Cílem empirické studie je zjistit, od koho ředitelé očekávají odbřemenění v provozních záležitostech školy a v jakých oblastech potřebu odbřemenění pociťují nejvíce, a přispět tak ke kvalitnímu ...nastavení školské politiky. V první části jsou obsažena teoretická východiska pro důležitost konceptu pedagogického leadershipu a je proveden úvod do problematiky českého decentralizovaného regionálního školství. Druhá a třetí část obsahuje metodologii a operacionalizaci základních pojmů a charakteristiku respondentů. Čtvrtá a pátá část představují výsledky empirické studie, a to za účelem představení východisek k v závěru formulovaným doporučením k modelu středního článku vzdělávací soustavy. V šesté části následuje diskuse limitů studie a v sedmé shrnutí a závěr pro tvůrce politik. Studie empiricky dokládá významnou potřebu poskytnout ředitelům základních škol podporu v oblasti provozních záležitostí školy a vůli ředitelů nechat se plně odbřemenit od administrace veřejných zakázek a větších investičních projektů. Závěrem je na bázi zjištění navrhnut model podpory školám vycházející z role obcí ve vzdělávacím systému, který může sloužit jako inspirace zamýšlenému střednímu článku podpory škol.
Although the ongoing global climate change elicits a shift in tree species composition along the vertical gradient, very extensive areas of pure Norway spruce Picea abies (L.) Karst. stands still ...occur out of their ecological optimum in the Czech Republic and Central Europe. Adaptive measures should be applied in these stands to promote productivity and stability. All measurements were performed in the 2018–2021 period on three permanent research plots located in the North-East part of Bohemia (Czech Republic). Based on the results, the most favourable way to increase solar radiation use efficiency expressed by canopy production index (CPI) and leaf area efficiency (LAE) is in-time heavy precommercial thinning application. The highest CPI and LAE values were observed in the Norway spruce stand after heavy pre-commercial thinning application (CPI = 2.00 and LAE = 1.59). In contrast, CPI = 1.26 and LAE = 0.99 were observed after the mild one, and CPI = 0.73 and LAE = 0.60 were reported in the control treatment with no silvicultural intervention. Overall, the presented results indicate a positive effect of heavy pre-commercial thinning on CPI and LAE in pure young Norway spruce stands. However, more effort should be devoted to studying the impact of different pre-commercial thinning intensities on solar radiation use efficacy across a broader gradient of site conditions, and future work should also be extended to other tree species.
Fast and precise leaf area index (LAI) estimation of a forest stand is frequently needed for a wide range of ecological studies. In the presented study, we compared side-by-side two instruments for ...performing LAI estimation (i.e. LaiPen LP 100 as a “newly developed device” and LAI-2200 PCA as the “world standard”), both based on indirect optical methods for performing LAI estimation in pure Norway spruce (Picea abies (Linnaeus) H. Karsten) stands under different thinning treatments. LAI values estimated by LaiPen LP 100 were approximate 5.8% lower compared to those measured by LAI-2200 PCA when averaging all collected data regardless of the thinning type. Nevertheless, when we considered the differences among LAI values at each measurement point within a regular grid, LaiPen LP 100 overestimated LAI values compared to those from LAI-2200 PCA on average by 1.4%. Therefore, both instruments are comparable. Similar LAI values between thinning from above (A) and thinning from below (B) approaches were indirectly detected by both instruments. The highest values of canopy production index and leaf area efficiency were observed within the stand thinned from above (plot A).
The paper analyses stand structure and production on two experimental forest stand series of mature pure and mixed Scots pine stands, growing on natural Scots pine sites in the Czech Republic. ...Sessile oak was the main admixed species. In mixed stands, Scots pine constituted the dominant level of the stand, admixed species grew mostly as subdominants. Admixture increased stand densities and aboveground biomass production compared to pure stands. Sessile oak with the 20–30% number share within the Scots pine stand led to an increase of the Scots pine tree dimensions and mean stem merchantable wood (DBH ≥ 7 cm) volume compared to the pure Scots pine stand of similar density. The Scots pine and sessile oak slenderness ratios increased in mixed stands compared to monocultures, however, the stand mechanical stability was not threatened.
