USING DENDROCLIMATIC ANALYSIS OF EXOTIC DECIDUOUS CONIFERS IN AN ABORETUM TO DOCUMENT TREE GROWTH IN RESPONSE TO CLIMATE CHANGE, NORTHEAST OHIO, USA

Dendroclimatic analysis of arboretum grown trees is an underutilized tool that can yield vital information on the climate response of exotic species and assess their value in terms of ecosystem services. Four species of exotic deciduous conifers growing in Secrest Aboretum, Wooster, Ohio, USA over the past century offer a unique opportunity to examine the climate response of trees growing in climates outside their natural ranges. This study of four well-replicated ring-width series provides information that can help anticipate future responses of each species in their native range to changing climates, which may ultimately be similar to the ongoing pluvial and warming in Northeast Ohio. Comparisons of tree growth with monthly climate records show that the growth of two larch species (Dahurian and European; Larix gmelinii and Larix decidua) have been limited primarily by summer precipitation, although this relationship has weakened since the mid-1970s coinciding with precipitation increases. Larch response to maximum summer temperatures is negative and thus future tree health, may be limited by future warming and increased evaporative demands. Exotic bald cypress (Taxodium distichum) and dawn redwood (Metasequoia glyptostroboides) stands maintain a positive robust precipitation response that persists through the present, in contrast to the larch. Dawn redwood is also a negative responder to maximum summer temperature, which could be factor of concern in the future, whereas, bald cypress responds positively to warming temperatures and are well suited for the ongoing pluvial and warming conditions of Northeast, Ohio reflecting its wetter, warmer endemic range. Taken together, this study is an example of tree response to climate gleaned from a largely untapped source of tree growth in arboreta that can be more broadly applied at other sites.