Monday, September 27, 2010

Meadows: more complex than they look

Well, the summer has come and gone, and Kaitlin’s and my research at the VINS Nature Center is winding down. My desk is piled high with plant specimens, data sheets, and leftover soil samples, and photographs virtually burst from the seams of my overstuffed hard-drive. Now is the time to examine all of our data, review some literature to help us interpret our findings, and propose management options for VINS’s meadow and pine forest. Our burning question is: How should VINS manage its meadow and pine forest to restore soil health, support plant diversity, further scientific research, educate the public, and benefit critters that hide or feed in these habitats? Based on a preliminary review of our findings, we have some ideas that we’d like to explore over the next 2 months.

Meadow Findings

At the foot of the path into the meadow is a sign asking the curious visitor, “What’s in a meadow?” When I first arrived at the Nature Center 3 months ago, my glib response was, “(yawn) Grass. More grass. Some flowers.” After 2.5 weeks of studying the vegetation in VINS’s meadow and visiting other meadows, I realized how short-sighted my perception was. Kaitlin and I discovered more than 20 wildflower species growing in the VINS meadow and even more graminoid (grass-like) species. Among the wildflowers, we saw beautiful orange butterfly milkweed, purple bergamot, three species of clover, hairy white oldfield aster, and birdsfoot trefoil. I used to think grass-like plants (sedges, grasses, and rushes) were boring, but now I have a newfound appreciation for them. Varying from yellow-greens to reds and bluish greys, carrying round or triangular stems, and bearing the tiniest flower-like structures (florets), some of which pop open when touched, these plants are marvels to behold. Take a look at the florets of a grass, sedge, or rush using a hand lens or microscope if you have the chance, and you’ll understand how clever nature is to have invented so many ways to reproduce!

The reproductive structures (floret) of a panic grass (Dichanthelium sp,)and a rush.

Kaitlin and I found that the VINS meadow has higher plant diversity than other meadows that are being actively managed (mowed). Much of this might stem from the fact that the VINS meadow was seeded with a wildflower mix about 3 years ago. But the diversity can’t solely be attributed to the wildflower mix, because we are seeing species at VINS that were not part of the wildflower mix. What else makes the VINS meadow so diverse? I think that it partly has to do with ecological succession (the process by which nature reclaims areas that have been disturbed by humans or extreme forces such as storms). Only 7 years ago, the VINS meadow was a sand/gravel pit, with exposed mineral soil at the surface. After land is cleared, when plants start to take root again, everything is fair game- anyone can move in. The hardiest plants who withstand dry soil and poor nutrients usually move in first. They start to create micro-habitats (eg. some shade, better soil) that enable other plants to move in. During early succession, the land is at its peak in plant diversity. After many years, the plant species best suited to the site will survive, and the rest will die off, leaving a smaller handful of species. Being a young meadow, the VINS meadow is in an early stage of succession.

The other two meadows we visited had been agricultural fields for 15 years or more, and they were managed every few years by mowing and/or brush hogging. It is possible that mowing and brush hogging scatter the seeds of the dominant plant species throughout a meadow, giving it a uniform look with low plant diversity. Or, perhaps they have lower diversity because they are older meadows. But how do you age a meadow when you are mowing it every few years? Does mowing set the clock back, moving the meadow to an earlier successional stage?

(From left to right: VINS meadow, Pippin meadow, Grandpa's Quarry meadow. The VINS meadow had the greatest plant species richness.

One thing we noticed when comparing the VINS meadow to the meadow by Pippin Inn was that the Pippin meadow had more structural diversity. The VINS meadow is dominated by low-lying herbaceous plants, with only a few shrubs and trees starting to grow around the periphery. The Pippin meadow is being managed for small mammal and bird habitat, so the land-owner has maintained many shrubs and crab apple trees around its periphery, which birds can perch and nest in. A large patch of raspberry shrubs also serves to attract birds when the shrubs are fruiting. Landowners who want to maintain their fields can manage their fields to support wildlife; for example, they could grow staghorn sumac to provide birds with winter fruit; they could mow early in the spring then wait 65 days to allow grassland birds to successfully nest and fledge; or they could increase the forbs: grass ratio by changing soil pH to improve pollinator habitat.

