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Unit 2 Lesson 7: Unit 2 Lesson 7: - Biodiversity - Endangered & Invasive Species Discussion - r & K selected species - Biodiversity Tree Game - Brown Bag Surprise Activity
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Lesson 7: Today’s Learning Targets I can identify characteristics of endangered and invasive species. I can explain the difference between r-selected and K-selected species Explain the importance of a keystone species I can explain what biodiversity means and the different types of biodiversity that exist.
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Biodiversity Tree Game Rules 1.Meet 3 other people in class and write their names on your card. 2.Stay standing (you are a tree). 3.Teacher = disease 4.“Dead tree falls” - reads out names on his/her card. 5.“Dead trees” who were called “fall” then they read names on their cards… 6.How many trees remain standing?
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Round 1 Douglas Fir Forest
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Biodiversity Tree Game Rules Round 2 1.Meet 3 other people in class and write their names on your card. 2.Stay standing (you are a tree). 3.Teacher = disease 4.“Dead tree falls” - reads out names on his/her card 5.“Dead trees” who were called “fall” only if you are the same species as the diseased tree! Then they read names on their cards… 6.How many trees remain standing?
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Round 2 Mixed forest
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Western DogwoodLodge Pole Pine Vine Maple Noble FirWestern White Pine Bigleaf Maple White FirWestern Red Cedar Western Hemlock
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Think about it… 1.What state do you think has the largest area of old-growth forest? Why? Alaska California Colorado Montana New Hampshire
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1930 - 2013
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2. What country do you think has the largest boreal forests? Brazil Chile Panama Russia United States Think about it…
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3. What country do you think has the largest deciduous forest? Brazil Chile Panama Russia United States
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Answer: United States of America
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Graded Assignment Homework – Graded Assignment Answer the questions associated with the biodiversity tree activity. Due ____
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What is the definition of endangered and invasive species?
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Endangered Species a species whose numbers are so small that the species is at risk of extinction
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Endangered Species – Think about it… What could cause the decline of a species? What can be done to slow or reverse the decline? What legislation has been enacted to protect endangered species? What might prevent an endangered species from rebounding quickly? What might some economic reasons to protect an endangered species? Ecological reasons?
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Invasive Species “an alien species whose introduction does or is likely to cause economic or environmental harm or harm to human health.”
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Human-Caused Reductions in Biodiversity Examples of Invasive Species – Eurasian milfoil – European green crab – Kudzu vine – Purple loosestrife – Zebra mussels Island ecosystems are particularly susceptible Example: New Zealand
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Invasive Species
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What is the difference between an r-selected and a K-selected species? (aka r-strategists & K-strategists)
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What do r and K stand for? r = intrinsic growth rateK = carrying capacity
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r-selected vs. K-selected species growth curves
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r-selected vs. K-selected species characteristics rK Unstable environment; density independent Stable environment; density dependent interactions Organism sizeSmallLarge Energy used to make each individual LowHigh Number of offspring produced ManyFew Timing of maturationEarlyLate (with much parental care) Life expectancyShortLong Lifetime reproductive events OnceMore than once
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Biodiversity
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Biodiversity of the Species Concept What is Biodiversity? – Genetic Diversity - measures variety of different versions of same genes within a species – Species Diversity - measures number of different kinds of organisms within a community – Ecological Diversity - measures richness and complexity of a community
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What is Species Diversity? – Species Richness - total number of species in a community – Species Evenness -relative abundance of individuals within each species
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What Are Species? Species definitions: – Reproductive isolation - organisms that breed in nature and produce fertile offspring – Phylogenetic species concept - emphasizes the cladistic relationships (branches on a taxonomic tree) – Evolutionary species concept – defines species in terms of evolutionary history
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Molecular Techniques DNA sequencing and other molecular techniques give insight into taxonomic and evolutionary relationships. – Genome - total DNA sequence that characterizes a species – Species classification or even identification of an individual can be done from samples such as blood, fur, or feces.
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Keystone Species Sometimes the loss of one species from a community can have a disproportionately large effect on the entire community. Keystone species play a role in its community that is far more important than its relative abundance might suggest. – Typically exist in low numbers – Could be predators, sources of food, mutualistic species or providers of other essential services
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Keystone Predator example (aka Predator-Mediated Competition)
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Other examples of Keystone Species A species that provides food for a community at times when food is scarce – Ex. plants that produce nectar and fruits (make up less than 1% of the plant diversity in the tropical forests of Central & South America) During a 3-month period when food is scarce for herbivores, they rely on the less abundant fruits and nectar for food, making those plants keystone species in that community
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Other examples of Keystone Species A species that is important because of its mutualistic interactions with other species – Ex. rare pollinator species in some communities, such as the flying fox bat found on South Pacific islands. It is the only pollinator and seed disperser for hundreds of tropical plant species. Unfortunately the flying foxes have been hunted for food to near extinction.
