23 research outputs found
Long-term standardized forest phenology in Sweden: a climate change indicator
Because climate change alters patterns of vegetative growth, long-term phenological measurements and observations can provide important data for analyzing its impact. Phenological assessments are usually made as records of calendar dates when specific phase changes occur. Such assessments have benefits and are used in Citizen Science monitoring. However, these kinds of data often have low statistical precision when describing gradual changes. Frequent monitoring of the phenological traits of forest trees and berries as they undergo gradual change is needed to acquire good temporal resolution of transitions relative to other factors, such as susceptibility to frosts, insects, and fungi, and the use of berries as a food resource. Intensive weekly monitoring of the growth of apical and branch buds and the elongation of shoots and leaves on four tree species, and the abundance of flowers and berries of bilberry and lingonberry, has been performed in Sweden since 2006. Here, we present quantitative methods for interpolating such data, which detail the gradual changes between assessments in order to describe average rates of development and amount of interannual variation. Our analysis has shown the active growth period of trees to differ with latitude. We also observed a change in the timing of the maximum numbers of ripening berries and their successive decline. Data from tree phenology assessments can be used to recommend best forestry practice and to model tree growth, while berry data can be used to estimate when food resources for animals are most available
Total ozone from zenith radiance measurements : An empirical model approach
At Vindeln monitoring of the total ozone has been done using the Dobson spectrophotometer #30 since 1991. The fundamental observation is done by observing the direct solar radiance. However, when clouds cover the sun an observation of the zenith radiance is collected. This type of measurement is called a zenith observation and by using an empirical relation one can deduce the total ozone. Up to now an old empirical relation based on data from Boulder USA has been applied. In this report we present the development and testing of a site specific empirical relation
Measurements of total ozone 2006-2008
This report summarises the quality control, quality assurance and measurements of total ozone at Norrköping and Vindeln for the period 2006-2008. Significant incidents affecting the measurements are noted. Daily data are listed and plotted
Measurements of total ozone 2006-2008
This report summarises the quality control, quality assurance and measurements of total ozone at Norrköping and Vindeln for the period 2006-2008. Significant incidents affecting the measurements are noted. Daily data are listed and plotted
Measurements of total ozone 2012-2015
This report summarises the quality control, quality assurance and measurements of total ozone at Norrköping and Vindeln for the period 2012-2015. Significant incidents affecting the measurements are documented. Daily data are listed and plotted. This work was supported by the Swedish Environmental Protection Agency.Rapporten sammanfattar kvalitetskontrollen, kvalitetssäkringen och mätningarna av totalozon vid Norrköping och Vindeln under perioden 2012-2015. Händelser som signifikant påverkat mätningarna är dokumenterade. Arbetet har finansierats av Naturvårdsverkets Miljöövervakning (programområdet Luft, delprogrammet ozonskiktets tjocklek) och denna period avser Avtal Nr. 211 1002 och 211- 14-002 med ärendenummer NV-11173-11 och NV-08341-13. Motsvaras vid SMHI av följande diarienummer 2014/492/10.3 samt 2012/1108/10.3
Oppfrost av granplanter: Størst skader med dyp markberedning og store hogståpninger
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