With the liberalization of the mining sector, a considerable demographic explosion is witnessed in Lubumbashi city (southeastern of the D.R. Congo). The resulting spatial urban expansion is unplanned, reducing the vegetation cover abundance within and around the city. To address this situation, Acacia auriculiformis, an alien species, has been planted without planning and monitoring. We quantify the spatio-temporal pattern dynamics of A. auriculiformis along the urban-rural gradient from the digitisation of Google Earth images from 2006, 2014 and 2021, and evaluate tree diversity through floristic inventory. Results showed that the plantation of A. auriculiformis, belonging to park, street trees and green spaces-types, increased in patch number and acreage, mostly in urban zone. The values of the patch which were highest in 2006 decreased in 2021, especially in the urban zone. Thirty-nine trees species were founded on A. auriculiformis plantations, with Albizia lebbeck, Albizia alba and Leucaena leucocephala being the most common. However, results showed that 20 species out of 39 species found are exotic, half of which are invasive species. However, 19 trees species are indigenous, mainly found in peri-urban zones. Although most tree species were observed in urban zones, the average diameters were greater in the peri-urban zone. Overall, obtained results appear to suggest that the sustainability of A. auriculiformis within the urban and peri-urban zones of Lubumbashi city appears uncertain since a considerable number of attracted species are found to be alien invasive trees that pose a threat to biodiversity conservation. There is an urgent need for adoption of a master plan for sustainable integration and monitoring of trees plantations for limiting erosion of indigenous phytodiversity and the spread of alien invasive species populations in the adjacent rural area.

In the Lubumbashi charcoal production basin (LCPB) in south-eastern DR Congo, agricultural and charcoal production activities regularly give rise to fires that lead to considerable degradation of the miombo open forest. This study analyzes the drivers of the spatio-temporal distribution of active fires and burnt areas in the LCPB by processing MODIS and Landsat data. In addition, a Kernel density analysis method (KDE) was used to estimate fire risk, while the effect of the road network and dwellings on vegetation fires was highlighted in areas between 0-3000m radius. Obtained results revealed that fires in the LCPB generally occur between April and November mainly during the day, between 11am and 12pm. These fires are concentrated in the central and south-western part of the LCPB, more specifically in the savannahs and near roads. From 2002 to 2022, an average of 11,237 active fires and an average of 6,337 km2 of burnt areas were recorded in the LCPB. Each year, these fires peak in August, and despite their steady decline, the few fires that have affected the forests have caused more devastation (more than 2790 km2 / year) than those observed in the fields and savannah. These figures highlight the imperative need to put in place fire prevention and management measures in the LCPB, with particular emphasis on awareness, monitoring and fire-fighting measures.

The overexploitation of forest resources in the charcoal production basin of the city of Lubum-bashi (DR Congo) is reducing the resilience of miombo woodlands and threatening the survival of the riparian as well as urban human populations that depend on it. We assessed the socio-economic value and availability of plant-based non-timber forest products NTFPs in the rural area of Lubumbashi through ethnobotanical (100 respondents) and socio-economic (90 respondents) interviews, supplemented with floristic inventories, in two village areas selected on the basis of the level of forest degradation. The results show that 60 woody species, including 46 in the degraded forest (Maksem) and 53 in the intact forest (Mwawa), belonging to 22 families are used as sources of NTFPs in both villages. Among these species, 25 are considered priority species. NTFPs are collected for various purposes, including handcrafting, hut building, and traditional medicine. Moreover, the ethnobotanical lists reveal a similarity of almost 75%, indicating that both local communities surveyed use the same species for collecting plant-based NTFPs, despite differences in the level of degradation of the miombo woodlands in the two corresponding study areas. However, the plant-based NTFPs that are collected from miombo woodlands and traded in the urban markets have significant economic value, which ranges from 0.5 to 14.58 USD per kg depending on the species and uses. NTFPs used for handicraft purposes have a higher economic value than those used for other purposes. However, the sustainability of this activity is threatened due to unsustainable harvesting practices that include stem slashing, root digging, and bark peeling of woody species. Consequently, there is a low availability of plant-based NTFPs, particularly in the village area where forest degradation is more advanced. It is imperative that policies for monitoring and regulation of harvesting, and promoting sustainable management of communities’ plant-based NTFPs priority, be undertaken to maintain their resilience.

Biodiversity conservation is a key factor in meeting sustainable development goals. This is even more important in cities, where green spaces are becoming increasingly scarce. This study analyzes the Kinshasa's proliferating ornamental plant nurseries, known as informal horticultural sites (IHS). The analysis focused on characterizing the profile of horticulturists, their production conditions and the ornamental species produced. Fifteen IHSs were sampled using the "snowball" technique, and 178 horticulturists were surveyed. Based on the socio-professional profile of the horticulturists, five groups of IHS are distinguished after a hierarchical classification on principal components. We found that IHSs exclusively employed men, most of whom were new to the trade, from all levels of education, and most of whom ranged from 19 to 45 years old. Production conditions are relatively similar from one site to another. However, all IHS are characterized by permanent land insecurity, the use of phytosanitary products, plant conditioning methods that are not very diversified and calibrated to growers' investment capacities, and diversified seed acquisition methods. A total of 139 ornamental species, most of them exotic, were identified. Of these, 37% are phanerophytes and 24% are considered potentially invasive. We suggest ways of professionalizing the activity and protecting the urban environment.

Although charcoal production is a source of income, it is often associated with deforestation due to the felling of trees in rural areas. The study quantifies the yield of carbonization in the rural area of Lubumba-shi, DRC, and identifies its determinants. By analyzing 20 kilns from professional producers in different villages, the study reveals that these charcoal producers build large kilns, containing an average of 46.9±21.5 m3 of wood from 19 species of miombo trees. The average carbonization yield is 10.2%, varying from village to village due to parameters such as kiln size, quantity of wood used, kiln coverage time, wind exposure, substrate type and tree species. It was noted that the moisture content and size of the wood did not correlate significantly with the quantity of charcoal harvested per kiln. Yield improvement should therefore take these parameters into account to enable charcoal producers to increase their income while adopting sustainable production practices.