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Other examples of Keystone Species A species that maintains habitats for other species (ecosystem engineers) Ex. North American beaver only makes up a small percentage of the total biomass of the North American forest, but the dams they build convert narrow streams into large ponds, thereby creating new habitats for pond-adapted plants and animals.
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How Many Species Are There? 1.2 million species are catalogued. Latest biodiversity estimate: 8.7 million eukaryotic species (+/- 1.3 million) – Invertebrates make up 76% of all known species, and probably most of yet to be discovered species. Tropical rainforests and coral reefs are biodiversity hotspots. – 34 hotspots (1.4% of world’s land area) contain 75% of the world’s most threatened mammals, birds and amphibians.
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Biodiversity Hotspots
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Benefits of Biodiversity Food – Wild plants could provide new sources of food or more genetic diversity for existing crops. Drugs and Medicines – More than half of all prescriptions contain some natural product. – Pharmaceutical companies actively prospect tropical countries for products. – Resources often extracted without compensation (biopiracy). Sharing profits provides an incentive to preserve native species.
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Benefits of Biodiversity Ecological Benefits – Soil formation, waste disposal, air and water purification, nutrient cycling, solar energy absorption, and biogeochemical and hydrological cycles all depend on biodiversity. We do not fully understand biological communities. Loss of a seemingly insignificant species can be damaging.
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Benefits of Biodiversity Aesthetic and Cultural Benefits – Hunting, fishing, camping, hiking, etc. – USFWS estimates Americans spend $104 billion annually on wildlife-related recreation. – Ecotourism can be an important form of sustainable economic development. – Existence (intrinsic) value - organisms have value in and of themselves.
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Brown Bag Surprise Activity
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Interpreting Scientific Data Palau Island (north of Australia) Norfolk Island Seychelles Island Patagonia Galapagos Island
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Lesson 7: So can you…? I can identify characteristics of endangered and invasive species. I can explain the difference between r-selected and K-selected species Explain the importance of a keystone species I can explain what biodiversity means and the different types of biodiversity that exist.
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Unit 2 Lesson 8: Unit 2 Lesson 8: - Problems associated with biodiversity - Habitat fragementation
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Threats to Biodiversity Extinction - elimination of a species – Natural Causes In undisturbed ecosystems, background rate appears to be one species per decade. – In this century, human impacts have accelerated that rate, causing perhaps hundreds to thousands of extinctions annually.
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Natural Extinction Fossil record suggests more than 99% of all species ever in existence are now extinct. Periodically, the Earth has experienced 5 mass extinctions. Permian period - 95% of marine species and nearly half of all plant and animal families died out 250 million years ago. End of Cretaceous - Dinosaurs and 50% of existing genera disappeared 65 million years ago.
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What are some man-made impacts that have caused reductions in biodiversity?
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Accelerating Extinction Rates Humans are accelerating the natural extinction rates by 100x to 1000x. – If present trends continue, between 22% and 47% of all plants species will become extinct within 50 years. Animals dependent upon them would also become extinct. – This is equivalent to other mass extinctions like the Cretaceous extinction.
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Human-Caused Reductions in Biodiversity Acronym HIPPO summarizes the issues: Habitat destruction Invasive species Pollution Population Overharvesting
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Human-Caused Reductions in Biodiversity Habitat Destruction – Habitat loss = greatest cause of extinction Conversion of forest to farmland, cities, etc. – Only 1/5 of remaining forest is old growth. Loss of habitat due to mining, dams, destructive fishing practices Habitat is fragmented into small, scattered plots
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Human-Caused Reductions in Biodiversity Invasive Species – Invasive (exotic) organisms thrive in new territory where they are free of usual predators, diseases, or resource limitations that limited them in original habitat. Over past 300 years, approximately 50,000 non-native species have become established in the U.S. – At least 4,500 are free-living. » 15% cause environmental damage.
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Human-Caused Reductions in Biodiversity Commercial Products and Live Specimens – Wildlife smuggling is very profitable. Fur, horns, live specimens, folk medicine Leopard fur coat = $100,000 Mature cactus = $1,000 5 million wild birds sold worldwide each year – Additional 3 million caught but die before reaching market 128 million tropical fish sold annually in U.S.
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Human-Caused Reductions in Biodiversity Bush meat market - more than 1 million tons of wild animals are sold for human food annually. Cyanide fishing is killing reefs in the Philippines and Indonesia. Cyanide released above coral reefs to stun fish. A single diver can kill all life on 200 sq. meters of coral reef in one day.
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