Population Ecology Population Density is the number of

Population Ecology

Population Density is the number of organisms per unit of area

Things that affect a Population’s Size (LIMITING FACTORS) Density-Dependent Limiting Factors Density-Independent Factors Competition Weather Predation Fires Parasitism Droughts/ Floods Crowding/Stress Human Activities BIOTIC (living) ABIOTIC (non-living)

Predation – what happened to the moose population as the wolf population increased?

Population Growth Rate, Emigration, Immigration, Exponential Growth, Logistic Growth, Carrying Capacity

Population Growth Rate • Definition – explains how a population grows • Formula to calculate growth rate Births – Deaths = Growth Rate Time

Factors Effecting Growth Rate of a Population • Natality – number of births • Mortality – number of deaths • Emigration – leaving or exiting a population • Immigration – moving into a population

Types of Growth in a Population • Logistic – population level balances out – Births = deaths and/ or… – Emigration = immigration

Types of Growth in a Population • Exponential – Births > Deaths and/ or… – Emigration < Immigration

Carrying Capacity • Definition – Maximum number of individuals in a species that an environment can support for the long term.

Carrying Capacity

What type of growth is this?

Human Population Growth Rate

Animal Adaptations • Behavior – Inherited • Instincts/ Reflexes • Territorial • Migration – Learned • Habituation • Imprinting • Defense – Mechanical – Chemical

Instinctive Behavior

Territorial Behavior

Migration

Hibernation and Estivation

Cryptic Coloration

Disruptive Color-shading

Counter-shading

Chemical Defenses

Plants adapt to their environment • Thorns – To stop animals from eating them • Thick stems and leaves – To hold water • Shape – Hold water, attract insects • Smell – Attract and Deter • Bright Colors – Attract and Deter • Creative Seeds – To be carried by animals, water or wind

Sweet Gum Tree – Seed Pods

Maple Trees – helicopter seeds

Dandelions

Piture Plant

Bromelliad

Cactus

Succulent

Fragrant Flowers

Brightly-colored Flowers

Geotropism - helps the roots grow down and the stems to grow up

Phototropism • Growth of a plant towards sunlight

Thigmotropism – plant’s response to touch – could be due to GROWTH, SEED DISPERSAL, FOOD, PROTECTION

Impatiens capensis https: //www. youtube. com/watch? v=w. O 8 -el. YLjd 4

Plant Hormones • Hormone (chemical messenger that plants use to control growth in response to their environment) – Auxin – regulates phototropism by stimulating the elongation of cells; keeps fruit from dropping – Giberellin – growth hormone that causes a plant to grow taller and increases the rate of seed germination and budding – Ethelyene - causes fruit to ripen