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- Western Tasmania, Australia contains some of the highest levels of biological endemism of any temperate region in the world, including vegetation types that are conservation priorities: fire-sensitive rainforest dominated by endemic conifer species in the genus Athrotaxis; and firetolerant buttongrass moorlands. Current management focuses on fire suppression, but increasingly there are calls for the use of prescribed fire in flammable vegetation types to manage these ecosystems. The long-term effects of climate and alternative management strategies on the vegetated landscape are unknown....AuthorsGabriel I. Yospin, Samuel W. Wood, Andres Holz, David M. J. S. Bowman, Robert E. Keane, Cathy WhitlockKeywordsSourceModeling Earth Systems and Environment. 1:16.Year2015
- The fates of individual species are often tied to synchronization of phenology, however, few methods have been developed for integrating phenological models involving linked species. In this paper, we focus on mountain pine beetle (MPB, Dendroctonus ponderosae) and its two obligate mutualistic fungi, Grosmannia clavigera and Ophiostoma montium. Growth rates of all three partners are driven by temperature, and their idiosyncratic responses affect interactions at important life stage junctures. One critical phase for MPB-fungus symbiosis occurs just before dispersal of teneral (new) adult...AuthorsAudrey Addison, James A. Powell, Barbara J. Bentz, Diana L. SixSourceJournal of Theoretical Biology. 368: 55-66.Year2015
- Recent bark beetle outbreaks in western North America have led to concerns regarding changes in fuel profiles and associated changes in fire behavior. Data are lacking for a range of infestation severities and time since outbreak, especially for relatively arid cover types. We surveyed fuel loads and simulated fire behavior for ponderosa pine stands of the Colorado Plateau 15-20 years after bark beetle infestation (i.e., "old-stage"). Increasing infestation severity resulted in reduced canopy bulk density, canopy base height, canopy cover, and litter loads whereas woody fuel loads were...AuthorsE. Matthew Hansen, Morris C. Johnson, Barbara J. Bentz, James C. Vandygriff, A. Steven MunsonKeywordsSourceForest Science. 61(4): 644-664.Year2015
- The Rocky Mountain Research Station (RMRS) is one of seven regional units that make up the USDA Forest Service Research and Development organization - the most extensive natural resources research organization in the world. We maintain 12 field laboratories throughout a 12-state territory encompassing the Great Basin, Southwest, Rocky Mountains and parts of the Great Plains (see map). Our research program serves the Forest Service as well as other federal and state agencies, international organizations, Tribes, academia, non-profit groups and individuals.SourceFort Collins, CO: U.S. Department of Agriculture, Forest Service, Rocky Mountain Research Station. 4 p.Year2015
- Mountain pine beetle-caused tree mortality has substantially changed live tree biomass in lodgepole pine ecosystems in western North America since 2000. We studied how beetle-caused mortality altered ecosystem carbon (C) stocks and productivity using a central US Rockies age sequence of ecosystem recovery after infestation, augmented with growth-and-yield model simulations. Field measurements showed that total C stocks were reduced by beetle outbreaks, although differences compared with undisturbed stands were not easily distinguished. Simulations with outbreaks showed long-term C losses...AuthorsE. Matthew Hansen, Michael C. Amacher, Helga Van Miegroet, James N. Long, Michael G. RyanSourceForest Science. 61(4): 665-679.Year2015
- Large trees provide many ecological services in forests. They provide seeds for reproduction and food, habitat for plants and animals, and shade for understory vegetation. Older trees and forests store large quantities of carbon, tend to release more water to streams than their more rapidly growing younger counterparts, and provide wood for human use. Mature trees of many species also record past climate in their rings, providing clues about how plants have endured enormous climate variability over the ages. Finally, large trees inspire and comfort many, helping to connect us with the...AuthorsMichael G. RyanKeywordsSourceNature Plants. 1: Article 15150.Year2015
