (%)
−0.1–1.6 −0.1–0.1 −0.2–0.2 −0.1–0.1
−0.1–0.1
within 5 km of a forest edge, near roads. These observations combined suggest that forest degradation and deforestation are facilitated by the increased access to intact forests that the roads provide (Fig. 4). Moreover, roads have facilitated the expansion of human habitations, which are now present within 10 km of Ebo Forest (Figs. 2b, 4, & Supplementary Fig. 7); a process increasingly threatening biodiversity and wildlife habitats and their conservation (Brandão, Jr & Souza, Jr, 2006; Pfaff et al., 2007).
FIG. 3 Change in land cover (water, urban area, cleared land, disturbed vegetation, natural forest) in the 8,916 km2 study area in the Littoral Region of Cameroon (Fig. 1) between 1975 and 2017.
Forest fragmentation
in South-east Asian landscapes where oil palm plantations have had negative effects on the abundance and occurrence of a wide range of taxa, including birds, invertebrates and mammals (Fitzherbert et al., 2008; Yue et al., 2015). Oil palm expansion in the south of the Littoral Region landscape is a major driver of current and ongoing regional deforestation, although Ebo Forest is protected to some degree by its steep and hilly terrain, which makes it less accessible. Logging and land clearing are two other major drivers of
deforestation we observed in the north-west of the Littoral Region. The proximity of a government-sanctioned active 30-year logging concession (FMU-00-004), adjacent to Ebo Forest in the north-east of the Littoral Region (Fig. 4), is a potential threat to the biodiversity of Ebo Forest and is a concern for unprotected forests in the region, which are also threatened by the extensive areas of sanctioned logging and mining concessions (Fig. 1). The infiltration of roads into the studied forests appears
to have contributed substantially to the progressive defor- estation in the region; for example, roads were found in all human-modified land uses, including deforested areas. Additionally, most of the identified deforestation occurred
There was a significant increase in forest fragmentation between 1975 and 2017 in the Littoral Region. For instance, there was a pronounced decline in inter-patch habitat con- nectivity in the forested area, as indicated by the significant decline in the extent of natural forest (Fig. 3). Connectivity is considered to be essential for conserving biodiversity at the landscape scale (Hodgson et al., 2011) and facilitating the movement of fauna (Vogt et al., 2009), and therefore the isolation of many forest patches in the study area threatens biodiversity (Fahrig, 2013) and the genetic integrity of the remnant species (Young et al., 1996). If the current trend in logging and farming activities is sustained there is likely to be ongoing isolation of natural forest in patches, which may lead to further biodiversity loss. This is because larger patches of natural forest provide better protection for a variety of habitats, and withstand anthropogenic threats and degradation better than smaller, fragmented forests (Laurance et al., 2018). The current trajectory of human land use in the region suggests that significant conservation areas, such as Ebo Forest, are increasingly at risk from frag- mentation and isolation of forest patches. A comparison of the 1975 and 2017 land-cover maps, for instance, revealed that substantial fragmentation occurred in the forest land- scapes of the Littoral Region as a result of deforestation (Fig. 3). The observed fragmentation and deforestation began in degraded areas and expanded gradually into nat- ural forest, resulting in an increase in the area of disturbed vegetation (Fig. 2).
Oryx, 2020, 54(6), 882–891 © 2019 Fauna & Flora International doi:10.1017/S0030605318000881
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