# Cyanobacterial Potential for Restoration of Loess Surfaces through Artificially Induced Biocrusts
If higher biomass would be present, the vegetation could control erosion and water loss. Because of its current environmental state, 12.8% of the Plateau's area experiences soil/sediment erosion greater than 10,000 t/km\({}^{2}\)/a [22]. It has been demonstrated that the high sediment concentration in the Yellow River (\(\sim\)16.4 billion tons of sediment annually) is a result of erosion from the sediments and soils on the Loess Plateau [21]. Dust particles can affect human and animal health either directly or by causing damage to the vegetation (Figure 1B), enhancing eutrophication of water systems (e.g., stimulating toxic algal blooms), or causing traffic accidents [23]. The dust causes mostly respiratory, ophthalmic, cardiac, and skin diseases [23]. Health consequences of desertification in loess regions have also been recognized. For more than a decade, a relationship between the distribution of loess/loess-like deposits and esophageal cancer has been adduced [24]. According to [PERSON] et al. [25], long-term ingestion of silica particles leads to an increased risk of esophageal cancer. Considering the economic, social, environmental, and health problems caused by desertification, finding a natural and environment-friendly solution for the restoration of loess surfaces, as well as other desertified landscapes, is essential. So far, a commonly used method for combating desertification and dust storms and for the restoration of degraded land has been revegetation [26]. In 1999, the project 'Grain for Green' was established as the most substantial financial ecosystem investment, with a budget of 40 billion dollars, in order to prevent and control erosion on the Chinese Loess Plateau [27; 28]. Although China had invested much effort and money in afforestation, there have been negative consequences to the environment as well, including a reduction in vegetation cover, loss of soil moisture [29], increase in soil erosion and above all, increased desertification rate [30] and continued sand storms [26]. According to [PERSON] et al. [31], one of the main reasons for failures in afforestation projects is the use of inappropriate plant species. Planting of trees or shrubs in areas where non-woody species present natural vegetation is not practical and leads to a decrease in water availability and loss of planted species or even native vegetation [26; 29]. It is thus justified to find a long-term, environmentally friendly, and ecosystem-adapted solution, which recognizes native bioprocesses and uses native biota for the stabilization and restoration of loess landscapes. Considering the diversity of factors influencing desertification, there is no universal solution to combat desertification [32]. The appropriate solution depends on the local environmental (including water availability) and social conditions [33; 34]. The crucial action in combating desertification is the restoration of appropriate vegetation and toposoil stability [35]. Even though the 'Grain for Green' project aimed to improve the state of the loess environment by planting trees and shrubs, an unexpected extensive development of biocrusts was observed, which later played a significant role in controlling soil erosion [28; 36]. Biocrusts are bio-sedimentary complexes composed of organisms (bacteria, cyanobacteria, algae, fungi, lichens, and mosses) associated with the particles [37; 38]. A special type of biocrust, BLCs, have been recognized to colonize loess sediment and can present significant biomass on the loess surfaces [3; 9; 39]. Biocrusts support many ecosystem functions by improving soil fertility and stability, reducing erosion by water and wind [40; 41], increasing soil infiltration and delaying runoff [42] and increasing the abundance of soil fungi and bacteria [43]. Biocrusts influence primary ecosystem processes [44] and play a significant role in maintaining and improving the state of the environment [45]. Thus, they improve surface properties and provide an environment for numerous organisms [46].