Dominance by Spartina densiflora slows salt marsh litter decomposition

DALEO, P.; MONTEMAYOR, D.; FANJUL, E.; ALBERTI J; BRUSCHETTI, M.; MARTINETTO, P; PASCUAL, J.; IRIBARNE, O.

JOURNAL OF VEGETATION SCIENCE

WILEY-BLACKWELL PUBLISHING, INC

Lugar: Londres; Año: 2020 vol. 31 p. 1182 - 1192

1100-9233

?Questions?:Due to their efficiencysequestering and storing atmospheric CO2,coastal vegetated systems are known to play a fundamental role inclimate change mitigation. While mostof the work evaluating carbon sequestration capacity has focused onglobal change factors that can affect carbon release from plantlitter decomposition 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 caninfluence decomposition not only through changes in liter quality butalso through changes in (micro-scale) soil environmental conditionssuch as humidity, soil temperature or solar radiation. ?Location?:We performed a field manipulative experimentin a South Western (SW) Atlantic salt marsh, in Argentina?Methods?:Wesimulatea selective disturbance (i.e. removal of the dominant grass speciesSpartinadensiflora)thus allowing removal plots to develop an alternative plantcommunity. To evaluate the effect of the dominant grass species onlitter decomposition, weperformed a litterbag approach experiment three years after theestablishmentof the removalplots. ?Results?:Resultsshowed that the presence of S.densiflorasignificantlydecreasedlitter 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.densifloraled to an alternative plant community, formed by otherwisesubordinate species, which is less densely packed, allowing highersoil radiation incidence and elevated midday soil temperature.?Conclusions?:Our resultssuggest that salt marsh litter decomposition, and thus Csequestration, is determined in part by the identity of the dominantplant, not only because of the quality of produced litter but also asa 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; direction: ltr; color: #000000; line-height: 200%; text-align: center; orphans: 2; widows: 2 }p.western { font-family: "Times New Roman", serif; font-size: 12pt; so-language: en-US }p.cjk { font-family: "Times New Roman", serif; font-size: 12pt; so-language: zh-CN }p.ctl { font-family: "Times New Roman", serif; font-size: 12pt; so-language: ar-SA }a:link { color: #0000ff }