endemic plants in sri lanka
TRANSCRIPT
ENDEMIC PLANTS IN SRI LANKA
INTRODUCTION TO ENDEMISM• Endemism is the ecological state of a species
being unique to a defined geographic location, such as an island,nation,country or other defined zone or habitat type. The extreme opposite of endemism is cosmopolitan distribution.
• There are two sub categories of endemism.1. Paleoendemism2. Neoendemism
• Paleoendemism Species that were formerly widespread but are now
restricted to a smaller area.
• Neoendemism Species that have recently arisen, such as through
divergence and reproductive isolation or through hybridization and polyploidy in plants.
WHAT ARE THE CAUSES OF ENDEMISM?
• Narrow ecological amplitude.• Poor adaptability.• Geographical barriers.• Changing climatic conditions.
Plants can be divided into 3 categories according to their habitats.
• Endemic Plants• Native Plants• Exotic Plants
INTRODUCTION TO ENDEMIC PLANTS
• “A plant that is native to a certain limited area”OR
• When a species is found only in a particular geographical region because of its isolation, soil and climatic conditions, it is said to be endemic.
• Endemic plants are special, because they are found only one location and no else where.
Examples for endemic plants in Sri Lanka
• Bedi –del (Artocarpus nobilis)• Binara (Exacum trinervium)• Bin-siyambala (Cassia kleinii)• Bowitiya (Osbeckia octandra)• Dawul Kurundu (Neolitsea cassia)• Etamba (Mangifera zeylanica)• Goraka (Garcinia quaesita)• Halmilla (Trichadenia zeylanica)• Hulan Kiriya (Stachyphrynium zeylanicum)• Idda (Walidda antidysenterica)• Kaduru (Strychnos trichocalyx)• Kaha-wewal (Calamus rivalis)• Keena (Calophyllum walkeri)
INTRODUCTION TO INDIGENOUS PLANTS
• Plants that indigenous to a given area in geologic time.
• This includes plants that have developed, occur naturally or existed for many years in an area.
• Not only one area but also can be found in several countries naturally.
• Also called as Native plants.
Examples for Indigenous plants in Sri Lanka
INTRODUCTION TO EXOTIC PLANTS
• Introduced species that does not naturally occur in the area and has been brought in accidentally or intentionally by man.
Endemic plants in Sinharaja Forest Reserve
• There are about 217 endemic plants can be found in Sri Lanka.
• About 140 plant species are located in Sinharaja Forest Reserve.
• In forest canopy layer, endemic plants are belonging to following families.
Family Dipterocarpaceae Dipterocarpus zeylanicus Doona congestifolia Doona trapezifolia Doona macrophylla Dipterocarpus hispidus
Family Celastraceae Kokoona zeylanica Bhesa zeylanica
Family CornaceaeMastixia tetrandra
Family SapotaceaeMadhuca fulva
Family MyristicaceaeMyristica dactyloides
Endemic plants in sub canopy layer
Family RubiaceaeDichilanthe zeylanica
Family ClusiaceaeCalophyllum bracteatum
Family SapotaceaePalaquium rubiginosum
Family MyrtaceaeSyzygium neesianum
Family SapindaceaeGlenniea unijuga
Endemic plants in ground layerFamily Euphorbiaceae
Agrostistachys coriaceaBridelia mooniAporusa lanceolate
Family RubiaceaeNargedia macrocapa
Family OlacaceaeStrombosa nana
IMPORTANCE OF ENDEMIC PLANTSSupply food resourcesMedicinal valueCommercial valueEcological valueAesthetic valueSupply fire woodMaintain the soil qualityMaintain the air qualityMaintain the water quality etc.
THREATS TO ENDEMIC PLANTSThe extinction of endemic plants is occurred due
to habitat degradation and loss.Following situations are affected.
Agricultural activitiesGlobal environment changeInvasion of non native speciesOver exploitation of resourcesHabitat fragmentationMiningEnvironmental pollutionOver populationNatural disasters etc.
WHAT IS RED LIST?
• A collection of the available information relative to endangered and threatened species.
RED LIST OF ENDEMIC PLANTS
• The Red List highlights that Sri Lanka permanent loss of five flowering plants, and fear for the 177 plants listed as “possibly extinct”
• Doona ovalifolia – Pini Beraliya is ‘Extinct in Wild’• Some plants, such as the Alphonsea hortensis and
Doona ovalifolia, are found only in the Botanical Gardens; so they are categorized “Extinct in the Wild”.
CONSERVATION OF ENDEMIC PLANTS• The goal of conservation is protecting endemic
plants• There are two basic approaches.
1) In-situ conservation2) Ex-situ conservation
IN- SITU CONSERVATION
• It simply means conservation of species in its natural ecosystems or even in manmade ecosystems.
• This strategy emphasizes the protection of endemic plants through a network of “Protected area”.
• Protected area means, An area of land specially dedicated to the
protection and maintenance of biological diversity and managed through legal effective means.
• There are different categories of protected areas which are managed with different objectives.
• E.g. Biosphere reserves,Strict nature reserves,National parks,Nature reserves,Jungle coridors etc.
EX-SITU CONSERVATION
• It is defined as “the conservation of component of biological diversity (sample of genetic diversity, particularly of endangered species) outside their natural habitats.
• It involves maintenance and breeding of endangered plants under partially or wholly controlled conditions.
• E.g. Botanical gardens,DNA banks, Pollen banks, Seed banks, Gene banks, Herbal gardens ,Nurseries etc.