Effect of thinning treatment on xylogenesis and phloemogenesis in young pure Norway spruce plantations - a case study from the Czech Republic

Result code in IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F00020702%3A_____%2F23%3AN0000107" target="_blank" >RIV/00020702:_____/23:N0000107 - isvavai.cz</a>

Result on the web

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DOI - Digital Object Identifier

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Result language

angličtina

Original language name

Effect of thinning treatment on xylogenesis and phloemogenesis in young pure Norway spruce plantations - a case study from the Czech Republic

Original language description

The influence of various silvicultural treatments and stand densities on tree growth response to climate is considered critical in determining forest preservation, particularly during drought episodes. Despite being the most represented and valuable traded wood species in the Czech Republic, Norway spruce (Picea abies L. Karst.) is becoming more sensitive to mortality due to its susceptibility to drought occurrences. Therefore, the relationship between forest management treatments, tree growth, and microclimate reactions must be clarified to predict tree survival in the face of ongoing climate change. The presented study investigates the effect of different thinning intensities on xylogenesis and phloemogenesis in the healthy, fully-leaved, and dominant 14-year-old Norway spruce trees (9 in total) growing in three distinct managed plots in the East-Bohemian forest stand. Pre-commercial thinning reduced stand density to 1,800 trees ha-1 (plot A; mild thinning) and 1,300 trees ha-1 (plot C; heavy thinning) in February 2020. Plot B was a control variant with no silvicultural intervention (4,500 trees ha-1). During the same year’s growing season, the trees were sampled (micro-cored) to evaluate to evaluate xylem and phloem formation (2020) every week. Preliminary findings indicate that thinning improves the rate of an overall increase in both xylem and phloem cells, as well as the total number of generated tracheids and sieve cells. The average number of produced xylem cells in control plot B was barely 140 mature cells, whereas plots C and A were found to be 175 and 200 mature cells, respectively. Moreover, the number of sieve cells formed by Norway spruce trees growing in plot C (heavy thinning) was noticeably increased (more than 20 on average), but the average number of sieve cells produced in plot B (control) in the respective growth period hardly exceeded 15 on average. On the other hand, thinning has negligible effect on the timings of the phenological phases of the xylem and phloem formation. Reduced stand density strengthens individual tree tolerance to drought stress, and the magnitude of this differential response varies among the same species along a climate gradient. Based on that and supported by our findings, thinning can help Norway spruce, sensitive to drought, to overcome adverse climate conditions. To attain the best results in total wood production, the intensity of the thinning strategy must be evaluated, and more research is needed to determine how the canopy density would behave in the years following the thinning application.

Czech name

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Czech description

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Type

O - Miscellaneous

CEP classification

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OECD FORD branch

40102 - Forestry

Project

<a href="/en/project/QK21020307" target="_blank" >QK21020307: Optimization of silviculture procedures for adaptation of forest ecosystems to climate change</a><br>

Continuities

P - Projekt vyzkumu a vyvoje financovany z verejnych zdroju (s odkazem do CEP)

Publication year

2023

Confidentiality

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů