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CO 2 fluxes of cryptogamic crusts
Author(s) -
JEFFRIES D. L.,
LINK S. O.,
KLOPATEK J. M.
Publication year - 1993
Publication title -
new phytologist
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.742
H-Index - 244
eISSN - 1469-8137
pISSN - 0028-646X
DOI - 10.1111/j.1469-8137.1993.tb03891.x
Subject(s) - dehydration , saturation (graph theory) , chemistry , carbon dioxide , photosynthesis , carbon cycle , water content , environmental chemistry , respiration , botany , ecology , biology , ecosystem , geology , biochemistry , mathematics , geotechnical engineering , organic chemistry , combinatorics
SUMMARY The carbon dioxide exchange of Microcoleus ‐ and Scytonema ‐dominated cryptogamic crusts as related to dehydration was measured in the laboratory with a modified discrete sampling technique and infrared gas analysis. The dehydration curves predicted that carboxylation and dark respiration rates for both crust types would become zero at from 4 to 5% water content (W) (approximately 16–23% soil saturation), with the water contents at which the rates became zero significantly lower in the second treatment cycle than the first. The dehydration curves predicted that net photosynthesis rates would become zero at 6.7–11.2% W (27–44% soil saturation), with the water contents at which the rates became zero significantly higher in the second cycle of treatment than the first.