Presentation on theme: "Ecology Unit- part 2 Modified by Beth Roland Jacobs Fork Middle School."— Presentation transcript:
Ecology Unit- part 2 Modified by Beth Roland Jacobs Fork Middle School
All living organisms need certain elements/compounds for life processes –Ex: your cells need Carbon,Hydrogen,Oxygen,Phosphorus,Nitrogen & Sulfur in order to live and reproduce (make more cells) Cycles in nature keep these elements moving from organisms to organism (and sometimes into the atmosphere) Biogeochemical Cycles (Matter moving through the environment)
The flow of a nutrient from the environment to living organisms and back to the environment Main reservoir for the nutrient is in the environment Transfer rates to and from reservoir are usually lower than the rates of exchange between and among organisms. Matter is recycled through an ecosystem – not one way flow
Three Categories Hydrologic cycle –Water Atmospheric cycles –Nitrogen and carbon Sedimentary cycles –Phosphorus and sulfur
Carbon in the Oceans Most carbon in the ocean is dissolved carbonate and bicarbonate Ocean currents carry dissolved carbon
Carbon in Atmosphere Atmospheric carbon is mainly carbon dioxide Carbon dioxide is added to atmosphere –Aerobic respiration, volcanic action, burning fossil fuels, decomposition of organic materials Removed by photosynthesis
Nitrogen Cycle Nitrogen is used in amino acids and nucleic acids (all living organism need nitrogen to make proteins) Main reservoir is nitrogen gas in the atmosphere Decomposers are vital to convert ammonia into: 1. usable nitrites & nitrates for plants (nitrogen fixation) 2. nitrogen gas (denitrification = puts it back into the atmosphere)
Phosphorus Cycle Phosphorus is part of phospholipids and all nucleotides –What are these? The basis of all DNA and cell membranes It is the most prevalent limiting factor in ecosystems Main reservoir is Earths crust; no gaseous phase (it never enters the atmosphere – like carbon and nitrogen)
Phosphorus Cycle GUANO FERTILIZER ROCKS LAND FOOD WEBS DISSOLVED IN OCEAN WATER MARINE FOOD WEBS MARINE SEDIMENTS excretion weathering mining agriculture uptake by autotrophs death, decomposition sedimentationsetting out leaching, runoff weathering uplifting over geolgic time DISSOLVED IN SOILWATER, LAKES, RIVERS uptake by autotrophs death, decomposition
Chapter 3 – Communities & Biomes Vocabulary to Know: –Limiting Factor –Succession Primary Secondary –Climax Community
Community All the populations that live together in a habitat Habitat is the type of place where individuals of a species typically live Type of habitat shapes a communitys structure
Biogeography The study of the distribution of organisms and the processes that underlie distribution patterns
Factors that Affect Distribution Geologic history Topography Climate Species interactions
Climate Average weather condition in a region Affected by: –amount of incoming solar radiation –prevailing winds –elevation
Rotation and Wind Direction Earth rotates faster under the air at the equator than it does at the poles Deflection east and west
Seasonal Variation Northern end of Earths axis tilts toward sun in June and away in December Difference in tilt causes differences in sunlight intensity and day length The greater the distance from the equator, the more pronounced the seasonal changes
Ocean Currents Upper waters move in currents that distribute nutrients and affect regional climates
Rain Shadow Air rises on the windward side, loses moisture before passing over the mountain
Biomes Regions of land characterized by habitat conditions and community structure Distinctive biomes prevail at certain latitudes and elevations
Chapter 5: Diversity & Conservation Importance to nature Importance to people –Oxygen –Diet –Medicines
Loss of Diversity Threatened Species Endangered Species Extinction of Species
Threats to Biodiversity Habitat Loss Habitat Fragmentation –Biotic Issues –Abiotic Issues Habitat Degradation –Air Pollution –Water Pollution –Land Pollution
Exotic Species Non-native organisms that move-in to a particular area There can be a lack of competitors = exponential growth Can take over the niches of native species Example: Page 124
Conservation Sustainable use: –Use what you need, but dont damage the ecosystem Is this a good example of sustainable use?
Humans & The Environment Ozone (O 3 ) Depletion –O 3 forms a good layer around the Earth –CFC release is breaking down the protective ozone layer –UV rays increase skin cancers & other cell mutations to plants & animals!
How is Acidity Measured? When we observe acid rain, acidity is measured in units called pH. The pH scale is from 0 to 14 –pH 7 indicates neutral –higher pH numbers = alkalinity (base) –smaller numbers = acid Well do more on pH in the Biochemistry chapter
Natural Acid Precipitation CO 2 combines with water to form a weak acid H 2 CO 3 (carbonic acid) But we are adding to the problem… –by adding nitric and sulfuric acids Look at the clean rain – its already slightly acidic???
Effects of Acid Precipitation In Japan, rain which registers pH 5.6 or less is considered acid rain; some 80-90% of the rain that falls in Japan in a year is acid rain. In Japan, acid rain with acidity equal to lemon juice has been observed at Mount Tsukuba in 1984 (pH 2.5) and at Kagoshima in 1987 (pH 2.45). The problem is even more serious in North America and Europe. In those regions, forests are withering and lakes becoming uninhabitable to fish, and stone structures such as buildings and bronze statues are being damaged by corrosion. 19701985
Humans & The Environment Global Warming –The Greenhouse Effect –Fossil fuels give off lots of CO 2 –This builds a blanket around the earth –It is predicted that the Earth temp. will increase ~5 0 C before 2050 = Ice age????
Carbon Dioxide Increase Carbon dioxide levels fluctuate seasonally The average level is steadily increasing Burning of fossil fuels & deforestation are contributing to the increase
Greenhouse Effect Greenhouse gases impede the escape of heat from Earths surface