Preliminary communication
Wood and Foliage Mass in Strawberry Tree (Arbutus unedo L.) Maquis on theArea of Vrgorac
Vlado Topić
; Institut za jadranske kulture i melioraciju krša Split
Lukrecija Butorac
; Institut za jadranske kulture i melioraciju krša Split
Goran Jelić
; Institut za jadranske kulture i melioraciju krša Split
Abstract
Stating of biomass in forest ecosystems and development of models for its quick estimation is an important part of investigation, especially on karst. During many years of research on research projects the authors have collected and partly published data about biomass for some important species on Mediterranean karst area of Croatia.
This paper presents the results of green wood and foliage mass measurement above soil level in maquis of strawberry tree (Arbutus unedoL.). Research was made and samples collected on permanent experimental plot on Vrgorac area. The plot has dimensions of 1 ha, the subplot number 15, which was excluded and on which measurements on vegetation was made and its basic structural data stated, has 100 m2(table 1). Canopy on subplot amounts to 69,61%, the medium height of sprout of strawberry tree is 1,61 m (maximal 2,30 m). Wood and foliage mass on experimental plot was measured separately for every bush as weight and volume, the independent estimation were the height of the bush, diameter of the crown and number of sprouts on the trunk. The weight of wood and leaf was measured in kg, the volume in m3, the height of the bush and diameter of bush crown in m. The volume of wood in research maquis, on the area of 100 m2, amounts to 0,095 m3, the volume of leaf 0,074 m3. The important part of the research also comprises the model for quick and reliable estimation of wood and leaf mass in these forest ecosystems. General lineal modelling was used for development of the model.
In table 3 it is evident that the height and wood volume is in strong correlation with number of sprouts on the trunk (r = 0,611) and bush height (r = 0,619) and in very strong correlation with crown diameter (r = 0,846). The weight and leaf volume are in strong correlation with bush height (r = 0,610), in very strong with number of sprouts on the trunk (r = 0,775) and crown diameter (r = 0,892). On the basis of number of sprouts on the trunk, bush height and diameter of the crown, as independent variables, the weight and wood and leaf volume of strawberry tree were estimated by univariate and multivariate regression analysis. In table 4 and figure 4 the regression models for estimation of weight and volume of wood and foliage of strawberry tree on experimental plot 15 are shown. By univariate regression analysis the significant dependance on weight and volume of wood and leaf with number of sprouts on the trunk, height of bush and crown diameter was stated. The results show that the number of sprouts explains 35,5% (ß = 0,611; p<0,0001), the height of the bush 36,5% (ß = 0,619; p<0,0001), the crown diameter 70,7% (ß = 0,846; p<0,0001) the variability of the weight and wood volume. The number of sprouts on the explains 59,2% (ß = 0,777; p<0,0001), the height of the bush 35,4% (ß = 0,610; p<0,0001) and crown diameter 79,0% (ß = 0,893; p<0,0001) of variability of leaf weight and volume. In figure 4, besides regression analysis of dependance of weight and volume of wood and leaf on number of sprouts on the trunk and diameter of the crown the equations of regression line beside the level of significance of 5% were given.
By multivariate regression analysis (table 4) the significal dependance of weight and tree volume and leaf with crown diameter was stated Td-(ß = 0,756; p<0,0001), Tl-(ß = 0,843; p<0,0001), while the significance for bush height was not stated Td-( ß = 0,142; p<0,233), Tl-( ß = 0,078; p<0,441).
The results of multivariate regression analysis show that the crown diameter and height of bush explain 71,1% of variability of weight and volume of wood (R2= 0,711) and 78,8% variability of weight and leaf volume (R2= 0,788).
All models can be applied for quick and reliable estimation of biomass of species (wood and leaf) in maquis of strawberry trees, especially with variables of crown diameter.
Keywords
wood and leaf mass; maquis of strawberry tree; weight and wood volume; weight and foliage volume; crown diameter; number of sprouts on the trunk
Hrčak ID:
72326
URI
Publication date:
14.10.2011.
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