Ecology: Adaptation to Survive |
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Ecology: Adaptation to Survive |
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| Before you and your class get started with this activity it
would be good that you have a good understanding of the background of how and why species
adapt to survive in their environment. Background: Every species has a unique set of adaptations that enables it to live in its environment. Some, like humans, starlings, and cheatgrass, have a wide tolerance to environmental constraints. Others, like Townsend's big-eared bats, three-toed woodpeckers, and the out-of-tune sticky tofieldia can survive only in the few niches where their unique habitat requirements are met. Most of Earth's biodiversity falls in the second category. Over time, species adapt to changing environmental conditions structurally and behaviorally. Small, light-colored leaves covered with fine hairs are a structural adaptation some desert plants have to conserve water. Being nocturnal is a behavioral adaptation many desert animals adopt for the same reason. Humans have succeeded in exploiting every habitat on Earth because the structural adaptations of our big brains and our hands enabled us to make the myriad behavioral adaptations necessary to live in so many places. Few environments are as hostile to life as Craters'. Temperatures range from -37 to 108 degrees. Plus, only about 17 inches of precipitation (mostly snow) falls annually. In spring it quickly melts off or seeps into the porous ground in time for summer winds and heat to evaporate every drop of moisture from the black landscape. Nevertheless, over 300 plant species cling to the nooks, crannies, and thin soils where life can exist at Craters. They go about enduring a permanent drought through tolerance, avoidance, and/or escape. Some plants are extraordinarily tolerant of drought. They can withstand cell moisture levels that would be lethal for other plants. Sagebrush and bitterbrush are exceptional at extracting water from dry soils and living on very little moisture. Plants can avoid drought with physical adaptations like the leaves of scorpionweed that funnel rain and dew toward its roots. Succulents like cacti collect water when it is abundant and retain it in their tissue. Rabbitbrush's small, light-colored leaves reduce evaporation. Plants escape drought by living in the few places where water is actually plentiful. Others, like the dwarf monkeyflower, carry out their entire life cycle during three moist weeks in the spring and survive as seeds during the rest of the year. The diversity of life at Craters is possible because of its microclimates. The bottom of crevices and cracks may be 15 degrees cooler than the surface. Windblown soil called loess collects there, like dust in the corners of your home, creating a place for plants to grow. The well established soil on the north side of old cinder cones can support Douglas fir trees. Water-loving ferns can live in the midst of a desert by living near the melting ice and cool air of a cave and in deep crevices. The ActivityNow that you have a bit of a background what type of life can exist at Craters of the Moon National Monument. We can do some exploration of how organisms adapt to their environment. For each question keep a journal that keeps a record of your thoughts and any other ideas that you come up with. 1st TaskYour first challenge is to try to tie your shoes without using your thumbs. Try really hard to tie your shoes. Can you do it? Write down why you thought you couldn't do it and compare your reasons with someone else in your class? Keep a list of reasons why you couldn't tie your shoes. 2nd TaskNow that we have untied shoes, try to write your name without using your thumbs. After you write you name (WITHOUT using your thumbs) trade names with a fellow classmate and ask them to read your name. Did they read your name correctly? Challenge!Why do you think we humans have thumbs? Try to come up with other examples of where thumbs are useful to you. Now, think about other animals or plants. For example, what special features dogs, birds, snakes have that humans do not have? Make a list of what special features these species Now can you come up with examples of how plants are adapted to life at Craters. Even if you don't don't know much about plant adaptation at Craters, you likely know it's hot and dry in summer and cold and snowy in winter. Those conditions are what plants must adapt to. What is the basic growth form of plants that live in such places? Are they big and showy with delicate bright green leaves or bent and gnarled with pale leathery leaves? If the latter, why? |
