scholarly journals EFFECTS OF PRE-GERMINATION TREATMENTS, SALT AND WATER STRESSES ON GERMINATION OF ACACIA EHRENBERGIANA HAYNE AND ACACIA SEYAL DEL. (MIMOSOIDEAE): TWO ALGERIAN NATIVE SPECIES

2017 ◽  
Vol 15 (4) ◽  
pp. 355-368 ◽  
Author(s):  
H BEN ZETTA
Keyword(s):  
Native Species ◽  
Acacia Ehrenbergiana ◽  
Acacia Seyal

Statut symbiotique et souches de rhizobia associées à l’Acacia tortilis subsp. raddiana [Acacia raddiana s. s.], mimosoïdée des régions désertiques de l’Algérie

Botany ◽  
2010 ◽  
Vol 88 (1) ◽  
pp. 39-53 ◽  
Author(s):  
Nazhat-Ezzaman Noureddine ◽  
Saïd Amrani ◽  
Fatiha Aïd
Keyword(s):  
Nous Avons ◽  
Acacia Tortilis ◽  
Ensifer Meliloti ◽  
Acacia Ehrenbergiana ◽  
Acacia Seyal

L’ Acacia tortilis (Forsskal) Hayne subsp. raddiana (Savi) Brenan [ Acacia raddiana Savi s. s.] est la légumineuse ligneuse la plus répandue dans les régions désertiques d’Algérie. En tant qu’espèce bien adaptée, elle offre un potentiel d’intérêt pour le boisement ou le reboisement de ces régions. Sa capacité d’établir une symbiose fixatrice d’azote avec les rhizobia constitue un caractère important pour son développement et son adaptation aux conditions du milieu. Pour ces raisons, nous avons mené une étude portant sur la prévalence de la symbiose chez cette espèce et sur la caractérisation des souches de rhizobia associées. L’étude a porté sur 101 plants provenant de neuf sites naturels et de huit pépinières et nous a permis d’établir que l’A. tortilis subsp. raddiana est généralement nodulé et fixateur d’azote, malgré les conditions édaphiques défavorables qui prévalent en milieu naturel et dans les pépinières du sud du pays. La caractérisation symbiotique de 51 souches de rhizobia associées à l’A. tortilis subsp. raddiana nous a permis de montrer que celles-ci ne sont pas très spécifiques et qu’elles sont capables, pour la plupart, de former des nodules fixateurs d’azote chez les autres espèces d’acacias des régions désertiques de l’Algérie, en particulier l’ Acacia seyal Del. et l’ Acacia ehrenbergiana Hayne. Ces souches représentent donc un potentiel pour la production d’inoculants destinés à la bactérisation de l’A. tortilis subsp. raddiana, mais également des autres espèces d’acacias. L’analyse des profils de restriction du gène de l’ARN 16S des souches de rhizobia associées a permis de mettre en évidence leur grande diversité. Elles étaient représentées essentiellement par les espèces du genre Ensifer avec une prédominance de l’ Ensifer meliloti et, dans une moindre mesure, par des espèces des genres Mesorhizobium et Rhizobium , comme cela a déjà été rapporté par de nombreux auteurs dans d’autres régions d’Afrique. En plus des espèces de rhizobia reconnues comme étant capables de s’associer avec l’A. tortilis raddiana, nous avons isolé cinq souches que nous n’avons pas pu identifier, par réaction en chaîne de la polymérase – polymorphisme de la longueur du fragment de restriction du gène de l’ARN 16S, et qui pourraient constituer une nouvelle espèce génotypique.

Ice-free area expansion compounds the non-native species threat to Antarctic terrestrial biodiversity

2019 ◽  
Author(s):  
Grant Duffy ◽  
Jasmine R Lee
Keyword(s):  
Human Activity ◽  
Native Species ◽  
Climate Scenario ◽  
Climatic Environment ◽  
Species Establishment ◽  
Suitable Habitats ◽  
Terrestrial Biodiversity ◽  
A Site ◽  
Area Expansion ◽  
Free Area

Warming across ice-covered regions will result in changes to both the physical and climatic environment, revealing new ice-free habitat and new climatically suitable habitats for non-native species establishment. Recent studies have independently quantified each of these aspects in Antarctica, where ice-free areas form crucial habitat for the majority of terrestrial biodiversity. Here we synthesise projections of Antarctic ice-free area expansion, recent spatial predictions of non-native species risk, and the frequency of human activities to quantify how these facets of anthropogenic change may interact now and in the future. Under a high-emissions future climate scenario, over a quarter of ice-free area and over 80 % of the ~14 thousand km2 of newly uncovered ice-free area could be vulnerable to invasion by one or more of the modelled non-native species by the end of the century. Ice-free areas identified as vulnerable to non-native species establishment were significantly closer to human activity than unsuitable areas were. Furthermore, almost half of the new vulnerable ice-free area is within 20 km of a site of current human activity. The Antarctic Peninsula, where human activity is heavily concentrated, will be at particular risk. The implications of this for conservation values of Antarctica and the management efforts required to mitigate against it are in need of urgent consideration.

