Since the 1960s, the countries of sub-Saharan Africa have been affected by an urban crisis due to the demographic explosion in cities and the resulting land pressure. These issues have resulted in the proliferation of spontaneous housing areas, which call the future of urban vegetation and its degree of inclusion in city planning into question. To analyze the current scientific knowledge on the development of urban landscapes, particularly in sub-Saharan Africa, a literature review on urban forestry covering the period of 1998–2022 was carried out in order to better guide future research works towards a greater consideration of urban forestry and its contribution to combating the adverse effects of climate change. Out of the 110 scientific papers selected, 50 were considered relevant because of their direct link with urban forestry. Based on the analysis of these papers, a classification of the articles according to five themes was carried out. These themes are the management of green spaces in urban areas, the functions of trees in an urban environment, the development of urban forestry, the characterization of urban tree flora, and the financing of urban forestry. Thus, the “function of trees in an urban environment and the characterization of urban tree flora” are the most addressed issues, being raised in 42% and 28% of articles, respectively. “Financing urban forestry” is practically not addressed (2%). The analysis of the 50 selected articles reveals a significant geographic concentration of urban forestry research. Countries such as South Africa, Kenya, and Ghana are more represented in the literature, while vast regions in Central and Western Africa (e.g., the Democratic Republic of Congo, Chad, and Niger) are the object of minimal or no documented research with regard to urban forestry. Future research should address these underrepresented themes, as they are crucial for the long-term sustainability of urban forestry projects. Particularly, research on financing mechanisms is essential to unlocking sustainable funding sources for urban forestry, a critical barrier to its expansion.

Pterocarpus erinaceus (Poir) is currently the most exploited and threatened spontaneous tree species in the Guinean-Sudanian and Sudano-Sahelian zones in West Africa. This work analyzed the density and color parameters of P. erinaceus wood in the phytogeographic zones (Sudanian, Guinean and Sahelian) in three countries in West Africa (Togo, Burkina Faso and Niger). The results obtained by studying 451 specimens taken from 95 trees showed significant differences in basic density and color parameter values (P < 0.001) based on phytogeographic zones. Individual tree samples from the Sahelian zone were denser (780 ± 63 kg · m − 3), darker (L* = 48.3 ± 0.6) and redder (a* = 8.2 ± 2) than those in the Guinean zone (basic density = 684 ± 53 kg · m−3; L* = 59.7 ± 0.5; a* = 6 ± 0.2) and the Sudanian zone (basic density = 725 ± 70 kg · m−3; L* = 53.7 ± 0.40; a* = 7.30 ± 0.2). At intra-tree scale, the results did not show a significant variation of basic density according to the number of rings counted from the pith (P > 0.05). This indicated that the age of the trees has little influence on the basic density of P. erinaceus wood.

Pterocarpus erinaceus (Poir.) (local name: Toti, Tem) is a species endemic to the Guinea-Sudan and Sudan-Sahel zones. It is over-exploited for its wood, which is sold in international trade to China and Indian markets. The selection of high performance wood based on wood properties and their vegetative reproduction represents the best option for the establishment of plantations with the aim of promoting the restoration of degraded natural resources. However, measurements of these characters are lengthy, time consuming and destructive, and difficult to perform in Togo because of the lack of equipment. An alternative to those methods is near infrared (NIR) spectroscopy. The aim of this study was to assess the efficiency and feasibility of near infrared spectroscopy for predicting the physical and mechanical properties and the colour parameters of P. erinaceus wood from Burkina Faso, Niger and Togo. The properties were determined by conventional method and correlated with near infrared spectra using partial least square regression. The partial least square regression models were tested by cross-validation and by external validation. The results of this study showed the possible use of near infrared spectroscopy to estimate the physical and mechanical properties and the colour parameters of P. erinaceus wood. In fact, when validating prediction models for radial and tangential shrinkage, the fibre saturation point (FSP) showed R² values of 0.70, 0.71, and 0.92, respectively, with ratio performance deviation values of 1.84, 1.87 and 3.57. For the colour parameters L*, a* and b*, the R² values were 0.83, 0.74 and 0.67, respectively, with ratio performance deviation values of 2.40, 2 and 1.70. The results showed that the basic density and fibre saturation point models were classed as good to very good, respectively. Near infrared spectroscopy can therefore be used to predict efficiently the properties of P. erinaceus wood for a large number of samples, enabling the incorporation of those traits in breeding criteria.

