Previous Page Table of Contents Next Page

Chapter VII






  1. The pan-tropical sample survey demonstrates that forest and land use change information can be produced on a global basis in a cost-effective, timely and statistically sound manner. The detailed land cover classification and interdependent image interpretation approach provide consistent information on the change process and, thus, valuable insight into the nature of man-land interaction.

  2. If continued over time, such surveys would lend factual support to global environmental research and policy making through detailed description of the processes of change, and the quantification of essential parameters, on a reliable basis.

    (from FP124, p41:Conclusions)

  3. A comparison of the characteristics and results of the FORIS database and the RS survey shows that there is strong complementarity between the two approaches as well as close correlation between their results; these factors call for the integration and continuation of both approaches. The integration of the two data sets will result in: (i) more reliable prediction models and, consequently, more detailed, homogeneous and up-to-date country level data; and (ii) more efficient stratification systems to optimize future sample rounds and expansion of RS results.

  4. The de-centralized approach followed during all phases of the survey, from its design to its full implementation, has fostered the creation of a network of institutions and individuals from developing and developed countries. This network of experienced interpreters and advisers, coherently focused on operational forest resource monitoring, has not only contributed to the success of the completed survey but it also constitutes a very important human and institutional resource/reference for future monitoring efforts at both global and national level. The far reaching impact of this cumulative experience should not be considered a small achievement.

Recommendations for future action

  1. In view of the information needs of the international community and, in particular, of the studies on global change, it is recommended that the building up of a consistent and reliable time series of observations of forest and land use be continued. Such a time series should include return visits to part of the sampling units included in the first round and an increment in the sample, both in space (new rounds) and in time (three dates in selected sub-samples). Keeping this in view, it is recommended that further statistical designs and analytical systems for a series of transition matrices be developed.

  2. It is recommended that the efficiency of the survey design be improved, by:

  3. it is recommended that in future survey rounds important improvements be made in ensuring satellite image quality and that more resources be invested in field verification and accuracy assessment. Improved spatial and spectral resolution of new and future satellites, associated with multi-temporal processing techniques of co-registration, will guarantee better image quality and, consequently, more accurate interdependent interpretation results. Field verification and accuracy assessment should be carried out more regularly with special attention to areas of complex and poorly discernible land cover1

  4. In order to permit the widest possible use and deeper analysis of results obtained, it is recommended that the RS survey be complemented with other data collected at field level:

  5. In order to respond to the issues mentioned above it is recommended that a multi-phase survey design, aimed at providing reliable data on the state and change of area, biomass and biodiversity for forests and other land cover/uses, be developed and implemented. A three-phase survey design is recommended:

phase I:wall-to-wall information (NOAA AVHRR classifications, FORIS spatial and statistical databases);
phase II:remote sensing sample, based on multi-date Landsat images;
phase III:field inventory sub-sample data.

Such a comprehensive approach is the only one that would allow the expansion of field information to wall-to-wall pan-tropical and global levels, with known level of reliability and in a timely, cost-effective manner. There is sufficient experience for the first two phases, that can be linked with minor effort, while the development of the field phase, providing ground truth and essential data on biomass, biodiversity and socio-economy, is at present the most challenging element in view of its operational complexity. For this third phase, a series of pilot projects in cooperation with national institutions is recommended, during which flexible and consistent field survey designs will be developed and tested.

  1. In view of the positive response to regional workshops and in order to enhance country capacity in producing reliable national change estimates, the further dissemination of sound monitoring procedures, such as the interdependent remote sensing analysis, and the promotion of its implementation to obtain location-specific information to support policy decisions, are recommended. It is also further recommended that at country level the classification system adopted in response to local needs be maintained compatible to the standard global classification system, in order to ensure full contribution of country-level data to the global data base.

1 Provisions for these improvements are already included in the FAO Project Proposal G.5221 “Programme for Continuous Assessment of Tropical Forest Resources using High Resolution Satellite Data”.

Previous Page Top of Page Next Page