On-farm tree planting and tree diversity in the Kigezi Highlands and Mabira Buffer Zones

A study was conducted on 105 farms around Bwindi Impenetrable National Park (BINP), Mgahinga Gorilla National Park (MGNP), Echuya and Mabira forest reserves between February and June 2000 to assess on farm tree planting and tree diversity. Group discussions and interviews were used to collect information on the following: farming history and land tenure, method of land acquisition, agricultural crops grown, tree species planted and those growing naturally, uses of trees and constraints to tree planting. On-farm survey was conducted to collect information on land size, tree diversity and management and the proportion of land under tree cover. The average land holding is 4.04 ha around BINP, MGNP and Echuya forest reserve and 13.63 ha around Mabira forest reserve. Land is bought or inherited in fragmented form. Less than 10% of the farms are under tree cover and 71% of the trees planted around BINP, MGNP and Echuya forest reserve are indigenous, whilst 31% are indigenous around Mabira forest reserve. The average number of tree species per farm around BINP was 11.43, MGNP 7.06, Echuya forest reserve 6.93 and Mabira forest reserve 10.26. It is concluded that farmers are willing to plant trees on their farms but the constraints to tree planting are lack of planting stock, small land sizes, poor extension service and farmers* perception that agricultural crops cannot be integrated with trees on the same piece of land

Effects of plant morphology on vegetation resistance, resilience and tolerance in Mabira forest reserve

A study was conducted in Mabira Forest Heserve between 1999 and 2001 to evaluate the J'csistance, tolerance and resilience of vegetation to human trampling. Trampling experiments were conducted in live lanes measuring 0.5 x 1.5 m in a Paspalum dominated grassland and a ]u.Hicia dominated secondary forest. Each lane •·cccived 25, 50, 200 and 500 tlasses. Measurements were taltcn em each lane on two adjaccnt30 x SO em sub-plots. The cover of each vascular plant species was cstimlltcd. The relative vegetation cove•· was computed as a measure of vegetation change. The hypothesis tested is that plant morphology is responsible fo1· val'ialions in vegetation response to different levels of trampling stress. The JusticiaSynedrel/a dominated herbaceous vegetation was more resistant, tolerant and resilient to IJ·ampling than the Paspalum dominated grassland. However there is a need to repeal the trampling experiment in situations with similar and or different vegetation types befo1·e the method can be adopted as a standard protocol for studying vcgellltion response to human trampling in forest recreation sites

Tree species diversity and abundance in coffee farms adjacent to areas of different disturbance histories in Mabira forest system, central Uganda

Coffee production in Uganda is done on small-scale farms containing a very significant tree component. However, there is little information on how tree species abundance, richness and diversity change in coffee farms as distance from forest changes. The main objectives of this study, therefore, were to assess (a) abundance and (b) diversity of tree species in the coffee production systems in proximity to disturbed and undisturbed forest around Mabira forest, one of Uganda's Robusta coffee-growing areas. Seventy-nine 0.1 ha plots were established in nine villages close to undisturbed and disturbed forest, and over 5 km from the forest. A total of 875 trees belonging to 63 species were recorded. There was significant similarity in species composition among the three study sites (analysis of similarity R = 0.09, p < 0.01; analysis of variance: F3,12 = 0.353, p = 0.79). Non-metric dimensional scaling supported these findings (stress value = 0.224 at k = 2) and showed that tree species composition in the three proximity categories was very similar. These results demonstrate that tree species composition and diversity is similar in coffee farms regardless of their distance from the nearest natural forest and forest exploitation history. (Résumé d'auteur

Assessing processes of long-term land cover change and modelling their effects on tropical forest biodiversity patterns – a remote sensing and GIS-based approach for three landscapes in East Africa: Assessing processes of long-term land cover change and modelling their effects on tropical forest biodiversity patterns – a remote sensing and GIS-based approach for three landscapes in East Africa

