Evaluation of the Seasonal Variation of the Soil Temperature as Function of the Influence of the Tide and Precipitation in a Tropical Mangrove

Abstract

The world over, mangrove areas are suffering from constant social and economic pressure. Few studies have been done regarding meteorological variables in mangrove regions. Information on mass and energy exchange at the soil surface under vegetation is a critical component of micrometeorological, climate, biogeochemical and hydrological models. Soil temperatures under forests are affected by incoming radiation and thermal characteristics of the soil. Mangrove forests soils are often covered with tidal water that influence the rate of mass and energy transfer between the soil and air above, thereby modifying the temperature in the soil. The goal of this study was to characterize the influence of tide and precipitation on the temporal variability of soil temperature for various depths in mangroves in tropical region. A field experiment was conducted on Santa Rita Island, Maceió, Brazil (Lat: 9° 42’ 18’’ S; Lon: 35° 48’ 32’’ W) in the period between October/94 to October/95. Data were permanently collected at depths of 5, 15 and 30 cm, as well as a sporadic profile collection of 1, 20, 45 and 95cm. It was then scanned every 10 seconds and stored an average of every 5 minutes in a datalogger. The results showed that the soil temperature profile has been altered by the incoming of the solar radiation at the floor of mangrove forest, as well because as of the tide and precipitation. It was also observed that the average maximum and minimum soil temperatures had occurred during the dry (27-29°C) and rainy months (24-25 °C), being that in the rainy period the average soil temperature in the greatest depths had been superior to the superficial layers.