Ecosystems comprise communities of living things and abiotic factors that surround them. At the next level is the variety of ecosystems at a particular place known as ecological diversity. It is slightly different from biodiversity, which is the variety of 'life'. It would not be incorrect to say that ecological diversity is a kind or level of biodiversity which includes organisms and processes at a very broad scale. All lifeforms, including microorganisms, and their physical environment make up an ecosystem which may be large or very small depending on the resources available to the organisms. The bigger an ecological system, the more ecological niches it contains because the variety of life is richer. The diversity of ecosystems in a particular geographic location is one thing, and diversity within those ecosystems is another.

The number of organisms existing in an ecosystem, including endangered species, indicates the health state of the ecosystem. Diversification occurs when a specific location has several niches available for organisms to thrive. Ecosystems grow in terms of the number of organisms and their interrelationships. More simply, when organisms from different groups feed on multiple organisms or even the same but at another time, biomass increases. If their resource use varies or if there is a time difference between their consumption, then the competition between them will be rare. All the processes taking place in an ecosystem together with the biological balance are dynamic traits of the system. Sometimes the dynamics are disturbed, while at others they work just well. When the balance between processes is lost or if the dynamics change in some way, ecosystems begin losing resilience. It means that if the damage continues, the system at one point will fail to cope with the stress. A species-rich ecosystem is nothing but a contributor to improved life quality.

Diversity within and among ecosystems arises when species begin adapting to newer conditions in the environment. Balanced ecosystems are known to evolve into different ones over thousands of years. Some ecosystems may have a lot of individuals in a species but the species variety among them might be limited. Others may have an average number of species but might be rich in diversity. If two such ecosystems were to be compared, chances are that the latter will possess the resilience needed to recover from some external stress. This resilience stems from the diversity the system contains. It will possibly be because of some species that exist in the system unlike the former where numbers are great but variety is low. However, in the present day, a fully balanced and functioning ecosystem appears to be an ideal case only because stressors are frequently introduced in the environment knowingly or unknowingly. Ever since we realized the benefits we could get from nature, we have been harming ecological systems relentlessly. Technological progress and increasing populations have taken a toll on ecological health all around.

Introduction of exotic species, extensive land use, pollution, logging, mining, overexploitation of resources, climate change, and many other factors have caused irreparable damage to ecosystems and their diversity. The causes of the damage are well-recognized but still, restoring an ecological system and its diversity is a big challenge because rarely is the initial and original state of the system known and understood. Once the natural balance is disturbed, species may or may not recolonize even after suitable conditions are recreated. A better option would be to establish a system in a place that previously did not house any. In this way, species might start afresh as they adapt to the new environment.

About the Author: Zainab Imran is fond of writing and is more interested to write about the environment.