养分添加对青藏高原高寒草甸丛枝菌根真菌的影响

基于海北站的养分添加实验平台探讨养分输入对青藏高原高寒草甸丛枝菌根真菌(AMF)的影响。实验处理包括: 1) 对照; 2) 10 gN/(m²•a)的氮添加; 3) 5 gP/(m²•a)的磷添加; 4) 10 gK/(m²•a)的钾添加。利用醋酸墨水染色法定量分析各处理下植物根系的AMF侵染率。结果表明, 氮添加使总的AMF侵染率显著减少27%, 但对AMF的丛枝丰度和囊泡多度无显著影响; 磷添加和钾添加对AMF均无显著影响, 但是磷添加使AMF侵染率有降低趋势。可以得到, 不同养分添加对高寒草甸植物与AMF的共生关系具有不同影响, 由此可能会引起物种组成等一系列的变化, 影响生态系统结构和功能, 因此在评估养分添加效应时应该考虑其对AMF的影响。

Effects of Nutrient Additions on the Arbuscular Mycorrhizal Fungal Colonization in the Alpine Meadow on the Tibetan Plateau

An experiment was conducted to investigate the effects of nutrient additions on the arbuscular mycorrhizal fungi (AMF) colonization in the alpine meadow at Haibei field station in China. Treatments of the experiment were control, N addition (10 gN/(m²•a)), P addition (5 gP/(m²•a)), and K addition (10 gK/(m²•a)), each with six replicates. With ink-vinegar staining method, mycorrhizal colonization of roots of the meadow plant community was quantified. Results showed that N addition significantly reduced total mycorrhizal root length colonization by 27%, but had no effect on the arbuscular and vesicular colonization. There was a trend towards reducing AMF colonization by the P addition, but not significantly. K addition did not influence the AMF colonization. The results indicate that there is different influence on the AMF in the alpine meadow with different fertilizer application, which may influence the structure and function of the ecosystem such as the change of species composition. So it is necessary to take the AMF into consideration when evaluating the effects of nutrient additions.