Sensitivity and effectiveness and of landscape metric scalograms in determining the characteristic scale of a hierarchic

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RESEARCH ARTICLE

Sensitivity and effectiveness and of landscape metric scalograms in determining the characteristic scale of a hierarchically structured landscape Na Zhang • Harbin Li

Received: 31 March 2012 / Accepted: 20 December 2012 / Published online: 6 January 2013 Ó Springer Science+Business Media Dordrecht 2013

Abstract Landscape metric scalograms (the response curves of landscape metrics to changing grain size) have been used to illustrate the scale effects of metrics for real landscapes. However, whether they detect the characteristic scale of hierarchically structured landscapes remains uncertain. To address this question, the scalograms of 26 class-level metrics were systematically examined for a simple random landscape, seven hierarchical neutral landscapes, and the real landscape of the Xilin River Basin of Inner Mongolia, China. The results show that when the fraction of the focal patch type (P) is below a critical value (Pc), most metric scalograms are sensitive to change in single-scale and lower-level hierarchical structure and insensitive to change in higher-level hierarchical structure. The scalograms of

Electronic supplementary material The online version of this article (doi:10.1007/s10980-012-9837-x) contains supplementary material, which is available to authorized users. N. Zhang (&) College of Resources and Environment, University of Chinese Academy of Sciences, 19A Yu Quan Road, Shijingshan District, Beijing 100049, People’s Republic of China e-mail: [email protected] H. Li USDA Forest Service Southern Research Station, Center for Forested Wetlands Research, Charleston, SC 29414, USA e-mail: [email protected]

only a few metrics measuring spatial aggregation and connectedness are sensitive to change in intermediatelevel hierarchical structure. Most metric scalograms explicitly identify the characteristic scale of a singlescale landscape and fine or intermediate characteristic scales of a multi-scale landscape for both simulated and real landscapes. When P exceeds Pc, only some metrics detect scale and change in structure. The scalograms of total class area and Euclidean nearest-neighbor distance cannot detect scale or change in structure in either case. Landscape metric scalograms are useful for addressing scale issues, including illustrating the scale effects of spatial patterns, detecting multi-scale patterns, and developing possible scaling relations. Keywords Hierarchically structured neutral landscape  Xilin River Basin of Inner Mongolia  FRAGSTATS  Class-level metric  Scale issues  Scale effect  Multi-scale pattern  Scaling

Introduction Dungan et al. (2002) proposed three scales of ecology: phenomenon, sampling and analysis scales. The phenomenon scale is based on the concept that patterns and processes have their own distinct scales at which their behaviors and dynamics can be most effectively described and understood (Clark 1985; Delcourt and Delcourt 1988). The phenomenon scale is also called the characteristic scale (CS) in a hierarchical system

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