Ecology mega notes

Factors That Influence the Characteristics and Distribution of Biomes Certain characteristics help to identify biomes. Temperature and precipitation are two of the most important abiotic factors. Other factors include latitude, elevation, and ocean currents. (c) McGraw Hill Ryerson 2007 Biomes of the World

Temperature and precipitation Biome Chart Practice: Identify the biome using the chart below. Ave annual precipitation of 175cm and ave annual temperature of 50C. Boreal Forest Temperature ranges 00C – 200C and receives about 100 cm of rain. Temperate Deciduous Forest (c) McGraw Hill Ryerson 2007

(c) McGraw Hill Ryerson 2007 Factors That Influence the Characteristics and Distribution of Biomes (continued) Latitude is an abiotic factor that influences biomes. Latitude is the distance north and south from the equator. Latitude influences both temperature and precipitation. The tropical zone has very warm temperatures and high precipitation. The tropical zone receives more direct sunlight than do temperate zones. Zones of the World (c) McGraw Hill Ryerson 2007

Temperature and precipitation Biome Chart Practice: Identify the biome using the chart below. Ave annual precipitation of 175cm and ave annual temperature of 50C. Boreal Forest Temperature ranges 00C – 200C and receives about 100 cm of rain. Temperate Deciduous Forest (c) McGraw Hill Ryerson 2007

(c) McGraw Hill Ryerson 2007 Factors That Influence the Characteristics and Distribution of Biomes (continued) Latitude is an abiotic factor that influences biomes. Latitude is the distance north and south from the equator. Latitude influences both temperature and precipitation. The tropical zone has very warm temperatures and high precipitation. The tropical zone receives more direct sunlight than do temperate zones. Zones of the World (c) McGraw Hill Ryerson 2007

(c) McGraw Hill Ryerson 2007 Factors That Influence the Characteristics and Distribution of Biomes (continued) Elevation is the height of a land mass above sea level and also influences biomes. Elevation effects temperature: The atmosphere is thinner at higher elevations, and therefore less heat is retained. (c) McGraw Hill Ryerson 2007

(c) McGraw Hill Ryerson 2007 Factors That Influence the Characteristics and Distribution of Biomes (continued) Elevation affects precipitation: On the windward sides of mountains, clouds filled with moisture rise and cool, then release rain or snow. On the leeward side of a mountain, which is the side sheltered from the wind, the air warms again, which allows it to absorb water, creating a dry land area. (c) McGraw Hill Ryerson 2007

(c) McGraw Hill Ryerson 2007 Factors That Influence the Characteristics and Distribution of Biomes (continued) Ocean currents are another abiotic factor that affects temperature and precipitation and therefore influences biome characteristics. Ocean currents carry warmth and moisture to coastal areas. Where warm currents meet land, temperate biomes are found. e.i. Both Canada’s and New Zealand’s temperate rainforest. (c) McGraw Hill Ryerson 2007

(c) McGraw Hill Ryerson 2007 Climatographs Climate refers to the average pattern of weather conditions of a large region over a period of 30 years or more. A climatograph shows the average temperature and precipitation for a location over a period of 30 years or more. Biomes are often defined using information in climatographs. Examine the differences between the climatographs for Tofino and Osoyoos (c) McGraw Hill Ryerson 2007

Biodiversity in Ecosystems By studying past and present ecosystems, we can better understand what may happen in the future. Historical ecology is the study of natural and written materials to better understand the ecology of a certain area. Many First Nations sources provide detailed knowledge of plants, animals, and natural occurrences of an area. Ecology is the “the study of the interrelationships between the biotic (living organisms) and abiotic (non-living) factors within a given environment. Ecosystems are the basic unit of ecology. See pages 34 - 36 (c) McGraw Hill Ryerson 2007

(c) McGraw Hill Ryerson 2007 An Ecosystem is: “A definable area containing a relatively self-sustained community of organisms interacting with their non-living surroundings.” Examples of Ecosystems Small pool of water Pond Lake Ocean Biosphere An ecosystem is made up of many parts. Abiotic factors include air, water, soil, nutrients, and light. Biotic factors include plants, animals, and micro-organisms. (c) McGraw Hill Ryerson 2007

(c) McGraw Hill Ryerson 2007 Habitats Within ecosystems are habitats. A habitat is where an organism lives. Pacific spotted scorpionfish, Malpelo, Pacific Ocean blends in with it’s habitat. The habitat of the red fox often includes the edges of forests or marshlands. (c) McGraw Hill Ryerson 2007

