The Brown Tree Snake (Boiga irregularis) is a Pacific invasive species causing devastating damages to the delicate Hawaiian ecosystems and the infrastructure for power supply, as well as harmful health risks to the islanders. The Brown Tree Snake (BTS) and its prevention and control in Hawaii is the topic of author Kimberly M. Burnett and colleagues’ research, funded by a USDA/ERS grant. Burnett, from the University of Puget Sound, developed a general model based on Guam’s BTS infestation that can be used to determine if prevention or control strategies would be most cost effective to keep the snake’s numbers low. Taking into account how the most advantageous expenditure paths change due to a motley of ecological factors, Burnett and her colleagues determined that it is more cost effective to find and eliminate the existing populations of snakes in Hawaii, rather than endeavor to entirely prevent its introductions to the island.
Ecological Economics 67: 66-74 (2008).
Molecular Ecology (2009) 18, 3603–3615
The Coqui frog, native to Puerto Rico, is considered invasive in the Hawaiian Islands due to a loud mating call, which surpasses levels decided fit for the ‘enjoyment of life.’ Research and experiments on Coqui frogs suggest that reduced genetic variation in the species does not negatively affect its invasion success.
Mary M. Peacock of the University of Nevada and her colleagues at Utah State University and the University of Georgia studied multiple populations in Puerto Rico and Hawaii. They determined that gene diversity and color pattern diversity were significantly higher in Puerto Rico than in the invaded regions of Hawaii. Allele counts in invaded areas were recorded at as much as half the number found in native Puerto Rico. Further, only two color patterns were found in Hawaii while five are known in Puerto Rico. The researchers also used their data to assert that their findings support a theory of two different introductions of the frogs in the invaded regions.
Miconia first arrived to Hawaii from Mexico as a nursery plant in 1961, a journey that was facilitated by humans. Their abilities to grow quickly, disperse seeds on a massive scale, and suffocate native plants have allowed them to spread across 10,000 acres of the Big Island. The large leaves of the Miconia compete for sunlight with the native plants with great success. As soon as the native plants and their roots die out, the soil is only held together by the roots of the Miconia which do not penetrate as deeply or cover as much of an area. The loosening of the soil and the channeling of rain water by the Miconia leaves have the potential for causing widespread erosion and large scale landslides.
Spearheading the cause to rid Hawaii of the Miconia are David Duffy and Greg Asner. Together they have tracked and mapped the locations of Miconia invasion. Asner uses aerial images of light reflections along with GPS coordinates of specific leaves he finds in the forest to identify problem areas before they get out of control. There are various volunteer efforts working as well, mainly attempting to control and contain the problem of the Miconia invasion.
While David Duffy and Greg Asner are certainly working hard to contain the Miconia, the effort on the whole could be prioritized at a much higher level and performed with more manpower. If Duffy’s assessment of the problem and prediction of future issues is accurate, then the problem seems to be more threatening than other people see it to be. In a place like Hawaii, where erosion is already an issue, the Miconia invasion’s threat to worsen the problem with massive landslides should be considered more serious. Concerning the efforts to contain the Miconia, I wonder especially how the plants can be removed or killed without causing more of a problem. Already the soil is loosened by the lack of roots, so if Miconia are then removed, will there be anything to prevent the occurrence of a landslide? Perhaps some other mode of prevention has been instituted that I am unaware of.
An invasive species, identified as Miconia calvescens, has caused a widespread scare in Hawai’i over the past decade. Recently added to the Hawai’i State Noxious Weed List, this plant has caused major destruction across thousands of acres of all of the Hawaiian islands. Miconia are capable of growing to be around fifty feet tall, with enormous oval-shaped leaves that cast an overbearing shadow across the ground floor of Hawaiian tropical jungles. They were introduced in 1961 as a house plant from South America, when they quickly dispersed from homely gardens to take over surrounding land. Exchange of the plants between gardeners greatly facilitated the growth of the plant throughout all of the Hawaiian islands.
The threat that Miconia pose is one of habitat destruction. They quickly grow into large shrubs or medium sized trees that take up a lot of area, and their leaves have gained the name “Purple Plague” and “Green Cancer” as a result of their coloring, a dark shade of green on top, and a purple shade on bottom. The size of the leaves is what causes the most damage; they are so large that they shade the bottom of the tropics from the sun by forming an expansive canopy that blocks any light from entering the lower floors of the jungle, as well as funneling rain in hard streams that beats the soil and strips it of any nutrients. The canopy of leaves deprives other species of the sunlight they need to perform the light-dependent stages of photosynthesis, and ultimately kill these native species of Hawai’i.
Greg Asner, an ecologist who works with the National Geographic team on eradicating this invasive species from the Hawaiian islands, has ingeniously changed U2 spy planes from the cold war to use to take light-sensitive images of entire forest canopies, and compares the images to measured light reflection readings from the air and from the ground, to identify large areas of Miconia growth, which teams are then able to search for and uproot. This is a very complex, and rather interesting, method of localizing invasive species, however it appears it may be too slow to get rid of a species that grows so fast. Unfortunately, other options would likely include harsh chemicals that could harm nearby native species, so it seems that, for now, the solution will work as long as teams work quickly. Preserving the biodiversity in the Hawaiian islands is essential, so eradicating this invasive weed should become a large effort to ensure success.
