Category Archives: Forest Ecology

You don’t look your age: pruning young forests to mimic old-growth forest

“I’m always looking at the age of the forest, looking for fish, assessing the light levels. Once you’ve studied it, you can’t ignore it.” Allison Swartz, a PhD student in the Forest Ecosystems and Society program in the College of Forestry at Oregon State, is in the midst of a multi-year study on forest stream ecosystems. “My work focuses on canopy structure—how the forest age and structure influences life in streams,” says Allison. “People are always shocked at how many organisms live in such a small section of stream. So much life in there, but you don’t realize it when you’re walking nearby on the trail.”

Three scientists holding large nets stand in a rocky forest stream. One wears a backpack with cable coming out of it.
No, that’s not a Ghostbuster backpack! Here, Allison is using an electrofishing device that stuns fish just long enough for them to be scooped up, measured, and released. From left to right: Allison Swartz, Cedar Mackaness, Alvaro Cortes. Photo credit: Dana Warren

Following a timber harvest, there is a big increase in the amount of light reaching the forest floor. The increase in light also results in an increase in stream temperatures. Fish such as salmon and trout, which prefer cold water, are very sensitive to temperature changes. Since these fish are commercially and recreationally important, Oregon’s water quality regulations include strict requirements for maintaining stream temperatures. As a result, buffer areas of uncut forest are left around streams during timber harvests. These buffer areas, like much of the forests in the Pacific Northwest, and in the United States in general, can be characterized as being in a state of regeneration. Dense, regenerating stands of trees from 20-90 years old, are sometimes called second-growth forest. These forests tend to let less light through than an old growth forest does. Allison’s work focuses on how life in streams responds to differences in forest growth stage.

A Pacific giant salamander – a top-level stream predator and common resident of Oregon’s forest streams. Photo credit Allison Swartz.

The definition of the term old-growth forest depends on which expert you ask, and there is even less agreement on the concept of second-growth forest. Nevertheless, broadly speaking an old-growth forest has a wide range of tree species, ages, and sizes, including both living and dead trees, and a complex canopy structure. Openings in the canopy from fallen trees allow a greater variety of plant species to be established, some of which can only take root under gaps in the canopy but which can persist after the gap in the canopy is filled with new trees. The tightly-packed canopy limits the amount of light that can reach the forest floor, including the surface of the streams that Allison studies.

Forest stream near Yellowbottom Recreation Area, Oregon. Credit: Daniel Watkins

Allison’s research project is focused on six streams in the MacKenzie river basin, which includes private land owned by the Weyerhaeuser company, parts of the Willamette National Forest, and federal land. At some of these sites, after an initial survey, gaps were cut into the forest canopy to mimic light availability in an old growth forest. Sites with cut canopies were paired with uncut areas along the same stream. The daily ebb-and-flow of aquatic species is monitored by measuring the oxygen content of the water. The aquatic and terrestrial ecosystems have mainly been studied separately, she explained, but the linkages between these systems are complex. Measurements of vertebrate species are carried out using electrofishing techniques. “We do vertebrate surveys which infludes a few species of fish and Pacific giant salamanders. We measure and weight them and then return them to the stream,” Allison explained.

Measuring cutthroat trout. Photo credit Allison Swartz.

Over the last few years, Allison has spent three months of the summer living and working at one of her research sites, the HJ Andrews Experimental Forest. “We didn’t have much in terms of internet the first few years, so you connect with people and with the environment more,” Allison said. 

Allison never expected to be in a college of forestry. Her background is in hydrology, and she spent some time working for the United States Geological Survey before beginning graduate work. She has enjoyed being part of a research area with such direct policy and management impacts. “We all use wood, all the time, for everything. So we can’t deny that we need this as a resource,” says Allison. “It’s great that we’re looking at ways to manage this the best we can—to make a balance for everybody.”

