Presentation on theme: "Ecological Succession Ecosystems are constantly changing in response to natural and human disturbances."— Presentation transcript:
Ecological Succession Ecosystems are constantly changing in response to natural and human disturbances.
ecological succession: series of predictable changes that occur over time in an ecosystem in response to natural and human disturbances.
Primary Succession Succession that occurs on surfaces where no soil exists: Sides of volcanoes Rock after glaciers melts
PIONEER SPECIES: The first species to populate an area after Primary Succession. Usually lichen and can grow on rock Lichens: formed symbiotic relationship between fungus and algae and can grow on bare rock
Primary Succession Soil starts to form as lichens and the forces of weather and erosion help break down rocks into smaller pieces When lichens die, they decompose, adding small amounts of organic matter to the rock to make soil Simple plants like mosses and ferns can grow in the new soil
Mount St. Helens Case study
1 year later
5 years after 15 years after
25 years after
Secondary Succession succession that occurs following a disturbance that changes an existing community without removing the soil wildfires, clearing of land for agriculture or development, wind storms, lakes that dry up, etc. Pre-existing seeds will germinate to establish new plants.
Yellowstone Fire 1988
Immediately after fire
2 months after fire
1 year later
20 years later
Station Fire 2009: Chaparral Succession
Decomposition of a fallen log Primary or Secondary Succession?
Old- field Succession Occurs in farmland that has been abandoned Grasses and weeds grow quickly, and procede many seeds that cover large areas
Maintenance of Prairie Ecosystems Before: high fuel load During controlled burn Just 2 months later
Succession in a Marine Ecosystem Large whale dies and sinks to barren ocean floor. Attracts scavengers and decomposers. Within a year, most of the tissue has been eaten, the decomposition of the whale enriches the surrounding sediments. When only the skeleton remains, bacteria begin to decompose the bones.
The Role of Climate
What Is Climate? Weather is the day-to-day condition of Earth's atmosphere at a particular time and place. Climate refers to the average year-after- year conditions of temperature and precipitation in a particular region.
Climate is caused by: trapping of heat by the atmosphere latitude transport of heat by winds and ocean currents amount of precipitation shape and elevation of landmasses
The Greenhouse Effect Atmospheric gases that trap the heat energy of sunlight and maintain Earth's temperature range include: carbon dioxide (CO 2 ) Methane (CH 4 ) water vapor (H 2 O)
The Greenhouse Effect The natural situation in which heat is retained in Earths atmosphere by this layer of gases is called the greenhouse effect. Sunlight Earths Surface Atmosphere Some heat escapes into space Greenhouse gases trap some heat
Greenhouse Effect in a Car
The Effect of Latitude on Climate Solar radiation strikes different parts of Earths surface at an angle that varies throughout the year. At the equator, energy from the sun strikes Earth almost directly. At the North and South Poles, the suns rays strike Earths surface at a lower angle.
Making Climate Graphs Climate graphs show us the two factors in a climate: Temperature and Precipitation
Making Climate Graphs Lets look at two climate graphs The line graph is temperature The bar graph is precipitation
Making Climate Graphs Lets look at two climate graphs The y-axis on the left is for temperature The y-axis on the right is for precipitation
Making Climate Graphs What trends can we see on these graphs? 1.Cold winters, hot summers 1.Even precipitation (no rainy season) 1.Moose Factory, Ontario gets much colder in the winter than Chicago,IL