scholarly journals Carbon pool trends and dynamics within a subtropical peatland during long-term restoration

2017 ◽  
Author(s):  
Paul Julian ◽  
Stefan Gerber ◽  
Alan L. Wright ◽  
Binhe Gu ◽  
Todd Z. Osborne
Keyword(s):  
Water Conservation ◽  
Temporal Trends ◽  
Florida Everglades ◽  
Nutrient Inputs ◽  
Conservation Area ◽  
Organic C ◽  
C Pools ◽  
C Dynamics ◽  
Hydrologic Condition

AbstractBackgroundThe Florida Everglades has undergone significant ecological change spanning the continuum of disturbance to restoration. While the restoration effort is not complete and the ecosystem continues to experience short duration perturbations, a better understanding of long-term C dynamics of the Everglades is needed to facilitate new restoration efforts. This study evaluated temporal trends of different aquatic carbon (C) pools of the northern Everglades Protection Area over a 20-year period to gauge historic C cycling patterns. Dissolved inorganic C (DIC), dissolved organic C (DOC), particulate organic C (POC), and surface water carbon dioxide (pCO2(aq)) were investigated between May 1, 1994 and April 30, 2015.ResultsAnnual mean concentrations of DIC, DOC, POC, and pCO2(aq)significantly decreased through time or remained constant across the Water Conservation Areas (WCAs). Overall, the magnitude of the different C pools in the water column significantly differed between regions. Outgassing of CO2was dynamic across the Everglades ranging from 420 to 2001 kg CO2yr-1. Overall the historic trend in CO2flux from the marsh declined across our study area while pCO2(aq)largely remained somewhat constant with the exception of Water Conservation Area 2 which experienced significant declines in pCO2(aq). Particulate OC concentrations were consistent between WCAs, but a significantly decreasing trend in annual POC concentrations were observed.ConclusionsHydrologic condition and nutrient inputs significantly influenced the balance, speciation, and flux of C pools across WCAs suggesting a subsidy-stress response in C dynamics relative to landscape scale responses in nutrient availability. The interplay between nutrient inputs and hydrologic condition exert a driving force on the balance between DIC and DOC production via the metabolism of organic matter which forms the base of the aquatic foodweb. Along the restoration trajectory as water quality and hydrology continues to improve it is expected that C pools will respond accordingly.

scholarly journals Phylogenetic Characterization of Methanogenic Assemblages in Eutrophic and Oligotrophic Areas of the Florida Everglades

2004 ◽  
Vol 70 (11) ◽  
pp. 6559-6568 ◽  
Author(s):  
Hector Castro ◽  
Andrew Ogram ◽  
K. R. Reddy
Keyword(s):  
16S Rrna ◽  
16S Rrna Gene ◽  
Water Conservation ◽  
Phylogenetic Analyses ◽  
Florida Everglades ◽  
Rrna Gene ◽  
Conservation Area ◽  
Clone Libraries ◽  
Phylogenetic Characterization ◽  
Acetoclastic Methanogen

ABSTRACT Agricultural activities have produced well-documented changes in the Florida Everglades, including establishment of a gradient in phosphorus concentrations in Water Conservation Area 2A (WCA-2A) of the northern Everglades. An effect of increased phosphorus concentrations is increased methanogenesis in the eutrophic regions compared to the oligotrophic regions of WCA-2A. The goal of this study was to identify relationships between eutrophication and composition and activity of methanogenic assemblages in WCA-2A soils. Distributions of two genes associated with methanogens were characterized in soils taken from WCA-2A: the archaeal 16S rRNA gene and the methyl coenzyme M reductase gene. The richness of methanogen phylotypes was greater in eutrophic than in oligotrophic sites, and sequences related to previously cultivated and uncultivated methanogens were found. A preferential selection for the order Methanomicrobiales was observed in mcrA clone libraries, suggesting primer bias for this group. A greater diversity within the Methanomicrobiales was observed in mcrA clone libraries than in 16S rRNA gene libraries. 16S rRNA phylogenetic analyses revealed a dominance of clones related to Methanosaeta spp., an acetoclastic methanogen dominant in environments with low acetate concentrations. A significant number of clones were related to Methanomicrobiales, an order characterized by species utilizing hydrogen and formate as methanogenic substrates. No representatives of the orders Methanobacteriales and Methanococcales were found in any 16S rRNA clone library, although some Methanobacteriales were found in mcrA libraries. Hydrogenotrophs are the dominant methanogens in WCA-2A, and acetoclastic methanogen genotypes that proliferate in low acetate concentrations outnumber those that typically dominate in higher acetate concentrations.

