Exploring the Interactions between Land Use, Climate Change and Carbon
Cycle using Satellite Measurements
Abstract
Most climate change impacts are linked to terrestrial vegetation
productivity, carbon stocks and land use change. Changes in land use and
climate drive the dynamics of terrestrial carbon cycle. These carbon
cycle dynamics operate at different spatial and temporal scales.
Quantification of the spatial and temporal variability of carbon flux
has been challenging because land-atmosphere-carbon exchange is
influenced by many factors, including but not limited to, land use
change and climate change and variability. The study of terrestrial
carbon cycle, mainly gross primary product (GPP), net ecosystem exchange
(NEE), soil organic carbon (SOC) and ecosystem respiration (Re) and
their interactions with land use and climate change, are critical to
understanding the terrestrial ecosystem. The main objective of this
study was to examine the interactions among land use, climate change and
terrestrial carbon cycling in the state of Texas using satellite
measurements. We studied GPP, NEE, Re and SOC distributions for five
selected major land covers and all ten climate zones in Texas using Soil
Moisture Active Passive (SMAP) carbon products. SMAP Carbon products
(Res=9 km) were compared with observed CO2 flux data measured at EC flux
site on Prairie View A&M University Research Farm. Results showed the
same land cover in different climate zones has significantly different
carbon sequestration potentials. For example, cropland of the humid
climate zone has higher (-228 g C/m2) carbon sequestration potentials
than the semiarid climate zone (-36 g C/m2). Also, shrub land in the
humid zone and in the semiarid zone showed high (-120 g C/m2) and low
(-36 g C/m2) potentials of carbon sequestration, respectively, in the
state. Overall, the analyses indicate CO2 storage and exchange respond
differently to various land covers, and environments due to differences
in water availability, root distribution and soil properties.