Population because you are holding it
Hello!
The amount of water in a river varies for each particular area. Whether the area has been receiving rainfall or a drought.
Seasons also play a role; if it's Spring, you may receive more rainfall and have a higher water levels. If it's Summer, you may experience a drought, causing lower water levels.
Although that was not very much information, I thought I'd provide a small bit of information. Hope it helps. :)
Answer:
The first organisms to appear in areas of primary succession are often mosses or lichens. These organisms are known as pioneer species because they are the first species present; pioneer species must be hardy and strong, just like human pioneers.
Explanation:
