Lecture 10: Biological Diversity PDF

WHAT IS BIOLOGICAL DIVERSITY? Refers to the variety of life-forms, commonly expressed as the number of species or the number of genetic types in an area. POPULATION – a group of individuals of the same species living in the same area SPECIES – all individuals that are capable of...

WHAT IS BIOLOGICAL DIVERSITY? Refers to the variety of life-forms, commonly expressed as the number of species or the number of genetic types in an area. POPULATION – a group of individuals of the same species living in the same area SPECIES – all individuals that are capable of interbreeding; a species is made up of populations 1 WHY DO PEOPLE VALUE BIODIVERSITY? Primary reasons: 1) Utilitarian 2) Public service 3) Ecological 4) Moral 5) Theological 6) Aesthetic 7) Recreational 8) Spiritual 9) Creative 2 WHY DO PEOPLE VALUE BIODIVERSITY? UTILITARIAN Means that a species or group of species provide a product that is of direct value to people. Plants and animals can be harvested for food Trees can provide lumber and fuel Some plants provide medicines 3 WHY DO PEOPLE VALUE BIODIVERSITY? PUBLIC SERVICE Means that nature and its diversity provide some service that is essential or valuable to human life and would be expensive or impossible to do ourselves. Taking up carbon dioxide Pollinating flowers 4 WHY DO PEOPLE VALUE BIODIVERSITY? ECOLOGICAL Refers to the fact that species have roles in their ecosystems, and that some of these necessary for the persistence of their ecosystems and persistence of life. Scientific research tells us which species have such ecosystem roles. Keystone Invasive species species 5 WHY DO PEOPLE VALUE BIODIVERSITY? MORAL Reason for valuing biodiversity is the belief that species have a right to exist, independent of their value to people. 6 WHY DO PEOPLE VALUE BIODIVERSITY? THEOLOGICAL Refers to the fact that some religions value nature and its diversity, and a person who subscribes to that religion supports this belief. 7 WHY DO PEOPLE VALUE BIODIVERSITY? The last four reasons for valuing nature and its diversity Aesthetic Have to do with the intangible (nonmaterial) ways Recreational that nature and its diversity benefit Spiritual people. Creative 8 WHY DO PEOPLE VALUE BIODIVERSITY? RECREATIONAL people enjoy getting out into nature, not just because it is beautiful to look at but because it provides us with healthful activities we enjoy. 9 WHY DO PEOPLE VALUE BIODIVERSITY? SPIRITUAL Contact with nature and its diversity often moves people, an uplifting often perceived as religious experience. 10 WHY DO PEOPLE VALUE BIODIVERSITY? CREATIVE Refers to the fact that artists, writers, and musicians find stimulation for their creativity in nature and its diversity. 11 WHY DO PEOPLE VALUE BIODIVERSITY? AESTHETIC Refers to the beauty of nature, including the variety of life. 12 BIOLOGICAL DIVERSITY BASICS 13  GENETIC DIVERSITY The total number of genetic characteristics of a specific species, subspecies, or group of species 14  HABITAT DIVERSITY The different kinds of habitats in a given unit area. 15  SPECIES DIVERSITY Has to do with the relative chance of seeing species as much as it has to do with the actual number present 1) Species richness – the total number of species 2) Species evenness – the relative abundance of species 3) Species dominance – the most abundant species 16  Which community is more diverse? Community A Community B 17  SPECIES DIVERSITY When ecosystems are lost, populations of the species that make up their biological communities are also lost. A species may disappear from a local ecosystem but remain in others. EXTIRPATION – the loss of a single population of a species EXTINCTION – means that all populations of a species have disappeared, an irreversible situation 18  SPECIES DIVERSITY ENDEMIC SPECIES – are species of plants and animals which belong to a particular region. 19 How rapidly are species being lost? Who has the highest risk of extinction (threatened)? 20  How rapidly are species being lost? Disease caused by chytrid fungi is one responsible Vulnerable to climate change (water loss) for their decline. AMPHIBIANS 21  SPECIES DIVERSITY Because of the network of community interactions among populations of different species within an ecosystem, the loss of one species can have a negative impact on the overall species richness of the ecosystem. – KEYSTONE SPECIES illustrates this effect 22  THE NUMBER OF SPECIES ON EARTH There are over one million species of organisms that have been studied and classified and around 5-10 million more that needs to be classified. How do scientists handle this vast numbers of organisms? What system of classification do they use to group these organisms in order to avoid chaos and confusion? TAXONOMY 23  TAXONOMY One of the first disciplines that evolved from the study of diversity of organisms. Deals with the diversity of organisms and all the relationships that may exist among them. The theory and practice of groupings and classifying organisms. 24  TAXONOMY: THE BINOMIAL One of the first disciplines that evolved from the study of diversity of organisms. Deals with the diversity of organisms and all the relationships that may exist among them. The theory and practice of groupings and classifying organisms. 