Unit 1 Class Notes PDF

UNIT I: ENVIRONMENT AND ECOSYSTEMS - Introduction to the course, Scope and Importance of Environment - Concept of an Ecosystem - Structure and Function of an Ecosystem – Producers, Consumers, and Decomposers - Energy Flow in the Ecosystem, Ecological Succession Food Chains, Food Webs, Ecological...

UNIT I: ENVIRONMENT AND ECOSYSTEMS - Introduction to the course, Scope and Importance of Environment - Concept of an Ecosystem - Structure and Function of an Ecosystem – Producers, Consumers, and Decomposers - Energy Flow in the Ecosystem, Ecological Succession Food Chains, Food Webs, Ecological Pyramids - Introduction, types, characteristic features, structure, and function of the following ecosystem: - Forest ecosystem Grassland Ecosystem, Desert Ecosystem, Aquatic ecosystems (ponds, streams, lakes, rivers, oceans, estuaries) - Biodiversity and its conservation  MULTIDISCIPLINARY NATURE ─ To encircle/ surround ─ interactions between physical, chemical, and biological systems Sociology Meteorology Social Political Framework Atmospheric Sciences Chemistry Hydrology Climate modelling. GIS Geology Engg., Coastal Geomorphology Management Soil Sciences Earth Green credits EIA Life Ecology Population dynamics Sedimentology Sciences Sciences Diseases Hydrogeology Oceanography  NEED FOR PUBLIC AWARENESS Global Environmental Problems Environmental Priorities in India Population Stabilization: Carrying capacity Over populations Natural resource assessment and Pollution management Depletion of Resources Strategies for environmental pollution Global change monitoring and control War Human settlement and public health Environmental Laws and regulation Environmental Education and Awareness Dynamic pressure of limited resources linking to Hazards and Disasters “Tragedy of Commons”- individuals promote their short terms welfare, which conflicts with long-term environmental interest  NEED FOR PUBLIC AWARENESS Communities are vulnerable to the impacts of climate change. Need to adapt to increase their resilience. The community needs to be made aware of the risks, acquire knowledge about the options that are available for a response, and be empowered to take their own actions Drivers for effective government policies Khatibi, F.S., Dedekorkut-Howes, A., Howes, M. et al. Can public awareness, knowledge and engagement improve climate change adaptation policies?. Discov Sustain 2, 18 (2021)  ECOSYSTEM ─ interaction of a variety of individual organisms with each other (same or different species) and their physical environment. ─ Self-contained system with specific nutrients and energy flow. ─ Individual→ Population→ Ecosystem → Biome→ Biosphere Ecosystem Biotic Abiotic Producers Climatic Conditions Consumers (Temperature, rainfall, sunlight, Decomposers (Saprophytes) Wind, Atmospheric gases) Scavengers Edaphic conditions Parasites (soil, pH, mineral nutrients) Phagotrophs and Osmotrophs Representation of the Structure of the Ecosystem  ECOLOGICAL PRINCIPLES ─ Homeostasis ─ Tendency of the body to seek and maintain balance within its internal environment even when it is undergoing external change: RESILIENCE ─ Limiting Factor ─ Limiting factors determine the productivity of organisms, populations, or communities ─ Law of thermodynamics ─ First law: Law of conversation of energy ─ Second Law: Disorder is constantly increasing, and during energy conversion, energy is converted into a less organized and useful form. ─ “Energy transfer from along the food chain in less than 10 % Are the activities of the biotic component Energy cycling of the ecosystem constant? Nutrient cycling  FOOD CHAIN AND FOOD WEB ─ Food Chain: unidirectional transfer of energy through the community. ─ Grazing food chain, Detrital food chain, Supplementary (Parasitic) food chain ─ Detrital food chain is common to all ecosystem Primary Producers Herbivores Carnivores ─ Food web: graphical description of interconnected feeding relationships among species in a community. ─ Mention 4 differences between the food chain and the food web  PRODUCTIVITY ─ is the rate of formation of energy and matter, which is stored in different species at different trophic levels. ─ Primary Productivity (dry wt. g calories/ unit area/ unit time): the rate at which chemical energy is produced from solar energy. ─ NPP of the earth is 320 dry g. calories / m2/ year ─Secondary Productivity: Rate with which energy is stored at different levels in consumers ─Gross Primary Productivity- is the total amount of organic matter produced through photosynthesis ─Net Primary Productivity- the amount of energy that remains available for plant growth ─Arrange in increasing order of