Treesearch
Displaying 24,281 - 24,290 of 65,208 Publications- Achieving adequate and desirable forest regeneration is necessary for maintaining native tree species and forest composition. Advance tree seedling and sapling regeneration is the basis of the next stand and serves as an indicator of future composition. The Pennsylvania Regeneration Study was implemented statewide to monitor regeneration on a subset of Forest Inventory and Analysis plots measured by the U.S. Forest Service. As management techniques are implemented to improve advance regeneration, assessments of the change in the forest resource are needed. When the primary focus is on...AuthorsJim Westfall, William McWilliamsSourceEnvironmental Monitoring and AssessmentYear2012
- Prices for grade hardwood lumber have remained stubbornly low for several years. But, just how low are lumber prices? While prices reported by Hardwood Market Report for #1C lumber in most Appalachian species have increased since the summer of 2009 low point, with the exception of yellow-poplar, they are 3 to 50 percent lower than they were in the fall of 2005. The species with the largest price declines include cherry, hard maple, soft maple, and red oak. Hardwood lumber prices are somewhat unique in that the different species do not necessarily trend with one another. During the early,...AuthorsWilliam LuppoldSourceHardwood Market Reports. 90(32): 1, 16-18.Year2012
- Efficient lignin depolymerization is unique to the wood decay basidiomycetes, collectively referred to as white rot fungi. Phanerochaete chrysosporium simultaneously degrades lignin and cellulose, whereas the closely related species, Ceriporiopsis subvermispora, also depolymerizes lignin but may do so with relatively little cellulose degradation. To investigate the basis for selective ligninolysis, we conducted comparative genome analysis of C. subvermispora and P. chrysosporium. Genes encoding manganese peroxidase numbered 13 and five in C. subvermispora and P. chrysosporium, respectively....AuthorsFrancisco J. Ruiz-Dueñas, Patricia Ferreira, Dimitrios Floudas, David S. Hibbett, Paulo Canessa, Elena Fernandez-Fueyo, Luis F. Larrondo, Tim Y. James, Daniela Seelenfreund, Sergio Lobos, Rubén Polanco, Mario Tello, Yoichi Honda, Takahito Watanabe, Takashi Watanabe, Jae San Ryu, Christian P. Kubicek, Monika Schmoll, Jill Gaskell, Kenneth E. Hammel, Franz St. John, Amber Vanden Wymelenberg, Grzegorz Sabat, Sandra Splinter BonDurant, Khajamohiddin Syed, Jagjit S. Yadav, Harshavardhan Dodapaneni, Venkataramanan Subramanian, José L. Lavin, José A. Oguiza, Gumer Perez, Antonio G. Pisabarro, Lucia Ramirez, Francisco Santoyo, Emma Master, Pedro M. Coutinho, Bernard Henrissat, Vincent Lombard, Jon Karl Magnuson, Ursula Kües, Chiaki Hori, Kiyohiko Igarashi, Masahiro Samejima, Benjamin W. Held, Kerrie W. Barry, Kurt M. LaButti, Alla Lapidus, Erika A. Lindquist, Susan M. Lucas, Robert Riley, Asaf A. Salamov, Dirk Hoffmeister, Daniel Schwenk, Yitzhak Hadar, Oded Yarden, Ronald P. de Vries, Ad Wiebenga, Jan Stenlid, Daniel Eastwood, Igor V. Grigoriev, Randy M. Berka, Robert A. Blanchette, Phil Kersten, Angel T. Martinez, Rafael Vicuna, Daniel CullenSourcePNAS , April 3, 2012, volume 109, number 14;2012Year2012
- This article reviews literature on the connection between urban green space access and environmental justice. It discusses the dynamics of the relationship as it relates to factors such as environmental quality, land use, and environmental health disparities. Urban development stresses the landscape and may compromise environmental quality. Since some communities are disproportionately impacted by changes in land use and land cover, understanding the environmental justice implications of changing the landscape is important. Likewise, the additive effects of degraded landscapes and decreased...AuthorsCassandra Johnson Gaither, Richard Schulterbrandt Gragg, Viniece JenningsSourceEnvironmental Justice 5(1):1-7Year2012
