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Ramet dynamics in a centrifugally expanding clonal sedge: a matrix analysis

Wikberg, Sofie LU and Svensson, B M (2006) In Plant Ecology 183(1). p.55-63
Abstract
Carex humilis is a clonal sedge that can form distinct rings of densely aggregated ramets. We hypothesize that rings form because both production of new ramets and ramet dispersal are positively correlated to ramet size. This would lead to an overrepresentation of fast-moving and large ramets with high ramet production at the periphery, whereas slow-moving and small ramets with low ramet production would mainly be found in the interior of rings. We use matrix models to analyse how ramet populations both at the periphery and in the interior develop in the absence of ramet dispersal. We found that the stable size class distributions of ramets predicted by the models were not different from the distributions found in the field. Also, the... (More)
Carex humilis is a clonal sedge that can form distinct rings of densely aggregated ramets. We hypothesize that rings form because both production of new ramets and ramet dispersal are positively correlated to ramet size. This would lead to an overrepresentation of fast-moving and large ramets with high ramet production at the periphery, whereas slow-moving and small ramets with low ramet production would mainly be found in the interior of rings. We use matrix models to analyse how ramet populations both at the periphery and in the interior develop in the absence of ramet dispersal. We found that the stable size class distributions of ramets predicted by the models were not different from the distributions found in the field. Also, the asymptotic ramet population growth rates (lambda(1)) were the same. Hence, we conclude that rings would form even in the absence of a link between ramet dispersal and ramet production. Further analysis of the matrix models showed that the ramet population increases at the periphery but decreases in the interior of rings because medium and large ramets produce fewer large ramets in the interior than at the periphery. We also found that the temporal variance in lambda(1) and transitions rates during the four study years was much higher at the periphery than in the interior. Our results suggest that rings may form because C. humilis ramets use below-ground resources from a much larger area than the one covered by the shoots. As the clone grows larger, the soil volume available to the ramets in the interior decreases because their access to soil outside the ring is cut-off by the ramets at the periphery. Ramet density in the interior is therefore decreasing. (Less)
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author
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organization
publishing date
type
Contribution to journal
publication status
published
subject
in
Plant Ecology
volume
183
issue
1
pages
55 - 63
publisher
Springer
external identifiers
  • wos:000238158000007
  • scopus:33745068937
ISSN
1573-5052
DOI
10.1007/s11258-005-9006-2
language
English
LU publication?
yes
additional info
The information about affiliations in this record was updated in December 2015. The record was previously connected to the following departments: Plant Ecology and Systematics (Closed 2011) (011004000)
id
b22f15fc-7415-46c1-9515-017d003fe6c9 (old id 159636)
date added to LUP
2016-04-01 12:34:44
date last changed
2021-05-25 01:54:45
@article{b22f15fc-7415-46c1-9515-017d003fe6c9,
  abstract     = {Carex humilis is a clonal sedge that can form distinct rings of densely aggregated ramets. We hypothesize that rings form because both production of new ramets and ramet dispersal are positively correlated to ramet size. This would lead to an overrepresentation of fast-moving and large ramets with high ramet production at the periphery, whereas slow-moving and small ramets with low ramet production would mainly be found in the interior of rings. We use matrix models to analyse how ramet populations both at the periphery and in the interior develop in the absence of ramet dispersal. We found that the stable size class distributions of ramets predicted by the models were not different from the distributions found in the field. Also, the asymptotic ramet population growth rates (lambda(1)) were the same. Hence, we conclude that rings would form even in the absence of a link between ramet dispersal and ramet production. Further analysis of the matrix models showed that the ramet population increases at the periphery but decreases in the interior of rings because medium and large ramets produce fewer large ramets in the interior than at the periphery. We also found that the temporal variance in lambda(1) and transitions rates during the four study years was much higher at the periphery than in the interior. Our results suggest that rings may form because C. humilis ramets use below-ground resources from a much larger area than the one covered by the shoots. As the clone grows larger, the soil volume available to the ramets in the interior decreases because their access to soil outside the ring is cut-off by the ramets at the periphery. Ramet density in the interior is therefore decreasing.},
  author       = {Wikberg, Sofie and Svensson, B M},
  issn         = {1573-5052},
  language     = {eng},
  number       = {1},
  pages        = {55--63},
  publisher    = {Springer},
  series       = {Plant Ecology},
  title        = {Ramet dynamics in a centrifugally expanding clonal sedge: a matrix analysis},
  url          = {http://dx.doi.org/10.1007/s11258-005-9006-2},
  doi          = {10.1007/s11258-005-9006-2},
  volume       = {183},
  year         = {2006},
}