Tuesday, December 26, 2017

Forest birds decline in Vermont

In one of the longest-running studies of its kind in North America, the Vermont Center for Ecostudies has documented a 14.2 percent decrease in forest birds in Vermont over the past 25 years. While not all of the 125 species included in the report are declining – and some are even increasing – the researchers say that the overall state of forest birds in the region raises critical concerns about birds and forests alike.
            Unlike the North American Breeding Bird Survey, which has conducted an annual assessment of bird populations along roadsides since 1966, the Vermont study provides data about birds in interior forests away from the effects of roads.
            “Forests are vital to our economy in Vermont, and birds are vital to the health of the
Canada warbler (Garth McElroy)
forest,” said biologist Steve Faccio, the lead author of the report. “This should serve as a wake-up call to focus our efforts on maintaining healthy forests and thinking about how we should do that.”
            The study used highly-skilled birders who traveled 31 forested transects twice during each breeding season and counted all of the birds they saw or heard at five sites along each transect. Most of the population declines they observed occurred during the first ten years of the study. After stabilizing for about a decade, bird numbers began decreasing again in 2008.
            An in-depth analysis of 34 of the most widely distributed species found that 13 have experienced significant declines, including Canada warbler, white-throated sparrow, great crested flycatcher and veery. Populations of just eight species have increased, among them American robin, red-eyed vireo and ovenbird.
            Faccio said that forest fragmentation, climate change, invasive species and threats on the birds’ wintering grounds could all be contributing factors to their decline. “Just because we’re seeing lower populations here doesn’t necessarily mean it’s something happening on the breeding grounds that’s causing the decline,” he said.
            Changes in habitat due to maturing forests could explain some of the declines. Habitat for species that nest or feed in the lower or middle canopy layers, for instance, could be affected through the natural progression of forest growth.
The birds that fared the worst in the study are the “aerial insectivores,” those that catch and eat insects on the wing, such as Eastern phoebe, Eastern wood pewee and least flycatcher.  The 11 species in this group declined by 45 percent.
            “That leads us to believe that there’s something going on with their prey, probably a combination of effects like pesticide use, changing climate and habitat,” Faccio said. “Polarized light pollution is having a devastating effect on broad groups of insects, which could lead to reproductive failure of some water-breeding insects.”
            The report recommends that those interested in managing their forests for birds should consider creating more structural diversity to emulate natural disturbances in mature forests, while also retaining a high proportion of large trees to support canopy and cavity nesters. Land managers should also focus on protecting uncommon forest types, contiguous forest blocks of more than 250 acres, and corridors that connect conservation areas.

This article first appeared in the fall 2017 issue of Northern Woodlands magazine.

Friday, December 22, 2017

Roasting chestnuts may make a comeback

It’s been about a century since Americans have been able to celebrate the holidays by roasting native chestnuts over an open fire. Almost every one of America’s more than 4 billion chestnut trees from Maine to Georgia was wiped out by chestnut blight, a fungal disease that spread like wildfire after its accidental introduction into the U.S. from trees imported from Japan to the Bronx Zoo in 1904.
The tree’s disappearance has dramatically changed the landscape of eastern North America. Chestnuts were once the dominant tree in eastern forests, and its wood was used for fence posts, railroad ties, utility poles and anything else that required rot-resistant lumber.
American chestnut tree, via The Rural Blog
Many of Rhode Island’s historic homes were once sheathed in it.
In addition, the edible nuts provided vital nutrition to wildlife and were an important element in cattle and hog feed. And because the nuts ripened right around Thanksgiving, they became a popular snack during the holiday season (and a key lyric in that most popular of Christmas carols).
All but the caroling ended soon after the blight took hold. The few chestnuts we eat these days come from non-native species imported from overseas.
But that may not be the case in the coming years, thanks largely to efforts by the American Chestnut Foundation and a little help from local volunteers. A number of research projects are underway designed to develop blight-resistant trees so the species can be restored in our forests.
URI Master Gardener Rudi Hempe is one of the volunteers. He and a team of about 25 other master gardeners who call themselves Rudi’s Rangers are growing a one-acre breeding orchard and a two-acre seeding orchard of chestnut trees on land owned by the South Kingstown Land Trust.
The trees they planted originated with seeds from a single tree in East Greenwich and another one in Exeter that apparently have a genetic abnormality that makes them immune to the blight. Those two parent trees are among the very few mature American chestnuts that did not succumb to the disease, and they are giving scientists a starting point for studying disease resistance.
When the trees planted and maintained by the master gardeners grow tall enough, Rudi’s Rangers will inoculate them with a low-dose of the blight in hopes that some will develop a resistance to the disease. Similar efforts are underway at three other locations in Rhode Island and at dozens more in Massachusetts, Maine and elsewhere in the tree’s original range.
In a separate study, the chestnut foundation is also crossing American chestnuts with a similar species from China that is naturally resistant to the disease. Five of those hybrid trees were planted at URI’s East Farm several years ago, and three of them are still going strong.
It is uncertain whether any of these studies – or others approaching the problem using biotechnology tools – will bear fruit. It’s likely to take a decade or more to find out. But we’ve waited far longer than that already. The wild trees have been gone for so long that almost no one alive today has any recollection of how stately a chestnut forest looked before the blight.
But hopefully, in the not too distant future, singing about roasting chestnuts will have a new, deeper meaning to carolers – and all Americans – once the majestic trees make their heralded return.

