- Slides: 85
Ecology Biosphere Energy Pyramid Ecosystems Populations
Your Habitat • Think about every organism that you encounter around school and your home. Make a list (include plant, insects, humans, pets, etc. ) • Create a diagram that shows how the organisms interact with each other.
Think about it • Classify: Which organisms on your list provide energy or nutrients to others? • Predict what would happen if all the plants in your diagram died. Explain your answer. • Why is it difficult to accurately predict changes in communities or organisms?
Ecology • Ecology is the study of interactions of organisms within their natural habitat. • What factors affect a habitat? • Abiotic factors: non-living. Sunlight, rocks, water, etc. • Biotic factors: living interactions, food web, carbon cycle, competition, symbiosis, etc
Levels of Organization • Individual Organism • Species: a group of similar organisms that can breed and produce fertile offspring – Horse + donkey = mule (non-fertile) • Population: a group of individuals of the same species that live in the same geographic region • Community: a collection of different populations that live in the same geographic region
Levels of Organization (continued) • Ecosystem: all of the organisms living in a specific place (biotic) together with their physical (abiotic) environment • Biome: a group of ecosystems with the same climate and similar dominant communities • Biosphere: the part of the planet (including land, water, and air) where all life exsists
Biosphere • The entire Earth is a balanced system. What affects one area can impacts all over the world. Can you list some global ecological situations? • Global Warming (greenhouse gases) • Ozone Layer (pollution using CFC’s) • Gulf Oil Spill • Rain Forest depletion (Amazon)
Rubippy Molecule (converts water + sunlight into Energy) What molecule is this synthetic for?
Energy Flow • Where does all energy for the Earth originate from? • Energy flows through an Ecosystem in only one direction (not recycled) • DIRECTION: Sun (or inorganic compounds) to autotrophs to heterotrophs
Autotrophs • Autotrophs start any energy pyramid as they are able to convert sun (light) or chemical energy into stored energy such as carbohydrates. – Photosynthesis: process of using light energy to convert carbon dioxide and water vapor into simple sugars and O 2 (CO 2 + H 2 O = C 6 H 12 O 6 + O 2) – Chemosynthesis: process of converting chemical energy by controlling chemical reactions to produce stored energy
Autotrophs • Give 3 examples of important types of organisms that represent producers • Plants • Phytoplankton • Bacteria
Heterotrophs • Heterotrophs = consumers: rely on other organisms for food – Herbivores get energy from eating only plants – Carnivores get energy from eating only animals – Omnivores get energy from eating both plants and animals – Detritivores feed off the remains (dead matter) or wastes of other organisms – Decomposers break down organic matter
• Food Chain shows how living things transfer energy by eating and being eaten. • A Food Web links together all of the food chains in an ecosystem • Each step in a food chain or food web is called a Trophic Level. – Producers are the first (bottom) trophic level – Consumers make up higher trophic levels • Energy Rule Only 10% of the energy available at one trophic level is passed to the organisms at the next trophic level
Ecological Pyramids • Energy Pyramids: energy available at each trophic level • Biomass Pyramids: amount of living tissue (living mass) at each trophic level • Pyramid of numbers: number of individual organisms at each trophic level.
Cycles of Matter • Energy and Matter flow through the biosphere differently – Energy flows in ONE DIRECTION – Matter is RECYCLED • Biogeochemical cycles move matter (carbon, nitrogen, water) through the biosphere. • All living things require water to survive
Water Cycle • Water is recycled. However, water can take various forms from liquid, to solid, to gas. – Percipitation – Condensation – Evaporation – Transpiration
Carbon Cycle • What organisms are responsible for taking carbon out of the air and converting it to organic material? • What type of organisms breakdown dead organic material into basic elements? • What are some examples of processes that put carbon (CO 2) into the air? (greenhouse effect)
Ecosystem • What is part of an ecosystem? • Two main keys of an ecosystem: biotic and abiotic factors determine the survival of an organism and the productivity of the ecosystem in which an organism lives. • Habitat is where an organism lives • Niche is an organism’s role in the environment
Relationships • Competition for resources (food, water, space) – What happens if two different species occupy the same niche in an environment? • Predation: one organism (predator) eats another organism (prey) • Symbiosis: organisms that live together – Mutualism - both species benefit – Commensalism – one species benefits and the other is neither helped or harmed – Parasitism – one species benefits (parasite) and the other is harmed (host)
Role of Climate • Environmental factors (atmosphere, temperature, precipitation) combine to produce weather and climate. – What is the difference between weather and climate? • Weather – day to day conditions of the Earth’s atmosphere • Climate – average yearly condition of temperature and precipitation in a region
Climate continued • What are the two main gases that are responsible for maintaining the Earth’s temperature range? – Explain the process (what is the process called? ) • Which one affects climate, Latitude or Longitude?
