The value of costing nature in the fight against invasive species

Increasingly we are seeing the terms ‘ecosystem services’, ‘ecosystem functioning’ and ‘ecosystem processes’ in the media and the scientific literature, to highlight the benefits the natural environment provides to our wellbeing.  Invasive species, from bivalves to balsams, have the potential to impact on ecosystem services, though it is widely accepted that there are gaps in our understanding within this field.

Ecosystem services can be defined as the ecosystem processes that we as humans benefit from and they can be categorised into four groups:

Provisioning: The ecosystem provides products essential for our everyday needs including timber, fuel, food, genetic resources and medicine.

Regulating: We gain from natural services including pollination of wild plants and crops by bees, by rivers and floodplains providing natural flood management, and climatic regulation.

Cultural: We benefit from natural spaces for recreation and social activity.  We find harmony in natural areas that are aesthetically pleasing.

Supporting: These services underpin all of those mentioned above.  Biological diversity promotes stability and a healthy ecosystem, nutrient acquisition and flow through the ecosystem by fungal and invertebrate decomposers, and primary production.

The north American beaver, Castor canadensis has had a catastrophic impact on Chile’s sub-Antarctic forests impacting on provisional services (picture courtesy of http://www.martinezbeavers.org)

Rusty Solutions for a Prickly Problem

The state of Queensland has got an alien thorny invader: Prickly acacia, or in scientific terms Acacia nilotica subspecies nilotica.

Prickly acacia invasion, north Queensland, Australia, Photo: Kunjithapatham Dhileepan, DEEDI, Australia

Prickly acacia is a shrub or small tree which belongs to the plant family Leguminosae, subfamily Mimosoideae, a family which also accommodates the sensitive plant Mimosa pudica, well-known as a curiosity house plant. The prickly invader A. nilotica is native to Africa, the Middle East and the Indian subcontinent and was introduced from India into Australia in the late 1890s. Originally imported as an ornamental, A. nilotica ssp. indica was later widely used as a shade and fodder tree for sheep. But what was initially a valued addition to the Australian flora soon became a menace. When the grazing regime in Australia changed from predominantly sheep to cows and the country also experienced a number of successive wet years, the balance swung in the favour of prickly acacia. The thorny shrub spread quickly and has now invaded around six million hectares of arid and semi-arid land in the State of Queensland. Acacia nilotica ssp. indica is also present in the Northern Territory as well as in Western Australia. Due to its substantial impact on the environment as well as on the economy, particularly on the livestock industry, prickly acacia was initially declared a noxious weed in Queensland in 1957. Subsequently the plant has also been listed as a “Weed of National Significance” for the whole of Australia. And Australians have every reason to be worried, as the prickly invader has got the potential to spread throughout the arid regions of the whole of northern Australia.

Alien Battlefield

Recent articles in Science, the NY Times and Nature have suggested that we should embrace invasive species and the resultant “novel ecosystems” and that those that do battle with such species are verging on xenophobic. This is a common cycle in many fields and I’m told that a discussion thread is considered closed once a poster has been described as xeonophobic or worse, if so this discussion could be over before it even begins. Nevertheless, a group of scientists and practitioners wrote a response which can be found on the ISSG website. The issues are certainly complex. It is true that preserving pristine ecosystems is a lost goal and there are probably none in existence anymore, but to do nothing and indeed to try to argue that the new system is one worth accepting suggests that the authors have either given up in the face of too difficult a task, or have seen an opportunity to publish something controversial. There are certainly “profits” of doom to be had on both sides. In order to get your invasive management project funded it is necessary to take the public with you and when engaging with the media evocative negative language can appear in print. On the other side it is easier to stand out from fellow authors if you challenge an accepted paradigm. In the case of weeds, it is generally understood that monocultures of the new plant are less biodiverse but more productive than the flora they replace and depending on your priorities their arrival could be a good or a bad thing. If we accept that biodiversity is a priority there are few arguments to be had for introducing new invasive exotic species except for biocontrol where the excellent paper by Van Driesche and many co-authors shows the potential benefits. It is this tool that was notably overlooked in the discussions despite choosing the Galapagos as a case study where there are excellent targets for weed biocontrol yet no funding has materialised despite the vast sums spent on vertebrate eradications.

Lantana on the Galápagos - a major invasive for which all hope is not lost

3D modelling: Not just for Hollywood, now for invasive species

An easily overlooked but vitally important component of invasive species management is accurate identification. Picture the scene: It’s Australia, it’s a Friday afternoon, a comprehensive fire ant management strategy has been drawn up, baits have been acquisitioned and an eager team of volunteers is ready to deal with this invasive foe and escape for the weekend. There are plenty of ants around… but nobody knows if they’ve found the right ones because the pesky little critters all look so similar! Scientists in Australia believe they have a solution – a database of 3D images of known species against which 2D photographs of organisms taken and uploaded in the field are compared, giving an estimate of their likely invasive or native status.

3D Ant – by Leo Blanchette, flickr

The Nagoya protocol and biological control by Matthew Cock

Since 2009, I have worked with the Global Commission on Biological Control and Access & Benefit Sharing of the International Organisation for Biological Control to raise awareness of the issues relating to biological control which may be affected under the Convention on Biological Diversity’s access and benefit sharing protocol which was finally agreed at COP10 in Nagoya, Japan, in October last year¹.

The IOBC Commission attended various background meetings, produced a report for the Global Commission on Genetic Resources for Food and Agriculture², followed by a Forum Paper in the journal BioControl³ and various news items culminating in a World View page in Nature⁴ the month before the Nagoya meeting. Basically, we put the case that biological control is a public good, that countries that supply biological control agents are also importers of biological control agents, that the best way forward would be to continue the 100+ years history of free multi-lateral exchange of biological control agents between countries as non-commercial research under any future access and benefit sharing protocol, and that benefit-sharing should be based on shared research activities.

Branson pickle

Sir Richard Branson, the billionaire entrepreneur, is reported to have applied for permits to introduce a colony of endangered lemurs to his British Virgin Islands (BVI), Mosquito and Necker. Having “rescued” the island of Mosquito from purchase by a hotel chain in 2007, his intention was to turn his £10 million Caribbean tax haven into an ecological showcase, a luxury hideaway for the mega rich, with plans for Balinese-style, carbon neutral villas whilst “cultivating and supporting the biodiversity, then introducing habitats (such as rainforests) for people who will live in symbiotic form”.

The fanciful whimsy of the rich and famous is nothing new, however this controversial proposal has hit the headlines in BVI because it would appear that Branson has been granted import permits by the Natural Resources and Labour Minister, Hon. Omar Hodge, against the recommendations of technical groups in the Agriculture and Conservation sectors and in contravention of Territory laws. The decision is being contested by the Ninth district elections contender, Lorie Rymer and a petition is reported to be in circulation and will later be submitted to the Governor Boyd McClearly, who is appointed by the Queen and exercises executive authority on her behalf. Meanwhile, Minister Hodge is standing firm but has apparently alienated members of the community by stating on local radio that he “doesn’t have to answer to anyone because he is the Minister”.

(Ring-tailed lemurs by Woodlouse, Flickr Creative Commons)

Blowing our trumpet

A well-balanced article about the biological control of Japanese knotweed was published today in a British newspaper. Most articles about the release of the Japanese knotweed psyllid (Aphalara itadori, pictured) that appeared last year were either dismissive of the idea of releasing a non-native insect to combat another non-native species, often on the grounds that the selected agents will also damage native species. Or the articles just copied bits of press statements.