“Ecology and Environment” is an important section of GS Paper-III from which in the previous year PT examinations (2013,2014 etc) 25 to 30 questions had been asked. Interestingly, the options given there, as alternative, were so close that most of the students, who had even finished this subject in their coaching classes, faltered by marking the incorrect answer. Hence, this subject requires a clear conceptual understanding to eliminate the close options given in the question paper of PT examination. In Mains, emphasis is there to test the candidate’s grasp of new developments taking place in the arena of Environment. A balance has been made in the SAVE classes, which you are going to experience.

It is interesting to note that UPSC, in past had repeatedly asked questions from the very basic concept of Ecosystem, which was included in VI or VII class NCERT books, but students applying their over scholastic analogy, faltered in their attempt to answer. So, the understanding of this chapter is the basic block to appreciate the issues related to environment. 
 

The reference book for understanding the concept of Bio-Diversity is NCERT class XII, Biology. Though, I do recommend that students should also go through the SAVE class of climatic regions of the world (from Physical Geography). From these concepts, every year you can expect some good number of questions. 
 

Of late, UPSC is posing more challenges to students by asking the basic issues which are persisting in news more often in the recent past. Needless to say, they are based on the basic concepts related to pollution, its consequences and its mitigation, which has been thoroughly analysed in this chapter. Students are further advised to complement these SAVE Classes with the "Environmental Issues" portion of the Section " Views on News". 

The burning topic of climate change needs special attention by Civil Services Aspirants vis-a-vis changes taking place at International forums and affecting the Geo-political equation between different nations. Along with development taking place in this field, the concept discussed in this chapter must be augmented with "View on News" and editorials of The Hindu. 
 

As a serious aspirant, students usually rote the different Acts, which they find difficult to recollect in the examination, as confusion persists in this area. Efforts have been made to streamline these concepts which most of the students find it easy to comprehend and retain.