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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
[email protected]
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
World population
in billion people
% continental
surface
1 Population (UNO 2004)
2 Area of agriculture
(Wood et al. 2001)
3 Degradation of land
~ 5 - 6 Mio. Hektar / Year (UNEP 2002)
4 Increase in cultivated area ~ 3,8- 5 Mio Hektar / Year (FAO 2003)
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
Concept „Successional Agroforestry“
•
•
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 species
according to 2 criteria:
Stratum + Lifetime
Font: adapted
from Milz, 2004
Goals: increasing coupling of different functional types
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/a
Soil: sandy loam, low fertility
Size: 1 hectar
Project start: 1994
Initial situation
after 10 years
Leguminosa trees trimmed
Fresh layer of leeves (ground)
Development of an organic soil horizon
Neighbours´ field
Successional system
Results
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
Project B:
semiarid zone
Prec.: ca. 550 mm/a pot. ETP: 2000 mm/a
Dry period: 7-9 Month, in periodical dry years 18 months
Size: 1500 collaborating farmers, 1000 m² experimental area
Project start: 1999/2000
Initiation of the successional system
in the rainy season
1. cultivation year
2. month of rainy season
Fotos: Instituto de Permacultura da Bahia
2. cultivation year
end of rainy season
3. cultivation year
end of rainy season
Fotos: Instituto de Permacultura da Bahia
3. cultivation year
beginning of dry season
Productivity
Medium
production kg/
ha
Production increase
through
successional AF
Regional Ø
800 kg/ha
factor 1
Rizinus successional
system
1497,5
~ factor 1,9
Productivity * per
ha success. system
3337.5
~ factor 4
Province
Cafarnaum
Rizinus
monoculture
* At least 5 additional crops in production
Project results
• 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
Comparison & Critical aspects:
• 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
Conclusions:
Concept „Successional Agroforestry“ is successful
 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!