D. G. Sutton

A late Holocene pollen record of deforestation and environmental change from the Lake Tauanui catchment, Northland, New Zealand

Late Holocene pollen and sediment records from the Lake Tauanui catchment, northern New Zealand, indicate that the lake formed about 5500 years ago following a series of volcanic events in the Tauanui Volcanic Centre. These volcanic events initiated a volcanosere resulting in a mixed conifer-hardwood forest. Dacrydium cupressinum was the dominant tree. Agathis australis was always present. Changes similar to those registered in other Northland pollen diagrams are apparent. At ca 4000 yr B.P., when the climate became cooler and drier than before, a fire occurred in the catchment area causing erosion of the surrounding slopes and some destruction of forest. Fluctuations in abundance of many forest species, including Ascarina lucida, A. australis and D. cupressinum, from ca 3500 yr B.P. indicate repeated disturbance, increasingly so after 1600 yr B.P. Summer droughts and increased frequency of cyclonic winds are suggested as the cause. Major anthropogenic deforestation events defined by palynology occurred across many parts of the New Zealand landscape at ca 700 yr B.P. At Lake Tauanui anthropogenic forest disturbance, radiocarbon dated to ca 1000 yr B.P., is indicated by significant decline in all tree and shrub elements with concomitant increase in pteridophytes, especially Pteridium esculentum. Charcoal concentration increases steadily from the onset of disturbance, and in the final phase after the arrival of Europeans, major clearance of vegetation is indicated. Herbs increase markedly in this period, in diversity and abundance.

A 4300 year palynological and sedimentological record of environmental change and human impact from Wharau Road Swamp, Northland, New Zealand

The palynology and sedimentology of the late Holocene Wharau Road Swamp, Northland, are described Organic sediment began accumulating ca 4300 yr B P ma valley as a result of damming by a basaltic lava flow from nearby Mount Te Puke Mixed conifer‐hardwood forest dominated the region until major anthropogenic forest clearance dated by radiocarbon at ca 600 yr B P Dacrydium cupressinum was the dominant taxon Agathis austrahs was always present until European clearance, with peaks in the pollen record at inferred ages of ca 3700 yr B P and ca 1800 yr B P Climate changes similar to those registered in other pollen diagrams from northern New Zealand are evident, and suggest that climate was wetter and warmer than at present before 4000 yr B P From about 2600 yr B P climate became drier and cooler, indicated by a decline in Ascanna lucida and D cupressinum A period of milder and wetter climate from ca 2000 yr B P is suggested by increases m D cupressinum A lucida and Cvathea Major forest disturbance at ca 600 yr...

The palynology and sedimentology of a coastal swamp at Awana, Great Barrier Island, New Zealand, from c. 7000 yr B.P. to present

Pollen and sediment analysis of two Holocene cores from Awana, Great Barrier Island, shows that at 7000 calibrated yr B P the local swamp was an estuanne salt marsh dominated by Restionaceae By c 6000 yr B P the water table was lower, and a fresh water swamp (Gleichenta‐Leptospermum) had replaced the salt marsh Regional conifer‐hardwood forest c 7000 yr B P was initially co‐dominated by Libocedrus and Dacrydmm cupressinum Libocedrus declined from c 6000 yr B P During the period c 6000‐c 2500 yr B P, relatively stable environmental conditions ensued with little change in local or regional vegetation Around 2500 yr B P, the swamp surface became drier and was invaded by Dacrycarpus and Laureha swamp forest This forest was subsequently repeatedly disturbed (not by fire), indicating climatic change to drier and windier conditions Ascanna lucida was periodically a major component of swamp forest Disturbance is also recorded in the clastic (mineral) sediments, where beds of sand within finer‐grained sediment and...

Analysis of plant microfossils in prehistoric coprolites from Harataonga Bay, Great Barrier Island, New Zealand

Abstract We show results of palynological and phytolith analysis of coprolites from Harataonga Bay, Great Barrier Island. Because human and dog diets may overlap considerably, the microfossil evidence does not with certainty indicate which of these two species deposited them. The coprolites give insights into prehistoric Maori agriculture, gathering of wild plants, diet, and time of year of site occupation. Gourd (Lagenaria siceraria) pollen found in the coprolites shows that this exotic cultigen was being cultivated in the area at the time. The presence of this taxon together with putative truffle spores in the coprolites suggests subsistence components involving both plant domestication and the gathering of wild plants.

