2Ecosystem- is a community and its physical and chemical environment. Examples of different ecosystemsTerrestrial ecosystems(e.g. Prairie, grassland, forest…….)Aquatic ecosystems(e.g. Pond, lake, stream…….)
3Roles in EcosystemsEach organism has its own place within an ecosystem.Ecological niche – an organism’s role in an ecosystem, consisting of its place in the food web, its habitat, it’s breeding area and time of day at which it is most active.
4Roles in EcosystemsEach species in an ecosystem tends to have a different niche, a different role to play. This helps to reduce competition between species.E.g. Even if two species eat the same food they are not in competition because they may:Live in different placesEat at different times
6Roles in EcosystemsE.g. Owls and hawks feed on many of the same organisms, but occupy distinctly different niches.Owls hunt down prey with in forestsHawk hunt down prey in grassland and open fieldsOwls are active during dusk and at nightHawk hunt by daylightCompetition is further reduced because owls and hawks nest in different areas.
8Competition for Niches When a new species enter an ecosystem, it causes a disturbance because it comes into competition for a niche with one or more of the species already in the ecosystem.Exotic species – species that are not native to an ecosystemThe introduction of new species happens naturally. Animals are mobile and can move from one ecosystem to another.
10Introduction of Exotic species The introduction of new species by humans to an ecosystem is one of the main causes of species depletion and extinction, second only to habitat loss.Problems with introducing Exotic Species:No natural population controls ( predators or diseases)Native species may not b able to compete for space, food or reproductive sites.Prey organisms may not have defence mechanisms.
14Supporting Biodiversity in Terrestrial Ecosystems
15Limiting FactorsDifferent ecosystems can support different species and varying numbers of organisms. This is due to limiting factors such asSoil composition - HumidityMoisture - TemperatureSunlight - NutrientsOxygen - CompetitorsPredators
16TaigaIn a forest, the amount of sunlight varies from the top of the canopy to the forest floor.In Taiga biomes, the mature trees are mostly conifers like spruce and pineThese trees can only support certain types of birds that have tough beaks for cracking open cones and nuts
17TaigaYear-round, these trees block the sunlight from reaching the forest floorThis determines the types of plants that can grow below the canopyIn the Taiga, we see shade loving plants like shrubs, mosses and fernsThese plants then determine which primary consumers exist in this ecosystemDeer and moose
18TaigaDue to the low growth on the forest floor, nesting animals are only successful if they are suitably camouflaged
19Deciduous ForestsHave higher temperatures and precipitation than TaigaAlso have more humusDecaying plant and animal matterThese conditions lead to a richer soil and support growth of deciduous trees
21Deciduous Forests Spring: sun can reach all the way to forest floor Summer: Canopy is full, so very little sun gets to the understorey.This is ok, because the understorey had the chance to grow in the spring and is already matureResulting in support for a diverse range of organisms
22Deciduous Forests Lots of leaf litter Full understorey Leafy canopy Many different insectsFull understoreyMoose and deerLeafy canopyVariety of birds and climbing mammals
24Water covers more than two-thirds of our planet. Ninety-seven percent of that water is saltwater.The oceans to a large extent control the weather patterns on our planet.Most fresh water exists as snow or ice
25Limiting factors of Aquatic Ecosystems Like terrestrial ecosystems, aquatic ecosystems are limited by three abiotic factors:The chemical environmentLight levelsTemperature
27Chemical environment The type of water: FreshwaterSaltwaterThe amount of oxygen dissolved in the water.The amount of dissolved oxygen depends on:Temperature (warmer water holds less)Pressure (more oxygen dissolved at sea level than mountain streams)And the amount of salt and other substances dissolved in the water (more salt, less oxygen)
28Chemical environment Any other dissolved substance E.g., Naturally occurring minerals, and organic pollutants.
29Limiting factors of Aquatic Ecosystems Light and temperature in an aquatic ecosystem may vary over the course of the year (seasonal changes), But these factors are also affected by the depth of the water.Depending on the depth of the body of water the amount of light available, the temperature and oxygen levels can all vary. This will have a significant impact on what organisms you can find.
