Dear Dutta,

Like human, a plant do not like to do for dissemination and dispersal. Plant and animal diversity (Biodiversity) perfectly follow some natural rules, so that ecological boundary automatically limits the above said projection of a plant. No need of Visa and passport to a plant for dispersal and immigration.

Normally five factors (abiotic) directly regulates growth and development of a plant. They are: Climate, soil condition, rainfall, topography and availability of soil nutrients.

A plant can move form one region to other landscape subject to availability and feasibility of above said abiotic factors. A mango can be domesticated in a desert areas if the areas are getting all mesophytic condition. A desert loving plant can move in a mesophytic environment.

But million dollars question is, could we keep our indigenous plant diversity in an intact form? Can we do some changes in abiotic factors according to an indigenous plant? It is a big challenge. Certainly we can not do it. So, invasion of invaive/ undesirable/exotic plants in our vegetational domain has become a big challenge now. It is because, nation India is situated at tropical line and touching 29 degree latitude in the global topography. At the same line, most of the South American nation falls e.g. Brazil and Colombia. Therefore, most of the wild/cultivated plants have moved towards Indian geographical zone.

Now your question, on the basis of agro-climatic zones plant diversity can be distinguished. My answer is yes. It can be, because, rainfall gradients, soil types, nutrient deficiency/abundance limits to the plant expansion. So, adoptive and adaptive characters of a plant for a different types of climatic condition which are naturally found in India can be clarified across different agro-climatic zones in India.

However, it is a surprising point today, most of the tropical loving plants are adopting some kind of traits which might be useful for survival in changing environment!

Many thanks............is there any method of categorization? if yes, what is the particular basis or is it the crucial interplay of many factors playing together?

Dear Dutta, classically, on the basis of climatic zone, it is earlier categorized. However, due to changing environment and fluctuation in seasonal behaviour, it is the need of an hour to understand that. I am not an agro-climatologist but on the basis of my experiences, I can say climate is one of key factor which outer and interplay for the modification, survival, species and speciation. Most important Plant functional changes e.g. growth, production and reproduction are showing strong relationships with changing environmental condition.

It is not a surprising thing, you can not found a diverse group of flowering plants (angiosperms) in the temperate climate. On the basis of paleo-botanical evidences, most of the angiosperms are shifted from polar region to hemisphere zone of earth (at 29 degree latitude where most of the tropical countries are on that line). That is why, in temperate region where climatic conditions are consistent, very little variation in the temperature through out year, prevail a least diversity of plants. It is the basic region, only evergreen type of plant species found.

Today, domestication and introduction of new agro-crops from one region to another part of country dramatically changed the natural demarcation of agro-climatic zone. So, it is now difficult to categorize on the basis of agro-climatic zone .