The July 2015 issue of Fauna & Flora International’s academic journal, Oryx, is dedicated to tree conservation. In this blog, Dave Gill and Rob Loveridge pay tribute to the scientists whose work is guiding the conservation of the ‘charismatic megaflora’.
On close inspection, trees reveal all sorts of secrets. In 2015 alone, scientists have discovered that different species communicate and send food to each other through their root systems, that tropical rainforests are home to an astounding 40,000-53,000 tree species and that 182 ‘carbon-hungry’ species store more than half of the Amazon Rainforest’s carbon.
Such research breathes new life into how we think of trees, and reminds us that the stories behind their existence are rarely simple.
But, more vitally, the work of tree conservation scientists also helps to define where and how best to take action for the world’s 9,000 tree species at risk of extinction.
The July 2015 issue of Oryx-The International Journal of Conservation is dedicated to the conservation of the world’s threatened trees. In the editorial, Sir Peter Crane poses the question: “Can we save the charismatic megaflora?” and the eight articles that follow look at a variety of approaches intended to do just that.
Identifying trees under pressure
The cover features the tropical Andes, where more than 60% of the tree species assessed by the authors (Tejedor-Garavito et al.) were deemed threatened with extinction – principally by habitat loss. The Red List they produced will guide conservation action in the Andean region, but the process of red listing, there and elsewhere, is hampered by a shortage of good data.
To date we know the conservation status of around one in five of the world’s trees. In their article, Newton et al. describe these challenges and propose an approach to accelerate Red Listing of trees, arguing that – with the advent of new computing and web technologies – now is the time to launch a global assessment of the world’s tree species.
Coming to terms with habitat loss
A common thread throughout the articles is the impact of habitat loss.
Rodríguez-Echeverry et al. revealed that the Patagonian cypress Fitzroya cupressoides lost 46% of its potential habitat in just 12 years. What’s worse, as smaller populations become surrounded by commercial plantations, their persistence depends on retaining connectivity between one another, which means that land-use planning, targeted restoration and sustainable agriculture are all necessary parts of the solution.
Other trees have been drawn even further into the extinction vortex.
With less than 1% of southern Brazil’s Araucaria forest remaining, many trees species there are rare, isolated, and failing to reproduce. Hoffmann et al. surveyed 68.7 km of trails, locating seed-producing trees for 38 of 71 known rare or threatened species.
They identified optimal timing of seed collection for these species, and their research is directly supporting restoration projects in southern Brazil.
Animals and trees in it together
In Queensland, Australia, Brown et al. investigated the ecology of the Endangered Alectryon ramiflora, which in 2013 had only 26 individuals remaining in the wild. Because individual trees from this species are either male or female and are rarely found close together, its survival depends on pollinators getting from A to B. With pollinators in the area now also rare, boosting their numbers will form an essential part of plans to recover this Endangered tree.
The interconnectedness of fauna and flora was also highlighted by David Beaune’s research in LuiKotale, in the Democratic Republic of Congo. Bonobos (a more amorous cousin of the chimpanzee) are fruit fanatics, and one individual will disperse an estimated 9.1 tonnes of seed in its lifetime.
Without this service, 95% of bonobo-dispersed trees failed to establish seedlings, so the future of these species is closely linked to that of the bonobo, itself threatened by hunting.
Making business scents
In the lower montane forests of Saint Lucia, Fauna & Flora International’s Jenny Daltry et al. set out to solve a conservation dilemma: can local tappers continue to harvest valuable incense from the aromatic resin of the lansan tree Protium attenuatum without further endangering the wild population?
After testing a variety of tapping regimes on 298 healthy trees, the authors found methods that could boost resin yield without harming tree growth, condition or mortality. These are now being adopted as part of a national management plan for the species, under which tappers are licensed to use lansan-friendly methods in dedicated areas of forest.
Pulling together for tree conservation
With so many trees on the edge of extinction, Cavendar et al. describe how the botanic garden community can play a more active part in their conservation. The challenges are manifold, but the opportunities appear to be far greater.
They point to the benefits of working together at a global scale, such as improving coordination to match skills and resources to particular conservation problems, and empowering gardens in biodiversity hotspots to participate in tree conservation locally.
The fate of the charismatic megaflora hangs in the balance, yet the articles in this issue of Oryx offer reasons for hope.
Not only do they highlight cases where conservation approaches are really working, the articles also show that there is real appetite from the global community to support field-based projects – whether it is through the acceleration of Red Listing, through the botanic garden community or through initiatives such as the Global Trees Campaign.