Spatial Pattern of Coast Redwood in Three Alluvial Flat Old-Growth Forests in Northern California

The spatial patterns of trees were investigated in old-growth redwood (Sequoia sempervirens [D. Don] Endl.) forests located in northern California to guide the design of restoration prescriptions. All stems ≥15 cm dbh were mapped and measured on three 1.5-ha plots. Patterns for trees in different size classes were analyzed separately with Ripley's K(d) function. Results revealed two patterns. At two sites, trees were randomly distributed throughout the stand and size classes were spatially independent of each other at scales of 0–50 m. At one site, a clumped spatial pattern was revealed for small- and medium-sized tree groups at small scales, whereas a random spatial pattern was detected for large trees at scales of 0–50 m. In addition, significant positive deviation from spatial independence at small scales suggested an attraction between tree groups. The spatial pattern of regeneration (trees