The impact of forest management methods on the ectomycorrhizal community and implications for forest productivity in needleleaf forests

Sammanfattning: Ectomycorrhizal fungi (ECM) form symbiotic relationships with trees by connecting to the roots, procuring soil nutrients in exchange for carbohydrates, and are an important contributor to plant growth. The forestry practice of clearcutting can be detrimental to the ECM community by removing its source of energy and creating unfavorable soil conditions, acutely reducing ECM diversity. This paper aims to examine existing literature for the effects of clearcutting on the ECM community as well as the potential impact of ECM diversity on plant growth, and attempt to determine if the use of alternate harvesting methods could promote plant growth through preservation of the ECM community. The following research questions will be answered: 1. What are the impacts of clearcutting on the ECM community compared to alternate harvesting methods? 2. How well do ECM correlate with tree growth? 3. Can the conservation of the ECM community through alternate harvesting methods have a positive impact on forest productivity? The results indicate that both clearcutting and dispersed tree retention cause a significant loss of ECM diversity. Retention forest patches can lifeboat the ECM community, however it does not speed up the recolonization of seedlings. Conflicting results indicate both a positive and negative correlation between ECM diversity and plant growth, likely depending on specific circumstances. ECM community composition is more closely linked to plant growth, with species adapted to nutrient turnover being the most important, however whether this extends to clearcut sites is uncertain. The reviewed literature was insufficient to draw a conclusion regarding the benefits of a retained ECM community in terms of forest productivity, however if there is no other mature forest in the vicinity, tree retention patches may be necessary for future recolonization of seedlings.