The work describes the processing and analysis of remote sensing time series data for a comparative assessment of changes in different tropical rainforest areas in East Africa. In order to assess the effects of the derived changes in land cover and forest fragmentation, the study made use of spatially explicit modelling approaches within a geographical information system (GIS) to extrapolate sets of biological field findings in space and time. The analysis and modelling results were visualised aiming to consider the requirements of three different user groups. In order to evaluate measures of forest conservation and to derive recommendations for an effective forest management, quantitative landscape-scale assessments of land cover changes and their influence on forest biodiversity patterns are needed. However, few remote sensing studies have accounted for all of the following aspects at the same time: (i) a dense temporal sequence of land cover change/forest fragmentation information, (ii) the coverage of several decades, (iii) the distinction between multiple forest formations and (iv) direct comparisons of different case studies. In regards to linkages of remote sensing with biological field data, no attempts are known that use time series data for quantitative statements of long-term landscape-scale biodiversity changes. The work studies three officially protected forest areas in Eastern Africa: the Kakamega-Nandi forests in western Kenya (focus area) and Mabira Forest in south-eastern Uganda as well as Budongo Forest in western Uganda (for comparison purposes). Landsat imagery of in total eight or seven dates in regular intervals from 1972/73 to 2003 was used. Making use of supervised multispectral image classification procedures, in total, 12 land cover classes (six forest formations) were distinguished for the Kakamega-Nandi forests and for Budongo Forest while for Mabira Forest ten classes could be realised. An accuracy assessment via error matrices revealed overall classification accuracies between 81% and 85%. The Kakamega-Nandi forests show a continuous decrease between 1972/73 and 2001 of 31%, Mabira Forest experienced an abrupt loss of 24% in the late 1970s/early 1980s, while Budongo Forest shows a relatively stable forest cover extent. An assessment of the spatial patterns of forest losses revealed congruence with areas of high population density while a spatially explicit forest fragmentation index indicates a strong correlation of forest fragmentation with forest management regime and forest accessibility by roads. For the Kenyan focus area, three sets of biological field abundance data on keystone species/groups were used for a quantitative assessment of the influence of long-term changes in tropical forests on landscape-scale biodiversity patterns. For this purpose, the time series was extended with another three land cover data sets derived from aerial photography (1965/67, 1948/(52)) and old topographic maps (1912/13). To predict the spatio-temporal distribution of the army ant Dorylus wilverthi and of ant-following birds, GIS operators (i.e. focal and local functions) and statistical tests (i.e. OLS or SAR regression models) were combined into a spatial modelling procedure. Abundance data on three guilds of birds differing in forest dependency were directly extrapolated to five forest cover classes as distinguished in the time series. The results predict declines in species abundances of 56% for D. wilverthi, of 58% for ant-following birds and an overall loss of 47% for the bird habitat guilds, which in all three cases greatly exceed the rate of forest loss (31%). Additional extrapolations on scenarios of deforestation and reforestation confirmed the negative ecological consequences of splitting-up contiguous forest areas but also showed the potential of mixed indigenous forest plantings. The visualisation of the analysis and modelling results produced a mixture of different outcomes. Map series and a matrix of maps both showing species distributions aim to address scientists and decision makers. The results of the land cover change analysis were synthesised in a map of land cover development types for each study area, respectively. These maps are designed mainly for scientists. Additional maps of change, limited to a single class of forest cover and to three dates were generated to ensure an easy-to-grasp communication of the major forest changes to decision makers. Additionally, an easy-to-handle visualisation tool to be used by scientists, decision makers and local people was developed. For the future, an extension of this study towards a more complete assessment including more species/groups and also ecosystem functions and services would be desirable. Combining a framework for land cover simulation with a framework for running empirical extrapolation models in an automated manner could ideally result in a GIS-based, integrated forest ecosystem assessment tool to be used as regional spatial decision support system.Die Arbeit beschreibt die Prozessierung und Analyse von Fernerkundungs-Zeitreihendaten für eine vergleichende Abschätzung von Veränderungen verschiedener tropischer Waldökosysteme Ostafrikas. Um Effekte der Veränderungen bzgl. Landbedeckung und Waldfragmentierung auf Biodiversitätsmuster abzuschätzen, wurden verschiedene räumlich explizite Modellierungssätze