Advanced

Lichens facilitate seedling recruitment in alpine heath

Nystuen, Kristin O. ; Sundsdal, Kristine ; Opedal, Øystein H. LU ; Holien, Håkon ; Strimbeck, George Richard and Graae, Bente J. (2019) In Journal of Vegetation Science 30(5). p.868-880
Abstract

Questions: How do mat thickness, physical structure and allelopathic properties of terricolous mat-forming lichens affect recruitment of vascular plants in dwarf-shrub and lichen heath vegetation?. Location: The mountains of Dovrefjell, central Norway. Methods: In autumn, seeds of ten vascular plant species were collected and sown in a common garden experiment with mats of six lichen species and bare soil controls as experimental treatments. We recorded growing season soil temperature and moisture, and seedling recruitment and growth after one year. The effect of lichen secondary compounds on germination was tested in a growth chamber experiment and compared to the lichen–plant interactions detected under field conditions. Results: The... (More)

Questions: How do mat thickness, physical structure and allelopathic properties of terricolous mat-forming lichens affect recruitment of vascular plants in dwarf-shrub and lichen heath vegetation?. Location: The mountains of Dovrefjell, central Norway. Methods: In autumn, seeds of ten vascular plant species were collected and sown in a common garden experiment with mats of six lichen species and bare soil controls as experimental treatments. We recorded growing season soil temperature and moisture, and seedling recruitment and growth after one year. The effect of lichen secondary compounds on germination was tested in a growth chamber experiment and compared to the lichen–plant interactions detected under field conditions. Results: The lichen mats buffered extreme soil temperatures and soil drying in dry weather, with soils below the thickest mats (Cladonia stellaris and C. rangiferina) experiencing the lowest temperature fluctuations. Seedling recruitment and seedling growth in the field and seed germination in the lab were species-specific. Seedling recruitment rates were overall higher within lichen mats than on bare soil, but the c. 6.5-cm-thick mats of C. stellaris reduced recruitment of many species. The lab experiment suggested no overall strong effect of lichen allelopathy on seed germination, and effects on seed germination were only moderately correlated with the lichen–plant interactions observed for seedling recruitment in the field. Conclusions: In harsh environments like alpine dwarf-shrub and lichen heaths, the presence of lichens and the resulting amelioration of the microclimate seem more important for vascular plant recruitment than are allelopathic effects often reported in lab experiments. We might therefore expect most terricolous lichens, depending on the plant species in focus, to facilitate rather than hamper the early stages of plant recruitment into lichen-dominated arctic-alpine heath vegetation.

(Less)
Please use this url to cite or link to this publication:
author
; ; ; ; and
organization
publishing date
type
Contribution to journal
publication status
published
keywords
Alectoria, Cetraria, Cladonia heath, Flavocetraria, ground lichen, lichen secondary metabolites, lichen–plant interaction, microclimate, seedling emergence, soil moisture, Stereocaulon, tundra, vascular plant colonization
in
Journal of Vegetation Science
volume
30
issue
5
pages
13 pages
publisher
International Association of Vegetation Science
external identifiers
  • scopus:85073484004
ISSN
1100-9233
DOI
10.1111/jvs.12773
language
English
LU publication?
no
id
121e6caf-23cf-4a61-9808-cdcb9b3f10f3
date added to LUP
2020-02-04 08:39:35
date last changed
2020-12-29 03:55:11
@article{121e6caf-23cf-4a61-9808-cdcb9b3f10f3,
  abstract     = {<p>Questions: How do mat thickness, physical structure and allelopathic properties of terricolous mat-forming lichens affect recruitment of vascular plants in dwarf-shrub and lichen heath vegetation?. Location: The mountains of Dovrefjell, central Norway. Methods: In autumn, seeds of ten vascular plant species were collected and sown in a common garden experiment with mats of six lichen species and bare soil controls as experimental treatments. We recorded growing season soil temperature and moisture, and seedling recruitment and growth after one year. The effect of lichen secondary compounds on germination was tested in a growth chamber experiment and compared to the lichen–plant interactions detected under field conditions. Results: The lichen mats buffered extreme soil temperatures and soil drying in dry weather, with soils below the thickest mats (Cladonia stellaris and C. rangiferina) experiencing the lowest temperature fluctuations. Seedling recruitment and seedling growth in the field and seed germination in the lab were species-specific. Seedling recruitment rates were overall higher within lichen mats than on bare soil, but the c. 6.5-cm-thick mats of C. stellaris reduced recruitment of many species. The lab experiment suggested no overall strong effect of lichen allelopathy on seed germination, and effects on seed germination were only moderately correlated with the lichen–plant interactions observed for seedling recruitment in the field. Conclusions: In harsh environments like alpine dwarf-shrub and lichen heaths, the presence of lichens and the resulting amelioration of the microclimate seem more important for vascular plant recruitment than are allelopathic effects often reported in lab experiments. We might therefore expect most terricolous lichens, depending on the plant species in focus, to facilitate rather than hamper the early stages of plant recruitment into lichen-dominated arctic-alpine heath vegetation.</p>},
  author       = {Nystuen, Kristin O. and Sundsdal, Kristine and Opedal, Øystein H. and Holien, Håkon and Strimbeck, George Richard and Graae, Bente J.},
  issn         = {1100-9233},
  language     = {eng},
  month        = {09},
  number       = {5},
  pages        = {868--880},
  publisher    = {International Association of Vegetation Science},
  series       = {Journal of Vegetation Science},
  title        = {Lichens facilitate seedling recruitment in alpine heath},
  url          = {http://dx.doi.org/10.1111/jvs.12773},
  doi          = {10.1111/jvs.12773},
  volume       = {30},
  year         = {2019},
}