BIOSPHERE Ecosystems:- How do they work?. General Structure of the Earth The Earth is an integrated system that consists of rock, air, water, and living.

BIOSPHERE

Ecosystems:-How do

they work?

General Structure of the Earth

•The Earth is an integrated system that consists of rock, air, water, and living things that all interact with each other.

•Scientists divided this system into four parts:

1. Atmosphere2. Hydrosphere3. Geosphere4. Biosphere

The Earth as a system – up close look

Parts of the earth's air, water, and soil where life is found

Biosphere

Smallest unit of a chemical element that exhibits its chemical properties

Ecosystem

Community

Population

Organism

A community of different species interacting with one another and with theirnonliving environment of matter and energy; ABIOTIC with BIOTIC

Populations of different species living in a particular place, and potentially interacting with each other

A group of individuals of the same species living in a particular place; specific geographical area and interbreed.

Cell

An individual living being

The fundamental structural and functional unit of life

Molecule

Atom

Chemical combination of two or more atoms of the same or different elements

Lithosphere- The Earth’s layers

These layers of material get progressively denser as you move toward the center of the Earth.

The lithosphere is the Earth’s crust and upper mantle; contains our nonrenewable fossil fuels and minerals.

Atmosphere

•The atmosphere is the mixture of gases that makes up the air we breathe

•Mostly found in the first 30 km above the Earth’s surface. (19 miles) - TROPOSPHERE

Hydrosphere

The hydrosphere makes up all of the water on or near the Earth’s surface

Much of this water is in the oceans, which cover nearly ¾ of the globe.

However, water is also found in the atmosphere, on land, and in the soil.

BiosphereThe biosphere is the part of the Earth where life exists; a thin layer at the Earth’s surface that extends from about 9 km (5.5 miles) above the Earth’s surface down to the bottom of the ocean.

The biosphere is therefore made up of parts of the lithosphere, the atmosphere, and the hydrosphere.

3 Factors that Sustain Life on Earth

• Solar energy –one way flow

• Cycling of crucial elements

• Gravity.

Solar energy flowing through the biosphere warms the atmosphere, evaporates and recycles water, generates winds and supports plant growth.

Greenhouse effect• warming of the surface and lower atmosphere of Earth • occurs when carbon dioxide, water vapor, and other

gases in the air absorb and reradiated infrared radiation.

• Without the greenhouse effect, the Earth would be too cold for life to exist.

• The gases in the atmosphere that trap and radiate heat are called greenhouse gases.

• The most abundant greenhouse gases are:–water vapor–carbon dioxide–Methane–nitrous oxide

How greenhouse gases lead to global warming: "An Inconvenient Truth", Al Gore

BIOMES

• Biomes are major areas where interactions between abiotic & biotic factors occur.

• They are groups of similar ecosystems characterized by:– precipitation– temperature ranges– soil properties– plant communities– animal communities.

Abiotic Factors • Non-living

• Soil• Temperature • Rainfall• Photosynthesis

• Net primary productivity

Biotic Factors • Living

• Succession • Biomass• Biodiversity • Trophic levels, food

chains, webs• Habitats and niches

Biomes

Biomes are based on climate (average precipitation and temperature)

The Earth’s Major Biomes

Tropical Rainforest• Canopy: dense covering of tree tops• Understory: 2nd story of shorter trees and vines

under the canopy• Fern Gully/Medicine Man

Monsoon Rainforest • Deciduous trees: broad leaves that fall• Wet/Dry season• “Jungle Book” forest

Tropical Savannah• In the tropics• Wet/dry season• Less rainfall than trop. Dry forest• Think “Lion King”

Desert

• Around 25-35o Latitude N and S • Plants and animal adaptations

– Spines, waxy cuticles, scales• Think “The Mummy” and “The Sahara”

Temperate Deciduous Forest• Mix of coniferous and deciduous trees• Humus (HUE-Mus) material formed from decaying

leaves….very fertile!!!• Forests with leaves that change colors• Think fairy tale forest “Snow White” and “Sleeping

Beauty”

Tundra• Permafrost: layer of

permanently frozen subsoil • “Ice Age”

Other interesting ecosystems…

• Mountain Ranges– On all continents– Abiotic and biotic factors change with ELAVATION (as u

go up)• Therefore plants and animals change VERTICALLY• Grassland at base woodland/pines

spruce/conifer forest tundra like open area at summit with wildflowers

• Polar Ice Caps– Border the Tundra– Cold year round– Characterized by ice and snow– Plants and algae are few but include Mosses and

Lichens– North Pole

• Sea ice and ice cap that covers Greenland• Polar bears, seals, insects and mites

– South Pole• 5 km thick layer of ice• Penguins and marine mammals

Aquatic Ecosystems

Biome Project: Biome Adventure Travel (EcoLabs & Field Activities)

Groups

Energy Flow through the Biophere

• Closed systems are systems that cannot exchange matter or energy with its surroundings.

