Proximity to urban fringe recreational facilities increases native biodiversity in an arid rangeland

2018 ◽  
Vol 40 (6) ◽  
pp. 555 ◽  
Author(s):  
Tamer Khafaga ◽  
Greg Simkins ◽  
David Gallacher

Urban developments affect neighbouring ecosystems in multiple ways, usually decreasing native biodiversity. Arabian arid rangeland was studied to identify the primary causes of biodiversity variation. Al Marmoum is a 990km2 area on the urban edge of Dubai, designated for ecological ‘enhancement’ and outdoor recreational use. The area lacks historical biodiversity data, but is thought to be primarily influenced by Arabian camel (Camelus dromedarius Linnaeus, 1758) herbivory. Perennial floral and faunal diversity was assessed at 54 sites. Counts of reintroduced ungulates (Arabian oryx Oryx leucoryx (Pallas, 1777), Arabian gazelle Gazella gazella cora (C.H. Smith, 1827) and sand gazelle G.subgutturosa marica (Thomas, 1897)) were made at 79 separate sites. Correlations of observed biodiversity with substrate type, anthropogenic structures, and ungulate distribution were assessed. Native biodiversity was substantially higher in north-north-west locations near recreational facilities, with the most likely cause being differential browsing pressure. Camel browsing faced greater communal regulation in the north-north-west, whereas oryx and gazelles congregated at feed points in the south-south-east that were farther from human activity. Arid rangeland in this socioecological landscape exhibits greater natural biodiversity at the urban fringe. Human activity reduces ungulate density, enabling a greater diversity of perennial flora, which then attracts non-ungulate fauna. Anthropogenic features can therefore offer conservation value in landscapes where ungulate populations are artificially elevated.

Author(s):  
Manuela Costa-Casais ◽  
Joeri Kaal

Este trabajo tiene por objetivo aportar algunos elementos para el debate sobre la reconstrucción paleoambien-tal, desde las disciplinas de las Ciencias de la Tierra, centrándose en el período cultural de la Alta Edad Media (siglos V-XI). El artículo se divide en tres apartados. El primero, introduce conceptos básicos sobre la evolu-ción ambiental: ideas generales sobre la reconstrucción paleoambiental y un breve comentario sobre la activi-dad humana en el contexto de los paleoambientes. El segundo, muestra una aproximación metodológica a la reconstrucción desde diferentes disciplinas de las Ciencias de la Tierra. En el tercero, se comentan algunos resultados recientes obtenidos en el noroeste peninsular utilizando ejemplos de archivos que, en este caso, están representados por suelos coluviales y sus señales geoquímicas, analizando los procesos naturales y otros inducidos por la actividad antrópica, con la finalidad de ilustrar los conceptos discutidos en la primera parte. A modo de conclusión, el artículo se cierra con unas pinceladas sobre el paisaje de la Alta Edad Media en el Noroeste Peninsular, a partir de la interpretación y reconstrucción de los datos obtenidos. The configuration of the cultural landscape during the early Middle Ages (5th-11th centuries): Environ-mental changes and human activity in the northwest of the Iberian Peninsula - This paper aims to promote the discussion of some elements relating to paleoenvironmental reconstruction, from the point of view of the Earth Sciences, focusing on the cultural period of the early Middle Ages (5th-11th centuries). The article is divided into three sections. In the first, the basic concepts of environmental evolution are introduced, such as the general ideas of paleoenvironmental reconstruction and a brief commentary on human activity in the context of paleoenvironments. The second section demonstrates a methodological ap-proach to reconstruction from the point of view of different disciplines of Earth Sciences. In the third section, recent results obtained in the northwest of the Iberian Peninsula are commented on, making use of samples of colluvial soils and their geochemical signals obtained from environmental archives. An analysis is made of both natural processes and those caused by human activity, in order to illustrate the concepts discussed in the first part. The article concludes with some comments on the landscape of the early Middle Ages in the north-west of the Peninsula, based on the interpretation and reconstruction of the data obtained.


Author(s):  
Daryl A. Cornish ◽  
George L. Smit

Oreochromis mossambicus is currently receiving much attention as a candidater species for aquaculture programs within Southern Africa. This has stimulated interest in its breeding cycle as well as the morphological characteristics of the gonads. Limited information is available on SEM and TEM observations of the male gonads. It is known that the testis of O. mossambicus is a paired, intra-abdominal structure of the lobular type, although further details of its characteristics are not known. Current investigations have shown that spermatids reach full maturity some two months after the female becomes gravid. Throughout the year, the testes contain spermatids at various stages of development although spermiogenesis appears to be maximal during November when spawning occurs. This paper describes the morphological and ultrastructural characteristics of the testes and spermatids.Specimens of this fish were collected at Syferkuil Dam, 8 km north- west of the University of the North over a twelve month period, sacrificed and the testes excised.


2014 ◽  
Author(s):  
Roald Amundsen ◽  
Godfred Hansen
Keyword(s):  

2003 ◽  
pp. 136-146
Author(s):  
K. Liuhto

Statistical data on reserves, production and exports of Russian oil are provided in the article. The author pays special attention to the expansion of opportunities of sea oil transportation by construction of new oil terminals in the North-West of the country and first of all the largest terminal in Murmansk. In his opinion, one of the main problems in this sphere is prevention of ecological accidents in the process of oil transportation through the Baltic sea ports.


Author(s):  
Angelina E. Shatalova ◽  
Uriy A. Kublitsky ◽  
Dmitry A. Subetto ◽  
Anna V. Ludikova ◽  
Alar Rosentau ◽  
...  

The study of paleogeography of lakes is an actual and important direction in modern science. As part of the study of lakes in the North-West of the Karelian Isthmus, this analysis will establish the dynamics of salinity of objects, which will allow to reconstruct changes in the level of the Baltic Sea in the Holocene.


Author(s):  
Eleonora P. Radionova

The associations and ecological conditions of the existence of modern diatoms of the North-West (Pridneprovsky), Prikerchensky and Eastern regions of the subtidal zone of the Black Sea are considered. Based on the unity of the composition of the Present and Sarmatian-Meotian diatom flora, an attempt has been made to model some of the ecological c situation of the Late Miocene Euxinian basin.


Sign in / Sign up

Export Citation Format

Share Document