Biodiversity and Biological Diversity

University:
High School
Course:
High School Literature
Academic year:

2020
Views:

0

Pages:

17
Author:

Thisara Hansaka

Biodiversity and Biological Diversity ; the difference • BIODIVERSITY Is the life on earth. • Includes all organisms and their interactions with biotic and abiotic components on earth. • Includes micro and macro organisms: plants , animals, bacteria, moulds ....... all unknown and known organisms......... • Include variability at genetic, species and ecosystem • levels Why biodiversity is important ??????? 1 BIODIVERSITY OF SRI LANKA; An overview 2 Why Sri Lanka has rich biodiversity ?? Tropical country with a significant variation in altitudinal range, rainfall and its pattern, geology, temperature, soil types, ........ 3 Climate of Sri Lanka RAINFALL •Types – monsoonal (SW, NE) convectional cyclonic orographic • Amount -(mean annual in mm) 2500-5000 Wet Zone (WZ) 1850-2500 Intermediate Zone (IZ) 1250-1850 Dry Zone (DZ) <1250 Arid Zone (AZ) • Rainy days – WZ (50%-75% days/yr) DZ (< 25% days/yr, 66% rainless) TEMPERATURE • Mean annual temperature 25-300C •Altitudinal change (decrease in 10C for each 150m) • Diurnal change – high in February/ March •Pan Evaporation Rates DZ, dry season 6mm/day wet season 3mm/day WZ lowland 2.5-3.5mm /day highlands (~2000m) 1.5-2.5mm/day 4 Topography/geographical landscape of Sri Lanka •from flat lowland to a mountainous region in elevations Lowest 0-125m, Middle 125m-750m Upper 750-2500m with two clear peneplains at Kadugannawa & Ramboda •Coastal plain 1760km Landforms of Sri Lanka ridge & valley, hill & valley, hill & ridge, Mountain, Mantled Plain, Flood plains, coastal plain, Dune, Beach etc 5 Geology of Sri Lanka • Greater part of island – rocks of Precambrian age Vijayan complex (lowlands NW, SE) SW group in SW parts highland series • Sedementary rocks at NW coast– limestones of Miocene age Soils of Sri Lanka Represents 14 great soil groups DZ- mainly reddish Brown earth WZ- red yellow podzolic soil Riverine+ flood plains – alluvial soil Beaches- regosols 6 Soil Map of Sri Lanka Panabokke , 1975 7 8 Ecosystem diversity of Sri Lanka Forest related ecosystems: Lowland rain forest / lowland evergreen forest Sub Montane evergreen forest Montane evergreen forest Moist semi evergreen / intermediate zone /moist monsoon forests Dry mixed evergreen / moist deciduous/dry monsoon forests thorn forest/scrub jungle Savanna Forest Swamp forest Mangroves Riverine forests Sparse forests *Forest plantations- Teak, Eucalyptus (E. gradis, E. robusta, E. microcorys), Pinus caribaea, Mahogany Swietenia macrophylla), , Acacia Grassland related ecosystems: Wet Pathana, Dry Pathana, Damana, Thalawa 9 Ecosystem diversity of Sri Lanka cont. Coastal and Marine ecosystems: Mangroves Salt marshes Sand dunes & beaches Mud flats Sea grass beds Coastal wetlands Lagoons & Estuaries *Coral reefs (about 2% of coastline) occur in southern & eastern areas Inland Aquatic ecosystems: Flood plains, Swamps, Streams / rivers Reservoirs & Ponds Villu Ponds/ tanks Wetlands 10 Ecosystem diversity of Sri Lanka Floristic region cont. Major vegetation type 1 Marine, Coastal, Salt marsh, Mangrove, Strand vegetation, Sand dunes 2 Dry mixed evergreen forests, Thorn forest, Damana and Villu grasslands 3 Intermediate forests 4 Dry mixed evergreen forests, Savanna 5 Wet evergreen forests 6 Wet evergreen forests, Thalawa grasslands 7 Wet evergreen forests 8 Aquatic flora 9 Wet evergreen forests 10 Sub montane forests 11 Wet evergreen forests, Dry pathana 12 Montane forests, sub montane forests 13 Montane forests, wet pathana 14 Montane forests, sub montane forests 15 Montane forests, wet