Search

Acacia tortilis is one of the valuable species growing in the southern regions of Iran, which is highly considerable for a variety of reasons such as stabilization of quicksand, medicinal uses and ecological functions. Low germination capacity of seeds, hard rooting of cuttings, the value of aesthetics and multiple medicinal uses highlight the importance of further research to explore methods for easy and efficient propagation of this species in vitro. However, seeds of A. tortilis were obtained from Khazar Center of Forest seeds located in Koloudeh, Mazandaran Province, Iran and a hot water treatment for 15 seconds was used for seed dormancy breakage. Then, seeds were cultured aseptically in MS basal medium without growth regulators. In this work, to investigate the reaction of seeds to different variables in culture medium, various concentrations of macro and micro nutrients (0, 1, 1/2, 1/4) were studied. Briefly, total treatments (T) were 10 and each treatment was replicated 3 times, with 10 members. Finally, ANOVA and Duncan tests were used to analyze data. Results showed that the best method for seed sterilization was obtained though using HgCl2 (0.5%) for 10 minutes and ethanol (70%) for one minute. In addition, results showed that the highest root and stem length, fresh and dry weight of stem and root belonged to T2 (macro elements + 1/4 micro elements), while T4 (macro elements + micro elements) was in the second order and the lowest values of the abovementioned parameters were found in T8.

Copyright of Caspian Journal of Environmental Sciences is the property of University of Guilan & Association of Universities of the Caspian Region States and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Background: Green composites, or Natural Fiber-Reinforced Polymer Composites, have emerged as promising alternatives to synthetic polymers due to their biodegradability, renewability, ease of processing, low density, cost, and energy consumption. Natural fibers are created from plants, animals, and minerals, offering higher structural advantages and better performance due to higher cellulose content and microfibril arrangement. The goal of this research is to evaluate the feasibility of using Acacia tortilis bark and Aerva javanica flowers (natural visible fibers) as a composite by extracting and characterizing their chemical composition and physical characteristics. Methods: The experiments have been done using standard methods using gravimetrical analysis and calculations. Results: The initial phase of our studies has shown that Acacia tortilis fibers can have competitive chemical composition and tensile properties compared to common natural fibers as well as Aerva javanica, is lighter, less dense, and has promising possibilities for utilizing its fiber in developing green composites. Conclusion: The preliminary findings indicate that Acacia tortilis fibers show competitive properties, surpassing common natural fibers and Aerva javanica, making them a promising candidate for green composite development. However, further extensive research is required for conclusive insights. [ABSTRACT FROM AUTHOR]

Many migratory bird species, several of which are in severe decline, and African residents spend the northern winter in the Sahel, by nature a huge savannah, half of which has been converted into farmland. We analyse the impact of such large-scale changes on birds. On average, woody cover is 38% lower on farmland than on savannah. More critically, farmers have drastically changed the vegetation communities of their farmland. In the arid and semi-arid zone, they partly removed bird-rich trees such as Umbrella Thorn Acacia tortilis and Desert Date Balanites aegyptiaca, yet further south they created a richer bird habitat by replacing the original woody species by Winter Thorn Faidherbia albida, a preferred tree species for Afro-Palearctic migrants (but less so for Afro-tropical residents). Still further south, two bird-poor trees, Shea Tree Vitellaria paradoxa and African Locust Bean Tree Parkia biglobosa, dominate farmland, causing birds, mainly Afro-tropical residents, to lose habitat. As a consequence of farming, arboreal migrants are confronted with habitat degradation in the northern arid zone and in the southern humid zone, but face more favourable wintering conditions in the sub-humid central zone. Ground-foraging birds are more abundant on savannah than on farmland; 24 bird species from this group, including three wheatear species and many residents, are more than twice as abundant on savannah. Conversion of savannah into farmland has mixed outcomes for ground-foraging birds, but were generally negative except for five species (including Western Yellow Wagtail Motacilla flava) which were more than twice as abundant on farmland than on savannah. Thus, the conversion of savannah into farmland represents a loss for many but not all bird species. [ABSTRACT FROM AUTHOR]

Premise: Tree growth is a fundamental biological process that is essential to ecosystem functioning and water and element cycling. Climate exerts a major impact on tree growth, with tree species often requiring a unique set of conditions to initiate and maintain growth throughout the growing season. Still, little is known about the specific climatic factors that enable tree growth in savannah and desert tree species. Among the global tree species, Acacia tortilis occupies one of the largest distribution ranges (crossing 6500 km and 54 latitudes), spanning large parts of Africa and into the Middle East and Asia. Methods: Here we collected climate data and monitored Acacia tortilis tree growth (continuous measurements of stem circumference) in its southern and northern range edges in South Africa (SA) and Israel (IL), respectively, to elucidate whether the growth–climate interactions were similar in both edges. Results: Growth occurred during the summer (between December and March) in SA and in IL during early summer and autumn (April–June and October–November, respectively). Surprisingly, annual growth was 40% higher in IL than in SA. Within the wide distribution range of Acacia tortilis, our statistical model showed that climatic drivers of tree growth differed between the two sites. Conclusions: High temperatures facilitated growth at the hot and arid IL site, while high humidity permitted growth at the more humid SA site. Our results confer an additional understanding of tree growth adaptation to extreme conditions in Acacia's world range edges, a major point of interest with ongoing climate change. [ABSTRACT FROM AUTHOR]

Lately, ensuring clear discrimination of the authenticity of natural honey is a concern not only to consumers but also to producers, traders and industries. The intrinsically simple nature of the honey composition, the distinguished health benefits as well as the high price make adulteration and falsification of the honey very common and the detection of authenticity very difficult. Samar honey (n = 59) and Talh honey (n = 64) produced from two species of Acacia trees (Acacia tortilis and Acacia gerrardii Benth, respectively) in different countries, including the United Arab Emirates, Saudi Arabia, Oman, and Yemen, has been studied by applying Multivariate Data Analysis. The discrimination is based on the official chemical quality parameters that inform about the nectary sources, including glucose, fructose, sucrose content, total reducing sugar, moisture content, acidity and diastase activity. Results show that the total reducing sugar, glucose and fructose were the most important positive loading descriptors that influence the quality of Samar and Talh honey. In addition, most of the Talh honey samples clustered at the top of the hierarchy, while Samar honey samples clustered at the bottom. The Multivariate Data Analysis indicates that the acidity and diastase activity are the most effective characteristics influencing the floral and geographical discrimination of both types of honey. This is the first study in the GCC area to discriminate between Samar and Talh honey using Multivariate Data Analysis by applying the principal component analysis and hierarchical cluster analysis. The Multivariate Data Analysis can be a helpful method to differentiate between Talh and Samar honey.

