To a forest garden to work, we need to create a dynamic similar to the one we can find in natural ecosystems. It is primarily about creating healthy soil, a good pest balance, good conditions for pollination and especially self-generated fertility, ie. a system that covers his own need of nutrients to the greatest extent possible. Dynamic accumulators belonging key plants needed to create this self-generating fertility. With dynamic accumulators means plants that take up minerals and nutrients from deeper soil layers and accumulating them in their leaves, branches, roots, etc.. When parts of the plant dies made of minerals available to other organisms and soil fertility in the upper soil layers (where it occurs most biological activity) increases.
What is a dynamic accumulator, there is not really any consensus in the literature. Most trees have the deep root system and contributes to soil fertility through the roots die back and lövnedfallet in autumn. The plants that are called dynamic accumulators seems to be especially good at taking up different nutrients and also has the ability to tillgängligöra them to the rest of the system in one way or another.
It is primarily nitrogen (N), potassium (K), phosphorus (P) och calcium (As) that tends to be limiting for woody plant growth. The nitrogen-fixing plants (N2) I will write about in a separate post, because not all of them also are dynamic accumulators. Some dynamic accumulators, such as comfrey, also supplies other nutrients to the upper soil layers, so as manganese (Mn), magnesium (Mg), sodium (In), sulfur (S), cobalt (Co), copper (With) or iron (Faith). Martin Crawford estimates that it takes about five years  in order to initiate the desired ecosystem dynamics of a forest garden and the dynamic accumulators plays a key role in this transition, provided that the other requirements for ecosystem dynamics are also satisfied.
What then are the appropriate dynamic accumulators for our Nordic conditions? Unfortunately, so far very little research work on dynamic accumulators , but here is a summary based on the information I have been able to find in the literature ([1, 3]), I added some plants that I know has a high content of minerals, as Good Henrik målla (Chenopodium bonus-henricus).
Woody dynamic accumulators
|Botanical name||Swedish name||Nutrients||Comment|
|Acer saccharum||SUGAR MAPLE||K, As|
|Juglans nigra||Black walnut||K, P Ca||Very good dynamic accumulator due. their pålrötter reaching long into the earth. However, contains leaves and roots Thread juglone which is growth inhibitory for many other plants.|
|Juglans spp.||Other walnuts||K, P||Good dynamic accumulators because their pålrötter reaching long into the earth. However, contains leaves and roots Thread juglone which is growth inhibitory for many other plants.|
|Robinia pseudoacacia||Robinia||K, As, N2||Nitrogen-fixing trees with wood of the same quality as oak. Hardy to zone 3 in Sweden.|
|Tilia cordata||Skogslind||P, As||The tender leaves are edible.|
Herbaceous dynamic accumulators
|Botanical name||Swedish name||Nutrients||Comment|
|Allium schoenoprasum||Chives||K, As|
|Brassica spp.||Perenna kålarter||P, S||Few of these are hardy in Sweden|
|Chamaemelum nobile||Roman Chamomile||K, P, As|
|Chenopodium album||Lambsquarters||As, P, K, Mn||Best known as an annual weed. Good human nutrition.|
|Chenopodium bonus-henricus||Good Henrik målla / Lungrot||K, P, As, Mg|
|Cichorium intybus||Cikoria||K, As|
|Filipendula ulmaria||Meadowsweet||P, K, As, Mg, S||Is also an indicator plant for phosphorus-rich habitats, can be used as coating materials for supplying the phosphorus.|
|Glycyrrhiza spp.||Species in lakritsrotsläktet||P, N2|
|Lupinus spp.||Lupiner||P, N2||Can be invasive under certain conditions.|
|Medicago sativa||Blålusern||Faith, N2||Nitrogen-fixing and good at taking up iron from the soil. Good at building soil because of its deep, finhåriga root system.|
|Nasturtium officinale||WATERCRESS||K, P, As, S, Faith, Mg, In||Accumulates most plant nutrients.|
|Rumex spp.||Acids and docks||K, P, As, Faith, In||Very good at taking up most plant nutrients.|
|Stellaria media||Vårarv||K, P||Often regarded as weeds. Edible.|
|Symphytum spp.||Vallört||K, P, As, With, Faith, Mg||One of the best herbage dynamic accumulators. The sterile variety 'Bocking 14' should be selected to prevent an invasion of comfrey.|
|Taraxacum officinale||Maskros||K, P, As, With, Faith||Often regarded as weeds. Based soil and is edible with very high nutritional values.|
|Urtica dioica||Stinging nettle||K, As, S, With, Faith, In||Often regarded as weeds. The young leaves are highly nutritious.|
|Vicia spp.||Vickerläktet||K, P, N2||Includes for example:. bondbönor (In. Bean, which, however, are one-year) and ärtvicker (In. pisiformis) which have edible beans.|
 Jacket, D. and E. Toensmeier, Edible forest gardens. White River Junction, Vt.: Chelsea Green Pub. Co., 2005.
 Ferguson, R. and S. Lovell, Permaculture for agroecology: design, movement, practice, and worldview. A review. Agronomy for Sustainable Development: p. 1-24, 2013.
 Kourik, R.K.M., Designing and maintaining your edible landscape naturally. Santa Rosa, CA; Emmaus, PA: Metamorphic Press ; Distribution, Rodale Press, 1986.