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1

Adaptive strategy to drought conditions: diurnal variation in water use of a Central Asian desert shrub

100%
Wang S.-S., Chen X., Zhou K.-F., Wang Q.
Polish Journal of Ecology
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2015
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tom 63
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nr 1
Water availability is one of the most important factors limiting photosynthetic assimilation of carbon dioxide and growth of individual plants in terrestrial ecosystems. It is especially important for desert shrubs because the diurnal water availability is particularly sensitive to climate change in arid ecosystems. Water use efficiency (WUE) is an indicator of water availability and is frequently used to assess plant performance in various ecosystems, particularly in arid ecosystems. The WUE of plants has been widely assessed using ecological methods and field measurements; however, these approaches are impractical to obtain numerous near-simultaneous estimates of plant water status at the landscape-scale. Consequently, landscape-scale assessments of plant water status are practically pursued through modeling. In this study, measurement and modeling of the diurnal variations of WUE were conducted for a native dominant desert shrub, Tamarix ramosissima, in its original habitat on the periphery of the Gurbantunggut Desert, China. The diurnal net photosynthesis (An), stomatal conductance (gs), and transpiration (Tr) were measured for each individual using a portable photosynthesis system. A coupled model of stomatal conductance, photosynthesis, and transpiration was applied to simulate the diurnal dynamics of An, gs, Tr, and WUE. The model explained 83, 47, 83, and 55% of the variance in the measured An, gs, Tr, and WUE values, respectively, for this desert ecosystem in which T. ramosissima is sparsely distributed. The results demonstrated that the coupled photosynthesis-stomatal conductance-transpiration model strategy is a promising approach to estimate water availability in desert ecosystems in Central Asia.
2
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Influence of regulated drip irrigation on productivity and physicochemical traits of tomato ‘Tofane’ under hot desert climate

100%
Azzeddine C., Mostapha B. B., Houria C.
Journal of Horticultural Research
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2020
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tom 28
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nr 1
3

Effects of litter accumulation on plant communities in fenced desert steppe

100%
Li X., Liu B., Chen L., Song N.
Polish Journal of Ecology
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2015
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tom 63
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nr 3
The litter decomposition plays an important role in nutrient circle of grassland ecosystem, the water holding ability of litter and physical and chemical characteristics have been studied exclusively over the past century. However, the effect of litter accumulation on plant community in desert steppe under fenced condition was little known. In this study, four typical plant communities were employed to identify the effects of litter accumulation on plant communities. The results showed the trend of litter accumulation amount in the four different types of plant communities was best represented by Birk model. The accumulation of litter had different effects on the number of seedlings. When litter accumulation reached 300–400 g cm⁻², green-up dates advance 7 days. The amount of seedling germination and the number of plant species reached a peak. Meanwhile, plant density, coverage, average height, richness, and evenness reached maximum values. It was concluded that when opposite fencing time was about 6 years, and the optimum amount of litter accumulation was about 300–400 g cm⁻², which could advance the green-up dates and increase the number of plant seedlings, and also improve or maintain community stability. Such a notion has to be taken into account for the development of an improved policy for environmental management in desert steppe.
4

Vegetation landscape analysis due to land use changes on arid lands

100%
Manjarrez-Dominguez C., Pinedo-Alvarez A., Pinedo-Alvarez C., Villarreal-Guerrero F., Cortes-Palacios L.
Polish Journal of Ecology
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2015
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tom 63
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nr 2
Fast land use changes have strongly affected arid and semi-arid regions at a global scale, affecting food security of the inhabitants of these regions. This study evaluated the fragmentation degree in the Chihuahua´s desert region of Mexico by using data from the Landsat TM sensor. Nine scenes, taken with Landsat TM5 sensor from the years 1990, 2000, and 2012, were used for the analysis. The coverage of seven land uses (grasslands, shrubland, croplands, sandy desert vegetation, forest, water bodies, and urban areas) was obtained under supervised classification techniques and the accuracy level was evaluated through the Kappa multi-varied discrete index. The classification showed a good reliance level having global accuracies of 93, 93.2 and 90.3% for the years 1990, 2000 and 2012, respectively. The fragmentation analysis showed an increase in the number of patches, an indicator of the ecosystem degradation process. The patches number increased from 8,354.23 in 1990 to 9,658.36 in 2000 and to 11,469 in 2012. Simpson and Shannon diversity indexes proved a clear fragmentation process. During the period of 1990−2012, grasslands were the most affected vegetation type with a reduction of 30.7% in its area. Such reduction was mainly attributed to invasions of shrubland communities and to an increase in cropland areas.
5

