RADIOCARBON DENDROCHRONOLOGY, ISOTOPE DENDROCLIMATOLOGY AND CONSERVATION OF MONUMENTAL ANGIOSPERM TREES OF THE WORLD

CERCETĂRI DENDROCRONOLOGICE CU RADIOCARBON, STUDII DENDROCLIMATOLOGICE CU IZOTOPI STABILI ȘI CONSERVAREA UNOR ARBORI ANGIOSPERMI MONUMENTALI DIN LUME

Cod proiect (Project code): PN-III-P4-ID-PCE-2020-2567

Acronim (Acronym):  RADISODEN

 

 

 

 

Abstract

Proiectul de cercetare continuă și extinde cercetările noastre dendrocronologice și dendroclimatologice precedente asupra unor arbori monumentali în regiuni care nu au fost încă cercetate din zone tropicale și temperate. A fost adăugată o nouă temă de cercetare, referitoare la protecția și conservarea arborilor monumentali. Cercetarea dendrocronologică se bazează pe metodologia noastră originală, care constă în datarea cu radiocarbon prin AMS a mostrelor de lemn recoltate din arbori angiospermi. Intenționăm lămurim definitiv problema arhiteturii, creșterii și vârstei baobabilor monumentali. Investigațiile noastre se vor focaliza îndeosebi asupra specimenelor aparținând genului Adansonia, și anume A. grandidieri din Madagascar și A. gregorii din Australia, dar și asupra A. digitata din Africa continentală. Vor fi investigați și arbori angiospermi respectabili din România, Moldova și Europa. Cercetarea dendroclimatologică va folosi ca indicator proxy inelele de creștere ale baoabilor, datate în prealabil cu radiocarbon. Reconstrucția climatică pe ultimii 1000-2000 ani, bazată pe analiza de izotopi stabili ai carbonului și oxigenului, se va focaliza asupra dinamicii Zonei de convergență intertropicală și a variabilității musonilor. Zonele țintă sunt Senegal, Angola, Namibia, Oman, Congo și Madagascar. Se va acorda o atenție deosebită protecției și conservării baobabilor monumentali din Senegal, Namibia și Madagascar, unde aceștia se află sub amenițare antropică severă.

Abstract

The research project continues and enhances our previous studies on dendrochronology and dendroclimatology of superlative angiosperm trees in new areas from tropical and temperate zones, which have not been studied. A new research topic, concerning the protection and conservation of monumental trees, was included. The dendorchronological research is based on our original approach, consisting of AMS radiocarbon dating of wood samples collected from large live trees. We intend to clarify definitively the aspects of the architecture, growth, age of monumental baobabs. Our investigation will focus especially on specimens belonging to the Adansonia genus, namely A. grandidieri from Madagascar and A. gregorii from Australia in particular but also A. digitata from mainland Africa. Large angiosperm trees from Romania, Moldova and Europe will also be investigated. The dendroclimatological research will use baobab growth rings, previously dated by radiocarbon, as proxy. The climate reconstructions over the last 1000-2000 years, which are based on stable carbon and oxygen isotope chemistry, will focus on Intertropical Convergence Zone dynamics and monsoon variability. Target areas include Senegal, Angola, Namibia, Oman, Congo and Madagascar. A particular attention will be given to the protection and conservation of baobab forests and monumental specimens from Senegal, Namibia and Madagascar, which are facing severe anthropic threats.

Obiectivul proiectului

Titlul proiectuluiCercetări dendrocronologice cu radiocarbon, studii dendroclimatologice cu izotopi stabili şi conservarea unor arbori monumentali din lumereflectă obiectivele proiectului şi cele 3 direcţii principale de cercetare, şi anume:
-cercetare dendrocronologică, prin datarea cu radiocarbon prin AMS a mostrelor de lemn recoltate din arbori angiospermi monumentali (îndeosebi baobabi), pentru determinarea vîrstei, creşterii şi arhitecturii acestora;
-studiu dendroclimatologic, prin analiză de izotopi stabili pe inele de creştere din baobabi monumentali, datate în prealabil cu radiocarbon, pentru determinarea modificărilor climatice din zonă în ultimii 1000-2000 ani;
-protecția și conservarea pădurilor de baobab şi specimenelor monumentale.

Project’s goals

The title of the project itself “Radiocarbon dendrochronology, isotope dendroclimatology and conservation of monumental angiosperm trees of the world” expresses the objectives and the three main research directions of the project, namely:
-dendrochronological research, based on AMS radiocarbon dating of wood samples collected from large live angiosperm trees (especially baobabs), for determining their age, growth and architecture;
-dendroclimatological study, based on stable isotope chemistry of growth rings, previously dated by radiocarbon, as proxy; this will offer paleoclimate information of the studied area over the last 1000-2000 years;
-protection and conservation of baobab forests and monumental specimens.

