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ES Ecology.

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Presentation on theme: "ES Ecology."— Presentation transcript:

1 ES Ecology

2 Biotic Factors Abiotic Factors
Ecology - Study of interactions between organisms and their environments. Ecosystems are communities of organisms and their abiotic environment. Biotic Factors Biosphere – life-supporting layer of Earth Biotic factors – all living organisms in a biosphere Abiotic Factors Nonliving factors in an environment Examples: Air currents Temperature Moisture Light Soil

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4 NATURAL CAPITAL Natural Capital = Natural Resources + Natural Services
Solar capital Air Air purification Renewable energy (sun, wind, water flows) Climate control UV protection (ozone layer) Life (biodiversity) Water Population control Water purification Waste treatment Pest control Figure 1.3 Key natural resources (blue) and natural services (orange) that support and sustain the earth’s life and economies (Concept 1-1A). Nonrenewable minerals iron, sand) Land Soil Food production Soil renewal Natural gas Nutrient recycling Oil Nonrenewable energy (fossil fuels) Coal seam Natural resources Natural services

5 Organization of Life Biosphere Ecosystems Communities Populations Organisms

6 Levels of Ecological Organization
Organisms are living things that can carry out life processes independently. Species are groups of organisms that are closely related and can mate to produce fertile offspring. Populations are groups of organisms of the same species that live in a specific geographical area and interbreed. An important characteristic of a population is that its members usually breed with one another rather than with members of other populations. Communities are groups of various species that live in the same habitat and interact with each other. Habitats are places where an organism usually lives. Every habitat has specific characteristics that the organisms that live there need to survive. If any of these factors change, the habitat changes.

7 Levels of Organization

8 Feeding Relationships
Autotrophs Heterotrophs Carnivores Omnivores Herbivores Decomposers

9 Autotrophs vs. Heterotrophs
Autotrophs fix their own energy from inorganic sources Autotrophs are the producers in an ecosystem Heterotrophs depend upon energy and carbon fixed by some other organism They are consumers, detritivores, or decomposers A mixotroph gets its energy from inorganic sources, but relies on inorganic sources of carbon

10 Food Web

11 Trophic Relationships
Autotrophs 1st level consumers (herbivores) 2nd level consumers 3rd level consumers 4th level consumers (top predators)

12 Atmospheric carbon is rarely limiting to plant growth
Ecosystems produce and process energy primarily through the production and exchange of carbohydrates which depends on the carbon cycle. Once energy is used, it is lost to the ecosystem through generation of heat Carbon is passed through the food chain through herbivory, predation, and decomposition, it is eventually lost to the atmosphere through decomposition in the form of CO2 and CH4 . It is then re-introduced into the ecosystem via photosynthesis. However, the amount of carbon present in a system is not only related to the amount of primary production, as well herbivory and predation (e.g., secondary production), it is also driven by the rates of decomposition by micro-organisms Atmospheric carbon is rarely limiting to plant growth Up to now, we have discussed how ecosystems produce and process energy, primarily through the production and exchange of carbohydrates This focus has also provided some insights with respect to the carbon cycle as well The energy cycle itself is a one way street, e.g., once energy is used, it is lost to the ecosystem through generation of heat Carbon is somewhat unique in terms of its cycle, because while carbon is exchanged through herbivory, predation, and decomposition, it is eventually lost to the atmosphere through decomposition in the form of CO2 and CH4 It is then re-introduced into the ecosystem via photosynthesis However, the amount of carbon present in a system is not only related to the amount of primary production, as well herbivory and predation (e.g., secondary production), it is ultimately driven by the rates of decomposition by micro-organisms Atmospheric carbon is rarely limiting to plant growth

13 Algae remove dissolved phosphorous from the water
When we look at other nutrients, a somewhat different picture emerges than with the energy cycle – e.g., phosphorous in a food chain within a small pond. Algae remove dissolved phosphorous from the water The phosphorous is then passed through different trophic levels through herbivory and predation. At each level there is some mortality, and then the phosphorous is passed to decomposers These organisms release phosphorous into the water where it is again taken up by primary producers and the whole cycle starts up again When we look at other nutrients, a somewhat different picture emerges than with the energy cycle Here we have an example of the pathways for exchange of phosphorous in a food chain within a small pond Algae remove dissolved phosphorous from the water The phosphorous is then passed through different trophic levels through herbivory and predation At each level there is some mortality, and then the phosphorous is passed to decomposers These organisms release phosphorous into the water Where it is again taken up by primary producers And the whole cycle starts up again Point – with most essential nutrients, there is a continuous recycling of nutrients

14 Key Elements of Biogeochemical Cycles
There are many different processes involved exchanges of the nutrients that are eventually used by the biotic component of our earth Discuss key elements From an ecosystem/community standpoint, we study nutrient cycling via understanding the exchange of materials and energy via food chains and food webs – e.g., the terrestrial or aquatic food webs However, there are many different factors involved in nutrient cycling outside of the community itself From an ecosystem/food web perspective, it is important to understand Where do the nutrients that ecosystems use come from What happens to the nutrients within the ecosystem itself What happens to the nutrients once they leave the ecosystem? Once nutrients are cycled through an ecosystem, how do they get back? What are the rates of exchange of nutrients between the different pools where they are found

15 Biogeochemical cycles
Pathways tracing storage & exchange of chemical elements between living & nonliving systems via atmosphere, hydrosphere, lithosphere, & biosphere called biogeochemical cycles. Chemical reactions form basis of biogeochemical cycles and take place in the lithosphere, atmosphere, hydrosphere & biosphere. Chemical elements unavailable at right time or proper concentration can become limiting factors which restrict or prevent growth of individuals, population, or species. Have been greatly altered over time by earth's biota. Essential to long-term maintenance of life on earth. Can be altered by human activities; alterations have both + & - consequences. We must recognize & balance.

