CHAPTER THREE
Four High-Priority Research Initiatives in Earth Surface Processes

Although each of the nine grand challenges in Earth surface processes embodies significant prospects for research advances, the committee suggests that these challenges can be collected into four major research initiatives (Figure 3.1). The idea of “research initiatives” is further developed in Chapter 4, but the essential proposal is that these initiatives are timely, high-priority research areas that are rich in scientific merit and will potentially transform the field of Earth surface processes. They will require new interdisciplinary approaches, including the integration of theories, models, and tools. The four high-priority research initiatives are (1) interacting landscapes and climate; (2) quantitative reconstruction of landscape dynamics across time scales; (3) the coevolution of ecosystems and landscapes; and (4) the future of landscapes in the “Anthropocene”. These initiatives are poised for launch by researchers but will require coordinated efforts to develop the new intellectual collaborations needed among communities of scientists. Working with new combinations of scientific approaches, tools, and models will achieve transformative advances in the study of Earth surface processes. The scientific objectives, challenges, and intellectual collaborations needed for these initiatives are outlined below. Chapter 4 suggests mechanisms to support development of the initiatives.

3.1
INTERACTING LANDSCAPES AND CLIMATE

Climate is thought to play a critical role in driving the flux of solutes and mass across landscapes and through ecosystems during weathering, mass transport, erosion, and deposition. Topography, vegetation, biogeochemical cycling, and snow and ice cover also influence climate locally as well as globally and over long time scales. Yet much remains unknown about the links and interactions between Earth surface processes and climate. The principal goal of a major research initiative in the area of climate-landscape interactions is to develop a quantitative understanding of climatic controls on Earth surface processes and landscape influence on climate over time scales that range from individual storm events



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CHAPTER THREE Four High-Priority Research Initiatives in Earth Surface Processes Although each of the nine grand challenges in Earth surface processes embodies sig- nificant prospects for research advances, the committee suggests that these challenges can be collected into four major research initiatives (Figure 3.1). The idea of “research initiatives” is further developed in Chapter 4, but the essential proposal is that these initiatives are timely, high-priority research areas that are rich in scientific merit and will potentially transform the field of Earth surface processes. They will require new interdisciplinary approaches, including the integration of theories, models, and tools. The four high-priority research initiatives are (1) interacting landscapes and climate; (2) quantitative reconstruction of landscape dynamics across time scales; (3) the coevolution of ecosystems and landscapes; and (4) the future of landscapes in the “Anthropocene”. These initiatives are poised for launch by researchers but will require coordinated efforts to develop the new intellectual collaborations needed among communities of scientists. Working with new combinations of scientific approaches, tools, and models will achieve transformative advances in the study of Earth surface processes. The scientific objectives, challenges, and intellectual collaborations needed for these initiatives are outlined below. Chapter 4 suggests mechanisms to support development of the initiatives. 3.1 INTERACTING LANDSCAPES AND CLIMATE Climate is thought to play a critical role in driving the flux of solutes and mass across landscapes and through ecosystems during weathering, mass transport, erosion, and deposi- tion. Topography, vegetation, biogeochemical cycling, and snow and ice cover also influence climate locally as well as globally and over long time scales. yet much remains unknown about the links and interactions between Earth surface processes and climate. The prin- cipal goal of a major research initiative in the area of climate-landscape interactions is to develop a quantitative understanding of climatic controls on Earth surface processes and landscape influence on climate over time scales that range from individual storm events 0

