Treesearch
Displaying 9,951 - 9,960 of 65,202 Publications- The total biomass of a stand is an indicator of stand productivity and is closely related to the density of plants. According to the self-thinning law, mean individual biomass follows a negative power law with plant density. If the variance of individual biomass is constant, we can expect increased stand productivity with increasing plant density. However, Taylor's power law (TPL) that relates the variance and the mean of many biological measures (e.g. bilateral areal differences of a leaf, plant biomass at different times, developmental rates at different temperatures, population densities...AuthorsGuohua Liu, Cang Hui, Ming Chen, Lauren S. Pile, G. Geoff Wang, Fusheng Wang, Peijian ShiKeywordsSourceJournal of Forestry ResearchYear2020
- The Hubbard Brook Ecosystem Study was established to use the small watershed approach to measure and model ecosystem element flux and cycling, but it has evolved to incorporate a complex matrix of projects studying a wide range of biogeochemical and ecological phenomenon. Fundamental to understanding many of these phenomenon is information regarding the structure and function of the defining life form there – trees. The northern hardwood-conifer forest that blankets the Hubbard Brook valley is a biological machine that transforms solar energy, water and mineral nutrients into organic...AuthorsTimothy J. Fahey, Paul SchabergSourceChapter 14. In: Fahey, T.J., ed. Synthesis of scientific research at Hubbard Brook. Woodstock ,VT: Hubbard Brook Research Founcation.Year2019
- Old trees (defined here as ≥150 years old) can be rare in many forests because of past timber harvest, uncharacteristically severe wildfires, and - increasingly - climate change. Old trees provide unique structural, ecological, scientific, and aesthetic values missing in forests containing only younger trees. Here we compile crossdated ages from over 10,000 living and dead trees sampled in montane forests of the central Rocky Mountains in Colorado and southern Wyoming, USA, to examine changes in age structure of the oldest trees since Euro-American settlement and to provide guidelines to...AuthorsPeter M. Brown, Benjamin Gannon, Michael A. Battaglia, Paula J. Fornwalt, Laurie Huckaby, Antony S. Cheng, Scott BaggettKeywordsSourceTree-Ring Research. 75(1): 34-48.Year2019
- Whole-tree harvesting (WTH) is increasingly used to extract forest biomass for energy and commercial wood products. Slash burning, which is used for fuels reduction and site preparation, also reduces aboveground biomass. Yet effects of incremental biomass reduction, from either WTH or slash burning, on long-term forest productivity and composition are poorly understood. This research uses data from a 50-year-old study in northern mixedwood (Picea – Abies – hardwood) stands on the Penobscot Experimental Forest in Maine, U.S.A., to address these concerns. Clearcutting was conducted in...AuthorsBethany Muñoz Delgado, Laura S. Kenefic, Aaron R. Weiskittel, Ivan J. Fernandez, Jeffrey G. Benjamin, Alison DibbleKeywordsSourceForest Ecology and ManagementYear2019
- Symbiotic nitrogen (N)‐fixing trees can provide large quantities of new N to ecosystems, but only if they are sufficiently abundant. The overall abundance and latitudinal abundance distributions of N‐fixing trees are well characterised in the Americas, but less well outside the Americas. Here, we characterised the abundance of N‐fixing trees in a network of forest plots spanning five continents, ~5,000 tree species and ~4 million trees. The majority of the plots (86%) were in America or Asia. In addition, we examined whether the observed pattern of abundance of N‐fixing trees was correlated...AuthorsDuncan N. L. Menge, Ryan A. Chisholm, Stuart J. Davies, Kamariah Abu Salim, David Allen, Mauricio Alvarez, Norm Bourg, Warren Y. Brockelman, Sarayudh Bunyavejchewin, Nathalie Butt, Min Cao, Wirong Chanthorn, Wei‐Chun Chao, Keith Clay, Richard Condit, Susan Cordell, João Batista Silva, H. S. Dattaraja, Ana Cristina Segalin Andrade, Alexandre A. Oliveira, Jan den Ouden, Michael Drescher, Christine Fletcher, Christian P. Giardina, C. V Savitri Gunatilleke, I. A. U. Nimal Gunatilleke, Billy C. H. Hau, Fangliang He, Robert Howe, Chang‐Fu Hsieh, Stephen P. Hubbell, Faith M. Inman‐Narahari, Patrick A. Jansen, Daniel J. Johnson, Lee Sing Kong, Kamil Král, Chen‐Chia Ku, Jiangshan Lai, Andrew J. Larson, Xiankun