This article first appeared in the Independent on December 21, 2017. 

Saturday, December 16, 2017

A merry year for Christmas tree growers

            Jean Bento knows that the weather is the primary factor determining the success or failure of local Christmas tree farms. As the owner of Patchet Brook Tree Farm in Tiverton, she’s happy to report that the weather in 2017 has been ideal.
            “The weather affects almost everything about this business,” she said.
            Bento explained that the rainy spring came along at just the right time to stimulate growth and keep newly-planted seedlings alive, but there wasn’t so much rain that it caused a fungus to build up on the needles. The summer wasn’t hot enough to dry out the trees or make the needles susceptible to dropping too soon. And the weather on Thanksgiving weekend – the first big weekend for sales – was perfect for families to visit local Christmas tree farms and tag or cut their trees.
            “It’s definitely been a good year for growing Christmas trees,” agreed Eric Watne, owner of Clark’s Christmas Tree Farm in Tiverton and president of the Rhode Island Christmas Tree Growers Association. “Rain in spring is key, but you also need some rain in the summer, too. When fir trees think they’re going to die, which will happen when we don’t get rain in the summer, they start producing pine cones, which is their way of propagating the species. That’s bad for Christmas trees because the tree’s nutrients go to the cones and the needles die.”
            That didn’t happen this year.
It also wasn’t a bad year for pests, according to University of Rhode Island entomologist Heather Faubert, despite concerns that gypsy moth caterpillars were going to feast on the needles.
“The gypsy moths didn’t turn out to be as bad as we feared,” she said. “Spider mites and scale insects are the other pests that can be a concern for Christmas tree growers. A few aren’t a problem, but if you get high numbers of them, the trees lose their color and the needles start to drop.”
            The conditions were so good this year, in fact, that the growers said that any trees negatively affected by last year’s drought have probably recovered.
            The only concerns Christmas tree farmers face this year have to do with competition from artificial trees, which have improved in appearance in recent years, and from the big box stores and street-corner sellers that typically get their trees from Quebec or Nova Scotia, where they are cut down as early as October.
            Jan Eckhart, owner of Sweet Berry Farm in Middletown, isn’t worried. He said nothing can compare to locally grown trees. And besides, “Christmas trees are a renewable resource. It’s like growing broccoli. The freshest you can possibly get is a farm grown tree from right here in Rhode Island.”
            While the window for selling Christmas trees is condensed into a few busy weeks, the growers agree that it’s their favorite time of year.
            “When people start showing up to buy their trees, they’re in such a great mood,” said Watne. “I get to be a little part of everybody’s Christmas. It’s a month-long Christmas party.”

This article first appeared in the Newport Mercury on December 14, 2017.