innerhalb eines geographischen Informationssystems (GIS) zur räumlichen und zeitlichen Extrapolation biologischer Felderhebungsdaten benutzt. Die Visualisierung der Analyse- und Modellierungsergebnisse erfolgte unter Berücksichtigung der Bedürfnisse von drei verschiedenen Nutzergruppen. Um Waldschutzmaßnahmen zu evaluieren und Empfehlungen für ein effektives Waldmanagement abzuleiten, sind quantitative Abschätzungen von Landbedeckungsveränderungen sowie von deren Einfluss auf tropische Waldbiodiversitätsmuster nötig. Wenige fernerkundungsbasierte Studien haben jedoch bislang alle der folgenden Faktoren berücksichtigt: (i) Informationen zu Veränderungen von Landbedeckung und Waldfragmentierung in dichter zeitlicher Sequenz, (ii) die Abdeckung mehrerer Jahrzehnte, (iii) die Unterscheidung zwischen mehreren Waldformationen, und (iv) direkte Vergleiche von unterschiedlichen Fallstudien. Hinsichtlich Verknüpfungen von Fernerkundung mit biologischen Felddaten sind bisher keine Studien bekannt, die Zeitreihendaten für quantitative Aussagen zu Langzeitveränderungen von Biodiversität auf Landschaftsebene verwenden. Die Arbeit untersucht drei offiziell geschützte Gebiete: die Kakamega-Nandi forests in Westkenia (Hauptuntersuchungsgebiet) sowie Mabira Forest in Südost-Uganda und Budongo Forest in West-Uganda (zu Vergleichszwecken). Es wurden Landsat-Daten für insgesamt acht bzw. sieben Zeitpunkte zwischen 1972/73 und 2003 in ungefähr gleichen Abständen erworben. Mit Hilfe von überwachten, multispektralen Klassifizierungsverfahren wurden für die Kakamega-Nandi forests und Budongo Forest jeweils 12 Landbedeckungsklassen (sechs Waldformationen) und für Mabira Forest zehn Klassen unterschieden. Eine Genauigkeitsprüfung mit Hilfe von Fehlermatrizen ergab Gesamtklassifizierungsgenauigkeiten zwischen 81% und 85%. Die Kakamega-Nandi forests sind durch eine kontinuierliche Waldabnahme von 31% zwischen 1972/73 und 2001 gekennzeichnet, Mabira Forest zeigt einen abrupten Waldverlust von 24% in den späten 1970ern/frühen 1980ern, während die Ergebnisse für Budongo Forest eine relativ stabile Waldbedeckung ausweisen. Während eine Abschätzung der räumlichen Muster von Waldverlusten eine hohe Deckungsgleichheit mit Gebieten hoher Bevölkerungsdichte ergab, deutet die Anwendung eines räumlich expliziten Waldfragmentierungsindexes auf eine starke Korrelation von Waldfragmentierung mit der Art von Waldmanagement sowie mit der Erreichbarkeit von Wald über Straßen hin. Um den Einfluss von Langzeit-Landbedeckungsveränderungen auf Biodiversitätsmuster auf Landschaftsebene für das kenianische Hauptuntersuchungsgebiet quantitativ abzuschätzen wurden drei Datensätze mit biologischen Felderhebungen zur Abundanz von Schlüsselarten/-gruppen verwendet. Zu diesem Zweck wurde die Zeitreihe zunächst um drei weitere Landbedeckungs-Datensätze ergänzt, die aus Luftbildern (1965/67, 1948/(52)) bzw. alten topographischen Karten (1912/13) gewonnen wurden. Zur Vorhersage der raum-zeitlichen Verteilung der Treiberameise Dorylus wilverthi wurden GIS-Operatoren und statistische Tests (OLS bzw. SAR Regressionsmodelle) in einem räumlichen Modellierungsablauf kombiniert. Abundanzdaten von drei sich hinsichtlich ihrer Abhängigkeit von Wald unterscheidenden Vogelgilden wurden direkt auf fünf Waldbedeckungsklassen hochgerechnet, die in der Zeitreihe unterschieden werden konnten. Die Ergebnisse prognostizieren Abundanzabnahmen von 56% für D. wilverthi, von 58% für Ameisen-folgende Vögel und einen Gesamtverlust von 47% für die Vogelgilden, was in allen drei Fällen eine deutliche Überschreitung der Waldverlustrate von 31% darstellt. Zusätzliche Extrapolationen basierend auf Szenarien bestätigten die negativen ökologischen Konsequenzen der Zerteilung zusammenhängender Waldflächen bzw. zeigten andererseits das Potential von Aufforstungen mit einheimischen Arten auf. Die Visualisierung der Analyse- bzw. Modellierungsergebnisse führte zu unterschiedlichen Darstellungen: mit einer Reihe von nebeneinander positionierten Einzelkarten sowie einer Matrix von Einzelkarten, die jeweils Artenverteilungen zeigen, sollen Wissenschaftler und Entscheidungsträger angesprochen werden. Aus den Ergebnissen der Landbedeckungsanalyse für die drei Untersuchungsgebiete wurden Landbedeckungsveränderungstypen generiert und jeweils in einer synthetischen Karte dargestellt, die hauptsächlich für Wissenschaftler gedacht sind. Um die wesentlichen Waldveränderungen auch auf einfache Weise zu den Entscheidungsträgern zu kommunizieren, wurden zusätzliche Karten erstellt, die nur eine aggregierte Klasse „Waldbedeckung“ zeigen und jeweils auf drei Zeitschritte der Zeitreihen begrenzt sind. Zusätzlich wurde ein leicht zu bedienendes Visualisierungstool entwickelt, das für Wissenschaftler, Entscheidungsträger und die lokale Bevölkerung gedacht ist. Für die Zukunft wäre eine umfassendere Abschätzung unter Berücksichtigung zusätzlicher Arten/-gruppen sowie auch Ökosystemfunktionen und –dienstleistungen wünschenswert. Die Verknüpfung einer Applikation zur Landbedeckungsmodellierung mit einer Applikation zur Ausführung von empirischen Extrapolationsmodellen (in stärkerem Maße automatisiert als in dieser Arbeit) könnte im Idealfall in ein GIS-basiertes Tool zur integrativen Bewertung von Waldökosystemen münden, das dann als räumliches Entscheidungsunterstützungssystem verwendet werden könnte

