Treesearch
Displaying 7,181 - 7,190 of 65,178 Publications- Despite its importance for forest regeneration, food webs, and human economies, changes in tree fecundity with tree size and age remain largely unknown. The allometric increase with tree diameter assumed in ecological models would substantially overestimate seed contributions from large trees if fecundity eventually declines with size. Current estimates are dominated by overrepresentation of small trees in regression models. We combined global fecundity data, including a substantial representation of large trees. We compared size–fecundity relationships against traditional allometric...AuthorsTong Qiu, Marie-Claire Aravena, Robert Andrus, Davide Ascoli, Yves Bergeron, Roberta Berretti, Michal Bogdziewicz, Thomas Boivin, Raul Bonal, Thomas Caignard, Rafael Calama, J. Julio Camarero, Connie Clark, Benoit Courbaud, Sylvain Delzon, Sergio Calderon, William Farfan-Rios, Catherine Gehring, Gregory Gilbert, Katie H. Greenberg, Qinfeng Guo, Janneke Hille Ris Lambers, Kazuhiko Hoshizaki, Ines Ibanez, Valentin Journe, Christopher Kilner, Richard Kobe, Walter Koenig, Georges Kunstler, Jalene LaMontagne, Mateusz Ledwon, James Lutz, Renzo Motta, Jonathan Myers, Thomas Nagel, Chase Nunez, Ian Pearse, Lukasz Piechnik, John Poulsen, Renata Poulton-Kamakura, Miranda Redmond, Chantal Reid, Kyle Rodman, C, Lane Scher, Harald Schmidt Van Marle, Barbara Seget, Shubhi Sharma, Miles Silman, Jennifer Swenson, Margaret Swift, Maria Uriarte, Giorgio Vacchiano, Thomas Veblen, Amy Whipple, Thomas Whitham, Andreas Wion, S. Joseph Wright, Kai Zhu, Jess Zimmerman, Magdalena Zywiec, James ClarkSourceProceedings of the National Academy of SciencesYear2021
- The Northwest Forest Plan (NWFP) is an ecosystem management plan for federal lands in the U.S. Pacific Northwest. To evaluate the NWFP’s effectiveness at conserving the marbled murrelet (Brachyramphus marmoratus), we estimated murrelet abundance at sea annually from 2000 to 2018 in inshore marine waters associated with the NWFP area. We divided this area of coastal waters into five geographic subareas corresponding with conservation zones established in the U.S. Fish and Wildlife Service’s recovery plan for the marbled murrelet. We used line transect distance estimation methods to account...AuthorsWilliam R. McIver, Scott F. Pearson, Craig Strong, Monique M. Lance, Jim Baldwin, Deanna Lynch, Martin G. Raphael, Richard D. Young, Nels G. JohnsonKeywordsSourceGen. Tech. Rep. PNW-GTR-996. Portland, OR: U.S. Department of Agriculture, Forest Service, Pacific Northwest Research Station. 37 p.Year2021
- North American forests are threatened by changes in climate and disturbance dynamics. Current efforts to model future vegetation and fire dynamics are challenged by the lack of mechanistic representation of ecological processes, the spatial resolution to capture landscape-level heterogeneity, and the ability to model regional spatial extents. To address these gaps, a dynamic vegetation model was adapted for regional applications to the western forests of the U.S. Here we present LPJ-GUESS-LMfireCF, a dynamic vegetation model that includes the ecological processes of a dynamic global...AuthorsKristen D. Emmett, Katherine Renwick, Benjamin PoulterKeywordsSourceEcological ModellingYear2021
- Plant diversity, habitat properties, and their relationships in karst caves remain poorly understood. We surveyed vascular plant and bryophyte diversities and measured the habitat characteristics in six karst caves in south China with different disturbance histories (one had been disturbed by poultry feeding, three had been disturbed by tourism, and two were undisturbed). The plant diversity differences among the six caves were analyzed using cluster analysis, and the relationships of plant diversity and microhabitat were assessed using canonical correspondence analysis. We found a total...AuthorsH Ren, F Wang, W Ye, Q Zhang, T Han, Y Huang, G Chu, D Hui, Qinfeng GuoSourceEcological IndicatorsYear2021