• Open systems are systems that can exchange both matter and energy with its surroundings.

• Today, the Earth is essentially a CLOSED system with respect to matter, but an OPEN system for energy as energy travels from plant to animal which is eaten by other animals. In the process, some energy is lost as heat to the environment.

Energy Flow in Ecosystems- From Producers to Consumers

• Some producers get their energy directly from the sun by absorbing it and converting it to a food source.

• Consumers get their energy indirectly by eating producers or other consumers.

• Organisms break down carbohydrates and other organic compounds in their cells to obtain the energy they need, usually through aerobic respiration.

Influence of Light Intensity & RainfallOn Plant Productivity

Organisms can be classified by what they eat.

Types of Consumers:• Herbivores• Carnivores• Omnivores• Decomposers- consumers that return nutrients from organic

wastes back to the environment • ex: bacteria & Fungi

• Detritivores-feed on the waste or dead bodies of other organisms • ex: caterpillars/ vultures

• Each time an organism eats another organism, an energy transfer occurs.

• This transfer of energy can be traced by studying food chains, food webs, and trophic levels.

Detritivores and Decomposers on a Log

Food Chain• A food chain is a sequence

in which energy is transferred from one organism to the next as each organism eats another organism.

• A food web shows many feeding relationships that are possible in an ecosystem.

Trophic levels• Each time energy is transferred, some of the energy

is lost as heat.• Therefore, less energy is available to organisms at

higher trophic levels.

Pyramid of Energy Flow

Fig 3.15

Trophic Levels/ BiomassMore living organisms at the base of the pyramid = more biomass

Showing energy loss from 1 trophic level to the next- grass stores 1,000 times more energy than the hawk at the top level.

Primary Productivity of Ecosystems

• Gross primary production (GPP) – Rate at which an

ecosystem’s producers convert solar energy into chemical energy as biomass; the rate is crucial

Net Primary Production (NPP)

NPP = GPP - respiration [by plants]– Rate at which producers use

photosynthesis to store energy minus the rate at which they use some of this energy through respiration (R).

• Net primary production takes into account plant cellular respiration.

Estimated Annual Average NPP in Major Life Zones and Ecosystems

BIODIVERSITY• An important RENEWABLE resource

4 major kinds:– Genetic biodiversity- a variety of genetic material within a species or

population– Species Diversity- the variety among the species or distinct types of

living organisms found in different habitats of the planet– Ecological Diversity- the variety of different biomes around the world;

all biological communities– Functional Diversity- biological and chemical processes or functions

such as energy flow and matter cycling needed for the survival of species and biological communities

SOIL• Soil formation greatly depends on the climate, and soils from

different biomes show distinctive characteristics.

• Temperature and moisture affect weathering and leaching. Wind moves sand and other particles, especially in arid regions where there is little plant cover. The type and amount of precipitation influence soil formation by affecting the movement of ions and particles through the soil, aiding in the development of different soil profiles.

Habitat vs. NicheNiche - the role a species plays in a community (job)

Habitat- the place in which an organism lives out its life (address)

• Series of predictable changes that occur in a community over time– Physical environment– Natural disturbance– Human disturbance

• Pioneer species– Any of the first species to move into a

devastated area• Climax community

– Fairly stable community that marks the end of succession

Ecological Succession

Primary Succession• Succession on land that occurs on

surfaces where no soil exists – Volcanic eruptions– Glaciers melting

Secondary Succession• Succession following a disturbance that

destroys a community without destroying the soil

• Natural – hurricane– fires

• Human disturbances– Farming– Forest clearing– Pollution (oil spills)

Fig. 5-16, p. 116

Time

Exposedrocks

Lichens andmosses

Small herbsand shrubs

Heath mat

Jack pine,black spruce,and aspen

Balsam fir,paper birch, andwhite spruceforest community

Primary Succession

Fig. 5-17, p. 117

Time

Annualweeds

Perennialweeds andgrasses

Shrubs andsmall pineseedlings

Young pine forestwith developing understory of oak and hickory trees

Mature oak and hickory forest

Secondary Succession

Nutrient Cycles

• Water• Carbon• Nitrogen• Phosphorus• Sulfur

HYDROLOGIC CYCLE• Natural renewal of water quality: 3 major processes

– Evaporation– Precipitation– Transpiration

• Alteration of the hydrologic cycle by humans– Withdrawal of large amounts of freshwater at rates faster

than nature can replace it– Clearing vegetation leads to increased runoff– Increased flooding when wetlands are drained

