Of course the major needs of a plant is CHLOROPHYLL, because chlorophyll makes the plant green then SUNLIGHT, because the process cant work without energy. Then WATER and CARBON DIOXIDE.
Hoping this could help
I believe it is keeping these regions warm because the water is flowing from the SOUTHERN part of these regions, like, how it starts from the bottom of the US, (aka Louisiana, Mississippi), and it gradually flows upward, but hot always overrules cold, so the cold water that it is flowing into is becoming warmer as it passes into the warm water from the gulf of Mexico.
Hope that this helps :)
The landscape in which limestone is eroded to form deep valleys and cavers are called Karst landscape or karst topography. This kind of development start occuring whenever the acidic water starts breaking down the bedrocks near the cracks. As the bedrock starts breaking down slowly, the cracks start to open up creating bigger holes. with passage of time the holes will become big enough to create an underground drainage system for the surface water to flow and form underneath. If the water is unable to flow out and becomes stagnant, then the Karst will start getting bigger.
Natrual variations i think
The supporting structure of the cell that is also involved in movement is most likely the cytoskeleton.