Rezultatele estimate

Rezultatele obţinute vor fi prezentate în rapoartele de cercetare/activitate întocmite la sfîrşitul fiecărei etape. Principalele rezultate vor fi diseminate într-un număr de 10-12 articole, care vor fi înaintate spre publicare în reviste ştiinţifice indexate ISI, ca de exemplu Radiocarbon, Dendrochronology, Plos One, Forests, Tree Physiology, Annals of Forest Science, Nuclear Instruments and Methods in Physics B, Frontiers in Climate, Plant şi reviste ce aparţin grupului Nature. De asemenea, acestea vor face obiectul a 5-7 prezentări la conferinţele internaţionale de radiocarbon, de exemplu  AMS-15 (Sydney, Australia 2021), Radiocarbon and Environment-3 (Gliwice, Polonia 2021), Radiocarbon-24 (Jerusalem, Israel 2022) şi la conferinţe despre climă şi modificări climatice.

Estimated results

The obtained results will be disclosed in research/activity reports, which will be delivered at the end of every research period. The main results will also be disseminated in a number of 10-12 articles, which will be published in ISI peer-reviewed international scientific journals, such as Radiocarbon, Dendrochronology, Plos One, Forests, Tree Physiology, Annals of Forest Science, Nuclear Instruments and Methods in Physics B,  Frontiers in Climate, Plants and journals which belong to the Nature group. We also envisage presenting our findings in at least 5-7 presentations at the main international radiocarbon conferences, i.e., AMS-15 (Sydney, Australia 2021), Radiocarbon and Environment-3 (Gliwice, Poland 2021), Radiocarbon-24 (Jerusalem, Israel 2022) and one or two climate conferences, which are to be disclosed.

Articole publicate

(Published papers)

 

1. A. Pătruţ, R.T. Pătruţ, L. Rakosy, D. Rakosy, I.A. Raţiu, K.F. von Reden, Radiocarbon investigation of the Big Baobab of Outapi, Namibia, Studia UBB Chemia, LXVI, 1,, 2021, 153-163, doi: 10.24193/subbchem.2021.1.12

 

2. A. Pătruţ, R.T. Pătruţ, J-M. Leong Pock-Tsy, P. Danthu, S. Woodbborne, L. Rakosy, I.A. Raţiu, Investigation of the Architecture and Age of Superlative Adansonia grandidieri from the Andombiry Forest, Madagascar, Forests, 2021, 12, 1258, doi.org/10.3390/f12091258

 

3. A. Pătruţ, L. Rakosy, R.T. Pătruţ, V. Bocoş-Binţinţan, I.A. Raţiu, J. Bodis, S. Woodborne, AMS Radiocarbon dating of the large pedunculate oak of Mercheaşa, Romania, Studia UBB Chemia, LXVI, 3, 2021, 255-263, doi: 10.24193/subbchem.2021.3.16

 

4. A. Pătruţ, R.T. Pătruţ, L. Rakosy, I.A. Raţiu, D.A. Lowy, K.F. von Reden, Age, growth and architecture of the Big Tree at Victoria Falls, Dendrochronologia, 70, 2021, 125898, doi.org/10.1016/j.dendro.2021.125898

Participare la conferințe științifice

 

Conferința internațională AMS-15 de la Sydney, Asutralia.

Participare cu o prezentare de tip poster:

 

A. Pătruţ, R.T. Pătruţ, L. Rakosy, D. Rakosy, I.A. Raţiu, W. Oliver, K.F. von Reden, Radiocarbon investigation of the large African baobabs of Outapi, Namibia.

Scientific conference participation

AMS-15 international conference, Sydeny, Australia.

Participated with a poster presentation:

 

A. Pătruţ, R.T. Pătruţ, L. Rakosy, D. Rakosy, I.A. Raţiu, W. Oliver, K.F. von Reden, Radiocarbon investigation of the large African baobabs of Outapi, Namibia.

Echipă și colaboratori

(Team and collaborators)

Project leader - Prof. Dr. Adrian Pătruț, Brainmap ID: U-1700-027W-4035, email: apatrut@gmail.com

Senior researcher - Prof. Dr. Laszlo Rakosy, Brainmap ID: U-1700-039C-4401

Research assistant - Dr. Ileana Rațiu, Brainmap ID: U-1900-061R-9515

Research assistant - Dr. Roxana Pătruț, Brainmap ID: U-1700-037S-8765

 



SCIENTIFIC AND TECHNICAL REPORT

on the implementation of the project entitled

 

Radiocarbon dendrochronology, isotope dendroclimatology and conservation of  monumental angiosperm trees of the world

(Acronym RADACLIR)

 

Code PN-III-P4-ID-PCE-2020-2567

Contract No. PCE 145/2021

________________________________

for the period January - December 2021

 

SUMMARY OF THE UNIQUE PHASE I (2021)

 

The project consists of 3 recurring phases with identical designation, each with 4 identical objectives and similar actions (action types). The differentiation is possible by the 1, 2 or 3 index, and I, II or III, respectively, which correspond to the three different years of the project period and also to the different investigated areas and angiosperm species. Accordingly, the phase for 2021 is called Phase 1 – The conservation and protection of monumental trees and their radiocarbon dating, and stable isotope analysis, respectively. The specific objectives of Phase 1 concern the radiocarbon dating of baobabs (objective 1.1), the climate study based on wood samples collected from baobabs and investigated by stable isotope analysis (objective 1.2), the measuring and dating of angiosperm trees in Romania and Europe (objective 1.3) and the dissemination of results (objective 1.4).

