Ch.25 Nonliving Environment Ecology

Section 1: Abiotic Factors Learning Objectives Identify common abiotic factors in most ecosystems List the components of air that are needed for life Explain how climate influences life in an ecosystem

Section 1: Abiotic Factors A. Living or once living features are called biotic factors  Biotic means “living” Abiotic factors are nonliving physical features  Prefix a means “not”  Examples: Air, soil, water, sunlight, temperature, and climate

B. Atmosphere – the air that surrounds Earth  78% Nitrogen  21% Oxygen  1% Argon, Carbon Dioxide (0.35%), other gasses Carbon Dioxide – required for photosynthesis Oxygen – required for respiration

C. Water – the major ingredient of the fluid inside the cells of all organisms  Most organisms: 50-90% water  The more water in an environment, the more organisms found there, and the more diverse those organisms are

Life in a desert is limited to species that can survive for long periods of time without water Thousands of species can live in lush rain forests where rain falls almost every day

D. Soil – a mixture of mineral and rock particles, the remains of dead organisms, water, and air  Soil is considered abiotic – mostly nonliving.  However, soil does contain living organisms and (bacteria, fungi, insects, worms, etc.) and decaying organic matter (humus)

E. Sunlight – the source of energy for most life on Earth  During photosynthesis, producers convert light energy into chemical energy that is stored in sugar molecules.  Energy is passed on to consumers who eat producers

F. Most organisms’ body temperatures should stay within the range of 0°C to 50°C for survival (32 - 122°F)  Anything below 0°C (32°F) water freezes  Anything above 50°C (122°F) can start to cook  Humans: 37°C (98.6 °F)

Temperature abiotic factor that can affect an organisms survival The penguin has a thick layer of fat to hold in heat and keep the bird from freezing. These emperor penguins huddle together for added warmth.

Temperature abiotic factor that can affect an organisms survival The Arabian camel stores fat only in its hump. This way, the camel loses heat from other parts of its body, which helps is stay cool in the hot desert.

1. Temperature is affected by latitude  Areas closer to the equator are warmer than areas farther from the equator

2. Elevation – distance above sea level that affects temperature, wind, and soil  Higher elevations: thinner atmosphere, cooler temperatures  Timberline – beyond this point, trees do not grow

G. Climate – an area’s average weather conditions over time, including temperature, precipitation, and wind. 1. For most living things, temperature and precipitation are the two most important components of climate.

Fairbanks, Alaska vs. Key West, Florida  Fairbanks: winter temperatures may be as low as -52 °C (-61°F) with more than 1 meter of snow  Key West: snow never falls, winter temperatures rarely fall below 5 °C (41°F)

2. Heat energy from the Sun creates air currents called wind. Wind is created by the uneven heating of Earth’s surface

The Rain Shadow Effect

Section 2: Cycles in Nature A. Earth’s biosphere contains a fixed amount of water, carbon, nitrogen, oxygen, and other materials that cycle through the environment and are reused by different organisms.

B. Water cycle – how water moves from the Earth’s surface to the atmosphere and back to the surface again

1. Evaporation – when liquid water changes into water vapor and enters the atmosphere 2. Condensation – the process of changing water from a gas to a liquid 3. When water drops become large and heavy enough, they fall to the ground as rain or other precipitation.

C. Nitrogen cycle – the transfer of nitrogen from the atmosphere to the soil, to living organisms, and back to the atmosphere.

1. Nitrogen fixation – a process in which some types of soil bacteria can form the nitrogen compounds that plants need. 2. Farmers replace nitrogen in the soil by growing nitrogen-fixing crops or using fertilizers that contain nitrogen compounds that plants need for growth.

D. Carbon cycle – how carbon molecules move between the living and nonliving world 1. Producers remove carbon dioxide gas from the air during photosynthesis 2. Respiration – the chemical process that provides energy for cells

Carbon Cycle

Section 3: Energy Flow A. Matter can be recycled over and over again, but energy is converted from one form to another.

1. During photosynthesis, producers convert light energy to chemical energy. 2. Chemosynthesis – the production of energy-rich nutrient molecules from chemicals

b. Some producers, found near volcanic vents on the ocean floor, use inorganic molecules as energy sources for chemosynthesis. Sulfolobes – producer bacteria

Energy stored in the molecules of one organism is transferred to another when one organism becomes food for another organism. 1. Food chains – a simple way of showing how matter and energy pass from one organism to another.

2. Food web – shows all the possible feeding relationships among the organisms in a community

C. Energy pyramid – shows the amount of energy available at each feeding level in an ecosystem

Discussion Question What two processes do producers use to convert abiotic factors to energy?

Discussion Question What two processes do producers use to convert abiotic factors to energy? Photosynthesis (sunlight available) Chemosynthesis (no sunlight available)