Thursday, December 14, 2017

Forecast calls for a snowy owl winter

            It’s looking more and more like the winter of 2017-18 is going to be a big year for snowy owls in southern New England. Large numbers of the iconic white birds have been observed throughout the Upper Midwest and Northeast since late November, and many have turned up in Rhode Island.
            Project SNOWstorm, a volunteer-based snowy owl tracking organization, is predicting that the attractive birds will invade much of the northern tier of the United States this winter. Hundreds of birds have already been sighted, including some as far south as North Carolina, Oklahoma and Missouri.
            Scott Wiedensaul, director of Project SNOWstorm, said it’s difficult to predict how many birds will travel to the area or how long they will stay. “There’s a little bit of voodoo and black magic in all of this,” he told Audubon magazine. But the signs point to it being a good year for snowy owl watching.
            Rhode Island has so far had visits by at least 17 snowy owls in recent weeks, according to Rachel Farrell, a member of the state’s Avian Records Committee. University of Rhode Island ornithologist Peter Paton reported seeing seven snowy owls on Block Island last week, and local birdwatchers have reported additional owls at Sachuest Point National Wildlife Refuge in Middletown, East Matunuck State Beach in South Kingstown, along the shores of the Narrow River in Narragansett, and elsewhere. One was even photographed perched on a chimney in a residential neighborhood in Providence, and another Providence bird – or perhaps the same one – was located at the headquarters of Save the Bay.
Just one or two snowy owls usually visit Rhode Island during a typical winter.
Snowy owls spend most of their lives in the Arctic feeding on lemmings on the tundra. But Farrell said that about every four years, when lemming numbers are high, the owls lay more eggs than usual. Many of the birds that hatch from those eggs end up migrating south in winter after being forced from their Arctic habitat by adult owls due to the reduced availability of food in the deep snow.
“It’s all due to the population cycling of lemmings,” she said. “They’re a boom or bust animal.”
Canadian scientists reported that snowy owls successfully raised an especially large number of young birds last summer.
This year’s irruption of snowy owls into the U.S. is not unprecedented. Four years ago, the the country experienced the largest influx of snowy owls since at least the 1920s, when several thousand owls spent the winter south of the Canadian border. Some traveled to places they had never before been reported, including Jacksonville, Fla., and Bermuda. More than 400 were observed in Pennsylvania alone, a state that seldom records more than 10 in a year.
            The birds that visit Rhode Island are usually found on beaches, farm fields and airports, which mimic their tundra homes, where they search for mice and voles. Owls that spend time in coastal locations often hunt for wintering ducks, something they don’t often eat on their breeding grounds.
            As exciting as it is to see a snowy owl, they can also be a nuisance and a safety hazard at airports. Paton and fellow URI professor Scott McWilliams will attempt to capture and relocate any owls that show up at Quonset State Airport and other undesirable locations this winter.
            The large number of snowy owls visiting the area is not necessarily a sign that the breeding population is growing, however. Farrell said that the population of snowy owls breeding in North America has declined by about 64 percent since 1970, though scientists are not sure why.
Unlike so many other rare birds that occasionally turn up in southern New England, snowy owls are easy to identify. Weighing in at about six pounds, it is the heaviest owl species in North America, and its white plumage and piercing yellow eyes make it unmistakable. Adult males may be pure white, the perfect camouflage for a bird that spends much of its life in a snowy environment. Younger birds are much more visible, with contrasting gray barring on their white bellies and wings that make them stand out as they perch on fence posts, beaches and snow-covered fields.
The Audubon Society of Rhode Island advises that those interested in going in search of snowy owls in the area should bring along binoculars or a spotting scope and stay at least 200 feet away from the birds, as the owls can be skittish. It also recommends staying quiet and refraining from making sudden movements that may frighten them. The owls are already rather stressed after their long migration and their efforts to find food in unfamiliar places, and rambunctious humans will add to their stress.
            “We still don’t know the magnitude of this year’s irruption yet,” concluded Farrell. “But it has already been fairly substantial. And it started a little earlier than the last one, so that may be a good sign for what’s to come.”

This story first appeared on EcoRI.org on December 14, 2017.

