Meeting reports: Research on Coupled Human and Natural Systems (CHANS): Approach, Challenges, and Strategies

Understanding the complexity of human–nature interactions is central to the quest for both human well-being and global sustainability. To build an understanding of these interactions, scientists, planners, resource managers, policymakers, and communities increasingly are collaborating across wide-ranging disciplines and knowledge domains. Scientists and others are generating new integrated knowledge on top of their requisite specialized knowledge to understand complex systems in order to solve pressing environmental and social problems (e.g., Carpenter et al. 2009). One approach to this sort of integration, bringing together detailed knowledge of various disciplines (e.g., social, economic, biological, and geophysical), has become known as the study of Coupled Human and Natural Systems, or CHANS (Liu et al. 2007a, b). In 2007 a formal standing program in Dynamics of Coupled Natural and Human Systems was created by the U.S. National Science Foundation. Recently, the program supported the launch of an International Network of Research on Coupled Human and Natural Systems (CHANS-Net.org). A major kick-off event of the network was a symposium on Complexity in Human–Nature Interactions across Landscapes, which brought together leading CHANS scientists at the 2009 meeting of the U.S. Regional Association of the International Association for Landscape Ecology in Snowbird, Utah. The symposium highlighted original and innovative research emphasizing reciprocal interactions between human and natural systems at multiple spatial, temporal, and organizational scales. The presentations can be found at ‹http://chans- net.org/Symposium_2009.aspx›. The symposium was accompanied by a workshop on Challenges and Opportunities in CHANS Research. This article provides an overview of the CHANS approach, outlines the primary challenges facing the CHANS research community, and discusses potential strategies to meet these challenges, based upon the presentations and discussions among participants at the Snowbird meeting

Constructions of Random Distributions via Sequential Barycenters

This article introduces and develops a constructive method for generating random probability measures with a prescribed mean or distribution of the means. The method involves sequentially generating an array of barycenters which uniquely defines a probability measure. Basic properties of the generated measures are presented, including conditions under which almost all the generated measures are continuous or almost all are purely discrete or almost all have finite support. Applications are given to models for average-optimal control problems and to experimental approximation of universal constants

Directionally Reinforced Random Walks

This paper introduces and analyzes a class of directionally reinforced random walks. The work is motivated by an elementary model for time and space correlations in ocean surface wave fields. We develop some basic properties of these walks. For instance, we investigate recurrence properties and give conditions under which the limiting continuous versions of the walks are Gaussian diffusion processes

Models of human-nature interactions: the biocomplexity approach

Estudiamos el acoplamiento de sistemas naturales y humanos en diversos sitios y culturas construyendo modelos de simulación de cuatro sitios que incluyen áreas protegidas; dos en Texas, Estados Unidos, y dos en Venezuela. En los sitios de Texas, se están convirtiendo legalmente los bosques en espacios urbanos de uso residencial, comercial, e industrial, mientras que en Venezuela se talan legal e ilegalmente los bosques para transformarlos en sistemas agrícolas de subsistencia. Las técnicas contemporáneas de modelación facilitan simulaciones de decisiones humanas y de la dinámica del ecosistema que pueden revelar patrones inesperados. Tales acoplamientos de los sistemas humanos y los sistemas naturales se reconocen actualmente como una forma de biocomplejidad. Nuestra metodología es flexible, para permitir la adaptación a cada uno de los sitios del estudio, capturando las características esenciales de los cambios respectivos de la utilización del territorio, y de las reacciones naturales y decisiones humanas. Las interacciones entre los humanos se simulan usando los modelos multi-agentes que actúan sobre modelos del paisaje forestal, y perciben la respuesta de los efectos de estas acciones en forma de cambios de hábitat ecológicos y dinámica hidrológica.We study coupled human-natural systems across sites and cultures building simulation models in four sites that include protected areas; two in Texas (USA) and two in Venezuela. In the Texas sites, forests are being converted legally to urban spaces of residential, commercial and industrial use, while in Venezuela forests are extra-legally clear-cut for subsistence agriculture. Modern modeling techniques facilitate the study of human decisions and ecosystem dynamics and can reveal unexpected patterns. Such couplings of human and natural systems are recognized as a form of biocomplexity. Our methodology is flexible to allow adaptations to the diverse study sites, capturing the essential characteristics of the changes in land use and cover and the effects on natural systems and human decisions. Human interactions are simulated using muti-agent models that act on models of forest landscape and perceive the response of these actions in the form of changes in habitat and hydrological dynamics.Este artículo resultó de dos talleres de síntesis geográfica y cultural como parte de un proyecto de Biocomplejidad en el ambiente financiado por la Fundación Nacional de Ciencia de los EE.UU. (subvención NSF CNH BCS-0216722). Los talleres fueron auspiciados por UNEG (en octubre de 2004) y ULA (en febrero de 2005)