 

The scientific activities of the research project performed during the January-December 2021 implementation period pursued the fulfillment of the objectives mentioned in the unique phase of the Project Implementation Plan for 2021.

Unique phase 1 (2021): Conservation and protection of superlative trees and the AMS radiocarbon investigation and stable isotope analysis of such trees (I).

Objective 1.1. Dating of baobabs (I). 

Action 1.1.1. Sample collection from 35 baobabs.

Objective 1.2. Climate study (I).

Action 1.2.1. Sample collection from 35 baobabs.

A number of 45 representative African baobabs (Adansonia digitata) from Senegal and Tanzania were measured and investigated. Samples for radiocarbon dating were collected from 36 specimens (compared to 35 envisaged) and from 3 baobabs for stable isotope analysis, respectively (compared to 3 envisaged).

An important visit to Senegal took place in September-October 2021, with special focus on the Dakar-M’bour-Fissel-Samba Dia area. With its 5-10 million specimens, Senegal is the country with the highest number of African baobabs in the northern hemisphere. Moreover, Senegal hosts the largest and oldest superlative baobabs of the northern hemisphere. 

In this respect, we mention the baobab located close to the Sinthiou-Keita settlement, in the proximity of Nianing town in the Thiès region. This baobab has the biggest wood volume V = 300  m3 in the northern hemisphere. It has a cluster structure composed of 3 common stems and 2 false stems (Fig. 1). The measurements are: height h = 22.5 m, circumference (at 1.30 m above ground level) cbh = 27.10 m. The baobab is around 750 years old.

Fig. 1. The Sinthiou-Keita baobab has the biggest wood volume (300 m3) in the northern hemisphere.

Our research team investigated the sacred baobab of Nianing, also in the Thiès region, which is a good candidate for the title of Senegal’s oldest tree. Its closed ring-shaped structure is formed by 11 main stems around a false cavity; 3 younger stems and a false stem are located outside the ring(s) (Fig. 2). Its measurements are: h = 18.7 m, cbh = 24.70 m and V = 180 m3.

Fig. 2. The Nianing baobab consists of 15 fused stems.

The baobab with the largest circumference in the northern hemisphere remains the baobab of Warang, Senegal. This remarkable tree has 18 stems. Its circumference now reaches cbh = 28.90 m. In 2019, we reported that the baobab, which was previously located on vacant land, was enclosed in a yard of a newly built house. We expressed our concern for the damage to the roots during the construction process and building of the fence (Fig. 3). Currently, discussions with the French owner revealed that she will protect the baobab as much as possible, paying it a special attention.

Fig. 3. The large baobab of Warang is now enclosed between the fence walls of a backyard and has become a sort of “household baobab”.

In August 2021, our research team travelled to Tanzania, focusing on the baobabs of Unguja island (Zanzibar). Unguja island has a total area of 1666 km2 and a maximum length of 83 km, hosting a number of 50.000 – 100.000 African baobabs. The majority are aggregated in the southern and northern regions and partly in the central region, usually in the coastal areas.

The largest baobab of Tanzania was located in Kizimkazi Dimbani in Zanzibar and had a wood volume of 300 m3. This specimen was severely damaged during a heavy storm, which led to its demise in April 2018. Some wood samples were collected from the remains of its trunk and branches.

Close to Kizimkazi, in Makunduchi, a grove of large baobabs can be found. The largest, which we called Makunduchi-1, exhibits a cluster structure and consists of 8 common and 7 false stems (Fig. 4). The measurements are: h = 19.5 m, cbh = 20.05 m, V = 180 m3. The baobab has particular spherical-shaped pods of large sizes.

In the central-western region of Unguja, south of Stone Town lies the Fumba Beach Lodge resort, right on the shores of the Indian Ocean. The resort hosts several African baobabs and the largest, which we called Fumba-1, grows among an unusual ancillary building area that reaches its crown. The baobab has 4 common and one false stems that are fused together forming a cluster structure (Fig. 5). Its measurements are: h  = 14.3 m, cbh = 21.45 m, V = 140 m3.

 

Fig. 4. The Makunduchi-1 baobab has 15 fused stems.

Actions 1.1.2. Pretreatment (80 segments), 1.1.3. AMS radiocarbon dating (80 segments) and 1.1.4. Calibration (80 segments).

85 wood segments were pretreated by the acid-base-acid or α-cellulose pretreatment method, then AMS (accelerator mass spectrometer) radiocarbon dated and subsequently calibrated (compared to 80 envisaged).

The radiocarbon dating by AMS was performed at the iThemba Laboratory for Accelerator Based Sciences (iThemba LABS) in Johannesburg (South Africa) and at the Hertelendi Laboratory of Environmental Studies (Isotoptech Zrt and MTA ATOMKI), Debrecen (Hungary).

