No matter where we are on Earth, we can observe changes in vegetation. Some changes are drastic, such as going from dormant to full growth during a temperate winter.
Vegetative growth is dependent on both surface temperature (which influences soil temperature) and precipitation (which influences soil moisture). Together these environmental variables help determine the beginning, duration, and end of the growing season; the latter marked by leaf senescence, when leaves of deciduous trees die and turn colors.
Climate scientists study evidence in the geologic record, such as fossils, to figure out what climate was like over hundreds of thousands of years (“paleoclimate”). One fossil they use is pollen, a part of a flowering plant that helps make a seed. Pollen can be blown into lakes, where it is preserved in sediment. Pollen from spruces, which do well in cold climates, can suggest what climate was like when spruce pollen was deposited.
Archaeological remains include artifacts (portable) and features (non-portable) made and used by humans. Archaeologists use these objects to understand how ancient people lived. How well archaeological remains survive depends on the materials they were made of, the ways they were used, the manner in which they were discarded, and the environment in which they were deposited. Organic remains generally decay in a short time unless preserved in special conditions.
Water moves from Earth’s surface to the atmosphere and then returns to the surface. This process is nearly always depicted in water cycle diagrams by arrows drawn in a circular direction.
However, the actual path water may take in its cycle is far more complicated. In this activity, you will discover multiple cycles by acting as water molecules and traveling through parts of the overall water cycle. In the end, your water cycle will look nothing like the conceptual model but will represent a more realistic cycle.