This is not so much an answer but a talking point.

The taxonomic/nomenclature process is artificial and created by humans for the sole use by humans. It is a relative measure that is dependent on the knowledge of the time (imagine the changes since Linneaus or even the fanciful "Bestiary" by M. S. Bodely).

Metrics such as diversity and richness indices are stochastic. They will be altered by not only "natural" environmental factors but and also extraneous (e.g., anthropomorphic) factors, including the taxonomic norms of the time, in ways that will expand our knowledge of these systems.

So the role of the researcher is to continue making these measurements and to plot and describe the variable nature of these systems within the context of the time of their study. Unfortunately, this level of uncertainty is not something that is easily handled within decision making (i.e., management), policy and politics. People want certainty where there cannot be any and see that as a weakness in the science rather than a lack of understanding on theirs.

The easiest resolve is to construct guidelines that apply to the development of policy and management. The following are the first three environmental principals taken the “Statement of Environmental Principles, Factors and Objectives”, Environmental Protection Authority, Western Australia, 2016 (http://www.epa.wa.gov.au/sites/default/files/Policies_and_Guidance/Statement%20of%20Environmental%20Principles%2C%20factors%20and%20objectives_Dec16_1.pdf):

“1. The precautionary principle

Where there are threats of serious or irreversible damage, lack of full scientific certainty should not be used as a reason for postponing measures to prevent environmental degradation.

In the application of the precautionary principle, decision should be guided by:

a. careful evaluation to avoid, where practicable, serious or irreversible damage to the environment; and

b. an assessment of the risk-weighted consequences of various options.

2. The principle of intergenerational equity

The present generation should ensure that the health, diversity and productivity of the environment is maintained or enhanced for the benefit of future generations.

3. The principle of the conservation of biological diversity and ecological integrity

Conservation of biological diversity and ecological integrity should be a fundamental consideration.”

Essentially, all that is being promoted is to think in terms of the dynamism of the environment, to understand the context in which the research was undertaken and to apply principles to allow for the stochastic nature of the systems. Most of all, be aware that new research may always overturn current thinking so nothing at all is set in stone.

In plant kingdom, species richness and it's diversity has huge implications on the development of acquired  and inherited traits , thereby, affecting the rhizosphere ecology much to the specific functioning of the species in particular and ecosystem as a whole.I wonder whether, such basis of functioning does exist in birds or other species...

There is richness in diversity of birds also. Several classification committees which exist to standardize bird taxonomy in different continents and sanction changes based on new science which is amenable to e--bird system with more clarity.

This is not so much an answer but a talking point.

The taxonomic/nomenclature process is artificial and created by humans for the sole use by humans. It is a relative measure that is dependent on the knowledge of the time (imagine the changes since Linneaus or even the fanciful "Bestiary" by M. S. Bodely).

Metrics such as diversity and richness indices are stochastic. They will be altered by not only "natural" environmental factors but and also extraneous (e.g., anthropomorphic) factors, including the taxonomic norms of the time, in ways that will expand our knowledge of these systems.

So the role of the researcher is to continue making these measurements and to plot and describe the variable nature of these systems within the context of the time of their study. Unfortunately, this level of uncertainty is not something that is easily handled within decision making (i.e., management), policy and politics. People want certainty where there cannot be any and see that as a weakness in the science rather than a lack of understanding on theirs.

The easiest resolve is to construct guidelines that apply to the development of policy and management. The following are the first three environmental principals taken the “Statement of Environmental Principles, Factors and Objectives”, Environmental Protection Authority, Western Australia, 2016 (http://www.epa.wa.gov.au/sites/default/files/Policies_and_Guidance/Statement%20of%20Environmental%20Principles%2C%20factors%20and%20objectives_Dec16_1.pdf):

“1. The precautionary principle

Where there are threats of serious or irreversible damage, lack of full scientific certainty should not be used as a reason for postponing measures to prevent environmental degradation.

In the application of the precautionary principle, decision should be guided by:

a. careful evaluation to avoid, where practicable, serious or irreversible damage to the environment; and

b. an assessment of the risk-weighted consequences of various options.

2. The principle of intergenerational equity

The present generation should ensure that the health, diversity and productivity of the environment is maintained or enhanced for the benefit of future generations.

3. The principle of the conservation of biological diversity and ecological integrity

Conservation of biological diversity and ecological integrity should be a fundamental consideration.”

Essentially, all that is being promoted is to think in terms of the dynamism of the environment, to understand the context in which the research was undertaken and to apply principles to allow for the stochastic nature of the systems. Most of all, be aware that new research may always overturn current thinking so nothing at all is set in stone.

Thank you for your responses.