How a man in a
monkey cage
decided to save
the planet,

...one tree at a time.

Andy Marshall’s renowned research goes to the root of conservation science – the health or otherwise of the 73,000 tree species growing on our planet, releasing oxygen, absorbing carbon dioxide, helping people, animals and the atmosphere breathe easier.

In 24 years of fieldwork in Africa, the UK and Australia, including five years of lab analyses at the University of the Sunshine Coast, and with major findings published in international journals and media, every breath Andy takes is for the love of flora and fauna.

So how did his tale start in a cage full of monkeys?

The UniSC Forest Research Institute Professor admits his career in threatened ecosystems and tropical biodiversity had a cheeky beginning – when he lived in a monkey cage for a week at a zoo in England.

The science student
and the monkeys

In 1998, the sign on the cage at the Paignton Zoo in Devon read: “Please throw the money into the enclosure to help raise 3,000 pounds to save the rainforest. Thankyou.”

Behind the bars was 21-year-old Cardiff University zoology student Andrew R Marshall, nametagged and clad in plaid as he pursued his unusual residency, which was quickly reported in newspapers.

A journalist took a snap of him laughing as he was fed a banana through the cage, no doubt watched by bemused macaques and marmosets.

“While I was studying my undergraduate degree, I saw an ad for volunteers for a wildlife conservation expedition to East Africa,” recalls Professor Marshall. “I decided to stay in a monkey cage in the zoo for a week to raise money for my trip.” As you do.

Commitment to the cause? Tick.
Sense of adventure? Tick.
Result? Success.

“Tanzania was exciting, a wonderful place, and I was offered a job with the expedition company the following year,” he says.

So began his dedication to measuring the biodiversity of that country, right through his postgraduate studies and academic work with the University of York until he joined UniSC and settled in Australia in 2017.

In fact, Tanzania stayed on Professor Marshall’s travel itinerary annually until COVID-19 shut global borders in 2020.

Now speaking in mid-2022, the Australian Research Council Future Fellow has again returned from Tanzania. He was one of USC’s first academics to resume overseas research following the lifting of border restrictions.

And he’s again in the news, this time via hundreds of media outlets from Europe to China to Australia, for collaborating with 150 researchers on every continent except snow-white Antarctica to answer the evergreen question: how many tree species exist in the world?

Seeing the wood for the trees

The answer – about 73,000 – is published in a paper in US journal PNAS, the result of decades of painstaking identification of trees both common and rare.

“It’s hugely exciting,” Professor Marshall says. “This new global dataset is a significant piece of the puzzle in ecology and biodiversity. It’s based on the identification of trees growing in millions of vegetation plots around the world.”

It’s also a new beginning in ecosystem biodiversity, with about 9,000 of the 73,000 estimated tree species yet to be discovered and needing names and scientific descriptions.

According to the research, led by Roberto Cazzolla Gatti of Purdue University and the Global Forest Biodiversity Initiative, “these findings highlight the vulnerability of global forest biodiversity to anthropogenic changes in land use and climate, which disproportionately threaten rare species and global tree richness.”

Almost 6,700 known tree species and 1,500 undiscovered species were estimated in Oceania, including Australia. The research found a ‘hot spot’ of likely undiscovered species in the tropical and subtropical moist forests of northeast Australia and the Pacific Islands.

Professor Marshall says that estimating the planet’s total number of tree species helps show how many different ecosystems exist and gauge the health of those systems.

“The better the information, the better we can inform national and international plans for conservation management and biodiversity targets – potentially saving endangered tree species in the process,” he says.

“The knock-on impacts of losing a species can be devastating – what if it’s the food of a native mammal or the habitat of an important seed-dispersing bird? Regional governments need to know how to prioritise ecosystem management.”

He says the publication of the paper by PNAS (The Proceedings of the National Academy of Sciences of the USA) is also nice recognition for the hard work required to identify trees “in the middle of nowhere”.

“You’ve got hundreds of tree species to ID and there’s no guidebook to flick through,” he smiles. “You’re trekking through a heavy rainstorm or crawling under a vine thicket getting scratched and bitten.