Cílem empirické studie je zjistit, od koho ředitelé očekávají odbřemenění v provozních záležitostech školy a v jakých oblastech potřebu odbřemenění pociťují nejvíce, a přispět tak ke kvalitnímu ...nastavení školské politiky. V první části jsou obsažena teoretická východiska pro důležitost konceptu pedagogického leadershipu a je proveden úvod do problematiky českého decentralizovaného regionálního školství. Druhá a třetí část obsahuje metodologii a operacionalizaci základních pojmů a charakteristiku respondentů. Čtvrtá a pátá část představují výsledky empirické studie, a to za účelem představení východisek k v závěru formulovaným doporučením k modelu středního článku vzdělávací soustavy. V šesté části následuje diskuse limitů studie a v sedmé shrnutí a závěr pro tvůrce politik. Studie empiricky dokládá významnou potřebu poskytnout ředitelům základních škol podporu v oblasti provozních záležitostí školy a vůli ředitelů nechat se plně odbřemenit od administrace veřejných zakázek a větších investičních projektů. Závěrem je na bázi zjištění navrhnut model podpory školám vycházející z role obcí ve vzdělávacím systému, který může sloužit jako inspirace zamýšlenému střednímu článku podpory škol.
One of the main ideas of non-native tree species introduction into forest stands is to replace declining native species. The same is also valid for industry; the wood of native species should be ...replaced by a wood of the same or even better quality. Douglas-fir is often compared to other coniferous tree species based on its production. This study compared Douglas-fir wood properties with European commercial species, namely Norway spruce, Scots pine, and European larch. Trees representing different sites and ages were tested for wood density, shrinkage, and compression strength. In all cases, Douglas-fir outclassed spruce and pine in density and strength. The difference was striking, especially for spruce, where the density was surpassed by Douglas-fir by more than 100 kg.m−3 (above 25%). In the case of compression, the strength of Douglas-fir was up to 12.3 MPa higher (above 33%) compared to spruce. The only species that obtained higher figures was larch. Wood shrinkage was comparable to European softwoods. Therefore, Douglas-fir wood can be regarded as an excellent and promising substitute for the European processing industry.
•Douglas-fir represents promising non-native species for Europe.•It should be a substitute, especially for Norway spruce in industry.•We tested some of the properties important for applications.•In contrast to previous studies, tested species grew together in the same stand.•Douglas-fir exceeded not only spruce but also Scots pine.
Leaf area index (LAI) is one of the most important characteristics of forest stands that affects the fundamentals of tree physiological processes, biomass production, and mechanical stability. The ...LAI results obtained by the semi-direct and indirect methods (the needle technique and an LAI-2000 PCA) in three European beech (
Fagus sylvatica
L.) stands and one sycamore maple (
Acer pseudoplatanus
L.) stand were compared with LAI estimated by litter traps during the 2013 growing season. Seasonal LAI was estimated using an LAI-2000 PCA which showed similar trends among the stands and strongly corresponded to phenological phases of deciduous stands in Europe, with the fastest rate of leaf area increment occurring during the first month following bud break. During the growing season, maximum stand LAI value was on June 19th and reached 4.5–5.1, and 4.0 in the beech and maple stands, respectively. The needle technique significantly underestimated (
p
< 0.05) direct LAI on average by 22.0% and 40.0% in the beech and maple stands, respectively. The LAI-2000 PCA insignificantly underestimated (
p
> .05) LAI on average by 15.1% and 5.8% in the beech and maple stands, respectively. All methods for LAI estimation at the stand level could be applicable in deciduous forest stands (beech, maple) with similar site and stand characteristics. However, calibration by direct method is necessary to obtain the required precision.
Norway spruce stands are established and managed along various site conditions in central Europe. Currently, spruce often grows at locations outside of its ecological optimum, resulting in extensive ...damage elicited by harmful abiotic and biotic factors, which relatively shortens the time to change this adverse status in the adaptation frame by foresters. Except for the rapid change in species composition through clear-cuts, another way is possible, i.e., stabilising current (especially young) spruce stands to extend the time required to implement adaptation measures. The assumption that different site conditions will have to be respected as part of this adaptation was confirmed by our study based on NFI data of the Czech Republic. A semiparametric generalized linear model (GAM) was used to model the relationship between the height-to-diameter ratio and forest stand age, differentially considering particular forest vegetation zones. Spruce stands with lower elevations attain a lower stability (expressed by their height-to-diameter ratio; HDR) than those in the mountains. The HDR culminated in lower and middle altitudes in the first half of the rotation period, representing the most critical timing and effectivity of silvicultural measures. Contrary to previous findings, we found higher HDR values at nutrient-rich sites than those at acid ones, especially up to 50–60 years old. Therefore, more research should be devoted to the issue concerning the same thinning regime under different site conditions.
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