Living With Weeds
Review by Meriel Watts, PhD – Feb 2015
“Living with Weeds – a New Paradigm” is a refreshing look at how we view and understand, or not, weeds. Penned by a scientist with GHD Pty Ltd (1), Australia and published in the Indian Journal of Weed Science, (2) it is a most interesting view of that subject which exercises so many in this country, and indeed around the world: how to manage/control/exterminate weeds.
Rich with wonderful quotes – for example Ralph Waldo Emerson’s “A weed is a plant whose virtues have not yet been discovered” – this paper entreats us to say: Hang on a minute, do we really need to control that weed or are we doing more harm than good and wasting valuable resources to boot.
Another excellent quote, which sets the mood for the paper: “Weeds are only weeds from our egotistical point of view, because they grow where we do not want them. In nature, however, they play an important and interesting role. … They represent human beings’ failure to master the soil, and they grow abundantly wherever people have made mistakes – they simply indicate our errors and nature’s corrections …” Ehrenfried Pfeiffer 1970
As Chandrasena points out, we ring our discourse with negative rather xenophobic expressions such as “invasive species”, “aliens”, “war on invasives”. He proposes that “in many ways, humans may also be regarded as’ weeds’, because we are highly adept at disturbing and colonising landscapes.”
Time then to rethink our attitude towards weeds, to remove the shackles of decades of negative thinking. We are never going to win ‘the war’ anyway, so maybe it would be more fruitful to try a positive approach. How might weeds actually be a good thing in the environment?
Well, for a start, they offer a lot of valuable ecological services for free. They provide food and/or habitat for many beneficial insects including bees; they can attract crop pests away from crops; many have medicinal and food values; they provide healing cover for soil and landscape we have messed up. They are dynamic and responsive to environmental changes. They can reduce soil erosion and nutrient losses, conserve soil moisture, add organic matter to the soil, improve soil structure and the functioning of beneficial microorganisms; and are essential for the compost heap. “For all other animals, except humans, weeds are undoubtedly a great resource.”
And then if we insist on the ‘utilising natures’ resources’ approach, weeds also can offer us a lot. Globally, there is interest in using this extraordinary amount of free biomass (5% of New Zealand is said to be covered by gorse) to produce a whole range of products including bricks, paper, baskets, mats, furniture, biofuels, and more.
So next time you regard a gorse plant with a sprayers eye, think of these things: it has beautiful, coconut-scented yellow flowers that would make an excellent perfume, and yield an excellent yellow dye; its healing powers as a flower essence have been utilised for more than 80 years (interestingly, for healing people who have given up hope and belief). It is nitrogen-fixing so is beneficial to the soil; goats love to eat the young green tips; it makes a great nursery plant for young native species when degraded bush. Think before you spray what a waste you are about to create.
I live on Waiheke Island, New Zealand, an island often disparagingly referred to as Weed-heke, or the Weed Capital of the World. We sustainably harvest the gorse on our farm, put it through a mulcher and are rewarded with wonderful, high nutrient mulch. Probably, we should leave it to help regenerate the bush, but it is too tempting ….
Of course, there are weeds in the wrong place at the wrong time, and management is needed, but it is time to get smart about weeds. Time to become “weed-literate”, to understand these valuable bio-resources
A timely reminder to Auckland Council, as it prepares to stop all non-chemical weed management in parks and reserves (in total opposition to its own policy) and return to a full-frontal chemical assault to – “save money.” ???
As Chandrasena says: “the overuse of herbicides, destructive land clearing and indiscriminate weed removal policies and practices, and a hate mentality that maligns species do more damage to native habitats and ecosystems” [than the weeds themselves].
(1) An international network of consultants on water, energy and resources, environment, property and buildings, and transportation.
DEBATE ON THE USE OF PESTICIDES – WAIHEKE SHOWS THE WAY
Comment by Hana Blackmore – Dec 2014
When Dr Meriel Watts spoke out about her frustration at the continued use of toxic herbicides by Council Park Rangers in Whakanewha Regional Park on Waiheke Island, she set in motion a welcome debate. The article in the Waiheke Gulf News ‘Outrageous’ chemical herbicide use highlights her concern that the spraying breaches Auckland Council policy to use chemicals only as a last resort. “It’s ugly, it’s unnecessary and it’s destabilizing the environment.” Her comments resulted in two letters published the following week.
Andy Spence, who has worked for 16 years in the park, whilst agreeing with Meriel that wherever feasible or possible weeds should be controlled manually – as has been successfully done – believes that the scale of the problem necessitates the use of herbicides. He also believes that the use of glyphosate has had no ill effect on the thousands of people who have enjoyed the park. John Smeed also had a problem with how noxious weeds could possibly be removed without herbicides and challenged Meriel to demonstrate her methods in a possible trial. He also had a problem with what he saw as the lack of references to back up her claims.
The following week saw not only a reply from Dr Watts and two other residents welcoming the debate, but several articles relating to the official launch of the Waiheke Weed and Restoration Advisory Panel (WRAP) which has been working positively since May 2014 on practical alternatives and management without the use of chemical sprays.
Meriel welcomes the timely debate and the opportunity to follow up on the excellent ideas voiced. Her letter outlines her experience and the long history of successful non-chemical weed management not only on Waiheke but throughout NZ and the world. She details her scientific concerns with the use of glyphosate and its effect in contaminating and destabilising aquatic ecosystems, as well as its unfortunate effect of encouraging the growth of root rot pathogens. She also outlines the adverse human health effects and points to her monograph on glyphosate for more than 350 references.
Daphne Mitten writes that the keys to successful manual weed management are understanding that we are part of nature, how natural processes work, and that it takes time to tip the balance back to healthy ecosystems. She details the use of so-called ‘bad’ weeds that can in fact be beneficial in restoring a diverse natural forest by creating a nursery bed for native seeds. Spraying these weeds she says only exacerbates the problem. Jo Davies would agree with this as she writes that we need to look beyond these ‘quick-fix solutions’ that have a long-term detrimental effect on human health and the environment. She argues that sprays are not actually cheap as the cost is deferred by having to spend vast amounts of money to restore polluted and degraded environments.
The Gulf News articles by journalist Rose Davis are informative and fascinating and build on the debate about the use of chemicals on the island. The official launch of WRAP kicked off with their tour of the 170 hectare Awaawaroa Eco Village land with Board Chair Paul Walden and Auckland Council biosecurity and parks staff. Awaawaroa founder, Rob Morton says their property is a model of what can be achieved without sprays which have not been used on the property for 20 years. Native bush is being restored with gorse and woolly nightshade being used as shelter and shading for native seedlings, and trees planted in thick kikuya ground cover which has not been cleared let alone sprayed. Rob notes that the trees have grown tall and strong and when they mature will create a canopy of dense shade and the kikuya disappears. Council budget constraints and possible cuts are discussed and the future challenges that will need to be faced in dealing with reserve management plans and weed management. Rob Morton noted that herbicides can seem like an easy option, but we have to think smarter about how nature can help to resolve its own weed infestation problems.
It is illuminating and heart-warming how community newspapers can focus very quickly and efficiently on local issues and bring the debate and challenges home in a way that national news fails to do. But the value of these newspapers, and the relevance to the rest of the country of the issues raised, is no small thing. They resonate with communities up and down New Zealand, if not across the world, and merit a far wider audience.
The Gulf News can be found at http://www.waihekegulfnews.co.nz