“You have to collect materials, and not just cut a stem. You might be waiting, making repeated trips, if it’s a flower that’s inconspicuous or only blooms seasonally or is quickly pollinated by beetles before falling. Then you’re in the lab and following individual ID processes that can take years.”

It’s this ability to combine the big picture with the specific characteristics of even the most secretive plants that has borne fruit for Professor Marshall’s research.

A custard apple tree
by any other name

One of his sweetest and most unexpected discoveries came in 2019, when he and two UK colleagues identified a new species of Mischogyne, a genus in the custard apple (Annonaceae) family that was previously considered to only have two species.

“It’s a tropical tree with white flowers that grows up to 20 metres tall, in the eastern mountains of Tanzania,” he says. “It has larger leaves and an unusual distribution pattern. We named it Mischogyne iddii after Amani Nature Reserve botanist Iddi Rajabu. He was stoked!”

Andy Marshall, front, and colleagues with Tabernaemontana stapfiana, in Tanzania in 2008

Andy Marshall, front, and colleagues with Tabernaemontana stapfiana, in Tanzania in 2008

While it’s one of several new species identified by Professor Marshall, who holds a joint position at the University of York where he completed his PhD and his Master of Research in Ecology and Environmental Management, he says the key is balancing their survival with agriculture and urbanisation, invasive plants and pests, weather events and climate change.

As he told Sci-News.com in 2019, “Now that we know it exists, we have to look at ways to protect it … Small forests need to be connected to others to ensure seed dispersal and species adaptation to climate change.”

For the past four years, Professor Marshall has also been assessing the impact of lianas (woody vines) on forest health and management, after he was awarded a $900,000 Australian Research Council Future Fellowship at UniSC.

The project, considered by the Australian Government to have critical national importance, has enabled intrepid PhD students to follow in his footsteps across Queensland and Tanzania. It also delivered his 100th published article in 2020.

“Lianas have a negative impact on forests because they grow up rapidly in disturbed areas of forest and compete intensely with trees for nutrients and light,” he says. “But they are also part of the forest ecosystem and biodiversity, and they provide food and pathways for animals.”

Now, back to those primates.
And penguins.
And flamingos?

You can get the
boy out of the zoo…

While Professor Marshall’s career has leaned into ecology rather than zoology, he’s never lost his soft spot for wildlife and animal welfare.

With his 2007 doctorate identifying human impacts on threatened monkeys in Africa, he was still publishing on them in 2017 – he was lead author on a paper in the Journal of East African Natural History evaluating the habitat of the critically endangered kipunji monkey.

And for 10 years until the move to Australia in 2017, he was Conservation Director of the UK’s Flamingo Land Theme Park and Zoo, running its conservation and research programs through the University of York.

He continues to publish on topics ranging from how zoo enclosures influence the breeding and behaviours of penguins and flamingos, to the educational effectiveness of live animal shows.

This 2021 paper, led by one of his PhD students, found a significantly higher animal knowledge in audiences after the shows, while recommending prioritising natural behaviours with a focus on conservation action.

Marshalling forces to
research and reforest

For this tireless researcher who calls himself a “happy dad with crazy twin boys” on Twitter (@Andy_R_Marshall), Australia, Africa and the UK are all home.

He looks forward to more discussions on the Sunshine Coast with his wife Cara about the potential of science to change the future for the better.

They met in a national park in Africa – of course – and she works in communications at the Ecological Society of Australia, striving to bridge the crucial gap between science and policy.

In Tanzania, he will continue branching out with partners at the community-based forest restoration charity he founded, Reforest Africa, and through a long-term research project he also founded, FoRCE, the Forest Restoration and Climate Experiment.

There’s ongoing development of a new forest nature reserve and management plan in Tanzania following grants totalling more than a million dollars in 2016.

“The idea is simple,” Professor Marshall says. “We want to plant trees to restore tropical forests and the research informs where and how we should this.”

And the 73,000 tree species research is already on to the next phase in Queensland.

“We’re setting up new vegetation plots across the Cassowary Coast and Atherton Tablelands, and hope to do similar on the Sunshine Coast,” he says.

A cost-benefit analysis, based on the newly published data, is also underway to help governments set priorities on native forest restoration.

