Effects of multiple climate change factors on exoenzyme activities and CO2 efflux in a tropical grassland

2020 ◽  
Vol 148 ◽  
pp. 107877
Author(s):  
Tássio Brito de Oliveira ◽  
Rosymar Coutinho de Lucas ◽  
Ana Silvia de Almeida Scarcella ◽  
Alex Graça Contato ◽  
Thiago Machado Pasin ◽  
...  
Keyword(s):  
Climate Change ◽  
Co2 Efflux ◽  
Change Factors ◽  
Tropical Grassland

scholarly journals Patterns of longer-term climate change effects on CO<sub>2</sub> efflux from biocrusted soils differ from those observed in the short term

2018 ◽  
Vol 15 (14) ◽  
pp. 4561-4573 ◽  
Author(s):  
Anthony Darrouzet-Nardi ◽  
Sasha C. Reed ◽  
Edmund E. Grote ◽  
Jayne Belnap
Keyword(s):  
Climate Change ◽  
Monsoon Season ◽  
Vascular Plant ◽  
Precipitation Amount ◽  
Co2 Flux ◽  
Co2 Exchange ◽  
Plant Responses ◽  
Co2 Efflux ◽  
Climate Change Effects ◽  
Altered Precipitation

Abstract. Biological soil crusts (biocrusts) are predicted to be sensitive to the increased temperature and altered precipitation associated with climate change. We assessed the effects of these factors on soil carbon dioxide (CO2) balance in biocrusted soils using a sequence of manipulations over a 9-year period. We warmed biocrusted soils by 2 and, later, by 4 ∘C to better capture updated forecasts of future temperature at a site on the Colorado Plateau, USA. We also watered soils to alter monsoon-season precipitation amount and frequency and had plots that received both warming and altered precipitation treatments. Within treatment plots, we used 20 automated flux chambers to monitor net soil exchange (NSE) of CO2 hourly, first in 2006–2007 and then again in 2013–2014, for a total of 39 months. Net CO2 efflux from biocrusted soils in the warming treatment increased a year after the experiment began (2006–2007). However, after 9 years and even greater warming (4 ∘C), results were more mixed, with a reversal of the increase in 2013 (i.e., controls showed higher net CO2 efflux than treatment plots) and with similarly high rates in all treatments during 2014, a wet year. Over the longer term, we saw evidence of reduced photosynthetic capacity of the biocrusts in response to both the temperature and altered precipitation treatments. Patterns in biocrusted soil CO2 exchange under experimentally altered climate suggest that (1) warming stimulation of CO2 efflux was diminished later in the experiment, even in the face of greater warming; and (2) treatment effects on CO2 flux patterns were likely driven by changes in biocrust species composition and by changes in root respiration due to vascular plant responses.

scholarly journals Patterns of longer-term climate change effects on CO<sub>2</sub> efflux from biocrusted soils differ from those observed in the short-term

2018 ◽  
Author(s):  
Anthony Darrouzet-Nardi ◽  
Sasha C. Reed ◽  
Edmund E. Grote ◽  
Jayne Belnap
Keyword(s):  
Climate Change ◽  
Monsoon Season ◽  
Vascular Plant ◽  
Co2 Exchange ◽  
Plant Responses ◽  
Co2 Efflux ◽  
Climate Change Effects ◽  
Altered Precipitation ◽  
The Face ◽  
Carbon Dioxide Co2

Abstract. Biological soil crusts (biocrusts) are predicted to be sensitive to the increased temperature and altered precipitation associated with climate change. We assessed the effects of these factors on soil carbon dioxide (CO2) balance in biocrusted soils using a sequence of manipulations over a nine-year period. We warmed biocrusted soils by 2 and, later, by 4 °C to better capture updated forecasts of future temperature, as well as altered monsoon-season precipitation at a site on the Colorado Plateau, USA. Within treatment plots, we used 20 automated flux chambers to monitor net soil exchange (NSE) of CO2 hourly, first in 2006–2007 and then again in 2013–2014, for a total of 39 months. Net CO2 efflux from biocrusted soils in the warming treatment increased a year after the experiment began (2006–2007). However, after 9 years and even greater warming (4 °C), results were more mixed, with a reversal of the increase in 2013 (i.e., controls showed higher net CO2 efflux than treatment plots) and with similarly high rates in all treatments during 2014, a wet year. Over the longer-term, we saw evidence of reduced photosynthetic capacity of the biocrusts in response to both the temperature and altered precipitation treatments. Patterns in biocrusted soil CO2 exchange under experimentally altered climate suggest that (1) warming effects were diminished later in the experiment, even in the face of larger warming and (2) likely drivers of the treatment effects were changes in biocrust species composition and changes in root respiration due to vascular plant responses.

scholarly journals Significance of soil respiration from biological activity in the degradation processes of different types of organic matter

2020 ◽  
Vol 1 (2) ◽  
pp. 171-179
Keyword(s):  
Climate Change ◽  
Organic Matter ◽  
Soil Moisture ◽  
Soil Respiration ◽  
Soil Temperature ◽  
Temperature Sensitivity ◽  
Soil Co2 Efflux ◽  
Co2 Efflux ◽  
Soil Co2 ◽  
Total Soil

