TY - JOUR
T1 - Riparian reforestation
T2 - are there changes in soil carbon and soil microbial communities?
AU - Mackay, John
AU - Cavagnaro, T
N1 - Funding Information:
We wish to thank the land-holders for access to their farms. Thanks to Ms. Lisa Oborne for assistance in the field and Dr. Precilla ‘Pree’ Johnson, Dr. EeLing Ng and Ms. Alicia Brown for technical assistance in the laboratory. This research was funded by the Australian Research Council Linkage Program ( LP0990038 ), which included: Victorian Department of Sustainability and Environment , Goulburn-Broken Catchment Management Authority (CMA), Victorian EPA , Kilter Pty Ltd. and the North Central CMA . TRC gratefully acknowledges the ARC for supporting his research via the award of a Future Fellowship ( FT120100463 ).
Publisher Copyright:
© 2016 Elsevier B.V..
PY - 2016/10/1
Y1 - 2016/10/1
N2 - Reforestation of pastures in riparian zones has the potential to decrease nutrient runoff into waterways, provide both terrestrial and aquatic habitat, and help mitigate climate change by sequestering carbon (C). Soil microbes can play an important role in the soil C cycle, but are rarely investigated in studies on C sequestration. We surveyed a chronosequence (0-23 years) of mixed-species plantings in riparian zones to investigate belowground (chemical and biological) responses to reforestation. For each planting, an adjacent pasture was surveyed to account for differences in soil type and land-use history among plantings. Two remnant woodlands were included in the survey as indicators of future potential of plantings. Both remnant woodlands had significantly higher soil organic C (SOC) content compared with their adjacent pastures. However, there was no clear trend in SOC content among plantings with time since reforestation. The substantial variability in SOC sequestration among plantings was possibly driven by differences in soil moisture among plantings and the inherent variability of SOC content among reference pastures adjacent to plantings. Soil microbial phospholipid fatty acids (PLFA, an indicator of microbial biomass) and activities of decomposition enzymes (β-glucosidase and polyphenol oxidase) did not show a clear trend with increasing planting age. Despite this, there were positive correlations between total SOC concentration and microbial indicators (total PLFA, fungal PLFA, bacterial PLFA and activities of decomposition enzymes) across all sites. The soil microbial community compositions (explored using PLFA markers) of older plantings were similar to those of remnant woodlands. There was a positive correlation between the soil carbon:nitrogen (C:N) and fungal:bacterial (F:B) ratios. These data indicate that in order to maximise SOC sequestration, we need to take into account not only C inputs, but the microbial processes that regulate SOC cycling as well.
AB - Reforestation of pastures in riparian zones has the potential to decrease nutrient runoff into waterways, provide both terrestrial and aquatic habitat, and help mitigate climate change by sequestering carbon (C). Soil microbes can play an important role in the soil C cycle, but are rarely investigated in studies on C sequestration. We surveyed a chronosequence (0-23 years) of mixed-species plantings in riparian zones to investigate belowground (chemical and biological) responses to reforestation. For each planting, an adjacent pasture was surveyed to account for differences in soil type and land-use history among plantings. Two remnant woodlands were included in the survey as indicators of future potential of plantings. Both remnant woodlands had significantly higher soil organic C (SOC) content compared with their adjacent pastures. However, there was no clear trend in SOC content among plantings with time since reforestation. The substantial variability in SOC sequestration among plantings was possibly driven by differences in soil moisture among plantings and the inherent variability of SOC content among reference pastures adjacent to plantings. Soil microbial phospholipid fatty acids (PLFA, an indicator of microbial biomass) and activities of decomposition enzymes (β-glucosidase and polyphenol oxidase) did not show a clear trend with increasing planting age. Despite this, there were positive correlations between total SOC concentration and microbial indicators (total PLFA, fungal PLFA, bacterial PLFA and activities of decomposition enzymes) across all sites. The soil microbial community compositions (explored using PLFA markers) of older plantings were similar to those of remnant woodlands. There was a positive correlation between the soil carbon:nitrogen (C:N) and fungal:bacterial (F:B) ratios. These data indicate that in order to maximise SOC sequestration, we need to take into account not only C inputs, but the microbial processes that regulate SOC cycling as well.
KW - C sequestration
KW - Fungi to bacteria ratio
KW - Phospholipid fatty acids (PLFA)
KW - Soil ecology
UR - http://www.scopus.com/inward/record.url?scp=84969749945&partnerID=8YFLogxK
U2 - 10.1016/j.scitotenv.2016.05.045
DO - 10.1016/j.scitotenv.2016.05.045
M3 - Article
SN - 0048-9697
VL - 566-567
SP - 960
EP - 967
JO - Science of the Total Environment
JF - Science of the Total Environment
ER -
