Uganda

Approaches to Land Cover / Land Use Trajectory Analysis

In Uganda, CIPEC researchers collaborate with colleagues from the Faculty of Forestry at Makerere University in Kampala (www.ufric.co.ug) to study a number of questions related to landscape change and how associated institutions affect these changes. The research is driven by broader questions that involve exploring the differences and similarities with change processes and institutions in the Western Hemisphere.

CIPEC's research in Uganda uses the methods of Remote Sensing and GIS analysis to map and monitor changes in forests and explores the causes and controls of land cover change across multiple scales of space and time. This information is vital in designing effective and equitable conservation policies and resource management strategies.

The CIPEC team is using pre-existing IFRI sites for many of the community and stand level studies, as well as a time series of remotely sensed images and GIS products (for information at broader scales). Ongoing research is now focused on spectral mixture analysis (SMA) for a quantitative analysis of change in above ground woody biomass. Such investigations of biomass change include understanding recent increases on edaphic grasslands and comparisons of biomass dynamics between forested and occupied lands. To understand biomass dynamics and other human-environment interactions, CIPEC researchers are investigating the relationship between the state and customary tenure systems of the Buganda Kingdom.

Current CIPEC research questions in Uganda:

1. Why have the boundaries of the state forest reserves of West Mengo (Mpigi) remained stable for 50+ years?
2. Have smallholders in the West Mengo (Mpigi) region maintained the flow of subsitence forest products to local users despite the great increase in demand for commercial fuelwood from Kampala over recent decades?
3. How have colonial and post-colonial state property rights arrangements been influenced by those of the traditional Buganda Kingdom? And, how do these explain biomass increases on occupied lands and boundary stability of state reserves?
4. What is the nature and magnitude of change in woody vegetation cover in Southern Uganda during the recent period of rapid growth in urban demand for fuel wood?

Interviews were conducted with key informants at community, sub-county, and district levels. This nested approach helped CIPEC researchers untangle the directional trends in woody cover occurring at different spatial scales. Archival research was also conducted to better understand the creation of the West Mengo (Mpigi) forest reserves, the decentralization of the colonial forest department, reserve demarcation, and reserve enforcement. Archival research also served to confirm findings derived from interviews with forest department officials regarding changes within the forest sector. These investigations also aided in understanding the relationship between state and customary tenure and administrative systems.

Investigating Human Causes of Land-Cover Change using Remote Sensing

Qualitative interpretations of multi-temporal composites from satellite images suggest that state institutions have largely maintained stable forest boundaries since their creation in the 1930's. Inspection of recent satellite images and aerial photographs suggests that woody biomass is increasing on populated agricultural lands of West Mengo (Mpigi District). Since 2001 CIPEC researchers have used a multi-disciplinary approach, which combines remotely sensed images, GIS coverages, and topographic maps in field surveys and key informant interviews. These datasets are useful for untangling the various mechanisms of observed land-cover change (or stability).

Nathan Vogt (IU/SPEA PhD candidate) discussing patterns of forest cover change during recent history with key informants (Photo by Joseph Bahati).

Multi-spectral color composite (January, 1995) Landsat TM Image (band 3 is blue, band 5 is green, and band 4 is red). In this composite forests are red and bare soil is blue. In the product the composite is draped over digital topography and displayed in an oblique orientation to aid key informants in locating their community on the landscape.

Boundaries of forest reserves have been stable for 45 years (between 1955 & 1995).

1950 Aerial Photograph	1995 Aerial Photograph

 

Landsat TM multi-temporal composite using the visible red bands where the 1974 band is set to blue, 1986 set to green, and 1995 set to red. In this composite stable forest is dark while recent cutting is depicted in red. Yellow lines mark the boundaries of the forest reserves. Blue lines delineate stable and enforced mailo (private) forest boundaries. This figure illustrates the awareness of and respect for reserve boundaries by the local population.

 

Linking Forest Cover and Biomass with Landsat Reflectance

Our research also hopes to establish the physical basis for spectral variation in vegetated terrains. We collected quantitative cover estimates in Uganda during the summer of 2003 in the field and using a small airplane. Hemispherical digital images were acquired from underneath canopies in which National Biomass Survey (NBS) 50x50m plots have been measured.

Joseph Bahati of the faculty of Forestry and Nature Conservation, Makerere University in Uganda and Nathan Vogt of CIPEC, collect reflectance spectra of soil in the equivalent bandwidths to those of Landsat Thematic Mapper satellite images. (Photo by Glen Green)

The photograph at left shows a typical view of a fallow field next to a forest (the photo at right). Banana and corn are also present. During these fallow periods fields are no longer actively cultivated though products may still be harvested from. Agricultural productivity revives during these periods. (Photos by Glen Green)

    

This is a hemispherical “fisheye” photograph was taken vertically from under a vegetation canopy in Uganda. Photographs like this one will be used to estimate the cover of vegetation on the landscape. This canopy is dominated by banana plants with are a source of a major food staple in Uganda. (Photo by Glen Green)

 

During several flights of a small airplane we also acquired high-resolution images over numerous NBS plots using a digital video camera, a still digital camera, a 35mm camera, and a portable spectrometer. Cover estimates will be made from these images and compared with NBS biomass and cover estimates. Reflectance spectra were also acquired with a field spectrometer using a lens and an integrating sphere; these measures will be compared with Landsat end-member images derived from Spectral Mixture Analysis (SMA). We hope these measures will provide more robust and objective ground truth data for mapping vegetation change in southern Uganda. (Photos by Glen Green)

 

    

High-resolution digital still image used to interpret the lower resolution satellite images. We will compare cover estimates from high resolution images acquired from an airplane like this one with estimates of cover based on analysis of Landsat images, thereby conducting ground-truthing for quantitative vegetation mapping in Uganda. (Photo by Glen Green and Nathan Vogt)

Publications:

Banana, A.Y., N.D. Vogt, W. Gombya-Ssembajjwe, and J. Bahati. Under review. Decentralization, Local Governance, and Forest Conditions: The Case of Forests in Mpigi District of Uganda. Submitted to World Development.

Vogt N.D, J. Bahati, J. Unruh, G.M. Green, A.Y. Banana, W. Gombya-Ssembajjwe, S. Sweeny. Under review. Untangling Mechanisms of Land-Cover Change: A Rapid, Policy-Relevant Analysis of Human-Environment Interactions at the Forest-Grassland Interface in Uganda. Submitted to Global Environmental Change: Human and Policy Dimensions.

Vogt, N.D., 2003. Understanding the Long Term Stability of the West Mengo (Mpigi) Forest Reserve Boundaries. CIPEC Working paper.

Uganda section of online supplement (by Nathan Vogt) to: Dietz, T., E. Ostrom, and P.C. Stern. The Struggle to Govern the Commons.  Science 2003 December 12; 302: 1907-1912.

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Last Updated: May 11, 2005
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