Greenhouse gas emissions from riparian zones are related to vegetation type and environmental factors

Riparian zones provide multiple benefits, including streambank stabilization and nutrient abatement. However, there is a knowledge gap on how the type of vegetation and environmental factors (e.g., soil temperature, moisture) within the riparian zone influence CO 2 and CH 4 emissions. Our objective was to quantify and compare CO 2 and CH 4 emissions from a herbaceous (grass) riparian zone (GRS), a rehabilitated riparian zone composed of deciduous trees, an undisturbed natural forested riparian zone with deciduous trees (UNF‐D) or coniferous trees (UNF‐C), and an agricultural field. Cumulative soil CO 2 emission ranged from 23 to 105 g CO 2 –C m –2 . Carbon dioxide emissions were greatest ( p  < .05) in the GRS zone and lowest ( p  < .05) in the UNF‐C riparian zone. The best predictors for CO 2 emissions were soil temperature and soil organic carbon (SOC) content. Cumulative CH 4 emission ranged from –23 to 253 g CH 4 –C m –2 . Methane emissions were greatest ( p  < .05) in the UNF‐D and lowest ( p  < .05) in the GRS riparian zone. The best predictors for CH 4 emissions were soil moisture, SOC, and photosynthetic photon flux density. The total CO 2 –C equivalent (i.e., CH 4 + CO 2 ) was greatest ( p  < .05) for the GRS and lowest ( p  < .05) for the UNF‐C riparian zone. The environmental factors controlling CO 2 and CH 4 emissions within the various riparian zones did not change; instead, changes were due to how vegetation within riparian zones influenced these controls.