- The US Forest Service's Forest Inventory and Analysis (FIA) program collects information on trees in areas that meet its definition of forest. However, the inventory excludes trees in areas that do not meet this definition, such as those found in urban areas, in isolated patches, in areas with sparse or predominantly herbaceous vegetation, in narrow strips (e.g., shelterbelts), or in riparian areas. In the Great Plains States, little is known about the tree resource in these noninventoried, nonforest areas, and there is a great deal of concern about the potential impact of invasive pests,...AuthorsAndrew J. Lister, Charles Scott, Steven RasmussenKeywordsSourceEnvironmental Monitoring and Assessment. 184(4): 2465-2474.Year2012
- Anthropogenic activity is altering the global disturbance regime through such processes as urbanization, deforestation, and climate change. These disturbance events alter the environmental conditions under which organisms live and adapt and trigger succession, thus setting the biota in otiion in both ecological and evolutionary space. The result is the mixing of species from different biogeographic regions and formation of novel communities of plants and animals. In this essay I present the point of view that this mixing and remixing of species is a natural response to the changing...AuthorsAriel LugoSourceSchlichter, T. and Montes, L., eds. Forests in development: a vital balance. Dordrecht: Springer Science + Business Media.Year2012
- Plant growth responses to rising atmospheric CO2 and O3 vary among genotypes and between species, which could plausibly influence the strength of competitive interactions for soil N. Ascribable to the size-symmetric nature of belowground competition, we reasoned that differential growth responses to CO2 and O3 should shift as juvenile individuals mature, thereby altering competitive hierarchies and forest composition. In a 12-year-long forest FACE experiment, we used tracer 15N and whole-plant N content to assess belowground competitive interactions among five Populus tremuloides genotypes,...AuthorsDonald R. Zak, Mark E. Kubiske, Kurt S. Pregitzer, Andrew J. BurtonKeywordsSourceGlobal Change Biology. 18: 1480-1488.Year2012
- Global anthropogenic activities are responsible for the modification of landscapes, creation of novel environments and movement of species across biogeographic regions. A consequence of this activity is the mixing of native and introduced species and the formation of novel biotic communities. We review the ecological consequences of the mixing of native and introduced species in the Caribbean Islands especially in Puerto Rico and the US Virgin Islands. Here we found documented examples indicating that novel communities of native and naturalized organisms are ubiquitous. The coexistence of...AuthorsT.A. Carlo, Joseph M. Wunderle Jr., Ariel LugoKeywordsSourceAnimal Conservation. 15(3): 233-241.Year2012
- Wildfire ignition distribution models are powerful tools for predicting the probability of ignitions across broad areas, and identifying their drivers. Several approaches have been used for ignition-distribution modelling, yet the performance of different model types has not been compared. This is unfortunate, given that conceptually similar species-distribution models exhibit pronounced differences among model types. Therefore, our goal was to compare the predictive performance, variable importance and the spatial patterns of predicted ignition-probabilities of three ignition-distribution...AuthorsAvi Bar Massada, Alexandra D. Syphard, Susan I. Stewart, Volker C. RadeloffKeywordsSourceInternational Journal of Wildland Fire - http://dx.doi.org/10.1071/WF11178Year2012
- Positive correlations between diversity and stability have been reported for a number of ecosystems and are thought to be caused by a stabilizing effect of differential species’ responses to environmental perturbation. Empirical field studies in which investigators tested for diversity–stability relationships are lacking for some taxonomic groups and typically have not included tests of the importance of other potential correlates of diversity or assemblage structure. We sampled stream fish assemblages and associated habitat variables at 36 sites over a 10-y period. Quantitative and...AuthorsScott R. Clark, Mel Warren, Jocob F. SchaeferKeywordsSourceFreshwater Science 31:882-894.Year2012