Soil surface organic layers in the Arctic foothills: development, distribution and microclimatic feedbacks
Thesis (M.S.) University of Alaska Fairbanks, 2013 Accumulated organic matter at the ground surface plays an important role in Arctic ecosystems. These soil surface organic layers (SSOLs) influence temperature, moisture, and chemistry in the underlying mineral soil and, on a global basis, comprise e...
Main Author: | |
---|---|
Other Authors: | , , |
Format: | Thesis |
Language: | English |
Published: |
2013
|
Subjects: | |
Online Access: | http://hdl.handle.net/11122/4478 |
id |
ftunivalaska:oai:scholarworks.alaska.edu:11122/4478 |
---|---|
record_format |
openpolar |
spelling |
ftunivalaska:oai:scholarworks.alaska.edu:11122/4478 2023-05-15T14:52:03+02:00 Soil surface organic layers in the Arctic foothills: development, distribution and microclimatic feedbacks Baughman, Carson A. Mann, Daniel Verbyla, David Valentine, David 2013-12 http://hdl.handle.net/11122/4478 en_US eng http://hdl.handle.net/11122/4478 Department of Forest Sciences Thesis ms 2013 ftunivalaska 2023-02-23T21:36:15Z Thesis (M.S.) University of Alaska Fairbanks, 2013 Accumulated organic matter at the ground surface plays an important role in Arctic ecosystems. These soil surface organic layers (SSOLs) influence temperature, moisture, and chemistry in the underlying mineral soil and, on a global basis, comprise enormous stores of labile carbon. Understanding the dynamics of SSOLs is a prerequisite for modeling the responses of arctic ecosystems to climate changes. Here we ask three questions regarding SSOLs in the Arctic Foothills of northern Alaska: 1) What environmental factors control their spatial distribution? 2) How long do they take to form? 3) What is the relationship between SSOL thickness and mineral soil temperature during the growing season? Results show that the best predictors of SSOL thickness and distribution are duration of direct sunlight during the growing-season, upslope-drainage-area, slope gradient, and elevation. SSOLs begin to form within decades but require 500-700 years to reach steady-state thicknesses. SSOL formation has a positive feedback on itself by causing rapid soil cooling. Once formed, mature SSOLs lower the growing-season temperature and mean annual temperature of underlying mineral soils by 8° and 3° C, respectively, which reduces growing degree days by 78%. How climate change in northern Alaska will affect the region's SSOLs is an open and potentially crucial question. 1.0. Introduction -- 2.0. Regional settings -- 3.0. Study sites -- 3.1. Smith Mountatin -- 3.2. Ikpikpuk River soil chronosequences -- 3.3. Nigu River landslides -- 4.0. Methods -- 4.1. Topographic controls over SSOL thickness -- 4.2. Timing of SSOL development along the Ikpikpuk River -- 4.3. Influence of SSOL development on belowground temperature -- 5.0. Results -- 5.1. Distribution of SSOLs on Smith Mountain -- 5.2. SSOL thickness modeling and validation -- 5.3. Inferring carbon stocks from modeled SSOL thickness -- 5.4. Time to SSOL development -- 5.5. Feedbacks of SSOL on soil temperature -- Discussion -- 6.1. ... Thesis Arctic Climate change Alaska University of Alaska: ScholarWorks@UA Arctic Fairbanks |
institution |
Open Polar |
collection |
University of Alaska: ScholarWorks@UA |
op_collection_id |
ftunivalaska |
language |
English |
description |
Thesis (M.S.) University of Alaska Fairbanks, 2013 Accumulated organic matter at the ground surface plays an important role in Arctic ecosystems. These soil surface organic layers (SSOLs) influence temperature, moisture, and chemistry in the underlying mineral soil and, on a global basis, comprise enormous stores of labile carbon. Understanding the dynamics of SSOLs is a prerequisite for modeling the responses of arctic ecosystems to climate changes. Here we ask three questions regarding SSOLs in the Arctic Foothills of northern Alaska: 1) What environmental factors control their spatial distribution? 2) How long do they take to form? 3) What is the relationship between SSOL thickness and mineral soil temperature during the growing season? Results show that the best predictors of SSOL thickness and distribution are duration of direct sunlight during the growing-season, upslope-drainage-area, slope gradient, and elevation. SSOLs begin to form within decades but require 500-700 years to reach steady-state thicknesses. SSOL formation has a positive feedback on itself by causing rapid soil cooling. Once formed, mature SSOLs lower the growing-season temperature and mean annual temperature of underlying mineral soils by 8° and 3° C, respectively, which reduces growing degree days by 78%. How climate change in northern Alaska will affect the region's SSOLs is an open and potentially crucial question. 1.0. Introduction -- 2.0. Regional settings -- 3.0. Study sites -- 3.1. Smith Mountatin -- 3.2. Ikpikpuk River soil chronosequences -- 3.3. Nigu River landslides -- 4.0. Methods -- 4.1. Topographic controls over SSOL thickness -- 4.2. Timing of SSOL development along the Ikpikpuk River -- 4.3. Influence of SSOL development on belowground temperature -- 5.0. Results -- 5.1. Distribution of SSOLs on Smith Mountain -- 5.2. SSOL thickness modeling and validation -- 5.3. Inferring carbon stocks from modeled SSOL thickness -- 5.4. Time to SSOL development -- 5.5. Feedbacks of SSOL on soil temperature -- Discussion -- 6.1. ... |
author2 |
Mann, Daniel Verbyla, David Valentine, David |
format |
Thesis |
author |
Baughman, Carson A. |
spellingShingle |
Baughman, Carson A. Soil surface organic layers in the Arctic foothills: development, distribution and microclimatic feedbacks |
author_facet |
Baughman, Carson A. |
author_sort |
Baughman, Carson A. |
title |
Soil surface organic layers in the Arctic foothills: development, distribution and microclimatic feedbacks |
title_short |
Soil surface organic layers in the Arctic foothills: development, distribution and microclimatic feedbacks |
title_full |
Soil surface organic layers in the Arctic foothills: development, distribution and microclimatic feedbacks |
title_fullStr |
Soil surface organic layers in the Arctic foothills: development, distribution and microclimatic feedbacks |
title_full_unstemmed |
Soil surface organic layers in the Arctic foothills: development, distribution and microclimatic feedbacks |
title_sort |
soil surface organic layers in the arctic foothills: development, distribution and microclimatic feedbacks |
publishDate |
2013 |
url |
http://hdl.handle.net/11122/4478 |
geographic |
Arctic Fairbanks |
geographic_facet |
Arctic Fairbanks |
genre |
Arctic Climate change Alaska |
genre_facet |
Arctic Climate change Alaska |
op_relation |
http://hdl.handle.net/11122/4478 Department of Forest Sciences |
_version_ |
1766323175945142272 |