Wang Juan, Liu Junjie, Liu Chao, Ding Xiaoyu, Ma Yonggang, Yang Jianjun, Xu Zhonglin
College of Ecology and Environment, Xinjiang University Urumqi China.
College of Geography and Remote Sensing Sciences, Xinjiang University Urumqi China.
Ecol Evol. 2024 Oct 8;14(10):e70329. doi: 10.1002/ece3.70329. eCollection 2024 Oct.
The restoration of alpine grasslands has garnered significant attention across various sectors. Historically, natural restoration has been the primary approach for grassland recovery, characterized by its prolonged duration. To expedite the recovery of degraded grasslands, it is essential to identify the limiting factors of restoration, enabling efficient and rapid recovery. Appropriate nitrogen (N) addition levels have been considered a potential strategy to enhance the recovery of grassland ecosystems and augment their ecological benefits. However, the effectiveness of N addition in alpine grassland restoration remains debated. This study investigated the impact of five N addition levels (CK: control [0 g/m]; LN: low N [5 g/m]; MN: medium N [10 g/m]; HN: high N [15 g/m]; SN: severe N [20 g/m]) and two experimental approaches (N addition once per year [NPY] and three times per year [NTY] at the same dosages) on plant and soil properties and the maximum restoration capacity of alpine meadows. Our findings reveal three key insights: The level of N addition was the primary factor influencing aboveground plant biomass and coverage. Plant diversity decreased under the NTY regime and increased with NPY in the Bayinbruck grassland. N addition significantly altered soil properties, including pH, salinity, soil organic carbon (SOC), soil-available phosphorus (AP), and soil total phosphorus (TP). Notably, soil TP, total nitrogen (TN), and AP substantially impacted plant community structure and diversity. Based on structural equation model (SEM) and analysis of variance (ANOVA), optimal grassland restoration was achieved with the HN (15 g/m) treatment under NPY and the MN and HN (10 and 15 g/m) treatments under NTY. Overall, our study offers crucial insights into the conservation, management, and restoration of grassland ecosystems on the Bayinbruck Plateau. It underscores the significance of N addition effects on plant communities, vegetation restoration, and soil properties.
高寒草原的恢复已在各个领域引起了广泛关注。从历史上看，自然恢复一直是草原恢复的主要方式，其特点是持续时间长。为了加速退化草原的恢复，必须确定恢复的限制因素，以实现高效快速的恢复。适当的氮（N）添加水平被认为是增强草原生态系统恢复并提高其生态效益的潜在策略。然而，氮添加在高寒草原恢复中的有效性仍存在争议。本研究调查了五个氮添加水平（CK：对照[0 g/m²]；LN：低氮[5 g/m²]；MN：中氮[10 g/m²]；HN：高氮[15 g/m²]；SN：重氮[20 g/m²]）和两种实验方法（每年添加一次氮[NPY]和每年添加三次氮[NTY]，剂量相同）对植物和土壤特性以及高寒草甸最大恢复能力的影响。我们的研究结果揭示了三个关键见解：氮添加水平是影响地上植物生物量和盖度的主要因素。在巴音布鲁克草原，NTY模式下植物多样性降低，而NPY模式下植物多样性增加。氮添加显著改变了土壤性质，包括pH值、盐分、土壤有机碳（SOC）、土壤有效磷（AP）和土壤总磷（TP）。值得注意的是，土壤TP、总氮（TN）和AP对植物群落结构和多样性有重大影响。基于结构方程模型（SEM）和方差分析（ANOVA），在NPY模式下，HN（15 g/m²）处理以及在NTY模式下MN和HN（10和15 g/m²）处理实现了最佳的草原恢复。总体而言，我们的研究为巴音布鲁克高原草原生态系统的保护、管理和恢复提供了重要见解。它强调了氮添加对植物群落、植被恢复和土壤性质影响的重要性。
