Transformation of pine monoculture to biodiverse food forest
Summary
The ‘great divide’ between nature and culture has put immense pressure on the stable state of the Earth System. To keep the Earth in a stable state, a system change is necessary. The transition from conventional agriculture or silviculture to perennial agroforestry food systems promises prosperity, however, the legitimacy of these claims needs to be assessed and quantified. To assess such a transition, this study has provided a broad baseline assessment of the soil quality, aboveground woody carbon stock and biodiversity of a pine production forest that will be transformed into a food forest system. Additionally, the outcomes of two soil regeneration methods have been compared experimentally and the possible effect of the system transition has been explored.
The forest in Overloon is characterised by acidified, nutrient poor, sandy soils, with a low CEC that is mainly taken up by ‘useless’ cations (H+ and Al+). The average aboveground woody carbon stock of the forest in Overloon is 72.2 Mg C/ ha, just below the Dutch average. The plant diversity of the forest is low: a total of only 31 plant species has been found, including planted trees and mosses. The addition of rock flour to a forest clearing has a significant effect on the amount of herbaceous saplings that emerged and surprisingly none of these species had been found in the forest before.
To turn this forest into a productive food forest system, the soil conditions will need to improve. Rich leaf litter is expected to turn on the nutrient pump which will turn the system from its downward spiral into an upward spiral of increasing fertility and decreasing acidification. Possibly the nutrient pump will need a helping hand of minerals (rock flour) to get started. The restoration of a healthy soil ecosystem will benefit many species, from fungi and plants up to the big carnivores; thus the entire system will become more biodiverse, productive, and resilient.