Monday, December 11, 2017

Changes to ecology of Narragansett Bay worry fishermen

            Narragansett Bay has experienced dramatic changes over the last century, from being a dumping place for sewage and industrial pollutants to a near paradise for recreational swimming and boating. But changes continue to occur, whether from the warming climate, invasive species, fluctuating wastewater effluent or other factors.
            As University of Rhode Island oceanography professor Candace Oviatt told an audience of fishermen, scientists and students last week, “I don’t think I’ve ever seen an average day on Narragansett Bay. The bay is always changing. Every year is different. Whether we like it or not, the bay is going to keep changing.”
            Oviatt’s comments were part of a daylong symposium sponsored by Rhode Island Sea Grant aimed at creating a dialogue between fishermen – many of whom are worried that the
Narragansett Bay photo by Frank Carini/EcoRI News
bay has gotten so clean that there is little food left for fish to eat – and scientists whose research tells a sometimes confusing story of how the changing bay ecology might give that erroneous impression.
            While most of the scientists claim that their research suggests that the biomass of fish and other creatures living in Narragansett Bay has changed little through the years, almost all said the composition of species that call the bay home has changed dramatically.
            A weekly fish trawl survey in two locations in the bay conducted since 1959 illustrates those changes. According to Jeremy Collie, the URI oceanography professor who directs the trawl, in the early years of the survey most of the species collected in the nets were fish and invertebrates that live on or near the bottom, like lobster, winter flounder, tautog, cunner and hake. Those species also happen to prefer cooler water.
            In recent years, the species that prefer warmer waters and that live higher in the water column have dominated the trawl survey results, including butterfish, scup and squid.
            “Very few species are standing still or swimming in place,” said Collie, noting that similar patterns have taken place in estuaries throughout the Northeast. “All are either increasing or decreasing. And some have had really big changes.”
            One of the major drivers of change in the bay is nutrient levels, primarily nitrogen and phosphorous, which largely come from discharges from wastewater treatment plants. Those nutrients stimulate the growth of plankton, which are fed upon by fish and a wide variety of marine invertebrates. But when nutrient levels are too high, it can cause harmful algae blooms and oxygen depletion in the water, which can lead to massive fish kills like the one that occurred in Greenwich Bay in 2003.
            Stricter discharge regulations for wastewater treatment plants since the mid-2000s has reduced nutrient levels significantly, leading to much clearer and cleaner water, especially in the upper bay. But it has prompted some fishermen, including lobsterman Al Eagles, to worry that Narragansett Bay has become “a dead bay.” Their concerns are in part because the decline of popular species like winter flounder and lobster seemed to occur at the same time that discharge regulations were tightened.
            Oviatt acknowledged that nutrient levels in the upper bay have declined by 50 percent since 2004, which resulted in a 33 percent decrease in “primary production” – the growth of plankton, especially algae. This has significantly decreased the size of the annual winter/spring plankton bloom that occurs throughout the bay and serves as the base of the food web, when it sinks to the bottom and is fed upon by crabs, fish and other species.
            “When we have a short winter/spring bloom, or no bloom, we have low input of organic matter to the sea floor,” Oviatt said. “The consequence is lower biomass to the benthos [seafloor] and pelagic fish dominating the bay.”
            She said this partly explains Collie’s findings that the species composition in the bay has shifted from bottom species to species living higher in the water column.
            “Are there fewer fish in the bay? I don’t think so,” she said. “We’ve had a dramatic decrease in the bottom community, which started in the 1990s. Our decapods [crustaceans like lobsters and crabs] have basically left the bay.”
            Oviatt said that nutrients in the bay are still three times higher than they were before Europeans colonized New England, but just a few decades ago, when more sewage was being discharged into local waters, nutrient levels were up to five times higher than in pre-colonial times.
            “Wastewater treatment facilities are still the major contributor of nutrients to the bay,” she said.
            Yet Oviatt and others said that decreases in nutrients from wastewater plants aren’t the only reason for the changes to marine life in Narragansett Bay.
            Robinson Fulweiler, a professor at Boston University who studies nutrients in the bay, said that the warming climate is causing some species to move northward to cooler waters and other species to arrive here from the south. And other factors complicate the situation.
            Responding to a question about the “best” level of nutrients in the bay, she said it depends on what you’re looking for. “The estuary a purist wants to go back to is not likely the one that fishermen might want.”

This article first appeared on EcoRI.org on December 10, 2017.

