Tue, Aug 03, 2021:On Demand
Background/Question/Methods
Urban green spaces provide important ecological, environmental, and cultural services, including biodiversity conservation and human wellbeing. However, a large portion of the urban greenspaces are often managed as highly manicured grassy lawns dominated by one or a few perennial grass species (often nonnative) that provide limited ecosystem services like aesthetics and recreation and support significantly less biodiversity. Managing urban green spaces as biodiverse perennial native meadows can have a multitude of ecosystem benefits. Relatively little is known about whether native urban meadows enhance supporting services by improving biodiversity and soil quality compare to lawns. In this study, we systematically sampled two types of green spaces – meadows (recently created three meadows; one created in previous brownfield and two created in previous lawns) and lawns (three lawns) at three different urban locations in Pittsburgh, Pennsylvania, USA. We compare plant species richness (alpha diversity), soil organic matter (SOM), total soil microbial biomass (MBC), and intra-radical arbuscular mycorrhizal (AM) fungal biomass between meadows and lawns. We hypothesized that creating urban meadows and management would increase alpha diversity, SOM, MBC, and AM biomass.
Results/Conclusions Results showed that urban meadows support a significantly higher alpha diversity (p<0.001) compared to lawns, regardless of their location. However, there was a significant effect of green space type (p<0.001) and the location of green spaces (p<0.001) on SOM and MBC in the soil, with higher SOM and MBC in urban lawns. Higher soil organic matter in the lawns suggests that long term management with continuous mowing and leaving aboveground vegetation on the ground help to accumulate soil organic matter compared to recently created meadows, which are not subject to frequent mowing. Greater soil microbial biomass in the lawns was due to a higher proportion of bacterial and saprophytic fungal biomass present in the lawns compared to meadows. In contrast, meadows harbor substantially higher AM (p<0.001) biomass than lawns, suggesting continuous mowing and disturbance in the lawns negatively effect AM biomass. Although SOM and MBC were higher in lawns, urban meadows supported greater plant diversity and AM biomass, which likely support other vital ecosystem services, such as pollinators and soil stability. Since high diversity plant communities such as meadows are critical for stable ecosystem function over time, long-term studies on the relationship between urban green spaces and ecosystem services are needed for the sustainable design and management of urban green spaces for ecosystem multi-functionality.
Results/Conclusions Results showed that urban meadows support a significantly higher alpha diversity (p<0.001) compared to lawns, regardless of their location. However, there was a significant effect of green space type (p<0.001) and the location of green spaces (p<0.001) on SOM and MBC in the soil, with higher SOM and MBC in urban lawns. Higher soil organic matter in the lawns suggests that long term management with continuous mowing and leaving aboveground vegetation on the ground help to accumulate soil organic matter compared to recently created meadows, which are not subject to frequent mowing. Greater soil microbial biomass in the lawns was due to a higher proportion of bacterial and saprophytic fungal biomass present in the lawns compared to meadows. In contrast, meadows harbor substantially higher AM (p<0.001) biomass than lawns, suggesting continuous mowing and disturbance in the lawns negatively effect AM biomass. Although SOM and MBC were higher in lawns, urban meadows supported greater plant diversity and AM biomass, which likely support other vital ecosystem services, such as pollinators and soil stability. Since high diversity plant communities such as meadows are critical for stable ecosystem function over time, long-term studies on the relationship between urban green spaces and ecosystem services are needed for the sustainable design and management of urban green spaces for ecosystem multi-functionality.