Action 1.2.2. Stable isotope analysis (5000 segments). Stable isotope analysis for determining the  δ13C and δ18O values were performed at the Stable Isotope Laboratory of iThemba LABS, Gauteng (South Africa).

Fig. 5. The Fumba-1 baobab, which grows directly on the beach, has its lower part submerged underwater from time to time.

Objective 1.3. Measuring and dating trees of Romania, Moldova and Europe (I)

In July 2021, our research team undertook a trip to the pasture of Mercheaşa village, Homorod commune, Braşov county. A superlative pedunculate oak (Quercus robur) located there was called the “Carpathian Elder”. This tree experienced increased media attention over the last years, which included an exaggerated age estimate of 900 years. The current measurements are: h = 17.6 m, cbh = 10.16 m, V = 50 m3. Dozens of daily visitors from all over the country visit the tree, which is considered to be “the oldest of Romania”. In order to dispel this myth, we collected samples for radiocarbon dating. The dating results indicated that the oak of Mercheaşa has a real age of around 560 years.

Fig. 6. The Mercheaşa oak has an age of “only” 560 years.

In October 2021, the research team travelled to the Sadova village, a suburb of Cîmpulung Moldovenesc city, Suceava county, where a centennial wych elm (Ulmus glabra) can be found. The elm is in a degraded state, missing a large chunk of its trunk. Furthermore, the trunk is mostly empty inside and only three branches of the original crown remain (Fig. 7). The current measurements are: h = 13.8 m, cbh = 6.77 m.

In the beginning of June, the research team travelled to Tenerife island, Spain. Here the endemic dragon trees (Dracaena draco) were investigated. The most representative specimens of the species were measured, with a special focus on the famous Icod tree, also known as “El drago milenario”.

Fig. 7. The wych elm of Sadova.

Actions 1.3.1. Measuring 40 trees, 1.3.2. Collecting samples of 4 trees, 1.3.3. Pretreatment (20 segments) and 1.3.4. AMS radiocarbon dating (20 segments).

A total of 56 trees were measured (compared to 40 envisaged), and samples were collected from 8 trees (compared to 4 envisaged), 30 segments (compared to 20 envisaged) were pretreated and subsequently radiocarbon dated.

Objective 1.4. Dissemination of results.

Action 1.4.1. The writing or publishing of 2-3 scientific papers.

In 2021, we published 4 scientific papers, all in ISI journals, out of which 2 are in the so-called red zone, according to the CNCS classification system. All papers mention that „The research was funded by the Romanian Ministry of Education CNCS-UEFISCDI under grant PN-III-P4-ID-PCE-2020-2567, No. 145/2021.”

Action 1.4.2. 3-5 presentations at international Conferences, such as AMS-15 (Sydney), Radiocarbon and the Environment (Gliwice) etc.

Due to the COVID-19 pandemic, the scheduled conferences were postponed for the next year, except for the AMS-15 conference in Sydney, which took place online.

Action 1.4.3. The writing of the annual activity report. This activity refers to the writing of the present report.

The contribution of the project to the development of human resources for research.
On the research team included a Ph.D. candidate, namely Roxana Pătruţ and a postdoctoral fellow, Dr. Ileana Raţiu.
The Ph.D. candidate partook in most (inter)national field trips, is a co-author of all 4 published papers and of the international AMS-15 conference presentation. In 2021, the Ph.D. candidate defended her thesis entitled 
The investigation of some superlative baobabs (Adansonia spp.) by AMS radiocarbon dating for assessing
 the ages, architecture and growth rates, and by stable isotope analysis respectively, for climate study” (Ph.D. supervisor: Prof. Dr. Laszlo Rakosy), which was based on data 
and results obtained via the current and previous research projects focusing on baobabs. In July 2021, she was granted the title of Doctor in Biology .
The postdoctoral researcher also partook in most field trips within or outside Romania. She is a co-author of all 4 published papers and of the AMS-15 conference presentation.

Conclusions

The information presented above shows that the objectives mentioned in the unique phase of the Project Implementation Plan for 2021 were fulfilled.

Additionally, all envisaged results were obtained.

 


SCIENTIFIC AND TECHNICAL REPORT

on the implementation of the project entitled

 

Radiocarbon dendrochronology, isotope dendroclimatology and conservation of monumental angiosperm trees of the world

(Acronym RADACLIR)

 

Code PN-III-P4-ID-PCE-2020-2567

Contract No. PCE 145/2021

________________________________

for the period January - December 2022

 

SUMMARY OF THE UNIQUE PHASE 2 (2022)

 

The project consists of 3 recurring phases with identical designation, each with 4 identical objectives and similar actions (action types). The differentiation is possible by the 1, 2 or 3 index, and I, II or III, respectively, which corresponds to the three different years of the project period and also to the different investigated areas and angiosperm species. Accordingly, the phase for 2022 is called Phase 2 – The conservation and protection of monumental trees and their radiocarbon dating and stable isotope analysis (II). The specific objectives of Phase 2 concern the radiocarbon dating of baobabs (objective 2.1), the climate study based on wood samples collected from baobabs and investigated by stable isotope analysis (objective 2.2), the measurement and dating of angiosperm trees in Romania and Europe (objective 2.3) and the dissemination of results (objective 2.4).