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LANDSCAPES ON THE EDGE GRAND CHALLENGES INITIATIVES Interacting Landscapes and Climate How Do Geopatterns What Does Our How Do Landscapes on Earth’s Surface Planet’s Past Tell Influence and Arise and What Do Us About Its Record Climate They Tell Us About Future? andTectonics? Processes? Quantitative Reconstruction of Landscape Dynamics How Does the Across Time Scales Biogeochemical What Are the How Do Ecosystems Reactor of the Earth’s Transport Laws That and Landscapes Surface Respond to and Govern the Evolution Coevolve? Shape Landscapes of the Earth’s Surface? from Local to Global Scales? The Coevolution of Ecosystems and Landscapes How Can Earth- How Will What Controls Surface Science Earth’s Surface Landscape Resilience Contribute Toward Evolve in the to Change? a Sustainable “Anthropocene”? Earth Surface? The Future of Landscapes in the “Anthropocene” FIGURE 3.1 Conceptual diagram illustrates the relationship among the nine grand challenges and four high-priority research initiatives. The nine grand challenges are interconnected at many intellectual and technical levels (schematically represented by the dashed lines; see Chapter 2 for details). Rising from the fusion of the nine grand challenges, the four high-priority research initiatives are particularly apt to advance understanding and promote interdisciplinary collaboration in Earth surface processes. to millennia. Longer-term interactions among climate, topography, and tectonics are the subject of a complementary initiative (see Section 3.2). Success with this research initiative has the potential to transform our understanding of the powerful role of climate in shap- ing and transforming the Earth’s surface and the feedbacks between surface change and climate. Such understanding is essential to efforts to predict landscape response to land use and climate change and to evaluate quantitatively the efficacy of various management plans and mitigation strategies. The primary science objectives for this initiative include the following: • Development of theory for the interactions among topography, land cover, and global, regional, and local climate that determine the biogeochemically and geo- morphically significant attributes of climate (for example, ground-air thermal histories, precipitation, runoff, winds, and waves). 0

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Four High-Priority Research Initiatives in Earth Surface Processes • Development of geomorphic transport laws that explicitly account for climate (probability distributions of temperature, precipitation, runoff, winds, and waves) and incorporate interactions with biota, including theories for river and glacier inci- sion; production, transport, routing, and deposition of sediment; and geochemical processes. • Monitoring, experimentation, and modeling of climatic controls on the weather- ing of rock and soil and their influence on physical erosion rates and vice versa. Climatic effects include both the direct effects of characteristics such as air or ground temperature and moisture flux and the indirect effects such as primary production and microbial processes, and incorporate the influence of land surface attributes and mass fluxes on biogeochemical cycles. • Study of the feedbacks between global and regional climate and (1) the operation of terrestrial carbon reservoirs (including the role of land use and climate change, fire, erosion, and deposition), and (2) the controls on atmospheric dust concentra- tion (including the evolution of soil composition, soil moisture, topography, and land cover in source regions). • Modeling and monitoring of landscape evolution under diverse and varying cli- matic conditions; identification of climatic signatures in landscapes; evaluation of thresholds of landscape response and the limits of resilience. • Development of theories for subglacial hydrology, basal sliding of glaciers, subglacial sediment deformation, and ocean-ice interactions at ice-sheet margins—processes critical for evaluating rates of glacier melting and potential thresholds of ice-sheet collapse. • Improvement of the coupling between surface processes and existing climate models, explicitly incorporating the effects, feedbacks, and conditions outlined above. Collaboration between Earth surface scientists and atmospheric scientists is the primary need for developing and advancing this initiative. Recent National Science Foundation (NSF)-supported workshops (Galewsky and Roe, 2008) have brought climate scientists together with geomorphologists, for example, to begin to identify key questions and col- laborative research opportunities for Earth surface processes. Because many new research questions in this area clearly cross boundaries between atmospheric science and Earth surface science, improved communication between these communities is essential for sig- nificant progress. Increasing the visibility and understanding of Earth surface science within the atmospheric sciences community, and vice versa, through analysis of common scientific objectives is important to help establish these links. 

