Topic 14 Ecology and Ecosystem PDF

BIOLOGY I ASB0204 Topic 14: Community and Ecosystem Ecology Biology Unit Centre of Foundation Studies for Science Universiti Putra Malaysia 1  Outline 14.1 Ecology of 14.2 Dynamics of an 14....

BIOLOGY I ASB0204 Topic 14: Community and Ecosystem Ecology Biology Unit Centre of Foundation Studies for Science Universiti Putra Malaysia 1  Outline 14.1 Ecology of 14.2 Dynamics of an 14.3 Biodiversity Communities Ecosystem Conservation Community Ecosystem Threats to structure interactions biodiversity Community Energy flow, Food Conservation interactions practices web and Predator-prey Ecological pyramids interactions Biogeochemical Symbiotic cycle relationship  Learning Outcomes 14.1 To define components of community and ecosystem To explain various community interactions including competition, predator-prey interactions and symbiotic relationships To list examples of community interactions 14.2 To describe the interaction between organisms with their environment To explain the energy flow through food web and ecological pyramids To describe various biogeochemical cycles and their importance to maintaining a balanced ecosystem 14.3 To explain types and threats to biodiversity To describe the conservation practices 3 14.1 Ecology of Communities Further reading: page 1185 What is community? A community is a group of populations of different species interacting with one another in the same environment. Community Structure Species composition Species diversity measure (species richness) of species richness and the a listing of various species individuals within each in that community. species within the community 4  Community Structure Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. kinkajou squirrel monkey moose anteater snowshoe hare jaguar bear tapir red fox bat wolf sloth a. b. (forest): © Charlie Ott/Photo Researchers,Inc.; (squirrel): © Stephen Dalton/Photo Researchers,Inc.; (wolf): © Renee Lynn/Photo Researchers, Inc.; (rain forest): © Michael Graybill and Jan Hodder/ Biological Photo Service; (kinkajou): © Alan & Sandy Carey/Photo Researchers, Inc.; (sloth): © Studio Carlo Dani/Animals Animals Species compositions are different, tropical rain forest has more species (higher species richness) 5  Community Interactions Further reading: page 1173 Habitat and Ecological Niche Includes its habitat and its interactions with other organisms Habitat Ecological niche The role a species plays in The area where an its community (includes organism lives and the methods species uses reproduces to meet energy, nutrient and survival demands e.g. dragonfly larvae habitat (pond and lake) pond must contain vegetation where the dragonfly larva hide from predators such as birds and fish Water must be clear (to see prey) and warm (for larvae to be active) 6  Further reading: page 1174 Fundamental Realized niche niche Fundamental niche Realized niche - Set of conditions under which it exists All conditions under which the in nature when adverse biotic organism can survive when conditions are present. adverse biotic condition is absent. ▪ Competition from ▪ Chthalamus & Semibalanus Semibalanus forces Chthalmus to occupy a can live in both deep and smaller realized niche on shallow intertidal zones higher and dryer habitat. Competition Between Populations Further reading: page 1176-1178 Competition between two laboratory populations of Paramecium ▪ Competition occurs when members of different species try to use the same Population Density P. aurelia grown resource such as light, space or separately nutrients that is in limited supply ▪ Experiment by G. F. Grause: ▪ Each population survived when Population Density grown separately P. caudatum grown separately ▪ Only one species survived when grown separately, the successful Paramecium population had a biotic potential than the unsuccessful population Population Density Both species grown together Time Competitive Exclusion Principle 8 No two species can indefinitely occupy the same niche at the same time Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.  Competition Between Populations Resource partitioning – Example the division of resources in order to decrease Hawk and owl feed on similar competition between two species prey (small rodents) Hawks – Owls – leads to niche specialization and less diurnal nocturnal niche overlap between species hunters hunters Competition and resource partitioning may lead to character displacement Character Displacement The tendency for characteristics to be more divergent when populations belong to the same community than Character displacement of finch when they are isolated beak size in Galapagos 9  Niche Specialization Among 5 Species of Coexisting Warblers Niche Specialization Cape May warbler Five different species of warblers occur in one spruce tree; same body size, all feed on a type of spruce caterpillar. Black-throated green warbler Bay-breasted Each species used different parts of the warbler tree – more specialized niche Blackburnian warbler Yellow-rumped warbler Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.  