Pinus and Prostomis: a dendrochronological and palaeoentomological study of a study of a mid-Holocene woodland in Eastern England

Tree-ring analysis of sub-fossil Pinus sylvestris L. and Quercus sp. and their associated sub-fossil insect assemblages from tree rot holes have been used to study a prehistoric forest buried in the basal peats at Tyrham Hall Quarry, Hatfield Moors SSSI, in the Humberhead Levels, eastern England. The site provided a rare opportunity to examine the date, composition, age structure and entomological biodiversity of a mid-Holocene Pinus-dominated forest. The combined approaches of dendrochronology and palaeoentomology have enabled a detailed picture of the forest to be reconstructed, within a precise time frame. The Pinus chronology has been precisely dated to 2921- 2445 BC against the English Quercus master curve and represents the first English Pinus chronology to be dendrochronologically dated. A suite of important xylophilous (wood-loving) beetles that are today very rare and four species that no longer live within the British Isles were also recovered, their disappearance associated with the decline in woodland habitats as well as possible climate change. The sub-fossil insects indicate that the characteristic species of the site's modern-day fauna were already in place 4000 years ago. These findings have important implications in terms of maintaining long-term invertebrate biodiversity of mire sites.

Insect faunas associated with Pinus sylvestris L. from the mid-Holocene of the Humberhead Levels, Yorkshire, U.K

This paper presents the results of recent palaeoentomological research carried out in the Humberhead Levels, South Yorkshire, UK, including the discovery of fossils of five species of beetle previously unknown in the British Isles. The significance of these and other Urwaldrelikt species is discussed in relation to the fragmentation of forest habitats, particularly those associated with Pinus sylvestris L. The Holocene history of this tree and its associated taxa is examined. The importance of fire habitats and the dependence of some pinicolous taxa on these habitats suggests that the decline of fire ecosystems may have had some impact on the changing biogeography of some species.

Patterns of variation at a mitochondrial sequence-tagged-site locus provides new insights into the postglacial history of European Pinus sylvestris populations

Due to their maternal mode of inheritance, mitochondrial markers can be regarded as almost 'ideal' tools in evolutionary studies of conifer populations. In the present study, polymorphism was analysed at one mitochondrial intron (nad 1, exon B/C) in 23 native European Pinus sylvestris populations. In a preliminary screening for variation using a polymerase chain reaction-restriction fragment length polymorphism approach, two length variants were identified. By fully sequencing the 2.5 kb region, the observed length polymorphism was found to result from the insertion of a 31 bp sequence, with no other mutations observed within the intron. A set of primers was designed flanking the observed mutation, which identified a novel sequence-tagged-site mitochondrial marker for P. sylvestris. Analysis of 747 trees from the 23 populations using these primers revealed the occurrence of two distinct haplotypes in Europe. Within the Iberian Peninsula, the two haplotypes exhibited extensive population differentiation (Phi(ST) = 0.59; P less than or equal to 0.001) and a marked geographical structuring. In the populations of central and northern Europe, one haplotype largely predominated, with the second being found in only one individual of one population.

The effects of multiple metal contamination on ectomycorrhizal Scots pine (Pinus sylvestris) seedlings

Experiments were conducted to investigate the effects of single and multiple metal contamination (Cd, Pb, Zn, Sb, Cu) on Scots pine seedlings colonised by ectomycorrhizal (ECM) fungi from natural soil inoculum. Seedlings were grown in either contaminated field soil from the site of a chemical accident, soils amended with five metals contaminating the site, or in soil from an uncontaminated control site. Although contaminated and metal-amended soil significantly inhibited root and shoot growth of the Scots pine seedlings, total root tip density was not affected. Of the five metals tested in amended soils, Cd was the most toxic to ECM Scots pine. Field-contaminated soil had a toxic effect on ECM fungi associated with Scots pine seedlings and caused shifts in ECM species composition on ECM seedlings. When compared to soils amended with only one metal, soils amended with a combination of all five metals tested had lower relative toxicity and less accumulation of Pb, Zn and Sb into seedlings. This would indicate that the toxicity of multiple metal contamination cannot be predicted from the individual toxicity of the metals investigated.