Seston and eutrophication on a tropical karst lake district: Lagunas de Montebello, Chiapas, Mexico

Mariana Vargas-Sánchez; Javier Alcocer; Luis A. Oseguera

doi:10.23818/limn.41.16

Regional Pelagic Rotifer Biodiversity in a Tropical Karst Lake District

Diversity ◽

10.3390/d12120454 ◽

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.

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Drawing as a Creative Approach to Researching Extant Garments: A Case Study Involving John Ruskin's Clothing

Costume ◽

10.3366/cost.2020.0164 ◽

2020 ◽

Vol 54 (2) ◽

pp. 202-221

Author(s):

Ingrid Mida ◽

Sarah Casey

Keyword(s):

Research Tool ◽

John Ruskin ◽

Lake District ◽

Curatorial Practice ◽

Dress History ◽

Absent Presence

Reading the clues embedded in extant clothing demands both imagination and patience since the subtle marks of wear, use and alteration may only become evident with extended observation and reflection. During the course of a project undertaken in conjunction with the bicentenary celebrations of John Ruskin's birth culminating in the exhibition of Sarah Casey's drawings in Ruskin's Good Looking! (8 February–7 April 2019), the authors studied the garments of John Ruskin at Brantwood, his former home in the Lake District. The life-sized drawings of these garments produced by Casey mapped the absent presence of the former wearer, allowed visitors the opportunity to better see and reflect on Ruskin's clothing, and also revealed the hidden histories of Ruskin's garments. Drawing, the making of marks with meaning, is not an obvious research tool in dress history and curatorial practice but, as this case study shows, can expose subtle details and reveal new insights.

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Use of Ornamental Trees in Dating of Abandoned Cemeteries on the Example of Thuja Occidentalis and Thuja Orientalis

Contemporary Trends in Geoscience ◽

10.2478/ctg-2012-0006 ◽

2012 ◽

Vol 1 (1) ◽

pp. 45-50

Author(s):

Magdalena Opała ◽

Leszek Majgier

Keyword(s):

Climatic Conditions ◽

The Other ◽

Lake District ◽

Thuja Occidentalis ◽

North Eastern ◽

The 1960S ◽

Thuja Orientalis ◽

Ornamental Trees ◽

Common Tree ◽

Local Habitat

Abstract Due to the lack of maintenance, abandoned cemeteries are often incorporated into the landscape. In many cases the information about the age of the cemetery is unavailable. To find out the approximate time of the formation of the cemetery the information recorded in the annual tree and shrub rings can be used. One of the most common tree species, planted for ornamental and symbolic purposes on the cemeteries, are Thuja orientalis and Thuja occidentalis. Alien to the Polish flora, these species adapted well to the local habitat and climatic conditions. The paper presents an attempt to apply dendrochronological dating to determine the age of the abandoned cemeteries in the region of the Great Masurian Lakes, part of the Masurian Lake District (north-eastern Poland). The study included five abandoned cemeteries. In total, 15 cores were taken from the trees. After applying the standard dendrochronological method, local chronologies for the studied species were established. The research indicated that the oldest found specimens - over 70 yrs old - are Thuja occidentalis individuals growing at the Słabowo cemetery. At the other sites the specimens of both Thuja species date back to the 1960s and early 1970s. Compared to the historical information regarding the age and origin of the studied objects, thujas growing there are much younger than the age of the cemeteries foundation. The presented method proved to be very helpful in understanding the time of Thuja occidentalis and Thuja orientalis introduction at the investigated cemeteries.

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