Intensity of organic matter decomposition in various landscapes of Caucasus [Daghestan]

100%
Fischer Z., Niewinna M., Yasulbutaeva I.
Polish Journal of Ecology
|
2006
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tom 54
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nr 1
Decomposition process in the soil of desert, steppe and mountain landscapes was studied in the region of Caucasus (Daghestan). The study sites differed mainly in average temperature and humidity being generally extremely dry with soil poor in organic matter. Two methods – bags with grass and cellulose filter paper discs were used. No dependence was found between the rate of decomposition of introduced organic matter and organic nitrogen content, and C:N ratio in soil, but strong dependence was found with temperature and humidity conditions. The measured rate of organic matter decomposition in soil of desert, steppe, and mountain sites indicated that the level of decomposition activity of these soils is high. In summer it is lowest in steppe (1.97 mg · g⁻¹ · 24 h⁻¹), whereas the highest in mountains (5.68 mg · g⁻¹ · 24 h⁻¹). The annual average rate of decomposition of cellulose discs and hay in mountain site was almost two times higher than in steppe site and nearly three times higher than in desert site. Mainly climatic conditions i.e. long-lasting drought (almost all the year) in desert as well as in steppe (January to August) are responsible for this difference.
6

Space partitioning among two sympatric species, sand cat (Felis margarita) and Ruppell’s fox (Vulpes rueppellii), in a desert landscape in Central Iran

80%
Akbari Feizabadi H., Naderi M., Ashrafi S., Hemami M. R.
Polish Journal of Ecology
|
2018
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tom 66
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nr 2
This study evaluates and compares habitat preferences and spatial niche breadth and overlap between two sympatrically occurring species, the sand cat (Felis margarita) and Rüppell's fox (Vulpes rueppellii), in a desert landscape of central Iran. A field survey from 2014 to 2016 was conducted to collect occurrence points for the two species as well as to identify their structural characteristics of used habitats in the occurrences points. Jacobs' index as a measure of habitat preference, Shannon and Levins' indices as measures of niche breadth, MacArthur, Levins and Pianka's indices as measures of niche overlap were calculated and interpreted. The results of this study showed that the sand cats are specifically restricted to sand dune and sabulous habitat type, whereas Rüppell's foxes have wider ecological amplitude. Sand cats only prefers sand dunes while Rüppell's foxes were found to prefer foothills, badlands, and sand dunes. Rüppell's foxes therefore had a wider niche breadth compared to the sand cats. The asymmetric MacArthur and Levins indices yielded a higher value of niche overlap for the sand cats compared to Rüppell's foxes, while the symmetric Pianka's measure of niche overlap was relatively high for both species. Such habitat preference and niche segregation between the two species may be a result of their feeding habits or the physical protective structure of their habitats attributes.
7

Panceriella emiratensis sp. nov. (Eucestoda, Linstowiidae) from desert monitor lizard, Varanus griseus (Daudin, 1803) in the United Arab Emirates

80%
Schuster R. K.
Acta Parasitologica
|
2012
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tom 57
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nr 2
Two hundred and twenty seven cestodes of the genus Panceriella were detected in the small intestine of a desert monitor lizard, Varanus griseus in the Dubai Emirate of the United Arab Emirates. Panceriella emiratensis sp. nov. is considerably shorter than the type species P. varanii and can be easily distinguished by the presence of an unsegmented neck, smaller numbers and smaller diameter of testes. Gravid segments contain a distinctly lower number of egg capsules.
8

Effects of ultra-violet radiation on cellular proteins and lipids of radioresistant bacteria isolated from desert soil

80%
Sajjad W., Khan S., Ahmad M., Rafiq M. M., Badshah M., Sajjad W., Zada S., Khan S., Hasan F., Shah A. A.
Folia Biologica
|
2018
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tom 66
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nr 1
9

