LIVING THINGS AND THE ENVIRONMENT • Ecosystem: – All the living and nonliving things that ENVIRONMENTAL SCIENCE interact in a particular area – An organism obtains food, water, shelter, and other Populations and Communities things it needs to live, grow and reproduce from its surroundings – Ecosystems may contain many different habitats Science 7 Science 7 LIVING THINGS AND THE LIVING THINGS AND THEIR ENVIRONMENT ENVIRONMENT • Habitat: • Biotic Factors: – The place and organism – The living parts of any lives and obtains all the ecosystem things it needs to survive – Example: Prairie Dogs – Example: • Hawks • Prairie Dog • Ferrets • Needs: • Badgers – Food • Eagles – Water • Grass – Shelter • Plants – Etc. Science 7 Science 7 LIVING THINGS AND THEIR LIVING THINGS AND THEIR ENVIRONMENT ENVIRONMENT • Abiotic Factors: • Abiotic Factors con’t – Water: – Sunlight: • All living things • Necessary for require water for photosynthesis survival • Your body is 65% • Organisms which water use the sun form • A watermelon is the base of the 95% water food chain • Plants need water for photosynthesis for food and oxygen production Science 7 Science 7 1 LIVING THINGS AND THEIR LIVING THINGS AND THEIR ENVIRONMENT ENVIRONMENT • Abiotic Factors Con’t • Abiotic Factors con’t – Oxygen: – Temperature: • Necessary for most • The temperature of living things an area determines • Used by animals the type of for cellular organisms which respiration can live there • Ex: Polar Bears do not live in the tropics • Ex: piranha’s don’t live in the arctic Science 7 Science 7 LIVING THINGS AND THEIR LIVING THINGS AND THEIR ENVIRONMENT ENVIRONMENT • Abiotic Factors con’t • Populations: – Soil: – All the members of one species in a particular area • Mixture of rock fragments, humus – Ex: the number of students in this class (nutrients), minerals, air, and water • Communities: • Soil type dictates flora in an area – All the different populations which live in an area – Ex: all the animals in the Seneca Park Zoo – Ex: all the animals in a forest Science 7 Science 7 DETERMINING POPULATION SIZE DETERMINING POPULATION SIZE • There are several methods of determining • 2. Indirect Observation population size – If members of a population are either small or hard • 1. Direct Observation: to find, counting their tracks or signs of life can give an estimate of population size – Actually counting, one by one, all of the members of a population – Ex: counting mud swallow nests instead of the birds – Ex: counting all the elephants in a Kenyan valley – Ex: counting spittle bug nests rather than the bugs – Ex: counting all the Robins in your backyard Science 7 Science 7 2 DETERMINING POPULATION SIZE DETERMINING POPULATION SIZE • 3. Sampling • 4. Mark and Recapture Studies – In most cases you cannot count every member of the – Researchers capture, tag and release a group of population animals in the environment – Sampling allows a researcher to count the number of – Later, they capture another group of organisms in organisms in a small area and multiply to find the the same area. number of organisms in a large area – If about ½ those caught are marked, then the first – If there are 25 deer in a 10 acre by 10 acre area, and group represented about ½ the population for that the forest is 100 times that size, there are species. approximately 2500 deer in the whole forest Science 7 Science 7 CHANGES IN POPULATION SIZE DETERMINING POPULATION SIZE • Populations change in size when new members enter the population or when members leave the population • Immigration and Emigration: • Birth Rate: – The number of births in a population in a certain – Immigration refers to the organisms which move into amount of time the population • Death Rate: – Emigration refers to the organisms which move out of the population – The number of deaths in a population in a certain amount of time Science 7 Science 7 POPULATION LIMITING FACTORS POPULATION LIMITING FACTORS • A limiting factor is an environmental factor • Food: that prevents a population from increasing – Organisms require food to survive • They determine the “carrying capacity” – When food is scarce, it of the environment becomes a limiting factor – Carrying Capacity: – If the environment cannot provide enough food for a • The largest population of a particular population, individuals organism that the environment can will be culled support Science 7 Science 7 3 POPULATION LIMITING FACTORS POPULATION LIMITING FACTORS • Space: • Weather: – Organisms require space – Temperature and to exist and reproduce precipitation limit – If a bird doesn’t have population growth room to nest, it will not – Ex: cold weather kills off reproduce, thus slowing insects limiting the population growth population – Plants need room to – Ex: frost or