Longleaf Pine Cone Prospects for 2016 and 2017

Regional cone crop forecast: failed for 2016, fair for 2017

by Zoё Hoyle, SRS Science Communications
SRS scientist Dale Brockway (left) and Hans Rohr count longleaf pine cones at Bladen Lakes State Forest near Elizabethton, NC, where Rohr is Supervisor. Partnerships like those with Rohr make the long-term study of longleaf pine cone production possible. Photo courtesy of the U.S. Forest Service.

SRS scientist Dale Brockway (left) and Hans Rohr count longleaf pine cones at Bladen Lakes State Forest near Elizabethton, NC, where Rohr is Supervisor. Partnerships — with state, federal, industry, nongovernmental organizations, universities, and private landowners — make the long-term study of longleaf pine cone production possible. Photo courtesy of the U.S. Forest Service.

Dale Brockway, research ecologist for the U.S. Forest Service Southern Research Station (SRS), recently published his annual summary of projected longleaf pine cone production for 2016 and 2017. The report shows an overall failure of the crop for 2016, and a fair outlook for  2017.

“Our estimates show the 2016 crop averaging only 3.4 cones per tree,” says Brockway, who is stationed at the SRS Restoring and Managing Longleaf Pine Ecosystems unit in Auburn, Alabama. “The natural variation that we usually see throughout the longleaf pine range is less evident this year, with all sites being fairly low in production.”

Only one site in Bladen County, North Carolina, produced more than 10 cones per tree. All other sites were below that level of output.

“Longleaf pine cone production was very high in 2014, and it’s not unusual for a year of high cone yield to be followed by a couple of years with much smaller crops,” says Brockway. “More productive years will follow, as trees recover their internal resources.”

To calculate the cone crop for the current year, data collectors use binoculars to count the number of green cones present in the crowns of mature longleaf pine trees growing on monitoring sites established in low-density longleaf pine stands across the region. Monitors also count the number of small unfertilized conelets (previously referred to as flowers) in the crowns of the same trees, to estimate the cone crop outlook for the following year.

“Based on counts of unfertilized conelets, we estimate the regional cone crop in October 2017 as fair, at 47.8 cones per tree,” says Brockway. “The cone crop forecast for 2017 varies from a bumper crop at one site to a failed crop at another, reflecting a good deal of natural variability. Keep in mind that estimates based on counts of unfertilized conelets are less reliable than those based on counts of green cones,  because unfertilized conelets often do not survive into the second year to become green cones.”

Under even-aged forest management, the minimum cone crop needed for successful natural regeneration is 750 green cones per acre, or 30 cones per tree assuming 25 seed-bearing trees per acre. Reports of cone crops classified as “fair or better” signal land managers to take advantage of the regeneration opportunity by applying prescribed fire to prepare receptive seedbeds before seed fall in October.

Managers using uneven-aged management methods, such as single-tree selection and group selection, are not as dependent on good cone crops, since even a small amount of seed falling each year is adequate to regenerate forests with a continuous canopy through time. But, they should still be aware of cone crop quality from year to year when making decisions. Either way, landowners and managers can access the full report to find more detailed information about sites near their own locations, since natural variation does cause cone production to differ from site to site.

Longleaf pine cone production has been monitored now for 51 years, with yearly production averaging 28 green cones per tree during that period. The single best crop, averaging 115 cones per tree, occurred during 1996. Fair or better cone crops have occurred during 49 percent of all years since 1966, with an increased frequency since the mid-1980s. Reasons for this increasing frequency may be related to genetic, environmental or management factors, or a combination of these.

Brockway and fellow SRS researchers Qinfeng Guo and Stan Zarnoch, along with Xiongwen Chen of Alabama A&M University, recently published findings based on analysis of long-term cone crop data that provide new insights into the reproductive pattern of longleaf pine in an environment with increasingly variable climatic conditions. An article published in the Journal of Sustainable Forestry explores the complexity of cone production in longleaf pine, while a more recently published article in the journal Ecosystem Health and Sustainability analyzes the life cycle and masting of longleaf pine under climate fluctuation.

Access the full longleaf pine cone report for 2016 and 2017.

Access the longleaf pine cone counting protocol.

For more information, email Dale Brockway at dbrockway@fs.fed.us

Access the latest publications by SRS scientists.

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Posted in Longleaf Pines

Studying Woody Biomass for Energy Across the U.S.

SRS scientists contribute to special journal issue on bioenergy

by Sarah Farmer, SRS Science Communications
Non-traditional equipment is tested for harvesting small trees as an energy crop. The red attachment is a sheer felling head, and allows the skidsteer to accumulate several small stems at a time. Photo by Dana Mitchell, U.S. Forest Service.

Non-traditional equipment is tested for harvesting small trees as an energy crop. The red attachment is a sheer felling head, and allows the skidsteer to accumulate several small stems at a time. Photo by Dana Mitchell, U.S. Forest Service.

Woody biomass includes stems, small branches, treetops, needles, leaves, and sometimes the roots of trees and shrubs. These materials are byproducts of forest management activities such as thinning, but they can also be a valuable source of bioenergy.

Five U.S. Forest Service Southern Research Station (SRS) scientists – John Stanturf, Emile Gardiner, Leslie Groom, Dana Mitchell and James Perdue – recently contributed to four review articles that were part of a special issue of the journal BioEnergy Research. SRS researchers collaborated on the journal articles with scientists and engineers from a number of universities and other agencies, including the Forest Service Northern Research Station, Pacific Northwest Research Station, and Forest Products Laboratory, as well as the USDA Agricultural Research Service and Natural Resources Conservation Service.

