Sediment characteristics of tropical, karst lakes and their relationship with watershed topography, lake morphometry, and human activities

2021 ◽  
Author(s):  
Javier Alcocer ◽  
Blanca Prado ◽  
Lucy Mora ◽  
Luis A. Oseguera ◽  
Margarita Caballero
Keyword(s):  
Human Activities ◽  
Lake Morphometry ◽  
Sediment Characteristics ◽  
Karst Lakes ◽  
Tropical Karst

Natural variation of profundal macroinvertebrate communities in boreal lakes is related to lake morphometry: implications for bioassessment

2009 ◽  
Vol 66 (4) ◽  
pp. 589-601 ◽  
Author(s):  
Jussi Jyväsjärvi ◽  
Kimmo T. Tolonen ◽  
Heikki Hämäläinen
Keyword(s):  
Environmental Factors ◽  
Human Activities ◽  
Natural Variation ◽  
Geographical Location ◽  
Boreal Lakes ◽  
Biological Assessment ◽  
Compositional Variation ◽  
Macroinvertebrate Communities ◽  
Lake Morphometry ◽  
Partial Canonical Correspondence Analysis

Modern biological assessment of aquatic systems is often based on the reference condition approach, which requires characterization of biota in undisturbed conditions. For this approach, it is essential to recognize the origins and degree of natural variation in communities. We used data from 55 minimally disturbed Finnish lake basins to investigate the natural variation of profundal macroinvertebrate community composition in relation to environmental factors. Partial canonical correspondence analysis showed that most (68% combined, 39% uniquely) of the total explained compositional variation (29%) was correlated with environmental variables insensitive to human activities, especially lake morphometry. In contrast, the unique contributions of geographical location and variables influenced by human activities (dissolved oxygen and total phosphorus) were substantially smaller (5.5% and 22%, respectively). All of the explained variation (38%–64%) of three widely used community metrics was also correlated with human-insensitive environmental factors. The results suggest that variation in undisturbed profundal invertebrate communities of reference sites is strongly dependent on variables insensitive to human activities and especially on those related to lake morphometry, suggesting that reference communities for bioassessment of impacted lakes should be rather predictable from these variables.

scholarly journals Zooplankton biodiversity in tropical karst lakes of southeast Mexico, Chiapas

2020 ◽  
Vol 91 (0) ◽  
pp. 913184 ◽  
Author(s):  
Rocío Fernández ◽  
Luis A. Oseguera ◽  
Javier Alcocer
Keyword(s):  
Karst Lakes ◽  
Southeast Mexico ◽  
Tropical Karst

Optimal allocation of sampling effort in lake sediment studies

1995 ◽  
Vol 52 (10) ◽  
pp. 2146-2158 ◽  
Author(s):  
David J. Rowan ◽  
Joseph B. Rasmussen ◽  
Jacob Kalff
Keyword(s):  
Optimal Allocation ◽  
A Priori ◽  
Sediment Accumulation ◽  
Point Sources ◽  
Sampling Effort ◽  
Sediment Texture ◽  
Lake Morphometry ◽  
Accumulation Rates ◽  
Sediment Characteristics ◽  
Sediment Distribution

A sampling algorithm requiring only bathymetric and catchment parameters has been derived from several recent empirical developments and should drastically reduce the number of sites and replicates necessary to characterize the distribution, trace element concentrations, and sediment accumulation rates of lake sediments. A test of this algorithm with sediments from 96 sites in three basins of morphometrically complex Jack Lake, Ontario, demonstrates the utility of this approach. A priori application of the algorithm would have reduced the number of sample sites on our sampling grid from 96 to 22 (a reduction of 77%), without losing precision. This reduction in sample sites (and in time and money expended) would allow for sampling additional lakes or sites of local significance (e.g., river or creek mouths, pollution point sources), or measuring additional parameters. The relationships between lake morphometry, sediment distribution, and sediment texture, along with the relationships between sediment texture and inter- and intra-site variability, can also be used to extrapolate sediment characteristics from a few samples to the whole lake or to predict the zone to which sediment is focused.

