How healthy is the soil at Madrona Marsh Nature Preserve?

ACTIVITY 3: Create a visual chart describing the habitat and showing the key nutrient measures for each sampled site: B1 (coastal prairie), B2 (upland prairie), B3 (vernal pool), and B4 (freshwater marsh). Upload a digital copy of your chart below.   

Optimal vernal pool soils are typically characterized by low-nutrient, high-organic, and poorly drained substrates that support specialized, rare flora. Essential soil measures include high organic matter (accumulated C and N), low pH (often 4–5), a clay/silt-rich texture to maintain, and high microbial biomass carbon. These areas require low nutrient input to prevent invasive plant dominance

Key Soil Nutrient and Physical Parameters

• Soil Texture: Clay and silt are critical to create a slow-permeability layer for water retention.

• Organic Carbon (C) and Nitrogen (N): Vernal pools tend to accumulate total organic carbon (TOC) and nitrogen at the bottom, with concentrations often decreasing with depth.

• pH Levels: Soils are generally acidic, with typical pH levels between 4 and 5, which limits nutrient availability and supports specialized species.

• Microbial Biomass: Measuring carbon microbial biomass per gram of dry soil is crucial for assessing soil health and biotic responses.

• Nutrient Load Management: Optimal soils are low in phosphorus and potassium. Excess nutrients, often from runoff, can trigger non-native plant invasion and decrease native diversity.