The Experts below are selected from a list of 3894 Experts worldwide ranked by ideXlab platform
Daniel A. Lowy - One of the best experts on this subject based on the ideXlab platform.
-
Searching for the Oldest Baobab of Madagascar: Radiocarbon Investigation of Large Adansonia rubrostipa Trees
PloS one, 2015Co-Authors: Adrian Patrut, Karl F. Von Reden, Pascal Danthu, Jean-michel Leong Pock-tsy, Roxana T. Patrut, Daniel A. LowyAbstract:We extended our research on the architecture, growth and age of trees belonging to the genus Adansonia, by starting to investigate large individuals of the most widespread Malagasy species. Our research also intends to identify the oldest baobabs of Madagascar. Here we present results of the radiocarbon investigation of the two most representative Adansonia rubrostipa (fony baobab) specimens, which are located in south-western Madagascar, in the Tsimanampetsotse National Park. We found that the fony baobab called “Grandmother” consists of 3 perfectly fused stems of different ages. The radiocarbon date of the oldest sample was found to be 1136 ± 16 BP. We estimated that the oldest part of this tree, which is mainly hollow, has an age close to 1,600 yr. This value is comparable to the age of the oldest Adansonia digitata (African baobab) specimens. By its age, the Grandmother is a major candidate for the oldest baobab of Madagascar. The second investigated specimen, called the “polygamous baobab”, consists of 6 partially fused stems of different ages. According to dating results, this fony baobab is 1,000 yr old. This research is the first investigation of the structure and age of Malagasy baobabs.
-
AMS radiocarbon dating of very large Grandidier's baobabs (Adansonia grandidieri)
Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms, 2015Co-Authors: Adrian Patrut, Karl F. Von Reden, Pascal Danthu, Jean-michel Leong Pock-tsy, László Rákosy, Roxana T. Patrut, Daniel A. Lowy, Dragos MargineanuAbstract:Abstract The article reports the AMS radiocarbon investigation of the two largest known Adansonia grandidieri specimens. The two baobabs, which are named Tsitakakoike and Pregnant baobab, are located in Southwestern Madagascar, near Andombiro. A third specimen from this area, the House baobab, was also investigated. According to measurements, Tsitakakoike is the biggest individual above ground level of all Adansonia species. The House baobab was selected for its exposed structure, which is identical to the closed ring-shaped structure with false cavities identified by us in large and old Adansonia digitata specimens. According to our research, Tsitakakoike and the Pregnant baobab have multi-stemmed cylindrical trunks which are mainly hollow; the two very large baobabs also possess a ring-shaped structure. The radiocarbon dates of the oldest wood samples collected from the large trunks were 1274 ± 20 bp for Tsitakakoike and 930 ± 20 bp for the Pregnant baobab. According to their original positions and to the architectures of the two A. grandidieri , the ages of Tsitakakoike and Pregnant baobab would be between 1300 and 1500 years. Therefore, A. grandidieri becomes the third Adansonia species with individuals that can live over 1000 years, according to accurate dating results.
-
age determination of large live trees with inner cavities radiocarbon dating of platland tree a giant african baobab
Annals of Forest Science, 2011Co-Authors: Adrian Patrut, Karl F. Von Reden, Daniel A. Lowy, Robert Van Pelt, Diana H Mayne, Dragos MargineanuAbstract:• Introduction For large trees without a continuous sequence of growth rings in their trunk, such as the African baobab (Adansonia digitata L.), the only accurate method for age determination is radiocarbon dating. As of today, this method was limited to dating samples collected from the remains of dead specimens.
Adrian Patrut - One of the best experts on this subject based on the ideXlab platform.
-
Searching for the Oldest Baobab of Madagascar: Radiocarbon Investigation of Large Adansonia rubrostipa Trees
PloS one, 2015Co-Authors: Adrian Patrut, Karl F. Von Reden, Pascal Danthu, Jean-michel Leong Pock-tsy, Roxana T. Patrut, Daniel A. LowyAbstract:We extended our research on the architecture, growth and age of trees belonging to the genus Adansonia, by starting to investigate large individuals of the most widespread Malagasy species. Our research also intends to identify the oldest baobabs of Madagascar. Here we present results of the radiocarbon investigation of the two most representative Adansonia rubrostipa (fony baobab) specimens, which are located in south-western Madagascar, in the Tsimanampetsotse National Park. We found that the fony baobab called “Grandmother” consists of 3 perfectly fused stems of different ages. The radiocarbon date of the oldest sample was found to be 1136 ± 16 BP. We estimated that the oldest part of this tree, which is mainly hollow, has an age close to 1,600 yr. This value is comparable to the age of the oldest Adansonia digitata (African baobab) specimens. By its age, the Grandmother is a major candidate for the oldest baobab of Madagascar. The second investigated specimen, called the “polygamous baobab”, consists of 6 partially fused stems of different ages. According to dating results, this fony baobab is 1,000 yr old. This research is the first investigation of the structure and age of Malagasy baobabs.