 

The scientific activities of the research project performed during the January-December 2022 implementation period pursued the fulfillment of the objectives mentioned in the unique phase of the Project Implementation Plan for 2022.

Unique phase 2 (2022): Conservation and protection of superlative trees and the AMS radiocarbon investigation and stable isotope analysis of such trees (II).

Objective 2.1. Dating of baobabs (I). 

Action 2.1.1. Sample collection from 25 baobabs.

Objective 1.2. Climate study (I).

Action 2.2.1. Sample collection from 2 baobabs.

A number of 30 representative African baobabs (Adansonia digitata) from Oman and Senegal were measured and investigated. Samples for radiocarbon dating were collected from 28 specimens (compared to 25 envisaged) and from 2 baobabs for stable isotope analysis, respectively (compared to 2 envisaged).

Two important visits to Oman took place in April (3 persons) and in August 2022 (2 persons), the second just during the south-east monsoon. Oman has a very interesting and unexpected African baobab population. With one exception, all baobabs are located in southern Oman, in the Dhofar Governorate. Many researchers consider these baobabs an impressive botanical reminder of Dhofar’s links with Africa.

The main investigation site is Wadi Hinna, a small semi-arid valley (3 km2) at the edge of the Dhofar Mountains (17º03' N, 54º36' E, altitude 300-360 m) and at 20 km from the coastal plain. Wadi Hinna hosts an unique water-limited cloud forest of African baobabs (Fig. 1). The precipitation (annual rainfall 130 mm) falls almost exclusively during the rainy season (mid-June to mid-September), in which moist air from the Indian Ocean, i.e., the south-east monsoon (called khareef), encounters the mountains leading to clouds and dense fog. The rainfall precipitation is significantly supplemented by horizontal precipitation, namely cloud water interception within the canopy of trees.

Fig. 1. The scenic entrance to the Baobab Forest of Wadi Hinna.

The 106 trees of the Baobab Forest grow on a slope among huge stones of sedimentary rocks, containing mainly limestone, which are moved by the force of water during the rainy season. In recent years, Wadi Hinna was divided into two parts, located at lower and higher altitudes, namely Wadi Hinna and Wadi Hasheer, according to the stratigraphic origin and composition. The trees have different shapes, sizes and structures.

 

Fig. 2. The Grand Baobab of Wadi Hinna during the dry season.

 

Fig. 3. The Grand Baobab Tree of Wadi Hinna during the rainy season.

The Baobab Forest hosts a giant specimen, namely the Grand Baobab Tree of Wadi Hasheer. It exhibits an open ring-shaped structure, which consists of 12 fused stems (Fig. 2, 3). The measurements are: height h = 19.2 m, circumference (at 1.30 m above ground level) cbh = 21.35 m, total wood volume V = 260 m3.

Being three times bigger than any other tree from Wasi Hinna and Wadi Hasheer, the Grand Baobab could be the Parent tree of all trees found in the Baobab Forest.

Another representative baobab from the forest has the code name WHI-1605, after its location (Wadi Hinna) and circumference (10.65 m). It exhibits an open ring-shaped structure and is composed of 6 partially fused stems (Fig. 4). Its dimensions are: h = 12.3 m, cbh = 16.05 m, V = 80 m3.

Fig. 4. The baobab WHI-1605 is located right next to the entrance to Wadi Hinna.

The best known baobab of Oman grows completely isolated in Dalkut, close to the border with Yemen. This baobab is named by the locals “Hiroum Dheeri” (in Arabic, “the tree from far away”). Its dimensions are: h = 13.5 m, cbh = 13.30 m, V = 50 m3. Its height was reduced to only 7.5 m, after that the highest branch broke in 2019-2020. Radiocarbon dating of a small fragment from the broken branch, still on the ground, indicates that the baobab is over 700 years old. This value suggests that the baobab of Dalkut was probably planted by an African traveler who would have passed through the area many centuries ago. The closest baobab to the one in Dalkut is in Wadi Hinna, at a distance of over 150 km.

 

Fig. 5. The baobab of Dalkut in 2017, when its top was still intact.

In October 2022, the Project Manager paid a new visit to Senegal, the country with the highest number of African baobabs in the northern hemisphere. Here we present other two representative Senegalese baobabs which were investigated.