Climate Zones • What affects climate? • • Sunlight (latitude) Ocean Currents (proximity) Wind Currents Topography
• Class A: Tropical • Temperature of the coldest month: > 18°C. This the climate where the most water- and heat-demanding crops (e. g. for instance oilpalm and rubber) are grown. The climate is also ideal for yams, cassava, maize, rice, bananas and sugarcane. Sub-classes are: • Af - No dry season, at least 60 mm of rainfall in the driest month Am - Monsoon type. Short dry season but sufficient moisture to keep ground wet throughout the year. Aw - Distinct dry season. One month with precipitation < 60 mm. i - Isothermal subtype. Annual range of temperature < 5°C
• Class B: Sub-Tropical • Arid regions where annual evaporation exceeds annual precipitation. Even the wettest variants of this climate are characterized by a marked dry season. The climate is, therefore, mostly unsuitable for the crops that require yearround moisture. The main crops are usually millet, sorghum and groundnuts. Sunshine is usually high, which leads to high productivity where a sufficiently long rainy season or irrigation ensure a sufficient water supply: rice, sugarcane and maize are also common crops under this climate. • The two main subclasses refer to the dominant vegetation types: BS (steppe climate) and BW (desert). They are further subdivided as h subtype (subtropical desert with average temperature > 18°C), k subtype (cool dry climate of the middle latitude deserts), and k' (temperature of the warmest month < 18 °C).
• Class C: Temperate • Average temperature of the coldest month < 18°C and > -3°C , and average temperature of warmest month >10°C. The main crops are the temperate cereals such as wheat, barley and Irish (white) potatoes. An important variant of this climate is the Mediterranean climate, characterized by the olive tree, and also very suitable for grapes. The main subdivisions include: • Cw - Winter dry season. At least 10 times as much precipitation in wettest month of summer as in driest month of winter Cs - Summer dry season. At least three times as much rain in wettest month of winter as in driest month of summer, the latter having less than 30 mm precipitation. Cf - At least 30 mm precipitation in the driest month, difference between wettest month and driest month less than for Cw and Cs • Additional qualifiers are a (hot summer, average temperature of warmest month > 22°C), b (cool summer, average temperature of warmest month < 22°C) and c (cool - short summer less than four months >10°C). Note that the "raw" temperate climate extends into what is actually BS and BW, as the "Dry" B type is superposed on the other types where only temperature is used to define the climate.
• Class D: Polar • Average temperature of the warmest month > 10°C and that of coldest month < -3°C. This climate grows essentially the same crops as the temperate climate, but seasons tend to be shorter and limited at the beginning and end by frost. • This climate type comprises mainly the Df subtype (at least 30 mm of rain in the driest month, difference between wettest month and driest month less than for Cw and Cs) and Dw (winter dry season - at least 10 times as much precipitation in wettest month of summer as in driest month of winter). Other codes used are: a (hot summer, average temperature of warmest month > 22°C), b (cool summer, average temperature of warmest month < 22°C), c (cool, short summer less than four months > 10°C) and d (average temperature of coldest month < 38°C).
What you really need • Tropical – most rainfall (typically all year), no distinct seasons, nearest to the equator, jungle type vegetation. Warmest average climate. 0 -30 degrees Latitude • Temperate – distinct seasons, seasonal rainfall, everything else is middle of the road. 30 -60 degrees Latitude. Vegetation includes more grains, potatoes, grasses, etc • Polar – coldest average climate, extreme seasons, lowest average rainfall, 60 -90 degrees latitude. Same crops as temperate, but shorter growing seasons.
• What do you get at the border of the tropical and temperate zones? Why? • Subtropical zone = deserts due to low moisture because of air currents.
Succession • What type of organism is the first to repopulate an area after a natural disaster or new formation? (Volcanic eruption, melting glacier) • Algae and fungi (lichens). Why? • What organisms are responsible for secondary succession? What essential material is needed for this to happen?
Populations • Example: The common jackrabbit reproduces every year. Assume a pair of rabbits produce an average of 6 offspring per litter (3 male and 3 female). Assume it takes 1 year for the new generation of rabbits to be able to reproduce. How many rabbits will there be in 1 year? 5 years? 7 years? 10 years? 20? (assuming no rabbits die) • Construct a graph (Population vs Time) to show your results.
Using Results • Why is the Earth not covered in rabbits? • As the rabbit population increases, what would be the impact of the plant population in their habitat? • As the rabbit population decreased due to lack of plants (food), what would happen to the plant population? Why?
Factors that affect population • Geographic distribution: range or area in which a specific population lives • Population Density: number of individuals per unit area (people per square kilometer) • What affects population density?
Population Growth • Growth rate: How quickly a population increases or decreases in size. • Factors: – Birth rate (amount per litter, infancy survival rate) – Death rate (what factors control death rates? ) – Number of organisms migrating in (immigration) or out (emigration) of a habitat
Infancy Mortality Rate
Exponential growth • Go back to the rabbit example. Now examine bacteria. Certain bacteria can reproduce every 24 minutes. How many bacteria will there be in one day (assume no bacteria die)? • Under ideal conditions a population will grow exponentially (unlimited resources) • What controls exponential growth in nature? – Lack of resources (resources are used up) – predators – disease
Logistic Growth • S shaped curve • Occurs when a population growth slows or stops. (levels out) • This is called carrying capacity. The population size where growth stops or the number of individuals of a specific species a given environment can support.
Limits to growth • Limiting factors: anything that slows population growth • Two kinds of limiting factors • 1) Density-dependent limiting factors rely on population size. – Competition – occurs when organisms are using the same ecological resource at the same time – Disease – Predator – prey relationships can affect the population size of both predator and prey – Amount of resources available
Limiting factors • Density-independent limiting factors: – Natural disasters – flood, earthquake, volcano – Human activities – damming rivers, roads, construction, etc – Both cause drastic drops in population size
Basic construction of a Fuel Cell