30Littoral ZoneLittoral Zone – is the area extending out from the lakeshore to the point where you can no longer find plants rooted.Most productive part of the lake.High amount of sunlight.
31Limnetic zoneLimnetic zone – the area of a lake or pond in which there is open water and sufficient light for photosynthesis to occur.Most common form of organism in the zone is plankton (small autotrophic and heterotrophic mircrooganisms.
32Profundal zoneProfundal zone – the region of a lake beneath the limnetic zone, in which there is insufficient light for photosynthesis to occur.Most of the time only source of nutrients in the zone are dead plants and animals that fall from the limnetic zone.Low oxygen due to bacteria decomposing dead organic matter.No sunlight no photosynthesis.
35Ecosystems are smaller regions in the biosphere. Complexity of ecosystems varies, depending not only on the organisms that live in them but also on abiotic factors such as climate and local geology.
36Canada has four major Biomes: Biome is a large geographical region with a specific climate, and the plants and animals that are adapted to that climate.Canada has four major Biomes:TundraTaigaTemperate deciduous forestGrassland
40Terrestrial ecosystems are ecosystems that are found anywhere on Earth that is not covered by water. Despite their many differences in each terrestrial region biotic and abiotic factors are interdependent.These factors can limit the size of populations and can also determine the number of species that survive in each ecosystem.
41Limiting FactorsAbiotic Factors that can limit Terrestrial ecosystems:SoilAvailable WaterTemperatureSunlight
42SoilThe quality and amount of soil are critical factors in determining the size and health of the plant community and the biodiversity of an ecosystem.
45SoilSoil pHHumans have been contributing to higher levels of acidity in many soils by burning fossil fuels.Burning of fossil fuels release sulphur dioxide and nitrogen oxides into the air which fall to earth as acid deposition.Acid deposition – the process by which sulphur dioxide and nitrogen oxides in the atmosphere form acidic compounds and fall to Earth’s surface. (Acid rain is an example of acid deposition)
46Available WaterThe amount of available water in an ecosystem help determine the size and health of populations and the biodiversity of an ecosystem.RecallSurface waterGround water
48Temperature Temperature affects both biotic and abiotic factors. Temperature can vary significantly throughout the year in an ecosystem.
49SunlightThe amount of sunlight determines what plants will grow in an ecosystem.In ecosystems around the equator receive more or less the same amount of daily sunlight.Regions at more southern or northern latitudes experience changes in the amount of sunlight during different times of the year.
51Aquatic EcosystemsAquatic ecosystems are sustained by the dynamic equilibrium among biotic and abiotic factors.When one or more of these factors changes, it can have profound effects on the ecosystem.
52Lake Ecosystems There are two types of lakes: Oligotrophic Lakes are typically deep and cold.Nutrient levels are low limiting size of producer populations.Limited numbers of only a few kinds of organisms.Water usually very clear.
53Lake Ecosystems Eutrophic Lakes are generally shallow and warmer. Very good supply of nutrients.Many species of photosynthetic organisms.Water is often murky.
54EutrophicationIn general oligotrophic lakes gradually become eutrophic over time and eventually filling in and becoming dry land.This process is call eutrophication.
58EutrophicationHuman sometimes accelerate eutrophication by adding nutrients to lakes:Human wastesFertilizersHousehold and Industrial productsThermal energyEutrophication
59Water PollutionWater pollution is any physical or chemical change in surface water or ground water that can harm living things.Water pollution can be grouped into five categories.Organic solid wasteDisease-causing organismsInorganic solids and dissolved mineralsThermal energyOrganic chemicals
61Water Quality Bacteria Dissolved Oxygen Biological Oxygen Demand Presence of coliform bacteria indicates that fecal matter is in water (and therefore more dangerous bacteria)Dissolved OxygenFewer pollutants means more dissolved oxygenBiological Oxygen DemandAmount of oxygen needed by decomposers to break down organic matterIndicates amount of organic matter in water (too much and no oxygen is left for fish to breathe)