Environmental Studies Grade 10 Biosphere to Ecosystems PDF

Environmental Studies Grade 10 Biosphere to Ecosystems Gr 10 Enviro Studies - Abiotic 1  I N T R O Some of these will be covered in Gr 11 + 12. Gr 10 Enviro Studies - Abiotic 2 10 Plant...

Environmental Studies Grade 10 Biosphere to Ecosystems Gr 10 Enviro Studies - Abiotic 1  I N T R O Some of these will be covered in Gr 11 + 12. Gr 10 Enviro Studies - Abiotic 2 10 Plant Tissues 3  Our Environmental Studies for Gr10: Environmental Studies Factors affecting Ecotourism & Biosphere Energy Flow Nutrient Cycles Biomes of SA ecosystems Human Impact Abiotic factors Trophic levels (sl. 15) ECOSYSTEM STUDY Food chains & Biotic factors webs Gr 10 Enviro Studies - Abiotic 10  Connect to this link. Biosphere online exercise Work through the information. Complete the “Practice” excrcise. Slideserve/Introd to Ecology 10 Plant Tissues 11 10 Plant Tissues 12  Abiotic Factors What do we mean by “Factors”? a circumstance, fact, or influence that contributes to a result; A component contributing to the overall outcome. Abiotic Factors: non-living chemical and physical parts of the environment that affect living organisms and the functioning of ecosystems. Gr 10 Enviro Studies - Abiotic 13  Abiotic Factors Divided into: 1. Physiographic factors - position and orientation of the land. 2. Edaphic Factors - soil related. 3. Physical Factors - Light, water, temperature etc. We will look at these one at a time and their various components: A diagrammatic view:... Gr 10 Enviro Studies - Abiotic 14  Latitude Aspect Orientation N/S Physiographic Gradient Elevation Soil pH Humus content ABIOTIC Edaphic factors Texture FACTORS Soil Air Amount of light Sunlight Day/night length Temperature Physical Water Enviro studies layout: Atmospheric Sl. 10 gases Gr 10 Enviro Studies - Abiotic Fire 15  Light and Radiant Energy Radiant energy from the sun sustains a constant inflow of energy to sustain life on earth. Some of this is converted to chemical energy by photosynthesis by the producers. It is also a source of heat: When the light strikes a surface, some of the light energy is absorbed and converted to heat. The amount of light will thus affect the rate of photosynthesis and the amount of heat. Gr 10 Enviro Studies - Abiotic 16  Light and Radiant Energy – Physiographic The amount of energy received by a surface is thus affected by the physiographic nature of the land: 1. Aspect – the geographical direction that the slope faces. 2. Latitude – where on the earth’s surface in relation to the poles and equator that the land is found. Gr 10 Enviro Studies - Abiotic 17  Abiotic Factors – Physiographic – 1. Aspect The sun will heat one side of a hill more than the side facing away from the sun. If there is more sunlight it will be: Warmer Drier In the southern hemisphere the sun will be mostly from the north. The yellow beams represent identical amounts of solar radiation, or energy. The red areas of the mountain slope show how much of the slope that heating energy is spread out over. eoas.ubc.ca Gr 10 Enviro Studies - Abiotic 18  Abiotic Factors - Physiographic Slopes in the Southern Hemisphere. 1. Aspect When we look at something we can only see it from our own aspect. In geography, the direction a slope faces – the side of a landform facing a particular direction. In the Southern Hemisphere, sun is predominantly from the ? Effects? Gr 10 Enviro Studies - Abiotic 19 Aspect of the terrain North Gr 10 Enviro Studies - Abiotic 20  Effect of Aspect on vegetation Which side of the hills gets the most sun? If this were the Southern hemisphere, would that slope face north or south? https://commons.wikimedia.org/wiki/File:Effects_of_aspect_on_vegetation-_SW_Idaho.JPG Gr 10 Enviro Studies - Abiotic 21 The effect of latitude on insolation In a similar way, the further the land is from the equator, the more ‘sloped’ the land will be in relation to the sun. 10 Plant Tissues 22 A similar effect happens depending on your latitude, and hemisphere. This phenomenon only happens in Hawaii (not really) – Physics Girl (4:00) 10 Plant Tissues 23  Abiotic Factors - Physiographic 2. Slope inclination / gradient Increases rate of run-off of rainfall Steeper: Faster the water flow, the bigger particles it can carry. à thinner soil, thus … à few plants