Main shoot characteristics in the mature black alder (Alnus glutinosa (L.) Gaertn.)

A comparative analysis was made for different measures of location and variation in height increment of the main stem of the mature black alder from the north−eastern region (N) and two southern regions (S1 and S2) of Poland. Correlation was found between annual height increment and tree age and height, as well as the number of the nodes along the shoot and the length of the internode. It was demonstrated that the trees producing long shoots in a given year would produce long shoots also in the successive years

Degree of damage to beech stands in the Klodzko Region

The study presents the assessment of damage to beech stands using four methods, including that taking into account the radial increment. The condition of stands in 2016, and the growth response of trees to the environmental changes since 1956 are described. The measurements and observations were carried out on 18 sample plots (tab. 1) located in south−western Poland. The mean defoliation accounts for 32.5% ranging from 16.9 to 56.9%, while the average defoliation class value is 1.62 ranging from 0.75 to 2.38. The proportion of trees was found to be the highest (approx. 60%) in class of moderate damage (fig. 1a). The mean value of vitality is 1.17 (ranging from 0.75 to 2.38). The proportion of trees in vitality classes differs significantly from that in defoliation classes. The highest number of trees (approx. 80%) was found to be within damage class of weakened trees (fig. 1b). The assessment of damage to trees based on synthetic damage index (defoliation and vitality combined using formula [1]) is similar to the assessment method based on tree vitality. The mean value is 1.07, ranging from 0.63 to 1.70. The largest proportion of trees (over 80%) was found to be within class 1 (fig. 1c). The index SynZ combines defoliation and vitality, as well as the growth response of trees over the last 15 years according to formula [2]. Its values range from 0.82 to 1.79 with 1.21 on average. The largest proportion of trees (over 70%) was found to be within damage class 1 (fig. 1d). The response of trees to environmental changes is an important indicator of the growth conditions. The proportion of trees with negative growth responses increases from period to period, while the proportion of trees with neutral and positive responses decreases (fig. 2). The analysed beech stands show fairly large differences in the level of the damage. The most likely cause of this situation are droughts occurring in recent growing seasons, especially in 2012. Of the methods deployed to assess damage to beech trees, the morphological−growth one is the most accurate, but the most laborious. Therefore, it is preferable to use a synthetic damage index as both tree defoliation and vitality can also be assessed outside the growing season

Criteria of assessment the damage to silver fir

The paper presents criteria of assessment the damage to silver fir that were elaborated on the basis of the features describing the development of fir crown that is assimilation apparatus condition (feature A), tree− top condition (feature B) and tree vitality (feature C). Feature A is based on the defoliation, feature B assesses length of last height increments and branching, while feature C takes into account loss of branches in the middle part of the crown and percentage of the alive shoots on branches of higher order. Determined criteria may be applied in methods of the assessment the damage to stands and forests of units of higher position in different classifications

Ksztaltowanie z wiekiem dlugosci korony olszy czarnej [Alnus glutinosa [L.]Gaertn.]

The paper provides research results concerning the relationship between age, absolute height and relative crown length of black alder. Analysis of the ratio of relative crown length to tree height of black alder trees allowed to develop a crown length model. Alder is capable of producing a secondary crown, which entails the shortening of the non−branched section of the trunk. A relationship has been found between the length of the primary crown and the length of the secondary crown depending on elongation of the secondary crown at the cost of shortening of the primary crown

The role of sylleptic shoots in shaping the black alder (Alnus glutinosa (L.) GAERTN.) crown architecture

Black alder is a species capable of producing sylleptic shoots. This process is also detected in alders at older age. The objective of this work is to characterise sylleptic shoots and to determine the role they play in the formation of crown branching. The empirical material used in the experiment was collected in the north and south of Poland and considers both young and old trees

Increment response of silver fir (Abies alba Mill.) to environmental conditions in relation to secondary crown

The study concerns the secondary sunny crown of silver fir trees, its length and density as well as the relationship between the length of primary and secondary crown between the radial increment and secondary crown characteristics. It also discusses the importance of secondary crown in the life and population growth of silver fir