Nav: Home

Protecting small forests fails to protect bird biodiversity

February 20, 2019

Simply protecting small forests will not maintain the diversity of the birds they support over the long run, a Rutgers-led study says. Forests need to be carefully monitored and managed to maintain their ecological integrity.

A major focus in conservation is acquiring forests - often at great expense - to expand the network of thousands of protected areas around the world. But conservationists cannot simply designate an area as "protected" and assume all species within the area will remain there, according to the study in Biodiversity and Conservation, which focused on a small Rutgers-owned old growth forest within William L. Hutcheson Memorial Forest in central New Jersey.

Though the forest could be considered ideal for many bird species because of its old growth status, nine species no longer nest there, the study says. These species, including the ovenbird (Seiurus aurocapilla) and American redstart (Setophaga ruticlla), were once common sights in the forest. Many other species have lower populations than would be expected.

"We argue that there must be a greater emphasis on monitoring and managing protected areas to achieve conservation goals," said lead author Jeffrey Brown, a doctoral student and member of the Lockwood Lab in the Department of Ecology, Evolution, and Natural Resources at Rutgers University-New Brunswick.

Previous research has shown that invasive plants have increased dramatically in the old growth forest, resulting in a generally open forest floor - except for a few dominant invasive plants such as Japanese stiltgrass - compared with the previously thickly carpeted floor. The population of white-tailed deer has also grown, leading to over-grazing of plants beneath the forest canopy and likely creating less suitable habitat conditions for ground-nesting and migratory birds that have largely disappeared.

Surprisingly little is known about the effectiveness of protected areas in preventing species extinction. Almost nothing is known about biodiversity over the long-term in smaller protected forests in temperate areas like New Jersey, the study says.

The study focused on Mettler's Woods, a 64-acre primeval oak-hickory forest that is one of the last uncut stands of its kind in the United States. The woods is within the Hutcheson Memorial Forest in Franklin Township, Somerset County.

It is a rare example in New Jersey of an uncut upland forest, and it was permanently protected from development and recreation in 1955. It was to be managed as a natural area and serve as an ecological field laboratory for long-term study, and it is one of thousands of similarly designated small forests around the world.

White oak trees in the forest are 235 years old, on average. Some trees that died in the last two decades were up to 350 years old.

Surrounding the old forest, which landed on the National Park Service Register of Natural Landmarks in 1976, is more than 500 acres of young forest, abandoned agricultural fields being taken over by plants and long-term research plots.

Jeff Swinebroad, a former Rutgers professor (now deceased), and his team captured and banded birds annually in the old forest from 1960 to 1967. Brown, Professor Julie Lockwood in the Department of Ecology, Evolution, and Natural Resources and others performed similar banding annually from 2009 to 2015.

"All of the evidence suggests that the forest has become less suitable habitat for several bird species over time, despite having protected status," Lockwood said. "In particular, migratory birds and those that nest on the ground were the most likely to be lost from the forest, while a few other groups such as woodpeckers have become more common."

In an effort to restore the forest floor plant community, Rutgers placed a deer-proof fence around the old growth forest in 2015 to try to limit overgrazing. Time will tell and future monitoring will reveal whether this effort succeeds and ground-nesting and migratory bird species return to the area.

Rutgers University

Related Biodiversity Articles:

Biodiversity is 3-D
The species-area relationship (SAC) is a long-time considered pattern in ecology and is discussed in most of academic Ecology books.
Thought Antarctica's biodiversity was doing well? Think again
Antarctica and the Southern Ocean are not in better environmental shape than the rest of the world.
Antarctica's biodiversity is under threat
A unique international study has debunked the popular view that Antarctica and the Southern Ocean are in much better ecological shape than the rest of the world.
Poor outlook for biodiversity in Antarctica
The popular view that Antarctica and the Southern Ocean are in a much better environmental shape than the rest of the world has been brought into question in a study publishing on March 28 in the open access journal PLOS Biology, by an international team lead by Steven L.
Temperature drives biodiversity
Why is the diversity of animals and plants so unevenly distributed on our planet?
Biodiversity needs citizen scientists
Could birdwatching or monitoring tree blossoms in your community make a difference in global environmental research?
Biodiversity loss in forests will be pricey
A new global assessment of forests -- perhaps the largest terrestrial repositories of biodiversity -- suggests that, on average, a 10 percent loss in biodiversity leads to a 2 to 3 percent loss in the productivity, including biomass, that forests can offer.
Biodiversity falls below 'safe levels' globally
Levels of global biodiversity loss may negatively impact on ecosystem function and the sustainability of human societies, according to UCL-led research.
Unravelling the costs of rubber agriculture on biodiversity
A striking decline in ant biodiversity found on land converted to a rubber plantation in China.
Nitrogen is a neglected threat to biodiversity
Nitrogen pollution is a recognized threat to sensitive species and ecosystems.

Related Biodiversity Reading:

Best Science Podcasts 2019

We have hand picked the best science podcasts for 2019. Sit back and enjoy new science podcasts updated daily from your favorite science news services and scientists.
Now Playing: TED Radio Hour

Jumpstarting Creativity
Our greatest breakthroughs and triumphs have one thing in common: creativity. But how do you ignite it? And how do you rekindle it? This hour, TED speakers explore ideas on jumpstarting creativity. Guests include economist Tim Harford, producer Helen Marriage, artificial intelligence researcher Steve Engels, and behavioral scientist Marily Oppezzo.
Now Playing: Science for the People

#524 The Human Network
What does a network of humans look like and how does it work? How does information spread? How do decisions and opinions spread? What gets distorted as it moves through the network and why? This week we dig into the ins and outs of human networks with Matthew Jackson, Professor of Economics at Stanford University and author of the book "The Human Network: How Your Social Position Determines Your Power, Beliefs, and Behaviours".