Light attenuation by early successional plants of the boreal forest

Citation
C. Shropshire et al., Light attenuation by early successional plants of the boreal forest, CAN J FORES, 31(5), 2001, pp. 812-823
Citations number
39
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Plant Sciences
Journal title
CANADIAN JOURNAL OF FOREST RESEARCH-REVUE CANADIENNE DE RECHERCHE FORESTIERE
ISSN journal
0045-5067 → ACNP
Volume
31
Issue
5
Year of publication
2001
Pages
812 - 823
Database
ISI
SICI code
0045-5067(200105)31:5<812:LABESP>2.0.ZU;2-A
Abstract
The influence of eight early successional plant species from the boreal for est on photosynthetically active radiation (PAR) were compared using a cont rolled plant competition study. Four woody (green alder, Alnus crispa (Ait. ) Pursh; upland willow, Salix humilis Marsh.; white birch, Betula papyrifer a Marsh.; wild red raspberry, Rubus idaeus L.) and four herbaceous (eastern bracken fern, Pteridium aquilinum L.; bluejoint grass, Calamagrostis canad ensis Michx.; large-leaved aster, Aster macrophyllus L.; fireweed, Epilobiu m angustifolium L.) plant species were studied using an additive density ex periment with jack pine (Pinus banksiana Lamb.) seedlings. The transmission of PAR through the plant canopies was measured using a line quantum sensor under six plant density treatments at the time of maximum canopy developme nt each year. Four measures of plant abundance (planting density, actual de nsity, projected leaf area index, and crown cover) were evaluated for their ability to predict PAR transmission through the plant canopies. Visual est imates of crown cover provided the best models each year. Vertical profiles of PAR transmission were used to compare the canopy structure among plant species and were used to refine the models. During the second growing seaso n, increasing crown cover of bluejoint grass and large-leaved aster had the largest influence on PAR. In the third season, green alder, upland willow, and white birch (along with bluejoint grass and fireweed at the jack pine crown level) had the greatest influence on PAR. PAR measurements taken from a nearby forest for several of the plant species indicate that the models developed from our controlled experiment are reasonably applicable to natur ally occurring plant populations.