Evaluating farm hedgerows for their climate change mitigation potential in the lower Fraser River delta of British Columbia

Project Lead: Bryanna Thiel
Project Type: MSc Soil Science
Supervisor: Dr. Sean Smukler
Project Partner: Delta Farmland and Wildlife Trust

Background and Rationale

To feed the global population, agricultural landscapes currently cover approximately 37% of the Earth’s surface (Sommer & Bossio, 2014), yet these landscapes also contribute substantially to global warming through elevated greenhouse gas (GHG) emissions from activities such as soil tillage, fossil fuel and fertilizer use, and livestock production. Developing land management strategies at both the farm-scale and landscape scale that can be employed by land users and policy makers to help mitigate the GHG contribution of agriculture is necessary, and will be critical as pressures to produce more food increase in the future. Recent studies have started to investigate how agroforestry systems can play a role in the climate change mitigation potential on farmland (Schoeneberger, 2008; Schoeneberger et al., 2012; Udawatta & Jose, 2012).  Research is being conducted in the lower Fraser River delta of British Columbia, Canada, because a unique opportunity exists here to investigate if different management strategies for non-production areas in the form of hedgerows (linear structures of perennial woody vegetation) affect the climate change mitigation potential of the agricultural landscape differently. Our project partner, Delta Farmland & Wildlife Trust, a local not-for-profit conservation organization works closely with farmers to optimize the regional ecosystem services of agricultural landscapes such as food production, nutrient cycling, provision of wildlife habitat, and even improved public awareness about landscape function. Their Hedgerow Stewardship Program introduces planted hedgerows onto farmland primarily for habitat purposes, however, knowledge of the climate change mitigation potential benefit of these areas compared to remnant hedgerows (naturally regenerated areas) is of great interest to DF&WT to improve their land management decisions and determine what role they can play in climate change mitigation in the region.

Objectives

The objectives of the study will be to quantify and compare 1) the carbon stored by the perennial vegetation in its biomass, 2) the carbon stored in the soil, 3) the rate of CO2-equivalent emissions being lost from the soil to the atmosphere by carbon dioxide, nitrous oxide and methane, from planted hedgerows, remnant hedgerows, and neighbouring production fields. If the net flow is positive (more carbon escaping the system than entering), the net mitigation potential is low, and if the net flow is negative (more carbon entering the system than leaving), the net mitigation potential is high.

Additionally, a goal of this investigation is to inform the Delta Farmland and Wildlife Trust about the differences in performance of these hedgerows to influence their Hedgerow Stewardship Program policies and farm management partnerships with farmers in the region.

Research Questions

  1. Do planted hedgerows perform differently than remnant hedgerows with regard to climate change mitigation?
  2. How do planted and remnant hedgerows perform relative to production fields for climate change mitigation?

Thesis 

Thiel, B. (2014). Evaluating farm hedgerows for their climate change mitigation potential in the lower Fraser River delta of British Columbia

Publications:

  1. Thiel, B., Krzic, S. Gergel, C. Terpsma, Black, A., Jassal, P., and S. M. Smukler. (2017). Soil CO2, CH4 and N2O emissions from production fields with planted and remnant hedgerows in the Fraser River Delta of British Columbia. Agroforest Syst. 91: 1139. https://doi.org/10.1007/s10457-016-9990-3
  2. Thiel, B., S.M. Smukler, M. Krzic, S. Gergel, and C. Terpsma. (2015). Using hedgerow biodiversity to enhance the carbon storage of farmland in the Fraser River delta of British Columbia. Journal of Soil and Water Conservation, 70:247–256.  doi: 10.2489/jswc.70.4.247

Photos: Visit the project’s photo page to see photos of the field work being conducted.

Video: What are the benefits of farmland hedgerows?

Project Briefs:

Brief#1 Hedgerow Benefits & the Delta, BC Hedgerow Project

Brief#2  Findings from the Farm-scale Analysis of the Delta, BC Hedgerow Study

Brief#3  Findings from the Landscape Analysis of the Delta, BC Hedgerow Study

Comprehensive Report:

Improving on-farm woody habitat management in the Lower Fraser Valley

References and Links

Schoeneberger, M. (2008). Agroforestry: working trees for sequestering carbon on agricultural lands. Agroforestry Systems, 75(1), 27–37. doi:10.1007/s10457-008-9123-8

Schoeneberger, M., Bentrup, G., de Gooijer, H., Soolanayakanahally, R., Sauer, T., Brandle, J., … Current, D. (2012). Branching out: Agroforestry as a climate change mitigation and adaptation tool for agriculture. Journal of Soil and Water Conservation, 67(5), 128A–136A. doi:10.2489/jswc.67.5.128A

Sommer, R., & Bossio, D. (2014). Dynamics and climate change mitigation potential of soil organic carbon sequestration. Journal of Environmental Management, 144, 83–87. doi:10.1016/j.jenvman.2014.05.017

Udawatta, R. P., & Jose, S. (2012). Agroforestry strategies to sequester carbon in temperate North America. Agroforestry Systems, 86(2), 225–242. doi:10.1007/s10457-012-9561-1