Identification of factors influencing the restoration of cyanobacteria-dominated biological soil crusts

PLoS One. 2014 Mar 13;9(3):e90049. doi: 10.1371/journal.pone.0090049. eCollection 2014.

Abstract

Biological soil crusts (BSCs) cover >35% of the Earth's land area and contribute to important ecological functions in arid and semiarid ecosystems, including erosion reduction, hydrological cycling, and nutrient cycling. Artificial rapid cultivation of BSCs can provide a novel alternative to traditional biological methods for controlling soil and water loss such as the planting of trees, shrubs, and grasses. At present, little is known regarding the cultivation of BSCs in the field due to lack of knowledge regarding the influencing factors that control BSCs growth. Thus, we determined the effects of various environmental factors (shade; watering; N, P, K, and Ca concentrations) on the growth of cyanobacteria-dominated BSCs from the Sonoran Desert in the southwestern United States. The soil surface changes and chlorophyll a concentrations were used as proxies of BSC growth and development. After 4 months, five factors were found to impact BSC growth with the following order of importance: NH4NO3 ≈ watering frequency>shading>CaCO3 ≈ KH2PO4. The soil water content was the primary positive factor affecting BSC growth, and BSCs that were watered every 5 days harbored greater biomass than those watered every 10 days. Groups that received NH4NO3 consistently exhibited poor growth, suggesting that fixed N amendment may suppress BSC growth. The effect of shading on the BSC biomass was inconsistent and depended on many factors including the soil water content and availability of nutrients. KH2PO4 and CaCO3 had nonsignificant effects on BSC growth. Collectively, our results indicate that the rapid restoration of BSCs can be controlled and realized by artificial "broadcasting" cultivation through the optimization of environmental factors.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Biomass
  • Calcium Carbonate / chemistry
  • Chlorophyll / chemistry
  • Chlorophyll A
  • Cyanobacteria / chemistry*
  • Desert Climate
  • Ecology
  • Ecosystem
  • Lichens / chemistry
  • Light
  • Nitrates / chemistry
  • Phosphates / chemistry
  • Poaceae
  • Potassium Compounds / chemistry
  • Soil Microbiology*
  • Southwestern United States
  • Temperature
  • Trees
  • Water

Substances

  • Nitrates
  • Phosphates
  • Potassium Compounds
  • Water
  • Chlorophyll
  • potassium phosphate
  • Calcium Carbonate
  • ammonium nitrate
  • Chlorophyll A

Grants and funding

The National Natural Science Foundation of China (Grant Nos 41071192 & 40701096), the West Light Foundation of the Chinese Academy of Sciences (No. B2008132), and the 111 project (No. B12007) provided funding for this research. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.