-
AMS radiocarbon dating of very large Grandidier's baobabs (Adansonia grandidieri)
Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms, 2015Co-Authors: Adrian Patrut, Karl F. Von Reden, Pascal Danthu, Jean-michel Leong Pock-tsy, László Rákosy, Roxana T. Patrut, Daniel A. Lowy, Dragos MargineanuAbstract:Abstract The article reports the AMS radiocarbon investigation of the two largest known Adansonia grandidieri specimens. The two baobabs, which are named Tsitakakoike and Pregnant baobab, are located in Southwestern Madagascar, near Andombiro. A third specimen from this area, the House baobab, was also investigated. According to measurements, Tsitakakoike is the biggest individual above ground level of all Adansonia species. The House baobab was selected for its exposed structure, which is identical to the closed ring-shaped structure with false cavities identified by us in large and old Adansonia digitata specimens. According to our research, Tsitakakoike and the Pregnant baobab have multi-stemmed cylindrical trunks which are mainly hollow; the two very large baobabs also possess a ring-shaped structure. The radiocarbon dates of the oldest wood samples collected from the large trunks were 1274 ± 20 bp for Tsitakakoike and 930 ± 20 bp for the Pregnant baobab. According to their original positions and to the architectures of the two A. grandidieri , the ages of Tsitakakoike and Pregnant baobab would be between 1300 and 1500 years. Therefore, A. grandidieri becomes the third Adansonia species with individuals that can live over 1000 years, according to accurate dating results.
-
age determination of large live trees with inner cavities radiocarbon dating of platland tree a giant african baobab
Annals of Forest Science, 2011Co-Authors: Adrian Patrut, Karl F. Von Reden, Daniel A. Lowy, Robert Van Pelt, Diana H Mayne, Dragos MargineanuAbstract:• Introduction For large trees without a continuous sequence of growth rings in their trunk, such as the African baobab (Adansonia digitata L.), the only accurate method for age determination is radiocarbon dating. As of today, this method was limited to dating samples collected from the remains of dead specimens.
Dragos Margineanu - One of the best experts on this subject based on the ideXlab platform.
-
AMS radiocarbon dating of very large Grandidier's baobabs (Adansonia grandidieri)
Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms, 2015Co-Authors: Adrian Patrut, Karl F. Von Reden, Pascal Danthu, Jean-michel Leong Pock-tsy, László Rákosy, Roxana T. Patrut, Daniel A. Lowy, Dragos MargineanuAbstract:Abstract The article reports the AMS radiocarbon investigation of the two largest known Adansonia grandidieri specimens. The two baobabs, which are named Tsitakakoike and Pregnant baobab, are located in Southwestern Madagascar, near Andombiro. A third specimen from this area, the House baobab, was also investigated. According to measurements, Tsitakakoike is the biggest individual above ground level of all Adansonia species. The House baobab was selected for its exposed structure, which is identical to the closed ring-shaped structure with false cavities identified by us in large and old Adansonia digitata specimens. According to our research, Tsitakakoike and the Pregnant baobab have multi-stemmed cylindrical trunks which are mainly hollow; the two very large baobabs also possess a ring-shaped structure. The radiocarbon dates of the oldest wood samples collected from the large trunks were 1274 ± 20 bp for Tsitakakoike and 930 ± 20 bp for the Pregnant baobab. According to their original positions and to the architectures of the two A. grandidieri , the ages of Tsitakakoike and Pregnant baobab would be between 1300 and 1500 years. Therefore, A. grandidieri becomes the third Adansonia species with individuals that can live over 1000 years, according to accurate dating results.
-
age determination of large live trees with inner cavities radiocarbon dating of platland tree a giant african baobab
Annals of Forest Science, 2011Co-Authors: Adrian Patrut, Karl F. Von Reden, Daniel A. Lowy, Robert Van Pelt, Diana H Mayne, Dragos MargineanuAbstract:• Introduction For large trees without a continuous sequence of growth rings in their trunk, such as the African baobab (Adansonia digitata L.), the only accurate method for age determination is radiocarbon dating. As of today, this method was limited to dating samples collected from the remains of dead specimens.
Karl F. Von Reden - One of the best experts on this subject based on the ideXlab platform.