25  TAXONOMY: THE BINOMIAL Musca domestica Lin. Kingdom: Animalia Phylum: Arthropoda Class: Insecta Order: Diptera Section: Schizophora Family: Muscidae Genus: Musca Species: domestica Author: Linnaeus Note: No two organisms can be given the same scientific name. Common name: Housefly 26  Genus: Solanum Solanum tuberosum Solanum lycopersicum 27 Where several different species and genera cohabitate, there is rich biodiversity. 28 A decrease in biodiversity is eminent worldwide. Vertebrates fell to 60% from the 1970s due to human causes. There is an annual decrease in wildlife by 2% (The Worldwide Fund for Nature and Zoological Society of London). 29  MAJOR CAUSE OF BIODIVERSITY LOSS ✔ Human population doubled in number since 1960 to 7.4 billion. 30  MAJOR CAUSE OF BIODIVERSITY LOSS ▪ Humans have industrialized the natural habitat of wildlife as well as marine life. ▪ Leaving these creatures with no place to live would eventually cause their deaths. 31 “The disappearance of wildlife is at an unprecedented rate.” –Marco Lambertini, Director of WWF International 32 EARTH MIGHT ENTER THE SIXTH MASS EXTINCTION! 33  EXTINCTION OF WILDLIFE EXTINCTION – the death of a species – the elimination of all the individuals of a particular kind. – Extinction is a natural and common event in the long history of biological evolution. – Extinction and loss of biodiversity are a major consequence of human domination of the Earth. 34  MASS EXTINCTION OF WILDLIFE MASS EXTINCTION – described as the disappearance of species at a rate of 1,000 faster than usual. The disappearance of species in a certain environment causes an imbalance in the ecosystem, producing more chaotic changes that harm the entire ecosystem. 35 BIODIVERSITY AND ECOSYSTEM 36  Understanding biodiversity within the concept of ecosystem needs a thorough study on the relationship of the biotic and the abiotic factors. Interdisciplinary approach is needed to study the ecosystem. Biodiversity plays a major Large number of golden snails in a role in this natural dynamics. certain area of a rice field can predict a low production of rice harvest. 37  On a positive view, the larger number of different species in a certain area can be a predictor of sustainable life in that area. Sustainability of the ecosystem ensures a better survival rate against any natural disaster. We must preserve and conserve the biodiversity of all creatures. 38  ROLE OF BIODIVERSITY IN THE STABILITY OF ECOSYSTEM One plant species, sensitive to drought. Several species, drought tolerant plant species may be present. 39 People will always depend on biodiversity and our health will ultimately depend upon the products and services that we acquire from the ecosystem. 40 CHANGES IN BIODIVERSITY 41 Humans inhabiting the forest would disturb the natural order of life. 42 Humans inhabiting the forest would disturb the natural order of life. Trees and plants would be affected in the land-clearing operations where the houses would be 43 built. Humans inhabiting the forest would disturb the natural order of life. Animals, insects, and all types of life forms in the cleared area would neither be displaced or most likely to be killed. 44 Humans inhabiting the forest would disturb the natural order of life. The food chain might be damaged. 45 When our ecosystem is not well taken care of, biodiversity encounters changes that may impact human health on such different levels. 46 THREATS TO BIODIVERSITY Identified by United Nations’ Environment Programme 47  THREATS TO BIODIVERSITY 1) Habitat loss and destruction 2) Alteration in ecosystem composition 3) Over-exploitation 4) Pollution and contamination 5) Global climate change 48  HABITAT LOSS AND DESTRUCTION Major contributing factor is the inhabitation of human beings and the use of land for economic gains. 49  HABITAT LOSS AND DESTRUCTION Agriculture Urban Deforestation Mining Environmental Development pollution Dam Power plants Irrigation Aquaculture construction 50  ALTERATION IN ECOSYSTEM COMPOSITION Alterations and sudden changes, either within species groups or within the environment, could begin to change the entire ecosystem. Alteration in ecosystems are critical factor contributing to species and habitat loss. 51  ALTERATION IN ECOSYSTEM COMPOSITION Introduction (intentional or non-intentional) of: EXOTIC (invasive) SPECIES - alien, nonnative, nonindigenous, or introduced species, are those that occur in areas outside of their natural geographic range. – Disrupt communities by competing with, preying on, or parasitizing native species – The lack of interspecific interactions that keep the newcomer populations in check is often a key factor in a non-native species becoming invasive In the absence of an evolutionary history with predators, animals may lack defense mechanisms or even a fundamental recognition of danger 52  ALTERATION IN ECOSYSTEM COMPOSITION The Pacific island of Guam was home to 13 species of forest bird– but no native snakes – when brown tree snakes arrived as stowaways on a cargo plane. 