Forest soil rehabilitation with tillage and wood waste enhances seedling establishment but not height after 8 years

Abstract

We evaluated soil conditions of rehabilitated log landings in the Interior Douglas-fir biogeoclimatic zone of British Columbia during the first 3 years after treatment and the growth of lodgepole pine ( Pinus contorta Dougl. ex Loud. var. latifolia Engelm.) on these log landings over 8 years. Rehabilitation treatments included combinations of tillage and the addition of either stockpiled topsoil or one of three organic amendments: hog fuel, sort-yard waste, and a wood waste – biosolids compost. The woody amendments were either applied as a surface mulch or incorporated into the soil after tillage. Tillage and addition of wood waste reduced soil bulk density and increased carbon content. Daytime soil temperatures in summer were lower under a hog fuel mulch than for the other treatments. The plots receiving hog fuel also had higher soil moisture content. One year after treatment, soil mechanical resistance for untreated soils, and those that were simply tilled, exceeded 2500 kPa for much of the growing season. Plots receiving wood waste had lower mechanical resistance. Use of wood waste in rehabilitation improved soil conditions and contributed to improved survival rates for planted lodgepole pine seedlings. Height growth after 8 years was not significantly affected by the treatments.

Using woody organic matter amendments to increase water availability and jump‐start soil restoration of desertified grassland soils of Ningxia, China

“…Indeed, incorporation of wood can enhance several important soil properties. Surface applications, such as mulch used in landscaping and coarse woody debris on forest floors (Bulmer et al ), have been shown to increase soil moisture. Less is known about the role or mechanisms by which incorporation of coarse wood chips into the soil can influence soil moisture regimes.…”

Impact of Waste Materials and Organic Amendments on Soil Properties and Vegetative Performance

“…Log yard fines (LYF) can increase water holding capacity and porosity [6] but have also been shown to reduce crop performance due to nitrogen immobilization [7]. For this reason, biosolids are often mixed with LYF and other wood byproducts as a means to reduce C : N and maintain nitrogen availability [8,9]. Others have utilized agricultural limestone or wood ash in biosolids mixtures to reduce metal bioavailability [3,10].…”

Relative bulk density as a measure of compaction and its influence on tree height

“…These areas may be unproductive unless soil rehabilitation is carried out. Trees growing on compacted soil are generally characterized by reduced root elongation (Whalley et al 1995) and, sometimes, by reduced height growth (Greacen and Sands 1980;Ares et al 2007;Bulmer et al 2007), but predictability varies. The variation in tree growth responses reported in different studies could have been caused by selection of compaction indicators that were not always successful in describing the relationship between soil compaction and tree growth or by the fact that compaction treatments did not reach growth-limiting levels in some studies.…”