Charles Smith led the botany basics workshop at Ellanor C. Lawrence Park for Fairfax Master Naturalists. (I studied the eastern section of this park for a class in 2014.) We met a lot of old friends from the plant world. Charles pointed out a non-native invasive that I had not seen before, Small Carpetgrass (apt name, that) (Arthraxon hispidus).
In the meadow, Charles pointed out Beaked Panicgrass (Panicum anceps). I need to look at this plant a few more times before I can grok it. A tip for learning sumacs: fruits hang down from Winged Sumac.
On the west side of Walney Road, we did a very short ascent of the Ridge Trail to a patch of woods that has been left alone by White-tailed Deer. Charles describes this view a “what a good forest looks like.”
In the afternoon, Chris Ruck and his team electrofished a short reach of Big Rocky Run. Again, this was not a complete, protocol-compliant survey, but rather some cherry-picking so that we could see what species could be found in the stream. Forgive me for geeking out on the equipment, but it’s pretty cool.
A circuit is established between the anode, the pole in Danielle’s right hand, and the cathode, the cable in her right hand. Fish in the water are stunned, and can be scooped up in a net for study, as Chris is doing in the image at right. Voltage and other electrical characteristics can be adjusted for water conditions. You want rubberized waders for this job; if you’re wearing breathable waders, you will probably feel an unpleasant tingle, or worse.
Some of the catch, ready for identification.
We turned up 13 of a possible 20 species or so, according to Chris’s accounts. We spent a lot of time with the keys and the minnow representatives (family Cyprinidae). A little easier to ID were these Fantail Darters (Etheostoma flabellare) at left, and these four sunfish species (at right).
Now, the linden, it turns out, is a radical tree, as different from an oak as a woman is from a man. It’s the bee tree, the tree of peace, whose tonics and teas can cure every kind of tension and anxiety—a tree that cannot be mistaken for any other, for alone in all the catalog of a hundred thousand earthly species, its flowers and tiny hard fruit hang down from surfboard bracts whose sole perverse purpose seems to be to state its own singularity.
Elizabeth G. Knight, writing in the Bulletin of the Torrey Botanical Club, 11:11/12 (November-December 1884), p. 134:
Salisburia adiantifolia Smith. [a synonym for Ginkgo biloba] — Although it has been known for several years that the ginkgo fruits abundantly each year in Central Park, yet, as a recent copy of Henderson’s “Handbook of Plants” states, that “there has been no fruit borne in this country,” and as Josiah Hoopes in “The Book of Evergreens” does not note the fruiting of any of the trees he knows, I venture to say to all who are interested in seeing the fruit and desire to obtain specimens that they will be supplied upon application to me at the Normal College, N. Y. City.
There are 47 million birdwatchers in the U.S., but only 2.6 million waterfowl hunters. Conservation of wetlands falls disproportionately on the shoulders of hunters. And that’s a problem because hunter participation is decreasing. With fewer hunters, who’s going to pay for wildlife conservation?
Ed Yong reports on research by Jianqiang Wu of the Chinese Academy of Sciences into one of my favorite creepy plants: dodder (Cuscuta sp.). Wu’s work indicates that distinct plants parasitized by a connecting dodder vine can use it to exchange chemical signals, say, in response to herbivory.
It’s not that dodder has evolved to do this. The parasite is a generalist with unfussy taste in hosts, so it doesn’t really benefit by improving the lives of the plants it attacks. And Wu still suspects that the transmission mechanism does more harm than good, by sapping its hosts of water and nutrients. But it’s perhaps surprising that it does any good at all.
Duarte S. Viana et al. have published research on the importance of migratory birds as a long-distance seed dispersal mechanism.
By sampling birds caught while in migratory flight by GPS-tracked wild falcons, we show that migratory birds transport seeds over hundreds of kilometres and mediate dispersal from mainland to oceanic islands.
A really strong workshop, with four good speakers, hosted by Virginia Native Plant Society at the University of Richmond. A theme emerged: interactions of plants with other organisms in the landscape, be they herbivorous White-tailed Deer (Odocoileus virginianus) (as discussed by Henry Wilbur, emeritus at the University of Virginia), or pollinating Eastern Tiger Swallowtails (Papilio glauca), who pick up pollen from Flame Azalea (Rhododendron calendulaceum) on their wings (only the second such association known, as discovered by Mary Jane Epps, postdoc at North Carolina State University [her work will soon be published]), or the unexpected linkage (through soil pH) of invasive Garlic Mustard (Alliaria petiolata) and the tiny arthopods known as springtails (Collembola), brought to us by Anne Alerding of Virginia Military Institute.
For me, the most interesting talk (and most challenging to follow along with) was Karen Barnard-Kubow‘s explication of her dissertation research on the genetics of American Bellflower (Campanulastrum americanum). This species has a range from the Virginia Coastal Plain to the breadbasket Midwest. Barnard-Kubow’s work has identified distinct clades: one in the East, one or two in the Appalachian Mountains, and one in the Midwest. Cross-breeding experiments on these populations suggests that the plant might be in the process of speciation. Her work also indicates that genetic material in the plant’s chloroplasts is sometimes inherited from the male parent, rather than strictly from the female, as received wisdom has it.
A recent paper by Jason M. Gleditsch and Tomás A. Carlo explores the impact on nesting success of Gray Catbirds (Dumetella carolinensis) breeding in Pennsylvania landscapes dominated by invasive Asian honeysuckles (Lonicera sp.). It turns out that they found little evidence to support the claim that honeysuckle represents an “ecological trap” of increased predation risk and poor nutritive value from fruits, contrary to the results of other researchers. Adult birds may have made more trips to the nest, bearing what some have called “junk food,” but body mass measurements of the nestlings, in this study, show that they grow up just fine.
Our results show that relationships between introduced fleshy-fruited plants and native birds are complex and not easily characterized as purely harmful or beneficial because they can include negative, neutral, or positive outcomes.
Sometimes, in the authors’ view, using an alien species is the best the birds can do, under the circumstances.
… the traditional and widespread categorical approach to invasive species management should be revised to prevent harming certain communities and ecosystems, especially areas in a process of self-recovery from heavy human disturbances.