SLIDESMANIA.COM What is biodiversity? It is the variety of living organisms (plants, animals and micro-organisms), the genetic differences among them and the variety of ecosystems in which they live. It is estimated that there are between 3 and 10 million species of living organisms on Earth. SLIDESMANIA.COM South Africa, a country of remarkable biodiversity SLIDESMANIA.COM ■ South Africa has only 2% of the earth's total land surface but is ranked as the third most biologically diverse country in the world, containing between 100 000 and 1 000 000 species of organisms, of which many are endemic. ■ Endemic species = a species that is found only in one place or specific region and nowhere else in the world. Why is there such diversity? SLIDESMANIA.COM ● The wide diversity is due to variations in climate, geology, soils and landscape forms (e.g. narrow coastal plain, steep escarpment, large plateau). ● In combination these variations give rise to broad vegetation zones which, together with their associated animal life, are called biomes. ● These include the Nama-Karoo, grassland, succulent Karoo, forest, savanna, fynbos, Albany thicket, desert and wetland biomes. In addition there is the marine biome. ● Each of these supports its own collection of plant and animal species. ● Interesting facts about SA biodiversity SLIDESMANIA.COM Distributional maps ❖ Distributional maps show where the various groups and species of plants and animals are to be found. ❖ These maps have been available for many years. ❖ However, now with improved technology, analytical equipment and methods of collecting information very accurate maps are being produced. These include general distribution, seasonal distribution as well as abundance. ❖ Sessile organisms, e.g. plants and certain seaweeds, need only one map. This could be revised at intervals to show changes, presence or absence and sometimes abundance of a species. SLIDESMANIA.COM ❖ Some motile organisms, e.g. birds and mammals, migrate. To get a true picture of their distribution, seasonal maps, showing presence or absence and, if possible, abundance would be needed. Such maps are of particular interest to animal behaviourists. SLIDESMANIA.COM Why are distributional maps becoming more important? It is well known that the distribution and abundance of organisms is changing, due to: ❖ large-scale landscape changes e.g. habitat loss, transformation, fragmentation and, in some cases, habitat creation ❖ climate change ❖ invasion by new species. Monitoring these distributional and abundance changes is vital for: SLIDESMANIA.COM ❖ making effective plans to manage the conservation of various populations and, in the process, biodiversity. ❖ recording the effects of global warming. Some projects producing distributional maps ❑ The Protea Atlas Project – recording distribution of proteas. ❑ Southern African Bird Atlas Projects - recording distribution and abundance of birds. ❑ Southern African Frog Atlas Project - recording distribution and status of all frogs. SLIDESMANIA.COM https://www.proteaatlas.org.za/ https://sabap2.birdmap.africa/ http://metadata.sanbi.org/srv/api/records/3975046c-08a4-45f0-8c2c-3c7235 f6f06b Threats to Biodiversity SLIDESMANIA.COM ● We live at a historic moment, a time in which the world's biological diversity is being rapidly destroyed. ● The present geological period has more species than any other, yet the current rate of extinction of species is greater now than at any time in the past. ● Ecosystems and communities are being degraded and destroyed, and species are being driven to extinction. ● The number of individuals in populations shrinks, unique populations and subspecies are destroyed, and remaining populations become increasingly isolated from one another. ● The cause of this loss of biological diversity at all levels is the range of human activity. SLIDESMANIA.COM What are the main threats to biodiversity in SA? 1. Land transformation 2. Overexploitation of natural biological resources 3. Climate change https://hbresearchproject.wixsite. com/hbresearchproject/opportu nities SLIDESMANIA.COM What are the main threats to biodiversity in SA? ● The major threat to biodiversity loss is land transformation as it leads to SLIDESMANIA.COM habitat loss and land degradation. ● The recent rapid human population growth with the resultant increased demands for food, energy and other commodities is the reason why land has been so dramatically transformed. To fulfil these human needs land has been transformed for: 1. Agriculture 2. Mining and industry 3. Development of cities 4. Roads. Agriculture SLIDESMANIA.COM ● Large areas of grassland and forest ecosystems (86% of the country) have been destroyed