Threats to Biodiversity PDF

Introduction Biodiversity, the variety of life on Earth, is essential for maintaining healthy ecosystems and ensuring the survival of all species, including humans. It provides critical ecosystem services such as clean air, water, food, and climate regulation. However, biodiversity is facing numero...

Introduction Biodiversity, the variety of life on Earth, is essential for maintaining healthy ecosystems and ensuring the survival of all species, including humans. It provides critical ecosystem services such as clean air, water, food, and climate regulation. However, biodiversity is facing numerous threats, including habitat destruction, climate change, pollution, and overexploitation. Understanding these threats and the importance of biodiversity helps us recognize the urgent need to protect and preserve the natural world for future generations.  Threats to Biodiversity habitat destruction diseases alien invasive climate species change genetic pollution hybridization over exploitation HUMAN OVER-POPULATION Habitat destruction Habitat destruction is defined as the complete elimination of a localized or regional ecosystem leading to the total loss of its former biological function. Factors causing habitat destruction are: Over-population, deforestation, pollution and global warning. Major reasons for habitat destruction Large scale industrial and commercial activities, are: mining, cattle rearing, commercial fishing, plantation cropping & agriculture, dam construction and encroaching Habitat fragmentation It occurs when remaining populations are isolated because the links between habitat patches have been destroyed. Habitat fragmentation is very critical for large territorial animals such as elephants. The breeding of these animals occurs only they are living in a large habitat.  Invasion by exotic species Large barriers support diversity in the area This is by enabling independent evolution by allopatric speciation Invasive species: species that breach the natural barriers that would normally keep them away Invasive species eliminate native species by: ➤ Occupying their niches ➤ By using resources of native species ➤ By competing with native species ➤ Causing diseases to native species Invasive Alien Species in the Philippines Resource Person: Carmelita I. Villamor, PhD Genetic pollution Occurs by uncontrolled hybridization. It is detrimental to rare species that come into contact with more abundant ones. Abundant species immediately colonize the new area, vanishing the rare species. Alters the genetic pool, which is an irreversible change.  Genetically modified (GM) crops to improve food production Golden Rice Bt (Bacillus thuringiensis) eggplant Golden Rice, or Malusog Rice, is a variety of rice genetically Developed by the University of the Philippines Los Baños engineered to produce beta-carotene, a precursor of (UPLB), it is a variety of eggplant that has been modified to vitamin A, in the grain, making it a potentially powerful tool resist the eggplant fruit and shoot borer (EFSB), a major to combat vitamin A deficiency, a major public health insect pest of eggplant in the Philippines, causing problem in many parts of the world, especially Southeast significant yield losses for farmers of up to 50-70%. Bt Asia where rice is a dietary staple. eggplant is projected to help reduce these losses and increase farmers' income with a 192% yield advantage. Over - exploitation Mangroves have been cleared for fuel wood Prawn farming, which has led to a decrease in the habitat essential for breeding of marine fish. Poaching Refers to the illegal hunting, capturing, or killing of animals, typically for their valuable parts. Hybridization (fusion of unrelated plants) Green Revolution popularized hybridization for increased yield Hybrid breeds originated in developed countries further hybridized with local varieties (in developing countries) This is to create high yield strains resistant to local climate and diseases High yielding breeds causes genetic erosion and gene pollution in wild sps. Genetic erosion and genetic pollution may destroy unique genotypes This creates a hidden crisis which could result in a severe threat to our food security or health  Global warming is one of the major threat to global Climate Change biodiversity Coral reefs (biodiversity hotspots) will be lost in 20 to 40 years if global warming continues at the current trend Carbon dioxide concentration in atmosphere affects morphology of plants Higher carbon dioxide concentration acidify oceans In 2004, an international collaborative study on four continents estimated that 10% of species would become extinct by 2050 due to global warming Climate change induces change in raining pattern Climate change also affects migratory animals and birds Biodiversity in polar and mountain region are vulnerable to climate changes  Diseases Reduction in habitat causing high population densities, encourages spread of diseases. Diseases can eliminate species from earth The cause of disease may be natural or anthropological Human activities sometimes speedup the severity of natural diseases Introduced species may carries pathogens along with them Viral epidemics in animals is major threat Animals are more prone to disease than plants Animals in captivity are also prone to diseases Human over-population World population (as of 2024): 8.2 billion In 1950 the population was 2.5 billion Population will reach 9 billion during the 21st century Increase in population leads to over exploitation of resources Forest area become reduced Population increase ultimately cause pollution increase Population explosion thus form the prime factor biodiversity depletion Population increase thus forms the prime cause for the other 7 main threats mentioned above Importance of Intrinsic/Ethical value Biodiversity ➤ Biodiversity has an intrinsic value because it is part of the natural world. ➤ Its conservation is important for the maintenance of natural ecological processes. ➤ It helps in the balancing of many natural cycles such as nutrients and water cycling, soil formation and retention, resistance against invasive species, pollination of plants, regulation of climate, recovery from natural disasters. ➤ Ethical value is based on a respect for life. ➤ Biodiversity provides a range of goods, from agricultural crops to Anthropocentric medicines and fibers, to which a direct value and cost can be Value assigned, provides us many things to fulfill our need including food, water, air and raw materials for clothes. ➤ Human beings are dependent on biodiversity for their health, well being and enjoyment. ➤ This value is associated with consumption and production.  Aesthetic Value This is expressed by humans seeking contact with nature. Natural and wild landscapes including many animals are aesthetically pleasing and provide opportunities to refresh. Biodiversity supports recreation and tourism. Economical/Market Value There are different procedures to valuate the benefits generated by biodiversity in terms of market-based techniques. Usually, market prices can be applied when direct benefits of biodiversity are involved: i.e. when consumer purchases the biodiversity-derived good. Example: People sell firewood, honey from the wild and they earn money.  Biodiversity is also politically and strategically important for us. It ensures the recognition of Political Value a zone or country in the world. The Philippines is one of 18 mega-biodiverse countries of the world, containing two- thirds of the earth's biodiversity and between 70% and 80% of the world's plant and animal species. The Philippines ranks fifth in the number of plant species and maintains 5% of the world's flora.  Scientific Value The scientific value of biodiversity is relevant because it provides many opportunities for research work. There is a large portion of the biodiversity about which we still do not know, which may be unpredictable. Still, lack of scientific knowledge leaves an enormous gap between the current realized values of biodiversity and its potential future value. Cultural Value The cultural value of biological diversity conservation for present and future generations is an important reason for conserving it today. Worshipping typical plants like Peepal (Ficus religiosa), Tulasi (Ocimum tenuiflorum), and different animals (some snakes as Naag Dewata) also highlights the importance of it.