scholarly journals Soil management effects on organic carbon in isolated fractions of a Gray Luvisol

2006 ◽  
Vol 86 (1) ◽  
pp. 141-151 ◽  
Author(s):  
A. F. Plante ◽  
C. E. Stewart ◽  
R. T. Conant ◽  
K. Paustian ◽  
J. Six
Keyword(s):  
Organic Matter ◽  
Crop Production ◽  
N Fertilization ◽  
Residue Management ◽  
Soil Organic C ◽  
Organic C ◽  
Straw Management ◽  
Soil C ◽  
C Pools

Agricultural management affects soil organic matter, which is important for sustainable crop production and as a greenhouse gas sink. Our objective was to determine how tillage, residue management and N fertilization affect organic C in unprotected, and physically, chemically and biochemically protected soil C pools. Samples from Breton, Alberta were fractionated and analysed for organic C content. As in previous reports, N fertilization had a positive effect, tillage had a minimal effect, and straw management had no effect on whole-soil organic C. Tillage and straw management did not alter organic C concentrations in the isolated C pools, while N fertilization increased C concentrations in all pools. Compared with a woodlot soil, the cultivated plots had lower total organic C, and the C was redistributed among isolated pools. The free light fraction and coarse particulate organic matter responded positively to C inputs, suggesting that much of the accumulated organic C occurred in an unprotected pool. The easily dispersed silt-sized fraction was the mineral-associated pool most responsive to changes in C inputs, whereas the microaggregate-derived silt-sized fraction best preserved C upon cultivation. These findings suggest that the silt-sized fraction is important for the long-term stabilization of organic matter through both physical occlusion in microaggregates and chemical protection by mineral association. Key words: Soil organic C, tillage, residue management, N fertilization, silt, clay

scholarly journals Heterogeneity of soil carbon pools and fluxes in a channelized and a restored floodplain section (Thur River, Switzerland)

2011 ◽  
Vol 8 (1) ◽  
pp. 1059-1091 ◽  
Author(s):  
E. Samaritani ◽  
J. Shrestha ◽  
B. Fournier ◽  
E. Frossard ◽  
F. Gillet ◽  
...  
Keyword(s):  
Soil Respiration ◽  
Spatial Heterogeneity ◽  
Soil Properties ◽  
Ecosystem Functions ◽  
Flood Disturbance ◽  
Organic C ◽  
C Pools ◽  
C Dynamics ◽  
Wide Range ◽  
Gravel Bars

Abstract. Due to their spatial complexity and dynamic nature, floodplains provide a wide range of ecosystem functions. However, because of flow regulation, many riverine floodplains have lost their characteristic heterogeneity. Restoration of floodplain habitats and the rehabilitation of key ecosystem functions has therefore become a major goal of environmental policy. Many important ecosystem functions are linked to organic carbon (C) dynamics in riparian soils. The fundamental understanding of the factors that drive the processes involved in C cycling in heterogeneous and dynamic systems such as floodplains is however only fragmentary. We quantified soil organic C pools (microbial C and water extractable organic C) and fluxes (soil respiration and net methane production) in functional process zones of adjacent channelized and widened sections of the Thur River, NE Switzerland, on a seasonal basis. The objective was to assess how spatial heterogeneity and temporal variability of these pools and fluxes relate to physicochemical soil properties on one hand, and to soil environmental conditions and flood disturbance on the other hand. Overall, factors related to seasonality and flooding (temperature, water content, organic matter input) affected soil C dynamics more than soil properties did. Coarse-textured soils on gravel bars in the restored section were characterized by low base-levels of organic C pools due to low TOC contents. However, frequent disturbance by flood pulses led to high heterogeneity with temporarily and locally increased pools and soil respiration. By contrast, in stable riparian forests, the finer texture of the soils and corresponding higher TOC contents and water retention capacity led to high base-levels of C pools. Spatial heterogeneity was low, but major floods and seasonal differences in temperature had additional impacts on both pools and fluxes. Soil properties and base levels of C pools in the dam foreland of the channelized section were similar to the gravel bars of the restored section. By contrast, spatial heterogeneity, seasonal effects and flood disturbance were similar to the forests, except for indications of high CH4 production that are explained by long travel times of infiltrating water favouring reducing conditions. Overall, the restored section exhibited both a larger range and a higher heterogeneity of organic C pools and fluxes as well as a higher plant biodiversity than the channelized section. This suggests that restoration has indeed led to an increase in functional diversity.

