Wang Ruidong, Dang Xiaohong, Gao Yong, Yang Xia, Liang Yumei, Zhao Chen, Duan Xiaoting
College of Desert Control Science and Engineering, Inner Mongolia Agricultural University, Hohhot, China.
Inner Mongolia Hangjin Desert Ecological Position Research Station, Ordos, China.
Front Plant Sci. 2022 Apr 8;13:850391. doi: 10.3389/fpls.2022.850391. eCollection 2022.
The atmospheric conditions of desert environments are important for the protection of Sand Barrier, and these conditions can affect and change the structure and performance of the sand barrier, causing them to lose their wind proofing and sand fixing benefits. In this study, we have first examined the key environmental factors that affect the exposure of sand barrier. Then, we assessed how key factors in the desert atmospheric environment affect structural aging and performance. The relative crystallinity and chemical composition changes in the sand barrier were measured by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), and X-ray photoelectron spectroscopy (XPS), and the main degradation factors and processes were discussed. The results showed that the degradation degree of the exposed sand barrier was mainly affected by moisture and ultraviolet radiation. Lignin was the main component and the source of photodegradation and photodiscoloration observed in the sand barrier. However, other polysaccharides, such as cellulose and hemicellulose, were less affected by photodegradation. The stress generated by alternating desorption-absorption was the main cause of the expansion and contraction, deformation, cracking, and warping observed in sand barrier. We also found a series of irreversible changes and losses that occurred, which affected the natural material properties of sand barrier exposed to atmospheric conditions for several years. Exposure times between 5 and 7 years were the most important turning point in time for determining the deterioration of the sand barrier. Our results highlighted the importance of the interactions between atmospheric factors and the exposed atmospheric sections of the sand barrier from the perspective of environmental effects. However, the exact mechanisms of the sand barrier deterioration still need further investigation. Nevertheless, our overall findings advanced the current understanding of the environmental effects of sand barrier for ecological restoration and desertification reversal, especially in stressful desert environments.
沙漠环境的大气条件对沙障的保护至关重要，这些条件会影响并改变沙障的结构和性能，使其失去防风固沙的作用。在本研究中，我们首先考察了影响沙障暴露的关键环境因素。然后，我们评估了沙漠大气环境中的关键因素如何影响结构老化和性能。通过X射线衍射（XRD）、傅里叶变换红外光谱（FTIR）和X射线光电子能谱（XPS）测量了沙障中相对结晶度和化学成分的变化，并讨论了主要的降解因素和过程。结果表明，暴露沙障的降解程度主要受水分和紫外线辐射的影响。木质素是沙障中观察到的光降解和光变色的主要成分和来源。然而，其他多糖，如纤维素和半纤维素，受光降解的影响较小。解吸-吸收交替产生的应力是沙障中观察到的膨胀、收缩、变形、开裂和翘曲的主要原因。我们还发现了一系列不可逆转的变化和损失，这些变化和损失影响了在大气条件下暴露数年的沙障的天然材料性能。5至7年的暴露时间是决定沙障劣化的最重要的时间转折点。我们的结果从环境影响的角度突出了大气因素与沙障暴露大气部分之间相互作用的重要性。然而，沙障劣化的确切机制仍需进一步研究。尽管如此，我们的总体研究结果推进了目前对沙障在生态恢复和荒漠化逆转方面环境影响的理解，特别是在压力较大的沙漠环境中。
