Conservation of Plants

Abstract Approximately 3.4% of the predicted total number of species on Earth is plants. Plants and their communities are an indispensable part of the Earth's biosphere as plants not only affect ecosystem functioning, but also provide essential ecosystem services for the benefit of humans. However, plants face many threats and current extinction rates have been estimated to be 100–1000 times higher than those of the prehuman era. The five most important drivers of plant extinction are: (1) habitat loss and fragmentation, (2) introduction of exotic species, (3) climate change, (4) overexploitation and (5) pollution. For conservation plans to be effective, four essential steps are needed to maintain viable plant populations in the long term. These include assessment of the biological status of a species, diagnosis of the causes of decline, prescription of management strategies that will counterbalance the decline, and implementation of management practices and further monitoring. Key Concepts: Approximately 17% of all known species on Earth are plant species, that is, approximately 215 600 species have been recorded. The tropical Andes, Mesoamerica and the Caribbean contain the highest plant diversity and therefore can be considered as the world's most important plant biodiversity hotspots. Increasing evidence that plant species diversity positively correlates with the efficiency of many ecosystem functions and services provides conservationists with strong scientific arguments for biodiversity conservation. Rare species are an important part of recent evidence‐based approaches to biodiversity analysis, prioritisation and conservation. Current rates of plant species extinction are estimated to be 100–1000 times higher than those of the prehuman era. One in five plant species is currently threatened with extinction. There are five major anthropogenic drivers of plant species loss: (1) habitat loss and fragmentation, (2) introduction of exotic species, (3) climate change, (4) overexploitation and (5) pollution. Each attempt to protect endangered plant species from going extinct should consist of four different steps: assessment, diagnosis, prescription and prognosis. Minimal Viable Population (MVP) size has been estimated at c . 5000 individuals. Although still an important concept, MVP sizes should not be considered as a magic number. A biodiversity audit consists of a methodology that aims at adopting the most efficient and feasible management interventions within a particular area, using quantitative data on all species present and considering the benefits and drawbacks for all stakeholders involved. An efficient plant conservation strategy should create: space for plants; improve environmental quality for plants, both in the designated areas for conservation and in the surrounding landscape matrix; develop a specific plant species conservation policy (including an in situ and possibly an ex situ component) and enlarge the social basis for plant conservation through education, information and participation.