Answer;
both positive and negative
Explanation;
-The elephant are keystone species, playing an important role in maintaining the biodiversity of the ecosystems in which they live. They may have both negative and positive interactions to the environment. For example, during the dry season, elephants use their tusks to dig for water, which has a positive impact to the surrounding.
-They clear large amounts of vegetation, which removes habitats for some organisms but makes the area inviting for other organisms. This has both positive and negative impact to the ecosystem.
True because <span>In ecology, a niche is a term describing the relational position of a species or population in its ecosystem to each other
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The correct answer is '<span>Oxygen is used up as algae is decomposed, reducing the amount available to other organisms.</span>' The additional nutrients in the water will result in an algal bloom. These algae will result in drastic oxygen fluctuation, from oxygen rich conditions during the day as algae photosynthesize, to anoxic conditions during the night when the algae respire. However, the algal bloom will eventually deplete the available nutrients, resulting in a vast algal die off. The decomposing algae result in anoxic conditions, and the effects are sometimes very obvious, with fish gasping for breath and dying.
F, reason being that it wouldn't do it faster.
Hope this helps