BGCI and Kew will hold a joint (virtual) conference on large scale tree planting in February next year aimed at policymakers and the financiers of large scale tree planting. Our primary aim is to ensure that no harm is done to biodiversity by mass tree planting and, if possible, that biodiversity may even be enhanced.

Partly in preparation for this conference, BGCI has been in contact with various tree planting initiatives, including IUCN’s Bonn Challenge Secretariat, the Trillion Trees Campaign (WWF, BirdLife and WCS), the Global Evergreening Alliance, and 1t.org (the World Economic Forum’s trillion trees initiative). Given that the botanical community is leading the Global Tree Assessment and we grow over 18,000 tree species in botanic gardens and arboreta, we believe that we have a role to play in helping to ensure that the right tree is planted in the right place and that diverse native species are part of tree planting portfolios.

Surely it is common sense to incorporate biodiversity, botanical data and botanical expertise into both the planning and practice of tree planting? Not necessarily it seems.

Firstly, unlike carbon, timber, crops etc. biodiversity is not a commodity. As long as this remains the case, market-based solutions to the loss of biodiversity are untenable. Secondly, few (if any) governments regard biodiversity as enough of a public good to commoditise it or fund it directly at the levels required. As the IPBES report states and as GBO5 confirms, governments have completely failed to protect biodiversity despite promising to do so every year since 1992. This severely limits the funding options for large scale tree planting. Corporates and governments want tree planting to pay for itself via commodity markets (carbon, timber) or by improving human livelihoods in the short term. Even philanthropic organisations are largely driven by the market-based model and virtually all of them prioritise people’s needs in the short term. If the funders are not paying to incorporate biodiversity into large scale tree planting then it is extremely difficult to make our case.

Secondly, I’m afraid to say that we are largely regarded as irrelevant. To a certain extent this is due to the drivers of large scale tree planting mentioned above but we also have a credibility problem. In our discussions with the IUCN Bonn Challenge Secretariat, for example, the question back to us is ‘What tools, information and expertise can you bring to the process?’ The answer? ‘Nothing off the shelf and ready to go.’ When it comes to data, the Global Tree Assessment is generating digital maps of native tree species distributions – reviewed by experts – but these are formatted for red list assessments, not for land use planners. On the practical side, we have propagation protocols for tens of thousands of plants scattered amongst thousands of botanic gardens but no central point where these data are collated and easy to get at. Similarly, many thousands of species have been reintroduced and translocated but the information on how to do this is widely scattered. It is easier to deploy expertise than data but even there it is difficult for non-botanists to find the expertise they need – hence BGCI’s new Directory of Expertise.

Thirdly, science itself has a credibility problem. Society doesn’t listen much to science. Large parts of society completely misunderstand science and see it as a competing belief system or dogma (cf. climate change) rather than a process of testing and consensus. Who reads high impact factor papers about biodiversity? Not many corporates, not many policymakers and not many philanthropists. Not many hands on, practical conservationists either. One of the reasons for this is that science itself rewards blue sky thinking and hypothesis driven questions, not the dogged grunt work associated with developing propagation protocols or other information that might be immediately useful to broader society. This really important part of science falls between stools. It doesn’t get funded and it isn’t prioritised.

So what needs to change? Just about everything. Governments need to recognise biodiversity for the public good that it is and pull every lever at their disposal to either commoditise it or directly pay for it. Society needs to recognise the importance of science in informing the decisions we urgently need to make to ensure life on Earth is sustainable. Science needs to value and reward the practical as well as the intellectual. The botanic garden community needs to put the practical conservation of biodiversity first – in our seed banks, in our living collections and, most importantly, out there in the landscape.

No need to wait for the others. Let’s get going.