Alex Chepstow-Lusty

TRACING 4,000 YEARS OF ENVIRONMENTAL HISTORY IN THE CUZCO AREA, PERU, FROM THE POLLEN RECORD

The Central Peruvian Andes stand out as a globally important center of cultural and biological evolution. This is sup- ported by its location at the heart of the former dominating Inca civilization (AD 1440-1534), itself built on remarkable preced- ing civilizations. These civilizations have arisen in this area possibly because of its exceptional natural biodiversity and its promi- nence as a center of domestication for numerous high altitude crops growing between 2,000-4,500 m a.s.l. Continuous environmental records for the Holocene from lake basin deposits in the Cuzco area would provide valuable information on how early human impact occurred. They would also assist in determining when the transition to agriculture took place in the southern highlands of present day Peru. A pollen record from Marcacocha, an in-filled lake basin at 3,300 m near Ollantaytambo indicates evidence of a deforested agricultural landscape earlier than 4,000 years ago. Major local climatic events at about AD 100 and 1050 in the record separate three contrasting land-use phases and may be linked to climatic events of a wider geographical occurrence. Most importantly these data furnish valuable insight into which cultures in Peru appeared to manage these fragile mountainous environments with minimal impact, and even evidence of agro-forestry using Alnus on a major scale. There are numerous lakes in the Cuzco area to provide a complete regional overview. A selection of these sites is presented. It is suggested that a series of con- tinuous records at different altitudes may fill the gaps in our understanding of the composition of natural vegetation communi- ties, including the distribution of Polylepis forest in existence prior to human impact. All this information will be important to agronomists, archaeologists, ecologists, and palaeoclimatologists alike.

4000 years of human impact and vegetation change in the central Peruvian Andes — with events parallelling the Maya record?

A lake-sediment sequence from Marcacocha in the central Peruvian Andes provides a well-dated and continuous vegetation record from an area rich in Inca and pre-Inca remains over the last 4000 years. Climatic changes in this record at AD 1-100 and AD 9001050 seem to be broadly contemporaneous with major arid events from Lake Chichancanab, Mexico, affecting the Maya civilization and corroborated by the Quelccaya and Huascaran ice cores in Peru.

Late Pliocene climatic change and the global extinction of the discoasters: an independent assessment using oxygen isotope records

Abstract High-resolution records (2–7 kyr) of Upper Pliocene Discoaster abundances obtained from six ODP/DSDP sites are assessed independently using oxygen isotope stratigraphy. Four Atlantic Ocean sites (DSDP Sites 552 and 607, and ODP Sites 659 and 662) comprise a transect from 56°N to 1°S and provide a record of latitudinal variations in Discoaster biogeography. Low-latitude sites in the Atlantic (ODP Site 662), Pacific (ODP Site 677), and Indian (ODP Site 709) oceans provide additional information about variability in Discoaster abundance patterns within the equatorial region. A common chronology, based on the astronomical time scale developed for ODP Site 677, has been established for all the sites. By integrating oxygen isotope data and Discoaster abundance records at each site we are able to independently evaluate the temporal and spatial distribution of D. brouweri and D. triradiatus in the 500 kyr prior to the extinction of the discoasters near the base of the Olduvai subchron. Major decreases in abundance are evident during some of the more intense late Pliocene glacial events. In particular, glacial isotope stages 82, 96, 98 and 100 are associated with distinct abundance minima. At these times, large-scale changes in surface hydrographic conditions appear to have suppressed Discoaster numbers on a global scale. The increase in abundance of D. triradiatus, which precedes the extinction of the discoasters by around 200 kyr, may also be related to the intensification of environmental pressures that accompanied the build-up of Northern Hemisphere ice sheets during the late Pliocene. In spite of contrasting geographic and oceanographic settings, the various D. brouweri and D. triradiatus records are remarkably similar. This demonstrates that the acme and extinction events are excellent biostratigraphic datums. The simultaneous extinction of D. brouweri and D. triradiatus at 1.95 Ma were synchronous events at both a regional scale within the Atlantic, and on a global scale between the three major oceans. However, the start of the D. triradiatus acme appears to have been diachronous, occurring some 40 kyr earlier in the Atlantic than in the Indo-Pacific, and hence the stratigraphic usefulness of this datum is regional rather than global.

Anthropogenic control of late-Holocene landscapes in the Cuzco region, Peru

The rise of complex Andean cultures is tied to increasingly sophisticated use of natural resources and infrastructural development. Considerable debate surrounds the extent to which these societies were forced to respond to changing climates or whether their modifications to the landscape minimized climate impacts. Here, we present a region-wide perspective of paleoecological changes around Cuzco, Peru using three lake sediment records. We investigate whether vegetation shifts in the three records occurred simultaneously, and explore whether such changes were due to climatic conditions or human activities, or both. A new paleoecological record from Lake Huaypo reveals a transition from Amaranthaceae (i.e. quinoa) cultivars to maize at c. 2800 cal. yr BP. This agricultural change is also documented at two other Andean lakes: Marcacocha (Chepstow-Lusty A (2011) Agro-pastoralism and social change in the Cuzco heartland of Peru: A brief history using environmental proxies. Antiquity 85: 570–582) and Pacucha (Valencia BG, Urrego DH, Silman MR et al. (2010) From ice age to modern: A record of landscape change in an Andean cloud forest. Journal of Biogeography 37: 1637–1647). Wetter climatic conditions are inferred to be a leading cause behind the change from Amaranthaceae to maize cultivation. At 1300 cal. yr BP, a rapid increase in Andean forest pollen types, especially Alnus, is observed at Huaypo, with similar changes occurring at Marcacocha at c. 1000 cal. yr BP and at Pacucha at c. 500 cal. yr BP. Drier paleoclimatic conditions at the time and the importance of Alnus, a species well-known for its ability to grow quickly and its widespread use for fuel and timber, suggest that the expansion was due partly to agroforestry. The Huaypo paleoecological record reveals that the practice of agroforestry first began during the Wari Period, and then continued through the Late Intermediate Period and period of Incan rule.