NPP: Desert, Deep Ocean, Coral reef, Lakes  MODELS FOR ENERGY FLOW Universal energy flow: gradual loss of energy at each level thereby resulting in less energy available at the next tropic level Single Channel model: The flow of energy takes place in a unidirectional manner through a single channel of producers to herbivores and carnivores. The entire system would collapse if the primary source of energy were cut off. At each tropic level, there occurs a progressive decrease in energy due to loss of energy as heat and utilized energy Graphical representation of single channel model  Double channel or Y-shape model a common boundary, light and heat flow as well as import, export, and storage of organic matter. It conforms to the basic stratified structure of ecosystems It separates the two chains i.e. grazing & detritus food chains in both time and space.  ECOLOGICAL PYRAMID Graphical representation of these trophic levels Eltonoian Pyramid is of three types: 1. Pyramid of energy 2. Pyramid of Number 3. Pyramid of biomass (productivity)  PYRAMID OF ENERGY The pyramid of energy is always uptight. Lindeman Law ( 10 % Law): When energy is transported from one trophic level to another, 90 % is used in the metabolic process, and only 10 % is transferred. ─The energy transferred from one trophic level to another is called ecological efficiency. ─Which has higher ecological efficiency marine or terrestrial ecosystem  PYRAMID OF NUMBER A pyramid of numbers indicates the number of individuals in each trophic level. # of carnivores # of herbivores # of producers Inverted pyramid: higher trophic level may have a larger standing crop than a lower trophic level. bird parasite insects deer tree grass The pyramid of numbers does not give a true picture of the food chain and are not very functional.  PYRAMID OF PRODUCTIVITY A pyramid of standing crop/ productivity indicates how much biomass is present in each trophic level at any one time. # of carnivores # of herbivores # of producers The size and growth of individuals may vary widely, the pyramids of numbers and productivity say little or nothing about the amount of energy moving through the ecosystem. How is the pyramid of energy biomass and productivity for the pond ecosystem?  NUTRIENT CYCLING Biogeochemical cycle The major difference between energy and nutrient flow is that nutrient flow is cyclic while energy flow is unidirectional. Cycling of nutrients can be in terrestrial {nitrogen cycle} and aquatic {carbon cycle}. Cycling of nutrients can be: Biological cycle- respiration, assimilation, excretion, decomposition, photosynthesis processes. Geological cycle- includes weathering, sedimentation, erosion, fossilization, and combustion processes. CARBON CYCLE NITROGEN CYCLE PHOSPHOROUS CYCLE SULFUR CYCLE  TYPES Ecosystem OF ECOSYSTEM Natural Artificial Terrestrial Aquatic Forest ecosystem Ponds (lentic) Freshwater Deserts ecosystem River (lotic) Grassland Lakes (lentic) ecosystem Oceans Deep water Marine Estuaries Coral reefs Wetlands/ Salt Marsh  LENTIC/ LOTIC ECOSYSTEM Based on solar irradiation Euphotic Zone: Presence of Sufficient light for photosynthesis. Profundal zone: lack of sufficient sunlight and oxygen. Mostly occupied by consumers. Benthic Zone: No sunlight and oxygen. Based on distance from land Littoral: a shallow zone near the shore. Rooted plants, phytoplankton Limnetic Zone: well-lit zone in open sea, running water, Species found are Zooplanktons and nektons  Based on productivity/ nutrient content Oligotrophic: less productive lake. Usually deep and step side with narrow littoral zone Eutrophic: High productive lake, rich in organic matter and nutrient Mesotrophic: intermediate level of productivity, medium-level nutrients, usually clear water with submerged aquatic plants.  MARINE ECOSYSTEM Oceans Deep water Estuaries Coral reefs Wetlands/ Salt Marsh letstalkscience.ca  Based on the light Photic, Euphotic, Disphotic, Aphotic Based on distance Intertidal Zone, Continental Self, Continental slope, Continental Rise, Open Ocean (Pelgaic), Basin (Abyssal) Based on depth in Pelagic Epipelagic, Mesopelagic Bathypelagic, Abyssopelagic Based on nutrients in Pelagic: Neritic and Oceanic letstalkscience.ca  WETLANDS “A wetland can be defined as an area of marsh, fen, peatland or water, natural or artificial, permanent or temporary with water static, flowing, fresh, brackish, salt, including area of marine water and depth less than 6m at the time of low tide (Ramsar Convention) Function: 1. Biodiversity, 2. Groundwater replenishment, Water filtration, S 3. Sediment retention, Erosion control, 4. Tourism, Retention of nutrients, 5. Mitigation against climate