PRESS-NEWS.org - Press Release Distribution
PRESS RELEASES DISTRIBUTION

Buried leaves reveal precolonial eastern forests and guide stream restoration

2013-11-14
(Press-News.org) Contact information: A'ndrea Elyse Messer
aem1@psu.edu
814-865-9481
Penn State
Buried leaves reveal precolonial eastern forests and guide stream restoration

Sediment behind milldams in Pennsylvania preserved leaves deposited just before European contact that provide a glimpse of the ancient forests, according to a team of geoscientists, who note that neither the forests nor the streams were what they are today.

"Milldams were built from the late 1600s to the late 1800s in Pennsylvania and other parts of the east," said Peter Wilf, professor of geosciences, Penn State. "We can't get information from historic records on what the area looked like before the dams because recording of natural history didn't really begin until the 1730s and was not detailed."

U.S. census shows that by 1840, tens of thousands of milldams existed in the mid-Atlantic region. About 10,000 of these were in Pennsylvania. In Lancaster County, estimates were one dam for every mile of stream. The abundance of dams in the area altered the landscape dramatically, according to the researchers.

"I see a potential modern day benefit for this research," said Sara J. Elliott, recent Penn State master's degree recipient, currently a research scientist associate at University of Texas Austin, Bureau of Economic Geology. "Attempts to restore precontact environments have been unsuccessful when the effects of milldams were not considered. Understanding the past forest makeup may provide a way to help get a successful and useful reconstruction."

The researchers looked at samples of 300-year-old leaves buried by sediment that backed up behind Denlinger's Mill in Lancaster County. The leaves came from trees on an outcrop above the dam. Because sediment quickly covered the leaf layer, the leaves that date from before the dam remain intact. When carefully separated and cataloged, the leaves reveal the makeup of the forest near the water's edge before milldams were built and forests were cleared. The researchers published their findings in today's (Nov. 13) issue of PLOS ONE.

Dorothy J. Merritts, chair, Department of Earth and Environment and Harry W. and Mary B. Huffnagle Professor of Geoscience, and Robert C. Walter, associate professor of geosciences, both of Franklin and Marshall College, who found the fossil leaf mat note that the Denlinger's Mill site was our 'Eureka' moment in the unraveling of this anthropogenic impact story."

"We expected to see evidence for single stream channels that meandered back and forth across the valley bottom landscape for millennia, " they wrote. "Instead, we found that most of the valley bottoms at the time of European contact were dominated by wetland ecosystems with numerous small, stable 'anastomosing' streams."

These branching and reconnecting streams were far different from the steep-banked meandering streams that, since the dams were breached, now cut through the silt deposits created by the dams.

"First we had to uncover the leaf mats and then try to get a sample," Elliott said. "The mats were fragile and delicate, and getting them back to the lab or just transferring them from one container to another was problematic."

Elliott carefully peeled away the leaves, stacked on top of each other in sticky mud and preserving gorgeous detail, to preserve as many pieces as possible. She then treated them in a variety of chemical baths, mounted them between large glass slides and cataloged their species.

"We got a lot of information that was not available from other sources," said Elliott.

The Denlinger's Mill site is unusual because of the rock outcrop and the trees that grow and grew there over the water. The leaves found in the stream bank preserve a snapshot of the trees growing directly above before European settlement, which Elliott then compared to the modern forest makeup.

The researchers found that the precontact forest was overwhelmingly American beech, red oak and sweet birch, similar to modern red oak/beech forests today. But box elder and another maple dominate the current forest that grows above the stream.

"It was intriguing to see samples from American chestnut, which isn't around anymore because of the chestnut blight," said Elliott. "On the whole though, the species are around today, just in different proportions and places."

The researchers think that reconstructing landscapes more along the lines of those that actually existed before the 1700s might be a more successful approach to restoration. Establishment of precolonial-like habitats might also decrease the amounts of nutrients from the legacy sediments that currently flow into the Chesapeake watershed and cause increased algal and plant growth.

"We now know that legacy sediment from the stream banks caused by the milldams is the major source of eutrophication in the Chesapeake area," said Wilf. "Not, as is usually assumed, modern agricultural runoff."



INFORMATION:



ELSE PRESS RELEASES FROM THIS DATE:

NIH study finds low-intensity therapy for Burkitt lymphoma is highly effective

2013-11-14
NIH study finds low-intensity therapy for Burkitt lymphoma is highly effective Adult patients with a type of cancer known as Burkitt lymphoma had excellent long-term survival rates—upwards of 90 percent—following treatment with low-intensity ...

Queen bee's honesty is the best policy for reproduction signals

2013-11-14
Queen bee's honesty is the best policy for reproduction signals Queen bees convey honest signals to worker bees about their reproductive status and quality, according to an international team of researchers, who say their findings may help to explain why honey bee populations ...