High abundance of legumes in drylands suggests that symbiotic nitrogen fixation provides an advantage in water-limited environments. However, the interactive effect of nitrogen availability and water scarcity on the nitrogen fixation strategies of dryland legumes remain largely unexplained. We conducted two experiments to test the effects of nitrogen availability and drought on symbiotic nitrogen fixation in two drought-adapted Acacia tree species. Seedlings were grown under deficient and sufficient levels of nitrogen and with and without an imposed drought to test the effect of resource availability on nitrogen fixation and plant growth. We found that seedlings that grew in extreme deficiency of nitrogen reached a similar biomass as seedling that grew with a sufficient supply of nitrogen, showing a high nitrogen-use efficiency. Nitrogen fixation was strongly downregulated (reduction of 90% in biomass allocation to nodules) when plants received sufficient nitrogen supply. Under nitrogen deficiency, drought had a slight negative effect on nodule biomass and total biomass. Under sufficient nitrogen, drought reduced nitrogen availability enough to induce an increase in symbiotic nitrogen fixation in the risk-averse A. raddiana but not in the risk-taking A. tortilis. We conclude that strong regulation of nitrogen fixation together with low nitrogen demand, and flexible strategies of carbon and nitrogen allocation, increase the chance of legume tree survival and establishment in dry and unpredictable environments. • The combination of water and nutrient limitation is globally common. • We analyzed growth and symbiotic nitrogen fixation in woody legumes under low water and nitrogen availabilities. • Strong downregulation strategy of N fixation was found when nitrogen was sufficient. • Low nitrogen demand allowed similar seedling growth with sufficient or deficient availability of nitrogen. • Regulation of nitrogen supply and demand sustained growth and survival under the combined stress of nitrogen and water. [ABSTRACT FROM AUTHOR]

Background: The evolutionary relationships between plants and their microbiomes are of high importance to the survival of plants in general and even more in extreme conditions. Changes in the plant's microbiome can affect plant development, growth, fitness, and health. Along the arid Arava, southern Israel, acacia trees (Acacia raddiana and Acacia tortilis) are considered keystone species. In this study, we investigated the ecological effects of plant species, microclimate, phenology, and seasonality on the epiphytic and endophytic microbiome of acacia trees. One hundred thirty-nine leaf samples were collected throughout the sampling year and were assessed using 16S rDNA gene amplified with five different primers (targeting different gene regions) and sequenced (150 bp paired-end) on an Illumina MiSeq sequencing platform.Results: Epiphytic bacterial diversity indices (Shannon–Wiener, Chao1, Simpson, and observed number of operational taxonomic units) were found to be nearly double compared to endophyte counterparts. Epiphyte and endophyte communities were significantly different from each other in terms of the composition of the microbial associations. Interestingly, the epiphytic bacterial diversity was similar in the two acacia species, but the canopy sides and sample months exhibited different diversity, whereas the endophytic bacterial communities were different in the two acacia species but similar throughout the year. Abiotic factors, such as air temperature and precipitation, were shown to significantly affect both epiphyte and endophytes communities. Bacterial community compositions showed that Firmicutes dominate A. raddiana, and Proteobacteria dominate A. tortilis; these bacterial communities consisted of only a small number of bacterial families, mainly Bacillaceae and Comamonadaceae in the endophyte for A. raddiana and A. tortilis, respectively, and Geodematophilaceae and Micrococcaceae for epiphyte bacterial communities, respectively. Interestingly, ~60% of the obtained bacterial classifications were unclassified below family level (i.e., “new”).Conclusions: These results shed light on the unique desert phyllosphere microbiome highlighting the importance of multiple genotypic and abiotic factors in shaping the epiphytic and endophytic microbial communities. This study also shows that only a few bacterial families dominate both epiphyte and endophyte communities, highlighting the importance of climate change (precipitation, air temperature, and humidity) in affecting arid land ecosystems where acacia trees are considered keystone species.

Background: The evolutionary relationships between plants and their microbiomes are of high importance to the survival of plants in general and even more in extreme conditions. Changes in the plant's microbiome can affect plant development, growth, fitness, and health. Along the arid Arava, southern Israel, acacia trees (Acacia raddiana and Acacia tortilis) are considered keystone species. In this study, we investigated the ecological effects of plant species, microclimate, phenology, and seasonality on the epiphytic and endophytic microbiome of acacia trees. One hundred thirty-nine leaf samples were collected throughout the sampling year and were assessed using 16S rDNA gene amplified with five different primers (targeting different gene regions) and sequenced (150 bp paired-end) on an Illumina MiSeq sequencing platform. Results: Epiphytic bacterial diversity indices (Shannon–Wiener, Chao1, Simpson, and observed number of operational taxonomic units) were found to be nearly double compared to endophyte counterparts. Epiphyte and endophyte communities were significantly different from each other in terms of the composition of the microbial associations. Interestingly, the epiphytic bacterial diversity was similar in the two acacia species, but the canopy sides and sample months exhibited different diversity, whereas the endophytic bacterial communities were different in the two acacia species but similar throughout the year. Abiotic factors, such as air temperature and precipitation, were shown to significantly affect both epiphyte and endophytes communities. Bacterial community compositions showed that Firmicutes dominate A. raddiana , and Proteobacteria dominate A. tortilis ; these bacterial communities consisted of only a small number of bacterial families, mainly Bacillaceae and Comamonadaceae in the endophyte for A. raddiana and A. tortilis , respectively, and Geodematophilaceae and Micrococcaceae for epiphyte bacterial communities, respectively. Interestingly, ~60% of the obtained bacterial classifications were unclassified below family level (i.e., "new"). Conclusions: These results shed light on the unique desert phyllosphere microbiome highlighting the importance of multiple genotypic and abiotic factors in shaping the epiphytic and endophytic microbial communities. This study also shows that only a few bacterial families dominate both epiphyte and endophyte communities, highlighting the importance of climate change (precipitation, air temperature, and humidity) in affecting arid land ecosystems where acacia trees are considered keystone species. [ABSTRACT FROM AUTHOR]

Lately, ensuring clear discrimination of the authenticity of natural honey is a concern not only to consumers but also to producers, traders and industries. The intrinsically simple nature of the honey composition, the distinguished health benefits as well as the high price make adulteration and falsification of the honey very common and the detection of authenticity very difficult. Samar honey (n = 59) and Talh honey (n = 64) produced from two species of Acacia trees (Acacia tortilis and Acacia gerrardii Benth, respectively) in different countries, including the United Arab Emirates, Saudi Arabia, Oman, and Yemen, has been studied by applying Multivariate Data Analysis. The discrimination is based on the official chemical quality parameters that inform about the nectary sources, including glucose, fructose, sucrose content, total reducing sugar, moisture content, acidity and diastase activity. Results show that the total reducing sugar, glucose and fructose were the most important positive loading descriptors that influence the quality of Samar and Talh honey. In addition, most of the Talh honey samples clustered at the top of the hierarchy, while Samar honey samples clustered at the bottom. The Multivariate Data Analysis indicates that the acidity and diastase activity are the most effective characteristics influencing the floral and geographical discrimination of both types of honey. This is the first study in the GCC area to discriminate between Samar and Talh honey using Multivariate Data Analysis by applying the principal component analysis and hierarchical cluster analysis. The Multivariate Data Analysis can be a helpful method to differentiate between Talh and Samar honey. [ABSTRACT FROM AUTHOR]

