Rojina Akter

Reactive oxygen species (ROS) are integral components of plant signaling networks that mediate interactions between plants and their environment, thereby regulating diverse physiological and biochemical processes. While controlled ROS production is essential for stress perception and signal transduction, excessive ROS accumulation induces oxidative damage. ROS-mediated lipid peroxidation of polyunsaturated fatty acids leads to the formation of highly electrophilic α,β-unsaturated carbonyl compounds collectively referred to as reactive carbonyl species (RCS). Under severe abiotic stress conditions, excessive RCS accumulation exerts cytotoxic effects and causes widespread cellular dysfunction. In contrast, at subtoxic levels, RCS function as important secondary messengers that modulate stress-responsive signaling pathways, including programmed cell death, stomatal regulation, and adaptive responses to abiotic stresses. This review critically synthesizes current advances in understanding the dual roles of ROS and RCS as both damaging agents and signaling molecules in plants. Particular emphasis is placed on the mechanistic basis of ROS-RCS crosstalk and their interactions in abiotic stress tolerance. Furthermore, this review highlights emerging research gaps and outlines future perspectives aimed at translating redox signaling insights into strategies for improving plant stress resilience under changing environmental conditions.

Cropland agroforestry practices are widely adopted over various land ecosystems in Bangladesh, offering the potential to capture carbon (C) and safeguard biodiversity. Lack of accurate assessments of biomass carbon and the diversity of woody perennials in cropland agroforestry practices across different land ecosystems presents a hurdle for the efficient execution of initiatives such as REDD + and comparable mechanisms. The present research sought to estimate biomass carbon stocks and diversity of woody species, exploring the influence of stand structure and diversity indices on these C stocks. We conducted woody perennials’ inventory in 180 sampling quadrates (10 m × 10 m) from cropland agroforestry practices in forest, plains land, and char land ecosystems. Altogether, we identified 42 woody species; however, the predominant species in three land ecosystems were Acacia auriculiformis, Gmelina arborea, and Tectona grandis. Swietenia macrophylla and Swietenia mahogany contributed the greatest amount of carbon stocks. Carbon stocks in woody perennials were 30–44% higher in plains land and forest land ecosystems compared to the char land ecosystem, attributable to significantly increased stand density, basal area and diameter. The significantly highest Shannon–Wiener index (2.75) and Margalef’s richness index (3.37) were found in forest land compared to other ecosystems. The highest total carbon stocks (131.27 Mg C ha−1) of cropland agroforestry were found in the forest land ecosystem, which had the greatest soil organic carbon, density, and richness of woody perennials. A rise in the richness and diversity index of woody species by one unit led to a concurrent increase of 12 and 8 Mg C ha−1 in carbon stocks, respectively. Cropland agroforestry practices in the forest land ecosystem are more diverse and could sequester more carbon stock than in the other two land ecosystems in Bangladesh. The biomass C stocks of woody species were positively correlated with stand structure and diversity, having the potential to contribute to biodiversity conservation in Bangladesh and other similar countries.

One of the most significant linchpins of the socioeconomic and livelihood milieu for rural farmers around the world is agroforestry. Several agroforestry practices are being employed by farmers in Bangladesh’s northern region, with Choi Jhal (Piper chaba)-based agroforestry being one of the most prevalent. Numerous researches have been conducted in different regions of Bangladesh to determine the potential livelihood for farmers who engage in diversified agroforestry, but hardly any comprehensive research has been carried out considering the aforementioned system as one of the most sustainable practices. To address this knowledge void, the present research was conducted in the Chinai union of Rajarhat Upazila in the Kurigram district of Bangladesh, surveying 105 Piper chaba farmers to assess the impact of this existing agroforestry system on their livelihood predicament. A mixed-method approach, including secondary data review, questionnaire survey, key informant interviews, focus group discussions and direct observations, were used for data collection and triangulation. To evaluate livelihoods and the problem severity, the Livelihood Improvement Index (LII) and the Problem Facing Index (FPI) were utilized, respectively. The findings demonstrate that the most suitable tree for Piper chaba cultivation is the betel nut (74.3%), and the majority (64.8%) of farmers have 41 to 90 Piper chaba plants. By strengthening farmers’ constant availability of food, fruit, timber, fodder, and fuelwood, this agroforestry system has markedly increased the sustainability of their livelihoods. This practice is thought to boost farmers’ livelihood capitals, with natural capital improving the most, while social capitals improve the least. However, eight major problems have been identified that farmers face while growing the crop and these must be remedied if different livelihood capitals are to be vastly improved. This research gives a full insight into the current Piper chaba production scenario and livelihood dynamics of local farmers, allowing some bold propositions to be formulated for further upgrading of their subsistence.

Industrial activities have various effects on biodiversity, posing significant threats to forest ecosystems. The current study describes the species composition, taxonomic diversity, and stand structure at Bhawal Sal forest, Gazipur, Bangladesh, as they are affected by industrialization. To achieve the goal, 30 different categorized industries within the forest were considered sampling points and three distance gradient sites viz. Site-1=Adjacent to industries (0m), Site-2=160m distance and Site-3=320m distance from industries were designated as treatments. A total of 90 quadrate plots (10m×10m) were taken randomly, of which 30 plots were from each site. Through forest inventory, 46 species (24 trees, 8 shrubs, 5 climbers, and 9 saplings) were recorded from three sites. The study revealed that the stand density and basal area of mature trees (257 stems ha⁻¹ and 8.06±0.60m²·ha⁻¹) at Site-1 were significantly lower due to diverse industrial operations than other sites. Statistically, all the biodiversity indices of mature trees; ShannonWieners index (1.72), Simpsons index (0.82), Margalefs index (1.38), Pielous evenness Index (0.39) was found to be lower at proximity to industries. The lowest species richness (12) of all plants was recorded from Site-1. However, the diameter and height distributions of Site-1 comprised young (1020cm·dbh) to medium-sized (20.130cm·dbh) trees, while the medium to large sized (>30cm·dbh) trees was contained at Site-3 in this study. The population structure of tree species at Site-1 also showed a fluctuating curve. Overall, this study highlights that plant ecosystems and tree population structure have declined tremendously due to industrialization. Hence, the current research could be significant for developing the management framework for the disturbed deciduous forest.