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Alder root nodules

Detailed Description

Root nodules are a symbiotic relationship between a plant and nitrogen-fixing bacteria. A symbiotic relationship is one where both organisms benefit. Nitrogen-fixing bacteria change inorganic nitrogen from the air into ammonia, a form of nitrogen most organisms can use. They also use a process called rock dissolution to release other nutrients, such as calcium and phosphorus, so plants and trees can use them.


Public Domain.