Spatial heterogeneity influences native and nonnative plant species richness.

Spatial heterogeneity may have differential effects on the distribution of native and nonnative plant species richness. We examined the effects of spatial heterogeneity on native and nonnative plant species richness distributions in the central part of Rocky Mountain National Park, Colorado, USA. Spatial heterogeneity around vegetation plots was characterized using landscape metrics, environmental/topographic variables (slope, aspect, elevation, and distance from stream or river), and soil variables (nitrogen, clay, and sand). The landscape metrics represented five components of landscape heterogeneity and were measured at four spatial extents (within varying radii of 120, 240, 480, and 960 m) using the FRAGSTATS landscape pattern analysis program. Akaike's Information Criterion adjusted for small sample size (AICc) was used to select the best models from a set of multiple linear regression models developed for native and nonnative plant species richness at four spatial extents and three levels of ecological hierarchy (i.e., landscape, land cover, and community). Both native and nonnative plant species richness were positively correlated with edge density, Simpson's diversity index and interspersion/juxtaposition index, and were negatively correlated with mean patch size. The amount of variation explained at four spatial extents and three hierarchical levels ranged from 30% to 70%. At the landscape level, the best models explained 43% of the variation in native plant species richness and 70% of the variation in nonnative plant species richness (240-m extent). In general, the amount of variation explained was always higher for nonnative plant species richness, and the inclusion of landscape metrics always significantly improved the models. The best models explained 66% of the variation in nonnative plant species richness for both the conifer land cover type and lodgepole pine community. The relative influence of the components of spatial heterogeneity differed for native and nonnative plant species richness and varied with the spatial extent of analysis and levels of ecological hierarchy. The study offers an approach to quantify spatial heterogeneity to improve models of plant biodiversity. The results demonstrate that ecologists must recognize the importance of spatial heterogeneity in managing native and nonnative plant species.

[1]  M. MacKenzie,et al.  Effects of sensor spatial resolution on landscape structure parameters , 1995, Landscape Ecology.

[2]  T. Stohlgren,et al.  Comparison of rangeland vegetation sampling techniques in the Central Grasslands , 1998 .

[3]  Steward T. A. Pickett,et al.  Patch dynamics and the design of nature reserves , 1978 .

[4]  Brian D. Inouye,et al.  SPATIAL HETEROGENEITY EXPLAINS THE SCALE DEPENDENCE OF THE NATIVE-EXOTIC DIVERSITY RELATIONSHIP , 2005 .

[5]  Marie-Josée Fortin,et al.  Landscape Ecology Comes of Age1 , 2005 .

[6]  Thomas J. Stohlgren,et al.  Rapid Assessment of Plant Diversity Patterns: A Methodology for Landscapes , 1997 .

[7]  Melinda Moeur,et al.  Spatial models of competition and gap dynamics in old-growth Tsuga heterophylla/Thuja plicata forests , 1997 .

[8]  J. Reynolds,et al.  A Simulation Experiment to Quantify Spatial Heterogeneity in Categorical Maps , 1994 .

[9]  Thomas J. Stohlgren,et al.  EXOTIC PLANT SPECIES INVADE HOT SPOTS OF NATIVE PLANT DIVERSITY , 1999 .

[10]  T. Simons,et al.  Spatial autocorrelation and autoregressive models in ecology , 2002 .

[11]  W. Cohen,et al.  Lidar remote sensing of above‐ground biomass in three biomes , 2002 .

[12]  R. Sanderson,et al.  Predicting the distributions of plant species at the regional scale: a hierarchical matrix model , 1995, Landscape Ecology.

[13]  Mark S. Boyce,et al.  Influence of habitat abundance and fragmentation on northern spotted owls in western Oregon , 1998 .

[14]  S. Pearson.  The spatial extent and relative influence of landscape-level factors on wintering bird populations , 1993, Landscape Ecology.

[15]  Kevin J. Rice,et al.  Habitat patchiness promotes invasion by alien grasses on serpentine soil , 2001 .

[16]  Richard Ferris,et al.  Maintaining Biodiversity in Forest Ecosystems , 1999 .

[17]  L. E. Kruger,et al.  National workshop on recreation research and management, Portland, Oregon, USA, 8-10 February 2005. , 2007 .

[18]  D. Gutiérrez,et al.  HABITAT DISTRIBUTION MODELS: ARE MUTUALIST DISTRIBUTIONS GOOD PREDICTORS OF THEIR ASSOCIATES? , 2005 .

[19]  E. Lee,et al.  Reductions in gas exchange of Populus tremuloides caused by leaf aging and ozone exposure , 1996 .

[20]  David R. Anderson,et al.  Model selection and multimodel inference : a practical information-theoretic approach , 2003 .

[21]  A. R. Johnson,et al.  A hierarchical framework for the analysis of scale , 1989, Landscape Ecology.

[22]  A. Magurran,et al.  Biological diversity : the coexistence of species on changing landscapes , 1994 .

[23]  Robert M. Zink,et al.  Bird species diversity , 1996, Nature.

[24]  M. R. Carter,et al.  Soil Sampling and Methods of Analysis , 1993 .

[25]  J. Neter,et al.  Applied linear statistical models : regression, analysis of variance, and experimental designs , 1974 .

[26]  Kent H. Redford,et al.  Biodiversity in Managed Landscapes: Theory and Practice. , 1996 .

[27]  J. Kolasa,et al.  Introduction: The Heterogeneity of Heterogeneity: A Glossary , 1991 .

[28]  M. Turner,et al.  LANDSCAPE ECOLOGY : The Effect of Pattern on Process 1 , 2002 .

[29]  Marie-Josée Fortin,et al.  Spatial Statistics in Landscape Ecology , 1999 .