- Invasive plants and native weeds (i.e., undesirable plant species) often have negative effects on native ecosystems. However, the effects of weed expansion on soil seed banks and seedling emergence in native forests have not been well investigated. In this study, we used a seedling emergence assay to assess the effects of expansion by a native weed, the perennial C4 herb Wollastonia biflora, on the soil seed bank and above-ground vegetation in forests on Yongxing Island, a coral island in the South China Sea. We found that W. biflora expansion was associated with a reduced abundance of...AuthorsYao Huang, Hai Ren, Jun Wang, Nan Liu, Shuguang Jian, Hongyue Cai, Dafeng Hui, Qinfeng GuoSourceGlobal Ecology and ConservationYear2021
- With evidence of pollinator declines and an increasing focus on restoration, interest is growing in investigating floral resources for native bees. Although native bees forage on shrubs, few studies have explored the pollinator communities of native shrubs and none have examined shrub-pollinator interactions in riparian areas of the northwestern United States. Life history traits of shrubs may make them particularly important resources for bees, especially in early spring—a key point in the lifecycle of many bee species. We conducted extensive hand-net surveys over 2 years in a large...AuthorsScott R. Mitchell, Sandra J. DeBano, Mary M. Rowland, Skyler BurrowsKeywordsSourceRestoration Ecology. 36: 478-490.Year2021
- Conservation efforts need reliable information concerning the status of a species and their trends to help identify which species are in most need of assistance. We completed a comparative evaluation of the occurrence of breeding for Cascades Frog (Rana cascadae), an amphibian that is being considered for federal protection under the U.S. Endangered Species Act. Specifically, in 2018–2019 we resurveyed 67 sites that were surveyed approximately 15 y prior and fit occupancy models to quantify the distribution of R. cascadae breeding in the Cascade Range, Oregon, USA. Furthermore, we conducted...AuthorsAdam Duarte, Christopher A. Pearl, Brome McCreary, Jennifer C. Rowe, Michael J. AdamsKeywordsSourceHerpetological Conservation and Biology. 16(2): 361-373.Year2021
- Frost damage is among the major limitations to reforestation and forest restoration projects worldwide. Investigations of environmental and genetic effects on frost resistance have focused on boreal and temperate tree species rather than tropical trees. Koa (Acacia koa A. Gray) is a valuable tropical hardwood tree species endemic to the Hawaiian Islands, USA. Koa occurs across a wide elevational gradient, and newly planted trees are subject to winter frost at high elevations. We sought to determine whether different koa populations show variation in freeze hardiness as a cold-tolerance...AuthorsLilian M. Ayala-Jacobo, Keith Woeste, Douglass F. JacobsKeywordsSourceForestsYear2021
- Many pollinator populations are experiencing declines, emphasizing the need for a better understanding of the complex relationship between bees and flowering plants. Using DNA metabarcoding to describe plant–pollinator interactions eliminates many challenges associated with traditional methods and has the potential to reveal a more comprehensive understanding of foraging behaviour and pollinator life history. Here we use DNA metabarcoding of ITS2 and rbcL gene regions to identify plant species present in pollen loads of 404 bees from three habitats in eastern Oregon. Our specific objectives...AuthorsKatherine A. Arstingstall, Sandra J. DeBano, Xiaoping Li, David E. Wooster, Mary M. Rowland, Skyler Burrows, Kenneth FrostKeywordsSourceMolecular Ecology. 30(20): 5266-5297.Year2021
- Key message. Quercus rubra half sib progenies (N = 93) expressed high levels of variance for both growth and stem form traits in three locations in Indiana, USA at age 11 or 12. Height, diameter, and volume were measured and sweep, branch angle, forking, and branch retention were rated using a (+ / −) system. Families selected for volume showed no unfavorable increases in sweep or branch angle and only a slight increase in branch retention. Context. Northern red oak (Quercus rubra L.) is the most planted hardwood in the central USA. Red oak seeds from sources with improved growth and form...AuthorsKeith Woeste, Carolyn C. Pike, James C. Warren, Mark V. V. CoggeshallKeywordsSourceAnnals of Forest ScienceYear2021