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 is gastrulation, What is gastrulation? How during gastrulation are the...

What is gastrulation? How during gastrulation are the first two germ layers formed? What are these germ layers? Gastrulation is the process by which a portion of the blastula w

Colibacillosis of newborn animals, Colibacillosis of newborn animals T...

Colibacillosis of newborn animals This is the commonest disease entity of newborn farm animals. In calves the disease  occurs in three forms, viz. enteric colibacillosis manif

White flowers is crossed with a dwarf plant, a) What new combinations of ch...

a) What new combinations of characteristics might arise in the offspring when a tall plant with white flowers is crossed with a dwarf plant (of the similar species) with red flower

Workplace exposure limits, Question 1: What are the heat-induced disord...

Question 1: What are the heat-induced disorders that may result from excessive exposure to a hot working environment? How can we alleviate such health problems? Question 2:

Detect adverse events of a given marketed drug product, Problem 1: Whic...

Problem 1: Which are the best  procedure to adverse events of a given marketed Drug product? Mention methodology / procedure to detect adverse events of a given marketed pro

Neo-lamarckism, NEO-LAMARCKISM Modem modified form of Lamarck theory...

NEO-LAMARCKISM Modem modified form of Lamarck theory is regarded as Neo-Lamarckism. Mc Dougall (1938) found that time taken for training the mice was reducing gradually

Conservation of biodiversity, Conservation of biodiversity is very importan...

Conservation of biodiversity is very important to maintain the ecological balance of ecosystem. Various steps for conservation of biodiversity: 1.           Creation of consc

Nucellus - ovule, Nucellus - Ovule Enclosed within the integuments li...

Nucellus - Ovule Enclosed within the integuments lies a homogenous mass of tissue which is termed as the nucellus. This is the tissue in which the female gametophyte differen

What causes the signs, In the case story, Reggie presented with three typic...

In the case story, Reggie presented with three typical signs of hip fracture-shortening, adduction, and the lateral rotation of the affected limb. What causes these signs? (HINT-th

Explain bioluminescence - ethological approach in taxonomy, Explain Biolumi...

Explain Bioluminescence - Ethological Approach in Taxonomy In those animals which exhibit bioluminescence. The pattern produced by the bioluminescence is used in taxonomy. It h

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