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-Number of trees per hectare (dbh >10 cm) in Manongarivo Special Reserve and in low elevation rainforests sites along the east coast of Madagascar.
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A forest inventory was conducted in lowland rainforest on the southwestern border of Manongarivo Special Reserve, nothwestern Madagascar. At 220 m elevation, a one hectare area (20 X 500 m) was sampled for all trees with a dbh of 10 cm or more. 90 species represented by 728 individuals, with a total basal area of 22.4 m2ha, were recorded in the plo...
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Citations
... is adapted to Sambirano's moist evergreen forests, but it apparently never dispersed to the Eastern Domain, nor did any close relative succeed in colonizing the moist evergreen forests. The central mountain range, despite being only 70 km wide and rarely exceeding 2000 m elevation, seems to act as an effective dispersal barrier between the two homologous lowland moist evergreen forests of Sambirano and the East, considered as distinct phytogeographic entities (Humbert, 1955;D'Amico & Gautier, 2000;Gautier & Goodman, 2003). Symmetrically, the eastern rainforest is inhabited by species such as C. antongiliense, C. apollonioides, C. ludiifolium, and C. tampinense that have long fusiform seeds, which could be adapted to large-bird dispersal following ingestion without preliminary mastication. ...
The Malagasy genus Capurodendron currently accommodates 26 described species and is the largest genus of the family Sapotaceae in Madagascar. These species are frequently logged because of their valued hardwood, which potentially puts them at risk of extinction. Species‐level identifications are often problematic, and this hinders both an accurate assessment of their conservation status and the development of effective protection measures. We sorted all the material (ca. 860 collections) available in the herbaria with significant collections for Madagascar into 47 putative species based on morphology. On 41 of these, for which we were able to retrieve suitable DNA, we conducted a phylogenetic reconstruction based on molecular sequences of 638 loci from 108 Capurodendron specimens, performing a target capture approach combined with next‐generation sequencing. Maximum likelihood (RAxML), pseudocoalescence (ASTRAL), and coalescence (STACEY) analyses showed that Capurodendron comprises two deeply divergent lineages. One, which includes a single species, is here newly described as C. subg. Reflexisepala based on its distinctive morphology. The second lineage contains all remaining species, which seem to have resulted from a rapid radiation event. The phylogenetic tree provides good support for most of the species hypothesized based on morphology, with the exception of two species‐groups that we have named the Arid Complex and the Eastern Complex. As many as 20 species‐level lineages genetically distinct from any of the currently recognized species were identified, 17 of which were morphologically well‐characterized, representing strong candidates for new species. This would suggest that Capurodendron is the most species‐rich endemic genus of plants in Madagascar. While 14 of these 20 clades are still under study, we here describe six species new to science: Capurodendron andrafiamenae (provisionally assessed as CR), C. aubrevillei (VU), C. birkinshawii (CR), C. naciriae (EN), C. randrianaivoi (CR), and C. sakarivorum (EN). Capurodendron oblongifolium comb. nov. (EN), previously regarded as a variety of C. perrieri, represents a distinct lineage that is here recognized at the species level. The newly described species are illustrated by line drawings and photographs from the field, and a preliminary threat assessment is provided. We discuss the evolutionary history of Capurodendron and also explore the question of node age estimates and their methodological limitations.
... Rank abundance curves in vanilla agroforestry fields by farmer in Imorona, Mananara-Nord; dotted curved line represents rank abundance values for lowland rain forest in northwest Madagascar (D' Amico andGautier, 2000). ...
"In this remarkable blend of ethnography, landscape history, and economic botany, Sarah Osterhoudt invites readers to understand the 'happy landscapes' of carefully cultivated vanilla-producing agroforests in northeast Madagascar. Drawing on the author's five years in the coastal village of Imorona over a twelve-year period, this is also a unique and extended study in landscape epistemology and narration.It explores how local residents of various social positions, external conservation/development agents, a resident anthropologist, and biophysical scientists each come to know and to describe the culturally imbued land and forests of Madagascar." From book review in Journal of Political Ecology, by Laura M. Yoder
... Several studies on the structure and biodiversity have been realised in the low and middle altitudes forests of African, Malagasy and the Neotropic regions (Villanueva, 1991;Pichiger et al., 1992Pichiger et al., , 1996Lejoly, 1995;Rabevohitra et al., 1996;Sonke, 1998;Collin, 1998;Rakotomalaza and Messmer, 1999;D'Amico and Gautier, 2000;Senterre et al., 2004). These studies highlighted quantitative measures for families and the species diversities of these forest types. ...
