Plants typical of the tundra are very short in stature or height. what is advantageous about this so called 'cushion plant form found in the tundra, relative to a tall plant?
a. wind speeds are lower closer to the ground, reducing convective heat loss from plants
b. daytime air temperatures are usually higher closer to the ground, leading to higher convective heat gain by leaves
c. daytime conductive heat gain from adjacent ground surface would be greater
d. all the above
e. b and c

Wetlands form where water and land meet. a lake with a wetland fringe can fill in with decayed plant and animal material to become a wet meadow. a pond can fill in to become a bog or fen. sediment can fill in a river marsh to become a swamp.flooding of coastal lowlands from rising sea levels has created broad coastal marshes that are protected from wave action by barrier islands or reefs. coastal wetlands also form when rivers deposit sediment as they reach the ocean. plants then take root and hold the soil firm against the forces of tides and waves.