-
Searching for the Oldest Baobab of Madagascar: Radiocarbon Investigation of Large Adansonia rubrostipa Trees
PloS one, 2015Co-Authors: Adrian Patrut, Karl F. Von Reden, Pascal Danthu, Jean-michel Leong Pock-tsy, Roxana T. Patrut, Daniel A. LowyAbstract:We extended our research on the architecture, growth and age of trees belonging to the genus Adansonia, by starting to investigate large individuals of the most widespread Malagasy species. Our research also intends to identify the oldest baobabs of Madagascar. Here we present results of the radiocarbon investigation of the two most representative Adansonia rubrostipa (fony baobab) specimens, which are located in south-western Madagascar, in the Tsimanampetsotse National Park. We found that the fony baobab called “Grandmother” consists of 3 perfectly fused stems of different ages. The radiocarbon date of the oldest sample was found to be 1136 ± 16 BP. We estimated that the oldest part of this tree, which is mainly hollow, has an age close to 1,600 yr. This value is comparable to the age of the oldest Adansonia digitata (African baobab) specimens. By its age, the Grandmother is a major candidate for the oldest baobab of Madagascar. The second investigated specimen, called the “polygamous baobab”, consists of 6 partially fused stems of different ages. According to dating results, this fony baobab is 1,000 yr old. This research is the first investigation of the structure and age of Malagasy baobabs.
-
AMS radiocarbon dating of very large Grandidier's baobabs (Adansonia grandidieri)
Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms, 2015Co-Authors: Adrian Patrut, Karl F. Von Reden, Pascal Danthu, Jean-michel Leong Pock-tsy, László Rákosy, Roxana T. Patrut, Daniel A. Lowy, Dragos MargineanuAbstract:Abstract The article reports the AMS radiocarbon investigation of the two largest known Adansonia grandidieri specimens. The two baobabs, which are named Tsitakakoike and Pregnant baobab, are located in Southwestern Madagascar, near Andombiro. A third specimen from this area, the House baobab, was also investigated. According to measurements, Tsitakakoike is the biggest individual above ground level of all Adansonia species. The House baobab was selected for its exposed structure, which is identical to the closed ring-shaped structure with false cavities identified by us in large and old Adansonia digitata specimens. According to our research, Tsitakakoike and the Pregnant baobab have multi-stemmed cylindrical trunks which are mainly hollow; the two very large baobabs also possess a ring-shaped structure. The radiocarbon dates of the oldest wood samples collected from the large trunks were 1274 ± 20 bp for Tsitakakoike and 930 ± 20 bp for the Pregnant baobab. According to their original positions and to the architectures of the two A. grandidieri , the ages of Tsitakakoike and Pregnant baobab would be between 1300 and 1500 years. Therefore, A. grandidieri becomes the third Adansonia species with individuals that can live over 1000 years, according to accurate dating results.
-
age determination of large live trees with inner cavities radiocarbon dating of platland tree a giant african baobab
Annals of Forest Science, 2011Co-Authors: Adrian Patrut, Karl F. Von Reden, Daniel A. Lowy, Robert Van Pelt, Diana H Mayne, Dragos MargineanuAbstract:• Introduction For large trees without a continuous sequence of growth rings in their trunk, such as the African baobab (Adansonia digitata L.), the only accurate method for age determination is radiocarbon dating. As of today, this method was limited to dating samples collected from the remains of dead specimens.
Pascal Danthu - One of the best experts on this subject based on the ideXlab platform.
-
Searching for the Oldest Baobab of Madagascar: Radiocarbon Investigation of Large Adansonia rubrostipa Trees
PloS one, 2015Co-Authors: Adrian Patrut, Karl F. Von Reden, Pascal Danthu, Jean-michel Leong Pock-tsy, Roxana T. Patrut, Daniel A. LowyAbstract:We extended our research on the architecture, growth and age of trees belonging to the genus Adansonia, by starting to investigate large individuals of the most widespread Malagasy species. Our research also intends to identify the oldest baobabs of Madagascar. Here we present results of the radiocarbon investigation of the two most representative Adansonia rubrostipa (fony baobab) specimens, which are located in south-western Madagascar, in the Tsimanampetsotse National Park. We found that the fony baobab called “Grandmother” consists of 3 perfectly fused stems of different ages. The radiocarbon date of the oldest sample was found to be 1136 ± 16 BP. We estimated that the oldest part of this tree, which is mainly hollow, has an age close to 1,600 yr. This value is comparable to the age of the oldest Adansonia digitata (African baobab) specimens. By its age, the Grandmother is a major candidate for the oldest baobab of Madagascar. The second investigated specimen, called the “polygamous baobab”, consists of 6 partially fused stems of different ages. According to dating results, this fony baobab is 1,000 yr old. This research is the first investigation of the structure and age of Malagasy baobabs.
