(1) "Red flowers at sunrise are better than fire, and the riverside is as green as blue." It reflects the influence of environmental factors on organisms, and temperature affects the distribution, growth and development of organisms. When spring comes, the water temperature rises, algae plants multiply and the river turns green. (2) "In April, the flowers in the world are exhausted, and the peach blossoms in the mountain temple are open." This reflects the influence of environmental factors and temperature on biology. Every time the altitude rises 1km, the temperature drops by about 6 degrees, and the temperature between mountains is different, forming a scene of peach blossoms just blooming in the mountains.
(3) "Qian Fan across the shipwreck, Wan Muchun in front of the diseased tree" embodies the biological principle of natural selection. Sick trees don't adapt to the environment and are eliminated by the environment, but thousands of trees thrive in front of the sick trees, adapt to the environment and survive, forming the scene of Wan Muchun.
So the answer is:
(1) As the water temperature rises, algae plants multiply.
(2) Temperature
(3) Natural selection (or survival of the fittest)