Vetiver Grass for the Pacific Islands

Recently I learned that the Pacific Island Ecosystem at Risk (PIER, http://www.hear.org/pier/index.html) had listed Vetiver Grass Chrysopogon zizaniodes (a.k.a Vetiveria zizanioides) as an invasive species. Obviously PIER is on pretty shaky grounds and it would appear its information is based on some very poor observations of a visit to Fiji by Albert Smith. Don Miller, a serious and respected ecologist wrote the following letter to PIER. The latter is of interest because not only does it refute PIER's assumptions but also sets out a good case and examples showing the vetiver is quite the opposite - showing no signs of invasive in many of the Pacific Islands. I quote:


"PIER,


I am concerned to read (http://www.hear.org/pier/species/chrysopogon_zizanioides.htm) the blatant errors in your page on Vetiver grass (Chrysopogon zizanioides).


I have been familiar with vetiver grass for many years in the Pacific Islands and in South East Asia. In that time I have never seen an example of vetiver grass reproducing by seed or becoming a weed.


I note that much credence appears to put on the reference by Smith (1979): to quote: "Habitat/ecology: In Fiji, "cultivated in gardens but is also escaped and naturalized, occurring along roadsides and contour lines. ...it may be considered a roadside weed"


I have studied the use of vetiver grass in Fiji and certainly saw it on roadsides and on contour lines. Why do you think it was present on roadsides and contour lines? It was planted there to prevent soil erosion from sugar cane farming and it has done that very very effectively for many decades. The reasons that the contour lines exist is because the vetiver grass trapped sediment and created the terraces after it had been planted in that pattern.


In other words the evidence of Smith has no credibility at all. He was clearly a person with poor observational skills and little training in plant propagation and agricultural practice.


Its presence in New Caledonia was also cited as evidence of invasiveness: In New Caledonia, "largement dispersé à présent, surtout en bords de routes" (MacKee, 1994; p. 63).


I have visited New Caledonia on three occasions and travelled the country in the company of a senior Department of Agriculture plant scientist. As he knew already, vetiver was introduced as thatching material and planted for that purpose by the released convicts - the "Caldoche" - who were allocated small plots of land after their release. Their lives were hard and their houses were built of mud with thatched roofs. The few remaining plantations of vetiver grass are where they were established over 100 years ago to provide thatch. The roadside plantings referred to were on one section of highway only, leading to the airport at Tontouta, and were almost certainly planted intentionally as a source of material for erosion control purposes. In a country ravaged by nickel mining there is a great need for material to control soil erosion and sediment production.


I have worked for 8 years in Vanuatu and vetiver grass had been established there about 1913. It had not spread from the lines intended to mark walking tracks, where it had been planted as a program to keep prisoners occupied. I managed to propagate the grass in nurseries and it has helped control what had previously been an unmanageable erosion problem that was destroying the island's coral reefs.


I worked on the islands of Atiu and Mangaia in the Cook Islands in the early 1990s and managed to find a single carefully nurtured vetiver grass plant on Atiu. It had been there for 28 years at least and was used as a source of perfume for massage oil. I was allowed to propagate from that plant and the resulting plants are now controlling the effects of past pineapple growing ventures on that island. On Mangaia I found four plants growing in a taro swamp. If vetiver was to seed and spread that would be the ideal environment. It had not spread as the plants were clearly very old and were confined where they had been planted at some unknown time. On that island too they vegetatively reproduced descendents of those few plants are now controlling the ravages of pineapple production.


I have also worked with vetiver grass in Thailand and Vietnam where, surprise, surprise, it has not become a weed either despite widespread plantings to control soil erosion.


What really concerns me (I am a environmental scientist with professional qualifications in both plant science and engineering, and 36 years practical experience as a researcher and as a tropical consultant) is that poorly researched websites like yours are believed by gullible people. Bad decisions are made as the result of your propagation of misinformation and countries that desperately need the erosion control benefits of environmentally friendly plants such as vetiver grass are deprived of that benefit.


By the logic of Albert C. Smith I would regard pineapples as being an invasive weed in Hawaii as they are widespread.....
I will expect to see a revision of your page very soon.


Thank you


Don Miller - Environment Education Advisor
The FFI "Ecoboat" - Environmental Education on Ha Long Bay
Ha Long City
Vietnam


END QUOTE


Dick Grimshaw, (The Vetiver Network Interantional)