Character Displacement in Finches on the Galápagos Islands Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Character Displacement Percent of Sample Species coexist on Abingdon, Bindloe, James, and Jervis Islands When the 3 species (G. fuliginosa, G. 50 fortis and G. magnirostris) co-exist in the 30 same island, their beak sizes are 10 appropriate to eating small-medium-, small medium large Beak Depth and large sized seeds, respectively. Percent of Sample G. fortis exists alone 50 on Daphne Island 30 10 small medium large When t2 species occupy separate Beak Depth island, their beaks have the same Percent of Sample intermediate size, which allow them to G. fuliginosa exists alone 50 on Crossman Island eat varies seed sizes 30 10 small medium large Competition in ground finches of the Beak Depth Galápagos has led to resource partitioning G. magnirostris G. fuliginosa G. fortis and niche specialization  Competition Between Two Species of Barnacles Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Competition prevents two high tide species of Barnacles from occupying as much of the intertidal zone as possible. Chthamalus Both exist in the area of area of competition competition between Chthamalus and Balanus. Balanus Above this area only Chthamalus, a small Barnacle survives, and low tide below it only Balaus, a large Barnacle survives  Predator-Prey Interactions Further reading: page 794 ▪ Predation One living organism, the predator, feeds on another, the prey – Predator is larger – Predator has lower reproductive rate – Prey usually entirely consumed Presence of predators can decrease prey densities, and vice-versa Population density of the predator can be affected by the prevalence of the prey, and vice versa 140 hare 120 lynx (thousands) 100 Number 80 Predator-prey Interaction 60 Between a Lynx and a Snowshoe 40 Hare 20 1845 1855 1865 1875 1885 1895 1905 1915 1925 1935 Fluctuations in the Numbers of the Varying Hare (Lepus americanus), University of Toronto Press, Toronto, 1937, reprinted 1974  Prey Defenses ▪ Mechanisms that thwart the possibility of being eaten by a predator. ▪ Prey species have evolved a variety of mechanisms that enable them to avoid predators, including: 1. Heightened senses - enhanced ability of prey animals to detect, interpret, and respond to potential threats from predators 2. Protective armor – involves developing hard or tough external covering (shells, exoskeleton, scales, plates, spines) 3. Tails and appendages that break off – temporary loss and antipredation adaptation that common in lizard, crabs and salamander. Animals can regenerate the loss part over time. 4. Startle response/fright – some preys have elaborate structures that cause startle response to predator, designed to confuse, frighten and surprise predator and giving the prey a chance to escape. 14  The large false head (resemble the head of alligator) of South Flounder is fish that blends American lantern fly may startle a in with its background. potential predator. eye false head a. Camouflage b. Warning colorization c. Fright a: © Gustav Verderber/Visuals Unlimited; b: © Zig Leszczynski/Animals Animals/Earth Scenes; c: © National Audubon Society/A. Cosmos Blank/Photo Researchers, Inc. Poison arrow frogs are brightly colored to warn predators that they are dangerous to the touch. 15 Activity : Scan to watch the videos. Write the examples of animals and how their antipredator defenses function Ability to blend into the background Camouflage (some have cryptic coloration), avoid being detected by predator Warning Antipredator defense which tells predator that the prey is potentially coloration dangerous Antipredator defense that confuses or False startles another animal eyespots 16  Other Types of Prey Defenses https://bugoftheweek.com/blog/2021/8/9/bird-droppings-nope- https://www.discovery.com/science/lizard-tails clever-moths-and-caterpillars-looking-like-poop-beautiful-wood- nymph-eastern-tiger-swallowtail-black-swallowtail-red-spotted- purple https://en.wikipedia.org/wiki/Brown_marmorated_stink_bug https://www.bioexplorer.net/animals-with-best-sensors.html/ https://www.nationalgeographic.com/animals/article/animals-armor-bioinspiration 17  Mimicry One species resembles another species that possesses an overt Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction antipredator defense or display. ▪ Batesian Mimicry - Mimic lacks defense of the organism it resembles (flower fly and longhorn beetle –incapable of stinging another animals) a. Flower fly b. Longhorn beetle ▪ Müllerian Mimicry - Mimic shares a protective defense with other species (bumblebee and yellow jacket wasp – similar appearance and both use stinging as c. Bumblebee d. Yellow jacket a: © Edward S. Ross; b: © Edward S. Ross; c: © James H. Robinson/Photo Researchers, Inc.; d: © defense Edward S. Ross Mimicry Among Insects 18  Symbiotic Relationships Further reading: page 1180-1182 What is symbiosis? An association between species in which at least one of the species is dependent on the other 19 Symbiotic Relationships - Parasitism Parasite derives nourishment from a host, and may use host as habitat and mode of transmission Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Small parasites tend to be endoparasites Ex: heartworms Larger parasites tend to be ectoparasites Ex: leeches Effect of parasites on the health of the host can range from slightly weakening them to killing them over time Courtesy the University of Tennessee Parasitology Laboratory Heartworm 20 Check out for more examples in your reference book  Symbiotic Relationships - Commensalism A symbiotic relationship in which one species benefits and the other is neither benefited nor harmed Clownfish living within tentacles of sea anemones (most fishes avoid the stinging tentacles of sea anemones) Many supposed examples may turn out to be mutualism or parasitism © Dave B. Fleetham/Visuals Unlimited Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Example: Cattle egrets stay near cattle, which flush out their prey from vegetation. Egrets remove ectoparasites from cattle. https://www.cbsnews.com/news/nature-up-close-cattle-egrets-masters-of-emigration/ 21 Check out for more examples in your reference book Symbiotic Relationships - Mutualism A symbiotic relationship in which both members benefit, need not be equally beneficial to both species Examples Bacteria that reside in human Termites would not be able to intestinal tract acquire food, digest wood if not for the but they also provide us with protozoans that inhabit their vitamins that we cannot intestinal tracts and digest synthesize ourselves cellulose 22  14.2 Dynamics of an Ecosystem In an ecosystem, ▪ Populations interact among themselves ▪ Populations interact with the physical environment The abiotic components The biotic components of an of an ecosystem are the ecosystem are living things nonliving components: that can be categorized according to their food source: Atmosphere Autotrophs Water Heterotrophs Soil 23 Dynamics of an Ecosystem 24  Dynamics of an Ecosystem Autotrophs Heterotrophs Require only energy and Need a preformed source of organic inorganic nutrients nutrients as they acquire food ▪ Generate the food necessary for the Consumers – consume food ecosystem generated by a producer Require only inorganic ▪ Herbivores - Feed on plants nutrients and an outside energy source to produce ▪ Carnivores - Feed on other organic nutrients animals ▪ Photoautotrophs ▪ Omnivores - Feed on plants and Land plants and animals algae ▪ Detritivores – Feed on ▪ Chemoautotrophs decomposing organic matter Some bacteria ▪ Decomposers – Break down dead organic matter 25 26  Energy Flow Further reading: page 810-813 Energy flow Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. – Begins when producers absorb solar solar energy energy heat – Make organic nutrients via photosynthesis – Organic nutrients are used by themselves producers – Organic nutrients are used by others consumers – Energy eventually dissipates into the environment as heat Inorganic nutrient pool heat energy heat decomposers nutrients 27  Energy Flow ▪ Energy flows through an ecosystem via photosynthesis ▪ Only a portion (10%) of the organic nutrients made by producers is passed on to consumers Organisms use organic molecules to fuel their own metabolism, growth, and reproduction Additional energy is lost through excretion, defecation, and organisms that die without being consumed Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Heat to environment n tio ira e sp rr la Energy to llu reproduction carnivores growth and ce dea exc th re 10% rule t io def n ec at Energy io n to detritus feeders © George D. Lepp/Photo Researchers, Inc. 28  Energy Flow Food Chain Diagram that show a single path of the energy flow Food web Represents interconnecting paths of energy flow Describes trophic relationships Trophic level: Level of nutrients within a food web or food chain Two food webs: Grazing food web Detrital food web 29  A grazing food web begins with a producer, in this case an oak tree. ▪ Insects, rabbits, and deer feed on leaves. ▪ Birds, chipmunks, and mice feed on fruits and nuts. They are omnivores because they also feed on caterpillars. A detrital food web begins with detritus ▪ Detritus is food for soil organisms such as earthworms. ▪ Earthworms are in turn fed on by carnivorous invertebrates. ▪ Invertebrates may be eaten by shrews or salamanders. A detrital food web member may become food for above ground carnivores, so the detrital and grazing food webs are joined. 