Forest Cross-Section Lab: Exploring Ecological Interactions…

Canopy Light and Beer-Lambert Law

The amount of sunlight reaching the forest floor is governed by the Beer-Lambert law, which describes how light intensity decreases exponentially as it passes through a medium. In this simulation, the thickness of the canopy and its leaf density affect the light available to understory plants. This principle explains why some species thrive in shady areas while others require full sunlight.

Manipulating the sunlight slider allows you to observe how different levels of light availability impact plant growth and distribution within the forest ecosystem.

Mycorrhizal Networks and Nutrient Exchange

Mycorrhizal fungi form symbiotic relationships with tree roots, facilitating nutrient exchange. These fungi absorb soil nitrogen and transfer it to trees in return for carbohydrates produced by photosynthesis. This mutualistic relationship enhances plant growth and resilience, particularly in nutrient-poor soils.

Adjusting the fungal sharing parameter demonstrates how increased or decreased nitrogen availability affects forest health and productivity.

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Deer Browsing Impact

Herbivory by deer significantly influences plant community composition. Deer browsing can lead to a shift in species dominance, favoring those that are less palatable or more resilient. This impact is particularly pronounced on seedlings and understory plants, which may be completely eliminated if browsing pressure is high.

The simulation allows you to observe the effects of varying deer population sizes over time, illustrating how herbivore dynamics can shape forest structure.

Soil Nitrogen Cycling

Nitrogen is a critical nutrient for plant growth and is cycled through the ecosystem by various processes. In this simulation, nitrogen availability affects both mycorrhizal fungi and plant growth. Litter decomposition contributes to soil nitrogen levels, while fungal networks redistribute it among trees.

Manipulating the nitrogen input slider helps you understand how external factors like rainfall or fertilizer application influence overall forest health.

Frequently asked questions

How does mycorrhizal fungi benefit both plants and soil?

Mycorrhizal fungi enhance plant growth by improving nutrient uptake, particularly of phosphorus and nitrogen, while also increasing water absorption. In return, they receive carbohydrates from the plants through photosynthesis.

What role does deer browsing play in forest ecology?

Deer browsing can alter species composition by selectively removing certain plant species, leading to changes in competition dynamics and potentially affecting ecosystem stability and biodiversity.

How does the Beer-Lambert law apply to canopy light in forests?

The Beer-Lambert law explains how light intensity decreases as it passes through a dense canopy. This principle is crucial for understanding which plant species can survive under different light conditions within the forest.

Why is soil nitrogen important for forest health?

Soil nitrogen is essential for plant growth and development. Adequate nitrogen levels support healthy vegetation, which in turn influences carbon sequestration, biodiversity, and overall ecosystem function.

Try it live

Everything above runs in your browser — open Forest Cross-Section Lab: Canopy Light, Mycorrhizal Carbon Network, Deer Browsing and Soil Nitrogen and change the parameters while it is running. Nothing is installed, nothing is uploaded, the whole model lives in one tab.

▶ Open Forest Cross-Section Lab: Canopy Light, Mycorrhizal Carbon Network, Deer Browsing and Soil Nitrogen simulation