The approach we take at Genus for remediation and restoration projects can be described, a bit over-simply, as doing as much as we can as quickly as we can while attempting to mimic nature whenever the situation allows us. One of the many tools that we can see nature use when bringing an imbalance back into equilibrium, over a large span of time, is diversification. We have been able to observe vegetative diversity in action and regularly emulate this technique in preparing projects for replanting.
While the research into the importance of diversification of plant species is relatively young, with many pilot studies only beginning in the 1990’s, much exploration has occurred since, especially into high-risk ecosystems like the North American Prairies. There is hope that similar insight can be found by applying the findings from these on-going studies to emerging high-risk ecosystems, such as coral reefs or old-growth forests. Findings from many of these research projects, especially those that run for several years or more, all lead towards a similar conclusion. Ecosystems with diverse plant species can generate soil that contains more essential plant nutrients, produce more plant biomass, and store more carbon. As well, results show that mono-planting can negatively impact the ecosystem as there is a risk of losing vital soil nutrients as time passes.
In the case of the Cedar Creek Biodiversity Experiment, a study nearing it’s third decade of work, researchers categorized almost two dozen different grassland species into three groups to study the effect planting combinations had in controlled areas. They found that mixtures of grasses, legumes, and herbaceous species accumulated higher levels of essential nutrients within the soil compared to mixed groups of plants within the same category. As projects such as this continue, more knowledge of ecosystem dynamics is revealed, often leading to discoveries of individual plant species being a vital component of the functioning ecosystem either above ground or below. As all things in nature are connected in some way, similar research into mycorrhizal fungi diversity shows that diversification within the arbuscular mycorrhizal fungi community impacts plant species diversity.
As explored previously, much of our work is with soil. Soil that would otherwise be teeming with diverse, microscopic life-forms supporting the plants and larger animals living within that environment, had a contamination not occurred. While extensive testing is required to monitor day-to-day how projects are developing, we’ve observed that plants cannot only be an indicator of progress but also tools themselves within the remediation and restoration process. Over the past several years, a specific category of plants has become very useful to us in preparing areas that will later be planted with either native species or applicable vegetation depending on the intended use for that land. Halophytes are salt-resistant, or salt-tolerant, plants that can thrive and complete their life cycles in soils, or near waters, containing high salt concentrations. Not only can they survive, but they also have practical applications as food crops or animal fodder. When looking at a remediation project, we are working to see improvements in three main areas: the soil, the water, and the vegetation. In our experience, whenever we have an opportunity to improve one of those areas we take it, because we almost always see improvements in the others as a result. Salt impacted soils, left bare, become more compacted and inhospitable to life as time moves on. By utilizing certain plants that can grow in those conditions, not only do we have an opportunity to fill the need for vegetation for the various animals that may be living in the area, but the roots of those plants help break up soils and increase drainage. Because plant species become adapted to thrive in specific conditions, as a project progresses and the concentration of salts decreases, those halophytes used initially to keep something in the ground become less aggressive and eventually are outperformed by the plants that will be used to finish a project. Kochia, a 'noxious' weed to many, has been very helpful to us in the early stages of some of our projects. Because of its tolerance to heat, drought, and saline soils, letting it self-seed early on assists us combating compaction in our soils and keeps them workable. Over the course of even just a few growing seasons, we find that without much intervention the Kochia becomes less prevalent and is replaced by other plant species.
In an undisturbed area, one could find dozens of different species in just a square meter space. The goal of our projects is to not only create a space that meets all the regulatory requirements by the end of the project, but to also ensure the overall ecosystem is self-sustaining long term. That requires more than a handful of uncoordinated plant species. Promoting ecological diversity on any scale, from small yards in urban areas to large restoration projects after an environmental impact, is something we feel is of benefit to us all.
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