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Comparison and evaluation explantates plantings of juniper (Juniperus communis), originally from PR Mšály (1981-1985)
BUBLÍK, Martin
Common juniper (Juniperus communis) is a tree or a shrub. This species is original in the Czech Republic which was very widespread in the landscape. It is from the lowland to the mountain range, which means that it is completely unmistakable for the soil species. It is classified as a critically endangered species in the Czech Republic, due to changes in landscape management. The aim of this work was mapping and surveying the situation on the mentioned localities, where the research was carried out in 2004-2005 and in 2015. At the Na Mšálech locality there were found 135 individuals. Based on the data found, the overall health condition was greatly aggravated by the populations under study, specifically at the Paris site.
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Arctic tundra dendrochronology
Lehejček, Jiří ; Svoboda, Miroslav (advisor) ; Monika, Monika (referee)
Historically unprecedented environmental change in the Arctic ecosystems is often given into the context of its past and possible future development. In the region where instrumental meteorological observations are scarce archives need to be investigated in order to address this issues. The comprehensive synthesis one of the archives: long-live circumpolar evergreen Juniperus communis L. shrub is presented here. 20 individuals from southwest Greenland were investigated at the cell anatomy level to understand the ecology of the species and unhide its potential for environmental and climate reconstructions. The findings are as follows:
i) Stop of exponential cross-sectional conduit-lumen widening with increasing age is in contrast with conduit-lumen nature of trees. This indicates that shrubs do not need to saturate their water and nutrient demands via traits of classical hydraulic conductivity law but rather developed different mechanisms. Extreme weather conditions result in prostrate growth form. However, different weather factors probably influence shrub growth differently: While snow and wind act mechanically (a), temperature influences the form of growth physiologically (b). a) So long as the young shrub stem has high resilience to bend back to an upright position after snow melt and so long as it can withstand the wind during the vegetation season it most likely grows upright and the conduit-lumens widen. b) Temperature, resp. freeze-thaw events are responsible for the shrubs preference of safety (finite size of conduit-lumens) over hydraulic efficiency, thus not allowing for more primary growth. All of these (and other) factors are apparently working together and the transition of vertical to more horizontal growth is gradual. As a consequence, the conduit-lumen sizes may not have to be further increased (due to ecophysiological restrictions possibly also must not) because water is no longer transported against gravity.
ii) Observed age/growth trend has to be taken into consideration for further employment of the wood anatomical parameter in paleoenvironmental studies. That is, shrub cell parameters can only be used for this purposes if correctly detrended. This allows for more accurate as well as longer reconstructions because youth trend was often neglected in reconstructions based on shrub annual-rings.
iii) The south-western Greenland Ice-Sheet (GrIS) melt rates reconstruction is presented for the whole 20th century. This part of GrIS is considered as the most active. According to the presented reconstruction current GrIS melt rates are not uncommon for the last century being comparable to first decades of 20th century. This finding is particularly important contribution to the debate on Atlantic meridional overturning circulation (AMOC). Too high fresh water inputs into the Northern Atlantic from GrIS melting may slow down or even stop the AMOC which would result in more continental climate in Europe. Presented results indicate that this threshold lies higher than observed current melt rates of GrIS.
Fascinating Juniperus comunnis species has shown to be able to address many ecological as well as environmental open questions and due to its longevity and abundant distribution has a great potential to become an important player in the Arctic research.
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Population juniper (\kur{Juniperus communis}) in the selected area
KOUPAL, Vít
The paper maps the community of Common Juniper (Juniperus Communis) encountered at Konrac, a site included in the Česká Kanada Nature Preserve. The site itself, or rather the common juniper growing there, does not have the benefit of special legal protection; consequently, no targeted steps have been taken to maintain the juniper community intact in the Konrac landscape - still, the site allowed to monitor the natural development of the community in conditions typical of the current methods of farming. The locality is described to encompass four main types of habitats: stony islands amid meadows; unplowed strips of land around former small fields; peripheries of open stands; and peripheries of close stands. The acquired (and subsequently processed) data point to the conclusion that the habitat at the unplowed margins of fields suits the common juniper communities quite well, even without any human intervention in the farming practices beyond what is implemented on the site now.
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Population of juniper (Juniperus communis) on dikes Třeboň ponds
PELÁN, Rudolf
Common Juniper (Juniperus communis) is a low-growing shrub or small tree, which is autochthonic and previousely widely distributed in the Czech Republic. Common Juniper occurrence is associated with sandy, drying and waterlogged soils from lowlands to mountains. It is retreating species from the middle of last century because of changes in landscape and agriculture. Now, it is endangered species of flora of the Czech Republic. The aim of this work was to map the population on selected areas of Třeboňsko focusing on the pond dikes and comparing with others. Next, there was dendrometry (forest mensuration), detection of individual specimens with using GPS and creating maps with location of Junipers. 190 specimens were founded on selected area, most of them were founded in forests and near ponds.
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The population of juniper (\kur{Juniperus communis}) in the selected area of the Pilsen Region
KELÍŠEK, Michal
Juniperus communis is a shrub or rather a small tree, original and widely-spread formerly in the Czech Republic. Nowadays it belongs to the endangered species. Its galbulas, called juniper berries, are used as spice or for production of alcoholic beverages. The aim of this work was to map the population of juniperus communis in the selected area of Pilsen region ? VKP Jalovcová stráň Odolenov, further to perform dendrological measurements and draw up maps. In the locality mentioned above the population of 253 pieces of original junipers and 260 pieces of seedlings, planted in 2010 ? 2011, was found out. Average height of 290 cms and a trunk circumference of 23 cms at original junipers (40 ? 50 years old) were found out.
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Juniperus communis ocurrence in South part of Protected Area Trebonsko
DVOŘÁK, Martin
In this work, I ´ve been monitoring occurrence of Juniperus communis in south part of {\clqq}CHKO Třeboňsko``, which is protected area. At first I´ve been studying literature specialized in focusing on problems of occurence Juniperus communis in the world and in this concrete area. Than I was systematically creating a net of all the exemplars in proper area, I ´ve been noting their characteristics and taking a photos. I was statistically analyzing the data and compare with other works, which are engaged in this issue.
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