Another vision of sound tree and forest management: Insights from traditional ash shaping in the Moroccan Berber mountains

Abstract

The dimorphic Ash tree (Fraxinus dimorpha) is a keystone species in the functioning of agrosylvo pastoral systems and livelihoods found on the northern slopes of the Atlas Mountains of Morocco. It grows in spontaneous woodlands and forests which are fully integrated within agro-ecosystems. Local populations have for centuries shaped ash stands by sequentially trimming and pollarding individual trees for providing fodder, house roof building material and ecosystem services for the overall social-ecological system. Exploitation follows very strictly observed 4-year cycles of exploitation of pollarded trees, which allows the harvesting of each individual tree for foliar forage after 4 years of regrowths, and at the same time 2 shaping and letting some well-grown branches develop for further cycles in order to provide diameter-standardized poles (after 8 years) and beams (after 28-32 years) for house roof construction. The management of tree regeneration is also illustrative of deep-seated Traditional Ecological Knowledge. Overgrazed trees or new seedlings are protected by means of stone walls. Resprouts with the most vigorous and straightest stems are selected and linked to each other, in order to favor, when growing, trunk anastomosis. This highly original practice allows an increase in foliage production of 36% after a 4-year cycle, compared to non-anastomosed trees, and promotes the resilience and longevity of the trees. The main discrepancies in the vision of what might constitute 'good' forest management between local stakeholders and professional foresters concern 1) the scale of the management unit (individual trees and overall forested landscape vs tree stand), 2) the partial (diffuse) exploitation of living trees vs intensive cycles of exploitation of the whole tree stand, and 3) flexibility and pro-active management of heterogeneity vs homogenization. This perspective offers an alternative basis for rethinking forest management strategies in a context of global change, and original insights for conserving anthropized forest ecosystems without excluding people.

Traditional Pollarding Practices for Dimorphic Ash Tree (Fraxinus dimorpha) Support Soil Fertility in the Moroccan High Atlas

“…Examples of how TEK provides insights into balanced forest management have been reported and discussed [5]. In Morocco, this approach was particularly documented by Genin et al [6] in the forested landscapes of the Aït M'hamed region in Azilal province, situated in the Central High Atlas. A unique traditional practice relative to dimorphic ash tree stands was described, consisting of strict periodic tree pollarding and favoring tree stem coalescence and fusion in order to improve the productivity of foliar fodder [6,7].…”

“…It is called "imts" in the local Amazigh language, and it grows primarily on rocky inclines and valleys, at altitudes between 1200 and 2000 m. For the local inhabitants, it is a multifunctional tree, which constitutes a keystone species in the functioning of their agro-silvo-pastoral systems and livelihoods [8]. It supplies them with firewood, poles, and beams for houses and agricultural tools, spices, tinctorial, and medicinal products [6]. But its most essential use is as fodder, in times when pasture is scarce and insufficient.…”

“…(2) multistemmed trunks with multiple 10-20 cm diameter stems located both in parklands and in the adjacent public forest; (3) single-stemmed trunks, which are the least frequently occurring morphotype; and (4) shrublike trees, which dominate the public forest (Figure 1) [6]. The most widespread morphotype within the privately owned lands is the anastomosed trunks.…”

“…Anastomosis promotes anatomical changes, such as increased proportion of parenchymatous cells and cross section surface area [9]. This singular practice is viewed by Genin et al [6] as an original and effective option for resource scarcity management in this region.…”

“…The case of F. dimorpha could help to develop a more global approach to ensure both the preservation and valorization of efficient TEK practices, and the conservation of ecosystemic functionality. Genin et al [6] showed that the practice of trunk anastomosis allowed a 36% increase in foliage production after a 4-year cycle of exploitation, compared with non-anastomosed trees, and promoted the resilience and longevity of the trees. The effects of this practice on belowground properties have still to be investigated.…”