Journal
PLANT AND SOIL
Volume 429, Issue 1-2, Pages 127-146Publisher
SPRINGER
DOI: 10.1007/s11104-018-3635-4
Keywords
Biological soil crust; CO2 gas exchange; Photosynthesis; Soil respiration
Categories
Funding
- Max Planck Society
- German Research Foundation [WE 2393/2-1, WE 2393/2-2]
Ask authors/readers for more resources
Background and Aims Biological soil crusts cover about one third of the terrestrial soil surfaces in drylands, fulfilling highly important ecosystem services. Their relevance to global carbon cycling, however, is still under debate. Methods We utilized CO2 gas exchange measurements to investigate the net photosynthetic response of combined cyanobacteria/cyanolichen-, chlorolichen- and moss-dominated biocrusts and their isolated photoautotrophic components to light, temperature, and water. The results were compared with field studies to evaluate their compatibility. Results Different biocrust types responded similarly, being inhibited by limited and excess water, saturated by increasing light intensities, and having optimum temperatures. Cyanobacteria/cyanolichen-dominated biocrusts reached their water optimum at lowest contents (0.52-0.78 mm H2O), were saturated at highest light intensities, and had a comparably high temperature optimum at 37 degrees C. Chlorolichen-dominated crusts had a medium water optimum (0.75-1.15 mm H2O), medium saturating light intensities and a moderate temperature optimum of 22 degrees C. Moss-dominated biocrusts had the highest water optimum (1.76-2.38 mm H2O), lowest saturating light intensities, and a similar temperature optimum at 22 degrees C. Isolated photoautotrophs responded similar to complete crusts, only isolated moss stems revealed much lower respiration rates compared to complete crusts. Conclusions In addition to their overall functional similarities, cyanobacteria/cyanolichen-dominated biocrusts appeared to be best adapted to predicted climate change of increasing temperatures and smaller precipitation events, followed by chlorolichen-dominated biocrusts. Moss-dominated biocrusts needed by far the largest amounts of water, thus likely being prone to anticipated climate change.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available