Geospatial variability of soil CO2–C exchange in the main terrestrial ecosystems of Keller Peninsula, Maritime Antarctica

Abstract. Integrated studies on the interplay between soils, periglacial geomorphology and plant communities are crucial for the understanding of climate change effects on terrestrial ecosystems of maritime Antarctica, one of the most sensitive areas to global warming. Knowledge on physical environmental factors that influence plant communities can greatly benefit studies on the monitoring of climate change in maritime Antarctica, where new ice-free areas are being constantly exposed, allowing plant growth and organic carbon inputs. The relationship between topography, plant communities and soils was investigated on Potter Peninsula, King George Island, maritime Antarctica. We mapped the occurrence and distribution of plant communities and identified soil–landform–vegetation relationships. The vegetation map was obtained by classification of a QuickBird image, coupled with detailed landform and characterization of 18 soil profiles. The sub-formations were identified and classified, and we also determined the total elemental composition of lichens, mosses and grasses. Plant communities on Potter Peninsula occupy 23% of the ice-free area, at different landscape positions, showing decreasing diversity and biomass from the coastal zone to inland areas where sub-desert conditions prevail. There is a clear dependency between landform and vegetated soils. Soils that have greater moisture or are poorly drained, and with acid to neutral pH, are favourable for moss sub-formations. Saline, organic-matter-rich ornithogenic soils of former penguin rookeries have greater biomass and diversity, with mixed associations of mosses and grasses, while stable felsenmeers and flat rocky cryoplanation surfaces are the preferred sites for Usnea and Himantormia lugubris lichens at the highest surface. Lichens sub-formations cover the largest vegetated area, showing varying associations with mosses.

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Soil CO<sub>2</sub> efflux errors are lognormally distributed – implications and guidance

Geoscientific Instrumentation Methods and Data Systems ◽

10.5194/gi-9-239-2020 ◽

2020 ◽

Vol 9 (1) ◽

pp. 239-254

Author(s):

Thomas Wutzler ◽

Oscar Perez-Priego ◽

Kendalynn Morris ◽

Tarek S. El-Madany ◽

Mirco Migliavacca

Keyword(s):

Random Error ◽

Carbon Sink ◽

Spatial Scales ◽

Good Practice ◽

Terrestrial Ecosystems ◽

Soil Co2 Efflux ◽

Co2 Efflux ◽

Soil Co2 ◽

Value Differences ◽

Distributional Assumptions

Abstract. Soil CO2 efflux is the second-largest carbon flux in terrestrial ecosystems. Its feedback to climate determines model predictions of the land carbon sink, which is crucial to understanding the future of the earth system. For understanding and quantification, however, observations by the most widely applied chamber measurement method need to be aggregated to larger temporal and spatial scales. The aggregation is hampered by random error that is characterized by occasionally large fluxes and variance heterogeneity that is not properly accounted for under the typical assumption of normally distributed fluxes. Therefore, we explored the effect of different distributional assumptions on the aggregated fluxes. We tested the alternative assumption of lognormally distributed random error in observed fluxes by aggregating 1 year of data of four neighboring automatic chambers at a Mediterranean savanna-type site. With the lognormal assumption, problems with error structure diminished, and more reasonable prediction intervals were obtained. While the differences between distributional assumptions diminished when aggregating data of single chambers to an annual value, differences were important on short timescales and were especially pronounced when aggregating across chambers to plot level. Hence we recommend as a good practice that researchers report plot-level fluxes with uncertainties based on the lognormal assumption. Model data integration studies should compare predictions and observations of soil CO2 efflux on a log scale. This study provides methodology and guidance that will improve the analysis of soil CO2 efflux observations and hence improve understanding of soil carbon cycling and climate feedbacks.

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Spatial and temporal variability in soil CO2–C emissions and relation to soil temperature at King George Island, maritime Antarctica

Polar Science ◽

10.1016/j.polar.2010.07.001 ◽

2010 ◽

Vol 4 (3) ◽

pp. 479-487 ◽

Cited By ~ 14

Author(s):

Newton La Scala ◽

Eduardo de Sá Mendonça ◽

Juliana Vanir de Souza ◽

Alan Rodrigo Panosso ◽

Felipe N.B. Simas ◽

...

Keyword(s):

Soil Temperature ◽

Temporal Variability ◽

Spatial And Temporal Variability ◽

King George Island ◽

Soil Co2 ◽

Maritime Antarctica

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Nematode communities of Byers Peninsula, Livingston Island, maritime Antarctica

Antarctic Science ◽

10.1017/s0954102011000174 ◽

2011 ◽

Vol 23 (4) ◽

pp. 349-357 ◽

Cited By ~ 12

Author(s):

Uffe N. Nielsen ◽

Diana H. Wall ◽

Grace Li ◽

Manuel Toro ◽

Byron J. Adams ◽

...

