How much surface water can gilgai microtopography capture?

The vision of the Long Term Agroecosystem Research (LTAR) network is to enable multi‐decadal, trans‐disciplinary, and cross‐location science to ensure the long‐term sustainability of U.S. agriculture. LTAR's primary goals are to: (1) Intensify agricultural productivity, (2) Improve ecosystem services related to agricultural production, and (3) Improve rural prosperity. The LTAR network includes 18 locations (sites). It includes 10 existing hydrologic observatories from the Agricultural Research Service‐Experimental Watershed Network (ARS‐EWN) that were established before the creation of LTAR. Background and an overview of the network are presented.

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“…(Harmel et al, 2004, 2006, 2013 Smith et al, 2019, 2020; Wagner et al, 2012; Baird, 1948; Kishne et al, 2014…”

Section: Overviewmentioning

confidence: 99%

Long term agroecosystem research experimental watershed network

Goodrich

Bosch

Ray

et al. 2022

Hydrological Processes

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“…10.1029/2019WR026473 -Quantified the effects of conservation practices on runoff, erosion, and water quality -Hydrologic processes of heavy clay soilscracking, shrink, and swelling (Baird, 1948;Haney et al, 2011;Harmel et al, 2004Harmel et al, , 2006Harmel et al, , 2008Harmel et al, , 2013Kishne et al, 2014;Smith et al, 2019;Wagner et al, 2012) (Flaten et al, 2019;Kleinman, 2017;Liu et al, 2017;McDowell & Sharpley, 2001;Miller et al, 2018;Smith et al, 2019;Spiegal et al, 2020; (Murphey & Grissinger, 1985;Shields et al, 1995Shields et al, , 1998 Baffaut et al, 2015Baffaut et al, , 2019Blanco-Canqui et al, 2002;Hjelmfelt & Wang, 1994;Kitchen et al, 2015Kitchen et al, , 1998Lerch et al, 2005Lerch et al, , 2011Wendt et al, 1986)…”

Section: Water Resources Researchmentioning

confidence: 99%

“…‐Hydrologic processes of heavy clay soils—cracking, shrink, and swelling (Baird, 1948; Haney et al, 2011; Harmel et al, 2004, 2006, 2008, 2013; Kishne et al, 2014; Smith et al, 2019; 2020; Wagner et al, 2012)…”

Section: Description Of Ars Experimental Watershedsmentioning

confidence: 99%

The USDA‐ARS Experimental Watershed Network: Evolution, Lessons Learned, Societal Benefits, and Moving Forward

Goodrich

Heilman

Anderson³

et al. 2021

Water Resources Research

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The U.S. Department of Agriculture‐Agricultural Research Service's (ARS) Experimental Watershed Network grew from Dust Bowl era efforts of the Soil Conservation Service in the mid‐1930s with the establishment of small experimental watersheds. In the 1950s, five watershed research centers with intensively instrumented watersheds at the scale of 100 to 700 km2 were established. Primary network research objectives were to quantify on‐site and downstream effects of conservation practices and develop rainfall‐runoff relationships for design of water conservation structures. With passage of the Clean Water Act in 1972, research objectives have evolved to add a variety of observations relevant to the water quality issues. Many of the watersheds within the network have served, and continue to serve, as core validation sites for satellite sensors. As a result of the network's long history and intensive monitoring, coupled with mission‐driven research, a deep knowledge base of watershed processes has been developed. This has led to the extensive development and validation of numerous watershed models that are in widespread use today. The visionary investments in building and maintaining this network and associated scientific investigations for more than half a century have not only resulted in numerous high‐impact research accomplishments but also a wide array of accomplishments that directly benefit society. The ARS Experimental Watersheds formed the core of the Conservation Effects Assessment Project (CEAP) as well as the recently established Long‐Term Agroecosystem Research (LTAR) network. LTAR will expand the mission of the ARS Watersheds Network to include agricultural intensification, maintaining or improving ecosystem services while enhancing rural prosperity.

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“…Despite apparent parallels with patterned ecosystems elsewhere, these earth-mound landscapes have not yet been studied within the conceptual framework of self-organization, even though the formation of mounds often involves the driving role of soil ecosystem engineers. Although purely physical mechanisms (swelling and shrinking of smectite clays in vertisols leading to development of gilgai microtopography [ 16 , 17 ]) may explain the formation of mounds in a few particular environments, most hypotheses envisage a driving role of organisms. Two different hypotheses ascribe to organisms very different roles.…”

Section: Introductionmentioning

confidence: 99%

The Surales, Self-Organized Earth-Mound Landscapes Made by Earthworms in a Seasonal Tropical Wetland

et al. 2016

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The formation, functioning and emergent properties of patterned landscapes have recently drawn increased attention, notably in semi-arid ecosystems. We describe and analyze a set of similarly spectacular landforms in seasonal tropical wetlands. Surales landscapes, comprised of densely packed, regularly spaced mounds, cover large areas of the Orinoco Llanos. Although descriptions of surales date back to the 1940’s, their ecology is virtually unknown. From data on soil physical and chemical properties, soil macrofauna, vegetation and aerial imagery, we provide evidence of the spatial extent of surales and how they form and develop. Mounds are largely comprised of earthworm casts. Recognizable, recently produced casts account for up to one-half of total soil mass. Locally, mounds are relatively constant in size, but vary greatly across sites in diameter (0.5–5 m) and height (from 0.3 m to over 2 m). This variation appears to reflect a chronosequence of surales formation and growth. Mound shape (round to labyrinth) varies across elevational gradients. Mounds are initiated when large earthworms feed in shallowly flooded soils, depositing casts that form ‘towers’ above water level. Using permanent galleries, each earthworm returns repeatedly to the same spot to deposit casts and to respire. Over time, the tower becomes a mound. Because each earthworm has a restricted foraging radius, there is net movement of soil to the mound from the surrounding area. As the mound grows, its basin thus becomes deeper, making initiation of a new mound nearby more difficult. When mounds already initiated are situated close together, the basin between them is filled and mounds coalesce to form larger composite mounds. Over time, this process produces mounds up to 5 m in diameter and 2 m tall. Our results suggest that one earthworm species drives self-organizing processes that produce keystone structures determining ecosystem functioning and development.

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How much surface water can gilgai microtopography capture?

Cited by 15 publications

References 28 publications

Long term agroecosystem research experimental watershed network

Long term agroecosystem research experimental watershed network

The USDA‐ARS Experimental Watershed Network: Evolution, Lessons Learned, Societal Benefits, and Moving Forward

The Surales, Self-Organized Earth-Mound Landscapes Made by Earthworms in a Seasonal Tropical Wetland

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