change, 6. Natural transport infrastructure  Marshes: shallow water that is mostly grassland. Can be fresh and saltwater Swamps: slow-moving streams, rivers, deeper than marshes. Have wood shrubs www.environment.gov.scot rather than grass Pichavaram Mangroves Bog and Fens: freshwater wetlands formed by glacial lakes. Low nutrients Estuaries: Enclosed bodies where freshwater meets salt water, high biodiversity, with https://i.pinimg.com/originals/11/95/6d/11956d 0d8a036eac25a4b72da86206c1.jpg brackish water https://south-asia.wetlands.org/  CORAL REEF diverse underwater (0- 60 m) ecosystem held by calcium carbonate secreted by corals. Individual coral is called a polyp, Shallow water corals feed on Zooxanthellae (algae)- Zooxanthellae provide colors to corals Temp range for survival- 20-21 degrees https://phys.org C, Salinity 27-30 %  Fringing Reefs: Attached to the margins of continents & form in areas with low rainfall runoff. Barrier Reefs: A lagoon separates them from land. They either form around islands or as lines parallel to the continental shore. Atolls: It is a ring-shaped island made up of coral reefs along with coral debris.  TERRESTRIAL ECOSYSTEM Taiga Cold-climate forests, northern latitudes. World’s largest terrestrial ecosystem Biotics: Coniferous trees, such as pines, some deciduous trees, herbivores- moose, elk, and bison, omnivores- bears Abiotic: little direct sunlight for much of the year. Taigas are home to large. Sub-arctic climate with extremely cold winters and mild summers. Tundra Found primarily north of the Arctic Circle. Biotic: short vegetation and essentially no trees. Caribou, polar bears, and musk ox are some of the notable species Abiotic: The soil is frozen and covered with permafrost for a large portion of the year. Temperate Forests Seasonal variation in climate Annual rainfall is about 750- 2000 mm and soil is rich in organic matter. Deciduous trees (oaks, maples, etc.) and coniferous trees (pines). These forests contain abundant micro-organisms, and mammals (hares, deer, fares, coyotes). Tropical Rain Forests Densely packed tall trees Prevents the growth of smaller plants. Temperature remains almost the same throughout the year. Grasslands Dominated by grasses. Occur in both tropical and temperate regions where rainfall is not enough to support the growth of trees. Deserts hot and low rain areas suffering from water shortage and high wind velocity. Prominent desert animals are reptiles, and burrowing rodent insects.  Ponds Assignment 1 Abiotic Heat, light, pH of water, CO2, oxygen, Components: calcium, nitrogen, phosphates 1. Write about the biotic, abiotic, ecological, commercial, and anthropogenic effects of Biotic Algae, Macrophytes like Hydrilla, Trapha, Components Typha (producers), Rotifers, protozoans, any of the five ecosystems below zooplanktons (Primary Consumers), Ponds insects and fish, (secondary consumers), Estuaries game fish, turtles, (tertiary consumers), Marshes bacteria, & fungi Tropical Rainforest Tropical scrub forest Ecological Biodiversity, Water Filtration and Temperate Rain forest Services Purification, Flood Mitigation, Groundwater Temperate Deciduous forest Recharge, Moderating local temperatures Evergreen coniferous/ Boreal and humidity level Tropical: Savannas Commercial Water supply, hydropower, tourism, Temperate Grassland forest Services Aquaculture and Fisheries Polar / Arctic Tundra Anthropogenic Chemical Runoff, Eutrophication, Tropical Desert effect Groundwater Depletion, Introduction of Temperate Desert Invasive Species, Habitat degradation, Urban Sprawl, Waste Disposal  ECOLOGICAL SUCCESSION Directional and sequential change of plant or community or ecosystem over time in an orderly sequence and later stabilized to form the climax progressive transformation until a stable community is formed. Succession may be initiated by: formation of a new, unoccupied habitat (e.g., a lava flow) disturbance of an existing community (e.g., fire, invasive). Primary succession: begins in areas where there is no soil initially, whereas succession that begins in areas where soil is already present is called Secondary succession.  Process of Succession: Nudation: Succession begins with the development of a bare site. Invasion: arrival of propagules and establishment and initial growth of vegetation Competition: As vegetation became well established, grew, and spread, various species began to compete for space, light, and nutrients. Reaction: During this phase, autogenic changes affect the habitat resulting in the replacement of one plant community by another. Stabilisation: The reaction phase leads to the development of a climax community Species: Pioneer, Middle, and Climax How do above species vary during ecological succession?  