Li, Yide Li, Luxiang Lin, YiChing Lin, Shirong Liu, Shawn K. Y. Lum, James A. Lutz, Keping Ma, Yadvinder Malhi, Sean McMahon, William McShea, Xiangcheng Mi, Michael Morecroft, Jonathan A. Myers, Anuttara Nathalang, Vojtech Novotny, Perry Ong, David A. Orwig, Rebecca Ostertag, Geoffrey Parker, Richard P. Phillips, Kassim Abd. Rahman, Lawren Sack, Weiguo Sang, Guochun Shen, Ankur Shringi, Jessica Shue, Sheng‐Hsin Su, Raman Sukumar, I‐Fang Sun, H. S. Suresh, Sylvester Tan, Sean C. Thomas, Pagi S. Toko, Renato Valencia, Martha I Vallejo, Alberto Vicentini, Tomáš Vrška, Bin Wang, Xihua Wang, George D. Weiblen, Amy Wolf, Han Xu, Sandra Yap, Li Zhu, Tak FungSourceJournal of EcologyYear2019
- In this report we provide a framework for assessing cross-boundary wildfire exposure and a case study application in the western U.S. The case study provides detailed mapping and tabular decision support materials for prioritizing fuel management investments aimed at reducing wildfire exposure to communities located proximal to national forests. The work was motivated by a number of factors, including a request from U.S. Department of Agriculture Undersecretary James Hubbard (Natural Resources and Environment) to assess community wildfire risk specifically from Forest Service lands,...AuthorsAlan Ager, Michelle A. Day, Palaiologos Palaiologou, Rachel M. Houtman, Chris Ringo, Cody R. EversKeywordsSourceGen. Tech. Rep. RMRS-GTR-392. Fort Collins, CO: U.S. Department of Agriculture, Forest Service, Rocky Mountain Research Station. 36 p.Year2019
- Individual tree growth and mortality drive forest stand dynamics and are universally important metrics of tree success. Studying factors that affect growth and mortality is particularly challenging in mixed-species, unevenaged systems due to their defining heterogeneity and strong temporal and spatial variability. The goal of this study was to determine the relative importance of individual tree attributes (i.e., species, size, neighborhood crowding, crown position) and environmental characteristics (i.e., soil moisture) in driving tree growth and survival in an uneven-aged, mixed species...AuthorsErin K.P. Fien, Shawn Fraver, Aaron Teets, Aaron R. Weiskittel, David HollingerKeywordsSourceForest Ecology and ManagementYear2019
- Cleavitt et al. (2018, Can. J. For. Res. 48(1): 23–31, doi:10.1139/cjfr-2017-0233) report a lack of sugar maple (Acer saccharum Marsh.) regeneration in Hubbard Brook Experimental Forest (HBEF), Watershed 5 (W5), following whole-tree clearcut harvesting and purport that harvesting-induced soil calcium depletion contributed to regeneration failure of this species. In New England, clearcutting is a silvicultural strategy used to promote less tolerant species, especially birch (Betula spp.; Marquis (1969), Birch Symposium Proceedings, USDA Forest Service; Leak et al. (2014), doi:10.2737/NRS-GTR...AuthorsScott Bailey, Robert P. Long, Stephen HorsleySourceCanadian Journal of Forest ResearchYear2019
- Forest spatial patterns influence many ecological processes in dry conifer forests. Thus, understanding and replicating spatial patterns is critically important in order to make these forests sustainable and more resilient to fire and other disturbances. The labor and time required to stem-map trees and the large plot size (> 0.5 ha) needed to study tree spatial patterns have limited our examination of how these patterns change as a function of site conditions and tree densities. We stem-mapped all trees>40 cm DBH within two large relict (minimally logged) pure ponderosa pine study sites...AuthorsJose Iniguez, James F. Fowler, W. Keith Moser, Carolyn H. Sieg, Scott Baggett, Patrick ShinKeywordsSourceForest Ecology and Management. 450: 117502.Year2019
- including North American mixed-pine ecosystems. Additionally, forest managers face increasing challenges to sustaining forests in the face of high uncertainty associated with response to climate change. The Adaptive Silviculture for Climate Change (ASCC) project was developed to provide operational-scale research opportunities to assess and demonstrate various adaptation approaches to forest management in regionally important forest types. The ASCC project framework includes three treatments (resistance, resilience, and transition) representing a gradient of silvicultural approaches aimed...AuthorsJacob J. Muller, Linda M. Nagel, Brian J. J. PalikKeywordsSourceForest Ecology and ManagementYear2019