TY - JOUR
T1 - Changes in soil carbon of pastures after afforestation with mixed species: Sampling, heterogeneity and surrogates
AU - Cunningham, Shaun
AU - Metzeling, K.J.
AU - MAC NALLY, Ralph
AU - THOMSON, Jim
AU - Cavagnaro, Cavagnaro
PY - 2012
Y1 - 2012
N2 - Accurate and efficient estimation of soil C is vital to understanding and monitoring the role of afforestation in C sequestration. Here, we focused on the potential of mixed-species plantings, for which there is negligible information but expanding investment due to their added environmental benefits. We surveyed soil C and N over a representative chronosequence (5–29 years old) of existing plantings, including measurements in the adjacent pastures to account for differences in soil type and land-use history among properties. Vegetation characteristics of the tree plantings were measured to identify potential surrogates for rapid assessment of soil C. Soil C was highly heterogeneous under the plantings and the adjacent pastures, with up to eight cores required to sample adequately a plot of 400 m2. Vegetation surrogates had limited success in predicting soil C after afforestation, with the only strong predictors being tree density and planting age. Three decades of afforestation with mixed species had not led to substantial changes in C concentration or content of the soil. The C:N ratio of soils increased with planting age suggesting that the C becomes more resistant to decomposition after afforestation. Over longer time scales, tree plantings are likely to have larger impacts on the amount and forms of soil C.
AB - Accurate and efficient estimation of soil C is vital to understanding and monitoring the role of afforestation in C sequestration. Here, we focused on the potential of mixed-species plantings, for which there is negligible information but expanding investment due to their added environmental benefits. We surveyed soil C and N over a representative chronosequence (5–29 years old) of existing plantings, including measurements in the adjacent pastures to account for differences in soil type and land-use history among properties. Vegetation characteristics of the tree plantings were measured to identify potential surrogates for rapid assessment of soil C. Soil C was highly heterogeneous under the plantings and the adjacent pastures, with up to eight cores required to sample adequately a plot of 400 m2. Vegetation surrogates had limited success in predicting soil C after afforestation, with the only strong predictors being tree density and planting age. Three decades of afforestation with mixed species had not led to substantial changes in C concentration or content of the soil. The C:N ratio of soils increased with planting age suggesting that the C becomes more resistant to decomposition after afforestation. Over longer time scales, tree plantings are likely to have larger impacts on the amount and forms of soil C.
KW - Afforestation
KW - C:N ratio
KW - Mixed-species plantings
KW - Sampling size
KW - Spatial heterogeneity
KW - Soil surrogates.
U2 - 10.1016/j.agee.2012.05.019
DO - 10.1016/j.agee.2012.05.019
M3 - Article
SN - 0167-8809
VL - 158
SP - 58
EP - 65
JO - Agriculture, Ecosystems and Environment
JF - Agriculture, Ecosystems and Environment
ER -