Paper · 2015 · Dissertationes Forestales

Optimal management of the Umbundu traditional land use system in the central Highlands of Angola

Cristobal Delgado-matas

7
claims
11
verbatim quotes
2
citations
3
research areas
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Open access · cc-by-nc-nd

Abstract

The study reviews one publication on the traditional land use system in Angolan highlands, three publications on modelling the growth and yield of nine tropical pine and six eucalypt species, and one publication on optimising the land use in Angolan highlands. The sources of data for the land use system analysis were two years field research and a review of previous studies going back to colonial times. The growth models were based on 19,388 radial increments from 1,059 measured pine trees and 10,499 radial increment observations measured on cores taken from 803 eucalypts trees. Linear programming (LP) was used to optimize the combination of alternative production systems. LP problems were formulated and solved for a baseline land use, improved diet, and maximal timber production land uses. The first study has implications for land use management (e.g. regarding length of fallow) and conflict management in Angola and elsewhere. The developed growth and yield model set included dominant height, diameter increment, tree height and self-thinning models for all the studies pine and eucalypt species. The model set makes it possible to simulate stand development on an individual tree basis. They showed good accuracy when the simulated stand development was compared to the observed development. Therefore, they can be used as a management planning tool in tropical pine and eucalypt plantations in Angola. The developed models were used in the last study to calculate the timber production in shortand long-rotation forestry. The last study showed that among the alternative production systems, cash crops under forest fallow showed the highest land expectation value (LEV). Changing diet by diversifying carbohydrate and protein sources increased LEV and reduced the seasonal need for women labour. In the maximal timber production alternative under food sufficiency constraint the optimal share of tree plantations was around 57% of the total land area.

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Claims 7

Method / resourceobservedoriginal resultmeasured

Claim · model-written summary

Growth and yield model sets included dominant height, diameter increment, tree height and self-thinning.

Taxon
pine and eucalypt speciese0
Outcome
dominant height, diameter increment, tree height and self-thinning modelse0

Not reportedComparatorValue

Verbatim

e0

“The developed growth and yield model set included dominant height, diameter increment, tree height and self-thinning models for all the studies pine and eucalypt species.”

✓ located verbatim in the source · abstract, characters 942–1112 · show in text ↑
Method / resourceobservedoriginal resultmeasured

Claim · model-written summary

The model set permitted individual-tree stand development simulation.

Taxon
pinePinust0
Outcome
simulate stand developmente0

Not reportedComparatorValue

Organisms pictured · Representative pictures of the matched species, not figures from the paper.

Pinus
Pinus · Taxon · picture of the genus (one of its species)Forest Service Northern Region from Missoula, MT, USA · Public domain · Wikimedia Commons ↗

Verbatim

e0

“The model set makes it possible to simulate stand development on an individual tree basis.”

✓ located verbatim in the source · abstract, characters 1113–1203 · show in text ↑
t0

“tropical pine and six eucalypt species”

✓ located verbatim in the source · abstract, characters 152–190 · show in text ↑
Method / resourceobservedoriginal resultpositivemeasured

Claim · model-written summary

Simulated stand development agreed well with observations.

Taxon
pinePinust0
Outcome
accuracye0
Comparator
observed developmente0

Not reportedValue

Organisms pictured · Representative pictures of the matched species, not figures from the paper.

Pinus
Pinus · Taxon · picture of the genus (one of its species)Forest Service Northern Region from Missoula, MT, USA · Public domain · Wikimedia Commons ↗

Verbatim

e0

“They showed good accuracy when the simulated stand development was compared to the observed development.”

✓ located verbatim in the source · abstract, characters 1204–1308 · show in text ↑
t0

“tropical pine and six eucalypt species”

✓ located verbatim in the source · abstract, characters 152–190 · show in text ↑
Associationobservedoriginal resultpositivemeasured

Claim · model-written summary

Cash crops under forest fallow had the highest land expectation value.

Taxon
cash cropse0
Treatment
forest fallowe0
Outcome
land expectation valuee0
Direction
higheste0

Verbatim

e0

“cash crops under forest fallow showed the highest land expectation value (LEV).”

✓ located verbatim in the source · abstract, characters 1609–1688 · show in text ↑
Intervention effectobservedoriginal resultpositivemeasured

Claim · model-written summary

Diet diversification increased land expectation value.

Taxon
pinePinust0
Treatment
Changing diet by diversifying carbohydrate and protein sourcese0
Outcome
LEVe0
Direction
increasede0

Not reportedComparator

Organisms pictured · Representative pictures of the matched species, not figures from the paper.

Pinus
Pinus · Taxon · picture of the genus (one of its species)Forest Service Northern Region from Missoula, MT, USA · Public domain · Wikimedia Commons ↗

Verbatim

e0

“Changing diet by diversifying carbohydrate and protein sources increased LEV and reduced the seasonal need for women labour.”

✓ located verbatim in the source · abstract, characters 1689–1813 · show in text ↑
t0

“tropical pine and six eucalypt species”

✓ located verbatim in the source · abstract, characters 152–190 · show in text ↑
Intervention effectobservedoriginal resultpositivemeasured

Claim · model-written summary

Diet diversification reduced seasonal demand for women’s labour.

Taxon
pinePinust0
Treatment
Changing diet by diversifying carbohydrate and protein sourcese0
Outcome
seasonal need for women laboure0
Direction
reducede0

Not reportedComparator

Organisms pictured · Representative pictures of the matched species, not figures from the paper.

Pinus
Pinus · Taxon · picture of the genus (one of its species)Forest Service Northern Region from Missoula, MT, USA · Public domain · Wikimedia Commons ↗

Verbatim

e0

“Changing diet by diversifying carbohydrate and protein sources increased LEV and reduced the seasonal need for women labour.”

✓ located verbatim in the source · abstract, characters 1689–1813 · show in text ↑
t0

“tropical pine and six eucalypt species”

✓ located verbatim in the source · abstract, characters 152–190 · show in text ↑
Method / resourceobservedoriginal resultsimulated

Claim · model-written summary

Optimal tree plantation share under maximal timber production and food sufficiency was around 57% of land.

Taxon
tree plantationse0
Outcome
optimal share of tree plantationse0
Value
around 57%e0
Qualifier
under food sufficiency constrainte0

Verbatim

e0

“In the maximal timber production alternative under food sufficiency constraint the optimal share of tree plantations was around 57% of the total land area.”

✓ located verbatim in the source · abstract, characters 1814–1969 · show in text ↑