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Abstract Detail



Ecological and evolutionary attributes of bryophytes of the boreal and arctic regions: New paradigms from interdisciplinary research

Loisel, Julie [1].

Modern Sphagnum growth driven by photosynthetically active radiation and growing season length: implications for Holocene carbon sequestration in peatlands.

High-latitude peatlands contain about one third of the world’s soil organic carbon, most of which is derived from partly decomposed Sphagnum plants. We investigated the effects of bioclimatic variables on the growth rate of peat-moss species Sphagnum magellanicum and S. fuscum. To fulfill this goal, we gathered and analyzed a large number of Sphagnum growth measurements taken in peatlands from around the world. Photosynthetically active radiation integrated over the growing season (PAR0) was the main predictor of Sphagnum growth in peatlands, with higher growth rates associated with milder climates and longer growing seasons, and vice versa. It is generally assumed that higher temperatures will increase peat decay, causing a positive feedback to climate warming and contributing to the global positive carbon cycle feedback. On the contrary, our findings support the hypothesis that growing season length is an important control of peatland biomass production over millennial timescales, and that increasing PAR0 as a result of global warming could promote Sphagnum growth. Several records of peat accumulation rates are in agreement with these findings. Assuming that production and decomposition have the same sensitivity to temperature, this enhanced growth could lead to greater peat-carbon sequestration, inducing a negative feedback to climate change.


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1 - UCLA, Geography, and Institute of the Environment and Sustainability, La Kretz Hall, suite 300, box 951496, Los Angeles, CA, 90095, USA

Keywords:
Peatland
Sphagnum
Carbon cycle.

Presentation Type: Symposium Presentation
Session: SY03
Location: Salon 10/The Shaw Conference Centre
Date: Monday, July 27th, 2015
Time: 11:15 AM
Number: SY03008
Abstract ID:928
Candidate for Awards:None


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