Soil productivity\nis essential to the sustained production of ecosystem goods and services and\nmonitoring the impacts of land management is critical for ensuring the\ncontinuation of productive forests.\u00a0 The\nNational Forest Management Act of 1976 (NFMA) mandates monitoring soil property\nchanges following management practices at all national forests, so they \u201cwill\nnot produce substantial and permanent impairment of the land\u201d.\u00a0 The Forest Soil Disturbance Monitoring\nProtocol (FSDMP) was developed by the U.S. Department of Agriculture Forest\nService (USFS) to ensure a standard method for collecting pre- and post-harvest\nsoil monitoring data.\u00a0 Data collected\nfollowing the FSDMP provide temporal and spatial insights into soil recovery\nrates and alteration of soil processes or hydrologic function following\ndisturbance.\u00a0 The objective of this study\nwas to 1) identify site factors and operational harvest impacts that alter\ndynamic soil properties, and 2) outline best management practices that account\nfor these site and operational factors.
\n\nPrior harvested\nstands on the Malheur National Forest in northeastern Oregon, USA were identified\nto reflect a range of soil types, climatic conditions, past timber harvest\nmechanisms and seasonal timing, as well as topographic position (slope,\naspect).\u00a0 Fifty-one stands were selected\nwithin a project area approximately 31,000 hectares\u00a0 and monitored retrospectively to evaluate\nsoil disturbance and site characteristics that influence soil recovery from\ntimber harvests completed within the past 5, 10, 20, or 40 years ago.
\n\nWe found that clay\nand silt content, spring moisture deficit, fall mean maximum temperature as\nwell as interactions between clay x silt content, depth to restrictive layer x\ncoarse fragment content, and silt x depth to restrictive layer had the most influence\non soil disturbance.\u00a0 Important\nmanagement considerations are (1) harvest operations that occurred during\nwinter months resulted in less soil disturbance, (2) greater clay content (relative\nto silt content) decreased the amount of soil disturbance, and (3) soils show a\ntrend toward recovery 10-years after harvest operations are complete.