COASTAL PRAIRIE SOILS

Coastal Prairie soils are typicaly poorly drained and shallow, with a hard clay pan beneath. They become parched when the weather is dry and gooey wet when there is available moisture. The clay pan beneath is thought to be the restricting element that hampers tree and woody shrub growth. Fire was a reinforcing element in this regard, suppressing plants that would otherwise shade out the herbaceous layer.

MYCORRHIZA IN PRAIRIE SOILS

Dr. Malcom Vidrine, Louisiana State University at Eunice, La

Mycorrhizae are fungi that form massive underground systems called mycelia. Two major groups of these Mycorrhizae occur: Endomycorrhizae (about 30 known species) that grow mycelia into the host plant’s roots and Ectomyorrhizae (about 5,000 know species, many restricted to a single host plant species or groups)   that simply surround the roots of the host plant like a glove or an epithelium (skin). They both exchange materials with the plants.e.g., sugars. The fungi are able to mobilize phosphorous in the soil to an extent that exceeds plants in general and further they share this precious substance with the plants in exchange for sugar. These mycorrhizae actually are so abundant in fertile soil as to create a matrix of mycelia that mobilize not only phosphorous but also other essential micronutrients in the soil.  Potassium is credited with assisting plants in the uptake of phosphorous but I do not know the mechanism.  As a last note, many weedy, early succession plants do not commingle with mycorrhizae—they are able to obtain phosphorous in sufficient quantities to out compete other ends.  We often see the microbial hyphae (mycelia) as merely part of the normal plant root systems. We see the bacterial nodules as part of the root system, we see the flower and often fail to see the small bee or fly inside it, we see the fruit disappear only to reappear as a seeding either in the dung of an animal or from its dead body.  We see fire as the great destroyer, only to later realize that it is essential to maintain prairies and Pine forests.  Nothing is as it appears at first glance—observation is required to separate the cow from the cow manure.