1. Histories of changing land use and vegetation of a 380-ha forested area in central Massachusetts (Prospect Hill tract of the Harvard Forest) were reconstructed to investigate (i) the environmental controls over land ownership patterns, agricultural practice and logging activity, and (ii) the vegetation response to these land-use factors. 2. Forest clearance and agricultural expansion parallel trends for central New England: increasing rates of deforestation through the late eighteenth century led to a peak in 1820-80 when more than 80% of the land was open. Reforestation on abandoned fields commenced in 1850 and increased progressively through the early twentieth century. 3. Ownership patterns varied temporally in turnover rate and size of individual holdings. Twenty-five lots comprising the study area were sold an average of 13 times in the period 1730-1910. Land sales were greatest in the period of speculation and low-intensity agriculture (1730-90), lowest during the transition to commercial agriculture and small-scale industry (1790-1840), and high during the period of agricultural decline in the mid to late 1800s. 4. Land use in the mid 1800s, including woodlot (13% of the study area), tilled fields (16%), pasture (70%) and marsh (1%), formed an intricate pattern best explained by soil drainage and proximity to farmhouses and town roads. This land-use pattern controlled the reforestation process: field abandonment and reforestation proceeded outward from poorly drained pasture adjacent to the continuous woodlots and eventually included productive tilled land. 5. The consequences of 250 years of land-use activity vary at different scales. Regionally, the distribution of modern and pre-settlement forest types match well despite structural changes and the loss of some tree species. At a landscape scale, modern forest characteristics are strongly controlled by land use. Canonical correspondence analysis indicates that community variation is best explained by historical factors (distinction between primary and secondary woodlands, forest age, cutting history and timing of site abandonment) and site factors (slope position and soil drainage). Picea rubens and Tsuga canadensis forests are restricted to primary woodlands, Pinus strobus and sprouts of Castanea dentata are largely confined to old pastures, and Betula populifolia, Populus spp. and Acer rubrum are most abundant in cut-over old-field Pinus stands. 6. Long-term forest trends in the twentieth century include a decrease in the importance of Pinus strobus due to logging and the 1938 hurricane, a gradual decline in early successional hardwoods (Betula populifolia, Populus spp.. Acer rubrum), and increase in later successional species (Quercus rubra, Q. velutina. Acer saccharum). Tsuga and northern-hardwood species (Acer saccharum. Fagus grandifolia) declined dramatically throughout the settlement period; however, the major forest trend over the past 100 years has been a continual increase in Tsuga.