Fig. 3-17, p. 66

Transpirationfrom plants

Evaporationfrom land

Precipitationto land

Precipitationto ocean

Evaporationfrom ocean

Condensation Condensation

Infiltrationand percolationinto aquifer

Surfacerunoff

Surface runoffRunoff

Globalwarming

Reduced recharge ofaquifers and floodingfrom covering land withcrops and buildings

Aquiferdepletion fromoverpumping

Increasedfloodingfrom wetlanddestruction

Pointsourcepollution

Groundwatermovement (slow)

Lakes andreservoirs

Ice andsnow

Ocean

Processes

Processes affected by humans

Reservoir

Pathway affected by humans

Natural pathway

HYDROLOGIC CYCLE

Carbon Cycle• Depends on Photosynthesis and Respiration• Link between photosynthesis in producers and

respiration in producers, consumers, and decomposers

• Alteration of the carbon cycle by humans Additional CO2 added to the atmosphere– Tree clearing– Burning of fossil fuels- energy and transportation

Fig. 3-18, p. 68

Pathway affected by humans

Diffusion

Transportation

Deforestation

Respiration

Respiration

Decomposition

Forest fires

Compaction

Burningfossil fuels

Photosynthesis

Animals(consumers)

Plants(producers)

Marine food websProducers, consumers,decomposers

Carbonin plants

(producers)

Carbonin fossil fuels

Carbon dioxidedissolved in ocean

Carbonin limestone ordolomite sediments

Carbonin animals

(consumers)

Processes

Reservoir

Natural pathway

Carbon dioxidein atmosphere

CARBON CYCLE

Nitrogen Cycle• Bacteria in action• Alteration of the nitrogen cycle by humans

Additional NO and N2O – Burning fuels– Destruction of forest, grasslands, and wetlands– Add excess nitrates to bodies of water– Remove nitrogen from topsoil

The Nitrogen Cycle

Annual Increase in Atmospheric N2 Due to Human Activities

Fig. 3-19, p. 69

Decomposition

Nitrogenloss to deepocean sediments

Nitrogenin atmosphere

Nitrogenin oceansediments Ammonia

in soil

Nitratein soil

Nitrogenin plants

(producers)

Nitrogenin animals

(consumers)Volcanicactivity

ElectricalstormsNitrogen oxides

from burning fueland using inorganicfertilizers

Nitratesfrom fertilizer

runoff anddecomposition

Nitrificationby bacteria

Denitrificationby bacteria

Uptake by plants

Bacteria

NITROGEN CYCLE

Phosphorus Cycle• Cycles through water, the earth’s crust, and living

organisms

• May be limiting factor for plant growth

• Alteration of the phosphorous cycle by humans – Clearing forests– Mining and human wastes– Removing large amounts of phosphate from the earth to

make fertilizers

Fig. 3-21, p. 71

Processes

Reservoir

Pathway affected by humans

Natural pathway

Phosphatesin mining waste

Phosphatesin sewage

Animals(consumers)

Bacteria

Plants(producers)

Phosphatesin fertilizer

Phosphatedissolved inwater

Phosphatein shallowocean sediments Phosphate

in deep oceansediments

Oceanfood webs

Phosphatein rock(fossil bones,guano)

Seabirds

Platetectonics

Erosion

Runoff

Runoff Runoff

PHOSPHORUS CYCLE

Sulfur Cycle• Sulfur found in organisms, ocean sediments, soil,

rocks, and fossil fuels

• SO2 in the atmosphere• DMS (Dimethyl Sulfide)- produced by marine algae• Sulfuric acid = acid rain; H2SO4 and SO4

-

Alteration of the sulfur cycle by humans Burn sulfur-containing coal and oil

– Refine sulfur-containing petroleum– Convert sulfur-containing metallic mineral ores

Fig. 3-22, p. 72

Processes

Reservoir

Pathway affected by humans

Natural pathway

Dimethylsulfide

a bacteriabyproduct

Sulfurin oceansediments

Sulfurin soil, rock

and fossil fuels

Sulfurin plants

(producers)

Sulfurin animals

(consumers)

Sulfur dioxidein atmosphere

DecayDecay

Uptakeby plants

Mining andextraction

Sulfuric acidand Sulfate

deposited asacid rain

Smelting Burningcoal

Refiningfossil fuels

Sulfur Cycle

Geographic Information Systems (GIS)

• A GIS organizes, stores, and analyzes complex data collected over broad geographic areas.

• Allows the simultaneous overlay of many layers of data.