Complex sentence: The narrow conical shape of northern conifers, and their downward-drooping limbs help them shed snow, many of them seasonally alter their biochemistry to make them more resistant to freezing, called "hardening".
Split into simpler sentences: The narrow conical shape of northern conifers, and their downward-drooping limbs help them shed snow. Many of them seasonally alter their biochemistry to make them more resistant to freezing, called "hardening".