Subjects: Geosciences >> Geography submitted time 2024-03-01 Cooperative journals: 《干旱区研究》
Abstract： The construction of mathematical models is one of the important methods to estimate shrub biomass. In this study, two desert shrubs, Reaumuria soongarica and Sympegma regelii, commonly found in the piedmont belt of the northern slopes of the mid Kunlun Mountains, were observed in this study. The whole-plant harvesting method was used, plant height (H), canopy area (S) and plant volume (V) were used as the independent variables, and plant above-ground biomass (W1), below-ground biomass (W2) and whole-plant biomass (W3) were used as the dependent variables, to establish function model. The optimal models for biomass estimation of these two desert shrubs were selected based on the largest determination coefficient (R2), the smallest estimated standard deviation (SEE) and significant level (P<0.001). The results showed that the optimal models for biomass estimation of R. soongarica and S. regelii were quadratic function model, except for the whole plant optimal prediction model of S. regelii was linear function model. For R. soongarica, the highest correlation was observed between plant volume (V) and biomass, with R2 ranged from 0.820 to 0.920. For S. regelii, the highest correlation between canopy area (S) and biomass was observed, with R2 ranged from 0.935 to 0.973. The optimal models for biomass estimation of R. soongarica and S. regelii all passed through significance test (P<0.001), with fit rates ranging from 84.1% to 95.6%, and these models could be used for biomass estimation. The results from this study will be very helpful for studying carbon stocks and evaluating carbon sink potential in desert ecosystem.
Subjects: Biology >> Botany submitted time 2023-03-13 Cooperative journals: 《干旱区研究》
Abstract： Leaves and roots respond to drought stress through morphological, physiological, and biomass accumulation changes. Alhagi sparsifolia is the dominant plant in the desert- oasis transition zone of Cele. We analyzed the characteristics of growth and physiological changes in leaves and roots of 1-year-old A. sparsifolia seedlings through a pot experiment. Results revealed the adaptive strategy of A. sparsifolia to drought stress. We simulated three water conditions (CK is well- watered: 70%-75% field capacity (FC); W1 is mild stress: 50%- 55% FC; W2 is severe stress: 25%-30% FC). The results show the following: (1) Drought significantly inhibited the growth of the aboveground and underground tissues of A. sparsifolia. The main manifestations are: leaf area, root length, root surface area, root tissue density, and soluble sugar content of leaves and roots decreased significantly under stress (P < 0.05). The leaf tissue density, leaf dry matter content, specific root length, proline and malondialdehyde contents of leaf and root increased. (2) In the early growth stage, the aboveground biomass of A. sparsifolia under all treatments was relatively high (root-shoot ratios under CK, W1, and W2 were 0.43 ± 0.14, 0.59 ± 0.1, and 0.83 ± 0.83), while in the late growth stage, the below-ground biomass under all treatments was relatively high. The root-shoot ratio was the highest under severe stress (3.12 ± 0.32). The results indicate that A. sparsifolia enhanced the investment of resources underground in the late growth stage, and the resource allocation characteristic is more obvious under severe drought stress. (3) Pearson-correlation analysis showed that there was a significant tradeoff between core traits related to leaf morphology and root physiology in A. sparsifolia (P < 0.05). Meanwhile, the leaf and root had synergistic changes in physiological metabolism. The results preliminary indicate the adaptive characteristics and A. sparsifolia seedlings under drought exhibit high dry matter storage, defense capacity, and low water consumption. A. sparsifolia can coordinate the resource allocation relationship between leaves and roots. At the same time, with drought stress time increased, the adaptive strategy of slow investment and conservative growth of A. sparsifolia was gradually formed. The results provide a reference for the restoration and management of desert vegetation in this region.
