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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.

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.

A 20-m sediment core from Rano Kau, Easter Island provides plant microfossil, arthropod fossil and high-resolution 14C sampling evidence for late Quaternary environments, ant (Formicidae) distributions and human activity. The record commences prior to or during the LGM, providing the two oldest dates for Rano Kau thus far, 20,340 ± 160 and 34,260 ± 440 BP. The vegetation at the time was mostly Arecaceae (palm)-dominated grassland-woodland, suggesting cooler/drier conditions than present. Near the start of the Holocene c. 12,500 cal BP, climate alleviation is indicated by Asteraceae shrubland increasing at the expense of grassland. There is an early to mid-Holocene sediment hiatus. The record recommences c. 3,500 cal BP, with in-washed clayey soils bearing charcoal and phytoliths of Polynesian-introduced Musa (banana) and mixed with wetland detritus, reflecting slumping as a result of forest clearance and gardening. Dates of material of other plants from the clay/detritus layers containing the Musa phytoliths are older than expected, within the range 3,680–2,750 cal BP, well before settlement of Eastern Polynesia. This could reflect horticultural material settling in an older part of the sediment column or age increase by reservoir effects. A long section of overlying unconsolidated detritus provides a progressively younger upward sequence from 2,840–2,870 to 930–810 cal BP, but dates are variable after 1,290–1,180 cal BP, where charcoal, disturbance-related pollen and older than expected ant exoskeletons demonstrate the inclusion of pre-aged material from the floating vegetation mat or upslope erosion in the sediment column. Arecaceae pollen declines sharply after 930–810 cal BP. Arthropod analysis reveals two new weevil species for Easter Island, and two ant taxa, Tetramoriumbicarinatum and Pheidole sp., the latter of which is also new for the island. Three of the four age determinations on ant remains suggest that ants were present prior to c. 2,500 cal BP, and probably associated with the period following the resumption of sediment accumulation c. 3,500 cal BP. Unless the apparent ant 14C ages have been increased by reservoir effects, these results question the long-accepted assumption that all Eastern Polynesia’s ant species have been introduced. [ABSTRACT FROM AUTHOR]

Abstract: Plant microfossil analysis was carried out on anthropogenic deposits from Yuku rock shelter, possibly occupied from before 14,200 cal. BP to recent times, in the Papua New Guinea Highlands. Elaeocarpus pollen has extremely high percentages throughout. Starch residues of lesser yam (Dioscorea esculenta) and one or more, undifferentiated Dioscorea species were identified, suggesting processing of these taxa since first use of the site. The latter include Dioscorea alata, Dioscorea bulbifera, Dioscorea nummularia and Dioscorea pentaphylla. Pollen and phytoliths of banana (Musa) appear 5200 cal. BP. We cannot differentiate between naturally growing and cultivated yams and bananas. Putative truffle (hypogeous Ascomycotina) spores in the deposits suggest foraging of truffles. [Copyright &y& Elsevier]

Presented here are results of analyses of sediments from a maar crater at Matukutureia, south Auckland. The record is discontinuous, reflecting formation of peat on the tuff surface after the eruption. The tuff section of the profile (3–7 million years old) has pollen of numerous extinct taxa and suggests broad-leaf beech ( Brassospora) forest with Casuarina and Agathis, and warm temperate conditions. A date of 15 051 ± 80 14C yr BP from the base of the overlying peat provides a minimum date for the eruption of McLauchlins Hill volcano. We cannot determine the timing of early Polynesian activities. [ABSTRACT FROM AUTHOR]

Microfossil (pollen, phytolith and diatom) analyses of 16 coprolites from a prehistoric settlement at Kohika, Bay of Plenty, New Zealand, provide evidence for coprolite age, season of site occupation, prehistoric Maori diet and palaeoenvironmental conditions. Because human and dog diets may overlap considerably, the microfossil evidence does not indicate with certainty which of these two species deposited them. However, we argue that it was very probably dog. The microfossil evidence suggests that the coprolites are pre-European (pre- c. ad 1800) and post-large scale Polynesian deforestation (post- c. 700 yr bp ), and that some were deposited in mid-summer. High values for puwhaSonchus type and raupo Typha pollen in some of the coprolites may provide direct evidence that these taxa were used as food by prehistoric Maori, as described later in ethnographic times. [Copyright &y& Elsevier]

Pollen diagrams from four sites along an altitudinal sequence on Mt Hauhungatahi support fossil wood data (Ogden et al., 1997) in suggesting a fluctuating Holocene tree-line not exceeding the altitude reached in the early Holocene. Tree-line forest at 1340–1390 m during the periods 10 100–7500 and 5400–3800 cal. BP was associated with patchy Subalpine scrub communities above and below this altitude. Rapid decline of this Halocarpus-Phyllocladus forest at c. 7500 cal. BP, and again c. 3800 cal. BP was probably due to volcanism. During 7500–5400 and 3800–1718 cal. BP tree-line forest was replaced by Subalpine scrub. The failure of forest to replace scrub during these two periods implies a long-lasting influence of the event which destroyed the forest, a continuation of disturbance events, or changed environmental conditions. After the Taupo volcanic eruption (1718 cal. BP) expansion of Libocedrus indicates an upwards movement of forest species into Subalpine scrub, followed by a decline. Volcanism has probably affected the vegetation of Mt Hauhungatahi directly and indirectly (through effects on soil drainage) throughout the Holocene. Results are consistent with increased climatic variability since 7500 cal. BP, and support the hypothesis that disturbance events can have persistent long-term effects on community composition and species distribution patterns. [ABSTRACT FROM AUTHOR]

Abstract: Chatham Island in the southwest Pacific Ocean is exposed on all sides to potential tsunami impact. In historical time, tsunamis are known to have inundated the coast on several occasions, with the largest event in 1868. Coastal dunes along the northeast coast of Chatham Island preserve sedimentary evidence of this and possibly earlier tsunami events, as localised gravel lags. However, these deposits lack a clear stratigraphic context and establishing their age is difficult. This study examines the sediment record in a freshwater wetland at Okawa Point, located directly landward of the dunes where apparent tsunami gravels occur. Sediment descriptions, pollen, foraminifera, chemical data and radiocarbon dates from cores are used to reconstruct the environmental history of the wetland. The record extends from ca. >43ka to the present and incorporates glacial, post-glacial and human-influenced phases. Throughout this time the wetland appears to have remained isolated from catastrophic marine inundation. The only evidence for saltwater intrusion is observed in the historic period, via geochemical, grain size and pollen data, which record a marine inundation event that forced the transport of a thin (cm-thick) deposit of dune and beach sand into the seaward edge of the wetland. This is interpreted as the signature of the 1868 tsunami. The lack of more widespread physical evidence for this and other tsunami events in the wetland is attributed to the morphological roughness afforded by coastal dunes and limited accommodation space for Holocene deposits. [Copyright &y& Elsevier]