We’re Searching for WHAT?

They hide on your clothes, in your car, and in your hair. When people normally find them they gasp in disgust, stomp them to death, fling them out windows, or burn them. So why, you might ask, were my stalwart companions and I seeking them out?

For science, of course!

The Battlefield is assisting the Center for Disease Control’s attempts to capture and test these obnoxious bloodsuckers for a couple different pathogens. You may already know that ticks can transmit Lyme Disease, Rocky Mountain Spotted Fever, and a lifelong allergy to mammalian meat. But did you know that they also transmit about ten other diseases, like Anaplasmosis, Babesiosis, and Powassan disease? The CDC website can tell you all about them, but I won’t link to it here so as not to distract my hypochondriac readers.

Unfortunately, these illnesses have become more of a concern in the recent years. Lyme disease is now listed as the US’s most common vector-born disease (meaning that insects or arachnids transmit the infectious microbes), affecting nearly 30,000 people a year. The CDC is understandably eager to better understand this pathogen.

And what do you know? The Battlefield has a multitude of ticks—perhaps more than any other National Park! So in the spirit of inter-agency collaboration (the theme of this summer) my team of natural resource conservationists scoured our forest floors in search of these vicious arachnids.

In order to collect the ticks, we drag a white sheet along the forest floor. Excited by the prospect of finding a host, ticks latch onto the fabric just as they would grab onto a hiker’s pants. Once we travel fifteen meters we flip the cloth over and methodically search for the infectious hitchhikers.

We search along the edges of trails where tourists are most likely to encounter these pests

This process is made more difficult by the ridiculously small size of these creatures. Grown ticks are fairly easy to detect, but most of what we find are in their larval or nymph stages and are only as big as a speck of dirt. To my dismay, after the very first flip our sheet was covered in thousands of specks of tick-sized dirt. Hunting ticks, it turns out, is an I-Spy game.

Our white sheet got dirty. Who could have predicted that?

When we find a tick, we can identify its species based off of its body shape and color. Deer ticks are very dark and teardrop shaped, whereas others are lighter and rounder. Once we have an ID, we wrangle the tiny monster into a vial with a toxic alcohol solution that kills and preserves the specimen.

This spider is ENORMOUS compared to the ticks we found

If you’d like to see tick-hunting in action, check out this footage from the field!: https://www.youtube.com/watch?v=MYlJ3yJCjcQ

Nature Photography by Allie Sloop

SCA intern Allie Sloop has taken some truly amazing pictures during her year at the Battlefield, and has graciously given me permission to share them with you. I hope you find them as beautiful as I do!

 

More pictures coming soon!

“The beauty and…

“The beauty and charm of the wilderness are his for the asking, for the edges of the wilderness lie close beside the beaten roads of the present travel.” -Theodore Roosevelt

In the sprawling metropolis of Northern Virginia, nowhere is this statement more true, or more important!

Why is the forestry cutting down trees?!

Nobody panic.

Contrary to common belief, sometimes harvesting trees is a necessary component of responsible forest management.

Say you have a forest stand that’s full of trees that, well, aren’t great. They might be super skinny, crooked, disease-ridden, or just species that you don’t want. One option is to cut them all down (that’s a clear cut). However, there might be a handful of trees in the stand that are really great. You don’t want to lose those.

The solution to this challenge is intuitive: like a child giving away all of her brown M&Ms, you simply keep the ones you like and get rid of the ones you don’t. Last week I helped out with the Conway’s TSI, or Timber Stand Improvement, to help the foresters do just that.

Like an omnipotent judge, I picked which trees we would save and which would fall to the chainsaw’s wrath. That is to say, I walked around the stand and spray-painted rings around the “keep” trees. What makes a keep tree, you ask?

Having passed my inspection, this tree receives its paint ring.

First, we searched for desirable species. Tulip poplar, cedar aspen, oak, hickory, and ash were all high on our list as they provide high quality lumber and valuable habitat for wildlife.

We ignored maples because  their lumber is not very valuable and they don’t benefit wildlife as much as some of the other species. That’s not to say that you shouldn’t plant maple, because they are fine trees in their own right. However, we were looking for the best of the best and maple just didn’t cut it. We also disregarded the abundant and fast-growing pines because, as Area Forester Blake put it: “they don’t need our help.” Invasives, of course, were rejected as well.

