Many plant seeds are considered to remain dormant for a period of time depending on various circumstances. Dormancy in seeds is often needed by some plants in order to preserve the life of some seeds before actual germination. In many cases, not all seeds of a plant will germinate at a specific period. Some will remain dormant and will only germinate on a staggered basis. Dormancy is important for many seeds because it may serve as form of protection from possible harsh weather conditions and elimination from herbivorous animals. With temporary dormancy, the seeds also require to remain viable and healthy for eventual germination. This is the very reason that dormant seeds continue to breathe or respire while being somewhat restricted in terms of germination. The seeds need to respire just enough air to keep them alive and make them last a period of natural dormancy.
In order for seeds to respire and continue to be alive and healthy, they also need to have enough moisture from water. Hydration is said to be very essential for seeds to survive a long dormancy period. Some seeds will remain dormant for several months, while there are also seeds that continue to be dormant for many years. There are also cases wherein the length of dormancy is dependent on various circumstances. There are seeds for example that have very hard outer shells and only extreme temperatures may be able to break them and allow for germination to occur. Other seeds also need to be pre-treated in order to proceed with the germination process. With coats that are literally impermeable, some plant seeds need pre-treatment in order to break the coats and allow the seed to grow and develop. With the possible long dormancy period, seeds must somehow continue to respire and breathe to prepare themselves in their succeeding growth stages.