Keyword(s):

Community Composition ◽

Abiotic Factors ◽

Biotic Interactions ◽

Terrestrial Ecosystems ◽

Nematode Species ◽

Trophic Group ◽

Maritime Antarctica ◽

Nematode Communities ◽

Livingston Island ◽

Harsh Conditions

AbstractThe nematode communities of Antarctica are considered simple. The few species present are well adapted to the harsh conditions and often endemic to Antarctica. Knowledge of Antarctic terrestrial ecosystems is increasing rapidly, but nematode communities remain to be explored in large parts of Antarctica. In soil samples collected at Byers Peninsula (Antarctic Specially Protected Area No. 126), Livingston Island we recorded 37 nematode taxa but samples showed great variation in richness and abundance. Nematode richness decreased with increasing soil pH, whereas total abundances, and the abundance of several trophic groups, were greatest at intermediate pH (around 6.5–7). Moreover, the community composition was mainly related to pH and less so to soil moisture. Trophic group, and total nematode, rotifer and tardigrade, abundances were generally positively correlated. Byers Peninsula is thus, by maritime Antarctic standards, a nematode biodiversity hotspot, and the presence of several previously unrecorded genera indicates that nematode species richness in maritime Antarctica is probably underestimated. Our results indicate that abiotic factors influence nematode communities with little evidence for biotic interactions. The unexplained heterogeneity in community composition is probably related to variation in microclimate, vegetation, topography and unmeasured soil properties, but may also be contributed to by biological processes.

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Elevated Tropospheric Ozone Concentration Alters Soil CO2 Emission: A Meta-Analysis

Sustainability ◽

10.3390/su13084571 ◽

2021 ◽

Vol 13 (8) ◽

pp. 4571

Author(s):

Enzhu Hu ◽

Zhimin Ren ◽

Sheng Xu ◽

Weiwei Zhang

Keyword(s):

Tropospheric Ozone ◽

Co2 Emission ◽

Meta Analysis ◽

Co2 Enrichment ◽

Terrestrial Ecosystems ◽

Soil Co2 Efflux ◽

Co2 Efflux ◽

Soil Co2 ◽

Soil C ◽

Soil Co2 Emission

Elevated tropospheric ozone (O3) concentration may substantially influence the below-ground processes of terrestrial ecosystems. Nevertheless, a comprehensive and quantitative understanding of O3 impacts on soil CO2 emission remains elusive, making the future sources or sinks of soil C uncertain. In this study, 77 pairs of observations (i.e., elevated O3 concentration treatment versus control) extracted from 16 peer-reviewed studies were synthesized using meta-analysis. The results depicted that soil CO2 efflux was significantly reduced under short-term O3 exposure (≤1 year, p < 0.05), while it was increased under extended duration (>1 year, p < 0.05). Particularly, soil CO2 emission was stimulated in nonagricultural ecosystems, in the free-air CO2 enrichment (FACE) experiment, and in the soils of lower pH. The effect sizes of soil CO2 efflux were significantly positively correlated with experimental duration and were significantly negatively correlated with soil pH, respectively. The ozone effect on soil CO2 efflux would be enhanced at warm temperatures and high precipitation. The duration of O3 exposure was the fundamental factor in analyzing O3 impacts on soil CO2 emission.

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Soil CO<sub>2</sub> efflux errors are log normally distributed – Implications and guidance

10.5194/gi-2019-10 ◽

2019 ◽

Author(s):

Thomas Wutzler ◽

Oscar Perez-Priego ◽

Kendalynn Morris ◽

Tarek El-Madany ◽

Mirco Migliavacca

Keyword(s):