Green belts, consisting mainly of natural forests, woodlands, and agricultural areas surrounding major cities, play an essential role in regulating urban development and controlling the expansion of metropolitan areas. Although this concept has been extensively studied in the world’s major metropolitan areas, it remains relatively unknown in many countries, particularly in Africa. There is a great need for research to better understand urban vegetation cover on the continent. This article proposes a systematic review of African publications on green cover for the period 2010 to 2024. A descriptive and thematic analysis of the selected scientific papers was carried out using a database established to examine the state of existing research and understanding of the management of these plant formations in Africa. The results of these analyses highlight several major challenges facing urban forestry, including increasing anthropogenic pressures, lack of urban planning that integrates urban forestry, and shortcomings in the management of existing forest landscapes. The thematic analysis has also helped to identify the topics addressed by African researchers, identify gaps in research, and suggest directions for future studies. Three priority areas emerge from this analysis: the conservation of natural or artificial green belts around cities, the impact of these forest landscapes on urban heat islands (climate impact), and the sustainability of ecosystem management in the context of sustainable urbanization. These guidelines will enable a better understanding and valorization of green belts in Africa, thus contributing to the construction of more sustainable cities and the efficient management of forest landscapes.

Pterocarpus erinaceus is an endemic and threatened plant species in arid and semiarid zones of West Africa and is highly exploited for timber, animal feeding, and various medicinal uses. The species is currently native to the Guinean forest-savannah mosaic ecoregion and reported from Senegal to Cameroon. The values of the main characteristics of the P. erinaceus forest stands (density, average diameter, average height and average stem height) vary significantly (P < 10−3) from the Guinean zone to the Sahelian zone. It has high technological performance and can be classified as heavy and very hard wood with a density of the order of 0.80 ± 0.07 g/cm3 and an average hardness of 12 ± 3.7 g/cm3. The species is the subject of large-scale international traffic between West Africa and Asia, which is by far the greatest threat to the species. The various uses induce repeated mutilation and increase pressures on the species resulting in a significant reduction in its natural populations. In response to this situation, measures are proposed, including large-scale plant production strategies, the definition of minimum felling diameters, policy measures, etc., to meet the restoration needs of natural stands of P. erinaceus and the fight against climate change.

Since the 1960s, the countries of sub-Saharan Africa have been affected by an urban crisis due to the demographic explosion in cities and the resulting land pressures. These have resulted in the proliferation of spontaneous housing areas which question the future of urban vegetation and its degree of inclusion in city planning. To analyze the state of knowledge on the research already carried out on the development of urban landscape, particularly in sub-Saharan Africa, a literature review on urban forestry covering the period 1998-2022 was carried out in order to better orient future research works for a greater consideration to urban forestry and their contributions in combating the adverse effects of climate change. Out of a set of 110 scientific papers selected, 50 were considered relevant because of their direct link with urban forestry. From the analysis of this papers, a classification of the articles according to 05 themes was carried out. These are: management of green spaces in urban areas, functions of trees in an urban environment, development of urban forestry, characterization of urban tree flora and financing of urban forestry. Thus, “function of trees in an urban environment and the characterization of urban tree flora” are the most addressed respectively at 42% and 28%. “Financing urban forestry” is practically not addressed (2%). The analysis of the 50 selected articles reveals a significant geographic concentration of urban forestry research. Countries like South Africa, Kenya, and Ghana are more represented in the literature, while vast regions in Central and Western Africa (e.g., Democratic Republic of Congo, Chad, and Niger) have minimal or no documented research on urban forestry. Future research should address these underrepresented themes, as they are crucial for the long-term sustainability of urban forestry projects. Particularly, research on financing mechanisms is essential to unlock sustainable funding sources for urban forestry, a critical barrier to its expansion.