- How trees sense source-sink carbon balance remains unclear. One potential mechanism is a feedback from non-structural carbohydrates regulating photosynthesis and removing excess as waste respiration when the balance of photosynthesis against growth and metabolic activity changes. We tested this carbohydrate regulation of photosynthesis and respiration using branch girdling in four tree species in a wet tropical rainforest in Costa Rica. Because girdling severs phloem to stop carbohydrate export while leaving xylem intact to allow photosynthesis, we expected carbohydrates to accumulate in...AuthorsShinichi Asao, Michael G. RyanKeywordsSourceTree Physiology. 35: 608-620.Year2015
- A challenge for the development of terrestrial biosphere models (TBMs) and associated land surface components of Earth system models (ESMs) is improving representation of carbon (C) exchange between terrestrial plants and the atmosphere, and incorporating biological variation arising from diversity in plant functional types (PFTs) and climate (Sitch et al., 2008; Booth et al., 2012; Prentice & Cowling, 2013; Fisher et al., 2014). Accounting for patterns in leaf respiratory CO2 release in darkness (Rdark) in TBMs and ESMs is crucial (King et al., 2006; Huntingford et al., 2013; Wythers et...AuthorsOwen K. Atkin, Keith J. Bloomfield, Peter B. Reich, Mark G. Tjoelker, Gregory P. Asner, Damien Bonal, Gerhard Bonisch, Matt G. Bradford, Lucas A. Cernusak, Eric G. Cosio, Danielle Creek, Kristine Y. Crous, Tomas F. Domingues, Jeffrey S. Dukes, John J. G. Egerton, John R. Evans, Graham D. Farquhar, Nikolaos M. Fyllas, Paul P. G. Gauthier, Emanuel Gloor, Teresa E. Gimeno, Kevin L. Griffin, Rossella Guerrieri, Mary A. Heskel, Chris Huntingford, Franc_oise Yoko Ishida, Jens Kattge, Hans Lambers, Michael J. Liddell, Jon Lloyd, Christopher H. Lusk, Roberta E. Martin, Ayal P. Maksimov, Trofim C. Maximov, Yadvinder Malhi, Belinda E. Medlyn, Patrick Meir, Lina M. Mercado, Nicholas Mirotchnick, Desmond Ng, Ulo Niinemets, Odhran S. O’Sullivan, Oliver L. Phillips, Lourens Poorter, Pieter Poot, I. Colin Prentice, Norma Salinas, Lucy M. Rowland, Michael G. Ryan, Stephen Sitch, Martijn Slot, Nicholas G. Smith, Matthew H. Turnbull, Mark C. VanderWel, Fernando Valladares, Erik J. Veneklaas, Lasantha K. Weerasinghe, Christian Wirth, Ian J. Wright, Kirk R. Wythers, Jen Xiang, Shuang Xiang, Joana Zaragoza-CastellsKeywordsSourceNew Phytologist. 206: 614.636.Year2015
- To provide an overview of the immediate and short-term hydrologic impacts of fire on infiltration, runoff, and erosion by water, and of the effectiveness of various mitigation treatments in the reduction of runoff and erosion in the years following the fire.AuthorsFrederick B. Pierson, C. Jason Williams, Pete R. RobichaudKeywordsSourceGreat Basin Factsheet Series Number 11. Sage Grouse Initiative. 6 p. Online: http://www.sagegrouseinitiative.com/category/great-basin-factsheet-series/Year2015
- Several forest diseases are causing serious threats to the native Hawaiian forest. Among them, koawilt disease (caused by Fusarium oxysporum) is damaging to native populations of koa (Acacia koa), and it also hinders koa restoration/reforestation. Because F. oxysporum likely represents a complex of species with distinct pathogenic activities, more detailed characterization is needed to better understand the F. oxysporum that is associated with koa wilt. Such data would allow assessments of genetic diversity and population structure, while also providing inferences as to whether the...AuthorsMee-Sook Kim, Jane E. Stewart, Nicklos Dudley, John Dobbs, Tyler Jones, Phil G. Cannon, Robert L. James, Kas Dumroese, Ned B. KlopfensteinKeywordsSourceIn: Ramsey, Amy; Palacios, Patsy, comps. Proceedings of the 63rd Annual Western International Forest Disease Work Conference; September 21-25, 2015; Newport, OR. Olympia, WA: Washington Department of Natural Resources; Logan, UT: Utah State University, Quinney College of Natural Resources. p. 133-135.Year2015