Sunday, December 10, 2017

Spotted turtles in trouble in Rhode Island

            A University of Rhode Island doctoral student who surveyed the state for freshwater turtles and studied their habitat preferences found that the once-common spotted turtle is in trouble, due largely to habitat disturbance.
            Scott Buchanan, a New Jersey native working in collaboration with URI Associate Professor Nancy Karraker, repeatedly visited 88 different wetlands in the state over three years and captured nearly 2,000 turtles of four different species. Just 50 were spotted turtles, a species considered by the state to be of high conservation concern and a candidate for the U.S. endangered species list.
            “Throughout their range, populations of spotted turtles have declined extensively, and we can certainly say with a good deal of confidence that’s also the case in Rhode Island,” said
Spotted turtle (Photo by Scott Buchanan)
Buchanan, who graduates from URI later this month. “I found that they are associated with wetlands in forested landscapes, which means they are susceptible to development, forest fragmentation, wetland alteration and other human disturbances.”
            Buchanan said that the largest populations of spotted turtles he found were in locations where human disturbance has been minimal. “So now it’s a matter of managing those landscapes in an appropriate way,” he added.
            Habitat alteration is not the only conservation concern the species faces, however. The illegal collection of wild turtles for the pet trade is also a problem.
            “Spotted turtles will command a formidable sum in the pet trade, which is unfortunate,” Buchanan said, noting that he encountered people during his research who had captured spotted turtles they intended to bring home to keep as pets but released them at his insistence. “It’s really easy for someone to deplete an entire population of them very quickly.”
During his turtle surveys, Buchanan also found a non-native turtle called a red-eared slider in more wetlands than he found spotted turtles. The slider is a species commonly purchased at pet stores and frequently released into the wild after their owners no longer wish to care for them. He said that wetlands close to human populations, especially those with easy access from roads, are the most likely place to find red-eared sliders in Rhode Island.
“They’re an especially detrimental invasive species,” he said. “It’s a good bet that all the sliders we found are turtles that were bought at pet stores. We don’t know if they’re reproducing in the wild.”
Eastern painted turtles and common snapping turtles, the two most common species of freshwater turtles in Rhode Island, were found in abundance during Buchanan’s turtle surveys.
“They were everywhere, with no strong pattern as to where we might find them across different landscape types,” he said.
What can be done to protect the region’s declining spotted turtle populations?
“It would mean protecting and preserving wetlands, especially forested wetlands, including small wetlands like vernal pools where they sometimes overwinter,” Buchanan said. “It would also mean minimizing fragmentation of the landscape surrounding those wetlands. And it’s also really important that we protect the turtles themselves from illegal collection. That’s an increasing concern among conservation biologists.”
As Buchanan prepares to graduate from URI, he will share his data with a region-wide team of biologists collecting information about the three turtle species being considered for inclusion on the U.S. endangered species list – spotted, wood and Blanding’s turtle.
“The habitat information we collected could help determine where populations of spotted turtles occur and help protect and appropriately manage those populations into the future,” he said.

Friday, December 8, 2017

What do plants hear?

            Plants and trees are seldom considered to have acute senses – at least not like those of many mammals. But scientists at the University of Western Australia discovered that plants have far more complex senses than previously believed, and they can even detect and respond to the sound of moving water.
            In a study led by Associate Professor Monica Gagliano, pea plants sensed sound vibrations from running water moving through pipes or in the soil, and the plant’s roots responded to that sound by moving toward the source of water. The study also revealed that plants avoid other sounds by moving away from them.
            The researchers put pea plants into containers with two tubes at the base, giving them a choice of directions for their roots to grow. They then exposed the plants to a series of sounds beneath each tube, including white noise, running water, and a recording of running water.  They found that the plants could tell where the source of the water was and their roots grew toward the water.
            “It was surprising and extraordinary to see that the plant could actually tell when the sound of running water was a recording and when it was real, and that the plant did not like the recorded sound,” said Gagliano, adding that when moisture was readily available in the soil, the plants did not respond to the sound of running water.
How the plants accomplish this feat is unknown. “The detection of acoustic vibrations, which are vibrations of mechanical nature, is likely to involve the same sensory systems plants use to detect touch – and they’re really good at that,” she said. “If correct, this would possibly involve touch genes and mechanoreceptors because sound is a touch-at-a-distance kind of phenomenon.”
These findings may explain how and why tree roots invade sewer pipes and could lead to the development of soundproof materials for pipelines.
“This would not only improve the sewer systems but reduce exorbitant repair and maintenance costs to municipalities worldwide and make the use of toxic chemicals currently used to clear the roots from the sewer system unnecessary, hence reducing environmental pollution and contamination,” Gagliano said.
The study also raises questions about the implications of noise pollution on plants. Might the increasingly noisy environment be drowning out the ability of plants to hear moving water? Gagliano calls that an open question that should be investigated.
“In animal communities, both in terrestrial and marine environments, these kinds of questions have been raised and the current available studies are showing that these effects are indeed serious and detrimental,” she said. “Based on our findings, it is reasonable to expect that this would be the case for plants, too. Acoustic pollution could mask important acoustic information and make life and survival for plants more difficult. And we have no idea of the long-term consequences of this form of anthropogenic disturbance to plant life.” 

This article first appeared in the fall 2017 issue of Northern Woodlands magazine.