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Biocrusts enhance soil fertility and Bromus tectorum growth, and interact with warming to influence germination

Plant and Soil

By:
https://doi.org/10.1007/s11104-017-3525-1

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Abstract

Background and aims

Biocrusts are communities of cyanobacteria, mosses, and/or lichens found in drylands worldwide. Biocrusts are proposed to enhance soil fertility and productivity, but simultaneously act as a barrier to the invasive grass, Bromus tectorum, in western North America. Both biocrusts and B. tectorum are sensitive to climate change drivers, yet how their responses might interact to affect dryland ecosystems is unclear.

Methods

Using mesocosms with bare soil versus biocrust cover, we germinated B. tectorum seeds collected from warmed, warmed + watered, and ambient temperature plots within a long-term climate change experiment on the Colorado Plateau, USA. We characterized biocrust influences on soil fertility and grass germination, morphology, and chemistry.

Results

Biocrusts increased soil fertility and B. tectorum biomass, specific leaf area (SLA), and root:shoot ratios. Germination rates were unaffected by mesocosm cover-type. Biocrusts delayed germination timing while also interacting with the warmed treatment to advance, and with the warmed + watered treatment to delay germination.

Conclusions

Biocrusts promoted B. tectorum growth, likely through positive influence on soil fertility which was elevated in biocrust mesocosms, and interacted with seed treatment-provenance to affect germination. Understanding how anticipated losses of biocrusts will affect invasion dynamics will require further investigation of how plant plasticity/adaptation to specific climate drivers interact with soil and biocrust properties.

Additional publication details

Publication type:
Article
Publication Subtype:
Journal Article
Title:
Biocrusts enhance soil fertility and Bromus tectorum growth, and interact with warming to influence germination
Series title:
Plant and Soil
DOI:
10.1007/s11104-017-3525-1
Volume:
429
Issue:
1-2
Year Published:
2018
Language:
English
Publisher:
Springer
Contributing office(s):
Southwest Biological Science Center
Description:
14 p.
First page:
77
Last page:
90
Country:
United States
Other Geospatial:
Colorado Plateau