Schultz Nick L, Sluiter Ian R K, Allen Geoffrey G, Machado-de-Lima Nathali M, Muñoz-Rojas Miriam
The Future Regions Research Centre, Federation University Australia, Ballarat, VIC, Australia.
School of Geography Earth and Atmospheric Sciences, The University of Melbourne, Parkville, VIC, Australia.
Front Microbiol. 2022 Jul 26;13:882673. doi: 10.3389/fmicb.2022.882673. eCollection 2022.
Soil cryptogamic biocrusts provide many ecological functions in arid zone ecosystems, though their natural reestablishment in disturbed areas is slow. Accelerating reestablishment of biocrusts may facilitate the establishment of vascular plant communities within the timeframes of restoration targets (typically 5-15 years). One technique is to inoculate the soil surface using slurries of biocrust material harvested from another site. However, this is destructive to donor sites, and hence the potential to dilute slurries will govern the feasibility of this practice at large spatial scales. We conducted a replicated experiment on a disturbed mine site to test the individual and combined effects of two strategies for accelerating soil cryptogamic biocrust reestablishment: (1) slurry inoculation using biocrust material harvested from native vegetation; and (2) the use of psyllium husk powder as a source of mucilage to bind the soil surface, and to potentially provide a more cohesive substrate for biocrust development. The experiment comprised 90 experimental plots across six treatments, including different dilutions of the biocrust slurries and treatments with and without psyllium. Over 20 months, the reestablishing crust was dominated by cyanobacteria (including and ), and these established more rapidly in the inoculated treatments than in the control treatments. The inoculated treatments also maintained this cover of cyanobacteria better through prolonged adverse conditions. The dilute biocrust slurry, at 1:100 of the biocrust in the remnant vegetation, performed as well as the 1:10 slurry, suggesting that strong dilution of biocrust slurry may improve the feasibility of using this technique at larger spatial scales. Psyllium husk powder did not improve biocrust development but helped to maintain a soil physical crust through hot, dry, and windy conditions, and so the potential longer-term advantages of psyllium need to be tested.
土壤隐花植物生物结皮在干旱区生态系统中发挥着多种生态功能，尽管它们在受干扰地区的自然恢复过程较为缓慢。加速生物结皮的恢复可能有助于在恢复目标的时间范围内（通常为5 - 15年）建立维管植物群落。一种技术是使用从另一个地点采集的生物结皮材料制成的泥浆接种土壤表面。然而，这对供体地点具有破坏性，因此泥浆稀释的可能性将决定这种做法在大空间尺度上的可行性。我们在一个受干扰的矿场进行了一项重复实验，以测试两种加速土壤隐花植物生物结皮恢复策略的单独和联合效果：（1）使用从原生植被采集的生物结皮材料进行泥浆接种；（2）使用车前草壳粉作为黏液来源，以粘结土壤表面，并可能为生物结皮发育提供更具粘性的基质。该实验包括六种处理的90个实验小区，包括不同稀释度的生物结皮泥浆以及有无车前草的处理。在20多个月的时间里，正在恢复的结皮以蓝细菌（包括 和 ）为主，并且这些蓝细菌在接种处理中比在对照处理中建立得更快。接种处理在长期不利条件下也能更好地维持这种蓝细菌覆盖。稀释的生物结皮泥浆，即残留植被中生物结皮的1:100，与1:10的泥浆表现相当，这表明生物结皮泥浆的强烈稀释可能会提高在更大空间尺度上使用该技术的可行性。车前草壳粉并没有促进生物结皮的发育，但有助于在炎热、干燥和多风的条件下维持土壤物理结皮，因此车前草的潜在长期优势需要进一步测试。
