Mechanistic explanation of regional variation in forest productivity and growth
Project funded by the Academy of Finland 2004-2007
University of Helsinki, Department of Forest Ecology:
Annikki Mäkelä, Eero Nikinmaa, Remko Duursma, Minna Pulkkinen, Pasi Kolari, Martti Perämäki, Janne Karimäki
Roderick Dewar, Denis Loustau, Celine Meredieu, Alex Bosc, Annabel Porte
The study developed operational methods for the prediction of productivity based on physiological theory and the combined use of appropriate measurements at leaf, canopy, and regional level. Results of the project include summary models predicting the long-term, stand-level productivity from regionally available inputs, derived from physiological processes defined and measured at the shoot level as instantaneous responses to high resolution driving variables, such as light and temperature. The study utilised (1) a variety of models at different scales, and advanced methods to combine the scales, (2) high quality physiological data (photosynthesis, transpiration, eddy covariance, soil, weather) at high temporal resolution, available at shoot and ecosystem level for several years, especially from the Hyytiälä and Värriö SMEAR research stations and from a site in Bordeaux, and (3) aggregated growth and site data, available to this study on a regional basis for the whole of Finland and sites in France.
Dewar RC, Franklin O, McMurtrie RE, Mäkelä A and Valentine HT. 2008. Optimal plant function explains responses to global change. Bioscience.
Duursma R.A., Kolari P., Perämäki M., Nikinmaa E., Hari P., Delzon S., Loustau D., Ilvesniemi H., Pumpanen J., Mäkelä A. 2008. Predicting the decline in daily maximum transpiration rate of two pine stands during drought based on constant minimum leaf water potential and plant hydraulic conductance. Tree Physiology 28, 265-276.
Mäkelä A., Pulkkinen M., Kolari P., Lagergren F., Berbigier B., Lindroth A., Loustau D., Nikinmaa E., Vesala T., Hari P. 2008. Developing an empirical model of stand GPP with the LUE approach: analysis of eddy covariance data at five contrasting conifer sites in Europe. Global Change Biology 14: 98- 108.
Duursma, R.A. and Mäkelä A. 2007. Summary models for irradiance interception and photosynthesis of non-homogeneous canopies. Tree Physiology 27:859-870
Mäkelä A., Kolari P., Karimäki J., Nikinmaa E., Perämäki M. and Hari P. 2006. Modelling five years of weather-driven variation of GPP in a boreal forest. Agriculture and Forest Meteorology 139:382-398.