School of Life Sciences | Ask A Biologist

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Survey of Birds

Survey of Birds

Survey of Birds

A study was done on the birds that use these rivers. The birds were identified and counted once during the summer and once during the fall, both in the morning and in the evening. As can be seen by the figure, the number of different kinds of birds seen in each study area was nearly the same (11 species along the wastewater study area and 10.5 along the control), but the total number of birds present was greatly increased along the wastewater study area.

Tree growth rates

Tree growth rates

Growth Rates of Selected Tree SpeciesTree growth rates 1

We wanted to see how nutrient-enriched wastewater might influence the rate of growth of the three dominant tree species. To determine this, we needed to measure how big around some trees were and then remove cores from them. Cores are pieces of wood that are removed from the tree (they look like a pencil) that let us see how much growth occurs each year.

Measuring Woody Plants

Measuring Woody Plants

Basic Measurements (basal area and density) of Woody Plants

 

Water Chemistry

Water Chemistry

water chemistry

Verde River

Verde River

Natural flow of water on the Verde River below Bartlett Dam.

Salt River

Salt River

Salt River

Release of wastewater from Phoenix to the Salt River.

Wastewater: Nature's Power Drink?

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Wastewater: Nature's Power Drink?

By Roy Marler
Illustrated by Dr. Biology

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  • Ecosystem: a group of different plants and animals that live together and are dependent on the area in which they live.
  • Invertebrates: animals that do not have a backbone... more
  • Riparian: the plants and animals found along the edges of rivers.
  • Species diversity: the number of different types of plants and/or animals found in an area.
  • Wastewater (effluent): treated water that is released from a city's Wastewater Treatment Plant... more

Have you ever wondered how some rivers just suddenly appear? Within Arizona, several cities now release wastewater into riverbeds, essentially creating "new" rivers. Rivers such as the Salt River from Phoenix, the Santa Cruz River downstream from Nogales and Tucson, and the Agua Fria River downstream from Prescott Valley all receive wastewater. Is wastewater different from water found in naturally occurring rivers, such as the Verde River?

How Do Seeds Travel?

How Do Seeds Travel?

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  • Current: the part of the air or water that is moving constantly in a single direction.
  • Hitchhiker: someone who travels by asking for free rides along the road.
  • Ocean Swell: a large, long wave or many waves happening after a storm.
  • Tide: the rising and falling of the ocean that happens twice a day. It is due to the gravity of the sun and the moon.

How Do Seeds Travel?

Plants may not be able to move from place to place, but seeds can. Here are some ways that seeds get around:dandelion seed

 

 

Seeds with wings - Some seeds have parachutes or wings like a glider. The wings and parachutes slow them down as they fall from the mother plant. Then the seeds are carried away from the mother by air currents. The dandelion seeds in this drawing are a great example.

Pocket Seed Viewer

Pocket Seed Viewer

Pocket SeedPocket Seed Viewer

Watch a seed germinate with your own seed viewer! Try this experiment at home or in the classroom. It only needs a few inexpensive materials to put together. Then use the Pocket Seed Data Packet to record your findings and  analyze the data.

How Long Can Seeds Live Underground?

How Long Can Seeds Live Underground?

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  • Dormant: something that is inactive. Not growing or developing.
  • Fossil: the remains, or an impression of remains of a plant or animal that existed in a past geological age that has been removed from the soil... more
  • Paleontology: a science dealing with the life of past geological periods. Often, people think of paleontology as only the study of fossils, like dinosaur bone hunters. Paleontologist study much more than bone fossils, including plants, pollen, spores, and seeds both living and fossilized. These scientists are called palynologists.
  • Radiocarbon: a chemical analysis tool used by scientists to find out how old organic materials are based on their content of the radioisotope carbon-14. Radiocarbon dating is believed to reliably tell the age of organic materials up to 40,000 years old. Also called carbon dating and carbon-14 dating... more

How long can seeds last?

You might be asking yourself, how long can a seed stay dormant? This is a question that scientists have tried to answer in many different ways. 

Scientists have found they can still germinate seeds found in preserved plant samples in an herbarium. An herbarium is a collection of pressed plants. The oldest living seed they have found this way is 90 yrs old. That's probably older than your grandmother!

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