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Grasslands may be more reliable carbon sinks than forests in California

Dass, Pawlok; Houlton, Benjamin Z.; Wang, Yingping and Warlind, David LU (2018) In Environmental Research Letters 13(7).
Abstract

Although natural terrestrial ecosystems have sequestered ∼25% of anthropogenic CO2 emissions, the long-term sustainability of this key ecosystem service is under question. Forests have traditionally been viewed as robust carbon (C) sinks; however, extreme heat-waves, drought and wildfire have increased tree mortality, particularly in widespread semi-arid regions, which account for ∼41% of Earth's land surface. Using a set of modeling experiments, we show that California grasslands are a more resilient C sink than forests in response to 21st century changes in climate, with implications for designing climate-smart Cap and Trade offset policies. The resilience of grasslands to rising temperatures, drought and fire, coupled with... (More)

Although natural terrestrial ecosystems have sequestered ∼25% of anthropogenic CO2 emissions, the long-term sustainability of this key ecosystem service is under question. Forests have traditionally been viewed as robust carbon (C) sinks; however, extreme heat-waves, drought and wildfire have increased tree mortality, particularly in widespread semi-arid regions, which account for ∼41% of Earth's land surface. Using a set of modeling experiments, we show that California grasslands are a more resilient C sink than forests in response to 21st century changes in climate, with implications for designing climate-smart Cap and Trade offset policies. The resilience of grasslands to rising temperatures, drought and fire, coupled with the preferential banking of C to belowground sinks, helps to preserve sequestered terrestrial C and prevent it from re-entering the atmosphere. In contrast, California forests appear unable to cope with unmitigated global changes in the climate, switching from substantial C sinks to C sources by at least the mid-21st century. These results highlight the inherent risk of relying on forest C offsets in the absence of management interventions to avoid substantial fire-driven C emissions. On the other hand, since grassland environments, including tree-sparse rangelands, appear more capable of maintaining C sinks in 21st century, such ecosystems should be considered as an alternative C offset to climate-vulnerable forests. The further development of climate-smart approaches in California's carbon marketplace could serve as an example to offset programs around the world, particularly those expanding into widespread arid and semi-arid regions.

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author
organization
publishing date
type
Contribution to journal
publication status
published
subject
keywords
Cap, Carbon cycle, Climate change, Drought, Forest, Grassland, Trade, Wildfire
in
Environmental Research Letters
volume
13
issue
7
publisher
IOP Publishing
external identifiers
  • scopus:85056560239
ISSN
1748-9318
DOI
10.1088/1748-9326/aacb39
language
English
LU publication?
yes
id
fcadb7a6-289e-4874-b8d3-69c89b4b3263
date added to LUP
2018-11-28 10:08:21
date last changed
2019-09-17 04:44:32
@article{fcadb7a6-289e-4874-b8d3-69c89b4b3263,
  abstract     = {<p>Although natural terrestrial ecosystems have sequestered ∼25% of anthropogenic CO<sub>2</sub> emissions, the long-term sustainability of this key ecosystem service is under question. Forests have traditionally been viewed as robust carbon (C) sinks; however, extreme heat-waves, drought and wildfire have increased tree mortality, particularly in widespread semi-arid regions, which account for ∼41% of Earth's land surface. Using a set of modeling experiments, we show that California grasslands are a more resilient C sink than forests in response to 21st century changes in climate, with implications for designing climate-smart Cap and Trade offset policies. The resilience of grasslands to rising temperatures, drought and fire, coupled with the preferential banking of C to belowground sinks, helps to preserve sequestered terrestrial C and prevent it from re-entering the atmosphere. In contrast, California forests appear unable to cope with unmitigated global changes in the climate, switching from substantial C sinks to C sources by at least the mid-21st century. These results highlight the inherent risk of relying on forest C offsets in the absence of management interventions to avoid substantial fire-driven C emissions. On the other hand, since grassland environments, including tree-sparse rangelands, appear more capable of maintaining C sinks in 21st century, such ecosystems should be considered as an alternative C offset to climate-vulnerable forests. The further development of climate-smart approaches in California's carbon marketplace could serve as an example to offset programs around the world, particularly those expanding into widespread arid and semi-arid regions.</p>},
  articleno    = {074027},
  author       = {Dass, Pawlok and Houlton, Benjamin Z. and Wang, Yingping and Warlind, David},
  issn         = {1748-9318},
  keyword      = {Cap,Carbon cycle,Climate change,Drought,Forest,Grassland,Trade,Wildfire},
  language     = {eng},
  number       = {7},
  publisher    = {IOP Publishing},
  series       = {Environmental Research Letters},
  title        = {Grasslands may be more reliable carbon sinks than forests in California},
  url          = {http://dx.doi.org/10.1088/1748-9326/aacb39},
  volume       = {13},
  year         = {2018},
}