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Mk. Analisis Ekosistem KARAKTERISTIK KETAHANAN EKOSISTEM Diabstraksikan: smno.psdl.pdkl.ppsub.2012/13 BIODIVERSITAS 1. Biodiversity = the amount of biological or living diversity per unit area. It includes the concepts of species diversity, genetic diversity and habitat diversity 2. Genetic diversity = the range of genetic material present in a gene pool or population of a species 3. Species diversity = variety among species per unit area. Includes both the number of species present and their abundance. 4. Habitat diversity = The range of different habitats or number of ecological niches per unit area in an ecosystem, community or biome. Conservation of habitat diversity usually leads to conservation of species and genetic diversity Diunduh dari: plattscience.wikispaces.com/file/.../18.+Biodiversity+in+Ecosystems.p...... 19/12/2012 BIODIVERSITAS: SPESIES & PROSES • Is key to the overall function of earth • In general Diversity = Stability • Biodiversity is – Nature’s insurance policy against change – The source of all natural capital for human use – The way chemical materials are cycled and purified – The end result of millions of years of evolution and irreplaceable Diunduh dari: plattscience.wikispaces.com/file/.../18.+Biodiversity+in+Ecosystems.p...... 19/12/2012 BIODIVERSITAS 1. Richness: The number of species per sample is a measure of richness. The more species present in a sample, the “richer” the sample. 2. Evenness: A measure of the relative abundance of the different species making up the richness of an area. Diunduh dari: plattscience.wikispaces.com/file/.../18.+Biodiversity+in+Ecosystems.p...... 19/12/2012 Quantifiying this Diversity – Simpson’s Index D = N (N – 1) ∑ n (n – 1) • Where D = diversity index N = total # of organisms of all species n = # of individuals of particular species Diunduh dari: plattscience.wikispaces.com/file/.../18.+Biodiversity+in+Ecosystems.p...... 19/12/2012 Quantifiying this Diversity – Simpson’s Index • High values of “D” suggests a stable and ancient site • A low value of “D” could suggest pollution, recent colonization, or agricultural management • Index normally used in studies of vegetation but can be applied to comparisons of diversity of any species Diunduh dari: plattscience.wikispaces.com/file/.../18.+Biodiversity+in+Ecosystems.p...... 19/12/2012 How does diversity exist? • Natural Selection = survival of the fittest • Fitness = a measure of reproductive success • If all individuals are variable • And populations produce large numbers of offspring without increase in population size • And resources are limited • And traits are heritable • Then those individuals who are best adapted to the environment will survive and pass on their genes • Gradually the gene frequency in the population will represent Diunduh plattscience.wikispaces.com/file/.../18.+Biodiversity+in+Ecosystems.p...... 19/12/2012 more ofdari: these “fit” individuals SELEKSI ALAMIAH • Environmental Pressures select for some genotypes over others • Alleles resulting in a beneficial trait will become more common • Heritable traits that increase survival chances are called adaptations • There are many niches or habitats and roles available in the environment • As populations adapt they fill new niches and over time may develop into new species Diunduh dari: plattscience.wikispaces.com/file/.../18.+Biodiversity+in+Ecosystems.p...... 19/12/2012 Diunduh dari: plattscience.wikispaces.com/file/.../18.+Biodiversity+in+Ecosystems.p...... 19/12/2012 Speciation • Certain circumstances lead to the production of new species through natural selection • Most common mechanism has 2 phases geographic followed by reproductive isolation 1. Geographic isolation groups of a population of the same species are isolated for long periods – A group may migrate in search of food to an area with different environmental conditions – Populations may be separated by a physical barrier (mountain range, river, road) – Catastrophic change by volcano eruption or earthquake dari: plattscience.wikispaces.com/file/.../18.