Despite their foresight, the foresters who established our permanent plots were not interested in seedlings or saplings. Consequently, we inherited extensive long-term records for trees, but not for seedlings. This is unfortunate as establishment is often the critical step in determining whether a species will succeed in a particular habitat (Grubb 1977, Harper 1975), and if so when. To compensate, we initiated observations of seedling demography in 1978. Seedlings were mapped along permanently marked transects 1-m wide and 10 to 50-m long. These transects cross the normal range of spatial variation in each stand. Annually, seedlings of all dominant tree species were mapped by Cartesian coordinates along each transect. Using data sheets prepared from the previous year's census, field crews have found it relatively easy to relocate survivors and to identify new ingrowth. The identity of each seedling, whether it was alive, and its height, and number of leaves (up to 20) were recorded. These data were checked systematically for a broad range of possible errors.

We initially established 10 intensive seedling study plots (250-300 m of transect) and 11 auxiliary seedling plots (ca 50m). The transects cross the normal range of spatial variation in a forest and thus allow us to document aver­ages for stands as well as heterogeneity within stands. Starting in 1989 we shifted to maintaining 5 intensive seedling plots representing three types of mature hardwood forest and two stands near the stage of transition from loblolly pine to hardwoods. Annual measurements continued through 1994, and again 1997-2001. For these five sites we also monitored sapling (> 1m tall and < 1 cm dbh) growth annually in a set of 4x50 m transects that overlap the seedling transects.