The highly desired tulip poplar also has beautiful flowers

Once we found a tree of the proper species, we looked for a few key traits. It had to be tall, straight, big-around, and healthy. If a tree met all of those criteria, I painted it.

While it’s awesome that these trees are growing out of a fallen relative, they still need to go.

On Monday, one of the Conway’s few yearly work days, a trio of part-time workers from the forestry came out and started to cut down everything that wasn’t marked. I did not envy their job: the 5 acre TSI stand was incredibly dense, and we only wanted to keep about 100 trees.

In other words, they had a lot of chain-sawing to do.

This harvest is designed to improve the overall quality of the stand. We kept the best trees so that future baby trees will have the strongest genes. Natural selection operates in much the same way, except in this case I was making the decisions. So really, the TSI operates under the principle of Caitlin’s Selection. That has a nice ring to it, don’t you think?

 

Invasion of the Plants!

“There’s a tree that grows in Brooklyn. Some people call it the Tree of Heaven. No matter where its seed falls, it makes a tree which struggles to reach the sky. It grows in boarded-up lots and out of neglected rubbish heaps. It grows up out of cellar gratings. It is the only tree that grows out of cement. It grows lushly…survives without sun, water, and seemingly without earth.”

-Betty Smith, A Tree Grows in Brooklyn

A symbol of Francie Nolan’s resilience and perseverance through a childhood of poverty and hardship, I always admired this tree. Now I’m not so sure. You see, her beloved tree of heaven is actually an invasive plant.

Invasive plants are non-native species that become prolific in their new environment, out-competing native neighbors, and upsetting the ecological balance of the area. Like a picky eater in a foreign country, deer and other herbivores avoid grazing  these unfamiliar plants. With no natural predators, these species grow ceaselessly until they have covered the land.

What’s really scary? Like my own experience with the tree of heaven, landowners often don’t know which plants are invasive and which are native. How many of these do you see around your home?

Wine berry (Rubus phoenicolasius): delicious but malicious!

Garlic mustard (Alliaria petiolata): for an easy ID, crush the leaves–do you smell garlic? If so, you’ve found it!

Japanese Honeysuckle (Lonicera japonica): Don’t let it fool you with its wonderful scent, it’s no good!

Oriental bittersweet (Celastrus orbiculatus): When it’s young, it can be easily confused with the native Greenbrier plant. To distinguish the two, look for thorns on the stem. Greenbrier has them, bittersweet does not.

Unfortunately, there are many, many others.

So now for some good news: we can manage invasive plants! The two general methods for control are mechanical and chemical. Common mechanical solutions are to pull out the plant, dig up the roots, mow it, or chop it down. Chemical techniques use targeted herbicides sprayed on the leaves, trunk, stem, or surrounding area to poison the plant.

I spent a day as an IPM (Invasive Plant Management) technician a while back, and it was pretty tough. You strap on a several gallon ghost-buster inspired backpack and walk through the spiderweb and tick infested forests and fields looking for invasives. When you find one, you cover its leaves in blue herbicide (dyed that way for our convenience), and move on. After five hours of spraying in the heat of summer, I started to really despise the plants. It’s as if they had no regard for how much work they created for me. How rude of them! (After several hours in the sun, ideas like the selfishness of plants seem completely logical).

Who ya gonna call?

Oh Deer!

“Just as a deer herd lives in mortal fear of its wolves, so does a mountain live in mortal fear of its deer.”

Aldo Leopold, “Thinking Like A Mountain.”

 

If you live in Virginia, you’ve probably heard that we have too many deer. Personally, I was never too concerned about this. Deer are cute, and aside from the occasional traffic hazard or garden pest, they didn’t seem too dangerous. Now, I’m learning just how wrong I was.

The trouble is, our deer are starving. And it’s no wonder: an average forest can sustainably feed 20-40 deer per square mile, but today we see herds up to 160 deer occupying the same space.

This overpopulation isn’t just sad, it endangers the forest too. Deer chow down on grasses and shrubs, but they also devour tree seedlings. No baby trees means that decades down the road we won’t have any big trees. Without trees, it’s not much of a forest, is it?

Data, Data, Data

In order to study the effects of deer grazing on tree diversity and growth, the Conway and the Battlefield set up deer exclosures, which are like 10×10 foot plant cages. A trained dendrologist, (or like yesterday, an enthusiastic intern), identify and count the seedlings in the deer-free exclosure and compare them to an area that the deer have been able to graze.

