Contrasting Development of Canopy Structure and Primary Production in Planted and Naturally Regenerated Red Pine Forests

Forests

MarkR. Kreider¹  ChristopherM. Gough²  Jeff Atkins²  LauraJ. Hickey²  RobertT. Fahey³  SheaB. Wales⁴ 

[1] Center for Environmental Sciences and Engineering, University of Connecticut, Storrs, CT 06269, USA;Department of Biology, Virginia Commonwealth University, Richmond, VA 23220, USA;;Department of Natural Resources and the Environment &Wildland Resources Department, Utah State University, Logan, UT 84321, USA;

关键词: Pinus resinosa Sol. Ex Aiton;    red pine;    net primary production;    leaf area index;    LiDAR;    canopy rugosity;    forest succession;    light;    fPAR;    chronosequence;    light use efficiency;   

DOI  :  10.3390/f10070566

来源: DOAJ

【 摘 要 】

Globally, planted forests are rapidly replacing naturally regenerated stands but the implications for canopy structure, carbon (C) storage, and the linkages between the two are unclear. We investigated the successional dynamics, interlinkages and mechanistic relationships between wood net primary production (NPP_w) and canopy structure in planted and naturally regenerated red pine (Pinus resinosa Sol. ex Aiton) stands spanning ≥ 45 years of development. We focused our canopy structural analysis on leaf area index (LAI) and a spatially integrative, terrestrial LiDAR-based complexity measure, canopy rugosity, which is positively correlated with NPP_w in several naturally regenerated forests, but which has not been investigated in planted stands. We estimated stand NPP_w using a dendrochronological approach and examined whether canopy rugosity relates to light absorption and light−use efficiency. We found that canopy rugosity increased similarly with age in planted and naturally regenerated stands, despite differences in other structural features including LAI and stem density. However, the relationship between canopy rugosity and NPP_w was negative in planted and not significant in naturally regenerated stands, indicating structural complexity is not a globally positive driver of NPP_w. Underlying the negative NPP_w-canopy rugosity relationship in planted stands was a corresponding decline in light-use efficiency, which peaked in the youngest, densely stocked stand with high LAI and low structural complexity. Even with significant differences in the developmental trajectories of canopy structure, NPP_w, and light use, planted and naturally regenerated stands stored similar amounts of C in wood over a 45-year period. We conclude that widespread increases in planted forests are likely to affect age-related patterns in canopy structure and NPP_w, but planted and naturally regenerated forests may function as comparable long-term C sinks via different structural and mechanistic pathways.

【 授权许可】

Unknown