- DeRose, Robert Justin
University of Maine Graduate School
Relationship between leaf area index (LAI) and relative density (RD) were examined in even-aged stands of Abies Balsamea (L.) Mill. and Picea rubens Sarge. Twelve sites distributed across the Acadian forest in Maine were used to test conformance to three hypothesized models of LAI over RD:A) constantly increasing LAI over increasing RD, B) constant LAI with increasing RD, or C) decreasing LAI with increasing RD. Multivariate ordination suggested young, pre commercially thinned (PCT), high-site-index (SI) A. balsamea stands should be analyzed separate from older, un spaced (NOPCT), lower-site P. rubens stands. All-sided A. balsamea LAIs ranged from 6.2 - 14.8 over RDs of 0.23-0.60, P. rubens LAIs ranged from 7.5 - 14.9 over RDs of 0.51 - 0.76. Data for both species suggested an increase in LAI with increasing RD. At a given RD, LAI was strongly and positively correlated with SI. Lack of data across a complete range of RDs for both stand types limited testing of any hypothesized relationship between LAI and RD; however, when LAIs were adjusted to a common SI conformance to trend A was evident.