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Forest regeneration within the treeline ecotone in the Giant Mountains under climate change
Cudlín, Ondřej ; Chumanová-Vávrová, Eva ; Edwards-Jonášová, Magda ; Heřman, Michal ; Štěpánek, Petr ; Cudlín, Pavel
Natural regeneration of mountain spruce forests began in the Giant Mountains 25 years ago after a reduction\nof severe and long-enduring air pollution. This process has been influenced by climatic change.\nThe aim of our contribution was to present background data for the potential elevational shift of spruce\nregeneration under conditions of climate change. These upslope shifts may also depend on constraints\nsuch as climate extremes, unfavourable soil conditions, absence of ectomycorrhizal symbionts, and lack of\nmicrosites suitable for seedlings. Since 2014, we have studied the main driving factors affecting Norway\nspruce regeneration, and in particular soil conditions, ectomycorrhizal symbionts, ground vegetation cover,\nand forest health, in six transects across the treeline ecotone located on a NW-to-NE transect through\nthe Giant Mountains. Microclimatic measurements showed that the mean difference in growing season\ntemperature between the montane spruce forests and forests at the treeline was −0.54°C. The model\nHADGEM2 predicted that in 20 years the temperature at the treeline will be similar to the current one at\nmontane elevations. The difference in prevailing soil types between the montane spruce forests and forests\nat the current treeline (i.e. podzol vs. ranker type) could be an important factor limiting success of the\nupslope spreading of spruce. Furthermore, areas covered by microsites favourable for natural spruce regeneration,\nespecially spruce litter patches, decaying wood, mosses, and Avenella flexuosa stands, were\nshown to decrease with increasing elevation. It is likely that spruce will move upslope in response to climate\nchange, but the process is likely to be slow or even blocked for some periods, especially by unfavourable\nsoil conditions and climatic extremes.
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Natural disturbances in central-european mountain spruce forests. A basis for forest restoration
Edwards-Jonášová, Magda ; Čermák, Martin
Risk of natural disturbances is a frequently discussed topic in the context of mountain spruce forests and global climate change. Recently, large-scale natural disturbances such as bark beetle outbreaks and windfalls have appeared relatively more frequently in Central-European mountain spruce (Picea abies L.) forests, which led to the enforcement of salvage logging even in some protected areas. Our study was performed as part of a long-term observation of recovery of spruce forests aff ected by bark beetle and windfall with and without interventions in two Central-European national parks, Šumava National Park in the Czech Republic and Tatra National Park in Slovakia. Th e results proved the ability of spruce forests to recover unassisted even from stand-replacing natural disturbances. Th eir biological legacies, which include standing and lying dead wood, are important for natural regeneration of tree species, and provide critical habitats for particular forest species. In comparison to natural disturbances, the artifi cial disturbances resulting from salvage logging destroyed a substantial part of the natural regeneration, which led to the need for artifi cial reforestation. Th us, the non-intervention strategy appears to be the best option for restoration of disturbed forests in the zone of mountain spruce forests. Based on our results, we propose that natural disturbances be considered as a basis for forest regeneration and restoration of their natural structure.
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Depoziční tok ozonu nad smrkovým porostem a jeho korelace s čistou ekosystémovou produkcí
Zapletal, M. ; Cudlín, Pavel ; Chroust, P. ; Urban, Otmar ; Pokorný, Radek ; Edwards-Jonášová, Magda ; Czerný, Radek ; Janouš, Dalibor ; Taufarová, Klára ; Medlen, A. ; Večeřa, Zbyněk ; Mikuška, Pavel ; Skácel, F.
Srovnání výsledků měření a modelování depozičního a stomatálního toku ozonu u smrku ztepilého v lokalitě Bílý Kříž v červenci a srpnu 2008. Zvýšené koncentrace ozonu snižují čistou ekosystémovou produkci, zvláště při vyšších teplotách a vysoké intenzitě globálního záření.
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Přirozená obnova horských smrčin: 10 let po kůrovci
Jonášová, Magda
Rozsáhlá plocha horských smrčin na Šumavě v oblasti Modravska byla v 90. letech minulého století napadena lýkožroutem smrkovým (Ips typographus (L.)). V bezzásahových porostech začíná být zřejmá přímá obnova smrkového lesa bez stádia s významným podílem pionýrských dřevin. Na holinách po zásazích proti kůrovci se krátce po vykácení dočasně objevily větrem šířené pionýrské druhy, po deseti letech ale tvořily pouze nepatrnou část celkového zmlazení. Věková i výšková struktura smrkového zmlazení byla na holinách ve srovnání s bezzásahovými porosty zredukována. Ve srovnání se samotným vlivem kůrovce měla těžba navíc negativní vliv na vegetaci bylinného i mechového patra.
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