2016
SCIENTIFIC REPORT
on the implementation of the project entitled
New research in dendrochronology and environmental climate change by using AMS/CFAMS radiocarbon dating and stable isotope analysis
Code PN-II-ID-PCE-2012-4-0393
Grant Nr. PN-II-ID-PCE-2013-76
________________________________
January – December 2016
Report for the period January – December 2016
The scientific activities performed during this time frame aimed the fulfillment of the objectives mentioned in the unique phase 2016. The main achievements will be presented and analyzed and some of the most important results will be discussed.
Objective 1. Baobab dating (IV).
Activity 1.1. Sample collection.
A number of 42 representative African baobabs (Adansonia digitata) from Botswana, Zimbabwe, Barbados, Zambia and Sri Lanka were measured and investigated. Wood sampled from 15 trees were collected (as compared to 5-9 baobabs envisaged).
Our field research team composed of 3 members visited Botswana and Zimbabwe in the period 31.03 – 20.04.2016. The trip to Botswana was motivated by a dramatic event, namely the fall of the Chapman baobab, the national icon that we investigated and dated in June 2015. The 6 stems of Chapman, perhaps the most famous African baobab, toppled suddenly in the morning of January 7, 2016. (Figs. 1 and 2). In 2015, we warned several lodge managing persons from Gweta that the large cavity, which extended through the base of 3 stems (probably caused by a veld fire in the 17th century), may become fatal to the tree over the next years.
Fig. 1. The painful image of the 6 fallen stems of Chapman.
Fig. 2. Another image presenting the fallen Chapman baobab.
We also noticed the relatively low water content of the stems, suggesting the stems to be anchored and water to be periodically supplied, maybe by helicopter. Somewhat surprisingly, the large baobab toppled and died only 6 months after our visit. The severe drought over the past few years particularly that of the rainy season in 2015-2016, also contributed to this tragic event. There was a lack of first rains that typically fall in the Ntwetwe Pan area starting September or October 2016, and become more abundant in November. The first rains fell only at the end of January 2016, being an unprecedented case in Southern Africa. The Chapman baobab blossomed in October and flushed leaves in November, depleting most of its water reserves, which could not be replenished because of the absence of rain. The Chapman had a mighty lateral root system, which developed over centuries. However, the penetration of roots in the soil in terms of depth was superficial, only up to ca. 1.5 m. The vertical stability of baobab stems also has a gravitational cause, due to their weight, which is associated with the water content. The stems of Chapman had already a partial lean (up to 15°), because of its open ring-shaped structure and old age. The unhappy combination of these factors triggered the collapse of a significant symbol of the vegetal world.
At the request of the project director, a research team from South Africa and Botswana, led by Dr. Stephan Woodborne, arrived simultaneously at Gweta for collecting wood samples from the fallen Chapman baobab with a 1.5 m long increment borer. The samples were collected for radiocarbon dating and stable isotope analysis.
This first trip of our research team continued in Zimbabwe, where many representative baobabs were investigated. We extracted samples from 7 large baobabs, each with a cbh (circumference at breast height, i.e. 1.30 m) over 20 m. The most interesting area was certainly the Savé Valley Conservancy. This protected land hosts thousands of baobabs, out of which 4 specimens (located north of Turgwe River) have huge dimensions (cbh over 23 m) and ages exceeding 1000 years.
The best known baobab of Savé Valley is located on the Mokore Ranch (Mokore Giant Baobab). Its dimensions are: height h = 23.2 m, circumference cbh = 28.11 m and a total wood volume V = ca. 320 m3 (Fig. 3). The Mokore baobab possesses 7 stems of different sizes and ages and a large false stem which acts as a structural support/anchor. The false stem is mainly empty and fissured; this fact might have dramatic consequences on the survival of this specimen in the near future. The Mokore baobab has a closed ring-shaped structure, with a ring composed of 4 stems, which close a false cavity. The cavity has an opening only in the upper part, at a height of over 5 m.
Fig. 3. The baobab of Mokore Ranch has the biggest circumference (28.11 m) of all trees in Zimbabwe.
A second representative baobab of Savé Valley can be found on the Chishakwe Ranch. It dimensions are: height h = 26.1 m, circumference cbh = 26.56 m and total wood volume V = ca. 375 m3 (Fig. 4). The Chishakwe baobab consists of 7 fused stems. It has a closed ring-shaped structure, with a ring of 5 or 6 stems that close completely a false cavity inside. The cavity has only a tall opening at a height of 7-8 m, which is inaccessible.
The following two investigated baobabs are basically unknown in the literature and are not included in the registers of the Tree Society of Zimbabwe. In 2011, a very old baobab was discovered in the Bedford Block which belongs to the Humani Ranch. It has a height h = 18.2 m, a circumference cbh = 23.65 m and a total wood volume of V = ca. 240 m3 (Fig. 5). The Humani Bedford baobab has a closed ring-shaped structure, which consists now of three fused stems that close partially a false cavity with the walls completely covered by bark. A fourth stem is missing; it toppled likely more than one century ago, thus opening the false cavity toward the west. The false cavity has an ellipsoidal base with the axes of 2.59 x 2.70 m at ground level and 2.54 x 2.98 m at 1.50 m. The maximum height of the cavity is 6.10 m. The baobab has massive branches, with diameters up to 2.2 m. The radiocarbon dating of samples shows that the Humani Bedford baobab is around 1800 years old and is now very likely the oldest living African baobab.
Fig. 4. The Chishakwe baobab is the tallest and the most massive African baobab of Zimbabwe (26.1 m, 375 m3).
Fig. 5. The Humani Bedford tree is the oldest living African baobab.
The fourth large baobab of Savé Valley is located on the Matendere Ranch (Matendere big baobab). It has a height h = 22.5 m, a circumference cbh = 26.30 m and a total volume V = ca. 300 m3 (Fig. 6). The Matendere baobab also has a closed ring-shaped structure, with 5 stems that incorporate a false cavity. Like in the case of Mokore and Chishakwe baobabs, the cavity of Matendere baobab has only a very tall opening, at a height over 6m.
Fig. 6. The Matendere baobab is one of the most impressive specimen of Zimbabwe.
The second major trip of the research team had for its destination Zambia and Sri Lanka, from 22.09 to 08.10.2016. The aim of the trip to Zambia was the identification of monumental baobabs which were not reported for this country. The biggest baobabs of Zambia are located in the area of the very scenic South Luangwa National Park. The most representative of them is the Lundu baobab, located in the Lundu plain from the north-eastern part of the park. The baobab has a closed-ring shaped structure, now with only 3 stems disposed around a false cavity. At least other 3 trunks are missing. A stem has fallen during a major fire in 2015, which affected severely the structure of the baobab. The Lundu baobab will probably perish within a few years. A large false stem, acting as a mechanical support, is fractured (Figs. 7 and 8). The actual dimensions of the Lundu baobab are: height h = 24.6 m, circumference cbh = 25.10 m and the total wood volume V = 200 m3. The cavity, which is opened due to a missing stem, is bell shaped with a height of 5.87 m and an ellipsoidal base with the axes of 2.43 x 3.56 m.
Fig. 7. General view of the Lundu baobab, the biggest specimen of Zambia, in september 2016.
Fig. 8. The Lundu baobab was severely affected by the fire of 2015.
Sri Lanka is famous for its dwarf or at least short baobabs, which were presented in a scientific paper in 2004. A number of 34 out of the 40 baobabs were mentioned in Mannar Island. Nevertheless, our field investigations in October 2016 found only 22 dwarf baobabs in Mannar. With one exception, these trees are not protected, being considered by the locals as useless. The only exception is the “Big Biobab” of the Palimunai neighborhood of Mannar Town, which is visited daily by hundreds or even thousands of tourists. It has a height h = 9.0 m, a circumference cbh = 20.01 m and a total wood volume V = ca. 100 m3 (Fig. 9). The baobab of Mannar Town has 6 trunks and a binding unit with no branches. It has a closed double ring shaped structure with two rings built out of 4 + 1 stems and 2 + 1 stems, respectively. This binding unit/stem is common to both rings. The two rings enclose 2 false cavities with openings in their ceilings, at heights of 3.30 m and 3.16 m. The horizontal distance between the 2 cavities is 1.40 m.
