. ECOLOGY AND ECOSYSTEM

Engr. Yvonne Ligaya F. Musico 1

ECOLOGY AND THE ENVIRONMENT


Ecology

The study of living organisms and their environments or habitatsThe study of the relationships between organism and their environment.


EnvironmentIt includes not only the physical but also the biological conditions under which an organism lives

RelationshipsInvolve interactions with the physical world as well as the interrelationships with the number of the species and individuals of the same species.


Why is Ecology important?

The study of Ecology is important because it helps us understand how pollution impacts our environment.A better understanding of how human induced changes affect organisms and their environment.


How do we describe life?An ability to replicate, the production of offspringPosses a genetic code such as DNA which has the ability to:

Self replicateStore all information about the organism and how to

constant essential functionsUtilize energy and matter from its surroundingsMaintain functionality in a hostile environmentAdapt to changes in the environment


EcosystemIt is a basic study area of ecologists.It is an organism or group or organisms and their surroundings. Example:

aquarium forestone’s backyard lakesgrasslands the earth


How does earth’s life adapt to changes in their surroundings?

Mutation – is a random changes in the genetic code (DNA) of an organism. Helpful genetics changes have a greater likelihood of being passed on to subsequent generations, the process of natural selection.Evolution – the change in the genetic code of a population brought about by natural selection


Trophic LevelDescribes its distance, in steps, from the prime source, the sun.


Trophic Levels within an Ecosystem



1. Abiotic -The non-living or the physical environment that surrounds the living organisms (the biotic component).


Trophic Levels within an Ecosystem2. Producers (Autotrophs) - Utilize energy from the sun and nutrients from the abiotic environment (carbon dioxide from the atmosphere or water, other nutrients from the soil or water) to produce protoplasm by means of photosynthesis.

ExampleGreen plantsphytoplankton



3. Consumers (Heterotrophs) - Depend on producers for their energy and synthesis needs. They feed on protoplasm produced on photosynthesis or on organisms from higher levels that indirectly consume protoplasm from photosynthesis



4. Decomposers - Utilize energy from wastes or dead organisms, completing the cycle by returning the nutrients to the soil or water and carbon dioxide to the air or water.



Abiotic Environment

Producers

Consumers

Decomposers


Energy and Trophic Levels


Energy and Trophic Levels

Trophic Levels in a Grassland Ecosystem


Concept of Energy Loss at Each Successive Trophic Level


Interspecies RelationshipsPredation – the feeding of one organism on anotherPredator – any various organisms (prey) that get food from other living organism but they do not live on or in the prey or they may or may not kill it.


BioconcentrationIt is the accumulation or increase in concentration of a substance as it proceeds up the food chain

Many high molecular weight organics are sparsely soluble in water but highly soluble in lipids (fatty tissue)This unequal solubility can lead to bioconcentration if the substances are not effectively metabolized by the organism.

20

Bioconcentration of DDT in an Aquatic EnvironmentSOURCE CONCENTRATION, ppmWater 0.00005 Plankton 0.04 Hard clam 0.42 Sheephead minnow 0.94 Chain pickerel (predatory fish) 1.33 Needlefish (predatory fish) 2.07 Heron (feeds on small animals) 3.57 Tern (feeds on small animals) 3.91 Herring gull (scavenger) 6.00 Osprey egg 13.8 Merganser (fish eating duck) 22.8 Cormorant (feeds on larger fish) 26.4 Ring billed gull 75.5

Source: Woodwell, George M., Charles F. Wurster, Jr., and Peter A. Isaacson, "DDT Residues in an East Coast Estuary: A Case of Biological Concentration of a Persistent Insecticide," Science, Vol. 156, pp. 821-824, May 1967.


BiodiversityThe variety among living organisms and the ecological communities they inhabit, gives ecosystems stability.

www.mass.gov


Limnology

The study of freshwater ecosystem


Lake StratificationEpilimnion – upper strata. In summer, will have a temperature above 4oC. A thermocline (sometimes metalimnion) is a thin but distinct layer in a large body of fluid (e.g. water, such as an ocean or lake, or air, such as an atmosphere) in which temperature changes more rapidly with depth than it does in the layers above or below.Hypolimnion– cool lower region.


Lake StratificationAs the temperature cools in the fall, the water temperature in the upper region of a lake begins to drop, increasing the density of waterAt this point, the upper region water will begin to displace the water in the lower region.When this occurs, the lake will “turn over.”


Population

A group of individuals of the same species occupying a given area.


World PopulationOn the face of the earth are approaching a population of 8 billion peopleOver 1/3 of the individuals are under the age of 15.Thus, billions of individuals are just coming into their most fertile reproductive age range.Numbers of people, represent power/influence. In other words, the more people in your army, organization, etc., the more power/influence you have.


ConsequencesThe question is what force(s) will bring the worlds population growth rate under control?Nature? Humans? To date we have not acknowledged a need to do so.


