Small wetlands provide crucial ecosystem services but are facing widespread loss and degradation. At present, small wetland complexes provide an alternative avenue for conservation; we used a dataset to illustrate how zeta diversity can be assessed in a small wetland complex. The small wetland complex studied consisted of nine hydrologically connected ponds, and all the ponds were connected by narrow ditches. Data collected included the composition of both zooplankton and phytoplankton communities, water physicochemical parameters, and hydrological connectivity. Two ways in which connectivity affects biodiversity, dispersal filtration (path distance-controlled biological diffusion) and environmental filtration (environment-selected species), were quantified. As a result, (1) 46 zooplankton and 119 phytoplankton species were identified, with species richness distribution significantly affected by water properties (explained variances of 68% and 39%, respectively), reflecting significant environmental filtration, and (2) both zooplankton and phytoplankton showed zeta diversity distance decay (p < 0.001), reflecting significant dispersal filtration, and (3) relatively rare species dominated community turnover, in which environmental filtration was far stronger than dispersal filtration. Overall, the small wetland complex in this study was characterized by hydrological connectivity, which not only allowed moderate biological connectivity but also promoted the coexistence of diverse habitats and communities. We emphasize the applicability of zeta diversity for assessing small wetland complexes, further demonstrating the value of small wetland complexes in promoting biodiversity such as species richness and species turnover.

Construction and demolition waste, when used as the substrates of constructed wetlands, provide notable environmental benefits: purification performances and substantial economic advantages compared with conventional substrates such as gravels. However, the high effluent pH induced by waste concrete severely restricts its practical application in such systems. The body of research focused on overcoming this limitation is rather limited. To address this limitation, this study proposed a strategy based on the configurations of acid alkaline substrates. A pilot-scale vertical flow constructed wetland experiment was carried out to evaluate the feasibility of this approach through three treatments: (1) waste concrete alone (Concrete), (2) waste concrete as the upper layer combined with perlite (an acidic substrate (Concrete + Perlite)), and (3) a uniform mixture of waste concrete and perlite (Mixed). The results demonstrate that the Concrete treatment exhibited a persistent high pH problem, where the effluent pH values remained above 9, even after five months of operation. In contrast, the Concrete + Perlite and Mixed treatments effectively mitigated the excessive effluent pH (<8.2). Relative to the Concrete treatment, both the Concrete + Perlite and Mixed treatments significantly enhanced the removal efficiencies of chemical oxygen demand (COD) (from 43.7% to above 68.5%), total nitrogen (TN) (from 31.8% to above 86.5%), and ammonium nitrogen (NH₄⁺-N) (from 96.7% to 96.9%), whereas the removal efficiency of total phosphorous (TP) showed only a slight decrease. No significant differences in pollutant removal performance were observed between the Concrete + Perlite and Mixed treatments. Moreover, the Concrete + Perlite and Mixed treatments substantially increased the bacterial diversity within the substrate biofilm compared with the Concrete treatment, although differences in the bacterial community composition between the Concrete + Perlite and Mixed were relatively minor. Overall, configuring pH-balanced substrates through the combination of acidic and alkaline matrices provided effective and sustainable integrity for promoting the resource of construction and demolition waste in constructed wetlands.

High-spatial-resolution fractions of absorbed photosynthetically active radiation (FPAR) and leaf area index (LAI) are important for characterizing urban vegetation productivity, yet reconstructing their continuous annual dynamics remains challenging. In this study, a phenology-constrained interpolation method was developed to reconstruct annual daily 10 m FPAR and LAI, which are key inputs to MOD17-based net primary productivity (NPP) estimation. Taking Nanjing, China, as a case study, six Sentinel-2 images and 8-day 500 m MOD15A2H FPAR/LAI data in 2023 were integrated. A four-step logistic function was fitted for cropland, while two-step logistic functions were applied to the other six vegetation types. The fitted curves achieved R² values of 0.69–0.95 for FPAR and 0.82–0.97 for LAI, indicating their capacity to characterize intra-annual vegetation dynamics. Cross-comparison with independent Sentinel-2 retrievals showed mean relative differences of −0.23% and −1.32% and mean absolute relative differences of 5.12% and 7.43% for FPAR and LAI, respectively. The reconstructed parameters were further used to illustrate NPP spatial patterns. The regional mean 10 m NPP differed by only 0.94% from the MOD17 500 m product, while showing stronger spatial heterogeneity. Maximum NPP was 1.31 versus 0.87 kg C·m⁻²·a⁻¹; pixels below 0.2 kg C·m⁻²·a⁻¹ accounted for 9.92% versus 0.84%, while those above 0.8 kg C·m⁻²·a⁻¹ accounted for 12.2% versus 0.10%. Because meteorological forcing was not downscaled and independent ground-based carbon-flux validation was unavailable, absolute NPP estimates should be interpreted cautiously and require further local calibration, whereas the reconstructed high-spatial-resolution FPAR and LAI provide valuable inputs for characterizing fine-scale patterns of urban vegetation productivity.

This study investigated the potential of waste concrete fines and carbonized waste concrete fines as soil amendments for the remediation of copper-contaminated soils through adsorption and solidification experiments. The Langmuir equation indicated that both waste concrete fines and carbonized waste concrete fines achieved high adsorption capacities of 27.60 mg/g and 27.71 mg/g, respectively. These construction wastes were as effective as steel slag and fly ash in stabilizing copper in soils, primarily by converting copper from weakly acid-extractable forms to reducible and oxidized states, while exhibiting no significant effect on the residual state of copper. The results suggest a promising application of construction wastes in soil remediation; however, further investigation is needed to understand their long-term effects and the migration of potentially toxic metals in plants.