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- In heterotrophic streams the retention and export of coarse particulate organic matter and associated elements are fundamental biogeochemical processes that influence water quality, food webs and the structural complexity of forested headwater streams. Nevertheless, few studies have documented the quantity and quality of exported organic matter over multiple years and under a range of conditions that includes both droughts and hurricanes. This study quantifies the export of coarse particulate organic matter (CPOM, > 12.7 mm), over 18 y in two headwater streams in north-east Puerto Rico....AuthorsTamara Heartsill Scalley, F.N. Scatena, Samuel Moya, Ariel LugoKeywordsSourceJournal of Tropical Ecology. 28: 127-139.Year2012
- Understanding tree growth in response to rainfall distribution is critical to predicting forest and species population responses to climate change. We investigated inter-annual and seasonal variation in stem diameter by three emergent tree species in a seasonally dry tropical forest in southeast Pará, Brazil. Annual diameter growth rates by Swietenia macrophylla demonstrated strong positive correlation with annual rainfall totals during 1997–2009; Hymenaea courbaril growth rates demonstrated weak positive correlation, whereas Parkia pendula exhibited weak negative correlation. For both...AuthorsJames Grogan, Mark SchulzeKeywordsSourceBiotropica. 44(3):331-340.Year2012
- The duration of migration of the endangered Kirtland’s Warbler (Setophaga kirtlandii) has not been previously documented. We estimated the average duration of spring migration for five male Kirtland’s Warblers by observing uniquely color-banded individuals at or near both the beginning and end of spring migration in Eleuthera, The Bahamas, and Michigan, respectively. We estimated the average duration of spring migration for these five individuals to have been no more than 15.8 days (range 13–23 days) and the average distance traveled to have been 144.5 km/day (96.1–169.1 km/day).AuthorsDavid N. Ewert, Kimberly R. Hall, Joseph M. Wunderle Jr., Dave Currie, Sarah M. Rockwell, Scott B. Johnson, Jennifer D. WhiteKeywordsSourceWilson Journal of Ornithology. 124(1):9-14Year2012
- We assessed current and historic land use and land cover in the Luquillo Mountains and surrounding area in eastern Puerto Rico, including four small subwatersheds that are study watersheds of the U.S. Geological Survey’s Water, Energy, and Biogeochemical Budgets (WEBB) program. This region occupies an area of 1,616 square kilometers, about 18 percent of the total land in Puerto Rico. Closed forests occupy about 37 percent of the area, woodlands and shrublands 7 percent, nonforest vegetation 43 percent, urban development 10 percent, and water and natural barrens total less than 2 percent....AuthorsS. Martinuzzi, I.K. Páres-Ramos, William A. GouldKeywordsSourceProfessional Paper 1789-B. Reston, VA (?): U.S. Department of the Interior, U.S. Geological Survey.Year2012
- Temperature is increasing at unprecedented rates across most of the tundra biome1. Remote-sensing data indicate that contemporary climate warming has already resulted in increased productivity over much of the Arctic2,3, but plot-based evidence for vegetation transformation is not widespread. We analysed change in tundra vegetation surveyed between 1980 and 2010 in 158 plant communities spread across 46 locations.We found biome-wide trends of increased height of the plant canopy and maximum observed plant height for most vascular growth forms; increased abundance of litter; increased...AuthorsSarah C. Elmendorf, Gregory H.R. Henry, Robert D. Hollister, Robert G. Bjork, Noemie Boulanger-Lapointe, Elisabeth J. Cooper, Johannes H.C. Cornelissen, Thomas A. Day, Ellen Dorrepaal, Tatiana G. Elumeeva, Mike Gill, William A. Gould, John Harte, David S. Hik, Annika Hofgaard, David R. Johnson, Jill F. Johnstone, Ingijorg Svala Jonsdottir, Janet C. Jorgenson, Kari Klanderud, Julia A. Klein, Saewan Koh, Gaku Kudo, Mark Lara, Esther Levesque, Borgthor Magnusson, Jeremy L. May, Joel Mercado, Anders Michelsen, Ulf Molau, Isla H. Myers-Smith, Steven F. Oberbauer, Vladimir G. Onipchenko, Christian Rixen, Niels Martin Schmidt, Gaius R. Shaver, Marko J. Spasojevic, Pora Ellen Porhallsdottir, Anne Tolvanen, Tiffany Troxler, Craig E. Tweedie, Sandra Villareal, Carl-Henrik Wahren, Xanthe Walker, Patrick J. Webber, Jeffrey M. Welker, Sonja WipfSourceNature Climate Change. Nature Climate Change. DOI: 10.1038/NCLIMATE1465Year2012
- AuthorsGrizelle Gonzalez, Christina M. Murphy, Juliana BelénKeywordsSourceSudarshana, P.; Nageswara-Rao, M.; and Soneji, J.R., eds. Tropical Forests. Intech (online publisher).Year2012
- AuthorsMarcela Zalamea, Grizelle Gonzalez, William A. GouldSourceSudarshana, P.; Nageswara-Rao, M.; and Soneji, J.R., eds. Tropical Forests. Intech (online publisher)Year2012
- Tropical forest managers need detailed maps of forest types for REDD+, but spectral similarity among forest types; cloud and scan-line gaps; and scarce vegetation ground plots make producing such maps with satellite imagery difficult. How can managers map tropical forest tree communities with satellite imagery given these challenges? Here we describe a case study of mapping tropical forests to floristic classes with gap-filled Landsat imagery by judicious combination of field and remote sensing work. For managers, we include background on current and forthcoming solutions to the problems...AuthorsThomas S. Ruzycki, Jay Benner, Shannon M. Voggesser, Barbara P. Scobie, Eileen Helmer, Courtenay Park, David W. Fanning, Seepersad RamnarineKeywordsSourceForest Ecology and Management. 279:147-166.Year2012
- The goals of this Luquillo Experimental Forest: Research History and Opportunities are to synthesize the new research that has emerged from the LEF since the publication of Brown et al. (1983) into a concise summary of key research findings and to highlight opportunities for future research that will contribute to a greater understanding of the structure and function of tropical forested ecosystems in a changing world. The basic structure of this publication remains similar to the Brown et al. version, but the data presented in each chapter reflect new knowledge and new ideas that have...AuthorsNancy L. Harris, Ariel Lugo, Sandra Brown, Tamara Heartsill ScalleyKeywordsSourceExperimental Forest and Range EFR-1. Washington, D.C: USDA Forest Service. 152 p.Year2012
- Avian diversity in agroscapes in Nicaragua’s north highlands. – Nicaragua’s highland forests are threatened by continual wood extraction and encroaching agriculture. Still, the effects of forest loss and fragmentation on avian communities remain little known. We used fixed-width point counts (distance sampling: 4843 detections during 86 h of observation) to characterize bird assemblages in agroforestry systems under five land uses (secondary and riparian forest, forest fallow, coffee plantations, and ‘open lands’, e.g., grass- and pasturelands with scattered trees) in three landscapes of...AuthorsWayne J. Arendt, Marvin Tórrez, Sergio VílchezKeywordsSourceOrnitología Neotropical. 23:113-131Year2012