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 să 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 proiectului “Cercetări dendrocronologice cu radiocarbon, studii dendroclimatologice cu izotopi stabili şi conservarea unor arbori monumentali din lume” reflectă 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.