Trace metals in the soils of Water Conservation Area of Florida Everglades: Considerations for ecosystem restoration

2016 ◽  
Vol 18 (2) ◽  
pp. 342-351 ◽  
Author(s):  
Salwinder S. Dhaliwal ◽  
Gurpal S. Toor ◽  
Ignacio A. Rodriguez-Jorquera ◽  
Todd Z. Osborne ◽  
Susan Newman
Keyword(s):  
Trace Metals ◽  
Water Conservation ◽  
Ecosystem Restoration ◽  
Florida Everglades ◽  
Conservation Area ◽  
Water Conservation Area

Landscape analysis of tree island head vegetation in water conservation area 3, Florida Everglades

Wetlands ◽  
2008 ◽  
Vol 28 (2) ◽  
pp. 276-289 ◽  
Author(s):  
Paul R. Wetzel ◽  
Timothy Pinion ◽  
D. Timothy Towles ◽  
Lorraine Heisler
Keyword(s):  
Water Conservation ◽  
Landscape Analysis ◽  
Florida Everglades ◽  
Conservation Area ◽  
Tree Island ◽  
Water Conservation Area

scholarly journals Heterogeneity of soil carbon pools and fluxes in a channelized and a restored floodplain section (Thur River, Switzerland)

2011 ◽  
Vol 15 (6) ◽  
pp. 1757-1769 ◽  
Author(s):  
E. Samaritani ◽  
J. Shrestha ◽  
B. Fournier ◽  
E. Frossard ◽  
F. Gillet ◽  
...  
Keyword(s):  
Soil Respiration ◽  
Spatial Heterogeneity ◽  
Soil Properties ◽  
Ecosystem Functions ◽  
Flood Disturbance ◽  
Organic C ◽  
C Pools ◽  
C Dynamics ◽  
Wide Range ◽  
Gravel Bars

Abstract. Due to their spatial complexity and dynamic nature, floodplains provide a wide range of ecosystem functions. However, because of flow regulation, many riverine floodplains have lost their characteristic heterogeneity. Restoration of floodplain habitats and the rehabilitation of key ecosystem functions, many of them linked to organic carbon (C) dynamics in riparian soils, has therefore become a major goal of environmental policy. The fundamental understanding of the factors that drive the processes involved in C cycling in heterogeneous and dynamic systems such as floodplains is however only fragmentary. We quantified soil organic C pools (microbial C and water extractable organic C) and fluxes (soil respiration and net methane production) in functional process zones of adjacent channelized and widened sections of the Thur River, NE Switzerland, on a seasonal basis. The objective was to assess how spatial heterogeneity and temporal variability of these pools and fluxes relate to physicochemical soil properties on one hand, and to soil environmental conditions and flood disturbance on the other hand. Overall, factors related to seasonality and flooding (temperature, water content, organic matter input) affected soil C dynamics more than soil properties did. Coarse-textured soils on gravel bars in the restored section were characterized by low base-levels of organic C pools due to low TOC contents. However, frequent disturbance by flood pulses led to high heterogeneity with temporarily and locally increased C pools and soil respiration. By contrast, in stable riparian forests, the finer texture of the soils and corresponding higher TOC contents and water retention capacity led to high base-levels of C pools. Spatial heterogeneity was low, but major floods and seasonal differences in temperature had additional impacts on both pools and fluxes. Soil properties and base levels of C pools in the dam foreland of the channelized section were similar to the gravel bars of the restored section. By contrast, spatial heterogeneity, seasonal effects and flood disturbance were similar to the forests, except for indications of high CH4 production that are explained by long travel times of infiltrating water favoring reducing conditions. Overall, the restored section exhibited both a larger range and a higher heterogeneity of organic C pools and fluxes as well as a higher plant biodiversity than the channelized section. This suggests that restoration has indeed led to an increase in functional diversity.

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