EGU22-13155
https://doi.org/10.5194/egusphere-egu22-13155
EGU General Assembly 2022
© Author(s) 2022. This work is distributed under
the Creative Commons Attribution 4.0 License.

Major CO2 losses from degradation of Mauritia flexuosa peat swamp forests in western Amazonia

Hergoualc’h Kristell1, van Lent Jeffrey1, Dezzeo Nelda1, Verchot Louis Vincent2, van Groenigen Jan Willem3, Lopez Mariela1, and Grandez-Rios Julio1
Hergoualc’h Kristell et al.
  • 1Center for International Forestry Research (CIFOR), Lima, Peru (k.hergoualch@cgiar.org)
  • 2Center for International Tropical Agriculture (CIAT), Cali, Colombia (l.verchot@cgiar.org)
  • 3Wageningen University and Research (WUR), Wageningen, The Netherlands (janwillem.vangroenigen@wur.nl)

Tropical peat swamp forests are major global carbon (C) stores that are particularly vulnerable to human intervention. In the Peruvian Amazonia they have been severely degraded through recurrent cutting of Mauritia flexuosa palms for fruit harvesting, and potentially been transformed from a CO2 sink into a significant source. To estimate emissions associated with degradation, we combined C stock changes in aboveground biomass with peat C losses along a gradient comprising undegraded (Intact), moderately degraded (mDeg) and heavily degraded (hDeg) palm swamps. Temporal and spatial dynamics of the main components of the peat C budget (heterotrophic soil respiration (Rh) and litterfall) were investigated (bi)monthly over three years, while annual site-specific root C inputs and default dissolved organic C exports were taken from the literature. Variables measured at tree or microtopographic level were site-scaled considering forest structural changes from degradation. Site-scale litterfall (Mg C ha−1 year−1) at the hDeg site (2.3 ± 0.5) was less than half the rate at the Intact and mDeg sites (5.2 ± 0.9 and 6.0 ± 1.6, respectively). Conversely, site-scale Rh (Mg C ha−1 year−1) was higher at the hDeg site (9.6 ± 0.6) than at the Intact and mDeg sites (7.5 ± 1.1 and 6.1 ± 0.5, respectively). The peat carbon budget (Mg C ha−1 year−1) indicated that medium degradation reduced the sink capacity of the soil (from -1.8 ± 1.8 at the Intact site to -0.3 ± 0.7 at the mDeg site) while high degradation turned the soil into a high C source (6.0 ± 0.6 at the hDeg site). The large total C stock loss rates of 23.5 ± 14.3 and 57.7 ± 14.3 Mg CO2 ha−1 year−1 at the mDeg and hDeg sites, respectively, which originated 94 and 77% from aboveground biomass changes clearly highlight the need for sustainable management of these peatlands.

How to cite: Kristell, H., Jeffrey, V. L., Nelda, D., Louis Vincent, V., Jan Willem, V. G., Mariela, L., and Julio, G.-R.: Major CO2 losses from degradation of Mauritia flexuosa peat swamp forests in western Amazonia, EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-13155, https://doi.org/10.5194/egusphere-egu22-13155, 2022.