scholarly journals The role of substrate type, moisture and temperature on the vertical growth of terricolous lichens

2018 ◽  
Author(s):  
Julián Monge-Nájera
Keyword(s):  
Water Levels ◽  
Soft Ground ◽  
Substrate Type ◽  
Main Determinant ◽  
Vertical Growth ◽  
Terricolous Lichens ◽  
The Caribbean ◽  
Terricolous Lichen ◽  
Recorded Temperature

AbstractLichens are traditionally divided into short “crustose”, intermediate “foliose” and tall “fruticose” types, a practice that hides a growth continuum. Substrate, temperature and water are thought to affect vertical growth, but such factors are difficult to measure, because, for example, the water actually available to lichens does not match rainfall patterns or even ground water levels. To reliably assess the effect of those factors, I recorded temperature, moisture, and substrate in and under individual terricolous lichen colonies in 60 fixed quadrats on April, August, October, and December of 2015 (Cerro de la Muerte, Costa Rica, 9°33′N; 83°45′W). The measurements were taken inside the colonies themselves (rather than on the general environment), covering an annual cycle of the relatively simple páramo habitat, where animals and vegetation have less impact than in lower ecosystems. The hypotheses were that lichens would grow taller on softer, warmer, and moister ground; on the Caribbean versant; and on the rainy season. Results matched the hypotheses, with one exception: lichens on soft ground were not taller than those on rock. Caribbean colonies were, on the average, 7 cm taller than those on the drier Pacific versant. Physiologically available water seems to be the main determinant of lichen vertical growth: more water means taller lichens and greater protection from climatic change for both the lichens and their microcommunities.

scholarly journals The Role of Substrate Type, Moisture and Temperature on the Vertical Growth of Terricolous Lichens

2018 ◽  
Author(s):  
Julián Monge-Nájera
Keyword(s):  
Water Levels ◽  
Soft Ground ◽  
Substrate Type ◽  
Main Determinant ◽  
Vertical Growth ◽  
Terricolous Lichens ◽  
The Caribbean ◽  
Terricolous Lichen ◽  
Recorded Temperature

Lichens are traditionally divided into short “crustose”, intermediate “foliose” and tall “fruticose” types, a practice that hides a growth continuum. Substrate, temperature and water are thought to affect vertical growth, but such factors are difficult to measure, because, for example, the water actually available to lichens does not match rainfall patterns or even ground water levels. To reliably assess the effect of those factors, I recorded temperature, moisture, and substrate in and under individual terricolous lichen colonies in 60 fixed quadrats on April, August, October, and December of 2015 (Cerro de la Muerte, Costa Rica, 9°33′N; 83°45′W). The measurements were taken inside the colonies themselves (rather than on the general environment), covering an annual cycle of the relatively simple páramo habitat, where animals and vegetation have less impact than in lower ecosystems. The hypotheses were that lichens would grow taller on softer, warmer, and moister ground; on the Caribbean versant; and on the rainy season. Results matched the hypotheses, with one exception: lichens on soft ground were not taller than those on rock. Caribbean colonies were, on the average, 7 cm taller than those on the drier Pacific versant. Physiologically available water seems to be the main determinant of lichen vertical growth: more water means taller lichens and greater protection from climatic change for both the lichens and their microcommunities.

scholarly journals Relative humidity, temperature, substrate type, and height of terrestrial lichens in a tropical paramo

2019 ◽  
Vol 67 (1) ◽  
Author(s):  
Julián Monge-Nájera
Keyword(s):  
Costa Rica ◽  
Relative Humidity ◽  
Substrate Temperature ◽  
Substrate Type ◽  
Main Determinant ◽  
Buena Vista ◽  
Terricolous Lichens ◽  
Different Shapes ◽  
Atmospheric Factors

Lichens are traditionally divided into types such as "crustose", "foliose" and "fruticose", with different shapes and heights. Substrate, temperature and water are thought to affect lichen height, but there are few studies regarding tropical paramo lichens. Along 2015 I measured those variables in the terricolous lichens of the Cerro Buena Vista, paramo (Costa Rica, 9°33' N & 83°45' W). The measurements were taken inside the lichens and in the substrate under them, in 61 randomly located quadrats (50 x 50 cm). Lichens grew taller on (1) warmer ground, (2) wetter ground, (3) the moister Caribbean slope, and (4) the season with heavier rainfall, as expected. Apparently, atmospheric factors are more important than substrate in the determination of temperature, relative humidity and growth of lichens. Physiologically available water seems to be the main determinant of lichen vertical growth in the Buena Vista paramo.

