Vegetation Type and Age Drive Changes in Soil Properties, Nitrogen, and Carbon Sequestration in Urban Parks under Cold Climate

Abstract

Urban green spaces provide ecosystem properties fundamental to the provision of ecosystem services, such as the sequestration of carbon and nutrients and serving as a reservoir for organic matter. Although, urban vegetation influences soil physico-chemical properties, it remains unknown whether ecosystem properties depend on plant species portfolios. We tested the influence of three common functional plant groups (evergreen trees, deciduous trees, grass/lawn) for their ability to modify soils in parks of various ages under cold climatic conditions in Finland. We hypothesized that (i) plant functional groups affect soils differently resulting in divergent ecosystem properties, and (ii) that these ecosystem properties also depend on park age. We included 41 urban parks of varying ages (10, 50, and >100 years) and additional control forests. Park soils were sampled for physico-chemical parameters up to 50 cm depth. Our data indicate that plant functional groups modify soils differently, especially between the evergreen and lawn treatments at 50 and >100 year old parks. Soils under evergreen trees had the lowest pH and generally the highest percentage organic matter, percentage total carbon and percentage total nitrogen. Soil pH remained the same, whereas concentrations of organic matter, total carbon and total nitrogen declined by depth. Soils in the reference forests had lower pH but higher percentages organic matter, total carbon, and total nitrogen than those in parks. We estimate that old parks with evergreen trees can store 35.5 and 2.3 kg N m −2 -considerably more than in urban soils in warmer climates. Our data suggest that plant-soil interactions in urban parks, in spite of being constructed environments, are surprisingly similar to those in natural forests.

Soil microbial communities are shaped by vegetation type and park age in cities under cold climate

“…As edaphic conditions in the intermediate and old parks were different from those in young urban parks (Setälä et al ., ), we expected differences in the composition of microbial communities. Our hypothesis was only partly verified, as the intermediate and old parks, irrespective of plant functional group, shared similar soil properties as well as bacterial and fungal communities.…”

“…Even though these parks shared lawn as ground cover, we considered the forested stands with evergreen and coniferous trees – but without a lawn equivalent – as the most relevant control for two reasons: (i) natural grasslands are rare in the boreal taiga belt and (ii) our experiment was primarily designed to compare the effects of trees on the soil microbial community. Our previous analyses have shown that soils in these forest and park sites as well as within the parks differ in their carbon and nitrogen stocks (Setälä et al ., ). In the current study, we focused on biotic soil attributes and hypothesized that:…”

“…Thus, the successional age of the ecosystem and the age of individual plants likely influence microbial communities (Banning et al ., ; Blaško et al ., ; Wu et al ., ), because soil properties including pH, total C and total N tend to change with plant age (Park et al ., ). Similar to natural systems, soil chemical properties can vary in predictable ways with age of development in urban green spaces (Setälä et al ., ) and microbial communities often shift with changes in edaphic conditions (Prescott and Grayston, ; Liu et al ., ). Urban areas have been considered socio‐ecological systems where ecological processes do not necessarily follow those documented in natural systems (Cadenasso et al ., ; Pickett et al ., ).…”

Urban meadows as an alternative to short mown grassland: effects of composition and height on biodiversity

“…, Setälä et al. ). There are also substantial differences in colonization potential as urban grasslands are often poorly connected (Hejkal et al.…”

Soil carbon sequestration in bermudagrass golf course fairways in Lubbock, Texas

“…The lowest mean pH (7.10; neutral) was identified at the 36‐yr‐old golf course, with older golf courses having moderately alkaline pH (80 yr = 7.92; 93 yr = 7.84) and younger golf courses having significantly higher soil pH (13 yr = 8.29; 19 yr = 8.52) when combining both soil depths (Table 4). The upper soil depth was less basic than the lower depth, which may indicate altered soil pH from management inputs or reflect pH reductions from increased SOM content (Ritchie & Dolling, 1985; Setälä et al., 2016). Alkaline soil pH is common to the region because of climatic conditions and carbonate accumulation (Holliday, 1990).…”