2026-10-11T19:31:13Z https://www.scidb.cn/oai

10.57760/sciencedb.00zub 2026-08-20T16:35:51Z

2026-08-20 Chemometrics of Calligonum junceum in 2021 doi:10.57760/sciencedb.00zub en Study site and experimental designThe research site is located at the Turpan Desert Botanical Garden, Chinese Academy of Sciences. The seeds of the study species originated from the eastern edge of the Junggar Desert in northern Xinjiang, China, and were introduced to the garden in the early 1970s. The standard plants selected for marked sampling were all mature individuals naturally germinated in 1982. The common garden experimental design effectively eliminated the interference of microhabitat and soil heterogeneity on plant trait expression in this extremely arid region, providing an ideal platform for accurately assessing plant ecological stoichiometric dynamics driven by phenological rhythms. Under the uniform habitat conditions of the common garden, Calligonum junceum could fully and stably express its genetically determined vegetative growth rhythms and resource allocation strategies (e.g., rapid tissue construction in spring, drought resistance and water retention in summer, and nutrient withdrawal and resorption in autumn). To ensure the basic survival of the plants during extreme summer drought and winter, the garden applied moderate supplemental furrow irrigation in summer and winter.Sampling and pretreatmentFrom April to October 2021, covering the complete phenological period of Calligonum junceum, continuous monthly sampling was conducted in the common garden. Six individuals with similar growth vigor were selected as standard plants. Taking the first sampling on April 10 as an example, five portions of mature branches (branch age <3 years, diameter ≤5 mm) and five portions of green assimilating shoots (current‑year, bright green, fully developed, and free of pests and diseases) were evenly clipped from the east, south, west, and north directions of the canopy of each marked plant. The same organs from each plant were pooled into independent replicate samples. Fresh samples after collection were promptly placed into self‑sealing bags, stored in portable coolers with ice packs, and transported to the laboratory as soon as possible. In the laboratory, green assimilating shoots and mature branches were strictly separated and placed into labeled envelopes for pretreatment: first, they were oven‑dried at 105 °C for 30 minutes to deactivate enzymes, and then dried at 65 °C to constant weight for subsequent nutrient element determination.Results presentation (figures and sections)Fig. 1 shows the map and the location of the study area; the two figures are combined into one in the article.Section 2.1 covers hierarchical partitioning, with a variance decomposition stacked plot. Fig. 2 presents the variance explanation rates of month, organ, and their interaction on the variation of nutrient elements and stoichiometric ratios in aboveground organs of Calligonum junceum, with a two‑way ANOVA provided as supplementary material.Section 2.2 addresses compositional differences. Fig. 3 shows the monthly dynamics of N, P, and K concentrations in different aboveground organs (assimilating shoots and mature branches) of Calligonum junceum. Fig. 4 displays the spatial distribution and monthly variation of stoichiometric ratios (N:P, N:K, P:K) in different aboveground organs.Section 2.3 is allometric relationship analysis, both by organ group and overall. Fig. 5 shows the allometric relationships among N, P, and K elements within different aboveground organs of Calligonum junceum. Fig. 6 presents the cross‑organ allometric allocation model of N, P, and K elements between assimilating shoots and mature branches.Section 2.4 is meteorological factor analysis, examining the effects of meteorological factors on NPK and their ratios across organs. Fig. 7 shows the independent explanatory power of meteorological factors on the variation of nutrient stoichiometric characteristics in different aboveground organs (assimilating shoots and mature branches) of Calligonum junceum. Fig. 8 presents the relative contribution rates of meteorological factors to the variation in nutrient content and stoichiometric ratios in assimilating shoots. Fig. 9 shows the relative contribution rates of meteorological factors to the variation in nutrient content and stoichiometric ratios in mature branches. Ecological stoichiometry; Monthly dynamics; Meteorological factors liu fan RESTRICTED dataset Science Data Bank