IMPACTS OF SETTLEMENT ON THE LANDSCAPE OF WILLSBORO, NY, AND LOCAL DROUGHT RECORDS: A TREE RING BASED PERSPECTIVE

In 1765 the Town of Willsboro was founded on the western shore of Lake Champlain in what is now northeastern New York. We are using tree ring records to better understand the timing and impacts of settlement on this landscape, and the impacts of climate on the settlers. Ring width chronologies from beams in old buildings for eastern hemlock, red spruce, red pine, and white ash have been successfully crossdated with regional master chronologies, while a floating white oak chronology is currently undated. We have also developed ring width chronologies for living red oak and red pine in the town.

Ages of buildings based on crossdated beams show good correspondence with the history of the town based on document sources. White ash beams are used in most of the older buildings (1780s-1830s) sampled but not thereafter, reflecting either local depletion of large trees of this species or a change in building material preference to eastern hemlock, which is used in many of the younger structures. A more general landscape impact is suggested by the local red pine chronology whose correlation with pine in an undisturbed area drops after 1790; this is when substantial expansion of Willsboro occurred and impacts such as livestock browsing, land drainage, and harvesting of fuel and building wood may have changed the tree ring signal in some local red pine. Impacts from both the initial founding and the c.1790s expansion of the town may also be responsible for stepwise changes in growth of some samples.

Dendroclimatic analysis of the living red oak and red pine chronologies shows a dominant drought signal. Reconstruction of a drought index using the red oak data indicates significant drought in Willsboro in 1849-50 and 1884, and documentary sources support this conclusion. The floating white oak chronology is an enigma because it does not crossdate with any existing oak chronologies from the region, some of which extend back to the 1660s. We hypothesize that these white oak originally grew in a local swamp and so contain an excess water signal in their ring width data rather than a regional drought record. If so, then this chronology may be a useful complement to existing dendroclimatic records of hydrometeorological variables for the region.