thus … à fewer animals. Gr 10 Enviro Studies - Abiotic 24  Abiotic Factors - Physiographic 3. Altitude / Elevation At elevations below 10km: At higher altitudes... a) Temperature – decreases with altitude b) Precipitation - colder, often more + more regular at higher altitude. c) Air pressure (thus also O2)decreases with altitude. How will these effects affect biodiversity? Gr 10 Enviro Studies - Abiotic 25  1 atm = 760 mmHg = 1,01325 bar = 101,325 kpa Source: How does altitude affect the body and why does it affect... Gr 10 Enviro Studies - Abiotic 26  Seasons – for interest Seasons (5:38) Earth Rocks! Stop the video when indicated to answer the questions. Gr 10 Enviro Studies - Abiotic 27  Position Aspect Orientation N/S Physiographic Slope Elevation Soil pH Humus content ABIOTIC Edaphic factors Texture FACTORS Soil Air Amount of light Sunlight Day/night length Temperature Physical Water Atmospheric gases Gr 10 Enviro Studies - Abiotic Fire 28  Abiotic Factors - Edaphic Factors affecting: 1. pH of the soil - eg Hydrangea colour affected by pH. 2. Plants are specific in what pH range they will grow. If specific plants will only grow in a soil of specific pH, how will that affect the animals that are there? Gr 10 Enviro Studies - Abiotic 29  Abiotic Factors - Edaphic 2. Humus content - how much organic matter is present. (not hummus – ground chickpeas + flavourings) Gr 10 Enviro Studies - Abiotic 30  Abiotic Factors - Edaphic 2. Humus content - how much organic matter is present. The humus content is composed of dead and decaying plant & animal matter. Benefits: Recycle nutrients (by means of the decomposers) Keep soil aerated by allowing gaps between particles - oxygen availability. Thus better drainage - prevents compaction. Increases surface area of the soil, thus as a sponge to hold water. Gr 10 Enviro Studies - Abiotic 31  Abiotic Factors - Edaphic 3. Texture Grain size and relative proportions. Grain size determine air and water holding capabilities. a) Sandy soils - large particles Allows drainage, thus… (How much water retained?) Low water retention. Gr 10 Enviro Studies - Abiotic 32 Gr 10 Enviro Studies - Abiotic 33  Abiotic Factors - Edaphic b) Clay Soils Very fine particles High water retention, thus Poor drainage May become waterlogged. Gr 10 Enviro Studies - Abiotic 34  Abiotic Factors - Edaphic c) Loam soils Good mixture of sand and clay. Plants do well, thus usually high humus content as well. 1. Holds some water, but has… 2. Sufficient drainage, and also 3. Allows air penetration Gr 10 Enviro Studies - Abiotic 35  Abiotic Factors - Edaphic 4. Soil Air This is the air filling the spaces between the particles that is not occupied by water. Amount of air depends on particle size. The more air, the more oxygen reaches the roots. Experimentally we can remove the water by heating it. Gr 10 Enviro Studies - Abiotic 36  Position Aspect Orientation N/S Physiographic Slope Elevation Soil pH Humus content ABIOTIC Edaphic factors Texture FACTORS Soil Air Amount of light Sunlight Day/night length Temperature Physical Water Atmospheric gases Gr 10 Enviro Studies - Abiotic Fire 37 Abiotic Factors - Physical 1. Sunlight 1. Sun is the source of (almost) all energy on the earth. 2. Photosynthesis and thus the biota are dependent on it. 3. Light is converted to heat when striking an object. What are the environmental implications of these aspects of light? 1. The supply of energy is constant and constantly replaces the energy lost to space and heat. 2. Photosynthesis keeps the O2 and CO2 levels balanced. 3. The heat is balanced by the greenhouse effect and keeps our planet from being a snowball. Gr 10 Enviro Studies - Abiotic 38  Abiotic Factors - Physical 1. Sunlight – the effects on an ecosystem are determined by: A) Amount of light. Each plant has different light needs / tolerance. Eg. Shade plants vs Aloes. Humans need for vitamin D (assists with absorption of calcium) – minimum 10 min/d. Gr 10 Enviro Studies - Abiotic 39  Abiotic Factors - Physical 1. Sunlight B) Day/night length. Plants respond to the sun in different ways. - Photoperiodism - the response of an organism to day/night length. Flowering, fruit set, seed germination, etc may all be influenced by the length of the day or night. Gr 10 Enviro Studies - Abiotic 40  Terminology: Animals active / flowers open in the day? Diurnal o from diū (“by day”) (e.g. diary – story of your day) o urnus, an adjectival suffix denoting time. Active at night? o nocturnal. o from Latin nox (“night”) Active at dusk or dawn? o Crepuscular (like leopard geckos…) o From creper (“dusky, dark”) Gr 10 Enviro Studies - Abiotic 41  Abiotic Factors - Physical 2. Temperature Plants and animals will have a variety of adaptations to different amounts of environmental heat. Some examples of adaptations to variation in temperature: A) Poikilothermic animals depend on heat from their environment to maintain metabolic functions. E.g. reptiles, fish, insects. In the absence of sufficient heat, they do not move. Greek poikilos ‘variegated, varied’. Those with a constant body temperature are called homoiothermic. Gr 10 Enviro Studies - Abiotic 42  Abiotic Factors - Physical If the temp changes by season: B) Migration is stimulated either by temperature change or day length. E.g. swallows moving between the Northern and Southern hemisphere summers. Gr 10 Enviro Studies - Abiotic 43  Abiotic Factors - Physical... Seasonal changes. Hibernation is used by some animals to escape the cold in winter. Snails, some frogs, escape a hot dry summer (lack of water) by aestivation. - remaining in a state of torpor / dormancy: Gr 10 Enviro Studies - Abiotic 44  Abiotic Factors - Physical... Seasonal changes. C) Dormancy. A period of no growth by plants when it is cold. Some may lose their above ground growth and regrow from the roots, (many herbs, grasses). Grass that has gone dormant in a dry winter period. Gr 10 Enviro Studies - Abiotic 45  Abiotic Factors - Physical... Seasonal changes. D) Deciduous habit - shedding leaves to avoid maintaining them in a period of reduced metabolic activity. For some a bulb or tuber only remains - onion, potato. Gr 10 Enviro Studies - Abiotic 46  What are the abiotic physical factors so far?... 1. Sunlight 2. Temperature Those coming up... 3. Water 4. Atmospheric gases 5. Fire Gr 10 Enviro Studies - Abiotic 47  Abiotic Factors - Physical 3. Water Plants are often specific about the amount of water they can live with. E.g. Mesophytes, rain forests, Xerophytes (plants in dry areas) xeros "dry, withered”) Gr 10 Enviro Studies - Abiotic 49 Abiotic Factors - Physical 3. Water Most animals lose water through sweat, panting, excretion, breathing. Very dependent on continual water availability. Gr 10 Enviro Studies - Abiotic 50  Abiotic Factors - Physical Some have adaptation to conserve water, eg: Reptiles: Dry skins (no sweat) Concentrated urine Burrowing in the heat. Nocturnal - out of heat during the day. Gr 10 Enviro Studies - Abiotic 51  Abiotic Factors - Physical How do plants get or conserve water? Plants get water from the soil, Lose it by transpiration __?__ Need a constant supply to get nutrients to the photosynthetic regions. Plants’ adaptations may a) conserve what water they have – ie. prevent water loss, or b) Allow for obtaining any water that may be available. Gr 10 Enviro Studies - Abiotic 52  Abiotic Factors - Physical a) Plant adaptations to conserve water. Most plants will have some adaptations to control water loss. Examples: Waxy cuticle – prevent water loss Gr 10 Enviro Studies - Abiotic 53  Abiotic Factors - Physical a) Plant adaptations to conserve water. Most plants will have some adaptations to control water loss. Examples: Dead leaves These may: Form a blanket to 1. Keep moisture in, or 2. Keep the soil cool to reduce evaporation. Gr 10 Enviro Studies - Abiotic 54  Abiotic Factors - Physical a) Plant adaptations to conserve water. Most plants will have some adaptations to control water loss. Examples: Leaves modified to thorns. Gr 10 Enviro Studies - Abiotic 55  Abiotic Factors - Physical a) Plant adaptations to conserve water. Most plants will have some adaptations to control water loss. Examples: Succulent leaves - water storage. Gr 10 Enviro Studies - Abiotic 56  Abiotic Factors - Physical a) Plant adaptations to conserve water. Most plants will have some adaptations to control water loss. Examples: Small leaves to reduce surface area. Gr 10 Enviro Studies - Abiotic 57  Abiotic Factors - Physical b) Plant adaptations to obtain water. Plants may also have a root system adapted to maximise water uptake: Shallow roots