Just behind the Presidential Palace, next to a road to Cap Manuel and the tourist port of Dakar, there is the so-called baobab of the President (Baobab du Président), traditionally called the Baobab from the Cornice East (Baobab de la Corniche Est). It was originally located in a small settlement on the outskirts Dakar, that was demolished in the 1990s. The baobab has now reached the middle of an asphalted road which covers its roots to a good extent and over which many hundreds of cars pass daily (Fig. 6). This is one of the largest and oldest single-stemmed baobabs in the world. The dimensions are: h = 14.7 m, cbh = 11.10 m, V = 65 m3 and its age is around 500 years. The very rich canopy has 7 primary branches, out of which one is broken. Unfortunately, its life cycle will be significantly shortened by the cars that drive around it and the measures of conservation are practically impossible to take due to its current position in an "official" area.

Fig. 6. The Baobab from the Cornice East of Dakar is now located in the middle of a paved road, which is heavily circulated.

Fig. 7. The Baobab of the Airport is located in the vicinity of the International airport Dakar-Thiès.

At a distance of 3.5 km from the International airport Blaise Pascal from Dakar-Thiès, in the middle

of a field with palm trees, we identified a superlative baobab with an impressive volume. Because of its location, we named it the Baobab of the airport (Fig. 7). It has a cluster structure and consists of 10 fused stems, out of which 2 are broken. Its dimensions are: h = 22.5 m, cbh = 20.25, V = 250 m3. It contains a common/normal cavity in one of the stems. The age of the Baobab of the airport, whose stems have different sizes and belong to different generations, is over 500 years.

Due to the restrictions imposed by the COVID-19 pandemic, which were much more severe than in Europe and which either did not allow foreign citizens to enter the country, or required a mandatory quarantine for 10-14 days, certain trips to countries such as Namibia, Angola, Madagascar, Australia, Brazil could not take place in 2022.

Actions 2.1.2. Pretreatment (60 segments), 1.1.3. AMS radiocarbon dating (60 segments) and 1.1.4. Calibration (60 segments).

70 wood segments were pretreated by the acid-base-acid or α-cellulose pretreatment method, then AMS (accelerator mass spectrometry) radiocarbon dated and subsequently calibrated (compared to 60 envisaged).

The radiocarbon dating by AMS was performed at the Hertelendi Laboratory of Environmental Studies (Isotoptech Zrt and MTA ATOMKI) of Debrecen (Hungary) and at the iThemba Laboratory for Accelerator Based Sciences (iThemba LABS) in Johannesburg (South Africa).

Action 2.2.2. Stable isotope analysis (5000 segments). The stable isotope analysis for determining the δ13C and δ18O values were performed at the Stable Isotope Laboratory of iThemba LABS, Gauteng (South Africa).

Objective 2.3. Measuring and dating trees of Romania, Moldova and Europe (II)

In February 2022, a research team (3 members) undertook a trip in the area of Muncel village, which belongs to the Baia de Arieş mining town of the Western Carpathians in Alba county, Romania. A monumental historic beech (Fagus sylvatica), called „The Emperor’s Beech” (Fagul Împăratului), can be found next to a forest road, on a hill at the height of around 40 m above the right shore of the Arieş river, near the Muncel village (Fig. 8). The name of the historic tree comes from Franz Joseph I, the Emperor of Austria (1850 – 1918), who visited Transylvania in 1852 and would have even seen the beech. The Emperor’s Beech is also famous for its marcescent leaves which, although they dry up in the fall and turn brown, remain preserved during the winter. The leaves do not fall until the spring, when the new green leaves emerge. The cause of the marcescence is not yet sufficiently understood. Its dimensions are: h = 23.2 m, cbh = 5.00 (5.33 m in 2009), V = 20 m3.  According to the radioarbon dating results, the Emperor’s Beech is around 420 years old. In 1995, the historic tree was declared a Natural Monument.

Fig. 8. The impressive canopy of the Emperor’s Beech, with marcescent leaves.

In July 2002, a member of the research team visited areas from the continenetal and insular Greece. On this occasion, several representative specimens of oriental planes (Platanus orientalis) and olive trees (Olea europea) were investigated an measured.

Actions 2.3.1. Measuring 30 trees, 2.3.2. Collecting samples from 3 trees, 2.3.3. Pretreatment (20 segments) and 2.3.4. AMS radiocarbon dating (20 segments).

A total of 35 trees were measured (compared to 30 envisaged), and samples were collected from 5 trees (compared to 3 envisaged), 25 segments (compared to 20 envisaged) were pretreated and subsequently radiocarbon dated.

Objective 2.4. Dissemination of results.

Action 2.4.1. The writing or publishing of 3-5 scientific articles in ISI indexed journals.  

 

In 2022, we submitted for publication 6 scientific articles, all in ISI indexed journals, out of which 2 are in the so-called red zone, according to the CNCS classification system. All articles mention that „The research was funded by the Romanian Ministry of Education CNCS-UEFISCDI under grant PN-III-P4-ID-PCE-2020-2567, No. 145/2021.” The 6 articles are the following:

1. A. Pătruţ, R.T. Pătruţ, V. Bocoş-Binţinţan, I.A. Raţiu, L. Rakosy, G. Zdrob, E. Vancă, K.F. von Reden, Radiocarbon investigation of two old elms from Romania, Studia UBB Chemia, 2022, LXVII, 1, 245-256. (doi: 10.24193/subbchem.2022.1.16).

