Succession: Changes over time What would your backyard look like if you didn’t mow it or do anything to it? What would it look like in 5 years? 10 years? 20 years? First, grass gets taller and weeds grow... Then, bushes start growing, trees appear… Later, animals move in and everything grows… Years later, the area is a forest!

Ecologists refer to the orderly, natural changes and species replacements that take place in the communities of an ecosystem as succession.

Primary Succession colonization of new sites by communities of organisms Lava destroyed everything in this area. When it cooled, it formed new land. The first species in this area is called a pioneer species.

Secondary succession the sequence of community changes that occurs after the community is disrupted by natural disaster or human actions. There was a fire here several years ago. Several species are starting to grow back.

The difference between primary and secondary succession The difference between primary and secondary succession... Secondary succession occurs in areas that previously contained life and soil. In primary succession, everything is new, including the land and soil.

A climax community is a stable, mature community that undergoes little or no change.

Climate Change

Climate Change Climate change: significant, long-lasting changes in weather patterns Includes… Intensity of weather Number of severe weather events Regional or Global

Is Climate Change the same as Global Warming? No! Global warming contributes to climate change Warmer temperatures affect world weather patterns: Rainfall amounts Storms Droughts Sea Level

Greenhouse Gases Greenhouse Gases are naturally present in the Earth’s atmosphere GGs help maintain a “healthy” global temperature by trapping heat Greenhouse Gases: Water vapor (H2O) Carbon Dioxide (CO2) Methane (CH4) Nitrous Oxide (N2O) Ozone (O3)

Greenhouse Effect “The Greenhouse Effect”: the “trapping” of heat by greenhouse gases in the atmosphere The “trapped” warms the Earth Greenhouse Effect is NORMAL, but has been amplified by human production of CO2

How does it work?

Humans  CO2 Production  Global Warming  Climate Change The BIG Picture! Humans  CO2 Production  Global Warming  Climate Change

-OZONE (O3) -CFCS? -WHY DO WE NEED OZONE? So what is Ozone?! -OZONE (O3) -CFCS? -WHY DO WE NEED OZONE?

Before Global Warming

After Global Warming

VERY close to ocean Result of coastal erosion

So… Officials had to move Cape Hatteras Lighthouse 2,870 feet inland! 1999-2000

Peterman Glacier, Greenland

How have humans changed the Earth BESIDES contributing to global warming?

Soil Erosion Erosion = loss of soil due to wind and/or water Annual soil loss in South Africa is estimated at 300 - 400 million tons What prevents it? Plants Roots hold soil Plants slow down water SO, Deforestation and urban, unsustainable development is bad!

DESERTIFICATION Occurs in DRY climates Once fertile soils become deserts Caused by a combination of farming, drought, and overdrawing groundwater Video!

Overfishing Bycatch: organisms caught accidentally (as a Byproduct) Usually discarded Reduced biomass in trophic levels Habitat modification/destruction *Video!* (maybe later) Save me!

Pollution Examples: DDT; garbage island *video*

Acid Rain Caused by mixture of sulfur and nitrogen with water vapor in the atmosphere Can Affect: Plant life & soils Aquatic environments Statues

Acid RAIN in NORTH AMERICA

Biodiversity: the diversity of life The diversity of living species within a biome

What are some threats to biodiversity? Habitat changes, fragmentation, destruction Hunting species to endangerment or extinction Introducing toxic substances into food webs (pollution) Introducing foreign species into environments (invasive species)