Process‐based and correlative modeling of desert mistletoe distribution: a multiscalar approach

Andrés Lira-Noriega,Curtis P Miller,Jorge Soberón

doi:10.1890/es13-00155.1

Andrés Lira-Noriega, Curtis P Miller + Show 1 more

Open Access

https://doi.org/10.1890/es13-00155.1

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Journal: Ecosphere	Publication Date: Aug 1, 2013
Citations: 22	License type: CC BY 3.0

Affiliation: University of Kansas, University of New Mexico

Abstract

Because factors affecting distributional areas of species change as scale (extent and grain) changes, different environmental and biological factors must be integrated across geographic ranges at different resolutions, to understand fully the patterns and processes underlying species' ranges. We expected climate factors to be more important at coarse resolutions and biotic factors at finer resolutions. We used data on occurrence of a parasitic plant (Phoradendron californicum), restricted to parts of the Sonoran and Mojave deserts, to analyze how climate and mobility factors explain its distributional area. We developed analyses at five spatial resolutions (1, 5, 10, 20, 50 km) within the distributional area of the disperser species, and compared ecological niche models from three commonly used correlative methods with a process‐based model that estimates colonization and extinction rates in a metapopulation framework. Correlative models improved when layers associated with hosts and disperser were used as predictors, in comparison with models based on climate only; however, they tended to overfit to data as more layers were added. Dispersal‐related parameters were more relevant at finer resolutions (1–5 km), but importance of extinction‐related parameters did not change with scale. We observed greater coincidence between correlative and process‐based models when based only on dimensions of the abiotic niche (i.e., climate), but a clearer and more comprehensive mechanistic understanding was derived from the process‐based algorithm.

Highlights

The relative roles of biotic and abiotic factors in determining distributions of species at specific spatial scales are a central organizing theme in ecology (Levin 1992)
Because factors affecting distributional areas of species change as scale changes, different environmental and biological factors must be integrated across geographic ranges at different resolutions, to understand fully the patterns and processes underlying species’ ranges
We developed analyses at five spatial resolutions (1, 5, 10, 20, 50 km) within the distributional area of the disperser species, and compared ecological niche models from three commonly used correlative methods with a process-based model that estimates colonization and extinction rates in a metapopulation framework

Summary

Introduction

The relative roles of biotic and abiotic factors in determining distributions of species at specific spatial scales are a central organizing theme in ecology (Levin 1992). Understanding how patterns at one scale are manifestations of or influence processes operating at other scales is a particular challenge (Levin and Pacala 1997, Pearson and Dawson 2003, Hastings et al 2010) The core of this challenge lies in disentangling how changes in scale affect the importance of different factors in shaping species’ distributional patterns and processes. When studying species’ distributions, it is useful to distinguish interacting variables from those that are dynamically uncoupled from the presence or abundance of the species in question (scenopoetic variables; Hutchinson 1978). These variables may have contrasting effects at fine versus coarse spatial resolutions (Wiens 1989). The many ways in which scenopoetic variables operate at different extents and resolutions can be used to explain distributions of the species

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