Abiotic Interactions in Ecosystems The abiotic components are what allow the biotic components to survive in an ecosystem. Abiotic factors include oxygen, water, nutrients, light and soil. Oxygen is produced by the green plants and certain micro-organisms and is used by animals and most other micro-organisms. Water is necessary for all life. Nutrients often enter the food chain with plants and are very important for growth. Light is required for photosynthesis, which is the process in plants that converts and stores the Sun’s energy into starches and carbohydrates. Soil not only contains water and nutrients but also is home to many plants and animals. Earthworms in soil See pages 37 - 38 (c) McGraw Hill Ryerson 2007

Biotic Interactions in Ecosystems A species is a group of closely related organisms that share similar characteristics and can reproduce with one another. A population refers to all the members of a particular species within an ecosystem. A community is all the populations of the different species that interact in a specific area or ecosystem. (c) McGraw Hill Ryerson 2007

Biotic Interactions in Ecosystems Symbiosis refers to the interactions between members of two different species that live together in a close association. There are three main types of symbiotic relationships: Commensalism Mutualism Parasitism See pages 39 - 43 (c) McGraw Hill Ryerson 2007

(c) McGraw Hill Ryerson 2007 Commensalism One species benefits, one is not affected. Examples: Barnacles on a whale Spanish Moss on tree branches – Spanish moss has no roots, it is an epiphyte. Epiphytes are plants that are supported by or anchored on other plants, but they don’t obtain nutrients and water from the host tree. (c) McGraw Hill Ryerson 2007

(c) McGraw Hill Ryerson 2007 Mutualism Both species benefit Examples: Bee gathering nectar from a flower Ants and the bull horn acacia plant. The ants live in hollow thorns on the plant and sip the plants nectar. In return for food and shelter, the ants aggressively protect the plant by fighting off other insects and animals by stinging them. (c) McGraw Hill Ryerson 2007

(c) McGraw Hill Ryerson 2007 Mutualism Continue (c) McGraw Hill Ryerson 2007

(c) McGraw Hill Ryerson 2007 Parasitism One species benefits, the other is harmed Parasites are usually much smaller and more numerous than their hosts. Parasites may live on or in their hosts feed on the host’s blood or body tissues. Usually, the host is not killed, but a parasite can cause great damage and weaken the hosts, sometimes causing death. Example: Hookworm living in dogs and or humans Mountain Pine beetle in Pine trees (c) McGraw Hill Ryerson 2007

(c) McGraw Hill Ryerson 2007 Parasitism Continue (c) McGraw Hill Ryerson 2007

(c) McGraw Hill Ryerson 2007 Niches A niche refers to the specific role an organism has within an ecosystem, physically, chemically and biologically. Within its niche, an organism interacts with other individuals of the same species or with individuals of other species. For example, great blue herons always live near water where they can fish, and near trees where they can nest. Only one organisms can occupy the same niche, at the same time in the same environment. See pages 44 - 47 (c) McGraw Hill Ryerson 2007

(c) McGraw Hill Ryerson 2007 Competition Competition occurs when a resource is needed by two or more individuals. Competition usually means resources are limited. This limits the size and health of that individual and perhaps that population. Some plants have characteristics that make them successful competitors. Example: spotted knapweed release chemicals into the soil, which prevents the growth of other plants and allows the knapweed to populate a field quickly. Coyotes compete over habitat or food sources. (c) McGraw Hill Ryerson 2007

(c) McGraw Hill Ryerson 2007 Predation Predation is the relationship between the “eaters” and the “eaten”. Predators have adaptations to help them catch their prey. Prey have adaptations to help avoid predators. Examples of adaptations include Spines Shells Poisonous substances Camouflage – blending into the environment Mimicry – a prey animal mimics another species that is dangerous or tastes bad. (c) McGraw Hill Ryerson 2007

Predator-Prey Relationships The numbers of predators and prey influence each other. Example: the size of the prey population can be affected by the number of predators. In the example of the lynx and the hare, The prey population grows when there are few predators. When the predator population is high, the prey population shrinks. (c) McGraw Hill Ryerson 2007

Biodiversity in Ecosystems Biodiversity refers to the variety and number of different individuals and species in an ecosystem. Healthy ecosystems generally have high biodiversity. Most biodiversity losses occur from the loss of habitat. Humans often have a negative impact on biodiversity. Many efforts are now made to lessen this impact in order to maintain biodiversity. Ecological management programs try to balance human progress with maintaining biodiversity. Wetlands provide habitats. See page 48 (c) McGraw Hill Ryerson 2007

