Tropical cyclone effects on vegetation resilience in the Yucatan Peninsula, México, between 2000-2012

Investigaciones Geográficas ◽

10.14198/ingeo.18499 ◽

2021 ◽

Author(s):

Gabriel Sánchez-Rivera ◽

Leticia Gómez-Mendoza

Keyword(s):

Tropical Cyclones ◽

Vegetation Index ◽

Yucatan Peninsula ◽

Lapse Rate ◽

Positive Effects ◽

Yucatán Peninsula ◽

Recovery Capacity ◽

Rate Of Recovery ◽

Long Term Studies

The resilience capacity of vegetation in the Yucatan Peninsula is influenced by the winds and rains of tropical cyclones. There are no recent long-term studies on cyclonic impacts on natural vegetation in the region despite their significant effects on infrastructure and biodiversity. The objective of this study was to identify the area impacted by 21 tropical cyclones between 2000 and 2012 and to quantify the recovery capacity of the vegetation by using standardized anomalies of the normalized vegetation index (aNDVI). MODIS images from NASA’s “Terra and Aqua” satellites were used to calculate the damaged areas by analyzing the frequency of pixels corresponding to each type of vegetation per impact zone. The results showed that in 67% of the tropical cyclones, the impacts on vegetation were negative —a decrease in aNDVI—but in 33% of the cyclones, positive effects were recorded —an increase in aNDVI—. The lapse rate of vegetation recovery varied in 52% of the cases; vegetation recovered between two and three weeks after each cyclonic event, while 38% of the cases recovered within four to five weeks of the cyclone landfall. Tropical forests suffered the most significant effects, followed by hydrophilic vegetation. The most destructive hurricanes were Emily, Wilma, and Dean. The rate of recovery laps ranged from 4 to 10 weeks after the hurricane hit. The results could improve assessments of vegetation vulnerability against severe hydrometeorological events and establish priority zones for prompt inspection.

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Assessment of Creatine in Sports Products

European Journal of Nutrition & Food Safety ◽

10.9734/ejnfs/2021/v13i430407 ◽

2021 ◽

pp. 61-63

Author(s):

Wenche Frølich ◽

Elisabet Børsheim ◽

Truls Raastad ◽

Livar Frøyland ◽

Ragnhild Halvorsen ◽

...

Keyword(s):

Food Safety ◽

Maintenance Dose ◽

Creatine Supplementation ◽

Creatine Phosphate ◽

Creatine Monohydrate ◽

Large Individual ◽

Novel Food ◽

Positive Effects ◽

Long Term Studies

The Norwegian Scientific Committee for Food Safety (Vitenskapskomiteen for mattrygghet, VKM) has at the request of the Norwegian Food Safety Authority (Mattilsynet) conducted an assessment of creatine in sports products (e.g. supplements). The evaluation has been performed by an ad hoc group, and assessed by the VKM Panel on nutrition, dietetic products, novel food and allergy. The evaluation of safety and possible risks of creatine supplementation in this opinion is based on previous reports, 23 original papers and 14 reviews from literature searches. Marketing and sales of sport products are increasing in the Nordic countries, with creatine supplements being one of four most common categories. In addition to be used by athletes, the use of creatine supplements seems to increase among general exercisers and young people. Creatine supplements are mainly used for their supposed effects on muscles mass and high intensity and short duration sport performances. Supplementation has been shown to result in higher concentration of creatine phosphate in the muscles, which is the limited substrate. For athletes, it is recommended a loading dose of 10-20 g/day for 4-7 days and a maintenance dose of 2-5 g/day for weeks or months. Some athletes continue the maintenance dose for several years. It is well documented that creatine supplementation has positive effects on muscle mass combined with strength training and performance during maximal exercise. There are however large individual variation in the response, and there are responders and non-responders. The new scientific literature, including long term studies, is in line with the EFSA (European Food Safety Authority) opinion from 2004. VKM Panel on nutrition, dietetic products, novel food and allergy supports the EFSA conclusion that supplementation of creatine in doses below 3 g/day is unlikely to pose any risks if the purity of the creatine compound is adequate. Scientific long-term studies with doses up to 5-10 g/day in adult athletes have shown no harmful effects, but there are no dose-response studies indicating a safe upper limit for creatine. The potential negative effects (impaired kidney function, weight gain and gastrointestinal disturbances) which have been published in non scientific journals and anecdotal reports have not found support in controlled systematic studies on healthy subjects. It has been indicated that individuals with impaired kidney functions should refrain from creatine supplements. Creatine-monohydrate is the most studied form of creatine supplements, and only creatine monohydrate has been included in the scientific investigations on adverse effects.