AEOLIAN ZONE: dry sediment 8000 (PARA BIOSPHERIC ZONE)- Dormant life 6000 ALPINE ZONE 4000 2000 Forest, meters Sea level Grasslands EUPHOTIC ZONE Continental Shelf, Estuaries 2000 4000 DYSPHOTIC ZONE DEPTH ABYSSAL 6000 8000 ─ How do material and energy flow in these systems? 10000  BIODIVERSITY Convention on Biological Diversity defines biodiversity as: variability among living organisms from all sources including, inter alia, terrestrial, marine, and other aquatic ecosystems and the ecological complexes of which they are a part; this includes diversity within species, between species, and of ecosystems. Level of Biodiversity 1. Genetic Diversity It refers to the variation of genes within species. This variation can exist between different populations of the same species as well as between individuals within a population. Adv: provides organisms and ecosystems with the capacity to recuperate after the change has occurred. Species Diversity Species diversity is a measure of the diversity within an ecological community. Incorporates both species richness (the number of species in a community) and species abundance. Species diversity is not evenly distributed across the globe. Ecosystem Diversity refers to the presence of different types of ecosystems. For instance, tropical south India with rich species diversity will have an altogether different structure compared to the desert ecosystem Functional Diversity refers to the diversity of ecological processes that maintain and are dependent upon the other components of diversity. E.g. competition, predation, parasitism.  Measures of Biodiversity 1. Alpha Diversity - refers to the average species diversity in a habitat or specific area. Alpha diversity is a local measure. 2. Beta Diversity - refers to the ratio between local or alpha diversity and regional diversity. This is the diversity of species between two habitats or regions 3. Gamma Diversity - is the total diversity of a landscape and is a combination of both alpha and beta diversity.  VALUE OF BIODIVERSITY Value categories Level of operation Commodity value Utilization value of organisms to Population and species humans as food, medicine diversity Amenity value The value of human visiting and Species and ecosystem viewing or learning diversity Ecological the importance of maintaining all Functional diversity integrity value functionally critical aspects of the ecosystem Ethical value Moral obligation on human not to Species and ecosystem drive other species to extinction diversity Option value The future evolutionary potential Genetic and population of species which can latter be diversity used or commodity value BIODIVERSITY HOTSPOTS  BIODIVERSITY HOTSPOTS Are areas that support natural ecosystems that are largely intact & where native species and communities associated with this ecosystem are well represented To qualify as a biodiversity hotspot, at least 1,500 vascular plants as endemics —a high percentage of plant life found nowhere else on the planet. A hotspot, in other words, is irreplaceable. It must have 30% or less of its original natural vegetation. It must be threatened. Endemic Species  THREAT TO BIODIVERSITY Loss of species, ecosystem, genes, and extinction Can cause: Reasons: Reduce the productivity of the Habitat destruction ecosystem, affecting energy and Poaching nutrient transport Exotic species Affects restoration and resilience Shifting cultivation Human-caused stress: Climate Natural calamities and disaster change Outbreak of diseases Natural disaster Pollution Extinction  EXTINCTION OF SPECIES Mass Extinction, Natural Extinction, Anthropogenic Extinction IUCN (International Union for Conservation of Nature, 1948) Red Data List, 1964 i. Extinct: the last individual has died or is nontrackable: Ex. Indian Cheetah ii. Extinct in the Wild: Species survive only in captivity iii. Critically Endangered: high risk of extinction; population declined by 80-90 % over the decade iv. Endangered: Very high risk of extinction as the population has declined by 50 -70% in a decade. Current population size (250) v. Vulnerable: High risk of endangerment in the wild vi. Near Threatened: Close to becoming threatened or may meet the criteria for threatened status. vii. Least Concern i. Data Deficient ii. Not Evaluated  BIODIVERSITY CONSERVATION METHODS CONSERVATION OF BIODIVERSITY: Objective: Maintain essential ecological processes Preserve diversity of species Make sustainable utilization of species and ecosystem METHODS OF BIODIVERSITY CONSERVATION: IN-SITU EX-SITU National Park, Gene Bank Biosphere Reserves, Seed Bank Wildlife