Towards optimizing acorn use as animal feed in Tunisia: evaluation and impact on natural regeneration

Boutheina Stiti,Mariem Khalfaoui,Abdelhamid Khaldi,Salima Bahri

doi:10.19182/bft2021.348.a31923

Abstract

In Mediterranean forests, besides the conflict between forest managers and local populations who are often poor and dependent on livestock for survival, the cost of raw materials used in animal feed is increasingly a burden for farmers. There is growing recognition that wise use of acorns can reduce feed costs and enhance sustainable participatory governance of these woodlands. This paper aimed to carry out a quantitative, qualitative and economic evaluation of acorn potential in a cork oak forest in north-western Tunisia and to investigate the impact of their post-dispersal on natural regeneration. Quantities were estimated in November and February, respectively for acorns collected directly from trees and from the ground. Time-dependent monitoring of acorn quality and numbers of new seedlings was also conducted from autumn 2014 to spring 2015. The results show a significant decrease in acorn quantity from 5.28 ± 4.61 t/ha in November to 0.684 ± 0.1 t/ha in February. However, this loss did not put the early stages of natural cork oak regeneration at risk since the percentage of acorns not able to germinate was estimated at only 37% in late February. Furthermore, the average number of new seedlings was estimated in April at 40,000 seedlings/ha. A model was fitted to predict tree acorn production and to establish the best agroforestry system to optimize acorn use. Based on acorn quantity and quality data, earlier acorns should be directed to nursery and livestock production and the later acorns to wildlife and natural regeneration.

Highlights

The last three centuries of cork oak forests commercial management have resulted in decline and deforestation in Mediterranean forest of the cork oak, Quercus suber
This study is important in the context of the optimization of the sustainable forest management development under climate warming and food security challenge and in accordance with the recommendations of FAO (Food & Agriculture Organization) in which it is registered to carry out enterprising agroforestry activities and ensure coordination between all the activities that contribute to the formation of landscapes and it is noted that the best way to save a forest is to manage it sustainably, taking advantage of the products and services it provides (FAO, 2012)
Acorns have been always considered as secondary products for cork oak forests, while management strategies were oriented toward the optimization of cork production

Summary

Introduction

The last three centuries of cork oak forests commercial management have resulted in decline and deforestation in Mediterranean forest of the cork oak, Quercus suber. Recent researches on cork oak forest services (Khalfaoui et al, 2020) showed that in north-western Tunisia, grazing (including acorns consumption) provided a high Economic Value of 0.16 M€/year in 2016. This value ranged from 33% to 48% of the Total Economic Value (TEV), depending on the stand density. The farmers are not involved in management and conservation issues exclusively fulfilled by Forest Administration which led to a critical and a conflictual situation These conflicts could be perceived through illegal practices such as forest fires, trees cutting and even violence against the forest administration agents

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