Review on propagules and its application in the restoration of alpine grassland ecosystems

The propagule is a collection of the seed and bud bank, which is the basis for the plant’s ability to renew sexually or asexually, and the fundamental source for the reproduction of daughter plants. It can spontaneously cope with catastrophic damage while maintaining the normal renewal and iteration of plant communities, and plays an important role in vegetation reconstruction and restoration. This article discusses the research progress of seed bank and bud bank, and discusses the relationship between them and ecological restoration. To further elaborate its functions and roles, taking the alpine grassland of the Qinghai–Tibet Plateau as an example, the effects of five types of ecological restoration measures on propagules and their impact mechanism on propagules were reviewed. The review believes that the combination of artificial intervention and natural restoration is an efficient means of ecological restoration in the future. The natural response of propagules can compensate for the single and unstable problems caused by various artificial means in the past. At the same time, the review clearly identifies that the lack of sufficient propagules and suitable microhabitats are the limiting factors for the restoration of degraded grassland. In the future, in all kinds of ecological restoration measures, the survival of the propagule can be improved by directly or indirectly increasing the quantity, quality, transmission intensity, and breadth of propagation. Therefore, propagules are a prerequisite for ecological restoration, and restoration measures are “catalysts.” Finding “catalysts” suitable for degraded habitats in the future is of practical significance to ecological restoration.