SOIL AND TREES

This project was created in order to explore the relationship between the location of a tree and its soil chemistry. We were driven by these questions: Do trees by streets have different soil chemistry than trees in parks? Do different tree species have different soil chemistry? Does the condition of the tree influence the chemistry of the soil? In the beginning we were looking at Ash, Oak, Maple, and Honeylocust trees. We stopped looking at the Ash trees because the Emerald Ash Borer impacts the condition of the tree. After analyzing the data we did not see any trends. That was partly due to the fact that we had a large number of samples from one species but very few samples from the other species. Therefore, we decided to refine the parameters of our project to purely looking at Honeylocusts and Maples. Citizens can contribute to this project by collecting more soil samples from Maples and Honeylocusts then analyzing the chemistry of those samples.

Soil texture impacts the health of the tree as each type of texture has pros and cons. If the soils contain a lot of sand that means there is a lack of nutrients or water since there is little chemical activity and water is not retained for long. Silt,similarly, does not have a lot of nutrients due to low chemical activity and this type of soil is prevalent in areas where air quality is poor. Soils that contain clay can maintain moisture very well, but the water adheres to the clay making it difficult for the plants to absorb that water. Clay is very chemically active so there is a lot of nutrients for the plants, however, a downside of clay is that it is difficult for roots to grow through them causing the roots to grow above ground.

A huge factor that determines soil quality is how the soil formed over thousands of years. For instance, the parent material (rocks) are weathered down by wind, water, etc which breaks the rocks into small grains of soil. The location also contributes to the quality of soil due to the amount of water, plant life, and minerals present in that area. Also, the amount of human interaction impacts the soil such as: gardening, pollution, and introduction of invasive species. Thus, we saw that the location can greatly impact how fertile the soil can be and wished to further investigate this scientific area.

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Citizen Science Soil Collection Program

This citizen science project was created by University of Oklahoma in order to collect more data on microscopic life in soil.

USDA Natural Resources Conservation Service Soil

Describes how soil is formed and what about the location of soil impacts its quality.

What is Soil Texture

Describes how soil texture affects plant health.

Estimating Soil Texture

Describes how to measure soil texture by using the Soil Texture Triangle.