High predatory efficiency and abundance drive expected ecological impacts of a marine invasive fish

2020 ◽  
Vol 637 ◽  
pp. 195-208 ◽  
Author(s):  
EM DeRoy ◽  
R Scott ◽  
NE Hussey ◽  
HJ MacIsaac
Keyword(s):  
Invasive Species ◽  
Native Species ◽  
Ecological Impact ◽  
Marine Species ◽  
Ecological Impacts ◽  
Negative Effects ◽  
Marine Predator ◽  
Eastern Gulf Of Mexico ◽  
Red Grouper ◽  
Per Capita

The ecological impacts of invasive species are highly variable and mediated by many factors, including both habitat and population abundance. Lionfish Pterois volitans are an invasive marine species which have high reported detrimental effects on prey populations, but whose effects relative to native predators are currently unknown for the recently colonized eastern Gulf of Mexico. We used functional response (FR) methodology to assess the ecological impact of lionfish relative to 2 functionally similar native species (red grouper Epinephelus morio and graysby grouper Cephalopholis cruentata) foraging in a heterogeneous environment. We then combined the per capita impact of each species with their field abundance to obtain a Relative Impact Potential (RIP). RIP assesses the broader ecological impact of invasive relative to native predators, the magnitude of which predicts community-level negative effects of invasive species. Lionfish FR and overall consumption rate was intermediate to that of red grouper (higher) and graysby grouper (lower). However, lionfish had the highest capture efficiency of all species, which was invariant of habitat. Much higher field abundance of lionfish resulted in high RIPs relative to both grouper species, demonstrating that the ecological impact of lionfish in this region will be driven mainly by high abundance and high predator efficiency rather than per capita effect. Our comparative study is the first empirical assessment of lionfish per capita impact and RIP in this region and is one of few such studies to quantify the FR of a marine predator.

Endangered Butterflies and their Non-Native Host Plants: Examining Shifting Values of Belonging in Restoration

2019 ◽  
Vol 3 (1) ◽  
pp. 1-9
Author(s):  
Robert M. Anderson ◽  
Amy M. Lambert
Keyword(s):  
Ecological Restoration ◽  
Native Species ◽  
Puget Sound ◽  
A Value ◽  
The Social ◽  
Remote Island ◽  
Scientific Truth ◽  
Native Host

The island marble butterfly (Euchloe ausonides insulanus), thought to be extinct throughout the 20th century until re-discovered on a single remote island in Puget Sound in 1998, has become the focus of a concerted protection effort to prevent its extinction. However, efforts to “restore” island marble habitat conflict with efforts to “restore” the prairie ecosystem where it lives, because of the butterfly’s use of a non-native “weedy” host plant. Through a case study of the island marble project, we examine the practice of ecological restoration as the enactment of particular norms that define which species are understood to belong in the place being restored. We contextualize this case study within ongoing debates over the value of “native” species, indicative of deep-seated uncertainties and anxieties about the role of human intervention to alter or manage landscapes and ecosystems, in the time commonly described as the “Anthropocene.” We interpret the question of “what plants and animals belong in a particular place?” as not a question of scientific truth, but a value-laden construct of environmental management in practice, and we argue for deeper reflexivity on the part of environmental scientists and managers about the social values that inform ecological restoration.

Ex Situ Conservation of Rare Medicinal Plants in the Botanical Garden (Institute) of Academy of Sciences of Moldova

2013 ◽  
Vol 40 (1) ◽  
pp. 43-48
Author(s):  
Nina Ciocârlan
Keyword(s):  
Native Species ◽  
Ex Situ Conservation ◽  
Botanical Garden ◽  
Ex Situ ◽  
Aromatic Plants ◽  
Medicinal And Aromatic Plants ◽  
Field Collection ◽  
Ecological Flexibility ◽  
Cultivation Techniques ◽  
Academy Of Sciences

Abstract This work refers to the native species of genus Astragalus L. (A. dasyanthus, A. ponticus), Adonis L. (A. vernalis, A. wolgensis) and Digitalis L. (D. lanata, D. grandiflora). The plants are cultivated in the Botanical Garden of Moldova in the field collection of the medicinal and aromatic plants. Investigation includes propagation aspects, research into cultivation techniques and conservation measures. The biological particularities and the phenologic rhythm are also registered. The obtained data shows the ecological flexibility of species and the possibility of preserving them in culture.

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