For this researcher determined to achieve practical results from his findings, the growth trajectory of his work is clear.

Andy Marshall’s renowned research goes to the root of conservation science – the health or otherwise of the 73,000 tree species growing on our planet, releasing oxygen, absorbing carbon dioxide, helping people, animals and the atmosphere breathe easier.

In 24 years of fieldwork in Africa, the UK and Australia, including five years of lab analyses at the University of the Sunshine Coast, and with major findings published in international journals and media, every breath Andy takes is for the love of flora and fauna.

So how did his tale start in a cage full of monkeys?

The UniSC Forest Research Institute Professor admits his career in threatened ecosystems and tropical biodiversity had a cheeky beginning – when he lived in a monkey cage for a week at a zoo in England.

The science student
and the monkeys

In 1998, the sign on the cage at the Paignton Zoo in Devon read: “Please throw the money into the enclosure to help raise 3,000 pounds to save the rainforest. Thankyou.”

Behind the bars was 21-year-old Cardiff University zoology student Andrew R Marshall, nametagged and clad in plaid as he pursued his unusual residency, which was quickly reported in newspapers.

A journalist took a snap of him laughing as he was fed a banana through the cage, no doubt watched by bemused macaques and marmosets.

“While I was studying my undergraduate degree, I saw an ad for volunteers for a wildlife conservation expedition to East Africa,” recalls Professor Marshall. “I decided to stay in a monkey cage in the zoo for a week to raise money for my trip.” As you do.

Commitment to the cause? Tick.
Sense of adventure? Tick.
Result? Success.

“Tanzania was exciting, a wonderful place, and I was offered a job with the expedition company the following year,” he says.

So began his dedication to measuring the biodiversity of that country, right through his postgraduate studies and academic work with the University of York until he joined UniSC and settled in Australia in 2017.

In fact, Tanzania stayed on Professor Marshall’s travel itinerary annually until COVID-19 shut global borders in 2020.

Now speaking in mid-2022, the Australian Research Council Future Fellow has again returned from Tanzania. He was one of UniSC’s first academics to resume overseas research following the lifting of border restrictions.

And he’s again in the news, this time via hundreds of media outlets from Europe to China to Australia, for collaborating with 150 researchers on every continent except snow-white Antarctica to answer the evergreen question: how many tree species exist in the world?

Seeing the wood for the trees

The answer – about 73,000 – is published in a paper in US journal PNAS, the result of decades of painstaking identification of trees both common and rare.

“It’s hugely exciting,” Professor Marshall says. “This new global dataset is a significant piece of the puzzle in ecology and biodiversity. It’s based on the identification of trees growing in millions of vegetation plots around the world.”

It’s also a new beginning in ecosystem biodiversity, with about 9,000 of the 73,000 estimated tree species yet to be discovered and needing names and scientific descriptions.

According to the research, led by Roberto Cazzolla Gatti of Purdue University and the Global Forest Biodiversity Initiative, “these findings highlight the vulnerability of global forest biodiversity to anthropogenic changes in land use and climate, which disproportionately threaten rare species and global tree richness.”

Almost 6,700 known tree species and 1,500 undiscovered species were estimated in Oceania, including Australia. The research found a ‘hot spot’ of likely undiscovered species in the tropical and subtropical moist forests of northeast Australia and the Pacific Islands.

Professor Marshall says that estimating the planet’s total number of tree species helps show how many different ecosystems exist and gauge the health of those systems.

“The better the information, the better we can inform national and international plans for conservation management and biodiversity targets – potentially saving endangered tree species in the process,” he says.

“The knock-on impacts of losing a species can be devastating – what if it’s the food of a native mammal or the habitat of an important seed-dispersing bird? Regional governments need to know how to prioritise ecosystem management.”

He says the publication of the paper by PNAS (The Proceedings of the National Academy of Sciences of the USA) is also nice recognition for the hard work required to identify trees “in the middle of nowhere”.

“You’ve got hundreds of tree species to ID and there’s no guidebook to flick through,” he smiles. “You’re trekking through a heavy rainstorm or crawling under a vine thicket getting scratched and bitten.

