Photosynthetic CO2 exchange and spectral vegetation indices of boreal mosses

Moss dominated ecosystems are an important part of the global terrestrial carbon cycle. Over large areas, remote sensing can be useful to provide an improved understanding of these ecosystems. Two boreal mossess (Pleurozium and Sphagnum) were assessed using remote sensing based spectral vegetation indices for estimating biochemical capacity and photosynthetic efficiency by varying net photosynthesis rate via changes in water content. In the laboratory, changes in the normalized difference vegetation index (NDVI) and chlorophyll index coincided with declining photosynthetic capacity due to desiccation. This effect was more dramatic in Sphagnum. The photochemical reflectance index (PRI) did not vary with changes in CO2 supply as anticipated, possibly due to overriding effects of changing water content. The water band index (WBI) was strongly related to water content but this relationship showed an uncoupling in the field. Bi-directional reflectance measurements indicated what WBI was sensitive to sensor, sun, and moss surface slope angles.

Authors

• Van Gaalen, Kenneth Eric
• University of Lethbridge. Faculty of Arts and Science

• Environmental monitoring -- Remote sensing
• Carbon cycle (Biogeochemistry) -- Remote sensing
• Photosynthesis -- Research
• Peat mosses -- Remote sensing
• Mosses -- Remote sensing
• Atmospheric carbon dioxide -- Environmental aspects
• Dissertations, Academic

Identifier

hdl:10133/293

OAI identifier oai:identifier

oai:opus.uleth.ca:10133/293