... Nevertheless in the other central African forests, new species always occur in spite the altitude and of the inventoried surface. One can presume that 1-ha surface is suitable for the study (D'Amico and Gautier, 2000;Nusbaumer et al., 2005). (Collin, 1998), Bees forest, L.0 et L.8 (Gesnot, 1994), Monte Alè n (Van Reeth, 1997), Nsork (Senterre, 2005), Odzala, (Van Asbroeck, 1997). ...
... It is remarkable that in the Cameroonian highland forests, Rubiaceae seem to be more important than in Neotropical (capital) and African lowland forests. At Manengouba it is the first in FIV accumulation values (FIV: 56.19), while it is 4 th with an FIV of 21.23 at Manongarivo (D'Amico and Gautier, 2000), 6 th with an FIV value of 14.71 at Yasuni (Balslev et al., 1987),10 th with an FIV value of 8.3 at Alto Ivon (Boom, 1986), 14 th with an FIV value of 7.79 at Jenera Herrera (Spichiger et al., 1996). The scarcity of Rubiaceae is observed as recorded in many lowland forests (Table 9). ...
... A forest inventory in Andohahela, Madagascar (Rakotomalaza and Messmer, 1999) recorded a value of 38.8%. In our study, the percentage of species represented by only one individual (32.5%) is lower than those reported in the above mentioned studies and is close to the value reported in Messa -28 % - (Tagne, 2007), but higher than -21.1%- (D'Amico & Gautier, 2000) in Manongarivo;-21.1 % -(D'Amigo and Gautier, 2000), -22 % - (Spichiger et al., 1992) in Alto Parana and -12,5 % - (Madiapevo, 2008) in Kala. ...
This study aims to assess the vegetation structure and diversity of woody species in the mountain forest of mount Manengouba, and compare the values obtained with those from other tropical regions of the world.
A quantitative inventory of a 1-ha plot was achieved by plots of rectangles taking into account all trees whose diameter at breast height (DBH) was superior or equal to 10 cm, and the parameters of floristic diversity were calculated using the standard methodology.
A total of 763 trees, belonging to 40 species, were inventoried. The total basal area was 61.6 m²/ha.. Most of trees had between 10 and 15 m height and diameters between 10 and 20 cm, but an important number of individuals attained even higher values, up to 25 m height and 115 cm of diameter. The 4 most important families in terms of density, diversity and dominance were Rubiaceae, Euphorbiaceae, Araliaceae and Myrsinaceae. They represent 70.8% of the Family Importance Value (FIV). The specific composition reveals that a small number of common species dominate the forest, 15% of species represent 54.59% of the Index of Value Importance (IVI). They are Macaranga occidentalis, Rapanea melanophloeos, Maesa lanceolata, Polyscias fulva, Psydrax arnoldianu and Rothmannia urcelliformis. A fraction of species (32.5%) is only represented by 1 individual.
In conclusion, in the Manengouba montane forest the diversity is weak, the density and dominance are in the higher fringes of the values obtained in most forests of tropical regions of the world. The family Rubiaceae displaced the family Leguminosae in the Manengouba forest even though the Leguminosae is the most important family in the lower and sub mountain forests of the tropical regions of the world.
... Congolese and Afro-mountain areas towards 1800 to 2200 m. While following the suggested subdivision, one notes that the Cameroonian sub-mountain stages are easily attached, from the floristic point of view, to the forests of low and average altitudes of Africa, Madagascar and the Neotropical area (Villanueva, 1991; Spichiger et al., 1992, 1996; Lejoly, 1995; Rabevohitra et al., 1996; Sonke, 1998; Collin, 1998; Rakotomalaza and Messmer, 1999; D' Amico and Gautier, 2000; Senterre et al., 2004; Senterre, 2005). They made it possible to circumscribe quantitative values for the families and the species of these woodland types. ...