53  OVER-EXPLOITATION Over-hunting, overharvesting, overfishing, or over-collecting of species can quickly lead to its decline. Changing consumption patterns of humans is often cited as the key reason for the unsustainable exploitation of natural resources. 54  OVER-EXPLOITATION Sports Hunting 55  POLLUTION AND CONTAMINATION Biological systems respond slowly to changes in their surrounding environment. Pollution and contamination cause irreversible damage to species and varieties. 56  GLOBAL CLIMATE CHANGE Both climate variability and climate change cause diversity loss. Species and populations may be lost permanently if they are not provided with enough time to adapt to changing climatic conditions. 57 CONSEQUENCES OF BIODIVERSITY LOSS 58  IMPORTANCE OF INTACT ECOSYSTEM Intact ecosystems functions best since the organisms composing them are specialized to function in that ecosystem to: o Capture o Transfer o Utilize o Lose both energy and nutrients 59  STABILITY AND DYNAMICS OF ECOSYSTEM Ecosystems are dynamic systems, and a static ecosystem would be a dead ecosystem – just as a static cell would be a dead cell. Dynamic Ecosystem Dead Ecosystem 60  RESISTANCE AND RESILIENCE OF ECOSYSTEM Different ecosystems may respond differently to the same disturbance; one may recover rapidly, and another may recover more slowly – or not at all. Ecologists sometimes use two parameters to describe how an ecosystem responds to disturbance. 1) RESISTANCE – the ability of an ecosystem to remain at equilibrium in spite of disturbances 2) RESILIENCE – how readily an ecosystem returns to equilibrium after being disturbed Ecosystems with higher biodiversity tend to be more stable with greater resistance and resilience in the face of disturbances, disruptive events. 61 As stated by Tilman, “The Earth will retain its most striking feature, its biodiversity, only if humans have the prescience to do so. This will occur, it seems, only if we realize the extent to which we use biodiversity (Rainforest Conservation Fund, 2017) 62 HEALTH, BIOLOGY, AND BIODIVERSITY 63 NUTRITIONAL IMPACT OF BIODIVERSITY Biodiversity is a vital element of a human being’s nutrition because of its influence on food production. Major factor that contributes to sustainable food production for human beings. Society must have access to a sufficient variety of nutritious food as it is a determinant of their health as human beings. 64  Almost all living organisms are dependent to their environment to live and reproduce. Basic needs of living organisms such as air, water, food, and habitat are provided by its environment. The evolution of human beings was due to the improved access to these basic needs. Advances in agriculture, sanitation, water treatment, and hygiene have had a far greater impact on human health than medical technology. 65  Although the environment sustains human life, it can also cause diseases… Lack of basic necessities is significant cause of human mortality. Environmental hazards increase the risk of cancer, heart disease, asthma, and other illnesses. ▪ Physical (pollution, toxic chemicals, food contaminants) ▪ Social (dangerous work, poor housing conditions, urban sprawl, poverty) Unsafe drinking water and poor sanitation and hygiene are responsible for a variety of infectious diseases (schistosomiasis, diarrhea, cholera, meningitis, gastritis). 66  In 2015, approximately 350,000 children under the age of five (mostly in the developing world) died from diarrheal diseases related to unsafe drinking water. Approximately 1.8 billion people used drinking water contaminated with feces. More than 2 billion people lacked access to basic sanitation. 67  HUMAN ILLNESSES RELATED WITH ITS ENVIRONMENT Parkinson’s disease Obesity Heart disease Occupational injuries Cancer Dysentery Chronic diseases Arthritis Obstructive pulmonary disease Malaria Asthma Depression Diabetes 68  ACTIVITIES PROMOTING HEALTH AND EXTEND HUMAN LIFE COULD HAVE ADVERSE ENVIRONMENTAL EFFECTS Food production Health care facilities o Pesticides o Hospitals use large quantities of o Fertilizers electricity and fossil fuels o Soil salinization o Produce medical wastes o Wastes produced by livestock Alteration of environment to o Carbon emissions from food prevent diseases manufacturing and transportation o Malaria was eradicated in the 1940s o Deforestation and 50s as a result of draining o Overfishing wetlands and spraying DDT to kill mosquitoes. o Reduction in mortality from starvation or disease can lead to overpopulation which stresses the environment. 69  SERIOUS IMPACT ON CLIMATE CHANGE Changes in global climate that are occurring as a result of global warming are likely to become leading cause of biodiversity. Corals are declining throughout the world. Safeguarding of coral reefs is essential to reduce the risk of floods as it reduce wave energy by 97% protecting over 100 million people all over the world. 70  Establishing protected areas slows the loss of biodiversity… Conservation biologists are applying their understanding of population, community, ecosystem, and landscape dynamics in establishing parks, wilderness areas, and other legally protected nature reserves. BIODIVERSITY HOT SPOT – a relatively small area with numerous endemic species, and a large number of endangered and threatened species 71 BIODIVERSITY HOT SPOTS 72