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Herbicidal control of bridal creeper (Asparagus asparagoides) in an ecologically sensitive environment

Jusaitis, Manfred

Asparagus asparagoides (bridal creeper) is a highly invasive noxious environmental weed in southern Australia. It poses a severe threat to biodiversity and conservation in temperate natural ecosystems. Pterostylis arenicola, a threatened terrestrial orchid endemic to South Australia, is directly imperilled by this weed in most of its remnant populations. The coincident growth phenologies of orchid and weed make for an ecologically sensitive environment when considering methods of weed control or eradication. To minimise impact on the orchid and its ecosystem, this paper examines the efficacy of herbicide application for A. asparagoides control using the weed wiping technique, comparing it to the conventional spray application method. The most prolonged control of A. asparagoides was achieved after a single wipe-application of 1.5 g a.i. (active ingredient) L 1 metsulfuron methyl, either alone or in combination with 120 g a.i.L 1 glyphosate, both treatments giving significantly better weed control five years after treatment than comparable spray applications. An investigation of the effect of glyphosate on cultures of the mycorrhizal fungus isolated from P. arenicola indicated a significant decline in mycelial growth with increasing herbicide concentration over the range 0.53.0 kg a.i. ha 1. These results provide further incentive for the use of ecologically sensitive herbicide application techniques, such as weed wiping, in areas of high conservation concern.

Update on the environmental and economic costs associated with alien-invasive species in the United States

Morrison, Doug

Pimentel, David

Zuniga, Rodolfo

Invading alien species in the United States cause major environmental damages and losses adding up to almost $120 billion per year. There are approximately 50,000 foreign species and the number is increasing. About 42% of the species on the Threatened or Endangered species lists are at risk primarily because of alien-invasive species.

Economics of Harmful Invasive Species: A review

Gren, Ing-Marie

Marbuah, George

McKie, Brendan

The purpose of this study is to review theoretical and empirical findings in economics with respect to the challenging question of how to manage invasive species. The review revealed a relatively large body of literature on the assessment of damage costs of invasive species; single species and groups of species at different geographical scales. However, the estimated damage costs show large variation, from less than 1 million USD to costs corresponding to 12% of gross domestic product, depending on the methods employed, geographical scale, and scope with respect to inclusion of different species. Decisions regarding optimal management strategies, when to act in the invasion chain and which policy to choose, have received much less attention in earlier years, but have been subject to increasing research during the last decade. More difficult, but also more relevant policy issues have been raised, which concern the targeting in time and space of strategies under conditions of uncertainty. In particular, the weighting of costs and benefits from early detection and mitigation against the uncertain avoidance of damage with later control, when the precision in targeting species is typically greater is identified as a key challenge. The role of improved monitoring for detecting species and their spread and damage has been emphasized, but questions remain on how to achieve this in practice. This is in contrast to the relatively large body of literature on policies for mitigating dispersal by trade, which is regarded as one of the most important vectors for the spread of invasive species. On the other hand, the literature on how to mitigate established species, by control or adaptation, is much more scant. Studies evaluating causes for success or failure of policies against invasive in practice are in principal non-existing.

Learning-by-catching: Uncertain invasive-species populations and the value of information

Burnett, Kimberly

D'Evelyn, Sean T.

Roumasset, James A.

Tarui, Nori

This paper develops a model of invasive species control when the species population size is unknown. In the face of an uncertain population size, a resource managers species-control efforts provide two potential bene ts: (1) a direct bene t of possibly reducing the population of invasive species, and (2) an indirect bene t of information acquisition (due to learning about the population size, which reduces uncertainty). We provide a methodology that takes into account both of these bene ts, and show how optimal management decisions are altered in the presence of the indirect bene t of learning. We then apply this methodology to the case of controlling the Brown Treesnake (Boiga irregularis) on the island of Saipan. We nd that the indirect bene tthe value of information to reduce uncertaintyis likely to be quite large.

Taking the sting out of the Little Fire Ant in Hawaii

Lee, Donna J.

Leung, PingSun

Motoki, Michael

Nakamoto, Stuart T.

Vanderwoude, Casper

Inthe1990's,LittleFireAnts(LFAs)founditswaytotheislandofHawaii,mostlikelytravelingwithashipmentof potted plantsfrom Florida.These plants weresubsequentlysold toconsumers along theeastcoast of theIsland, alongwithLittleFireAntcolonieslivinginthepottingmedium.LFAisnowthrivingandcontinuestospread.Fifteenyearsaftertheinitialdetectionin1999,LFAhasspreadtoover4000locationsontheislandofHawaiiandhas beenfoundinisolatedlocationsonKauai,Maui,andOahuIslands.Currenteffortsareexpectedtocontaintheinfestations on the otherislands but signi cant additional investment isneeded tohalt therapid spread of LFA on the island of Hawaii. Increased management expenditures can suppress infestations; reduce spread between sectors; and decrease long-term management costs, damages, and stings.| Animmediateexpenditureof$8millioninthenext23yearsplusfollow-upprevention,monitoring,andmitigation treatments will yield $1.210 billion in reduced control costs, $129 million in lowered economic damages, 315 million fewer human sting incidents, and 102 million less pet sting incidents over 10 years.| Over35years,thebene tsinclude$5.496billioninreducedcontrolcosts,$538millionlesseconomicdamages, 2.161 billion fewer human sting incidents, and 762 million fewer pet sting incidents.

