Plant and animal remains are decomposed adding humus (the dark part of the topsoil). Together, this mixture makes soil. It is a process that can take up to 500 years to make 1 inch!
Hydric soils are defined as soils formed under conditions of saturation, flooding or ponding long enough during the growing season to develop anaerobic conditions within the upper part of the soil profile. In other words, water fills all the pores and there is no oxygen in the soil for part or all of the growing season.
Hydric soils often develop chloritic patches. These are light to medium green patches in the soil. Chorite in parent rocks react with water and form these green patches. Sometimes in bottomland soils, dark black manganese nodules form about the size of a pea.
There are several types of landscapes that can produce hydric soils
Ponds and lakes: areas that typically retain water year round. Vegetation varies from marsh grasses, pond plants and swamp trees. Soils in these areas typically stay 100% saturated year round unless there are periods of drought.
Depressional areas collect and store runoff water from the surrounding landscape after rain events. Saturation is not sustained for long periods after rain events. Mineral soils are likely to be present and may or may not be hydric. Vegetation can consist of trees, shrubs and herbs.
Flood plains that are seasonally flooded may contain hydric soils. Hydric soils usually form in the backwater area, where water is retained for extended periods of time. Soils are typically mineral with trees and shrubs being the dominant vegetation.
Seeps occur at the bases of slopes where the groundwater table intersects the soil surface (Figure 1). They are often found where a slope grades into flat land. The high water table in seeps is sustained by groundwater discharge. There can be mineral or organic soils, and the vegetation in and around the seep can consist of trees, shrubs and herbs.
This is a two stage earthcache that will take you to two locations in the park. This is stage one.
At stage 1 GZ, you will be between a body of water and a deciduous forest. You will need to get a soil sample from both the forest and from an area covered by water. You are going to make a 'soil plug' so you can inspect the soil. Insert the garden shovel as deep as you can. Gently pull out the blade and insert across from the first cut. Gently twist the shovel around to the first cut and now pull out the 'plug' Do this for both the forest soil and the hydric soil. When you remove both plugs, compare them.
What color differences, do you see? How deep does the dark top layer go in both? Which has a larger top humus layer? Does the hydric soil exhibit any light green patches or very dark black nodules? Do you see any of these in the forest soils? What type of landscape is this hydric soil?
Please replace your soil plugs where you got them!
For stage 2, go to N 35° 57.345 W 079° 44.000
At stage 2 GZ, you will be on a boardwalk in the middle of a deciduous forest. You will need to get a soil sample from both the area just below the boardwalk and the forested area on either end of the boardwalk. You are going to make a 'soil plug' so you can inspect the soil. Insert the garden shovel as deep as you can. Gently pull out the blade and insert across from the first cut. Gently twist the shovel around to the first cut and now pull out the 'plug' Do this for both the forest soil and the hydric soil. When you remove both plugs, compare them. What color differences, do you see? How deep does the dark top layer go in both? Which has a larger top humus layer? Does the hydric soil exhibit any light green patches or very dark black nodules? Do you see any of these in the forest soils? What type of landscape is this hydric soil?
Please replace the soil plugs where you got them!
What differences do you see between the four soil plugs? Why do you suppose there are differences between these four spots, especially since they are so close to each other? Shouldn't soil in this small area be the same? Why or why not?
To log this earthcache, send the answers to the above questions in an email to markcase@aol.com . List the subject as Hydric Soils: GC3KDPR and the first line of the email. Although optional, pictures are always welcome of you enjoying the site!
When you have completed your examination, please replace the soil plugs where you got them!!!!