Search Results (4)

Salt stress is a key environmental factor that has adverse effects on plant growth and development. High salinity induces a series of structural and functional changes in the morphological and anatomical features. The physiological and biochemical changes in K. foliatum in response to salt stress in natural environments are still unclear. Based on this, this study compared and analyzed the differences in the physiological and biochemical indicators between the leaf and root tissues in high-salt and low-salt habitats, selecting K. foliatum as the research object. The results showed that the chlorophyll contents in the leaves of K. foliatum decreased in the high-salt habitat, while the thicknesses of the upper and lower epidermises, as well as the thicknesses of the palisade tissue, significantly increased. The high-salt environment led to decreases in the N and P contents in the leaves and root tissues of K. foliatum, resulting in changes in the stoichiometric ratio of elements. The concentrations of C, N, and P in the roots of K. foliatum were lower than those in the leaves. The accumulation of Na⁺ in the K. foliatum roots was greater than that in the leaves, and the roots could promote the transport of sodium ions to the leaves. The contents of starch and soluble sugar in the leaves showed higher proportions in the high-salt habitat than in the low-salt habitat, while the changes in the roots and leaves were the opposite. As the salt content increased, the proline contents in the leaves and roots of K. foliatum significantly increased, and the proline contents in the roots of K. foliatum were lower than those in the leaves. The leaves and roots exhibited higher levels of peroxidase and superoxide enzymes in the high-salinity habitat than in the low-salinity habitat. The superoxide dismutase (SOD) activity of the K. foliatum leaves and catalase (CAT) activity of the roots were the “central traits” in the high-salt habitat. In the low-salt habitat, the leaf malondialdehyde (MDA) and root C/N were the central traits of the leaves and roots, indicating that K. foliatum adapts to changes in salt environments in different ways. Full article

Shrubs are the main dominant plants in arid desert systems and play an important role in maintaining the biodiversity, ecosystem services and stability of desert ecosystems. Studies have shown that the survival of a large number of shrub species in desert areas under the influence of climate change is significantly threatened, with different species showing different response strategies. To test the tolerance of different shrub species to climate change, this study selected 10 dominant shrub species (ancient relict shrub species and regional endemic shrub species) in the Alashan desert area as the research object. Based on a field survey of species distribution, a species distribution model was developed to simulate the suitable distribution area of shrub species under current conditions and under future climate change scenarios. The distribution changes of ancient relict and regional endemic shrub species under the climate change scenarios were tested, and the tolerance of the two types of shrub to climate change was analyzed. The results showed that under different climate change scenarios, except for Ammopiptanthus mongolicus, the total suitable area of four out of the five relict plants was relatively stable, the potential distribution area of Tetraena mongolica increased, and the future distribution pattern was basically consistent with the current distribution. However, the suitable area of typical desert plants was unstable under different climate change scenarios. Except for Kalidium foliatum, the suitable distribution areas of four out of the five shrubs showed different degrees of reduction, and the distribution location showed significant migration. Based on the research results, climate change will lead to the reduction and displacement of the distribution area of typical desert shrubs, while relict shrubs will be less affected by climate change. This is because, compared to desert species, relict plants have a longer evolutionary history and have developed a wider range of adaptations after experiencing dramatic environmental changes. This study provides a scientific basis for actively responding to the impacts of climate change on desert ecosystems. Full article

The article presents data on phylogeny, genome size, and ploidy of species of the genus Kalidium Moq. in the flora of Kazakhstan. Genus Kalidium belongs to the tribe Salicornieae of the subfamily Salicornioideae of the family Chenopodiaceae and unites eight species, the main range of which covers the Iranian-Turanian and Central Asian deserts. There are four species in the flora of Kazakhstan: K. foliatum, K. caspicum, K. schrenkianum, and the recently described K. juniperinum. Populations of species of the genus Kalidium in the saline deserts of Kazakhstan occupy large areas, often forming monodominant communities. Sometimes there is a joint growth of two and very rarely three species of the genus. During the period of fieldwork (2021–2022), populations were identified in which these species grew together with a predominance, in most cases, of K. caspicum. Samples of representatives from 15 populations were collected for research. Selected plant samples were studied by flow cytometry to determine plant ploidy. Sequencing of nrITS and two chloroplast fragments were used to build a phylogenetic tree, including sequences from the NCBI database., A phylogenetic tree of species of the genus Kalidium was compiled, which takes previously published data into consideration. In the valley of the middle reaches of the Syrdarya River, tetraploid populations of K. caspicum were found. A hybrid between K. foliatum and K. caspicum was found in the Ili River valley (Almaty region, Uigur district). To identify phylogenetic processes at the intraspecific level, the SCoT (Start codon targeted) fingerprinting method was used. Full article

Quantification of the water budget of an arid inland river ecosystem is essential but still a challenge for the sustainable development of water resources. In situ observed data were used to analyze the monthly and annual water budgets and the soil hydrological cycle for six typical ecosystems in the Heihe River Basin (HRB). The two-source model was used to partition evapotranspiration (ET) into transpiration (T) and evaporation, after which the validated model was applied to quantitatively analyze the biological water use fraction [T/Ecosystem Water Supply (WS)] for different ecosystems. There were differences in the water budgets of the different ecosystems due to differences in climate, vegetation, soil, and external inputs. Precipitation in the HRB decreased from upstream to downstream, whereas there was a gradual increase in ET. External sources of water (e.g., natural runoff from upstream, irrigation in the middle reaches, and groundwater recharge in the lower reaches) to soil layers played an important role in regulating the water budgets of HRB ecosystems. Cropland obtained the maximum biological water use fraction (0.50), followed by Populus euphratica (0.49), alpine meadow (0.49), alpine swamp meadow (0.44), Tamarix ramosissima (0.42), and Kalidium foliatum (0.4). The soil water residence time (at a depth of 40 cm) varied from 14 d to 97 d (average of 60 d). The order of plant species in terms of soil water residence time was: K. foliatum (88 d) > T. ramosissima (72 d) > alpine meadow (68 d) > alpine swamp meadow (63 d) > cropland (53 d) > P. euphratica forest (20 d). Differences in the biological water use fraction and soil water residence time could be attributed to the characteristics of the water budget for each ecosystem. This study quantified the water budget, biological water use, and soil hydrological cycle across typical ecosystems in HRB, and can act as a reference for ecosystem management of the arid inland river basin. Full article