Sediments are the material basis for the development of eolian landscapes, and dune sediments contain key information about dune formation and development. Through field sampling and indoor laser particle sizer experiments, this study compiled the most comprehensive and open database of particle size characteristics of different types of dune surface sediments across the Kubuqi Desert (n = 396 sample areas). The surface sediments of parabolic dunes, crescent dunes and chains, reticulate dune chains, compound dunes, ridge–honeycomb dunes, shrub-coppice dunes, and inter-dune lowlands in the Kubuqi Desert were studied. The grain-size parameters of dune sediments were measured, and their geographical patterns assessed. The methodology and datasets in this paper are also applicable to other arid regions and are a valuable resource for comparative studies of different types of dunes in deserts, which can provide important data for the formation and evolution of dunes, as well as deserts, sand sources, and the restoration of weathered environments.

Artificial shelterbelts in arid and semi-arid regions play a key role in controlling land degradation, regulating wind erosion, and maintaining ecological security. However, their long-term protective effectiveness increasingly depends on accurate degradation diagnosis and targeted management of aging and degraded stands. This study developed a comprehensive health assessment and degradation grading framework for poplar shelterbelts in the Kubuqi Desert, northern China, using an indicator system covering stand structure, community structure, soil conditions, health risks, and external disturbances. Indicator weights were determined using the entropy weight method, and degradation grades were classified by combining the technique for order preference by similarity to ideal solution (TOPSIS) model with the rank-sum ratio (RSR)–Probit method. The results showed that soil conditions and stand structure were the dominant dimensions distinguishing degradation status, with weights of 50.98% and 25.30%, respectively. Grade I, Grade II, Grade III, and Grade IV stands accounted for 21.88%, 25.00%, 34.38%, and 18.75% of the plots, respectively, indicating that lightly and moderately degraded stands were predominant. Degradation grades were also associated with changes in understory cover and surface soil nutrients, especially decreases in soil organic matter and alkali-hydrolyzable nitrogen. Based on these results, grade-specific management strategies were proposed, including conservation and maintenance, density regulation, assisted restoration, and near-natural transformation. This framework provides a practical basis for diagnosing degradation status and guiding the renewal and management of aging shelterbelts in arid sandy regions.

As a vital component of the desert ecological protection system, the edge-locked forests of the Kubuqi Desert play a crucial role in mitigating wind erosion, stabilizing sand, maintaining soil and water, and restricting desert expansion. In this paper, six types of standard protection forests in the Kubuqi Desert, namely Salix psammophila (SL), Elaeagnus angustifolia (SZ), Salix matsudana (HL), Corethrodendron fruticosum+Salix psammophila (YC + SL), Caragana korshinskii + Populus simonii (XYY + NT), and Elaeagnus angustifolia + Salix matsudana (SZ + HL), were investigated. Notably, the vertical differentiation patterns of soil carbon (C), nitrogen (N), phosphorus (P), and ecological stoichiometric ratios, as well as soil particle size features within the 0–100-cm soil layer under protection forests with different allocation modes, were systematically and comprehensively analyzed. The study’s findings showed that: (1) Among the six configuration types, SZ, NT + XYY, and SL exhibited higher soil SOC and TN concentrations. Both soil SOC and TN content decreased with increasing soil depth, whereas soil TP content displayed no considerable variation among different stand types or soil depths. (2) Based on the N/P threshold hypothesis, N was the limiting nutrient element for the growth of edge-locked forests in the region. (3) The understory soils of different configurations of edge-locked forests mainly comprised sand. The silt and clay contents of SL and NT + XYY were substantially higher than those of the other four configurations. The vertical distribution patterns of particle size and parameter characteristics had variations. (4) Soil C, N, P, and stoichiometric characteristics are affected by vegetation type, soil depth, and soil texture. In conclusion, SZ and SL can be used as the dominant tree species in the edge-locked forests of the Kubuqi Desert, and the NT + XYY mixed forest configuration pattern displays the most apparent soil improvement effect. This study’s findings offer a scientific reference and foundation for restoring vegetation and enhancing the ecological environment in desert regions. In addition, they provide a theoretical foundation for establishing and managing edge-locked forests.

Sediments are the material basis for the development of eolian landscapes, and dune sediments contain key information about dune formation and development. The surface sediments of parabolic dunes, crescent dunes and chains, reticulate dune chains, compound dunes, ridge–honeycomb dunes, shrub-coppice dunes, and inter-dune lowlands in the Kubuqi Desert were studied. The grain-size parameters of dune sediments were measured, and their geographical patterns assessed. In the Kubuqi Desert, parabolic dunes contain the coarsest sediment and shrub-coppice dunes the finest. The average grain size of the overall surface sediment is 2.14–2.73 φ, with poor sorting, which is in the middle of the grain-size range compared with other deserts globally. The depositional environment of the Kubuqi Desert is dominated by eolian and flood deposition; the Yellow River, inland rivers, and seasonal alluvial-flood channels alter the dynamic conditions of the desert depositional environment. The major proximal material sources of surface sediments in the Kubuqi Desert are fluvial sediments remaining after Yellow River channel oscillation, fluvial alluvium and sediments in the Yellow River valley, remnant-slope deposits weathered from mountain bedrock, and stream-phase alluvial deposits in dry denuded uplands. The crescent dunes and chains and the compound dunes have a common sediment source.