Kauai, Hawaii – This year marks the 40th observation of Earth Day, and so it’s fitting that the United Nations General Assembly has declared 2010 as the International Year of Biodiversity. The world body selected this year with the goal of halting the loss of biodiversity and, at a minimum, raising general awareness of the rich, complex tapestry of life which is considered a basic barometer of the Earth’s health and a leading indicator of how rich (or poor) we are as a planet.
In the United States, perhaps nowhere is the loss of biodiversity more apparent, or on the minds of a larger segment of the general public, than in Hawaii. Owing to its location as one of the most remote island chains in the world, Hawaii’s flora and fauna represent some of the world’s most unique life forms.
The few plants, animals and insects that reached these volcanic islands millions of years ago evolved in near-total isolation without threat from predatory animals or aggressive plants. The result is highly specialized species that were, and still are, often limited to very distinct environments such as a lone island or, in many cases, a single mountain, valley or ridge.
Hawaii’s residents are all too familiar with their unfortunate distinction as the “extinction capital of the United States.” Tiny Hawaii, occupying just one percent of the country’s landmass, is home to about thirty percent of its threatened and endangered species, including 330 federally listed plants and animals.
Last month, the US Department of Interior added 45 rare native Hawaiian plants, along with two birds and one insect, to the list. These newly listed species are endemic to just one island – Kauai – and found nowhere else on earth.
If they die off there, that’s it. Forever.
Wrestling to salvage the biodiversity of Hawaii are people like Keren Gundersen, project manager for the Kauai Invasive Species Committee. She describes how the partnership of government, private and nonprofit organizations is on the front lines of battling aggressive plants and animals that threaten to devastate native species.
Plants with innocuous-sounding names like strawberry guava, kahili ginger and Australian tree fern have found their way into the Hawaiian Islands and are running wild through native forests. One of the biggest threats to Hawaii’s watershed ecosystems and the rich biodiversity they house is Miconia calvenscens, known simply as miconia, the “purple plague” and even “green cancer.”
Gundersen explains how extremely aggressive plants like miconia can spread though a diverse forest and, in a very short time, transform it into a monotypic forest, robbing it of all its former biodiversity with impacts far beyond the forest itself.
“Miconia has taken over three-quarters of Tahiti and destroyed its watersheds,” Gundersen says. Because miconia is aleopathic, it prevents other seeds from growing below it, robbing the forest of an understory. When it rains, its huge leaves accumulate more water which results in greater erosion that ultimately damages the island’s coastal reefs.
In addition to invasive plants, biodiversity in Hawaii is threatened by non-native ungulates such as deer, goats and cattle and by wild pigs.
“Kauai, in particular, is the biodiversity hotspot in the Hawaiian archipelago,” says Gundersen. “These islands developed in isolation, so our native plants are very passive. We have raspberries without thorns and mints without scents because there were no predators. Native plants are very slow-growing because they don’t need to outcompete one another.”
In Hawaii and other islands, natural predators that would ordinarily keep introduced organisms in balance are absent and so, left unchecked, plants and animals can multiply disproportionately fast. Snakes (effectively absent in Hawaii) could devastate native bird populations, wild pigs spread aggressive alien seeds, and even the waste from the invasive Puerto Rican coqui frog can alter the chemical makeup of the forest floor, impacting which plants will grow.
Trae Menard, director of the Kauai Program for The Nature Conservancy says that while people tend to focus on loss of biodiversity in terms of rare and endangered plants and animals, many of the losses which have equally or potentially greater ramifications are those which go largely unseen, such as tiny insect pollinators or huge native forests with all their complex components.
Loss of biodiversity is a global problem, but Menard points out that in Hawaii, with both high species diversity and high endemism, the rate of loss can happen much faster and is more pronounced. Like other Pacific islands such as New Caledonia and New Zealand, Hawaii’s biodiversity is particularly vulnerable.
And while people in Hawaii may be used to regularly hearing about invasive species, Menard points to invasives in Florida, California and Illinois, with its invasive Asian carp, as examples of similar problems confronting Hawaii’s continental cousins.
The loss of biodiversity is likely to be exacerbated by climate change, Menard says.
“Invasive species are considered invasive for a reason. They can adapt to novel environments and are able to survive in disturbed conditions better than native plants,” Menard explained. Pointing to recent research projects that indicate Hawaii’s drier leeward areas may experience a five to 10 percent decrease in rainfall as the climate changes, Menard says drier forests will become more susceptible to fires and invasive species. Less rainfall, or periodic episodes of extreme rainfall, will affect overall hydrology, watersheds, plants, animals and insects.
