Thierry Otto

Environmental Roots of the Late Bronze Age Crisis

The Late Bronze Age world of the Eastern Mediterranean, a rich linkage of Aegean, Egyptian, Syro-Palestinian, and Hittite civilizations, collapsed famously 3200 years ago and has remained one of the mysteries of the ancient world since the event’s retrieval began in the late 19th century AD/CE. Iconic Egyptian bas-reliefs and graphic hieroglyphic and cuneiform texts portray the proximate cause of the collapse as the invasions of the “Peoples-of-the-Sea” at the Nile Delta, the Turkish coast, and down into the heartlands of Syria and Palestine where armies clashed, famine-ravaged cities abandoned, and countrysides depopulated. Here we report palaeoclimate data from Cyprus for the Late Bronze Age crisis, alongside a radiocarbon-based chronology integrating both archaeological and palaeoclimate proxies, which reveal the effects of abrupt climate change-driven famine and causal linkage with the Sea People invasions in Cyprus and Syria. The statistical analysis of proximate and ultimate features of the sequential collapse reveals the relationships of climate-driven famine, sea-borne-invasion, region-wide warfare, and politico-economic collapse, in whose wake new societies and new ideologies were created.

The Sea Peoples, from Cuneiform Tablets to Carbon Dating

The 13th century BC witnessed the zenith of the Aegean and Eastern Mediterranean civilizations which declined at the end of the Bronze Age, ∼3200 years ago. Weakening of this ancient flourishing Mediterranean world shifted the political and economic centres of gravity away from the Levant towards Classical Greece and Rome, and led, in the long term, to the emergence of the modern western civilizations. Textual evidence from cuneiform tablets and Egyptian reliefs from the New Kingdom relate that seafaring tribes, the Sea Peoples, were the final catalyst that put the fall of cities and states in motion. However, the lack of a stratified radiocarbon-based archaeology for the Sea People event has led to a floating historical chronology derived from a variety of sources spanning dispersed areas. Here, we report a stratified radiocarbon-based archaeology with anchor points in ancient epigraphic-literary sources, Hittite-Levantine-Egyptian kings and astronomical observations to precisely date the Sea People event. By confronting historical and science-based archaeology, we establish an absolute age range of 1192–1190 BC for terminal destructions and cultural collapse in the northern Levant. This radiocarbon-based archaeology has far-reaching implications for the wider Mediterranean, where an elaborate network of international relations and commercial activities are intertwined with the history of civilizations.

Dynamics of the association between a long-lived understory myrmecophyte and its specific associated ants.

Myrmecophytic symbioses are widespread in tropical ecosystems and their diversity makes them useful tools for understanding the origin and evolution of mutualisms. Obligate ant–plants, or myrmecophytes, provide a nesting place, and, often, food to a limited number of plant–ant species. In exchange, plant–ants protect their host plants from herbivores, competitors and pathogens, and can provide them with nutrients. Although most studies to date have highlighted a similar global pattern of interactions in these systems, little is known about the temporal structuring and dynamics of most of these associations. In this study we focused on the association between the understory myrmecophyte Hirtella physophora (Chrysobalanaceae) and its obligate ant partner Allomerus decemarticulatus (Myrmicinae). An examination of the life histories and growth rates of both partners demonstrated that this plant species has a much longer lifespan (up to about 350xa0years) than its associated ant colonies (up to about 21xa0years). The size of the ant colonies and their reproductive success were strongly limited by the available nesting space provided by the host plants. Moreover, the resident ants positively affected the vegetative growth of their host plant, but had a negative effect on its reproduction by reducing the number of flowers and fruits by more than 50%. Altogether our results are important to understanding the evolutionary dynamics of ant–plant symbioses. The highly specialized interaction between long-lived plants and ants with a shorter lifespan produces an asymmetry in the evolutionary rates of the interaction which, in return, can affect the degree to which the interests of the two partners converge.

Isotopic values of the Amazon headwaters in Peru: comparison of the wet upper Río Madre de Dios watershed with the dry Urubamba-Apurimac river system

RATIONALEnThe Amazon River is a huge network of long tributaries, and little is known about the headwaters. Here we present a study of one wet tropical Amazon forest side, and one dry and cold Atiplano plateau, originating from the same cordillera. The aim is to see how this difference affects the water characteristics.nnnMETHODSnDifferent kind of water (spring, lake, river, rainfall) were sampled to determine their stable isotopes ratios (oxygen 18/16 and hydrogen 2/1) by continuous flow isotope ratio mass spectrometry (IRMS). These ratios coupled with chemical analysis enabled us to determine the origin of the water, the evaporation process and the water recycling over the Amazon plain forest and montane cloud forest.nnnRESULTSnOur study shows that the water flowing in the upper Madre de Dios basin comes mainly from the foothill humid forest, with a characteristic water recycling process signature, and not from higher glacier melt. On the contrary, the water flowing in the Altiplano Rivers is mainly from glacier melts, with a high evaporation process. This snow and glacier are fed mainly by Atlantic moisture which transits over the large Amazon forest.nnnCONCLUSIONSnThe Atlantic moisture and its recycling over this huge tropical forest display a progressive isotopic gradient, as a function of distance from the ocean. At the level of the montane cloud forest and on the altiplano, respectively, additional water recycling and evaporation occur, but they are insignificant in the total water discharge.

