Lo_f, M., D.C. Dey, R.M. Navarro and D.F. Jacobs
In this article, we synthesize the current state-of-knowledge concerning mechanical site preparation for improved tree establishment when carried out in different forest restoration situations, point out critical research gaps and provide some recommendations for future directions. Mechanical site preparation often results in improved seedling survival and growth. However, if not intensive methods with much soil disturbance are used, it is a rather ineffective tool for controlling competing vegetation. Methods such as scarification, mounding and subsoiling also lead to multiple interactions among soil physical and chemical properties that affect plant survival and growth, and it may be difficult to determine the actual cause–effect relationship of any positive seedling responses. Several management objectives such as soil protection and increased biodiversity are many times relevant during forest restoration, and mechanical site preparation methods should be implemented carefully because they can have large impacts on the environment.