Acacia albida, Acacia luederitzii, and Acacia tortilis are dominant acacia species in Botswana and have the potential to rehabilitate the heavy metal degraded environment. To establish this claim, experiments to assess the influence of mycorrhizal inoculation and fly ash amendments on the survival, growth and heavy metal accumulation of these species in mine tailings were conducted. A two-factor (AM inoculation × fly ash) in CRD was done on each of the three Acacia species consisting of four treatments: control (no mycorrhizal, no fly ash coded as − AM/− FA), with mycorrhizal but no fly ash (+ AM/− FA), no mycorrhizal but with fly ash (− AM/+ FA), and with mycorrhizal and with fly ash (+ AM/+ FA). After 24 weeks, results showed that the survival and dry matter yield of all Acacia species were enhanced by 10% with fly ash amendments. However, mycorrhiza inoculation alone improved the survival of A. albida and A. luederitzii but reduced that of the A. tortilis in mine tailings. Fly ash amendments increased the pH of the mine tailings, reduced the availability of Cu, Ni, Pb, Mn and Zn and consequently reduced the concentration of these metals in shoots. On the other hand, it increased the availability of As in the mine tailings. In addition, mycorrhizal inoculation reduced the concentration of these metals in shoots regardless of fly ash amendments. Overall, combined mycorrhizal inoculation and fly ash amendment enhanced the establishment of A. luederitzii in heavy metal-contaminated soils by reducing the heavy metal availability and metal uptake, thus increasing the survival and dry matter yield of plants. [ABSTRACT FROM AUTHOR]

Aims In plant eco-physiology, less negative (enriched) carbon 13 (13C) in the leaves indicates conditions of reducing leaf gas exchange through stomata, e.g. under drought. In addition, 13C is expected to be less negative in non-photosynthetic tissues as compared with leaves. However, these relationships in δ 13C from leaves (photosynthetic organs) to branches, stems and roots (non-photosynthetic organs) are rarely tested across multiple closely related tree species, multiple compartments, or in trees growing under extreme heat and drought. Methods We measured leaf-to-root 13C in three closely related desert acacia species (Acacia tortilis , A. raddiana and A. pachyceras). We measured δ 13C in leaf tissues from mature trees in southern Israel. In parallel, a 7-year irrigation experiment with 0.5, 1.0 or 4.0 L day−1 was conducted in an experimental orchard. At the end of the experiment, growth parameters and δ 13C were measured in leaves, branches, stems and roots. Important Findings The δ 13C in leaf tissues sampled from mature trees was ca. −27‰, far more depleted than expected from a desert tree growing in one of the Earth's driest and hottest environments. Across acacia species and compartments, δ 13C was not enriched at all irrigation levels (−28‰ to ca. −27‰), confirming our measurements in the mature trees. Among compartments, leaf δ 13C was unexpectedly similar to branch and root δ 13C, and surprisingly, even less negative than stem δ 13C. The highly depleted leaf δ 13C suggests that these trees have high stomatal gas exchange, despite growing in extremely dry habitats. The lack of δ 13C enrichment in non-photosynthetic tissues might be related to the seasonal coupling of growth of leaves and heterotrophic tissues. [ABSTRACT FROM AUTHOR]

Methylation has been the most widely used conventional tool in the structural characterization of polysaccharides. In the series of developments in methylation methods employing a diverse range of solvents and methylating reagents under basic conditions, the main emphasis relied upon inclusive solubilization of polysaccharides during the reaction procedure. In our laboratory, Acacia tortilis ssp. raddiana (Savi) Brenan polysaccharide (AcTP) has been reported for antidiabetic activity and hence its chemical structure has been investigated. AcTP was found to be composed of L-rhamnose, L-arabinose, D-mannose, D-galactose, D- galacturonic acid, and D-glucuronic acid in molar ratio 1:34:1:10:2:2 respectively. The polysaccharide was subjected to Hakomori methylation protocol for linkage analysis. However, the method encountered following limitations: undermethylation, partial degradation of polysaccharide, and decline in solubility of methylated product in hydrolytic and reducing reagents for further derivatization to partially methylated alditol acetates (PMAA). The limitations were circumvented by applying key modifications in standard protocol viz. in situ production of methylsulfinyl methyl sodium; purification of a product by dialysis; replacing 0.15M H2SO4 by 4M trifluoroacetic acid and performing the reduction by NaBH4 in methanol/chloroform (7:3) solvent system. Permethylation of AcTP to PMAA was realized by the proposed modified method and glycosyl linkages were studied by GC-MS. The monosaccharide composition based on alditol acetate investigation and successive PMMA analysis demonstrated complete methylation without any significant degradation establishing the worthiness of the modified method. The methylation was also confirmed by FTIR results. Unlike the original protocol, the modified method is more feasible, efficient, effective and can be used for permethylation of neutral as well as acidic polysaccharides. [ABSTRACT FROM AUTHOR]

Eco-friendliness and availability of green fiber reinforced based composites attracted many as a potential replacement for non-biodegradable synthetic fiber. Green composites are biodegradable and less susceptible to health hazards during the utilization for engineering application. Furthermore, natural fibers tend for application of light weight engineering products and provide satisfactory mechanical properties that pose challenges on massive application of green fibers as reinforcement in composite structures. The main objective of this paper is to extract and characterize Acacia tortilis as natural fiber for green composite. ASTM standard for sample preparation and experimental testing of fiber bundles were used. After successful extraction of the fiber, chemical composition, density and tensile test of mechanical property were performed as well as effect of chemical treatment was studied for bundles of fiber and a promising result were obtained. Validation with published results indicates that acacia tortilis fiber can be considered as a potential natural fiber for the application as a green composite.

For the management and sustainable use of natural bio-resources it is necessary to quantify and valorize this heritage. In the case of the floristic diversity of Acacia tortilis, the only natural woody stand in Bechar-Algeria, scanty studies have been undertaken. Hence in this study, the general overview of the flora diversity state in the 58 plots of 9 stations was made by the analysis of various indexes: Shannon, Simpson, species evenness, floristic richness, disturbance index, biological and biogeographically spectra. We listed 103 species belonging to 37 families and 85 genus, the important plants belonged to the Asteraceae and Brassicaceae. The most important species are: Pulicaria crispa, Asteriscus graveolens, Launea arborescens, Matricaria pubescens, Moricandia arvensis, Farsetia aegyptiaca, Zilla macroptera. The biological spectrum indicated a dominance of the Chamaephytes and the predominance of the Therophytes; the phytogeographic spectrum showed an important endemism (44%) in which 36% species belong to the Saharo- Arabian element; The Shannon, Simpson, and Evenness diversity indices, were relatively high, thereby indicating a diversity variation between the stations, witch increased South towards North. It was prominent in Zouzfana, Taghit, and Abadla stations, and the higher values of disturbance Index reflected the greater level of anthropization in these courses. The future accumulation of this regression, many risk loss of the last naturally wall of desertification, biodiversity, national economy and sand advancement. Therefore, it is recommended to apply pastures protection, pastoral charge control, and elaborate an environmental value of this species. [ABSTRACT FROM AUTHOR]

Highlights • Al Samr forests in the hyper-arid deserts of Abu Dhabi require groundwater irrigation. • Through Law 5, groundwater (GW) allocation for forest irrigation is being controlled. • Measured water use of Al Samr is low at 3–10 L d−1, <15% of that being applied now. • Water use of Al Samr irrigated with treated sewage effluent is 25% higher than with GW. • Proximal sensing of tree shadows can be used to predict Al Samr water use. • We recommend that irrigation allocation for GW be 15 L d−1, and 12.5 L d−1 for TSE. Abstract The arid forests planted in Abu Dhabi provide a variety of valuable ecosystem services. The forests need to be irrigated, and currently groundwater (GW) provides the bulk of this water. However GW recharge is very low, and reserves are rapidly dwindling and becoming more saline. In 2016, Law 5 was passed in Abu Dhabi with the objective to set GW extraction limits and define irrigation-usage allowances. Here we sought to define the usage allowance for Al Samr trees, and this work complements our previous research on Al Ghaf and Al Sidr forests. We have measured tree water-use, ET c, using sapflow monitoring of GW-irrigated trees, and trees irrigated with treated sewage effluent (TSE). Maximum rates of tree water-use, ET c, were found to around 10 L d−1, and there are two distinct deciduous periods where ET c briefly dropped below 2 L d−1. The total annual water use of the TSE-irrigated trees was 2.2 kL y−1, which is about 25% higher than the 1.8 kL y−1 for the GW-irrigated trees. For Law 5, we recommend that the irrigation allocation for Al Samr trees be simply based on a constant ET c of 10 L d−1. So for GW irrigation, allowing for a 25% factor-of-safety, and a 25% salt-leaching fraction, the recommended allocation would be 15 L d−1. This represents a saving of 75% from the current practice of irrigation 60 L d−1. For TSE, without the need for salt leaching, the irrigation allocation would only need to be 12.5 L d−1. [ABSTRACT FROM AUTHOR]