Managing the VINS Meadow

At the VINS meadow, where there is little topsoil and few soil microorganisms, we wonder what we can do to help soil development. One strategy that we might experiment with is burning, because burning can help to release nutrients from plant matter into the soil. We also wonder whether burning is an effective way to control the spread of invasive plants in the meadow. The tricky part is timing the burning so that it kills off the invasive plants after they have spent their energy reserves but before they produce seeds. We wouldn’t want to burn so early that they have a chance to regrow with more nutrients at their disposal. Also, if you have many different invasive plants, each with unique flowering times, then how do you address all of them simultaneously? Addressing them all with one burn might not be possible.

These are all important issues for VINS to consider in its future management of the meadow. In order to decide what management strategies to employ, we first need to define our management objectives. All good land management must begin with clear goals, so one can choose the best strategies to move in the direction of those goals. Do we want to increase plant diversity? What plants do we want the meadow to favor- native grasses, native wildflowers, flowers native to Vermont, or all plants, including those from Europe that have been naturalized (ie. non-native but not invasive)? What animals do we want to support- deer, grassland birds, small mammals, pollinators, or microorganisms? My next step is to outline several different management/research options and their possible effects on the meadow flora and fauna, so VINS can choose the strategies that best fulfill their management objectives. Coming up next: the results of our small mammal survey and our quest to discover the hidden potential of the pine forest (could it have been a red oak-black oak forest 300 years ago?).

Tuesday, July 13, 2010

Rooting out the invaders

Hello friends!

I (Kaitlin) am the second half of the “Who” described by Bryarly in the previous post. I’m a recent graduate of Swarthmore College with a Biology major, originally from South Salem, NY, and I’ve spent the last years focusing on plant and forest ecology.

This summer, I’m hoping to harness my love of all things leafy and green by assisting Bryarly in her examination of the meadow and by taking the fullest advantage of what the VINS Nature Center property has to offer. Which is to say, a lot. With its winding nature trails and beautiful grounds, it’s been easy for this New Yorker to fall in love with Vermont.

So, what exactly will I be doing this summer? I’ll be examining arthropod biodiversity in the soil of the VINS property, concentrating on the Meadow mentioned by Bryarly in the previous post. They might just be creepy crawlers to most, but the biodiversity of soil microarthropods is a convenient way to monitor and detect possible declines in the health of an ecosystem, as microarthropods are integral to good soil quality.

I’m excited for this week since all necessary equipment is arriving and I’ll be taking samples very soon. I can’t wait to see what squirmy things we extract from the soil. But more on that later!

For now, I’d like to share what else Bryarly and I have been up to. But to do that, I’ve got to introduce you to some enemies of mine:

From left to right: Dame's rocket, water milfoil, and garlic mustard
[Photos courtesy of Fish and Wildlife Service]

These aren’t just my enemies. These are the enemies of all land managers. These seemingly innocuous plants are invasives, which means that they aggressively colonize areas that could have otherwise been utilized by native plants—plants that belong in Vermont.

In a volunteer effort that brought together workers from Student Conservation Assocation, US Army Corps of Engineers, VINS, Marsh Billings Rockefeller National Historic Park, Vermont Youth Conservation Corps, and Queechee State Park, Bryarly and I participated in a collaborative work day to weed the land (and water) of these opportunistic pests.

The first part day was spent on land, clearing patches of garlic mustard and Dame’s rocket all along the Ottauquechee River. There must have been twenty of us, and the sight of us all hunkering down and pulling weeds must have been a sight to see for cars passing along Quechee Main Street.

We were careful to place the offending plants in black plastic bags, where their seed pods could be carried safely away.

