Recently, the plight of plants has been hitting the news. Apparently ‘more than a third of critically endangered plant species cannot be saved from extinction’ by seed banks, and ‘test-tube trees’ are a potential solution to this.
To put the headlines into context, there are nearly 400,000 plant species, and each year 2000 more are discovered. 21% (around 80,000 species!) are threatened with extinction, and it is likely we will lose many species before we even know they exist. Plants form the base of almost every food web because they convert the sun’s energy into food, supporting us, and every other non-photosynthesising organism. Take the plants away and ecosystems collapse, along with the vital processes they perform that provide us with clean air and water, oxygen to breath, food, clothes and more.
Worryingly, in the midst of this decline, society has been afflicted by plant-blindness; "the inability to recognise the importance of plants in the biosphere and in human affairs". The wonderful world of plants is reduced to an insignificant green blur, that isn't relevant or interesting in our-day-to-day lives. Stephen Blackmore, a prominent plant conservationist, explains "in a world of 7 billion people, where more than half of us live in cities, we have simply forgotten how the world works".
Despite this, botanists and conservationists have come up with a brilliant plan of action. A Global Strategy for Plant Conservation (GSPC), which aims to "halt the continuing loss of plant diversity' through education (to fight plant-blindness), research and conservation (see below), involving 16 targets to carry out between 2011 and 2020.
One of these, target number 8, is "at least 75% of threatened plant species in ex situ collections", i.e. in seed banks, arboretums and botanical gardens. Unlike the rest of the targets, seed banks have been hitting the news.
So what exactly is the role of seed banks in conserving plant diversity? Seeds banks are relatively simple - collect the seeds, dry the seeds, freeze the seeds- and the cheapest way of ‘saving’ as much plant biodiversity as possible. In Europe we are currently on target, with 62.7% of threatened species conserved in seed banks. But is it enough?
They are a safety net to stop species going extinct. Many species have been brought back from the brink using seed banks, including the world's smallest waterlily from Rwanda. It had gone extinct in the wild, when scientists managed to germinate the very last seeds remaining, found forgotten in a German seed bank. Seed banks have also been useful in ecological restoration, where "seed augmentation helped rescue populations from the brink of extinction".
Seed banks are also are an invaluable research tool, giving access to vast amounts of genetic information. Genetic sequencing of plants can help improve survival of plant species. For example, diseases can decimate plant populations, and by identifying alleles responsible for resistance, species survival chances are greatly improved. This has been done with Ash trees, in the hopes that resistant trees can be identified and planted in affected areas. This will ensure tree cover is not lost, ensuring minimal ecological disruption.
Seeds banks can be incredibly useful, and an invaluable safety net. However it is crucial to recognise that they are part of a wider strategy and not the be all and end all of conserving plants.
Whilst genetic diversity can be stored, the species won't carry out their ecological role as a frozen spec in a freezer. Peter Wyse Jackson, director of the Missouri Botanical Garden elaborates:
"ex situ is often regarded as preservation rather than conservation. In contrast, in situ conservation, at least in theory, allows plant populations to develop and evolve in, and as part of, the ecosystem of their natural habitat ".
On top of that, as previously mentioned, a third of endangered plants do not survive using this method, including 36% of trees (such as some of our favourites, like coffee, avocado and cocoa trees), 33% of critically endangered plants and 10% of medicinal plants.
It's useful at this stage to cast our eye over how to conserve a species in the long term:
Seed banks play only part of the solution in the final step of long-term conservation. Fortunately, this is reflected in the GSPC (figure 1), which covers research into plant diversity and decline, and education of the public, as well as conservation.
Sadly, there is nowhere near enough funding to have a realistic chance of meeting the 16 targets set out by the GSPC. This is highlighted by the fact that in the US “despite plants comprising the majority of the federal endangered species list (57%), in 2011 they received less than 3.86% of federal endangered species expenditures”. This brings us back around to plant-blindness, the reason behind this lack of funding. If people care about something, there will be more money available for it. In general, people know and care very little about plants, meaning that the funding just isn't there. When put into context that all the air we breathe and food we eat ultimately comes from plants, and that the combined turnover from timber, fuel wood, and medicinal plants is just shy of $110 billion per year, it seems mad that we don't care.
If we really want to give plants, and therefore ourselves, a fighting chance, we need to begin to see again. We need to peel off our blindfolds and appreciate the fresh air from oaks, and birches and beeches. We need to see how the daisies and dandelions amongst the grass are providing food for our pollinators, and how hedgerows are havens for everything from door mice to blue tits.
To sum up, seed banks are a crucial part of the solution. They provide a platform for research and seeds for ecological restoration. However, it must be recognised that they are just one cog in the wheel of conservation, and to get that wheel rolling we need money. The more we see, the more we learn, the more we care, and the faster that wheel can spin.
