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Forest management documents related to the whole Czech Republic contain detailed information about the state of forest stands and tree species. A subset of the data was prepared for stands of Douglas-fir (Pseudotsuga menziesii; 46,929 records) and Norway spruce (Picea abies; 37,761 records from stands where Douglas-fir was also present). Growth models for both species were constructed in the form of simplified Korf ’s function. The data set was divided into subsets according to forest vegetation (altitudinal) zones (FAZ) and groups of edaphic categories. On acidic habitats, both tree species reached maximum growth rate in the 5th FAZ. However, on habitats affected by water this occurred in the 4th FAZ. In the model example at the age of 140 years, Douglas-fir shows an average of 4% higher stand volumes in comparison to Norway spruce, while the felling volume as part of thinning, or left in the stand to decay, is about 32% higher in Douglas-fir. [ABSTRACT FROM AUTHOR]

Communities of epigeic beetles were studied using pitfall trapping on 10 plots with the different stage of decline and clear-cut plots without coarse woody debris. Species richness (number of all species, S), total species diversity as the Shannon-Wiener’s index (H) and equitability (e) were calculated in the DBreleve. The Ward’s method of hierarchical agglomerative classification with Euclidean distance was used for the differentiation of the communities on the plots. Species data for this analyse were represented by logarithm-transformed activities [log(x+1)]. The single-factor analysis of variance (ANOVA) was used for statistical testing of differences in structural parameters (e.g. species richness and diversity) amongst distinguished groups of the plots. The species diversity and activity differs on glades without trees and coarse woody debris. The highest number of species was found in clear-cut areas. The lowest number of species was found on the plots with the living forest particularly invaded by bark beetle. This fact is caused by the fact that the clear-cut plots are invaded by ubiquitous and anthropotolerant species with good migration possibilities. These species are adapted to habitats without trees and are able to leave even in the habitats with very sparse or without vegetation. Species living in the forest even under the bark beetle attack are often stenotopic and adapted to the forest microclimate (higher humidity and low average temperature). These species are very sensitive to great difference in the daily changes of microclimate. The study of beetle communities support the hypothesis that the keeping of dead tree stands on plots after bark beetle outbreak is better for biodiversity conservation than the cutting down of trees and the abolishment of stems.

The forest stands of Douglas-fir [Pseudotsuga menziesii (Mirbel) Franco] and Norway spruce [Picea abies (L.) Karst.] in the South Bohemian uplands (Czech Republic) represent an artificial community of a neophyte (native to North America) and indigenous species (with natural distribution in mountain forests). Ecological characteristics of these two tree species and their response to climatic factors were studied using tree ring analyses and correlation of growth indices for tree-to-tree and between trees and historical parameters of climate (average air temperatures, sum of precipitations and relative air humidity). The two datasets were analysed using multidimensional methods. The ordination analysis shows a considerable difference between both tree species. Growth of both species differed significantly by districts and plots. The effect of climate was studied using correlations as floating time-window. Our results showed that average air temperature had a stronger effect on Douglas-fir growth, for which an increment decrease was found at higher temperatures between May 25th and June 24th. Also, the average maximum air temperature affected the growth of Douglas-fir more strongly than that of Norway spruce. More precipitation was associated with a similar positive effect on the growth of both tree species. Air humidity had a significant effect on growth of both studied tree species and the effect of air humidity was more significant than of distinct precipitation. The combined effects of lack of precipitation and high temperature in vegetation period was the major limiting factor for radial growth. Douglas-fir showed higher productivity (+17.2%) and resistance to climate extremes compared to Norway spruce. Our results suggest that a mixed stand could be more resistant in terms of growth stability than mono-specific stands, as the two studied species exhibited different reaction to climate extremes. Our study further showed that mixed stands with high species diversity had a higher production potential (+13.1%). [ABSTRACT FROM AUTHOR]

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One of the factors that could affect spruce and pine stands and consequently seed quality is a long-term climate change. The aim of the presented study is to evaluate the seed quality data of these tree species between the years 1973 and 2015 in relation to the temperature and precipitation in the territory of the Czech Republic during that period. The average absolute weight of Scots pine seeds during the reference period corresponded to the value provided in the Czech Standard ČSN 48 1211 (2006); on the contrary, decrease in weight of Norway spruce seeds was apparent. No significant changes in germination energy and germination capacity have been observed over the years in regard to Scots pine. Germination energy has declined significantly in Norway spruce, and a stronger correlation has also emerged with germination capacity of full seeds. It turned out that the germination capacity of pine seeds is influenced by higher temperatures in the summer after blossom (June to August), while, in turn, the germination energy by the subsequent lower average temperatures in October to December. The correlation between total rainfall and seed quality was negative in February of the year preceding the harvest and in August of the year of harvest. Results in regard to Norway spruce showed a negative correlation between germination energy and average temperatures in March to August of the year of maturing. Correlation between precipitation and seed quality was not proved. [ABSTRACT FROM AUTHOR]

Influence of allochtonous stands introduced Douglas-fir (Pseudotsuga menziesii) on understory vegetation was studied on 44 plots in Czechia territory. Stands had to be 60 years old at least. Norway spruce (Picea abies), European beech (Fagus sylvatica), oaks -- Sessile and Pedunculate (Quercus petraea and Q. robur) and other commercial tree species (Tilia cordata, Acer pseudoplatanus, Pinus sylvestris and Larix deciduas) stands were chosen to compare. Compared stands had always the same habitat conditions as Douglas-fir plot. Results have shown that Douglas-fir stands have not unambiguous characteristic species of the herb layer, but they show higher increase of nitrophilous species. [ABSTRACT FROM AUTHOR]

Copyright of Opera Corcontica is the property of Sprava Krkonosskeho Narodniho Parku and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Opera Corcontica is the property of Sprava Krkonosskeho Narodniho Parku and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Germination and viability of stored European beech (Fagus sylvatica) seeds can vary depending upon the time when the tests are done during seed storage. To determine the possible sources of such variation the germination (GERM), germination rate expressed as mean germination time (MGT) and viability (VIAB) of six beechnut lots (three lots from two crop years) were determined monthly for one year using controlled laboratory conditions and standard tests. Higher GERM of some lots occurred when tests for stored seeds were carried out in spring and early autumn while other lots germinated better during summer tests. Similarly, different germination speed (dormancy release) and VIAB were observed in different months for different lots. However, no consistent seasonal fluctuation in GERM, MGT or VIAB of the beechnuts was observed in the tests. The reason for this fluctuation seems to be initial quality (germination and dormancy) of beechnut lots rather than any endogenous factors. [ABSTRACT FROM AUTHOR]