scholarly journals Preface

1965 ◽  
Vol 249 (759) ◽  
pp. 258-258
Keyword(s):  
Geographical Distribution ◽  
Endemic Species ◽  
Scientific Interest ◽  
Ecological Stability ◽  
Ecological Balance ◽  
Tristan Da Cunha ◽  
Ecological Evolution ◽  
Gough Island ◽  
Island Group

The four islands of the Tristan da Cunha-Gough Island group are very isolated. They contain a unique fauna and flora. Knowledge of these is very incomplete in important respects. Such knowledge could not only help towards understanding the origins of the geographical distribution of plants and animals, it could also throw valuable light on the factors governing colonization of isolated regions. But it is not only the unique biota which is of scientific interest in these islands. We have here a natural ecological balance between the endemic species of an impoverished and therefore simple fauna and flora. Such islands could thus allow us to study with comparative ease the factors which control ecological stability; a study of the great importance to mankind today. Moreover, fortunately there have now been found in these islands evidence of datable remains of the geologically recent biota, so that there is a reasonable chance that we shall one day be able to trace the ecological evolution in time.

scholarly journals Revised population estimate and trends for the Endangered Northern Rockhopper Penguin Eudyptes moseleyi at Tristan da Cunha

2011 ◽  
Vol 21 (4) ◽  
pp. 454-459 ◽  
Author(s):  
BRAD ROBSON ◽  
TREVOR GLASS ◽  
NORMAN GLASS ◽  
JAMES GLASS ◽  
JERRY GREEN ◽  
...  
Keyword(s):  
World Population ◽  
Small Satellite ◽  
Rockhopper Penguin ◽  
Tristan Da Cunha ◽  
The World ◽  
Gough Island ◽  
Island Group ◽  
Population Counts ◽  
Global Population ◽  
Repeat Count

AbstractAround 80% of the world population of Northern Rockhopper Penguin Eudyptes moseleyi is found at Tristan da Cunha and Gough Island in the South Atlantic Ocean, where populations appear to be declining. However, numbers of birds at Middle Island, a small satellite island of Nightingale Island at Tristan Cunha, have not been counted since 1973 when an estimated 100,000 pairs were recorded. Updated population counts were obtained for all four islands at Tristan da Cunha (Tristan, Inaccessible, Nightingale and Middle islands) in 2009 providing a census of the whole island group and the first repeat count of Middle Island. Estimated breeding numbers at these four islands were Tristan 6,700 pairs, Inaccessible 54,000 pairs, Nightingale 25,000 pairs and 83,000 pairs at Middle Island. These counts confirm that Tristan da Cunha is a vitally important site for this ?Endangered? species holding over 65% of the global population and that breeding number have been relatively stable over the last 30 years.

scholarly journals Investigating impact of land-use and land cover changes on hydro-ecological balance using GIS: insights from IIT Bombay, India

2021 ◽  
Vol 3 (3) ◽  
Author(s):  
Aman Srivastava ◽  
Pennan Chinnasamy
Keyword(s):  
Land Use ◽  
Land Cover ◽  
Surface Runoff ◽  
Forest Cover ◽  
Google Earth ◽  
Negative Consequences ◽  
Ecological Stability ◽  
Barren Land ◽  
Ecological Balance ◽  
Lulc Changes

AbstractThe present study, for the first time, examined land-use land cover (LULC), changes using GIS, between 2000 and 2018 for the IIT Bombay campus, India. Objective was to evaluate hydro-ecological balance inside campus by determining spatio-temporal disparity between hydrological parameters (rainfall-runoff processes), ecological components (forest, vegetation, lake, barren land), and anthropogenic stressors (urbanization and encroachments). High-resolution satellite imageries were generated for the campus using Google Earth Pro, by manual supervised classification method. Rainfall patterns were studied using secondary data sources, and surface runoff was estimated using SCS-CN method. Additionally, reconnaissance surveys, ground-truthing, and qualitative investigations were conducted to validate LULC changes and hydro-ecological stability. LULC of 2018 showed forest, having an area cover of 52%, as the most dominating land use followed by built-up (43%). Results indicated that the area under built-up increased by 40% and playground by 7%. Despite rapid construction activities, forest cover and Powai lake remained unaffected. This anomaly was attributed to the drastically declining barren land area (up to ~ 98%) encompassing additional construction activities. Sustainability of the campus was demonstrated with appropriate measures undertaken to mitigate negative consequences of unwarranted floods owing to the rise of 6% in the forest cover and a decline of 21% in water hyacinth cover over Powai lake. Due to this, surface runoff (~ 61% of the rainfall) was observed approximately consistent and being managed appropriately despite major alterations in the LULC. Study concluded that systematic campus design with effective implementation of green initiatives can maintain a hydro-ecological balance without distressing the environmental services.