Composting of waste plant materials and its use in agriculture and landscape sites is an environmental friendly way of reducing waste material and conserving the environment. In this perspectives a survey has been performed at the Dubai based International Center for Biosaline Agriculture to compost the plants based waste material (lawn cuttings-grass) to compost. The material was inoculated with a consortium of microbes leading to form stable and mature compost with high organic matter (38%). In order to conduct seed germination tests, Fulvic acid was extracted from the compost. A pot experiment was conducted over a period of 30 days in the green house to study the effect of Fulvic acid on the seed germination, and plant growth of Prosopis cineraria (L.) Druce (Ghaff) and Acacia tortilis (Forssk.) Hayne. Seeds of both trees were treated with Fulvic acid at 0.5% and 1% and water treatment was used as control. Generally seed germination and biomass were increased at both rates of fulvic acid. However, a pronounced increase was found in seed germination when fulvic acid was used at 1.0% (Prosopis cineraria 27%; Acacia tortilis 20% increase over control). Similarly biomass (shoot and root) of A. tortilis and P. cineraria was increase 34% and 94% respectively.

Savanna ecosystems span a diverse range of climates, edaphic conditions, and disturbance regimes, the complexity of which has stimulated long‐standing interest in the mechanisms that maintain tree–grass coexistence. One hypothesis suggests that tree establishment is strongly limited by one or several demographic bottlenecks at early stages of the tree life cycle. A major impediment to testing this hypothesis is the lack of data on the relative strengths of different bottlenecks across key environmental gradients.To identify demographic bottlenecks that limit early tree establishment (0–18 months), we conducted a series of transplant experiments with two savanna trees species (Acacia robusta and Acacia tortilis) across a natural rainfall and soil fertility gradient in the Serengeti ecosystem, Tanzania. We tested the interactive effects of precipitation, herbivory, seed scarification, grass competition, water limitation, and tree species identity on two key life stages: germination and early seedling survival (0–2 months), and juvenile seedling survival (2–18 months).Germination and early seedling survival increased as a function of rainfall, in the absence of herbivores and when seeds were scarified. Juvenile seedling survival, in contrast, decreased with rainfall but increased in the absence of herbivores. Grass removal had the single strongest (positive) effect on juvenile seedling survival of any treatment. Soil moisture monitoring and grass‐addition treatments revealed that grasses negatively affected seedlings in ways that were not necessarily linked to soil moisture.A demographic model combining all effects across early life stages showed that the strength of grass competition on juvenile seedling survival was the key factor limiting early tree establishment. While rainfall had an unexpected opposing effect on the two life stages, the net effect of mean annual precipitation on early tree establishment was positive.Synthesis. Successful tree establishment in Serengeti is maximized by a seemingly unlikely sequence of events: (a) scarification of seeds by browsers, (b) heavy rainfall to promote germination, (c) intensive grazing (but absence of browsers), and (d) dry conditions during juvenile seedling growth (>2 months) to reduce competition with grasses. By considering a wide suite of conditions and their interactions, our experimental results are relevant to ongoing debates about savanna vegetation dynamics and structural shifts in tree:grass ratios. Successful tree establishment in Serengeti is maximized by a seemingly unlikely sequence of events: (a) scarification of seeds by browsers, (b) heavy rainfall to promote germination, (c) intensive grazing (but absence of browsers), and (d) dry conditions during juvenile seedling growth (>2 months) to reduce competition with grasses. By considering a wide suite of conditions and their interactions, results from our transplant experiments are relevant to ongoing debates about savanna vegetation dynamics and structural shifts in tree:grass ratios. [ABSTRACT FROM AUTHOR]

Highlights • The adaptation period of finishing pigs to incremental levels of Vachellia tortilis leaf meal diets was determined. • Increasing levels of Vachellia tortilis leaf meal diets produces a positive linear relationship with adaptation period of finishing pigs. • The linear increase gives a clear sign that pigs require more time to adapt to higher levels of V. tortilis leaf meal diets due to the presence of secondary compounds. • Increasing V. tortilis with 1 g/kg DM, increases the adaptation period by 0.027 days. Abstract The study was conducted to determine if Vachellia tortilis leaf meal inclusion affect the adaptation periods in finishing pigs. A total of 48 clinically healthy male Large White × Landrace male pigs with a mean (± SD) body weight of 63.8 ± 3.28 kg aged 14 weeks were used. Pigs were assigned to individual pens in a completely randomized design and allotted to each of six experimental diets which contained 0, 30, 60, 90, 120 and 150 g/kg DM of V. tortilis leaf meal. The adaptation period was measured daily while average daily feed intake (ADFI) and average daily gain (ADG) were calculated weekly with gain: feed ratio (G: F) of pigs. Regression analyses was used to analyse the data. There was a quadratic decrease (P < 0.001) in ADFI, while ADG increased linearly (P < 0.001) with incremental level of V. tortilis leaf meal. Incremental level of V. tortilis leaf meal increased G: F ratio quadratically (P < 0.001). A linear increase in adaptation period was observed (P < 0.05) with increasing inclusion level of V. tortilis leaf meal. As the leaf meal inclusion increased by 1 g/kg DM, the adaptation period increased by 0.027 days. Variation of feed intake, expressed as a coefficient of variation of feed intake, increased linearly (P < 0.05) with increasing inclusion level of V. tortilis leaf meal. Adaptation period of finishing pigs is influenced by the inclusion level of V. tortilis leaf meal diets, by causing a positive linear relationship, therefore pigs fed increasing levels of V. tortilis leaf meal diets required more time to adapt. [ABSTRACT FROM AUTHOR]

Acacia tortilis is a medium to large canopied tree, widely planted in desert regions of Hormozgan province in Iran. It is considered one of the most important species for reforestation of arid areas and to reduce desertification. To protect the trees against pests and diseases, a comprehensive and ecofriendly control plan is required. In recent years, a stinkbug species was observed on A. tortilis. It severely damages the trees by feeding on sap and producing honeydew that promotes sooty mold growth. The aim of the present study was to identify this stinkbug pest to species level and characterize its bacterial endosymbiont fauna with a view to designing a control program. Phylogenetic analyses using a partial COI gene sequence indicated that Nysius cymoides was the pest species damaging the trees. Sequencing of 16S rRNA and wsp showed that N. cymoides harbors two obligate endo symbionts: "Candidatus Schneideria nysicola" and "Candidatus Sulcia muelleri" and three facultative endosymbionts: Wolbachia, Pantoea, and Enterobacter. This work is the first report of Nysius cymoides as a serious pest on Acacia tortilis as well as the first characterization of its bacterial endosymbiont fauna. [ABSTRACT FROM AUTHOR]

The article discusses the relationship between growth parameters, rainfall and soil type, and establishment of Vachellia tortilis (Forssk.) Hayne tree population in Limpopo Bushveld, South Africa. It states that study was conducted in the University of Limpopo's Syferkuil Experimental Farm and the Sondela Nature Reserve in the Limpopo Province.

