Articles containing the keyword 'runkovalunta'

The study is part of a project designed to elucidate the nutrient budget of a Scots pine (Pinus sylvestris L.) stand. Results of variation in the nutrient contents were compared with those obtained for the previous growing season.

The potassium and calcium contents varied the greatest in the humus layer. However, in the bottom and field layer vegetation and needles the variation in the nitrogen content was the greatest. The nutrient contents of the needles were affected by the physiological stage of development, needle age and the position in the crown of the tree. The nutrient content of the rainfall increased in the order: free rainfall, throughfall, and stem flow.

The PDF includes a summary in Finnish.

• Lehtonen, E-mail: il@mm.unknown

This study forms part of a project designed to elucidate the total nutrient budget of a Scots pine (Pinus sylvestris L.) stand in Central Finland during the 1974 growing period. Precipitation has been divided up into precipitation, throughfall and stemflow.

The acidity of the rainwater was found to increase in the order – Precipitation, throughfall and stemflow. The electrolyte content of the rain water from throughfall and stemflow was higher than that of precipitation. The nutrient contents of precipitation were rather low. Throughfall and stemflow were found to leach some nutrient from the trees. This was most clear in the case of potassium. The total amounts of nutrients reaching the ground in throughfall were found to be smaller than those in precipitation. On the other hand, the amounts of potassium, calcium and magnesium in stemflow were clearly greater than those in precipitation.

The PDF includes a summary in English.

• Lehtonen, E-mail: il@mm.unknown
• Kellomäki, E-mail: sk@mm.unknown
• Westman, E-mail: cw@mm.unknown

Stand precipitation and stemflow studies became necessary in connection with hydrologic studies, for instance, to explain the deviations resulting from rains in the ratios between the water content of peat and the groundwater level, throughfall during rains of variable heaviness, and effect of stand treatment on soil moisture level. In this project the distribution of rainfall in stands differing in species composition and density was studied in Central Finland in 1963–1965 in fifteen stand precipitation sample plots. In addition, rain gauges were situated under individual Scots pine (Pinus sylvestris L.), Norway spruce (Picea abies (L.) H. Karst.) and birch (Betula sp.) trees.

The average precipitation in the open was 4.8 mm, the corresponding precipitation in the stand was 77% for birch, 71% for pine and 62% for spruce. Measurements of stemflow from individual sample trees showed that less than ¼ mm (about 1.5%) during a 15 mm rain in a pine stand. In the spruce stands stemflow is negligible. A part of the sample plots was in drained peatlands with a dense vegetation of small shrubs. The shrub layer retention was about 10% even during heavy rain. In a small forest clearing, the bordering effect of the forest was seen up to the distance of 5 metres from the edge of the forest. During the period of study, on an average 3% more precipitation was recorded in the clearing than in the open, the difference being probably due to the stronger wind effect in the open.

The PDF includes a summary in English.

• Päivänen, E-mail: jp@mm.unknown

Distribution of rainfall in in a Scots pine (Pinus sylvestris L.) stand and in an open place in Alajärvi in Central Finland was studies in 1959–1960. Density of the about 80 years old stand was 0.36 and the height of the trees 8–14 m. The dependence of throughfall and dependence of stemflow on 24-hour precipitation, and dependence of the distribution of 24-hour precipitation on the amount and nature of precipitation was calculated.

The precipitation of the crown of the forest depended on the rainfall. When the rainfall in the open place was over 7 mm, the rainfall within the forest was in average 89% of the rainfall in the open place, but if the rainfall in the open place was less than 1 mm, the rainfall within the forest was only 64% of that in the open place. Total stemflow in the pine stand was only 0.4%, and interception loss was 13.6%.

The PDF includes a summary in English.

• Seppänen, E-mail: ms@mm.unknown