Sæt disse i rækkefølge fra mest til mindst produktiv, hvilke er P limited og hvilke er N limited? Hvilke er ombrotrophic og hvilke er minerotrophic? Hvor er det mest syre? Hvor er det højest turnover rate? Bog, Fen, swamp, Marsh

Bogs have lower fertility (less nutrients), Are more acidic due to rainwater imput. This means they have more organic peaty soils. Bogs have low productivity and a slow nutrient turnover. Often P-limited. Minerotrophic systems tend to be more Nitrogen limited. This is because there is inorganic nitrogen in rainwater, but no natural input of phosphorus in rain water. Also because plants need much more nitrogen than phosphorus. Only few ecosystems need phosphorus.