The Sights and Sounds of Purple Martins

The aesthetic beauty and spiritual connectivity the Native Americans have to the Purple Martin is undeniably strong, it’s no wonder the general public have embraced this special bird and encouraged their presence by adding nest boxes in their backyards. However, it’s this strong embrace in urbanized areas that could be stifling the ability for these animals to find and utilize forest habitats that could be spelling trouble for the birds’ future success. Currently the Purple Martin is listed in the state of Oregon as a “Sensitive-Critical Species” and our guest Lorelle Sherman, a 2nd year Masters student in the Department of Forest Ecosystems and Society, is going to help us understand how humans have possibly altered their natural tree-nesting behavior of the Purple Martin population.

Male Purple Martins who are the largest birds in the Swallow group. Photos curtsey of the Cornell Lab of Ornithology

These are birds with an eye-popping iridescent blue-purple body, sleek black wings with a forked tail that aid in its magnificent maneuverability allowing them to fly at speeds of 45 mph or faster. The Purple Martins often nest in groups to help protect each other from predators, their colonial personalities help generate southing chitchat between birds, and they’re very happy to live in artificial nest boxes. So much so that on the east coast of the US they live almost exclusively in bird boxes. Therein lies the problem – these birds are common on the east coast because they completely depend on habitat provided to them by humans; some researchers worry they have lost the generational knowledge of going to the forest to find suitable homes. Conversely, along the west coast of the US they generally utilize cavities in snags (standing dead trees) as their nesting site, but adding backyard bird boxes for the Purple Martin are becoming more common.

Purple Martin in a natural tree snag (standing dead tree) habitat.

Purple Martins are aerial insectivores meaning they only eat insects while they are in flight. Here is a classic yummy meal for the bird.

Although humans are supplementing places for these birds to nest, high quality habitat in forested areas are shrinking because our natural ecosystems are in peril. Purple Martins have historically depended on wildfires to clear open areas for better hunting grounds, but with the onset of fire-suppression efforts across the west these birds are more reliant on clearcuts typical of industrial forestlands. Couple these regional patterns with the recent global finding that flying insect populations (Martins’ food source is exclusively from eating insects while in-flight) in the tropics are expected to decline as much as 20%, and from 1989-2016 German nature preserves have documented a 75% decline flying insects biomass. It’s no surprise that aerial insectivores being the most rapidly declining group of birds in North America. If scientists are to better understand avian populations, the habitat qualities and the relative availability of food necessary for their survival must be assessed simultaneously.

Lorelle is banding a Purple Martin near a wetland to be able to track it’s movements in the future

Lorelle will help us untangle the effects of declining insect populations, possibly driven by a warming climate, and overlay those links with how humans on the west coast are putting up more artificial bird boxes making it easier to for birds to disregard forests as potential habitat all together. She is slowly uncovering the hidden elements of these critical birds by studying the food sources in two different habitats, an upland forest and along waterways with artificial bird boxes, and the birds’ willingness to seek out ideal habitat. Lorelle has grown up infatuated by birds her whole life, often running away from home just to sit underneath a tree to observe her flying friends overhead. At the age of eight her parents got her binoculars to cultivate her love of birds that she carried through her undergraduate research experiences in Vermont studying Double-crested Cormorants and Great Horned Owls. After a landing a dream job at a non-profit focusing on environmental education and green infrastructure in Pennsylvania she decided it was a good time to return to school to pursue a graduate degree. She originally moved to Oregon to work at the Bandon National Wildlife Preserve, but is now a Masters Student with Dr. Joan Hagar while continuing her outreach activities volunteering for birding festivals such as the Oregon Shorebird Festival and the Birding & Blue Festivals. In her free time you can find Lorelle running away from the office and searching for mushrooms, wild edibles, or other elusive birds.

Join us Sunday October 21st at 7PM on 88.7FM, or listen live, to learn more about Purple Martins and how these birds are intimately tied to the natural ecosystems around us as well as the urbanized spaces we occupy together.

