Post-harvest impact assessments

Timber harvesting and extraction affect forest ecosystems in profound ways. The impact includes direct and indirect effects on individual plant and animal species, as well as broad changes in ecosystem structure and function. The impact of timber harvesting is a combined result of felling and skidding. The visible marks and physical evidence of harvesting can be measured on the trails and both sides of them. Damage on the ground as a result of harvesting activities which then influences water quality in creeks and rivers in the harvesting compartment, usually occur in proximity to the skid trails or roads. Much of this damage stems from a lack of planning and control of forestry operations.

Planning is an integral component of reduced impact logging and thus an important part of environmentally sound forest harvesting operations. To determine the degree to which a harvesting operation has followed a harvesting plan and met the stated objectives while complying with established standards of practice, a post-harvest assessment should be carried out.

What are harvesting assessments?

Harvesting assessments provide feedback about the quality of forest harvesting "operations and may be undertaken regularly for every harvesting operation or for selected operations chosen at random. Harvesting assessments should be carried out by qualified staff in the presence of the managerial and supervisory personnel responsible for the harvesting operation.

While in-process assessments permit the observation of workers and equipment in action and allow immediate corrective steps to be taken if needed, post-harvest assessments, concentrate on measuring the impacts and the degree to which standard practices have been followed. Such assessments should ideally produce a written report that is sent to the forest management company or agency, relevant government authorities and the logging crews.


The FAO programme on post-harvest assessments aims to share information and experience which will enable countries to properly plan, execute and control improved harvesting practices, thus increasing the value of harvested products and services while reducing forest waste and the environmental impact on forest stands.

Over the next three years, FAO will be focusing on developing guidelines for undertaking post-harvest assessments. These guidelines will be tested using country-specific case studies, the results of which will be published in the case studies.

last updated:  Wednesday, April 23, 2008