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

Into which classes are mollusc divided, Q Into which classes are mollusc di...

Q Into which classes are mollusc divided? What are some representing beings of each class? The phylum Mollusca is divided into five main classes: pelecypods, or bivalves (Pelec

Tolerance to cold and freezing temperatures, Normal 0 false f...

Normal 0 false false false EN-IN X-NONE X-NONE MicrosoftInternetExplorer4

Explain light in cell metabolism, Explain Light in cell Metabolism? Ene...

Explain Light in cell Metabolism? Energy for almost all organisms on earth is derived directly or indirectly from light energy produced by the sun. Sunlight consists of energy

Subatomic Particles, We have end of semester exams coming up meaning that a...

We have end of semester exams coming up meaning that a majority of it will be over subatomic particles

Mechanisms of different species of animal, Mechanisms of different species ...

Mechanisms of different species of animal In an animal when the need to change the focal power of the eye arises, different mechanisms are there in different species of animal

Evolutionary implications of natural regulation, Evolutionary Implications ...

Evolutionary Implications of Natural Regulation Many changes in abundance can be attributed to changes in extrinsic factors such as weather, disease or predation. But some cha

What is the etiological agent of visceral leishmaniasis, What is the etiolo...

What is the etiological agent of visceral leishmaniasis? How is the disease transmitted and what are its typical manifestations? Visceral leishmaniasis is caused by the protozo

General examination - heart failure, The patient will appear anxious and dy...

The patient will appear anxious and dyspnoeic. Patients in chronic heart failure are usually malnourished and even cachectic. Chronic passive venous congestion may produce exophtha

Explain waste produced during surgical process, Q. Explain Waste produced d...

Q. Explain Waste produced during surgical process? Some of the waste products produced during a surgical process are dressings, sponges, gloves or other soft material dripping

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