**4. Valorization elements for a sustainable conservation of the park**

#### **4.1 Attributes of a reference ecosystem in the Sudano-Sahelian zone**

A set of characteristics gathered from the present study of the MGNP constitute particular assets for this protected area. This analysis could lead to greater appreciation and a positive impact on the conservation of the park if an effective management approach were applied by the local communities and decision-makers.

The work carried out in the MGNP shows a structural vegetation dynamic with increasing density and size of individuals, and major socio-economic and ecosystem roles, as perceived by various stakeholders in the management process [25]. Phases of reforestation are observable from the analysis of its diachronic evolution by remote sensing [19, 25]. The other major indicators identified for the development of the MGNP are mainly related to the diversity of its flora and its structure, which is considered sufficiently stable [16–19, 23, 24]. This predominantly exuberant vegetation is illustrated by the two images in **Figure 3**. The anthropisation indices noted are certainly inherent to its functioning, and justify the characterization of its resilience. Its compositional diversity is particularly high, with a very rich flora constituting a gene bank (110 species of woody plants, Shannon-Weaver index evaluated at 4.54 bits and Simpson's index at 0.90). Several species that are rare in the natural environments surrounding the park and even vulnerable or threatened at the global level are found there (*Afzelia africana*, *Khaya senegalensis*, *Dalbergia melanoxylon...*). The importance value index (IVI) of families and species shows its great heterogeneity (floristic groups of ligneous plants with more than 25 species with a high IVI and 30 families). The density and basal area of individuals are also high (2694.16 stems/ha and 43.88 m2 /ha), indicating a low impact of the various environmental constraints. Its high woody phytomass indicates high production (331.73 tMS/ha on average for each CU). There is also a strong presence of specific Sudanian or Guinean elements, indicating adaptability to the quality of the soil and favorable climatic conditions. The specificities of the Oxisols, which are widespread in the region, are generally preserved. The high proportion of sarmentous and lianascious individuals sometimes makes the undergrowth impenetrable, and mechanisms of self-destruction or natural mortality indicate that this ecosystem has followed a trajectory towards quasi-typical Sudano-Sahelian vegetation without major disturbances. Remote sensing data show that savannization is certainly underway, especially in CU3, but to a limited extent.

With the implementation of an effective management system, these ecosystemic and scientifically beneficial values of the MGNP could make it eligible as

#### **Figure 3.**

*Characteristics of exceptional vegetation in the Sudano-Sahelian zone: (a) Regreening of the mosaic of dense dry forest and shrub thickets in the rainy season; (b) image of a dense to open dry forest in the same season.*

a UNESCO World Heritage Site. The MGNP presents itself as close to a natural habitat model for *in situ* conservation of biological diversity*,* representative of the ecological and biological processes involved in the evolution and development of ecosystems in this geographical area of Cameroon. Leaving aside the smallness of its area, this is also a feature in line with criterion C of the IUCN definition of key biodiversity areas [42]. Other plant formations in the Sudano-Sahelian zone can benefit from the sustainable conservation of the values identified in the MGNP.

## **4.2 Implications for the sustainable management of Sudano-Sahelian ecosystems**

The assessment of the explanatory mechanisms of vegetation evolution in MGNP via remote sensing [22], did not reveal highly significant correlations between the characteristics of the park's flora on the one hand and rainfall and demographic factors on the other. Circumstances related to the inaccessibility of the flora, as well as the dangers of entering the park due to popular belief, would have sufficiently reduced anthropic pressures. This low anthropisation, combined with the irrefutable climatic variability in this region, has nevertheless resulted to increasing of savannization noticeable in CU3 [16].

In view of the floristic assets of the MGNP, there would therefore be a great benefit in respecting conservation measures, or even in implementing management plans for ecosystems in the Sudano-Sahelian zone, which give an important place to the safeguarding of the flora, with the hope of obtaining a regeneration of the vegetation similar to that of the MGNP. To confirm this hypothesis, the work carried out by Donfack [43] showed phytoecological characteristics of 30-year-old fallows that were quite similar to the vegetation of the MGNP. Ecological restoration and rehabilitation projects for Sudano-Sahelian ecosystems in the area could thus be based on the compositional and structural foundations of the MGNP.
