Puerto Rico

Mapping the Climate of Puerto Rico, Vieques and Culebra

DALY C.,HELMER E. H.,QUIÑONES M. Mapping the Climate of Puerto Rico, Vieques and Culebra. International Journal of Climatology. Int. J. Climatol. 23: 1359-1381 (2003).

Abstract: 
Spatially explicit climate data contribute to watershed resource management, mapping vegetation type with satellite imagery, mapping present and hypothetical future ecological zones, and predicting species distributions. The regression based Parameter-elevation Regressions on Independent Slopes Model (PRISM) uses spatial data sets, a knowledge base and expert interaction to generate GIS-compatible grids of climate variables. This study applied PRISM to generate maps of mean monthly and annual precipitation and minimum and maximum temperature for the Caribbean islands of Puerto Rico, Vieques and Culebra over the 1963-1995 averaging period. PRISM was run under alternative parameterizations that simulated simpler interpolation methods as well as the full PRISM model. For temperature, the standard PRISM parameterization was compared to a hypsometric method, in which the temperature/elevation slope was assumed to be -6.5°C/km (HYPS). For precipitation, the standard PRISM parameterization was compared to an inverse-distance weighting interpolation (IDW). Spatial temperature patterns were linked closely to elevation, topographic position, and coastal proximity. Both PRISM and HYPS performed well for July maximum temperature, but HYPS performed relatively poorly for January minimum temperature, due primarily to lack of a spatially varying temperature/elevation slope, vertical atmospheric layer definition, and coastal proximity guidance. Mean monthly precipitation varied significantly throughout the year, reflecting seasonally differing moisture trajectories. Spatial precipitation patterns were associated most strongly with elevation, upslope exposure to predominant moisture-bearing winds, and proximity to the ocean. IDW performed poorly compared to PRISM, due largely to the lack of elevation and moisture availability information. Overall, the full PRISM approach resulted in greatly improved performance over simpler methods for precipitation and January minimum temperature, but only a small improvement for July maximum temperature. Comparisons of PRISM mean annual temperature and precipitation maps to previously-published, hand-drawn maps showed similar overall patterns and magnitudes, but the PRISM maps provided much more spatial detail.

Food Web Structure and Basal Resource Utilization along a Tropical Island Stream Continuum, Puerto Rico

March, JG, and CM Pringle. 2003. Food web structure and basal resource utilization along a tropical island stream continuum, puerto rico. Biotropica 35 (1) (MAR): 84-93.

Abstract: 
Tropicals treamf ood webs are thought to be based primarilyo n terrestriarl esources( leaf litter) in small forested headwatesrt reamsa nd algalr esourceisn largerw, iders treamsI. n tropicali slands treamst, he dominantc onsumeras re often omnivorousfr eshwatesrh rimpst hat consumea lgae,l eaf litter,i nsects,a nd others hrimpsW. e useds tablei sotope analysist o examine( 1) the relativei mportanceo f terrestriaal nd algal-basedfo od resourcest o shrimpsa nd other consumersa nd determine( 2) if the relativeim portanceo f thesef ood resourcecs hangeda longt he streamc ontinuum. We examined8 15N and 813Cs ignatureos f leaves,a lgae,m acrophytesb, iofilm,i nsects,s nails,f ishes,a nd shrimpsa t threes ites (300, 90, and 10 m elev.)a longt he Rio EspirituS anto,w hichd rainst he CaribbeanN ationalF orestP, uerto Rico. Isotopes ignatureos f basalr esourcews ered istincta t all sites.R esultso f two-source6 13Cm ixingm odelss uggest that shrimpsr eliedm oreo n algal-basedca rbonr esourcetsh an terrestrialldye rivedr esourceas t all threes itesa longt he continuum.T his studys upportso therr ecentf indingsi n tropicals treamsd, emonstratintgh ata lgal-basedre sourceas re very importantt o streamc onsumers,e ven in small forestedh eadwaters treams.T his study also demonstratetsh e importanceo f doing assimilation-baseadn alysis( i.e., stablei sotope or trophicb asis of production)w hen studying food webs.

