The influence of climate change on recent peat accumulation patterns of Distichia muscoides cushion bogs in the high‐elevation tropical Andes of Colombia

Abstract

[1] Extensive cushions of Distichia muscoides found at high elevations in the Andes form deep deposits of peat and function as peatland. The location of Distichia peatlands at the highest elevations makes them susceptible to the effects of global change including global warming. Accumulation rates of organic matter are the key function of peatland ecosystems and are highly susceptible to changes in climate. This study used Pb activity with depth indicated rapid accumulation in recent times. Organic matter had a mean accumulation rate of 1400 g m À2 yr À1 during the past 10 years, with values well above the observed regional accumulation rate of 300-400 g m À2 yr À1 . The same pattern was observed in peat accretion rates, with growth rates of 1-2 cm per year during the last 10 years. Cushion plants engineer their own environment, allowing the system to be less susceptible to direct changes in climate. However, the high rates of peat accretion in recent times may be originated from increasing temperatures and excess water from nearby glacier melt. However, glaciers are predicted to disappear during the next 20 years in the northern Andes, reducing water inputs in tropical high-elevation ecosystems.

Long‐term monitoring of tropical alpine habitat change, Andean anurans, and chytrid fungus in the Cordillera Vilcanota, Peru: Results from a decade of study

“…Andean peatlands, such as the D. muscoides ‐dominated peatland in the Sibinacocha watershed, are azonal vegetation systems that depend on hydrological support year round, which may come from ground water, precipitation, or glacial outflow (Squeo, Warner, Aravena, & Espinoza, ). Melting glaciers provide a persistent inflow of water necessary for the maintenance and sustained growth of D. muscoides‐ dominated peatland vegetation (Benavides, Vitt, & Wieder, ), and periglacial lakes in the Cordillera Vilcanota region are widely observed to experience water level declines following the initial melt‐water pulse as retreating ice diminishes glacial provision of inflow (Hanshaw & Bookhagen, ). If the dominant source of water for a peatland system shifts or disappears—such as may occur with glacial runoff and outflow—then the peatland system may seasonally desiccate and eventually die‐off if no other hydrological support continues.…”

“…As cushion plants age and die, it is common for tussock grasses to colonize their centers in general alpine cyclical succession (Mark & Bastow, 2005) as observed in this study. The complete loss of glaciers driven by climatic changes is expected to have an overall effect of reducing Distichia-dominated habitat and wetlands (Anthelme, Cavieres, & Dangles, 2014;Benavides et al, 2013;Cooper et al, 2015;Herrera & Anthelme, 2015), for which these high-elevation anuran species are dependent for breeding and survival.…”

Rapid decline of snow and ice in the tropical Andes – Impacts, uncertainties and challenges ahead

“…5). Indeed a recent study in the páramo environment of the Colombian Andes suggests that glacier retreat and the excess meltwater, in combination with increased temperature may have led to higher rates of peat accretion in tropical wetlands (Benavides et al, 2013). The enhanced accumulation of organic biomass may, however, only be temporary, if glacier meltwater indeed spurred this enhanced carbon uptake.…”

Drivers of peatland water table dynamics in the central Andes, Bolivia and Peru

“…Several wetland types are common in the Andes, including seasonally saturated wet meadows that have mineral soils, and perennially saturated peat accumulating wetlands, regionally termed bofedales and referred to in this paper as peatlands (Chimner et al, In press;Cooper et al, 2010). The rate of organic matter production and accumulation in Andean peatlands are among the fastest known in the world (Benavides, Vitt, & Wieder, 2013;Cooper, Kaczynski, Slayback, & Yager, 2015;Earle & Aravena, 2003;Hribljan et al, 2015). In most valleys, peatlands initiated 3,000-10,000 years BP (Engel et al, 2014;Hribljan et al, 2015), have peat 3-10 m thick, and have been dominated by the same plant species for this vast time (Engel et al, 2014), indicating tremendous hydrological and ecological stability.…”