MATERIALS:
·         Flowering plant
·         Gloves
·         Hand shovel

BACKGROUND

An environment refers to the surroundings of an area.  Environments are different from place to place, and change with time.  Within environments you have different parameters that allow ecosystems to maintain themselves.  In order to restore or to make an environment friendly again to native species, environmentalists need to understand the entire ecosystem. 

Although the media talks about chemicals being harmful to our environment they fail to point out that chemicals make-up everything.  There are good and bad chemicals depending on how specific organisms react to them.  What is good for one species might be harmful to other species.  Chemicals can "control" an environment, and can also influence organisms that live in that specific environment.

Major land and aquatic ecosystems require the following components in order to be maintained.

1.    Sunlight - the ultimate source of energy for primary producers, controls a photochemical process

2.    Inorganic substances - carbon, nitrogen, oxygen, minerals, and water

3.    Organic compounds - fats, proteins, carbohydrates

4.    Climate or weather - wind, water currents, temperature, rain, snow, and humidity

5.    Producers - autotrophic organisms for most part green plants, that capture sunlight, convert energy into organic nutrients, and release oxygen

6.    Macroconsumers - heterotrophic organisms, animals for the most part that eat other organisms or organic matter

7.    Microconsumers - decomposer organisms, largely bacteria and fungi that break down the  organic components of dead organisms

The life cycle of a plant varies depending on the individual species. There are, however, certain requirements for life that most plants need. The growth of a plant is dependent upon light, water, oxygen, carbon dioxide, minerals in the soil, temperature and microbes in the soil. Light, water, and carbon dioxide are needed for photosynthesis which produces food for the plant. Oxygen is needed when it is dark, because the plant then needs oxygen to maintain itself. The correct temperature, soil, and minerals are all needed when the plant first germinates and subsequently grows. Soil helps bind the roots so the plant can anchor itself. Microbes in the soil include a number that are beneficial to plants. Microbial activity helps bring about the decay of organic material (dead plant material and animals) necessary for the production of soil. Temperature or light intensity varies for each type of plant, and this helps explain global plant distribution; light intensity or temperature also effects the rate of photosynthesis in plants; the time at which a plant flowers and the rate at which water loss occurs in a plant (transpiration.)

When these requirements are static for a seed, it will begin to grow or germinate. Sufficient food and minerals are stored in almost all seeds, so that these factors do not limit germination. As water is absorbed by a seed, the inner tissue swells more rapidly than the seed coat. The penetration of water allows the tissues to become hydrated and enzyme activity increases. The food that is stored in the cotyledons or the endosperms are now digested and used.

PROCEDURE:

NOTE:  Before beginning, the prior year’s plants should be removed from the planter boxes if they are still in place.  You will also need to weed the boxes as much as possible.  Crabgrass in particular needs to be removed.

1 Tell students today they are going to transplant their milkweed plants in the science garden and plant some seeds from other type of plants and watch them grow in the following weeks.  They also get to weed around the plants in the science garden so the plants have more space to grow.  They can use garden gloves and trowels for work in the garden.

2.  Review quickly what a plant needs to grow. (air, sun, water, space, soil, nutrients, etc.)

3.  Each class will get a planter box to replant a portion of the milkweed.  For the milkweed they will need to dig holes that are deep enough for the entire roots to fit and be cover with dirt.

4.  Next they get to each plant a couple of seeds.  Student should just make a shallow hole about an inch deep and add the seed and cover it with dirt.  Successful seeds in prior years included sunflowers and corn since they grow very quickly and students can see them sprout and grow before the end of the year.  Native wildflowers like poppies are great too.

5.  Have students take turns planting milkweed and seeds.  The other students can weed the garden while they are waiting to plant.

6.  Tell students that the 4^th graders have been producing natural fertilizer (“compost”) that they will be adding to plants in the science garden. You can ask for some of it so second grade students can add it to the boxes while they plant their plants.

7.  Students need to water their plot before they leave and classes are responsible to check on their plants.  If the planters are not getting watered by the sprinklers, the teachers should let the office know so the sprinklers can be adjusted.  Classes need to water the boxes by hand until they get sprinkler water.

Return to NGSS Model