How Does Climate Affect Plant Growth



	How Does Climate Affect Plant Growth? Cindy Fry, Sandy Kelnhofer, Barbara Quintasket Paschal Sherman Indian School, Omak, Washington
	Summary Students compare plant samples obtained from two different sites to explore how climate affects plants. Grade level First Time required Two 45-minute class periods, plus a fieldtrip Materials Two Douglas Fir trees - One growing in a dry environment, one in a wet environment Tree core sampler Plastic bags for transporting the core samples Paper strips to be used as measuring tools Trays for examining the tree samples Magnifying glasses Rulers Science journals Pictures of Douglas Fir trees Samples of Douglas Fir branch, cones, bark Goals By completing this lesson, students will understand that plant growth is affected by climate and habitat, learn some cultural background about the Douglas Fir and gain experience in using the science process skills. Science standards addressed National Science Standards Abilities necessary to do scientific inquiry Organisms and environments Systems, order and organization Science as a human endeavor Science and technology in local challenges American Indian Science Standards Elements of nutrition and how they were understood and applied in the diets of American Indians prior to the arrival of the Europeans Earth, air, fire and water and how they served as a basis for traditional American Indian production of clothing, housing, tools and food Teacher tips Bookmark the web site prior to class for easy access. Locate two sites, one dry and one moist, that contain Douglas Fir trees that you can sample. Background information A plant's growth can be greatly affected by the habitat and climate in which it grows. Factors like temperature, sunlight, precipitation, soil moisture, soil nutrients, and length of growing season can all affect plant growth. In trees, less than optimal growing conditions can slow the rate of growth of a tree, or change its shape. Trees add a ring of growth, known as an annual ring, each year. The annual rings provide a profile of the life history of the tree. During years of unfavorable growing conditions, the tree may grow more slowly than in other years, an effect which is evident in the narrower annual ring it forms that year. The Douglas Fir (Pseudotsuga menziesii) is an important cultural plant for the Colville People. It is known as tsk'ilhp in the Okanogan language. It was used in many different ways in the traditional lifestyle of years past, and is still used today. For example, some of these firs form a rare sugar known as melezitose, which was highly prized by Okanogan. It was eaten raw, or used to sweeten black tree lichen or balsamroot seeds. Douglas Fir wood was used to make a number of items, including tipi poles and spear shafts. The boughs were used in making roofs on temporary shelters, in bedding (especially for those in mourning), and as under flooring in winter houses. Boughs were also used on the floor of the sweathouse, and to scrub the body, leaving the body clean and fresh smelling. Parts of the tree are also used to make medicines for a variety of conditions, as well as hair and skin tonic. Procedure Engagement Show a picture and samples from a Douglas Fir to students and tell them that they will be conducting an experiment with this tree species. Invite an Okanogan elder to visit your classroom to talk about the traditional uses of Douglas Fir by Okanogan people. Ask them to teach the students how to say the tree's name in the Okanogan Salish language. Exploration Take a trip with your class to a local dry environment. Ask students to observe and record the climate of the area in their science journal. Use the core sampler to obtain a plug from a Douglas fir there. Place the sample, along with cones, twigs and needles from the tree in the plastic bag Have students use paper strips to measure and record the diameter of the tree trunk. Repeat steps 2 - 4 in a moist environment with the same kind of tree. In the classroom, lay out the tree samples in trays. Allow students to use tools to observe and measure the samples. Have them compare the two samples of needles, cones, and twigs, and observe the differences between them. Have them record their observations using drawings and text in their journals. Have students count and measure the rings in each core sample and record. Explanation Facilitate a discussion about how the two samples compare. Encourage students to share their hypotheses about why the two tree samples differ. Ask students to write a hypothesis explaining the sample differences in their journals. Elaboration Invite a tribal forester or botanist to go on a fieldtrip or visit the class to talk about plant growth and environment. Evaluation Examine student journals for evidence of content knowledge and process skill development. Observe students as they investigate for good cooperative learning skills and habits of mind of a scientist. Follow up activities Plant several seeds of the same type of plant in your classroom. Change the environment of each plant and watch the differences appear in growth patterns. Visit the web site The Great Plant Escape at http://www.urbanext.uiuc.edu/gpe/ . This is an interactive site that has general plant information. Resources Web sites The Great Plant Escape - An interactive site with kids activities, information and mysteries about plants. http://www.urbanext.uiuc.edu/gpe/

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