... Family importance value of the 15 most important plant families in Kouoghap and other (lowland) tropical forests mainly reported by D'Amico and Gautier (2000) ...
... A forest inventory in Andohahela, Madagascar, Rakotomalaza and Messmer (1999) recorded a value of 38.8%. At Manongarivo, Madagascar, the percentages of species represented by only one individual was 21.1% (D' Amico and Gautier, 2000 ...
Batoufam is a village of the high lands of the West of Cameroon, situated about 20 km to the South of Bafoussam (5°14' to 5°18' N latitude and 10°20' to 10°31' E longitude), inside the Batoufam-Bayangam caldeira of the volcanic massif of Bangou. The sacred forest Kouoghap (SF) is located on the south-eastern side of this caldeira at 1,450 to 1,550 m elevation. It is estimated today at 47 ha. The 2.5 ha sampling (10 plots of 25 x 100 m) includes all the trees of a diameter at breast height (DBH) of 10 cm or more. 3,173 trees and lianas belonging to 95 species and 31 families, with a total basal area of 90.37 m 2 /ha, were recorded. Most of the trees were between 10 to 20 m high, with a diameter of 10 to 20 cm. Some of them reach 25 to 30 m in height and 120 cm in diameter. The 6 most important families in terms of diversity, density and dominance are Meliaceae, Leguminosae, Moraceae, Sapotaceae, Rubiaceae and Bignoniaceae. Together they account for 57.31% of the total family importance values (FIV). In this forest, a few of the common species dominate: 11.57% of all species account for 52.34% of the total importance value index (IVI). Only 9.4% of species are represented by one individual. The species with higher IVI are: Syncepalum cerasiferum, Tricalysia macrophylla, Trilepisium madagascariense, Markhamia tomentosa, Funtumia africana, Vitex grandifolia, Lovoa trichilioides, Polyscias fulva, Dracaena arborea, Trichilia rubescens and Carapa grandiflora. The forest appears typical of Guinean lowland rainforest in general on one hand, and the altitude forests on the other hand. In this last option, it is worth noting that 4.2% of species are orophytes that occur widely in the austral and pantropical area, and 1.05% in the austral and subantartic area. These results permit SF Kouoghap to be placed in the archipelago Afro-Cameroonian highlander, according to the phytogeographic classification of White. The specific richness of the studied forest is lower than those of the equatorial rainforests.
New species to science are still being discovered and described, often from remote habitats. Madagascar is well known for its high species richness and exceptional levels of endemism across taxonomic groups. With an estimated 2,000 plant species still to be described from Madagascar, efforts are underway to gain better understanding of the Cyperaceae or sedges native to the island. Here, we describe and illustrate a new species of Scleria P.J. Bergius from a remote area in northern Madagascar. Using molecular data from the markers ITS, ndhF and rps16, we place the new species in Scleria sect. Abortivae Cherm. ex Bauters which is largely restricted in distribution to Madagascar. An identification key to the species of this section occurring in Madagascar is provided.
Global patterns of regional (gamma) plant diversity are relatively well known, but whether these patterns hold for local communities, and the dependence on spatial grain, remain controversial. Using data on 170,272 georeferenced local plant assemblages, we created global maps of alpha diversity (local species richness) for vascular plants at three different spatial grains, for forests and non-forests. We show that alpha diversity is consistently high across grains in some regions (for example, Andean-Amazonian foothills), but regional 'scaling anomalies' (deviations from the positive correlation) exist elsewhere, particularly in Eurasian temperate forests with disproportionally higher fine-grained richness and many African tropical forests with disproportionally higher coarse-grained richness. The influence of different climatic, topo-graphic and biogeographical variables on alpha diversity also varies across grains. Our multi-grain maps return a nuanced understanding of vascular plant biodiversity patterns that complements classic maps of biodiversity hotspots and will improve predictions of global change effects on biodiversity.