+Biodiversity+in+Ecosystems.p...... 19/12/2012 – ADiunduh few individuals carried away by wind or water to new area Speciation 2 2. Reproductive Isolation mutation and natural selection operate independently on the 2 populations to change allele frequencies = divergence • If divergence continues long enough genetic differences may prohibit (1) interbreeding between populations and/or (2) production of viable, fertile offspring • One species has become 2 through divergent evolution • For most species this would take millions of years • Difficult to document & prove this process Diunduh dari: plattscience.wikispaces.com/file/.../18.+Biodiversity+in+Ecosystems.p...... 19/12/2012 Northern population Arctic Fox Early fox population Spreads northward and southward and separates Adapted to cold through heavier fur, short ears, short legs, short nose. White fur matches snow for camouflage. Different environmental conditions lead to different selective pressures and evolution into two different species. Southern population Gray Fox Adapted to heat through lightweight fur and long ears, legs, and nose, which give off more heat. Diunduh dari: plattscience.wikispaces.com/file/.../18.+Biodiversity+in+Ecosystems.p...... 19/12/2012 Consequences of Plate Activity • Speciation processes rely on physical separation of organisms • Plate techtonics – can lead to separation of gene pools – mountain ranges form, faults separating land masses – Can link species and land areas e.g. land bridges Diunduh dari: plattscience.wikispaces.com/file/.../18.+Biodiversity+in+Ecosystems.p...... 19/12/2012 Consequences of Plate Activity II • Plate techtonics generates new habitats – Island chains over hotspots – Hawaii – Mountain habitats – Himalayan mountains – also associated effects on surrounding areas – Hydrothermal vent communities – Changes climate on land masses – continents drift into new climate zones e.g. antarctica was once covered by tropical rainforest now barren polar ice fields Diunduh dari: plattscience.wikispaces.com/file/.../18.+Biodiversity+in+Ecosystems.p...... 19/12/2012 1. Succession effects Diversity • Succession – gradual establishment or reestablishment of ecosystems over time • Pioneer species Climax species – Low diversity at first, few species can tolerate harsh conditions (r selected species) – Most diverse in middle of succession, slower growing species start to fill in – Low diversity at the end, climax species often strongest competitors (K selected species) • Diversity is a function of disturbance intermediate disturbance hypothesis Diunduh dari: plattscience.wikispaces.com/file/.../18.+Biodiversity+in+Ecosystems.p...... 19/12/2012 Lichens and mosses Exposed rocks Small herbs and shrubs Heath mat Jack pine, black spruce, and aspen Balsam fir, paper birch, and white spruce climax community Time Diunduh dari: plattscience.wikispaces.com/file/.../18.+Biodiversity+in+Ecosystems.p...... 19/12/2012 Species diversity 0 100 Percentage disturbance Diunduh dari: plattscience.wikispaces.com/file/.../18.+Biodiversity+in+Ecosystems.p...... 19/12/2012 2. Habitat diversity influences species & genetic diversity • More complex areas (more diverse habitats) often have higher species & genetic diversity • Ex. Tropical rainforest & Coral reef • In both cases, high degree of structural / spatial complexity • Promotes coexistence by niche partitioning & diversification Diunduh dari: plattscience.wikispaces.com/file/.../18.+Biodiversity+in+Ecosystems.p...... 19/12/2012 Harpy eagle Blue and gold macaw Ocelot Producer to primary consumer Primary to secondary consumer Squirrel monkeys Climbing monstera palm Katydid Slaty-tailed trogon Green tree snake Secondary to higher-level consumer Tree frog All producers and consumers to decomposers Ants Bromeliad Fungi Diunduh dari: plattscience.wikispaces.com/file/.../18.+Biodiversity+in+Ecosystems.p...... 19/12/2012 Bacteria 45 Emergent layer Harpy eagle 40 35 Toco toucan Canopy 30 Height (meters) 25 20 Understory Wooly opossum 15 10 Brazilian tapir 5 Black-crowned antpitta 0 Shrub layer Ground Ground layerlayer Diunduh dari: plattscience.wikispaces.com/file/.../18.+Biodiversity+in+Ecosystems.p...... 19/12/2012 Complex ecosystems with a variety of nutrient & energy pathways provides stability • Energy is key to the function of all ecosystems • Biogeochemical cycles recycle necessary materials through system • More pathways for energy & matter = more stable • Insurance against natural or human changes Diunduh dari: plattscience.wikispaces.com/file/.../18.