Disturbance and long-term patterns of rainfall and throughfall nutrient fluxes in a subtropical wet forest in Puerto Rico

2007 ◽  
Vol 333 (2-4) ◽  
pp. 472-485 ◽  
Author(s):  
T. Heartsill-Scalley ◽  
F.N. Scatena ◽  
C. Estrada ◽  
W.H. McDowell ◽  
A.E. Lugo
Keyword(s):  
Puerto Rico ◽  
Nutrient Fluxes ◽  
Subtropical Wet Forest

scholarly journals Plant responses to simulated hurricane impacts in a subtropical wet forest, Puerto Rico

2010 ◽  
Vol 98 (3) ◽  
pp. 659-673 ◽  
Author(s):  
Aaron B. Shiels ◽  
Jess K. Zimmerman ◽  
Diana C. García-Montiel ◽  
Inge Jonckheere ◽  
Jennifer Holm ◽  
...  
Keyword(s):  
Puerto Rico ◽  
Plant Responses ◽  
Hurricane Impacts ◽  
Subtropical Wet Forest

scholarly journals Population of Puerto Rico not displaced by Hurricanes (for now): It’s the economy

2019 ◽  
Author(s):  
Matt Kaneshiro ◽  
Collin McCarter ◽  
Mario Marazzi ◽  
Alexis R Santos-Lozada
Keyword(s):  
Puerto Rico ◽  
Population Change ◽  
Population Decline ◽  
Data Sources ◽  
Quality Data ◽  
Economic Data ◽  
High Quality Data ◽  
Economic Downturns ◽  
Employment Trends

In September 2017, Hurricane Maria made landfall on Puerto Rico and caused 102 billion worth of damages, demolishing the electric grid and severely affecting essential daily services that continued as of the second half of 2019. Amidst the chaos, analysts were expected to provide stakeholders with impact estimates immediately following the hurricane. Unfortunately, this strong need for fast information after the disaster coincided with limited options for high-quality data sources to help stakeholders address challenges such as resource allocation and bond-pricing. Given the stabilization of data sources since the hurricanes, this paper examines historical demographic and economic data to give a long-term view of population change in Puerto Rico. First, we juxtapose population, employment, hurricanes and significant economic events to make the argument that the clearest driver of population decline in Puerto Rico is simply the economic health of the island (i.e. employment). Second, we focus on Pre- and Post-Hurricane Irma/Maria migration estimates to highlight the spike in outmigration following the hurricanes, as well as the, return immigration in the first half of the first half of 2018. Finally, we study historical net outmigration and employment trends to illustrate the short-lived outmigration impacts of hurricanes while also highlighting the long-term outmigration impacts of economic downturns. In short, we argue that the primary reason people are leaving Puerto Rico is the struggling economy and not hurricane-related destruction. The hurricanes simply exacerbated the economic-related outmigration trends and we believe that any serious plans for Puerto Rico’s restoration must include special attention to stimulate the economy.

scholarly journals Analyzing the Impact of Climate Factors on GNSS-Derived Displacements by Combining the Extended Helmert Transformation and XGboost Machine Learning Algorithm

2021 ◽  
Vol 2021 ◽  
pp. 1-13
Author(s):  
Hanlin Liu ◽  
Linqiang Yang ◽  
Linchao Li
Keyword(s):  
Machine Learning ◽  
Puerto Rico ◽  
Reference Frame ◽  
Learning Algorithm ◽  
Virgin Islands ◽  
Machine Learning Algorithm ◽  
Climate Factors ◽  
Helmert Transformation ◽  
The Impact

