AN INTRODUCTION TO ECOLOGY AND THE BIOSPHERE

I am the Lorax.I speak for the trees.I speak for the trees, for the trees have no tongues.

Interactions between organisms and the Interactions between organisms and the environment limit the distribution of speciesenvironment limit the distribution of species

Ecology the study of the interactions between organisms and their

environments Involves biotic and abiotic factors of the environment

Biotic factors Living All organisms that are part of an individual’s environment

Abiotic factors Nonliving Chemical and physical factors Temperature, soil, climate patterns, water, sunlight, salinity

Ecology is studied on many different levels of organization

Organism ecology how an organism’s structure, physiology, and behavior meets

challenges posed by its environment Population ecology

analyzes factors that affect population size and how and why it changes through time

Community ecology examines how interactions between species affect community

structure and organization Systems ecology

emphasizes energy flow and chemical cycling between organisms and the environment

Biome Major type of

ecosystem that occupies a very broad geographic region.

Rocks, Soil pH, mineral composition, and physical

structure of rocks and soil affect plant growth and nutrient needs of animals

Disturbances volcanoes, hurricanes, floods, fires can

wipe out biological communities and create completely new ecosystems

Climate Major components Temperature Precipitation Sunlight Wind

Climate Macroclimates

patterns Global, regional,

local Microclimates

Small-scale environmental variations

Under a log

Aquatic Biomes are diverse and dynamic systems that cover most of the Earth

Make up the largest part of the biosphere (75% of the earth’s surface)

Two major types Fresh water Marine

All aquatic biomes display vertical stratification

Aquatic biomes Vertical stratification Photic Zone

light penetration photosynthesis

Aphotic zone very little or no light

Benthic Zone Bottom Sand, inorganic matter

and organic sediments Detritus~ dead organic

matter; food for benthic organisms

Thermocline Narrow layers of fast temperature change that separate a warm upper layer

of water and cold deeper waters. Thermal stratification~ vertical temperature layering Biannual mixing~ spring and summer Turnover~ changing water temperature profiles; brings oxygenated water from the surface to the

bottom and nutrient rich water form the bottom to the surface

Freshwater biomes Two types

Standing Lakes and wetlands

Moving Rivers and streams.

Estuary area where freshwater

merges with ocean Current

Prominent physical attribute Great diversity of organisms

in vertical zones and from headwaters to mouth

Freshwater biomes Littoral zone Shallow, well-lit, close to

shore Rooted and floating aquatic

plants Limnetic zone

Open surface water, farther from shore

Phytoplankton Profundal zone

Deep, aphotic

Freshwater biomes Lake classification Oligotrophic

Deep water Nutrient poor, oxygen

rich Eutrophic

Shallow water Nutrient rich, oxygen

poor

Mari

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bi

omes

Intertidal zone~ area where land meets water

Neritic zone~ shallow regions over continental shelves

Pelagic zone~ open water of any depth Benthic zone~ seafloor bottom Abyssal zone~ benthic region in deep

oceans Coral Reef ~ cnidarians that secrete hard

calcium carbonate shells, which vary in shape and support the growth of other corals, sponges and algae.

Terrestrial biomes Climate largely determines the distribution

and structure of terrestrial biomes

Terrestrial biomes Precipitation and temperature are the driving

forces

Terrestrial biomes Tropical forests

Pronounced vertical stratification. Canopy is so dense that little light breaks through. Forests are marked by epiphytes. Rainfall varies. Greatest biodiversity of all terrestrial biomes

Savanna Grasses with few trees Dominant herbivores are insects Fire is a dominant abiotic factor.

Many plants are adapted to fire Two Seasons – rainy and dry

Plant growth heavy during rainy season Animals migrate Drought

Terrestrial biomes Temperate deciduous (broad-

leaf) forest Dense stands of deciduaous trees

that require sufficient moisture More open and not as tall as

rainforest Stratified

Top layer –trees-one or two layers Shrubs Herbaceous stratum

Trees drop leaves in fall Many mammals hibernate Many birds migrate to warmer

climes

Terrestrial biomes Chaparral

Dominated by dense, spiny, evergreen shrubs

Coastal areas Mild rainy winters Long hot dry summers Plants are adapted to fires

Temperate grassland Seasonal drought Occasional fires Large grazing mammals These factors prevent significant

growth of trees Soil is rich in nutrients

Good agricultural areas

Terrestrial biomes Desert

Sparse rainfall Plants and animals are adapted to

conserve and store water Temperature extreme – both hot and cold Contain many CAM plants and plants with

adaptations that prevent animals from consuming them such a spines on cactus.

A plant that utilizes the Crassulacean acid (CAM) as an adaptation for arid conditions. CO2 entering the stomata during the night is converted into organic acids, which release CO2 for the Calvin cycle during the day, when the stomata are closed.

Terrestrial biomes Tundra

Permafrost – permanently frozen layer of soil

Very cold temperature High winds Little rainfall No trees or tall plants About 20% of the earth’s

surface

Terrestrial biomes Coniferous forest – Boreal forest -

Taiga Cone bearing trees

Pine Spruce Fir

The conical shape of conifers prevents much snowfall from accumulating on the tree branches

Long cold winters Short summers

Be A Tree Hugger