30 Grazing and Detrital Food Web Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Autotrophs Herbivores/Omnivores Carnivores owls nuts birds hawks leaf-eating insects deer foxes leaves chipmunks rabbits skunks detritus snakes mice mice a. death death death fungi and bacteria in invertebrates detritus carnivorous invertebrates salamanders shrews b. 31  Ecological Pyramids Ecological Pyramids ▪ Only about 10% of the energy of one Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. trophic level is available to the next trophic level top carnivores 1.5 g/m2 Explains why few top carnivores can be supported in a food web ▪ Ecological pyramids carnivores 11 g/m2 Depict the flow of energy with large losses between successive trophic levels herbivores 37 g/m2 May be based on the number of organisms or the amount of autotrophs biomass at each trophic level 809 g/m2 32  Ecological Pyramids Example: If this is the food chain, https://ib.bioninja.com.au/options/option-c-ecology-and-conser/c2-communities-and-ecosyste/ecological-pyramids.html shows the relative shows the total shows the amount of number of mass of organisms energy trapped per organisms at at each stage of a area in a given time each stage of a food chain period at each stage food chain of a food chain https://ib.bioninja.com.au/options/option-c-ecology-and-conser/c2-communities-and-ecosyste/ecological-pyramids.html 33  Pyramid of Biomass ▪ Pyramids of biomass Biomass – Number of organisms x dry weight of the organic matter within one organism Biomass of the producers is expected to exceed the herbivores, which should exceed that of the carnivores In aquatic ecosystems, the herbivores may have a greater biomass than the producers due to the fact the aquatic algae are consumed at such a high rate Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. https://www.differencebetween.com/difference-between-pyramid-of-biomass-and-pyramid-of-energy/ zooplankton relative phytoplankton dry weight 34  Biogeochemical Cycle Definition: the pathway by which chemicals circulate through ecosystems involve in both living (biotic) and nonliving (geologic) compositions Chemical cycling involves: Reservoir : source normally unavailable to producers (e.g carbon present in calcium carbonate shells on ocean bottoms Exchange pool: source from which organism obtain chemicals (e.g atmosphere or soil) Certain chemicals can move along food chains in biotic community and never enter an exchange pool 35  Biogeochemical Cycle Carbon cycle Water cycle Nitrogen cycle Phosphorus cycle 36 https://www.youtube.com/watch?v=2D7hZpIYlCA https://www.youtube.com/watch?v=leHy-Y_8nRs  Water Cycle Also known as hydrologic cycle Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. 37 Aquifers: a body of porous rock or sediment saturated with groundwater.  Water Cycle Fresh water is first distilled from salt water through evaporation During evaporation : water changes to gaseous state ▪ The sun’s rays cause fresh water to evaporate from seawater, leaving the salts behind ▪ Water evaporates from land and plants (evaporation from plants is called transpiration), water evaporates from bodies of fresh water. Next, condensation occurs (gas is converted into liquid). ▪ Example: vaporized fresh water rises into atmosphere, collects in the form of clouds, cools and falls as rain over the oceans and lands (precipitation) ▪ Some of water from precipitation (e.g. rain, snow, sleet, hail and fog) makes its way to the ground and saturates the Earth to a certain level. 38 ▪ Water eventually returns to the ocean.  Carbon Cycle 39 Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.  Carbon Cycle CO2 in the atmosphere is the exchange pool for carbon cycle On land, plants take up CO2 from the air through photosynthesis. The CO2 is incorporated into nutrients and used by both autotrophs and heterotrophs. When organisms including plant conduct cellular respiration, carbon is returned to the atmosphere as CO2. Carbon is incorporated back into plants through photosynthesis In aquatic ecosystems, exchange of CO2 is indirect. CO2 in the air combines with bicarbonate ions (HCO3-). This is the main source for algae. When aquatic organisms engage in cellular respiration, the CO2 they give off become HCO3-. The amount of water is in equilibrium with the amount of CO2 in the air. 40  Phosphorus Cycle Watch this video on phosphorus cycle Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. 