16 Water cycle Evaporation Transpiration Precipitation Runoff Groundwater

17 Carbon cycle Combustion Photosynthesis Respiration Decomposition
Fossil fuels

18 Carbon Cycle ·  Carbon is foundation of all organic compounds, i.e. compounds containing C (& 1 C-H bond) & formed by living things. · Carbon cycle linked to biochemical cycles of C, O, & H · In gas phase, C stored in atmosphere primarily as CO2 & other organic & inorganic molecules. · CO2 exchanged between atmosphere & large bodies of water by diffusion. Plants remove C from atmosphere thru photosynthesis (Ps), light-dependent conversion of CO2 & water to organic sugars & free O2. Vegetation, primarily trees, major storehouse for C in living tissue. C returned to atmosphere through respiration, process of oxidizing sugars to release E, CO2, & water, or by burning C enters rock cycle as organic material carried to wetlands & oceans & slowly incorporated into newly-forming rock.

19 Nitrogen Cycle Atmospheric nitrogen Runoff Fertilizers Decomposition
Nitrogen fixing Synthesis of amino acids

20 Nitrogen Cycle · N2made biological available to organisms thru N fixation, conversion of N to NH3, NO3, or amino acids (AA). · Lightning accounts for some N fixation, but living things account for bulk of conversion. · Higher plants & animals may live in symbiotic association w/N-fixing microbes or cyanobacteria, ↑ soil & tissue concentrations of fixed N. · Free-living soil bacteria help cycle NH3 & carry out denitrification, release of fixed N from soils & waters to atmosphere, thus completing N cycle. · Fixed N is important limiting nutrient in oceans & terrestrial ecosystems. · Thru heavy use of agricultural fertilizers (containing industrially-fixed N) & thru combustion of fossil fuels & other materials, humans have accelerated flux of N in various phases of cycle & ↑ pollution of water & air.

21 Phosphorous Cycle

22 Human Impact on the Phosphorous Cycle
Sewage treatment facilities and fertilizer also add large amounts of phosphates to aquatic systems, causing eutrophication (overfertilization) of lakes. Leads to increased algae!

23 Rule of 10 Only 10% of energy is transferred from one trophic level to the next. Example: It takes 100 kgs of plant materials (producers) to support 10 kgs of herbivores It takes 10 kgs of herbivores to support 1 kg of 1st level predator

24 Organic matter in animals Dead organic matter Organic matter in plants
Figure 1.4 Nutrient cycling: an important natural service that recycles chemicals needed by organisms from the environment (mostly from soil and water) through organisms and back to the environment. Decomposition Inorganic matter in soil

25 Symbiosis A long-term interaction between two organisms where "long-term" is defined in generations for at least one of the organisms and the interaction is physically intimate. Often the symbiosis will consist of one organism, the symbiont, living either on or inside of the other organism (the host). Symbioses can be classified in terms of the location of symbiont as well as in terms of the impact of the symbiont on the host. There are parasitic, mutualistic, or commensal symbioses in which the host is either harmed, helped, or neither harmed nor helped by the symbiosis, respectively (the symbiont, on the other hand, usually is helped by the interaction).

26 Symbiosis – “living together”
Relationship Type Species A Species B Commensalism + Mutualism Parasitism - + means the organism benefits 0 means the organism neither benefits or is harmed - means the organism is harmed

27 Biomes

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29 A Delicate Balance

30 Causes of Environmental Problems
Population growth Wasteful and unsustainable resource use Poverty Failure to include the harmful environmental costs of goods and services in their market prices Insufficient knowledge of how nature works 30

31 Some Resources Are Not Renewable
Nonrenewable resources Exist in fixed quantity in earth’s crust. Economically depleted when costs too much to obtain what is left. Energy resources Metallic mineral resources Nonmetallic mineral resources Solutions: Reuse Recycle 31

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33 Degradation of Normally Renewable Natural Resources and Services
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34 Our Ecological Footprints Are Growing
- Biologically productive land and water needed to supply renewable resources and absorb waste for each individual. - Humanity’s eco footprint: exceeds by about 39% the earth’s ecological capacity. 34

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36 Natural Capital Use and Degradation
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37 Cultural Changes Have Increased Our Ecological Footprints
12,000 years ago: hunters and gatherers Three major cultural events Agricultural revolution Industrial-medical revolution Information-globalization revolution 37

38 We Are Out of Control

39 NATURAL CAPITAL DEGRADATION
Major Human Impacts on Terrestrial Ecosystems Deserts Grasslands Forests Mountains Large desert cities Conversion to cropland Clearing for agriculture, livestock grazing, timber, and urban development Agriculture Figure 7.20 Major human impacts on the world’s deserts, grasslands, forests, and mountains. Question: Which two of the impacts on each of these biomes do you think are the most harmful? Timber extraction Soil destruction by off-road vehicles Release of CO2 to atmosphere from burning grassland Mineral extraction Hydroelectric dams and reservoirs Soil salinization from irrigation Conversion of diverse forests to tree plantations Increasing tourism Overgrazing by livestock Urban air pollution Depletion of groundwater Increased ultraviolet radiation from ozone depletion Damage from off-road vehicles Oil production and off-road vehicles in arctic tundra Land disturbance and pollution from mineral extraction Pollution of forest streams Soil damage from off-road vehicles

40 Studying Nature Reveals Four Scientific Principles of Sustainability
Reliance on solar energy Biodiversity Population control Nutrient cycling 40

41 Solutions For Environmental or Sustainability Revolution
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