Influence of light, temperature and salinity on dissolved organic carbon exudation rates in Zostera marina L.

Kaldy, James E.

doi:10.1186/2046-9063-8-19

Cited by 29 publications

(22 citation statements)

References 56 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Radial oxygen loss from roots also decreases sediment sulfide concentrations (Pagès et al 2012), potentially enhancing denitrification and decreasing chemolithoautotrophic DNRA (Brunet and Garcia-Gil 1996). Seagrass ecosystems accumulate sediment carbon through increased sedimentation and the release of carbon exudates from living roots (Kaldy 2012;Greiner et al 2013). This sediment carbon may support nitrate reduction since reduced carbon substrate is necessary for both denitrification and fermentative DNRA, and a high C : N ratio may enhance both fermentative and chemolithoautotrophic DNRA (Tiedje et al 1982;Burgin and Hamilton 2007).…”

mentioning

confidence: 99%

Push‐pull incubation method reveals the importance of denitrification and dissimilatory nitrate reduction to ammonium in seagrass root zone

Aoki

McGlathery

2017

Limnol. Oceanogr. Methods

View full text Add to dashboard Cite

In this study, we developed a push‐pull incubation method to measure denitrification and dissimilatory nitrate reduction to ammonium (DNRA) in subsurface sediments of subtidal seagrass meadows. This subtidal push‐pull technique, adapted from a push‐pull method developed for intertidal salt marshes, used mini‐piezometers to directly sample pore water in the root zone of the seagrass during an in situ incubation. The pore water was amended with 15 NO3− and with Ar(g) as a tracer gas, and the denitrification products (28N2(g), 29N2(g), and 30N2(g)) were measured with membrane inlet mass spectrometry (MIMS), using the Ar tracer to correct for dilution and gas loss. Production of 15 NH4+ was also measured using hypobromite oxidation and MIMS to determine rates of DNRA. Using this new technique, subsurface rates of denitrification and DNRA were determined to be 17.5 μmol N m−2 h−1 and 14.7 μmol N m−2 h−1, respectively, for a restored Zostera meadow. Rates showed substantial spatial variability, likely due to both heterogeneous conditions in the root zone sediment and variable in situ conditions. When compared to traditional core and slurry incubations, push‐pull rates were greater and more variable, suggesting that the push‐pull technique more accurately captures heterogeneity and the natural range of denitrification and DNRA in subsurface sediments under field conditions. In vegetated systems with low water column nitrate concentrations, the majority of denitrification and DNRA occurs below the sediment surface, and the subtidal push‐pull technique provides an effective method to assess these subsurface rates.

show abstract

mentioning

confidence: 99%

Push‐pull incubation method reveals the importance of denitrification and dissimilatory nitrate reduction to ammonium in seagrass root zone

Aoki

McGlathery

2017

Limnol. Oceanogr. Methods

View full text Add to dashboard Cite

show abstract

“…Local Z. marina plants tend to have long leaf lengths (>100 cm) and only 20 to 40% of total biomass as rhizome + root tissue (Kaldy 2012). Although studies indicate carbon translocation to belowground tissues of Z. marina (Wetzel & Penhale 1979, Zimmerman & Alberte 1996, recent work suggests a limited capacity for Z. marina to influence sediment biogeochemical processes directly through organic carbon exudation (Boschker et al 2000, Kaldy 2012). The chemical composition of seagrassderived dissolved organic constituents in the sediments remains unresolved.…”

Section: Discussionmentioning

confidence: 99%

In situ 13C tracer experiments elucidate carbon translocation rates and allocation patterns in eelgrass Zostera marina

Kaldy¹,

Brown²,

Andersen³

2013

Mar. Ecol. Prog. Ser.

View full text Add to dashboard Cite

Zostera marina L. carbon dynamics have been intensively studied, yet in situ translocation rate estimates remain elusive, particularly for north temperate seagrasses. To better understand carbohydrate synthesis, allocation and use in Z. marina, we conducted summer and winter in situ 13 C labeling experiments and measured the δ 13 C of bulk tissue and individual carbohydrate compounds. Leaf tissue exhibited immediate isotope enrichment within hours of the tracer pulse. As the isotope ratio of the leaf tissue decreased over a period of days, enrichment became more evident in the belowground tissues (rhizome and roots) not directly exposed to the 13 C-dissolved inorganic carbon label, indicating that non-structural carbohydrate was translocated belowground. Rhizome δ 13 C increased for up to 2 wk after the 13 C label pulse. The isotopic enrichment of glucose, fructose and sucrose were similar and significantly greater than the enrichment of myo-inositol. Maximum enrichment occurred in the glucose pool, with leaf tissue at 258 ± 61 ‰ and rhizome tissue at 55.1 ± 28.8 ‰ during the July 2004 labeling period. Leaf excess 13 C loss rates (4 d average) were on the order of 11% 13 C d −1 , while the excess 13 C accumulation rate in the rhizome combined with roots was about 1.5% 13 C d −1 (4 d average). Whole plant excess 13 C loss rates as a result of respiration, detrital production and exudation ranged between about 8.8 and 10% 13 C d −1 (4 d average). The results provide important estimates of carbon uptake and translocation that can be used to better understand whole plant carbon budgets as well as the transfer of seagrass-derived carbon to other trophic communities.