Effect of vegetation and soil conditions on burrow structure and site selection of rare desert rodent – Iranian jerboa (Allactaga firouzi)

80%
Naderi G., Hemami M. R., Mohammadi S., Riazi B., Karami M., Kaboli M., Alesheikh A. A.
Polish Journal of Ecology
|
2011
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tom 59
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nr 2
The Iranian jerboa (Allactaga firouzi Womochel, 1978) is one of the rarest rodent species in the world and it has been reported exclusively from a single site in central Iran. Because of its restricted geographical distribution and habitat degradation, it has been classified as Critically Endangered in the IUCN Red List. From April 2007 to February 2009 on a small area (2200 ha) of semi-arid grazed steppe (altitude 2000 m, surface covered by bare soil and/or scarce shrub and grass vegetation) we studied the architecture structure of burrow system and burrow site selection of Iranian jerboa. Three types of burrows including temporary burrows, winter and s ummer burrows were detected in the studied habitat. Habitat characteristics such as the percentage cover of: bare soil, pebble and cobble and desert plant species like Anabasis aphylla, Artemisis siberi, and Peganum harmala, as well as the selected chemical soil parameters (content of calcium sulfate, calcium carbonate) were measured in the burrow sites and compared with similar variables measured at random plots in the non-burrow sites. The principal component analysis successfully distinguished between the burrow sites and the non-burrow areas. The burrow site selection was mainly influenced by percentage cover of bare soil, vegetation type, soil texture and chemistry.
10

Differential effects of grazing on plant functional traits in the desert grassland

80%
An H., Li G.
Polish Journal of Ecology
|
2014
|
tom 62
|
nr 2
Plant functional traits are linked with environmental factors, individuals and ecosystem structure and functions as plants respond and adapt to the environment. Here, the whole-plant traits (plant height and plant biomass), leaf morphological (leaf area, leaf dry mass and specific leaf area) and chemical traits (leaf carbon, nitrogen, phosphorus contents, C/N and N/P ratio) of six dominant species (Cynanchum komarovii Al, Euphorbia esula Linn, Glycyrrhiza uralensis Fisch, Lespedeza potaninii Vass, Agropyron mongolicum Keng and Stipa breviflora Griseb) were studied in the desert grassland of China, with a grazing experiment including four grazing intensity (0.00, 0.45, 1.00, 1.50 sheep ha–1). The effect of grazing on leaf morphological traits were significant for the six dominant species, while the effects on whole-plant traits were highly significant for S. breviflora, A. mongolicum, G. uralensis, L. potaninii and C. komarovii. Three of the six species (S. breviflora, A. mongolicum and L. potaninii) decreased in plant height (PH) with increasing grazing intensity, while specific leaf area (SLA) and leaf N (Nmass) showed the opposite trend. The whole-plant traits were significantly positively correlated with leaf dry mass (LM), but significantly negatively correlated with leaf nitrogen and phosphorus contents. The first principal component analysis (PCA) axis corresponding to plant size (PH and PB) and leaf size (LA and LM), while the second axis of PCA to leaf chemical traits (Nmass, P, C and N/P). Variations of plant traits in response to grazing were mainly explained by size trait and chemical traits. The functional traits cannot be the only basis for predicting plant species in response to grazing, and a functional analysis of the trade-off between plant traits is also needed.
11

Charcoals from Neolithic site at Nabta Playa [E-75-6], Egypt

80%
Barakat H. N.
Acta Palaeobotanica
|
1995
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tom 35
|
nr 1
12

Nitrate-drought interactions on growth, osmoprotectants and antioxidant system of the oil accumulating desert plant jojoba

71%
Farghaly F. A., Galal H. K., Radi A. A. F., Abdel-Basset R.
Journal of Biology and Earth Sciences
|
2013
|
tom 03
|
nr 1
13

Mycoflora of some medicine plants growing in the Egyptian Eastern desert

70%
Badran R. A. M., El-Zawahry A. M.
Acta Mycologica
|
1994
|
tom 29
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nr 2
14

Przystosowanie się wielbłąda do braku wody (obalenie pokutującej dotąd legendy)

70%
I.V.
Wszechświat
|
1957
|
nr 02
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