Monitoring Breeding Birds at Shaw Nature Reserve

The best time to start a long-term dataset is 25 years ago. The second-best time is now!

Summer solstice is the height of the bird breeding season at Shaw Nature Reserve. Dozens of species are singing, from Dickcissels in the open prairies, to Prothonotary Warblers in the damp forests along the Meramec River, to near-ubiquitous Blue-gray Gnatcatchers, seemingly everywhere.

 

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For six days this month, two students and I are counting birds systematically across Shaw Nature Reserve to learn how they are influenced by ecological restoration. Birds are a common focus for monitoring restoration projects because they can be observed efficiently over large areas, and because they often respond quickly to changes in ecosystem structure. Ovenbirds, for instance, prefer the dark shade of closed-canopy forests, whereas Kentucky Warblers replace them in woodlands that have been burned (fire is a common restoration strategy in many Missouri ecosystems).

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Locations of bird counting stations at Shaw Nature Reserve. Each point is at least 100 meters from the edge of a management unit and at least 200 meters from any other station.

A typical bird survey goes like this:

  • 4:20 AM. I pour a travel mug of coffee, pick up a student to help record data, and drive to Shaw Nature Reserve in the dark. There are way too many deer along the side of I-44.
  • ~5:00 AM. We arrive at Shaw Nature Reserve in twilight and hear a cacophony of birds singing over one another. Indigo Buntings scatter from the loop road ahead of our car.
  • ~5:15 AM. We arrive at the first bird counting station and record the temperature, cloud cover, and wind speed. For five minutes, we write down each bird that we hear or see. Sometimes during these early morning counts, nocturnal birds, like Chuck-will’s-widow, are still calling.
  • ~5:30-10:00 AM. After we finish a point, I set my GPS to navigate to the next point on our route and we continue to record birds until mid-morning, by which time it is warm and many birds have stopped singing (although the Red-eyed Vireos are still going strong).
Combo

Leighton Reid (left) listens to Wood Thrushes and Northern Parulas while REU student Joseph Smith (Lake Superior State University, right) records data. As indicated by the abundant bush honeysuckle (Lonicera maackii; e.g., by Leighton’s right leg), this particular part of the reserve has yet to be restored.

This is our inaugural bird survey at Shaw Nature Reserve. Unlike many of my projects, this one does not have explicit apriori hypotheses; I’m not trying to “test” anything. Instead, I intend for these data to be used for monitoring and demonstrating progress. Over time, I hope and expect these observations to provide a record of biodiversity change as portions of the reserve are restored and managed.

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Counting Common Yellowthroats, Dickcissels, and Red-winged Blackbirds at dawn at the Wetland Mitigation Bank.

For more information on breeding birds at Shaw Nature Reserve, you can explore citizen science observations on eBird, including this printable checklist of birds recorded in June during the past 10 years.

Environmental determinants of plant community change during restoration at Shaw Nature Reserve

Olivia Hajek spent 10 weeks this summer studying woodland restoration at Shaw Nature Reserve with CCSD scientist Leighton Reid. She participated in MBG’s NSF-funded Research Experience for Undergraduates (REU) program.

WildFlowers

Wildflowers in the restored Dana Brown Woods: purple milkweed (Asclepias purpurescens; left) and buffalo clover (Trifolium reflexum; right).

During my ten weeks in Missouri, I completed a research project evaluating the role environmental conditions play in restoration at Shaw Nature Reserve.  Specifically, I worked in the Dana Brown Woods management unit, a part of the Missouri Ozark foothills that features diverse plant communities across its heterogeneous landscape.  Sixteen years ago, the Dana Brown Woods was a closed-canopy woodland highly invaded by eastern red cedar.  However, restoration practices including reintroduction of fire and mechanical removal of woody shrubs like eastern red cedar have dramatically changed plant communities since 2000.  I was very fortunate coming into this project because there was extensive data about the plant communities in the Dana Brown Woods from 2001-2012 while restoration was occurring.  A local botanist, Nels Holmberg, monitored understory plants beginning a year before the first fire, creating complete information about the plant community before restoration and as it changed over time.

We wanted to see how different environmental conditions affect how plant communities change over time in response to restoration.  To answer this question, we visited 300 points across the woodland and measured several environmental parameters, including aspect, slope, rockiness, elevation, and juniper stump density (juniper stumps decay slowly, so many of the trees cut in 2006 were still visible).

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Fieldwork in Dana Brown Woods. Olivia makes friends with a hog peanut (Amphicarpaea bracteata).