Image taken from http://www.hawaiiecoregionplan.info/threats.html
Image taken from http://www.pbs.org/strangedays/episodes/invaders/experts/miconia.html
The Big Island of Hawaii is considered to be a paradise. With the palm trees swaying in the wind, the fresh pineapple, and the delicious macadamia nuts. However, none of these things are actually Hawaiian. Even the forest is beginning to become mostly made of foreign plants including the Miconia. The Miconia is a beautiful plant with large leaves that have purple undersides. It is this beautiful plant that threatens to create devastating landslides that could potentially kill the coral reefs. This plant started its invasion in the mid 1800′s when a European man saw the tree and found it breathtaking. He shipped the plant back to his home in Europe. In 1961, Hawaii accepted a specimen of this tree for a greenhouse. Before long, the beauty of the Miconia captured an audience and was eventually sold in nurseries. From there, it didn’t take long for the tree to spread all over the island. It had the help of the Japanese White Eye bird, who ate the small fruit and spread the hundreds of seeds over a vast area of land. Today, the Miconia inhabits 10,000 acres of land and is casting shadows over the native plants. The native plants are dying and leaving only the short sparse roots of the Miconia to hold the soil together. With heavy rains, there is a very strong possibility that there will be lanslides in areas where the Miconia is dominant.
There are many groups of people who want to be rid of the Miconia on the Big Island. They want to see the native plants of Hawaii to flourish once again and to save the land from disappearing into the sea. To get rid of the invader, the Hawaii conservationists are using GPS signal to pinpoint where the growth of Miconia is plentiful. They also use technology that allows them to see how light reflects off of the Miconia leaves. The people then take pictures of the forest canopy from helicopters with special cameras that detects the amount of light being reflected back. To figure out where the Miconia is, they find where there are patches of a specific light reflectivity that are consistent with samples of leaves from the intruder. After they obtain this information, the people go out to get rid as many Miconia as possible. They all do this in hopes that one day, Miconia will disappear from Hawaii, leaving the native plants to create their own natural paradise.
Invasive species truly are impacting a variety of places all over the world. Although many are silently dwelling underwater or burrowing through wood, others are right out in the open, outcompeting native species and tampering with natural ecosystems. This is the case in Hawaii with the Miconia tree. The tree was originally transported to the island due to the physical attractiveness and unique leaves with purple undersides. However, what began as a few harmless plants quickly erupted into a much bigger issue, with the Miconia rapidly spreading to take over large areas of the island. The most visible problem this alien species creates is erosion. By growing taller than surrounding vegetation and blocking the sunlight, plants around the trees die out. Since the roots of the Miconia do not reach deep into the soil, the cliffs of the island become extremely vulnerable to landslides and excessive erosion.
To counteract the spread of the tree, a powerful mix of physical manpower and advanced technology has been used. By photographing the landscape of Hawaii with many different cameras with advanced light sensors, an ecologist named Greg Asner has been able to accurately map out where large populations of Miconia exist. Then, it is up to organized groups to seek out and destroy the unwanted species.
I was impressed with the technology being used to attempt to solve the issue of Miconia in Hawaii. Although biocontrol has proven effective in removing some alien species such as the water hyacinth, I think the only way we stand a chance to restore ecosystems back to their natural states is by using these creative and advanced techniques. It is unfortunate that Asner has deducted such an effective way to map out exactly where the trees are living without a fast and effective way to destroy them. However, I’m sure if the Miconia continue to grow in population this quickly, more people will become aware of the issue and more will be done.
Through the film, “Strange Days on Planet Earth” (2005), director Edward Norton has achieved his goal of promoting awareness of invasive species. Narrating from a neighborhood cul-de-sac, Norton’s explains the local impacts of these micro- and macroscopic organisms. In a series of well-edited sequences, the viewer is transported to a New Orleans invested by termites, a Lake Victoria covered in water hyacinth, and a Hawaii overgrown with miconia. Each location had vivid explanations of what precipitated the infestation, what the result was, and what is currently being done.
A striking observation from each location is how such small human actions could trigger huge ecological ramifications, as shown through flashbacks sequences in the film. A simple foreign plant given as a gift could take over an entire forest. Organisms invisible to the human eye can easily be transported long distances on clothing, shipping cargo, and any mode of transportation they can find. One of the scientists in the film even noted that he was wearing specialized boots to prevent even himself from spreading the species he was studying to foreign areas.
Globalization, as explained by the film, is one of the primary causes of such spreads. Never before had animals had the mobility to cross such vast distances and establish holds in foreign habitats. The skyrocketing rate of world trade expansion has overridden animal migration, natural selection, and adaptation. Foreign species are being haphazardly inserted into ecosystems that can not cope with them. Variety of species is on the decline, and as emphasized in the movie, animals found nowhere else in the world are being out-competed by new invaders.
