New in July 2015 from the ISC

In July 2015 the following datasheets were published on CABI’s Invasive Species Compendium (ISC). You can explore the open-access ISC here: www.cabi.org/isc

July invasivesAkebia quinata (five-leaf akebia) – a highly invasive, aggressive vine native to East Asia, A. quinata has been introduced as an ornamental to Canada, Europe, Oceania and the USA. It can outcompete native understory plants and young trees, and its dense growth can block sunlight and prevent the germination of native plants.

Geophagus brasiliensis (pearl cichlid) – an ornamental freshwater fish native to southeast Brazil, G. brasiliensis has been introduced to Australia, Florida, the Philippines and Taiwan. Its fast growth, opportunistic diet and broad environmental tolerances have allowed it to colonize new waterways, particularly artificial and disturbed habitats.

Rudbeckia laciniata (thimbleweed)R. laciniata is an ornamental perennial plant that has been introduced to China, Japan, New Zealand and Europe. Native to eastern North America, thimbleweed grows best in bright, humid areas, such as wetlands, forest edges and roadsides. By producing lots of seeds and spreading from rhizome fragments, it can form dense monocultures which outcompete native plants.

Other invasive species datasheets recently published include:

Brugmansia suaveolens (white angel’s trumpet)
Chrysemys picta (painted turtle)
Macaranga tanarius (parasol leaf tree)
Paederia foetida (skunkvine)
Umbra pygmaea (eastern mudminnow)

Investigating the impacts of the invasive species Prosopis in Baringo, Kenya

The Baringo district northwest of Nairobi is one of the regions in Kenya where a number of mesquite species, Prosopis spp., were introduced some 40 years ago as part of poverty alleviation efforts. The trees were intended to provide, among other benefits, additional income.

Today Baringo is one of the most heavily invaded regions in eastern Africa, with severe consequences for the rural communities. As part of the kick-off meeting of the recently launched, Swiss government funded R4D (research for development) project called “Woody Weeds”, the project team visited the district, one of the case study areas in the project.

During this two-day visit, two communities were visited which suffered from high Prosopis invasion levels. These communities gave an interesting first insight into the dilemmas that have arisen due to Prosopis invasion. The first community we visited utilizes Prosopis for charcoal production and hopes to benefit in the future also from selling Prosopis wood to a local power plant; by utilizing this invasive species the community members gain some financial benefits and at the same time reduce the impacts of this plant on their land.

Irrespective of how the local communities deal with this invasive species, one of the main challenges in management is to find ways to slow down or reduce the spread of Prosopis and mitigate its negative impacts in Baringo (and elsewhere). While the government of Kenya supports local communities in utilizing Prosopis, there is, so far, little scientific evidence that utilization indeed slows down or even stops the spread of this aggressive invader.

One of the key tasks of the “Woody Weeds” project will therefore be the evaluation of the impacts on the environment and rural livelihoods of the various management options against Prosopis and other woody invasive species, such as management by utilization, physical, chemical or biological control, or doing nothing, and to inform decision-makers about the key findings.

Urs Schaffner, CABI

New in June 2015 from the ISC

It’s been a bumper month for the ISC, with 42 new datasheets published and the total number of full datasheets topping 2000. You can explore the open-access ISC here: www.cabi.org/isc


A selection of new datasheets published to the ISC in June 2015.

A selection of new datasheets published to the ISC in June 2015.

Bothriocephalus acheilognathi (Asian fish tapeworm) – in the past few decades this tapeworm has spread from its native East Asia to all continents except Antarctica, largely thanks to the aquaculture and pet trade. A parasite of over 200 fish species, infections of B. acheilognathi negatively impact the aquaculture industry and have been responsible for 90% mortality rate in grass carp in the past. Environmental impacts are still largely unknown, but the Asian fish tapeworm is thought to be adversely affecting some endangered species.

Deparia petersenii subsp. petersenii (Petersen’s lady fern) – an aggressive, fast-growing perennial fern that can form thick ground cover and outcompete native plants. Native to Asia, New Guinea and Polynesia, Petersen’s lady fern has been introduced as an ornamental and is now invasive in Madeira, the Azores, southeastern USA, southeastern Brazil and Hawaii.

Trioceros jacksonii (Jackson’s chameleon) – native to Kenya and Tanzania, this chameleon has been introduced via the pet trade to California and Hawaii. It may pose a threat to native Hawaiian insects and snails that it preys on.

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On the trail of an ancient invasive

‘if men were not employed to prune these trees… they would cover the country, completely invading it.’

Sound familiar? It could be a description of any number of invasive trees, from the trumpet tree (Cecropia peltata) spreading through West Africa to the candlenut tree (Aleurites moluccanus) currently invading Pacific islands. But it’s actually an account by Mas’ūdī, writing over a thousand years ago in the Islamic year 332 (943 CE).

Ficus benjamina

Has Ficus been a problem for over a thousand years?    © K.M. Kochummen.

Born in Baghdad around 890 CE, Mas’ūdī was a prolific writer and adventurer extraordinaire. His world-history-meets-travelogue, The Meadows of Gold, contains many fantastic stories, from jewelled tombs to Viking battles, but it was his account of an apparent invasive – referred to simply as the banyan tree – that caught my attention, and I was keen to find out more.

