Change in conditions of an ecosystem lead to change in organisms?

Question

Let's think about the slash and burn method and its effects on the ecosystem. Cutting down trees that rise all the way up to the canopy would expose the plants at ground level to more light, so would change an abiotic factor so changes the conditions required for survival. These plants are not adapted to the high light intensity so would find it hard to survive and compete, through inter-species competition, with newly arrived plant species that are much more adapted to the extra light intensity. Obviously this would cause a dramatic reduction in the numbers of the previous plant species and would result in migration of the animals due to lack of food, assuming they can't feed on the newly arrived plants, and a change in the food chain. In what ways do this affect the local and regional ecosystem, and what problems could it produce (both from an ecosystem and human perspective)? These types of land-use changes are often seen as problematic in conservation biology (as "...a bad thing"). Wouldn't the new plant species bring in new animals that do feed on them and a new equilibrium be reached just with different species? Is it to do with the reduced biodiversity or danger of extinction of indigenous organisms? As you have probably realized I don't exactly understand this topic perfectly and would appreciate any amendments or extra information to the paragraphs above. Thanks in advance.

Answer 1

It may be important to remember that many populations have evolved in a way suitable for their environment, but not necessarily ideal for it.