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Silva Fennica vol. 26 no. 3 | 1992

Category : Article

article id 5486, category Article
Kari Löyttyniemi, Risto Heikkilä, Seppo Repo. (1992). Pine tar in preventing moose browsing. Silva Fennica vol. 26 no. 3 article id 5486. https://doi.org/10.14214/sf.a15647
Keywords: Pinus sylvestris; Scots pine; Alces alces; repellent; moose; browsing damage; control
Abstract | View details | Full text in PDF | Author Info

The efficacy of pine tar as a moose (Alces alces L.) contact repellent was tested in young Scots pine (Pinus sylvestris L.) stands suffering from moose damage in Southern Finland during the winter 1981–82. Application of tar to shoots by spraying protected the trees satisfactorily throughout the winter.

The PDF includes an abstract in Finnish.

  • Löyttyniemi, E-mail: kl@mm.unknown (email)
  • Heikkilä, E-mail: rh@mm.unknown
  • Repo, E-mail: sr@mm.unknown
article id 5485, category Article
Pekka Ripatti. (1992). Yksityistilojen metsäalan muutokset Kaakkois-Suomessa 1986-1991. Silva Fennica vol. 26 no. 3 article id 5485. https://doi.org/10.14214/sf.a15646
English title: Forest area changes of non-industrial private forest holdings in southeast Finland, 1986–1991.
Original keywords: yksityismetsät; yksityismetsätalous; Kaakkois-Suomi; tilakoko
English keywords: Finland; private forestry; farm size; forest holdings
Abstract | View details | Full text in PDF | Author Info

The aim of the study was to describe the total change of forest area in non-industrial private forest holdings in southeast Finland, 1986–1991. The average gross decrease of forest area was 1.7 hectares, whereas the average gross increase was 1.2 hectares. Consequently, the average size of holdings decreased from 32.5 to 32.0 hectares. The most important factors affecting the changes of forest area were the inheritance system, resulting in a decrease of 0.7 ha, and reclassification of forestry land, producing an increase of 0.4 ha per holding. The increase of small, under 10 ha holdings accounted for much of the structural change.

The PDF includes an abstract in English.

  • Ripatti, E-mail: pr@mm.unknown (email)
article id 5484, category Article
Jyrki Kangas, Timo Pukkala. (1992). A decision theoretic approach applied to goal programming of forest management. Silva Fennica vol. 26 no. 3 article id 5484. https://doi.org/10.14214/sf.a15645
Keywords: forest management; models; forest planning; decision analysis; goal programming; optimization methods
Abstract | View details | Full text in PDF | Author Info

An alternative approach to formulating a forestry goal programming problem is presented. First, single objective optima levels are solved. The Analytical Hierarchy Process is applied in the estimation of a priori weights of deviations from the goal target levels. The ratios of the weights can be interpreted as relative importance of the goals, respectively. The sum of the weighted deviations from all single optima levels associated with the management goals is minimized. Instead of absolute deviations, relative ones are used. A case study problem of forest management planning with several objectives, measured in different units, is analysed.

The PDF includes an abstract in Finnish.

  • Kangas, E-mail: jk@mm.unknown (email)
  • Pukkala, E-mail: tp@mm.unknown
article id 5483, category Article
Erkki Verkasalo. (1992). Relationships of the modulus of elasticity and the structure of Finnish Scots pine wood. Silva Fennica vol. 26 no. 3 article id 5483. https://doi.org/10.14214/sf.a15644
Keywords: Pinus sylvestris; wood properties; wood anatomy; wood structure; tracheids; modulus of elascticity; stereology
Abstract | View details | Full text in PDF | Author Info

The paper presents preliminary results on the relationships of the longitudinal modulus of elasticity (E) in bending, based on ISO Standard 3349 tests on small, clear specimens, and some basic characteristics of Finnish Scots pine (Pinus sylvestris L.) wood. A manual image analysis method – quantitative stereological counting – was introduced and applied for the investigations of wood structure.

