Hydro-climatic conditions and dynamic response of nitrogen and carbon in an area of caatinga, Pernambuco

Abstract

Soil moisture has a primary role in the processes of biogeochemical cycling of nitrogen and other nutrients. In addition to controlling primary productivity, soil moisture affects microbial activity, determining the rate of biogeochemical cycling and, ultimately, the availability of nitrogen and other nutrients. In arid and semi-arid environments the temperatures are high, the rainfall is scarce and water availability is low and highly variable in space and time. The consequences of this hydro-climate pattern on nutrient cycling on this type of environment are not yet fully understood. However, not only precipitation, but also other climate forcing, such as radiation and wind action, can influence the biogeochemical cycles in arid and semi-arid environments. This project aims to examine the effects of various hydro-climatic forcing (e.g. precipitation, radiation, temperature, wind speed, etc.) on the biogeochemical cycles in a caatinga environment. The study will take place at São João, Pernambuco, in two areas: natural and anthropized caatinga. Soil and water in their diverse compartments (precipitation, internal precipitation, runoff, gravitational and interstitial soil water) will be sampled. Laboratory analysis will be performed in order to determine the carbon and nitrogen dynamics and characterize the transfer of chemical species between the terrestrial and atmospheric environment. focusing on the context of the soil profile. In addition, Will be evaluated the coupling between the hydrological cycle and biogeochemical cycles, enabling the existence of other abiotic controls in addition to humidity, which act as driving force for nutrient availability. (AU)