Influence of mechanized timber harvesting on soil compaction in northern hardwood forests

Abstract

Evaluating and refining methods to minimize soil compaction during timber harvesting is important for maintaining soil health and long-term forest productivity. This is especially important when harvesting methods change over time. In this study, a hybrid harvesting method was used with the trees cut by one machine, in-forest processing of trees by other machines, and transporting the wood to the roadside by a forwarder on silt loam soils during the summer months. Two methods for sampling soils with mixed horizons in logging trails were developed to determine the baseline values of soil bulk density for longterm monitoring and to compare soils from nonmixed B horizons with those of B horizons from nontrafficked areas. For both methods, paired soil samples, in and outside of logging trails, were collected to determine the difference in bulk density between trails and nontrafficked areas. Soil compaction in trails was greatest where the soils adjacent to trails had low bulk densities and for locations that were closest to landings. These results are important in the context of climate change, as more summer logging is expected to occur in areas traditionally cut in the winter because of longer frost-free periods and more winter precipitation occurring as rain. More logging during the expanding snow-free season could translate to a greater degree of compaction and longer soil recovery times over a larger portion of the forested landscape.

Change in soil carbon, nitrogen, and phosphorus after timber harvesting in northern hardwood forests

“…While we do not have data to compare the amount of slash within and outside of trails, we observed trees being delimbed directly over the trails. For the units of our study, Puhlick and Fernandez (2020) also reported that mean slash biomass in trails ranged from 102 to 166 Mg ha −1 , and photos reveal that slash was concentrated in trails as directed by foresters.…”

“…The reduction in post‐harvest stocks was partially driven by reductions in O horizon fine fraction mass, which could be related to post‐harvest stand and soil conditions that were favorable for decomposition of fine organic materials. While the summer of 2018 (when harvesting took place) was drier in northern Maine compared to 30‐year precipitation trends (Puhlick & Fernandez, 2020), the following summer (when the post‐harvest soil samples were collected) was wetter. This could have resulted in soil moisture conditions that were favorable for decomposition of O horizon fine fraction materials between the time when pre‐ and post‐harvest samples were collected.…”

“…The soils of the installations formed in glacial till, and the soil texture of upper mineral soil horizons tended to be silt loam based on feel and soil taxonomic descriptions. The soil series of both installations are described in detail by Puhlick and Fernandez (2020).…”

Climate change‐triggered land degradation and planetary health: A review

“…Climate change can alter soil porosity through compaction, hardening, sealing, and slaking (breakdown of soil after wetting). It can also lead to the loss of soil organisms like earthworms (Chan, 2011), and shortened recovery times due to longer frost-free periods (Puhlick & Fernandez, 2020).…”