Patterns of woody plant abundance, recruitment, mortality, and growth in a 65 year chronosequence of old-fields

摘要: We surveyed vegetation along forest margins in a 65-year chronosequence of old-fields at the Cedar Creek Natural History Area east-central Minnesota, USA, to identify successional patterns woody plants and determine if these were correlated with soil nitrogen. predicted that shrub tree abundance, size, distance occurrence from edge would be field age or Instead we did not find trends abundance composition species. Even oldest trees shrubs was low concentrated areas close forest. Though larger present further edges older fields, average height less than 126 cm all fields. Since looked various local factors (local seed sources, deer browsing, aspect) their relation recruitment, mortality, growth explain variation among fields shrubs. The three most common species (Quercus rubra, Q. macrocarpa,and Populus tremuloides) had higher relative seedlings, two (Q. rubra macrocarpa) large adjacent forests high conspecific adults. Most taller 20 cm browsed by shorter 1995 they 1993. Mortality for 30 cm indicating mortality size-dependent. Forest aspect significantly influence demography any Our results suggest seedling recruitment largely determined proximity sources may persist so communities resemble forests. Deer significant factor suppression populations through repeated browsing which reduces elevates prolonging period time remain susceptible size-dependent mortality.