Final answer:
Hardseededness helps seeds to spread their germination over several growing seasons, thus improving the survival chances of plant species by utilizing a dormancy strategy. Environmental cues and treatments like vernalization can break this dormancy to allow germination.
Step-by-step explanation:
Hardseededness, or hard seed coats, is used by seeds to spread germination over more than one growing season. This adaptation is crucial for the survival of certain plant species, as it allows seeds to remain dormant and viable under conditions that are unfavorable for germination, such as extreme temperatures or drought. The presence of a hard seed coat effectively spaces out the timing of germination, ensuring that not all seeds germinate at once, which could be disastrous if conditions turn unfavorable.
Such dormancy mechanisms are akin to a bet-hedging strategy, broadening the window of opportunity for at least some of the seeds to find the right conditions to sprout and grow. Several environmental cues, like moisture, temperature, and light, can break this dormancy. In some cases, vernalization, which is the exposure of seeds to cold temperatures, is necessary to trigger germination. This ensures, for example, that seeds germinate in spring when conditions are more suitable for seedling survival. Other treatments can include scarification, presoaking in hot water, or even passage through an animal's digestive system to weaken the seed coat and promote germination.