Mark Horrocks

Environmental change during the last glacial maximum (c. 25 000-c. 16 500 years BP) at Mt Richmond, Auckland Isthmus, New Zealand

Abstract A 2 m section at the base of Mt Richmond contains a palynological record of the last glacial maximum (LGM) (c. 25 000‐c. 16 500 14C years BP) vegetation of the Auckland Isthmus. Three silicic tephra layers derived from the Taupo Volcanic Centre (Okaia Tephra c. 23 500 14C years BP, Kawakawa Tephra c. 22 500 14C years BP) and the Okataina Volcanic Centre (Okareka Tephra c. 18 000 14C years BP), both centres lying within the Taupo Volcanic Zone, provide the basis of the chronology supported by radiocarbon dates. The pollen diagram is divided into two pollen zones separated by the deposition of a locally derived basaltic ash. From c. 25 000–23 000 14C years BP the site was initially a eutrophic lake fringed by Leptospermum and Typha, which altered to a Cyperaceae/Leptospermum‐dominated swamp. The regional vegetation at the time was beech‐dominated forest; canopy conifers were present but formed a minor part of the local forest. From c. 23 000–16 500 14C years BP regional forest was further restricted to local patches in extensive shrubland/grassland. Temperatures may have been depressed by more than 4–5°C. The eruption of a local volcano dammed the swamp outlet resulting in a return to lacustrine conditions. Local volcanism may have accelerated vegetation change already under way as a result of climate change to cooler conditions. This record provides a view of LGM vegetation of the Auckland Isthmus and a template for earlier cold stages of the Quaternary.

Holocene vegetation, environment, and tephra recorded from Lake Pupuke, Auckland, New Zealand

Abstract Lake Pupuke provides a near‐complete, high‐resolution environmental record of the Holocene from northern New Zealand. Tephra beds constrain the timing of a range of proxy indicators of environmental change, and demonstrate errors in a radiocarbon chronology. Agathis australis forest progressively increases from c. 7000 yr BP and, in conjunction with indicators of reduced biomass productivity, support a model of long‐term climate change to drier conditions over the Holocene. However, except for Agathis, conifer‐hardwood forest dominated mainly by Dacrydium cupressinum shows little change throughout the pre‐human Holocene, suggesting environmental stability. Dramatic vegetation change occurred only within the last millennium as a result of large‐scale Polynesian deforestation by fire. This happened a short time before the local eruption of c. 638 cal. yr BP Rangitoto Tephra. The identification of two eruptions of tephra from Rangitoto volcano has implications for future hazard planning in the Auckland region, because the volcanoes were previously considered single event centres. Changes in atmospheric circulation since the Late Glacial, possibly causing lower frequency of distal ashfall in Auckland during the Holocene, complicates the use of long‐term records in hazard frequency assessment.

Starch grains and xylem cells of sweet potato (Ipomoea batatas) and bracken (Pteridium esculentum) in archaeological deposits from northern New Zealand

Starch grains and xylem cells found in prehistoric coprolites and a stone mound provide direct evidence for agriculture. Fossil starch and xylem (vessel elements) of introduced sweet potato (Ipomoea batatas) root in a mound at Pouerua suggests these structures were used to cultivate this species. Sweet potato starch and xylem in coprolites from Great Barrier Island provide evidence for cultivation and diet. Fossil starch grains and xylem (tracheids) of bracken rhizome in coprolites from Kohika provide the earliest direct evidence for the use of this native plant in New Zealand as a carbohydrate food source. Analysis of xylem in starch storage organs is a valuable addition to the study of starch preserved in archaeological deposits.

Forensic Palynology: Variation in the Pollen Content of Soil on Shoes and in Shoeprints in Soil

Soil samples taken from and between consecutive shoeprints within a localized area were analyzed for pollen and compared with each other and with soil samples from the shoes that made the prints. The purpose was to establish the forensic value of using such samples to determine whether or not there is an association between people and crime scenes. This was done by determining the degree to which pollen assemblages in shoeprints in soil from within the same localized area differ, and the degree to which pollen assemblages in soil on shoes differ from assemblages in shoeprints in soil made by those shoes. The samples from and between the shoeprints showed a high degree of similarity, suggesting that pollen assemblages of such samples from within a localized area are homogeneous. A change in sampling depth from 1 mm to 20 mm did not significantly alter the pollen content of samples. The pollen content of the two soil samples from the shoes showed a close similarity to each other and to the soil samples from and between the shoeprints, indicating that pollen assemblages from soil on shoes do not differ significantly from assemblages in shoeprints in soil made by those shoes.

Palynology: its position in the field of forensic science.

