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The article reports the AMS (accelerator mass spectrometry) radiocarbon investigation of the historic Grand Baobab of Mahajanga. The largest African baobab of Madagascar exhibits a cluster structure, which consists of 6 fused ordinary stems and of 3 small binding stems. Two samples were collected from the largest stem and from a primary branch, out of which several tiny segments were extracted and dated by radiocarbon. The oldest dated sample segment had a radiocarbon date of 214 ± 17 BP, which corresponds to a calibrated age of 265 ± 25 calendar years. The dating results indicate that the Grand Baobab of Mahajanga is 275 ± 25 years old.

The article discloses the AMS (accelerator mass spectrometry) radiocarbon dating results of the Egg baobab, a superlative Grandidier baobab (Adansonia grandidieri) from the Andomiry Forest, Atsimo-Andrefana region, Madagascar. The investigation of the baobab shows that it consists of 5 perfectly fused stems and exhibits a closed ring-shaped structure with a very large false cavity inside. The calculated overall wood volume of the Egg baobab is 450 m3. Two wood samples were collected from the exterior of the stems, out of which nine tiny segments were extracted and dated by radiocarbon. The oldest sample segment had a radiocarbon date of 921 ± 24 BP, which corresponds to a calibrated age of 840 ± 25 years. According to this value the Egg baobab is 875 ± 75 years old.

Madagascar is one of the leader producer and exporter of lychee, clove and vanilla in the world. These three crops were introduced and developed on the east coast of Madagascar more than a century ago in the context of colonial agriculture. Since then, innovative complex agroforestry systems (AFS) were designed by smallholders that associate a high diversity of species and constitute the basis for the export of these products. In Atsinanana and Analanjirofo (literally : clove forest) regions, these AFS not only combine clove and lychee trees but also a high diversity of fruit and forest tree species, and herbaceous crops that are or have been of strategic economic importance such as vanilla, coffee or pepper. Some crops are also intended to feed the local market or the on-farm consumption as breadfruit, jackfruit, or sugarcane. Moreover these AFS provide a wide bunch of ecosystemic services for local population: the diversification process improves socio-economic resilience of vulnerable farmers by balancing incomes and providing numerous cultural, social and environmental services. The paper, based on numerous farm surveys and field observations in the areas of Toamasina and Fenerivo, proposes a typology of AFS, mainly characterized by structures (species composition and association) and practices. The diversity observed contributes significantly to the resilience of the socio-ecological system. In the future, the orientation of these socio-ecological systems toward more resilient trajectories will highly depend on the development of their capacities to reconcile the constraints of highly competitive international value chains such as lychee, clove or vanilla, which are greatly influenced by the demand located in developed and emerging countries, with the complexity of the existing systems.

Interactions between farmers and agrobiodiversity are key drivers of agroecosystems sustainability and of the resilience of such systems to perturbations, but research into the human/nature interactions have overlooked some important aspects of agrobiodiversity management. In particular, farmers' ecological knowledge of the spatial organisation of plant diversity remains an open question, although knowledge and practices have major implications for the efficient and sustainable use of natural resources. • Our study addresses this question by analysing how farmers spatially organise plant species in agroforests based on their knowledge of species interactions and interactions with the environment. The Analanjirofo region on the north-east coast of Madagascar provides an interesting context to explore this issue in clove-based agroforests, as these systems were developed by farmers as a sustainable alternative to the traditional system of shifting rice cultivation. • Using an emic approach, that is based on the farmers' perspective, and participatory mapping, we studied plant diversity and its spatial organisation in 17 clove-based agroforests and in 28 management sub-units defined by farmers in a village of Vavatenina district. The plant functions and farmers' knowledge of plant interactions with clove tree were recorded in semi-structured interviews, and the interactions were represented in a cognitive map. • Farmers manage more than 50 plant species associated with diverse functions. Analysis of participatory maps identified four main types of species association as a function of the age of the clove trees and the associated plant diversity, and different spatial organisation patterns as a function of the topography and the surrounding species. Analysis of farmers' knowledge provided valuable insights into spatial organisation practices, how farmers perceive the adaptation of plant species to biophysical heterogeneity of the environment and whether they can be asso

Over the past years, our research on baobabs mainly focused on the largest Malagasy species, namely the Reniala or Grandidier baobab (Adansonia grandidieri Baill.). The biggest A. grandidieri are located in the Morombe area, especially in the so-called Andombiry Forest. This giant forest of Reniala hosts well over 6000 mature individuals, out of which more than 30 have very large sizes, i.e., circumferences over 20 m. We investigated, measured and dated by AMS radiocarbon the largest specimens. We found that all large Grandidier baobabs are multi-stemmed. They mostly exhibit a closed ring-shaped structure, with a false cavity inside. In this architecture, which enables Grandidier baobabs to reach very large sizes, the stems that build the ring typically have similar ages. Here we present the AMS radiocarbon investigation of two large baobabs, A 215 (girth 21.50 m) and A 257 (girth 25.70 m). According to dating results, the baobab A 215 has an age of only 375 years. It consists of four fused stems and has a closed ring-shaped structure. The baobab A 257 has the second largest trunk of all known live Reniala trees. It also exhibits a closed ring-shaped structure, with five fused stems around a false cavity, which has an opening toward the exterior. The dating results indicate that A 257 is around 900 years old.