Palynology, sedimentology and environmental significance of Holocene swamps at northern Kaitoke, Great Barrier Island, New Zealand.

Pollen and sediment analyses of two cores from coastal freshwater swamps at northern Kaitoke (Kaitoke Swamp and Police Station Swamp), Great Barrier Island, show that c. 7300 calibrated yr B.P. Kaitoke Swamp was an estuary with tidal flats. Avicennia, now absent from the swamp area, was present in the estuary. By c. 4500 yr B.P. fresh water conditions had developed at the Kaitoke Swamp site as marine influences decreased. Around the same time, fresh water swamp conditions commenced at the Police Station Swamp site on the surface of a low lying area of a Late Pleistocene dune. A sandy layer at Kaitoke may represent rapid infilling followed by a dry soil surface until c. 1000 yr B.P. Conifer‐hardwood forest on the hills surrounding the sites c. 7300‐c. 1800 yr B.P. was dominated by Dacrydium and Metrosideros. During this period, environmental conditions were relatively stable, with little change in forest composition. Between 1800 yr and 800 yr B.P. Kaitoke Swamp was reflooded, and the Police Station Swamp extended as a shallow lake over the nearby dune flat. These new shallow swamps were invaded by swamp forest (mainly Dacrycarpus with some Laureha). The presence of charcoal and Ptendmm spores above the Kaharoa Tephra suggests that major Polynesian deforestation at northern Kaitoke began c. 600 calibrated yr B.P.

Pollen and phytoliths in stone mounds at Pouerua, Northland, New Zealand: implications for the study of Polynesian farming

High-resolution pollen and phytolith analyses can provide direct evidence for farming in archaeological landscapes. This is demonstrated here in the analysis of two mounds at Pouerua, northern New Zealand, where evidence indicates both functional and temporal differences between the structures, and the presence of gourd Lagenaria siceraria provides direct, unequivocal evidence that this crop was cultivated and that the site was used as a garden.

A Late Quaternary palynological and sedimentological record from two coastal swamps at southern Kaitoke, Great Barrier Island, New Zealand.

Pollen and sediment analyses of two cores from southern Kaitoke (Forsythes’ Paddock and Blackwells Bush), Great Barrier Island, show that at c 7500 cal yr B P, the area was an estuary with tidal flats and Avicennia By c 3000 cal yr B P, a Restionaceae (Leptocarpus) salt marsh had developed in the estuary as marine influences lessened By c cal 2550 yr B P, tresh water swamp (Cypencede‐Gleichenia‐Leptospermum) had replaced the salt marsh Conifer‐hardwood forest surrounding the southern Kaitoke sites from c 7500‐c 2800 cal yrBP was dominated by Dacrydium Mettosideros and Libocedius After c 2800 cal yr B P, Metrosideros was replaced by Agathis, Pin llocladm and Prumnopitvs taxifolta, suggesting climatic change to more variable conditions The presence ot the Kaharoa Tephra suggests that major Polynesian deforestation at southern Kaitoke began c 600 cal yr B P Minor pre‐Kaharoa fire disturbance is evident c 1750 cal yr B P and c 1290–970 cal yr B P

Wetland Microfossils in Soil: Implications for the Study of Land Use on Archaeological Landscapes

Abstract In this study we identify wetland microfossils in agricultural soils in Polynesian stone mounds at Pouerua, northern New Zealand. These include diatoms, sponge spicules, pollen, and fern and algal spores. As the presence of these microfossils is most likely anthropogenic and, as the soils are porous and free-draining, this shows that wetland microfossils can provide evidence for land use (in this case agriculture) in dryland archaeological landscapes. However, whether the microfossils in the mounds at Pouerua are related to pre- or post-European activity is uncertain because at this stage the rate of microfossil percolation in local soils is unknown.