Unit 6 Organisms and the Environment 2013 - 2014.

Unit 6Organisms and the Environment

2013 - 2014

Definitions:

• Abiotic - a nonliving condition or thing that influences or affects an ecosystem.

• Biotic - a living thing like a plant or an animal, something that was alive or something that has the potential for life that influences or affects an ecosystem

• Primary Succession - the development of plant and animal communities over time in an area where no soil had existed

• Secondary Succession - the development of plant and animal communities over time in an area where there was a disturbance but the soil was still present

• Ecological Succession - the gradual replacement of one type of ecological community by another in the same area over time

• Climax Community – an ecological community where plant and animal populations remain stable and exist in balance.

Definitions:

• Environment – the biotic and abiotic surroundings or conditions in which a person, plant or animal lives or operates.

• Habitat - the area or environment where an organism or ecological community normally lives or occurs

• Microhabitat – a small, specialized environment such as a schoolyard or a clump of grass

• Population - a group of individuals of the same species that live together in the same area at the same time

• Species - a group of organisms that share common attributes and have the same name

• Surface Water – water found on the surface of the earth, such as rivers, streams, lakes, creeks, etc.

• Groundwater - water found beneath the surface of the earth (underground) it is supplied by run-off. It is the source of water in springs and wells.

• Porosity – the measure of a rock’s ability to hold water

• Permeability – is a measure of the ease with which water can move through a porous rock.

Definitions:

• Sustainability - a method of harvesting or using a resource so that the resource is not depleted or permanently damaged.

• Biodiversity - the interaction between living and nonliving organisms, how they are different and how they relate to each other in their natural habitat

Give 3 examples of pioneer species and identify them for

Primary or Secondary Succession

• Primary Succession - Lichens, mosses

• Secondary Succession - Weeds, grasses and wildflowers

For primary successionorder these: • Rock

• Lichens/Bacteria• Wildflowers• Shrubs• Pine trees • Hardwood trees• Forest

For secondary succession

order these:

• Crabgrass• Horseweeds• Shrubs• Pine trees • Pine forest• Hardwood trees

Answer the following questions:

• What is the goal of ecological succession?

Equilibrium

2. List the steps in primary succession.

After a geologic event, bare rock is exposed to the environment.

Stage 1:

• Pioneer organisms, such as lichens, are the first to inhabit the area.

• Lichens give off acid, which breaks the rock down into soil.

Stage 2:

• Once a small amount of soil is present, moss may start to grow on in the area.

• As moss dies and decays, organic matter is added to to soil.

• The soil progressively

becomes thicker and

contains more

nutrients.

Stage 3: • Ferns begin to grow. As they die

they are decomposed and added to the soil.

• Weeds, wildflowers and grasses will start to grow when the soil is thick enough.

• As grasses and weeds die, they are decomposed and added to the soil.

Stage 4:

• When soil is thick enough, bushes and small trees will start to grow.

• Pine trees are the first type of trees to grow in an area since they

require less water and fewer soil nutrients.

Stage 5:

• When the soil becomes rich enough, deciduous trees start to grow.

• Deciduous trees have the ability to grow taller than pine trees.

• Leaves fall each year and decompose to add nutrients to the soil.

• After a period of time, deciduous trees take over the area since they grow taller and have better ability to get light energy for photosynthesis.

Climax Forest - The End of Succession

• Eventually a mature temperate deciduous forest

forms.

• Wild flowers and

small shrubs

adapted to living

with low amounts

of light may grow

on the forest floor.

3. List the steps in secondary succession.

Occurs in areas where there was a disturbance, soil is exposed to the environment.

Steps:

• Because soil is present, weeds will first start to grow.

Grasses and wildflowers will follow the weeds.

• Then shrubs and small trees will begin to grow.

• Pine trees and then deciduous trees will grow.

• Eventually a climax forest will regrow.

4. How does biodiversity affect the sustainability of an ecosystem?

• The more biodiversity in an ecosystem, the more

sustainable it is.

• More (Higher) biodiversity = more sustainability• Less (Lower) biodiversity = less sustainability

The more biodiverse an ecosystem means there are a greater variety of species and the ecosystem is better able to carry out natural processes in the face of external stress.

5. What are three negative effects excess (TOO MUCH) fertilizer can have on the environment?

Too much fertilizer isn’t helpful! It just runs off in the next rain….

• runs off into the watershed and pollutes the

water• aquatic plants like algae will be overstimulated

with results like algae bloom• causes respiratory diseases in animals and

people who drink contaminated water

6. What are some of the effects on a community if it uses more groundwater than it replaces?

Overuse of groundwater can cause wells to dry up. This can lead to expensive and often futile attempts to keep up with the dropping water table by drilling deeper and deeper wells.

When too much water is withdrawn from the ground, the land can collapse, a process called subsidence. When groundwater fills spaces in the soil, it supplies part of the internal strength of the ground. When the water is removed, leaving openings filled only with air, the weight of the overlying earth compacts and crushes the spaces.

In this photograph of California's San Joaquin Valley, the dates on the pole mark the former heights of the ground. In the span of 50 years, water pumping for irrigation led to nearly 30 feet of subsidence.

Removing too much groundwater can leave underground holes, leading to sinkholes

A sinkhole opened in the middle of a Florida highway, near a residential area in 2004

http://youtu.be/ZEvCP7TXIEU

The sinkhole appeared in downtown Guatemala City,

swallowing a three-story building

7. List 3 ways humans negatively impact groundwater. Describe the effects.

• Over fertilization of crops can lead to runoff and seepage into groundwater supplies, polluting the water

• Litter and trash – pollute surface and groundwater supplies

• Overuse of ground water – removing too much ground water can lead to sink holes and subsidence, as well as deplete the resource

8. List 2 ways an area can be disrupted to

the point that secondary succession will occur.

• Natural disruption–Fire, Floods, Tsunamis, Tornadoes, etc.

• Human disruption– Building a shopping mall, house, road– Mining– Farming

9. Draw and label the steps of the water cycle.