The bagged garlic mustard
[Photo courtesy of Treenen Sturman]

The second part of the day was spent on canoes on Dewey’s Pond, and the entire afternoon, all I could think was, “I can’t believe how lucky I am to be here!” The sky was the perfect blue that belongs to Vermont alone, and the lily pads were crowned with little stars of white flowers.

Unfortunately, Dewey’s pond is also subject to an invasive plant, an aquatic species called Water Milfoil that has finely whorled leaves. The far end of Dewey’s pond, opposite from the landing, is covered with the plants, so we paddled our canoes out and started pulling.

We looked like sea monsters, pulling out slimy, green coils of leaves, but I’d be lying if said I didn’t thoroughly enjoy myself. It was a wonderful afternoon in the sun, made more wonderful by the fact that we were able to actively rehabilitate the land and water in our community...all by removing invasive plants.

Members of the USACE Crew
[Photo courtesy of Treenen Sturman]

Wednesday, July 7, 2010

The Who, What, Why, and How of Our Research

Who am I?
I (Bryarly) am a graduate student in the M.S. Field Naturalist Program at the University of Vermont. Having spent several summers in the Arctic, assessing soil and water quality on degraded lands that were being restored, I am interested in researching how ecosystems recover from human land-use, and how we can help support this process. Kaitlin will be assisting me, while also exploring her own research questions on soil fauna.

What am I studying at VINS?
The VINS Nature Center is located on a 47-acre property, which has seen a smorgasbord of human land uses over the past 150 years, if not the past 10,000 years. As I drove down the hill toward the parking lot for the first time, I saw a long grassy meadow to my left; arriving in June, I saw swathes of purple lupines in bloom, intermixed with patches of grass, shades of green, yellow, and bluish-gray. When you see a meadow in Vermont, there's a good chance that people used/managed the land recently, because "Vermont wants to be forest"- leave a field for long enough and it will be all trees. Unless you're in the alpine zone or a wetland.

VINS meadow in June, previously a sand and gravel quarry

Sure enough, there used to be a sand and gravel quarry where the meadow now is. My task is to figure out ways that VINS can manage the meadow to support biodiversity. Shall they keep it a meadow to diversify Vermont's landscapes? After all, meadows are scarce around here, and they provide habitat for many butterflies, birds, and small mammals. If VINS keeps it a meadow, how can they manage it to improve soil fertility and to lend it the characteristics of an older meadow that has had more time to evolve? Or, should VINS help it become forest again, since that is what it's naturally moving toward? These are some of the questions I'll be wrestling with this summer.

There is another puzzle at the Nature Center- a few-acre white pine stand that emerged more than 50 years ago when animals used the land for pasture and ate the tasty maple and beech seedlings, while leaving the bitter pine seedlings alone. Again, is there some way to manage this pine grove to increase the diversity of plants and animals living here? If this forest were never touched by humans, what would be growing here? Another enigma for us to explore.

The white pine grove, previously sheep pasture

Why am I studying this?
Landowners in Vermont and beyond wonder what to do with lands like these: an abandoned agricultural field, pine-filled sheep pasture. Restoration researchers wonder how active management can affect the evolution of an ecosystem. We are hoping that some of the lessons we learn here can be transferred elsewhere. Not to mention, it's satisfying to imagine that after years of people degrading a landscape, there may be something we can do to restore/improve a landscape for our leafy, furry, and feather-bearing friends.

How will we go about exploring these questions?
First, we will get to know the meadow and pine grove intimately- its current conditions. What the soil feels like (texture), how well it drains (moisture), how nutritious it is (phosphorus, nitrogen, potassium content, pH); and what plants are growing there. Then we will bop around the countryside looking for sites within 50 miles or so of the Nature Center that have similar characteristics but are further along in their development trajectory (ie. ecologically more complex)- other meadows and forests that grow on sandy, well-drained soils in a similar climate. These will serve as reference sites, examples of what the VINS meadow and pine grove could be. Stay tuned to hear about the challenges and little mysteries we encounter along the way.