Evaluation of the fidelity of isotope records as an environmental proxy in the coral Montastraea

Watanabe, T., A. Winter, T. Oba, R. Anzai, and H. Ishioroshi. 2002. Evaluation of the fidelity of isotope records as an environmental proxy in the coral montastraea. Coral Reefs 21 (2) (JUL): 169-78.

Abstract: 
Many studies of climate variability in the Tropical Ocean have used high-resolution chemical tracer records contained in coral skeletons. The complex architecture of coral skeletons may lead to the possibility of biases in coral records and it is therefore important to access the fidelity of coral geochemical records as environmental proxies. Coral skeletal records from the same coral colony, and even the same corallite, may show large variation due to differing extension rates, formational timing of the skeletal elements, colony topography, and sampling resolution. To assess the robustness of the skeletal record, we present d13C and d18O data based on different sampling resolutions, skeletal elements, and coral colonies of Montastraea faveolata species complex, the primary coral used for climate reconstruction in the Atlantic. We show that various skeletal elements produce different isotopic records. The best sampling rate to resolve the full annual range of sea surface temperature (SST) is 40 samples per year. This sampling frequency also consistently recovered SST variability measured at weekly intervals. A sampling rate of 12 times per year recovered 84% of the annual range recording average monthly SST changes through the year. Six samples per year significantly decreased the ability to resolve the annual SST range. The d18O recorded from two adjacent colonies were very similar, suggesting that this isotope can be trusted to record environmental changes. The d13C, on the other hand, remained highly variable, perhaps as a result of the activity of symbiotic algae (zooxanthellae).

Greater Soil Carbon Sequestration under Nitrogen-Fixing Trees Compared with Eucalyptus Species

Resh, SC, D. Binkley, and JA Parrotta. 2002. Greater soil carbon sequestration under nitrogen-fixing trees compared with eucalyptus species RID A-2703-2010. Ecosystems 5 (3) (APR): 217-31.

Abstract: 
Forests with nitrogen-fixing trees (N-fixers) typically accumulate more carbon (C) in soils than similar forests without N-fixing trees. This difference may develop from fundamentally different processes, with either greater accumulation of recently fixed C or reduced decomposition of older soil C. We compared the soil C pools under N-fixers with Eucalyptus (non-N-fixers) at four tropical sites: two sites on Andisol soils in Hawaii and two sites on Vertisol and Entisol soils in Puerto Rico. Using stable carbon isotope techniques, we tracked the loss of the old soil organic C from the previous C4 land use (SOC4) and the gain of new soil organic C from the C3, N-fixer, and non-N-fixer plantations (SOC3). Soils beneath N-fixing trees sequestered 0.11 + 0.07 kg m-2 y-' (mean ± one standard error) of total soil organic carbon (SOCT) compared with no change under Eucalyptus( 0.00 ± 0.07 kg m-2 y-1; P = 0.02). About 55% of the greater SOCT sequestration under the N-fixers resulted from greater retention of old SOC4, and 45% resulted from greater accretion of new SOC3. Soil N accretion under the N-fixers explained 62% of the variability of the greater retention of old SOC4 under the N-fixers. The greater retention of older soil C under N-fixing trees is a novel finding and may be important for strategies that use reforestation or afforestation to offset C emissions.

Coral skeletal carbon isotopes (d13C and D14C) record the delivery of terrestrial carbon to the coastal waters of Puerto Rico

Moyer, R. P., and A. G. Grottoli. 2011. Coral skeletal carbon isotopes (delta(13)C and delta(14)C) record the delivery of terrestrial carbon to the coastal waters of puerto rico. Coral Reefs 30 (3) (SEP): 791-802.