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LANDSCAPES ON THE EDGE 3.2 QUANTITATIVE RECONSTRUCTION OF LANDSCAPE DyNAMICS ACROSS TIME SCALES One of the paradoxes of Earth’s surface is that locally it can evolve and change abruptly, with dramatic consequences for humans and ecosystems, yet overall it may evolve slowly enough that observations on scales of human lifetimes are insufficient to characterize more than a small slice of its dynamics. By greatly expanding our time horizon, we may gauge important but rare events and perceive dynamics that emerge only on time scales of thousands to tens of millions of years or more—for example, the interplay of surface processes and tectonics that links the landscape to the Earth’s interior. This major research initiative is focused on developing a bridge in time from instants to eons, using quantitative reconstruction of landscape dynamics across time scales based on emerging high-resolution information recorded in extant landscapes and the sedimentary record. Discoveries highlighted in this report show that the world we see today reflects evolu- tion over a wide range of time scales, and that the longer the time scale, the stronger is the coupling between the Earth’s surface and its interior. Together with new techniques for dating and measuring features and processes at the Earth’s surface, new conceptual models of how tectonic and climatic effects come into play at different time scales open the way to building a unified view of the landscape across the full range of time scales on which it evolves. A confluence of interest has developed with regard to how the surface evolves on increasing time scales and how to mine the long-term archive of preserved events for information on the variability of surface dynamics, and in particular, the frequency of rare but potentially catastrophic events. Thus, the goals of this initiative are (1) to understand how the interplay of tectonics, climate, biota, lithology, and surface processes creates landscapes from human to planetary time scales, and (2) to extract information on event frequency and rates of evolution from landscape archives over this range of time scales. Reconstructed time-sequence evolution of the Earth’s surface will be used (1) to test and inspire models that couple tectonics, cli- mate, biota, and landscape evolution; (2) to constrain the frequencies and causes of rare but important surface events; and (3) to provide baseline information on pre-human landscapes as a guideline for restoration and management. The primary science objectives for this initiative include the following: • Improving methods for quantitative reconstruction of past Earth surface states (terrestrial paleoclimate, hydrology, soil characteristics, sediment transport and erosion rates, subsidence or uplift rate) from the fragmentary record of landforms, paleobotany, geochemistry, paleo-soils, and sedimentary deposits. • Developing detailed paleoclimate, tectonic, and sedimentary records of abrupt changes in Earth surface processes and of landscape resilience over long time 

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Four High-Priority Research Initiatives in Earth Surface Processes scales to understand the tolerable limits of stochastic variability within different geomorphic systems. • Developing and testing quantitative predictive models for the Earth surface system with explicit coupling across time scales. Important focus areas for improvement of current models include the use of realistic crust and mantle rheologies; investigation of possible coupling to mantle convection; modeling glacial erosion and transport; and coupling to biogeochemical cycles. • Developing and improving technical capabilities and data collection in near-surface geophysical methods (for example, high-frequency seismic reflection, ground- penetrating radar, and electrical resistivity profiling) to image and measure Earth’s near-surface structure and physical properties in three dimensions. The essential intellectual collaborations for this initiative to succeed are those between researchers with knowledge of deep- and surface-Earth processes. A particular challenge may be to coordinate collaboration among industry, engineering, and academic researchers that is essential to facilitate the exchange of knowledge, tools, and models among these communities. The identification of critical, complementary research objectives may initiate some of the needed interactions. 3.3 THE COEVOLUTION OF ECOSySTEMS AND LANDSCAPES Rapidly growing interest in research at the interface of biota and Earth surface processes—the life-landscape connection—is giving rise to the emerging fields of geobiology, biogeomorphology, and ecohydrology, among others. With new ways of measuring how the living and nonliving surfaces co-organize and an increasing ability to link biotic pro- cesses and landscape evolution, the opportunity exists to forge a new understanding of the coevolution of ecosystems and landscapes and to address pressing problems of future environmental change. This initiative could lead to the transfer of basic concepts and theories on physical systems to ecological research, and to the use of ecological principles to guide coupled ecosystem and landscape modeling. A grand goal is to build the capability to predict future coupled ecosystem and landscape states under varying climate and land-use conditions. Developing this predictive capability is of importance for a number of societally relevant issues, such as the future states of rivers and their ecosystems in response to anthropogenic activity, the evolution of tidal marshlands under sea-level rise, or the erosional stability of landscapes and terrestrial carbon reservoirs in response to increased seasonal thawing. As in global climate modeling, the records stored in paleoecologic, geomorphic, and paleosol archives can serve as tests for modeling. Such shared model building will identify, in turn, key field datasets and processes that are in need of focused studies. 