Random Error ◽

Carbon Sink ◽

Spatial Scales ◽

Good Practice ◽

Terrestrial Ecosystems ◽

Soil Co2 Efflux ◽

Co2 Efflux ◽

Soil Co2 ◽

Distributional Assumptions ◽

Normally Distributed

Abstract. Soil CO2 efflux is the second largest carbon flux in terrestrial ecosystems. Its feedback to climate determines model predictions of the land carbon sink, which is crucial to understanding the future of the earth system. For understanding and quantification, however, observations by the most widely applied chamber measurement method need to be aggregated to larger temporal and spatial scales. The aggregation is hampered by random error that is characterized by occasionally large fluxes and variance heterogeneity that is not properly accounted for under the typical assumption of normally distributed fluxes. Therefore, we explored the effect of different distributional assumptions on the aggregated fluxes. We tested the alternative assumption of log-normally distributed random error in observed fluxes by aggregating one year of data of four neighbouring automatic chambers at a Mediterranean savanna-type site. With the lognormal assumption, problems with error structure diminished and more reasonable confidence intervals were obtained. While the differences between distributional assumptions diminished when aggregating data of single chambers to an annual value, differences were important at short time scales and were especially pronounced when aggregating across chambers to plot level. Hence we recommend as a good practice that researchers report plot-level fluxes with uncertainties based on the log-normal assumption. Model-data integration studies should compare predictions and observations of soil CO2 efflux at log scale. This study provides methodology and guidance that will improve the analysis of soil CO2 efflux observations and hence improve understanding of soil carbon cycling and climate feedbacks.

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Spatial variability models of CO2 emissions from soils colonized by grass (Deschampsia antarctica) and moss (Sanionia uncinata) in Admiralty Bay, King George Island

Antarctic Science ◽

10.1017/s0954102010000581 ◽

2010 ◽

Vol 23 (1) ◽

pp. 27-33 ◽

Cited By ~ 24

Author(s):

Eduardo de Sá Mendonça ◽

Newton La Scala ◽

Alan Rodrigo Panosso ◽

Felipe N.B. Simas ◽

Carlos E.G.R. Schaefer

Keyword(s):

Spatial Variability ◽

Spatial Pattern ◽

Carbon Cycling ◽

Vegetation Cover ◽

Terrestrial Ecosystems ◽

Deschampsia Antarctica ◽

King George Island ◽

Maritime Antarctica ◽

Admiralty Bay ◽

Sanionia Uncinata

AbstractSoil CO2 emission is an important part of the terrestrial carbon cycling and is influenced by several factors, such as type and distribution of vegetation. In this work we evaluated the spatial variability of soil CO2 emission in terrestrial ecosystems of maritime Antarctica, under two contrasting vegetation covers: 1) grass areas of Deschampsia antarctica Desv., and 2) moss carpets of Sanionia uncinata (Hedw.) Loeske. Highest mean emission was obtained for the Deschampsia (4.13 μmol m-2 s-1) developed on organic-rich soil with a strong penguin influence. The overall results indicate that soil temperature is not directly related to the spatial pattern of soil CO2 emission at the sites studied. Emission adjusted models were Gaussian and exponential with ranges varying from 1.3 to 2.8 m, depending on the studied site and vegetation cover.

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Soil–landform–plant communities relationships of a periglacial landscape at Potter Peninsula, Maritime Antarctica

Solid Earth Discussions ◽

10.5194/sed-6-2261-2014 ◽

2014 ◽

Vol 6 (2) ◽

pp. 2261-2292 ◽

Cited By ~ 3

Author(s):

E. L. Poelking ◽

C. E. R. Schaefer ◽

E. I. Fernandes Filho ◽

A. M. de Andrade ◽

A. A. Spielmann

Keyword(s):

Climate Change ◽

Plant Communities ◽

Terrestrial Ecosystems ◽

Maritime Antarctica ◽

Climate Change Effects ◽

Ornithogenic Soils ◽

Physical Environmental Factors ◽

Potter Peninsula

Abstract. Integrated studies on the interplay between soils, periglacial geomorphology and plant communities are crucial for the understanding of climate change effects on terrestrial ecosystems of Maritime Antarctica, one of the most sensitive areas to global warming. Knowledge on physical environmental factors that influence plant communities can greatly benefit studies on monitoring climate change in Maritime Antarctica, where new ice-free areas are being constantly exposed, allowing plant growth and organic carbon inputs. The relationship between topography, plant communities and soils was investigated in Potter Peninsula, King George Island, Maritime Antarctica. We mapped the occurrence and distribution of plant communities and identified soil–landform–vegetation relationships. The vegetation map was obtained by classification of a Quickbird image, coupled with detailed landform and characterization of 18 soil profiles. The sub-formations were identified and classified, and we also determined the total elemental composition of lichens, mosses and grasses. Plant communities at Potter Peninsula occupy 23% of the ice-free area, at different landscape positions, showing decreasing diversity and biomass from the coastal zone to inland areas where sub-desert conditions prevail. There is a clear dependency between landform and vegetated soils. Soils with greater moisture or poorly drained, and acid to neutral pH, are favourable for mosses subformations. Saline, organic-matter rich ornithogenic soils of former penguin rookeries have greater biomass and diversity, with mixed associations of mosses and grasses, while stable felseenmeers and flat rocky cryoplanation surfaces are the preferred sites for Usnea and Himantormia lugubris lichens, at the highest surface. Lichens subformations cover the largest vegetated area, showing varying associations with mosses.

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