Dendrochronology in the dry tropics: The Ethiopian case

T. H G Wils, U. G W Sass-Klaassen, Z. Eshetu, A. Bräuning, A. Gebrekirstos, C. Couralet, I. Robertson, Ramzi Touchan, M. Koprowski, D. Conway, K. R. Briffa, H. Beeckman

Research output: Contribution to journalArticle

36 Citations (Scopus)

Abstract

Dendrochronology is developing outside temperate and boreal regions. Over the past decade substantial progress has been made in Mediterranean and wet tropical regions. However, research in dry tropical regions, notably those of sub-Saharan Africa, has remained fragmentary. Here, we try to identify the unique challenges and opportunities of dendrochronology in the dry tropics. First, we briefly review the status of dendrochronology outside temperate and boreal regions with an emphasis on sub-Saharan Africa. Subsequently, we focus upon one of those areas where dendrochronology in the dry tropics is at the forefront of scientific advance: Ethiopia. A detailed review of tree ring studies in the lowlands and highlands highlights the complexity of ring formation and made us identify four major types of growth ring expression: anatomically not distinct rings, multiple rings per year, annual rings and multiple missing rings. This complex tree growth behaviour is associated with large-scale variations in precipitation regime (unimodal to multimodal) and relatively small-scale variations in tree sensitivity to water availability. Literature results are used to develop a scheme that can be used to predict differences in growth ring formation along gradients in these two factors. Because of the exceptional growth sensitivity of and the importance of local site conditions (topography, biological factors, etc.) for most trees sampled, those growing at the limits of their ecological amplitude are prone to possess multiple rings per year or multiple missing rings. In such circumstances, site selection should not always take place at the limits of the ecological amplitude of a species, but may sometimes have to be diverted to more mesic environments. Successful studies are now appearing, such as those reporting correlations between tree ring chronologies and Blue Nile river flows.

Original languageEnglish (US)
Pages (from-to)345-354
Number of pages10
JournalTrees - Structure and Function
Volume25
Issue number3
DOIs
StatePublished - Jun 2011

Fingerprint

dendrochronology
growth rings
Sub-Saharan Africa
tropical region
tree ring
Africa South of the Sahara
tropics
Growth
Nile River
Chronology
site selection
arid region
Ethiopia
river flow
water availability
tree growth
topography
chronology
Biological Factors
lowlands

Keywords

  • Acacia
  • Juniperus procera
  • Ring formation
  • Tree rings
  • Wood anatomy

ASJC Scopus subject areas

  • Forestry
  • Plant Science
  • Physiology
  • Ecology

Cite this

Wils, T. H. G., Sass-Klaassen, U. G. W., Eshetu, Z., Bräuning, A., Gebrekirstos, A., Couralet, C., ... Beeckman, H. (2011). Dendrochronology in the dry tropics: The Ethiopian case. Trees - Structure and Function, 25(3), 345-354. https://doi.org/10.1007/s00468-010-0521-y

Dendrochronology in the dry tropics : The Ethiopian case. / Wils, T. H G; Sass-Klaassen, U. G W; Eshetu, Z.; Bräuning, A.; Gebrekirstos, A.; Couralet, C.; Robertson, I.; Touchan, Ramzi; Koprowski, M.; Conway, D.; Briffa, K. R.; Beeckman, H.

In: Trees - Structure and Function, Vol. 25, No. 3, 06.2011, p. 345-354.

Research output: Contribution to journalArticle

Wils, THG, Sass-Klaassen, UGW, Eshetu, Z, Bräuning, A, Gebrekirstos, A, Couralet, C, Robertson, I, Touchan, R, Koprowski, M, Conway, D, Briffa, KR & Beeckman, H 2011, 'Dendrochronology in the dry tropics: The Ethiopian case', Trees - Structure and Function, vol. 25, no. 3, pp. 345-354. https://doi.org/10.1007/s00468-010-0521-y
Wils THG, Sass-Klaassen UGW, Eshetu Z, Bräuning A, Gebrekirstos A, Couralet C et al. Dendrochronology in the dry tropics: The Ethiopian case. Trees - Structure and Function. 2011 Jun;25(3):345-354. https://doi.org/10.1007/s00468-010-0521-y
Wils, T. H G ; Sass-Klaassen, U. G W ; Eshetu, Z. ; Bräuning, A. ; Gebrekirstos, A. ; Couralet, C. ; Robertson, I. ; Touchan, Ramzi ; Koprowski, M. ; Conway, D. ; Briffa, K. R. ; Beeckman, H. / Dendrochronology in the dry tropics : The Ethiopian case. In: Trees - Structure and Function. 2011 ; Vol. 25, No. 3. pp. 345-354.
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