7300 years of vegetation history and climate for NW Malta: a Holocene perspective

Abstract

Abstract. This paper investigates the Holocene vegetation dynamics for Burmarrad in Northwest Malta and provides a pollen-based quantitative palaeoclimatic reconstruction for this centrally located Mediterranean archipelago. The pollen record from this site provides new insight into the vegetation changes from 7280 to 1730 cal BP which correspond well with other regional records. The climate reconstruction for the area also provides strong correlation with southern (below 40 • N) Mediterranean sites. Our interpretation suggests an initially open landscape during the early Neolithic, surrounding a large palaeobay, developing into a dense Pistacia scrubland ca. 6700 cal BP. From about 4450 cal BP the landscape once again becomes open, coinciding with the start of the Bronze Age on the archipelago. This period is concurrent with increased climatic instability (between 4500 and 3700 cal BP) which is followed by a gradual decrease in summer moisture availability in the late Holocene. During the early Roman occupation period (1972-1730 cal BP) the landscape remains generally open with a moderate increase in Olea. This increase corresponds to archaeological evidence for olive oil production in the area, along with increases in cultivated crop taxa and associated ruderal species, as well as a rise in fire events. The Maltese archipelago provides important insight into vegetation, human impacts, and climatic changes in an island context during the Holocene.

Precipitation changes in the Mediterranean basin during the Holocene from terrestrial and marine pollen records: a model–data comparison

“…An east-west pattern of climatic change during the Holocene is also suggested in the Mediterranean region (e.g., Combourieu Nebout et al, 1998;Geraga et al, 2010;Colmenero-Hildago et al, 2002;Kotthoff et al, 2008;Dormoy et al, 2009;Finné et al, 2011;Roberts et al, 2011Roberts et al, , 2012Luterbacher et al, 2012;Guiot and Kaniewski, 2015). An east-west division during the Holocene is observed from marine and terrestrial pollen records (Dormoy et al, 2009;Guiot and Kaniewski, 2015), lake-level reconstructions (Magny et al, 2013), and speleothem isotopes (Roberts et al, 2011).…”

Fire as a motor of rapid environmental degradation during the earliest peopling of Malta 7500 years ago

“…In many areas, the valley sides and floors have been eroded to bare rock. Similar to other islands and coastal areas in the Mediterranean region, the vegetation of Malta is influenced by the intense heat and low precipitation experienced during the summer months, as well as the human activity that has increased in the area over the last millennia (Grove and Rackham, 2001; Carroll et al, 2012;Gambin et al, 2016). The three main seminatural vegetation types presently found on the island are maquis (Ceratonia siliqua, Olea europaea, Pistacia lentiscus, Rhamnus alaternus and R. oleoides), garrigue (Thymbra capitata, Erica multiflora, Euphorbia melitensis, Teucrium fruticans and Anthyllis hermanniae) and steppe (Lygeum spartum (clay slopes) Hyparrhenia hirta, Andropogon distachyus, Brachypodium retusum, Stipa capensis, Aegilops geniculata, Carlina involucrata, Notobasis syriaca, Galactites tomentosa, Asphodelus aestivuus, and Urginea pancration); along with some smaller community types, such as woodland and coastal wetlands, as well as freshwater, sand dune and rocky habitats which are all important for the rare endemic species that can be found within them (Schembri, 1997).…”

The 4.2 ka BP Event in the Mediterranean region: an overview

“…As anticipated, the authors tend to assume that most of the cave recharge occurs during winter (or autumn-winter) and most of the δ 18 O signal should be related to this condition (Deininger et al, 2017). In some instances, the complex interpretation of δ 18 O as a direct climatic proxy has led different authors to prefer δ 13 C of speleothem calcite as a better hydrological indicator of local conditions (e.g., Genty et al, 2006;Göktürk et al, 2011). The number of factors influencing the final δ 13 C value of a speleothem (e.g., Mühlinghaus et al, 2009) make this proxy probably just as, if not more, complicated as δ 18 O, and in addition, for the strong influence of soil-CO 2 production on the final 13 C/ 12 C ratio on speleothems, a change in land use and deforestation can have a particularly prominent effect, making it particularly sensitive to human impact above and within the cave.…”

“…2; Table 1). The main reason for excluding some records is the presence of long hiatuses (thousands of years) over the 4.2 ka BP Event that may not necessarily relate to climatic conditions, e.g., Villars, Chauvet, and La Mine caves (Genty et al, 2006) and Carburangeli Cave (Frisia et al, 2006). Some records have been rejected for their U-Th chronologies, as shown in later studies (e.g., Savi Cave; Frisia et al, 2005), with ages disputed in Belli et al (2013).…”