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Tropical Cyclones in the North Atlantic Basin and Yucatan Peninsula, Mexico: Identification of Extreme Events

International Journal of Design & Nature and Ecodynamics ◽

10.18280/ijdne.160204 ◽

2021 ◽

Vol 16 (2) ◽

pp. 145-160

Author(s):

Gabriel Sánchez-Rivera ◽

Oscar Frausto-Martínez ◽

Leticia Gómez-Mendoza ◽

Ángel Refugio Terán-Cuevas ◽

Julio Cesar Morales Hernández

Keyword(s):

Tropical Cyclones ◽

North Atlantic ◽

Extreme Events ◽

Yucatan Peninsula ◽

Atlantic Basin ◽

North Atlantic Basin ◽

The North ◽

Yucatán Peninsula ◽

The North Atlantic

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Vertical Differences in the Long-Term Trends and Breakpoints of NDVI and Climate Factors in Taiwan

Remote Sensing ◽

10.3390/rs13224707 ◽

2021 ◽

Vol 13 (22) ◽

pp. 4707

Author(s):

Hui Ping Tsai ◽

Geng-Gui Wang ◽

Zhong-Han Zhuang

Keyword(s):

Climate Change ◽

Minimum Temperature ◽

Vegetation Index ◽

Climatic Factors ◽

Maximum Temperature ◽

Climatic Data ◽

Positive Effects ◽

Central Regions ◽

Long Term Trends

This study explored the long-term trends and breakpoints of vegetation, rainfall, and temperature in Taiwan from overall and regional perspectives in terms of vertical differences from 1982 to 2012. With time-series Advanced Very-High-Resolution Radiometer (AVHRR) normalized difference vegetation index (NDVI) data and Taiwan Climate Change Estimate and Information Platform (TCCIP) gridded monthly climatic data, their vertical dynamics were investigated by employing the Breaks for Additive Seasonal and Trend (BFAST) algorithm, Pearson’s correlation analysis, and the Durbin–Watson test. The vertical differences in NDVI values presented three breakpoints and a consistent trend from positive (1982 to 1989) to negative at varied rates, and then gradually increased after 2000. In addition, a positive rainfall trend was discovered. Average and maximum temperature had similar increasing trends, while minimum temperature showed variations, especially at higher altitudes. In terms of regional variations, the vegetation growth was stable in the north but worse in the central region. Higher elevations revealed larger variations in the NDVI and temperature datasets. NDVI, along with average and minimum temperature, showed their largest changes earlier in higher altitude areas. Specifically, the increasing minimum temperature direction was more prominent in the mid-to-high-altitude areas in the eastern and central regions. Seasonal variations were observed for each region. The difference between the dry and wet seasons is becoming larger, with the smallest difference in the northern region and the largest difference in the southern region. Taiwan’s NDVI and climatic factors have a significant negative correlation (p < 0.05), but the maximum and minimum temperatures have significant positive effects at low altitudes below 500 m. The northern and central regions reveal similar responses, while the south and east display different feedbacks. The results illuminate climate change evidence from assessment of the long-term dynamics of vegetation and climatic factors, providing valuable references for establishing correspondent climate-adaptive strategies in Taiwan.

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Testing the “tropical storm” hypothesis of Yucatan Peninsula climate variability during the Maya Terminal Classic Period

Quaternary Research ◽

10.1016/j.yqres.2016.05.006 ◽

2016 ◽

Vol 86 (2) ◽

pp. 111-119 ◽

Cited By ~ 8

Author(s):

Martín Medina-Elizalde ◽

Josué Moises Polanco-Martínez ◽

Fernanda Lases-Hernández ◽

Raymond Bradley ◽

Stephen Burns

Keyword(s):

Tropical Cyclones ◽

Yucatan Peninsula ◽

Tropical Storm ◽

Classic Maya ◽

Classic Period ◽

Proxy Records ◽

Terminal Classic ◽

Yucatán Peninsula ◽

Precipitation Record ◽

Terminal Classic Period

AbstractWe examine the “tropical storm” hypothesis that precipitation variability in the Yucatan Peninsula (YP) was linked to the frequency of tropical cyclones during the demise of the Classic Maya civilization, in the Terminal Classic Period (TCP, AD 750—950). Evidence that supports the hypothesis includes: (1) a positive relationship between tropical storm frequency and precipitation amount over the YP today (proof of feasibility), (2) a statistically significant correlation between a stalagmite (Chaac) quantitative precipitation record from the YP and the number of named tropical cyclones affecting this region today (1852—2004) (calibration sensu lato), and, (3) correlations between the stalagmite Chaac precipitation record and an Atlantic basin tropical cyclone count record and two proxy records of shifts in macroscale climate and ocean states that influence Atlantic tropical cyclongenesis. At face value, regional paleotempestology proxy records suggest that tropical storm activity in the YP was either similar or significantly lower than today during the TCP. The “tropical storm” hypothesis has implications for our understanding of the role the hydrological cycle played in the collapse of Classic Maya polities and the role of tropical storms in possibly ameliorating future drought in the YP and other tropical regions.