Empirical studies of the relationship between aspects of the landscape and human emotions have been fruitful over the last few decades. In fact, we are awash in data that describes a correlation between natural landscapes and positive human feelings. While this plethora of data has been useful to various disciplines, it has not lead to an explanatory theory as to why and how the landscape should have this affect This paper proposes that the discipline of evolutionary psychology provides an explanatory theory. Rather than a broad explanation, evolutionary psychology drills down on ancient problems of survival and relates those problems to contemporary behavior. Our connection to tree canopy is used as an example of this approach. [ABSTRACT FROM AUTHOR]

Three Acacia species: A. farnesiana, A. tortilis and A. longifolia, were investigated for seasonal variations of the phytochemical constituents and their influence on in-vitro anti-inflammatory activities. Samples of leaves and bark of the three species were collected in two different seasons and extracted using 50% and 70% ethanol. LC-MS analysis revealed the presence of rutin in the leaves of all three species, while catechin was commonly present in the bark. Other major components included vicenin 2, isoquercitrin, kaempferol 3-O-rutinoside and isorhamnetin 3-O-rutinoside in A. farensiana leaves, while A. longifolia leaves contained myricetin 3- O -rhamnoside, quercitrin and luteolin. The level of rutin varied according to the flowering period being highest in winter in A. tortilis (245.4 μg/mg) and A. longifolia (3.0 μg/mg). The content of total phenolics (TPC) showed a marked variation among the three species, which was reflected to some extent in the COX-1 and COX-2 enzymes inhibition. Optimization modeling was performed for better visualization and utilization of the data showing a strong inverse correlation between TPC and the mean inhibition of COX-2 in case of the leaves (r = 0.783). Finally, cluster analysis of the data obtained from the leaf samples reflected on the taxonomical classification of the species. [ABSTRACT FROM AUTHOR]

Aims: Addressing plant responses to water stress is critical to understand the structure of plant communities in water-limited environments and to forecast their resilience to future changes in climate. In a semiarid agroforestry system in the Sahelian savannah of Leona (Senegal), we selected nine common tree species and explored their stress-resistance mechanisms. These species represent a variety of life forms and are of high regional socio-economic importance. We hypothesized that different species would show different suites of traits to cope with water stress and expected to identify functional groups differing in strategies to withstand water shortage. Methods: Along a dry and a wet season, we monitored four traits reflecting above- and below-ground strategies of resource acquisition such as predawn leaf water potential (ψpd), specific leaf area (SLA), leaf thickness and leaf area index (LAI). We also measured two morphological traits: trunk diameter and tree height. LAI and ψpd were measured six times during the dry and rainy seasons, and the other traits were measured once. Important Findings: We identified two functional classes subdivided into two functional groups of each class. The first class included deciduous and semi-deciduous species that generally had large SLA, low leaf thickness and small-to-intermediate inter-seasonal variations in ψpd. The second class included evergreen species of two functional groups that differ in SLA, leaf thickness and the magnitude of inter-seasonal variations of ψpd throughout the year. The four functional groups identified in this study represent plant strategies differing in their response to changing environmental conditions. [ABSTRACT FROM AUTHOR]

Genetic diversity and structure of populations at the edge of the species’ spatial distribution are important for potential adaptation to environmental changes and consequently, for the long-term survival of the species. Here, we combined classical population genetic methods with newly developed network analyses to gain complementary insights into the genetic structure and diversity of Acacia tortilis, a keystone desert tree, at the northern edge of its global distribution, where the population is under threat from climatic, ecological, and anthropogenic changes. We sampled A. tortilis from 14 sites along the Dead Sea region and the Arava Valley in Israel and in Jordan. In addition, we obtained samples from Egypt and Sudan, the hypothesized origin of the species. Samples from all sites were genotyped using six polymorphic microsatellite loci.Our results indicate a significant genetic structure in A. tortilis along the Arava Valley. This was detected at different hierarchical levels—from the basic unit of the subpopulation, corresponding to groups of trees within ephemeral rivers (wadis), to groups of subpopulations (communities) that are genetically more connected relative to others. The latter structure mostly corresponds to the partition of the major drainage basins in the area. Network analyses, combined with classical methods, allowed for the identification of key A. tortilis subpopulations in this region, characterized by their relatively high level of genetic diversity and centrality in maintaining gene flow in the population. Characterizing such key subpopulations may enable conservation managers to focus their efforts on certain subpopulations that might be particularly important for the population’s long-term persistence, thus contributing to species conservation within its peripheral range. [ABSTRACT FROM AUTHOR]

Vachellia tortilis is a tree belonging to the family Fabaceae that inhabits high temperature and dry environments of the world. It is ecologically and economically significant amongst others of the genera Vachellia and Senegalia. It is native to Namibia and several other countries. Various parts of the V. tortilis plant are used for different therapeutic purposes both in the traditional and pharmacological settings. However, V. tortilis is vulnerable to pathogenic infection to which they lack natural resistance and little is known regarding the pathogens responsible for such infections. The aim of the study was to isolate and identify the fungal species associated with twig dieback disease in V. tortilis. Pure cultures from diseased V. tortilis were grown using potato dextrose agar (PDA) and DNA was subsequently isolated and later amplified in a PCR reaction using ITS1 and ITS4 primers. Sequencing and BLAST search revealed the identity of the isolates as; Penicillium rubefaciens, Penicillium herbarum, Trichoderma longibrachiatum and Trichoderma harzianum. Results indicated that P. herbarum was associated with disease symptoms in A. tortilis, T. longibrachiatum and T. harzianum were antagonistic fungi while the effect of P. rubefaciens on V. tortilis remained unknown. It is recommended that further investigations using Koch’s postulates should be performed on V. tortilis using the isolates. [ABSTRACT FROM AUTHOR]

Tree recruitment in savannas proceeds in multiple stages characterized by successive filters occurring at the seed and seedling stages. The 'demographic bottleneck' hypothesis suggests that such filters ultimately restrict tree density and prevent trees from dominating grasses in savannas, but many of the demographic transitions underlying this assumption have not been quantified. We investigated how short- (1-2 years) and long-term (40 + years) rainfall patterns influenced seed production, infestation, and viability for two dominant species, Acacia robusta and Acacia tortilis across the Serengeti ecosystem mean annual precipitation gradient over a two-year period. We found that neither production, nor infestation, nor viability was influenced by rainfall. Pod production differed between species and increased with tree height in A. robusta. Mean infestation proportion in 2013 was higher (mean ± SE; 0.28 ± 0.08) in A. tortilis than in A. robusta (0.11 ± 0.05) but the trend reversed in 2014, when A. tortilis (0.33 ± 0.10) had lower infestation than A. robusta (0.61 ± 0.09). Under laboratory conditions, A. tortilis and A. robusta seeds had maximum germination (= viability) proportions of 70 and 20%, respectively. Mean seed viability was more than five-fold higher (0.46 ± 0.19) in A. tortilis than in A. robusta (0.08 ± 0.10). Our study has produced important estimates for seed stage demographic dynamics that can be used for modeling tree dynamics in Serengeti system, and savannas in general. [ABSTRACT FROM AUTHOR]

