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It is the holiday season and decorated conifers are everywhere. Seeing all of the dressed-up firs and spruces reminds me that Ferrebeekeeper’s tree category has so far betrayed a distinct bias towards angiosperms (flowering plants). Yet the conifers vastly outdate all flowering trees by a vast span of time. The first conifers we have found date to the late Carboniferous period (about 300 million years ago) whereas the first fossils of angiosperms appear in the Cretaceous (about 125 million years ago) although the flowering plants probably originated earlier in the Mesozoic.
The first known conifer trees resembled modern Araucaria trees. They evolved from a (now long-extinct) ancestral gymnosperm tree which could only live in warm swampy conditions—a watery habitat necessitated since these progenitor trees did not cope well with dry conditions and also probably utilized motile sperm. Instead of relying on free-swimming gametes and huge seeds, the newly evolved conifers used wind to carry clouds of pollen through the air and were capable of producing many tiny seeds which could survive drying out. Because the evergreen cone-bearing trees could survive in drier conditions, the early conifers had immense competitive advantages. These advantages were critical to survival as the great warm swamps of the Carboniferous dried out. The continents, which had been separated by shallow oceans and seas, annealed together into the baking dry supercontinent of Permian Pangaea. In the arid deserts and mountains, the conifers were among the only plants which could survive.
This ability to live through any condition helped the conifers get through the greatest mass extinction in life’s history—The Permian–Triassic (P–Tr) extinction event, (known to paleontologists as “the Great Dying”). Thereafter, throughout the Mesozoic they were the dominant land plants (along with cycads and ginkgos which had evolved at about the same time). The Mesozoic saw the greatest diversity of conifers ever—the age of dinosaurs could just as well be called the age of conifers. Huge heard of sauropods grazed on vast swaths of exotic conifers. Beneath these strange sprawling forests, the carnosaurs hunted, the early birds glided through endless green canyons, and the desperate little mammals darted out to grab and hoard the pine nuts of the time.
Although flowering plants rapidly came to prominence towards the end of the Cretaceous and have since become the most diverse plants, today’s conifers are not in any way anachronisms or primitive also-rans. They still out-compete the flowering trees in cold areas and in dry areas. Conifers entirely dominate the boreal forests of Asia, Europe, and North America—arguably the largest continuous ecosystem on the planet except for the pelagic ocean. They form entire strange ecosystems in the Araucaria moist forests of South America—which are relics of the great conifer forests of Antarctica (the southern continent was once a warmer happier place before tectonics and climate shift gradually dragged its inhabitants to frozen death).
The largest trees—the sequoias and redwoods–are conifers. The oldest trees—bristlecone pine trees and clonal Spruces–are conifers (excepting of course the clonal colonies). Conifers are probably the most commercially important trees since they are fast-growing staples of the pulp and the timber industries. Timber companies sometimes buy up hardwood forests, clear cut the valuable native deciduous trees and plant fast growing pines in their place to harvest for pulp. In fact all of the Christmas trees which are everywhere around New York come from a similar farming process. The conifers are nearly everywhere—they have one of the greatest success stories in the history of life. It is no wonder they are the symbol of life surviving through the winter to come back stronger. They have done that time and time again through the darkest and driest winters of the eons.