[30]  G. Gee,et al.  Particle-size Analysis , 2018, SSSA Book Series.

[31]  Thomas J. Stohlgren,et al.  Species-environment relationships and vegetation patterns: effects of spatial scale and tree life-stage , 1998, Plant Ecology.

[32]  Monica G. Turner,et al.  Predicting the spread of disturbance across heterogeneous landscapes , 1989 .

[33]  T. Stohlgren,et al.  Monitoring shifts in plant diversity in response to climate change: a method for landscapes , 2004, Biodiversity & Conservation.

[34]  A. Klute.  Methods of soil analysis. Part 1. Physical and mineralogical methods. , 1988 .

[35]  Marc J. Mazerolle,et al.  Patch characteristics and landscape context as predictors of species presence and abundance: A review1 , 1999 .

[36]  John G. Kie,et al.  LANDSCAPE HETEROGENEITY AT DIFFERING SCALES: EFFECTS ON SPATIAL DISTRIBUTION OF MULE DEER , 2002 .

[37]  S. Pickett.  Chapter 21 – Patch Dynamics: A Synthesis , 1985 .

[38]  R. Peet.  Forest vegetation of the Colorado Front Range , 1981, Vegetatio.

[39]  Arthur L. Spingarn.  Forest Fragmentation and Alien Plant Invasion of Central Indiana Old‐Growth Forests , 1992 .

[40]  Monica G. Turner,et al.  Scale and heterogeneity in habitat selection by elk in Yellowstone National Park , 2003 .

[41]  W. Baker,et al.  DISTURBANCE AND STAND DYNAMICS IN PONDEROSA PINE FORESTS IN ROCKY MOUNTAIN NATIONAL PARK, USA , 2003 .

[42]  R. O'Neill,et al.  Scale problems in reporting landscape pattern at the regional scale , 1996, Landscape Ecology.

[43]  Steven F. Oberbauer,et al.  Landscape scale evaluation of understory light and canopy structure : methods and application in a neotropical lowland rain forest , 1996 .

[44]  S. Weiss,et al.  GLM versus CCA spatial modeling of plant species distribution , 1999, Plant Ecology.

[45]  P. White,et al.  The Ecology of Natural Disturbance and Patch Dynamics , 1986 .

[46]  P. Risser.  Landscape Ecology: State of the Art , 1987 .

[47]  C. Flather,et al.  Plant species invasions along the latitudinal gradient in the United States , 2006 .

[48]  Teja Tscharntke,et al.  SCALE‐DEPENDENT EFFECTS OF LANDSCAPE CONTEXT ON THREE POLLINATOR GUILDS , 2002 .

[49]  Roland R. Roth,et al.  Spatial Heterogeneity and Bird Species Diversity , 1976 .

[50]  Eric J. Gustafson,et al.  Quantifying Landscape Spatial Pattern: What Is the State of the Art? , 1998, Ecosystems.

[51]  J. Wiens.  Population Responses to Patchy Environments , 1976 .

[52]  S. Archer,et al.  WOODY PLANT ESTABLISHMENT AND SPATIAL HETEROGENEITY IN GRASSLANDS , 2003 .

[53]  M. L. Cadenasso,et al.  Landscape Ecology: Spatial Heterogeneity in Ecological Systems , 1995, Science.

[54]  M. Kauffman,et al.  Heterogeneity shapes invasion: host size and environment influence susceptibility to a nonnative pathogen. , 2006, Ecological applications : a publication of the Ecological Society of America.

[55]  B. Milne.  Heterogeneity as a Multiscale Characteristic of Landscapes , 1991 .

[56]  T. Stohlgren,et al.  Riparian zones as havens for exotic plant species in the central grasslands , 1998, Plant Ecology.

[57]  A. Perera,et al.  Sensitivity of landscape pattern indices to input data characteristics on real landscapes: implications for their use in natural disturbance emulation , 2004, Landscape Ecology.

[58]  K. O. Niemann,et al.  Simulation and quantification of the fine-scale spatial pattern and heterogeneity of forest canopy structure: A lacunarity-based method designed for analysis of continuous canopy heights , 2005 .

[59]  M. Turner.  Landscape ecology in North America: past, present, and future , 2005 .

[60]  R. Peet.  Forests of the Rocky Mountains , 1988 .

[61]  Arthur S. Lieberman,et al.  Landscape Ecology , 1994, Springer New York.

[62]  John A. Wiens,et al.  Landscape mosaics and ecological theory , 1995 .

[63]  Marie-Josée Fortin,et al.  SPATIAL ANALYSIS OF LANDSCAPES: CONCEPTS AND STATISTICS , 2005 .

[64]  Bruce T. Milne,et al.  Effects of changing spatial scale on the analysis of landscape pattern , 1989, Landscape Ecology.

[65]  R. Peet,et al.  Gradient analysis of latitudinal variation in southern Rocky Mountain forests , 1991 .

[66]  W. Cohen,et al.  Lidar Remote Sensing for Ecosystem Studies , 2002 .

[67]  R. Haining.  Spatial Data Analysis in the Social and Environmental Sciences , 1990 .

[68]  K. McGarigal,et al.  FRAGSTATS: spatial pattern analysis program for quantifying landscape structure. , 1995 .

[69]  M. Turner,et al.  WINTER HABITAT USE BY LARGE UNGULATES FOLLOWING FIRE IN NORTHERN YELLOWSTONE NATIONAL PARK , 1995 .

[70]  Joseph K. Berry,et al.  Landscape analysis of plant diversity , 1997, Landscape Ecology.

[71]  Pierre Dutilleul,et al.  Spatial Heterogeneity against Heteroscedasticity: An Ecological Paradigm versus a Statistical Concept , 1993 .