“You have to collect materials, and not just cut a stem. You might be waiting, making repeated trips, if it’s a flower that’s inconspicuous or only blooms seasonally or is quickly pollinated by beetles before falling. Then you’re in the lab and following individual ID processes that can take years.”

It’s this ability to combine the big picture with the specific characteristics of even the most secretive plants that has borne fruit for Professor Marshall’s research.

A custard apple tree
by any other name

One of his sweetest and most unexpected discoveries came in 2019, when he and two UK colleagues identified a new species of Mischogyne, a genus in the custard apple (Annonaceae) family that was previously considered to only have two species.

“It’s a tropical tree with white flowers that grows up to 20 metres tall, in the eastern mountains of Tanzania,” he says. “It has larger leaves and an unusual distribution pattern. We named it Mischogyne iddii after Amani Nature Reserve botanist Iddi Rajabu. He was stoked!”

While it’s one of several new species identified by Professor Marshall, who holds a joint position at the University of York where he completed his PhD and his Master of Research in Ecology and Environmental Management, he says the key is balancing their survival with agriculture and urbanisation, invasive plants and pests, weather events and climate change.

As he told Sci-News.com in 2019, “Now that we know it exists, we have to look at ways to protect it … Small forests need to be connected to others to ensure seed dispersal and species adaptation to climate change.”

For the past four years, Professor Marshall has also been assessing the impact of lianas (woody vines) on forest health and management, after he was awarded a $900,000 ARC Future Fellowship at UniSC.

 The project, considered by the Australian Government to have critical national importance, has enabled intrepid PhD students to follow in his footsteps across Queensland and Tanzania. It also delivered his 100th published article in 2020.

“Lianas have a negative impact on forests because they grow up rapidly in disturbed areas of forest and compete intensely with trees for nutrients and light,” he says. “But they are also part of the forest ecosystem and biodiversity, and they provide food and pathways for animals.”

Now, back to those primates.
And penguins.
And flamingos?

You can get the
boy out of the zoo…

While Professor Marshall’s career has leaned into ecology rather than zoology, he’s never lost his soft spot for wildlife and animal welfare.

With his 2007 doctorate identifying human impacts on threatened monkeys in Africa, he was still publishing on them in 2017 – he was lead author on a paper in the Journal of East African Natural History evaluating the habitat of the critically endangered kipunji monkey.

And for 10 years until the move to Australia in 2017, he was Conservation Director of the UK’s Flamingo Land Theme Park and Zoo, running its conservation and research programs through the University of York.

He continues to publish on topics ranging from how zoo enclosures influence the breeding and behaviours of penguins and flamingos, to the educational effectiveness of live animal shows.

This 2021 paper, led by one of his PhD students, found a significantly higher animal knowledge in audiences after the shows, while recommending prioritising natural behaviours with a focus on conservation action.

Marshalling forces to
research and reforest

For this tireless researcher who calls himself a “happy dad with crazy twin boys” on Twitter (@Andy_R_Marshall), Australia, Africa and the UK are all home.

He looks forward to more discussions on the Sunshine Coast with his wife Cara about the potential of science to change the future for the better.

They met in a national park in Africa – of course – and she works in communications at the Ecological Society of Australia, striving to bridge the crucial gap between science and policy.

In Tanzania, he will continue branching out with partners at the community-based forest restoration charity he founded, Reforest Africa, and through the long-term research project he also founded, FoRCE, the Forest Restoration and Climate Experiment.

There’s ongoing development of a new forest nature reserve and management plan in Tanzania following grants totalling more than one million dollars in 2016.

“The idea is simple,” Professor Marshall says. “We want to plant trees to restore tropical forests and the research informs where and how we should this.”

And the 73,000 tree species research is already on to the next phase in Queensland.

“We’re setting up new vegetation plots across the Cassowary Coast and Atherton Tablelands, and hope to do similar on the Sunshine Coast,” he says.

A cost-benefit analysis, based on the newly published data, is also underway to help governments set priorities on native forest restoration.

For this researcher determined to achieve practical results from his findings, the growth trajectory is clear.

Andy Marshall, front, and colleagues with Tabernaemontana stapfiana, in Tanzania in 2008

Andy Marshall, front, and colleagues with Tabernaemontana stapfiana, in Tanzania in 2008