. The Canadian field-naturalist. 1973 Notes 53 A Restricted Habitat for Mushrooms (Agaricaceae) in the Mackenzie River Delta, Northwest Territories The Salix alaxensis-Equisetum arvense succession- al community in the Mackenzie River Delta occurs primarily on the convex bank of shifting channels where young levees are rapidly aggrading due to sediment accumulation during the spring flood. Such levees annually receive 8-10 cm of alluvium which contracts upon drying to form desiccation cracks (Figure 1), agarics then grow on the exposed decaying ligne- ous material. They probably form a mycorrhi
. The Canadian field-naturalist. 1973 Notes 53 A Restricted Habitat for Mushrooms (Agaricaceae) in the Mackenzie River Delta, Northwest Territories The Salix alaxensis-Equisetum arvense succession- al community in the Mackenzie River Delta occurs primarily on the convex bank of shifting channels where young levees are rapidly aggrading due to sediment accumulation during the spring flood. Such levees annually receive 8-10 cm of alluvium which contracts upon drying to form desiccation cracks (Figure 1), agarics then grow on the exposed decaying ligne- ous material. They probably form a mycorrhizal relationship with the roots of Salix alaxensis which are also exposed by desiccation cracks at this time. In the study area (northeast-central Mackenzie Delta) Omphalina species are found only in the Salix alaxensis - Equisetum arvense community where they grow exclusively in desiccation cracks (Figure 2). A simple geomorphic process is thus largely responsible for the presence of one of the more characteristic members of this Figure 1. Dessication crack 40 cm deep in sediment on a rapidly aggrading slipoff slope in the Mac- kenzie River Delta. Note the layers of organic material. An interesting feature of this community is the presence of three mushrooms of the family Agari- caceae (genera Inocybe, Omphalina, and Corti- nariiis), which grow in the cracks that bisect the shrinking sediment. These fungi form mycelia, but they do not develop to a mature stage, partly be- cause fructifications can not develop until post- flood drainage is complete in early July (the species are thus immature and can not be identi- fied). At this time, new cracks expose a portion of the buried layer of the previous year's dead leaves and other organic matter that also contain mycelia, especially of Omphalina species. These Figure 2. One of the mushrooms {Omphalina sp.) that grow only in desiccation cracks in the Salix alaxensis - Equisetem arvense community of the Mackenzie River De
Size: 1830px × 1365px
Photo credit: © Book Worm / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookauthorottawafieldnaturalistsclub, bookcentury1900, bookcolle
