*3.1.4 Dynamics of plant biological and fauna diversities*

Before concluding this section, it would be important to highlight the variation in floristic and wildlife biodiversity from natural environments to oil palm plantations. This would give and idea of the real impact of oil palm plantations on the biodiversity decrease within the landscapes studied. Taking the floristic level, **Tables 4** and **5** show that biodiversity in terms of species and families is so important in protected areas and dense forest than anywhere else. This is quite conspicuous in Campo Ma'an National Park. Hence the advantage of avoiding installing oil palm plantations next to protected areas or in dense forests because they considerably reduce biodiversity.

As fauna is concerned, the survey show that forest degradation is one of the major infringements to the loss and decline of wildlife for more than 50% of the surveyed population. It happens through the clearing of hectares of forest land which drive to


**Table 5.** *Biological diversity index.*

#### *Environmental Impacts of the Oil Palm Cultivation in Cameroon DOI: http://dx.doi.org/10.5772/intechopen.97862*

the destruction of wildlife habitats and the disappearance of species. There are almost any game (porcupines, monkeys, antelopes, etc.) and some species have already completely disappeared from the area (such as the elephant that disappeared from Njock-Loumbe, *Njock* meaning the elephant). In addition, the oil plantation guards confiscate the small mammals such as rodents that are caught in these single-crop farming.

Biodiversity impacts is the most documented facet of environmental oil palm effects. Land clearance for oil plantations removes, fragments and damages important wildlife habitats, leading to a high loss of species. The species these forests support are highly adapted to rainforest habitats and are often unique. Clearing tropical forests for oil palm results in strong local and regional biodiversity declines [21]. It is link to the fact that oil palm is commonly produced in monocultures which affect the habitat of great mammals and their biodiversity declines from 47 to 90% [26] or 65–90% [23]. Also, the mammal diversity in oil palm strongly depends on the proximity of natural forests [21, 26]. In Cameroon, great APES are endangered by the spread of oil palm plantations around protected areas like Campo Ma'an, Ebo, Korup etc. And in other areas, due to oil palm expansion, elephant have disappear like in Njockloumbe village at Ngwéi. The IUCN Red List of Threatened Species documents 321 species for which oil palm is a reported threat [21]. Meijaard et al. [26] added that species those threatened are made up 3.5% of the taxa threatened by annual and perennial non-timber crops (9,088 species) and 1.2% of all globally threatened taxa (27,159 species) in 2019.

As we saw on **Table 4**, the highest diversity of animal species in oil palm areas, however, is generally found in the wider landscape that includes remnant patches of native vegetation. Factors that are likely to positively influence biodiversity values in both industrial-scale and smallholder plantations include higher landscape heterogeneity, the presence of large forest patches and connectivity among these and the plant diversity and structure of undergrowth vegetation.

It is clear that oil palm becomes the source of deforestation and land degradation. The statistics compute from image processing help calculating the deforestation rate in the main studying sites. In Sanaga Maritime, from 1986 to 2013, deforestation rate is estimated at 23.61%. Ngwéi deforestation is estimated at 45.94% in 38 or 40 years, with an overall rate of 697.22 ha/year between 1975 and 2013. Deforestation in Ekondo-Titi is accessed at a rate of 22.74% in 37 years, i.e. 0.61% per year and especially 150.34 ha/year of Atlantic forests against 67.07 ha/ year for mangroves. Let's take the detail case of both Ekondo-Titi and Ngwéi subdivisions to illustrate the results of images processing (**Figures 3** and **4**).

**Table 6** emphasizes the synthesis of deforestation linked to the expansion of oil palm. The estimate of total deforestation varies according to administrative units and the dynamics of elaeis cultivation, and in this sense, the Ngwéi landscape appears to be more threatened.

**Table 7** summarizes the perception of the populations in terms of ecological impacts. This shows the illusion that the people of Sanaga Maritime and Ngwéi have of thinking that the situation is not changing and of underestimating the deforestation linked to palm oil. However, they have clearly seen the decrease in wildlife. On the other hand, Ekondo-Titi recognizes the impact of oil palm cultivation both on the forest and wildlife.

**Table 8** below shows negligible positive impact (3.5%) on fauna and NTFPs with overwhelming negative impact (55) (96.5%), meaning that oil palm cultivation largely undermines the resilience of the natural environment. The impact is more on surface water, flora and fauna (biodiversity), soils, natural habitats and nontimber forest products (NTFPs).

Based on remote sensing techniques, one can deduce that in the various literature, the case of Indonesia and Malaysia have been well identified compared to African

#### **Figure 3.**

*Land cover and land use in Ekondo-Titi between 1978 and 2016 thanks to Landsat (1978), Map Box images (1.5 m resolution) and Google Earth (2016). The original forest and mangrove has disappeared everywhere apart from the North western part of the map. Smallholders' farms are spreading north western wards.*

#### **Figure 4.**

*Land cover and land use in Ngwéi District between 1975 and 2016 from Landsat (1975) and Google Earth image. A small portion southwards and a great areas northwards of the images remains intact and need to be preserved. Numerous smallholders' farms oil palm widespread and scattered in the central part of the image show that the Ngwéi District is the hold almost more than 30% of the areas producing red oil within the Sanaga Maritime Division.*

countries producers like Nigeria, Ghana, Ivory Coast and Cameroon. Remote sensing studies of a subset of plantations in 20 countries suggests that around 45% of oil palm plantations in Southeast Asia came from areas that were forests in 1989. The estimates vary from one region to another being at 31% in South America, 7% in Africa and 2% in Central America. For Indonesia and Malaysia, the estimates were 54% and 40% respectively [22, 26, 27]. Another estimation gave during the last 40 years, 47% and 16% of total deforestation by oil palm in Malaysia and Indonesia, respectively [21, 28]. Those statistics could be compared to what we observed in Ngwéi (45,94%)

#### *Environmental Impacts of the Oil Palm Cultivation in Cameroon DOI: http://dx.doi.org/10.5772/intechopen.97862*


### **Table 6.**

*Deforestation and oil palm expansion in the three sites.*


#### **Table 7.**

*Perception of livelihood ecological impacts through questionnaire and landscape methods.*

and Ekondo Titi (22,74%) as well as Sanaga maritime (23,61%) productive basins. According to Ordway et al. [25], oil palm expansion dynamics in sub-Saharan Africa have been overlooked. They proved that 67% of oil palm expansion from 2000 to 2015 occurred at the expense of forest in the Southwest region of Cameroon.

Coincidentally, these are priority areas often safeguarded by the policies of the World Bank and the African Development Bank (ADB), because they are elements of the natural heritage of a country.
