Integrating Species Mixtures in Tree Growth Functions for Forest Development Models in Switzerland (Swiss-SpeMixMod)

• Research unit: COST
• Project number: C14.0041

Key words (English)

Basal area increment; nonlinear mixed-effects model; species mixtures; Switzerland; National Forest Inventory; long-term forest monitoring

Research programs (English)

COST-Action FP1206 - European mixed forests: Integrating Scientific Knowledge in Sustainable Forest Management (EuMIXFOR)

Short description (English)

Mixtures of tree species have recently gained attention in forest science and management for economic and ecological reasons. Increased productivity in mixed vs. mono-specific forests has been found in several European studies. However, such effects are not yet represented in empirical forest scenario models such as MASSIMO, which is used for estimating Switzerland's potential wood supply and for calculations of the forest management reference level in the Swiss Greenhouse Gas Inventory. Thus, the main objective of this project is to quantify the effects of species mixtures on tree growth along Switzerland's environmental gradients, and to prepare this knowledge for the use in forest scenario calculations. The project comprises three statistical approaches: 1) a systematic overview of the distribution of mixed and mono-specific forests is elaborated based on data from the Swiss National Forest Inventory (NFI), 2) effects of species mixtures on tree growth under various environmental conditions are quantified based on nonlinear mixed-effects models fitted to NFI data, and 3) these statistical models including mixture effects are evaluated and improved based on long-term forest inventory data. Since large ecological gradients and diverse forest types are present in Switzerland, we expect that our findings will be of interest for the whole European research community dealing with mixed forests. The developed approaches are intended for the future use in European collaborations.

Further information (English)

Full name of research-institution/enterprise: Swiss Federal Institute for Forest, Snow and Landscape Research WSL Group leader

Partners and International Organizations (English)

AT; BE; BA; BG; HR; CZ; DK; EE; FI; FR; DE; EL; HU; IE; IT; LV; LT; NL; NO; PL; RO; RS; SK; SI; ES; SE; TR; UK; CA; US; AR; MA; DZ; TN; UA

Abstract (English)

Since April 2016, after a cost-neutral delay due to personnel changes and a maternity leave, intensive progress has been achieved in the project Swiss-SpeMixMod. The work on the first step of the scientific work plan presented in the project proposal has successfully started. First descriptive analyses about the frequency of different species mixture types in Switzerland have been conducted, as well as descriptive analyses about their changes between the first (years 1983-1985) and the third (years 2004-2006) National Forest Inventory (NFI). Furthermore the sensitivity of these results to the classification system used for defining species mixtures has been evaluated. These preliminary results were documented in an internal report, which is attached to this scientific report (Mina, M. 2016. Descriptive analysis of Swiss NFI data to identify most frequent mixed and mono-specific forests. Internal report on the project Swiss-SpeMixMod, 10 pages).

References in databases (English)

Swiss Database: COST-DB of the State Secretariat for Education and Research Hallwylstrasse 4 CH-3003 Berne, Switzerland Tel. [phone] Swiss Project-Number: C14.0041