This week in the woods, we had good initial sugaring days, with some daytime temperatures reaching the 50s, and even saw swelling buds on a red elderberry in Fairlee, Vermont. This forest shrub flowers in May or June, before some other area plants have even leafed out, and provides vital early-spring food for numerous pollinators, mammals, and birds.
At this time of year, after the consumption of much other fruit and before the first fruiting of plants like red elderberry, staghorn sumac (like smooth sumac) provides great value for wildlife. The bright red, fuzzy drupes grow in conical clusters on female flowers, and their acidity, hairiness, and low flesh-to-seed ratio mean that animals do not favor them and often leave them alone through the winter. However, because they remain on the tree year-round, they become critical for the survival of deer, squirrels, and birds, regardless of taste. About 300 species of birds (such as the black-capped chickadee, pictured here) may feed on this emergency food source – and humans can also chew on and spit out these fruits for hydration and a burst of tartness.
In December, we noted that willows host many gall-making insects and wrote about the willow beaked-gall midge. This week, we observed two more gall types on willows. The willow pinecone gall resembles its namesake, which can cause some confusion given that it grows on a genus of deciduous tree. In summer, female gall gnat midges (Rabdophaga strobiloides) deposit their eggs in willows’ terminal buds, and as the resulting larvae feed, they secrete chemicals that prompt the stems to produce these structures. Through winter, the hardened, multi-layered galls insulate the pupae and protect them from predators until they emerge as adults in the spring. The process causes no significant damage to the hosts. Crown galls, caused by the bacterium Agrobacterium tumefaciens, appear on over 600 plant species. Before reaching a host plant, the bacterium resides in the soil, and correspondingly, most galls appear near the base of the tree rather than in its crown. After the bacterium enters the host plant (often through an injury), a unit of extra DNA called a plasmid, separate from any chromosome, splices itself into the plant’s genetic material. The change prompts the tree to make special amino acids and growth regulators to produce the disfiguring burl as well as compounds called opines that the bacterium prefers to consume. The burls cause varying degrees of damage to their hosts and at times impede water and nutrient movement.
What have you noticed in the woods this week? Submit a recent photo for possible inclusion in our monthly online Reader Photo Gallery.