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

Absorption of food - zoology, ABSORPTIO N OF FOOD Absorption from Mo...

ABSORPTIO N OF FOOD Absorption from Mouth Here negligible tobacco, alkohal and some medicines as isoprenailne glycerol tri nitrite is absorbed. Absorptio n from Sto

Find out risk factors for coronary disease, Q. Find out risk factors for co...

Q. Find out risk factors for coronary disease? 1) Tobacco Smoking, the single most preventable cause of death is a leading risk factor for CAD, cerebrovascular accident and

Define the factors that affect the rate of drying, Define the Factors that ...

Define the Factors that Affect the Rate of Drying? Factors that affect the rate of drying are as follow: 1) The fat content of the food-Higher fat contents generally result

Tapeworm, life cycle of tapeworm in detail

life cycle of tapeworm in detail

Predisposing factors and pathphysiology of meningitis, Predisposing Factors...

Predisposing Factors The patients with diabets mellitus, malignancies and those on immunosuppressive drugs have reduced resistance and are more susceptible to develop meningi

Cultural and religious values, Wildlife has influenced language, art, relig...

Wildlife has influenced language, art, religion and social customs of many societies worldwide, and wild animals figure prominently in many cultures even today. In all cultures of

Define age as a determinants of nutrient requirements, Define Age as a dete...

Define Age as a determinants of nutrient requirements? Age: Requirements change with increasing age between birth and maturity. Nutrient requirements per unit body weight are h

What is h shaped incision and what is its purpose, Q. What is H shaped inci...

Q. What is H shaped incision and what is it's purpose? This type of incision is especially useful for: The anterior maxilla or mandible. Accurately identified implant

What are the sign of horner''s syndrome, What are the sign of Horner's synd...

What are the sign of Horner's syndrome? 1. Miosis, 2. ptosis, 3. enophthalmos, 4. anhidrosis and 5. heterochrome iridis.

Explain about human auditory sensitivity, What are the structures that part...

What are the structures that participate in the human auditory sensitivity? The structures of the human auditory sensitivity are the ears (external, middle and internal), the

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