2017) however, its impact on long-term peat accumulation remains unstudied. The effect of this practice substantially alters the composition and structure of the forest (Hergoualc’h et al. 2012), fruit harvesting continues to involve cutting down entire palms. Even though more sustainable (climbing) techniques exist (Horn et al. flexuosa palms (locally referred to as “ Aguaje”) and palm weevils ( Rhynchophorus palmarum) that grow inside dead palms are highly demanded products in the regional market and are important sources of vitamins and proteins for rural communities (Pacheco Santos 2005).
flexuosa palms from natural stands without drainage or fire. In contrast, anthropogenic degradation of peatland in the Peruvian Amazon is mostly related to recurrent harvesting of M. Therein Southeast Asia, peatlands are under great pressure from agricultural expansion, artificial drainage, and fires, which result in considerable GHG emissions (Gaveau et al. The challenges that Peruvian peatlands face are substantially different from those in Southeast Asia. 2017), and greenhouse gas (GHG) fluxes (Teh et al. 2017), the characterization of degradation (Hergoualc’h et al. ( 2009a) explored their extent, research further expanded into other fields such as palaeoecology (Roucoux et al. Interest in the carbon pools of the Peruvian Amazon peatlands has increased in recent years. Mauritia flexuosa-dominated palm swamp forests are the dominant peatland ecosystem type in the Peruvian Amazon (Draper et al. Peru is estimated to harbor one of the largest extents of tropical peatlands in the world (Gumbricht et al. 2015) use this balance to predict long-term peat accumulation via vegetation-specific characteristics such as decomposition speed and primary production. Models such as the Holocene Peat Model-HPM (Frolking et al. 2005 Hergoualc’h and Verchot 2011 Hoyos-Santillan et al. In natural conditions, the portion of SOM that is decomposed and emitted as carbon dioxide (CO 2) or methane (CH 4) is usually outweighed by the continuous input of fresh litter and roots (Jauhiainen et al. 2004), as continuous input of organic material from lowland tropical evergreen vegetation combined with anaerobic soil conditions lead to a build-up of soil organic matter (SOM) over time (Jauhiainen et al. In addition, tropical peatlands are among the most efficient terrestrial ecosystems for carbon sequestration (Dommain et al. 2011) and are crucial for mitigating climate change (Murdiyarso et al. Tropical peatlands are a globally important carbon stock of 87–350 GtC (Gumbricht et al. These changes might alter long-term carbon and GHG balances of the peat, and the role of these ecosystems for climate change mitigation, which stresses the need for their protection. flexuosa harvesting could result in a significant increase of in situ CO 2 fluxes and a simultaneous decrease in CH 4 emissions via pneumatophores. Lastly, the density of pneumatophore decreased drastically as the result of forest degradation and was positively correlated to in situ CH 4 emissions. There was no significant response of nitrous oxide (N 2O) emissions to WFPS variation. Methane (CH 4) was produced in limited amounts and exclusively under water-saturated conditions. The response of CO 2 production to changes in water-filled pore space (WFPS) followed a cubic polynomial relationship with maxima at 60–70% at the three sites. Soils from the degraded sites consistently produced more carbon dioxide (CO 2) than soils from the intact site during in vitro incubations. The soil phosphorus and carbon content and carbon-to-nitrogen ratio as well as the litterfall nitrogen content and carbon-to-nitrogen ratio were significantly affected by forest degradation. To understand underlying factors driving GHG emissions, we examined the response of in vitro soil microbial GHG emissions to soil moisture variation, and we tested the potential of pneumatophores to conduct GHGs in situ. We studied peat and litterfall characteristics along a forest degradation gradient that included an intact site, a moderately degraded site, and a heavily degraded site.
This is an important type of forest degradation in the region that could lead to changes in the structure and composition of the forest, quality and quantity of inputs to the peat, soil properties, and greenhouse gas (GHG) fluxes. Tropical peatlands in the Peruvian Amazon exhibit high densities of Mauritia flexuosa palms, which are often cut instead of being climbed for collecting their fruits.