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Displaying 351 - 360 of 1,330 Publications
- La realidad del cambio climático, representado por el incremento de temperatura y concentración atmosférica de CO2, y su relación con causas antropogénicas ya no admite discusión. Este incremento genera profundos cambios en los patrones de distribución de lluvias afectando la disponibilidad de agua para cultivos. En 1975 la población mundial sobrepasó los 4 millardos y en el 2015 acaba de sobrepasar los 7 millardos, con lo cual la vulnerabilidad al cambio climático de la producción agrícola alcanza una dimensión de política de estado. Los factores que determinan la capacidad productiva de...AuthorsErnesto Medina, Grisel Velásquez, Ismael Hernández ValenciaKeywordsSourceRev. Fac. Agron. (UCV) 42 (1): 25-37.Year2016
- Disturbance shapes plant communities over a wide variety of spatial and temporal scales. How natural and anthropogenic disturbance interact to shape ecological communities is highly variable and begs a greater understanding. We used five censuses spanning the years 1990–2011 from the 16-ha Luquillo Forest Dynamics Plot (LFDP) in northeast Puerto Rico to investigate the interplay of human land-use legacies dating to the early 20th century and two recent hurricanes (Hugo, 1989 and Georges, 1998). The LFDP is a landscape mosaic comprised of an area of mature subtropical wet forest and three...AuthorsJames Aaron Hogan, Jess K. Zimmerman, Jill Thompson, Christopher J. Nytch, María UriarteKeywordsSourceEcosphereYear2016
- The PREDICTS project—Projecting Responses of Ecological Diversity In Changing Terrestrial Systems (www.predicts.org.uk)—has collated from published studies a large, reasonably representative database of comparable samples of biodiversity from multiple sites that differ in the nature or intensity of human impacts relating to land use. We have used this evidence base to develop global and regional statistical models of how local biodiversity responds to these measures. We describe and make freely available this 2016 release of the database, containing more than 3.2 million records sampled at...AuthorsLawrence N. Hudson, Joseph M. Wunderle Jr., And OthersSourceEcology and EvolutionYear2016
- A module to simulate glacier runoff, PRMSglacier, was added to PRMS (Precipitation Runoff Modeling System), a distributed-parameter, physical-process hydrological simulation code. The extension does not require extensive on-glacier measurements or computational expense but still relies on physical principles over empirical relations as much as is feasible while maintaining model usability. PRMSglacier is validated on two basins in Alaska, Wolverine, and Gulkana Glacier basin, which have been studied since 1966 and have a substantial amount of data with which to test model performance over...AuthorsAshley Van Beusekom, R. J. VigerKeywordsSourceJournal of Geophysical Research: Earth SurfaceYear2016
- AuthorsAriel Lugo, B. SantiagoKeywordsSourceActa Cientifica. Special 30th Anniversary Edition. Vol. 30(1-3): 329 pYear2016
- Governance is key to sustainable urban transitions. Governance is a system of social, power, and decision-making processes that acts as a key driver of resource allocation and use, yet ecologists even urban ecologists–seldom consider governance concepts in their work. Transitions to more sustainable futures are becoming increasingly important to the management of many ecosystems and landscapes, and particularly so for urban systems. We briefly identify and synthesize important governance dimensions of urban sustainability transitions, using illustrations from cities in which long- term...AuthorsTischa A. A. Munoz, Lindsay K. Campbell, D.L. Childers, Morgan Grove, D.M. Iwaniec, S.T.A. Pickett, Michelle Romolini, Erika S. SvendsenKeywordsSourceEcosphere, 7 (11), 1-11.Year2016
- Fire is one of the main factors directly impacting Amazonian forest biomass and dynamics. Because of Amazonia’s large geographical extent, remote sensing techniques are required for comprehensively assessing forest fire impacts at the landscape level. In this context, Light Detection and Ranging (LiDAR) stands out as a technology capable of retrieving direct measurements of vegetation vertical arrangement, which can be directly associated with aboveground biomass. This work aims, for the first time, to quantify post-fire changes in forest canopy height and biomass using airborne LiDAR in...AuthorsLuciane Sato, Vitor Gomes, Yosio Shimabukuro, Michael Keller, Egidio Arai, Maiza dos-Santos, Irving Brown, Luiz AragãoKeywordsSourceRemote Sensing. 8(10): 839-.Year2016
- The Alaska Arctic Vegetation Archive (AVA-AK, GIVD-ID: NA-US-014) is a free, publically available database archive of vegetation-plot data from the Arctic tundra region of northern Alaska. The archive currently contains 24 datasets with 3,026 non-overlapping plots. Of these, 74% have geolocation data with 25-m or better precision. Species cover data and header data are stored in a Turboveg database. A standardized Pan Arctic Species List provides a consistent nomenclature for vascular plants, bryophytes, and lichens in the archive. A web-based online Alaska Arctic Geoecological Atlas...AuthorsDonald A. Walker, Amy L. Breen, Lisa A. Druckenmiller, Lisa W. Wirth, Will Fisher, Martha K. Raynolds, Jozef Šibík, Marilyn D. Walker, Stephan Hennekens, Keith Boggs, Tina Boucher, Marcel Buchhorn, Helga Bültmann, David J. Cooper, Fred J.A Daniëls, Scott J. Davidson, James J. Ebersole, Sara C. Elmendorf, Howard E. Epstein, William A. Gould, Robert D. Hollister, Colleen M. Iversen, M. Torre Jorgenson, Anja Kade, Michael T. Lee, William H. MacKenzie, Robert K. Peet, Jana L. Peirce, Udo Schickhoff, Victoria L. Sloan, Stephen S. Talbot, Craig E. Tweedie, Sandra Villarreal, Patrick J. Webber, Donatella ZonaKeywordsSourcePhytocoenologia. 46(2): 221-229.Year2016
- Deforestation rates have declined in the Brazilian Amazon since 2005, yet degradation from logging, fire, and fragmentation has continued in frontier forests. In this study we quantified the aboveground carbon density (ACD) in intact and degraded forests using the largest data set of integrated forest inventory plots (n = 359) and airborne lidar data (18,000 ha) assembled to date for the Brazilian Amazon. We developed statistical models relating inventory ACD estimates to lidar metrics that explained 70% of the variance across forest types. Airborne lidar-ACD estimates for intact forests...AuthorsMarcos Longo, Michael Keller, Maiza N. dos-Santos, Veronika Leitold, Ekena R. Pinagé, Alessandro Baccini, Sassan Saatchi, Euler M. Nogueira, Mateus Batistella, Douglas C. MortonKeywordsSourceGlobal Biogeochemical Cycles. 30(11): 1639-1660.Year2016
- This report presents the results of the fifth global scientific assessment undertaken by the GFEP initiative. The report set out to gain deeper understanding of the meaning of illegal logging and related timber trade, its scale, drivers and consequences. It provides a structured synthesis of available scientific and expert knowledge on illegal logging and associated timber trade while adding to existing studies and reports by sharing new insights, including a criminology perspective and new information about timber and timber product trade flows as well as exploring future policy options...AuthorsB. Cashore, K. McGinley, S. Leipold, P.O. Cerutti, G. Bueno, S. et al. CarodenutoKeywordsSourceIllegal Logging and Related Timber Trade - dimensions, drivers, impacts and responses. A global scientific rapid response assesment report. . D. Kleinschmit, S. Mansourian, C. Wildburger and A. Purret (eds.), International Union of Forest Research Organizations (IUFRO), Vienna pp. 119-131.Year2016