+Biodiversity+in+Ecosystems.p...... 19/12/2012 Human activities • Modify succession by adding disturbance • Logging, Grazing, Burning – all prevent natural successional processes • Fragmenting habitats by development • Isolate populations more likely to get diseases, succumb to local disturbances • We simplify ecosystems tall grass prairie converted to wheat farms more vulnerable Diunduh dari: plattscience.wikispaces.com/file/.../18.+Biodiversity+in+Ecosystems.p...... 19/12/2012 Cleared plots for grazing Highway Cleared plots for agriculture Diunduh dari: plattscience.wikispaces.com/file/.../18.+Biodiversity+in+Ecosystems.p...... 19/12/2012 Any ecosystem’s capacity to survive change may depend on its diversity, resilience, and inertia Diunduh dari: plattscience.wikispaces.com/file/.../18.+Biodiversity+in+Ecosystems.p...... 19/12/2012 ECOSYSTEM STABILITY STABILITAS EKOSISTEM 1. The vast majority of natural ecosystems experience regular environmental change, or disturbances. 2. Most ecologists describe ecosystem stability as the ability of an ecosystem to maintain its structure and function over long periods of time and despite disturbances. 3. Ecosystem structure includes physical and geological structures of the landscape, the number and diversity of species present, the population sizes of those species, and the ways in which these populations interact. 4. Ecosystem function refers to processes such as water and nutrient cycling and biomass productivity that the ecosystem provides. . Sumber: www.aisd.net/aisd/Portals/73/.../12F%20Ecosystem%20Stability.ppt ………… diunduh 19/12/2012 RESISTENSI & RESILIENSI 1. There are two main components to ecosystem stability: resistance and resilience. 2. An ecosystem displays resistance if keeps its structure and continues normal functions even when environmental conditions change. 3. An ecosystem displays resilience if, following a disturbance, it eventually regains its normal structure and function. . Sumber: www.aisd.net/aisd/Portals/73/.../12F%20Ecosystem%20Stability.ppt ………… diunduh 19/12/2012 STABILITAS EKOSISTEM 1. Ecosystems that show a high degree of stability may have different combinations of resistance and resilience. 2. Research has shown that species diversity is often the key to both ecosystem resistance and resilience. 3. An ecosystem rich in biodiversity will likely be more stable than one whose biodiversity is low. Infer If an ecosystem has low biodiversity, is it more or less stable than an ecosystem of high biodiversity? . Sumber: www.aisd.net/aisd/Portals/73/.../12F%20Ecosystem%20Stability.ppt ………… diunduh 19/12/2012 HOW DOES ENVIRONMENTAL CHANGE AFFECT ECOSYSTEM STABILITY? 1. Communities respond to environmental change in ways that reflect the responses of the species and populations in the community. 2. Species respond to environmental change in ways that enable them to maintain homeostasis. 3. Populations respond in ways that reflect the success or failure of members of the population to survive and reproduce. . Sumber: www.aisd.net/aisd/Portals/73/.../12F%20Ecosystem%20Stability.ppt ………… diunduh 19/12/2012 STABILITAS EKOSISTEM • Changing environmental conditions can cause the decline of local biodiversity. If this happens, an ecosystem’s resistance and/or resilience may decline. The end result is that the ecosystem loses stability. • Ecosystems that are less stable may not be able to respond to a normal environmental disturbance, which may damage ecosystem structure, ecosystem function, or both. . Sumber: www.aisd.net/aisd/Portals/73/.../12F%20Ecosystem%20Stability.ppt ………… diunduh 19/12/2012 How does natural environmental change affect ecosystem stability? • Fires, heavy storms, and natural climate change can cause major changes in local populations of plants and animals. • A decline in natural biodiversity can make an ecosystem less stable. Apply Concepts What is one example of a local natural environmental change? How did it impact ecosystem stability? . Sumber: www.aisd.net/aisd/Portals/73/.../12F%20Ecosystem%20Stability.ppt ………… diunduh 19/12/2012 How does environmental change caused by human actions affect ecosystem stability? 1. Humans affect ecosystem stability in many ways, including habitat loss, introduction of nonnative species, release of pollution into food webs, and contribution to climate change. 