Research Notes for Land Managers

This publication, produced by the Cottonwood Ecology Group, covers key findings in the following topic areas and includes major conservation and restoration implications and practical recommendations.

  • How climate changes may affect the distribution of cottonwoods in the Southwest,
  • The importance of keeping edge species,
  • Genetic diversity in Fremont cottonwoods and its implications for a diverse dependent community,
  • How genetic variation in host trees drives arthropod evolutionary processes,
  • Understanding foundation species and their reach into the surrounding ecosystem,
  • How beavers affect biological diversity through differential herbivory,
  • Factors that affect riparian biodiversity and habitat quality,
  • Why it’s important to match restored cottonwood plantings to the genetic diversity in the wild,
  • The detrimental effects of increased tamarisk cover.
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A Framework for Community and Ecosystem Genetics: From Genes to Ecosystems, Nature, 2006.

Can heritable traits in a single species affect an entire ecosystem? This article reviews research studies that show that such traits in a common tree have predictable effects on community structure and ecosystem processes. Because these ‘community and ecosystem phenotypes’ have a genetic basis and are heritable, we can begin to apply the principles of population and quantitative genetics to place the study of complex communities and ecosystems within an evolutionary framework.

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From Genes to Ecosystems: A Synthesis of the Effects of Plant Genetic Factors across Levels of Organization, Philosophical Transactions of the Royal Society, 2009

Using two genetic approaches and seven different plant systems, Bailey et al. present findings from a metaanalysis that examined the strength of the effects of plant genetic introgression and genotypic diversity across individual, community, and ecosystem levels. These findings have evolutionary implications.

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Phenotypic Variation in Nurse Traits and Community Feedbacks Define an Alpine Community, Ecology Letters, 2011

Much is known about facilitation, but virtually nothing about the underlying genetic and evolutionary consequences of this important interaction. Michalet et al. assessed the potential of phenotypic differences in facilitative effects of a foundation species to determine the composition of an alpine community in Arizona.

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Community Heritability Measures the Evolutionary Consequences of Indirect Genetic Effects on Community Structure, Evolution, 2006

Using simulated and natural communities of arthropods inhabiting North American cottonwoods (Populus), Schuster et al. show that when species comprising ecological communities are summarized using a multivariate statistical method, nonmetric multidimensional scaling (NMDS), the resulting univariate scores can be analyzed using standard techniques for estimating the heritability of quantitative traits.

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Community and Ecosystem Genetics: A Consequence of the Extended Phenotype, Ecology, 2003

Whitham et al. present evidence that the heritable genetic variation within individual species, especially dominant and keystone species, has community and ecosystem consequences. These consequences represent extended phenotypes, i.e., the effects of genes at levels higher than the population. They also discuss the implications of their findings.

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Extending Genomics to Natural Communities and Ecosystems, Science, 2008

An important step in the integration of ecology and genomics is the progression from molecular studies of relatively simple model systems to complex field systems. The recent availability of sequenced genomes from key plants is leading to a new understanding of the molecular drivers of community composition and ecosystem processes.

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A Community and Ecosystem Genetics Approach to Conservation Biology and Management, 2010

A review of the community and ecosystem genetics approach in the book Molecular Approaches in Natural Resource Conservation and Management that includes some management implications.

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Community Specificity: Life and Afterlife Effects of Genes, Trends in Plant Science, 2012

A review of the literature that shows that genetic specificity exhibits both life and afterlife effects; it is a widespread phenomenon occurring in diverse taxonomic groups, aquatic to terrestrial ecosystems, and species-poor to species-rich systems. The review also suggests that specificity is a major driver of the biodiversity and stability of the world’s ecosystems.

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A Geographic Mosaic of Genetic Variation within a Foundation Tree species and Its Community-level Consequences, Ecology, 2009

Knowledge of the manner in which genetic variation within a tree species affects associated communities and ecosystem processes across its entire range is important for understanding how geographic mosaics of genetic interactions might develop and support different communities. Barbour et al. studied genetic variation across eight geographical races of the forest tree Eucalyptus globulus, which representits natural distribution across southeastern Australia.

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Publications by the Cottonwood Ecology Group

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  • Northern Arizona University
  • National Science Foundation
  • University of Tasmania
  • Bureau of Reclamation
  • Merriam Powell Cemter for Environmental Research