pathana 11 Ecosystem diversity of Sri Lanka *Urban cont. and Built up areas: Street trees Domestic gardens Arboreta/ forests Parks Wetlands *Agricultural ecosystems: (agro-biodiversity) Paddy lands Horticultural farms Small crop holdings/ other field crops Crop plantations Agroforestry systems Chena lands 12 Species diversity (Fauna) Native Number of species Butterflies 223 Land molluscs 201 Dragonflies 67 Carabid Beetles 398 Fresh Water Crabs 25 Shrimps 16 Mammals Birds Reptiles Amphibians Fresh Water Fishes 76 206 174 35 46 Endemic spp 20 65 49 127 25 7 ( %) 8 83 42 24 100 30 14 23 81 19 32 16 10 52 65 42 Introduced species : fish> other groups (snails, beetles) 13 Species diversity (Flora) Native/ Indigenous species: • About ¼ are located in the SW zone in floristic regions 6,7,9. •Abeywickrama (1987), Flowering plants 2900 (23% endemic= 830),Ferns and allies 314 (57% endemic), Mosses 575, Liverworts 190, Fungi 1920 (403 are mushrooms), Algae 896 and over 200 Lichens are native to us. •Bandaranayake and Sultanbawa (1991), Angiosperms 3368, Gymnosperms 01, Pteridophytes 34. •Senaratne (2000) 4143 flowering plants belong to 214 families and 1522 genera. •Latest information in the Red List 2012 Endemism of Sri Lanka •About 90% of our endemic plants are confined to the southwestern zone (mainly in the rain forests). •According to Gunatilake (1988) about 740 from 830 endemics (trees 274/306, shrubs 198/230, herbs 268/294). •According to Herath (2007), out of 4143 plants 1025 (98 families, 353 genera) 24.7% is endemic to Sri Lanka. There are two endemic genera (Stemonoporus and Adrorhizon) in SW of Sri Lanka while there are no plant families endemic to Sri Lanka. 14 Introduced plants (aliens/ exotics) About 25 % of our flora consists of exotic plants. •With time it could become a part of natural landscape and be naturalised. (about 32% has been naturalized). •Sometimes an exotic or an introduced plant could aggressively invade changing the biodiversity of natural or semi natural habitats. Agriculturally important species (socio- economically important species) + Crop wild relatives i.e part of biodiversity which nurtures people and which are nurtured by people 15 What are the centers of origin of crops ? * Vavilov’s 8 centers : East Asia, Tropical Asia, South -West Asia, New East, Mediterranean, Abyssinia, Andean, Central America (including Mexico) Crop Primary center Secondary center Sorgham Africa S. Asia+, Latin America Finger millet E. Africa S. Asia Bean & groundnut L. America Sub Sahara Africa Maize & Cassava L. America Indo- Chinese Area Barley Middle East Ethiopia Rye & Oats Near East & Mediterranean Weeds in European fields Rubber L. America Indo- China 16 Crop wild relatives of Sri Lanka Rice (Oryza) Oriza sativa (cultivated species) Oryza eichingeri A. Peter Oryza nivara Sharma et Shastry Oryza rhizomatis Vaughan Oryza rufipogon Griff. Oryza granulata Green Gram/Black Gram etc (Vigna) Vigna radiata (cultivated species) Vigna aridicola N. Tomooka & Maxted Vigna dalzelliana Vigna radiata var. sublobata Vigna stipulacea Vigna trilobata Vigna trinervia Piper Piper nigrum L., (cultivated species) Piper zeylanicum Miq., Piper walkeri Miq Piper hymenophyllum Miq Piper sylvestre Lam., Piper trineuron Miq., Piper siriboa L., Piper chuvya (Miq.) C. DC. Piper betle L., (cultivated) Piper longum L., Cinnamomum Cinnamomum verum J. Presl (cultivated species) Cinnamomum dubium Nees Cinnamomum ovalifolium Wight Cinnamomum litseaefolium Thw. Cinnamomum citriodorum Thw. Cinnamomum capparucoronde Blume Cinnamomum sinharajaense Kostermans Banana (Musa) Musa paradisiaca L (cultivated species) Musa acuminate Colla. Musa balbisiana Colla. 17