Lorelle at the age of 8 continuing her passion for the outdoors with with her grandfather; note the binoculars which were one of the many steps to foster her love for birds.

Ways and Means: Attitudes Toward Methods of Restoring American Chestnut Trees

“The Christmas Song” or “Chestnuts Roasting on an Open Fire” by Bob Wells and Mel Tormé is an iconic song in American culture, but most Americans will never experience a chestnut roast (at least not with American chestnuts).

A mighty blight

The American chestnut was a widespread North American native tree that covered nearly 200,000 miles of Appalachian forest. In 1904, the American chestnut trees in the Bronx Zoo were dying from a then unknown disease, Chestnut Blight. In the next forty years, Chestnut Blight spread across the estimated 4 billion American chestnut trees. Now American Chestnut trees are seen only as giant stumps, juveniles never reaching maturity, and rarely, adult fruit-bearing trees.

Since the decline of the American chestnut, Appalachian forests have changed. Chestnuts have been replaced by oaks, and it is likely that many organisms that relied on the chestnut trees for food or shelter have had to adapt to new conditions or have been displaced. The loss of the chestnut also led to the loss of financial income for many Appalachian people. In addition to chestnuts as a food source, the American chestnut provided decay resistant timber and tannins for tanning hide. The American chestnut and its decline is remembered through oral and written history. Members of older generations from Appalachia tell stories of enormous trees and later forests of white wooden chestnut skeletons.

Restoring the chestnut

Josh skiing in the mountains of Big Sky, Montana.

The restoration of the chestnut is an active project that faces many challenges. First, few Americans have seen an American chestnut tree, and few are familiar with their decline via Chestnut Blight. Since the restoration of the American chestnut would require policy changes and action across 200,000 miles, spanning multiple state governments, it is necessary to assess the extent the public might disfavor or favor this restoration. Our guest this week,Josh Petit from Forest Ecosystems and Society, is seeking to understand the attitudes of Americans toward the chestnut restoration. In particular, Josh is surveying a sample of the US population to compare attitudes toward a controversial method of chestnut restoration,  the use of genetic engineering.

Ways and Means

You may be familiar with genetic engineering to modify the genome of an organism to achieve a specific goal. Many of the crops we eat have in some way been modified to aid harvest, growth, and/or resistance to pests and disease. The methods for restoring the American chestnut are:

  • Selective breeding with related, blight-resistant Asian chestnuts
  • Modifying the genome of American chestnuts with Asian or other related chestnut genes (cisgenics)
  • Modifying the genome of American chestnuts with foreign genes or genes from wheat (transgenics)

Josh conducting research during a study abroad program in tropical North Queensland, Australia.

It is important to assess the attitudes of the public to transgenics because the introduction of  genes from wheat has been the most successful method at enhancing resistance toward chestnut blight. Recently, negative media has led to the misunderstanding that genetically modified organisms (GMOs) have adverse effects on consumers (humans) and ecosystems. However, these claims are not based in sound science and have been refuted. Although GMOs are being supported as alternatives to crop and forest species extinction, ultimately chestnut restoration relies on majority vote in favor or against a specific strategy. Thus, assessing attitudes toward restoration methods is tantamount to restoration efforts.

The Guy for the Job

A native of Ohio, Josh Petit attended Xavier University and majored in Political Science. He credits a Semester at Sea for broadening his world view and exposing him to different cultures. He learned that culture is important in all aspects of daily life. In retrospect, perhaps it is no surprise that he is currently studying an iconic tree and how culture has driven attitudes toward its restoration.

Josh participating in a Fijian traditional village celebration and homestay–taking turns playing guitar.

