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Stormwater ponds (SP) are increasingly used for water management along roads and in urban environments. How these infrastructures compare to natural wetlands in terms of biodiversity remains unclear, however. Studies to date have evaluated the subject in general terms, without considering the different zones in SP and wetlands (from aquatic, at the pond edge, to terrestrial, at the upper bank) or other local and regional factors. In this project, we aimed to compare the taxonomic diversity and composition of plant communities established in four different zones of SP with that in either roadside or remote natural wetlands. We also evaluated the effect of various local and regional factors on those communities. Our results show that, globally, the species composition of the lower, wetter zones was similar between SP and natural wetlands, especially roadside wetlands, while higher, drier zones showed significant differentiation. Factors explaining observed differences between SP and both roadside and remote natural wetlands were water level fluctuations, road proximity, slope, and age of the SP. Stormwater ponds also exhibited lower beta diversity than both types of wetlands. Nonetheless, our study suggests that with some modifications in their design, SP have the potential to harbour more wetland plant communities. [ABSTRACT FROM AUTHOR]

Questions: The latitudinal biodiversity gradient; i.e., the increase in biodiversity towards the equator, is one of the most prominent biodiversity patterns. Nevertheless, many questions remain to be answered about the influence of multiple environmental factors on the latitudinal biodiversity gradient, especially for mosses, and the functional diversity of mosses and vascular plants. This study aims at evaluating the influence of latitude, climate, environmental variables, and habitat types (bog vs fen) on taxonomic and functional diversity (α‐diversity and β‐diversity) and the composition of vascular plant and moss species. Location: 49° N to 55° N in Northwestern Quebec, Canada. Taxon: Mosses, vascular plants. Methods: We used a database containing 376 phytosociological plots (400 m2) sampled in boreal peatlands located along a 600‐km latitudinal gradient. We evaluated changes in α‐diversity and β‐diversity in response to latitude, longitude, climate, and local abiotic variables for both taxonomic groups using linear mixed effect models. We evaluated the effects of these variables on taxonomic and functional composition using variance partitioning by redundancy analysis. Results: Moss diversity increased with latitude, although the effects were masked by environmental variables, whereas vascular plant diversity decreased with latitude in fens and did not vary with latitude in bogs. We observed a decrease in taxonomic and functional uniqueness with latitude. Moss and vascular plant taxonomic and functional composition were primarily structured by contrasting local conditions in bogs and fens, whereas climatic variations along the latitudinal gradient played a secondary role. Conclusions: Our results highlight the contrasting biodiversity patterns in both peatland types and the importance of local habitat conditions in structuring vascular plant and moss diversity. These patterns varied depending on the diversity indicator used, as α‐ and β‐diversity and functional and taxonomic diversity were often decoupled. Future studies should therefore include more than one diversity indicator and consider the differences between ecosystems and taxon groups. [ABSTRACT FROM AUTHOR]

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We have compiled a large dataset of peat and soil cores from temperate and boreal regions of eastern Canada to develop a simple field method for estimating the mass of soil organic carbon (SOC) stored in undisturbed wetlands (peatlands, swamps and marshes). We show that it is possible to predict the SOC mass in different wetland types by measuring the organic-rich soil layer thickness in the field. Using this new dataset, we found that SOC mass can be estimated either by using the linear regression equation between peat or soil thickness and SOC mass or by multiplying peat or soil thickness by a mean SOC density. We also show that SOC mass can be estimated by determining the degree of peat humification in the northern peatlands investigated. In this dataset, the precision of estimates is higher for peatlands than mineral wetlands (marshes and swamps), mainly due to the lack of empirical soil core data. The simple approach proposed here could be applied in different wetland regions worldwide where carbon density data from soil cores are available. This cost- and timeefficient method could benefit regional or national-scale carbon inventories. [ABSTRACT FROM AUTHOR]