Rainforest change analysis in Eastern Africa : A new multisourced, semi-quantitative approach to investigating more than 100 years of forest cover disturbance

Forest change and disturbance of the past strongly influence the state of today’s forests and their biodiversity. However, knowledge of former forest landscape states can be subject to misunderstanding and the practical management of forests requires the establishment of correct narratives of forest cover change. This thesis therefore investigates the long-term forest change and anthropogenic factors at work within three tropical rain forests of high biodiversity and high use value in Kenya and Uganda. A wide range of data sources are employed for a semi-quantitative analysis. Starting from an existing time series of satellite imagery classifications the research incorporates the visual interpretation of historical aerial photography, forestry records, maps of both topographic and thematic type, archive documents, oral histories, place name meanings, and fossil pollen evidence. GIS is used as the means to manage and focus the evidence and to analyse the wide range of data. In combination the sources allow the building of a narrative characterised by variation across both space and time. The localised reality of forest change is reflected in the inclusion of case studies from which forest narratives of each of the three main forest areas are subsequently constructed. The forest cover time series are extended back to around 1910 for each of the forests and thus to a pre-commercial exploitation state; they reveal losses of 60% and 43% of the forests of Kakamega-Nandi and Mabira respectively. These losses have been arrested in recent years while Budongo Forest has shown negligible change across the full period with the first losses recently occurring outside the forest reserves. The long-term approach has revealed fluctuations in forest cover, most notably in Mabira Forest across the 20th century and in parts of the Kakamega-Nandi area both across decades and across millennia. A landscape view shows these areas to have long-existed as mosaics of forest, woodland and grassland, and the loss of grassland over the last century has exceeded that of forest. The study identifies an historic role for disease and tribal conflict in the creation and protection of forest cover in East Africa but also traces a development in the underlying causes of forest cover change towards commercial and governance factors. The creation of a population time series demonstrates that population density cannot be described as the main driver of deforestation. Two spatially-explicit indices distinguish between locally and commercially-driven disturbances and are compared with an index of forest cover change. Results reveal a localised pattern and that commercial disturbance has played an especially large role in the degradation and fragmentation of the Kakamega-Nandi forests while local disturbance is shown to be most dramatic in Mabira Forest. Most of Budongo Forest has been persistently degraded by systematic commercial exploitation. It is suggested that these forests should be managed with recognition of their mosaic heritage but also as dynamic and changing entities. The study concludes that while the heterogeneity found within forest landscapes is often due to human disturbance, ecologists should also consider natural processes, including variations in past climate, for explanations. The cumulative nature of disturbance is highlighted with the recommendation that past commercial exploitation should be included in any assessment of forest degradation. The use of GIS and the creation of disturbance indices is recommended as a viable means of quantitatively assessing forest degradation and of distinguishing between the contributions of different types of disturbance. The most under-used resources available for researching long-term forest change are stated to be topographic maps and forestry archives. The quantitative data they provide can be usefully supported by qualitative information, most flexibly provided by forest history interviews

Saving Mabira Rainforest: Using Public Interest Litigation in Uganda to Save Mabira and Other Rainforests

In August 2011, President Yoweri Kaguta Museveni announced that he planned to give away part of Mabira rainforest to a sugar corporation to grow a sugarcane plantation and enhance sugar production in the country. The President had made a similar proposal in 2007 and only abandoned it after public and environmental groups received it with immense resistance. The Ugandan government has also given away other forest land to private investors, including parts of Bugala Island in Lake Victoria to a vegetable company to grow palm trees. This Note argues that the Ugandans opposed to the give-away of forest land to private companies can bring public interest litigation under Article 50 of the Uganda Constitution. The Note further proposes that to save private forests, Uganda should seek guidance from U.S. case law on applying the public trust doctrine to trust resources on private property

PROTECTION OF FOREST RESOURCES UNDER INTERNATIONAL LAW: A CASE OF MABIRA FOREST IN UGANDA

Mabira forest is a tropical high forest resource within Uganda. Forestry biodiversity is the total variety of living organisms that exist in a forested area and includes plants, animals, fungi, and microbes among others. Uganda is blessed with diversity of natural habitats, species and genetic resources in its forests and it is one of the most diverse countries in Africa, with 11% among others. Uganda is blessed with diversity of natural habitats, species and genetic resources in its forests and it is one of the most diverse countries in Africa, with 11% and 7% of the world‘s bird and mammal species respectively.1 The importance of these forests goes beyond the national jurisdictions. It benefits the globe. This pushes emphasis on sustainable forest management and development