Nearly two weeks of surveying, sampling and studying plants in the territory have left botanists visiting from the United Kingdom Royal Botanic Gardens more hopeful about the status of some native and endangered plant species, but worried about others, they said in a presentation at the J.R. O’Neal Botanic Gardens Tuesday.
Some plants are thriving because of the protection they have in national parks. For example, Acacia anegadensis, commonly known as poke-me-boy, is a tree once thought to grow only on Anegada. To their surprise, the botanists found a large and mature population of the trees during their daylong survey of Fallen Jerusalem.
“I’m delighted to report that … we managed to find 44 individuals, some very large ones,” said Colin Clubbe, head of the UK Overseas Territories Conservation Programme.
The territory’s original population of another plant, Machaonia woodburyana, was destroyed by road construction at Nail Bay, Mr. Clubbe said.
“I thought I was going to have a seizure,” he said, to illustrate his surprise and disappointment at the loss. The flowering plant, found only in the Virgin Islands and United States VI, is listed as critically endangered by the International Union for Conservation of Nature, but Mr. Clubbe and his team discovered a second population at Gorda Peak, another national park.
At the Tuesday presentation, the botanists also described the technological tools they have been working on during the trip, such as an online herbarium. The herbarium has searchable records of all the plant samples in Kew’s physical herbarium, including high-resolution photos and information about where and when the samples were taken.
“Now they’re available on your desktop, rather than having to travel to west London,” Mr. Clubbe said. The team demonstrated the herbarium and two other web databases of plant life.
Mr. Clubbe and two other Kew botanists — Sara Barrios and Martin Hamilton — spent much of Saturday hiking through the bush in Jost Van Dyke. After a quick meeting with Susan Zaluski, executive director of the JVD Preservation Society, to discuss likely locations for two plants the botanists hoped to find, the group headed for the top of Brown Ghut.
The mission for the day was to take a general stock of which plants grow in the area and, with luck, to find two relatively rare plants. One, Malpighia woodburyana, commonly known as mad dog or stinging bush, had been seen on JVD on a previous trip.
“We’re hoping to find more individuals and to take samples,” Mr. Clubbe said. The team carried equipment to cut small leaves or flowers from plants in the field and preserve them for shipment to Kew’s herbarium, a collection of plants from around the world.
They weren’t far down the steep ghut before they saw it. The pale green leaves looked like they were edged with short, white hairs.
The hairs are the plant’s defence against predators, and where its common name comes from, according to the botanists.
“If you touch it, it makes you itch like a mad dog,” Mr. Clubbe said. Mr. Hamilton added that the sensation after touching the leaves – or worse, the young stems – is the same as one would get from handling insulation fibre.
Mr. Hamilton used gloved hands to clip a leaf from the mad dog and drop it into a zip-top bag that he had prepared with silica crystals.
“The silica dries the sample quickly so that its DNA stays intact,” Mr. Clubbe said. Once the sample is back at Kew, the DNA can be compared with that of other samples to see if different plant populations are closely related or truly the same species. The mad dog sample from JVD, for example, might be compared with others gathered at Anegada.
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“This is important for conservation because you need to know if you’re protecting one species or a few,” Mr. Clubbe said.
Each team member carried a palm-sized computer. They noted the geographic location of the mad dog, plants growing nearby and other environmental factors and snapped a few high-resolution photos, all to be included in the herbarium.
The team found an “extended population” of mad dog on JVD, making four or five stops along the ghut to note individuals or clumps of the plant.
The team never saw the other plant they had hoped to find, Bastardiopsis egersii.
Conservation challenges
In JVD, as on other islands the botanists have studied, non-native species pose one of the biggest threats to conservation of rare native plants. In Brown Ghut, feral goats have eaten a lot of the native bush, and they have damaged it so that it has a hard time regenerating. This places stress on the ecosystem.
“Stressed ecosystems are where you see invasives really take hold,” Mr. Clubbe said. All around the island, he pointed to trees and bush that came from as far away as Africa. They compete with native plants for resources, and sometimes push out the native plants.
The other major challenge for conservation is land development. The VI government requires an environmental impact assessment for most large development projects so that before any construction begins, the government and developers can understand what, if any, sensitive habitat they might disturb. Surveying the islands’ plant population helps give government more evidence on which to base development decisions.
“We’re moving toward more evidence-based conservation generally,” Mr. Clubbe said.
The challenge overall is to balance development, which is required to foster tourism and economic growth, and the territory’s natural environment, Mr. Hamilton said. He described how on other islands, development has damaged the environment so much that the travellers who used to put the most into the local economy no longer want to visit.
“All they get are cruise ship passengers and the occasional spring breakers and family vacations — people who don’t spend much,” he said of such islands.