scholarly journals A juvenile Tristan albatross (Diomedea dabbenena) on land at the Crozet Islands

Polar Biology ◽  
2020 ◽  
Author(s):  
Alexander L. Bond ◽  
Christopher Taylor ◽  
David Kinchin-Smith ◽  
Derren Fox ◽  
Emma Witcutt ◽  
...  
Keyword(s):  
Atlantic Ocean ◽  
Cytochrome B ◽  
Adult Male ◽  
Mitochondrial Gene ◽  
Small Population ◽  
South Atlantic ◽  
South Atlantic Ocean ◽  
Tristan Da Cunha ◽  
Gough Island ◽  
Dispersal Events

AbstractAlbatrosses and other seabirds are generally highly philopatric, returning to natal colonies when they achieve breeding age. This is not universal, however, and cases of extraordinary vagrancy are rare. The Tristan Albatross (Diomedea dabbenena) breeds on Gough Island in the South Atlantic Ocean, with a small population on Inaccessible Island, Tristan da Cunha, ca 380 km away. In 2015, we observed an adult male albatross in Gonydale, Gough Island, which had been ringed on Ile de la Possession, Crozet Islands in 2009 when it was assumed to be an immature Wandering Albatross (D. exulans). We sequenced 1109 bp of the cytochrome b mitochondrial gene from this bird, and confirmed it to be a Tristan Albatross, meaning its presence on Crozet 6 years previous, and nearly 5000 km away, was a case of prospecting behaviour in a heterospecific colony. Given the challenges in identifying immature Diomedea albatrosses, such dispersal events may be more common than thought previously.

Reassessment of Tristan da Cunha Gelidium (Gelidiales, Rhodophyta) species

2020 ◽  
Vol 63 (5) ◽  
pp. 455-462
Author(s):  
D. Wilson Freshwater ◽  
Sue Scott ◽  
Enrico M. Tronchin ◽  
Gary W. Saunders
Keyword(s):  
Southern Africa ◽  
Endemic Species ◽  
Red Algae ◽  
Genetic Group ◽  
The Third ◽  
Tristan Da Cunha

AbstractThree endemic species of Gelidium have been described from the remote Tristan da Cunha archipelago. A recent barcode survey of Tristan da Cunha red algae in combination with the clarification of vouchers for previously sequenced specimens has prompted a molecular and morphological reassessment of these species. Analyses of rbcL and COI-5P data indicated that all sequenced Tristan da Cunha specimens represented a single taxon, and furthermore that this genetic group was conspecific with Gelidium micropterum from southern Africa. Morphologically the Tristan da Cunha specimens represented either Gelidium concinnum or Gelidium regulare, and there was a grade of character states between both of these species, as well as G. micropterum. Based on these results the synonymy of G. concinnum and G. regulare under G. micropterum is proposed and an expanded description of G. micropterum provided. None of the studied Tristan da Cunha specimens clearly fit the description of the third endemic species, Gelidium inflexum, and its status could not be determined.

