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& Key message This data set provides unique empirical data from triplets of Scots pine (Pinus sylvestris L.) and European beech (Fagus sylvatica L.) across Europe. Dendrometric variables are provided for 32 triplets, 96 plots, 7555 trees and 4695 core samples. These data contribute to our understanding of mixed stand dynamics. Dataset access at http://dx.doi.org/10. 5061/dryad.8v04m. Associated metadata available at https://metadata-afs.nancy.inra.fr/geonetwork/apps/ ge orche str a/?uuid=b3e0 98 ca-e 68 1-49 10 -909 9-0e25d3b4cd52&hl=eng.

Research Highlights: In Central Europe, Douglas fir became more responsive to summer drought in recent years. Background and Objectives: Until now, Douglas fir has been considered a tree species resistant to drought. However, how Douglas fir will be able to cope with the increasing frequency and intensity of summer heat waves remains a question. The long-term variability in the climate response of Douglas fir in Central European conditions has not been fully explored. The aim of the study was to identify climatic factors controlling the stem radial growth of Douglas fir and Norway spruce, and to examine the temporal changes in tree responses to key climatic variables related to drought stress. Materials and Methods: We analysed the pattern of the climate–growth relationship of Douglas fir and Norway spruce, growing in mixed stands distributed between 260 and 600 m above sea level, which corresponds with the altitudinal zone of intensive spruce dieback in the Czech Republic. Nine-site tree-ring-width chronologies were developed for each tree species. Pointer year analysis and correlation analysis in combination with principal component analysis were used to identify climatic factors limiting their growth. Moving correlation function was computed to assess temporal changes of the climate–growth relationship. Results: In the entire 1961–2015 period, growth of both species was positively related to summer precipitation. The response to temperature differed between species. While spruce was negatively affected by the temperatures in summer months, the increments of Douglas fir were positively correlated with the temperatures in February and March. However, moving correlation analysis revealed recently increasing sensitivity to summer temperatures also for Douglas fir. Higher responsiveness of Douglas fir to drought was also revealed by the increasing frequency of negative pointer years in the 2003–2015 period. Conclusions: The recommendations of Douglas fir as a suitable alternative tree species for declining spruce stands at lower altitudes must be regarded with caution.

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The Small-leaved lime (Tilia cordata Mill.) is currently not commercially important species, therefore the knowledge of biomass partitioning in a tree is rather incomplete. Moreover, lime biomass is estimated mostly using biomass functions designated for other species, without the knowledge of limits of such a use. For these reasons, we developed functions for the estimation of lime biomass in the aboveground woody parts. The functions were parameterized using 81 tree samples collected in two plots in the czech republic. in addition, we compared the biomass estimates produced by our functions with estimates produced by a function for beech, which have been obviously used as a surrogate for missing lime models in the czech republic and Slovakia.on average, 78% of lime aboveground biomass was found to account for tree stem, 20% for branches and 2% for stump. average biomass density was 374 kg m −3 and no significant differences between tree compartments were found. accuracy of all models in terms of the root Mean Square error (rMSe) significantly differed between tree diameter classes; in case of total aboveground biomass, the rMSe was ca. 20% of the average biomass weight in a given class up to a diameter of 45 cm, and then it rose sharply. The rMSe was higher in case of compartments with variable dimensions, such as branches and stump. rMSe was slightly higher in case of estimates produced using a beech-specific function than using that developed in the current study (average rMSe 27.95 and 29.42%, respectively); at the same time, beech-specific function overestimated lime stem biomass by ca 12%. The almost equal rMSe implies the usability of both parameterisations for lime biomass estimation, though the correction of the mentioned overestimation should be applied. Key words: biomass weight and volume; wood density; temperate forests; tree compartments Abstrakt lípa malolistá (Tilia cordata Mill.) v současnosti nepředstavuje hospodářsky významnou dřevinu, což je jeden z důvodů proč jsou poznatky o distribuci její biomasy v rámci stromu značně nekompletní. Kromě toho, biomasa lípy je většinou hodnocená pomocí rovnic navrhnutých pro jiné dřeviny, přičemž možné nedostatky tohoto postupu jsou ve značné míře neznámé. Z těchto důvodů jsme na základě údajů zís-kaných z 81 stromů na dvou plochách v České republice vytvořili parametrizace rovnic pro odhad dřevnatých částí nadzemní biomasy lípy. následně jsme porovnali odhady objemu biomasy lípy získané pomocí námi navrhnutých modelů s odhadem získaným modelem parametrizovaným pro buk, který je v České republice a na Slovensku pro hodnocení biomasy lípy obvykle používaný.v průměru připadalo 78% nadzemní biomasy na kmen stromu, 20% na korunu a 2% na pařez. Průměrná hustota biomasy činila 374 kg na m −3 a nebyl zjištěn signifikantní rozdíl mezi hustotou jednotlivých kompartmentů. Přesnost všech modelů v intencích procentuální rMSe (root Mean Square error) byla vyšší do tloušťkové třídy 45 cm, následně se zhoršila. v případě celkové nadzemní biomasy se pohybovala kol...