Addressing the information gap at the core of tropical tree ring research

A variety of emerging research directions in tropical tree demography requires traditional measures of tree size to be anchored by accurate aging techniques. Relating morphometric stages to tree age has been a difficult area of research in the tropics, as non-linear drivers of tree growth make determination of tree growth rate and age more difficult to determine, relative to temperate zones. However, the use of isotopic dating analyses of heartwood tissues extracted by increment bore coring is becoming increasingly widespread. Increment bore coring is a standard and integral practice in dendrochronological study; yet the long term effects on the health of cored trees are little studied and biased to temperate regions. We used meta-analysis to assess what we can know from the available data on tree responses to coring and to help make reasonable decisions in accessing valuable tree ring data. We report a significant reduction in the extent of decay responses with decreasing latitude of study site, but found no significant effect of tree successional status or wood density on the amount of damage accrued. The lack of knowledge surrounding tree responses to bore wounding presents a significant challenge for the use of tree core dating to understand plant demography, particularly for rare and threatened species. We also, therefore, explore best practice methodologies for increment bore coring and provide a five point framework for documenting the effects of bore damage upon trees.