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Bryophyte-Cyanobacteria Associations during Primary Succession in Recently Deglaciated Areas of Tierra del Fuego (Chile).

Authors :
Arróniz-Crespo, María
Pérez-Ortega, Sergio
De los Ríos, Asunción
Green, T. G. Allan
Ochoa-Hueso, Raúl
Casermeiro, Miguel Ángel
de la Cruz, María Teresa
Pintado, Ana
Palacios, David
Rozzi, Ricardo
Tysklind, Niklas
Sancho, Leopoldo G.
Source :
PLoS ONE; May2014, Vol. 9 Issue 5, p1-14, 14p
Publication Year :
2014

Abstract

Bryophyte establishment represents a positive feedback process that enhances soil development in newly exposed terrain. Further, biological nitrogen (N) fixation by cyanobacteria in association with mosses can be an important supply of N to terrestrial ecosystems, however the role of these associations during post-glacial primary succession is not yet fully understood. Here, we analyzed chronosequences in front of two receding glaciers with contrasting climatic conditions (wetter vs drier) at Cordillera Darwin (Tierra del Fuego) and found that most mosses had the capacity to support an epiphytic flora of cyanobacteria and exhibited high rates of N<subscript>2</subscript> fixation. Pioneer moss-cyanobacteria associations showed the highest N<subscript>2</subscript> fixation rates (4.60 and 4.96 µg N g<superscript>−1</superscript> bryo. d<superscript>−1</superscript>) very early after glacier retreat (4 and 7 years) which may help accelerate soil development under wetter conditions. In drier climate, N<subscript>2</subscript> fixation on bryophyte-cyanobacteria associations was also high (0.94 and 1.42 µg N g<superscript>−1</superscript> bryo. d<superscript>−1</superscript>) but peaked at intermediate-aged sites (26 and 66 years). N<subscript>2</subscript> fixation capacity on bryophytes was primarily driven by epiphytic cyanobacteria abundance rather than community composition. Most liverworts showed low colonization and N<subscript>2</subscript> fixation rates, and mosses did not exhibit consistent differences across life forms and habitat (saxicolous vs terricolous). We also found a clear relationship between cyanobacteria genera and the stages of ecological succession, but no relationship was found with host species identity. Glacier forelands in Tierra del Fuego show fast rates of soil transformation which imply large quantities of N inputs. Our results highlight the potential contribution of bryophyte-cyanobacteria associations to N accumulation during post-glacial primary succession and further describe the factors that drive N<subscript>2</subscript>-fixation rates in post-glacial areas with very low N deposition. [ABSTRACT FROM AUTHOR]

Details

Language :
English
ISSN :
19326203
Volume :
9
Issue :
5
Database :
Complementary Index
Journal :
PLoS ONE
Publication Type :
Academic Journal
Accession number :
96282279
Full Text :
https://doi.org/10.1371/journal.pone.0096081