The movements of Earth in relation to the Sun generate a strong annual cycle of radiation and temperature that further affects other environmental factors such as soil moisture and air humidity. Environmental factors affect physiological processes and therefore, identification and understanding of their nature is… Read More »Abiotic environmental factors
Photosynthesis is the most fundamental process in plants because it provides raw material for growth and stores energy for later use in vital functions. In photosynthesis, the energy of solar radiation is converted into chemical form using atmospheric carbon dioxide and soil water. Meanwhile, oxygen… Read More »Photosynthesis
There are plenty of methods available to measure photosynthesis. The method we use is actually a measurement of the carbon dioxide catch: We enclose a small part of the tree inside a chamber and follow the change of CO2 concentration in the air of this chamber.… Read More »How to measure photosynthesis?
Hyytiälä Forestry Field Station, located in Juupajoki, Southern-Finland, is a unit of the Department of Forest Sciences in the University of Helsinki. Its mission is to enable forestry teaching and research in field conditions. We have collected our data from SMEAR II station, which is… Read More »The measuring station, SMEAR II
The measuring concept is actually quite simple. We place a chamber on a small soil surface area and follow the change in CO2 concentration of the air in this chamber. The efflux of carbon dioxide from soil is usually higher than the photosynthetic uptake of ground… Read More »How to measure soil respiration?
Many years of measurements have provided a lot of information on the behaviour of the forest, how it photosynthesizes, transpires and respires. We know more or less what to expect the tree will do according to the time of the year, the availability of light, the air and soil temperature and the water availability… Read More »How to model photosynthesis?
Years of measurements have produced a lot of information on soil respiration. We know more or less how the respiration rate is related to changing environmental conditions, as plant respiration and soil respiration follows temperature exponentially. Approximately, respiration rates doubles for every 10°C increase in… Read More »How to model soil respiration?
A greenhouse gas is a gas in the atmosphere that absorbs and emits radiation within the thermal infrared range causing the greenhouse effect. Carbon dioxide (CO2) is one of the chief greenhouse gases. Its concentration has increased as a result from fossil fuel emissions (i.e.… Read More »Forests
The dynamics of a boreal forest throughout the year is strongly marked by the seasonality of the subarctic climate, which is the climatic area in the world where boreal forests thrive. In this area, forests typically experience a long cold season and a relatively short… Read More »Year in a forest
Species composition in forests is mainly driven by climate (which determines air temperature), and by latitude (which determines light intensity). However, natural plant communities influence the present environment as well. Succession describes these natural changes in an ecosystem. Plant species, especially trees, change the air… Read More »Lifetime of a forest