Patterns of early cohort development following shelterwood cutting in three Adirondack northern hardwood stands

Remeasurement and chronosequence techniques were used to describe early dev elopment in three Adirondack northern hardwood stands for up to 26 years fo llowing shelterwood seed cutting to 35-65% canopy cover. Earlier herbicide treatments had controlled dense American beech (Fagus grandifolia) understo ries in the stands, leaving them devoid of advance regeneration. Deer (Odoc oileus virginianus borealis) had also been reduced by hunting and through n atural losses. Findings showed that total stems (stems greater than or equa l to 0.3 m tall) and saplings (stems greater than or equal to 2.54 cm DBH) followed distinct patterns of development among the stands, Total stems pea ked around five years after seed cutting, suggesting that most new individu als had initiated by that time. By 10 years total stems were declining subs tantially, indicating that crown closure had occurred and growing space was becoming limiting within the new cohort. By 19 years sapling abundance had peaked, and by 26 years numbers had begun to decline. Non-linear regressio n techniques were used to model consistent patterns of development among th e stands. Observed patterns of self-thinning were related to the timing of canopy closure and subsequent stratification within the new cohort. (C) 199 9 Elsevier Science B.V. All rights reserved.