5/3 Agenda Deforestation: human impact, photosynthesis, energy transfer, primary productivity, biodiversity Turn in: Practice cladogram questions Homework: 1. Transformation Video and Notes 2. Transformation FRQ practice question

Deforestation Overview Deforestation: destroying trees/plants, usually in reference to rainforests or large areas of trees Human impact: Humans are cutting down trees for a variety of reasons Farming Agriculture Developments Increase in human population plays a role Less trees=less photosynthesis-->High CO2, lower O2 Primary Productivity is lower Less Energy/Food Available for Primary Consumers Throws a whole ecosystem out of balance

Deforestation

Human Impact Humans are the reasons for deforestation There are a variety of reasons that deforestation happens This is just one example of human impacts on the environment As the human population increases, the impact on the environment also increases

Population Growth Exponential vs. Logistic Carrying capacity exists for all populations At the most basic, population growth equals births minus deaths The equations get more complicated once growth rates and carrying capacity are accounted for

Population Growth Equations

Biodiversity Ecosystems with a high amount of biodiversity are more stable More likely to survive fluctuations in the environment or natural disasters Deforestation is one example of how biodiversity decreases Can also decrease by invasive species or extinction Causes a snowball effect If one food source dies off, whatever eats is may also die off, and so on and so on Keystone species play a major role in food webs and ecosystem balance

Energy Transfer The amount of available energy decreases as you go up in trophic level At each level, the organism uses the majority of the energy for life processes, so only about 10% is available to be passed on to the next consumer Remember that energy is never destroyed, just transferred into different forms As deforestation destroys trees, that leaves less energy and food for primary consumers, which can affect the whole food chain

Primary Productivity Gross primary production= amount of chemical energy plants produce in a given time Net primary productivity= GPP– energy used in cellular respiration NPP is the amount of energy left over for consumers This can be thought of as biomass added to the plant (glucose)

Group Review Assignment Pick Two Topics: Human impact Population Growth Biodiversity Energy Transfer Primary Productivity Ecosystems Overall Create 1 review resource for each topic Concept maps Practice problems Quizlets Flashcards Posters Storybook Diagrams/Pictures Example calculation Share your review resources with your group by the end of class Theses will be graded as a classwork grade.