Molecular systematics, character evolution, and pollen morphology of Cistus and Halimium (Cistaceae)

Pollen analysis and parsimony-based phylogenetic analyses of the genera Cistus and Halimium, two Mediterranean shrubs typical of Mediterranean vegetation, were undertaken, on the basis of cpDNA sequence data from the trnL-trnF, and trnS-trnG regions, to evaluate limits between the genera. Neither of the two genera examined formed a monophyletic group. Several monophyletic clades were recognized for the ingroup. (1) The “white and whitish pink Cistus”, where most of the Cistus sections were present, with very diverse pollen ornamentations ranging from striato-reticulate to largely reticulate, sometimes with supratectal elements; (2) The “purple pink Cistus” clade grouping all the species with purple pink flowers belonging to the Macrostylia and Cistus sections, with rugulate or microreticulate pollen. Within this clade, the pink-flowered endemic Canarian species formed a monophyletic group, but with weak support. (3) Three Halimium clades were recovered, each with 100% bootstrap support; all Halimium species had striato-reticulate pollen. Two Halimium clades were characterized by yellow flowers, and the other by white flowers.

Medieval coastal Syrian vegetation patterns in the principality of Antioch

The coastal area of Jableh, in the vicinity of the Saladin and Al-Marquab castles, is a fertile alluvial plain located on the northwestern part of Syria, in what was once the crusader Principality of Antioch. In order to detail the coastal environment during the crusader period in the Middle East, palynological analyses have been conducted on the underlying coastal-alluvial deposits. The recovered sediments represent a continuous record of the environmental history of the area spanning a c. AD 850—1850 cal. yr period, from the Muslim Era up to and including the late Ottoman times. During the local crusader period (AD 1100—1270), the area was dominated by an arborescent mattoral mixed with a xerophytic shrub-steppe. The alluvial plain was slightly waterlogged and colonized by a wetland meadow with an open vegetation of steppe-like character on bare surfaces and fresh arable soils. The riparian and open deciduous riverine forests were weakly developed. Signs of agricultural activities are mainly recorded for the High Medieval period (AD 1000—1300), with an increase of vineyards in the coastal area. Since c. AD 1250 cal. yr until the end of the crusader period, agricultural activities never reached the same intensity as during the Mameluke Sultanate and the Ottoman Empire.

First assessment of water and carbon cycles in two tropical coastal rivers of south‐west India: an isotopic approach

RATIONALEnThe contribution of tropical coastal rivers to the global carbon budget remains unmeasured, despite their high water dynamics, i.e. higher run-off with their basin characteristic of warm temperature. Two rivers draining the western part of the Western Ghats, the Swarna (length 80 km) and Nethravati (147 km) Rivers, were studied for water and carbon cycles.nnnMETHODSnThe stable isotope ratios of oxygen (δ(18) O values), hydrogen (δ(2) H values) and carbon (δ(13) C values) were used to understand the water circulation, the weathering processes and the carbon biogeochemical cycle. The river water samples were collected during the dry post-monsoonal season (November 2011).nnnRESULTSnThe δ(18) O and δ(2) H values of river water suggested that the monsoonal vapour source and its high recycling have a dominant role because of the orographical and tropical conditions. The absence of calcareous rocks has led to dissolved inorganic carbon (DIC) mainly originating from atmospheric/soil CO2 , via rock-weathering processes, and the low soil organic matter combined with high run-off intensity has led to low riverine dissolved organic carbon (DOC) contents. The δ(13) C values increase from upstream to downstream and decrease with increasing pCO2 . There is a positive relationship between the δ(13) CDIC values and the DOC concentrations in these two rivers that is contrary to that in most of the studied rivers of the world.nnnCONCLUSIONSnThe higher evapotranspiration supported by tropical conditions suggests that there are higher vapour recycling process in the Swarna and Nethravati basins as studied from the water δ(18) O and δ(2) H values. The basin characteristics of higher rainfall/run-off accompanied by warm temperature suggest that the δ(13) C value of riverine DIC is mainly controlled by the weathering of source rocks (silicates) with variation along the river course by CO2 degassing from the river water to the atmosphere and is less dominated by the oxidation of DOC.

Holocene evolution of Portus Pisanus, the lost harbour of Pisa

The ancient harbour of Pisa, Portus Pisanus, was one of Italy’s most influential seaports for many centuries. Nonetheless, very little is known about its oldest harbour and the relationships between environmental evolution and the main stages of harbour history. The port complex that ensured Pisa’s position as an economic and maritime power progressively shifted westwards by coastal progradation, before the maritime port of Livorno was built in the late 16th century AD. The lost port is, however, described in the early 5th century AD as being “a large, naturally sheltered embayment” that hosted merchant vessels, suggesting an important maritime structure with significant artificial infrastructure to reach the city. Despite its importance, the geographical location of the harbour complex remains controversial and its environmental evolution is unclear. To fill this knowledge gap and furnish accurate palaeoenvironmental information on Portus Pisanus, we used bio- and geosciences. Based on stratigraphic data, the area’s relative sea-level history, and long-term environmental dynamics, we established that at ~200 BC, a naturally protected lagoon developed and hosted Portus Pisanus until the 5th century AD. The decline of the protected lagoon started at ~1350 AD and culminated ~1500 AD, after which time the basin was a coastal lake.