Imitating Natural Ecosystems through Successional Agroforestry

for the Regeneration of Degraded Lands

A Case Study of Smallholder Agriculture in Northeastern Brazil

Jennifer Schulz - Jorge Aubad

Jennifer.schulz@uah.es

Overview

1. Land use and degradation worldwide

2. Objective and Strategy

3. Cultivation concept

4. Case studies in Northeastern Brazil

5. Conclusions

Land use and degradation globally

3 Degradation of land ~ 5 - 6 Mio. Hektar / Year (UNEP 2002)4 Increase in cultivated area ~ 3,8- 5 Mio Hektar / Year (FAO 2003)

1 Population (UNO 2004)

2 Area of agriculture (Wood et al. 2001)

% continental surface

World population in billion people

Objective and Strategy

Objective: Regeneration of degraded agricultural land and environmental functions and services on areas of land use

Landscape scale: Environmental functions need to be gradually replaced on the area of agricultural land use

Strategy for land use: Approximation of agricultural uses to natural ecosystems Imitation of the functional principles of local natural

ecosystems

Guiding image: « natural, intact ecosystems »

Imitation of structure and function of ecosystems

Guiding image: « natural, intact ecosystems »

Imitation of structure and function of ecosystems

Perennialism and Diversity

Vegetation strategies: Optimal use of locally limited ressources (solar energy, water, nutrients)

Succession: 1. Maximum accumulation of biomass 2. Coupling / Association of functional different,

mostly complementary species

Short cycles of water, energy and nutrients, reduction of losses

Concept „Successional Agroforestry“

Font: Götsch, 1997

• Imitation of successional trajectories of the local ecosystem• Acceleration of natural processes through systematic

interventions: dense seeding of fast growing plants (first successional

step includes mainly pioneer colonizers e.g. Leguminosae)

systematic trimming production of mulch for fast accumulation of organic material

systematic creation of gaps through cuttings for

the plantation of use-plants of a higher successional level

Concept „Successional Agroforestry“

Selection of a mixture of locally endemic and culture speciesaccording to 2 criteria:

Stratum + Lifetime

Goals: increasing coupling of different functional types

Concept „Successional Agroforestry“

Font: adapted

from Milz, 2004

Case studies on degraded areas in Northeastern Brazil

1/3 of population of brazil

~ 88% smallholder farmers

Degradation of soils: ca. 50%

Desertification ca. 181.000 km2

strong rural- urban migration

Font: EMBRAPA, 2000

Project A: humid coastal zone

Precipitation: 1300-2000 mm/aSoil: sandy loam, low fertilitySize: 1 hectarProject start: 1994

Initial situation

after 10 years

Leguminosa trees trimmed Fresh layer of leeves (ground)

Neighbours´ field Successional system

Development of an organic soil horizon

Regeneration of a degraded unproductive site   

Provision food, construction- and firewood

High level of subsistency for 4 persons on 1 hectar

and increased income due to direct marketing of

organic products including:

Banana, mango, jackfruit, papaya, coffee, avocado, cocoa,

orange, lime, cupuaçu, açai, corn, rice, beans, cassava

Results

Project B:semiarid zone

Prec.: ca. 550 mm/a pot. ETP: 2000 mm/aDry period: 7-9 Month, in periodical dry years 18 monthsSize: 1500 collaborating farmers, 1000 m² experimental area Project start: 1999/2000

Fotos: Instituto de Permacultura da Bahia

2. cultivation year end of rainy season

1. cultivation year 2. month of rainy season

Initiation of the successional system in the rainy season

3. cultivation year end of rainy season

3. cultivation year beginning of dry season

Fotos: Instituto de Permacultura da Bahia

Productivity

Province Cafarnaum

Medium production kg/

ha

Production increase through

successional AF

Rizinus monoculture

Regional Ø 800 kg/ha

factor 1

Rizinus successional system

1497,5 ~ factor 1,9

Productivity * per ha success. system

3337.5 ~ factor 4

* At least 5 additional crops in production

• Participation of 1500 farmer families in 5 communities

facilitated by a payment of 18 US$ per month during 4 years

from the 4th year on - complete subsistency possible

• Regeneration of degraded sites and increase of

productivity without irrigation and external inputs

Decrease of risk for harvest loss through diversity of

perennial and anual plants higher resilience

Provision of environmental goods as an existential basis

Reduction of the strong rural-urban migrations

Project results

• farmers adopt SAF rather in drier zones and conditions of stronger degradation

Critical for success are:

• Capacity building in two directions:

Local knowledge in exchange with external expert impulse

- Training of multiplicators

Organisation of local knowledge exchange and the creation

of farmers associations

Development of local market chains for organic products

Comparison & Critical aspects:

Concept „Successional Agroforestry“ is successful

Conclusions:

Regeneration of an existential basis, local ecological

knowledge and farmers empowerment

improvement of the local livelihood

Stabilization and regeneration of environmental regulation functions at local scale

Potential for regeneration of regulation functions on critical areas within the landscape

Thank you for your attention!