Dominance by Spartina densiflora slows salt marsh litter decomposition

PEDRO DALEO; MONTEMAYOR DIANA; EUGENIA FANJUL; ALBERTI JUAN; BRUSCHETTI, C.M.; MARTINETTO, P.; PASCUAL JESUS; OSCAR IRIBARNE

JOURNAL OF VEGETATION SCIENCE

WILEY-BLACKWELL PUBLISHING, INC

Lugar: Londres; Año: 2020 vol. 31 p. 1181 - 1191

1100-9233

Questions?: Dueto their efficiency sequestering and storing atmospheric CO2,coastal vegetated systems are known to play a fundamental role inclimate change mitigation. While most of the workevaluating carbon sequestration capacity has focused on global changefactors that can affect carbon release from plant litterdecomposition through changes in (large-scale) environmentalconditions, less is known about the possible effects of the loss (orreplacement) of dominant species. We hypothesized that dominant marshplants can influence decomposition not only through changes inliter quality but also through changes in (micro-scale) soilenvironmental conditions such as humidity, soil temperature or solarradiation.?Location?:We performed a field manipulative experiment in a South Western (SW)Atlantic salt marsh, in Argentina?Methods?: Wesimulate a selective disturbance (i.e. removal of the dominant grassspecies Spartina densiflora) thus allowing removal plots todevelop an alternative plant community. To evaluate the effect of thedominant grass species on litter decomposition, weperformed a litterbag approach experiment three years after theestablishment of the removal plots. ?Results?:Results showed that the presence of S.densiflora significantly decreasedlitter decomposition directly by producing less labile litter, butalso by effects that seem to be related to its structure as standingdominant vegetation. The experimental removal of S.densiflora led to an alternative plantcommunity, formed by otherwise subordinate species, which is lessdensely packed, allowing higher soil radiation incidence and elevatedmidday soil temperature.?Conclusions?:Our results suggest that salt marsh litter decomposition, andthus C sequestration, is determined in part by the identity of thedominant plant, not only because of the quality of produced litterbut also as a consequence of thestructure of vegetation. Changes in species diversity, above all thedominant species in these coastal systems, could have large impactson carbon turnover and mitigation capacity of these ecosystems. p { margin-bottom: 0cm; line-height: 200%; text-align: center; orphans: 2; widows: 2 }p.western { font-family: "Times New Roman", serif; so-language: en-US }p.cjk { font-family: "Times New Roman", serif }p.ctl { font-family: "Times New Roman", serif; so-language: ar-SA }a:link { color: #0000ff }