Dietary inclusion of tannin-rich leguminous leaf meals beyond threshold levels can impose toxicity and compromise welfare of pigs. The objective of the study was to determine the response of metabolites, carcass characteristics and internal organs of finishing pigs to Acacia tortilis leaf meal inclusion levels. Thirty Large White × Landrace pigs (61.6 ± 1.23 kg bodyweight) were randomly allotted to six dietary treatments, to give five replicates per treatment. The treatments contained 0, 50, 100, 150, 200 and 250 g/kg of A. tortilis leaf meal and were rendered iso-energetic and iso-nitrogenous. An increase in A. tortilis inclusion was related to an initial increase and then a decrease in feed intake (P < 0.05), weight gain (P < 0.001) and feed conversion ratio (P < 0.05). Serum concentrations of iron and activities of aspartate aminotransferase and alkaline phosphatases increased quadratically (P < 0.001) as A. tortilis leaf meal increased. There was a significant linear increase in alanine aminotransferase activity with leaf meal incremental level. Hepatosomatic index, scaled kidney weight and scaled heart weight increased linearly (P < 0.001) as A. tortilis increased. There was a quadratic increase in the relative weight of lungs (P < 0.001) as leaf meal increased. Although quadratic decreases (P < 0.01) in cold-dressed mass and dressing percentage were observed with incremental levels of A. tortilis leaf meal, there was a linear decrease (P < 0.05) in backfat thickness. It was concluded that serum biochemistry, internal organs and carcass characteristics respond differently to increases in A. tortilis inclusion. The A. tortilis leaf meal can be supplemented in finishing pig diets at low levels before feed efficiency and carcass characteristics are negatively affected. [ABSTRACT FROM AUTHOR]

Study of Acacia tortilis seed germination under different abiotic constraints. Since Tunisian acacia populations are threatened by regression, we analyzed as a preliminary study the germination behavior of the species in order to plan subsequently for a preservation and rehabilitation program. In this context and to optimize acacia seed germination and to overcome and remove the obstacle of tegumentary inhibition, we have in a first attempt tested several physical (scarification, boiled water) and chemical (sulfuric acid) pretreatments under different temperatures. Thus, we could determine the optimal germination conditions that have been used afterwards for evaluating the germination capacity of the species under different osmotic constraints. Several concentrations of NaCl (0 to 22 g.l-1) and PEG (0 to -8 bars) were applied on seeds. Parameters related to germination capacity and kinetic were assessed and analyzed. Thus, soaking seeds in concentrated sulfuric acid for one hour allowed us to improve the germination rate and its speed. When studying the effect of the temperature on the germination process, we showed that 25°C could improve the rate and average time of germination. Under osmotic stress, we found a highly significant treatment effect (PEG concentrations) on the germination rate and average time of germination, and the species did not display a high drought tolerance behavior (since germination is totally inhibited under -8 bars). Moreover, the study of the effect of salt stress on germination revealed a highly significant effect of NaCl concentrations on the germination rate and average time of germination, and a good level of salt tolerance since it succeeded to germinate under high salt concentrations (21% of germination rate under 22 g.l-1NaCl). In conclusion, our study clearly showed that germination capacity of Acacia tortilis under the environmental constraints and factors is sufficiently assured to consider this species for a reforestation program and to extend consequently its area of distribution.

The canopy effects of an exotic and indigenous tree species on soil properties and understorey herbaceous plant species were investigated on the Njemps Flats, Baringo district, Kenya. Samples of soil and herbaceous plant species were obtained within the canopies of systematically selected P. juliflora (exotic) and A. tortilis (indigenous) trees, and from adjacent open areas. Standing biomass, frequency and cover of understorey plant species were significantly (P

Prosopis chilensis-Prosopis juliflora hybrid (hereinafter referred to as Prosopis species) invade riverine Acacia woodlands and replace indigenous Acacia tortilis through mechanism that are not yet well understood. Therefore, we tested the hypothesis that dense shade and allelopathic effects of Prosopis species may reduce the germination and growth of A. tortilis more strongly than that of Prosopis species through greenhouse studies. We first evaluated the germination of A.tortilis and Prosopis species seeds with increasing concentration of unleached and leached Acacia or Prosopis litter in soil. Subsequently, we evaluated the growth of A. tortilis and Prosopis species seedling in response to concentration of Acacia or Prosopis litter at different light intensity regimes. Unleached Prosopis litter inhibited germination of A. tortilis and Prosopis species seeds with increase in litter concentration in the soil. Leached Acacia or Prosopis litter had no effect on seed germination but enhanced growth and shoot nutrient concentrations of A. tortilis and Prosopis species seedlings. Growth response to light intensity treatments was similar in both A. tortilis and Prosopis species seedling. The findings suggest that the lack of A. tortilis seedlings under Prosopis canopies in nature may be partially explained by Prosopis litter allelopathy on A. tortilis seed germination. [ABSTRACT FROM AUTHOR]

Among several agroforestry practices in the Central Rift Valley (CRV) of Ethiopia,Acacia tortilis-dominated Parkland agroforestry systems are common. Utilizable information regarding the effects of the tree species on soil conditions in Ethiopia is very scarce to be of use for improved agricultural productivity. This study was conducted in three land use types in CRV areas in Oromia National Regional State in Ethiopia. The aim of the study was to determine the effects of A. tortilis on soil fertility variations along a gradient from the tree base to open area in different land use types. Soil samples from surface layers (0–15 cm) were taken at four concentric transects distances from tree base (0.5, 2 and 4 m), compared with soil samples from the adjacent open areas (15 m distance from the tree canopy cover), and then analyzed following the standard procedures. The results of the study indicated that except for Na the amount of soil nutrients under A. tortilis were significantly varied (P < 0.05) in the land use types. Generally, comparisons between under the canopy and outside the canopy of the tree species indicated a highly significant difference on major soil fertility parameters. The effect of the tree species on soil fertility parameters was significantly higher with the distance from the tree base to outside of the canopy. But soil texture was not affected, indicating that it is more related to parent material and land use practices than the tree influence. The study revealed that the indigenous Parkland agroforestry practices of A. tortilis tree improve soil fertility. Hence, the soil patches observed under A. tortilis trees can be important local nutrient reserves, leading to soil heterogeneity in an otherwise uniform agricultural landscape. This may be important for the agricultural landscape health and on farm biodiversity conservation in agricultural landscapes of similar agroecological conditions. [ABSTRACT FROM AUTHOR]

Acacia tortilis ssp. raddiana (Savi) Brenan commonly known as Israeli Babool has contributed immensely for sand dunes management in Indian desert leading to wind erosion control and increased biological productivity. The species is extensively used in traditional medicine system for a number of therapeutic applications and as nutraceutical. The polysaccharide was isolated in 43.6% yield from gum exudates. The monosaccharides, L-arabinose, D-galactose D-glucose, L-rhamnose and D-mannose were determined in molar ratio of 78.1%, 18.64%, 0.60%, 1.71% and 0.74% respectively. The molar ratio of uronic acids was studied using diverse spectrophotometric methods and compared with GLC. The content of D-galacturonic acid and D-glucuronic was determined as 3.88% and 4.35% respectively by GLC. The results were compared with the spectrophotometric methods. The results using DMP as chromogenic reagent are closer to that obtained by GLC. Structural analysis of the polysaccharide may provide scientific basis for nutraceutical, pharmaceutical and biological applications of gum exudates from A. tortilis , which is extensively planted in India. [ABSTRACT FROM AUTHOR]

