How do seeds grow in the wild despite not usually being buried under soil?



For context, I mostly mean plants that distribute their seeds onto topsoil such as tumbleweeds or maple trees. In the case of tumbleweed, the parent plant dries out and bounces around to spread their seeds and in the case of maple trees their seeds have a helicopter-esque “blade” that lets them spin and land further away from the parent plant. In both of these examples, the seed lands on top of soil and I was wondering how it works that they sprout from that location.

In: Biology

Either they are driven into the soil by rain, covered with soil by wind, or the root can sprout downwards and grow into the soil. There is no rule that seeds must all start underground, the roots of the plant just need to end up in the ground (usually) and the plant needs to get established before it dries out, blows away, etc.

Starting under the soil is a good way for the plant to get established before it dries out or blows away, which is why humans plant this way for best results. And some plants in some environments may require that. But for many plants, at least SOME seeds can grow wherever or however they fall. Most plants produce a large number of seeds because it’s not that reliable, though.