Document: PET-3-4-15

Causes and consequences of variation in forest productivity and N cycling: From patch to region and seedling to ecosystem

REICH, P.* ¹, M.TOBIN ¹, J.L.MACHADO ¹, M.WALTERS ¹, S.OLLINGER ³, K.WYTHERS ¹ and D.WEDIN ²

University of Minnesota, St. Paul, MN 55108 USA ¹
University of Nebraska, Lincoln NE 68583 USA ²
University of New Hampshire, Durham, NH 03824 USA ³

Abstract:
Climate, soils, site history, vegetation type and stage of vegetation development all influence uptake (i.e., productivity), storage and turnover of C and N. We compare variation in N cycling at a range of scales (from fine-scale within forest to regional scales) and ask how and when this matters to woody plant growth and production. Examples include fine-scale heterogeneity of N cycling within cold temperate forests and its relationship to both mature trees and tree seedlings. We also ask about the role of vegetation feedbacks and disturbances, such as fire and logging, in regulating inter-stand variation in C and N cycling, using boreal, northern hardwood and oak savanna ecosystem studies as examples. Finally, we use process modeling to examine how well our collective understanding of ecosystem physiology and biogeochemistry allows us to predict patterns and magnitude of C and N cycling under these various conditions, and then use this understanding to simulate potential responses to global change elements such as CO₂, N, ozone and land use history.

Keywords: Forest productivity, nitrogen cycling

This abstract is being presented at: 2:05 PM in session:
Symposium # 10: Integrating Ecosystem and Landscape Ecology: Causes and Consequences of Spatial Heterogeneity in Ecosystem Processes.