Marsh Marigolds (Caltha palustris): the influence of abiotic factors on distribution.

Abstract

The abiotic factors of an environment may play an important role in the distribution of the organisms within a given habitat type. One common wetland plant, Marsh Marigold (Caltha palustris) has a patchy distribution. In testing our central hypothesis that the abiotic properties of the water and soil determine the distribution of C. palustris, we examined its distribution with regard to pH, moisture and organic contents of the soil, and concentrations of dissolved nitrogen, dissolved phosphorus, and dissolved calcium ions. We took water and soil samples from the zone of root growth in two swamp and two stream sites in northern Michigan. These samples were taken from areas that either contained C. palustris or had no plants within a one meter radius. Two-by-two ANOVA showed no significant difference between the sites with and without C. palustris for any of our tested variables. Although C. palustris can grow in a relatively wide pH range, there may be a limit on each end of the pH spectrum at which the plants cannot grow. Soil moisture did not seem to play a significant role. Organic content of the soil also did not seem to limit the presence of C. palustris, suggesting nutrient levels are already sufficient or that the plant may obtain necessary mineral nutrients from other sources. Concentrations of nitrogen and phosphorus did not seem to limit presence either. Other abiotic or biotic factors may limit the distribution of C. palustris.