Biodiversity andLimiting Factors

Chapt 5-2

Factors that cause population growth to decrease

Minnesota has 3 diverse biomes

Biodiversity

� The period since the emergence of humans an ongoing biodiversity reduction and an accompanying loss of genetic diversity. This is due to:– Hunting species to extinction– Introducing toxic chemicals into food

webs– Introducing a foreign species to a new

environment

Invasive Species

� http://www.youtube.com/watch?v=rJDVg35qPNs (4:21 minutes)

Biodiversity Health� Biodiversity boosts ecosystem productivity

where each species, no matter how small, all have an important role to play. For example:– A larger number of plant species means a greater

variety of crops– Greater species diversity ensures natural

sustainability for all life forms– Healthy ecosystems can better withstand and

recover from a variety of disasters.

Sustainability� Sustainability describes how biological

systems remain diverse, robust and productive over time, a necessary precondition for the well-being of humans and other organisms.

� Long-lived and healthy wetlands and forests are examples of sustainable biological systems.

Density Dependent Factors

� A limiting factor that depends on population size

� Limiting factors

Food supply

� Disease– Ex. Dutch Elm disease

� Stress– Predator-prey– Competition– Overcrowding

DENSITY INDEPENDENT

� Limiting factor that affects all populations in similar ways, regardless of population size

Examples: Natural disasters

Hurricane Katrina

Katrina Continued

More of Katrina

One more of Katrina

Density Independent

� Human Activities - damming, cutting forests, building roads

Things to study for the test

� Relationships within an environment– Biotic vs abiotic– symbiosis– Preditor-prey– Mutualism

– Commensalisms– Niches– Habitat– competition

� Levels of organization

- biosphere– Biomes– Ecosystem

– Community– Population– Organism/species

Test stuff

Cycles in Nature:– Atmosphere to soil (N2 - NO3) denitrification,

nitrification– Carbon Cycle Photosynthesis/ respiration (O2 - CO2)

– H2O Cycle– Phosphorus Cycle

More

� Populations graphs– Exponential– Logistic– Predator prey– Extinction

– 3 different possible phases on graphs

– Carrying capacity

� Limiting factors on populations– Density dependent– Density independent– Limiting factors

Biodiversity

Sustainability

resources

Big Arrow

� Trophic levels� Autotrophs� heterotrophs� Detrivore� Decomposer� Productivity� Food chain� Food web

� Immigration� Emigration� Omnivore� Carnivore� Herbivore� Natality� mortality

Partner Quiz

� 1. Autotrophs use light energy to power chemical reactions that convert CO2 and H2O into ____– A. water and carbohydrates

– B. oxygen and carbohydrates– C. energy and proteins– D. energy and fats