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LANDSCAPES ON THE EDGE The primary science objectives for this initiative include the following: • Improvement of theory and observations that relate spatial patterns and dynamics of biota to landscape setting (topography, hydrology, and geology) for given climatic conditions. • Development of models that incorporate both the geomorphic transport laws and the requisite biogeochemical equations to account mechanistically for the role of biota. • Development of landscape evolution theory that includes the effects of biota (and its possible coevolution with landscape). • Development of models to predict the coevolution of climate, biota, and landscape processes under a scenario of increased greenhouse gases. • Development of observations and models for the interaction of biota with stream channel and floodplain morphology and dynamics. Significant advances in this initiative depend on development of sustained, long- term collaborations between the biological and Earth surface sciences. Recent workshops that have helped to establish some of the needed interactions (e.g., the Binghamton Geo- morphology Symposium on Geomorphology and Ecosystems; see also Chapter 2). Inte- grating ecology, geology, hydrology, and atmospheric science to examine biological-physical feedbacks that shape landscapes could be linked to ongoing efforts at the 26 Long Term Ecological Research (LTER) Network sites in order to foster interdisciplinary approaches (see also Chapter 4). An important opportunity for potential coordination of these types of interdisciplinary efforts was announced early in 2009 by the NSF through Dear Col- league Letters: Emerging Topics in Biogeochemical Cycles1 and Multi-scale Modeling,2 with objectives that include understanding how Earth’s biological systems respond to and influence its physical and chemical conditions (see also Chapter 4). 3.4 THE FUTURE OF LANDSCAPES IN THE “ANTHROPOCENE” Human activity is changing Earth’s surface, both markedly and rapidly; these changes are likely to increase with an expanding human footprint across the globe. Over the past several decades, substantial advances have been made in understanding the range and extent of human impacts on Earth surface systems. These advances, coupled with technologi- cal breakthroughs, present significant opportunities to develop answers to a fundamental, compelling, and urgent question: How can we understand, predict, and respond to rapidly http://www.nsf.gov/pubs/2009/nsf09030/nsf09030.jsp. 1 http://www.nsf.gov/pubs/2009/nsf09032/nsf09032.jsp. 2 

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Four High-Priority Research Initiatives in Earth Surface Processes changing landscapes that are increasingly altered by humans? Although individual disci- plines have tackled different aspects of this question, a focused effort is now needed across disciplines to anticipate and mitigate future impacts, as well as to factor the changes that have already occurred into human decision processes. The overarching goal of this major initiative is to transform our understanding of human-landscape systems—integrated sys- tems characteristic of the “Anthropocene”—and our ability to predict how they might evolve in the future. This initiative transcends many disciplines spanning the natural and social sciences and engineering. A range of scientific expertise will be necessary to integrate theories, models, and approaches toward predictive capacity for human-landscape systems. The new interdisciplinary knowledge produced will be critical for guiding landscape management and restoration and informing environmental policy. Such guidance will be vital as human population grows and natural resource challenges are increasingly confronted, and as we strive toward a sustainable Earth surface for the next generation. The primary science objectives for this initiative include the following: • Improved understanding of the long-term legacies of human impacts on landscapes and quantification of current rates of impacts (e.g., from mining, grazing, deforesta- tion, creation of impervious surfaces, agricultural erosion and pollution, flow and sediment impoundment)—especially in environments that are sensitive to global climate change. • Development of mechanistic models linking multiple and cumulative effects of human activity. • Development of integrated models of the complex interactions within human- dominated landscapes, incorporating decision making and human behavior. • Greater understanding and predictive capacity for coupled human-landscape dynamics. • Capacity building to anticipate and guide options for mitigating, reversing, and adapting to human-caused landscape change. • Coordinated collection and database management of sociological and geographical information on land use for incorporation into quantitative models. Developing this initiative requires new, sustained collaborations among Earth surface scientists and a range of social and behavioral scientists including economists, political scientists, psychologists, sociologists, and human geographers. This range of expertise is necessary to develop the capacity to predict coupled human-landscape dynamics, to incor- porate decision-making and human perception and valuation in quantitative models, and to build integrated assessment tools needed by society. Partnership among Earth surface sci- entists, engineers, practitioners, and planners is also needed to use manipulated landscapes 

