Mao Zhuxin, Wang Yuchao, Li Qian, Li Weimin, Wang Hong, Li Yang, Yue Ming
Xi'an Botanical Garden of Shaanxi Province/Institute of Botany of Shaanxi Province, Xi'an, China.
Key Laboratory of Resource Biology and Biotechnology in Western China, Northwest University, Xi'an, China.
Front Plant Sci. 2023 Jan 13;13:1105718. doi: 10.3389/fpls.2022.1105718. eCollection 2022.
Fire and mowing are crucial drivers of grass growth. However, their effects on soil properties, microbial communities, and plant productivity in dry-alkaline grasslands have not been well investigated. This study evaluated the effects of mowing (slightly and deeply) and fire on vegetation traits (Tiller number per cluster and plant height) and biomass (plant dry weight), and soil availability of N, P, and K, as well as soil microorganism abundance in a system. We designed one control and three experimental grass plots (slightly and deeply mowed, and burned) in 2020-2021 in the Xi'an Botanical Garden of Shaanxi Province, Xi'an, China. Tiller number, plant height per cluster, and soil N, P, and K availability during growth decreased significantly ( < 0.05) in all treatments compared to the control. However, this effect was much greater in the deep-mowing plot than in the other plots. After harvest, deep mowing induced the greatest effect on biomass among all treatments, as it induced a 5.2-fold decrease in dry biomass relative to the control. In addition, both fire and mowing slightly redistributed the community and diversity of the soil bacteria and fungi. This redistribution was significantly greater in the deep-mowing plot than in other plots. In particular, relative to the control, deep mowing increased the abundance of and especially among soil bacterial communities, but significantly ( < 0.05) decreased and increased abundance among soil fungal communities. We conclude that nutrient limitation (N, P, and K) is crucial for growth in both mowing and fire grasslands, whereas deep mowing can induce soil nutrient loss and microorganism redistribution, further restraining grass sustainability in dry-alkaline grasslands.
火烧和刈割是草地生长的关键驱动因素。然而，它们对干旱盐碱化草地土壤性质、微生物群落和植物生产力的影响尚未得到充分研究。本研究评估了轻度和重度刈割以及火烧对植被性状（每簇分蘖数和株高）、生物量（植物干重）、土壤氮、磷、钾有效性以及土壤微生物丰度的影响。我们于2020 - 2021年在中国陕西省西安市植物园设计了一个对照和三个实验性草地样地（轻度刈割、重度刈割和火烧）。与对照相比，所有处理在生长期间的分蘖数、每簇株高以及土壤氮、磷、钾有效性均显著降低（P < 0.05）。然而，这种影响在重度刈割样地比其他样地更大。收获后，重度刈割在所有处理中对生物量的影响最大，因为与对照相比，其导致干生物量下降了5.2倍。此外，火烧和刈割均对土壤细菌和真菌群落的组成及多样性产生了轻微的重新分布作用。这种重新分布在重度刈割样地比其他样地更为显著。特别是，相对于对照，重度刈割增加了土壤细菌群落中[具体细菌种类1]尤其是[具体细菌种类2]的丰度，但显著（P < 0.05）降低了土壤真菌群落中[具体真菌种类1]的丰度并增加了[具体真菌种类2]的丰度。我们得出结论，养分限制（氮、磷和钾）对刈割和火烧草地中的[草种名称]生长至关重要，而重度刈割会导致土壤养分流失和微生物重新分布，进一步限制干旱盐碱化草地中草的可持续性。