to collect surface precipitation. Gr 10 Enviro Studies - Abiotic 58  Abiotic Factors - Physical b) Plant adaptations to obtain water. Plants may also have a root system adapted to maximise water uptake: Tap root to reach deep water sources Gr 10 Enviro Studies - Abiotic 59 Gr 10 Enviro Studies - Abiotic 60  Abiotic Factors - Physical Hydrophytes must cope with high water environment Floating leaves - trapped air Kariba weed Salvinia molesta Gr 10 Enviro Studies - Abiotic 61  Abiotic Factors - Physical Hydrophytes must cope with high water environment Air spaces amongst the cells E.g. water lily leaf. Note very limited xylem, No cuticle. Gr 10 Enviro Studies - Abiotic 62  What are the abiotic physical components? 1. Sunlight 2. Temperature 3. Water 4. Atmospheric gases 5. Fire Gr 10 Enviro Studies - Abiotic 63  Abiotic Factors - Physical - Air 4. Atmospheric gases The main gases of air are: Oxygen O2 Needed by ‘all’ life for cellular respiration. (definition?)= chemical breakdown of (Respiration molecules to release energy; = Oxidation) (not anaerobes which are first forms of life on earth) O2 produced by process called … Photosynthesis Maintained at 21% of atmosphere – by plants, algae, cyanobacteria. UCAR SciEd Gr 10 Enviro Studies - Abiotic 64  Abiotic Factors - Physical - Air Carbon Dioxide CO2 Produced during respiration Used during photosynthesis to make glucose. Atmospheric level should be 0,035% Gr 10 Enviro Studies - Abiotic 65  Abiotic Factors - Physical - Air Nitrogen N2 Biologically unusable as N2 gas. Bacteria (Nitrobacter) convert to usable oxides NO2 Needed by plants for protein synthesis. 78% in the atmosphere Gr 10 Enviro Studies - Abiotic 66  Abiotic Factors - Physical - Air Water Vapour H2O Released by transpiration and evaporation Condense in the atmosphere and forms precipitation. Gr 10 Enviro Studies - Abiotic 67  Abiotic Factors - Physical - Air Wind Moving air. Caused by differences in air pressure around the globe, or Differences in heat on a local level. Wind increases transpiration. Used for flight, seed & pollen dispersal. Gr 10 Enviro Studies - Abiotic 68  Abiotic Factors - Physical - Fire Fire Source: Wikipedia An important part of the ecology of fynbos, savanna and grassland ecology. Removes accumulated vegetation and leaf litter that may prevent a light rain reaching the soil, or shade the soil to keep it too cold. Prevent other species from germinating. Gr 10 Enviro Studies - Abiotic 69  Abiotic Factors - Physical - Fire Abiotic responses to fire: (has beneficial and deleterious effects) Burning strips the plants of leaves and smaller branches. Transpiration is reduced (no leaves), thus more moisture in the soil. Soil is exposed to the sun (warming, or desiccation) Exposes soil to water erosion, but also allows water to soak in more. Loss of organic matter means nutrients may be lost to the ecosystem, but minerals left behind in the ash become more available. Gr 10 Enviro Studies - Abiotic 70  Abiotic Factors - Physical - Fire Biotic responses to fire: Some seeds are stimulated to germinate by fire / smoke / intense heat. Access of the sun to the soil will stimulate some seeds to germinate because of light. Gr 10 Enviro Studies - Abiotic 71  Abiotic Factors - Physical - Fire Response of different biomes: Savanna plants will produce new nutritious growth (replacing old unpalatable tougher species) after a fire, attracting herbivores. These more palatable tracts allow for the overgrazed favoured species to recover. Grasslands burn more readily than shrub or forest ecosystems, and move quickly burning leaves and stems, but minimally affecting the soil. This is important for recycling nutrients in grasslands. Gr 10 Enviro Studies - Abiotic 72  Abiotic Factors - Physical - Fire Fynbos has co-evolved with fire: The soil is poor, and fire is prevalent, so investment in surviving roots is inefficient. Plants thus become obligate seeders. Seeding allows for the parent plant to die but leave a rich deposit of seeds that o Germinate after a fire o May be buried by insects (ants) Gr 10 Enviro Studies - Abiotic 73  What are the abiotic physical factors so far?... 1. Sunlight 2. Temperature 3. Water 4. Atmospheric gases 5. Fire Now complete your mind map of Physical components with all the parts. Gr 10 Enviro Studies - Abiotic 74