An inventory of vascular plants endemic to Italy

Phytotaxa ◽  
2014 ◽  
Vol 168 (1) ◽  
pp. 1 ◽  
Author(s):  
LORENZO PERUZZI ◽  
FABIO CONTI ◽  
FABRIZIO BARTOLUCCI
Keyword(s):  
Geographical Distribution ◽  
Endemic Species ◽  
Vascular Plants ◽  
Northern Italy ◽  
Alpine Region ◽  
Regional Level ◽  
Vascular Flora ◽  
Administrative Region ◽  
Italian Flora ◽  
Endemic Flora

For the purpose of the present study we considered as Italian endemics those specific and subspecific taxa occurring in Italy that are not found elsewhere with the exception of Corsica (France) and Malta. This study presents an updated list of the endemic taxa in the Italian flora, including their geographical distribution at regional level. Italy is characterized by 1371 endemic species and subspecies (18.9% of the total vascular flora): three taxa belong to Lycopodiidae, one to Polypodiidae, two to Pinidae and 1365 to Magnoliidae (three paleoherbs, 221 monocots and 1144 eudicots). The endemic flora belongs to 29 orders, 67 families and 304 genera. Sicily, Sardinia, Calabria and Abruzzo are the four regions richest in endemics. About 58% of endemics are confined to a single administrative region. The most represented orders, families and genera are: Asterales, Caryophyllales and Asparagales, Asteraceae, Plumbaginaceae and Caryophyllaceae, Limonium, Centaurea and Hieracium, respectively. The phytogeographic isolation of Sardinia and Sicily and the separation of peninsular Italy from Northern Italy is confirmed. The relative isolation of Puglia with respect the remaining southern Italian pensinsular regions is also confirmed. Alpine region endemics (from northern Italy) are underrepresented.

scholarly journals The Sinking of Another Tristan da Cunha Moss Endemic and Its Phytogeographical Consequences

2020 ◽  
Vol 89 (3) ◽  
Author(s):  
Ryszard Ochyra ◽  
Vítězslav Plášek
Keyword(s):  
Atlantic Ocean ◽  
Southern Hemisphere ◽  
Endemic Species ◽  
Distribution Patterns ◽  
South Atlantic ◽  
South Atlantic Ocean ◽  
Original Material ◽  
The Third ◽  
Tristan Da Cunha ◽  
Central South

<p>The original material of <em>Isopterygium tristaniense </em>Dixon, an endemic species of the Tristan da Cunha archipelago in the central South Atlantic Ocean, is taxonomically evaluated and some details of its morphology are illustrated. The species is found to be conspecific with the Holarctic <em>Pseudotaxiphyllum elegans </em>(Brid.) Z.Iwats. and it is the third record of the species in the Southern Hemisphere. The global distribution of this species is reviewed and the distribution patterns of the South Atlantic mosses are briefly discussed.</p>

Hydroids (Cnidaria: Hydrozoa) from Tristan da Cunha and St. Helena

2015 ◽  
Vol 8 ◽  
Author(s):  
Horia R. Galea
Keyword(s):  
Shallow Water ◽  
New Records ◽  
Present Report ◽  
Tristan Da Cunha ◽  
Gough Island ◽  
The Common ◽  
St Helena ◽  
World Records ◽  
Second World

The present report provides the first account of the shallow water hydroids of St. Helena, which comprises 17 species, and adds nine new records to the hydrozoan fauna of the Tristan da Cunha group of islands, raising their number to 34. A total of 34 species, belonging to five families of Anthoathecata and eight families of Thecata, are discussed herein. Although distributional data are given for each species, brief diagnoses are provided for the lesser known or unidentifiable species, and the common taxa are occasionally accompanied by succinct remarks. Illustrations are provided for nearly all species in order to justify their identification and to facilitate identification by others.Fiordlandia protectaandFilellum bouvetensis,both from Gough Island, represent the second world records and extend their known area of distribution.

scholarly journals El conocimiento florístico actual del Noroeste de México: desarrollo, recuento y análisis del endemismo

2018 ◽  
Vol 96 (3) ◽  
pp. 555
Author(s):  
José Luis León de la Luz ◽  
Jon Paul Rebman ◽  
Thomas R. Van Devender ◽  
José Jesús Sánchez-Escalante ◽  
José Delgadillo-Rodríguez ◽  
...  
Keyword(s):  
Climate Change ◽  
Geographical Distribution ◽  
Endemic Species ◽  
Baja California ◽  
Species Level ◽  
Baja California Sur ◽  
Structural Composition ◽  
Nw Mexico ◽  
Species Survival ◽  
Endemic Genera

