Presentation on theme: "CHAPTER 4: Ecosystems & Communities"— Presentation transcript:
1CHAPTER 4: Ecosystems & Communities 4-1 The Role of Climate4-2 What Shapes an Ecosystem4-3 & 4-4 Biomes
2California State Standards Students know how to analyze changes in an ecosystem resulting from changes in climate, human activity, introduction of nonnative species, or changes in population size.Stability in an ecosystem is a balance between competing effects.Students know biodiversity is the sum total of different kinds of organisms and is affected by alterations of habitats.
34-1 The Role of Climate Objectives Identify the causes of climate. Explain how Earth’s temperature range is maintained.Identify Earth’s three main climate zones.
44-1 The Role of Climate I. Weather vs. Climate A. Weather is the of Earth’s atmosphere at a particular time and place.B. Climate refers to the average,of temperature and precipitation in a particular region. Climate is determined by:1.2. Transport of heat by3. Shape and elevation ofday-to-day conditionyear-after-yearconditionsLatitudewinds and oceancurrentslandmasses
5Unequal Heating of the Earth SunlightMost direct sunlight90°N North Pole66.5°N23.5°S66.5°S90°S South PoleArctic circleTropic of CancerEquatorTropic of CapricornDifferent Latitudes
8What is the Greenhouse Effect? SunlightSome heatescapesinto spaceGreenhousegases trapsome heatAtmosphereEarth’s surfaceWhat is the Greenhouse Effect?
9II. The Greenhouse Effect A. Temperatures on Earth remain for life because of the atmosphere.B. Gases Responsible for trapping heat energy:1. Carbon dioxide – from burning of fossil fuels; rain forest deforestation and burning. Approx of the problem.2. Methane – from livestock feedlots, swamps, and coal mines. Approx of the problem.3. Water vaporsuitable50%18%
104. CFC’s – formerly from spray cans, now from refrigeration; air conditioners. Approx of the problem.5. Oxides of nitrogen – from power plants, industry (any heat producing process). Approx of the problem.20%10%
11C. These gases function like the glass. windows of a greenhouse C. These gases function like the glass windows of a greenhouse. These gases trap the inside Earth’s atmosphere.penetrates the gases of the atmosphere and strikes the Earth’s surface. Here it is transformed into heat or infrared energy (IR). Much of the IR escapes the atmosphere, while the remainder is absorbed and held in the atmosphere byheat energy of sunlightUltraviolet lightgreenhouse gases.
132. With an increase of abnormally high. levels of carbon dioxide 2. With an increase of abnormally high levels of carbon dioxide and other greenhouse gases, more and more escaping IR is , thereby creating a pronounced global warming.human-createdcaught and held
15Global Warming Global Warming Worldwide temperatures have climbed more than 1ºF over the past century.
16D. The Probable Scenarios of Global Warming: 1. 2. Shift north of 3. An increase in4. Sea levelDroughtsclimatic zonesdestructive stormactivityriseCheck this out!
17Quiz #1What is weather?The day to day condition of Earth’s atmosphere at a particular time and place.What is climate?The average year after year conditions of temperature and precipitation in a particular region.
18Quiz #1 cont. The greenhouse effect causes an increase in Carbon dioxideTemperatureOxygenWater
19Quiz #1 cont.Sunlight strikes the Earth’s surface most directly in what region?Polar zoneTemperate zoneTropical zone
204-2 What Shapes an Ecosystem? ObjectivesIdentify interactions that occur within communitiesDescribe how ecosystems recover from a disturbance
211. CompetitionGive me that nut!Between organisms of the same species
23So what is this tree competing for? LightWaterNutrients
24I. Community Interactions A. Community interactions, such as competition, predation, and various forms of symbiosis, can powerfully affect an ecosystem.1. Competition: occurs when organisms of the same or different species attempt touse an ecological resource in the same place at the same time.
25What are the possible outcomes of competition? LOSEORWINBecause The competitive exclusion principle states that no two species can occupy the same niche in the same habitat
33B. Symbiosis (cont.)2. Commensalism – one benefits, other is neither helped or harmed.EX: hawks and cactus plants, epiphytes and trees, shrimp and sea anemonesp. 93
34B. Symbiosis (cont.)3. Parasitism – one benefits, other not benefited. One lives in or on the body of another taking energy from the host. Host is not usually killed.Tapeworm
35Tape worm: Can range from 1 m to 30 m in a Sperm Whale. The head has a mouth with hooked appendages that allows it to hook to its host’s intestinal liningRight behind the head, the neck grows segments that make up the rest of the elongated wormThe worm absorbs nutrients from its hostMay be picked up by swallowing a small amount of water from a lake or river. Also by eating undercooked meat.Head of a tapeworm
36Oak Treehopper suck sugar rich juices from trees
37Symbiotic Relationship Draw this table on page 3 of your Lecture NotesSymbiotic RelationshipHostSymbiontCommensalismMutualismParasitism+++-+
39Are Ecosystems & Communities always stable? NO!Ecosystems and communities are ALWAYS CHANGING!Why?Natural processes/disturbancesHuman disturbances
40II. Ecological Succession A. Ecological succession = An ecological sequence of changes in the plants and animals making up a community in a given area.Succession is a gradual replacement oforganisms in a given area over a periodof time.
41II. Ecological Succession B. These changes are predictable and orderly and continue until a stable orOnce reaching its biological destiny,C. Two general types: Primary & Secondaryclimaxcommunity is reached.acommunity retains the final complementof species which mature over time.
