Initial soil respiration response to biomass harvesting and green-tree retention in aspen-dominated forests of the Great Lakes region

Valerie J. Kurth; John B. Bradford; Robert A. Slesak; Anthony W. D’Amato

doi:10.1016/j.foreco.2014.05.052

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Initial soil respiration response to biomass harvesting and green-tree retention in aspen-dominated forests of the Great Lakes region

Valerie J. Kurth·John B. Bradford·Robert A. Slesak·Anthony W. D’Amato

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Abstract

Contemporary forest management practices are increasingly designed to optimize novel objectives, such as maximizing biomass feedstocks and/or maintaining ecological legacies, but many uncertainties exist regarding how these practices influence forest carbon (C) cycling. We examined the responses of soil respiration (R s ) to biomass harvesting and green-tree retention in an effort to empirically assess their impacts on C cycling. We measured R s and soil microclimatic variables over four growing seasons following implementation of these management practices using a fully replicated, operational-scale experiment in aspen-dominated forests in northern Minnesota. Treatments included three levels of biomass removal within harvested areas: whole-tree harvest (no slash deliberately retained), 20% slash retained, and stem-only harvest (all slash retained), and two levels of green-tree retention: 0.1 ha aggregate or none. The relative amount of biomass removed had a negligible effect on R s in harvested areas, but treatment effects were probably obscured by heterogeneous slash configurations and rapid post-harvest regeneration of aspen in all of the treatments. Discrete measurements of R s and soil temperature within green-tree aggregates were not discernible from surrounding harvested areas or unharvested control stands until the fourth year following harvest, when R s was higher in unharvested controls than in aggregates and harvested stands. Growing season estimates of Rs showed that unharvested control stands had higher R s than both harvested stands and aggregates in the first and third years following harvest. Our results suggest that retention of larger forest aggregates may be necessary to maintain ecosystem-level responses similar to those in unharvested stands. Moreover, they highlight the innate complexity of operational-scale research and suggest that the initial impacts of biomass harvest on R s may be indiscernible from traditional harvest in systems where incidental breakage is high.

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Forest Ecology and Management Article

Source-reported bounding extent: 41.4° to 48.85° latitude; -92.11° to -76.3° longitude. This indicates report coverage, not an exact sampling location. View area on OpenStreetMap.

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Valerie J. Kurth, John B. Bradford, Robert A. Slesak, Anthony W. D’Amato. 2014. Initial soil respiration response to biomass harvesting and green-tree retention in aspen-dominated forests of the Great Lakes region. https://doi.org/10.1016/j.foreco.2014.05.052

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