Josh became interested in ecology, biology, and the interface of the two with humans while working for Q4 International Marketing an ecotourism company in Panama. This lead him to pursue a Master’s in Natural Resources with a marine ecology focus from Virginia Tech. However, his most recent work withOregon Parks and Recreation Department lead him to pursue a PhD at Oregon State University. With the State Parks, Josh conducted surveys in Oregon Parks and sought to connect behavior, impacts, and social science to ecology and recreation. Now at Oregon State University, Josh is working with Mark Needham andGlenn Howe to understand the drivers of attitudes toward using biotechnologies for restoring American chestnut trees.

Hear more about Josh’s research and his journey to now this week on Inspiration Dissemination. Tune in to KBVR Corvallis 88.7FM on Sunday July, 30 at 7 pm, or live stream the show.

Magical Mushrooms, Mischievous Molds

Panorama of the whitebark pine seedling at the Dorena Genetic Resource Center (USFS)

Did you know that whitebark pine is the highest elevation tree here in the Pacific Northwest? If you have driven the Rim Road of Crater Lake National Park, you may have noticed a huge gnarly tree lovingly known by few as the “Grandmother” whitebark pine. These trees withstand harsh winds and cold temperatures, giving them a krummholz or “crooked wood” appearance. Some grow nearly horizontal.

Zolton’s favorite whitebark pine at the rim of Crater Lake

As one of the few tree species that grow at high elevations, whitebark pine acts as an ecosystem foundation species, making it possible for other plants, fungi, and animals to utilize higher elevation environments. Growing together, a population of whitebark pines form ecological islands and promote biodiversity in subalpine areas. For example, the Clark’s Nutcracker and whitebark pine have been coevolving for eons. The Clark’s Nutcracker is the only bird that can break open the pine cones of whitebark pine. While the bird eats some of the seeds, it also cashes them and can disperse the seeds many miles away. Other species such as rodents and bears eat the seeds as well.

Much more research is needed to fully understand the ecological importance of whitebark pine in its characteristic ecosystem. However, recently whitebark pine research is focused on another interaction, that of whitebark pine with an invasive plant pathogen, white pine blister rust. Since the 1900s, this pathogen has dramatically reduced populations of whitebark pine and other 5-needle pines of North America. This means that whitebark pine populations and the biodiversity islands it forms at high elevations are in trouble.

Zolton with his experimental seedlings at Dorena.

Fortunately, some populations show natural resistance to the pathogen, and our guest, Zolton Bair from the department of Botany and Plant Pathology, is comparing the transcriptomes, the collection of genes expressed as RNA, of resistant and susceptible trees to understand tree defense against white pine blister rust. Be on the lookout for his dissertation defense this year!

As a teenager, Zolton loved collecting and identifying mushrooms. Through a class called magical mushrooms, mischievous molds he realized that fungi are very important to humans as food, medicine, and can be problematic for farmers. He became interested in plant pathology after conducting undergraduate research in a mycology lab that focused on the spread of fungal spores between agricultural fields.

Experimental plot: Keep off!

You do not want to miss this week’s episode of Inspiration Dissemination with our guest Zolton Bair. Tune into KBVR Corvallis 88.7 FM this Sunday January, 22 at 7 pm to hear about Zolton’s journey from barefoot mushroom hunting in Virginia to studying plant pathology here at Oregon State, and we promise you won’t be disappointed to learn more about the awesome tree story of whitebark pine.

Not a local listener? Follow this link to stream the show live.

Mosquito soup in the Brazilian rainforest

Fieldwork in the Brazilian Amazonia meant continuously trying to outsmart their savviest opponents…ants!

Fieldwork in the Brazilian Amazonia meant continuously trying to outsmart their savviest opponents…ants!

Deforestation in Brazil due to cultivation of monoculture crops, such as soybean, has profoundly impacted wildlife populations. In the lab of Taal Levi in the Department of Fisheries and Wildlife, wildlife biologist Aimee Massey has adopted a quantitative approach to studying this impact. During her first and second year of graduate school, Aimee traveled to Brazil for fieldwork and data collection, collaborating with researchers from Brazil and the UK. During this trip, she collected 70,000 biting flies, including mosquitoes and sandflies, by engineering 200 fly traps constructed from 2-liter soda bottles, netting, and rotting beef. Aimee installed biting traps throughout 40 individual forest patches, which are regions delineated by their physical characteristics, ranging approximately in size from the OSU campus to the state of Rhode Island.

