Growth and yield of nine pine species in Angola

Delgado-Matas, Cristobal; Pukkala, Timo

doi:10.1007/s11676-012-0239-3

Cited by 7 publications

(6 citation statements)

References 12 publications

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“…It is 1700 m a.s.l. (above sea level) with a mean annual temperature of 20 • C and rainfall ranges from 1200 to 1600 mm per annum [63, [72][73][74]. The climate is humid mesothermal with dry winters and warm summers.…”

Section: Description Of the Study Areamentioning

confidence: 99%

Dynamic Patterns of Trees Species in Miombo Forest and Management Perspectives for Sustainable Production—Case Study in Huambo Province, Angola

Chiteculo

Surový

2018

Forests

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This paper aims to assess important forest parameters, including tree density, diameter at breast height (DBH), and age distribution, investigate the dynamic growth of miombo tree species, and employ this information to design a management framework in miombo forests. The delineation of the management zones was based on unsupervised land cover classification that began with three zones where ground data was collected and increased to five zones. Eighteen circular plots (25.2 m radius) were randomly distributed over the study areas to assess the current situation and potential growth patterns for each species. The patterns of the six most representative tree species of miombo in Angola were described and we used KORFiT 2.4 software to fit data and develop growth curves for at least three miombo species. Growth function fitness was evaluated by root mean squared error (RMSE), coefficient of determination (R 2 ), significance of the parameters (p < 0.05), and Akaike's information criterion (AIC). The diameter distribution of miombo tree species resembled a typical distribution of uneven-aged forest stands; higher DBH classes had lower abundances of tree species. Logistic and Gompertz growth functions were the best fits for miombo tree species. Brachystegia spiciformis Benth., is suggested as a potential species for timber management in the region because they displayed high growth potential to more quickly reach an assumed minimum DBH of 20 cm. This study concluded that miombo forest stands present an irregular structure in which DBH distribution illustrated only two patterns: many small stems and a bimodal forest structure.

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Section: Description Of the Study Areamentioning

confidence: 99%

Dynamic Patterns of Trees Species in Miombo Forest and Management Perspectives for Sustainable Production—Case Study in Huambo Province, Angola

Chiteculo

Surový

2018

Forests

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“…With an area of approximately 34,270 km 2 and a population of approximately 1.9 million inhabitants, Huambo province is divided into 11 municipalities. It is 1700 m a.s.l., with a mean annual temperature of 20 • C, and annual rainfall ranges from 1200 to 1600 mm [47][48][49]. The climate is humid meso-thermal with dry winters and warm summers.…”

Section: Study Areamentioning

confidence: 99%

Defining Deforestation Patterns Using Satellite Images from 2000 and 2017: Assessment of Forest Management in Miombo Forests—A Case Study of Huambo Province in Angola

et al. 2018

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A few studies have recently been published on changes in land use/land cover (LU/LC) of Angolan Miombo forests, however, none have attempted to offer forest management solutions for degraded Miombo forests. Landscapes are witness to past and present natural and social processes influencing the environment, where each period in the past leaves footprints on the landscape's development, which can be described by a continual decrease in forest area over time. The expansion of degraded areas from 2000 to 20017 began near urban areas where many Miombo forests have been eliminated or highly degraded, particularly in the southwest and northeast of the Huambo province. Large areas of degraded forests were observed along the Benguela railway (Caminho de ferro de Benguela). Our detailed analysis of the landcover map suggests that the impact has been devastating and there is no form of forest protection, which leads to unregulated exploitation. Descriptions of the Miombo forest dynamics are explained using height-diameter curves developed for different vegetation types that provide important insights about forest structures in the management zones. The height-diameter models differed for all vegetation types, and four management zones (MZ) were created based on a set of particular attributes. The vegetation types differed in each management zone, which included agricultural land and bare soil (MZ-E), grassland or savanna (MZ-C), open Miombo forests (MZ-B), and closed Miombo forests (Miombo forests). The four management zones were easily identified on the available maps and the height-diameter models developed represent a fundamental tool for future studies on forest planning.Sustainability 2019, 11, 98 2 of 20 agreed definition of forest degradation which makes the discussion more complex [3]. Deforestation is considered the result of the clearing of land for agriculture [4], both for the large-scale production of global commodities [5,6] and, in Africa, for small-scale production of food and cash crops [7]. Deforestation is among the most commonly studied phenomena in the frontier literature, as it is often associated with negative impacts on the global climate and biodiversity [6,8]. The scale of the environmental legacy of deforestation is dependent on both the magnitude and timing of historic land cover changes, not merely the snapshot of forest cover that is directly observable today [9][10][11][12][13][14]. The most important anthropogenic alterations of natural environments have always been the clearing of forests to establish cropland and pasture, and the exploitation of forests for fuelwood and construction materials. Analysing landscape changes due to past and present natural and social processes at different scales over time constitutes the departure point for landscape management because of close links between forests and physical attributes of the landscape. The mix of LC and LU (landscape composition) usually includes agricultural lands and native vegetation, and human dwellings in villages and urban areas. Th...

