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P.D. JENKINS AND S.M. GOODMAN 



Fig. 5 View down old road in the Vohibasia Forest that was cut for geological exploration. Note the relatively dense understorey and sandy soils lacking 

 leaf litter or humus. The trapping site of Microgale nasoloi was to the right of the road and about 10 m into the forest. (Photograph by S. M. Goodman). 



isolated mountain of Analavelona rising to over 1300 m (FTM, 

 1979). On the basis of earlier botanical classifications, Humbert & 

 Cours Darne (1965) described the upper zone of the Analavelona 

 Forest as low sclerophyllous forest ('Foret basse sclerophylle'), 

 surrounding areas of low-lying forests to the east (e.g. Zombitse- 

 Vohibasia) as dry dense forest ('foret dense seche') and to the west 

 as Didiereaceae and Euphorbia bush ('Didiereacees et Euphorbia 

 haut fourre'). The nearest low sclerophyllous forest to the 

 Analavelona Massif is in the Isalo range, about 110 km to the east. 

 Thus, according to this classification the massif holds a different 

 flora from the immediately surrounding forests. 



On the eastern side of the Analavelona Massif the foothills start at 

 about 600 m, and the lower limit of the forest is at about 1000 m and 

 runs to the upper reaches of the mountain. On the basis of botanical 

 research conducted in this forest by Nathalie Messmer and Pierre 

 Jules Rakotomalaza during the March 1998 expedition to the site, in 

 the lower altitudinal portion of the forest massive emergent Ficus 

 and Eugenia trees with diameter at breast height of 95-1 10 cm reach 

 heights of up to 25 m. The generic composition of these forest trees 

 indicate that the site is a mixture of eastern humid and western 

 deciduous forest. Considerable ground humus and leaf litter and 

 some epiphytic plants are present, the understorey is open and small 

 streams drain the steep hills. These characteristics are unlike 

 sclerophyllous forest, therefore the classification presented by 

 Humbert & Cours Darne (1965) for Analavelona is inaccurate, 

 although it is possible that the final summital ridge of the mountain 

 is dominated by sclerophyllous plants. On the basis of numerous 

 phytological characteristics the portion of the forest that we visited 



is much closer to Humbert & Cours Darne's mid-elevation humid 

 forest ('types humides, moyenne altitude (800-1300 m)'). In sum- 

 mary, the forested portion of the Analavelona Massif is heterogenous 

 with regards to vegetative structure, particularly differences be- 

 tween the western and eastern slopes (Koechlin et al„ 1974). 



The Analavelona Massif is distinctly moister than any other 

 region of southwestern Madagascar that we are aware of, including 

 portions of the Isalo Massif. Presumably on the basis of orographic 

 position, Analavelona receives regular and considerable precipita- 

 tion and even during the dry season the summital zone is often 

 shrouded in mist. The extant fauna and flora contain elements that 

 indicate that this site may be a refuge for biota that had much more 

 extensive distributions in southwestern Madagascar when this re- 

 gion was moister in the relatively recent geological past (Raxworthy 

 and Nussbaum, 1997; Goodman, unpublished). The known small 

 mammal community of Analavelona is relatively depauperate and 

 consists of three tenrecid lipotyphlans (Tenrec ecaudatus, Echinops 

 telfairi and Microgale nasoloi), one soricid (Suncus madagas- 

 cariensis), one introduced murine rodent (Rattus rattus) and one 

 nesomyine rodent (Eliurus myoxinus) (Goodman, unpublished). 



Trapping 



Generally on Madagascar, pit-fall buckets have produced good 

 results in capturing ground-dwelling vertebrates, particularly rep- 

 tiles, amphibians, and lipotyphlans (Raxworthy & Nussbaum, 1994; 

 Goodman et ai, 1996). During the April 1993 mission to the 

 Zombitse Forest 528 pit-fall bucket days were amassed; in January 

 1996 in the Vohibasia Forest, 165 pit-fall bucket days; and in March 