Fig. 9. The image shows the Big Biobab of Mannar Town, the largest dwarf baobab in the world.
Activity 1.2. Pretreatment of samples.
Activity 1.3. Radiocarbon dating by AMS and CFAMS.
Activity 1.4. Paleoclimate calibration.
The 3 activities are interconnected, as they precede, define, and follow the AMS radiocarbon dating.
The number of pretreated, dated and calibrated samples was 80 (as compared to 75 envisaged), including some samples which we collected in 2015. Because the steps of radiocarbon investigation take 3-5 months, the dating results of some samples collected in 2016 will be available only in 2017.
According to the Project Implementation Plan, the AMS radiocarbon dating was performed at the NOSAMS Facility of the Woods Hole Oceanographic Institution, Woods Hole, Massachusetts (U.S.A.), by using the AMS Pelletron®Tandem 500 kV system. It is also possible that in 2017 certain samples will be dated at the Hertelendi Laboratory of Debrecen (Hungary), which possesses a compact AMS EnvironMICADAS.
Objective 2. Measuring and dating monumental trees of Romania and Europe (III).
Activity 2.1. The collecting of samples.
Complete measurements of 40 monumental trees were performed (compared to 30 envisaged) from Romania, Hungary, Germany and Greece. Wood samples from 15 trees were collected (out of 10 envisaged). The investigated trees belong to the following species: pedunculate oak (Quercus robur), sessile oak (Quercus petraea), olive tree (Olea europaea), black poplar (Populus nigra), white poplar (Populus alba), sweet chestnut (Castanea sativa), oriental plane (Platanus orientalis).
Activity 2.2. Pretreatment of samples.
Activity 2.3. Radiocarbon dating by AMS.
Activity 2.4. Paleoclimate calibration.
Once again, these 3 activities are associated, because they precede, define and follow the radiocarbon dating. A number of 28 samples (as compared to 20 foreseen) were pretreated, dated and calibrated.
Objective 3. The climate research of wood samples collected from 6 baobabs (III).
Activity 3.1. The pretreatment of samples.
Activity 3.2. The stable isotope analysis.
Wood samples collected from 8 baobabs (as compared to 6 baobabs envisaged) were pretreated and investigated by stable isotope analysis. The analysis measure the carbon isotopes composition, which is based on the fractionation of the 13C and 12C stable isotopes, expressed by δ13C, which is fixed and registered in each growth ring. A number of around 3000 samples were analysed. The analysis have been performed at the iThemba Laboratories, Cape Town and at the University of Pretoria (South Africa), by utilising a TC/EA pyrolysis system associated with a DeltaV Plus mass spectrometre (for isotopes).
Objective 4. The climate research of wood samples collected from 3 pedunculate oaks from Romania.
Activity 4.1. Collecting a complete section with 450 annual rings.
Activity 4.2. The pretreatment of samples.
Activity 4.3. The stable isotope analysis.
The complete section with 450 growth rings was collected from a monumental baobab from the Breite Conservancy located in the proximity of Sighişoara. The samples were pretreated and analysed according to the protocol presented at the activities 3.1 and 3.2. A number of 600 samples were analysed.
Objective 5. Dissemination of results (IV).
Activity 5.1. The writing of the activity report.
Activity 5.2. The writing of scientific articles.
The (envisaged) stage results.
1. The annual activity report;
2. Submission of 2-3 manuscripts to scientific journals which are ISI indexed;
3. The publication or acceptance for publication of 2-3 articles in ISI indexed scientific journals (which were submitted in 2015-2016, while the other articles will be published in 2017);
In 2016, up to present, a number of 5 articles were published in peer-reviewed ISI international journals, out of which one was published only on-line in .pdf version, by Radiocarbon (as compared to 2-3 foreseen articles).
A list of articles folows:
1. Adrian Patrut, Roxana T. Patrut, Pascal Danthu, Jean-Michel Leong Pock-Tsy, Laszlo Rakosy, Daniel A. Lowy, Karl F. von Reden, AMS radiocarbon dating of large za baobabs (Adansonia za) of Madagascar, PLoS ONE, 2016, 11(1), e0146977. doi:10.1371/journal.pone.0146977. (impact factor: 3.054).
Abstract. The article reports the radiocarbon investigation results of Anzapalivoro, the largest za baobab (Adansonia za) specimen of Madagascar. Several wood samples collected from the large inner cavity and from the outer part/exterior of the tree were investigated by AMS (accelerator mass spectrometry) radiocarbon dating. For samples collected from the cavity walls, the age values increase with the distance into the wood up to a point of maximum age, after which the values decrease toward the outer part. This anomaly of age sequences indicates that the inner cavity of Anzapalivoro is a false cavity, practically an empty space between several fused stems disposed in a ring-shaped structure. The radiocarbon date of the oldest sample was 710 ± 25 BP, which corresponds to a calibrated age of 675 ± 20 yr. Dating results indicate that Anzapalivoro has a closed ring-shaped structure, which consists of 5 fused stems that close a false cavity. The oldest part of the biggest za baobab has a calculated age of 850 years. We also dated a second za baobab, the Big cistern baobab, which was hollowed out for water storage. This specimen, which consists of 4 fused stems, was found to be 250 years old.
2. Stephan Woodborne, Patience Gandiwa, Grant Hall, Adrian Patrut, Jemma Finch, A regional stable carbon isotope dendro-climatology from South African summer rainfall area, PLoS ONE, 2016, 11(7):e0159361. doi:10.1371/journal.pone.0159361. (Impact factor: 3.054).
Abstract. Previous carbon isotope analysis of four baobab (Adansonia digitata L.) trees from the Pafuri region of South Africa yielded a 1000-year proxy rainfall record. Here we present the analysis of five additional baobabs from the Mapungubwe region, approximately 200km to the west of Pafuri. The new Mapungubwe record correlates significantly with local rainfall, but there are significant differences when compared with the Pafuri record at certain times in the past. Both records confirm that the Medieval Warm Period was substantially wetter than present, and the Little Ice Age was the driest period in the last 1000 years. Dry conditions appear to persist in the Mapungubwe area until about AD 1840. The trees from Mapungubwe show sub-annual and super-annual rings, whereas two of the Pafuri trees showed annual growth ring structures. A possible reason for this may be that the Mapungubwe region is drier than Pafuri and episodic growth corresponds to rainfall events rather than continuous growth through the rainy season. It may be linked to the recently identified baobab species, Adansonia kilima nov.. While acknowledging the differences between the Pafuri and Mapungubwe records, they are combined to provide a regional climate proxy record for the northern summer rainfall area of southern Africa.
3. Adrian Patrut, Laszlo Rakosy, Roxana T. Patrut, Ileana-Andreea Ratiu, Edit Forizs, Daniel A. Lowy, Dragos Margineanu, Karl F. von Reden, Radiocarbon dating of a very old African baobab from Savé Valley, Zimbabwe, Studia UBB Chemia, 2016, LXI, 4, 7-20. (Impact factor: 0.148).
Abstract. The article reports the AMS radiocarbon investigation results of the Humani Bedford baobab, an old African baobab from Savé Valley, Zimbabwe. Two wood samples were collected from the large inner cavity. Several segments were extracted from these samples and analysed by AMS (accelerator mass spectrometry) radiocarbon dating. We found that the age values of segments increase with the distance into the wood. This major anomaly is characteristic to multi-stemmed baobabs with a closed ring-shaped structure and a false cavity inside. The investigation of the Humani Bedford baobab evinced that the baobab consists of three fused stems. The fourth stem of the ring is missing. The oldest dated segment was found to have a radiocarbon date of 1655 ± 14 bp, which corresponds to a calibrated age of 1575 ± 30 yr. The dating results show that the stems which build the ring stopped growing toward the false cavity more than 600 yr ago. By considering the position of the oldest segment in the investigated stem, we concluded that the Humani Bedford baobab is around 1800 yr old. According to our dating results, the Humani Bedford baobab becomes the oldest living African baobab.
