Climate-driven thresholds for chemical weathering in postglacial soils of New Zealand


Jean L Dixon, Oliver A Chadwick, Peter M Vitousek


Journal of Geophysical Research: Earth Surface


Chemical weathering in soils dissolves and alters minerals, mobilizes metals, liberates nutrients to terrestrial and aquatic ecosystems, and may modulate Earth's climate over geologic time scales. Climate-weathering relationships are often considered fundamental controls on the evolution of Earth's surface and biogeochemical cycles. However, surprisingly little consensus has emerged on if and how climate controls chemical weathering, and models and data from published literature often give contrasting correlations and predictions for how weathering rates and climate variables such as temperature or moisture are related. Here we combine insights gained from the different approaches, methods, and theory of the soil science, biogeochemistry, and geomorphology communities to tackle the fundamental question of how rainfall influences soil chemical properties. We explore climate-driven variations in weathering and soil development in young, postglacial soils of New Zealand, measuring soil elemental geochemistry along a large precipitation gradient (400-4700 mm/yr) across the Waitaki basin on Te Waipounamu, the South Island. Our data show a strong climate imprint on chemical weathering in these young soils. This climate control is evidenced by rapid nonlinear changes along the gradient in total and exchangeable cations in soils and in the increased movement and redistribution of metals with rainfall. The nonlinear behavior provides insight into why climate-weathering relationships may be elusive in some landscapes. These weathering thresholds also have significant implications for how climate may influence landscape evolution and the release of rock-derived nutrients to ecosystems, as landscapes that transition to wetter climates across this threshold may weather and deplete rapidly. Abstract Copyright (2016), . The Authors.



How is this information collected?

This collection of Montana State authored publications is collected by the Library to highlight the achievements of Montana State researchers and more fully understand the research output of the University. They use a number of resources to pull together as complete a list as possible and understand that there may be publications that are missed. If you note the omission of a current publication or want to know more about the collection and display of this information email Leila Sterman.