Date of Award

6-2013

Document Type

Open Access

Degree Name

Bachelor of Arts

Department

Environmental Science and Policy

First Advisor

Steven Rice

Language

English

Keywords

climate change, carbon, canopy, structures

Abstract

With climate change becoming a greater problem the ability of plants to photosynthesize and sequester carbon becomes more important for us to understand. Sphagnum moss stores more than a third of the world’s soil carbon. Much is understood about the physiology of Sphagnum, but what is generally not understood is the effect of variation in canopy organization in Sphagnum: why are they both rough and smooth? This study examined whether different canopy structures influenced how the canopy uses different angles of light for photosynthesis. The first step was modeling photosynthesis in two simulated structures (rough and smooth) as the angle of light changes. Following Lambert’s cosine law, relative photosynthesis was determined by integrating light absorbance and intensity of light the plant receives. The model showed both structures decrease in relative photosynthesis as the angle of light decreases following the same path. The second part was to test empirically using rough and smooth samples made from Sphagnum fallax. Photosynthesis was measured using the Licor 6400. Five samples, both rough and smooth, were made and each was tested 4 times, first at 90 degrees and then 45 degrees. The samples followed the model with no significant differences in net photosynthesis between the rough and smooth samples at either angle. When compared to the model, the rough, but not the smooth, showed significantly greater rates of photosynthesis at low light angles. Further study is needed to understand if there is a reason for the two canopy structures of Sphagnum in relation to photosynthesis.

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