However, there is still hope. The film outlined several measures used to fight these invaders. Precisely allocated poison was used to kill off swarms of New Orleans termites right in their networks of tunnels. Water Hyacinth in Lake Victoria are being kept off the banks through careful use of risky bio-control. Miconia is being cleared from the forest of Hawaii by organized groups of volunteers and solo environmentalists. With cinematography that is pleasing to the eye, “Strange Days on Planet Earth” (2005) raises an important issue to all species in this new, globalized world.
The Miconia plant has taken root on an island far from its origins in native Mexico. The islands of Hawai’i are the unlucky recipients of the Miconia, a plant that seems determined to take over the vegetation of the tropic islands. It was first transported from Mexico as a decorative plant, considered beautiful because of the brilliant coloring of its leaves’ undersides. Upon introduction to Hawai’i, the Miconia soon flourished and spread. Currently, it can be found occupying 10,000 acres on the Big Island.
The plant endangers native species by growing above the vegetation line and blocking the sunlight from the plants below. Starved for the light they need to live, native plants die, leaving Miconia roots the only ones supporting the soil. Because Miconia roots are few and relatively shallow, the danger of erosion quickly becomes a reality in Miconia-dominated areas of forest. In the event of a large rain or runoff from the hillsides, the chance of a landslide is alarmingly high. The Miconia plants would be unable to sustain their position in such conditions and the runoffs from such a landslide would head straight for the ocean, covering delicate coral and endangering the aquatic species that make coral their homes.
A species of bird called the Japanese white-eye, another introduced species, has had a part in spreading this plant. When the Miconia plant flowers, it produces thousands of seeds, many of which are transported about the islands by the Japanese white-eye. Once these seeds find soil, they take root and a new area of growth is established. The Miconia plant flowers three times a year, making it a very prolific plant, detrimentally so in an area where it is unwanted.
Scientist Greg Asner, followed in the National Geographic “Strange Days on Planet Earth” documentary episode Invaders, has undertaken a project to create aerial maps of Miconia infestations using a variety of technology—helicopter remote sensing, satellite photos, simple walks through the vegetation to record plant locations, etc. With these maps, he hopes to be able to manage the infestations before they become too large, mainly through the work of volunteers.
The efforts made by Asner, and other involved researchers, seem to be the best course of action to take with such prevalent invaders. I was impressed by the variety of venues through which Asner collects the information to create his maps of Miconia infestations—he takes into account leaf size and plant height as well as simple longitudinal and latitudinal measurements. I think that if public interest remains concerned about the spread of Miconia, Asner’s method of management will continue to succeed. However, if public interest falls, it will be difficult to continue. The focus of the public is a powerful tool in any effort to stop the force of invasive species like the Miconia.
“Strange Days on Planet Earth” is a documentary created by National Geographic and narrated by Edward Norton. It was created to provide a general audience with a glimpse at a problem that is plaguing the global community. The documentary details the problems associated with invasive species and provides examples from Uganda to New Orleans. Each example shows a different facet of the problem that the global community faces. The documentary opens with Jim Carlton’s work in an Oakland Port. He is in the process of making one of twenty rapid assessments in the area to determine new species in the area. His introduction is brief, but he is reintroduced later.
The viewer sees Claudia Riegel’s research of the Formosan subterranean termite. An invasive species introduced to America after the September 1945 Japanese surrender. When the Americans left they made crates from local wood, but the termites were in the wood. Once in America, the termites prospered in New Orleans because its climate is hot and sticky, similarly to the termites’ native land, and Orleans is composed mostly of wood. The termites then out competed native species because they can live above and below ground unlike the natives, which are only, settle below ground. The viewer even sees the efforts being made to eliminate the species.
Next, James Ogwang’s efforts to save Uganda’s Lake Victoria are shown. Here the viewer sees how the water hyacinth brought Uganda to its knees. Although the events in this part are quite riveting, details will be saved for SW3.
Finally, the documentary shows David Duffy’s research in Hawaii. In Hawaii, Duffy and Greg Asner are working to stop the miconia from destroying the island. The plant was brought to the island as a gift from Europe, but it soon got into the wild and began to outgrow surrounding vegetation. The growth began to shade lower growth until only miconia remained in the area. Areas where this occurred now have loose soil and are therefore prone to landslides. Asner is trying to find miconia colonies by determining how they reflect the sun and using this to find them from the air.
“Strange Days” then shows the viewers that scientists are not the only people contributing to these efforts. Civilians all over the world volunteer to help. In Uganda local fisher are helping to fight the water hyacinth. In America, the Weed Warriors are helping to eliminate the ice plant in their state.
The documentary is put together quite well and provides excellent insight for those who do not know very much about this issue. National Geographic’s usage of the word invaders became a motif present throughout the documentary. Edward Norton primarily uses when he describes the invasive species like they are an invasive alien army. He uses words and phrases such as “alien powers”, “invader assault”, and “encounter with aliens.” These puns provide brief levity to a serious matter. Also, I found one statistic to be quite powerful; 99% of the species in San Francisco, by weight, are foreign. An impressive and powerful statistic that ends an informative documentary.