Stachowicz Lab University of California, Davis

John J. Stachowicz

Professor of Evolution and Ecology
4330 Storer Hall
(530) 752-1113

Ph.D., Marine Sciences, University of North Carolina at Chapel Hill (1998)

B.A., Biology, Dartmouth College (1993)

Curriculum Vitae: pdf
In the broadest sense, the unifying theme of my research is the ecological causes and consequences of biodiversity. The vast diversity of life forms in the marine environment (many of the animal phyla are exclusively marine, or nearly so) makes it a rewarding system for addressing these sorts of issues. I have found seaweeds and marine invertebrates to be particularly tractable experimental subjects and have conducted research involving a diverse suite of invertebrate taxa including corals, hydroids, crabs, echinoderms, polychaetes, ascidians, bryozoans, and gastropods. The main issues my research has focused on are outlined below.

(1) The effects of species diversity on communities and ecosystems
(2) The ecological consequences of genetic diversity
(3) Positive interactions and mutualisms
(4) The ecology and evolution of decorator crabs
(5) Biological invasions

Effects of species diversity on communities and ecosystems

  While the relationship between species diversity and community stability has long been a topic of theoretical interest to ecologists, recent concern about the loss of biodiversity has prompted renewed interested in what the consequences of diversity loss might really be. We have worked on three fronts in this research area: documenting patterns of change in biodiversity in real systems, performing experiments to demonstrate the mechanisms by which diversity does and does not affect communities and ecosystems, and collaborating with other ecologists, conservation biologists and economists to test links between the loss of biodiversity and the provision of goods and services to humans by natural ecosystems.


Ecological consequences of genetic diversity

  Some communities, such as coral reefs, kelp forests, and seagrass beds may be comprised of a single dominant species, and genetic diversity within these species may play an analogous role to species diversity in more speciose systems. Through manipulative field experiments and laboratory mesocosms, we have been examining the effects of genetic diversity in the eelgrass Zostera marina on community function and stability. Field experiments show that genetic diversity enhances community resistance to natural disturbances by grazing geese and algal bloom as well as experimentally imposed disturbances. These differences in disturbance response affect the abundance of epifaunal grazers such as amphipods and other small crustaceans on seagrasses.


Positive Interactions and Mutualisms

  Ecological investigations of the past several decades have focused on negative interactions (competition and predation) and how they affect population and community structure. Although positive interactions (interactions in which one at least one species benefits and neither is harmed were studied decades ago, there has been limited effort to factor them into our models or thinking about factors impacting populations and communities. My work tries to balance this by using experimental investigations of positive interactions to study the population biology of the participants and the effects of these interactions on communities as a whole.


Ecology and Evolution of Decorator Crabs

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  Decorator crabs are a diverse group of brachyuran crabs within the superfamily Majoidea that have the unusual habit of "decorating" their carapace with bits of algae and invertebrates. They accomplish this by attaching these materials to specialized hooked setae on their carapace that hold decorations in place much in the same way that Velcro latches onto fabric. We study the fascinating natural history of these crabs and use phylogenetic methods to examine what these crabs can tell us about the ecology and evolution of antipredator behaviors in general. These crabs and our work on them was featured on the ABC evening news on Halloween 2006 in a piece on animals that "dress up for Halloween"


Invasion Biology

  Introduction of species to new biogeographic regions poses both challenges for conservation of native communities and opportunities for increasing our ecological understanding of the forces governing the assembly, structure and functioning of these communities. Work in our lab on invasions focuses on aspects of communities that either promote or retard the success of invasive species. Much of this work has involved either the effects of native diversity on invasion resistance or the effects of climate change on the relative success of native vs. exotic species.