Object of study and observed pattern

The organism chosen for study is a plant.
Its identity is unknown, as it has not leafed out yet. It is found on either side of the walking path that passes through the conservation area.

Across the environmental gradient from marsh to grassland, it appears to be more abundant in the region between the marsh and the grassland, becoming scarcer as the grassland becomes more established. It is not found along the water’s edge.
Location 1: along the water’s edge – organism not found.
Location 2: area between water’s edge and grassland area – organism is well distributed and abundant.
Location 3: grassland area – organism is scarce.
No changes were observed in the organism’s character across the environmental gradient. No measurements were taken – only qualitative observations were made.

One underlying process that might contribute to the observed pattern is soil moisture content. Soil closer to the water’s edge is likely to have higher soil moisture content, while the grassland soil is likely to have lower soil moisture content.
Hypothesis: This plant requires a specific soil moisture content in a range between the very wet conditions near the water’s edge and the drier conditions in the grassland.
Prediction: The average height of the plant will decrease as soil becomes drier or wetter outside the plant’s preferred moisture range.

Potential response variable: Height of plant (continuous).
Potential explanatory variable: Soil moisture content (continuous).