2. A. Pătruţ, R.T. Pătruţ, L. Rakosy, I.A. Raţiu, N. M. Nassor, K.F. von Reden, Radiocarbon investigation of two large African baobabs from Kizimkazi, Zanzibar, Tanzania, Studia UBB Chemia, 2022, LXVII, 3, 143-153. (doi: 10.24193/subbchem.2022.3.09).

3. A. Pătruţ, R.T. Pătruţ, L. Rakosy, W. Oliver, I.A. Raţiu, D.A. Lowy, G. Shiimbi, S. Woodborne, K.F. von Reden, Radiocarbon Investigation of the Historic African Baobabs of Omusati, Namibia, Forests, 2022, 13, 1899. (doi.org/10.3390/f13111899).

4. A. Pătruţ, V. Bocoş-Binţinţan, R.T. Pătruţ, D. Parţilă, I.A. Raţiu, L. Rakosy, K.F. von Reden, Radiocarbon dating of the historic Emperor’s Beech from Muncel, Baia de Arieş, Romania. Studia UBB Chemia, 2022, LXVII, 4. (doi: 10.24193/subbchem.2022.4.11).

5. R.T. Pătruţ, A. Garg, A. Pătruţ, S. Woodborne, L. Rakosy, I.A. Raţiu, The first radiocarbon investigation of the Indian banyan (Ficus benghalensis L.). Current Science.

6. R.T. Pătruţ, S. Woodborne, A. Pătruţ, G. Hall, I. Robertson, C.W. Winterbach, L. Rakosy, I.A. Raţiu, A 900-Year Isotopic Proxy Rainfall Record from Central Botswana. Radiocarbon.

The abstracts of the 6 articles are:

1. Radiocarbon investigation of two old elms from Romania.

ABSTRACT. The paper reports the AMS (accelerator mass spectrometry) radiocarbon investigation results of two superlative elms from Romana, the very large field elm of Calafat, with a wood volume of 85 m3, and the wych elm of Sadova. Two wood samples were extracted from each elm and were analysed by AMS radiocarbon. The oldest dated sample from the elm of Calafat had a radiocarbon date of 350 ± 19 BP, which corresponds to a calibrated age of 415 ± 25 years, while the oldest sample from the elm of Sadova had a radiocarbon date of 188 ± 24 BP, corresponding to a calibrated age of 260 ± 25 years. These values indicate high ages for the two elms, namely 430 ± 25 years or the elm of Calafat and 400 ± 25 years for the elm of Sadova.

2. Radiocarbon investigation of two large African baobabs from Kizimkazi, Zanzibar, Tanzania.

ABSTRACT. The article reports the AMS (accelerator mass spectrometry) radiocarbon dating results of Kizimkazi Big tree and Kizimkazi II baobab, two large African baobabs from Zanzibar, Tanzania. Unfortunately, both baobabs toppled and died in 2020 and 2018 during violent storms. The investigation of the two baobabs evinced that the first of them, which was also the biggest tree of Tanzania, consisted of 5 stems, out of which 2 were false ones, and had a closed ring-shaped structure. The second baobab was composed of 4 fused stems and had a cluster structure. Several wood samples were collected from the two baobabs. Seven segments were extracted from the samples and dated by radiocarbon. The oldest segment from Kizimkazi Big tree had a radiocarbon date of 312 ± 18 BP, corresponding to a calibrated age of 380 ± 10 calendar years. According to dating results, the Kizimkazi Big tree died at the age of 400 ± 25 years. The oldest segment from Kizimkazi II baobab had a radiocarbon date of 137 ± 17 BP, corresponding to a calibrated age of 190 ± 10 calendar years. This value indicates that the Kizimkazi II baobab was 250 ± 25 years old when it died.

3. Radiocarbon Investigation of the Historic African Baobabs of Omusati, Namibia.

ABSTRACT. The Omusati region belongs to the historic Ovamboland, an area of northern Namibia populated by tribes of the Ovambo group. Four very large African baobabs of Omusati played an important role in historic events of the area, such as the tribal wars and the Namibian War of Independence. The four historic baobabs are Ombalantu baobab (8 stems; circumference 24.50 m), Okahao baobab (4+ stems; around 25 m), Amadhila baobab (12 stems; 25.35 m) and Sir Howard baobab (9 stems; 31.60 m). Two historic baobabs collapsed totally or partially. The stems of Amadhila baobab toppled and died in 2021, while 3 stems of Okahao baobab collapsed long time ago, but are still alive. Our research aimed to determine the architecture and age of these baobabs. Three baobabs (Ombalantu, Amadhila, Sir Howard) exhibit a closed ring-shaped structure, with a false cavity inside. One baobab (Okahao) had an open ring-shaped structure, before its collapse. Several wood cores were extracted from the baobabs and investigated by radiocarbon dating. The dating results indicate ages of 770 ± 50 years years for Ombalantu baobab, 650 ± 50 years for Okahao baobab, 1100 ± 50 years for Amadhila baobab and 750 ± 50 years for Sir Howard baobab.

