The Excel sheet contains three phenological data sets for leaf bud burst of bírch, and flowering ... more The Excel sheet contains three phenological data sets for leaf bud burst of bírch, and flowering on bird cherry and rown, collected in Finland since 1848 and covering gepgraphically Southers and Central Finland. Data was collected by layman members of the FInnish Society of Science and Letters, and more lately the Zoological Museum of University of Helsinki.<br><br>Contact: tapio.linkosalo@iki.fi, Jari.Valkama@Helsinki.fi (Zoological Museum)<br><br>
Cells are the basic functional units in forest ecosystems. Plants have strong cell wall, formed b... more Cells are the basic functional units in forest ecosystems. Plants have strong cell wall, formed by cellulose and lignin. Cell membrane isolates the cell from its surroundings, starch acts as storage and enzymes enable synthesis of new compounds. Membrane pumps allow penetration of cell membrane and pigments capture of light energy. We call enzymes, membrane pumps and pigments as functional substances. The biochemical regulation system changes the concentrations and activities of the functional substances: In summer, metabolism is very active, but in winter, vegetation is dormant and tolerates low temperatures. The action of the biochemical regulation system generates emergent regularities in the functional substances, called the state of the functional substances. The effect of environmental factors on metabolism is built in the complex chain of enzymes, membrane pumps and pigments, acting in each metabolic task. The process-specific state of functional substances and the environmental factors determine the rate of each metabolic process. Microbes have dominating role in the soil. Together with soil fauna, microbes break down macromolecules with extracellular enzymes to small molecules that can penetrate the microbial cell membrane through membrane pumps. The microbial metabolism utilises the small carbon-rich molecules for the energy needs, growth and synthesis of the extracellular enzymes.
Phenological models constructed from observations of one species are often extrapolated to predic... more Phenological models constructed from observations of one species are often extrapolated to predict the phenology of other species. In this study, time series of the flowering and bud burst of several boreal zone trees were collected. The observation series were regressed against each other in pairs to test mutual variation. In addition, two models of phenology, one based on chilling requirement, and the other assuming ontogenetic development starting from a signal from the light climate were fitted to the phenological time series. The root mean square error of the regression models forecasting one observation series with another was quite constant for all event pairs, and the smaller the closer in time the events took place. It seems that different plant species react to climate variables in a similar manner, thus the use of the same models for different species and phenomena is justified. The light climate triggered model, albeit more simple, gave estimates that were better than those of the regression models between the events, while the average residuals of the estimates from the chilling triggered model were considerably larger. It was concluded that the chilling requirement component was redundant for prediction accuracy in the spring phenology models of boreal trees.
We combine a process-based growth model for even-aged Norway spruce (Picea abies (L.) Karst.) wit... more We combine a process-based growth model for even-aged Norway spruce (Picea abies (L.) Karst.) with economics and optimization. Carbon storage is subsidized based on stand growth and product decay. We include detailed optimized thinnings and timber quality features and present cost functions for stand-level CO2 storage. In contrast to earlier studies, our results suggest that changing thinning strategies and postponing thinnings are at least as important as lengthening the rotation period when considering economically efficient carbon storage. The role of thinning is most important in less fertile sites. Contrary to the generic Faustmann model, a higher interest rate increases rotation length on our fertile site. Including carbon release from decaying timber products as reductions from carbon subsidies only has minor effects on optimal solutions. The fertile site stores more discounted carbon. However, with a 1% interest rate, the less fertile site is cost-efficient up to 13 CO2 t·ha−1, and with a 3% interest rate, it is cost-efficient up to 14 CO2 t·ha−1. After these points, carbon storage on the fertile site becomes cheaper. The economic costs of carbon storage suggest that it is optimal to apply carbon storage in Norway spruce forests to meet greenhouse gas reduction commitments.
City trees planted in parks and along streets are typically grown to large size in nurseries befo... more City trees planted in parks and along streets are typically grown to large size in nurseries before being transplanted to their final growing sites. According to tendering rules within the European Union (EU), any business may compete for public contracts in any EU country, and this applies to purchases of valuable lots of nursery trees. There is however a risk of poor transplanting success if the trees are imported from very distant locations with a different pace of spring development. The aim of this study was to implement a Thermal Time model to predict the spring development of Tilia trees to find out in which geographical area the spring development is sufficiently similar to conditions in southern Finland, so that the success of transplantation of the trees is not unduly risked. We used phenological observations collected at the International Phenological Gardens (IPGs) over the whole of Europe, together with ERA-Interim weather data to estimate the model parameters, and then used the same date to predict the onset of leaf unfolding ofTilia during the years 1980 to 2015. Producing maps of phenological development of Tilia, we concluded that there are no large risks of frost damage if tree import area is limited to northern parts of Baltics or to the west coast of Scandinavia.
... taitto/ Text layout: Ilkka Kangasperko Kansikuva/ Cover picture: Tapio Linkosalo Kielentarkas... more ... taitto/ Text layout: Ilkka Kangasperko Kansikuva/ Cover picture: Tapio Linkosalo Kielentarkastus/ Revision of English: Roderick McConchie ... Työssä käytettiin kahta kevätfenologiaa selittävää mallia, joista ensim-mäinen (Sarvas 1972, 1974) aloittaa ontogeneettisen kehityksen ...
