Greenhouse gas emissions from riparian zones are related to vegetation type and environmental factors
Megan Baskerville, Amir Behzad Bazrgar, Namratha Reddy, Enoch Ofosu, Naresh V. Thevathasan, Andrew M. Gordon, Maren Oelbermann
Abstract
Abstract 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.