Invasives Blog

Is promoting the utilisation of invasive non-native species for commercial or other uses e.g. as a feed for livestock, use as a fuel or to produce biogas, a help or a hindrance to their control?

A view from Arne Witt, CABI Regional Coordinator, Invasives (Africa & Asia):

Promoting the utilization of any invasive non-native species (INNS) has largely contributed to their spread, especially in most developing countries which don’t have the capacity to develop and implement effective integrated management strategies.  Utilization as a control can only be effective if it forms part of an integrated management plan – on its own it merely exacerbates the problem.  There are many examples of where INNS have been intentionally spread by individuals because they have been led to believe that they can enrich themselves by growing and then utilizing an INNS – at low densities many INNS are beneficial, but it does not stay that way for very long – short-term benefits but long-term costs.

One needs to remember that utilization works from “inside out” whereas “control or management” works from “outside-in”.  In other words, the most cost-effective way to utilize an INNS is at the largest and densest infestations. As such you would build your biogas plant or sawmill in an area where the costs with regard to transport are lowest. In addition, you would not “eradicate” any of the plants you utilize – it is expensive and time-consuming to do so and why would you want to anyway, you want a renewable resource, so getting the plants to coppice, so that you can use them again in the future, is exactly what you want.  This is largely what is happening in Africa – those utilizing prosopis for charcoal do not apply herbicide to the cut stumps or dig out the rootstock – they want the plants to coppice. The same happens in India with regard to the utilization of lantana – communities don’t kill the lantana, they allow it to coppice. In addition, it does not make economic sense to utilize plants growing individually or in small pockets away from these dense infestations, especially in developing countries where we have poor infrastructure.  For a control/management strategy to be effective we need to work from the “outside-in”, removing individual plants or small isolated stands first before moving onto the dense stands – utilization works in the opposite way which is why it is ineffective as a management strategy on its own.

African landscape dominated by prosopis (Arne Witt, CABI)

Creating a “perverse incentive” such as the utilization of an INNS could also have further ramifications down the line. For example, authorities were unable to release seed-feeding biocontrol agents for prosopis in Kenya because various NGO’s and other agencies had led people to believe that it was “green gold” and that it was going to contribute significantly to Kenya’s economy. Pretty much like the introduction of Leucaena leucocephala was going to kickstart the green revolution in Africa.  Despite the utilization of prosopis this noxious weed continues to spread in Kenya. It should also be noted that those largely benefitting from charcoal production are often outsiders or landless individuals while the communities affected by weeds, such as prosopis, hardly receive any benefits from its utilization.

The fact that one creates an “industry” around an INNS makes it significantly more difficult to introduce an effective management strategy even if the costs of the weed outweigh the benefits. For example, it has been shown that the costs of Acacia mearnsii in South Africa far outweigh the benefits that accrue from its use. However, the industry is so developed that the government can’t possibly shut it down – now tax payers have to carry the burden of management while the industry continues to reap the benefits – a clear case of privatizing profits and socializing costs.

Ironically the utilization of INNS has become the darling of many NGO’s and donors – it’s easier to demonstrate benefits to communities within 3-5 years by developing and implementing a utilization strategy – it is significantly more difficult to demonstrate/show how you have benefited thousands of communities by stopping the spread of an INNS. I suppose it’s a similar scenario with regard to restoration – it’s easier to demonstrate how you have restored a habitat by planting 10,000 trees than how you have protected an existing forest.

This sudden surge in the recent past with regard to the utilization of INNS as the panacea with regard to management is worrisome. We are not dealing with the real causes such as a lack of effective policy and implementation thereof, little awareness and virtually no capacity, especially in developing countries, to manage INNS. A large contributing factor is that many donors and NGO’s continue to promote various INNS as the answer to all of our problems without looking at the long term implications thereof. There are solutions, it’s not a lost cause, we can turn things around.

Anyway, for fear of bearing the wrath of utilization protagonists I would just like to reiterate that I am not opposed to utilization, but it can only be effective as long as it forms part of an integrated and well managed strategy which needs to include awareness creation, capacity building and good enforcement, elements which are often in short supply in many developing countries.

Arne Witt