2. Ecosystems are frequently destroyed for agricultural activity and urban development. Clearing patches of habitat can split ecosystems into pieces, a process called habitat fragmentation. . Sumber: www.aisd.net/aisd/Portals/73/.../12F%20Ecosystem%20Stability.ppt ………… diunduh 19/12/2012 STABILITAS EKOSISTEM • Remaining pieces of habitat become habitat “islands” surrounded by a different habitat. The smaller a habitat island is, the fewer species can live there, and the smaller their populations can be. Predict Sea otters, a keystone species, eat sea urchins, which in turn eat kelp. In the 1990s, sea otter populations off the coast of Alaska declined because orcas ate large numbers of otters. What effect did this have on the sea otters’ ecosystem? • A keystone species is one that has a strong and/or widereaching impact on a community’s stability. If a keystone species declines in number, the ecosystem . Sumber: www.aisd.net/aisd/Portals/73/.../12F%20Ecosystem%20Stability.ppt ………… diunduh 19/12/2012 becomes much less stable. STABILITAS EKOSISTEM 1. Humans sometimes introduce organisms into a new habitat, where it can become invasive and threaten biodiversity and ecosystem structure. 2. An invasive species is a nonnative species that spreads widely in a community. Nonnative species become invasive if their new surroundings lack natural population checks such as predators or competitors. 3. Invasive species usually cause local native biodiversity to decline and therefore affect ecosystem stability. . Sumber: www.aisd.net/aisd/Portals/73/.../12F%20Ecosystem%20Stability.ppt ………… diunduh 19/12/2012 STABILITAS EKOSISTEM • Many pollutants, including pesticides and acid rain, impact plant and animal populations. These changes, in turn, threaten biodiversity. • Organisms are adapted to their environments and have specific tolerance ranges to conditions such as temperature. If conditions change beyond an organism’s tolerance, the organism must move to another location or face extinction. • Increases in Earth’s average temperatures could affect ecosystem structures and functions. • Scientists are not yet sure how predicted changes in global climate within the next several decades will affect ecosystem stability worldwide. . Sumber: www.aisd.net/aisd/Portals/73/.../12F%20Ecosystem%20Stability.ppt ………… diunduh 19/12/2012 ECOSYSTEM PRODUCTIVITY PRODUKTIVITAS EKOSISTEM Food webs, food chains, pyramids – you can also look at ecosystems through their productivity. Productivity is the rate at which chemical energy is produced in an ecosystem – expressed as ‘gram of organic matter per square metre per year’ . Sumber: lynclarkson.wikispaces.com/.../4.+ECOSYSTEMS+DIFER+IN+...………… diunduh 19/12/2012 PRODUKTIVITAS PRIMER EKOSISTEM 1.Gross primary productivity (GPP) is the rate at which an ecosystem's producers convert solar energy into chemical energy as biomass. 2. Net primary productivity (NPP) is the rate at which energy for use by consumers is stored in new biomass. NPP = GPP – R [rate at which producers use biomass] . Sumber: lynclarkson.wikispaces.com/.../4.+ECOSYSTEMS+DIFER+IN+...………… diunduh 19/12/2012 PRODUKTIVITAS EKOSISTEM Generally ecosystems with the highest net productivity are those with the greatest accumulated producer biomass More The higher the net primary production of an ecosystem, chemi the more food is available for consumer organisms and the greater the biomass of More consumers living in that ecosystem. cal produ More energ cer photos y biom ynthesi stored ass s in organi . Sumber: lynclarkson.wikispaces.com/.../4.+ECOSYSTEMS+DIFER+IN+...………… diunduh 19/12/2012 WHY DO PRODUCTION RATES DIFFER? 1. Why does a desert ecosystem have a lower productivity than a tropical rainforest? 2. What affects do temperature and hours of sunlight have on productivity? 3. List some limiting factors for ecosystems? 4. Explain why Australia does not have rich fishing grounds near its coast. . Sumber: lynclarkson.wikispaces.com/.../4.+ECOSYSTEMS+DIFER+IN+...………… diunduh 19/12/2012 AN ECOSYSTEM IN DARKNESS 1. 2. 3. 4. 5. If light is needed for photosynthesis, but does not penetrate to the depths of the ocean, how does a consumer in ocean darkness feed? Explain how producers can exist in the dark depths of the ocean. Explain the difference between photosynthetic organisms and chemosynthetic organisms. What is the energy source for photosynthetic organisms? What is the waste product? What is the energy source for chemosynthetic organisms? What is the waste product? . Sumber: lynclarkson.wikispaces.com/.../4.