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Preliminary study of long-term wind characteristics of the Mexican Yucatán Peninsula

Energy Conversion and Management ◽

10.1016/j.enconman.2009.03.018 ◽

2009 ◽

Vol 50 (7) ◽

pp. 1773-1780 ◽

Cited By ~ 10

Author(s):

Rolando Soler-Bientz ◽

Simon Watson ◽

David Infield

Keyword(s):

Yucatan Peninsula ◽

Yucatán Peninsula ◽

Wind Characteristics ◽

Preliminary Study

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Phytoplankton of the northern coastal and shelf waters of the Yucatan Peninsula, southeastern Gulf of Mexico, Mexico

Check List ◽

10.15560/9.4.771 ◽

2013 ◽

Vol 9 (4) ◽

pp. 771 ◽

Cited By ~ 11

Author(s):

Fany Del Carmen Merino-Virgilio ◽

Yuri B. Okolodkov ◽

Ana C. Aguilar-Trujillo ◽

Jorge A. Herrera- Silveira

Keyword(s):

Gulf Of Mexico ◽

Phytoplankton Community ◽

Yucatan Peninsula ◽

Toxic Species ◽

Centric Diatoms ◽

Yucatán Peninsula ◽

Long Term Monitoring ◽

Term Monitoring

Based on long-term monitoring (2001-2012) and four oceanographic cruises (2010-2012) in the coastal and shelf waters of the Yucatan Peninsula, SE Gulf of Mexico, a list of 306 strictly phytoplanktonic and tychoplanktonic species from 131 genera is presented: centric diatoms (83 species), raphid diatoms (47), araphid diatoms (22), Dinoflagellata (124), Cyanoprokaryota (18), Ebriacea (2), Chlorophyceae (3), Dictyochophyceae (2), Euglenophyceae (2), Cryptophyceae (1), Prymnesiophyceae (1), and Raphidophyceae (1). Diatoms also dominated the number of genera (80) followed by dinoflagellates (39) and cyanobacteria (11). The genera most abundant in species were Chaetoceros Ehrenb. (23 species), Protoperidinium Bergh (23) and Ceratium Schrank (17). The relative richness in species of the genus Oxytoxum (11 species) is related to the tropical affiliation of the phytoplankton community. Most of the tychoplanktonic diatoms (57 species out of a total of 152 diatoms, or 37.5%) were observed principally from coastal samplings. Eighteen potentially toxic species were found.

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Short-Term Variability in Alaska Ice-Marginal Lake Area: Implications for Long-Term Studies

Remote Sensing ◽

10.3390/rs13193955 ◽

2021 ◽

Vol 13 (19) ◽

pp. 3955

Author(s):

Anton M. Hengst ◽

William Armstrong ◽

Brianna Rick ◽

Daniel McGrath

Keyword(s):

Vegetation Index ◽

Google Earth ◽

Landsat 8 ◽

Lake Area ◽

Dynamic Features ◽

Short Term ◽

South Central ◽

Short Term Variability ◽

Long Term Studies

Lakes in direct contact with glaciers (ice-marginal lakes) are found across alpine and polar landscapes. Many studies characterize ice-marginal lake behavior over multi-decadal timescales using either episodic ~annual images or multi-year mosaics. However, ice-marginal lakes are dynamic features that experience short-term (i.e., day to year) variations in area and volume superimposed on longer-term trends. Through aliasing, this short-term variability could result in erroneous long-term estimates of lake change. We develop and implement an automated workflow in Google Earth Engine to quantify monthly behavior of ice-marginal lakes between 2013 and 2019 across south-central Alaska using Landsat 8 imagery. We employ a supervised Mahalanobis minimum-distance land cover classifier incorporating three datasets found to maximize classifier performance: shortwave infrared imagery, the normalized difference vegetation index (NDVI), and spatially filtered panchromatic reflectance. We observe physically-meaningful ice-marginal lake area variance on sub-annual timescales, with the median area fluctuation of an ice-marginal lake found to be 10.8% of its average area. The median signal (slow lake growth) to noise (physically-meaningful short-term area variability) ratio is 1.5:1, indicating that short-term variability is responsible for ~33% of observed area change in the median ice-marginal lake. The magnitude of short-term area variability is similar for ice-marginal and nonglacial lakes, suggesting that the cause of observed variations is not of glacial origin. These data provide a new context for interpreting behaviors observed in multi-decadal studies and encourage attention to sub-annual behavior of ice-marginal lakes even in long-term studies.

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