Take a seat, Get out your PENCIL! On your desk you should only have a… – – Pencil Four Papers to be checked in this order on a pile on the top of your desk. – Mark Return Recapture Lab Carrying Capacity Lab Mini Webquest Note Sheet Carrying Capacity Worksheet I will check these during your quiz Changes to Populations 4 factors that effect the size of a population Increase Population – – Decrease Population – – 1) Birth 2) Immigration (entering a population) 3) Death 4) Emigration (leaving a population) See if you can create an equation using these 4 terms for Population Growth, Population Decrease, Population Stability Is the population increasing or decreasing? Populations Increase: – Population Remains Stable: – When Immigration + Births > Death + Emigration When Immigration + Births = Death + Emigration: Populations Decrease: – When Immigration + Births < Death + Emigration What are Limiting Factors? Anything that prevents the growth of a population What would happen without limiting factors? Carrying Capacity (k) The maximum population a species can maintain in a certain area without damaging the ecosystem. Population can stabilize at K What happens when a population goes above carrying capacity? Populations can crash if #s go above K 29 introduced in 1944 More than 6,000 by 1963 Down to 42 Seasonal Fluctuations What will happen with World Population? Everybody Out of Their Seats Go to the back of the room… You are all the population of deer in PA. Lets progress through the year, and test the effects of limiting factors on a population. Ideally we will have 5 deer at the end of the year before breeding. Limiting Factor #1: Space Territorial Animals need a large amount of space. Loss of Habitat causes the decline of many species. Who took my towel? Loss of Space/Habitat Example: Bluebirds Loss of trees/wooden posts caused a huge decline Between 1935-1985 numbers declined by 90% Limiting Factor #2 Food and Water Leads to death via dehydration, starvation Some animals will emigrate Organisms that rely on one type of food are severely affected Food and Water Example: Snowshoe Hare and Lynx Limiting Factor #3: Climate and Weather Temperature changes can affect plants and animals Floods and storms can cause death & destruction of habitat Climate Changes Example: Mosquito Populations Mosquitoes breed in standing water Rainfall creates puddles of standing water Temperature Changes: Coffee Habitat Impact of Temperature Rise on Robusta Coffee in Uganda. *Developing countries, whose economies often rely heavily on one or two agricultural products, are especially vulnerable to climate change. *This graphic shows that With an increase of only 2 degrees Celsius, there would be a dramatic decrease in the amount of land suitable for growing Robusta coffee in Uganda. Limiting Factor #4: Cover Protection from predators Protection from weather Cover Example: Ruffed Grouse Ruffed Grouse- Requires brushy forests for cover and food. Most of Pa’s forest were logged (cut down) 80 to 100 years ago. They grew into brushy forest allowing grouse populations to increase. Forests are now maturing reducing cover and food causing populations to decline. Land development has also reduced populations Limiting Factor #5: Increase Predation An increase in the number of predators to an area will impact prey species. Predation Example: House Cats! Predicted that in one year house cats kill 1 billion songbirds! Limiting Factor #6: Disease Spread quickly through high density populations Can devastate populations with low genetic diversity Disease: West Nile Virus Mosquito born disease 5,697 crows reported dead in NYS in 1999 White Nose Syndrome Fungus that has killed over one million bats 90-100% of some species of hibernating bats are in danger of being killed. Limiting Factor #7: Light Plants that cannot tolerate too much or too little light can be affected Light Example: Tree Growth and Shade Aspen Pine Poplar = intolerant, will dominate young forests Beech, Fir, Hemlock, Maple = tolerant will dominate older forests Limiting Factor #8: Human Presence Close proximity to humans causes some species to emigrate Other species thrive Reflection Think of an example where an organism does not have enough limiting factors. What is the organism, how does this affect the habitat around that organism? Changes in Population Competition Limiting factors lead to competition among organisms for available resources A loss in a limiting factor can contribute to a decline in populations Increased due to exotic species Exotic Species- Introduced species not native or endemic to the area in question.