Newly discovered mechanism suggests novel approach to prevent type 1 diabetes

2013-11-14
Newly discovered mechanism suggests novel approach to prevent type 1 diabetes Experimental findings could lead to new, inexpensive therapy using a naturally occurring bile acid Boston, MA – New research led by Harvard School of Public Health (HSPH) demonstrates ...

National project tracks the spread of UK flu and extends monitoring to schools

2013-11-14
National project tracks the spread of UK flu and extends monitoring to schools New findings reveal who is most likely to get flu and how long it takes to recover Are Northerners really more likely to get flu? Does regular exercise help you ...

Study finds widespread use of opioid medications in nonsurgical hospital patients

2013-11-14
Study finds widespread use of opioid medications in nonsurgical hospital patients Significant variation in use shown in different regions of the country; hospitals that had higher prescribing rates also had higher rates of adverse events BOSTON ...

Women with asthma could face a delay in becoming pregnant

2013-11-14
Women with asthma could face a delay in becoming pregnant Women with asthma could take longer to conceive, according to new research. The study, published online today (14 November 2013), in the European Respiratory Journal, adds new evidence ...

NHS 111 increases ambulance and urgent and emergency care use

2013-11-14
NHS 111 increases ambulance and urgent and emergency care use Call handling service did not reduce pressures during first year of operation, as intended The call handling service NHS 111 increased the use of ambulance and urgent and emergency care services ...

Resting pulse rates of UK pre-teens have risen during past 30 years

2013-11-14
Resting pulse rates of UK pre-teens have risen during past 30 years Rise does not seem to be linked to overall weight gain; implications for future cardiovascular health The resting pulse rate of UK pre-teens may have risen by up to two beats a minute during ...

Moderate coffee consumption may reduce risk of type 2 diabetes by 25 percent

2013-11-14
Moderate coffee consumption may reduce risk of type 2 diabetes by 25 percent The Institute for Scientific Information on Coffee highlights the latest research on coffee consumption in the prevention of type 2 diabetes 14 November, 2013 – Regular, moderate coffee consumption may ...

IU cognitive scientists ID new mechanism at heart of early childhood learning and social behavior

2013-11-14
IU cognitive scientists ID new mechanism at heart of early childhood learning and social behavior Google Glass-like eye-tracking technology pinpoints hands as the object of parents' and toddlers' attention BLOOMINGTON, Ind. -- Shifting the emphasis from gaze ...

LAST 30 PRESS RELEASES:

Major review highlights latest evidence on real-time test for blood – clotting in childbirth emergencies

Inspired by bacteria’s defense strategies

Research spotlight: Combination therapy shows promise for overcoming treatment resistance in glioblastoma

University of Houston co-leads $25 million NIH-funded grant to study the delay of nearsightedness in children

NRG Oncology PREDICT-RT study completes patient accrual, tests individualized concurrent therapy and radiation for high-risk prostate cancer

Taking aim at nearsightedness in kids before it’s diagnosed

With no prior training, dogs can infer how similar types of toys work, even when they don’t look alike

Three deadliest risk factors of a common liver disease identified in new study

Dogs can extend word meanings to new objects based on function, not appearance

Palaeontology: South American amber deposit ‘abuzz’ with ancient insects

Oral microbes linked to increased risk of pancreatic cancer

Soccer heading does most damage to brain area critical for cognition

US faces rising death toll from wildfire smoke, study finds

Scenario projections of COVID-19 burden in the US, 2024-2025

Disparities by race and ethnicity in percutaneous coronary intervention

Glioblastoma cells “unstick” from their neighbors to become more deadly

Oral bacterial and fungal microbiome and subsequent risk for pancreatic cancer

New light on toxicity of Bluefin tuna

Menopause drug reduces hot flashes by more than 70%, international clinical trial finds

FGF21 muscle hormone associated with slow ALS progression and extended survival

Hitting the right note: The healing power of music therapy in the cardiac ICU

Cardiovascular disease risk rises in Mexico, despite improved cholesterol control

Flexible optical touch sensor simultaneously pinpoints pressure strength and location

Achalasia diagnosis simplified to AI plus X-ray

PolyU scholars pioneer smart and sustainable personal cooling technologies to address global extreme heat

NIH grant aims for childhood vaccine against HIV

Menstrual cycle and long COVID: A relation confirmed

WMO report on global water resources: 2024 was characterized by both extreme drought and intense rainfall

New findings explain how a mutation in a cancer-related gen causes pulmonary fibrosis

Thermal trigger

[Press-News.org] Buried leaves reveal precolonial eastern forests and guide stream restoration