Ecosystem Consequences of Soil Warming

Ecosystem Consequences of Soil Warming
Author: Jacqueline E. Mohan
Publisher: Academic Press
Total Pages: 592
Release: 2019-04-27
Genre: Science
ISBN: 0128134933

Ecosystem Consequences of Soil Warming: Microbes, Vegetation, Fauna and Soil Biogeochemistry focuses on biotic and biogeochemical responses to warmer soils including plant and microbial evolution. It covers various field settings, such as arctic tundra; alpine meadows; temperate, tropical and subalpine forests; drylands; and grassland ecosystems. Information integrates multiple natural science disciplines, providing a holistic, integrative approach that will help readers understand and forecast future planetwide responses to soil warming. Students and educators will find this book informative for understanding biotic and biogeochemical responses to changing climatic conditions. Scientists from a wide range of disciplines, including soil scientists, ecologists, geneticists, as well as molecular, evolutionary and conservation biologists, will find this book a valuable resource in understanding and planning for warmer climate conditions. Emphasizes biological components of soils, plants and microbes that provide linkages to physics and chemistry Brings together chapters written by global scientific experts with interests in communication and education Includes coverage of polar, alpine, tropical, temperate and dryland ecosystems

Disturbance Effects on Soil Carbon and Greenhouse Gas Emissions in Forest Ecosystems

Disturbance Effects on Soil Carbon and Greenhouse Gas Emissions in Forest Ecosystems
Author: Scott X. Chang
Publisher: MDPI
Total Pages: 232
Release: 2020-05-23
Genre: Science
ISBN: 3039286668

Forest ecosystems are often disturbed by agents such as harvesting, fire, wind, insects and diseases, and acid deposition, with differing intensities and frequencies. Such disturbances can markedly affect the amount, form, and stability of soil organic carbon in, and the emission of greenhouse gases, including CO2, CH4, and N2O from, forest ecosystems. It is vitally important that we improve our understanding of the impact of different disturbance regimes on forest soil carbon dynamics and greenhouse gas emissions to guide our future research, forest management practices, and policy development. This Special Issue provides an important update on the disturbance effects on soil carbon and greenhouse gas emissions in forest ecosystems in different climate regions.

Methane and Carbon Dioxide Cycling in Soils of the Harvard Forest

Methane and Carbon Dioxide Cycling in Soils of the Harvard Forest
Author: Alexa Jaeger
Publisher:
Total Pages: 18
Release: 2018
Genre:
ISBN:

Soil is Earth's largest terrestrial carbon pool (Oertel et al., 2016) and can act as a net source of greenhouse gases (GHG). However, if organic material accumulates in soils faster than it is converted to CO2 by cellular respiration, soil becomes a smaller GHG source and even has the potential to become a GHG sink. Not much is known about factors that drive soil to be a source or a sink of GHG. Soil temperature and moisture have both been shown to correlate with CH4 emissions and temperature has been shown to correlate with CO 2 emissions (Jacinthe et al., 2015). Currently these relationships are not well constrained, particularly in upland soils, which are soils found at elevations between 100 and 500 m (Carating et al., 2014). Soil from the Harvard Forest was collected and used in two in-lab flux experiments to constrain the effect that soil moisture has on i.) the rate of CH4 and CO2 production/consumption and ii.) the fraction of injected CH4 that is oxidized to CO2 by soil microbes. The first experiment involved injecting vials containing soil samples with CH4 , taking an initial measurement with a residual gas analyzer (RGA), incubating for three days, and taking final measurements using the RGA. The results of this experiment indicated that cellular respiration is an important carbon source in these soils, with more CO2 coming from cellular respiration than from the oxidation of CH4. The second experiment involved injecting vials containing soil samples with CH4 and 14CH4 as a tracer, incubating for six days, and analyzing CO2 from each sample using a scintillation counter. This experiment showed a weak trend indicating that increased soil moisture may result in decreased CH4 oxidation. Results showed that decays per minute from the samples were lower than in a control. These results indicated that not all CO 2 from each sample was successfully captured and analyzed using the methods here. So while the trend may hold true, it should be supported by reconducting the experiment using a more reliable means of CO2 capture. The unexpected results from both experiments indicated that there is still much to be learned about the reactions that occur in these soils and how to perfect laboratory methods to study them.

Effect of Three Afforestation Practices on Greenhouse Gas Fluxes

Effect of Three Afforestation Practices on Greenhouse Gas Fluxes
Author: Witness Mojeremane
Publisher: LAP Lambert Academic Publishing
Total Pages: 280
Release: 2014-02
Genre:
ISBN: 9783659482861

A field experiment was established at Harwood Forest to investigate the effects of drainage, mounding and fertilisation on soil properties, environmental variables and carbon dioxide (CO2), methane (CH4) and nitrous oxide (N2O) fluxes from an organic-rich peaty soil. The three greenhouse gases are actively changed between landscapes. Drainage significantly increased CO2, reduced CH4 fluxes but did not affect N2O fluxes. Mounding increased CH4 fluxes, reduced N2O but did not affect CO2. CO2, CH4 and N2O were increased by fertilisation. CO2 fluxes were mainly controlled by soil temperature, while CH4 was driven primarily by water table depth. N2O fluxes changed with changes in soil temperature and water table depth. Drainage and fertilisation were by far the most important afforestation practices tested in this in this work in terms of accelerating GHG fluxes from soil. Drainage increased overall CO2e fluxes, while the NPK fertilisation was the largest contributor to the total