Multidimensional analysis of landscape dynamics in a Central African forest‐savannah mosaic

Abstract

Most landscape cover assessments for conservation programmes rely largely on remote sensing analyses. These analyses, however, neglect how people inhabiting protected zones perceive and structure land cover. Using socio-ecological systems (SES) analysis in a forest-savannah mosaic on the Congo Basin forest edge (Democratic Republic of Congo), we investigated how human practices, landscape perceptions and land use patterns affected forest cover. We conducted remote sensing analysis using a Sentinel-2 satellite image and 187 GPS landmarks, producing a land cover map with 11 classes. Our results yielded an 81.85% correspondence with additional 164 GPS landmarks, a robust score in tropical areas. We conducted 40 individual interviews, eighteen focus group discussion workshops and nine months of participant observation of human practices to identify 19 land units and elaborate a granular SES system structuring the landscape. Integrating local knowledge and practices with general ecological and agronomic processes, we developed a landscape dynamics model revealing progressive forest colonisation of savannahs. Our methods demonstrate that a forest-edge landscape cover evaluation through remote sensing and local knowledge can contribute to finer-grained assessment of land cover and ecosystem services. This assessment can assist conservation efforts by considering local populations' practices on and perceptions of landscape change. Résumé La plupart des études de couverture terrestre effectuées dans le cadre de programmes de conservation s'appuient en grande partie sur des analyses basées sur la télédétection. Cependant, ces analyses négligent la façon dont les populations habitant dans les zones protégées perçoivent et structurent la couverture terrestre. À l'aide d'analyses portant sur les systèmes socio-écologiques (SEE) effectuées dans une mosaïque de forêts et de savanes située à la lisière de la forêt du Bassin du Congo (République démocratique du Congo), nous avons étudié la façon dont les pratiques humaines, la perception de la couverture terrestre et la structure de l'utilisation des terres affectait la couverture forestière. Nous avons réalisé une analyse basée sur la télédétection en utilisant une image satellite Sentinel 2 et 187 repères GPS pour produire une carte de la couverture terrestre contenant 11 catégories. Nos résultats ont montré une correspondance de 81.85% avec 164 repères GPS supplémentaires, | 693 DEMICHELIS Et aL.

Socio-ecological approach to a forest-swamp-savannah mosaic landscape using remote sensing and local knowledge: a case study in the Bas-Ogooué Ramsar site, Gabon

“…The landscape dynamics model we developed using an SES approach shows that, in the absence of human activities, the environment will gradually become more closed, with the disappearance of open ecosystems dominated by herbaceous vegetation in favor of forests in the long term. This dynamic of forest expansion at the expense of savannahs has been observed elsewhere in Gabon (Sebag et al, 2016) and in other countries in Central Africa (Demichelis et al, 2020;Ploton et al, 2022). In a context of climate change, these dynamics are expected to accelerate in African savannas in the coming decades (Stevens et al, 2016).…”

“…But with the reduction or extinction of large mammal populations, fires are now the dominant factor in places without livestock, and therefore the main driver of their equilibrium (Sebag et al, 2016;Demichelis et al, 2020;Ploton et al, 2022;Puttick et al, 2022). Locally, these fires are mainly set by hunters to attract wildlife from the forest to feed on the young regrowth of grasses.…”

“…However, the integration of local knowledge with remotely sensed data remains marginal, and often problematic (Sulieman & Ahmed, 2013;Yiran et al, 2012). However, some recent studies around the world, particularly in the fields of conservation, development and risk management, have successfully integrated the two types of information (Del Rio et al, 2018;Demichelis et al, 2020;Bonilla-Moheno et al, 2021). This integration is mainly based on the concept of the socio-ecological system (SES; Ostrom, 2009), by considering the landscape dynamics and structure as the results over time of the interactions between human populations and their environment.…”

A century of village mobilities and landscape dynamics in a forest-savannah mosaic, Democratic Republic of Congo

“…This map categorizes the landscape into 11 different classes according to a hybrid categorization based on the field surveys that accounted for structure and botanical composition and local perception of the landscape. The methodology used to produce this map, as well as the description of landscape classes, can be found in a previously published article (Demichelis et al, 2020).…”

Spatiotemporal Variation in Bonobo (Pan paniscus) Habitat Use in a Forest–Savanna Mosaic

“…The Manzano study site is at the southwestern periphery of the bonobos' geographic range (Bolobo Territory, DRC) and consists of a forest-savanna mosaic (Inogwabini et al 2008;Pennec et al 2016). Located at the edge of the Congo Basin, this mosaic probably originates from both natural and anthropogenic influences, including seasonal fires in savannas and slash-and-burn agriculture (Demichelis et al 2020;Namur 1990). In this forest-savanna mosaic environment, bonobo density and dietary diversity falls within the range of the more forested bonobo study sites (Hashimoto et al 1998;Inogwabini et al 2008;Mohneke and Fruth 2008;Narat 2014;Sabater Pi and Vea 1990;Serckx et al 2014Serckx et al , 2015Uehara 1988;Van Krunkelsven 2001).…”