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The degradation of urban ecology, particularly in metropolitan areas distinguished by dense populations and impervious surfaces, presents a worldwide challenge linked to swift urban expansion. Despite extensive documentation of urbanization's impact on broad regions or specific urban ecosystems over defined time periods, there remains a scarcity of studies investigating the spatiotemporal dynamics of landscape pattern (LP) changes in specific ecosystems at small-to-medium scales within inland megacities as a response to urbanization. Therefore, this work focused on the Bailuwan Wetland Park (BWP) in Chengdu, an inland megacity in southwestern China. Employing satellite imagery data from selected years spanning the previous decade (2010–2021, encompassing 2010, 2012, 2015, 2018, and 2021), this investigation delved into the influences of urbanization on the LP over various time-frames and across different land use/land cover (LULC) types. Our study revealed that urbanization has a significant impact on the patch-/landscape-level characteristics, including the class area (CA), number of patches (NP), patch density (PD), percentage of landscape (PLAND), aggregation index (AI), contagion index (CONTAG), largest patch index (LPI), landscape shape index (LSI), fractal dimension index (FRAC_MN), Shannon's diversity (SHDI), and evenness index (SHEI). Over the period from 2010 to 2021, NP and PD experienced notable increases, while landscape shape (LSI/FRAC_MN) exhibited greater complexity and fragmentation (PLAND) intensified. Further, landscape heterogeneity (AI/CONTAG) and diversity (SHDI/SHEI) decreased. Particularly significant was the conversion of 52 ha of agricultural land to vegetation, resulting in heightened complexity and fragmentation in vegetation patterns. Additionally, the CA of lakes and rivers decreased following the establishment of the park, while the CA and NP of bare land presented significant increases. These findings suggest that rapid urbanization significantly influences the spatial–temporal dynamics of wetland landscape patterns. Consequently, it is imperative for society to prioritize the restoration and protection of urban constructed wetlands. [ABSTRACT FROM AUTHOR]

The degradation of urban ecology, particularly in metropolitan areas distinguished by dense populations and impervious surfaces, presents a worldwide challenge linked to swift urban expansion. Despite extensive documentation of urbanization’s impact on broad regions or specific urban ecosystems over defined time periods, there remains a scarcity of studies investigating the spatiotemporal dynamics of landscape pattern (LP) changes in specific ecosystems at small-to-medium scales within inland megacities as a response to urbanization. Therefore, this work focused on the Bailuwan Wetland Park (BWP) in Chengdu, an inland megacity in southwestern China. Employing satellite imagery data from selected years spanning the previous decade (2010–2021, encompassing 2010, 2012, 2015, 2018, and 2021), this investigation delved into the influences of urbanization on the LP over various time-frames and across different land use/land cover (LULC) types. Our study revealed that urbanization has a significant impact on the patch-/landscape-level characteristics, including the class area (CA), number of patches (NP), patch density (PD), percentage of landscape (PLAND), aggregation index (AI), contagion index (CONTAG), largest patch index (LPI), landscape shape index (LSI), fractal dimension index (FRAC_MN), Shannon’s diversity (SHDI), and evenness index (SHEI). Over the period from 2010 to 2021, NP and PD experienced notable increases, while landscape shape (LSI/FRAC_MN) exhibited greater complexity and fragmentation (PLAND) intensified. Further, landscape heterogeneity (AI/CONTAG) and diversity (SHDI/SHEI) decreased. Particularly significant was the conversion of 52 ha of agricultural land to vegetation, resulting in heightened complexity and fragmentation in vegetation patterns. Additionally, the CA of lakes and rivers decreased following the establishment of the park, while the CA and NP of bare land presented significant increases. These findings suggest that rapid urbanization significantly influences the spatial–temporal dynamics of wetland landscape patterns. Consequently, it is imperative for society to prioritize the restoration and protection of urban constructed wetlands.

Highlights • Removal of vegetation in stormwater retention basins degrades water quality. • Removal of vegetation in stormwater retention basins increases cumulative GHG flux. • Constructed wetlands have lower GHG emissions compared to stormwater basins. • Constructed wetlands improve water quality compared to conventional stormwater basins. Abstract The city of Winnipeg (Manitoba, Canada) has numerous conventional stormwater retention basins to attenuate stormwater runoff. Significant operational resources are applied to control the proliferation of aquatic macrophytes and filamentous algal mats in these conventional stormwater retention basins to meet the aesthetic expectations of surrounding residents. Recent urban developments in the city of Winnipeg have used constructed wetlands to handle stormwater as opposed to conventional basins. We examined the differences in water quality, greenhouse gas emissions and cumulative greenhouse gas fluxes between conventional stormwater retention basins and urban constructed wetlands. Additionally, we examined how water quality and greenhouse gas emissions were impacted by the removal of submersed aquatic vegetation in conventional stormwater retention basins. Our results indicate large phytoplankton blooms were consistently reduced both pre and post treatment in the urban constructed wetlands (chlorophyll- a = 13 µg l−1 and 33 µg l−1) relative to the untreated conventional stormwater retention basins (chlorophyll- a = 56 µg l−1 and 128 µg l−1) and treated conventional stormwater retention basins (chlorophyll- a = 58 µg l−1 and 405 µg l−1). Mean daily greenhouse gas fluxes were lower pre and post treatment in the urban constructed wetlands (CO 2 eq = 26.5 kg ha−1 d −1 and 53.1 kg ha−1 d −1) relative to the untreated (CO 2 eq = 85.5 kg ha−1 d −1 and 89.0 kg ha−1 d −1) and treated conventional stormwater retention basins (CO 2 eq = 98.5 kg ha−1 d −1 and 129.8 kg ha−1 d −1). Over the 22 week period, mean total basin cumulative CO 2 eq flux was lowest in the urban constructed wetlands (6,447 g ha−1 d −1) compared to the untreated (12,631 g ha−1 d −1) and treated (17,633 g ha−1 d −1) conventional stormwater retention basins. The combined treatments (herbicides and harvesting) applied to the conventional stormwater retention basins to remove aquatic vegetation result in poorer water quality and appear to stimulate methane emissions resulting in noticeably higher cumulative fluxes of greenhouse gases from these basins. The use of urban constructed wetlands in new residential areas should result in enhanced water quality and reduced cumulative greenhouse gas fluxes, while avoiding the cost associated with macrophyte removal. [ABSTRACT FROM AUTHOR]