In situ edaphic factors affecting seed germination and seedling emergence of three framework species of Acacia were investigated with the intent of developing fundamental and scalable restoration capacity for Arabian dryland restoration. Direct seeding represents the most efficient means to restore vegetation at the landscape scale and this study provides insight into edaphic and ecological limitations, as well as effective protocols governing the use of native seeds for restoration in hyper-arid environments. The study was conducted in extant Acacia woodland habitat on conserved land (Thumamah Nature Park) in close proximity to Riyadh, Saudi Arabia. Broad-scale direct seeding using un- and pretreated Acacia gerrardii, A. tortilis, and A. ehrenbergiana seed, and two seed burial depths were implemented across three sites with distinct soil surface characteristics. Eight weeks post-sowing, random samples for each species × seed treatment × burial depth combination were excavated, sieved, and categorized as follows: failed to germinate, germinated but died prior to emerging, or successfully emerged. We show that germination and emergence of Acacia gerrardii, A. tortilis, and A. ehrenbergiana were driven by a three-way interaction among species, site, and seed burial depth. Treating seed with the signaling compound Moddus did not have a definitive effect, positive or negative, on any of the species investigated. Acacia gerrardii was the only species that exhibited widespread emergence, though emergence was not consistent across sites or burial depths. Germination was highest in disturbed soil (up to 69% for A. gerrardii), but very few (<2%) successfully emerged; a greater proportion of germinants in sandy soil emerged (up to 44% for A. gerrardii) even though the overall germination was less. Though species-dependent, a 2-cm sowing depth was most effective in sand; while in disturbed soil, sowing depths of 1 and 2 cm were comparable; and no germination was observed in gravelly clay soil. Sandy soil exhibited rapid water infiltration (107.6 mm min), and post-sowing surface crusting was a non-factor (0.44 kg cm). Disturbed soil exhibited moderate water infiltration (1.46 mm min) and post-sowing surface crusting was double that of sand (0.88 kg cm) and restrictive on seedling emergence. Gravelly clay exhibited extremely poor water infiltration (0.12 mm min), and surface crusting was severe (4.49 kg cm) and an order of magnitude greater than sand. The medium-coarse sand fraction, a key driver of the observed soil surface processes, was greatest in sand (55%) and significantly less and uniform in the disturbed (22%) and gravelly clay (22%) soils. Our findings demonstrate that soil surface characteristics and associated processes can dictate ecological processes at depths as shallow as 1-2 cm, and that soil crusts that slow water infiltration and impede seedling emergence rapidly reconstitute after disturbance; both are important considerations for restoring dryland vegetation. [ABSTRACT FROM AUTHOR]

Large herbivore browsing leads to above-ground compensatory growth for some species of Acacia trees, but strength and variation of the relationship are poorly understood. Acacia tortilis is a keystone species in East African savannas and experiences a wide range of browsing pressure. In this study, terminal bud scale scars were used to measure yearly shoot elongation in A. tortilis experiencing various levels of elephant browsing at three mesic sites in northern Tarangire National Park, Tanzania. For all four years of growth, twig elongation remained very similar across elephant browsing pressure from minimal to heavy. Although never significant, twig elongation in 2013, 2011 and 2010 was somewhat higher in trees experiencing moderate elephant browsing pressure, suggesting a possible tendency toward compensatory growth. However, growth in 2012 had a slight negative correlation with browsing pressure. Further research can test whether A. tortilis compensates for moderate elephant browsing by elongating twigs more and if that growth slows slightly at higher browsing pressure. Overall A. tortilis tolerates elephant browsing extraordinarily well, but because the elephant population in Tarangire National Park is large and growing, managers should continue to monitor this keystone for decreased growth and tree mortality. [ABSTRACT FROM AUTHOR]

Salt-tolerant plants are known to remove excess soluble salts from the soil and thus may be used in land reclamation. We studied the responses of the trees, Balanites aegyptiaca L. (Zygophyllaceae), as well as the Fabaceae, Acacia tortilis (Forssk) Hayne, and Tamarindus indica L. to salinity. Three experiments were conducted on germination, in the laboratory; seedling performance in a lath house; and the impact of the tree species on soil productivity in the field in Afar regional state along the Awash river, eastern Ethiopia. Mixtures of salts, composed of chlorides and sulfates, were tested at different concentrations in both germination and lath house experiments in randomized complete block designs. Seedling root collar diameter and height were measured every 2 weeks. Soil samples were collected from randomly selected pots to examine the effect of salinity on soil properties. The effects of trees on in situ soil productivity were studied by collecting 72 soil samples at different distances from the tree and different soil depths. The soil productivity index was calculated by summing the products of sufficiency of available water capacity, aeration, bulk density, pH, electrical conductivity, and the weighting factor for each layer. The study revealed that germination percentage and rate decreased significantly with increasing salt concentrations. The effects of the three tree species on soil properties were significantly different at 12.2 dS m salinity level compared to the control. A. tortilis was the least salt sensitive. Balancing the key requirements of adequate germination and growth and the ability to reduce the salt concentration of the soil solution, B. aegyptiaca is the species with the most potential. Therefore, the study suggests to use B. aegyptiaca as agroforestry trees in the form of parkland in arid and semi-arid areas where salinity problems are prominent. [ABSTRACT FROM AUTHOR]

Wadi Helo (WH), in the United Arab Emirates, is a famous archeological site and protected area in the Hajar Mountains in the Arabian Peninsula. We investigated effects of topography, aspect, and altitude on floral diversity and species composition in this heterogeneous, mountainous, and highly arid environment. Using twenty transects distributed from the mountains top to the wadi bed; eighty plots, 100 m2each, were selected for vegetation analysis. Classification of vegetation using TWINSPAN showed three groups in the wadi bed and five in the mountains, each distinguished by different dominant species.Forsskaolaea tenacissima, Rhazya stricta, Tephrosia apolina, Notoceras bicorne, Acacia tortilis, andFagonia indicawere dominants of the microhabitats of the wadi bed. Gorges were dominated withDodonaea viscosaandLavandula subnoda. The other four groups were found on the mountain slopes and were associated with particular aspects (being north-, south-, west-, or east-facing). The dominant species for these different aspects were, respectively:Boerhavia elegans; Ochradenus aucheriandHelianthemum lippii; Moringa peregrina; andEuphorbia laricaandCenchrus ciliaris. Altitude showed highly significant positive relationship with species frequency (P < 0.001). South-facing slopes had the highest species richness and concentration of dominance. We concluded that the distribution of dominant species was a reflection of their ecological requirements and adaptations. Seven plant species were recorded as new to the flora of the UAE. These, plus ten additional species that had been reported as rare in only one of the two published floras of the UAE were highlighted as meriting greater priority in conservation. [ABSTRACT FROM AUTHOR]

