Principal source:
Compiler: IUCN/SSC Invasive Species Specialist Group (ISSG)
Review: Lloyd Loope, USGS, Maui, Hawaii, USA
Publication date: 2010-06-29
Recommended citation: Global Invasive Species Database (2024) Species profile: Miconia calvescens. Downloaded from http://iucngisd.org/gisd/speciesname/Miconia+calvescens on 05-11-2024.
Physical disturbance: Invasion by miconia has eliminated native forest understorey vegetation, increasing rapid runoff and potential for soil erosion and landslides on steep slopes. \r\n\r\n\r\n
Modification to Hydrology: Dense stands of miconia may damage watershed functions; there may be a significant change in the water balance, with an increase in runoff and a potential reduction in groundwater recharge, but this plausible result has yet to be fully investigated and documented (Burnett et al. 2006).\r\n\r\n
Economic/Livelihoods: Potential (as yet hypothetical) losses from an invasion of miconia on Oahu to groundwater recharge may conceivably be as high as $137 million per year (Kaiser and Roumasset 2002, in Burnett et al. 2006). Increased sedimentation could likely incur surface water quality damages; potential costs for Oahu have been estimated to be almost $5 million per year (Kaiser and Roumasset 2000, in Burnett et al. 2006). Comparable damage is possible on other Hawaiian islands, though the greatest economic impact is likely to be on Oahu, where 85% of Hawaii’s population is located.\r\n\r\n
Agricultural: Control programs underway since about 1995 have prevented significant agricultural impacts in the Hawaiian Islands. Invading miconia in ranchland near Hana, Maui in 1995-2000 was successfully removed. Theoretically, runoff from miconia stands could trigger erosion and loss of agricultural soil fertility (Chan-Halbrendt et al. 2007), but this has not yet happened or at least has not been documented.\r\n\r\n
Competition: When compared with a large group of native species M. calvescens appears to be better suited to capture and use light, which is consistent with its rapid spread in Hawaiian environments (Baruch Pattison & Goldstein 2000). Invasive characteristics of the species include rapid growth, fairly early maturity (after four years or more), production of large quantities of fruits and seeds, and effective seed dispersal by birds.\r\n\r\n
Threat to Endangered Species: In Tahiti, 70-100 native plant species, including 35-45 species endemic to French Polynesia, are directly threatened with extirpation by invasion of miconia into native forests (Meyer and Florence 1996).\r\n
Hawaii is home to a great number of rare and endemic plant, bird and invertebrate species at risk of global extinction, including over 350 federally endangered species. Upper Kipahulu Valley of Haleakala National Park on Maui, Hawaii, is a prime stronghold of Hawaiian biodiversity, containing stands of ohia (Metrosideros polymorpha) and koa (Acacia koa) that provide the primary habitat for rare native Hawaiian plants, birds and insects. Proactive response of Haleakala National Park personnel originally triggered a community-wide response to the miconia invasion in Hawaii about 30 years after M. calvescens had first been introduced to the State.
Preventative measures: A Risk Assessment of Miconia calvescens for Hawaii and other Pacific islands was prepared with a resulting score of 14, meaning it is likely to cause significant ecological or economic harm in the Pacific. Csurhes (2008) has prepared an assessment for Australia.\r\n
Biological Control:\r\nA range of fungi, weevils, leaf-feeding beetles, nematodes, wasps, butterflies and moths have been found in South and Central America which damage miconia. . In miconia’s invaded range in Hawaii, the non-native Chinese rose beetle (Adoretus sinicus) can cause up to 50% defoliation on individual leaves, but it has never been widespread and has never been observed to cause mortality (Medeiros et al. 1997). The high level of host specificity of the leaf-defoliating sawfly (Atomacera petroa) makes it a good potential control for M. cavescens (Badenes-Perez & Johnson 2007a). Since miconia seeds are dispersed by birds, fruit- and flower-eating insects including could help manage this weed (Badenes-Perez & Johnson 2007b). A fruit-feeding gall wasp (Allorhogas sp.) and a fruit-feeding beetle (Apion sp.) were evaluated for host specificity in Brazil by Badenes-Perez and Johnson (2007a). Other natural enemies (especially insects) are currently being sought in Brazil (since 1995) (please see Seixas Barreto & Killgore 2007 for further information), Costa Rica (please see Picanco et al. 2005 for further information), the Dominican Republic and Ecuador.\r\n
Legislation: Laws prohibiting the sale of Miconia calvescens in Queensland was passed in 1997 (Cshures 1998).\r\n
Education and Awareness: \"Ho'ike o Haleakala\" is an environmental education curriculum specific to Maui, produced by a partnership of school teachers, agencies, and community organisations, led by Haleakala National Park (Loope Starr & Starr 2004). The curriculum is available online (www.hear.org/hoike). \r\n
A growing interest of the public on Maui in meaningful hands-on ecological restoration projects is partially related to a growing interest in the heritage of the native Hawaiian people and proliferation of potential volunteer projects (www.hear.org/volunteer/maui/). Volunteers participate in a number of restoration projects, including one involving endangered dry forest plant species on private lands (Loope Starr & Starr 2004). \r\n
Campaigns to inform the public of the threat of miconia, including fliers and media coverage, were launched in the Society Islands (Meyer & Malet 1997).\r\n
Integrated management: Combining physical removal with chemical treatment has been employed to control miconia in the Society Islands. Trees (greater than four to five meters) were cut with a machete or a small chain saw and herbicide was systematically applied to the exposed stumps to prevent resprouting. After several trial with different herbicides, Gbnoxone (Triclopyr + 2,4-D) in diesel solution (one liter per 20 liters) applied carefully to cut stumps provided effective control with few resproutings compared with other chemicals used. 2,4-D is also said to be one of the most acceptable chemicals from an environmental point of view since it is not residual (Meyer & Malet 1997).