Comparison of Temperature Regimes of Two Temperate Herbaceous Wetlands in the Course of the Growing Season

Abstract

Wetlands are habitats with highly variable species composition, hydrology and functioning in terms of energy exchange and forming of local climate. We compared two graminoid temperate wetlands situated nearby and at similar latitude to see how much their temperature characteristics differed with changing conditions during a growing season. The results showed that the two habitats, a littoral zone of a fishpond and a wet meadow, differed markedly. The daily means at 2 m were on average higher in the littoral as a consequence of lower temperature minima in the wet meadow. However, the daily maxima at 2 m were higher in the wet meadow due to advection of warm air from the surrounding habitats. We suppose that the temperature of the air at 2 m was predominantly influenced by temperature characteristics of the surrounding habitats (i.e. local meteorology). The temperature within vegetation and at the soil surface was dependent on the soil water content. This relation was stronger in the wet meadow than in the littoral due to the complex microtopography of the latter Carex dominated habitat. Vegetation played an important role in influencing temperature at the soil surface and within the vegetation cover, i.e. in the very proximity of the land surface. Because of the higher LAI, this trend was stronger in the wet meadow.