Energy Flow in Ecosystems (c) McGraw Hill Ryerson 2007

Energy Flow in Ecosystems Biomass is the total mass of all living things in a given area. Biomass can also refer to the mass of a particular type of matter, such as organic materials used to produce biofuels. Biomass is generally measured in g/m2 or kg/m2 . The most successful animal species, in terms of biomass, is probably the Antarctic krill, with a biomass of about 500 million tonnes. (c) McGraw Hill Ryerson 2007

Energy Flow Within an organism’s niche, the organism interacts with the ecosystem by: Obtaining food from the ecosystem Contributing energy to the ecosystem Plants are called producers because they produce carbohydrates from carbon dioxide, water, and the Sun’s energy. Consumers get their energy by feeding on producers or other consumers. Decomposition is the breakdown of wastes and dead organisms by organisms called decomposers through the process of biodegradation. Bees are consumers. (c) McGraw Hill Ryerson 2007

Energy Flow and Energy Loss in Ecosystems:Food Chains Scientists use different methods to represent energy moving through ecosystems. Food chains Food webs Food pyramids Food chains show the flow of energy in an ecosystem. Each step in a food chain is a trophic level Producers = 1st trophic level Primary consumers = 2nd trophic level Secondary consumers = 3rd trophic level Tertiary consumers = 4th trophic level Examples of terrestrial and aquatic food chains See pages 59 - 60 (c) McGraw Hill Ryerson 2007

Predator/Prey and Food Chains (c) McGraw Hill Ryerson 2007

Energy Flow and Energy Loss in Ecosystems: Food Chains (continued) Consumers in a food chain can be classified as: 1. Detrivores 3. Carnivores 2. Herbivores 4. Omnivores See page 61 (c) McGraw Hill Ryerson 2007

Detrivores Detrivores – consumers that obtain energy and nutrients from dead organisms and waste matter Examples include earthworms, bacteria and fungi. Detrivores feed at every trophic level. Detrivores have their own, separate food chains and are very numerous. (c) McGraw Hill Ryerson 2007

Herbivores Herbivores – primary consumers Herbivores eat plants (producers) only. (c) McGraw Hill Ryerson 2007

Carnivores Carnivores – secondary or tertiary consumers Secondary consumers eat non-producers, such as herbivores. Tertiary consumers eat secondary consumers. Also called top consumers or top carnivores. (c) McGraw Hill Ryerson 2007

Omnivores Omnivores – consumers that eat both plants and animals Examples include humans and bears. (c) McGraw Hill Ryerson 2007

Energy Flow and Energy Loss in Ecosystems: Food Webs This food web represents a terrestrial ecosystem that could be found in British Columbia. Most organisms are part of many food chains. Food webs represent interconnected food chains. Food webs are models of the feeding relationships in an ecosystem. Arrows in a food web represent the flow of energy and nutrients. Following the arrows leads to the top carnivore(s). See page 62 (c) McGraw Hill Ryerson 2007

Energy Flow and Energy Loss in Ecosystems: Food Pyramids Food pyramids show the changes in available energy from one trophic level to another in a food chain. Energy enters at the first trophic level (producers), where there is a large amount of biomass and therefore much energy. It takes large quantities of organisms in one trophic level to meet the energy needs of the next trophic level. Each level loses large amounts of the energy it gathers through basic processes of living. 80 – 90 % of energy taken in by consumers is used in chemical reactions in the body and is lost as thermal energy. There is very little energy left over for growth or increase in biomass. Ninety percent of this mouse’s food energy is used to maintain its life functions.

Energy Flow and Energy Loss in Ecosystems: Food Pyramids (continued) Food pyramids are also known as ecological pyramids. Ecological pyramids may show biomass, population, or energy numbers. The amount of life an ecosystem can contain is based on the bottom level of the ecological pyramid, where producers capture energy from the Sun. Each level in the energy pyramid = a loss of 90 % of total energy available. Lower trophic levels have much larger populations than upper levels. This shows the importance of maintaining large, biodiverse populations at the lowest levels of the food pyramid. See pages 63 - 64 (c) McGraw Hill Ryerson 2007 Take the Section 2.1 Quiz

(c) McGraw Hill Ryerson 2007