Abstract:  Here we examine the current state of palynology in the field of forensic science. Forensic palynology is discussed with reference to other forensic disciplines to help understand what is required for its progress. Emerging developments are also discussed. Palynomorphs potentially deliver excellent trace evidence, fulfilling the requirements relating to the transfer, persistence, and detection of such evidence. Palynological evidence can provide very powerful investigative and associative evidence. Despite this, the application of palynology to forensic science has had mixed success. There are many anecdotal stories where pollen evidence has had spectacular successes. But it is extremely underutilized in most countries because it is labor‐intensive and requires considerable expertise and experience, there is a lack of control over sample collection and inadequate resourcing and funding, and its crime‐solving power is not well known. Palynology has been applied to forensic problems in an unstructured way, resulting in a lack of formalized discussion of the underlying principles. As there is renewed questioning of the acceptability of most evidence types in the current legal environment, there is a need for the establishment of palynological evidence through validation‐type studies and experimentation, and the implementation of independent proficiency testing.

Sub-sampling and Preparing Forensic Samples for Pollen Analysis

The main forensic application of palynology is in providing associative evidence, assisting to prove or disprove a link between people and objects with places or with other people. Although identification and interpretation of pollen is a specialist job, sub-sampling and preparing pollen samples for analysis may be carried out by non-specialists. As few forensic laboratories have residing palynologists, laboratories may wish to reduce the cost of analysis or risk of contamination by doing their own sub-sampling and preparation. Presented is a practical guide for sub-sampling and preparing forensic samples for pollen analysis, providing a complete standard procedure for both the palynologist and non-specialist. Procedures for sub-sampling include a wide variety of materials commonly collected for forensic analysis (soil, clothing and other fabrics, footwear, twine and rope, firearms, granulated materials, plant and animal material, and illicit drugs), many of which palynologists will not be familiar with. Procedures for preparation of samples (pollen concentration) are presented as a detailed, step-by-step method. Minimizing the risks of laboratory and cross-sample contamination during sub-sampling and preparation is emphasized.

Fine Resolution of Pollen Patterns in Limited Space: Differentiating a Crime Scene and Alibi Scene Seven Meters Apart

In an alleged rape case, the pollen content of soil samples from the suspects clothing was compared with that of soil samples from the alleged crime scene (an alleyway) and from the alibi scene (next to a driveway) to determine whether or not the suspect had been at the alleged crime scene. Although only 7 m apart, the two scenes had significantly different soil pollen representations due to their different vegetation. Because of this close proximity, however, these differences in pollen representation were in the amounts of the same pollen types rather than in the numbers of different pollen types. The clothing samples showed a very strong correlation with each other and with the sample from the alleged crime scene in the amounts of pollen types present, very strongly supporting the contention that the suspect had been at the alleged crime scene.

Effect and timing of increased freshwater runoff into sheltered harbor environments around Auckland City, New Zeland

Two short cores of late Holocene, low tidal, estuarine sediment from the sheltered fringes of the Aucklands Waitemata Harbor, New Zealand, record the following changes through time since human colonization: an abrupt decline and disappearance of marine molluscs, a major decline and virtual disappearance of ostracods, an abrupt decline in calcareous foraminifera (mostlyAmmonia spp.), a rapid increase, in abundance of agglutinated foraminifera, large diatoms, and freshwater thecamoebians, and an increase in sedimentation rate, but no consistent trend in change of grain size. The up-core foraminiferal changes mimic their present day up-estuary zonation, which correlates strongly with decreasing salinity and pH. In both localities the faunal changes can be correlated with the documented local land-use history and increased freshwater runoff over time. At the head of the Waitemata Harbor, in Lucas Creek estuary, three phases of foraminiferal faunal change occurred: minor changes during initial Polynesian forest clearance (1500–1800 AD), a major change in early European times (1840–1870 AD) with clearance of most of the remaining native forest, and another small change in very, recent times (∼1990s) with urbanization in the Lucas Creek catchment. On the eastern, seaward fringes of the Waitemata Harbor, in the smaller Tamaki Estuary, no faunal changes occurred in association with complete forest clearance and establishment of pastoral farming in Polynesian and early European times (before 1950s). Major foraminiferal and other faunal changes occurred in the late European period (1960s–1970s) coincident with the onset of major urbanization spreading throughout the Tamaki catchment. Our results suggest increased freshwater runoff is the major culprit for many of the observed biotic changes in the urbanized estuaries of New Zealand.

Plant remains in coprolites: diet of a subalpine moa (Dinornithiformes) from southern New Zealand

Abstract Analysis of plant macrofossils and pollen in putative coprolites (2538 ± 95 14C years ago) of Megalapteryx didinus, a southern subalpine species of the extinct moa, indicates that this bird browsed branchlets of forest trees (mainly Nothofagus), and grazed on tussockland and lake edge herbs (Poaceae, Cyperaceae, Isoetes). The data provide the first direct evidence of diet of an upland moa.

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...