Abstract: 
Tropical small mountainous rivers deliver a poorly quantified, but potentially significant, amount of carbon to the world’s oceans. However, few historical records of land–ocean carbon transfer exist for any region on Earth. Corals have the potential to provide such records, because they draw on dissolved inorganic carbon (DIC) for calcification. In temperate systems, the stable- (d13C) and radiocarbon (D14C) isotopes of coastal DIC are influenced by the d13C and D14C of the DIC transported from adjacent rivers. A similar pattern should exist in tropical coastal DIC and hence coral skeletons. Here, d13C and D14C measurements were made in a 56-year-old Montastraea faveolata coral growing *1 km from the mouth of the Rio Fajardo in eastern Puerto Rico. Additionally, the d13C and D14C values of the DIC of the Rio Fajardo and its adjacent coastal waters were measured during two wet and dry seasons. Three major findings were observed: (1) synchronous depletions of both d13C and D14C in the coral skeleton are annually coherent with the timing of peak river discharge, (2) riverine DIC was always more depleted in d13C and D14C than seawater DIC, and (3) the correlation of d13C and D14C was the same in both coral skeleton and the DIC of the river and coastal waters. These results indicate that coral skeletal d13C and D14C are recording the delivery of riverine DIC to the coastal ocean. Thus, coral records could be used to develop proxies of historical land– ocean carbon flux for many tropical regions. Such information could be invaluable for understanding the role of tropical land–ocean carbon flux in the context of land-use change and global climate change.

Review of Use of Isotopes in Studying the Natural History of Puerto Rico

Evaristo J. Review of Use of Isotopes in Studying the Natural History of Puerto Rico. University of Pennsylvania. 2012.

Abstract: 
This review summarizes the earth and environmental science research papers in Puerto Rico that used isotopic techniques between 1965 and 2011. The range of applications in isotope-related research in Puerto Rico has grown steadily, led by the ubiquitous utility of stable isotope ratios in biogeochemical (δ13C, δ15N) and ecological (δ13C, δ15N, δD) research. Moreover, research in climatology has grown in recent years, spanning from the evaluation of the fidelity of isotope records (δ18O, δ13C) as an environmental proxy to the elucidation of multidecadal variability for paleoclimate reconstructions (δ18O and Sr/Ca). On the other hand, in addition to using isotope ratios, hydrological studies in Puerto Rico have also used trace element data to answer flow source (δD, δ18O, 87Sr/86Sr) and solute source (Ge/Si) questions, as well as in examining groundwater/surface flow relationships (222Rn). Finally, various isotope data have been used in trying to understand geomorphological (10Be, δ30Si) and geophysical (Pb, Nd, and Sr) phenomena. It is hoped that this review will be able to contribute to stimulating future interests in isotope-related research as applicable in the LCZO or Puerto Rico, in particular, and/or in comparable humid tropical settings, in general.

Wind characteristics on the Caribbean island of Puerto Rico

Altaii, K. and R.N. Farrugia (2003), “Wind characteristics on the Caribbean island of Puerto
Rico”, Renewable Energy, 2003. 28(11): 1701-1710.

Abstract: 
Wind data was measured at a number of sites on the Caribbean island of Puerto Rico over a 24 calendar-month time frame. The wind data gathered at four sites is envisaged to shed new light on the wind characteristics of this tropical island with an emphasis on the climate’s suitability for wind energy technology applications. Characteristics such as the diurnal, monthly and annual wind speed are subjectively investigated to determine the sites’ potential for further studies in the wind measurement field. Reasonable wind conditions for wind energy conversion system installation seem to exist in and around Aguadilla and Ponce.

The Status of Puerto Rico’s Forests, 2003

Brandeis, Thomas J.; Helmer, Eileen H.; Oswalt, Sonja N. 2007. The status of Puerto Rico's forests, 2003. Resour. Bull. SRS-119. Asheville, NC: U.S. Department of Agriculture Forest Service, Southern Research Station. 72 p.

