IFEVA   02662
INSTITUTO DE INVESTIGACIONES FISIOLOGICAS Y ECOLOGICAS VINCULADAS A LA AGRICULTURA
Unidad Ejecutora - UE
artículos
Título:
Plant litter decomposition in a semi-arid ecosystem controlled by photodegradation
Autor/es:
AMY T. AUSTIN; LUCÍA VIVANCO
Revista:
NATURE
Editorial:
MacMillan Press
Referencias:
Año: 2006 vol. 442 p. 555 - 558
ISSN:
0028-0836
Resumen:
The carbon balance in terrestrial ecosystems is determined by the
difference between inputs from primary production and the
return of carbon to the atmosphere through decomposition of
organic matter1. Our understanding of the factors that control
carbon turnover in water-limited ecosystems is limited, however,
as studies of litter decomposition have shown contradictory
results and only a modest correlation with precipitation25. Here
we evaluate the influence of solar radiation, soil biotic activity and
soil resource availability on litter decomposition in the semi-arid
Patagonian steppe using the results of manipulative experiments
carried out under ambient conditions of rainfall and temperature.
We show that intercepted solar radiation was the only factor that
had a significant effect on the decomposition of organic matter,
with attenuation of ultraviolet-B and total radiation causing a 33
and 60 per cent reduction in decomposition, respectively. We
conclude that photodegradation is a dominant control on aboveground
litter decomposition in this semi-arid ecosystem. Losses
through photochemical mineralization may represent a shortcircuit
in the carbon cycle, with a substantial fraction of carbon
fixed in plant biomass being lost directly to the atmosphere
without cycling through soil organic matter pools. Furthermore,
future changes in radiation interception due to decreased cloudiness,
increased stratospheric ozone depletion, or reduced vegetative
cover may have a more significant effect on the carbon balance
in these water-limited ecosystems than changes in temperature or
precipitation.
we evaluate the influence of solar radiation, soil biotic activity and
soil resource availability on litter decomposition in the semi-arid
Patagonian steppe using the results of manipulative experiments
carried out under ambient conditions of rainfall and temperature.
We show that intercepted solar radiation was the only factor that
had a significant effect on the decomposition of organic matter,
with attenuation of ultraviolet-B and total radiation causing a 33
and 60 per cent reduction in decomposition, respectively. We
conclude that photodegradation is a dominant control on aboveground
litter decomposition in this semi-arid ecosystem. Losses
through photochemical mineralization may represent a shortcircuit
in the carbon cycle, with a substantial fraction of carbon
fixed in plant biomass being lost directly to the atmosphere
without cycling through soil organic matter pools. Furthermore,
future changes in radiation interception due to decreased cloudiness,
increased stratospheric ozone depletion, or reduced vegetative
cover may have a more significant effect on the carbon balance
in these water-limited ecosystems than changes in temperature or
precipitation.
carbon turnover in water-limited ecosystems is limited, however,
as studies of litter decomposition have shown contradictory
results and only a modest correlation with precipitation25. Here
we evaluate the influence of solar radiation, soil biotic activity and
soil resource availability on litter decomposition in the semi-arid
Patagonian steppe using the results of manipulative experiments
carried out under ambient conditions of rainfall and temperature.
We show that intercepted solar radiation was the only factor that
had a significant effect on the decomposition of organic matter,
with attenuation of ultraviolet-B and total radiation causing a 33
and 60 per cent reduction in decomposition, respectively. We
conclude that photodegradation is a dominant control on aboveground
litter decomposition in this semi-arid ecosystem. Losses
through photochemical mineralization may represent a shortcircuit
in the carbon cycle, with a substantial fraction of carbon
fixed in plant biomass being lost directly to the atmosphere
without cycling through soil organic matter pools. Furthermore,
future changes in radiation interception due to decreased cloudiness,
increased stratospheric ozone depletion, or reduced vegetative
cover may have a more significant effect on the carbon balance
in these water-limited ecosystems than changes in temperature or
precipitation.
we evaluate the influence of solar radiation, soil biotic activity and
soil resource availability on litter decomposition in the semi-arid
Patagonian steppe using the results of manipulative experiments
carried out under ambient conditions of rainfall and temperature.