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LANDSCAPES ON THE EDGE for experimentation and to incorporate feedback mechanisms in scientific frameworks for human-landscape systems. Collaboration with geospatial scientists is additionally neces- sary to integrate existing and emerging geospatial technologies into modeling efforts, to facilitate data mining and management, and to link remote-sensing studies with field and modeling approaches. Increased collaboration among Earth surface scientists (e.g., ecolo- gists, geomorphologists, and geochemists) and climate scientists is also necessary to address the interactions with global climate change. Developing intellectual collaborations with social scientists represents a major challenge and a significant opportunity for Earth surface scientists. This area is one in which com- paratively little work has been done traditionally, particularly in investigating geomorphic systems. yet, transformative advances require bridging the real and perceived gaps between the approaches of the natural scientists and those of social scientists. Initial efforts have incorporated social sciences into research at NSF’s LTER sites (see also Section 2.6 and Box 4.1), at other environmental observatories (e.g., Vajjhala et al., 2007), and within eco- hydrology programs (e.g., in UNESCO). Recent work has also addressed the integration of social sciences into climate-change research (e.g., NRC, 2007b; Nagel et al., 2009). Critical breakthroughs will require accelerating these efforts and initiating new ones that focus on human-landscape systems in which geomorphic processes are central. NSF announced its goal to increase collaboration between the geosciences and social and behavioral sciences in February 2009 through the Dear Colleague Letter: Environment, Society, and Economy.3 The augmented funding available provides an opportunity for potentially developing this initiative on the future of human landscapes (see also Chapter 4). 3.5 SUMMARy Interest in Earth surface processes has grown substantially in recent years in response to a confluence of exciting scientific discoveries, greater awareness of the impacts of humans and climate on Earth’s surface, new tools and instruments for acquiring data, and increased societal demand for scientific guidance to understand, manage, and restore landscapes. These advances, along with the development of disciplinary programs at NSF that ad- dress research at the Earth’s surface, have been positive for the field and for society (see also Chapter 4). Nevertheless, the field of Earth surface processes has reached a point at which the imminent research questions cross multiple disciplinary boundaries and require new intellectual collaborations and approaches. The four initiatives outlined in this chapter offer exceptionally promising directions with the potential to lead the field toward major phases of scientific discovery. They are designed to yield fundamental knowledge of past and present Earth surface systems in order to develop predictive capabilities for the future. http://www.nsf.gov/pubs/2010/nsf1003/nsf1003.jsp. 3 

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Four High-Priority Research Initiatives in Earth Surface Processes Because of unprecedented rates of change occurring on Earth’s surface from the combined effects of human impacts and global climate change, this knowledge is pressing and urgent for both science and society. The four initiatives are suggested to focus the efforts of the research community, as well as those of NSF and other agencies (see also Chapter 4 and Appendix C), toward achieving these goals. Development of the four initiatives could lead to a new generation of researchers with an increased ability to work in interdisciplinary settings. Rapidly growing numbers of new researchers (faculty and students) within the field underscore a critical need for investigator- driven research opportunities (see also Chapter 4 and Appendix C). Significant progress on the complex problems highlighted in the initiatives will require increasing collaboration among a range of scientists who may not have worked together previously, presenting key challenges to the development and success of the initiatives. The intellectual collaborations needed for each of the initiatives vary; they include interactions between Earth surface scientists and atmospheric and biological scientists, between researchers with knowledge of deep- and surface-Earth processes, and between Earth surface scientists and social and geospatial scientists and engineers. The development and refinement of tools for data col- lection will require a new level of collaboration between academia and industry. Specific needs in technology, data collection, and the establishment of monitoring networks and community facilities are outlined in Chapter 4, as are specific organizational mechanisms to support development of the four high-priority research initiatives. 

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