Plant and Soil

, Volume 294, Issue 1, pp 219–233

Impacts of forest gaps on soil properties and processes in old growth northern hardwood-hemlock forests

Regular Article

DOI: 10.1007/s11104-007-9248-y

Cite this article as:
Scharenbroch, B.C. & Bockheim, J.G. Plant Soil (2007) 294: 219. doi:10.1007/s11104-007-9248-y

Abstract

We examined the influence of treefall gaps on soil properties and processes in old growth northern hardwood-hemlock forests in the upper Great Lakes region, USA. We found significantly greater solar radiation, soil moisture contents and soil temperatures in gaps compared to adjacent closed canopy plots. Gaps had significantly less exchangeable base cations (K, Ca, and Mg) compared to forest plots in the upper mineral soil (0–25 cm). Gaps also had significantly more dissolved organic N and extractable nitrate at depth (25–50 cm), indicating increased nutrient leaching in gaps. In-situ N mineralization was significantly greater in gaps and edge plots compared to forest plots. We found significantly greater potential N mineralization (measured in the laboratory at 25°C and 40% water holding capacity) in forest compared to gap plots. Microbial biomass N was significantly greater (ca. two-fold) in the gap edge compared to both gaps and closed forest. Using principal component analyses we found that edge plots were positively correlated with all principal components, indicating increased in-situ and potential N mineralization, microbial biomass N, soil NO3 and NH4+, and soil organic matter. The gap edge may be a region of optimal microclimate and substrate to enhance microbial biomass and activity within these forest ecosystems.

Keywords

Old growth forestMicrobial biomassNitrogen mineralizationTreefall gap and edge

Abbreviations

PMWSP

Porcupine Mountains Wilderness State Park

HMC

Huron Mountain Club

PMN

Potential N mineralization

MBN

Microbial biomass N

DON

Dissolved organic N

SOM

Soil organic matter

Nmin

N mineralization (in-situ)

Copyright information

© Springer Science+Business Media B.V. 2007

Authors and Affiliations

  1. 1.Department of Soil ScienceUniversity of WisconsinMadisonUSA