Abstract: 
Puerto Rico’s forest cover continues to increase and is now 57 percent for mainland Puerto Rico, 85 percent for Vieques, and 88 percent for Culebra. Subtropical dry forest occupies 50 346 ha, 6832 ha, 2591 ha, and 6217 ha on the islands of Puerto Rico, Vieques, Culebra, and Mona, respectively. Subtropical moist forest, the most prevalent forested life zone on mainland Puerto Rico, had 49 percent forest cover or 258 861 ha of forest. Subtropical wet and rain forest occupies 161 503 ha, lower montane wet and rain forest occupies 11 723 ha at the highest elevations, and mangrove forest occupies 7920 ha in coastal areas. Puerto Rico’s forests were found to have over 1,602,378,689 trees over 2.5 cm in diameter and 10 607 847 m2 of basal area, and to hold 36.6 million Mg of sequestered carbon. There were 3,112 trees, 19.2 m2 of basal area, 68.25 m3 of merchantable stem volume, and 80 Mg of aboveground biomass in an average hectare of forest. The subtropical moist and wet and rain secondary forests inventoried in 1990 are still young and increasing in average basal area, which rose from 13.2 mm2/ha in 1980, to 15.2 m2/ha in 1990, to the current level of 20.9 mm2/ha. The most important tree species were the African tuliptree [Spathodea campanulata] Beauv., American muskwood [<="" i="">] (L.) Sleumer, cabbagebark tree [Andira inermis] (W. Wright) Kunth ex DC., and pumpwood [Cecropia schreberiana] Miq. Few unhealthy, stressed trees werenoted and widespread pest and disease problems were not observed. Only 12.9 percent of live trees had some type of damage or disease. Average per-hectare amounts of down woody material, forest floor duff, and forest floor litter generally increased as the forest environment became more humid. Small-to-medium forest fire fuels were most common in subtropical dry forests, while medium-to-large fuels were most common in more humid forest life zones.

Harmonic and Simple Kriging Analyses of Diurnal Precipitation Patterns in Puerto Rico

Sen-Roy S, Balling JrRV:
"Harmonic and Simple Kriging Analyses of Diurnal Precipitation Patterns in Puerto Rico",
Caribbean Journal of Science 41 (2) : 181-188 (Aug 2005)

Abstract: 
ABSTRACT.—Relatively large, topographically complex tropical islands can produce diurnal precipitation patterns that vary considerably over relatively short distances. In this investigation, we assembled a variety of databases to analyze diurnal rainfall patterns in Puerto Rico. We found strong diurnal cycles for all parts of the island with times of maximum frequency or total that ranged from pre-dawn in the east to midafternoon in the west. The pattern is similar to findings from Hawaii, and appears related to the daily pattern of katabatic and anabatic winds interaction with the predominant easterly trade winds. The diurnal pattern in rainfall was consistent through the year and not significantly affected by local sea-surface temperatures, El Niño-Southern Oscillation, and/or the North Atlantic Oscillation.

MAPPING THE CLIMATE OF PUERTO RICO, VIEQUES AND CULEBRA

CHRISTOPHER DALY, E.H. HELMER, AND MAYA QUIÑONES 2003. Mapping the Climate of Puerto Rico, Vieques and Culebra.. Int. J. Climatol. 23 :1359-1381 .

Abstract: 
Spatially explicit climate data contribute to watershed resource management, mapping vegetation type with satellite imagery, mapping present and hypothetical future ecological zones, and predicting species distributions. The regression based Parameter-elevation Regressions on Independent Slopes Model (PRISM) uses spatial data sets, a knowledge base and expert interaction to generate GIS-compatible grids of climate variables. This study applied PRISM to generate maps of mean monthly and annual precipitation and minimum and maximum temperature for the Caribbean islands of Puerto Rico, Vieques and Culebra over the 1963-1995 averaging period. PRISM was run under alternative parameterizations that simulated simpler interpolation methods as well as the full PRISM model. For temperature, the standard PRISM parameterization was compared to a hypsometric method, in which the temperature/elevation slope was assumed to be -6.5°C/km (HYPS). For precipitation, the standard PRISM parameterization was compared to an inverse-distance weighting interpolation (IDW). Spatial temperature patterns were linked closely to elevation, topographic position, and coastal proximity. Both PRISM and HYPS performed well for July maximum temperature, but HYPS performed relatively poorly for January minimum temperature, due primarily to lack of a spatially varying temperature/elevation slope, vertical atmospheric layer definition, and coastal proximity guidance. Mean monthly precipitation varied significantly throughout the year, reflecting seasonally differing moisture trajectories. Spatial precipitation patterns were associated most strongly with elevation, upslope exposure to predominant moisture-bearing winds, and proximity to the ocean. IDW performed poorly compared to PRISM, due largely to the lack of elevation and moisture availability information. Overall, the full PRISM approach resulted in greatly improved performance over simpler methods for precipitation and January minimum temperature, but only a small improvement for July maximum temperature. Comparisons of PRISM mean annual temperature and precipitation maps to previously-published, hand-drawn maps showed similar overall patterns and magnitudes, but the PRISM maps provided much more spatial detail
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