last post criticism of sources created some pretty big ripples and aroused a lot of debate, especially in social media. whether Caragana arborescens (Caragana arborescens) is edible or not, we still do not, but I can tell you that our Russian-speaking friend search in Russian publications do not give any answer to the question. In the Russian-speaking world, it is used mostly as a medicinal plant (and tensile plant for bees) and even where it appeared a lot of reports about the possible toxicity of the plant is consumed in large quantities.
Another topic that came up in this context is the so-called dynamic accumulators. Dynamic accumulators I have written about on this blog and then proceeded most from what is written in the woodland garden literature [2, 5, 6], without any further source criticism. The basic idea behind them is that they are plants that can take up minerals from deeper soil layers, accumulate them in their leaves and enrich the upper soil layers with them when they shed leaves in autumn. In the woodland garden literature describes dynamic accumulators indispensable to bring together the nutritional balance of forest garden.
The problem is that the very concept of dynamic accumulator completely lacking in scientific. It was pointed out by several readers in reference to a Article sort of debate on permaculturenews.org. The writer tells us where the term was coined by author Robert Kourik in the book "Designing and Maintaining your edible landscape – Naturally” , a real classic in this field. Both Kourik and several other authors later regretted that they took with lists of dynamic accumulators, taking the view that there was no evidence behind it all. Even the writer of permaculturenews.org mean that there is not a single scientific study that has investigated the dynamic accumulators and it might as well abandon the concept. Instead, he thinks that we should investigate the mineral contents of various plant leaves to determine whether any plant is good to enrich the culture with minerals or not.
I wanted to get my own opinion about it and found out that the concept of dynamic accumulator is not something that the scientific community knows. However, the actual mechanism interestingly well-researched. The technical term is "nutrient uplift" or "elements translocation" and searches on these terms and variations of them led me to a lot of interesting sources. Many plants with deep root system obtains namely a competitive advantage by pulling up minerals from deep soil layers . Where there is not the same competition as in the upper soil layers that just teeming with plant roots that everyone wants the most coveted minerals. In dry climates have even seen some trees send their roots down to depths not to draw up water, but to pumping down water, so that fungi and bacteria can establish themselves deep in the otherwise dry Earth to help leach nutrients from the mineral-rich mountain .
Some plants are so good at this redistribution of nutrients that can completely change the growing conditions in one place. With the right plant, a formerly quite unproductive land suddenly produce large amounts of biomass. Instead of calling these plants for dynamic accumulators, I think acceleratorväxt is a better term, because it describes clearly what actually happens. Most pronounced is this phenomenon of so-called invasive species (as park like, Fallopia japonica, Solidago gigantea, Solidago gigantea eller jätteloka, Heracleum mantegazzianum). They have several different strategies to quickly take over vulnerable ecosystems, but one of them is right to draw up nutrients from deep soil layers, allowing them to quickly produce a lot of biomass. The park slide case it is incredible 13 times more biomass production per square meter than before the invasion, while the amount of nutrients in circulation increased by around 50% . Often, the fallout from these plants also readily biodegradable and thus increases the turnover rate in the overall ecosystem, upsetting the previous balance completely . What is interesting is that this mechanism works best in places with relatively low fertility and that invasive species have been difficult to improve the already fertile lands , a clear parallel words to kvävefixerarna, works best when it is a bit short of nitrogen in the system.
Planting invasive plants to increase turnover in the forest garden teaches, however, for several reasons to be a bad idea. In addition to risk destroying nearby ecosystems, several of the invasive species, namely the entrenched on the ground and lock the succession in a position that does not help forest garden. However, it should be kinder species may also increase the turnover rate in the cultivation, but do not set out with a lot of problems. Here I had hoped for a clear and delicate plant lists in the literature, but I failed to find.
In summary, I mean that the concept of dynamic accumulators are tricky and suggests instead using the term accelerator plant. By that I mean a plant:
- have deep roots,
- can redistribute nutrients from deep soil layers
- has a high biomass production
and which can thus increase the turnover rate overall in the culture.
Based on this definition, I have made a separate statement that both are based on the sparse information I have been able to find in the literature [1, 10, 11] and some assumptions based on my own plant knowledge. An important aspect that I have taken in the selection of the plants are able to accumulate calcium in the topsoil. The higher calcium content, the more worms there namely in the soil and the more stable the pH, while the total biomass production goes up if there is a lot of calcium available . What I can add is that many accelerator plants also are nitrogen-fixing, and these plants I have left out here. Are you interested in them, I recommend the list in a post from last winter. Note that this list is preliminary and that I am very grateful if you want to add more species. I am particularly interested in species that have similar properties to the sterile vallörtssorterna 'Bocking 4’ and 'Bocking 14', who have deep root systems and can produce enormous quantities of leaf mass, but there is a risk that they could spread.
 Augusto, L., J. Ranger, D. Binkley, and A. Rothe, Impact of several common tree species of European temperate forests on soil fertility. Ann. For. Sci., 59(3): p. 233-253, 2002.
 Crawford, M., Creating a forest garden : working with nature to grow edible crops. Totnes: Green Books, 2010.
 Dassonville, N., S. Vander Hoeven, W. Gruber, and P. Meerts, Invasion by Fallopia japonica increases topsoil mineral nutrient concentrations. Ecoscience, 14(2): p. 230-240, 2007.
 Ehrenfeld, J.G., Effects of Exotic Plant Invasions on Soil Nutrient Cycling Processes. Ecosystems, 6(6): p. 503-523, 2003.
 Hemenway, T., Gaia's Garden: a guide to home-scale permaculture. White River Junction, Vt.: Chelsea Green Pub., 2009.
 Jacket, D. and E. Toensmeier, Edible forest gardens. White River Junction, Vt.: Chelsea Green Pub. Co., 2005.
 serf, E.G. and R.B. Jackson, The distribution of soil nutrients with depth: Global patterns and the imprint of plants. Biogeochemistry, 53(1): p. 51-77, 2001.
 Kourik, R. and M. Kane, Designing and maintaining your edible landscape naturally. Santa Rosa, CA; Emmaus, PA: Metamorphic Press ; Distribution, Rodale Press, 1986.
 McCulley, R.L., E.G. serf, W.T. Pockman, and R.B. Jackson, Nutrient uptake as a contributing explanation for deep rooting in arid and semi-arid ecosystems. Oecologia, 141(4): p. 620-628, 2004.
 Neirynck, J., S. Mirtcheva, G. Sioen, and N. Lust, Impact of Tilia platyphyllos Scop., Fraxinus excelsior L., Acer pseudoplatanus L., Quercus robur L. and Fagus sylvatica L. on earthworm biomass and physico-chemical properties of a loamy topsoil. Forest Ecology and Management, 133(3): p. 275-286, 2000.
 Reich, P.B., J. Oleksyn, J. Modrzynski, P. Mrozinski, S.E. Hobbie, D.M. Eissenstat, J. Chorover, O.A. Chadwick, C.M. Hale, and M.G. Lukens, Linking litter calcium, earthworms and soil properties: a common garden test with 14 tree species. Ecology Letters, 8(8): p. 811-818, 2005.
 Vander Hoeven, S., N. Dassonville, and P. Meerts, Increased Topsoil Mineral Nutrient Concentrations Under exotic invasive plants in Belgium. Plant and Soil, 275(1): p. 169-179, 2005.