The articles cover all aspects of the bioenergy supply chain – from cultivation in fields or forests, to harvest, to conversion into a final product. Since 2009, Forest Service scientists and engineers have contributed to more than 60 peer-reviewed journal articles about forest operations – a branch of industrial engineering that includes designing, implementing, or improving technologies in the forest sector – and logistics, which includes the harvest, handling, processing, transportation, and storage of woody biomass.

“In practice, operations and logistics blend science, engineering, and management functions to efficiently and effectively meet the needs of customers and society,” says Mitchell, a coauthor of one of the papers. “Forests provide products like biomass, and also help clean the water and air, offer food and shelter to wildlife, and provide opportunities for recreation and other benefits.”

In addition, some tree species, or genotypes within a species, have extra abilities and can help remove chloride, selenium, heavy metals, and other pollutants from former landfill sites, old mine tailings, and other contaminated areas. The process is called phytoremediation, and poplars, willows, and their hybrids are especially effective. These species are also used across the globe to generate bioenergy, and are promising candidates for U.S. bioenergy operations.

Even when grown as bioenergy crops, trees provide valuable ecosystem services. Fast-growing trees such as eucalyptus, pine, and poplar can be grown in plantations and harvested after less than 20 years. “These short-rotation woody crops could be an integral component of regional and national energy portfolios,” says Stanturf, a coauthor of one of the papers. “While they’re growing, they can store carbon, clean the air and water, and improve the soil.”

The renewed interest in biofuels provides an opportunity to use small-diameter trees, which grow thickly in many forests and can represent a fire hazard. In some forests, harvesting small trees to create biofuels will support forest restoration and fire prevention. Currently, forest management contracts to mitigate fire risk cost the Forest Service – and by default, the taxpayer – $500 to $1500 per acre.

Although the ultimate goal is that woody biomass removal is valuable enough to pay for itself, partial success will still extend the fire-risk mitigation budget and allow for more acres to receive need treatments. Forest Service scientists continue to develop new strategies for providing the country with sustainable and cost-effective strategies for growing, harvesting, and using forest biomass.

Read Ecosystem services of woody crop production systems.

Read Environmental technologies of woody crop production systems.

Read Forest operations and woody biomass logistics to improve efficiency, value, and sustainability.

Read A survey of bioenergy research in Forest Service Research and Development.

 

For more information, email John Stanturf jstanturf@fs.fed.us.

Access the latest publications by SRS scientists.

 

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Posted in Biomass and Bioenergy, Forest Operations, Forest Products

Partnership to Better Understand Harvest Methods for Ramps Launched in Michigan

by Patty Matteson, SRS Public Affairs
Jim Chamberlains sets up plots to study the sustainability of ramp harvests in Michigan. Photo courtesy of U.S. Forest Service.

Jim Chamberlain reviews placement of study plots where ramps have been harvested for commercial purposes in northwest Lower Michigan. Photo by Michelle Baumflek.

The U.S. Forest Service Southern Research Station (SRS) and Virginia Tech are partnering with the newly formed Institute for Sustainable Foraging (ISF) based in Traverse City, Michigan, to study ramp harvesting techniques used by private landowners and harvesters in Northern Michigan. This research will be used to better understand harvest methods necessary to ensure sustainability of ramp populations over time.

Native to the hardwood forests of eastern North America, ramps emerge in moist, shady areas of forests in late March or April, when the plant sends up a circle of smooth broad leaves that die back when the overhead trees are fully leafed out. People collect both the leaves and spicy bulb of the plant as a spring tonic and increasingly, as a culinary specialty.

Jim Chamberlain, SRS research forest products technologist, along with Michelle Baumflek, an ethnobotanist and post-doctoral research associate at Virginia Tech, have installed study plots where ramps have been harvested for commercial purposes in northwest Lower Michigan. These sites will be revisited in subsequent years to examine the effects that foraging may have on plant density, size, and other indicators of population health to help determine how they may be sustainably harvested.

The study’s fieldwork will provide scientific data for the ISF, a non-profit established with the support of Tamarack Holdings, a group of businesses, Michigan foragers, botanists and others. These entities all share a common and growing interest in assuring the long-term sustainability of ramps and other foraged goods. “By adding Michigan, researchers are able to add to their ongoing studies a whole different region of the country, where ramps are native and the population is more prolific,” says Brian Bourdages, the program manager at Tamarack Holdings. “Results from the study will help the ISF to better assess their sustainable foraging standards.”

“The research in Michigan will help provide valuable information on how ramps can be grown and harvested sustainably there and in other forests,” says Chamberlain. “I am really excited about this partnership with Virginia Tech and the Institute for Sustainable Foraging and how it will expand our knowledge of ramp conservation and management.”

Baumflek spoke of her excitement at seeing the prolific nature of the ramp patches in Michigan. “In the mountains of North Carolina, where I’ve been doing much of my work, ramps rely on mesic cove habitats, which limits their distribution to smaller, steeper and more confined areas than here in this part of Michigan. It’s amazing to see such large and healthy populations of ramps covering the forest floor.”

“It is also important to acknowledge that our field methodology was adapted from research by SRS research plant ecologist Joan Walker in western North Carolina,” said Baumflek. “Walker has been monitoring ramp patches that are subject to gathering pressure on federal forest land for over 15 years.”

John Munsell, associate professor and forest management extension specialist in Virginia Tech’s Department of Forest Resources and Environmental Conservation, had this observation about the study’s expansion, “This partnership is significant not only for improving ramps harvesting but more generally because of what it achieves among the agencies, industries, and institutions focusing on non-timber forest products. Stakeholder cooperation is necessary to move in a fundamental direction toward sustainability and we are well on our way.”

For more information, email Jim Chamberlain at jchamberlain@fs.fed.us.

Access the latest publications by SRS scientists.

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Posted in Forest Products, Non-Timber Forest Products, Uncategorized, Upland Hardwoods
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