Example of assessed technology / approach from Sehoul,

The Cork oak assisted regeneration vs other Forest techniques

Abdellah Laouina, Miloud Chaker, Mohammed Aderghal, Rachida Nafaa, Jamal Al Karkouri, Mostafa Antari, Issam Machmachi, Yousra Laghazi, et Nadia Machouri Moroccan DESIRE team, Chaire UNESCO-GN,

Rabat

Symposium “Assessing Benefits of SLM – key for success”, 19 October 2009

The aims of the assessment :

• -to identify existing and new strategies to prevent or mitigate land degradation and desertification

• -to select a set of these identified strategies for evaluation and documentation with the WOCAT methodology.

• -to experiment these strategies in some fields and make a follow-up with some required techniques of measurement

The overall objective is to be able, after some years of experimentation to propose successful strategies for extension and improve.

The field work programmed is the monitoring of these techniques and approaches in order to determine their real efficiency, in term of degradation mitigation, social benefits and farm’s yield increase.

Main problems of degradation in the region

• In the pastures, the over-grazing leads to the degradation of the vegetation cover and to the reduction of palatable species;

• In the cultivated area, the problems are more related to techniques of land use, not adapted to the climate, to the weak soils and to the slopes gradient.

• a-The decrease of soil moisture, due to the delayed and reduced precipitations in autumn, or the early dryness in spring, leads to a reduction of the grain yield and of the biomass and represents an important factor of crisis, both for agriculture and livestock.

• b-The concentration, in some years of special events with heavy rains, during autumn, on land which is still completely bare, produce very important runoff and soil erosion.

• c-The decrease of the piezometric level, due to over exploitation of wells and to the increase of runoff in the fields.

For this presentation: the case of the techniques for forest degradation mitigation

Inside the forest, the social situation of the populations explains the rapid retreat and clearing of the vegetation cover, the non regeneration of cork oak and the multiplication of poor species

I- Diagnostic%

%; Chêne liège Normal; 20%

%; Chêne liège Clair; 15%

%; Chêne liège Epars; 15%

%; Chêne liège en mélange avec

Essences secondaires; 3%

%; Chêne liège Dense; 45%

%; Régénération assistée de Chêne

liège; 2%

Types of cork oak covers

-Forest protection and management to reduce the pression and to plan the use and exploitation of the forest resources,

but problem of non regeneration of cork oak

II- Several techniques and approaches to reduce the forest degradation

-Plantation of exotic fast growing species, pine and eucalyptus, to improve the yield, but it can have negative impacts

The importance of runoff and gullying under eucalyptus

-Assisted cork oak plantation, in some of the degraded areas,

as a strategy for the sustainability of the forest

Assisted cork oak plantation has many benefits-It assures the cork oak regeneration,-It improves the cork yield-It reduces the land degradation, by the decrease of overland flow and the increase of infiltration.

Assisted cork oak plantation Technical aspects

• The soil preparation consists in a deep ‘ploughing along strips of 3m wide, separated by strips non ploughed and non cut of 2 m wide.

• After the deep plough, the seeding or planting is made with a density of 3 m x 5m

• installation of metallic fences to assure the non penetration of flocks.

• The maintenance consists in the destruction of herbs and in the soil hoeing. During the 2 first years, some water supply is made. Phyto - treatment is also important.

• The work is made by companies, in the framework of a contract with the services of forests.