Anthropogenic impacts on tropical karst lakes: “Lagunas de Montebello,” Chiapas

Ecohydrology ◽  
2018 ◽  
Vol 11 (8) ◽  
pp. e2029 ◽  
Author(s):  
Javier Alcocer ◽  
Martín Merino-Ibarra ◽  
Luis A. Oseguera ◽  
Oscar Escolero
Keyword(s):  
Anthropogenic Impacts ◽  
Karst Lakes ◽  
Tropical Karst

scholarly journals Regional Pelagic Rotifer Biodiversity in a Tropical Karst Lake District

Diversity ◽  
2020 ◽  
Vol 12 (12) ◽  
pp. 454
Author(s):  
Rocío Fernández ◽  
Javier Alcocer ◽  
Luis A. Oseguera
Keyword(s):  
Species Richness ◽  
National Park ◽  
Calanoid Copepods ◽  
Lake District ◽  
Eutrophic Lakes ◽  
Oligotrophic Lakes ◽  
Karst Lakes ◽  
Competitive Interference ◽  
Karst Lake ◽  
Tropical Karst

The species richness, composition, abundance, and biomass of pelagic rotifers were determined in 17 karst lakes of the “Lagunas de Montebello” National Park, Chiapas, Mexico. The species richness of the region (21 species) and single lakes (1–12 species) was smaller than that of other Mexican, tropical, and temperate lakes. It is worth noting the high dissimilarity in species composition—about half (52%) of the species were observed in only 1–3 lakes. A total of eight rotifer families, all from the Monogononta subclass, were recorded. Keratella americana was the species with the highest occurrence (13 lakes), followed by Ptygura sp. (8 lakes). The abundance (0 to 536 ind L−1) and biomass (0 to 21 µg L−1) of rotifers were low. The highest values of species richness, abundance, and biomass were found in eutrophic lakes, and the lowest in oligotrophic lakes. The low values of rotifer biodiversity, abundance, and biomass in the Montebello lakes are probably the product of the interaction of different factors—such as environmental homogeneity (all water bodies are karst lakes), the low availability of “good-quality” food, and predation by cyclopoid copepods in the eutrophic lakes, and the low availability of food, and competitive interference by calanoid copepods and cladocerans in the oligotrophic lakes.

Local Policy for a Protected Environmental Area Management: The Case of Limiting Motorized Vehicles in Park of Canigou in Pyrenées Orientales

2018 ◽  
Vol 1 (1) ◽  
Keyword(s):  
Climate Change ◽  
Human Activities ◽  
Energy Use ◽  
Local Level ◽  
Air Traffic ◽  
Small Scale ◽  
Individual Action ◽  
Local Policy ◽  
Motorized Vehicles ◽  
Local Levels

“We regard the recent science –based consensual reports that climate change is, to a large extend, caused by human activities that emit green houses as tenable, Such activities range from air traffic, with a global reach over industrial belts and urban conglomerations to local small, scale energy use for heating homes and mowing lawns. This means that effective climate strategies inevitably also require action all the way from global to local levels. Since the majority of those activities originate at the local level and involve individual action, however, climate strategies must literally begin at home to hit home.”

Spatiotemporal Changes of Riverbed and Surrounding Environment in Yongding River (Beijing section) in the Past 40 Years

2020 ◽  
Vol 64 (4) ◽  
pp. 40407-1-40407-13 ◽  
Author(s):  
Ran Pang ◽  
He Huang ◽  
Tri Dev Acharya
Keyword(s):  
Economic Development ◽  
Water Conservation ◽  
Human Activities ◽  
Urban Areas ◽  
Water Volume ◽  
Cropland Area ◽  
The Past ◽  
Surrounding Environment ◽  
Spatiotemporal Changes ◽  
Yongding River