-
Pollen wall ultrastructure of the genus Adansonia L. species
Plant Systematics and Evolution, 2015Co-Authors: Elysée N. Rasoamanana, Pascal Danthu, Onja Razanamaro, Perle Ramavovololona, Ralalaharisoa Z. Ramamonjisoa, Jean Luc Verdeil, Maria Suárez-cerveraAbstract:The genus Adansonia (baobabs, Malvaceae) includes nine tropical species grouped in the Brevitubae, Longitubae and Adansonia sections. The ultrastructure of pollen from eight species of baobabs was studied using transmission electron microscopy. The pollen grains correspond to 3-colporate and 4-colporate types. The ectexine is formed by a perforate tectum with isolated spinules. An important distinguishing feature between the Brevitubae section and the Longitubae and Adansonia sections was observed in the infratectum. The apertural region was similar in all the species studied here. However, the most unusual structure was observed in the apertural margins where the ectexine consisted of a thick lamellate annulus and the endexine had a cracked appearance; the intine was composed of a well-developed oncus under the endopore with unusual fibrillar structures and the outer layer had a remarkable structure consisting of columns. Despite the few differences observed in the structure of the pollen wall within the genus, an original arrangement of the structure found in the aperture of the Adansonia pollen grains studied provides additional information about the new types of apertural structures. This type of sporoderm adds to our knowledge of the diversity of angiosperm pollen. Moreover, this apertural structure is probably an adaptation that occurs during the formation of the pollen tube and of harmomegathy.
-
AMS radiocarbon dating of very large Grandidier's baobabs (Adansonia grandidieri)
Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms, 2015Co-Authors: Adrian Patrut, Karl F. Von Reden, Pascal Danthu, Jean-michel Leong Pock-tsy, László Rákosy, Roxana T. Patrut, Daniel A. Lowy, Dragos MargineanuAbstract:Abstract The article reports the AMS radiocarbon investigation of the two largest known Adansonia grandidieri specimens. The two baobabs, which are named Tsitakakoike and Pregnant baobab, are located in Southwestern Madagascar, near Andombiro. A third specimen from this area, the House baobab, was also investigated. According to measurements, Tsitakakoike is the biggest individual above ground level of all Adansonia species. The House baobab was selected for its exposed structure, which is identical to the closed ring-shaped structure with false cavities identified by us in large and old Adansonia digitata specimens. According to our research, Tsitakakoike and the Pregnant baobab have multi-stemmed cylindrical trunks which are mainly hollow; the two very large baobabs also possess a ring-shaped structure. The radiocarbon dates of the oldest wood samples collected from the large trunks were 1274 ± 20 bp for Tsitakakoike and 930 ± 20 bp for the Pregnant baobab. According to their original positions and to the architectures of the two A. grandidieri , the ages of Tsitakakoike and Pregnant baobab would be between 1300 and 1500 years. Therefore, A. grandidieri becomes the third Adansonia species with individuals that can live over 1000 years, according to accurate dating results.
-
Vulnerability of baobab species to climate change and effectiveness of the protected area network in Madagascar: Towards new conservation priorities
Biological Conservation, 2013Co-Authors: Ghislain Vieilledent, Cyrille Cornu, Aida Cuní Sanchez, Jean-michel Leong Pock-tsy, Pascal DanthuAbstract:Baobab species are representative of the high biodiversity and endemism rates that place Madagascar in the top three of the countries with the highest biodiversity in the world. In this study, we estimated the vulnerability of three endangeredMalagasy baobab species (Adansonia grandidieri Baill., Adansonia perrieri Capuron and Adansonia suarezensis H. Perrier) to climate change and the effectiveness of the protected area network (PAN) for the future conservation of these species. To estimate the environmental niche of the species, we used an original data-set based on satellite image analysis to detect species presence and an ensemble modelling approach using three species distribution models (GLM, GAM and MaxEnt). We projected the species distribution in 2050 and 2080 using an ensemble forecasting approach combining the three species distribution models and three global circulation models for climate projections. Mea- sures of connectivity were employed to assess the present and future effectiveness of the existing PAN. Among the three baobab species studied, two are severely threatened by climate change (A. perrieri and A. suarezensis), in part because the present PAN does not overlap with future species distribution areas. Recently, strong efforts have beenmade in designing an optimised PAN to conserveMadagascar outstand- ing biodiversity. Nevertheless, its future effectiveness is questioned by the potential shifts in species dis- tributions due to predicted changes in climate. In the context of climate change, alternative strategies such as ecological restoration would also have to be adopted to conserve biodiversity in Madagascar
