Root system development in naturally regenerated Douglas-fir saplings as influenced by canopy closure and crowding

Ch. Kuehne, Ch. Karrié, D.I. Forrester, U. Kohnle and J. Bauhus
Additional contact information
Ch. Kuehne: School of Environment and Natural Resources, Freiburg University, Freiburg, Germany
Ch. Karrié: School of Environment and Natural Resources, Freiburg University, Freiburg, Germany
D.I. Forrester: School of Environment and Natural Resources, Freiburg University, Freiburg, Germany
U. Kohnle: Forest Research Institute Baden-Württemberg, Freiburg, Germany
J. Bauhus: School of Environment and Natural Resources, Freiburg University, Freiburg, Germany

Journal of Forest Science, 2015, vol. 61, issue 9, 406-415

Abstract: Documented information on the growth dynamics and related silvicultural manipulation of naturally regenerat­ed Douglas-fir beneath a canopy shelter is scarce. We hypothesized that long regeneration phases creating dense cohorts of Douglas-fir advanced regeneration beneath a closed canopy of mature trees have a negative impact on the formation of a stable root system. We therefore studied the influence of shading and competition on root system characteristics of 28 naturally regenerated, ca 3 m tall Douglas-fir saplings growing either without immediate competitors or in dense neighbourhoods, and these situations were located either beneath a closed canopy or in large canopy openings. Both canopy shelter and neighbourhood crowding limited sapling growth and root system development. Saplings from groups located beneath the canopy, although significantly older than the saplings growing in the open, exhibited lower root-to-shoot ratios. When growing in the open, maximum width, total length, and total biomass of root systems was much lower for saplings with than without competitors. In contrast, reductions in root development owing to competition within the sapling cohort were less pronounced under closed canopy conditions. Our results suggest that irrespective of the level of canopy closure, high sapling densities in naturally regenerated young Douglas-fir stands should be reduced early to improve root system development and hence physical stability.

Keywords: natural regeneration; competition; shading; physical tree stability; carbon allocation; root-to-shoot ratio (search for similar items in EconPapers)
Date: 2015
References: View complete reference list from CitEc
Citations:

Downloads: (external link)
http://jfs.agriculturejournals.cz/doi/10.17221/53/2015-JFS.html (text/html)
http://jfs.agriculturejournals.cz/doi/10.17221/53/2015-JFS.pdf (application/pdf)
free of charge

Related works:
This item may be available elsewhere in EconPapers: Search for items with the same title.

Export reference: BibTeX RIS (EndNote, ProCite, RefMan) HTML/Text

Persistent link: https://EconPapers.repec.org/RePEc:caa:jnljfs:v:61:y:2015:i:9:id:53-2015-jfs

DOI: 10.17221/53/2015-JFS

Access Statistics for this article

Journal of Forest Science is currently edited by Mgr. Ilona Procházková

More articles in Journal of Forest Science from Czech Academy of Agricultural Sciences
Bibliographic data for series maintained by Ivo Andrle ().