Alpine and Arctic tundra shrub populations show similar ontogenetic growth trends but differing absolute growth rates and lifespan

0568954 - BÚ 2024 RIV NL eng J - Journal Article
Lehejček, J. - Trkal, F. - Doležal, Jiří - Čada, V.
Alpine and Arctic tundra shrub populations show similar ontogenetic growth trends but differing absolute growth rates and lifespan.
Dendrochronologia. Roč. 77, February (2023), č. článku 126046. ISSN 1125-7865. E-ISSN 1612-0051
R&D Projects: GA ČR(CZ) GA21-26883S
Institutional support: RVO:67985939
Keywords : alpine plant growth * climate change * arctic
OECD category: Plant sciences, botany
Impact factor: 3, year: 2022
Method of publishing: Limited access
https://doi.org/10.1016/j.dendro.2022.126046

The majority of terrestrial primary production is performed by plants, the ontogenetic growth trends of which significantly influence biomass and carbon dynamics. Here, we present a study of ontogenetic trends in primary (apical) and secondary (stem thickening) growth of plants in Arctic (Svalbard, Norway) and alpine (Krkonose, Czechia) populations of the black crowberry (Empetrum nigrum), the dominant plant species of certain tundra communities. The environmental conditions in alpine areas are more favourable for plant growth than those in the High Arctic, where temperatures are lower, there is less precipitation and soils are shallower, among other differences. These differences were clearly reflected in significant distinctions in absolute growth rates and shrub age between the populations under study. However, we found almost no divergence in ontogenetic growth trends between the populations (based on ring width measurements made from the base to the top of plants, known as serial sectioning). In both populations, primary and secondary stem base growth decrease over the course of ontogeny whereas secondary stem top growth and basal area increment increase. No significant differences in the slope of the trends were found in either primary or secondary stem base growth. Trends of the growth ratio between basal area increment and primary growth revealed neither absolute nor relative differences between the populations. Ontogenetic trends in the shrubs analysed were surprisingly stable despite the prominently dis-similar environmental conditions. Empetrum plants have adapted to the different environments by altering their absolute growth rate only. This adaptation has probably also resulted in the different longevity of plants constituting the study populations, confirming the theory that slower-growing plants live longer. Primary growth and secondary stem base growth seem to be more basic characteristics of plant growth compared to basal area increment and secondary growth at the apex because the latter two seem to be dependent on the absolute growth rate.
Permanent Link: https://hdl.handle.net/11104/0346071