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“…The military conflict during 1961 to 2002 drove mass migrations from rural areas to the region's urban centres and coastal cities, including the capital Luanda. This exodus created strong commercial ties between the highland region and the coastal economic centres (Delgado-Matas and Pukkala 2012). The highlands are currently home to around 2.86 million people, mostly from the Umbundu ethnic group, of which 48.7% live in rural areas (INE 2012).…”

Section: Land Use Changes In Angolan Highlandsmentioning

confidence: 99%

“…This area covers 7,904,000 ha of flat plateau crossed with valleys and low hills with an altitude of up to 1500 m. Annual precipitation varies between 1100 and 1400 mm. Soils are mainly acidic (pH 5.5-6.5) and have a low nutrient content (Diniz 1973;Delgado-Matas and Pukkala 2012). During the colonial period, the area was densely populated, and inhabited by a third of Angola's rural population.…”

Section: Study Areamentioning

confidence: 99%

“…Increasing prices of cash crops in the urban centres will increase the demand on sites with the highest LEV under cash crop cultivation regimes, i.e., Ombanda and Onaka sites. These site classes are not abundant in the region, which could create conflicts related to the ownership of these sites, conflicts between community and individual rights (Deininger and Castagnini 2006;Delgado-Matas and Pukkala 2012), and occupation of underutilized former European farms. This study findings eventually can be considered for a larger geographical scope of southern Africa highlands and other inter-tropic regions.…”

Section: Analysis Of Main Findings On This Researchmentioning

confidence: 99%

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

Delgado-Matas¹

2015

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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 short-and 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.Keywords: Land use management, Pinus spp., Eucalyptus spp., linear programming, growth models, Umbundu Land Use System (ULUS). ABSTRAKTIVäitöskirjan tutkimuskokonaisuus kattaa yhden julkaisun perinteisestä maankäyttösysteemistä Angolan ylänkömailla, kolme julkaisua yhdeksän trooppisen mäntylajin ja kuuden eukalyptuslajin kasvusta ja tuotoksesta, sekä yhden julkaisun maankäytön optimoimisesta Angolan ylänkömailla. Maankäyttösysteemien analyysin aineisto on peräisin kahden vuoden kenttätyöstä ja kirjallisuuskatsauksesta, joka ulottuu aina siirtomaa-aikoihin. Kasvumallit perustuivat 19,388 läpimitankasvuhavaintoon 1,059:sta männystä ja 10,499 läpimitankasvuhavaintoon 803 eukalyptuksesta. Vaihtoehtoisten maankäyttömuotojen optimaalinen kombinaatio haettiin lineaarisella ohjelmoinnilla (LO). LO-ongelmat muodostettiin tämänhetkistä ruokavaliota tavoittelevalle maankäytölle, parannetulle ruokavaliolle sekä vaihtoehdolle, jossa maksimoidaan puuntuotosta niin, että ruuan tuotanto paikalliselle väestölle on samalla riittävää.Ensimmäisellä tutkimuksella on vaikutuksia maankäytön suun...

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Growth and yield of nine pine species in Angola

Cited by 7 publications

References 12 publications

Dynamic Patterns of Trees Species in Miombo Forest and Management Perspectives for Sustainable Production—Case Study in Huambo Province, Angola

Dynamic Patterns of Trees Species in Miombo Forest and Management Perspectives for Sustainable Production—Case Study in Huambo Province, Angola

Defining Deforestation Patterns Using Satellite Images from 2000 and 2017: Assessment of Forest Management in Miombo Forests—A Case Study of Huambo Province in Angola

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

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