We ask a lot of our forests. We demand food, water, and wood for shelter, but we also ask it to be natural, biodiverse, healthy, and ever-lasting. To many, these things seem at odds. How could we extract resources while maintaining healthy and sustainable ecosystems? With extensive research, forethought, and the right tools we can balance all these values at once. Albeit that balance often treads the knifes edge. This is why we need every proven tool at our disposal to assist us with that balance. Herbicides may be one of these tools. To find out how it measures up we speak to ecologists and researchers about its ecological impact in the long term. We must follow the science if we want all values to persist. No values have to suffer if all values are considered equal.
Your Forest Podcast by Matthew Kristoff
Glyphosate and Biodiversity with John Nash and Matthew Olson
Episode highlight
John Nash and Matthew Olson discuss the use, effects and ecological impact of herbicides in forest management citing research studies and sharing popular opinions on the same.
Resources
Episode 60 - Pesticides with Ryan Prosser: https://yourforestpodcast.com/episode-1/2019/4/6/0nmjhtlqmqqcjm7289suub61vaxodq
New Herbicide Study findings and Field Tour Guide https://fgrow.friresearch.ca/herbicidefacts
The Austin Pond Study: https://www.academia.edu/29076147/Midrotation_response_of_ground_vegetation_to_herbicide_and_precommercial_thinning_in_the_Acadian_Forest_of_Maine_USA
Effects of herbicide treatments on biotic components in regenerating northern forests: Lautenschlager, R.A. and Sullivan, Thomas P. https://maineforest.org/wp-content/uploads/2019/05/Effects-of-herbicide-treatments-on-biotic-components.pdf
Shannon-Wiener Index of Diversity: https://www.encyclopedia.com/earth-and-environment/ecology-and-environmentalism/environmental-studies/shannon-wiener-index-diversity
Ecosystem Management Emulating Natural Disturbance. EMEND Study: https://emend.ualberta.ca
Sponsors
West Fraser: https://www.westfraser.com/
GreenLink Forestry Inc.: http://greenlinkforestry.com/
Damaged Timber: https://www.damagedtimber.com/
Giveaway
Enter YourForest10 at checkout at the Damaged Timber store for a 10% discount!
Quotes
17.51 - 18.02: “We have to practise sound ecologically based management in our forests and woodlands to ensure that there is a resource not only for present generations but also for future generations.” (Matthew Olson)
1.08.25 - 1.08.34: “I think everybody in the forest industry... that would be their end goal, is to try and emulate as much as possible what's going on naturally in the environment.” (John Nash)
1.21.55 - 1.22.15: “As foresters, we’re always trying to have a positive impact... on the environment. We want to consider... biodiversity, we want to consider habitat, because foresters, I think, are just as big users of the forest as anybody else... and have as much respect for the forest as anybody else”. (John Nash)
Takeaways
Forestry: “As much a creative outlet as it is a career path” (10.10)
Olson is Assistant Professor of Environmental Science teaching the forestry classes at Stockton University in New Jersey, USA. He grew up pursuing many activities in the woods and has always thought of them as welcoming recreational spaces. He wants to ensure that forests are cared for, healthy and can provide recreational opportunities to others too. He enjoys teaching about forests to his students and making them engaged in forestry.
Jack of all trades (12.53)
Nash is a Forest Ecologist with GreenLink Forestry. He had always enjoyed the forests in Northern Ontario and Manitoba, and his father was a hard rock geologist, in whose footsteps he followed for 15 years. After having a family, he changed his major to environmental studies and biology and was mentored by Jeff Wang. Nash enjoys the multidisciplinary aspect of ecology and increasing his knowledge about many different disciplines under ecology.
Respecting the various demands on forests (17.12)
Olson points out that along with being recreational, the woods also provide wood products. His focus is on extracting timber from forests and woodlands in a way that “doesn’t undercut our ability to meet present and future needs” and keeps ecosystems healthy for all. Nash comments that industrial and recreational pressures on forests need to be balanced, and that forest management is an important aspect of fire management.
