Major Threats to Plant Diversity
It is estimated that there are around 400.000 plant species in the world, and at least 25% are threatened with extinction. Humans are the main cause of extinction and the principle threat to species at risk of extinction.
- Habitat loss and degradation are the leading threats.
- Introductions of alien species. Some of the worst include cats and rats, green crabs, zebra mussels, the African tulip tree and the brown tree snake. Introductions of alien species can happen deliberately or unintentionally, for example, by organisms "hitch-hiking" in containers, ships, cars or soil.
- Over-exploitation. Resource extraction, hunting, and fishing for food, pets, and medicine threatens many species.
- Pollution and disease
- Climate change induced by humans is increasingly recognised as one of the most serious threats. Climate change has many effects, from altering migratory species patterns to causing coral bleaching.