Succession Succession – the orderly natural changes and species replacements that take place in...
-
Upload
theodora-cox -
Category
Documents
-
view
215 -
download
0
Transcript of Succession Succession – the orderly natural changes and species replacements that take place in...
Succession
• Succession – the orderly natural changes and species replacements that take place in the communities of an ecosystem
• Takes a long time, not easily observable
• Occurs in stages
Primary Succession
• From a disturbance, such as rocks moving to expose new soil starts Primary succession.
• Pioneer species set up such as mosses and lichens
• As these species die, they create soil for further species
• Shrubs, ferns, grasses come next
• Pines, beeches and maples colonize after that
• When the community stabilizes, a climax community is established– How can you tell?
Secondary Succession
• Occurs when interrupted by natural disasters or human actions
• Occurs in areas that previously contained life and soil.
• Pioneer species maybe different since the soil is already present
• Occurs by the same process as primary succession.
• Takes less time– Why?
Biomes
• Ecosystems that have similar kinds of climax communities are called Biomes.
• Biomes are limited by temperature and precipitation (terrestrial types)
• There are two major types of biomes– Aquatic (those in the water, sea) (3/4 of the
Earth)– Terrestrial (those on land)
Marine Biomes
• Estuary – coastal body of water, in part surrounded by land where freshwater and saltwater mix.
• Scientists separate marine biomes into two parts:– Photic Zone : portion of the
biome shallow enough to allow light through
• Plankton, juvenile marine organisms
– Aphotic zone : deeper water where light cannot penetrate
• Adapted to life in the dark.
Terrestrial Biomes - Tundra
• Tundra – Circles the poles, treeless with long summer days and short periods of winter sunlight
• Under the topsoil is a frozen part called permafrost.
• Soil is nutrient poor and can’t hold larger plants & trees
• Small mammals live there like owls and lemmings
Taiga
• Taiga – just south of the tundra
• Warmer than the Tundra, land of fir & spruce trees
• Canada, Northern Europe & Asia
• Contains larger species like Caribou, snowshoe hare
Desert
• Desert – driest biome with sparse plant life
• Less than 25 cm of precipitation
• Organisms have adapted to conserve water (mice, scorpions, snakes, owls, etc)
Grassland
• Grasslands – covered by grasses and similarly small plants
• 25 – 75 cm of precipitation
• Occupies more area than any other land biome
• Good for growing crops• Dominated by grazing
animals (bison)
Temperate Forest
• Temperate Forest – above and below the equator
• Nutrient rich soil with Hardwood trees
• 70 to 150 cm of precipitation
• Home to many forest animals (bears, squirrels, salamanders)
Tropical Rain Forest
• Tropical Rain Forest – located at the equator
• Warm and wet with lush plant growth
• Average 25C, with 200-600 cm of rain
• Home to the most amount of species on the planet
• Has many niches due to the layers of the rainforest (forest floor, trees, canopy, etc)