Date of Completion

2021

Document Type

Honors College Thesis

Department

Natural Resources

Thesis Type

Honors College

First Advisor

Gillian Galford

Keywords

carbon, soil, tropical ecology, land use change, agroforestry

Abstract

The task of integrating the scattered needs of both people and nature at a multitude of scales remains daunting in the field of environmental science. This study examined one facet of this pursuit by determining the potential sustainability and ecosystem services provided by a proposed agroforestry initiative in Loreto, Peru. Specifically, the study evaluates the mechanisms and dynamics of soil carbon sequestration as a response to land use change in the Peruvian Amazon. Both fine root biomass and soil organic carbon (SOC)- measured as loss-on-ignition- was analyzed over a vertical gradient in a primary tropical forest, a traditional slash-and-burn cultivated chacra, a post-cultivation secondary forest, and a 10-year-old agroforest to assess the quantity and mechanisms of soil carbon sequestration in Loreto, Peru. Analysis of these metrics indicate that the chacra contained the greatest concentration of SOC resulting from recent and repeated burning events. At the same time, the SOC of the agroforest is nearly identical to that of the undisturbed mature forest, but displaced deeper in the soil profile. Notably, the agroforest was found to contain the greatest fine root content and most protected SOC out of all land uses. When evaluated in concert with the impacts of land use change on abiotic soil physical properties, the unique land use history of the agroforest creates the optimal conditions for long-term soil carbon build-up and protection. A history of burning added carbon to the soil while promoting infiltration and a subsequent translocation of SOC downward where SOC is readily protected via mineral and iron-oxide associations. Additionally, the maintenance of semi-permanent woody vegetation within cultivated management provides continuous litter input, deep root structures, and erosion control. Crucially, evaluating the agroforestry initiative for sustainability must also consider the cultural and socioeconomic needs of impacted campesinos and their communities. This study reviewed the initiative using a transformed version of the DWISH procedure to consider the simultaneous social and ecological limitations of a novel land management system. together, these investigations suggest that employing agroforestry can promote both cultural/socioeconomic and ecological sustainability.

Creative Commons License

Creative Commons Attribution-Noncommercial-No Derivative Works 3.0 License
This work is licensed under a Creative Commons Attribution-Noncommercial-No Derivative Works 3.0 License.

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