ARBORETUM NEWS (NATURALISTSNOTES)

Drought Affects Plants and the Critters that Depend Upon Them

SUNDAY, JULY 15, 2012

Brown, yellow, and wilted green leaves are falling. Day after day the hot sun beats down on crisp brown grass and the parched earth. Small ponds are drying up. Am I in south Texas or Arizona? Is it Autumn or am I dreaming?
Madison has not received any rain for almost two months and is experiencing a moderate drought with temperatures in the upper 90’s and low 100’s! How is this affecting plants? Have you noticed the lovely white flowers of Queen Anne’s-lace and pretty blue chicory blooming along roadsides and in brown lawns? These ecological invasive weeds are very drought tolerant. Also, native prairie plants have special adaptations for survival. And, plants that have been watered appear to be surviving while others are going into early dormancy or dying.
Curtis prairie looks green but close observation reveals that even drought-adapted species are stressed. Grass blades are folded. Plants are wilted and shorter than usual. Flowers bloom for a brief time producing few seeds, if any. However, yellow coneflower, hoary vervain and deep rooted silpniums especially compass plant and rosin weed are showy and providing sustenance for insects and other animals. Plants respond differently to drought depending on factors such as soil, site, competition, and special adaptations.
With so few flowers in bloom and plants wilting, what are butterflies nectaring on? What are their caterpillars eating? Incidentally, record low numbers of butterflies were seen during the 22nd Madison Audubon Butterfly count held July 1st. With few plants producing seeds and fruits, what are the birds eating? With very few mosquitos, (isn’t that a blessing for all of us) what are bats and dragonflies eating? Wetlands are drying up. How are turtles, frogs, and other wetland inhabitants coping? Survival strategies do exist. Hint- dormancy, diapause and estivation.
This sunny hot 95 degree afternoon, three women joined me for a 1:00pm Curtis Prairie tour. Instead we enjoyed many beautiful native prairie flowers blooming in the gardens surrounding the visitor’s center. Thanks to Susan Carpenter and her volunteers for watering and providing a lovely oasis for insects and all of us to enjoy. Do not miss the display of floral beauty in the midst of a very dry landscape. The following are in bloom: bergamot, compass plant, yellow coneflower, mountain and dotted mint, gayfeather, wild quinine, ox-eye, ironweed, rosinweed, spotted and purple joe pye weed, American bellflower, harebell, sweet black eyed and black eyed susan, starry campion, white sage, blue, hoary and hairy white vervain, white and purple prairie clover, evening primrose, culver’s root, swamp milkweed, wild petunia, rattlesnake master, Canada tick-clover, flat top and new England aster, gaura, butterfly weed and sweet Indian plantain (hasteola suaeolens).
Let us follow Aldo Leopold’s wise words from his Sand County Almanac, 1948. “We abuse land because we regard is as a community belonging to us. When we see land as a community to which we belong, we may begin to use it with love and respect.” And let us use water wisely.
I am happy to report our Arboretum bluebirds are have a good season so far. To date they have fledged 35 young. Six boxes have nests with a total of 24 eggs!

-Sylvia Marek, naturalist

Located between Lake Wingra and the West Beltline Highway at 1207 Seminole Highway, the University of Wisconsin-Madison Arboretum features the restored prairies, forests and wetlands of pre-settlement Wisconsin. This 1,260-acre arboretum also houses flowering trees, shrubs and a world-famous lilac collection. Educational tours for groups and the general public, science and nature-based classes for all ages and abilities, and a wide variety of volunteer opportunities for groups, families and individuals are available.