Abstract
Warming climate trends will shift the soil thermal gradient and thus
impact the soil-nutrient dynamics. This impact will be more pronounced
in areas where air temperatures have been significantly less than those
of the vadose zone. It has been observed that the soil nitrogen content
in the form of nitrate and ammonium has increased in water bodies with
an increase in temperature. This observation can be owed to the reason
that the denitrification process is significantly affected by warm
temperatures. Nitrogen content in the soil thus can be expected to
change due to increasing temperatures. The present study attempts to
find the effect of air temperature on soil root zone properties (viz.
soil temperature and soil moisture content at different depths)
consequently affecting soil-nutrient status. A support vector regression
(SVR) model was trained to develop a regression between air temperature
and soil nitrogen status at different soil moisture contents. The model
was applied to simulate the future (i.e. years 2030 and 2050) soil
nitrogen content at different depths for different soil temperatures and
moisture contents. The effect of increasing temperature on the fate of
soil nitrogen was predicted based on the optimal temperature range
required for the chemical reactions. The model used the data from
experimental watershed Bear Brook Watershed, Maine and soft data from
the Global Land Data Assimilation System (GLDAS) for prediction and
validation purposes.