Search Results (4)

A predominant management practice to reduce wind erosion in the arid deserts of northwest China is the planting of shrubs. However, the carbon sequestration capacity of these sand-fixing plantations has not received much attention. In this study, the carbon sequestration capacity of six typical sand-fixing plantations (Haloxylon ammodendron (C. A. Mey.) Bunge, Caragana korshinskii Kom., Tamarix ramosissima Ledeb., Calligonum mongolicum Turcz., Artemisia desertorum Spreng. and Hedysarum scoparium Fisch. & C. A. Mey.) in the Shiyang River Basin were compared and analyzed. We evaluated how carbon sequestration may vary among different species, and examined if plantation age or management style (such as the additional construction of sand barriers, enclosure) positively or negatively influenced the carbon storage potential of these plantation ecosystems. Our results showed that all six plantations could store carbon, but plant species is the controlling factor driving carbon stock accumulation in plantations. The actual organic carbon stored beneath 25-year-old T. ramosissima, H. ammodendron, C. korshinskii, H. scoparium, C. mongolicum and A. desertorum plantations was 45.80, 31.80, 20.57, 20.2, 8.24 and1.76 Mg ha⁻¹, respectively. Plantations using a clay–sand barrier had 1.3 times the carbon sequestration capacity of plantations that only used wheat straw and sand barriers. Similarly, enclosed plantations had 1.4 times the carbon storage capacity of unenclosed plantations. Plantation age greatly impacts carbon sequestration capacity. A 25-year-old H. ammodendron plantation has a carbon sequestration capacity three times greater than that of 3-year plantation. We conclude that while afforesting arid areas, H. ammodendron and T. ramosissima should be prioritized, and priority also should be given to using clay–sand barrier and enclosure. Full article

Considering the importance of soil moisture in hydrological processes, it is crucial to understand the water distribution and time stability of different aerial shrub soils. There are few studies on the soil moisture of aerial vegetation in the northeastern margin of the Tengger Desert. Based on long-term monitoring data from the aerial seeding area in the northeastern margin of the Tengger Desert, the distribution characteristics of soil moisture and the temporal stability of soil moisture were studied. From June to October 2022, the soil moisture monitoring instrument WatchDog was used to monitor the long-term soil moisture changes (0–200 cm) in the four aerial afforestation plots of Hedysarum scoparium, mixed forest land (Hedysarum scoparium dominant species), mixed forest land (Calligonum mongolicum dominant species), and Calligonum mongolicum. The Spearman rank correlation coefficient was used to study the temporal stability of soil moisture in the four plots. Rainfall data were collected through small weather stations. The results show that the average soil water storage of four kinds of aerial shrub land in the study area was the highest in August, and the average soil water storage of different forest lands was different. The soil water content of the surface layer (0–30 cm) fluctuated the most in different months. The variation in soil water content in the shallow layer (30–100 cm) was smaller than that in the surface layer. The fluctuation of soil water content in the middle layer (100–150 cm) and deep layer (150–200 cm) was relatively stable. There was no strong variability in soil moisture content, and the temporal variation coefficient of surface soil moisture was the highest (31.44–39.8%), which showed moderate variability. The temporal variation coefficient of soil moisture in the shallow, middle and deep layers of all kinds of plots was significantly reduced, and the soil moisture stability of different aerial shrub land was the same. Spearman rank correlation analysis showed that the spatial pattern of soil water content in the surface layer (0–30 cm) and deep layer (150–200 cm) was more stable over time, that is, the temporal stability of soil water content was higher, and the temporal stability of soil water content in the middle and shallow layers of different types of shrub land was different. The research results help us to understand the soil hydrological process in the aerial seeding afforestation area in the northeastern margin of Tengger Desert, rationally arrange soil moisture monitoring points, efficiently manage and utilize water resources in the aerial seeding area, and provide a theoretical basis for local vegetation restoration and the optimization of the ecological environment. Full article

Understanding the integrated effects of vegetation types on the physicochemical properties and quality of sandy soils is crucial for guiding vegetation reconstruction and ecological restoration in desertified areas. This study selected three vegetation types at the southern edge of the Mu Us sandy land, including fenced Leymus secalinus Tzvel. grassland (LS), natural Hedysarum mongolicum Turcz (HM) forest land, and Salix cheilophila Schneid. (SC) forest land, as well as sandy land as a control (SD). The differences in the soil physicochemical properties were investigated by collecting soils from three layers within 0–60 cm. The soil quality index (SQI) was calculated using principal component analysis to comprehensively evaluate the soil quality. This study found that the soil physicochemical properties differed significantly among the plots and layers, and the soil properties exhibited a vertical distribution, with chemical indicators concentrated in the surface layer. As depth increased, differences in soil properties between the vegetation and control plots diminished, with vegetation influence mainly in the 0–20 cm layer. Among all the sample sites, the 0–20 cm layer of LS had the highest organic matter content (5.98 g/kg), which was 2.25, 2.28, and 4.71 times that of HM, SC, and SD, respectively. Moreover, LS had the lowest bulk density (1.35 g/cm³), which was 0.89, 0.91, and 0.86 times lower than that of HM, SC, and SD, respectively. The effects of different vegetation restoration types on the comprehensive quality of soil were different, as shown in LS (0.15) > HM (0.11) > SC (0.10) > SD (0.08). In conclusion, all three vegetation restoration types significantly affected the soil physicochemical properties and led to different degrees of variability of soil indexes in the vertical profile, and the fenced grassland restoration type may be preferable for ecological restoration and reconstruction in this region. Full article

This study aimed to screen out the shrub species which can promote the seed germination and seedling growth of Amygdalus pedunculata Pall. and offer insight for ecological environment governance of the coal mines subsidence area in Mu Us Sandy Land, Yulin City of Shaanxi Province. The indoor bioassay method was used to study the aqueous leaf extracts from Amorpha fruticosa Linn., Hedysarum mongolicum Turez., Sabina vulgaris Ant., and Hippophae rhamnoides Linn. under different concentration gradients to examine seed germination, initial growth, and physiological and biochemical of two Amygdalus pedunculata varieties (YY-1 from Yuyang County (YY) and SM-6 from Shenmu County (SM), Shaanxi Province, China). The results showed that with aqueous leaf extracts concentrations at lower concentrations of 0.025 (T1) and 0.05 g·mL⁻¹ (T2) from A. fruticosa, H. mongolicum, and S. vulgaris significantly promoted seed germination and seedling growth of two A. pedunculata varieties. Moreover, H. rhamnoides aqueous leaf extracts had the strongest inhibitory effect on seed germination and seedling growth of A. pedunculata, and death occurred at concentrations of 0.15 (T4) and 0.20 g·mL⁻¹ (T5). The enzyme activity and chlorophyll content of the A. pedunculata leaves decreased with an increase in the aqueous leaf extracts concentration of the four shrubs; the change trend of malondialdehyde content was the opposite. Root activity of the A. pedunculata increased and then decreased. The H. mongolicum and S. vulgaris are the most suitable mixed tree species for YY-1, while H. mongolicum and A. fruticosa are the most suitable mixed tree species for SM-6 at a relatively low density with more security. The results provide a theoretical basis and technical support for the establishment of an artificial mixed forest of A. pedunculata in the coal mine subsidence area of Mu Us Sandy Land. Full article