Relationship between radiation interception and photosynthesis in forest canopies: effect of stand structure and latitude

• Published in: Ecological modelling 1989, Vol.49 (1), p.73-87
• Main Authors: Oker-Blom, Pauline, Pukkala, Timo, Kuuluvainen, Timo
• Format: Article
• Language: English
• Subjects: Animal and plant ecology; Animal, plant and microbial ecology; Biological and medical sciences; CANOPY; COUVERT; CUBIERTA DE COPAS; Demecology; FOTOSINTESIS; Fundamental and applied biological sciences. Psychology; General aspects; PHOTOSYNTHESE; PHOTOSYNTHESIS; RADIACIONES; RADIATION; RADIATIONS
• ISSN: 0304-3800; 1872-7026
• DOI: 10.1016/0304-3800(89)90044-6

Interception of radiation and the consequent potential photosynthesis was studied, by sing a simulation model, in structurally different forest stands at latitu udes 40° and 60°. The studied stands were of two different types with respect to the leaf-area distribution: horizontally homogenous canopies and canopies with an aggregation of leaves into individual crowns. The effect of canopy structure on interception of radiation and photosynthesis was studied by varying leaf area index, stand density, and crown size and shape. In none of the studied cases was the relationship between accumulated radiation interception and photosynthesis strictly linear, but on a longer time-scale (one growing season) this non-linearity was not very pronounced. Neither canopy structure nor latitude substantially affected the slope of the relationship. In conclusion, while properties of canopy structure and incoming radiation determine the actual amount of radiation intercepted by the canopy, the conversion efficiency between intercepted radiation and photosynthesis appeared to be rather insensitive to differences in canopy structure and in properties of incoming radiation.