Morillas Lourdes, Roales Javier, Cruz Cristina, Munzi Silvana
Centre for Ecology, Evolution and Environmental Changes, Faculdade de Ciências, Universidade de Lisboa, Campo Grande, Bloco C2, 1749-016 Lisbon, Portugal.
Departamento de Sistemas Físicos, Químicos y Naturales, Universidad Pablo de Olavide, Ctra. Utrera Km 1, 41013 Seville, Spain.
J Fungi (Basel). 2022 Mar 23;8(4):333. doi: 10.3390/jof8040333.
Climate change and atmospheric nitrogen (N) deposition on drylands are greatly threatening these especially vulnerable areas. Soil biocrust-forming lichens in drylands can provide early indicators of these disturbances and play a pivotal role, as they contribute to key ecosystem services. In this study, we explored the effects of different long-term water availability regimes simulating climate changes and their interaction with N addition on the physiological response of the soil lichen . Three sets of this lichen were subjected to control, reduced watering, and reduced watering and N addition (40 kg NHNO ha year) treatments for 16 months. Finally, all samples were subjected to daily hydration cycles with N-enriched water at two levels (40 and 80 kg NHNO ha year) for 23 days. We found that reduced watering significantly decreased the vitality of this lichen, whereas N addition unexpectedly helped lichens subjected to reduced watering to cope with stress produced by high temperatures. We also found that long-term exposure to N addition contributed to the acclimation to higher N availability. Overall, our data suggest that the interactions between reduced watering and increased N supply and temperature have an important potential to reduce the physiological performance of this soil lichen.
气候变化以及旱地大气氮沉降正极大地威胁着这些尤为脆弱的地区。旱地中形成土壤生物结皮的地衣能够为这些干扰提供早期指示，并发挥关键作用，因为它们对关键生态系统服务有贡献。在本研究中，我们探究了模拟气候变化的不同长期水分可利用状况及其与添加氮的相互作用对土壤地衣生理响应的影响。将三组这种地衣分别进行对照、减少浇水以及减少浇水并添加氮（40千克硝酸铵每公顷每年）处理，持续16个月。最后，所有样本在两个氮添加水平（40和80千克硝酸铵每公顷每年）下用富含氮的水进行每日水化循环处理，持续23天。我们发现减少浇水显著降低了这种地衣的活力，而添加氮意外地帮助了遭受减少浇水的地衣应对高温产生的胁迫。我们还发现长期暴露于添加氮有助于适应更高的氮可利用性。总体而言，我们的数据表明减少浇水与增加氮供应及温度之间的相互作用极有可能降低这种土壤地衣的生理性能。
