College of Desert Control Science and Engineering, Inner Mongolia Agricultural University, Hohhot, Inner Mongolia, China.
Inner Mongolia Autonomous Region Water Conservancy Development Center, Inner Mongolia Autonomous Region Water Conservancy Development Center, Hohot, Inner Mongolia, China.
PeerJ. 2022 Jul 14;10:e13363. doi: 10.7717/peerj.13363. eCollection 2022.
This study was aimed to explore the compensatory growth ability and influence mechanism of at the decaying phase in feldspathic sandstone areas of Ordos, and clarify the stubble height when the compensatory growth ability of was the strongest.
The forests in the decaying phase from an exposed feldspathic sandstone zone of Ordos were chosen. The compensatory growth ability of at stubble height of 0 cm (S), 10 cm (S), 15 cm (S), 20 cm (S) and control (CK) was investigated with forests at the decaying stage in the exposed feldspathic sandstone areas of Ordos. Relationships of compensatory growth ability of and understory soil properties with understory soil stoichiometric features as well as the response mechanism to stubble height were explored.
(1) Overcompensatory growth of in feldspathic sandstone areas occurred at all stubble heights. Especially, the plant height compensation index (1.45) and biomass compensation index (1.25) at the stubble height of 15 cm were both larger compared with other stubbling treatments. These results indicate the stubble height of 15 cm can well promote the growth of the ground part of . (2) All stubble heights significantly affected the contents and eco-stoichiometric ratios of soil organic carbon (SOC), total nitrogen (TN), total phosphorus (TP) in understory soils, but the influence rules differed. SOC, TN, and TP contents at all stubble heights were larger than those of the control, and maximized at the stubble height of 15 cm. The carbon(C): phosphorus(P) ratio, and nitrogen (N):(P) ratio after stubbling treatments were all lower compared with the control, and minimized to 19.52 and 1.84 respectively at the stubble height of 15 cm. (3) The understory C:N:P stoichiometric ratio of in feldspathic sandstone areas is jointly affected by compensatory growth, stubble height, and soil physicochemical properties. The total explanation rate determined from RDA is 93.1%. The understory soil eco-stoichiometric ratio of is mainly affected by soil moisture content (contribution of 87.6%) and total porosity (7.9%), indicating soil moisture content is the most influential factor. The findings will offer some new clues for eco-construction and theoretically underlie soil-water loss administration.
本研究旨在探讨鄂尔多斯长石砂岩区衰退阶段油松的补偿生长能力及其影响机制，并明确其补偿生长能力最强时的萌生高度。
选择鄂尔多斯长石砂岩暴露区衰退阶段的油松林。利用鄂尔多斯长石砂岩暴露区衰退阶段的油松林，研究了萌生高度为 0 cm（S）、10 cm（S）、15 cm（S）、20 cm（S）和对照（CK）的油松的补偿生长能力。探讨了油松补偿生长能力与林下土壤性质及其与林下土壤化学计量特征的关系，并探讨了对萌生高度的响应机制。
（1）在所有萌生高度下，长石砂岩区油松都出现了超补偿生长。尤其是在萌生高度为 15 cm 时，株高补偿指数（1.45）和生物量补偿指数（1.25）均大于其他萌生处理。这表明萌生高度为 15 cm 可以很好地促进油松地面部分的生长。（2）所有萌生高度均显著影响林下土壤有机碳（SOC）、全氮（TN）和总磷（TP）的含量和生态化学计量比，但影响规律不同。所有萌生高度下的 SOC、TN 和 TP 含量均大于对照，且在萌生高度为 15 cm 时最大。萌生处理后的 C：P 比和 N：（P）比均低于对照，且在萌生高度为 15 cm 时分别最小至 19.52 和 1.84。（3）长石砂岩区油松林下 C：N：P 化学计量比受补偿生长、萌生高度和土壤理化性质的共同影响。从 RDA 确定的总解释率为 93.1%。油松林下土壤生态化学计量比主要受土壤含水量（贡献 87.6%）和总孔隙度（7.9%）的影响，表明土壤含水量是最具影响力的因素。研究结果将为生态建设提供一些新的线索，并从理论上为土壤水分流失管理提供依据。