for crop production and stock grazing. ● Bad land-use practices have further reduced biodiversity. These practices include: - Monoculture which destroys all the natural flora and fauna leading to considerable loss of biodiversity. ● Intensive use of agrochemicals (pesticides and fertilizers) reduces biodiversity further by: - Polluting nearby aquatic habitats from water run-off or increasing the chance of exotic plant invasion. - Expansion of farming into unsuitable areas Agriculture SLIDESMANIA.COM ● Overgrazing - a change in species composition by trampling and selective grazing, eg in the Succulent Karoo the succulent plants are heavily grazed. - permanent loss of some species, eg the palatable annuals. - an invasion of certain unpalatable annuals and invasive alien species, eg Ageratum species and Chromolaena odorata (triffid weed), which threaten the biodiversity of the savanna, grassland and forest margins. - a change in soil ammonia and nitrate content, due to the extra animal faeces and urine. - extensive degradation of the natural grazing land with the risk of topsoil loss and accelerated desertification and the resultant reduction in biodiversity. Mining and industry SLIDESMANIA.COM The loss of biodiversity resulting from mining and industry is due to: ● Clearing of vegetation for the construction of industrial infrastructure which causes habitat destruction and fragmentation. ● Industrial waste and pollution which affects riparian habitats and the biota within rivers and nearby wetlands. riparian = along or near river banks biota = all organisms in a given area ● Industrial emissions released into atmosphere which affect terrestrial and aquatic organisms receiving rain from the polluted atmosphere. Development of cities ❑ Natural habitats and the biota they contained are destroyed when cities and housing schemes are built, eg in the Western Cape many wetlands have been filled in for housing. ❑ Another negative effect is the urban environmental pollution, both of soil and water which: ❑ Alters the distribution of species and communities. SLIDESMANIA.COM ❑ Affects the health of organisms resulting in some species becoming extinct, e.g. frogs in wetlands. Very interesting facts! This is where you section ends. Duplicate this set of slides as many times you need to go over all your sections. SLIDESMANIA.COM Roads - Construction and upgrading of roads SLIDESMANIA.COM ● Large areas of the environment being destroyed for the establishment of big quarries for stones and gravel for road building. ● Vegetation being cleared and wildlife being displaced. ● Weed species invading the disturbed area. ● Animals not being able to cross highways due to large concrete barriers in the centre of the highways. ● Habitats being fragmented, e.g. roads crossing interconnected water-bodies and natural grasslands create a barrier to the migration of species and increase the risk of population decline and possible extinction. Roads – Vehicles on roads ● 'road kill' of for example tortoises, owls and mongooses. ● Significant amounts of pollution. ● Toxic exhaust emissions and oil, grease and fuel spillages will threaten biota near roads and adjacent aquatic habitats. SLIDESMANIA.COM Overexploitation of natural biological resources SLIDESMANIA.COM ● Over-collection of medicinal plant products could lead to a loss of biodiversity. ● Due to population growth there is an increase in the demand for these by the traditional medicine market. ● Loss of biodiversity could be avoided if plans were to be put in place to replace these overharvested plants. ● International and domestic demand for some species, ● often for illegal trade, could lead to their becoming endangered or extinct and affect the ecosystems they exist in. For example, perlemoen, animal parts (rhino horns) Climate change ● Climate change, with land degradation, is the greatest threat to biodiversity. ● Each organism is adapted to a certain set of climatic conditions and when these conditions change, e.g. it gets warmer or colder or wetter, it could: bring about changes in distribution of species and communities. contribute to species extinctions. encourage the spread of alien organisms. SLIDESMANIA.COM SLIDESMANIA.COM How is biodiversity being used as a tourist draw card? ● Theme-based packages ● Tours to threatened and/or unique ecosystems ● Community-controlled ventures ● Hunting packages SLIDESMANIA.COM Aesthetic value of biodiversity ● The extraordinary range of biological diversity in South Africa is a treasure that enriches our lives as it offers recreational, aesthetic and spiritual satisfaction. ● For example South Africa offers: flower viewing and bird and game watching. SLIDESMANIA.COM
