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nr 01
PL
Do waloryzacji terenów rolnych można użyć różnych wskaźników oceniających rolniczą przestrzeń produkcyjną. W wykorzystywanych metodach oceny przestrzeni rolniczej wyróżniamy grupy czynników naturalnych lub antropogenicznych. Celem pracy jest przedstawienie istniejących metod oceny rolniczej przestrzeni produkcyjnej i czynników uwzględnianych przy jej waloryzacji. Autor w pracy przedstawia także propozycję czynników, które obecnie powinno się uwzględniać w pracach waloryzujących rolniczą przestrzeń produkcyjną.
EN
Various factors can be used to evaluate agricultural production area. Factors used in the common evaluation methods of agricultural area can be classified into two groups: natural and anthropogenic. Aim of this study is to present, the existing evaluation methods of agricultural production area and the factors used for ist valorization. Factors which should currently be used in the evaluation of agricultural production area are proposed.
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tom 157
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nr 10
EN
The studies were based on the empirical material collected from 88 sample plots located in 78 beech−pine stands and 10 pine stands with beech undergrowth. The effect of the competition of beech trees from the understorey and pine trees on the radial increment (r) and basal area increment (g) was investigated. The strength of the competition was determined using distance−independent indices, which did not take into account the position of a tree in the stand. The effect of the competition on the basal area growth of both beech and pine trees was found to be greater than on the radial growth.
5
Content available Analiza rozkładu pierśnic w drzewostanach bukowych
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EN
We developed functions that describe the relationship between the stand top height and age for Scots pine (Pinus sylvestris), Norway spruce (Picea abies), silver fir (Abies alba), European larch (Larix decidua), English oak (Quercus robur), European beech (Fagus sylvatica), black alder (Alnus glutinosa) and silver birch (Betula pendula). We applied model proposed by Cieszewski for that purpose. The top height at the age of 100 years obtained from the developed models is a stand site index. Prior to the determination of function coefficients we analysed the height growth rate for each species to provide similar course of the height growth curves for the majority of trees. It required the elimination of trees whose height growth rate differed from the course parallel to the age axis. These were usually trees that remained under canopy for too long and reacted with an intensive increase in height growth after removal of the canopy, trees after insect gradation or trees growing in areas drained during their growth. The site index functions are the first stage of yield tables development. It is planned to introduce them into stand growth models, which will increase the accuracy of forecasting the development of wood resources.
EN
This paper addresses the question of whether or not and to which extent two common tree species mixtures (Norway spruce – European beech; sessile and pedunculate oak – European beech) vary in volume growth from their monocultures. To this end, the results from selected long−term experimental plots located in Germany, Poland and Switzerland, with many of them under survey since the 1890's, were employed. We found than on average both type of mixtures exceeded volume growth in pure stands by almost 30%. The analysis at the species level showed than only a Norway spruce response to mixture was neutral on average, while other tree species were benefitted by mixture. An empirical derived model for mixed stand of oak and European beech disclosed that the interaction can range from facilitation and overyielding on poor sites, through the neutral response under mesotrophic conditions, up to underyielding on fertile sites triggered by competition.
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