Figure 7

<p>The four surveyed areas and estimates of human population density and distances to main roads as indicator of access to markets of forest products. Population censuses based on LandScan 2001 Global Population Database (Oakridge, TN: Oak Ridge National Laboratory <a href="http://www.ornl.gov/gist/" target="_blank">http://www.ornl.gov/gist/</a>). Map source: Foiben-Taosarintanin'i Madagasikara (FTM)</p

Figure 4

<p>In the NDVI analysis (Normalised Difference Vegetative Index), the dense mature forests show multiple peaks due to differences in species composition, the regenerating forest is separated with lower NDVI values, while degraded forest and open land has distinctly different patterns. The examples given here are subsets (1.5×1.5 km) from the 2000 Landsat 7ETM+image.</p

Figure 1

<p>The Androy region is situated in the southernmost part of Madagascar between Lat 24°13′ and 25°24′S and Long 45°20′ and 46°26′ E. Four areas (I–IV) were selected for detailed field investigations. Yellow squares with numbers indicate plots used in ground truthing.</p

Figure 8

<p>The relationship between forest cover change (%) during 1984–2000 in Androy, and human population density Population censuses based on LandScan 2001 Global Population Database (Oakridge, TN: Oak Ridge National Laboratory <a href="http://www.ornl.gov/gist/" target="_blank">http://www.ornl.gov/gist/</a>). The analysis was based on 1 km² plots (n = 564) throughout the area covered with forest either in 1984 or 2000.</p

Figure 2

<p>Pictures from the four surveyed areas a) degraded/thinned forest (Area I), b) regenerating forest (Area II), c) stable forest (Area III), d) forest patch protected by local taboos (Area IV). Pictures taken in January 2005.</p

Figure 6

<p>Changes in forest cover (ha) in the four surveyed areas (Area I–IV) based on analyses of Landsat images from 1984, 1993 and 2000.</p

Figure 5

<p>Time-series analysis of changes in forest cover based on satellite images (dry season synoptic views from 25 June 1984 (Landsat 5 TM), 15 April 1993 (Landsat TM) and 28 May 2000 (Landsat 7 ETM+) from Androy, southern Madagascar. Three patterns of forest cover change between 1984 and 2000 is presented: 1) red-reddish areas-loss of forest, 2) blue-bluish areas–increase of forest cover and 3) green areas–stable forest.</p

Ground truthing based on vegetation and demographic analyses in areas I (transect), II, III (plots 20×20 m) and IV (plots and transects see 24).

*<p><i>A. procera</i> produces clearly visible tree rings, which due to occasional supra-annual periods of draught, may not necessarily correspond to annual growth rings . The cores (0,5 cm in diameter) were drilled at breast height through the center of stems>10 cm dbh using a standard dendrochronology drill.</p

Figure 3

<p>The result of cluster-analyses (PAHC) of vegetation data and demographic data of <i>Alluaudia procera</i> from plots 20×20 m in regenerating (n = 5) and dense mature forests (n = 4) in northern central Androy. The distance is based on average group linkages. Variables included in the model: height, diameter, proportion of juveniles (<2 m) of <i>Alluaudia procera</i> and abundance estimates of woody species>1 m height. The analysis was used for validation of the forest classification in the Landsat images.</p