show abstract

“…The rhizospheres of plants assigned to the sod treatment group were left undisturbed. The rhizomes of plants in the wash treatment were trimmed to retain five internodes connected to the first five root bundles (74), and rhizomes of sod transplants were standardized by trimming to lengths matching those of washed plants. Plant leaves were standardized across treatments by trimming to 50 cm (75).…”

Section: Methodsmentioning

confidence: 99%

Recovery and Community Succession of theZostera marinaRhizobiome After Transplantation

Wang

English

Tomàs

et al. 2020

Preprint

View full text Add to dashboard Cite

18Seagrasses can form mutualisms with their microbiomes that facilitate the exchange of 19 energy sources, nutrients, and hormones, and ultimately impact plant stress resistance. Little is 20 known about community succession within the belowground seagrass microbiome after 21 disturbance and its potential role in the plant's recovery after transplantation. We transplanted 22 Zostera marina shoots with and without an intact rhizosphere and cultivated plants for four 23 weeks while characterizing microbiome recovery and effects on plant traits. Rhizosphere and 24 root microbiomes were compositionally distinct, likely representing discrete microbial niches. 25 Furthermore, microbiomes of washed transplants were initially different from those of sod 26 transplants, and recovered to resemble an undisturbed state within fourteen days. Conspicuously, 27 changes in microbial communities of washed transplants corresponded with changes in 28 rhizosphere sediment mass and root biomass, highlighting the strength and responsive nature of 29 the relationship between plants, their microbiome, and the environment. Potential mutualistic 30 microbes that were enriched over time include those that function in the cycling and turnover of 31 sulfur, nitrogen, and plant-derived carbon in the rhizosphere environment. These findings 32 highlight the importance and resiliency of the seagrass microbiome after disturbance. 33 Consideration of the microbiome will have meaningful implications on habitat restoration 34 practices. 35Importance 37 Seagrasses are important coastal species that are declining globally, and transplantation 38 can be used to combat these declines. However, the bacterial communities associated with 39 seagrass rhizospheres and roots (the microbiome) are often disturbed or removed completely 40 prior to transplantation. The seagrass microbiome benefits seagrasses through metabolite, 41 nutrient, and phytohormone exchange, and contributes to the ecosystem services of seagrass 42 meadows by cycling sulfur, nitrogen, and carbon. This experiment aimed to characterize the 43 importance and resilience of the seagrass belowground microbiome by transplanting Zostera 44 marina with and without intact rhizospheres and tracking microbiome and plant morphological 45 recovery over four weeks. We found the seagrass microbiome to be resilient to transplantation 46 disturbance, recovering after fourteen days. Additionally, microbiome recovery was linked with 47 seagrass morphology, coinciding with increases in rhizosphere sediment mass and root biomass. 48Results of this study can be used to include microbiome responses in informing future restoration 49 work. 52The rhizobiome has long been recognized to have important impacts on plant growth and 53 health (1). The microbes of the rhizobiome, which directly interact with and are influenced by 54 the roots (2), can benefit their plant hosts through recycling and producing bioavailable nutrients 55 (3-5), increasing disease resistance through competition with or in...

show abstract

Influence of light, temperature and salinity on dissolved organic carbon exudation rates in Zostera marina L.

Cited by 29 publications

References 56 publications

Push‐pull incubation method reveals the importance of denitrification and dissimilatory nitrate reduction to ammonium in seagrass root zone

Push‐pull incubation method reveals the importance of denitrification and dissimilatory nitrate reduction to ammonium in seagrass root zone

In situ 13C tracer experiments elucidate carbon translocation rates and allocation patterns in eelgrass Zostera marina

Recovery and Community Succession of theZostera marinaRhizobiome After Transplantation

Contact Info

Product

Resources

About