Concluding remarks

Abstract

Our book covers a wide range of phenomena in boreal forests and in the atmosphere. We combine biological, physical, meteorological, microbiological and chemical knowledge to get a holistic picture of the interactions between boreal forests and climate change. Close interactions between ecologists and physicists have been characteristic of the work done in our research team, called APFE (Aerosol Physics and Forest Ecology). Ecological and physical phenomena have similarities and specific features that make this cooperation fruitful. In addition, modern instrumentation is based on physics and without understanding the basis of measurements, it is impossible to properly utilise new capabilities to gain information from forests. Processes are the engine of interaction between boreal forests and the atmosphere. The processes generate concentration, temperature and pressure differences which are necessary for transport. Physical and chemical processes are spontaneous, i.e., they occur whenever the necessary substances and energy are available. Biological processes, in contrast, need also active substances, enzymes, pigments or membrane pumps which enable or greatly accelerate chemical reactions. Processes in connection with weak transport also accumulate material, such as stable organic compounds in vegetation, aerosols in the air, water in clouds and ammonium ions on soil particles.