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<article language="en">
	<journal>
		<journal_title>Hydrology and Earth System Sciences</journal_title>
		<journal_url>www.hydrol-earth-syst-sci.net</journal_url>
		<issn>1027-5606</issn>
		<eissn>1607-7938</eissn>
		<volume_number>14</volume_number>
		<issue_number>1</issue_number>
		<publication_year>2010</publication_year>
	</journal>
	<doi>10.5194/hess-14-25-2010</doi>
	<article_url>http://www.hydrol-earth-syst-sci.net/14/25/2010/</article_url>
	<abstract_html>http://www.hydrol-earth-syst-sci.net/14/25/2010/hess-14-25-2010.html</abstract_html>
	<fulltext_pdf>http://www.hydrol-earth-syst-sci.net/14/25/2010/hess-14-25-2010.pdf</fulltext_pdf>
	<start_page>25</start_page>
	<end_page>45</end_page>
	<publication_date>2010-01-08</publication_date>
	<article_title content_type="html">Earth&apos;s Critical Zone and hydropedology: concepts, characteristics,  and advances</article_title>
	<authors>
		<author numeration="1" affiliations="1">
			<name>H. Lin</name>
			<email>henrylin@psu.edu</email>
		</author>
	</authors>
	<affiliations>
		<affiliation numeration="1" content_type="html">The Pennsylvania State University, Department of Crop and Soil Sciences, 116 Agricultural Sciences and Industry Building, University Park, PA 16802, USA</affiliation>
	</affiliations>
	<abstract content_type="html">The Critical Zone (CZ) is a holistic framework for integrated studies of
water with soil, rock, air, and biotic resources in the near-surface
terrestrial environment. This most heterogeneous and complex region of the
Earth ranges from the vegetation top to the aquifer bottom, with a highly
variable thickness globally and a yet-to-be clearly defined lower boundary
of active water cycle. Interfaces among different compartments in the CZ are
critical, which provide fertile ground for interdisciplinary research. The
reconciliation of coupled geological and biological cycles (vastly different
in space and time scales) is essential to understanding the complexity and
evolution of the CZ. Irreversible evolution, coupled cycling, interactive
layers, and hierarchical heterogeneity are the characteristics of the CZ,
suggesting that forcing, coupling, interfacing, and scaling are grand
challenges for advancing CZ science. Hydropedology – the science of the
behaviour and distribution of soil-water interactions in contact with
mineral and biological materials in the CZ – is an important contributor to
CZ study. The pedosphere is the foundation of the CZ, which represents a
geomembrance across which water and solutes, as well as energy, gases,
solids, and organisms are actively exchanged with the atmosphere, biosphere,
hydrosphere, and lithosphere, thereby creating a life-sustaining
environment. Hydropedology emphasizes in situ soils in the landscape setting, where
distinct pedogenic features and soil-landscape relationships are essential
to understanding interactive pedologic and hydrologic processes. Both CZ
science and hydropedology embrace an evolutionary and holistic worldview,
which offers stimulating opportunities through steps such as integrated
systems approach, evolutionary mapping-monitoring-modeling framework, and
fostering a global alliance. Our capability to predict the behaviour and
evolution of the CZ in response to changing environment can be significantly
improved if cross-site scientific comparisons, evolutionary treatment of
organized complex systems, and deeper insights into the CZ can be made.</abstract>
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