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Impact of Restoration and Management on Aggregation and Organic Carbon Accumulation in Urban Grasslands
Author(s) -
Yost Jenifer L.,
Egerton-Warburton Louise M.,
Schreiner Kathryn M.,
Palmer Corey E.,
Hartemink Alfred E.
Publication year - 2016
Publication title -
soil science society of america journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.836
H-Index - 168
eISSN - 1435-0661
pISSN - 0361-5995
DOI - 10.2136/sssaj2015.10.0383
Subject(s) - grassland , soil carbon , environmental science , mollisol , total organic carbon , aggregate (composite) , soil science , soil water , agronomy , environmental chemistry , chemistry , materials science , biology , composite material
Core Ideas Few studies have examined SOC accrual in restored urban grasslands. We examined SOC accrual in 14 restored and native grasslands in Chicago. Short‐term (<7 yr) restoration increased microaggregate OC toward levels in native prairies. Longer‐term restoration did not improve total SOC or aggregate OC. Differences in SOC were linked to soil moisture, N, texture, and inputs of C 4 –C among sites. Understanding the patterns of soil organic carbon (SOC) accumulation in restored grasslands is necessary to determine their potential to sequester atmospheric CO 2. Patterns of SOC accrual after grassland restorations are generally based on studies in former agricultural fields, and these studies show an increase in SOC and aggregated‐associated OC over time. In this study, we quantified SOC accrual in a series of restored grasslands situated within the matrix of the Chicago metropolitan region. Soil samples were collected from unmanaged (no restoration), short‐term (<7 yr), and longer‐term restorations (>10 yr) and from native prairie remnants located on Mollisols or Alfisols and analyzed using a combination of physical fractionation (aggregate size) and chemical measurements (organic C [OC], 13 C/ 12 C natural abundance). We found that (i) total SOC declined after restoration and remained significantly lower in restored than unmanaged soils, (ii) patterns of aggregate OC in longer‐term restorations were more similar to those in unmanaged than to prairie sites, and (iii) microaggregate OC levels and C 4 –C inputs into aggregate fractions were significantly higher in short‐ than longer‐term restorations. Thus, an increasing time under management did not enhance SOC accrual. For all sites, path models showed that SOC accrual was correlated with soil N, texture, and moisture, whereas C 4 –C inputs were significant model terms only in short‐term restorations and prairie sites. Taken together, these results indicate the need to consider inter‐relationships among vegetation and soil factors as influences on SOC accrual rather than simply time under management.