Introductory Ecology
Defined Ecology is the study of the interactions between living organisms and the living (biotic ) and non-living (abiotic) components of the ecosystem
Questions Imagine that you are an ecologist. What is the most general ecological statement of fact that you can make? What is a more specific ecological statement that you can make regarding life on Earth?
Examples of Abiotic Factors Sunlight Oxygen Rocks & Minerals Climate Humidity Lightning Gravity Water Elevation Temperature Topography Wind
The Most Important Abiotic Factors SUNLIGHT WATER
Earth’s Tilt & The Sun The distribution and intensity of sunlight is dependent on the tilt of Earth’s axis and its position relative to the Sun during its annual revolution Due to latitudinal difference seasons are apparent in the temperate mid-latitudes
Seasons Autumnal or Fall Equinox (September) suns rays directly over the Equator Winter Solstice (December) suns rays directly over the Tropic of Capricorn Vernal or Spring Equinox (March) suns rays directly over the Equator Summer Solstice (June) suns rays directly over the Tropic of Cancer
Air Currents & Moisture at the Equator Sunlight at the equator cause warm moist air to rise In the upper atmosphere much of this moist air cools, condenses, and falls as rain, while the remaining dried air is diverted north and south The diverted dry air descends at 30o north and south This circulation is called a Hadley Cell
Hadley Cells
Biomes Major types of terrestrial ecosystems that cover large regions of Earth What biomes are determine by the Hadley cells? What happens between these biomes during the course of an annual circuit around the sun?
The Distribution of Other Biomes Biome are characterized by the climate (sunlight and moisture) and the major type(s) vegetation that have adapted to that climate
Temperature & Moisture Gradients Tundra Coniferous Forest Desert Grassland Deciduous Forest Tropical
Biome Vegetation Tundra Grasses, small wildflowers, cushion plants, and lichen Coniferous Forest Evergreen Needle bearing Trees Desert Cactus Grassland Grasses Deciduous Forest Broadleaf Trees that lose their leaves Tropical Forest Broadleaf Evergreen Trees