An assessment of tree species going extinct, and impact on biodiversity
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Facing extinction - 18% of Indian tree species
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- The story: Around 18% of India’s tree species stare at the possibility of extinction, according to the London-based Botanic Gardens Conservation International. India has 2,603 tree species, of which 650 are endemic (native) to certain parts, and 469 of them are threatened.
- What threats: The main threats are forest clearance for various projects; other forms of habitat loss including exploitation for timber, medicine, etc; and the spread of invasive pests and diseases.
- Global Tree Assessment: This Assessment was undertaken over the past five years by 500 experts to compile extinction risk information for 58,497 tree species worldwide. It found that 30% of tree species around the world are threatened with extinction. It also found that at least 142 tree species are already extinct in the wild.
- The report warned of concerns related to ecosystem collapse globally due to increasing tree diversity loss and mass mortality of trees in certain regions.
- In the Indo-Malaya region, which covers India, 41 tree species are extinct, the highest globally compared to other regions. Around 3,819 species are threatened and 1,068 species are near threatened, among 13,739 species in the region.
- Global landscape: The largest number of tree species are in the Neotropics (Central and South America , 23,631 tree species), followed by Indo-Malaya (tropical Asia , 13,739 species) and the Afrotropics (Africa south of the Sahara, including Madagascar, 9,237 species).
- The country with highest tree diversity is Brazil with 8,847 tree species, followed by Colombia. New Zealand, Madagascar and New Caledonia (all islands) have the greatest proportion of endemic tree species with over 90% of species being found nowhere else.
- Larger megadiverse countries (Brazil, China, Colombia, Indonesia, etc) have a large number of tree species and also a large number of threatened species. India’s proportion of threatened tree species is also higher than the global average of 11%.
- Types of species: Some of the most commonly known species in the country are nearing extinction.
- For example, Agarwood trees in India produce a resin used in perfumes, incense and medicines, and the huge demand for this has led to populations of eight Aquilaria and 15 Gonystylus species declining to a point at which they are now categorised as threatened by the International Union for Conservation of Nature (IUCN) Red List.
- Several Eucalyptus species in Australia are threatened; Diospyros egrettarum, endemic to Mauritius is critically endangered, threatened by an invasive exotic plant species; Madagascan species of Diospyros and Dalbergia have been severely exploited to supply the Chinese market as have Dalbergia species from Central America, the report has flagged.
- A biodiversity crisis: The world is facing a biodiversity crisis and around a million animal and plant species are estimated to be threatened with extinction as per evaluations by Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services in 2019. Trees are highly visible in most landscapes and are excellent biodiversity indicators. Concern about ecosystem collapse is increasing, owing to growing recognition that the process can be very abrupt, as seen in bleaching and death of large parts of the Great Barrier Reef in 2016/17.
- Trees and ecosystems: Unlike species extinction, ecosystems that have collapsed do not disappear, but transition into some other type of ecosystem due to anthropogenic pressures and stress. Wherever trees occur they support a wide range of other species from their position at the base of trophic pyramids in ecological networks. For example, 2,300 species are associated with native oak trees in the UK. If species at the base of trophic pyramids become extinct this might lead to an extinction cascade leading potentially to ecosystem collapse,” the report said. Entire communities of trees, and other associated species, can be threatened simultaneously.
- The fallout in India: Indian experts point to measures taken to protect biodiversity but are concerned too. India has a very well-established network of Protected Areas (PAs) that encompass nearly 5% of its land mass. These PAs that are backed by strong legislations are the hot spots of biodiversity in the country. Besides, community owned lands in large parts of Nortradt India are also major sources of biodiversity. Legislations such as Forest Conservation Act, Wildlife Protection Act and Biodiversity Act are majorly responsible for protecting India’s rich biodiversity. But ever increasing human population, expansion of agriculture, demand for natural resources and linear development projects “pose serious threats” to safeguard India’s biodiversity.
- EXAM QUESTIONS: (1) Explain the causal link between disappearance of tree species and ecosystem degradation. (2) What role does biodiversity play in the natural system of planet Earth? Explain with facts. (3) India's efforts at protecting biodiversity need a booster. Explain how.
#Trees #GlobalTreeAssessment #Biodiversity #ClimateChange #Anthropogenic
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