Pandit Govind Ballabh Pant Memorial Lecture: II

in particular habitat, finally there is richness of communities in an ecological zone. In
any community or ecosystem there are “keystone species” which have direct or
indirect effect on the survival of other species in an ecosystem. A simple relationship
between habitat destruction and productivity in relation to life form and overall
biodiversity is shown in Figure 12. Ecosystem dynamics is still not understood, nor
are molecular mechanisms underlying higher categories. There are efforts to bring in
molecular aspects in phylogenetic and taxonomic categories like species, genera,
families and phyla. Both biosphere and ecosystems are amenable to natural and
human induced changes; physical chemical, biological and environment. Ecosystem
science is still in infancy. So far, it has been concerned with inventorization of megagroups
of organisms and has overlooked the micro-organisms and marine biota
altogether. It has also not paid attention to process underlying ecosystem/ biosphere
transformation. A major question remains unanswered: as to what causes extinction
of widespread dominance of a species? Are there any physiological, genetic and
ecological attributes that lead to extinction or dominance? Systematic investigation
on different aspects of this problem need to be taken up.
Some of the usual aspects of study of ecosystems include inventroization and
establishment of databases. This would enable to take stock of the present level of
knowledge. Generally microorganisms have been left out of consideration in
ecosystem studies. But now it must receive special attention. For the collection of
raw data, use can be made of parataxonomists, provided however, there is clarity
about the sampling techniques. In other words, it should be clear as to what, how
and where to sample, so that one is clear about the sites and biotic groups to be
maintained. Quality of data is considerable importance for proper monitoring.
Besides enumeration of species their distribution and life forms, at the level of
ecosystems, there is need to understand functions that these species perform
regarding their capacity for nitrogen fixation, decomposition of organic matter and
as saprophytes, pollinators grazers etc; this together with the capability of
ecosystems to capture, store and transfer energy, nutrients and water e.g. the
whole range of biogeochemical cycles need investigation. Finally, the ecosystem
need to be evaluated in terms of the services that these render to humanity: clean
air, water, quality of life and above all, resilience to change and capacity for
regenerability (Solbrig, 1991). Some of the foregoing aspects are summarized in Fig.
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