<p class="Pa1"><strong>Background</strong>: Floristic knowledge of Northwestern (NW) Mexico was mainly carried out by American botanists until the first half of XX century.</p><p class="Pa1"><strong>Question</strong>: Do the ancient and recent botanical explorations carried out in the study area, are already enough to document in a conclusive way both the floristic and structural composition?</p><p class="Pa1"><strong>Methods</strong>: The authors are botanists and managers of the herbaria included in the floristic compilation (BCMEX, HCIB, SD, and USON), each herbarium has been devoted to document the flora of the states of NW Mexico in the last three decades. The floristic information was obtained mainly of the herbaria databases (around 110,000 entries), historic bibliographic information and recent collects from the same authors. The databases consulted are composed by 27,117 collect sites.</p><p class="Pa1"><strong>Results</strong>: The final database obtained consists of 5,865 taxa at the species level and intraspecific categories. By state, Sonora is the most biodiverse with 3,762 taxa, Baja California has 2,583 and Baja California Sur has 2,070. The Mexican NW is relatively poor in total number of species, but the number of endemic taxa is high. Within this region there are 941 endemic species, where 294, 391, and 79 correspond to the states of Baja California, Baja California Sur, and Sonora, respectively; in addition, there are 177 endemic species shared among these three states. The NW region also has 18 endemic genera, included in 10 families.</p><strong>Conclusions</strong>: As result of this review, there is excellent floristic knowledge background for NW Mexico, but there are still geographic areas still inaccessible, which includes all kind of topography, that explored could increase the total flora and endemism rate. Presently, the climate change put into risk the species survival, and hence it is a priority that conservation programs be established especially in terms of endemic species, since many of them have a restricted geographical distribution.

Rediscovery and new data on distribution of the imperfectly known Philippine endemic Etlingera pubimarginata (Zingiberaceae; Alpinieae)

Phytotaxa ◽  
2019 ◽  
Vol 394 (1) ◽  
pp. 105
Author(s):  
MARK ARCEBAL K. NAIVE ◽  
CESAR G. DEMAYO ◽  
GRECEBIO JONATHAN D. ALEJANDRO
Keyword(s):  
Geographical Distribution ◽  
Endemic Species ◽  
Conservation Status ◽  
Comparative Morphology ◽  
Taxonomic Description

Recent exploration on the mountains of Northern Mindanao, Philippines resulted in the recollection of Etlingera pubimarginata, an enigmatic endemic species recollected after a lapse of over a century. An amended taxonomic description with colour photographs as well as comparative morphology to its allied species, geographical distribution, and conservation status are provided.

Synthesis of Mexican Symphypleona (Hexapoda: Collembola): updated checklist with ecological and geographical distribution

Zootaxa ◽  
2019 ◽  
Vol 4671 (1) ◽  
pp. 55-66
Author(s):  
CÉSAR S. MAGAÑA-MARTÍNEZ ◽  
JOSÉ G. PALACIOS-VARGAS ◽  
JOSÉ L. NAVARRETE-HEREDIA
Keyword(s):  
Leaf Litter ◽  
Geographical Distribution ◽  
Endemic Species ◽  
Habitat Preferences ◽  
Quintana Roo

A taxonomic list of recorded Symphypleona from Mexico is presented. Data also includes a nomenclatorial update, distribution per political entity and habitat preferences. It is indicated that 28 genera and 73 species are currently distributed in 23 of the 32 states of Mexico. Quintana Roo represents the most diverse state (27 species) followed by Jalisco and Hidalgo (20 spp.). Reviews consulted indicate that eleven endemic species have been recorded so far from Mexico. According to the literature, one-third of the collected specimens across Mexico from leaf litter have yielded Symphypleona. The three most diverse genera recorded are, Sminthurides with 9 species, Sminthurinus and Sminthurus with 7 species each. 

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