The predominant aim of the current study was to evaluate the spatial dynamics of the riparian coverage of the area of influence of the Chambo River in the area of the river’s source (middle-high basin), between 2500 and 3000 m.a.s.l. For its execution, Landsat 7 images from the year 2000, RapidEye from the year 2009, and Spot 6 from the year 2019 were used in the time range of 2000–2009 and 2009–2019. These were subjected to supervised classification by applying the maximum likelihood algorithm, identifying five classes of soil cover, being pasture, crops, soil-remnants of paramo, forest, and anthropic. The classification results were validated by calculating the precision measures and the kappa index. With the use of cross-tabulation matrices, the gains, losses, and persistence in the two periods studied were identified. There, it was determined that, in the first study period, the soil cover-paramo remnants presented the highest percentage of loss (26.70%), the crop cover the highest percentage of gain (28.91%), and in the second period, the crop class presented the highest percentages of losses (18.94%) and gains (17.29%). The cartographic projection of the area for the year 2030 predicts that the areas anthropic category will increase by 1.27%, that of forest will decrease by 1.19%, that of soil-remnants of paramo will gain 0.79%, and crop and pasture cover will decrease by 0.45% and 0.43%, respectively. The results obtained allow for the transitions between coverages to be attributed to population growth, afforestation, reforestation, deforestation and agricultural activities, volcanic eruptions, land colonization, and expansion of agricultural activity. Complementary studies are recommended that involve livelihoods and water quality, which facilitate the identification of vulnerable areas to propose adaptation, prevention, and/or restoration measures.

Microplastics (MPs) are emerging pollutants whose fate after removal from wastewater remains uncertain. Constructed wetlands (CWs), as nature-based solutions with high retention of MPs, provide a suitable context to assess MP fate through extended interactions with sediments, vegetation, and microbial communities. This study evaluated MP distribution and aging in two sequential horizontal subsurface flow CWs (secondary wastewater treatment CW1 and sludge treatment CW2) in a residential area (Spain), in operation since 2014. Fibers were identified as the predominant type across depth profiles, with polymer-type abundance linked to urban wastewater inflows. Vertical patterns revealed denser polymers and smaller MPs accumulating in deeper layers, while lighter or later-introduced particles remained near the surface. MP distribution varied with treatment configuration, showing peak concentrations either in the top 5 cm at the CW1 inlet zone (566 MP/g) or in the deepest layer at the CW2 (464 MP/g). An exploratory phenomenological MP balance model reproduced the observed 97% removal efficiency by accounting for substrate retention and estimating accumulation and loss terms. A significant decrease in MP abundance from the inlet to the center confirmed efficient retention, with vegetation roots exhibiting MP levels equivalent to ∼34%-150% of the local substrate concentrations. Evidence of physical deterioration and spectra-detected chemical alterations (oxidation, hydrolysis) reflects long-term environmental aging and suggests potential pathways for polymer degradation. These findings support the hypothesis that CW conditions may favor MP aging, consistent with studies reporting microbiota-driven polymer degradation in similar natural environments. Further research should employ complementary techniques to confirm polymer aging mechanisms and optimize microbiota-based CWs to enhance MP removal.