How close did you pay attention to the landscape the last time you went for a hike in a national park? Did you notice the variety of trees or plants, the birds, the insects? Could you tell where there had been a fire or a flood? More subtly, could you see where the nutrient sinks in the ecosystem were? Most of us probably can't answer that last question, but researchers at Isle Royale National Park have uncovered some intriguing contributions to the park's biodiversity.