Sugar Rush: Sugar and Science in the British Caribbean

2021 ◽  
Vol 14 (2) ◽  
pp. 128-150
Author(s):  
Nicole A. Jacoberger
Keyword(s):  
Nineteenth Century ◽  
Eighteenth Century ◽  
Sugar Beet ◽  
Local Knowledge ◽  
Cane Sugar ◽  
Technological Innovations ◽  
Foreign Competition ◽  
The Caribbean ◽  
A Site

This article examines the contrasting evolution in sugar refining in Jamaica and Barbados incentivized by Mercantilist policies, changes in labor systems, and competition from foreign sugar revealing the role of Caribbean plantations as a site for experimentation from the eighteenth through mid-nineteenth century. Britain's seventeenth- and eighteenth-century protectionist policies imposed high duties on refined cane-sugar from the colonies, discouraging colonies from exporting refined sugar as opposed to raw. This system allowed Britain to retain control over trade and commerce and provided exclusive sugar sales to Caribbean sugar plantations. Barbadian planters swiftly gained immense wealth and political power until Jamaica and other islands produced competitive sugar. The Jamaica Assembly invested heavily in technological innovations intended to improve efficiency, produce competitive sugar in a market that eventually opened to foreign competition such as sugar beet, and increase profits to undercut losses from duties. They valued local knowledge, incentivizing everyone from local planters to chemists, engineers, and science enthusiasts to experiment in Jamaica and publish their findings. These publications disseminated important findings throughout Britain and its colonies, revealing the significance of the Caribbean as a site for local experimentation and knowledge.

Flying to Paradise: The Role of Airlift in the Caribbean Tourism Industry

2016 ◽  
Author(s):  
Sebastian Acevedo Mejia ◽  
Lu Han ◽  
Marie Kim ◽  
N. Laframboise
Keyword(s):  
Tourism Industry ◽  
The Caribbean ◽  
Caribbean Tourism

scholarly journals The role of the reef–dune system in coastal protection in Puerto Morelos (Mexico)

2018 ◽  
Vol 18 (4) ◽  
pp. 1247-1260 ◽  
Author(s):  
Gemma L. Franklin ◽  
Alec Torres-Freyermuth ◽  
Gabriela Medellin ◽  
María Eugenia Allende-Arandia ◽  
Christian M. Appendini
Keyword(s):  
Sand Dunes ◽  
Coastal Flooding ◽  
Water Levels ◽  
Coastal Protection ◽  
Dune System ◽  
Fore Reef ◽  
Extreme Water Levels ◽  
Reef Environments ◽  
Storm Impact

Abstract. Reefs and sand dunes are critical morphological features providing natural coastal protection. Reefs dissipate around 90 % of the incident wave energy through wave breaking, whereas sand dunes provide the final natural barrier against coastal flooding. The storm impact on coastal areas with these features depends on the relative elevation of the extreme water levels with respect to the sand dune morphology. However, despite the importance of barrier reefs and dunes in coastal protection, poor management practices have degraded these ecosystems, increasing their vulnerability to coastal flooding. The present study aims to theoretically investigate the role of the reef–dune system in coastal protection under current climatic conditions at Puerto Morelos, located in the Mexican Caribbean Sea, using a widely validated nonlinear non-hydrostatic numerical model (SWASH). Wave hindcast information, tidal level, and a measured beach profile of the reef–dune system in Puerto Morelos are employed to estimate extreme runup and the storm impact scale for current and theoretical scenarios. The numerical results show the importance of including the storm surge when predicting extreme water levels and also show that ecosystem degradation has important implications for coastal protection against storms with return periods of less than 10 years. The latter highlights the importance of conservation of the system as a mitigation measure to decrease coastal vulnerability and infrastructure losses in coastal areas in the short to medium term. Furthermore, the results are used to evaluate the applicability of runup parameterisations for beaches to reef environments. Numerical analysis of runup dynamics suggests that runup parameterisations for reef environments can be improved by including the fore reef slope. Therefore, future research to develop runup parameterisations incorporating reef geometry features (e.g. reef crest elevation, reef lagoon width, fore reef slope) is warranted.

Sign in / Sign up

Export Citation Format

Share Document