Moss stage - xerarch, Biology

Assignment Help:

Moss Stage - Xerarch

The accumulation of soil, particularly in the crevices and depressions of rock favours the growth of certain xerophytic mosses, e.g., species of Polytrichum, Tortula and Grimmia. The spores of these mosses are brought by the blowing wind. They have more or less the same power of withstanding desiccation as that of foliose lichens.

The lichens and mosses grow together and compete 'with one another. The rhizoids of mosses and foliose lichens compete for water and nutrients, and the stems of the former attain greater height than the latter. The plants in the lower strata, i.e., the lichens die, and the mosses grow. The mosses form cushion-like structure that may be a few centimetres in thickness. The substratum is thus gradually built up and is widened. The foliose lichens gradually give way to mosses that overtop the lichens. Many times, all three stages may be found on a single rock surface, the pioneers occupying the most exposed places.


Related Discussions:- Moss stage - xerarch

What are the three parts of a dna nucleotide, What are the three parts of a...

What are the three parts of a DNA nucleotide, and how are they connected to each other? The three types are a deoxyribose sugar, a phosphate group, and a nitrogenous base. The

Describe the dinosaurs in multimedia tutorials, Describe the Dinosaurs in m...

Describe the Dinosaurs in multimedia Tutorials? Travel back to a time when dinosaurs ruled the earth. Learn about the different types of dinosaurs and practice building your ow

Define brain stem, Define Brain Stem Brain stem consists of three parts...

Define Brain Stem Brain stem consists of three parts i.e. midbrain, pons and medulla oblongata. The functions of the Brain Stem are: Brain stem contains points of cranial

Explain whipping foam method, Explain Whipping foam method? Whipping is...

Explain Whipping foam method? Whipping is the most common method used as it forms bubbles by cutting the surface and introducing air into liquid.  Repeated action makes the

Indifferences in ionic composition, Indifferences in ionic composition Answ...

Indifferences in ionic composition Answer A. across membranes can be created through the action of ATP driven pumps as long as number of negative and positive ions on remain equal

Determine the occurrence of vitamin A, Determine the Occurrence of vitamin ...

Determine the Occurrence of vitamin A In the vegetable kingdom, vitamin A  probably occurs in the form of its provitamins which belong to the group of carotenes. Carrots, spina

Autonomic nervous system, A.N.S. (Autonimic Nervous System) Name given ...

A.N.S. (Autonimic Nervous System) Name given by Langley . Controled by Hypothelamus. Partially independent system. Controls involuntary actions as heart beat, breathing,

Explain about catheters and guide wires, Q. Explain about Catheters and Gui...

Q. Explain about Catheters and Guide Wires? The commonly used guide wires vary in diameter from 0.012 to 0.052; with 0.035 or 0.038 being the most commonly used sizes. The stan

Bacterial food infections, Food infection occurs when a pathogen enters the...

Food infection occurs when a pathogen enters the gastrointestinal tract and multiplies. Microorganisms can penetrate into the intestinal mucosa and grow there, or they can pass thr

Systematics, binomial nomenclature is not applicable to

binomial nomenclature is not applicable to

Write Your Message!

Captcha
Free Assignment Quote

Assured A++ Grade

Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!

All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd