The Study of

Ecology

The Study of Ecosystems

Chapter 47 The Biosphere

47�1 Earth: A Living Planet

Ecology

� “The study of the interactions of organisms with one another and their physical surroundings.”

� Biotic - living organisms� Plants, animals, fungi, micro-organisms

Abiotic – non-living factors� Abiotic – non-living factors�Water, soil, air, rocks, sunlight, weather

� Living vs. non-living vs. dead.

Biosphere� “The part of the Earth where life exists.”

� Biosphere includes:

�Atmosphere – Air

� Up to 8 kilometers above the surface� Up to 8 kilometers above the surface

�Hydrosphere – Water

� 70% of Earth Surface

�Lithosphere – Ground/surface

� Over 8 kilometers below the surface

Ecosystems

� “A given areas physical features [abiotic] and living

organisms [biotic].”

� Living things in an ecosystem are referred to as a

community.community.

� An ecosystem can be smaller than a drop of water.

Ecological Succession� The gradual change from one ecological community

to another.

� This process can take several decades to thousands of years.

� Stages of Succession

� The first organisms are called “pioneerpioneerpioneerpioneer” species.� The first organisms are called “pioneerpioneerpioneerpioneer” species.

� These are able to survive in the full sun.

� Next are various “intermediateintermediateintermediateintermediate” species.

� These survive in a mixture of sun and shade.

� Final stage is called “climaxclimaxclimaxclimax” species.

� These survive in shade in the early stages.

Wildlife Use of Various Stages of Land Cover Type

Old-field Succession Showing Changes of Vegetation and Wildlife

A Biome: An environment that has a

Biomes

A Biome: An environment that has a characteristic climax community.

47-2 Land Biomes

Two types: Land and Aquatic

Land Biomes are named for the dominant climax plant community

World Biomes

1. Tundra: Northernmost land Biome

�Nearly treeless, most trees are only 2 – 3 meters tall

�Migratory animals�Migratory animals�Elk, caribou, wolves, ptarmigan

�Permafrost – permanently frozen subsoil�Lots of stored carbon

2. Taiga: Coniferous Forest� Conifer trees [cone bearing]

� Spruce, pine, fir, redwood� Up to 60 meters tall

� Ground thaws in the summer � Ground thaws in the summer

although not for long in some places

� Many animals hibernate or migrate during the winter� Black bear, moose, grouse

3. Temperate Deciduous Forest� Plants that lose all their leaves in the fall

� Oak, maple, beech� The amount of leaf litter provides nutrients for future growth

� Changing seasonsTemperature and length of daylight trigger cells to harden and � Temperature and length of daylight trigger cells to harden and then leaves to drop; protection from water loss when ground is frozen

� A great variety of seed plants provide food for many species of animals

4. Grassland:

¼ of Earth’s land surface� Prairies, plains, savannas, pampas, steppes

� Two types – tropical and temperate� Tropical – close to the Equator : hot all year

� Varies from very wet to very dry

� Temperate – hot summers and cold winters� Great Plains

� Animals include herbivores and the carnivores that feed on them� Bison, wildebeests, wolves, lions

5. Tropical Rain Forest� Year-round temperatures above 250 C : 200 – 400 cm of rainfall

� Contain more species that all the rest of the land biomes combined

� Warm temperatures and wet conditions cause decomposition at a very fast rate. Rainforest soils are not very thick so tall plants must find ways to support themselves.

� Disappearing at a rate of 100 acres per second

6. Desert� Less than 25 cm of rainfall per year

� Two types : Hot and Cold

Plants and animals must endure the extremes� Plants and animals must endure the extremes� Cactus, Reptiles

47-3 Aquatic Biomes

Water Ecosystems :

Freshwater, Marine and EstuariesFreshwater, Marine and Estuaries

Factors Affecting Organisms in Aquatic EcosystemsFactors Affecting Organisms in Aquatic EcosystemsFactors Affecting Organisms in Aquatic EcosystemsFactors Affecting Organisms in Aquatic Ecosystems

� Light intensity – turbidity of water

� Dissolved Oxygen – cool water holds more

� Carbon Dioxide – reacts with other chemicals to change the pH

� Carbon – largest storage of Global Carbon on Earth� Carbon – largest storage of Global Carbon on Earth

� Availability of organic and inorganic nutrients� Nitrogen

� Phosphorus

� Potassium

� Sulfur

Freshwater Biomes

� Rivers, streams, creeks, ponds lakes

� Provide much of our drinking water

� Source of food

Marine Biomes� Cover 70% of Earth’s surface

� Photic Zone� Sunlight only penetrates so far, depending on water clarity.

� 30 meters in North Atlantic

� 200 meters in South Pacific� 200 meters in South Pacific

� Oceanographers divide the marine biomes into 4 ecologically distinct zones.� Depends on:

� Depth

� Distance from shore

1. Intertidal2. Neritic

3. Open-Sea 4. Deep-Sea

1. Intertidal

�Area from high to low tide on shore�Most difficult area to live

�Exposed to open air several times a day

�Wave action impacts�Wave action impacts

�Most impact from humans

�Adaptations of plants and animals?

2. Neritic

� From low tide line to edge of open-sea zone

�Sunlight can reach the bottom� Lots of plants – algae [seaweed]

� Then lots of animalsThen lots of animals

�Adaptations of plants and animals?

3. Open-Sea

� Top layers home to oxygen producing Phytoplankton�Nutrients are scarce

� Currents move nutrients from lower regions to regions near surface

� Adaptations of plants and animals?

4. Deep-Sea

� High pressure, low temperature, total darkness

� Thermal vents�Areas where volcanically heated water rises from opening �Areas where volcanically heated water rises from opening in the ocean floor

� Bacteria – Chemosynthesis

� Adaptation of plants and animals

Estuaries� Areas where fresh and salt water mix or where two chemically different fresh water mix

� Salt marshes, mouths of rivers flowing into the ocean

�Mouths of rivers flowing into large bodies of fresh water

� Extremely important because they serve as breeding and development grounds for young fish, invertebrates

� Act to mediate effects of storm surge during hurricane

� Sea level rise will profoundly impact this biome

47 – 4 Energy and Nutrients

Building the Web of Life

Energy� All living things on Earth depend on the Sun for their energy.

� Less than .1% is used by living things

About 1/2 of the energy plants absorb is used immediately� About 1/2 of the energy plants absorb is used immediately� The rest is stored as carbohydrates

� Animals that eat plants obtain that energy

Flow of Energy through an Ecosystem

� Begins with solar energy� < 1% of all of the Sun’s Energy striking the Earth is used by living things

� ½ of energy absorbed by plants is stored for use later in photosynthesis

� Then animals eat the plants to obtain their own energy or eat the Then animals eat the plants to obtain their own energy or eat the organisms that have eaten the plants

� When living things die their stored nutrients are broken down to be used again

� Energy flows through a system while nutrients are recycled

Flow of Energy

� Ultimate source of energy for ALL living things is the

� Producers – Plants, Algae, Phytoplankton� Living things that can make their own food

� Consumers –Animals, Zooplankton

Sun

� Consumers –Animals, Zooplankton� Living things that get their food from producers or other consumers

�Decomposers – Bacteria, Fungi� Living things that obtain their energy from non-living organic matter

� Each step is called a trophic or feeding level

The flow of energy� Producer - [Autotroph] makes own food and releases oxygen

� Photosynthesis � Photo [light] + Synthesis [to make food]

� Consumer - [Heterotroph] must grow or hunt own food� LevelsLevels

� Herbivore - plant eater� Carnivore - animal eater� Omnivore - plant and animal eater

� Decomposer - [Saprophyte] Breaks down plant and animal material� Recycle nutrients to be used again

� examples bacteria and fungus

Energy Transfer from level to level� Only 10% of the energy available is used by each succeeding level

� As energy passes up the trophic levels there is less and less available available

� Each level has a biomass which is the total mass of all living things in that level

Energy within an ecosystem

�Sun’s energy is stored in plants.

� Herbivores eat plants. Utilizing only 10% of the available energy [90% is released as wastes & heat]energy [90% is released as wastes & heat]

� Carnivores eat herbivores. Utilizing only 10% of the available energy [ therefore using only 1% of the available energy from the plants]

Ecological PyramidsPyramid of EnergyPyramid of EnergyPyramid of EnergyPyramid of Energy

Pyramid of BiomassPyramid of BiomassPyramid of BiomassPyramid of Biomass

Pyramid of NumbersPyramid of NumbersPyramid of NumbersPyramid of Numbers