Survival of artificially regenerated Scots pine on till soils with respect varying dielectric properties
2002
Sutinen, R. | Teirila, A. | Panttaja, M. | Sutinen, M.L.
Artificial regeneration to Scots pine (Pinus sylvestris L.) has faced substantial economical losses in Finnish Lapland on sites underlain by glacial tills and formerly covered by stands dominated by Norway spruce (Picea abies (L.) Karst.). We studied the survival of pine seedlings and saplings with respect to soil dielectric permittivity (epsilon), as dependent on soil water content (theta(v)), of ploughed tills. The epsilon values (theta(v)) were determined beneath 10 500 pines varying in age between 2 and 41 years and growing on 21 sites, 500 per site. Based on the logistic regression models, the survival rate of 2- to 7-year-old seedlings was independent of the soil epsilon (i.e., theta(v)). In contrast, a significant correlation between the survival rate of 12- to 16-year-old saplings and soil epsilon was observed. In this age-class, a survival rate of 50% with epsilon50 = 15.1, with epsilon50 = 17.0 for planted saplings and epsilon50 = 12.7 for sowed saplings, were obtained. Of the 2000 pine trees aged between 20 and 41 years, 96.5% were observed to be growing on dry tills with epsilon < 15 with mean epsilon = 9.9. The results of this study suggest that artificial regeneration of Scots pine in Lapland is risky on moist and wet tills (epsilon > 15, theta(v) > 0.27 cm3(.)cm-3).
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