Strong Feelings Polarized IndividualsOne side feels that people are a natural resource and the crisis is an economic and political one. A second group involves religious groups, who contend that any proposals related to artificial birth control and abortion are counter to their religious beliefs, an example is that they undermine traditional family values.At the opposite pole are those who feel that indeed there is a crisis and we must bring it under control quickly.

Human Population

The human population increased at a slow rate until 1200 to 1600 AD Development of agriculture, technology, industry and medicine has given humans ability to increase their numbers at a phenomenal rate .World population is now doubling approximately each 40 years


Effects of Increased Population

The effects of our increased in population are evident everywhere on earth. They range from pollution of the air, land, and water to diminish natural habitat.


Estimating Population GrowthP = P0ert

Where:P = population at time tP0 = population at time 0

r = population growth rate, yeart = time in years


Sample ProblemIn 1950 the world population was estimated to be 2.5 billion. In 1990 it was estimated to be 5.5 billion. Assuming this growth rate will sustained,

a) Calculate the world population in A.D. 2020.

b) Determine the year the global population will reach 10 billion.


Habitat

It is a place where population or an individual of a given species lives. Each habitat has a characteristic range of physical and chemical conditions such as the amount of light, temperature, the depth of the water and so on.


Wetlands

It is a semi-aquatic area that is either inundated or saturated by water for varying periods during each year and that supports aquatic vegetation.


Rain Forests

Treed areas with a closed canopy and more than 25 inches of rainfall per year These forests are estimated to hold 50% or more of all species, yet they are now account for only 7% of the earth’s surface

Biogeochemical Cycles



What Supports Life on Earth?

Life exists in only a thin layer just above and below the earth's surface, the biosphere. The atmosphere is composed of mostly nitrogen (78%) and oxygen (21%)Biogeochemical cycles


The BiosphereBiosphere – contains all of the living things on Earth.

Atmosphere – airHydrosphere - waterLithosphere – soil/rock

Constitute the abiotic, or nonliving component


Great Spheres of Living and Nonliving Material


The atmosphere is a layer of gases surrounding a material body of sufficient mass that is held in place by the gravity of the body.The hydrosphere is the water contained on earth, the oceans, rivers, lakes, polar caps, groundwater, atmospheric water, etc. The lithosphere is the upper geologic formations which contain and support life.

Great Spheres of Living and Nonliving Material

Layers of Atmosphere

Layers of AtmosphereThe troposphere is where all weather takes place; it is the region of rising and falling packets of air. The air pressure at the top of the troposphere is only 10% of that at sea level (0.1 atmospheres). There is a thin buffer zone between the troposphere and the next layer called the tropopause.

Layers of AtmosphereAbove the troposphere is the stratosphere, where air flow is mostly horizontal. The thin ozone layer in the upper stratosphere has a high concentration of ozone, a particularly reactive form of oxygen. This layer is primarily responsible for absorbing the ultraviolet radiation from the Sun.

Layers of AtmosphereAbove the stratosphere is the mesosphere and above that is the ionosphere (or thermosphere), where many atoms are ionized (have gained or lost electrons so they have a net electrical charge). The ionosphere is very thin, but it is where aurora take place, and is also responsible for absorbing the most energetic photons from the Sun, and for reflecting radio waves, thereby making long-distance radio communication possible.


Biogeochemical Cycle

A summary of the different chemical repositories where a particular elements resides, coupled with the pathways that convert and transport the element from one repository or form to another.


Global biogechemical cycles - Distribute nutrients throughout the earth’s atmosphere and upper geologic layers.Cybernetic system - One in which feedback causes self-regulation and stability to some degree.


Carbon Cycle


Carbon Cycle


Nitrogen Cycle


Nitrogen Fixation - The reaction wherein nitrogen-fixing bacteria convert nitrogen from the air through reduction reactions to ammonia or ammonium. Nitrification - The process which certain soil bacteria strip ammonia or ammonium of electron and nitrate is released as reaction product, then other soil bacteria use nitrate for energy metabolism, yields nitrate.


Sulfur Cycle


Hydrologic Cycle

The movement of water in the earth’s atmosphere, on the surface, and below the surface – a process powered by sun’s energy.


Hydrologic Cycle


Water Budget Inputs = Outputs P = ET + R + I + S

WhereP = precipitation [cm or in]ET = evapotranspiration or evaporation plus transpiration [cm or in]R = runoff [cm or in]I = infiltration [cm or in]S = storage [cm or in]


Sample ProblemA 1 km2 watershed has been monitored recently to estimate the summer evapotranspiration. August rainfall was 4 cm, and the runoff from the area was 5000 m3. Infiltration was estimated to be 0.7 cm. Storage can be assumed negligible. What was the total evapotranspiration?

Thank You

Kingsoft OfficeMake Presentation much more fun

Date post:	08-Dec-2023
Category:	Documents
Upload:	independent
View:	0 times
Download:	0 times

. ECOLOGY AND ECOSYSTEM

Documents