A variety of climate factors influence the precision of the long-term Global Navigation Satellite System (GNSS) monitoring data. To precisely analyze the effect of different climate factors on long-term GNSS monitoring records, this study combines the extended seven-parameter Helmert transformation and a machine learning algorithm named Extreme Gradient boosting (XGboost) to establish a hybrid model. We established a local-scale reference frame called stable Puerto Rico and Virgin Islands reference frame of 2019 (PRVI19) using ten continuously operating long-term GNSS sites located in the rigid portion of the Puerto Rico and Virgin Islands (PRVI) microplate. The stability of PRVI19 is approximately 0.4 mm/year and 0.5 mm/year in the horizontal and vertical directions, respectively. The stable reference frame PRVI19 can avoid the risk of bias due to long-term plate motions when studying localized ground deformation. Furthermore, we applied the XGBoost algorithm to the postprocessed long-term GNSS records and daily climate data to train the model. We quantitatively evaluated the importance of various daily climate factors on the GNSS time series. The results show that wind is the most influential factor with a unit-less index of 0.013. Notably, we used the model with climate and GNSS records to predict the GNSS-derived displacements. The results show that the predicted displacements have a slightly lower root mean square error compared to the fitted results using spline method (prediction: 0.22 versus fitted: 0.31). It indicates that the proposed model considering the climate records has the appropriate predict results for long-term GNSS monitoring.

scholarly journals A Refined Methodology for Defining Plant Communities Using Postagricultural Data from the Neotropics

2012 ◽  
Vol 2012 ◽  
pp. 1-9 ◽  
Author(s):  
Randall W. Myster
Keyword(s):  
Puerto Rico ◽  
Plant Community ◽  
Plant Communities ◽  
Association Strength ◽  
Old Field ◽  
Species Groups ◽  
Banana Plantations

How best to define and quantify plant communities was investigated using long-term plot data sampled from a recovering pasture in Puerto Rico and abandoned sugarcane and banana plantations in Ecuador. Significant positive associations between pairs of old field species were first computed and then clustered together into larger and larger species groups. I found that (1) no pasture or plantation had more than 5% of the possible significant positive associations, (2) clustering metrics showed groups of species participating in similar clusters among the five pasture/plantations over a gradient of decreasing association strength, and (3) there was evidence for repeatable communities—especially after banana cultivation—suggesting that past crops not only persist after abandonment but also form significant associations with invading plants. I then showed how the clustering hierarchy could be used to decide if any two pasture/plantation plots were in the same community, that is, to define old field communities. Finally, I suggested a similar procedure could be used for any plant community where the mechanisms and tolerances of species form the “cohesion” that produces clustering, making plant communities different than random assemblages of species.

scholarly journals The dilemma of controlling cultural eutrophication of lakes

2012 ◽  
Vol 279 (1746) ◽  
pp. 4322-4333 ◽  
Author(s):  
David W. Schindler
Keyword(s):  
Large Scale ◽  
Ecosystem Processes ◽  
Nutrient Fluxes ◽  
Nutrient Cycles ◽  
Case Histories ◽  
Short Term ◽  
Ecosystem Responses ◽  
Lake Recovery ◽  
Recent Claim

The management of eutrophication has been impeded by reliance on short-term experimental additions of nutrients to bottles and mesocosms. These measures of proximate nutrient limitation fail to account for the gradual changes in biogeochemical nutrient cycles and nutrient fluxes from sediments, and succession of communities that are important components of whole-ecosystem responses. Erroneous assumptions about ecosystem processes and lack of accounting for hysteresis during lake recovery have further confused management of eutrophication. I conclude that long-term, whole-ecosystem experiments and case histories of lake recovery provide the only reliable evidence for policies to reduce eutrophication. The only method that has had proven success in reducing the eutrophication of lakes is reducing input of phosphorus. There are no case histories or long-term ecosystem-scale experiments to support recent claims that to reduce eutrophication of lakes, nitrogen must be controlled instead of or in addition to phosphorus. Before expensive policies to reduce nitrogen input are implemented, they require ecosystem-scale verification. The recent claim that the ‘phosphorus paradigm’ for recovering lakes from eutrophication has been ‘eroded’ has no basis. Instead, the case for phosphorus control has been strengthened by numerous case histories and large-scale experiments spanning several decades.

scholarly journals Tricks of the Slave Trade

2017 ◽  
Vol 91 (1-2) ◽  
pp. 1-29
Author(s):  
Edgardo Pérez Morales
Keyword(s):  
Nineteenth Century ◽  
Puerto Rico ◽  
Slave Trade ◽  
Small Scale ◽  
Human Beings ◽  
Transatlantic Slave Trade ◽  
Slave Traders ◽  
Cuban Sugar ◽  
Trading Activities

