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Effects Of Calcium Silicate Treatment On The Composition Of Forest Floor Organic Matter In A Northern Hardwood Forest Stand, Ankit Balaria, Chris E. Johnson, Peter M. Groffman, Melany C. Fisk

Civil and Environmental Engineering

Calcium amendment can help improve forest sustainability in stands that have been impacted by chronic acid deposition. An important component of this improvement is the stimulation of the microbial activity that supports ecosystem nutrient cycling processes. To test the hypothesis that Ca treatment alters the structure and solubility of organic matter substrates, an important driver of microbial activity, we investigated the effect of wollastonite (CaSiO₃) treatment on soil organic matter (SOM) and hot-water-extractable organic matter (HWEOM). We found a decrease in the HWEOM content of forest floor soils within two years of treatment with a high dosage of …

Effects Of Calcium Treatment On Forest Floor Organic Matter Composition Along An Elevation Gradient, Ankit Balaria, Chris E. Johnson, Peter M. Groffman

Civil and Environmental Engineering

Calcium amendment is a restorative option for nutrient-depleted, acidic soils in the forests of the northeastern United States. We studied the effects of watershed-scale wollastonite (CaSiO₃) application on the structural composition of soil organic matter (SOM) and hot-water extractable organic matter (HWEOM) at the Hubbard Brook Experiment Forest in New Hampshire 7-9 years after treatment, along an elevation gradient. Soils in the high-elevation spruce/fir/birch (SFB) zone contained significantly greater amounts of HWEOM compared to lower elevation hardwood soils, likely due to differences in litter quality and slower decomposition rates in colder soils at higher elevation. The only significant …

Compositional Characterization Of Soil Organic Matter And Hot-Water Extractable Organic Matter In Organic Horizons Using A Molecular Mixing Model, Ankit Balaria, Chris E. Johnson

Civil and Environmental Engineering

Purpose Microbial decomposition of soil organic matter (SOM) is generally believed to be heterogeneous, resulting in the preferential loss of labile compounds such as carbohydrates and proteins and the accumulation of recalcitrant compounds such as lipids and lignin. However, these fractions are difficult to measure directly in soils. We examined patterns in the biomolecular composition of SOM and hot-water-extractable organic matter (HWEOM) by using a molecular mixing model (MMM) to estimate the content of carbohydrates, protein, lipids, and lignin.

Materials and methods Organic-horizon soils from Spodosols at the Hubbard Brook Experimental Forest in New Hampshire, USA were analyzed for this …

Effects Of Calcium Addition On Structure And Bioavailability Of Soil Organic Matter, Ankit Balaria

Civil and Environmental Engineering - Dissertations

The northeastern USA has a long history of acid rain, which has impacted soil fertility and raised concerns about the sustainability of the forests in the region. To facilitate recovery of these forests, calcium addition, in the form of wollastonite, was evaluated as a remedial tool at Hubbard Brook Experimental Forests in New Hampshire, USA. In order to study the effects of these amendments on soil organic matter and soil microbes, I characterized the structural chemistry of soil organic matter (SOM) and its hot-water extractable organic matter (HWEOM) fraction for Hubbard Brook soils and studied the changes in the structure …