12.27.07

Seeds of Change; Mother Knows Best

Posted in American bellflower, Biology at the University of Virginia, Evolutionary biologist, Galloway, Jacob Canon, Mountain Lake Biological Station, The Oscar Show, UVa College of Arts & Sciences, University of Virginia, adaptation, environmental conditions, environmental science, environmental scientist, genetic, maternal effects at 12:36 pm by Jacob Canon

Today’s show, taken from an article published on the Oscar web site written by Melissa Maki, is about evolutionary biologist Laura Galloway. Galloway’s work indicates that maternal plants give cues to their offspring helping them adapt to their environment.

Have you ever heard the phrase, “I didn’t fall far from the tree.” Well, this can be especially important in the plant world. When habitat changes, animals migrate, but how do immobile organisms like plants cope when faced with alterations to their environment? This is an increasingly important question in light of new environmental conditions brought on by global climate change.

Evolutionary biologist Laura Galloway, an associate professor of Biology at the University of Virginia, recently completed a study of the American bellflower. This University of Virginia study, published in the Nov. 16 issue of The Journal Science, demonstrated that plants grown in the same setting as their maternal plant performed almost three and a half times better than those raised in a different environment. Indicating that maternal plants give cues to their offspring that help them adapt to their environmental condition.

What led to this line of inquiry was, a number of years ago Galloway observed that plants that had experienced drought had smaller seeds than those that had not. It was this highly visible physiological change within only one generation that intrigued her. This focused Galloway’s research on the transmission of environmental information between maternal plants and their offspring.

The American bellflower is a native wildflower that commonly grows in both shaded areas and areas that receive full sunlight for at least part of the day. Conducted in a natural habitat at the University of Virginia’s Mountain Lake Biological Station in Southwest Virginia, Galloway planted some seeds in light conditions similar to their maternal plants and some in different light. She found that plants growing in the same setting as their maternal plant outperformed those planted in a different environment.

Since plant adaptation is typically studied on a permanent, genetic level rather than in direct response to environmental conditions, Galloway’s insights are unique. Seeds typically fall close to their maternal plant, they grow in a similar environment. But, when seeds are dispersed to different environments, Galloway found that the plants may suffer for one generation, but as long as the seeds of those plants grow locally, their offspring will recover.

Galloway said, “We found a temporary mechanism of adaptation to local environmental conditions. Historically, maternal effects have been viewed as a complicating factor — an inconvenience. But we have found that they can dramatically influence the performance of an individual.

You’ve been listening to the Oscar Show… I’m Jacob Canon. I would like to thank all of you who have joined me this year exploring many of the topics of research at the University of Virginia.

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12.20.07

Planting the Seeds of Change

Posted in Eastern Shore, GPS, Hog Island Bay, Jacob Canon, The Oscar Show, UVa College of Arts & Sciences, University of Virginia, VIMS, Virginia Institute of Marine Science, coastal bays, crustaceans, environmental science, environmental scientist, marine life, restoration at 11:55 am by Jacob Canon

Today, from an article found on the Oscar web site written by Faris Samarrai, we discuss the efforts being made by environmental scientist Karen McGlathery to reestablish the natural environment needed to insure those crustaceans and other marine life can thrive and return to their previous population levels on Virginia’s Eastern Shore.

As environmental scientist Karen McGlathery slips from the side of the boat into the shallow, murky waters of Hog Island Bay, one of three major lagoons on the oceanside of Virginia’s Eastern Shore, the chill of the morning water hits her, she exclaims “Oh, that’s cold.”

McGlathery is the University of Virginia’s lead investigator on a project to restore sea grasses to the region. Last fall she worked with a team of scientists from VIMS, the Virginia Institute of Marine Science, to seed a 500-acre area of Hog Island Bay with eelgrass, a submerged sea grass that is common in temperate waters worldwide. It was hoped it would establish a meadow that may eventually spread outward, potentially propagating new areas.

McGlathery and her team of graduate students, a few undergrads and even a couple of local high school students, are now back to see if the grass is growing. The team finds the site using GPS — the Global Positioning System — to pinpoint their plots, which are not visible from the surface of the turbid water. They wade and snorkel along the beds, taking measurements of the length of the grass and the extent to which it has spread. They also take core samples from the muddy bottom, and water samples for later analysis. McGlathery said, “what we learn from these studies will help us determine the baseline conditions for future restoration efforts.”

Sea grass once flourished in the seaside bays of the Eastern Shore. But in the late 1920s and early 1930s a pathogen began killing the grasses. A hurricane in 1933 essentially finished them off. In the years since, the bay bottoms have been mostly muddy and barren. A once thriving scalloping and fishing industry collapsed. “I’ve read accounts by old watermen of how the water here was once crystal clear and that the sea grass meadows were so extensive and visible from the surface that it looked like a lawn of long grass,” McGlathery said.

Not anymore. The water is murky green most days and even muddy on windy days. Without extensive sea grass beds to stabilize the bottom, the sediment is continually stirred up, blocking out the sunlight needed by eelgrass to photosynthesize and flourish. But when grasses grow well, they stabilize the bottom, clear up the water and serve as habitat for an assortment of creatures: scallops, crabs, shrimp, mollusks, and the fish that feed on these animals.

McGlathery is encouraged by what she is finding. Most of the half and one acre plots in the 500-acre area are doing well. Apparently, about 10 percent of the 1.5 million seeds that were scattered last fall took root and the plants are growing. Many are 12 to 18 inches long. McGlathery is not surprised. Prior to the seeding, she and her team surveyed the area, tested the sediment and the water quality, and determined that the area might be receptive to a crop of eelgrass.

VIMS has conducted similar work during the past 10 years in South Bay, a lagoon to the south of Hog Island Bay, that extends between the barrier islands of the Virginia. “In areas of South Bay there are now lush sea grass beds… as far as you can swim, continuous meadows,” McGlathery said. “It shows that we can not only get these grasses to grow, but we can also get them to thrive.” And recently, scientists discovered a few sparse natural areas of eelgrass in Hog Island Bay, likely seeded by tide and current from the manmade beds in South Bay.

It is hoped that these restoration efforts will allow the coastal bays to regain their health and vitality, leading to the return of the indigenous marine populations in the waters of the Eastern Shore.

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