41  Phosphorus Cycle Phosphorous from oceanic sediments moves onto land due to geologic uplifts On land, the very slow weathering of rocks places phosphate ions PO3- and HPO4- into the soil Some of these are available to plants, which use phosphate in a variety of molecules including phospholipids, ATP and nucleotides Animals eat producers and incorporate some of the phosphate into teeth, shells and bones Death and decay of all organisms and the decomposition of animal wastes make phosphate ions available to producers once again (phosphate is usually limiting inorganic nutrients for plants – influence the population size within ecosystem Some phosphate naturally runs off into aquatic ecosystem, later trapped in sediments. Phosphate in marine sediments does not become available to producers on land until geologic upheaval exposes sedimentary rocks on land – the cycle begins again 42  Nitrogen Cycle 1. Nitrogen fixation 2. Nitrification 3. Assimilation 4. Ammonification 5. Denitrification Watch this video for a simplified version of nitrogen cycle Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. 43  Nitrogen Cycle Plants take up ammonium, NH4+ and nitrate, NO3- Biological fixation – Cyanobacteria (aquatic environment) and free- Nitrogen fixation living bacteria (soil) convert N2 into ammonium (NH4+) N2 is converted to a Atmospheric N2 is fixed by bacteria. form that plant Nitrogen-fixing bacteria (e.g. Rhizobium) in legumes (beans, peas) make organic compounds containing nitrogen available to the host can use plants, so that the plant can form proteins and nucleic acids. Nitrification N2 is converted to nitrate, NO3- in the atmosphere when cosmic radiation, meteor trails, and lightning provide the energy needed for The production of nitrogen to react with oxygen nitrate, NO3- during Ammonium (NH4+) in the soil from various sources including the nitrogen cycle decomposition of organisms and animal wastes is converted to NO3- Ammonium (NH4+) is converted to nitrite NO2- by bacteria (ammonia oxidizers, e.g. Nitrosomonas) Nitrite is converted to nitrate NO3- by nitrite-oxidizing bacteria (e.g. Nitrobacter)  Nitrogen Cycle Assimilation Plants take up NH4+ and NO3- from the soil and use these ions to produce proteins and nuclei acids Ammonification When an organism excretes waste or dies, the nitrogen in its tissues is in the form of organic nitrogen (e.g. amino acids, DNA). Various fungi and prokaryotes then decompose the tissue and release inorganic nitrogen back into the ecosystem as ammonia Denitrification The conversion of nitrate back to nitrogen gas, which then can enters the atmosphere Carried out by denitrifying bacteria living in the anaerobic mud of lakes, bogs, and estuaries process as a part of their metabolism Denitrification would counterbalance nitrogen fixation if not for human activities 45  14.3 Biodiversity and Conservation Biology Biodiversity - variety and complexity of all life on earth Three types of diversity: Genetic diversity Species diversity Ecosystem diversity Differences in DNA Variety of habitats, niches within a given species Variety of species within a community and species interactions Includes component: total number of species (species richness) and distribution of individuals among species (species evenness) in a particular Genetic variation of color in area Dendrobatus auratus  Habitat loss to land development Deforestration Economic exploitation Logging – main of natural resources cause of extinction and loss of biodiversity Threats to Overfishing biodiversity Destructive in Malaysia fishing – fish bombing and Pollution cyanide fishing Pollution alters the affects coral ecosystem chemical reefs, mangroves Poaching balance, biological and coastal water Hunting for profit diversity and its increase the risk capacity to support of extiiction biological forms  Habitat Restoration Conservation Involves scientific way to return Techniques ecosystem to their natural state Three key principles Habitat Preservation 1. Start quickly to avoid losing the Prioritize areas that contains remaining fragments of the biodiversity hotspots, e.g; small area original habitat having concentration of endemic 2. Understand natural histories of species habitat and mimic natural process to bring about Keystone species – species that restoration influence viability of community, 3. Goal of restoration is extinction can lead to loss of sustainable development (self biodiversity, e.g; bat, sharks sustaining and still providing services to human) Metapopulation – essential to preserve because of past habitat fragmentation, e.g; Grizzly bear THANK YOU