The Excel sheet contains three phenological data sets for leaf bud burst of bírch, and flowering ... more The Excel sheet contains three phenological data sets for leaf bud burst of bírch, and flowering on bird cherry and rown, collected in Finland since 1848 and covering gepgraphically Southers and Central Finland. Data was collected by layman members of the FInnish Society of Science and Letters, and more lately the Zoological Museum of University of Helsinki.<br><br>Contact: tapio.linkosalo@iki.fi, Jari.Valkama@Helsinki.fi (Zoological Museum)<br><br>
Cells are the basic functional units in forest ecosystems. Plants have strong cell wall, formed b... more Cells are the basic functional units in forest ecosystems. Plants have strong cell wall, formed by cellulose and lignin. Cell membrane isolates the cell from its surroundings, starch acts as storage and enzymes enable synthesis of new compounds. Membrane pumps allow penetration of cell membrane and pigments capture of light energy. We call enzymes, membrane pumps and pigments as functional substances. The biochemical regulation system changes the concentrations and activities of the functional substances: In summer, metabolism is very active, but in winter, vegetation is dormant and tolerates low temperatures. The action of the biochemical regulation system generates emergent regularities in the functional substances, called the state of the functional substances. The effect of environmental factors on metabolism is built in the complex chain of enzymes, membrane pumps and pigments, acting in each metabolic task. The process-specific state of functional substances and the environmental factors determine the rate of each metabolic process. Microbes have dominating role in the soil. Together with soil fauna, microbes break down macromolecules with extracellular enzymes to small molecules that can penetrate the microbial cell membrane through membrane pumps. The microbial metabolism utilises the small carbon-rich molecules for the energy needs, growth and synthesis of the extracellular enzymes.
Phenological models constructed from observations of one species are often extrapolated to predic... more Phenological models constructed from observations of one species are often extrapolated to predict the phenology of other species. In this study, time series of the flowering and bud burst of several boreal zone trees were collected. The observation series were regressed against each other in pairs to test mutual variation. In addition, two models of phenology, one based on chilling requirement, and the other assuming ontogenetic development starting from a signal from the light climate were fitted to the phenological time series. The root mean square error of the regression models forecasting one observation series with another was quite constant for all event pairs, and the smaller the closer in time the events took place. It seems that different plant species react to climate variables in a similar manner, thus the use of the same models for different species and phenomena is justified. The light climate triggered model, albeit more simple, gave estimates that were better than those of the regression models between the events, while the average residuals of the estimates from the chilling triggered model were considerably larger. It was concluded that the chilling requirement component was redundant for prediction accuracy in the spring phenology models of boreal trees.
We combine a process-based growth model for even-aged Norway spruce (Picea abies (L.) Karst.) wit... more We combine a process-based growth model for even-aged Norway spruce (Picea abies (L.) Karst.) with economics and optimization. Carbon storage is subsidized based on stand growth and product decay. We include detailed optimized thinnings and timber quality features and present cost functions for stand-level CO2 storage. In contrast to earlier studies, our results suggest that changing thinning strategies and postponing thinnings are at least as important as lengthening the rotation period when considering economically efficient carbon storage. The role of thinning is most important in less fertile sites. Contrary to the generic Faustmann model, a higher interest rate increases rotation length on our fertile site. Including carbon release from decaying timber products as reductions from carbon subsidies only has minor effects on optimal solutions. The fertile site stores more discounted carbon. However, with a 1% interest rate, the less fertile site is cost-efficient up to 13 CO2 t·ha−1, and with a 3% interest rate, it is cost-efficient up to 14 CO2 t·ha−1. After these points, carbon storage on the fertile site becomes cheaper. The economic costs of carbon storage suggest that it is optimal to apply carbon storage in Norway spruce forests to meet greenhouse gas reduction commitments.
City trees planted in parks and along streets are typically grown to large size in nurseries befo... more City trees planted in parks and along streets are typically grown to large size in nurseries before being transplanted to their final growing sites. According to tendering rules within the European Union (EU), any business may compete for public contracts in any EU country, and this applies to purchases of valuable lots of nursery trees. There is however a risk of poor transplanting success if the trees are imported from very distant locations with a different pace of spring development. The aim of this study was to implement a Thermal Time model to predict the spring development of Tilia trees to find out in which geographical area the spring development is sufficiently similar to conditions in southern Finland, so that the success of transplantation of the trees is not unduly risked. We used phenological observations collected at the International Phenological Gardens (IPGs) over the whole of Europe, together with ERA-Interim weather data to estimate the model parameters, and then used the same date to predict the onset of leaf unfolding ofTilia during the years 1980 to 2015. Producing maps of phenological development of Tilia, we concluded that there are no large risks of frost damage if tree import area is limited to northern parts of Baltics or to the west coast of Scandinavia.
... taitto/ Text layout: Ilkka Kangasperko Kansikuva/ Cover picture: Tapio Linkosalo Kielentarkas... more ... taitto/ Text layout: Ilkka Kangasperko Kansikuva/ Cover picture: Tapio Linkosalo Kielentarkastus/ Revision of English: Roderick McConchie ... Työssä käytettiin kahta kevätfenologiaa selittävää mallia, joista ensim-mäinen (Sarvas 1972, 1974) aloittaa ontogeneettisen kehityksen ...
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