“Hawaii is a model for the future of what is going to happen elsewhere around the globe. Who knows what we are really in for? But changes are going to happen really fast and because invasive species can adapt, they will survive,” Menard said.
On a positive note, Menard said that because Hawaii has been dealing with these problems for a relatively long time, and because the islands are so remote, Hawaii serves as a test-case that can offer its experience and lessons to the rest of the world.
“What we learn to make our ecosystems more resilient is going to be valuable globally,” he said.
Menard also believes Hawaii can be a model of partnership between private landowners, nonprofits and government agencies working together toward a common goal.
“It’s not all bleak. I think we collaborate really well in Hawaii and while we have some serious [environmental] challenges, working together is probably our best hope for success,” Menard said.
So why is it worth protecting Hawaiian or, for that matter, any other native plants?
Ken Wood, a research biologist at the National Tropical Botanical Garden (NTBG) on Kauai, has spent much of the last 25 years literally hanging around (with ropes on cliffs) with many of the world’s rarest endemic plants, not only in Hawaii, but around the Pacific, from the Marquesas to Micronesia.
“A lot of people ask that … ‘why is it worth protecting native plants?’ What makes them special?” Here Wood becomes philosophical.
“There isn’t one set answer, but to me it’s just a simple fundamental that there is diversity on this earth. That diversity came in a natural way and these naturally occurring beings have a right to continue to live, grow and reproduce, just as humans do,” he said.
Wood says anything people can do to contribute to their survival is important. He says we should not let distractions like war, development, industry, or other human pursuits detract from protecting and appreciating the divine natural wonders of the world.
In a practical sense, Wood points to the physical detriment caused by the loss of biodiversity and human alteration of natural ecosystems.
“When you start to lose native plants, there is a temperature change even in local areas, not only globally. There’s a coolness in a natural forest with moisture contained in the watershed and all kinds of mosses on the ground and shrub layers absorbing rainfall which it retains for long periods.
“If you lose that to cultivated or developed areas, you lose that coolness and the ability for all types of birds, insects and plants to survive. It just gets smaller and smaller and things start to fall apart,” Wood said.
Witness to this massive loss of biodiversity, and actively working to document and protect the world’s plants is Professor Sir Ghillean Prance, science director for the Eden Project, former director of the Royal Botanic Gardens, Kew and a 25-year veteran of The New York Botanical Garden. He is also a trustee and senior research fellow at NTBG.
For half a century Professor Prance has traveled the world collecting, studying and teaching about the world’s tropical flora and fauna. Since 2001, he has regularly visited Hawaii to study its unique species which, he says, from an evolutionary stand point are as significant as anything Darwin found in the Galapagos.
From Africa to the Amazon and across Europe, Asia and the Pacific, botanist Prance has had his finger on the earth’s pulse, watching as the planet sighs, heaves, and convulses under the onslaught of man.
Concern about the loss of biodiversity is nothing new for Prance. In 1974, he edited a book called “Extinction Is Forever” and, over his career as a botanist, he has also evolved into an ecologist. He says the International Year of Biodiversity is a good way to raise awareness and draw attention to efforts to stem the tide of extinction and hopefully influence policy makers, but he is alarmed by the rate of loss.
Professor Prance recalls traveling in the Amazon region in the 1970’s and being jolted as rainforests were cut down in favor of agriculture such as soy beans. “It is a shock to go back to an area where you have collected interesting things and seen the value of the biodiversity and then find that it has been converted completely.”
The professor is heartened to see how changes in Brazilian law now forbid the cutting of virgin rainforest for soy plantations, and a greater interest and awareness of environmental issues around the world.
But he recognizes biodiversity remains under incredible pressure from mankind and from climate change abetted by lackluster, non-binding climate accords, unambitious cuts in CO2 emissions and the continued slashing of tropical forests, such as the peat forests of Indonesia.
Yet he gains hope from other changes he sees, especially in young people around the world.
“In the places I travel there’s much more concern and enthusiasm about the environment today. Somehow the message is getting out, and while it’s too slow, it’s encouraging.
“There’s still a great deal of habitat loss and then, above all, you have climate change. Until we can get a handle on climate change, I don’t think we will really fully stop the loss of biodiversity,” Professor Prance said.