Land-cover change threatens tropical forests and
biodiversity in the Littoral Region, Cameroon MAHMOUD I. MAHMOUD,MASON J. CAMPBELL ,S EA N S LO A N MOHAMMED ALAMGIR andWILLIAM F. L AURANCE
Abstract Tropical forest regions in equatorial Africa are threatened with degradation, deforestation and biodiversity loss as a result of land-cover change. We investigated his- torical land-cover dynamics in unprotected forested areas of the Littoral Region in south-western Cameroon during 1975–2017, to detect changes that may influence this impor- tant biodiversity and wildlife area. Processed Landsat im- agery was used to map and monitor changes in land use and land cover. From1975 to 2017 the area of high-value forest landscapes decreased by c. 420,000 ha, and increasing forest fragmentation caused a decline of c. 12%inthe largest patch index. Conversely, disturbed vegetation, cleared areas and urban areas all expanded in extent, by 32%(c. 400,000 ha), 5.6% (c. 26,800 ha) and 6.6% (c. 78,631 ha), respectively. The greatest increase was in the area converted to oil palm plantations (c. 26,893 ha), followed by logging and land clearing (c. 34,838 ha), all of which were the major factors driving deforestation in the study area. Our findings highlight the increasing threats facing the wider Littoral Region, which includes Mount Nlonako and Ebo Forest, both of which are critical areas for regional conservation and the latter a proposed National Park and the only siz- able area of intact forest in the region. Intact forest in the Littoral Region, and in particular at Ebo, merits urgent protection.
Keywords Biodiversity loss, Cameroon, deforestation, Ebo Forest, equatorial Africa, logging, oil palm, roads, wildlife
Supplementary material for this article is available at
https://doi.org/10.1017/S0030605318000881
Introduction
covering 3.6 million km2, with the majority concentrated in the greater Congo Basin. These forests harbour c. 2,000 species of vertebrates and .10,000 plant species (Orme
A MAHMOUD I. MAHMOUD (Corresponding author,
orcid.org/0000-0002-0432-
0429), MASON J. CAMPBELL,SEAN SLOAN,MOHAMMED ALAMGIR and WILLIAM F. LAURANCE Center for Tropical Environmental and Sustainability Science, College of Science and Engineering, James Cook University, Cairns, Queensland 4878, Australia. E-mail
mahmoud.mahmoud@
jcu.edu.au
Received 4 May 2018. Revision requested 12 June 2018. Accepted 13 June 2018. First published online 29 August 2019.
frica’s tropical forests are the most extensive after those of the Amazon (Cincotta et al., 2000; Sosef et al., 2017),
et al., 2005; WWF, 2017). They also provide numerous and valuable environmental services, including carbon storage, protection of threatened ecosystems, hydrological func- tioning (Abernethy et al., 2016), and medicinal products (Colfer, 2012). African forests also provide significant socio- economic resources, including plant and animal products, food, medicine, products of cultural value, and building and construction materials. Tropical African forests are threatened by a wide array
