Ecologies

Water pollution caused by petroleum-derived volatile organic compounds such as benzene, toluene, ethylbenzene, and xylenes (BTEX), as well as methyl tert-butyl ether (MTBE), poses a growing threat to aquatic ecosystems and human health. These contaminants, together with the organic matter and nutrients present in municipal wastewater, highlight the need for sustainable treatment technologies adapted to tropical conditions. This study evaluated the removal efficiency of BTEX, MTBE, and conventional pollutants using hybrid constructed wetlands (HCWs) that combine vertical subsurface flow (VSSF-CW) and horizontal subsurface flow (HSSF-CW) systems. Two plant species—Heliconia latispatha and Phragmites australis—were tested, along with a polyculture and an unvegetated control. The hybrid systems treated synthetic influents formulated to simulate contaminated municipal wastewater. Parameters including COD, TSS, N–NH₄⁺, N–NO₃⁻, P–PO₄³⁻, BTEX, and MTBE were monitored and analyzed using ANOVA and Tukey’s test (p < 0.05). Vegetated systems achieved COD removal efficiencies exceeding 85%, compared with 72% in the control. Phragmites australis obtained the highest removal of suspended solids (92 ± 3%) and ammonium nitrogen (88 ± 2%), whereas Heliconia latispatha exhibited superior phosphorus removal (84 ± 4%). The polyculture displayed a synergistic effect, achieving removal rates of 93% for benzene, 91% for toluene, and 88% for MTBE, with statistically significant differences relative to the control (p < 0.05). In conclusion, hybrid constructed wetlands planted with Heliconia latispatha and Phragmites australis demonstrated high efficiency and stability in removing BTEX, MTBE, and conventional pollutants under tropical conditions, positioning themselves as a sustainable, low-cost, and esthetically valuable treatment alternative.

The monitoring of wildlife habitats is crucial for effective conservation efforts, particularly where biodiversity faces significant threats. This study aimed to monitor the biodiversity of wild mammals in a protected area (PA) of Northeastern Bangladesh, with a particular focus on detecting previously unrecorded species using camera traps. We deployed nine camera traps across 19 locations inside the PAs of Satchari National Park (SNP) from May 2024 to April 2025. Further, the camera-trap data were analyzed to evaluate the existing wild mammals, along with their activity patterns and seasonal variations, in SNP. Our study identified the Asiatic black bear in SNP for the first time, representing a significant contribution to biodiversity records of Bangladesh. Among the other frequently documented wild mammals were the wild boar, northern pig-tailed macaque, and barking deer, whereas less commonly detected species included the crab-eating mongoose and jungle cat. Activity pattern analysis of Asiatic black bear revealed a predominantly nocturnal-to-crepuscular behavior, with distinct bimodal peaks during early morning and evening. The present study showed that the Asiatic black bear was active in pre-monsoon and winter; however, it was absent during the rainy season, suggesting seasonal habitat use or detectability challenges. This is the first study to confirm the presence of Asiatic black bears in PAs of SNP using camera traps. These findings also highlight the importance of long-term biodiversity monitoring for continued conservation efforts to protect the diverse wildlife of SNP. The detection of previously undocumented wild mammals highlights the ecological importance of SNP, urging authorities to tighten the ongoing conservation initiatives. Understanding the diel and seasonal activity patterns would instruct the timing of conservation and habitat management strategies. This study also makes the integration of camera-trap monitoring into long-term biodiversity management to guide evidence-based conservation policies in Bangladesh’s PAs.

The Sunn pest (Eurygaster integriceps Puton) ranks among the most harmful pests affecting wheat yield and grain quality in Kazakhstan. In particular, it poses a serious threat to regions in which winter wheat cultivation is dominant. Climate change, parasites, predators, and recent transformations in agriculture and human activities in Kazakhstan and throughout Central Asia have significantly influenced the population dynamics of the Sunn pest. This study reports the findings on Sunn pest population dynamics in Kazakhstan’s winter wheat growing regions from 2022 to 2024, based on surveys of 233 hectares across four regions. In total, 1753 specimens of the Sunn pest were studied. The obtained results were analyzed in comparison with historical data (1991–2020) and recent findings in this field. We found that a combination of ecological factors are the main determinants of the Sunn pest population dynamics in different regions of the country. The pest population increased in seasons with optimal temperature (sum of effective temperatures—SET) and humidity conditions (hydrothermal coefficient—HTC), as well as when wheat cultivation areas and forest belts expanded. Moreover, the results highlighted that the pest population is controlled by the activity of egg parasites (Telenomus) in the south, unfavorable weather conditions during overwintering in the east and west, and the growing of resistant varieties in the southeast of the country. Compared to wild grasses, wheat crops increased the reproductive potential of the pest.