I have an opportunity to help advise a group of people who share a coniferous forest farm which suffered a great loss in tree stock during a windstorm in summer 2014. The forest has already been restocked with conifer seedlings as part of a reforestation grant available through the state. The forest service agent said that in order to fulfill the obligations of the grant, the "weeds" had to be cleared from around the base of each seedling to give it a fighting chance. The agent suggesting applying RoundUp. It became the plan to be implemented this weekend until a minority of the group found out and expressed concerns. Now there is an opportunity to change their minds about how to sustainably manage the establishment of these conifers.
I'm hoping for some permaculture alternatives to present to the group (who are not permies), so that they can make an informed decision (hopefully one that takes the whole ecology of the land into account). The site is several acres (so hand-scalping (aka weeding) has already been eliminated from the options, because they are unwilling/unable to perform the necessary labor).
More about the site and situation:
Temperate Climate: located in North Idaho. USDA 6a.
The land slopes to meet a large lake on one side. Part of the concern with applying RoundUp is its negative effects on aquatic environments, including amphibians who also live terrestrially, and there is a possibility of surface water or herbicide-containing groundwater reaching the lake or the wetland areas near it.
The mature conifers that are left are currently showing signs of heat and drought stress as Idaho has been in a drought since before the windstorm occurred (2014).
One of my thoughts was to plant a guild (lily of the valley, daffodil?) ring of flower bulbs which would suppress competing grasses without interfering with the seedlings' resources, but most of the examples of planting under conifers that I've been able to find are only with existing mature conifers... not companion plantings which help a conifer get established.
Does anyone have experience helping conifers get established without the use of herbicides? What worked well? What didn't? Any ideas are welcome.
Thank you for reading and considering solutions to this challenge.
I applaude your efforts to help dissuade these landowners on the use of Roundup. Aside from the contamination concerns, there is growing evidence that the use of Roundup chelates minerals in the soil and negatively affects beneficial soil organisms.
I work on primarily wetland/riparian restoration projects in NW Montana, but I also work in more upland grassland/forest communities. My suggestion for your site would be to place a combination of forest duff, chunks of rotting logs, and conifer limbs and/or logging slash around each re-planted conifer seedling. Since I'm not intimately familiar with your site, I'm not sure how much of these materials is available on-site, especially if the site was salvage-logged following the wind storm in 2014. Also, I'm assuming an experienced tree planting crew restocked the site, so hopefully they utilized these types of materials when planting to provide welcoming micro-sites for the trees.
Regardless of whether the conifers were properly micro-sited or not, placing as much duff, rotting logs and slash as possible would benefit the trees in the following ways. First, duff from a nearby, undisturbed forest would provide seeds (grasses, forbs, shrubs, trees) and inoculum for soil biological organisms that are appropriate for the site. Just a small handful of duff per tree would be sufficient. Large chunks of rotting logs can serve multiple purposes: shading (if placed on the south side of the seedling), organic matter and inoculum (primarily for beneficial fungi), water retention, and short to mid-term smothering of herbaceous species that might compete with the trees. Conifer limbs and/or logging slash would simply complement several or most of the functions the rotting logs would serve.
Forest soils are dominated by fungal species (far outnumbering bacterial species), so the fine (duff), coarse (limbs), and large (rotting logs) woody debris would help to inoculate, nurture and feed the soil fungi in proximity to the trees, giving you the best chance of success. Hopefully, these types of materials are close at-hand. If so, it seems to me that placing these materials wouldn't take much, if any, longer than someone stumbling through the forest with a 4 gallon backpack sprayer spraying Roundup! And, it would be a whole lot more fun!
I was involved in a tree planting project last year where we planted Englemann spruce in a riparian area that had been pretty aggressively logged about 25 years ago. Regeneration of spruce, cottonwood and other native trees has been poor on this site ever since. The stumps left behind from the logging, however, provided great micro-sites for us to plant in. We planted on the north sides of stumps, and there was generally still a good amount of duff left around the stumps. We were also able to tear off large chunks from stumps or nearby downed logs to place around seedlings to provide more shade, organic matter, inoculum, suppression of reed canarygrass, etc.
We have a grant from a state government body to reveg a 500m fence line with three rows of trees and shrubs. We've just received the documentation today and we are supposed to do two sprayings with a knock-down herbicide (roundup) before the planting and then spot spraying afterwards.
We thought instead we'd slash, rip then spray a few times with horticultural vinegar (29% acetic acid) before planting then use the vinegar for spot control post planting. We have yet to put this to the funding body but their agent thinks they'll be happy with our plan. They just want the plants to have a decent chance at getting established.
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