Les paysages agraires de la côte nord-est malgache sont marqués par des rizières et des systèmes agroforestiers diversifiés, dominés par une ou plusieurs cultures de rente (giroflier, litchi, vanille, café) ainsi que des productions vendues localement et/ou autoconsommées (fruits, café, tubercules, bois). Cette diversification répond à une stratégie d'intensification des systèmes et de diversification des revenus. Les ménages combinent ainsi une résilience directe par l'autoconsommation du riz comme une résilience " économique " indirecte, basée sur la vente des produits de rente dont le revenu permet l'achat du riz manquant et l'amélioration des conditions de vie. Cette stratégie, même si elle dépend des fluctuations des prix sur le marché international, atténue l'impact de ces aléas sur les revenus.

The article presents the AMS (accelerator mass spectrometry) radiocarbon dating results of the Giant of Bevoay, which is a very large Grandidier baobab (Adansonia grandidieri Baill.) of Madagascar. The investigation of this baobab shows that it has a cluster structure, which consists of 3 perfectly fused stems. The calculated wood volume of the tree is 520 m3, which makes it the third largest Grandidier baobab and also the third largest individual of all Adansonia species. Two samples were collected from the outer part of the stems. The oldest dated sample segment had a radiocarbon date of 525 ± 23 BP, which corresponds to a calibrated age of 585 ± 10 years. According to this value, the Giant of Bevoay is 825 ± 50 years old.

© The Author(s), 2019. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Patrut,Roxana T.; Patrut,Adrian; Pock-Tsy,Jean-Michel Leong; Woodborne,Stephan; Rakosy,Laszlo; Danthu,Pascal; Ratiu,Ileana-Andreea; Bodis,Jeno; Von Reden,Karl. Radiocarbon investigation of a superlative Grandidier Baobab, the Big Reniala of Isosa. Studia Universitatis Babes-Bolyai Chemia, 64(4), (2019): 131-139, doi:10.24193/subbchem.2019.4.10., The article discloses the accelerator mass spectrometry (AMS) radiocarbon dating results of the Big Reniala of Isosa, which is a massive Grandidier baobab (Adansonia grandidieri Baill.) of Madagascar. The investigation of this baobab shows that it consists of 5 perfectly fused stems and exhibits a cluster structure. The calculated wood volume of the tree is 540 m3, which makes the Big Reniala of Isosa the largest individual of all Adansonia species and also the biggest known angiosperm in terms of volume. Several samples were collected from the outer part of the stems. The oldest dated sample had a radiocarbon date of 934 ± 24 BP, which corresponds to a calibrated age of 845 ± 25 years. This value indicates an age of 1000 ± 100 years for the big Reniala of Isosa., The investigation and sampling of the baobab was authorised by the Forestry Direction of the Ministry of Environment, Ecology and Forestry of Madagascar and by the Madagascar National Parks. The research was funded by the Romanian Ministry of National Education CNCS-UEFISCDI under grant PN-III-P4-ID-PCE-2016-0776, No. 90/2017.

Centella asiaticais aherbal plant generally used for its curative properties. Two foliar morphotypes were recently identified in Madagascar: a reniform tetraploid (2n = 4x = 36) in the Center and the East of the island and a round diploid (2n = 2x = 18) in the West. The objective of this study was to evaluate the nutritional properties of these two morphotypes and to compare them with other green leafy vegetables. Reniform leaves were collected in Antananarivo and Moramanga and round leaves were collected in Tsiroanomandidy and Analavory. Macronutrient content wasdetermined by standard methods, mineral contents were analysed by inductively coupled plasma atomic emissionspectroscopy. Ascorbic acid and carotenoids were quantified byHPLC.Food composition showed significant differences between the morphotypes. Reniform leaves have higher protein content (19–22 % dry weight (DW)) than round leaves (17–21 % DW). Lipid content are from 2.5 to 6.0 % DW. Reniform leaves have higher iron content than round leaves. Iron content of C. asiatica's leaves range from 3.8 to 12.5 mg/100 g fresh weight (FW). Reniform leaves from Moramanga have the highest protein, lipid and iron content.Round leaves from Analavory have the highest calcium and magnesium content, which can cover 41 % and 17 % of the Recommended Dietary Allowances (RDA), respectively. Leaves of C. asiaticahave low vitamin C content (1.3 to 7.7 mg/100 g FW). Consumption of 100 g of C. asiaticaleaves could cover 10 to 21 % of vitamin A daily requirements of women for reniform leaves and 21 to 37 % of vitamin A requirement of women for round leaves. Round leaves from Analavory have the highest β-carotene content. It is hoped that from these findings, the people of Madagascar will be encouraged to include C. asiaticain their diets for its nutritional benefits.

The article discloses the accelerator mass spectrometry (AMS) radiocarbon dating results of the Big Reniala of Isosa, which is a massive Grandidier baobab (Adansonia grandidieri Baill.) of Madagascar. The investigation of this baobab shows that it consists of 5 perfectly fused stems and exhibits a cluster structure. The calculated wood volume of the tree is 540 m3, which makes the Big Reniala of Isosa the largest individual of all Adansonia species and also the biggest known angiosperm in terms of volume. Several samples were collected from the outer part of the stems. The oldest dated sample had a radiocarbon date of 934 ± 24 BP, which corresponds to a calibrated age of 845 ± 25 years. This value indicates an age of 1000 ± 100 years for the big Reniala of Isosa.