4. Adrian Patrut, Roxana T. Patrut, Laszlo Rakosy, Jenő Bodis, Daniel A. Lowy, Edit Forizs, Karl F. von Reden, African baobabs with double closed ring-shaped structures and two false cavities: Radiocarbon investigation of the baobab of Golconda Fort, Studia UBB Chemia, 2016, LXI, 4, 21-30 (factor de impact: 0.148).
Abstract. The article discloses the results of radiocarbon investigation of the baobab of Golconda Fort, Hyderābād, India, which is the largest African baobab outside Africa. Two wood samples were collected from the large inner cavity; of these we extracted several segments for AMS (accelerator mass spectrometry) radiocarbon dating. The oldest sample segment had a radiocarbon date of 342 ± 22 bp, which corresponds to a calibrated age of 430 ± 20 yr. We estimate that the oldest part of the baobab has an age of 475 ± 50 yr. The investigation of the baobab of Golconda Fort revealed that it consists of 6 + 2 fused stems. Six stems build two rings that close two distinct false cavities, while two additional stems are located outside the rings. We called this new type of architecture double closed ring-shaped structure with two separate false cavities.
5. Adrian Patrut, Stephan Woodborne, Karl F. von Reden, Grant Hall, Roxana T. Patrut, Laszlo Rakosy, Pascal Danthu, Jean-Michel Leong Pock-Tsy, Daniel A. Lowy, Dragos Margineanu, The growth stop phenomenon of baobabs (Adansonia spp.) indentified by radiocarbon dating, Radiocarbon, 2016, doi:10.1017/RDC.2016.92 (Impact factor: 4.565).
Abstract. The article reports the growth stop phenomenon, which was documented only for baobabs, i.e., for trees belonging to the Adansonia genus. The identification of growth stop was enabled by radiocarbon dating, which allows a complex investigation of samples collected from the trunk/stems of baobabs. In several cases, the outermost rings of baobabs, which were close to the bark, were found to be old, with ages of several hundreds of years, instead of being very young. Dating results of samples collected from 6 baobabs are presented. For multi-stemmed baobabs, the growth stop may occur only for one or several stems. We identified four factors that may induce the growth stop: (i) stress determined by severe climate conditions, (ii) old age, (iii) the need to keep a stable internal architecture and (iv) the collapse of stems that survive this trauma. Baobabs and their stems affected by growth stop may survive for several centuries, by continuing to produce leaves, flowers and fruits. This phenomenon was associated with the capacity of baobabs to store large amounts of water in their trunks/stems in the rainy season. This reservoir of water is used over the dry season and allows the trees to survive prolonged drought periods.
Two other manuscripts disclosing results obtained in the framework of this research project were also prepared:
a. Adrian Patrut, Stephan Woodborne, Grant Hall, Roxana T. Patrut, Laszlo Rakosy, Daniel A. Lowy, Karl F. von Reden, The life and death of the Chapman baobab, a symbol of Botswana, assessed by AMS radiocarbon dating.
b. Adrian Patrut, Karl F. von Reden, Roxana T. Patrut, Laszlo Rakosy, Sebastien Garnier, Dragos Margineanu, Following Adanson: The dwarf baobabs of Magdalene Island investigated by radiocarbon dating.
Other 2 manuscripts entitled: False stems of baobabs identified by radiocarbon dating and Ring counting versus calibrated radiocarbon dates for large and old baobab trees are in preparation.
After which all samples collected in 2016 will be dated by AMS radiocarbon, we will submit additional 2 other scientific articles.
The data presented in this Scientific Report demonstrate that all objectives and activities envisaged in the Project Implementation Plan for 2016 have been fulfilled and achieved. All anticipated results for 2016 have been obtained.
PROJECT MANAGER,
Prof. Dr. Adrian Patrut
2015
SCIENTIFIC REPORT
on the implementation of the project entitled
New research in dendrochronology and environmental climate change by using AMS/CFAMS radiocarbon dating and stable isotope analysis
Code PN-II-ID-PCE-2012-4-0393
Grant Nr. PN-II-ID-PCE-2013-76
________________________________
for the period January – December 2015
Report for the period January – December 2015
The scientific activities of the research project pursued the fulfillment of the objectives mentioned in the unique phase of the Project Implementation Plan for 2015. The main achievements will be presented and the most important obtained results will be also discussed.
Objective 1. Baobab dating (III).
Activity 1.1. Sample collection.
A number of 35 representative baobab specimens (Adansonia spp.) from Tanzania, Botswana, Australia and Senegal were measured and investigated. Wood samples were collected from 16 specimens (as compared to 8 baobabs envisaged).
Our research team, composed of 3 membres, paid a first visit to Tanzania and Botswana, in the time frame 08.06 – 02.07.2015. There are no official data or any scientific investigation about representative African baobabs, i.e., large and potentially old specimens, from Tanzania. For finding such trees, we visited several areas of Tanzania, namely the Selous Game Reserve, Kondoa district and Lake Manyara National Park.
The most impressive baobab of the Selous Game Reserve is certainly “Mwana Mungu” (in Swahili “Child of God”). It has a height h = 22.6 m, a circumference at breast height, i.e., at 1.30 m above ground cbh = 20.13 m and a total wood volume V = ca. 200 m3 (Fig. 1). The large baobab consists of 2 fused stems and it also possesses 4 false stems, which act as anchors in the sandy soil.
Fig. 1. General view of “Mwana Mungu”, the largest baobab of
Selous Game Reserve, Tanzania (cbh = 20.13 m). Two adjacent false trunks,
disposed in V-shape, with an opening of ca. 35º; that offer a much better
stability in sandy soils, can be observed to the right.
Our research performed in the Dodoma-Kondoa area, at an elevation of 1100-1400 m, provided very interesting results. Close to the national road between Dodoma and Arusha, at km 80 and an altitude of 1180 m, in the Chenene Hill zone, we identified a specimen which might be the biggest baobab of mainland Tanzania (Fig. 2). Its parametres are the following: h = 16.8 m, cbh = 24.51 m and V = ca. 230 m3. The baobab has an incomplete ring-shaped structure, which consists of 4 fused stems and one false stem. Due to the very sandy soil, the tree has a significant lean. It also hosts several beehives, exploited by the local population.
The big baobab located in the centre of Kondoa Mijni (Kondoa Urban), at an elevation of 1382 m, is an important symbol of the town (Fig. 3). Our measurements provided the following values: h = 23.3 m, cbh = 21.20 m, V = ca. 200 m3. The baobab has a quasi-cylindrical trunk, which consists of a main stem which has fused over time with several smaller stems that sprouted from the roots.
Fig. 2. The baobab of Chenene Hill (cbh = 24.51 m) showing its trunk which has an important lean toward the west.
Fig. 3. The old baobab located in the central market of Kondoa (cbh = 21.20 m).
The investigation of the 2 large baobabs from the Dodoma-Kondoa area is of special interest, because Pettigrew identified just in this region a new baobab species, which was named mountain African baobab (Adansonia kilima).
In the Lake Manyara National Park, we identified a big baobab located on the top of a hillock (Fig. 4). Its dimensions are the following: h = 19.2 m, cbh = 21.30 m, V = ca. 180 m3. It has a large trunk which is composed of several fused stems having different ages.
Fig. 4. View of the largest baobab of Lake Manyara (cbh = 21.30 m).
