Different types of biocrusts affect plant communities by changing the microenvironment and surface soil nutrients in the Qinghai-Tibetan Plateau

Abstract

Biocrusts (biological soil crusts), which impact plant community characteristics and soil properties, are an important feature of soil surface in terrestrial ecosystem and called ecosystem engineers in arid and semi-arid habitats. The Qinghai-Tibet Plateau is located in arid and semi-arid regions, and the information on how biocrusts play a role in this ecosystem is still rare. In this study, the effects of different types of biocrusts (lichen-moss crusts, moss crusts, and bare ground as control) on plant diversity and soil physicochemical properties were evaluated and the key environmental factors associated with biocrust characteristics were analyzed in alpine steppe. The results showed that biocrusts affected the structure and diversity of plant community. The lichen-moss crusts were linked with lower plant diversity and plant species richness in degraded alpine steppe in the Qinghai-Tibetan Plateau. The cover of lichen crusts was positively correlated with plant cover while the cover and thickness of moss crusts were negatively correlated with plant cover. Moss crusts significantly reduced soil temperature and soil moisture content. Biocrusts significantly reduced the pH values of soil surface layer (0–1 cm) and deeper layer (5–10 cm). Soil total C (78.10 ± 6.53 g/kg), and total N (5.05 ± 0.21 g/kg) were highest in the soil surface layer (0–1 cm) where lichen-moss crusts were present. Our results indicated that the different types of biocrusts affect plant communities by changing the microenvironment and soil nutrients in the Qinghai-Tibetan Plateau. Further studies on the relationships between soil, biocrusts, and plants on a larger scale in the Qinghai-Tibetan Plateau are necessary.

Keywords:

• Lichen-moss crusts
• moss crusts
• plant diversity
• Qinghai-Tibetan Plateau

Acknowledgments

The authors thank Warwick Badgery and Kesi Liu for his help in language and research thinking. The authors thank the staff at the grassland station of Guinan County for proving assistance in the experiment. In addition, we would like to thank Tibetan herdsmen Jiacuo Longduo for help in life.

Additional information

Funding

This research was funded by the National Key S&T Special Projects of China [No. 2016 YFC0501902] and Qinghai Innovation Platform Construction Project [2017-ZJ-Y20].