Transcript PRA - World Agroforestry Centre

Ethnobotanical surveys
Roeland Kindt
Outline
• What is ethnobotany
• Rapid or in-depth surveys
• Herbarium specimens
• Selection of informants
• Estimating the completeness of surveys
• Local classification systems
• Bioprospecting
What is ethnobotany
• interactions of people and plants
• biological ethnobotany: economic botany
(species, local names, uses)
• anthropological ethnobotany: cultural
context (holistic)
Rapid or in-depth surveys
• Rapid: PRA, planning
• In-depth: holistic, statistically sound
– herbarium specimens
– use
– classification systems
– environment, people and interactions
– phonetic
– bioprospecting
– economic validation
Herbarium specimens
• Botanical identity
• Fieldpress: frame, straps, newspaper, blotting
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paper, ventilators
Field notebook: label information, local
identification (name, smell, taste, exudates, bark
characterististics, charcoal, …)
Plant dryer?
Voucher: all parts (fertile), presentation (fill)
Duplicates for herbaria
Newspapers and time
Selection of informants
• As for PRA: random (populations),
targeted (specialists)
• Avoid bias (season, location)
• Local specialist user groups
– living specimens (herbarium?)
– context
– permanent forest plots
Estimate completeness
• Breath: categories surveyed/total
• Depth: Σ (subcategories surveyed/total) /
total
• Replication: number of samples / total
• floristic or ethnofloristic categories
• stop when breath and depth remain the
same, while replication is sufficient
0
20
40
60
pooled sites
80
100
0
50
100
150
species richness
200
250
Local classification systems
• plant names
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– primary name (wattle)
– secondary name (black wattle)
– complex primary name (peppertree)
“I don’t know”, “flower”, “fruit”
under- or overdifferentiation
Local specialists
parallel classification systems (general vs.
medicinal)
Bioprospection
• Potential
– 60 % top 150 prescription drugs
– 5-15 % of 250-500 K plant spp. sampled
– 1 / 5-10 K molecules screened drug
• But:
– micro-organisms, marine, insects, animal and
human genetics, bioinformatics
– more focus on development of screens to use
on molecular libraries
Bioprospection (2)
• Ethnobotanical surveys more successful in
detecting biological activity
– but: screens not always available
• IPR
– but: only half of pharmaceutical companies use
ethnobotanical info, and 80% only from
literature searches, mainly after detection
• Alternative: confirm activity of local
medicine and provide feedback
(domestication)
Ethnobotany and tree
domestication
• Uses and management
• Priority setting
• Local classification
• Validation (market surveys)
• Participatory approach to domestication
(selection)
Local management of diversity
Use group
Firewood
Fruit
Timber
Construction
Shade
Boundary demarcation
Medicine
Soil fertility improvement
Charcoal
Ornamental
Households
Main reasons for diversity (households, %)
that desire
minimum
two species
(%)
Species ContiEach
Species
Risk
Testing
differ in nuous species
use
avoidance
charac- supply has good different
teristics
characniches
teristics
2 (3)
28 (36) 23 (29)
0 (0)
5 (6)
0 (0)
25 (32) 44 (57) 14 (18)
1 (1)
3 (4)
2 (3)
27 (38) 18 (25) 15 (21)
1 (1)
10 (14)
15 (21)
49 (72)
3 (4)
14 (21)
0 (0)
2 (3)
0 (0)
16 (28) 14 (24) 27 (47)
0 (0)
1 (2)
0 (0)
26 (46)
3 (5)
16 (28)
8 (14)
1 (2)
0 (0)
23 (66) 9 (26)
9 (26)
0 (0)
0 (0)
2 (6)
0 (0)
0 (0)
10 (67)
0 (0)
0 (0)
0 (0)
2 (14) 5 (36)
3 (21)
0 (0)
1 (7)
0 (0)
2 (22) 1 (11)
2 (22)
0 (0)
0 (0)
0 (0)
78 (100)
77 (99)
71 (92)
68 (88)
58 (89)
57 (75)
35 (71)
15 (31)
14 (52)
9 (41)