Contemporary Descriptions of the Historic Tree Plantations, Home of Franklin D. Roosevelt and Eleanor Roosevelt National Historic Sites

Nowak, Christopher; Van Gorp, William

Inventory and analysis of extant tree plantations established by Franklin. D. Roosevelt on Roosevelt family lands in Hyde Park, Dutchess County, New York. In mid-summer 2008, the boundaries of each tree plantation were defined in the field using a closed traverse method where the azimuth and distance of each plantation edge was measured in the field (combinations of temporary “courses” and “traverse stations”) and closed via normal correction approaches. The current shape and area of the plantations are different than the shape when originally planted due to edge mortality of planted trees and encroachment of surrounding forests, usually naturally regenerated hardwood trees. The approximate center of each plantation was located and defined using a GPS unit. Each waypoint had an estimated accuracy of ± 25 feet based on an average of 50 location measurements in each plantation. A site-level map showing the location of each plantation was created using information collected in the field. A data layer showing plantation boundaries was created using the traverse information and visual evidence on aerial photography. Layers showing the location of streams, water bodies, roads, railroads, and buildings were created using the aerial photos. All layers in the map use the NAD83 (North American Datum 1983) datum and a Transverse Mercator projection system. All planted trees were measured for DBH and assessed for crown class (dominant, co-dominant, intermediate or overtopped). In many plantations, there were trees of other species in the stand area, but these were not measured due to time and funding constraints. A 100% inventory was used to account for planted trees, except in the largest plantations (Plantations 3, 10a, 10b, 12 and 16) where strip transects were used to produced estimates of plantation characteristics (strips were 20 feet wide and spaced apart from 50 to 100 feet; percent sample ranged from 10.1 to 27.7%). The total number of trees measured for the study was 2,016. Soil type for each plantation was determined using the Web Soil Survey developed by the U.S. Department of Agriculture, Natural Resources Conservation Service Conventional stand-based descriptors were calculated for each plantation: numbers of planted trees per acre, basal area per acre (square feet), and average DBH (inches). These statistics were combined with species type and plantation area to calculate a Risk Rating Score for each plantation, as follows (low score = lower risk). A total Risk Rating Score of between 5 and 12 was judged to be low risk, 13 to 18 as moderate risk, and > 18 high risk. It is expected that high risk plantations may persist for another 15 years only if active management is applied, moderate risk plantations may persist for up to 50 years without active management, and low risk plantation for perhaps 100 years or more.