Search

Search Results

• 1. [Article] Soil respiration flux in response to soil temperature, moisture, and pH

  Soil respiration has been identified as one of the largest natural sources of CO₂ to the global carbon cycle. Small alterations in the magnitude of soil respiration can have potentially large effects on ...

  Citation × Citation Citation Abstract Copy Title: Soil respiration flux in response to soil temperature, moisture, and pH Author: Murphy, Bailey Soil respiration has been identified as one of the largest natural sources of CO₂ to the global carbon cycle. Small alterations in the magnitude of soil respiration can have potentially large effects on concentrations of atmospheric CO₂ , making the rate at which respiration occurs of great scientific interest (Martin et al. 2012; Schlesinger & Andrews 2000). This experiment addresses the relationships between the rate at which soil respires and the temperature, moisture content, and pH of the soil. Soil respiration is largely dependent on factors that influence the chemical and microbial properties of the soil, as well as the plant activity. Some of these factors include soil and air temperatures, soil moisture, and soil pH. As our climate changes, these factors have the potential to be altered considerably. Understanding the relationship between these factors and the rate of soil respiration is vital to understanding the implications of an altered climate on soil respiration, and the resulting changes and feedback mechanisms in the amount of CO₂ being added back into the system. WS1 within the H.J. Andrews forest is an ideal setting for this experiment, as the contrast in soil conditions at the various survey plot locations on the North and South facing slopes of the watershed offer an opportunity for comparison of these factors. Title: Soil respiration flux in response to soil temperature, moisture, and pH Author: Murphy, Bailey Soil respiration has been identified as one of the largest natural sources of CO₂ to the global carbon cycle. Small alterations in the magnitude of soil respiration can have potentially large effects on concentrations of atmospheric CO₂ , making the rate at which respiration occurs of great scientific interest (Martin et al. 2012; Schlesinger & Andrews 2000). This experiment addresses the relationships between the rate at which soil respires and the temperature, moisture content, and pH of the soil. Soil respiration is largely dependent on factors that influence the chemical and microbial properties of the soil, as well as the plant activity. Some of these factors include soil and air temperatures, soil moisture, and soil pH. As our climate changes, these factors have the potential to be altered considerably. Understanding the relationship between these factors and the rate of soil respiration is vital to understanding the implications of an altered climate on soil respiration, and the resulting changes and feedback mechanisms in the amount of CO₂ being added back into the system. WS1 within the H.J. Andrews forest is an ideal setting for this experiment, as the contrast in soil conditions at the various survey plot locations on the North and South facing slopes of the watershed offer an opportunity for comparison of these factors. Close

• 2. [Article] Soil-Climate Feedbacks: Understanding the Controls and Ecosystem Responses of the Carbon Cycle Under a Changing Climate

  Soil organic matter (SOM) decomposition and formation is an important climate feedback, with the potential to amplify or offset climate forcing. To understand the fate of soil carbon (C) stores and fluxes ...

  Citation × Citation Citation Abstract Copy Title: Soil-Climate Feedbacks: Understanding the Controls and Ecosystem Responses of the Carbon Cycle Under a Changing Climate Author: Reynolds, Lorien Year: 2016 Soil organic matter (SOM) decomposition and formation is an important climate feedback, with the potential to amplify or offset climate forcing. To understand the fate of soil carbon (C) stores and fluxes (i.e., soil respiration) under future climate it is necessary to investigate responses across spatial and temporal scales, from the ecosystem to the molecular level, from diurnal to decadal trends. Moreover, it is important to question the assumptions and paradigms that underlie apparently paradoxical evidence to reveal the true nature of soil-climate feedbacks. My dissertation includes research into the response of soil respiration in Pacific Northwest prairies to warming and wetting along a natural regional climate gradient (Chapter II), and then delves deeper into the mechanisms underlying SOM decomposition and formation, examining the temperature sensitivity of SOM decomposition of prairie soils that were experimentally warmed for ~2 yr, and a forest soil in which litter-inputs were manipulation for 20 yr (Chapter III), and finally testing soil C cycling dynamics, including mineral-associated C pools, decomposition dynamics, and the molecular nature of SOM itself, under litter-manipulation in order to understand the controls on SOM formation and mineralization (Chapter IV). This dissertation includes previously published and unpublished coauthored material; see the individual chapters for a list of co-authors, and description of contributions. Title: Soil-Climate Feedbacks: Understanding the Controls and Ecosystem Responses of the Carbon Cycle Under a Changing Climate Author: Reynolds, Lorien Year: 2016 Soil organic matter (SOM) decomposition and formation is an important climate feedback, with the potential to amplify or offset climate forcing. To understand the fate of soil carbon (C) stores and fluxes (i.e., soil respiration) under future climate it is necessary to investigate responses across spatial and temporal scales, from the ecosystem to the molecular level, from diurnal to decadal trends. Moreover, it is important to question the assumptions and paradigms that underlie apparently paradoxical evidence to reveal the true nature of soil-climate feedbacks. My dissertation includes research into the response of soil respiration in Pacific Northwest prairies to warming and wetting along a natural regional climate gradient (Chapter II), and then delves deeper into the mechanisms underlying SOM decomposition and formation, examining the temperature sensitivity of SOM decomposition of prairie soils that were experimentally warmed for ~2 yr, and a forest soil in which litter-inputs were manipulation for 20 yr (Chapter III), and finally testing soil C cycling dynamics, including mineral-associated C pools, decomposition dynamics, and the molecular nature of SOM itself, under litter-manipulation in order to understand the controls on SOM formation and mineralization (Chapter IV). This dissertation includes previously published and unpublished coauthored material; see the individual chapters for a list of co-authors, and description of contributions. Close