Soil Science and Nutrient Cycling

Soil is a living, dynamic medium, and its responsible for so much more than just plant support. The main players in soil nutrient cycling are microorganisms, organic matter, and the mineral components. Here's the breakdown:

1. Nutrient Cycling: This refers to the process where nutrients move through the soil, plants, and organisms, getting used and recycled. Plants absorb minerals and nutrients (like nitrogen, phosphorus, potassium) through their roots, and when plants die, they decompose and release those nutrients back into the soil for the future plant growth.
2. Organic Matter: When plants or animals die, they contribute organic matter to the soil. This decomposes and turns into humus-a rich, dark organic substance that improves soil structure, water retention, and nutrient availability. Its the magic behind fertile soil.
3. Microbes and Soil Life: Tiny organisms like fungi, bacteria, and earthworms play huge roles in breaking down organic matter and cycling nutrients. For example, nitrogen-fixing bacteria in the soil convert atmospheric nitrogen into a form that plants can use (this is key in agriculture and forestry).
4. Soil Horizons: Soil is made up of layers, or horizons, which influence nutrient availability. The O-horizon (organic layer) contains decomposing plants, while the A-horizon (topsoil) is where most of the nutrient cycling occurs.
5. Soil pH and Nutrient Availability: The pH of the soil can greatly affect how nutrients are available to plants. Most plants prefer slightly acidic to neutral soils (pH 6-7), but too much acidity or alkalinity can lock certain nutrients away from plants, impacting growth.
6. The Carbon Cycle in Soils: Carbon is sequestered in the soil through plant photosynthesis and stored as organic carbon inn the soil. This is why soil health is often considered a key player in mitigating global warming. Soils can act as a carbon sink, helping to draw down carbon dioxide from the atmosphere.

Seed collection, germination, and growing trees-its super impactful to teach people how to engage in growing your own trees. The process involves choosing the right seeds, understanding soil requirements, stratification (cold treatment for some seeds), and finally creating the perfect environment for germination. Once they start growing, you can learn about nurturing your trees to ensure they become healthy, productive plants.

(Petawawa Rapids, Centennial Park)

Exposed Earth's mantle/surface.

500 Million to ~1 billion years ago
 The Ottawa Valley "hills" used to be bigger than the Himalayas so by comparison you can imagine a present day before and after visual between the two.

Metamorphic: Gneiss

Gneiss is the strongest/highest grade of metamorphasism. A cool perspective to look at it is realizing it is the base of what once was (and where they exist).. Mountains!!!

The flow of glacier runoff was intense it cut the Barron, I will get into that later... But first... How does Gneiss form? With help from a geologist, professor and ChatGPT here is the sum of my knowledge.

The best I can explain it is the characterization by which compacted layers of sediments and volcanic flow transformed into different minerals (most common of all is quartz). Interesting fact, though these sediments transform through compressional events (Pressure + Time + Heat) the chemicals (carbon, the stuff you and I are made of) remain identical. Fascinating stuff.

Lighter rock (Felsic): Quartz, Feldspar
Darker rock (Mafic): Biotite mica, Amphibole (Hornblende), Garnet (if present), Pryroxene (higher-grade gneiss)

Formed under high pressure and temperature deep within the Earths crust causing the original rock to recrystalize and form these layers.

Over billions of years!... There were multiple meteor events, and over the last billion there were many continental collisions. Existing rocks (sedimentary + igneous) already buried deep within the Earths crust transformed to Gneiss with time, heat and pressure. An abundance of minerals recrystallized and grouped together.. you may recognize them by their variants in colors, lightness and darkness in the "bands" or "belts".
TLDR: No cliffs yet.

But another fun fact, this is the same process in which silver veins formed. The minerals (suggestively from meteors and meteorites) essentially melted and with pressure, time and heat they formed a great deal of belts. If you want to see some of the most pure and historically fascinating silver extraction sites in Ontario, please visit Cobalt. The Nipissing vein and area is a true local wonder. The reason they don't touch it for extraction is theoretically because it is a geologically niché silver deposit, the labour involved to extract it is more intensive and economically inefficient but the quality is pure.. More pure than many other sites around the world. It's an exciting place to visit with the perspective of its identity!

Back to evolutionary theory...
500 Million to ~1 billion years ago:
The mountain belts erode... the Himalayas are an example of a mountain belt.  The Ottawa Valley "hills" used to be bigger than the Himalayas so by comparison you can imagine a present day before and after visual between the two.
It is basically an extended linear zone resulting from plate tectonics specifically during a collision.. resulting in raised, deformed, thick crusts.
Eventually the deep metamorphic rock is exposed. (example... Canadian Shield)
TLDR: Relentless erosion.

~500 million years ago:
Plate tectonics chill out.
Canadian shield is the Earth's exposed mantle mostly dry from where the regions, at one point, had flooded with shallow seas. 
TLDR: Hard, stubborn rock. Vibin.

~2 million to 12,000 years ago
Continental glaciers bulldoze Ontario. 
Landscape formation.

~10,000 to 18,000 years ago:
Glacial retreat.
Meltwater retreating to Atlantic Ocean (in the Ottawa Valley) expose weaknesses in the rock forming rivers such as the Barron cliffs with exposed cliff faces.  The runoff was 1000X the volume of Niagara Falls coming down the Barron into the Petawawa and subsequently the Ottawa River.