Vegetation community composition in wetlands created following oil sand mining in Alberta, Canada

Ultrashort-term responses of riparian vegetation restoration to adjacent cycles of ecological water conveyance scheduling in a hyperarid endorheic river basin

The management of ecological water conveyance (EWC) can allow riparian vegetation communities to survive the threat of degradation in hyperarid inland areas and promote the health of groundwater-recharged riparian ecosystems. However, the ultrashort-term effects of periodic EWC scheduling on riparian vegetation remain unclear. This study explored the spatiotemporal differentiation in species structure (herbs, shrubs, and trees), diversity (measured by the Simpson, Shannon-Wiener, Pielou, and Margalef indices), stability (evaluated via Godron fitting distances and abundance-biomass comparison curves), and integrity (proxied by the vegetation-based index of biotic integrity) of vegetation communities in the downstream Heihe River Basin, China. Empirical orthogonal function, Pearson correlation, canonical correspondence analysis (CCA), and partial CCA methods were used to evaluate the effects of dominant habitat environmental factors from the hydrogeographic features, soil physicochemical properties, and anthropogenic impacts. The results showed that the riparian vegetation community diversity, stability, and integrity varied moderately to slightly with hierarchical distance from near wetlands (<200 m; containing mainly herbs) to far desert edges (>800 m; occupied by shrubs/subshrubs). The middle transition zone (200-800 m; occupied mostly by trees/subtrees) had the best diversity and integrity but relatively poor stability. The most significant influencing factors were EWC and soil moisture. The simple diversity, fair-level integrity, and disturbed but not irreversibly damaged stability of the vegetation community were generally improved by 14.82%, 20.33%, and 30.57%, respectively, in the pre-EWC period but worsened in the post-EWC period. The difference in spatially distributed EWC quantities caused more apparent vegetation restoration in high water-supplied subareas where certain biological community instability existed. Therefore, adequate EWC management can be considered a prerequisite for the maintenance of high richness and structural stability in local communities and requires a good balance between interregional vegetation abundance and enhanced environmental tolerance.

Biodiversity Impact of Green Roofs and Constructed Wetlands as Progressive Eco-Technologies in Urban Areas

The total amount of sealed surfaces is increasing in many urban areas, which presents a challenge for sewerage systems and wastewater treatment plants when extreme rainfall events occur. One promising solution approach is the application of decentralized eco-technologies for water management such as green roofs and constructed wetlands, which also have the potential to improve urban biodiversity. We review the effects of these two eco-technologies on species richness, abundance and other facets of biodiversity (e.g., functional diversity). We find that while green roofs support fewer species than ground-level habitats and thus are not a substitute for the latter, the increase in green roof structural diversity supports species richness. Species abundance benefits from improved roof conditions (e.g., increased substrate depth). Few studies have investigated the functional diversity of green roofs so far, but the typical traits of green roof species have been identified. The biodiversity of animals in constructed wetlands can be improved by applying animal-aided design rather than by solely considering engineering requirements. For example, flat and barrier-free shore areas, diverse vegetation, and heterogeneous surroundings increase the attractiveness of constructed wetlands for a range of animals. We suggest that by combining and making increasing use of these two eco-technologies in urban areas, biodiversity will benefit.