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The impacts of invasive weeds in Chitwan National Park, Nepal

Mikania (Mikania micrantha) is a tropical vine which is native to the Americas. Often referred to as the ‘Mile-a-Minute Weed,’ mikania grows rapidly in areas of high rainfall and has become highly invasive in parts of Asia and the Pacific. Under the Convention on Biological Diversity, invasive species are defined as alien species that threaten native ecosystems, habitats or species and in Nepal, mikania and other invasive plants such as chromolaena (Chromolaena odorata) are becoming increasingly problematic within the Chitwan National Park (CNP). There, the plants are having a serious negative impact on native grasses, shrubs and the one-horned rhinoceros, and by implication, deer and tiger populations. They are also affecting the local people who reside in the buffer zones and rely on the park for fodder and other materials.

A rhino amongst chromolaena

A rhino amongst chromolaena

Rhinos

In a specific study on mikania, scientists from the National Trust for Nature Conservation, Nepal with support from CABI and the Zoological Society of London have found a significant negative relationship between high mikania coverage and the population of rhinos. This is because the mikania vine smothers the fodder plants that the rhinos feed on. This could also be influencing their movement to other areas of the park where they feed on resources and crops important to local people. This in turn may exacerbate conflict between the residents of the buffer zones and the wildlife in the area.

Deer and Tigers

The reduction in fodder plants is likely also to cause a mirrored decrease in the number of deer in the park. Deer feed on similar plants to the rhinos and the impact of mikania on native vegetation is therefore likely to affect their feeding behaviour in a comparable manner. As a result a decrease in deer numbers is likely to have a negative impact on tiger populations, with tiger numbers being directly related to the populations of their prey.

Local people

The residents of the buffer zones surrounding the CNP are known to rely on the core area of the park for resources such as fodder, which they use to feed their livestock. These residents recognise that fodder availability within the park has decreased and report that collecting materials now takes three times as long as it has in previous years to gather the same amount of fodder. Reduced fodder has been attributed to flooding of the park and the spread of invasive plant species. In particular, a high proportion of local residents report that mikania has a significant negative impact on the fodder growing in the park.

Sustainable control of mikania weed

CABI piloted using a rust fungus (Puccinia spegazzinii) as a classical biological control agent for mikania weed in India. This highly host specific and damaging pathogen has now been released in Papua New Guinea and Taiwan, where it is having a significant impact on the growth of the weed. The rust has recently been released on a number of other Pacific Islands, and could be considered for release in Nepal.

New Strategy Receives Thumbs Up

Group photo GA 2015

This week in Douala, Cameroon, the General Assembly of the African Union’s InterAfrican Phytosanitary Council (IAPSC) gave the thumbs up to IAPSC’s new strategic plan. IAPSC Director Dr Jean Gerard Mezui M’Ella thanked all the organisation’s partners who had assisted in the preparation of the plan, especially FAO’s Regional Office for Africa for funding the work. Titled “For Better Plant Health in Africa”, the plan identifies four key impact areas, and names a number of partners, including CABI, whose support will be important in its operationalization.

Following on from earlier discussions with IAPSC, CABI Africa’s Roger Day made a presentation on “A Plant Health Management System (PHIS) for IASPC”, corresponding to output 2.3 of the strategy. The ideas were well received by the General Assembly, which immediately appointed a small task force to develop a proposal as a basis for mobilising resources. The General Assembly also adopted a resolution saying it “Welcomes the cooperation between CABI and IASPC on Plant Health Information Systems, and urges them to develop further the ideas for putting in place an effective PHIS, and calls upon international partners to avail financial and technical resources for implementing such an important project”.

For further information contact IAPSC (au-cpi@au-appo.org) or CABI (Africa@cabi.org).

New in May 2015 from the ISC

In May 2015 the following datasheets were published on CABI’s Invasive Species Compendium (ISC). You can explore the open-access ISC here: www.cabi.org/isc

Bubalis

Bubalis bubalis (Asian water buffalo) – domesticated herds of the Asian water buffalo are widely kept across Asia and southern Europe, where they are considered naturalised and not invasive. However, introduced populations in Australia and South America have proved more problematic. B. bubalis competes with cattle in South American grazing land, and has significant negative impacts on rainforests, floodplains and tropical savannahs in northern Australia.

Fibropapillomatosis – thought to be caused by Chelonid herpesvirus 5, fibropapillomatosis is a disease of sea turtles that causes internal and external tumours. Although considered benign, these tumours can hinder swimming, feeding, sight, buoyancy and even breathing, sometimes leading to death. Fibropapillomatosis occurs most commonly in green turtles, but has been reported in six other species, and is now considered a tropical pandemic, with infection rates above 70% in some regions.

Lygodium microphyllum (old world climbing fern) – native to tropical and subtropical Africa, Asia and Oceania, the old world climbing fern was introduced to the USA as an ornamental in the mid-1900s. It has aggressively invaded forested wetlands, particularly in Florida, where it smothers undergrowth, shrubs and even tall trees – you may recognise L. microphyllum as the rampant invasive in the banner at the top of the ISC homepage.

Other invasive species datasheets recently published include:

Alopecurus myosuroides (black-grass)

Ammophila arenaria (marram grass)

Batis maritima (saltwort)

Conium maculatum (poison hemlock)

Leiothrix lutea (red-billed leiothrix)

Linaria vulgaris (common toadflax)

Pastinaca sativa (parsnip)

Poecilia latipinna (sailfin molly)

Rhizophora mangle (red mangrove)

Salsola paulsenii (barbwire Russian thistle)

Stachytarpheta cayennensis (blue snakeweed)

Vicia villosa (hairy vetch)

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