TY - JOUR
T1 - Dendrochronology in the dry tropics: the Ethiopian case
AU - Wils, T.
AU - Sass-Klaassen, U.
AU - Eshetu, Z.
AU - Bräuning, A.
AU - Gebrenirstos, A.
AU - Couralet, C.
AU - Robertson, I.
AU - Touchan, R.
AU - Koprowski, M.
AU - Conway, D.
AU - Briffa, K.R.
AU - Beeckman, H.
PY - 2011
Y1 - 2011
N2 - 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 notdistinct 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.
AB - 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 notdistinct 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.
KW - climate-growth relationships
KW - tree-ring analysis
KW - pterocarpus-angolensis
KW - rhizophora-mucronata
KW - isotope ratios
KW - stable carbon
KW - africa
KW - forests
KW - dynamics
KW - reconstruction
U2 - 10.1007/s00468-010-0521-y
DO - 10.1007/s00468-010-0521-y
M3 - Article
VL - 25
SP - 345
EP - 354
JO - Trees-Structure and Function
JF - Trees-Structure and Function
SN - 0931-1890
IS - 3
ER -