Gymnosperms

Living gymnosperms form a small (∼1,100 species) but globally distributed clade of seed plants. They have a deep evolutionary history and extensive fossil record stretching back more than 300 million years, predating the much more diverse angiosperms by more than 150 million years. Although gymnosperms are a small component of extant plant species richness, they are common in many forest ecosystems, especially montane and boreal forests, where they may dominate woody plant biomass. Gymnosperms often occupy biological extremes, including some of the oldest (bristlecone pines ∼5,000 years old), largest (giant sequoia ∼1,500 tons), and tallest (coast redwoods >110 m) plants on Earth. Gymnosperm wood ('softwood') is also economically important for lumber and in paper production. Their long evolutionary history, intrinsic biological interest, and importance in human life combine to give gymnosperms a more prominent place in scientific literature than one might expect based on their relatively low diversity. This primer will discuss some basic aspects of their biology, ecology, and evolutionary history.