How planting density and grazing intensity affect the above- and below-ground carbon pools in a dryland ecosystem?

Abstract

Climate change is known as one of the most important environmental challenges. Sequestration of carbon in terrestrial ecosystems is a low-cost option that may be available in the near-term to mitigate increasing atmospheric CO2 concentrations, while providing additional benefits. In this study, we estimated the effects of planting density and grazing intensity on the potential of Atriplex canescens for carbon sequestration in a rangeland in Qazvin Province, Iran. The experimental design consisted of a randomized block design, including two planting densities (2 × 2m and 4 × 4m) and four grazing intensity treatments simulated by different plant pruning intensities. We observed no significant difference between the rate (%) of organic carbon in the treatments of density, grazing intensity, and their interaction in the 0-30cm and 30-80cm soil layers. Between the treatments of height pruning, control (no pruning) and light grazing, had the highest total biomass and total carbon. The total biomass carbon content of 2370 kg m-2 in the 2×2m treatment was about twice as much that of 4x4m treatment. These findings can be useful in rangeland management plans.