First thoughts on herbicides (22.54)
Growing up in New Jersey, Olson thought herbicides were only applied in yards and farmlands, not the woods, and only learnt about herbicide application in vegetation management at university. He was concerned about their use, but his mind was opened by Dr. Robert Wagner, who used a rigorous experimental framework to explain the pros and cons of herbicide technology. Nash had not heard much about herbicides being contentious till recently.
Olson and The Austin Pond Study (26.55)
In his post-doctoral research, Olson was introduced to The Austin Pond Study (long-term effects of herbicide and precommercial thinning treatments on species composition, stand structure, and net present value in spruce-fir stands in Maine) and worked on long-term data sets of silviculture studies to evaluate long-term consequences in the woods. He has been involved with the new experimental design overlays and new treatments of The Austin Pond Study.
Herbicides and biodiversity (30.33)
Nash was involved in a similar study in the early 2000s but it had more of a focus on the impacts of herbicides on trees. The study he is involved in now has a focus on biodiversity, collecting information about lower vegetation. He investigated if herbicides affect sites in any way in the long term using many biodiversity indicators to understand the impact of herbicides on soil properties. Olson, too, used biodiversity as a way to evaluate the impact on soil.
Differences in herbicide-treated and untreated areas (38.40)
In his study, Nash found no significant differences between the areas that had herbicide application and those that didn’t, other than there was much more feather moss in the undertreated areas. Olson discusses that glyphosate was tested in the Austin Pond study, and 20-30 years later, the treated areas were conifer-dominated, while the untreated areas were deciduous-dominated, but there weren’t any other effects seen in the soil.
Pre-research and post-research differences of opinion (43.46)
Nash wasn’t biased towards any outcome of herbicides before beginning his study. Olson had noticed during The Austin Pond Study that sprayed areas had lower diversity and unsprayed areas had rich floors. However, in his later study, he found that areas that had precommercial thinning had the highest richness in diversity and cover, irrespective of herbicide application. Both explain that glyphosate does not last long in the soil and breaks down into non-toxic forms.
What glyphosate really does (53.18)
Olson highlights that glyphosates are more selective against aspen than against maple and that areas were sampled extensively to have definitive data. Nash found that there was a 5% difference in cover on average with 3 indicator species, and there were some differences in earlier flora. Olson is interested in doing a follow-up study to investigate the life cycle aspects of the plants.
Additional perspectives (1.06.28)
Nash believes that long-term data following forest fires would be valuable to integrate into the current studies. Olson shares that not just the intensity of burns but different factors of the burns will predict future outcomes of the forest. He wants to broaden the spectrum of different management intensities, including areas where ecological forest management and silviculture are being applied. Nash refers to some such studies being done in the southeastern states.
The fluctuations in biodiversity (1.10.55)
Nash explains that biodiversity can be investigated by seeing if herbicides inhibited vegetation or stopped the competing vegetation enough to support the desired vegetation. Chemical analyses and accounting for micro variants in the soil must be done for this. Olson claims that affecting the forest composition and structure may have habitat impacts that are detrimental to some species and beneficial to others. The Austin Pond study is being revamped to do this.
Nash and Olson on herbicides (1.21.33)
Nash is of the opinion that most people understand they are having an impact on the environment, and those who enjoy the forest have a lot of respect for it. He supports the use of herbicides in forest management. Olson laments that people think forests are not impacted by humans, and they have negative perceptions about applying herbicides to manage forests. He has seen more positive effects of herbicides than negative.
The advantages of forest management (1.29.41)
One of the advantages of forest management and silviculture is that we can increase crop rotation and supply the economy with more wood, Nash says. Olson mentions the control of the government on crown land and offers that producing the same amount of timber on a smaller acreage can free up some other areas for different uses while maintaining the same ecological function on those areas. Forest management is a mitigation strategy to manage climate change and protect biodiversity.
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