Plant Conservation – PPP2019

We began with Toby Pennington who wanted to highlight the problems faced by dry tropical forest. More than half of the global tropics are dry. Tropical dry forests are distributed across Latin America and the Caribbean in South America, and are highly threatened, with less than 10% of their original extent remaining in many countries.

So what is a biome?. “[A] biome is a multiscale phenomenon, spanning several large‐scale spatial levels, including global climatic zones, continents and landscapes at subcontinental and supraregional scales.”

What is a savanna? Most savannas have trees, but they’re not forests, as they’re open. Pennington described biome blindness, people forgetting major vegetation types. The biodiversity of the dry tropics is special, Pennington said. There are 11,349 flowering species in the Amazon. Yet thare are 11,384 flowing species in the Cerrado. That’s (a fraction) more, and 30% of those species are endemic. So a plan “Let’s plant trees to mitigate climate change” could be a whole new ecological catastrophe.

Dryflor found over seven thousand woody species in just 1600 or so sites in Latin America and the Caribbean. Pennington highlighted how dry tropical forest doesn’t follow the rules? Is biodiversity higher closer to the equator? No one told Mexico’s forests, which are the most biodiverse dry tropical forests.

So it’s bad news that 50% of the Cerrado has disappeared. Loss varies with districts in the south and southwest of the Cerrado have experienced the greatest land conversion and are the least protected. Pennington argued that restoration at scale will be critical for drop tropical biomes. The Bonn Challenge needs 5 million hectares of Cerrado restored. It can be $7000 a hectare at the moment. You can do it cheaper with seed, but how do you do that over 5 million hectares. Where does the seed come from?

Also what situation are you restoring to? When the systems mature, the climate will be very different. It would be eccentric to restore a site to a dying state.

Cicely A. Marshall looked at priorities for conservation and the economic demands of bauxite mining. If you think you know mining, then I should have caught a copy of the image of a bauxite mine. It’s a strip mine. It’s destructive, but it’s also a quarter of Guinea’s economy. It reminded of some of the strip-mining I’d seen in Australia’s north, where forest is removed.

To examine sites, Marshall uses RBS, Rapid Botanical Survey. They collect every vascular plant they can find. They get local names and uses as well as plants. They categorise the plants using a star rating to identify rarity. Using these ratings they can calculate a hotspot score. Every plat species of tropical Africa has a published star rating. That makes the system a replicable and transferable method of measuring plant rarity.

The highest scoring habitat is wet bowé and riverine forest is close behind. The plants here have limited range. Around 40% of plants had a use, with many of them used medicinally. Bowé is burnt for cattle to graze. The riverine forests are also not valued locally.

The surveys provide a method to negotiate biodiversity conservation with local communities and mining concessions. Where possible effects of mining can be mitigated, and the survey can also identify what plants need to be restored.

I had no reading for Jenny Williams work on drone survey mapping of illegal deforestation detection. I know small drones have been proven useful in forest assessments. But that’s it. I had drone envy from the start.

The film shots tend to be helicopter-style drones. Drones for survey are more like a plane. It flies at the same height, which calibrates the photos, with the camera pointing down. Taking overlapping photos enables you to build a 3D model of the area you’re surveying.

80% of the original forest of Madagascar has been lost. 18 million people rely on the forest for subsistence. Despite people deforesting their land, they still wanted people in to survey.

Antje Ahrends talked about rubber. Natural rubber remains important as it cannot be matched by synthetic rubber. The price rubber is very volatile, and it’s currently very high. Pathogens in Brazil have led to many of the plantations now being planted in SE Asia. In Xishuangbanna, SW China, rubber occupied 22% of the area by 2010, but consequences for forest biodiversity have not been explored much.

90% of rubber plantations are in novel environments. But there’s a high risk of plantation failure. This can lead to a high risk of loss-loss scenarios.

Plantations are spreading based on their proximity to the closest plantation. Farmers are copying their neighbours. This means plantations are expanding into marginal lands in ‘protected’ areas. For many places, rubber planting poses a serious threat to biodiversity and environmental services while not producing the expected economic returns.

The Industry, if not the farmers, would like to develop a synthetic rubber that can match natural rubber. This would enable security of supply against the threat of pathogens. It’s not an alternative to Hevea yet, but Ahrends has identified some plats like Kasakh dandelion as a possible alternative, as 2500 plants produce latex.

Some companies are also working to secure sustainable supplies, but it’s not happening overnight. A boycott is not the answer as this will lead to small farmers clearing more land for other cash sources. A possible solution would be some for of certification, but bigger companies would be able to bear the costs of certifying for fair-trade rubber, while poor farmers could not.

The conference closed with Paul Smith talking about integrated plant conservation. He suggested that grant reviewers may need therapy, as reading so many grant applications paints a bleak picture of the state of the world. Humans have transformed more than 50% of the ice-free terrestrial landscape. Transformed landscapes are now the norm. A more positive response is that plant diversity enables human innovation adaptation and resilience.

“There is no technological reason why any plant species should become extinct”, said Smith. Botanic gardens could help with this The world’s botanic gardens hold around a third of all known plant species in their living collectiona. Though he added that botanic gardens are disproportionately temperate, with 93% of species held in the Northern Hemisphere.

The BGCI are proposing a global strategy for Plant Conservation. They have the best-equipped seed banks, as they’re stocking wild as well as crop seed. They have coordinated to produce a PlantSearch for what plants are held, ThreatSearch for what the local risks are, and GardenSearch for searching for expertise. So species most at threat can be matched with expertise.

BGCI is now working to help set up consortia to work on species that cannot be seed banked. The aim is to achieve goals like zero tree extinctions. “The technical challenges are manageable,” Smith said, “but we need to accept the challenge.” This is a cultural problem. He has proposed that botanic gardens to conserve ecosystems as well as species. We need to be able to match scientific expertise with application at scale.

Otherwise, botanic gardens become “sites of curiosity, place where you come to see extinct plants.”