snow can ruin capture sunlight, if large a citrus crop trees block the sun, small – Ex: an early frost can kill plants will not thrive off your garden and the under them limit vegetable population Science 7 Science 7 HOMEWORK ADAPTING TO THE ENVIRONMENT • Page 28 • Natural Selection: – the way that changes which make organisms better suited to • Numbers 1-5 their environments occur • Use COMPLETE SENTENCES !!!!!!! • Adaptations: – The behavior and physical characteristics of a species that allows it to survive successfully in the environment • Niche: – An organism’s role or how it makes a living – Type of food, how it gets its food, what critters use the organism for food Science 7 Science 7 ORGANISM INTERACTIONS ORGANISM INTERACTIONS • Competition: • Predation: – The struggle between organisms to survive in a – When one organism kills and eats another habitat with limited resources • Predator: – Limited amounts of food, water, and shelter cause – Organism doing the killing organisms to be in conflict with each other • Prey: – Organism being killed and eaten Science 7 Science 7 4 EFFECT OF PREDATION ON A SYMBIOSIS POPULATION • An increase in predation, decreases the • A close relationship between two species population size that benefits at least one of them. • A decrease in predation, increases the population size – Ex: Moose and Wolves on Isle Royale, in Lake Superior • Moose pop. rose, Wolf pop. Rose • Moose pop. fell due to predation, wolf pop. fell due to lack of prey Science 7 Science 7 SYMBIOTIC RELATIONSHIPS SYMBIOTIC RELATIONSHIPS • Commensalisms: • Mutualism: – A relationship in which one species benefits and the – A relationship where BOTH species benefit other is neither helped nor harmed – Ex: – Ex: • Honey Bees and Dandelions • Robins building their nest in a maple tree – Honey bees use nectar for food, and dandelions get their – However: commensalism is rare in nature since one pollen spread from plant to plant or both of the organisms involved are either helped or harmed a little Science 7 Science 7 SYMBIOTIC RELATIONSHIPS SYMBIOTIC RELATIONSHIPS • Parasitism: – One organism lives on or inside another; thus • Parasitism Example: harming it – Deer Tick – Parasite: • The organism that benefits; lives on or in another organism – Host: • The organism that is harmed; is fed on by the parasite • Usually not killed because then the parasite loses its food source Science 7 Science 7 5 HOMEWORK CHAPTER 1 TEST • Populations • Communities • Page 38 • Biotic and Abiotic Factors • Questions 1-5 • Population Dynamics • Complete Sentences!!!!!!! • Limiting Factors • Adaptations • Interactions between Organisms Science 7 Science 7 ENERGY FLOW IN ECOSYSTEMS • Producers: – Organism that can make its own food ENVIRONMENTAL SCIENCE – These organisms are generally plants – Means of energy production is primarily, but not always photosynthesis Chapter 2 Ecosystems and Biomes Science 7 Science 7 ENERGY FLOW IN ECOSYSTEMS ENERGY FLOW IN ECOSYSTEMS • Consumers: • Decomposers: – Organisms which obtain energy by consuming other – Organisms that break organisms down wastes and dead – Herbivores: organisms to return raw • Consumers that eat plants materials to the – Carnivores: environment; RECYCLERS • Consumers that eat only other animals • Fungi: – Omnivores: – Molds and mushrooms • Consumers that eat both plants and animals • Bacteria: – Scavengers: – Single celled organisms • Carnivore that feeds on dead, decaying organisms Science 7 Science 7 6 FOOD CHAINS AND WEBS FOOD CHAINS AND WEBS • Food Chains: • Food Webs: – A series of events – 2 or more overlapping in which ONE food chains in an organism eats ecosystem another and – How 2 or more organisms obtains energy interact with their environment in terms of energy transfer Science 7 Science 7 ENERGY PYRAMIDS HOMEWORK • A diagram that shows the amount of energy that moves from one feeding level to another in a food web • Page 50 – Most energy is available at the producer level • Numbers 1-5 – At each higher level of the pyramid, less energy is • Complete Sentences!!!!! available than at the level below – Only about 10% of energy from one level is transferred to the next level Science 7 Science 7 CYCLES OF MATTER THE WATER CYCLE • Water Cycle: – A continuous process by which water moves from earth’s surface to the atmosphere and then back – Evaporation: • Process where liquid water, gains heat, and becomes water vapor (gas) – Condensation: • The process where water vapor loses heat, and becomes a liquid water droplets to form clouds – Precipitation: • Any form of water which falls to earth from the atmosphere Science 7 Science 7 7 THE CARBON/OXYGEN CYCLE THE NITROGEN CYCLE • These two cycles are • How Nitrogen moves through the linked – Produces use carbon environment from