4. Radiocarbon dating of the historic Emperor’s Beech from Muncel, Baia de Arieş, Romania.

ABSTRACT. The article reports the AMS (accelerator mass spectrometry) radiocarbon dating results of the historic Emperor’s Beech from Muncel, Baia de Arieş, Romania. Two wood samples were collected from the large tree, out of which four segments were extracted and analysed by AMS radiocarbon. The oldest dated sample segment had a radiocarbon date of 233 ± 18 BP, which corresponds to a calibrated age of 365 ± 5 years. This value sugests an age of 420 ± 20 years for the Emperor’s Beech. Thus, the historic beech started growing around the year 1600.

5. The first radiocarbon investigation of the Indian banyan (Ficus benghalensis L.).

ABSTRACT. The paper discloses the first radiocarbon investigation of Ficus benghalensis, which was performed on the large Indian banyan of Narora. The banyan was discovered during floristic surveys in the Upper Ganga Ramsar Site, Uttar Pradesh, India and ranks as the tenth largest banyan  in the world by its 4069 m2 crown spread. The tree has a unique architecture, with just four prop roots supporting the main stem. The oldest sample was found to be 346 ± 40 BP, which corresponds to a calibrated age of 425 ± 35 calendar years. The radiocarbon dating results indicate an age of 450 ± 50 years for the Indian banyan of Narora. The age value represents the oldest accurate dating result for the species. Several protection measures are included to ensure the long-term survival of this archaic tree.

6. A 900-Year Isotopic Proxy Rainfall Record from Central Botswana.

ABSTRACT. High resolution climate archives for southern Africa are essential for designing and validating climate projections. For southern Africa and Botswana in particular, the interannual rainfall variability is associated with sea surface temperatures in the Agulhas Current Core region, which determine the east-west displacement of tropical temperate troughs (TTTs). Stable carbon isotope analysis and radiocarbon dating of the African baobab (Adansonia digitata L.) can provide reliable reconstructions of rainfall variability in its distribution area. We obtained a proxy rainfall record for central Botswana based on the historic Chapman baobab, which collapsed in 2016 during an intense El Niño event. The two investigated samples of the oldest stems of the baobab, which exhibited an open ring-shaped structure composed of 6 stems, provide insight into the precipitation regime over the last millennium, showing centennial and decadal scale variability. The results indicate that the lowest rainfall occurred during the Little Ice Age (1300-1350), while the Warm Medieval Period was marked by relatively stable precipitation. Previous studies suggested positive sea surface temperature (SST) anomalies in the Mozambique Channel led to an eastward movement of the TTTs but our proxy record shows a westward displacement in the past, causing drought in north-eastern South Africa and wetter conditions in the central part of southern Africa. The positive rainfall correlation with SST anomalies and ENSO reversed after 1900, causing a gradual decrease in precipitation and confirming the current aridity trend for Botswana.

The first 4 articles were published in 2022, article 5 is waiting a final decision from the reviewers, while article 6 will be evaluated by the reviewers.

Action 2.4.2. 1-2 presentations at International Conferences.

Due to the COVID-19 pandemic, the 24th Radiocarbon Conference, scheduled for 2021, was postponed. The Conference took place at ETH Zürich (Schwitzerland) between September 11-18, 2022. Two members of the research team participated at this conference with the following presentations:

1. A. Pătruţ, M. Molnar, R.T. Pătruţ, L. Rakosy, I.A. Raţiu, D. Rakosy, J.J. Brown, T. Varga, AMS Radiocarbon investigation of the African baobabs from the semiarid cloud forest of Wadi Hinna, Dhofar, Oman.

2. R.T. Pătruţ, S. Woodborne, A. Pătruţ, G. Hall, I. Robertson, C.W. Winterbach, L. Rakosy, I.A. Raţiu, A 900-Year Isotopic Proxy Rainfall Record from Central Botswana.

 

Action 2.4.3. The writing of the annual activity report. This activity refers to the writing of the present report.

The contribution of the project to the development of human resources for research.
Since the beginning of the project the research team a Ph.D. candidate, namely Roxana Pătruţ, and a postdoctoral researcher, Dr. Ileana Andreea Raţiu.
In 2021, the Ph.D. candidate defended her thesis, which was based on data and results obtained via the current and previous research projects focused on baobabs. She also was granted the title of Ph.D. in biology.
In 2022, Dr. Roxana Patrut participated at field investigations in Romania and Oman, is a co-author of all 6 mentioned scientific articles and of the 2 presentations at the 24th Radiocarbon Conference.  
The postdoctoral researcher also participated at field investigations in Romania and at the 24th Radiocarbon Conference in Schwitzerland.
She is a co-author of the 6 mentioned scientific articles and of the 2 presentations at the Radiocarbon Conference.

 

CONCLUSION

The information presented above shows that all objectives mentioned in the unique phase of the Project Implementation Plan for 2022 were fulfilled. Additionally, all envisaged results were obtained.