Prevention, Eradication and Containment of Invasive Species: Illustrations from Hawaii

Burnett, Kimberly

Kaiser, Brooks

Pitafi, Basharat A.

Roumasset, James

Invasive species change ecosystems and the economic services such ecosystems provide. Optimal policy will minimize the expected damages and costs of prevention and control. We seek to explain policy outcomes as a function of biological and economic factors, using the case of Hawaii to illustrate. First, we consider an existing invasion, Miconia calvescens, a plant with the potential to reduce biodiversity, soil cover, and water availability. We then examine an imminent threat, the potential arrival of the Brown Treesnake (Boiga irregularis). The arrival of the snake to Guam has led to native bird extirpations, power outages, and health costs.

Distribution, relative abundance, and habitat relationships of landbirds in the Vava'u group, Kingdom of Tonga / by David W. Steadman and Freifield, Holly B.

Available Online

Freifield, Holly B.

Steadman, David W.

We assessed the distribution, relative abundance, and habitat preferences of the 12 indigenous, resident species of landbirds that survive in the Vavau Group, Kingdom of Tonga. We surveyed 16 islands, 10 of which are previously unmentioned in ornithological literature. The islands vary in land area (0.02-96 kn?), habitat composition, elevation (20- 215 m), and distance (O-lo.1 km) from the largest island of Uta Vavdu. We conducted point counts along transects on 14 of the islands, and placed each count location into one of five habitat categories. Of the 11 species of landbirds that are widespread and at least locally common, 7 (Purple-capped Fruit-Dove Ptilinopus porphyraceus, Pacific Pigeon Ducula pacijca, Common Barn-Owl Tyto alba, White-rumped Swiftlet Collocalia spodiopygia, Collared Kingfisher Halcyon chloris, Polynesian Tiiller Lalage maculosa, Polynesian Starling Aplonis tabuensis) certainly or probably occur on each of the 16 islands. One species (West Polynesian Ground-Dove Gallicolumba stairii) is extremely rare (one small population on one island). Three species that we did not record (Many-colored Fruit-Dove Ptilinopus perousii, Blue-crowned Lorikeet Vini australis, Fiji Shrikebill Clytorhynchus vitiensis) probably have been extirpated from Vavau. The species richness and relative abundance of landbirds on islands in Vavau are affected more by deforestation and other human activities than by island area, elevation, or isolation.

Pig Trap - Model CEN NC - Rope snare (Brochure) / Piége á cochons - Modéle CEN - Collet-corde

Island and Ocean Ecosystems, BRB

Conservatoire d'espaces Naturels (CEN)

Brochure (French & English) on setting up pig traps.

An invasive ant distribution database to support biosecurity risk analysis in the Pacific

Island and Ocean Ecosystems, BRB

Burne, Allan R.

Cooling, Meghan

Gruber, Monica A.

Invasive species are one of the most serious threats to biodiversity. Up-to-date and accurate information on the distribution of invasive species is an important biosecurity risk analysis tool. Several databases are available to determine the distributions of invasive species and native species. However, keeping this information current is a real challenge. Ants are among the most widespread invasive species. Five species of ants are listed in the IUCN list of damaging invasive species, and many other species are also invasive in the Pacific. We sought to determine and update the distribution information for the 18 most problematic invasive ant species in the Pacific to assist in Small Island Developing States with risk analysis. We compared the information on six public databases, conducted a literature review, and contacted experts on invasive ants in the Pacific region to resolve conflicting information. While most public records were accurate we found some new records had not yet been incorporated into the public databases, and some information was inaccurate. The maintenance of public databases faces an enormous challenge in balancing completeness (~15 000 ant species in this case) with accuracy (the impossibility of constantly surveying) and utility.

Understanding Sea-Level Rise and Variability

Aarup, Thorkild (ed.)

Church, John A. (ed.)

Wilson, W. Stanley (ed.)

Woodworth, Philip L. (ed.)

Millions of people are crowded along the coastal fringes of continents, attracted by rich fertile land, transport connections, port access, coastal and deep-sea fishing, and recreational opportunities. In addition, significant populations live on oceanic islands with elevations of only a few meters. Many of the world's megacities, cities with populations of many millions, are situated at the coast, and new costal infrastructure developments worth billions of dollars are being undertaken in many countries. This coastal development has accelerated over the past 50 years, but it has taken place with an assumption that the stable sea levels of the past several millenia will continue; there has been little consideration of global sea-level rise. Global sea-level rise and its resultant impact on the coastal zone, one of the consequences of global climate change, has been identified as one of the major challenges facing humankind in the 21st century. Impacts on the environment, the economy, and societies in the coastal zone will likely be large.

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