Ancient Woodlands

NOTE: Harvard Forest did not provide written metadata. Rather, this metadata was written by the Martha's Vineyard Commission based on a phone conversation with Harvard Forest staff in Dec. 2023. Utilizing Harvard Forest's "Ancient Woodlands" data of 2019, the Martha's Vineyard Commission ran the Identity geoprocessing tool with that dataset and the MVC's 12/22/2023 version of the Open Space Conservation data for Martha's Vineyard. This process retained all of the Ancient Woodlands data and superimposed the attributes of [Level of Protection] and [OS_ID] into the Ancient Woodlands polygons. This permits one to readily analyze the data to see where Ancient Forests are currently protected in perpetuity, etc. Please see the Description section for background about Harvard Forest's delineation of the Ancient Woodlands. A domain table is provided which explains the Level of Protection codes. The [OS_ID] is a numeric ID which links back to the MVC's Open Space Conservation dataset. OS_ID is a unique identifier within that dataset. The numbers before the hyphen is the Town ID. 62 = Chilmark, 89 = Edgartown, 104 = Aquinnah, 221 = Oak Bluffs, 296 = Tisbury, 327 = West Tisbury. The Ancient Woodlands data were produced by Harvard Forest in Dec. 2019. Data for Martha's Vineyard were received from Harvard Forest in November of 2023. Looking at historic maps and older aerial photographs, Harvard Forest noted for 4 time periods when forest was present on the map or photo. Locations where forest was present for all 4 time periods, were regarded as 'Ancient Woodlands'. The 4 time periods reviewed were: circa 1850, circa 1890, 1938, 1993. Then the data were updated, based on Google's November 2018 photos, for recent development or new agricultural areas. Areas where development or agricultural fields existed were removed from the Ancient Woodlands dataset. The areas delineated in this dataset, represent Ancient Woodlands present as of year-end 2018. Please note: Ancient Woodlands are not the same as "Old Growth Forest". The specific citation for the 1850 and 1890 map are unknown. Harvard Forest georeferenced those maps in ArcGIS software. The 1938 black and white aerial photographs were georeferenced by a consultant hired by Harvard Forest. As an aside FYI, the 1993 photographs (color infrared? black & white?) is the same year of photography which was used for The Nature Conservancy's vegetation delineation of Martha's Vineyard. Not sure if Harvard Forest used the exact same photos as the TNC project but the time period is the same. Harvard Forest is in the process of analyzing the potential ecological benefit of these Ancient Woodlands. Preliminary results show these area have more huckleberry than non-Ancient Woodland areas. The Martha's Vineyard Commission did convert the Harvard Forest Ancient Woodlands data from multi-part polygons to single-part polygons prior to running the Identity analysis.