Urban Risks

URiS - ISSN 2516-1857 - © ISTE Ltd

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The dry forests of Boeny, in north-western Madagascar, are home to unique biodiversity but are under serious threat from deforestation, bush fires and anthropogenic pressures. This study aims to characterise the flora, avifauna and herpetofauna of the Mandravasarotra and Antsanitia sites and to assess the pressures exerted on these ecosystems. Floristic surveys were carried out using linear transects and quadrats, while direct observations and microhabitat surveys were used to inventory birds and reptiles. A total of 53 plant species were recorded, 81% of which are endemic to Madagascar, mainly distributed among small trees and shrubs. The average density of individuals per hectare varies between sites, with a total basal area of 13.9 m²/ha. The avifauna comprises 13 species, including several forest-dwelling and endemic species, while 10 species of reptiles have been observed, mainly in grassy areas and forest edges. Diversity indices and forest structure indicate high richness but marked fragmentation. Identified anthropogenic pressures include slash-and-burn farming, illegal logging, and extensive grazing, which compromise natural regeneration and habitat connectivity. These results highlight the importance of appropriate conservation measures, combining strict protection, ecological restoration, and the involvement of local communities. This study thus provides a scientific basis for planning the conservation of the dry forests of Boeny and contributes to knowledge of the threatened forest ecosystems of north-western Madagascar.

Recurrent flooding in Quebec has revealed the limits of a fragmented and reactive risk management approach. To address these challenges, the ARIAction team developed RésiliAction, an integrated tool for assessing territorial resilience. Based on cross-mapping of hazards and various dimensions of vulnerability to use a risk analysis, it enables the evaluation, prioritization, and justification of land-use projects according to their capacity for resilient adaptation. Developed through co-construction with ministries and municipalities, the tool is built on thirteen criteria and eight resilience orientations encompassing social, environmental, economic, and institutional dimensions. In the municipality of Maria, it was used with a risk analysis and to assess the resilience score of the proposed land-use scenario in the face of coastal hazards. RésiliAction has proven to be an operational and equitable lever for supporting the transition toward sustainable and climate-adaptive planning. Its multi-scale scope and compatibility with the new regulatory framework make it a strategic instrument for strengthening the resilience of Quebec’s territories.

Population growth and the expansion of economic activities coupled with rapid urbanization have significantly exposed the global urban population to noise levels that can have detrimental effects on health. The problem is even more concerning in low-income countries such as Cameroon, where despite the existence of legislation against noise, its application is not respected. This study aims to analyze the entirety of Cameroonian acoustic legislation in order to promote its application. After collecting and analyzing data on the legal framework for noise in Cameroon and noise level measurements, the diagnosis of noise pollution conducted in the city of Yaoundé revealed that noise control legislation is not being respected, leading to an increase in noise levels exceeding the limit values recommended by the Standards and Quality Agency (ANOR) and the World Health Organization (WHO). In this context, it is essential that environmental management institutions implement actions to reduce noise pollution and ensure a peaceful environment.

Several studies have been carried out on the germination of seeds defecated by lemurs, but the seasonal variation in germination rates and the latent period of seeds of species consumed by Eulemur coronatus have not yet been studied. Two groups of E. coronatus were therefore monitored in order to carry out ex situ germination tests, with the aim of assessing the seasonal variation in the germination rate and the latency period of the seeds of two species consumed (Treculia madagascariensis and Xanthocercis madagascariensis). The focal animal sampling method (Altmann, 1974) was used to collect behavioural data during 2021-2022. The results showed that seed germination rates from fecal matter during the dry season were higher (72.5% and 57.5%) than during the wet season (32.5% and 42.5%) for both species. According to the Cox hazard model, the latent period of fecal seeds is shorter during the dry season for the Treculia madagascariensis species, while for the Xanthocercis madagascariensis species, the latent period of fecal seeds is similar between the dry and wet seasons. The variation in the germination rate and the latent period between the two seasons depends on the species.