The Pygmy Forests of the Mendocino coast stretch from Gualala to the south all the way to Ft. Bragg in the North. These trees, although miniature in height, have stood for a long time; the majority of them are over 100 years old. To complete this earthcache you will need to walk the entire boardwalk, which is only about 0.2 miles.
The pygmy forest itself resides over five different terraces. These terraces were uplifted over the last 500,000 years up to a peak elevation of 650 feet. Each terrace, if roughly rounded, was formed in 100,000 years. These terraces were formed by rising and falling sea levels. The biggest factor for the rising and falling sea levels were glacial activity. The San Andreas fault zone lays about 3.5 miles to the west and probably also had some influence on the creation of the terraces.
The Trees
The reason why the trees here are so small is because of the soil and lack of slope. The flatness of the terraces does not let erosion take place; when it rains, the rainwater leaches most of the basic nutrients away, leaving behind extremely acidic soil. Acidic soil creates a hostile environment for plant growth because the acidity prevents root growth. In addition, slow growth and poor drainage leads to wet soil, which in turn deprives the soil of oxygen available to the roots. Combined, these factors lead to stunted plant grow.
Podzol
Podzol is soil that has developed from rainfall over many thousands of years. This soil forms as a product of a high rate of leaching due to a lack of drainage. Moisture seeps through the surface layers of the soil, carrying along with it minerals such as calcium, sodium, and potassium. Ultra-fine pieces of clay also filter through the topsoil with the minerals. The nutrients and minerals accumulate in the soil zone below, creating a hardpan, a dense layer of soil. After a few centuries, a hard ash-white layer forms above the hardpan. This layer is essentially sterile. The picture above is a prime example of podzol. You can clearly see that the white soil is podzol not only because of its color but also because there is little to no growth in it. (Note: this picture was not taken at the pygmy forest and this picture is just a demonstration of Podzol, not Noyo and Blacklock)
Types of Podzol in the Northern California Pygmy Forests
There are two distinct types of Podzol found in the Pygmy Forests in Northern California - they are Noyo and Blacklock soils.
Noyo Soil
This layer of soil covers the hard podzol layer. This soil is part podzolized (not completely sterile) and allows plants to grow in it. It is the result of sand dune minerals that have been weathered to clay. Noyo soil is found more often on the newer terraces and it mildly stunts plant growth.
Blacklock Soil
Blacklock soil is made up of quartz that has been eroded into a powder. Blacklock soil originated in depressions where bogs formed. Overtime, the seasonal bogs leached away many minerals - leaving only a super hard, very podzolized soil. This soil is found on the older terraces and is known to cause severely stunted pygmy forests.
Logging Requirements
Please email me the answers through the email in my profile. I will only reply if you have answered a question incorrectly.
To answer questions 1 & 2, you will need to use the Pygmy Forest Evolution informational panel and your GPS.
1. Based on the terrace height and the corresponding age, how old is the Podzol here?
2. Which type of Podzol is this section of Pygmy Forest on?
3. How come there are towering redwoods so close to the Pygmy Forest?
4. OPTIONAL - Please take a photo of you and your GPS OR your GPS with the Pygmy forest in the background.