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Litter Input Controls on Soil Carbon in a Temperate Deciduous Forest
Author(s) -
Bowden Richard D.,
Deem Lauren,
Plante Alain F.,
Peltre Clément,
Nadelhoffer Knute,
Lajtha Kate
Publication year - 2014
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/sssaj2013.09.0413nafsc
Subject(s) - litter , plant litter , temperate climate , deciduous , soil horizon , environmental science , soil carbon , agronomy , soil organic matter , temperate rainforest , soil water , forest floor , chemistry , zoology , nutrient , ecosystem , ecology , soil science , biology
Above‐ and belowground litter inputs in a temperate deciduous forest were altered for 20 yr to determine the importance of leaves and roots on soil C and soil organic matter (SOM) quantity and quality. Carbon and SOM quantity and quality were measured in the O horizon and mineral soil to 50 cm in five treatments (control, double litter [DL], no litter [NL], no roots [NR], no inputs [NI]). After two decades of doubled litter addition, soil C and SOM did not increase. However, leaf litter exclusions reduced soil C (O and mineral horizons combined) by 24% in NL and 33% in NI treatments. In the mineral soil, the largest declines occurred in the 0‐ to 10‐cm depth (0.93–2.01 kg C m −2 ), although losses were observed throughout the entire solum. The NR treatments showed no losses of C. Thermal characterization of SOM quality differed among treatments in the 0‐ to 10‐cm depth. Patterns of CO 2 evolution during SOM combustion revealed differences in SOM quality between surface and deeper horizons. Our work shows that the sources of litter are important in controlling soil C. Leaf litter made important contributions to maintaining current stocks of soil C; increased leaf litter did not increase soil C, but decreases in litter inputs resulted in rapid soil C declines. Root litter may ultimately provide more stable sources of soil C. Management activities or environmental alterations that decrease litter inputs in mature forests can lower soil C content; however, increases in forest productivity and the resulting increased litter production seem unlikely to increase soil C sequestration.