The oaks and pines of the middle successional group are also the most ubiquitous, having the widest range, and growing in the most diverse environments. Although they most often appear together, there seems to be a distinct separation due to some unknown factor. My speculation is that one species, probably the oak, prefers a wetter environment. Another possibility is salt spray. While salt spray provides essential nutrition for beachgrass, it kills other species. Some such as bear oak, Quercus illicifolia, are very salt tolerant. Others, such as pitch pine, are very intolerant. The identification of oaks was very difficult due to small differences within species.    Peter@PeterRomanelli.com    508-487-4570