The main results were consistent with those from the prior research. The range of E was 9.7 to 19.1 GPa. Increase in especially fibre density index (R2 = 0.95), weight density and specific gravity (R2 = 0.90), Runkel’s ratio, coefficient of cell rigidity and number of growth rings per cross-sectional unit area, but also in latewood percentage (R2 = 0.58) resulted in an increase in E. Increase in growth ring width, particularly in the width of the late wood section within a ring (R2 = 0.63 to 0.90) had a reverse effect. Cell wall thickness did not show any clear effect. Except for tracheid diameter, the relationships were stronger for the variables determined in the tangential than in the radial wood direction.

Quantitative stereological counting has been used to some degree in the Finnish wood research. The procedure is technically feasible and easy to use. A large sample of counting areas is frequently needed to obtain accurate mean results for the size and distribution of the features. Because the actual analysis points are located at a fixed distance from each other, the method is not in principle well suited for wood with a regular and simple structure, as Scots pine. However, the good correlations between E and some characteristics obtained with stereological counting did not support this misgiving.

The PDF includes an abstract in Finnish.

  • Verkasalo, E-mail: ev@mm.unknown (email)
article id 5482, category Article
Heljä-Sisko Helmisaari. (1992). Spatial and age-related variation in nutrient concentrations of Pinus sylvestris needles. Silva Fennica vol. 26 no. 3 article id 5482. https://doi.org/10.14214/sf.a15643
Keywords: Pinus sylvestris; spatial variation; nutrients; sampling; nutrient concentration; conifer needles
Abstract | View details | Full text in PDF | Author Info

Spatial and age-related variation in nutrient concentrations of Scots pine (Pinus sylvestris L.) needles was studied during 1984–86 in three stands of different stages of development. The dry weight of current needles was significantly (p < 0.05) higher in the tree top than in a composite sample representing the whole crown. However, there were no significant differences in the concentrations of nutrients in needles between upper and lower crown levels. The concentrations of mobile nutrients N, P, K and Mg decreased with increasing needle age whereas the concentrations of poorly mobile nutrients Ca, Mn and Fe increased during needle ageing. The coefficient of variation for nutrient concentrations varied irregularly when only a few trees were sampled but stabilized when tree number was ten or more.
The PDF includes an abstract in Finnish.

  • Helmisaari, E-mail: hh@mm.unknown (email)
article id 5481, category Article
Pekka Nygren, Pertti Hari. (1992). Effect of foliar application with acid mist on the photosynthesis of potassium-deficient Scots pine seedlings. Silva Fennica vol. 26 no. 3 article id 5481. https://doi.org/10.14214/sf.a15642
Keywords: Pinus sylvestris; photosynthesis; nutrient deficiency; seedlings; acid deposition; potassium concentration
Abstract | View details | Full text in PDF | Author Info

The interactive effects of potassium deficit and foliar application with acid water (pH 5.5, 4.5, 4.0 and 3.0 given consecutively) on CO2 exchange rate of Pinus sylvestris L. seedlings was investigated in field conditions. No reduction of the CO2 exchange rate was observed in the seedlings supplied with sufficient potassium. Only the seedlings having the lowest needle K concentration (2.4 mgg-1) had an apparently low CO2 exchange rate before the applications with acid water. The CO2 exchange rate of most of the seedlings with low needle K concentration (3.9–6.0 mgg-1) decreased after the acid water application. The threshold acidity for the reduction varied between pH 4,0 and 3.0 depending on the needle K concentration. The reduction was more apparent at high irradiance. It was concluded that acid precipitation disturbs the CO2 exchange only in conditions of mineral nutrient deficit.

The PDF includes an abstract in Finnish.

  • Nygren, E-mail: pn@mm.unknown (email)
  • Hari, E-mail: ph@mm.unknown

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