Welcome to my website! I am an ecologist and evolutionary biologist interested in the natural history of plants and their interactions with herbivores and mutualists. I started out as an amateur nature-lover and over the years slowly found my way to studying plants and insects full-time!
Currently, I am an NSF-PRFB postdoc in Marjorie Weber's lab at Michigan State University. For my post-doc I am studying evolutionary patterns of stickiness and sand-entrapment in plants and the ecological consequences of this strange defense for plants and insects. With a variety of wonderful collaborators, I have other cool projects in the pipeline as well (pollination! seed dispersal! floral volatiles! fire ecology!).
I did my dissertation with Rick Karban at UC-Davis and previously worked with Doug Morse, Christine Janis, and Beth Brainerd at Brown University during and after my undergraduate years there.
I am interested in natural history and use that as my primary tool in examining ecological interactions and evolutionary patterns in various plant-insect interactions (herbivory, protective mutualisms, and pollination). I spend a lot of time just poking around, taking pictures, making observations, and collecting plants and seeds; most of my projects and ideas have come from these jaunts.
My research on sticky plants is below. See the Abronia page for research on sand verbena ecology and evolution and Trichostema laxum page for research on fire and pollination of a wonderful little mint. Visit the publication page for a larger overview of the research I've done, its mostly plants, but with some dabbling in insects, birds, and even fish!
My CV is here.
Twitter: @Saab95adventure for my nature, bicycle, and car ramblings.
Direct and indirect defense of sticky plants: ecology and evolution
My primary research is on sticky plants which are unequivocally the coolest plants. The insects that live on those plants are unequivocally the coolest insects.
A great diversity of plants - over a hundred families of both monocots and dicots - have independently evolved stickiness of aerial parts. This collection of traits (there is more than one way to stick to a cat) acts as a direct or indirect defense and serves myriad other physiological functions. My research on stickiness mediated defenses concerns two distinct mechanisms.
1) Insects which incidentally land on the surfaces of sticky plants are often entrapped in the goo, and this carrion provides scavenging predators (spiders, true bugs) with a food source. These same predators reduce the herbivore load on a plant by consumption or interference. Sticky plants in California are characterized by a very consistent predator community, which are ubiquitous on - and adapted to moving on - sticky plants, nomatter the plant family (i.e. they are ecologically, and not phylogenetically specialized). The interactions between these predators, as well as between predators and herbivores, have interesting, important, and largely unexplored, effects on the plant.
2) A subset of sticky plants are 'psammophorous' ('sand-carrying') and are naturally coated in a layer of windblown substrate, generally sand. We've found that this covering - entrapped by the same sticky trichomes discussed above - protects the plant against herbivory. It does this not through camouflage, as might be expected, but instead acts directly on herbivores: wearing down mouthparts and slowing their growth.
Sticky seeds, an entirely separate can of worms
Like aerial parts of a plant, the diaspores (dispersed units, whether individual seeds, whole or not-whole fruit) can be sticky in a great diversity of ways. You are surely familiar with burrs (physically "sticky"), and probably some sticky fruit - many manzanitas, for example. But the most common way for "seeds" (= diaspores) to be sticky is to have a mucilage layer. Like the chia, flax, and basil seeds you might have in yogurt, cereals, or fancy drinks (or plantain seeds in Metamucil), thousands of plant species have seeds which are dry - or driable - but when wet get covered in a snotty-mucousy-viscid substance. There are a ton of hypotheses about its function - all of which are probably right in some species, at some time - but remarkably little ecological study has occurred on this ubiquitous and interesting trait.
Huge post-fireTrichostema laxum !!!