August 2018 – Field Notes

Field Notes: A Tale of Cypress Trees and Floods

by Senior Area Forester Scott Bachman

Earlier this summer my co-workers and I were finally able to get out and measure a harvest in Southampton County. The harvest had been in a stand of bottomland hardwoods. The landowner retained a riparian buffer on both sides of the stream channel during the harvest to protect the water quality of a significant tributary of the Blackwater River. The Blackwater River is a designated Scenic River in Southeastern Virginia that eventually flows past the City of Franklin and into North Carolina. It is a substantial source of fresh water for the Albemarle Sound. This buffer qualified the landowner to take advantage of the Riparian Buffer Tax Credit Program.

Heavy spring rains had finally stopped and the water had finally subsided enough to walk the harvest area. We headed out to the tract early in the morning to beat the fast-rising temperature. Unfortunately, we were not early enough!

On-site, our team split up since the harvest was on both sides of the broad bottomland flat. I took the far side of the property. After a half hour or so, I began to curse my choice of where I was working. It was hot and occasionally flooded. I even scared a great blue heron out of the harvest area. You know it is a wet area when the great blue herons are hunting in it!

About that time it dawned on me how lucky I was that this was my office for the day! I had just seen a great blue heron up close. Up on the highlands of this tract there were a couple bobwhite quail whistling, trying to court the favor of a female. Around my feet were a myriad of frogs jumping from one puddle to another. Signs of life were everywhere around me.

People may not think about a harvested area as a nursery but it surely is.

Not only were signs of animal life abundant in the rapidly drying rich soil, but under my muddy boots were thousands of tiny bald cypress seedlings along with regenerating grasses, forbs and other tree species.

Bald cypress has an interesting method of recolonizing a disturbed wet flood plain. You might assume that the seedlings result from seed that fell from a tree directly over the spot that is now supporting the carpet of cypress seedlings. That may happen in some cases, but cypress trees drop their seed in the late fall and early winter when water levels at their base may be high and rising. Bottomland forests are not typically harvested during seed fall due to this high water level. Where could all this seed come from if it did not come from trees that were on the site?

Cypress seed is not heavy. As the fall flood waters creep into the bottomland areas it carries the seeds of cypress trees growing in the watershed. During the flooding season, the seed will float downstream or perhaps even upstream! As spring fades to summer the water level in our swamps drops. Bald cypress seeds simply float with the floods until waters recede and they are deposited on the freshly laid layer of silt! During years of very high water, cypress seeds can be carried well up into what might be considered “high land” These dryland cypress may have more competition from other trees but if they get sufficient sunlight, they will do well and eventually become spectacular members of the forest canopy.

Bald cypress seedlings that develop on the wet soils in swamps must be able to grow tall enough to be higher than the flood waters when they return in the winter. Because of this, cypress trees are very fast growing trees in their youth. The Virginia Department of Forestry nursery grows and sells bald cypress seedlings. These trees are one-year-old seedlings. When they arrive on your doorstep they are often more than three feet tall! The seedlings I saw were, at most, probably only two months old.

Living in Southeastern Virginia, I have developed a fondness for bald cypress. The feather-like foliage is beautiful in the summer and striking in fall color. As a gymnosperm species it is unique in that it drops its foliage in the winter.

Bald cypress is an excellent yard/urban tree. In dry settings the tree will not develop the characteristic knees found on trees in its native wetland site. It is very tolerant of poor soils and soil compaction, relatively pest free, rot resistant and fast growing. The fine feathery “leaves” are easy to clean from yards with either a rake or blower. Just make sure you have plenty of space when planting this tree. Cypress can easily top 80 feet tall and live for hundreds of years!

Field Notes: Quail on the Comeback?

by Forester Travis Tindell

All photos courtesy of Dwight Dyle, DGIF

Imagine a quiet morning. You stop and listen, the trees swaying gently as a breeze rolls through. The birds have been calling since before you woke up. The birdsong continues as you tune in, and then you hear it: the three-part whistle of the northern bobwhite. This bird is elusive and more often heard than seen. They call to each other in the springtime with the distinctive “Bob…WHITE!” song. These small red-brown birds are treasured by many, and many organizations are uniting to assist in their recovery.

Northern bobwhite (colinus virginiaus) populations have decreased significantly in the past half-century. Many biologists attribute this to the reduction of suitable habitat. Virginia is one of 25 states that is the focus for rehabilitation of the population by the National Bobwhite Conservation Initiative.

Northern bobwhite has specific habitat requirements that in the past two centuries have decreased due to modern land use practices. Quails’ needs include a variety of native grasses and forbs for food, areas of brush for cover and nesting and openness in the forest. This type of environment is found in arid parts of the U.S., such as Kansas, or in the fertile early successional environments of the Coastal Plain, including Virginia.

Historically, quail were found in areas of Virginia where burning occurred frequently, an event that opened the woods while prompting the growth of the fresh grasses and forbs quail depend on.

