Elevational patterns in taxonomic diversity have been widely studied, but there has been little attention given to patterns in functional gene diversity. We used a metagenomic approach – along with amplicon data - to study trends in functional gene diversity in bacteria along a 2,300 m elevational gradient on Mt. Norikura, Japan. We hypothesized that in accordance with a global scale study by Bahram et al. (2018), functional gene diversity would show a mid-elevation minimum, due to a pH minimum pH and MAP maximum in the mid-elevations. Instead, we observed a mid-elevation maximum in functional gene diversity, and a decrease with increasing pH values from acidic to near neutral. We also found a weak negative relationship between OTU diversity and functional diversity. There appear to be no obvious ecological mechanisms to explain why the observed mid-elevation peak in functional diversity occurs. The trends observed here demonstrate that it is also necessary to consider more complex localised trends that would largely remain hidden from broad global studies. The fact that functional gene diversity in bacteria is decoupled from taxonomic diversity emphasizes that each should be treated as separate dimensions of diversity.

分类学多样性中的升高模式已经被广泛研究，但是很少关注功能基因多样性中的模式。我们使用了宏基因组学方法以及扩增子数据，研究了山上海拔2300 m的细菌中功能基因多样性的趋势。日本Norikura。我们假设根据Bahram等人的全球规模研究。（2018），由于中等海拔的pH最低pH和MAP最高，功能基因多样性将显示最低海拔。取而代之的是，我们观察到功能基因多样性的中间最高值出现最大值，并且随着pH值从酸性增加到接近中性而下降。我们还发现OTU多样性和功能多样性之间的弱负相关性。似乎没有明显的生态机制来解释为什么观察到的功能多样性中峰出现。这里观察到的趋势表明，还必须考虑更复杂的本地化趋势，而这些趋势在很大程度上仍未被广泛的全球研究所掩盖。细菌中功能基因多样性与分类学多样性脱钩的事实强调，每种细菌应被视为多样性的独立维度。