Who knew fieldwork could be such a balancing act?!…especially when trying to avoid poisonous insects and thorns. Let’s hope the next branch Aimee reaches for is not of the slithering snake kind!

Who knew fieldwork could be such a balancing act?!…especially when trying to avoid poisonous insects and thorns. Let’s hope the next branch Aimee reaches for is not of the slithering snake kind!

Subsequent DNA analysis on biting flies provides a relatively unbiased source of wildlife tracking, since mosquitoes serve as a repository of DNA for the wildlife they have feasted upon. DNA analysis also provides information regarding diseases that may be present in a particular patch, based on the bacterial and viral profile. For example, sandflies are carriers of protozoa such as leishmania, which cause the disease leishmaniasis. To analyze DNA, Aimee uses bioinformatics and metabarcoding, which is a technique for assessing biodiversity from an environmental sample containing DNA. Different species of animals possess characteristic DNA sequences that can be compared to a known sequence in an online database. By elucidating the source of the DNA, it is possible to determine the type of wildlife that predominates in a specific patch, and whether that animal may be found preferentially in patches featuring deforestation or pristine, primary rain forest.

Learning about human/wildlife interactions while drinking tea with camel’s milk in Laikipia, Kenya.

Learning about human/wildlife interactions while drinking tea with camel’s milk in Laikipia, Kenya.

Aimee completed her undergraduate studies at University of Maine, where she quickly discovered she wanted to study biology and chemistry in greater depth. She planned to attend med school, and was even accepted to a school in her junior year; however, an introductory fieldwork course in Panama spent exploring, doing fieldwork, and trekking made a deep impression on her, so she decided to apply to graduate school instead. Aimee completed a Masters degree in environmental studies at the University of Michigan, during which time she spent 4 months at the Mpala Research Centre in the middle of the Kenyan plateau, just north of the Masai Mara. Following completion of her Masters degree, Aimee spent a year as a research assistant at the University of New Hampshire working with small mammals. Before beginning her PhD studies at OSU, Aimee spent two months in Haines, Alaska doing fieldwork with her future PI, Taal Levi. After she finishes her PhD, Aimee plans to focus on conservation work in New England where she is originally from.

Having fun after fieldwork; Aimee’s eulachon fish catch of the day in Haines, Alaska. One is better than none!

Having fun after fieldwork; Aimee’s eulachon fish catch of the day in Haines, Alaska. One is better than none!

Tune in on October 23rd, 2016 at 7PM on the radio at 88.7FM KBVR, or stream live, to hear more about Aimee’s adventures in Brazil, and why her graduate work is shaping our understanding of how deforestation impacts biodiversity.

 

Forestry Forensics 101

Look out tropical tree thieves! Beware, Pacific pine pilferers! Kristen Finch is on the case!

Sunday April 26, Kristen joined the hosts of Inspiration Dissemination to discuss her study of wood chemistry in Douglas Fir. Kristen’s love of leafy things began in 7th grade when she realized that polyploid strawberries with more than two sets of chromosomes are really big and juicy. This amazed her, because whereas the strawberries benefit from this genetic disposition, a human being would probably die from it!

Photo-for-Bio-300x225

Kristen’s admiration of the plant kingdom led her to study Ponderosa Pines with her undergraduate mentor and OSU alum, Dr. Ann Willyard. After completing her degree in biology at Hendrix College in Arkansas, Kristen took some time to find out what kind of research she wanted to do in botany by interning at Fairchild Tropical Botanical Garden. Extracting DNA from Caribbean Mahogany, a process that can take up to ten days, gave her a sense of appreciation for other potential methods of analysis.

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