Next, our research team visited the islands of Zanzibar, namely the biggest island also called Unguja. The baobabs can be found especially on the southern part of Unguja, around the Kizimkazi village. The biggest specimen is positioned at Kizimkazi Mkunguni, at only 80 m from the beach (Fig. 5). Its dimensions are: h = 21.8 m, cbh = 22.02 m, V = ca. 300 m3. In terms of volume, the Big baobab of Kizimkazi is considerably larger than the baobab of Chenene Hill and becomes the biggest baobab of Tanzania. Its trunk consists of 3 fused stems and a false stem.
Fig. 5. The baobab of Kizimkazi Mkunguni, Zanzibar is the biggest specimen of Tanzania.
The next destination of the research team was Botswana. The investigations were performed in the Central District, in the area of the Salt Makgadikgadi Pans. This region hosts some well-known historic baobabs, such as the Chapman baobab, Green baobab or the Baines baobabs.
The Chapman baobab, named after the elephant hunter who visited it in 1852, is probably the most famous African baobab. Located close to the Ntwetwe Pan, the wonderful baobab is a landmark in this very arid area (Fig. 6). The closest baobab, i.e., the Green baobab, can be found at a distance of 10 km. The Chapman baobab possesses an open ring-shaped structure. Its trunk consists of 6 main stems partially fused up to a height of 1.5-3 m. The 6 stems belong to 3 different generations. The measurements provided the following values: h = 22.6 m, cbh = 25.90 m şi V = ca. 275 m3. Over time, some stems have collapsed and died while other new stems emerged, providing the current architecture. The Chapman baobab has a huge cavity produced by burns, which extends down to the base of 3 stems. The cavity is now inhabited by wild African bees. Its expansion, caused by decaying processes through microorganisms could prove fatal for the big baobab.
Fig. 6. The Chapman baobab with its 6 main stems, rises majestically over the salt lakes in Botswana.
The roots of Chapman, which can be seen up to 100 m from the tree, provide a better anchorage (buttress roots) in the sandy soil. Some of them have been vandalised by tourists.
We found one of the biggest concentrations of very large baobabs both inside and around the Planet Baobab Lodge, Gweta. Here we measured over 10 baobabs with cbh values greater than 12 m. The largest baobab within the Planet Baobab Lodge has a peculiar shape due to a long false stem buttress with an unusual form, resembling a baobab fruit (Fig. 7). The dimension of this baobab are: h = 24.2 m, cbh = 20.64 m şi V = ca. 180 m3. The trunk consists of 4 main stems, out of which one seems to be the oldest and the starting point of its cluster type structure.
After attending the 22nd International Radiocarbon Conference in Dakar, 2 membres of our research team investigated during the time frame 20-25.11.2015, representative baobabs of Senegal, the country which hosts the most imposing baobabs of the northern hemisphere.
Fig. 7. The best known specimen from the Planet Baobab Lodge in Gweta, Botswana, showing its false stem with an original shape (see left side of the image).
The Magdalene island, located in the Atlantic Ocean, at only 3.8 km from a central Dakar beach, hosts 60 dwarf baobabs, which have shrub-like shapes. These dwarf baobabs have been mentioned for the first time in 1749, by the French naturalist Michel Adanson. The island has a volcanic origin and is not inhabited by humans. It is thought that the dwarf shape of the baobabs is an adaptation to the island conditions, which is basically a tall cliff with a surface of 15 ha, where strong winds blow periodically.
The largest dwarf baobab is called ”Parasol” (in French ”sun umbrella”), due to its specific shape (Fig. 8). Its maximum height reaches only h = 6.0 m and its trunk consists of 2 main units. The central unit is built up of 5 fused stems and has a circumference of 15.60 m. The baobab has a massive canopy and continues its development. The total wood volume is around 50 m3.
The second largest baobab of Magdalene island is the sacred dwarf baobab of the Lebou cult (Fig. 9). It comprises 4 stems, fused up to a height of 1.10m. Our measurements provided the following values: h = 6.7m, cbh = 10.60 m şi V = 16m3. This baobab could be the oldest tree of Madeleine island.
Fig. 8. The dwarf baobab ”Parasol”.
Fig. 9. The sacred dwarf baobab of the Lebou cult.
The oldest baobab of Senegal and of the northern hemisphere could be the historic baobab ”Gouye Ndiouly” (in Wolof ”baobab of the circumcised”) of Kahone, the old capital of the Saloum kingdom, currently located in the Kaolack district (Fig. 10). Underneath this baobab the 49 kings of the Guelewars dynasty have been enthroned between 1593 – 1939. This was also a place for circumcisions and for swearing the oath of allegiance to the king. Nowadays, ”Gouye Ndiouly” is a collapsed tree, resembling somewhat the famous Dorslandboom of Namibia, the oldest known baobab that we investigated in 2014. The baobab has toppled ca. 200 years ago and only one stem of its original structure is still alive. From the collapsed stems, 4 new stems have emerged and other 3 stems have emerged from the still standing/surviving original stem. Currently, the baobab, which has been reborn through the new young stems, has a maximum height of h = 16.0 m, a reconstructed circumference cbh = 14.40 m and a volume V = ca. 80 m3.
Fig. 10. General view of the historic ”Gouye Ndiouly” baobab of Kahone, Senegal.
The disclosed research referred exclusively to the African baobab (Adansonia digitata). Our research team has extended the investigations to the Adansonia genus also to the Australian baobab (Adansonia gregorii), called boab. In the time frame 05.08-21.08.2015, 3 membres of our research team visited the northern regions of Australia. The investigations took place especially in the Kimberley region in the north-west of the country, where the majority of boabs can be found. Basically, our investigations covered over 1000 km from the west to the east, i.e, from Broome to Wyndham, passing by Derby and Fitzroy Corossing.
Fig. 11. The historic Australian baobab so-called ”Wyndham Prison tree”. One can notice the entrance to the large false inner cavity.
There is a high density of baobabs in the Kimberley area comprising probably around 1-2 million individuals. On the downside, most boabs are young or very young, having ages under 100-150 years. We assume that the number of individuals with an age over 500 years is quite low, perhaps up to a dozen trees.
Here, we present one of the most spectacular old Australian baobab, located on the King River Road, at only 31 km from Wyndham. Known as the ”Wyndham Prison tree”, this historic baobab has been a temporary prison in the 19th century, for the aboriginals captured by British authorities on their way to Wyndham (Fig. 11). The baobab possesses a closed ring-shaped structure, composed of 5 perfectly fused stems. The false cavity has a height of 4.90 m and a volume around 15 m3. This cavity was used as a temporary prison in the past. Our measurements provided the following values: h = 13.6 m, cbh = 11.58 m, V = ca. 50 m2. At a first glance, the age of this Australian baobab could be around 1000 years.
Activity 1.2. Pretreatment of samples.
Activity 1.3. Radiocarbon dating by AMS and CFAMS.
Activity 1.4. Paleoclimate calibration.
The 3 activities are associated, because the first one precedes and the last one is subsequent to radiocarbon dating. The number of pretreated, dated and calibrated samples was 60 (as compared to 45 envisaged), including some samples which we collected in 2014. Because all steps of the radiocarbon investigation take several months, the dating results of some samples collected in 2015 will be available only in 2016.
According to the Project Implementation Plan, the AMS radiocarbon dating was performed at the NOSAMS Facility of the Woods Hole Oceanographic Institution, Woods Hole, Massachusetts (U.S.A.), by using the AMS Pelletron®Tandem 500 kV system.
The dated wood samples originate from trees which belong to baobab species (Adansonia spp.). Some dating results have been presented at the “Radiocarbon 22” International Conference (Dakar, Senegal, November 15-20, 2015). Other obtained results were or will be disclosed in scientific articles.
A main aim of our research is still the investigation of the architecture, growth and age limit of the most representative baobab species from mainland Africa, African islands, especially Madagascar, and Australia, by using AMS radiocarbon dating.
Objective 2. Measuring and dating monumental trees of Romania and Europe (II).
Activity 2.1. The measuring of monumental trees.
