5 Jul 2024

A World within Worlds: Bryophytes of the Botanic Garden

Leila Franzen

In celebration of Wales Nature Week, today we’re diving into the fascinating world of mosses!

Hidden away at the Botanic Garden there are over 130 recorded bryophyte species and many more that remain unrecorded. We treasure bryophytes here at the Garden for their diverse appearances and unique ecosystem roles. You may know bryophytes better as mosses but mosses are just one group belonging to bryophytes. The lesser known liverworts and hornworts also belong to this group, filling similar ecological niches.

Bryophytes differ from other plants in reproducing via spores or plant fragments. They also have no true roots or vascular system, absorbing all their nutrients directly from the atmosphere or rain. Their leaves are usually only one cell thick and so they have no ability to retain water like plants with waxy leaves. Instead, during drought they curl up their leaves and slow their metabolism, waiting for the next rainfall. Mosses represent a total lack of resistance to the whims of the environment; they have a go with the flow approach to life and are a lesson in patience.

As is the case with most wildlife in the UK, bryophytes are becoming increasingly threatened. This is mainly due to habitat loss but also to other factors such as pollution and climate change. Some species need an extra helping hand and so in our Science Centre we are cultivating the rare moss Tortula canescens for the purpose of returning this beautiful species to its natural habitat.

Tortula canescens is mainly a coastal moss, growing on acidic soil that is intermittently desiccated during the summer. It is known at less than 10 sites in Wales and is almost entirely limited to the Cornish coast in England. This bryophyte conservation work is part of the Natur Am Byth Project. The next species we will be propagating is Bartramia stricta, a moss that produces tiny green sporophytes that resemble apples, earning it its place amongst a few other species called apple mosses.

Sadly, bryophytes are often overlooked and misunderstood, which is why here at the Garden, we have decided to celebrate them as part of Wales Nature Week. So next time you pass a moss, take the time to look a little closer and watch as a world within worlds reveals itself.

The National Botanic Garden of Wales is supported by Welsh Government’s Nature Networks Fund, funding work to deliver infrastructure improvements on Waun Las NNR, allowing us to manage the site for improved biodiversity and engage with visitors on our natural heritage.