Soil respiration is a major component of global carbon cycle. Therefore, it is crucial to understand the environmental controls on soil respiration for evaluating potential response of ecosystems to climate change. In a temperate deciduous forest (located in Northern-Hungary) we added or removed aboveground and belowground litter to determine total soil respiration. We investigated the relationship between total soil CO2 efflux, soil moisture, and soil temperature. Soil CO2 efflux was measured at each plot using soda-lime method. Temperature sensitivity of soil respiration (Q10) was monitored via measuring soil temperature on an hourly basis, while soil moisture was determined monthly. Soil respiration increased in control plots from the second year after implementing the treatment, but results showed fluctuations from one year to another. The effect of doubled litter was less significant than the effect of removal. Removed litter and root inputs caused substantial decrease in soil respiration. We found that temperature was more influential in the control of soil respiration than soil moisture. In plots with no litter Q10 varied in the largest interval. For treatment with doubled litter layer, temperature sensitivity of CO2 efflux did not change considerably. The effect of increasing soil temperature is more conspicuous to soil respiration in litter removal treatments since lack of litter causes greater irradiation. When exclusively leaf litter was considered, the effect of temperature on soil respiration was lower in treatments with added litter than with removed litter. Our results reveal that soil life is impacted by the absence of organic matter, rather than by an excess of organic matter. Results of CO2 emission from soils with different organic matter content can contribute to sustainable land use, considering the changed climatic factors caused by global climate change.

scholarly journals Effects of multiple climate change factors on the tall fescue-fungal endophyte symbiosis: infection frequency and tissue chemistry

2010 ◽  
Vol 189 (3) ◽  
pp. 797-805 ◽  
Author(s):  
Glade B. Brosi ◽  
Rebecca L. McCulley ◽  
Lowell P. Bush ◽  
Jim A. Nelson ◽  
Aimée T. Classen ◽  
...  
Keyword(s):  
Climate Change ◽  
Tall Fescue ◽  
Fungal Endophyte ◽  
Infection Frequency ◽  
Change Factors ◽  
Tissue Chemistry

Impact of Climate Change Factors on Weeds and Herbicide Efficacy

2016 ◽  
pp. 107-146 ◽  
Author(s):  
Aruna Varanasi ◽  
P.V. Vara Prasad ◽  
Mithila Jugulam
Keyword(s):  
Climate Change ◽  
Impact Of Climate Change ◽  
Change Factors

Novel use of climate model data for deriving future flood risk underwriting and risk selection data – A Hong Kong Case Study

2021 ◽  
Author(s):  
Rebecca Alexandre ◽  
Iain Willis
Keyword(s):  
Climate Change ◽  
Hong Kong ◽  
Flood Risk ◽  
Climate Model ◽  
Risk Mitigation ◽  
Flood Damage ◽  
Flood Frequency ◽  
Commercial Building ◽  
Model Data ◽  
Change Factors

&lt;p&gt;The re/insurance, banking and mortgage sectors play an essential role in facilitating economic stability. As climate change-related financial risks increase, there has long been a need for tools that contribute to the global industry&amp;#8217;s current and future flood risk resiliency. Recognising this gap, JBA Risk Management has pioneered use of climate model data for rapidly deriving future flood risk metrics to support risk-reflective pricing strategies and mortgage analysis for Hong Kong.&lt;/p&gt;&lt;p&gt;JBA&amp;#8217;s established method uses daily temporal resolution precipitation and surface air temperature Regional Climate Model (RCM) data from the Earth System Grid Federation&amp;#8217;s CORDEX experiment. Historical and future period RCM data were processed for Representative Concentration Pathways (RCPs) 2.6 and 8.6, and time horizons 2046-2050 and 2070-2080 and used to develop fluvial and pluvial hydrological model change factors for Hong Kong. These change factors were applied to baseline fluvial and pluvial flood depths and extents, extracted from JBA&amp;#8217;s high resolution 30m Hong Kong Flood Map. From these, potential changes in flood event frequency and severity for each RCP and time horizon combination were estimated.&lt;/p&gt;&lt;p&gt;The unique flood frequency and severity profiles for each flood type were then analysed with customised vulnerability functions, linking water depth to expected damage over time for residential and commercial building risks. This resulted in quantitative fluvial and pluvial flood risk metrics for Hong Kong.&lt;/p&gt;&lt;p&gt;Newly released, Hong Kong Climate Change Pricing Data is already in use by financial institutions. When combined with property total sum insured data, this dataset provides the annualised cost of flood damage for a range of future climate scenarios. For the first time, our industry has a tool to quantify baseline and future flood risk and set risk-reflective pricing for Hong Kong portfolios.&lt;/p&gt;&lt;p&gt;JBA&amp;#8217;s method is adaptable for global use and underwriting tools are already available for the UK and Australia with the aim of improving future financial flood risk mitigation and management. This presentation will outline the method, provide a comparison of baseline and climate change flood impacts for Hong Kong and discuss the wider implications for our scientific and financial industries.&lt;/p&gt;

Improving the Understanding of Climate Change Factors with Images

2016 ◽  
pp. 43-63
Author(s):  
Geoff Russell
Keyword(s):  
Climate Change ◽  
Carbon Dioxide ◽  
Climate Models ◽  
Technical Literature ◽  
Causal Factors ◽  
Physical Sense ◽  
The Public ◽  
Change Factors ◽  
Mass Marketing ◽  
Focal Issue

In Australia, the public got its first mass marketing about climate change and the measures that would be required to avoid it, by TV images of black balloons and Professor Tim Flannery turning off light switches. Journalistic coverage has been similarly dominated by household electricity. More technical literature is generally dominated by the concept of “carbon dioxide equivalence” (CO2eq) as spelled out in the Kyoto protocol. This concept isn't used in climate models because it makes no physical sense. The use of CO2eq and the focus on household electricity has lead to a profound mismatch between the causal factors as understood by climate scientists and causal factors as perceived by the public. “The public” here isn't just the general public, but people of many backgrounds with a strong interest in climate change but without the deep knowledge of professional climate scientists. We need images consistent with climate models, which accurately rank the causes of climate change and guide proposed actions. Such images point to meat as a key focal issue.

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