A plant micro-reserve (abbr. PMR) is a type of small nature reserve that conserves rare or threatened plant species. A micro-reserve centers around a single habitat or plant habitat, and is usually smaller than 20 hectares. They also serve as hotspots for biodiversity monitoring, seed collection, and plant management. A PMR may be located on public or private land, and is established by a governmental agency securing a voluntary turnover of the area. They are managed by national, regional, or local governments, or by individuals, families, or non-governmental organizations.
The concept of a PMR was first piloted in the Spanish province of Valencia in 1990, and was subsequently funded by the European LIFE programme. The concept spread to other regions of Spain, and then to other countries in Europe. In Latvia, the existing program of Woodland Key Habitats (WKHs) was adapted into a network of PMRs that received funding to purchase private land for reserves from 2001 to 2011. In Cyprus, the concept was further developed by incorporating strategies like intensive management and planting new seedlings of endangered species. Additional projects have also been started in Bulgaria, Slovenia, and Egypt. PMR advocates have proposed applications of the concept in Madeira, China, and in various parts of Italy.