A preliminary overview of the effects of seasonal drought and animal pressure around watering points on plant species using adaptative strategy analyses in the Tunisian arid zone

2006 ◽  
Vol 32 (1) ◽  
pp. 39-48
Author(s):  
Mohamed Tarhouni ◽  
Azaiez Ouled Belgacem ◽  
Belgacem Henchi ◽  
Mohamed Neffati
Plant Ecology ◽  
2017 ◽  
Vol 219 (1) ◽  
pp. 57-67 ◽  
Author(s):  
Jason M. Nicol ◽  
George G. Ganf ◽  
Keith F. Walker ◽  
Ben Gawne
Keyword(s):  

2014 ◽  
Vol 62 (8) ◽  
pp. 674 ◽  
Author(s):  
J. L. Silcock ◽  
A. J. Healy ◽  
R. J. Fensham

Lack of basic data to assess plant species against IUCN Red List criteria is a major impediment to assigning accurate conservation status throughout large areas of the world. Erroneous assessments will be most prevalent in vast poorly surveyed areas where herbarium collections are sparse. In arid environments, assessments are further confounded by extreme temporal variability and poor understanding of the nature and magnitude of threats. We systematically re-assess the conservation status of an arid-zone flora. The status of all 1781 vascular plant species occurring across 635 300 km2 of inland eastern Australia was initially assessed through herbarium records and expert interviews. This process generated a list of apparently rare and potentially threatened species, which guided a targeted survey program over 4 years. Search effort and key data on populations of candidate species found were recorded and used to assess 91 species against IUCN criteria. One-third of species were widespread and abundant at least in certain seasons, but had been deemed rare due to sparse collections. The conservation status of 20, mostly newly recognised species from restricted habitats, was upgraded and 14 remained listed because of having restricted areas of occupancy. With the exception of 12 artesian spring species, continuing declines were documented for just six species. The criterion that allows for listing of species because of extreme fluctuations (in combination with restricted and fragmented populations) needs to be carefully interpreted in arid zones, where these fluctuations may be apparent rather than real, and may actually confer resilience to grazing for some species. Our approach facilitates robust conservation assessments across vast and poorly known arid regions, distinguishing species that have merely been lost in space and time from those that are at risk of extinction.


Author(s):  
A.S. Baimukhambetova ◽  
◽  
M.A. Egorov ◽  
A.K. Azhikova ◽  
D.K. Magzanova ◽  
...  

In an experiment on white rats, the regenerating effect of biologically active substances of plant species growing in the Astrakhan region was shown: Achillea micrantha Willd., Helichrysum arenarium, Glycyrrhiza glabra L., Helichrysum nogaicum Tzvel. The article presents data from planimetric studies of damaged skin. The results obtained make it possible to consider extracts as the basis of tissue repair stimulants, as well as to recommend them as anti-inflammatory and wound healing agents.


Mammalia ◽  
2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Fatine Lasgaa ◽  
Farid Bounaceur ◽  
Mounia Baha ◽  
Stéphane Aulagnier

Abstract One species of the family Ctenodactylidae, the Common gundi, Ctenodactylus gundi, occupies a restricted area between the Saharan and Mediterranean domains where annual rainfall is between 50 and 400 mm. Its presence seems also conditioned by the vegetation, so its feeding ecology was investigated by the microhistological analysis of faeces collected in two stations (Baniane and Bazem) of the Aurès massif (Eastern Algeria) during two years from June 2015 to May 2017, and by the evaluation of the available food. The diet included a total of 34 plant species, 16 in Baniane and 20 in Bazem. Results show that in Baniane, Asteraceae were predominant with Artemisia herba-alba (relative abundance, A% = 33.13%), followed by Fabaceae with Argyrolobium uniflorum (A% = 20.32%) and Poaceae with Aristida sp. (A% = 14.95%). In Bazem, the most consumed plant species were Lamiaceae with Thymus ciliatus (A% = 42.77%) and Poaceae with Lolium rigidum (A% = 13.19%). Overall, C. gundi fed on a large number of plant species, and its diet appeared to be influenced more by the diversity than by the availability of vegetation. Seasonal variations in diet indicate that this rodent eats perennial vegetation throughout the year and opportunistically consumes annual plants to a lesser extent in the spring, with a certain time shifting between the two stations probably due to rainfall and temperature differences.


2019 ◽  
Author(s):  
Corrine Duncan ◽  
Nick Schultz ◽  
Wolfgang Lewandrowski ◽  
Megan Good ◽  
Simon Cook

AbstractSeed germination traits are key drivers of population dynamics, yet they are under-represented in community ecology studies, which have predominately focussed on adult plant and seed morphological traits. We studied the seed traits and germination strategy of eight woody plant species to investigate regeneration strategies in the arid zone of eastern Australia. To cope with stochastic and minimal rainfall, we predict that arid seeds will either have rapid germination across a wide range of temperatures, improved germination under cooler temperatures, or dormancy and/or longevity traits to delay or stagger germination across time. To understand how temperature affects germination responses, seeds of eight keystone arid species were germinated under laboratory conditions, and under three diurnal temperatures (30/20°C, 25/15°C and 17/7°C) for 30 days. Seeds of species in this study are currently stored for minesite restoration projects, hence we tested for decline in seed viability across 24 months in dry storage at similar storage conditions (≈20°C). Six of the eight arid species studied had non-dormant, rapidly germinating seeds, and only two species had physiological dormancy traits. Seed longevity differed widely between species, from one recalcitrant species surviving only months in storage (P50 = <3 months) and one serotinous species surviving for many years (P50 = 84 months). Our results highlight the importance of understanding the reproductive strategies of plant species in arid environments. Rapid germination, the dominant seed trait of species included in this study, allows arid species to capitalise on sporadic rainfall. However, some species also exhibit dormancy and delayed germination; this an alternative strategy which spreads the risk of germination failure over time. We highlight important seed traits and germination strategies of plants from an arid zone with stochastic rainfall and discuss the implications for their restoration.


2019 ◽  
Vol 67 (3) ◽  
pp. 268 ◽  
Author(s):  
Ben P. Miller ◽  
David R. Symons ◽  
Matthew D. Barrett

The association of rare plant species and Banded Iron Formation (BIF) ranges in semiarid Western Australia is a noted phenomenon. These ranges are also a focus of iron ore exploration and mining. Decisions and planning required for development, conservation and management resulting from this interest, often consider translocation of these threatened species. Nonetheless, little is known about the ecology of BIF-endemic species to support any such decisions. We assessed population structure, patterns of growth, mortality, recruitment, reproduction and in situ seedbank persistence for two declared rare flora species. The shrub Darwinia masonii, and sedge Lepidosperma gibsonii are endemic to an area &lt;40 km2 on the south-western boundary of the Australian arid zone. Both species were found to be long lived and slow growing, with evidence for reliance on rare events such as fire, and high rainfall years, including, for some processes, consecutive high rainfall years for growth, reproduction and recruitment. Retrieval and germination of seed batches shows that both species’ seedbanks are long-lived, with seasonal dormancy cycling. This, together with the ability of mature plants to survive through years not supporting growth, and, for L. gibsonii, to resprout after fire, are key mechanism for persistence in this unpredictable and low rainfall environment.


Sign in / Sign up

Export Citation Format

Share Document