Asian Journal of Environment & Ecology

Capacity of a Red Cabbage (Brassica oleracea var. capitata) Cyanidin to Neutralize Sodium Hypochlorite Toxicity in Daphnia magna Straus

Jacive Pérez Jiménez — 2026-11-03

Residual sodium hypochlorite (NaClO) discharged after disinfection may adversely affect aquatic organisms. This study examined whether anthocyanins extracted from red cabbage (Brassica oleracea var. capitata f. rubra) could reduce NaClO concentration and attenuate its toxicity to Daphnia magna. Anthocyanins were extracted using methanol and 2% hydrochloric acid (80:20), concentrated, purified and separated by column chromatography. Thin-layer chromatography was used to characterise the fractions. NaClO concentration was measured by iodometric titration, while acute toxicity was evaluated through 24-hour D. magna viability assays conducted in triplicate. The extraction yield was 4.59% (w/w). Of 15 coloured fractions, fraction 3 exhibited a retention factor of 69.23%, consistent with its tentative identification as cyanidin. The estimated 24-hour median lethal concentration (LC₅₀) of NaClO was 0.11 mg/L. Fraction 3 caused no observed mortality at the concentrations evaluated in the extract-only bioassays. Addition of 0.02 mg/L of the cyanidin-rich fraction reduced the measured NaClO concentration in an initial 0.11 mg/L solution by up to 93%. In combined-exposure bioassays, the tested extract concentrations were associated with complete D. magna survival after 24 hours. These findings suggest that the cyanidin-rich fraction may reduce NaClO-associated acute toxicity under the experimental conditions. More specific chemical characterisation and evaluation in complex water matrices are needed to establish its wider applicability.

Impact of Rice Cultivation on Woody Vegetation in the Sudanian-Sahelian Zone of Cameroon

Benoît Maralossou — 2026-11-06

Rice is a staple food for populations in the Sudano-Sahelian zone of Cameroon, but the expansion of its cultivation may contribute to the degradation of natural vegetation. This study analysed the impact of rice cultivation on the structure and floristic composition of woody vegetation in the rice-producing basins of Lagdo and Yagoua. Floristic surveys were conducted in three vegetation types—rice fields, savannahs and fallow land—at both locations. Three randomly selected 50 m × 50 m plots were surveyed within each vegetation type. Overall, 723 woody individuals belonging to 67 species, 47 genera and 24 families were recorded. Savannah vegetation showed the highest floristic diversity, whereas rice fields showed the lowest. The Shannon diversity index was 3.69 bits in savannah, 2.00 bits in fallow land and 0.64 bits in rice fields. In Lagdo, the species with the highest ecological importance values included Anogeissus leiocarpus (21.05%), Balanites aegyptiaca (14.53%) and Mangifera indica (13.94%). In Yagoua, Balanites aegyptiaca (72.25%), Acacia seyal (23.27%) and Anogeissus leiocarpus (16.66%) were prominent. The rice field at Lagdo contained two woody species, whereas none was recorded in the Yagoua rice field. These findings indicate lower woody-plant diversity in rice-growing areas than in surrounding savannah and fallow vegetation and highlight the need for sustainable management of woody vegetation within rice-producing landscapes.

Mapping the Global Evidence Base of Urban Green Infrastructure Research: Geographies, Methods and Outcomes

Rekha Dhammar — 2026-11-03

Urban green infrastructure (UGI) has become a prominent organising concept in research on climate adaptation, biodiversity, public health and the equitable provision of ecosystem services. Yet the visibility of an extensive literature does not establish that its geographical coverage, measurement practices or policy implications are equally robust. This critical narrative review maps the structure and evidential reliability of UGI scholarship by integrating bibliometric syntheses, cross-city assessments, field studies, systematic reviews and research on planning and governance. Publications from 1990 to 24 August 2026 were considered, with earlier or foundational conceptual work retained where relevant. Evidence was identified through accessible scholarly indexes, regional research platforms, journal records and citation-based searching, and was appraised for construct validity, geographical representativeness, study design, outcome measurement and transferability. The literature shows substantial convergence on the capacity of well-configured vegetation to moderate local heat, support selected taxa and contribute to stormwater management. Confidence becomes more conditional when claims concern city-wide effects, population health causality, distributive equity, net economic value and durability under climatic change. Bibliometric and thematic maps show that research is increasingly interdisciplinary, but that the locations where evidence is produced, the cities represented in datasets and the places to which recommendations are applied are not equivalent. Remote sensing has extended geographical reach without resolving differences in vegetation quality, access, land tenure or lived experience. Furthermore, green investments may reproduce environmental inequalities when their governance, maintenance and displacement effects are neglected. The review advances an evidence-mapping framework distinguishing research visibility, spatial coverage, causal credibility, social relevance and implementation readiness. It proposes priorities for longitudinal comparative designs, under-represented urban contexts, genuinely multifunctional assessments, and evaluation of who benefits over time. A credible global evidence base requires not only more studies but also better alignment between place, mechanism, measurement and public purpose.