Around 1808, Spaniards’ ability to outfit and successfully complete slaving expeditions to Africa paled in comparison to the skill of French and British slavers. In the wake of British Abolitionism and the Cuban sugar revolution, however, some Spaniards learned the tricks of the slave trade and by 1835 had brought over 300,000 captives to Cuba and Puerto Rico (most went to Cuba). This article presents evidence on the process through which some Spaniards successfully became slave traders, highlighting the transition from early trial ventures around 1809–15 to the mastering of the trade by 1830. It pays particular attention to the operations and perspectives of the Havana-based firm Cuesta Manzanal & Hermano and to the slave trading activities on the Pongo River by the crewmen of the Spanish ship La Gaceta. Although scholars have an increasingly solid perception of the magnitude and consequences of the Cuba-based trade in human beings in the nineteenth century, the small-scale dynamics of this process, ultimately inseparable from long-term developments, remain elusive. This article adds further nuance to our knowledge of the post-1808 surge in the Spanish transatlantic slave trade.

Long-term decline of a winter-resident bird community in Puerto Rico

2012 ◽  
Vol 22 (1) ◽  
pp. 63-75 ◽  
Author(s):  
John Faaborg ◽  
Wayne J. Arendt ◽  
Judith D. Toms ◽  
Katie M. Dugger ◽  
W. Andrew Cox ◽  
...  
Keyword(s):  
Puerto Rico ◽  
Bird Community ◽  
Resident Bird

scholarly journals Monitoring Corruptible Politicians

2016 ◽  
Vol 106 (8) ◽  
pp. 2371-2405 ◽  
Author(s):  
Gustavo J. Bobonis ◽  
Luis R. Cámara Fuertes ◽  
Rainer Schwabe
Keyword(s):  
Puerto Rico ◽  
Longitudinal Data ◽  
Municipal Governments ◽  
Sustained Reduction

Does monitoring corrupt activities induce a sustained reduction in corruption? Using longitudinal data on audits of municipal governments in Puerto Rico, we show corruption is considerably lower in municipalities with timely audits—before elections. However, these municipalities do not exhibit decreased levels of corruption in subsequent audits, even while mayors in these benefit from higher reelection rates. Our results suggest that audits enable voters to select responsive but corruptible politicians to office. Audit programs must disseminate results when they are most relevant for voters—shortly before an election—and ensure that these programs are sustained, long-term commitments. (JEL D72, H83, K42, O17)

scholarly journals Potassium Supplying Power of the Major Upland Inceptisols of Puerto Rico

1969 ◽  
Vol 64 (1) ◽  
pp. 9-28
Author(s):  
Fernando Abruña
Keyword(s):  
Puerto Rico ◽  
Long Range ◽  
Field Experiments ◽  
Pot Experiment ◽  
First Year ◽  
Moisture Regime ◽  
Exchangeable K ◽  
Intensive Cropping ◽  
K Release

Capacity of the nine most extensive upland Inceptisols of Puerto Rico to supply potassium (K) was determined through intensive cropping in pots with Pangola grass during 4 consecutive years. In addition, field experiments were conducted on two of these soils, Mucara and Pandura, for comparison. Seven of the lnceptisols tested formed under a udic moisture regime. They supplied an average of 279/kg of K/ha to Pangola grass during the first year, and then dropped to 110, 114, and 93 kg/ha for the second, third and fourth years, respectively. The average of 106 kg/ha for the last 3 years probably represents the long term capacity of this group to supply K to plants. The amount of K released by Mucara and Pandura soils (both udic lnceptisols) in the field experiments agreed fairly well with values obtained in the pot experiments. Two of the lnceptisols tested formed under a ustic moisture regime released and average of 507 kg of K/ha during the first year, and then 254, 233, and 140 kg/ha the last 3 years. The average K release per year for the last 3 years was 209 kg/ha. However, the long range K supplying capacity of these soils is probably lower than this value. The exchangeable K values obtained at the beginning of the pot experiment were significantly correlated with the amount of K extracted by Pangola grass during the first year of cropping in pots, whereas the HN03-soluble K values were correlated with the average release of K during the last 3 cropping years.

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