In June 2018, I assisted the Department of Game and Inland Fisheries and The Nature Conservancy (TNC) in a survey of northern bobwhite populations on public and private lands. The survey took place in Sussex County in the Big Woods State Forest, as well as in the neighboring Big Woods Wildlife Management Area and the Piney Grove Preserve (owned by TNC). This area is of national interest for quail conservation and unique in that three agencies are involved with the management of the 7,574 acre property.

In this study the surveyor listened for four different species of birds in addition to the northern bobwhite: field sparrow, indigo bunting, eastern towhee, and prairie warbler. The presence of all these species is an important indicator that the habitat is suitable for bobwhite.

Northern bobwhite used to be a very widespread species in America. As many agencies continue efforts to rebuild population numbers of this and other birds, I was proud to do a small part to better understand a unique treasure of our American landscape.

Field Notes: Castles in the Field

by Senior Area Forester Scott Bachman

In my youth I spent hours playing in the creeks around my home. I grew up in an area where streams were full of rocks and fast-flowing, cool water. Back in the day we would turn over the rocks and try to catch the crayfish lurking underneath. The plan was to wait for the water to flush out the stirred up silt and then grab the crayfish (or crawdad, if you like) behind the pincers without getting clawed. Sometime we were successful and other times we would let out a yelp and the crawdad would swim free. I now live in an area where the water is slow flowing and tannin-stained. There are no rocks to turn over to catch crayfish; but I know they make their homes in our slow water streams. How can I tell?

Like me as a kid, you may have seen chimney-like spires of dirt in wet areas along streams. We called them snake holes, not knowing what they really were. Somewhere along my way in life I learned that these chimneys were not made by snakes but rather by the very crayfish we tried to catch. The other day while doing a GPS job for a Riparian Buffer Tax Credit, I noticed perhaps hundreds of these chimneys in the drying soil of the harvest area. It got me thinking that I really don’t know much about crayfish and their place in Virginia’s fauna.

I called my friend Eric Brittle, a Fisheries Biologist with the Virginia Department of Game and Inland Fisheries (DGIF), to see what he knew about crayfish. It was a very rainy day when we talked on the phone or I would not have caught him in the office. He said, “I’m looking at the DGIF Crayfish poster right above my desk. It shows 25 of the native species of crayfish in Virginia as well as four non-native crayfish.” Eric is a fin fish biologist, not an invertebrate specialist, but he did know one thing for sure: if you want to catch large mouth bass (a non-native fish on the Atlantic slope of Virginia, by the way…that’s a story for another time) or bowfin during crayfish molting season, use a crayfish pattern lure! He told me that predator fish will nearly switch their diet completely to take advantage of the tasty, newly molted crayfish.

All crayfish are crustaceans. They have an exoskeleton just like their saltwater cousins, blue crabs and lobsters. As a crustacean, they can grow only by shedding their exoskeleton to allow room for growth. According to Brian Watson, the DGIF biologist assigned to invertebrates, on average, a crayfish will molt two times as they go between stages of reproductive to non-reproductive living. After molting a crayfish is very vulnerable to predators. Their shell is soft and the big claws are of little use fending off a raccoon or a hungry fish. This is why Eric suggested using a crayfish lure for that lunker bass.

Well back to the crayfish castles that started this whole thing. I never really knew what the purpose of these little stacks of mud was. It turns out that they really don’t have a purpose other than that they represent the housekeeping duties of the occupant. According to the Mountain Lake Biological Station of the University of Virginia, The Appalachian brook crayfish, just one of our crayfish species in Virginia, (current taxonomy according to Brian Watson shows that Virginia has 27 native and 6 non-native crayfish. This may change with better biology) can dig a burrow in the bottom of the creek that can go as deep as 1 meter (that’s a little over three feet to us non-research folks)! If they have an opening on dry land the castings or dirt from keeping their burrow open are forced out of the hole and form the castles. If the hole is in flowing water the sediment is simply washed down stream.

Crayfish, like other underground dwellers, may have more than one opening to their burrow. In the case of crayfish, their burrow must be below water level since they breathe through gills like fish.

Crayfish are solitary animals, living alone in their burrow. The crawfish do venture out of their homes to find food and a mate. When the water temperature is correct, these freshwater lobsters reproduce. The female will hold her fertilized eggs under her tail until the young emerge from the egg. They will stay with the female until they molt for the third or fourth time. Then it is off to find their way in the world. If they do not leave the natal burrow, mom is more than likely going to eat them!

Crayfish have a wide diet. They are predatory and will eat anything they can catch. They will eat tadpoles, small fish, insects and other small creatures. They also eat plant material. They are an important part of the food web, breaking down dead fish and other animals in their environment and cycling the nutrients.

So the next time you are out in the field (or if you are like a lot of folks in Tidewater right now mowing their saturated lawns) and see castles of mud, know there is a crayfish down there somewhere doing their part to keep our world going.

In parting, Eric told me that his grandmother told stories of “fishing for crayfish” as a young girl. She would find a crayfish mound and lower a bit of meat scrap like bacon fat tied on a string into the hole. A steady slow pull on the string would sometime bring a crayfish to the surface. I’m not sure I am that patient even if they do taste like lobster. It sure would take a lot of them to make a meal.