**1. Introduction**

Bryophytes are indeed an amazing group! For more than 470 million years, they have advanced over terrestrial environments, being responsible for the formation of the first layers of organic soil. This allowed the installation of other terrestrial plants and was responsible for about 1/3 of the oxygen available for the breathing of all living beings that later occupied these environments [1].

They cover a very large area of the planet, generally where other plants cannot grow. If we consider mountains, much of the tundra and taiga and the bark of trees which are covered with mosses, the photosynthetic area is probably greater than that of other plants combined, even though they are so small and delicate. In boreal forests, mosses may be the smallest components in biomass, but they represent the greatest coverage and have the highest primary productivity, in addition to being faster in the accumulation of nutrients, contributing to the thermal development of the environment with consequent development of the permafrost. In this way, they positively affect nutrient cycling in these ecosystems, affecting also the vascular plants [2]

Bryophytes are of unparalleled resistance, sprouting again after hundreds of years covered by ice (from 400 to 1530 years—already detected) or even if kept for years in herbaria in conditions of extreme dehydration and darkness. There are even specific genes to resist to climate changes [3–6].
