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In light of the significance that ecosystem service research is likely to play in linking conservation activities and human welfare, systematic approaches to measuring, modeling and mapping ecosystem services (and their value to society) are sorely needed. In this paper we outline one such approach, which we developed in order to understand the links between the functioning of the ecosystems of Tanzania’s Eastern Arc Mountains and their impact on human welfare at local, regional and global scales. The essence of our approach is the creation of a series of maps created using field-based or remotely sourced data, data-driven models, and socio-economic scenarios coupled with rule-based assumptions. Here we describe the construction of this spatial information and how it can help to shed light on the complex relationships between ecological and social systems. There are obvious difficulties in operationalizing this approach, but by highlighting those which we have encountered in our own case-study work, we have also been able to suggest some routes to overcoming these impediments.

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This study explores infestation density of Leptocybe invasa on five commercially grown Eucalyptus species in Coastal, Plateaux, and Southern Highlands agroecological zones of Tanzania. Infestation density between agroecological zones, Eucalyptus species, age classes and tree crown parts, relationship between stand altitudes and the magnitude of infestation, damage index, species age, and abundance of L. invasa on different Eucalyptus species were examined. There were significant differences in infestation between zones and Eucalyptus species. Eucalyptus tereticornis was more affected, followed by E. camaldulensis, and E. saligna was the least while E. grandis and E. citriodora were not affected. No significant differences in damage between different crown parts were observed. Trees with age of 1-3 yr were damaged more than those of age 4-6 yr. Pest infestation increased with an increase of L. invasa abundance but decreased with an increase of altitudes. Control efforts needs to focus on controlling the spread of the pest, using silvicultural methods and planting resistant Eucalyptus species.

The eastern arc mountains (EAMs) are a chain of isolated mountains (534,000 ha) in Kenya and Tanzania surrounded by arid woodlands and influenced by the Indian Ocean. In 1900 there was three times the amount of forest cover there is today. Much of the original forests have been converted into agricultural crops. These mountains are recognized as a globally important 'hot spot' by World Wide Fund for Nature (WWF) and World Conservation of Union (IUCN) for forest biodiversity and are major national, regional and local sources of hydropower, water and wide array of forest-based benefits and agricultural production. In February 2000 we began a 3-year evaluation of forest health, land-use change and information sharing in the EAMs. Permanent sample plots were used to evaluate forest health. This paper summarizes the baseline data from eighteen permanent sample plots in the east Usambara's and nine in Ulugurus. The eastern arc web site (http://www.easternarc.org) was established, continues to expand and contains some detailed information on the project. Information gathered will assist land managers, planners, policy makers, interested communities (villages) and individuals in decision-making. These data can also provide an early warning system of stresses on forest catchments.