Activity 2.2. The collecting of samples.
Complete measurements of 40 monumental trees from Romania, Hungary and Moldavia were performed (as compared to 30 envisaged) Wood samples from 6 trees were collected (out of 5 envisaged). The investigated trees belong to the following species: pedunculate oak (Quercus robur), sessile oak (Quercus petraea), ash (Fraxinus excelsior), black poplar (Populus nigra), white poplar (Populus alba), elm (Ulmus spp.), London plane (Platanus x hispanicum).
Activity 2.3. Pretreatment of samples.
Activity 2.4. Radiocarbon dating by AMS and CFAMS.
Activity 2.5. Paleoclimate calibration.
Once again, the 3 activities are associated, because they precede, define and follow the radiocarbon dating. A number of 20 samples (14 foreseen) were pretreated, dated and calibrated.
Objective 3. The climate study of wood samples collected from 2 baobabs (III).
Activity 3.1. The pretreatment of samples.
Activity 3.2. The stable isotope analysis.
Wood samples collected from 4 baobabs (2 envisaged) were pretreated and investigated by stable isotope analysis. The analysis measured the carbon isotopes composition and is based on the fractionation of the 13C and 12C stable isotopes, expressed by δ13C, which is fixed and registered in each growth ring. Because the isotope fractionation is influenced during the photosynthesis by the temperature, air humidity and soil humidity, the variability of the δ13C parametre can be used as proxy for a climate research. The analysis have been performed at the iThemba Laboratories, Cape Town (South Africa), by utilising a TC/EA pyrolysis system associated with a DeltaV Plus mass spectrometre (for isotopes).
Some results of the climate research based on stable isotope investigation are disclosed in the article entitled A regional stable carbon isotope dendro-climatology from the South African summer rainfall area, which was submitted and is in the evaluation process (see article Nr. 7, Obiective 4, Activity 4.2).
Objective 4. Dissemination of results (III).
Activity 4.1. The writing of the activity report.
Activity 4.2. The writing of scientific articles.
Activity 4.3. Making presentations for scientific conferences.
Activity 4.4. Making and sustaining presentations at the “Radiocarbon 22” International Conference, Dakar, Senegal.
The (envisaged) stage results.
1. The annual activity report;
2. Submission of 2-3 manuscripts to scientific journals which are ISI indexed;
3. The publication or acceptance for publication of 2 articles in ISI scientific journals (which were submitted in 2014-2015);
4. Giving two presentations at the “Radiocarbon 22” International Conference, Dakar, Senegal.
Objective 4 and the corresponding activities are associated with the results envisaged to be delivered at the end of the unique phase 2015. Thus, this activity report was prepared and it reflects the achievement of the envisaged objectives and the fulfillment of the expected results.
In 2015, we published a number of 5 articles in scientific journals which are ISI indexed and a sixth article was accepted and will be published in January 2016 (as compared to 2-3 articles envisaged).
These articles are the following:
1. Adrian Patrut, Stephan Woodborne, Karl F. von Reden, Grant Hall, Michele Hofmeyr, Daniel A. Lowy, Roxana T. Patrut, African Baobabs with False Inner Cavities: The Radiocarbon Investigation of the Lebombo Eco Trail baobab, PLoS ONE, 2015, 10(1): e0117193. doi: 10.1371/journal.pone.0117193. (ISI impact factor: 3.234).
2. Adrian Patrut, Karl F. von Reden, Pascal Danthu, Jean-Michel Leong Pock-Tsy, Roxana T. Patrut, Daniel A. Lowy, Searching for the oldest baobab of Madagascar: Radiocarbon investigation of large Adansonia rubrostipa trees, PLoS ONE, 2015, 10(3): e0121170. doi: 10.1371/journal.pone. 0121170. (ISI impact factor: 3.234).
3. Stephan Woodborne, Grant Hall, Iain Robertson, Adrian Patrut, Mathieu Rouault, Neil J. Loader, Michele Hofmeyr, A 1000-year carbon isotope rainfall proxy record from South African baobab trees (Adansonia digitata L.), PLoS ONE, 2015, 10(5): e0124202. doi: 10.1371/journal.pone.0124202. (ISI impact factor: 3.234).
4. Adrian Patrut, Karl F. von Reden, Pascal Danthu, Jean-Michel Leong Pock-Tsy, Laszlo Rakosy, Roxana T. Patrut, Daniel A. Lowy, Dragos Margineanu, AMS radiocarbon dating of very large Grandidier’s baobabs (Adansonia grandidieri), Nucl. Instr. Meth. B (Nuclear Instruments and Methods in Physics Section B), 2015, 361: 591-598. doi: 101016/ j.nimb.2015.04.044. (ISI impact factor: 1.124).
5. Adrian Patrut, Stephan Woodborne, Roxana T. Patrut, Grant Hall, Laszlo Rakosy, Karl F. von Reden, Daniel A. Lowy, Dragos Margineanu, Radiocarbon dating of African baobabs with two false cavities: The investigation of Luna tree, Studia Univ. Babes-Bolyai Ser. Chem., 2015, 60(4), 7-19. (ISI impact faactor: 0.191).
6. Adrian Patrut, Roxana T. Patrut, Pascal Danthu, Jean-Michel Leong Pock-Tsy, Laszlo Rakosy, Daniel A. Lowy, Karl F. von Reden, AMS radiocarbon dating of large za baobabs (Adansonia za) of Madagascar, PLoS ONE, nr. PONE-D-15-40192R1, accepted for publication / in press (ISI impact factor: 3.234).
In 2015, a number of 5 articles were or will be submitted for publication (as compared to 2-3 envisaged), out of which one was published (Nr. 5, în the previous list) and another was accepted for publication and is in press (Nr. 6). Another article is in the process of evaluation (Nr. 7, in the following list) and other two articles (Nr. 8 and 9) have been prepared and will be submitted for publication:
7. Stephan Woodborne, Patience Gandiwa, Grant Hall, Adrian Patrut, Jemma Finch, A regional stable carbon isotope dendro-climatology from the South African summer rainfall area, PLoS ONE, nr. PONE-D-15-43522, in evaluation (ISI impact factor: 3.234).
8. Adrian Patrut, Stephan Woodborne, Karl F. von Reden, Grant Hall, Roxana T. Patrut, Laszlo Rakosy, Pascal Danthu, Jean-Michel Leong Pock-Tsy, Dragos Margineanu, The growth stop phenomenon of baobabs (Adansonia spp.) identified by AMS radiocarbon dating, Radiocarbon (ISI impact factor: 2.228).
All these articles mention our research project as funding source for the disclosed research results by the following statement: ”The research was funded by the Romanian Ministry of National Education CNCS-UEFISCDI under grant PN-II-ID-PCE-2013-76”.
Other 3 articles, which present results obtained in 2015, are in preparation.
In 2015, our research team participated with 2 members and 2 accepted presentations (2 envisaged) at the well-known “Radiocarbon 22” International Conference (Dakar, Senegal, November 15-20, 2015):
A. Adrian Patrut, Stephan Woodborne, Karl F. von Reden, Grant Hall, Roxana T. Patrut, Laszlo Rakosy, Pascal Danthu, Jean-Michel Leong Pock-Tsy, Daniel a. Lowy, Dragos Margineanu, The growth stop phenomenon of baobabs (Adansonia spp.) identified by AMS radiocarbon dating.
B. Roxana T. Patrut, Karl F. von Reden, Stephan Woodborne, Laszlo Rakosy, Adrian Patrut, Grant Hall, Sébastien Garnaud, Daniel A. Lowy, Dragos Margineanu, Radiocarbon dating of African baobabs (Adansonia digitata ) with ring-shaped structures and false cavities.
The data presented in this Scientific Report demonstrate that all objectives and activities envisaged in the Project Implementation Plan for 2015 have been fulfilled and achieved. All anticipated results for 2015 have been obtained.
