Final published version
Research output: Contribution to Journal/Magazine › Journal article › peer-review
Short-term effect of deep shade and enhanced nitrogen supply on Sphagnum capillifolium morphophysiology. / Bonnett, Samuel Alexander Festing; Ostle, Nick; Freeman, Chris.
In: Plant Ecology, Vol. 207, No. 2, 01.04.2010, p. 347-358.Research output: Contribution to Journal/Magazine › Journal article › peer-review
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TY - JOUR
T1 - Short-term effect of deep shade and enhanced nitrogen supply on Sphagnum capillifolium morphophysiology
AU - Bonnett, Samuel Alexander Festing
AU - Ostle, Nick
AU - Freeman, Chris
PY - 2010/4/1
Y1 - 2010/4/1
N2 - Sphagnum capillifolium mesocosms collected from an ombrotrophic blanket bog were subjected to controlled photon flux densities (control and shaded) and nitrogen (low and high) treatments between November 2003 and August 2004. Shading significantly reduced biomass of S. capillifolium (P < 0.001), whilst nitrogen (N) supply significantly increased biomass (P < 0.05) suggesting that S. capillifolium was limited by N. There was no significant interaction between shading and N on biomass. S. capillifolium responded to shading via morphophysiological and biochemical alterations to the photosynthetic tissues such as (1) break down of anthocyanins involved in photoprotection of chloroplasts, (2) translocation of N from mineralized N or old tissues and (3) allocation of translocated N to photosynthetic pigments. The results suggest that S. capillifolium can tolerate both low and high light intensities, as well as high N supply via morphophysiological responses but does not acclimate to deep shade, since biomass was reduced. Anthocyanins rather than carotenoids appear to play an essential role in photoprotection with translocation serving as the important source of N. It has been suggested that global change in temperature and N availability may lead to increased vascular plant growth that could increase shade leading to a shift from Sphagnum spp. to vascular species in peatlands. However, the species S. capillifolium appears to tolerate deep shade and high N deposition due to the mechanisms shown here suggesting that this species may continue to persist in peatland ecosystems.
AB - Sphagnum capillifolium mesocosms collected from an ombrotrophic blanket bog were subjected to controlled photon flux densities (control and shaded) and nitrogen (low and high) treatments between November 2003 and August 2004. Shading significantly reduced biomass of S. capillifolium (P < 0.001), whilst nitrogen (N) supply significantly increased biomass (P < 0.05) suggesting that S. capillifolium was limited by N. There was no significant interaction between shading and N on biomass. S. capillifolium responded to shading via morphophysiological and biochemical alterations to the photosynthetic tissues such as (1) break down of anthocyanins involved in photoprotection of chloroplasts, (2) translocation of N from mineralized N or old tissues and (3) allocation of translocated N to photosynthetic pigments. The results suggest that S. capillifolium can tolerate both low and high light intensities, as well as high N supply via morphophysiological responses but does not acclimate to deep shade, since biomass was reduced. Anthocyanins rather than carotenoids appear to play an essential role in photoprotection with translocation serving as the important source of N. It has been suggested that global change in temperature and N availability may lead to increased vascular plant growth that could increase shade leading to a shift from Sphagnum spp. to vascular species in peatlands. However, the species S. capillifolium appears to tolerate deep shade and high N deposition due to the mechanisms shown here suggesting that this species may continue to persist in peatland ecosystems.
KW - Anthocyanin
KW - Biomass
KW - Nitrogen
KW - Photosynthetic pigments
KW - Shading
KW - Sphagnum capillifolium (Ehrh.) Hedw
U2 - 10.1007/s11258-009-9678-0
DO - 10.1007/s11258-009-9678-0
M3 - Journal article
AN - SCOPUS:77951976956
VL - 207
SP - 347
EP - 358
JO - Plant Ecology
JF - Plant Ecology
SN - 1385-0237
IS - 2
ER -