Stem responses to damage: the evolutionary ecology of Quercus species in contrasting fire regimes.
* The ability of tree stems to recover from damage is critical for tree survival and may explain species distributions across disturbance regimes. Two primary responses to stem damage, decay compartmentalization and wound closure, act in concert to limit decay and pathogen spread. A previous study demonstrated a tradeoff between wound responses that varied with anatomical traits, but its wide taxonomic range made it hard to analyze responses in an evolutionary context. * Here, we tested the stem wound responses of 13 species of Quercus inhabiting three habitats across a gradient of fire intensity. We also quantified anatomical and structural traits and phylogenetic position, in order to assess the relative contributions of ecological adaptation and phylogenetic history in determining traits. * Xylem anatomical traits were phylogenetically constrained, while phloem traits and damage responses varied with habitat. Across habitats, hammock and sandhill species closed bark wounds effectively, whereas scrub species limited the spread of xylem decay. There was a tradeoff between wound closure and decay compartmentalization within the white+live oaks. * The fact that some wound response traits are phylogenetically constrained while others respond to ecological pressures suggests that damage responses integrate mechanisms operating at several levels within plants.
Romero
Claudia
C
Department of Botany and Zoology, University of Florida, Bartram 227, PO Box 118525, Gainesville, FL 32611-8525, USA.
Bolker
Benjamin M
BM
Department of Botany and Zoology, University of Florida, Bartram 227, PO Box 118525, Gainesville, FL 32611-8525, USA.
Edwards
Christine E
CE
Department of Botany and Zoology, University of Florida, Bartram 227, PO Box 118525, Gainesville, FL 32611-8525, USA.|Florida Museum of Natural History, PO Box 117800, University of Florida, Gainesville, FL 32611-7800, USA.
D000704:Analysis of Variance; D005075:Biological Evolution; D004463:Ecology; D017753:Ecosystem; D005390:Fires; D005431:Florida; D052585:Phloem / Q000033:anatomy & histology; D010802:Phylogeny; D018547:Plant Stems / Q000033:anatomy & histology / Q000502:physiology*; D025341:Principal Component Analysis; D019655:Quantitative Trait, Heritable; D029963:Quercus / Q000033:anatomy & histology / Q000502:physiology*; D013045:Species Specificity; D052584:Xylem / Q000033:anatomy & histology