Abstract
Coarse woody debris (CWD) is an important component of natural forests and is now being used in reclaiming oil sands land to control erosion, enhance diversity, and function as longer term storage of organic matter. However, the impact of woody debris on reclaimed ecosystems may vary depending on the amount applied and the soil it is applied to. We studied the impact on the plant community (including tree regeneration and understory plants) and soil properties of four levels of CWD cover (None, Low, Moderate, High) on two reclamation soils (forest floor-mineral mix and peat-mineral mix) and natural post-fire soils. Significant differences were observed among soil types in terms of the plant community and soil properties but fewer differences were attributable to CWD. However, overall native plant species’ diversity and abundance decreased with High CWD while cover of non-native species on the reclaimed soils greatly decreased with Low CWD. Natural seedling regeneration density of trembling aspen was unaffected by CWD on both reclamation soil types. The soil nutrient supply rates and soil moisture were significantly different among soil types but there were no differences among debris treatments while soil temperature decreased with CWD. Overall, a Low (up to 30% ground cover) woody debris application appears to be optimal for maintaining native plant species diversity and abundance while controlling undesirable plant species.
Highlights
Coarse woody debris (CWD) plays many critical roles in the functioning of forest ecosystems, which varies from understory plant establishment to nutrient cycling
This application of CWD has been used as an erosion control measure in oil sands reclamation but there may be other ecological benefits related to the plant community and soil properties, which deserve further study
The experimental design for this study consists of three site types (PMM and forest floor-mineral mix (FFMM) from the reclamation site and Fire as the natural benchmark comparison) and four levels of CWD (None, Low, Moderate, High) with nine randomly located sampling blocks in peat-mineral mix (PMM), 11 in FFMM, and 10 in Fire
Summary
Coarse woody debris (CWD) plays many critical roles in the functioning of forest ecosystems, which varies from understory plant establishment to nutrient cycling. Other impacts of CWD in forests include a long-term carbon and nutrient store [7,8], a control on greenhouse gas emissions from soil [9], and habitat for many different species of both vertebrate and invertebrate wildlife [10,11] Given this important ecological role of CWD in forests, there is greater interest in expanding the use of CWD as a site amendment in land reclamation projects following oil sands mining. Smaller-sized trees and undesirable species may be available for use in reclamation activities as a surface amendment to be applied on top of the cover soils This application of CWD has been used as an erosion control measure in oil sands reclamation but there may be other ecological benefits related to the plant community and soil properties, which deserve further study. We wanted to refine these impacts based on the amount of CWD present on the site to help inform land reclamation practitioners who are applying, or would like to apply, CWD to their sites
Sign-in/Register to view highlights & summary 
Published Version (
Free)
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call