Tidiness in field notes is essential…but sometimes you have to settle for legibility

In case you are wondering, identifying tree seedlings is like trying to match baby pictures with your adult coworkers: sometimes they look identical, but often they all just seem the same.

It’s hard to believe tulip poplars start out so small!

But at least with baby pictures you are guaranteed a 1-1 match. Seedlings, on the other hand, often look like they aren’t even trees, just as the infant stage of some shrubs and vines can look like seedlings. For instance, let’s just say it’s possible to find a baby hickory only to discover that its leaves are incredibly sticky. So like a proper scientists, you touch the leaves, then compare to another plant, touch them again, rub your face to dislodge a mosquito, and continue on. Hours later, when you present your results to Area Forester Blake, you discover that Northern Virginia poison ivy looks just like a hickory seedling…and that now it’s all over your face. Science is rewarding, dear reader, but sometimes the pursuit of knowledge has a cost!

The tools of a dendrologist: field guide, measuring tape, pen from a hotel room, and a Rite in the (impending) Rain notebook

 What have we found?

In the past, the results of these surveys have been dramatic: barren forest floors contrasted sharply with the green from the exclosures. But since the Conway began annual deer-hunts reducing the overpopulation, the differences between their control and test plots have been minimal. While many animal-lovers (myself included) don’t enjoy the thought of state-sanctioned deer hunts, they seem to be an effective solution. The primary alternative is implementing deer birth control, which seems impractical given the large size of the Conway.

If you’re interested, the following NY Times article really dives into the debate:http://maplewood.blogs.nytimes.com/2009/03/02/turning-deer-control-into-a-science/?_php=true&_type=blogs&_r=0

Oh, and as a final note:  washing with TecNu after exposure to poison ivy is a life-saver!

 

Field Gear

I call it “tick season chic”

Somedays, I Wish the Early Bird Woke Up Later

It’s 5:45 AM. The traffic to DC is starting to pile up, the sun is still below the horizon, and SCA Intern Allie Sloop and I are already in the field. And to answer your unspoken question: caffeinated Cliff bars and coffee, that’s how.

We’re looking and listening for the Henslow’s Sparrow, a bird species of concern.You can see it (and hear it) here: http://www.allaboutbirds.org/guide/henslows_sparrow/sounds

Volunteers claim to have seen it on the Battlefield, and we’re anxious to confirm its presence.

Our search is pretty simple. Allie has dozens of points set up around the Park. In the morning we walk out to a few of them and play the Henslow’s song. Tsi-lick! The call continues for thirty seconds, and then we listen for a response for thirty more. We repeat this process for five minutes, and then continue to the next point. If we hear or see something that resembles the sparrow, we’ll take notes. Unfortunately, we’re not having much luck. Despite searching for nearly a year, Allie still hasn’t seen the bird.

However, the mornings are still amazingly informative for yours truly. Allie is kind (and patient) enough to answer all of my ornithological questions, and as a result I’m beginning to recognize some of our Battlefield regulars. We have swallows and turkey vultures by the score, red-winged blackbirds, mourning doves, Eastern meadowlarks, pileated woodpeckers, and dozens of others (the Park claims to be home to nearly 150 bird species in total).

Last week, I saw a young red-winged blackbird trying to attract a mate by puffing up his chest and singing. The video below shows a more mature bird going through the same process: https://www.youtube.com/watch?v=q3QicOAiBXk

A few hours later, we saw two tiny (but mighty) birds chasing away a much-larger American Kestrel. Then  we spied a group of vultures (or a “venue”) drying their wings on top of a pavilion. It’s amazing what you see before the world wakes up!

 

 

 

How to Core a Tree (A Visual Aid)

To give you a better idea of how physically difficult it is to extract a tree core, consider the size of the increment borer in my hands above. Now compare that to the size of the tree (over 6 ft in circumference). If anyone is looking for a new and exciting upper body workout, I highly recommend it!

Now, what about an unhealthy tree core?

While the last picture showed a healthy tree core, this photo demonstrates a spectrum of tree rot. The dark spots on the wood show where disease has infiltrated the tree. Often it is impossible to see this damage just by looking at the exterior of the plant, which leads to the ominous question:  what’s really going on beneath the bark of your forest?