Higher Plants
Vascular Plants become Higher Plants

(cross ref to Essential diagram)
The Higher plants simultaneously need both the stem hardened and the roots extended to bring in the water to create the pressurised vascular system that makes for the supporting structure, that enables these plants live in drier ground. 
After the vascular plants evolved on to the land and able to grow much taller, along came flowering plants, angiosperms, now the most numerous of the modern plants. Many of their flowers, are designed to attract pollinators, are the product of co-evolution with insects (which evolved after the soil), along with animals resulting in an efficient means of uniting sperm and egg. Their fruits are often designed to aid in the dispersal of their seeds. So these insects probably came after the first terrestrial plants, soils and soil animals, as flying insects only started to evolve 350 mya. It is not hard to imagine that the new environment – called air, was a new environment colonised by trees. 

Does that mean, soil animals first co-evolved with first vascular plants, in particular conifers, and then the evolution of plants afterwards benefitted from ‘flying; insects’ – for pollination?

Once the plants evolved in the volcanic dust, this, plant remains, and small soil animals could have got washed or blown away. Some as we saw The Geological Society saying oceans were being eutrophied by plant remains and volcanic dust. However, elsewhere soil could be carried and start making more. Only then can plants take over the world, not just the volcanic ashes. The nutrients from those original volcanoes 350 mya are still being recycled in the soil substrate to this day. 

As the serial of murals at  mural at Botanic Garden Smith College shows at 400 mya plants were still small, but over next 100my became more complex. View Mural panels

It seems that both springtails first came out of the sea. Springtails still need to be near water, and spring away when getting dry. 

Oribatid mouthparts are also marine, with adaptations to deal with air currents.