PARENT SESSION
Organized Oral Session 47: Insights, challenges, and future directions in modeling forest dynamics at multiple scales
Organizer(s): C Tripler, C Canham, C Messier, and M Papaik
Thursday, August 11, 1:30 PM - 5:00 PM, Meeting Room 510a, Level 5, Palais des congrès de Montréal

Great Mountain Forest revisited: Neighborhood dynamics of a northeastern forest.

Canham, Charles¹, ¹ Institute of Ecosystem Studies, Millbrook, NY

ABSTRACT- It has been over a decade since publication of the first papers describing SORTIE, a spatially-explicit, individual-based model of forest dynamics. The model was originally developed for Great Mountain Forest (GMF), a transitional oak-northern hardwood forest in southern New England. The model was extraordinarily simple: shading of juveniles by adult trees was the only form of interaction between individuals included in the model. The model, however, provides a framework for thinking about a broad range of neighborhood processes in forests. Research at Great Mountain Forest in the past decade has provided a great deal of mechanistic and empirical detail on phenomena ranging from animal population dynamics to feedbacks between tree species and soil nutrient dynamics. For example, we now know that most of the fine-scale spatial variation in tree species distribution within GMF is governed by spatial heterogeneity in soil parent material and a complex set of feedbacks from canopy trees. Saplings of all of the dominant tree species have been shown to respond to fertilization treatments, but the responses are highly species specific, with individual species responding to variation in calcium, potassium, nitrogen and/or pH. Differential browsing by white-tailed deer has a strong effect on the competitive hierarchy of sapling growth and survival. There is also now reason to conclude that the dispersal functions used in the original model underestimate effective seed dispersal and seedling dispersion. I will revisit the basic conclusions of the original SORTIE papers in light of these studies.

Key words: SORTIE, neighborhood processes