Success of the plantation, but after 10 years, the trees didn’t grow enough, due to competition with cistus shrubs

Success of the plantation, after 5 years, the grass species cover is important

But there are also cases of total failure

III- Assessment by comparison of various covers

• Assisted regeneration, 5 years, protected and closed for grazing,

• Assisted regeneration, 10 years, opened for grazing,

• Eucalyptus and pine,

• Natural cork oak forest with diverse steps in term of density (dense, clear, scattered)

0

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Reg 1.MD Reg 2.OP Eu Pin CL Dense CL Clair CL Epars

Arbres

Arbustes

Herbacées

Litière

Sol nu

Types of land cover in various types of forests

Rate of trees, shrubs, herbs and litter in the soil cover

Taux de recouvrement des diverses formations en 2008 et 2009

0%

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08

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09

Reg2.OP-08

Reg2.OP-09

Eu-08 Eu-09 Pin-08 Pin-09 CLDense-

08

CLDense-

09

CLNormal-

08

CLNormal-

09

CLClair-08

CLClair-09

CLEpars-08

CLEpars-09

Cistes Autres Arbustes Asphodéle Herbacées pérennes Herbacées annuelles Litière Sol nu

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Eu Pin CLDense

CLNormal

CL Clair CLEpars

Ph

yto

mas

se e

n k

g m

atiè

re v

erte

/ha

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Nb

d'e

spèc

es /

m²

Herbacées Arbustes Nbre espèce /m2-2009

Biomass and diversity of species (herbs and shrubs)

Biomass of the herbs (Asphodel + others) and shrubs (Cistus+ others)

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/cm

²

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Co

hés

ion

(K

Pa)

Résistance à la pénétration (Kg/cm²) 2008 Cohésion du sol (KPa) 2009

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5

1 2 3 4 5 6 7 8 9 10

Pén

étro

mét

rie

kg/c

m²

Chêne liège de 5 ans(mis en défens)

Chêne liège naturelpâturé

Chêne liège de 10 ans(fortement pâturé)

Moy_CL 5ans

Moy_CL naturel

Moy_CL 10 ans

Variation of the penetrometry in 3 plots of land of cork oak according to the degree of pasture (10 measurements in each plot, realized measures 27/4/2008).

Humidité du sol (%)

Courbes d'infiltration

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160

2 5 10 15 20 25 30 35 40 45 50 55 60 65 70

Durée de l'expérience en mn

mm

in

filt

rés

/ h

eu

re

Forêt mise en défens Forêt de chêne pâturée Inculte

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Temps (mn)

Ru

isse

llem

ent

cum

ulé

(m

l)

Forêt de chêne régénérée de 10 ansfortement pâturée

Forêt de chêne naturel pâturée

Rain simulation, Runoff measurement

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Régénération CL pâturée Ruissellement (mm/h)Précipitation en mm/hRégénération CL mis en défens Humidité (%)Chène liège dense Humidité (%)Régénération CL pâturéeHumidité (%)

Intensité pluviale

Ruissellement

Humidité TDR

Effect of grazing on the runoff generation (rain simulation)

Refus d'infiltration dans la forêt pâturée (hydrophobie)

0

5

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45

1 4 7 10 13 16 19 22 25 28 31 34 37 40 43 46 49 52 55 58

Temps de simulation (mn)

hu

mid

ité (

%)

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Ru

iss (

ml)

Humidité(%) Ruissellement foret(ml)

The pression on the forest leads to less density cover, to less quality of the cover, to more sensitive soil to the rain intensity, more runoff generation and less infiltration

The regeneration of cork oak is a much more interesting technique compared to eucalyptus planting or simple protection without cork oak regeneration

Biomass Cycle with photos selected by the farmers

The socio-economic assessment was not less important compared with the bio-physical one.

But in the case of the forest, the state is the land owner and the inhabitants are considered as users with some limited rights, they often overcome.

The most efficient management, the assisted regeneration, is still limited in term of surface, due to many constraints.

So, the results of the assessment are not enough to orient for a good decision.

IV- The socio-economic assessment

Conclusion

In the region, the main constraint is the availability of fodder for livestock.

• The forest provides an important part of the needs as long as it is enough well managed.

• But degradation of the vegetation cover leads to less income (cork, fire wood, fodder) and at the same time to less stability of the land.

• The negative choices in term of management can have the same effects.

• But, the short and the long term effects should be both considered.