Transcript Slide 1
Unit 2 Review Topics • • • • • Ecosystems- energy, food chains, webs Biomes (general, not specific) Nutrient cycles Succession and Eutrophication Biodiversity – Importance of – Threats to – How to protect Ecosystems • Producers, consumers • Who eats what? Herbivores, Omnivores and Carnivores • Trophic levels and energy- more energy at the bottom (plants) than top (predators) • Role of decomposers • Be able to read a food web/chain and identify trophic levels Biomes • • • • Difference between weather and climate Climate, altitude, latitude determine flora Plant life determines animal life Know the biome YOU live in Nutrient Cycles • Carbon, Nitrogen, Phosphorus- never run out, just continually cycle through earth systems • C-cycle: – Photosynthesis/Respiration: trades carbon between life and atmosphere – CO2 can be dissolved in surface waters and used by marine life – C can be stored in sediments to become future limestone or fossil fuels – Humans burning fossil fuels release more CO2 into atmosphere Nutrient Cycles • N-cycle – We cannot use atmospheric Nitrogen (N2 with a triple bond) – Nitrogen fixation converts N2 nitrates, ammonia which plants can use – N fixing bacteria do this in soils and roots of legumes – Denitrification: bacteria convert usable nitrogen back to N3 – Humans: fix nitrogen to make fertilizers Nutrient Cycles • P-cycle – Phosphates found in rocks – Weather and water dissolve phosphates in water for plants to uptake – Humans get P from plants and animals – Humans mine phosphates and use them as fertilizers Eutrophication • Succession happening too quickly in an aquatic ecosystem • Excessive N and P enter ecosystem, algae blooms • Decomposers eating dead algae use up all available oxygen • Lake/pond slowly suffocates life inside • Human influence: fertilizer runoff, animal waste, detergents Succession • The evolution of an ecosystem • Primary- no soil there before (bare rock) • Secondary- soil present, ecosystem disturbed • Pioneer species- first to colonize area • Climax community- end result, mature ecosystem • Takes a long time- 100-2000 years Biodiversity- Importance • Agriculture- need different crops in case one fails • Medical- untapped medicines in organisms yet to be researched/discovered • Ethical- all organisms deserve right to life • Aesthetic- variety is pleasing, beautiful, ecotourism • Ecosystem stability- remove one species, the whole system could collapse; everything’s important Biodiversity- Threats • Mass extinctions have happened naturally but humans are creating their own by – Habitat destruction and fragmentation – Introducing invasive species – Pollution – Over-hunting/harvesting – poaching Biodiversity- Protection • Saving a species: captive breeding, preserving genetic specimens, zoos • Ecosystem approach – Setting aside wilderness areas, nature preserves, national parks – Federal Laws: Wilderness Act, ESA – International treaties: CITES to help poaching and animal trade • Why don’t people care? –not a priority, unaware Species? • • • • • • Endemic- native; only found there Keystone- crucial to function of ecosystem Pioneer- colonizes landscape first Invasive- non-native, destructive Threatened- about to be endangered Endangered- about to be extinct Don’t forget... • • • • • Biodiversity Hotspot Socratic/Articles Case Study Parking Lot lab Biome project HW packet Trash Ball Review Game • 2 teams • Everyone has number on each team: 1A, 1B, 2A, 2B • Each person is asked a question individually • If correct, +1 point AND they can shoot trash ball into basket for extra points – Across room +3 – 6 feet away +1