42Primary Succession1. Primary succession: a form of succession that begins with _ _. Assume no soil is present when this process begins. Examples: recently formed volcanic island or bare rock areas scoured by glacial action.bare rock
43Primary Successiona. Pioneer species are the first to colonize the area. Example:b. As they grow, lichens produce carbonic acids whichlichen (a combination of fungus andalgae).slowly break down the parent rock to form a basic shallow pocket of soil.
45Examples of Primary Succession GlacierMoss and Lichen
462. Secondary SuccessionThis occurs in communities that were established and then disturbed in some manner.Example: burned over area of chaparral. The fire-ravaged area begins re-growth soon after the ashes cool down. This climax stage will generally be reached in years in most cases.
50Quiz #2 cont.A form of symbiosis in which both organisms benefit is calledMutualismParasitismCommensalismPredation
51Quiz #2 cont.Natural disturbances, such as fires or hurricanes, can result inCommensalismCompetitionParasitismSuccession
52Quiz #2 cont.The first species to populate an area at the beginning of primary succession are called. . .Pioneer Species
534-3: BiomesObjectiveIdentify the characteristics of major land biomes
544-3 BiomesI. BIOMES: are areas that are similar in climate and other physical factors.A. A biome is an environment that has a characteristicB. There are of biomes:1. Land biomes2. Aquatic biomesclimax community2 main types
57TundraLocated in the far northern parts of North America, Europe, and AsiaThe tundra has permanently frozen subsoil called permafrostInsects, particularly flies, are abundantVast numbers of birds nest in the tundra in the summer to eat the insects and migrate south in the winter.Principal mammals include reindeer, Artic wolves, Artic foxes, Arctic hares, lemmings, and polar bearsThough the number of individual organisms in the tundra is high, the number of species is small
62Taiga/Conifer ForestFound in the northern Canada and much of the world’s northern regionsDominated by conifer (evergreens) forests, like spruce and firLandscape is dotted with lakes, ponds, and bogsHas very cold wintersIs the largest terrestrial biomeCharacterized by heavy snowfallPrincipal large mammals include moose, black bear, lynx, elk, wolverines, and porcupinesFlying insects and birds are prevalent in summer
63Taiga PlantsNeedle like leaves help reduce water loss and aid in the shedding of snowThe shape of many conifer trees helps shed heavy snow to save branches from breaking
64Taiga Animals Hibernation Migration Producing a thick layer of insulating feathers or fur
66Temperate Deciduous Forest/Boreal Forest Found in the northeast of North AmericaThe leaves on some trees and plants change colors as the seasons change.Rich soil due to decomposition of leaf litterPrincipal mammals include: squirrels, deer, foxes, and bears that are dormant or hibernate through the cold winter
67Temperate Deciduous Plants Broad leaves can capture a lot of sunlight for a treeThick bark protects against the cold wintersIn autumn, deciduous trees drop their leaves to minimize water loss
68Temperate Deciduous Animals HibernationMigrationFood storage (for the winter)
70GrasslandCharacterized by low total annual rainfall or uneven seasonal occurrence of rainfall, making conditions inhospitable for forestsGrass is the dominant plant lifeServe as grazing areas for large numbers of animals or as farming grounds or plantations by humansPrincipal grazing mammals include bison and pronghorn antelope in the US, and wildebeest and gazelle in AfricaBurrowing mammals, such as prairie dogs and other rodents, are common
71Grassland PlantsDuring a fire, while above-ground portions of grasses may perish, the root portions survive to sprout againExtensive root systems prevent grazing animals from pulling roots out of the groundPrairie grasses have narrow leaves which lose less water than broad leavesMany grasses take advantage of exposed, windy conditions and are wind pollinatedSoft stems enable prairie grasses to bend in the wind
72e. Tropical Rain Forest Precip: high Temp: hot Soil: poor Diversity: highTrees: denseGrasses: sparse
73Tropical Rain ForestFound near the equator with abundant rainfall, stable temperatures, and high humidityHas the greatest diversity of species of any biomeDominant trees are very tall with interlacing tops that form a dense canopy
74Tropical Rainforest Plants Some plants climb or grow on other plants to reach the sunlightDrip-tips on leaves help shed excess waterProp roots help support plants in the shallow soilSome plants collect rainwater into a central reservoir
75Tropical Rainforest Animals So many creatures living here, there is great competition for light, food, and space and as a result some animals have become specialized. This means that they adapted to eating a specific plant or animal that few others eat.CamouflagePoisonous animals use bright colors to warn predators
77DesertIt receives less than 10in of rainfall per year; not even grasses can surviveExperiences the most extreme temperature fluctuations of any biome.Characteristic plants are the drought-resistant cacti with shallow roots to capture as much rain as possible during hard and short rains.
78Desert PlantsThe lack of leaves help reduce water loss. Leafless plants conduct photosynthesis in their green stems.Long root systemsSpines discourage animals from eating plants for water.Flowers that open at night lure pollinators who are more likely to be active during the cooler night.Slower growing requires less energyLeaves with hair help shade the plantWaxy coating reduces water loss
79Desert Animals Stay in the shade Burrow to escape the heat Most animals are nocturnal (come out at night)Estivation—like hibernation, except these animals are not avoiding the cold, but the heat! Helps conserve moisture.Obtain water from diet
80Quiz #3 Which biome has the lowest average temperatures? Highest? Lowest Temp TundraHighest Temp Tropical dry forestWhich biome has the lowest average precipitation? Highest?Lowest Precip Desert & TundraHighest Precip Tropical rain forest
812. Aquatic biomes (cont.)a. Fresh water – streams, lakes, ponds, etc.
82b. Salt water (marine): main photosynthesizers = phytoplankton