Project Manager,
Prof. dr. Adrian Pătruţ
SCIENTIFIC REPORT
on the implementation of the project entitled
New research in dendrochronology and environmental climate change by using AMS/CFAMS radiocarbon dating and stable isotope analysis
Code PN-II-ID-PCE-2012-4-0393
Grant Nr. PN-II-ID-PCE-2013-76
________________________________
for the period January – December 2014
Report for the period January – December 2014
All scientific activities of the research project pursued the fulfillment of the objectives mentioned in the unique phase 2014 of the Project Implementation Plan. The main achievements will be presented and some of the most important results will be discussed.
Objective 1. Baobab dating (II).
Activity 1.1. Sample collection.
A number of 40 representative African baobabs (Adansonia digitata) from South Africa, Namibia and Zimbabwe were measured and investigated. Wood samples were collected from 20 trees (as compared to 15-20 baobabs envisaged). Some trees are known by baobab researchers; however, the majority of the investigated baobabs are not mentioned in the litterature and are known only by the local population.
Some of the obtained results were unexpected. Thus, we discovered that the highest density of huge baobabs in the world is in the area of Outapi town, of the Ovamboland region, Namibia, in the vicinity to the border with Angola. Here, we measured 10 individuals with circumference values at 1.30 m (cbh) over 20 m, out of which 4 individuals with cbh values exceeding 24 m. According to the radiocarbon dating results, these trees grow very fast in the sandy and salty soils.
We found out that two of these baobabs, out of which one was completely unknown, are among the 5 largest African baobabs in the world. The huge Sir Howard baobab of Tsandi (Fig. 1) has a height h = 23.8 m and a circumference cbh = 31.60 m. The tree has a cluster type structure with 4 fused stems; it also possesses 5 false stems, which act as anchors in the sandy soil.
The second giant baobab was discovered in a backyard in the Outapi town, where its cavity was used to deposit materials and even some domestic waste. It has the following dimensions: h = 22.1 m, cbh = 30.60 m. According to our investigation, this impressive baobab has a closed ring-shaped structure with 4 fused stems that close a false cavity. Both trees have remarkable volume values, of over 300 m3.
Fig. 1. The huge Sir Howard baobab of Tsandi is one of the largest African baobabs.
Activity 1.2. Pretreatment of samples.
Activity 1.3. Radiocarbon dating by AMS and CFAMS.
Activity 1.4. Paleoclimate calibration.
The 3 activities are associated, because the first one precedes and the last one is subsequent to the radiocarbon dating. The number of pretreated, dated and calibrated samples was 105 (as compared to 60 envisaged), including some samples which we collected in 2013.
According to the Project Implementation Plan, the AMS radiocarbon dating was performed at the well-known NOSAMS Facility of the Woods Hole Oceanographic Institution, Woods Hole, Massachusetts (U.S.A.), by using the AMS Pelletron®Tandem 500 kV system.
The dated wood samples originate from trees which belong to the 4 investigated baobab species (Adansonia spp.) in 2013 and 2014, namely the African baobab (Adansonia digitata), Grandidier baobab (Adansonia grandidieri), fony baobab (Adansonia rubrostipa) and za baobab (Adansonia za).
A main aim of our research was to determine the architecture, growth and age limit of the largest baobab specimens of continental Africa and Madagascar by using AMS radiocarbon dating. After which the oldest parts/trunks of the two oldest known baobabs and angiosperms, i.e. Dorslandboom (Namibia) and Glencoe (South Africa), died in 2005 and 2009, we learned that the oldest standing individual started dying and will probably collapse completely over the next years. We visited Holboom („hollow baobab”) (Fig. 2), the huge baobab located in the Nyae Nyae Conservancy, in the Otjozondjupa province of eastern Namibia, in May 2014. The road had been inaccessible for 5 months and the tree was isolated between areas flooded by temporary lakes. The western stem or left arm, which broke off in 2012, was partially decomposed. We found out that the main cavity walls also collapsed and the right arm is partially broken and will collapse soon (Fig. 3). Holboom is still the tallest and stoutest living African baobab. Its main dimensions are: h = 30.2 m and cbh = 35.10 m. Holboom has a strange structure, with 5 fused stems in a closed double ring-shaped structure that close 2 false cavities. The baobab also has 2 additional stems outside the rings, which represent the so-called „arms”.
Fig. 2. Holboom, the impressive baobab of eastern Namibia, is dying. The stem which represented its left arm has fallen and is partially decomposed.
The fact that, during the last 10 years, the oldest African baobab individuals or at least their oldest stems died or are dying, as well as the continuous decrease of the African baobab populations over the past 100-150 years, indicate that the climate modifications (toward a more warmer and aride climate), have affected and continue to affect significantly this species.
The radiocarbon dating results also evinced another unexpected fact, namely that many large baobabs have stopped growing over the past centuries. We called this new phenomenon „growth stop”.
Fig. 3. The image shows the main inner cavity of Holboom. Its ceiling and several cavity walls have collapsed.
Objective 2. Measuring and dating monumental trees of Romania and Europe (I).
Activity 2.1. The measuring of monumental trees.
Activity 2.2. The collecting of samples.
Complete measurements of 45 monumental trees were performed (compared to 30 envisaged) from Romania, France, Italy, Spain etc. Wood samples from 6 trees were collected (out of 6 envisaged). The investigated trees belong to the following species: oak (Quercus robur), ash (Fraxinus excelsior), black poplar (Populus nigra), white poplar (Populus alba), olive tree (Olea europaea), walnut (Juglans regia), dragon tree (Dracaena draco).
Activity 2.3. Pretreatment of samples.
Activity 2.4. Radiocarbon dating by AMS and CFAMS.
Activity 2.5. Paleoclimate calibration.
Once again, the 3 activitites are associated, because they precede, define and follow the radiocarbon dating. A number of 24 samples (20 foressen) were pretreated, dated and calibrated. The obtained results will be available in 2015 and will be presented in 1-2 scientific articles, which will be submitted for publication.
Objective 3. The climate study of baobab wood samples.
Activity 3.1. The pretreatment of samples.
Activity 3.2. The stable isotope analysis.
Wood samples collected from several baobabs were pretreated and investigated by stable isotope analysis. These baobab specimens originate from South Africa, namely from the Kruger National Park (Pafuri Section) and from the Mapungubwe National Park, i.e. from the so-called Limpopo basin. The analysis measured the carbon isotopes composition and is based on the fractionation of the 13C and 12C stable isotopes, expressed by δ13C, which is fixed and registered in each growth ring. Because the isotope fractionation is influenced during the photosynthesis by the temperature, air humidity and soil humidity, the variability of the δ13C parametre can be used as proxy for a climate research. The analysis were performed at the iThemba Laboratories, Cape Town (South Africa), by utilising a TC/EA pyrolysis system associated with a DeltaV Plus mass spectrometre (for isotopes).
Objective 4. Dissemination of results (II).
Activity 4.1. The writing of the activity report.
Activity 4.2. The writing of scientific articles.
Activity 4.3. Making presentations for scientific conferences (AMS-13 conference, France).
The (envisaged) stage results.
1. The annual activity report;
2. The submitting of 3 scientific articles to scientific journals which are ISI indexed;
3. The publishing or accepting for publishing of 2 articles in ISI scientific journals;
4. Two presentations at the international AMS-13 conference.
Objective 4 and the corresponding activities are associated with the results envisaged to be delivered at the end of the unique phase 2014. Thus, this activity report was prepared and it reflects the achievement of the envisaged objectives and the fulfillment of the expected results.
We emphasise that our research team is the only one in the world, which use AMS radiocarbon dating for determining the age, architecture and growth of large and live angiosperm trees. Until recently, the investigation of the true age of baobabs remained almost unique, as it was limited to dating samples collected from the remains of dead specimens which decay quickly. Our research is based on a new methodology which also allows to investigate and date standing and live specimens. This approach consists of AMS radiocarbon dating of small wood samples collected from inner cavities, deep incisions/entrances in the trunk, fractured/broken trunks and from the outer part/exterior of large baobabs.
