Below-ground carbon gradients surrounding Saskatchewan's native agricultural copses

Area of Science:

• Agricultural Science
• Ecosystem Carbon Storage
• Soil Science

Background:

• Understanding agricultural land carbon storage is vital for developing carbon markets.
• Below-ground ecosystems hold two-thirds of global carbon.
• Carbon storage in native prairie woody vegetation remains understudied.

Purpose of the Study:

• To quantify below-ground carbon storage in native trembling aspen (Populus tremuloides) copses.
• To compare carbon storage in native copses versus surrounding agricultural fields.
• To identify key soil horizons influencing carbon storage differences.

Main Methods:

• Collected leaf, fibric, humic layer (LFH), and soil samples (up to 60 cm) from 142 locations in Saskatchewan's Black soil zone.
• Sampled under six native woody copses and 24 transects extending into agricultural fields.
• Quantified total, organic, and inorganic carbon using temperature ramping, analyzing by soil horizons.

Main Results:

• A clear carbon gradient was observed from the copse into the agricultural field.
• Native copses stored 111% more total carbon than agricultural fields, mainly as organic carbon.
• The LFH and A-horizon were the most significant contributors to carbon storage differences.

Conclusions:

• Native copses store substantially more organic carbon (82-90%) compared to planted shelterbelts.
• These findings underscore the importance of including native woody vegetation in Canadian Prairies carbon models.
• Quantifying below-ground carbon in native vegetation is essential for effective carbon market development.