of anthropogenic activities that imperil natural ecosystems and biodiversity. For instance, the few previous studies conducted in the threatened forests of the Cross–Sanaga River region (Fa et al., 2006), the Gulf of Guinea biodiver- sity hotspot (Oates et al., 2004), and the greater Congo Basin (Laurance et al., 2015) identified deforestation as a major factor driving both forest loss and degradation (Hosonuma et al., 2012; Ordway et al., 2017; Aleman et al., 2018). Deforestation, along with other smallholder activities in African tropical forests, is also known to damage impor- tant wildlife habitats, leading to biodiversity loss and the destruction of forest-based livelihoods. However, the extent to which small vs large landholder activities influence land- cover change and conservation in these forests remains unclear. Known drivers of forested land-cover conversion include industrial logging (Laporte et al., 2007), agricultural expansion (van Soesbergen et al., 2017), settlement expan- sion (Mahmoud et al., 2016) and road infrastructure expan- sion (Alamgir et al., 2017; Laurance et al., 2017; Mahmoud et al., 2017). These processes can also lead to forest fragmen- tation and degradation, resulting in depauperate forests with significantly reduced biodiversity compared to intact forests (Fahrig, 2003; Haddad et al., 2015; Laurance et al., 2018). The rate and scale of land-cover change currently occur-
ring in equatorial Africa is unprecedented and unsustain- able (Tchuenté et al., 2011). However, there is a paucity of studies examining human-driven land-cover change and threats to conservation at fine spatial scales in unprotect- ed yet still highly biodiverse regions of equatorial Africa. Regional studies examining land-cover change have often been at a coarse scale, and many of the findings are based on inferences (Singh et al., 2017; Thompson et al., 2017). Consequently, many of these regional studies overlook challenges associated with localized land-use and land-cover change processes such as selective logging, small-scale log- ging, land clearing and the establishment of smallholder oil palmplantations, particularly in areas of high biodiversity
Oryx, 2020, 54(6), 882–891 © 2019 Fauna & Flora International doi:10.1017/S0030605318000881
Page 1 |
Page 2 |
Page 3 |
Page 4 |
Page 5 |
Page 6 |
Page 7 |
Page 8 |
Page 9 |
Page 10 |
Page 11 |
Page 12 |
Page 13 |
Page 14 |
Page 15 |
Page 16 |
Page 17 |
Page 18 |
Page 19 |
Page 20 |
Page 21 |
Page 22 |
Page 23 |
Page 24 |
Page 25 |
Page 26 |
Page 27 |
Page 28 |
Page 29 |
Page 30 |
Page 31 |
Page 32 |
Page 33 |
Page 34 |
Page 35 |
Page 36 |
Page 37 |
Page 38 |
Page 39 |
Page 40 |
Page 41 |
Page 42 |
Page 43 |
Page 44 |
Page 45 |
Page 46 |
Page 47 |
Page 48 |
Page 49 |
Page 50 |
Page 51 |
Page 52 |
Page 53 |
Page 54 |
Page 55 |
Page 56 |
Page 57 |
Page 58 |
Page 59 |
Page 60 |
Page 61 |
Page 62 |
Page 63 |
Page 64 |
Page 65 |
Page 66 |
Page 67 |
Page 68 |
Page 69 |
Page 70 |
Page 71 |
Page 72 |
Page 73 |
Page 74 |
Page 75 |
Page 76 |
Page 77 |
Page 78 |
Page 79 |
Page 80 |
Page 81 |
Page 82 |
Page 83 |
Page 84 |
Page 85 |
Page 86 |
Page 87 |
Page 88 |
Page 89 |
Page 90 |
Page 91 |
Page 92 |
Page 93 |
Page 94 |
Page 95 |
Page 96 |
Page 97 |
Page 98 |
Page 99 |
Page 100 |
Page 101 |
Page 102 |
Page 103 |
Page 104 |
Page 105 |
Page 106 |
Page 107 |
Page 108 |
Page 109 |
Page 110 |
Page 111 |
Page 112 |
Page 113 |
Page 114 |
Page 115 |
Page 116 |
Page 117 |
Page 118 |
Page 119 |
Page 120 |
Page 121 |
Page 122 |
Page 123 |
Page 124 |
Page 125 |
Page 126 |
Page 127 |
Page 128 |
Page 129 |
Page 130 |
Page 131 |
Page 132 |
Page 133 |
Page 134 |
Page 135 |
Page 136 |
Page 137 |
Page 138 |
Page 139 |
Page 140 |
Page 141 |
Page 142 |
Page 143 |
Page 144 |
Page 145 |
Page 146 |
Page 147 |
Page 148 |
Page 149 |
Page 150 |
Page 151 |
Page 152 |
Page 153 |
Page 154 |
Page 155 |
Page 156 |
Page 157 |
Page 158 |
Page 159 |
Page 160 |
Page 161 |
Page 162 |
Page 163 |
Page 164