The climate research, which uses as proxy annual growth rings extracted from large and old baobabs, is associated with a previous AMS radiocarbon dating results in order to establish a time/age scale of the investigated samples. This original climate research is very important for areas without native gymnosperms, such as Africa. The climate research was performed in a collaboration between the iThemba Laboratories (South Africa), the Swansea University (United Kingdom) and our research team.
A number of 5 scientific articles were submitted for publication (as compared to 3 articles envisaged) to international scientific journals with an impact factor between 1,186 and 3,534, as follows:
1. Adrian Patrut, Stephan Woodborne, Karl F. von Reden, Grant Hall, Michele Hofmeyr, Daniel A. Lowy, Roxana T. Patrut, African baobabs with false inner cavities: The radiocarbon investigation of the Lebombo Eco Trail baobab, Plos One (impact factor: 3,534).
2. Adrian Patrut, Karl F. von Reden, Pascal Danthu, Jean-Michel Leong Pock-Tsy, Roxana T. Patrut, Daniel A. Lowy, Searching for the oldest baobab of Madagascar: Radiocarbon investigation of large Adansonia rubrostipa trees, Plos One (impact factor: 3,534).
3. Stephan Woodborne, Grant Hall, Iain Robertson, Adrian Patrut, Mathieu Rouault, Neil J. Loader, Michele Hofmeyr, A 1000-year carbon isotope rainfall proxy record from South African baobab trees (Adansonia digitata L.), Plos One (impact factor: 3,534).
4. Adrian Patrut, Karl F. von Reden, Stephan Woodborne, Daniel A. Lowy, Laszlo Rakosy, Roxana T. Patrut, Sebastien Garnaud, Architecture, age and growth of the African baobab assessed by radiocarbon dating, Ann. For. Sci. (Annals of Forest Science) (impact factor: 1,536).
5. Adrian Patrut, Karl F. von Reden, Pascal Danthu, Jean-Michel Leong Pock-Tsy, Laszlo Rakosy, Roxana T. Patrut, Daniel A. Lowy, Dragos Margineanu, AMS radiocarbon dating of very large Grandidier’s baobabs (Adansonia grandidieri), Nucl. Instr. Meth. B (Nuclear Instruments and Methods in Physics Section B) (impact factor: 1,186).
All 5 articles mention that: „The research was funded by the Romanian Ministry of National Education CNCS-UEFISCDI under grant PN-II-ID-PCE-2013-76”.
There has been some delay in the AMS radiocarbon dating at the Woods Hole Oceanographic Institution, due to maintenance work and an upgrade of the accelerator. This determined a slight delay in the analysing and interpreting of results, and the preparation and submission of the scientific papers, which started only end of July 2014.
Our first 2 manuscripts were accepted for publication, and will be published within the next weeks. The third article is about to be accepted, while the last 2 papers will have a longer evaluation period, due to some specific journal standards.
Here we provide the abstracts of the above mentioned 5 papers. These abstracts summarise our main results:
1. African baobabs with false inner cavities: The radiocarbon investigation of the Lebombo Eco Trail baobab (doi:10.1371/journal.pone.0117193)
Abstract. The article reports the radiocarbon investigation results of the Lebombo Eco Trail tree, a representative African baobab from Mozambique. Several wood samples collected from the large inner cavity and from the outer part of the tree were investigated by AMS radiocarbon dating. According to dating results, the age values of all samples increase from the sampling point with the distance into the wood. For samples collected from the cavity walls, the increase of age values with the distance into the wood (up to a point of maximum age) represents a major anomaly. The only realistic explanation for this anomaly is that such inner cavities are, in fact, only natural empty spaces between several fused stems disposed in a ring-shaped structure. We named them false cavities. Several important differences between normal cavities and false cavities are presented. Eventually, we dated other African baobabs with false inner cavities. We found that this new architecture enables baobabs to reach large sizes and old ages. The radiocarbon date of the oldest sample was 1425 ± 24 bp, which corresponds to a calibrated age of 1355 ± 15 yr. The dating results also show that the Lebombo baobab consists of five fused stems, with ages between 900 and 1400 years; these five stems build the complete ring. The ring and the false cavity closed 800–900 years ago. The results also indicate that the stems stopped growing toward the false cavity over the past 500 years.
2. Searching for the oldest baobab of Madagascar: Radiocarbon investigation of large Adansonia rubrostipa trees (doi:10.1371/journal.pone.0121170)
Abstract. 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 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 1136±16 bp. We determined 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 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.
3. A 1000-year carbon isotope rainfall proxy record from South African baobab trees (Adansonia digitata L.)
Abstract. A proxy rainfall record for northeastern South Africa based on carbon isotope analysis of four baobab (Adansonia digitata L.) trees shows centennial and decadal scale variability over the last 1000 years. The record is in good agreement with a 200-year tree ring record from Zimbabwe, and it indicates the existence of a rainfall dipole between the summer and winter rainfall areas of South Africa. The wettest period was c. AD 1075 in the Medieval Warm Period, and the driest periods were c. AD 1635, c. AD 1695 and c. AD1805 during the Little Ice Age. Decadal-scale variability suggests that the rainfall forcing mechanisms are a complex interaction between proximal and distal factors. Higher rainfall oscillations are significantly associated with lower sea-surface temperatures in the Agulhas Current core region and a negative Dipole Moment Index in the Indian Ocean. The correlation between rainfall and the El Niño/Southern Oscillation Index is non-static with temporal inversions in the rainfall response. The effect is weak and it appears that the El Niño phenomenon is an enabling rather than a causative contributor to rainfall variability. The effect of both proximal and distal oceanic influences are insufficient to explain the rainfall change between the Medieval Warm Period and the Little Ice Age, and the evidence suggests that this was the result of a northward shift of the subtropical westerlies rather than a southward shift of the Intertropical Convergence Zone.
4. Architecture, age and growth of the African baobab assessed by radiocarbon dating
Abstract.
Context The remarkable dimensions of several African baobabs (Adansonia digitata L.) suggests that the iconic tree lives to an old age and might be the longest living angiosperm. The article reports results of the investigation of 34 representative African baobabs, including the largest and oldest specimens.
Aims Our research was focused on multiple questions regarding the architecture of the African baobab and its evolution from young to old ages, the age limit of the species and its growth during the life cycle.
Methods The research is based on AMS (accelerator mass spectrometry) radiocarbon dating of small wood samples collected from inner cavities and from different areas of the trunk of large baobabs.
Results The results demonstrate that all large baobabs are multi-stemmed. We identified the open and closed ring-shaped structures, which are the most important architectures that enable baobabs to reach old ages and large sizes. We also identified the false cavities, which are large natural empty spaces between fused stems disposed in a closed ring-shaped structure. The oldest baobabs were found to have ages up to 2,000 years.
Conclusion The African baobab is the first species for which these new architectures and architectural elements are reported.
5. AMS radiocarbon dating of very large Grandidier’s baobabs (Adansonia grandidieri)
Abstract. The article reports the AMS radiocarbon investigation of the two largest known Adansonia grandidieri specimens. The two baobabs, which are called Tsitakakoike and Pregnant baobab, are located in Southwestern Madagascar, near Andombiro. According to measurements, Tsitakakoike, which has a girth of 27.36 m and a total wood volume of 455 m3, is the biggest individual above ground level of all Adansonia species. Several wood samples collected from the outer part of their trunks were dated by radiocarbon. We found that both baobabs possess multi-stemmed quasi-cylindrical trunks, which are mainly hollow. They have a closed ring-shaped structure with a false cavity inside, which is similar to that we identified and described in large and old Adansonia digitata. The radiocarbon dates of the oldest dated samples were 1274±20 bp for Tsitakakoike and 962±20 BP for the Pregnant baobab. According to the original position of the oldest samples and to the architectures of the two Adansonia grandidieri, we consider that the ages of both trees are between 1300-1500 years. By these values, Adansonia grandidieri becomes the third Adansonia species with individuals older than 1000 years, according to accurate dating results.
