Here is a food for thought: What is that one important contribution of humans to our ecosystems?
An honest probe would perhaps yield no answer.
Big cat holding the ecosystem together Source - PhotoShelter Inc 2014An ecosystem can be simply explained as a combination of communities of living beings and their physical environment in which they live. Though complex and constantly changing, it is said that no two ecosystems are the same. Each ecosystem has its importance at the regional or the local level and is also inter-connected with other ecosystems of the earth. For instance, an alpine forest and a tropical rainforest are climate specific and regional but together they act as air filters, providing us with oxygen. Similarly, different ocean currents help in maintaining the balance of the climate.
In any given ecosystem, there is a ‘keystone’ or a predator that is at the top of the food chain holding that ecosystem together. In India, it is the big cat species like tiger, leopard and snow leopard depending on the region. In the Rocky Mountains of America, it is the wolves. These predators keep a check on the growth of the herbivorous population, which helps in keeping a check on the over grazing of forest.
Thus various species of plants, trees, fungi, ferns, insects, birds and microbes flourish and make the forest healthy or balanced. A healthy forest is always rich in water as trees help in retaining and conserving water on which all species are dependent.
Some interesting examples in history have shown us how a simple change or shift in species has wreaked havoc with local ecosystems. In 1958, Mao Dezong of China passed a decree to eliminate sparrows as it was believed that they were eating into the grains supply being produced by the farmers. As sparrows were killed off, huge swarms of locusts swooped in destroying all standing crop resulting in a famine that killed 38 million people. Another famous example is that of wild rabbits, a species alien to Australia, was introduced in 1859 so that local settlers could go hunting. The rabbits multiplied quickly resulting in the loss of many local species of flora and fauna.
One can argue that many species of plants and animals have become extinct over the years and we still continue to thrive. One can also argue that any changes brought along due to these shifts can be mitigated through technology that continues to evolve over time. But it is also true that we still have not been able to fully understand the implications of the shifts and changes in these ecosystems that might impact our future. Many species have disappeared without us even understanding their role in the health of the planet, much less figuring out ways to mitigate its probable impact.
As E.O. Wilson, an American biologist and naturalist (b. 1929) said, “If all of mankind were to disappear, the world would regenerate back to the rich state of equilibrium that existed ten thousand years ago. If insects were to vanish, the environment would collapse into chaos.”
And along with it, so would humans.
Must watch: What happened when wolves, the keystone predator were re-introduced in Yellowstone National Park in the U.S. How Wolves Change Rivers