Subjects: Agriculture, Forestry,Livestock & Aquatic Products Science >> Other Disciplines of Agriculture, Forestry,Livestock & Aquatic Products Science submitted time 2022-06-02 Cooperative journals: 《干旱区研究》
Abstract：研究南疆盆地油莎豆（Cyperus esculentus）滴灌覆膜的效果和最适宜的灌溉制度，为构建南疆盆地油莎豆节水高产管理栽培模式提供参考。通过1 a的试验，在覆膜（M）和不覆膜（NM）条件下，设置3种水分处理水平，即：CK 处理（对照，以当地常用灌溉量 5316.45 m3 hm-2 ）、T1 处理（灌溉量为 3431.40 m3 hm-2）和 T2 处理（灌溉量为4133.85 m3hm-2 ），灌溉频率为6~10 d，研究覆膜和水分控制对油莎豆生长、品质、产量和水分利用效率的影响。结果表明：（1）油莎豆的密度受水处理的影响显著（P＜0.05），而根冠比受水处理影响不显著（P＞0.05）。（2）覆膜处理的草粗脂肪、可溶性淀粉、可溶性糖含量比未覆膜平均提高58.82%、3.35%和17.20%，覆膜处理块茎的粗脂肪含量、可溶性淀粉、可溶性糖含量均高于未覆膜的，分别增加了7.48%、2.56%和2.55%，且水处理间差异不显著（P＞0.05），但是均在T2处理达到最大。（3）产量和水分利用效率随灌溉量增加呈先增加后降低的趋势，其中覆膜条件下， T2处理的草和块茎的产量最大，分别为 3974.55 kghm-2和 5253.85 kghm-2，较 CK 处理分别显著增加 6.45%和 36.95%（P＜0.05），较未覆膜条件下， T2和CK平均产量显著增加29.41%和34.76%（P＜0.05），水分利用效率也在T2处理达到最大值，其中覆膜处理下，草和块茎在T2处理的水分利用效率较CK显著提高38.63%和34.33%（P＜0.05）；与T2（覆膜）处理相比，未覆膜条件下CK、T2处理的草和块茎的水分利用效率分别显著提高38.91%和34.33%（P＜0.05），覆膜处理对草的水分利用效率差异不显著（P＞0.05），但是对块茎的水分利用效率差异显著（P＜0.05）。因此，在覆膜条件下，灌溉定额为133.85 m3 hm-（2T2）时，不仅提高了油莎豆的品质和产量，也提高了水分利用效率，节约水资源。
Subjects: Biology >> Botany submitted time 2022-03-28 Cooperative journals: 《干旱区研究》
Abstract：氮素和水分是影响荒漠植物生长的重要因素，而全球变化主要驱动因素的氮沉降和干旱会直接改变土壤中这2种资源的可利用性。以塔克拉玛干南缘优势植物疏叶骆驼刺（Alhagi sparsifolia Shap.）一年生幼苗为研究对象，设置了盆栽试验。通过添加不同水平的N肥和水分，用于模拟不同水平的N沉降速率（0, 3.0, 6.0, 9.0 gm-2a-1）和水分条件（干旱和充分水），探究这2种因素对骆驼刺叶片与细根化学计量特征的影响。结果表明：（1）除叶片P含量外，N和水分添加独立或交互作用影响骆驼刺叶片和细根的养分状况。干旱条件下，N添加显著降低了叶片N、Mn、Zn、Cu等元素含量（P），而在一定程度上提高了细根对这些元素的吸收；（2）骆驼刺细根中富集着Mn、Zn、Cu、Fe等微量元素，而将N、P、K等大量元素更多地分配给叶片；（3）干旱胁迫条件下施加3.0 gm-2a-1，水分充足条件下添加6.0 gm-2a-1或9.0 gm-2a-1，可以显著缓解骆驼刺细根的N限制（N：P）；（4）骆驼刺叶片和细根的营养元素在器官内和器官间存在复杂的相互作用，器官间的这种相互关系发生的比率大于器官内部，细根次之，叶片最低。这些结果表明骆驼刺在环境资源波动的背景下，能够协调地上和地下的养分关系；外源的N输入可以改善骆驼刺细根的养分状况，为荒漠植被修复和养分高效管理提供了科学参考。
Hits
Hits
Downloads
Comment