0467097 - BÚ 2017 RIV CZ eng J - Journal Article
Doležal, Jiří - Lehečková, Eliška - Sohar, Kristina - Altman, Jan
Oak decline induced by mistletoe, competition and climate change: a case study from central Europe.
Preslia. Roč. 88, č. 3 (2016), s. 323-346. ISSN 0032-7786. E-ISSN 0032-7786
R&D Projects: GA MK(CZ) DF12P01OVV005
Keywords : dendrometers * moving response function * growth–climate relationships
Subject RIV: EH - Ecology, Behaviour
Impact factor: 3.000, year: 2016

It is predicted that rising temperatures and extreme summer droughts will adversely affect the growth of pedunculate oak (Quercus robur) and contribute to local population decline. Furthermore, such oaksmay become prone to infestation with mistletoe (Loranthus europaeus) and competition from neighbouring trees. We tested these predictions in the warm, south-eastern part of the Czech Republic, a drought-prone area where oaks die prematurely. We compared the radial growth patterns of eight categories of oaks differing in age (younger or older than 60 years), presence of neighbouring trees (solitary versus grouped) and infestation with mistletoe (infested versus healthy), and their responses to variation in both annual and intra-annual temperature (T) and precipitation (P).We analysed long-term data from tree rings and detailed dendrometer records of daily increments using moving correlations and regression trees. Oak growth is affected by (i) dry and cold winters, resulting in root damage and water shortages during summer, (ii) a cool and wet March–April, hampering the onset of earlywood growth, and (iii) a hot and dry May–July period, reducing latewood formation. Latewood width increases when February P > 55 mm, March T > 3.3 °C, April P < 60 mm, May P > 50 mm, June T < 19 °C and August P > 40 mm. Latewood width decreases with tree age, mistletoe infestation and competiton from neighbouring trees. Grouped trees that compete for soil water are more prone to June–July droughts but less harmed by cold springs than solitary oaks. These results provide support for the crucial role of climate change (decline in rainfall and increase in summer temperatures over the last three decades) and biotic interactions (mistletoe hemiparasites, inter-tree competition) in oak growth and population decline.
Permanent Link: http://hdl.handle.net/11104/0265235