Abstract Yongding River is one of the five major river systems in Beijing. It is located to the west of Beijing. It has influenced culture along its basin. The river supports both rural and urban areas. Furthermore, it influences economic development, water conservation, and the natural environment. However, during the past few decades, due to the combined effect of increasing population and economic activities, a series of changes have led to problems such as the reduction in water volume and the exposure of the riverbed. In this study, remote sensing images were used to derive land cover maps and compare spatiotemporal changes during the past 40 years. As a result, the following data were found: forest changed least; cropland area increased to a large extent; bareland area was reduced by a maximum of 63%; surface water area in the study area was lower from 1989 to 1999 because of the excessive use of water in human activities, but it increased by 92% from 2010 to 2018 as awareness about protecting the environment arose; there was a small increase in the built-up area, but this was more planned. These results reveal that water conservancy construction, agroforestry activities, and increasing urbanization have a great impact on the surrounding environment of the Yongding River (Beijing section). This study discusses in detail how the current situation can be attributed to of human activities, policies, economic development, and ecological conservation Furthermore, it suggests improvement by strengthening the governance of the riverbed and the riverside. These results and discussion can be a reference and provide decision support for the management of southwest Beijing or similar river basins in peri-urban areas.

An Exploration of Elements of Folklore in Ntuli’s Translation of Mandela’s Long Walk to Freedom

2018 ◽  
Vol 28 (2) ◽  
Author(s):  
Rose Masubelele
Keyword(s):  
Human Activities ◽  
Human Life ◽  
Language And Culture ◽  
The People ◽  
Story Pattern

 The telling of stories forms an integral part of human activities. It dominated pre-modern cultures and is still a human preoccupation today. All aspects of human life may be turned into a story, which may take one of many forms. Stories may be original creations in the language and culture in which they are told, or they may be derived—that is, they may be taken from another language and culture. Whatever the case, the people who are telling or retelling the story pattern the language they use in a manner that will arouse interest in their audience. It is against the backdrop of retelling stories that this article examines Ntuli’s use of elements of folklore in his translation of Mandela’s Long Walk to Freedom. The elements to be explored in Ntuli’s translation include proverbs and idioms. Gottschall’s notion of The storytelling animal underpins the discussions in this article. Accordingly, the article demonstrates how the use of the elements of folklore helped the translator to adorn his work in order to assert his presence in the text and to relate the receptor to modes of behaviour relevant to their culture. 

THE COMPOSITION AND DISTRIBUTION OF BENTHIC FORAMINIFERA AT CORAL REEF ECOSYSTEM IN THOUSANDS ISLAND

2013 ◽  
Vol 5 (1) ◽  
Author(s):  
Lumban Nauli Lumban Toruan ◽  
Dedi Soedharma ◽  
Kresna Tri Dewi
Keyword(s):  
Coral Reef ◽  
Human Activities ◽  
Close Association ◽  
Mesh Size ◽  
Coral Reef Ecosystem ◽  
Composition Distribution ◽  
Benthic Foraminifers ◽  
High Nutrient ◽  
Binocular Microscope ◽  
Reef Ecosystem

Composition and distribution of foraminifers are affected by human activities and have close association with coral reef ecosystem. The aims of this research were to investigate the benthic foraminifers’ composition and distribution in sediment of coral reef ecosystem. Eleven stations of Karang Bongkok, Pramuka, and Onrust Island were observed in this study. The sediments were taken from surface substrate up to 2 cm under the substrate. Samples were washed on sieve with mesh size 0,063 mm, and then dried in oven with 50°C of temperature  for two hours. After separating from the sediment, the foraminifers were laid on foraminiferal slide and indentified using binocular microscope. The highest composition of symbiont-bearing foraminiferal assemblages which associated with reef ecosystem was in East Pramuka (78.17%) and the lowest was in South Onrust (21,83%). The opportunistic type had the highest composition in South Onrust (38.67%) and the lowest was in South Karang Bongkok. In west Pramuka had the highest composition of heterotrophic type (57.17%) and the lowest was in North Onrust (11.33%). Onrust Island was dominated by opportunistic type, indicating high nutrient. The highest amount of foraminifers’ taxa was found in Karang Bongkok with good coral reef coverage, while the lowest in Onrust facing with Jakarta Bay. Keywords: composition, distribution, benthic foraminifers, coral reef.

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