The radiocarbon scientific community has 2 main international events, which are organized every 3rd year, namely the Radiocarbon International Conference and the AMS International Conference. The AMS-13 International Conference took place in Aix-en-Provence (France), from August 24 to August 29, 2014. Our research team participated with 3 presentations (only two of them were envisaged), which were delivered by the project manager. Here we present the original abstracts, such as they were included in the Thirteenth International Conference on Accelerator Mass Spectrometry Program and Abstracts Handbook, on pages 132-134:
1. GAA 48, page 132 in Programme and Abstracts Handbook of „The Thirteenth International Conference on Accelerator Mass Spectrometry”
Topic: General AMS Applications
Topic Code: GAA
Age determination of large trees with false inner cavities:
AMS radiocarbon dating of the Lebombo Eco trail baobab
Adrian Patrut1, Stephan Woodborne2, Karl von Reden3, Grant Hall4, Roxana Patrut5, Daniel Lowy6, Michele Hofmeyr7, Dragos Margineanu1
1Faculty of Chemistry, Babeş-Bolyai University, Cluj-Napoca, Romania.
2iThemba Laboratories, Somerset West, 7129, South Africa.
3NOSAMS Facility, Dept. of Geology & Geophysics, Woods Hole Oceanographic Institution,
Woods Hole, MA 02543, U.S.A.
4Mammal Research Institute, University of Pretoria, South Africa.
5Faculty of Biology and Geology, Babeş-Bolyai University, Cluj-Napoca, Romania.
6Nova University, Alexandria Campus, Alexandria, VA 22311-509, U.S.A.
7SANParks Scientific Services, Skukuza, 1350, South Africa
Several anomalies were observed in the AMS radiocarbon dating of wood samples collected from inner cavities of large live African baobabs (Adansonia digitata L.). Normally, the age values of samples collected from large central cavities should decrease continuously from the cavity walls toward the outer part of the trunk/stem. However, we found that in many cases the age values increase from the cavity walls up to a certain distance in the wood, after which they decrease toward the outer part. The only explanation for these anomalies is that such cavities are, in fact, only natural empty spaces between fused stems diposed in a ring-shaped structure. We named them false cavities.
The first African baobab for which we noted these anomalies, that made possible the identification of false cavities, was the Lebombo Eco trail baobab, located in the Limpopo Park, Mozambique. Here we present the complete AMS results of segments originating from 6 long samples from the Lebombo baobab. The dating results indicate that the tree consists of 5 perfectly fused stems that close almost completely a large false inner cavity. The radiocarbon date of the oldest segment was found to be of 1425±24 BP, which corresponds to a calibrated age of 1335±15 years. The dates also indicate that the stems have stopped growing toward the false cavity over the past 500 years.
The research was funded by the Romanian Ministry of National Education CNCS-UEFISCDI under grant PN-II-ID-PCE-2013-76.
2. GAA 48, page 133 in Programme and Abstracts Handbook of „The Thirteenth International Conference on Accelerator Mass Spectrometry”
Topic: General AMS Applications
Topic Code: GAA
Searching for the oldest Malagasy baobab:
AMS radiocarbon investigation of large Adansonia rubrostipa and Adansonia za trees
Adrian Patrut1, Karl von Reden2, Jean-Michel Leong Pock-Tsy3, Daniel Lowy4, Roxana Patrut5, Pascal Danthu3,6
1 Babeş-Bolyai University, Faculty of Chemistry, Cluj-Napoca, Romania.
2NOSAMS Facility, Dept. of Geology & Geophysics, Woods Hole Oceanographic Institution,
Woods Hole, MA 02543, U.S.A.
3DP Forêt et Biodiversité, Antananarivo, Madagascar.
4Nova University, Alexandria Campus, Alexandria, VA 22311-509, U.S.A.
5 Babeş-Bolyai University, Faculty of Biology and Geology, Cluj-Napoca, Romania.
6Cirad, UPR BSEF, Montpellier, France.
Six of the nine baobab species (Adansonia spp.) are endemic to Madagascar. The two species with the largest total population are Adansonia rubrostipa Jum. & H. Perrier (Fony baobab) and Adansonia za Baill. (Za baobab); each species is represented by well over one million individuals.
This research is the very first investigation of the architecture and age of A. rubrostipa and A. za. Large individuals belonging to the two species, located in Southern Madagascar, were investigated; the primary method of analysis was AMS radiocarbon dating of wood samples collected from their trunks.
The results indicate that big specimens of the two baobab species are typically multi-stemmed and exhibit cluster or ring-shaped structures. According to radiocarbon dates, the oldest known baobab of Madagascar is the so-called “Grandmother”, a triple-stemmed A. rubrostipa individual which grows in the Tsimanampetsotsa National Park. The dating results suggest an age of 1,600 years. Thus, A. rubrostipa becomes the second Adansonia species with “millenarian” trees, i.e. trees that can live over 1,000 years.
The research was funded by the Romanian Ministry of National Education CNCS-UEFISCDI under grant PN-II-ID-PCE-2013-76.
3. GAA 49, page 134 in Programme and Abstracts Handbook of „The Thirteenth International Conference on Accelerator Mass Spectrometry”
Topic: General AMS Applications
Topic Code: GAA
Structure and age of the Grandidier’s baobab (Adansonia grandidieri )
determined by AMS radiocarbon dating
Adrian Patrut1, Karl von Reden2, Jean-Michel Leong Pock-Tsy3, Laszlo Rakosy4, Roxana Patrut4, Daniel Lowy5, Dragos Margineanu1, Pascal Danthu3,6
1 Babeş-Bolyai University, Faculty of Chemistry, Cluj-Napoca, Romania.
2NOSAMS Facility, Dept. of Geology & Geophysics, Woods Hole Oceanographic Institution,
Woods Hole, MA 02543, U.S.A.
3DP Forêt et Biodiversité, Antananarivo, Madagascar.
4Babeş-Bolyai University, Faculty of Biology and Geology, Cluj-Napoca, Romania.
5Nova University, Alexandria Campus, Alexandria, VA 22311-509, U.S.A.
6Cirad, UPR BSEF, Montpellier, France.
The genus Adansonia belonging to the Bombacoideae, a subfamily of Malvaceae, consists of nine species. Six species are endemic to Madagascar and have a natural distribution only here. The Grandidier’s baobab (Adansonia grandidieri Baill.) is the biggest and most famous of the six Malagasy baobab species.
Grandidier's baobab is classified as endangered species by the IUCN Red List 2006. However, recent high-resolution satellite images demonstrate that the total population of Grandidier’s baobab is much larger than previous estimates, surpassing one million individuals.
The research presented here is the first investigation of the architecture and age of the Grandidier’s baobab. Several very large individuals from the Morombe-Andombiro-Andavadoaka area, including Tsitakakoike, the largest Malagasy baobab, were examined; the main method used was AMS radiocarbon dating of wood samples collected from their trunks. The results suggest that, in terms of total wood volume, the largest Grandidier’s baobabs might exceed the largest African baobabs (Adansonia digitata L.). The performed research also indicates that big Grandidier’s baobabs are typically multi-stemmed, with very large and tall closed empty spaces inside their quasi-cylindrical trunks. According to radiocarbon dates, the ages of the oldest Grandidier’s baobabs are over 1,000 years.
The research was funded by the Romanian Ministry of National Education CNCS-UEFISCDI under grant PN-II-ID-PCE-2013-76.
The information presented in this Scientific Report supports our statement that all objectives and activities envisaged in the Project Implementation Plan for 2014 have been fulfilled and achieved. All anticipated results for 2014 have been obtained.
Project Manager,
Prof. dr. Adrian Pătruţ