Tightly closed cones in some conifers are adapted to open in response to

Conifers are the gymnosperms that are adapted to survive in cold temperatures. The leaves of the conifers are needle-like to survive in the harsh climatic conditions. Due to needle-like shape of the leaves, the leaves can not hold snow in winters. Similarly, the cones are also adapted to survive in cold temperatures.
The tightly closed cones in some conifers are adapted to open in response to CHANGE IN ENVIRONMENTAL CONDITIONS. The cones close when the weather dry.