My understanding is that many (most?) living plants did die; what survived were seeds that could wait around for conditions to be a bit less apocalyptic before sprouting, kinda like what happens with major wildfires. Similarly, the animals that survived were a lot of creatures that could live off seeds and other remaining plant matter (such as small mammals, which had previously been an underdog in the Mesozoic).
plants are very adaptable, depending on the clade. some can only sprout if their seeds are damaged fires, or if they have a period of dormancy. genetically, polyploidy has given plants significant advantages as well, having multiple copies(more than 2, in series of 2s and odd numbers) allow some alleles to evolve without causing detrimental effects. plus mycoheterotrophic plants started to evolve(just before or around this time, in many lineages to take advantage of fungal symbionts and low light, the tradeoff is they are rare for the most part.
Obligatory IANAP (I am not a paleontologist).
My understanding is that many (most?) living plants did die; what survived were seeds that could wait around for conditions to be a bit less apocalyptic before sprouting, kinda like what happens with major wildfires. Similarly, the animals that survived were a lot of creatures that could live off seeds and other remaining plant matter (such as small mammals, which had previously been an underdog in the Mesozoic).
plants are very adaptable, depending on the clade. some can only sprout if their seeds are damaged fires, or if they have a period of dormancy. genetically, polyploidy has given plants significant advantages as well, having multiple copies(more than 2, in series of 2s and odd numbers) allow some alleles to evolve without causing detrimental effects. plus mycoheterotrophic plants started to evolve(just before or around this time, in many lineages to take advantage of fungal symbionts and low light, the tradeoff is they are rare for the most part.