This study aimed to investigate the effects of compost addition on leaf area index (LAI), diameter growth and enhancement of seed production and quality in Acacia tortilis established under supplementary drip irrigation. Three composted fertilizer doses (2.5 kg, 5 kg and 7.5 kg/ tree) were compared to NPK (18-18-5 at a rate of 250 gram per tree) and control unfertilized plots. Effects of compost application on leaf area index (LAI), diameter growth, relative monthly diameter increment (RMDI) were monitored during two consecutive years (2014 and 2015). Then the impacts on pods and seeds production, seed weight, seed number per kg, seed quality (NPK and protein), germination per cent and mean germination time (MGT) were determined. Addition of fertilizers produced high effects on LAI. In 2014 NPK resulted in highest LAI values in most measurements, alternatively the status was changed in 2015 where, higher doses of compost produced higher LAI values. LAI results exhibited temporal variability that was associated with the seasonal variation of the year. The results demonstrate higher RMDI and diameter growth under NPK and compost at rate of 7.5 kg/tree treatments. Pods production was higher in plots treated with higher doses of compost. However, seed/husk ratio was higher in NPK plots. There is observed association between fruit and seed production with LAI. NPK and protein contents in seeds, were also, influenced by the presence of organic fertilizers. Cumulative germination and MGT were correlated with seed weight and were higher in plots treated with compost. The results highlight the importance of organic fertilizers under dry land conditions that produced higher LAI and growth which enhanced seed production and quality. [ABSTRACT FROM AUTHOR]

Copyright of Phytothérapie is the property of John Libbey Eurotext Ltd. and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

This study was conducted to investigate the structuring of two sympatric and coflowering acacia species - Acacia ehrenbergiana (Hayne) and Acacia tortilis (Forsk.) - in relation to their flowering period distribution, floral reward partitioning, nectar secretion dynamics, and visitor assemblages. This research was performed in an arid climatic zone of the Arabian Peninsula (Saudi Arabia). To determine if there is partitioning of pollinators between the two species their peak flowering periods were monitored and the peak time of pollen release through the day was quantified as the ratio of polyads to anthers. The nectar sugar secretion dynamics were estimated following nectar sugar washing techniques. The types and frequency of visitors were recorded and correlated. The two species varied in their peak flowering time within a season and peak pollen release time within a day. Moreover, both species secreted significant amounts of nectar sugar. The sharing of pollinators and the partial monopoly of certain visitors were observed. The two sympatric acacia species are structured into a partial temporal separation of their peak flowering and pollen release times, which appears to be an adaptation to minimize pollinator competition. [ABSTRACT FROM AUTHOR]

Acacia tortilis is abundantly present in Saudi Arabia but its neuro-pharmacological activity has not yet been evaluated. In this study, the antidepressant by Forced swim test, Anxiolytic (Light and Dark box) and sedative effects (by using Open Field) of Acacia leaves extract were evaluated in mice. Aqueous extracts of the Acacia tortilis leaves were prepared. Two different doses (400 and 800 mg/kg) of the extracts were administered to the mice orally (p.o.). In exploratory behavior, Acacia leave extract (800 mg/kg) produced a significant reduction (Veh, 91.00 ± 5.26; Acacia 800 mg/kg, 46.33 ± 3.24 p < 0.05) similar to the effect observed with chlorpromazine (CPZ) (Veh, 91.00 ± 5.26; CPZ 1.0 mg/kg, 24.20 ± 3.40 p < 0.05). A dose-dependent significant decrease in immobility time was also observed in mice and this effect was comparable to its positive control (Imipramine). However, In light-dark box test, mice treated with high dose (800 mg/kg/day) spent significant ( p < 0.05) time on the light side of the light-dark box similar to positive control DZP. (Veh, 114.40 ± 6.30 s; Acacia 800 mg/kg, 162.2 ± 14.9; DZP 1.0 mg/kg, 184.20 ± 9.24 p < 0.05). The present research propounded that Acacia tortilis leave extract contains some active ingredients with potential anxiolytic activity at low doses and antidepressant and sedative activity at high doses. [ABSTRACT FROM AUTHOR]

Questions What are the relative contributions of short-term canopy and long-term soil effects of a savanna tree species in explaining differences in biomass, species density and composition of understorey plants (1) between trees and open areas, and (2) below trees between the northern and southern sides of the trees? Location Acacia tortilis tree savanna ecosystem, southern arid Tunisia (Bou Hedma National Park). Methods We measured environmental conditions (soil and microclimate) on the northern and southern sides of the trees and in open areas between trees. We also manipulated light on the southern side of the trees with a shade cloth, and cross-transplanted soils between north and south sides of the trees while testing for soil disturbance. The response of the vegetation was analysed with CCA and univariate analyses. Results Differences in species composition, richness and biomass of understorey communities between trees and open areas were mostly due to long-term soil effects of A. tortilis, mainly nutrients and water, whereas differences below trees were due to short-term effects of the trees, in particular on light and temperature conditions. Additionally, the soil disturbance induced by our soil transplantation treatment modified species composition and density, likely because of disruption of the soil crust. Conclusions Our study provides additional evidence that savanna trees have the potential to increase the diversity of arid systems at the landscape level. We showed that two main mechanisms are involved: (1) trees improve soil conditions, in particular nutrients and water, resulting in differences between trees and open areas; (2) within trees, there is heterogeneity of light and temperature conditions under the crown, resulting in vegetation differences. [ABSTRACT FROM AUTHOR]

Soil erosion and desertification are the main problems faced by the Bou-Hedma National Park in South-Tunisia. Restoration of the original woodland cover, particularly by afforestation and reforestation with Acacia tortilis ssp. raddiana , has been recognized as efficient to combat further degradation of the environment in this protected area. In order to study effects of woodland restoration and future trends in Bou-Hedma, it is essential to accurately assess its current situation. This paper addresses a monotemporal assessment of the population structure of A . tortilis . An extensive field inventory was performed to provide deeper insight into the dendrometric characteristics of this keystone species. Next, a spatially explicit and repeatable method is developed to model key tree attributes like crown diameter, volume and tree height from which the structural composition of the A . tortilis population in the Bou Hedma National Park is derived. This method involves analysis of a very high resolution (VHR) GeoEye-1 image within an OBIA (Object-based Image Analysis) framework. The remote sensing (RS) results show that the population of A . tortilis is typified by an irregular population structure and confirm the findings of Noumi and Chaieb (2012) suggesting regressive population dynamics. The RS approach demonstrates potential for monitoring purposes in this particular setting of an arid environment. [ABSTRACT FROM AUTHOR]

Chemical composition and nutritional evaluation as well as physicochemical and functional properties of seed flour of Acacia tortilis (Forssk.) Hayne ssp. raddiana were studied. The results indicated that seeds contained 5.30% moisture, 3.99% ash, 9.19% fat, 14.31% fiber, 27.21% protein and 45.30% carbohydrates. Potassium was the predominant element followed by calcium and then phosphorous. Phytic acid, tannins and trypsin inhibitor as antinutrients were detected. The amino acid profile compared well with FAO/WHO recommended pattern except for cystine/methionine, isoleucine, tyrosine/phenylalanine, lysine and threonine. Also, the first limiting amino acid was lysine. Fatty acid composition showed that linoleic acid was the major fatty acid, followed by palmitic, stearic, oleic and arachidic acids. The seed oil showed absorbance in the ultraviolet ranges, thus it can be used as a broad spectrum UV protectant. For physicochemical and functional properties, acacia seeds flour had excellent water holding index, swelling index, foaming capacity and foam stability. [ABSTRACT FROM AUTHOR]