Capacity of Desert Algal Crusts to Fix Atmospheric Nitrogen1
- A. N. Macgregor and
- D. E. Johnson2
Approximately 4% of the soil surface of an area of desert grassland in the Sonoran Desert of southern Arizona possessed algal-crust formations. Samples of dry intact algal crusts were examined for nitrogen fixation by the acetylene-ethylene method. Three hours after being moistened, algal crusts produced detectable levels of ethylene. Premoistened algal crusts were capable of producing ethylene equivalent to 0.7 µg of N/cm2 of algal crust per hour. On the basis of these findings, 1 ha of desert grassland may receive a nitrogen input of 3 to 4 g of N/hour (0.3 mg to 0.4 mg N/m2 per hr) following a rainfall.Please view the pdf by using the Full Text (PDF) link under 'View' to the left.
Copyright © .