Just from field observations, we could see noticeable differences in the environment and plant community composition across the woodland.  Higher slopes were rockier, covered in old juniper stumps, and rich in sunflowers, whereas the lower regions near the Meramec River floodplain had deeper soil and more mesic plant species, like spicebush.

Data analysis confirmed that environmental gradients moderated plant community change over time. Higher, rockier areas experienced greater plant species turnover and greater increases species richness and abundance from 2001-2012, whereas shaded valleys changed relatively little.

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Plant composition change from 2001-2012 increased with elevation, particularly during spring surveys. BC = Bray-Curtis dissimilarity, which measures the difference in plant species composition between a plot in 2001 and itself in 2012. Juniper, red oak, and white oak were subjectively determined habitat classifications at the outset of the study.

Our observations were likely driven by differential fire behavior across the woodland. Historically, fires were a frequent disturbance in the Ozark foothills. Four prescribed fires from 2001-2012 probably had larger impacts on the drier upland areas than in the wet lowlands, which would not have burned as well.

Quantifying how ecological restoration practices, like prescribed fire, vary across environmental gradients is important for land management planning, especially in the Ozark foothills where the landscape is so heterogeneous.

Poster

Leighton stood by while Olivia presented her research to the public at Sensational Summer Nights.

Vegetation changes at Shaw Nature Reserve

CCSD scientists Leighton Reid, Matthew Albrecht, and Quinn Long are teaming up with restoration ecologist James Trager and botanist Nels Holmberg to learn how ecological restoration has affected herbaceous plant communities in an eastern Missouri woodland.

What happens to Missouri’s grasses and forbs when you remove invasive shrubs? When you return prescribed fire to a degraded woodland? How do restoration impacts differ for summer-blooming plants and spring ephemerals? For dry hilltops versus mesic hollows? These are a few of the questions that we hope to address with a long-term dataset from Shaw Nature Reserve.

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Nels Holmberg (left) and Quinn Long (right) discuss the finer points of blackberry identification at Shaw Nature Reserve.

Shaw Nature Reserve encompasses 10 km2 of woodlands and glades along the Meramec River in eastern Missouri. Missouri Botanical Garden purchased the land in 1925 when coal pollution in Saint Louis was so bad that it was killing plants; the garden decided to move its collections to the country where the air was pure. Ultimately the city cleaned up, the collections stayed in Saint Louis’s Tower Grove neighborhood, and the property along the Meramec became a nature reserve and popular hiking area.

Like other ecosystems in the Missouri Ozark foothills, Shaw Nature Reserve changed considerably during the last century. Fire, once a regular disturbance, became scarce, allowing junipers to crowd in on the glades. Invasive species, like Amur honeysuckle, spread into the woodlands and created dense, understory thickets.

blue wood aster (Symphyotrichum cordifolium)

Blue wood aster (Symphyotrichum cordifolium) – a late bloomer in the Dana Brown Woods.

Twenty five years ago, Shaw Nature Reserve began to counteract these changes through ecological restoration. Staff and volunteers cleared invasive shrubs and began to periodically burn the landscape.

In 2000, restoration ecologist James Trager and botanist Nels Holmberg designed a study to monitor restoration effects on herbaceous vegetation. Holmberg surveyed 30 transects twice per year from 2000-2012, recording the abundances of more than 360 plant species. Restoration in this area started in 2003, so the first two years of Holmberg’s transects represent a pre-restoration baseline against which we can compare data from the subsequent decade.

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Holmberg’s dataset contains more than 50,000 rows. Thanks to Christian Schwarz for digitizing them!

Recently, we plotted Holmberg’s transects on Google Earth. The images show clear changes since restoration began almost 15 years ago.

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Holmberg’s transects transposed on a 1995 aerial photo of Shaw Nature Reserve – zoomed in on the Dana Brown Woods. This photo was taken in early spring before most trees leafed out. Dark vegetation is predominantly eastern red cedar (Juniperus virginiana). Holmberg originally grouped the transects into three classes based on the dominant vegetation.

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Juniper clearing began in 2006. This is what the summer-time forest looked like the year before…

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…and after juniper clearing. By 2006 the Dana Brown Woods had been burned twice with prescribed fires, and a lot of the junipers had been cut out. Compare the open/brown areas in this photo with the solid green canopy in 2005.

DBW2014

The most recent imagery, from October 2014, shows some fall color. Note that “red oak” mostly refers to upland Shumard oak, Quercus shumardii.

Our plan for 2016 is to analyze changes in understory vegetation composition over twelve years. Stay tuned for more information in this ongoing project!