Agro-pastoralism and social change in the Cuzco heartland of Peru. A brief history using environmental proxies

The author shows how pollen and oribatid mites recovered from the small lake of Marcacocha provide a detailed proxy record of agro-pastoralism over the last 4200 years in the central Andes. The introduction of highland maize and weeding practices 2700 years ago corresponds with major settlement development, as well as evidence for large herds of llamas not only facilitating trade but supplying abundant fertilizer and fuel in the form of excrement. Prolonged droughts and pre-Colombian epidemics probably influenced many of the social changes observed.

Magnetic properties of charcoal rich deposits associated with a Roman bath-house, Butrint (Southern Albania)

Abstract A section adjacent to a building structure at Shen Deli, Butrint, Southern Albania exposes what is believed to be the remains of a former Roman bath-house. This section shows a transition from the underlying natural marsh clay into an archaeological deposit, which is both the basal remains of a building structure, and what appears to be an ash and charcoal enriched midden. The micro and macrocharcoal, magnetic and physical properties indicate a number of phases in the archaeological deposits, culminating in the micro and macrocharcoal rich and magnetically enhanced midden. The magnetic properties of these deposits are strongly related to the charcoal content that is probably a reflection of the ash content. The midden deposit is strongly enhanced in both superparamagnetic and low coercivity magnetite. The charcoal content and magnetic properties of the midden indicate a high content of wood-ash produced at the bath-house site, which is consistent with the anticipated fuel source for the region in Roman times.

Palaeoclimatic control of Upper Pliocene Discoaster assemblages in the North Atlantic

Abundance variations of six Pliocene species of the nannofossil genus Discoaster were analyzed over the time interval 1.89–2.95 Ma at five sites in the North Atlantic; DSDP 552 (56°N), DSDP 607 (41°N), ODP 659 (18°N), ODP 658 (20°N) and ODP 662 (1°S). Individual species are compared between the five sites as a percentage of the total Discoaster assemblage, using age models based mainly on Discoaster datums (3 control points used at each site). The sampling interval is approximately 3 kyrs. Discoaster brouweri, the only species covering the complete time interval became a less significant component of the assemblages with increasing latitude during the interval prior to 2.3 Ma. Discoaster triradiatus shows a distinct abundance acme at all sites between 1.89–2.7 Ma. Discoaster surculus increased in relative abundance with higher latitudes and upwelling conditions (ODP Site 658). Discoaster pentaradiatus is an important component of the assemblages at all sites, but displays an inverse abundance relationship with D. surculus as a function of increasing latitude and upwelling conditions. Discoaster tamalis and Discoaster asymmetricus are reduced at low latitudes and in upwelling conditions and increase relative to D. brouweri at higher latitudes, where there is strong evidence for taxonomic affinity.

Hydrological and land-use changes in the Cuzco region (Cordillera Oriental, South East Peru) during the last 1200 years: a diatom-based reconstruction

A quantitative diatom analysis was carried out on a sediment core from the small infilled lake basin of Marcacocha (Cuzco-region, SE Peru), in order to reconstruct environmental changes between 800 and 1850 AD. Five stratigraphical zones were distinguished by means of constrained cluster analysis. Very few diatoms were present between 790 and 1070 AD, probably reflecting dry and cool conditions, at a time when anthropogenic impact was limited around the basin. The transition at ca. 1070 AD was the most pronounced, and corresponded with a marked shift towards higher temperatures, as deduced from plant macroremains and the pollen record. This coincided with a sudden climate shift from cold and dry conditions towards warmer and even drier conditions, as recorded elsewhere in tropical South America. Between 1070 and 1650 AD diatoms (mainly the genus Epithemia Ktzing) became more abundant, together with charophyte oospores, suggesting the existence of a stable, shallow lake. The transition in diatom composition and abundances at ca. 1650 AD, with peaks centered on 1700 AD, lag behind the start of the Little Ice Age (around 1490-1530 AD), though match increased cooling at the end of the 17th and early 18th century as recorded in Peruvian ice cores. This could be caused by a threshold that was passed after the lake level had lowered sufficiently due to a cooling and drying climate, as well as infilling processes. Further transitions in the diatom community may be interpreted less in terms of climatic change, but as increasing sensitivity to local environmental changes, such as a lake level decrease and lake infilling. A hiatus in diatom abundance observed between ca. 1750 and 1810 AD, could be associated with increasing colonization of Juncaceae around the lake margin and rapid infilling, possibly linked to the construction of drainage canals clearly visible today. The final stage of infilling occurred after ca. 1845 AD, with complete colonization of the remaining lake surface by Juncaceae, with further accumulation of peats.

Book Review: Third millennium BC climate change and Old World collapse

on the shelves of academics. A complete up-to-date bibliography guides the reader to explore the contentions touched upon within the text and the imaginative use of illustrated reconstructions clarifies the nature of Neolithic sttlement. Notwithstanding the deficiencies of Chapter 2, this book fills a gap in the literature despite the four or more similarly titled texts currently in print. Its appeal is primarily the style of writing usedclear, concise and avoiding the verbosity that tends to obscure the information contained in many archaeological texts. The hefty price tag will probably confine this book to libraries, which is unfortunate as every student of the European Neolithic would benefit from owning a copy; let us hope the paperback will soon be with us.