We show that intercepted solar radiation was the only factor that
had a significant effect on the decomposition of organic matter,
with attenuation of ultraviolet-B and total radiation causing a 33
and 60 per cent reduction in decomposition, respectively. We
conclude that photodegradation is a dominant control on aboveground
litter decomposition in this semi-arid ecosystem. Losses
through photochemical mineralization may represent a shortcircuit
in the carbon cycle, with a substantial fraction of carbon
fixed in plant biomass being lost directly to the atmosphere
without cycling through soil organic matter pools. Furthermore,
future changes in radiation interception due to decreased cloudiness,
increased stratospheric ozone depletion, or reduced vegetative
cover may have a more significant effect on the carbon balance
in these water-limited ecosystems than changes in temperature or
precipitation.
1. Our understanding of the factors that control
carbon turnover in water-limited ecosystems is limited, however,
as studies of litter decomposition have shown contradictory
results and only a modest correlation with precipitation25. Here
we evaluate the influence of solar radiation, soil biotic activity and
soil resource availability on litter decomposition in the semi-arid
Patagonian steppe using the results of manipulative experiments
carried out under ambient conditions of rainfall and temperature.
We show that intercepted solar radiation was the only factor that
had a significant effect on the decomposition of organic matter,
with attenuation of ultraviolet-B and total radiation causing a 33
and 60 per cent reduction in decomposition, respectively. We
conclude that photodegradation is a dominant control on aboveground
litter decomposition in this semi-arid ecosystem. Losses
through photochemical mineralization may represent a shortcircuit
in the carbon cycle, with a substantial fraction of carbon
fixed in plant biomass being lost directly to the atmosphere
without cycling through soil organic matter pools. Furthermore,
future changes in radiation interception due to decreased cloudiness,
increased stratospheric ozone depletion, or reduced vegetative
cover may have a more significant effect on the carbon balance
in these water-limited ecosystems than changes in temperature or
precipitation.
we evaluate the influence of solar radiation, soil biotic activity and
soil resource availability on litter decomposition in the semi-arid
Patagonian steppe using the results of manipulative experiments
carried out under ambient conditions of rainfall and temperature.
We show that intercepted solar radiation was the only factor that
had a significant effect on the decomposition of organic matter,
with attenuation of ultraviolet-B and total radiation causing a 33
and 60 per cent reduction in decomposition, respectively. We
conclude that photodegradation is a dominant control on aboveground
litter decomposition in this semi-arid ecosystem. Losses
through photochemical mineralization may represent a shortcircuit
in the carbon cycle, with a substantial fraction of carbon
fixed in plant biomass being lost directly to the atmosphere
without cycling through soil organic matter pools. Furthermore,
future changes in radiation interception due to decreased cloudiness,
increased stratospheric ozone depletion, or reduced vegetative
cover may have a more significant effect on the carbon balance
in these water-limited ecosystems than changes in temperature or
precipitation.
25. Here
we evaluate the influence of solar radiation, soil biotic activity and
soil resource availability on litter decomposition in the semi-arid
Patagonian steppe using the results of manipulative experiments
carried out under ambient conditions of rainfall and temperature.
We show that intercepted solar radiation was the only factor that
had a significant effect on the decomposition of organic matter,
with attenuation of ultraviolet-B and total radiation causing a 33
and 60 per cent reduction in decomposition, respectively. We
conclude that photodegradation is a dominant control on aboveground
litter decomposition in this semi-arid ecosystem. Losses
through photochemical mineralization may represent a shortcircuit
in the carbon cycle, with a substantial fraction of carbon
fixed in plant biomass being lost directly to the atmosphere
without cycling through soil organic matter pools. Furthermore,
future changes in radiation interception due to decreased cloudiness,
increased stratospheric ozone depletion, or reduced vegetative
cover may have a more significant effect on the carbon balance
in these water-limited ecosystems than changes in temperature or
precipitation.