Potential soil carbon sequestration in a semiarid Mediterranean agroecosystem under climate change: Quantifying management and climate effects

Abstract

Climate change is projected to significantly impact vegetation and soils of managed ecosystems. In this study we used the ecosystem Century model together with climatic outputs from different atmosphereocean general circulation models (AOGCM) to study the effects of climate change and management on soil organic carbon (SOC) dynamics in semiarid Mediterranean conditions and to identify which management practices have the greatest potential to increase SOC in these areas. Five climate scenarios and seven management scenarios were modeled from 2010 to 2100. Differences in SOC sequestration were greater among management systems than among climate change scenarios. Management scenarios under continuous cropping yielded greater C inputs and SOC gain than scenarios under cereal-fallow rotation. The shift from rainfed conditions to irrigation also resulted in an increase of C inputs but a decrease in the SOC sequestered during the 2010-2100 period. The effects of precipitation and temperature change on SOC dynamics were different depending on the management system applied. Consequently, the relative response to climate and management depended on the net result of the influences on C inputs and decomposition. Under climate change, the adoption of certain management practices in semiarid Mediterranean agroecosystems could be critical in maximizing SOC sequestration and thus reducing CO 2 concentration in the atmosphere.

The Potential Impact of Climate Change on Soil Properties and Processes and Corresponding Influence on Food Security

“…Soil management techniques such as no-till systems may result in lower CO 2 emissions from and greater C sequestration in the soil as compared to management systems based on intensive tillage (Figure 3) [16][17][18][19][20], although some recent studies have indicated that no-till systems may simply result in higher C accumulations in the upper 15-20 cm of the soil with no increase in C when the entire soil profile is considered [21][22][23]. Other management changes such as using cover crops, crop rotations instead of monocropping, and reducing or eliminating fallow periods can lead to C sequestration in soil [16,24] as can returning land from agricultural use to native forest or grassland [25,26]. Sequestration of C tends to be rapid initially with declining rates over time ( Figure 3) [26][27][28].…”

Tillage Effects on Soil Quality after Three Years of Irrigation in Northern Spain

“…For instance, soil C losses associated to the implementation of irrigation have been reported in other semi-arid areas [52]. Modeling scenarios also point out the possibility of C losses upon irrigation adoption in the long term [53,54]. To date, the consequences of introducing irrigation on SQ indicators in the region and an overall SQ assessment under irrigation have not been addressed.…”

Change in Soil Organic Carbon Stocks under 12 Climate Change Projections over New South Wales, Australia

“…Lal (2004) and Gottschalk et al (2012) reported higher latitude regions undergoing overall losses and tropical regions undergoing overall gains. At the country or regional level, SOC change under climate change has been spatially simulated in a number of recent studies, ranging from 250 m to over 50 km resolution, including in North America Follett et al, 2012;Dib et al, 2014;Zhong and Xu, 2014;Byrd et al, 2015;Orem et al, 2015), in Asia (Hashimoto et al, 2012;Zhao et al, 2013Zhao et al, , 2015, and in Europe and the Mediterranean region (Smith et al, 2005(Smith et al, , 2006Álvaro-Fuentes and Paustian, 2011;Álvaro-Fuentes et al, 2012).…”