Sanctuaries, Botanical garden Wetlands Zoological Garden Biodiversity Hotspots Sacred Trees and Lakes Natural Gene pool  BIODIVERSITY CONSERVATION METHODS IN-SITU 1. Aims to protect total ecosystem 2. Create protected areas 3. Promote sustainable management 4. Protect and restore of degraded land 5. Integrate of conversation and biodiversity 6. Create natural corridors EX-SITU 1. Relocate endangered species from their natural habitat corridors  BIODIVERSITY PROTECTED AREA Objective Features Zone Activities Conservation of No person resides in Core Developmental activities like National Park species of a habitat the park other than forestry, poaching, hunting, with minimal or very public servants on and grazing on cultivation are low intensity of duty and persons not permitted. National Park human activity permitted by the are declared by the Central chief wildlife warden. Government resolution Conservation of No person resides in Core, Harvesting of timber, collecting species and habitats the park other than Buffer, minor forest products and by manipulative public servants on and private ownership rights are Wildlife Sanctuary management duty and persons Restorati allowed. Boundaries of permitted by the on sanctuaries are not well defined chief wildlife and controlled biotic warden. interference is permitted.. The State Government may, by notification.  Objective Features Zone Activities Conservation of the Both natural and Core, National governments and remain natural resource and human-influenced Buffer, under sovereign jurisdiction the improvement of ecosystem; Restoration, Biosphere Reserve the relationship substantial human Transition between humans and settlement the environment Criteria for designation of Biosphere Reserves A site must contain an effectively protected and minimally disturbed core area. The core area should be typical of a biogeographical unit and large enough to sustain viable populations representing all trophic levels in the ecosystem. Involvement/cooperation of local communities to bring experiences to link biodiversity conservation and socio-economic development. Areas potential for preservation of traditional tribal or rural modes.  STRUCTURE OF BIOSPHERE RESERVES CORE ZONE: habitat for numerous plant and animal species, including Core Zone higher order predators, and may contain centers of endemism. Conserve the wild relatives of economic species Buffer zone Represent genetic reservoirs. Transition zone Free from human pressures external to the system. BUFFER ZONE: protection of the core zone in its natural condition. Restoration sites, limited recreation, tourism, fishing, grazing, etc. Research and educational activities are to be encouraged. TRANSITION ZONE: This includes settlements, croplands, managed forests and areas for intensive recreation and other economic uses characteristics of the region.  ECO-SENSITIVE ZONES National Wildlife Action Plan (2002-2016) Land within 10 km of the boundaries of national parks and wildlife sanctuaries is to be notified as eco-fragile zones or Eco-Sensitive Zones (ESZ). Areas beyond 10 km can also be notified by the Union government as ESZs if they hold larger ecologically important “sensitive corridors”. What is the Significance of ESZs? Minimize the Impact of Development Activities In-situ Conservation Minimize the Negative Impact on Fragile Ecosystems: 'Shock Absorber’ What are the Challenges and Threats to Eco-Sensitive Zones? What can be the Way Forward?  INTERNATIONAL CONVENTION FOR BIODIVERSITY CONSERVATION Convention on International Trade in Endangered Species in Wild Fauna and Flora (CITIES) Aim to ensure international trade in the specimen doesn’t threaten their survival Reduce economic incentive to poach endangered species and destroy their habitat Convention on Convention of Migratory Species of Wild Animals (CMS) Green Peace: opposing environmental abuse, saving endangered species, and increasing public awareness United Nation Environment Program World Wide Fund for Nature TRAFFIC: The wildlife trade monitoring network is a strategic alliance between IUCN and WWF to ensure trade of wild plants and animals is not a threat to nature.  NATIONAL CONVENTION, ORGANISATION, & PROJECT OR BIODIVERSITY CONSERVATION Wildlife Protection Act, 1972 Madras Crocodile Bank Trust (MCBT) National Tiger Conservation Act Salim Ali Centre of Ornithology and natural The Biodiversity Act, 20222 History Zoological Survey of India Wildlife Institute of India Botanical Survey of India Gene Campaign Project Tiger Project Snow Leopard Project Elephant SAVE (Saving Asia’ s Vulture from Extinction Rhinoceros Conservation Ganges River Dolphin Conservation