+ECOSYSTEMS+DIFER+IN+...………… diunduh 19/12/2012 KEY ENERGY PROCESSES • Photosynthesis: use of chlorophyll. Energy storing process. – • Cellular Respiration: – – • 6 CO2 + 6 H2O + solar energy C6H12O6 + 6 O2 Aerobic Respiration: energy releasing process. C6H12O6 + 6 O2 6CO2 + 6 H2O + energy (ATP) Anaerobic Respiration – Ex. Fermentation: energy releasing process used by yeast and bacteria . Sumber: lynclarkson.wikispaces.com/.../4.+ECOSYSTEMS+DIFER+IN+...………… diunduh 19/12/2012 PRIMARY PRODUCTION AND ENERGY FLOW ENERGY FLOWS: solar (or nuclear) input heat output NUTRIENTS RECYCLE: mass conservation inorganic ↔ organic . Sumber: www2.yk.psu.edu/~mph13/EnergyFlow.18.ppt...………… diunduh 19/12/2012 TINGKAT TROFIK • Trophic Level: Position in a food web determined by number of energy transfers from primary producers to current level: – – – – Primary producers occupy first level. Primary consumers occupy second level. Secondary consumers occupy third level. Tertiary consumers occupy fourth level. . Sumber: www2.yk.psu.edu/~mph13/EnergyFlow.18.ppt...………… diunduh 19/12/2012 PRODUSEN – KONSUMEN . Sumber: www2.yk.psu.edu/~mph13/EnergyFlow.18.ppt...………… diunduh 19/12/2012 PRODUKSI PRIMER • Primary production: Fixation of energy by autotrophs in an ecosystem. – Rate of primary production: Amount of energy fixed over a given period of time. • Gross primary production: Total amount of energy fixed by autotrophs. • Net primary production: Amount of energy leftover after autotrophs have met their metabolic needs. . Sumber: www2.yk.psu.edu/~mph13/EnergyFlow.18.ppt...………… diunduh 19/12/2012 KONTROL PRODUKSI PRIMER • Bottom-Up Controls – Influences of physical and chemical factors of an ecosystem. • Top-Down Controls – Influences of consumers. . Sumber: www2.yk.psu.edu/~mph13/EnergyFlow.18.ppt...………… diunduh 19/12/2012 Actual Evapotranspiration and Terrestrial Primary Production • Rosenzweig estimated influence of moisture and temperature on rates of primary production by plotting relationship between annual net primary production and annual actual evapotranspiration (AET). – AET: Annual amount of water that evaporates and transpires off a landscape. • Cold dry ecosystems tend to have low AET. . Sumber: www2.yk.psu.edu/~mph13/EnergyFlow.18.ppt...………… diunduh 19/12/2012 Evapotranspiration & Terrestrial Primary Production . Sumber: www2.yk.psu.edu/~mph13/EnergyFlow.18.ppt...………… diunduh 19/12/2012 PRODUKSI PRIMER NETO . Sumber: www2.yk.psu.edu/~mph13/EnergyFlow.18.ppt...………… diunduh 19/12/2012 PRODUKSI PRIMER & KESUBURAN TANAH • Significant variation in terrestrial primary production can be explained by differences in soil fertility. – Shaver and Chapin found arctic net primary production was twice as high on fertilized plots as unfertilized plots. – Bowman suggested N is main nutrient limiting net primary production in a dry tundra meadow, and N and P jointly limit production in a wet meadow. . Sumber: www2.yk.psu.edu/~mph13/EnergyFlow.18.ppt...………… diunduh 19/12/2012 PRODUKSI PRIMER NETO . Sumber: www2.yk.psu.edu/~mph13/EnergyFlow.18.ppt...………… diunduh 19/12/2012 PRODUKSI PRIMER . Sumber: www2.yk.psu.edu/~mph13/EnergyFlow.18.ppt...………… diunduh 19/12/2012 POLA PRODUKSI PRIMER AKUATIK • Several studies have found quantitative relationship between phosphorus and freshwater phytoplankton biomass. • Several studies support generalization that nutrient availability controls rate of primary production in freshwater ecosystems. . Sumber: www2.yk.psu.edu/~mph13/EnergyFlow.18.ppt...………… diunduh 19/12/2012 PRODUKSI PRIMER BIOMASA ALGAE . Sumber: www2.yk.psu.edu/~mph13/EnergyFlow.18.ppt...………… diunduh 19/12/2012 PRODUKSI PRIMER DANAU Carpenter proposed piscivores and planktivorous fish can cause significant deviations in primary productivity. – Carpenter and Kitchell proposed the influence of consumers on lake primary productivity propagate through food webs. • Trophic Cascade Hypothesis . Sumber: www2.yk.psu.edu/~mph13/EnergyFlow.18.ppt...………… diunduh 19/12/2012 PRODUKSI PRIMER DANAU . Sumber: www2.yk.psu.edu/~mph13/EnergyFlow.18.ppt...………… diunduh 19/12/2012 PRODUKSI PRIMER DANAU . Sumber: www2.yk.psu.edu/~mph13/EnergyFlow.18.ppt...………… diunduh 19/12/2012 PRODUKSI PRIMER DANAU . Sumber: www2.yk.psu.edu/~mph13/EnergyFlow.18.ppt...………… diunduh 19/12/2012