Caddo Lake, situated on the border of northeast Texas and northwest Louisiana, USA is a medium-sized lake dominated by stands of baldcypress (Taxodiwn distichum). A study of tree growth was initiated at Caddo Lake to address concerns about the health of the baldcypress ecosystem. The lake has been subjected to several dramatic water-level changes over the past 200 years, including water-level stabilization following dam construction in 1914. To assess the long-term growth trends of baldcypress trees and determine if a recent growth decline is occurring at Caddo Lake, increment cores were taken from 52 trees. The cores were crossdated and rings between the years 1900 and 1992 measured to the nearest 0.01 mm. Most cores were characterized by high variation in year-to-year growth. Although increasing growth rates were observed at most locations, trees from two backwater areas of the lake had recent growth rates lower than their long-term average. Growth amounts at these two sites were, however, within the historic range of variation. No recruitment was observed. From these data, we can conclude that the historic, extreme changes in hydrologic regime and the current stabilized water levels have not resulted in an overall decline in baldcypress growth at Caddo Lake.