Biological conservation projects conducted in inhabited areas are often based on the combination of ecological diagnostics and study of practices and use of the environment by local communities. They less frequently integrate the influence of the perception and representation of nature on these practices, while these should also be taken into account in the initiation of sustainable conservation actions. We carried out a long-term study combining biological and social science approaches in North-western Madagascar in the Antrema protected area (with dry forest/savannah/coastal ecosystems), including an analysis of the use and perception of nature by its inhabitants. Together with the study of tree diversity, forest structure and biomass in 7 forest fragments, we estimated population densities of whole communities of diurnal and nocturnal lemurs, one of which is considered sacred. We interviewed local resource users from several villages using classical methods of social anthropology supplemented with perception tests derived from sensory evaluation methods. The structure of forest fragments as well as their basal area and richness in tree species varied with human pressure on specific plants (timber extraction) or with historical changes in pasture management (forest regrowth). Lemurs were generally abundant, with a high total biomass compared to other dry forests. Although the inhabitants of Antrema (Sakalava, Tsimihety, and Betsileo) still strongly adhered to local use rights and shared deeply rooted knowledge about the forest, the use and perception of nature (e.g., regarding the sacred lemur Propithecus coronatus) have changed since the Antrema protection project in 2000. The results suggest that local communities tend to integrate traditional rules about nature with international environmental regulation, perhaps a sign of a new ecological awareness. However, in the new management mode accompanying this transition, it can also be a means of local empowerment that takes advantage of a program supporting pro-environmental management of the Antrema area.
We recognize 30 species of the pantropical genus Xylopia L. from Madagascar and an additional three species from the Mascarene Islands. Of the six sections of the genus, three are represented in the region: sect. Xylopia, sect. Verdcourtia, and sect. Stenoxylopia. All species are endemic, and many are microendemics of conservation concern. The greatest species richness occurs in humid forests below 1000 m. Taxonomic review supports the hypothesis that the genus dispersed to Madagascar from continental Africa five times. Ten new species are described: Xylopia anomala D.M.Johnson & N.A.Murray, sp. nov., X. australis D.M.Johnson & N.A.Murray, sp. nov., X. carinata D.M.Johnson & N.A.Murray, sp. nov., X. galokothamna D.M.Johnson & N.A.Murray, sp. nov., X. lokobensis D.M.Johnson & N.A.Murray, sp. nov., X. longirostra D.M.Johnson & N.A.Murray, sp. nov., X. marojejyana D.M.Johnson & N.A.Murray, sp. nov., X. ravelonarivoi D.M.Johnson & N.A.Murray, sp. nov., X. retusa D.M.Johnson & N.A.Murray, sp. nov., and X. sclerophylla D.M.Johnson & N.A.Murray, sp. nov. An identification key, technical descriptions, illustrations, and distribution maps are provided.
1. Tropical cyclones (TCs) are large-scale disturbances that regularly impact tropical forests. Although long-term impacts of TCs on forest structure have been proposed, a global test of the relationship between forest structure and TC frequency and intensity is lacking. We test on a pantropical scale whether TCs shape the structure of tropical and subtropical forests in the long term. 2. We compiled forest structural features (stem density, basal area, mean canopy height and maximum tree size) for plants >= 10cm in diameter at breast height from published forest inventory data (438 plots >= 0.1ha, pooled into 250 1 x 1-degree grid cells) located in dry and humid forests. We computed maps of cyclone frequency and energy released by cyclones per unit area (power dissipation index, PDI) using a high-resolution historical database of TCs trajectories and intensities. We then tested the relationship between PDI and forest structural features using multivariate linear models, controlling for climate (mean annual temperature and water availability) and human disturbance (human foot print). 3. Forests subject to frequent cyclones (at least one TCs per decade) and high PDI exhibited higher stem density and basal area, and lower canopy heights. However, the relationships between PDI and basal area or canopy height were partially masked by lower water availability and higher human foot print in tropical dry forests. 4. Synthesis. Our results provide the first evidence that tropical cyclones have a long-term impact on the structure of tropical and subtropical forests in a globally consistent way. The strong relationship between power dissipation index and stem density suggests that frequent and intense tropical cyclones reduce canopy cover through defoliation and tree mortality, encouraging higher regeneration and turnover of biomass. The projected increase in intensity and poleward extension of tropical cyclones due to anthropogenic climate change may therefore have important and lasting impacts on the structure and dynamics of forests in the future.
