Articles by Antti Haapanen

Radial growth of Scots pine (Pinus sylvestris L.) was investigated in seven camping areas located in Southern Finland. Radial growth reduction of 20–40% were found. The magnitude of this reduction was related to the amount of damage in the trees, and the age of the trees. A loss of humus, exposure of the roots and soil compaction were associated with the use of area but not related to the reduction in growth.

The PDF includes a summary in Finnish.

• Nylund, E-mail: ln@mm.unknown
• Haapanen, E-mail: ah@mm.unknown
• Kellomäki, E-mail: sk@mm.unknown
• Nylund, E-mail: mn@mm.unknown

The ground cover vegetation and tree growth at several camping sites in Southern Finland were investigated. The deterioration of ground vegetation appeared to be unavoidable in these areas, and only a few grass species were tolerant to heavy trampling. Only moderate deterioration was, however, detected when the trampling level was lower than 10,000–15,000 user days. On the other hand, the ground cover was completely destroyed when the trampling level exceeded 100,000 user days. A considerable decrease in radial growth appeared to be associated with destruction of the ground vegetation. The decrease was abrupt and was found to continue throughout the whole period of use. After ten years’ use the growth in the trampled areas was 35% lower than that that of the untrampled areas. A further decrease in radial growth is expected in the future. 

The PDF includes a summary in Finnish. 

• Nylund, E-mail: mn@mm.unknown
• Haapanen, E-mail: ah@mm.unknown
• Kellomäki, E-mail: sk@mm.unknown
• Nylund, E-mail: ln@mm.unknown

The study is the first report of a larger project concerning fire ecology in the Finnish boreal forests. Modern forestry has never been practiced in the Ulvinsalo strict nature reserve (2,500 ha) in Northern Finland in the county of Kuhmo. Forest fires have been uncommon because of mosaic of mineral and peat soils. The forests are mostly Norway spruce (Picea abies (L.) H. Karst.) dominated with Scots pine (Pinus sylvestris L.) often as the oldest trees of a stand. Forest fires were dated by counting annual rings from cambium to the fire scar in pines. 73 stands covering 1,207 ha were surveyed, over 80% of which was on mineral soil.

50% of the area had burned at least once during the life time of the present pine trees. 48 different forest fires were found, the first being from the year 1712 and the latest from 1969. The average time elapsed between the fires was about 82±43 years, and range 18–219 years. It was assumed that the stands where no fire scars were found, had, however, regenerated after fires but no fires have occurred since after that. In latter part of the 19th century 21 forest fires were dated, in the other half centuries only 4–9. This may have been caused by the increased human activity in the late 1800’s. The fire rotation of the area is 280 years, and spruce is almost the only tree species, which can regenerate in the present situation.

The PDF includes a summary in English.

• Haapanen, E-mail: ah@mm.unknown
• Siitonen, E-mail: ps@mm.unknown

The aim of the study was to determine which characteristics of tree stands could be used in urban noise control and to develop guidelines for practical urban forestry. The attenuation of artificially produced noise was measured in various types of stands. The effect of tree stands on noise attenuation has been analysed using a model based on the physics of sound propagation.

The results show that the excess noise attenuation caused by trees can be in good situations 60% measured in energy units, compared with the attenuation caused by geometric spreading. This is 5–8 dB. The total amount of needles, leaves and branches of a stand proved to be the most important factors in noise attenuation. However, the density and height of a stand had rather high value in predicting the behaviour of noise in tree stands. Based on multiple regression between noise attenuation and tree species composition, density and height of a stand it was developed the nomograms with which the noise level at a certain point can be predicted when the tree stand characteristics, the distance and the noise level of the noise source are known and on the opposite way.

The PDF includes a summary in Finnish.

• Kellomäki, E-mail: sk@mm.unknown
• Haapanen, E-mail: ah@mm.unknown
• Salonen, E-mail: hs@mm.unknown