D. Zahradník

Models for predicting aboveground biomass of European beech (Fagus sylvatica L.) in the Czech Republic.

We developed optimal models for predicting the aboveground biomass of European beech ( Fagus sylvatica L.) applicable to the national forest inventory data of the Czech Republic. The models were based on a data set of 81 beech trees collected in 19 stands that represent a wide range of stand and site conditions. The relationship between biomass and tree dimensions (diameter D, height H) was modelled using non-linear regression equations with one ( D) or two ( D, H) independent variables and two or three parameters (D2, DH2, DH3 models). Subsequently additional predictor variables, i.e. tree age, site index and altitude, were added to the basic models. The inclusion of tree age ( T) and altitude (

Picea abies provenance test in the Czech Republic after 36 years - Central European provenances.

Norway spruce (Picea abies [L.] Karst.) provenances from Central Europe (Hercynian-Sudetes area) were evaluated in a long-term experimental project (Germany-Czech Republic) 36 years after the outplanting. The growth characteristics, mortality and qualitative morphological characteristics of 64 spruce provenances were evaluated on the experimental plot Ledeč-Zaháj, in the Czech-Moravian Highland region of the Czech Republic, in typical conditions for Norway spruce cultivation. Results show 15–20% differences in height and radial growth between provenances and insignificant differences in qualitative characteristics e.g. stem shape, branch density and shape and also health state. Environmental variables that significantly influenced production characteristics include longitude, latitude and altitude of the original locations of the provenances, while average annual temperature and average annual precipitation were not significant. Given conditions of the experimental plot, optimal production occurred with those provenances originally from 49–51 N latitude and 13–20 E longitude.

Comparison of tree volume equations for small-leaved lime (Tilia cordata Mill.) in the Czech Republic

Although the small-leaved lime (Tilia cordata Mill.) is a native tree in the Czech Republic, there are no volume tables, and its volume has so far been estimated according to beech (Fagus sylvatica L.) tables. In order to increase accuracy of timber volume calculations, the most appropriate volume equations should be selected to develop volume tables specifically for lime. Based on literature sources eight volume equations were selected, and their accuracy was tested by statistical evaluation of assessed parameters and differences between calculated and sampled lime tree volume. Eighty-one sample trees were randomly selected for this study. The most suitable equation was Børsets equation according to the evaluation of equation parameters and comparison of the results obtained from the volume formula and from sample trees (difference of mean value 0.000009 m3). Finally, the calculated lime volumes were compared with the beech tables. The lime volumes are higher than beech volumes according to beech tables and positive differences for the lime, which varied from 0.05 m3 to 0.35 m3, support the need for new lime volume table.

One common structural feature of “words” in protein sequences and human texts

Frequently discussed analogy between genetic and human texts is explored by comparison of alternation of polar and non-polar amino-acid residues in proteins and alternation of consonants and vowels in human texts. In human languages, the usage of possible combinations of consonants and vowels is influenced by pronounceability of the combinations. Similarly, oligopeptide composition of proteins is influenced by requirements of protein folding and stability. One special type of structure often present in proteins is amphipathic α-helices in which polar and non-polar amino acids alternate with the period 3.5 residues, not unlike alternation of consonants and vowels. In this study, we evaluated the contribution made by amphipathic alternations to the protein sequence texts (20–24%). Their proportion is lower than respective values for alternating words in human texts (57–89%). The proteomes (full sets of proteins for selected organisms) were transformed into ranked sequences of n-grams (words of length n), including periodical amphipathic structures. Similarly, human texts were transformed into sequences of alternating consonants and vowels. Analysis of the vocabularies shows that in both types of texts (human languages and proteins) the alternating words are dominant or highly preferred, thus, strengthening the analogy between these two types of texts. The contribution of amphipathic words in the upper parts of the ranked lists for 10 analyzed proteomes varies between 58 and 74%. In human texts respective values range between 90 and 100%.