Implications of meltwater pulse events for soil biology and biogeochemical cycling in a polar desert

• Published in: Polar Research
• Main Authors: Becky A. Ball, J.E. Barrett, Mike N. Gooseff, Ross A. Virginia, Diana H. Wall
• Format: Article in Journal/Newspaper
• Language: English
• Published: Norwegian Polar Institute 2011
• Subjects: Water pulse; climate change; polar desert; International Polar Year; discrete warming events; soil biogeochemistry; envir; geo; McMurdo Dry Valleys; Ice; permafrost; Polar Research
• Online Access: https://doi.org/10.3402/polar.v30i0.14555; https://doaj.org/article/5a6b4d3024eb4211b1bef6ab6cd6c265

The McMurdo Dry Valleys are one of the most arid environments on Earth. Over the soil landscape for the majority of the year, biological and ecosystem processes in the dry valleys are constrained by the low temperatures and limited availability of water. The prevalence of these physical limitations in controlling biological and ecosystem processes makes the dry valleys a climate-sensitive system, poised to experience substantial changes following projected future warming. Short-duration increases in summer temperatures are associated with pulses of water from melting ice reserves, including glaciers, snow and permafrost. Such pulses alter soil geochemistry by mobilizing and redistributing soil salts (via enhanced weathering, solubility and mobility), which can alter habitat suitability for soil organisms. Resulting changes in soil community composition or distribution may alter the biogeochemical processes in which they take part. Here, we review the potential impacts of meltwater pulses and present new field data documenting instances of meltwater pulse events that result from different water sources and hydrological patterns, and discuss their potential influence on soil biology and biogeochemistry. We use these examples to discuss the potential impacts of future climate change on the McMurdo Dry Valley soil ecosystem.