Abstract Stomata characteristics of two extinct conifer Cheirolepidiaceae species, Pseudofrenelopsis gansuensis and Pseudofrenelopsis dalatzensis , were used to reconstruct the atmospheric carbon dioxide concentration levels during the late Albian of the Cretaceous. A sequence of fossil samples was collected from five beds in the Dalazi Formation in the Zhixin and Luozigou basins of Jilin Province, northeastern China. The stomatal index was used to estimate the palaeo- p CO 2. The average stomatal index value of the two species was 4.1 and the atmospheric CO 2 content was c. 1200 ppmv by the average of Recent standardization and Carboniferous standardization. During the short interval from 104.8 ± 0.5 Ma to 104.0 ± 0.4 Ma in the late Albian, the atmospheric CO 2 content presents a decreasing tendency, with the highest value being c. 1300 ppmv in the Luozigou Basin. In addition, the higher atmospheric CO 2 values of the late Albian are likely linked to a ‘greenhouse climate’ during the time of Oceanic Anoxic Event 1c (OAE1c).

ABSTRACT The northern Rocky Mountain Trench of eastern British Columbia is a broad valley mantled by glaciolacustrine terraces supporting a complex mix of mesic-temperate (“interior wet belt”) forests that are strongly affected by terrain and substrate. Neither the geomorphic history during early Holocene deglaciation nor the vegetation history of the origin of the Tsuga heterophylla (western hemlock) and Thuja plicata (western redcedar) populations in the interior wet-belt forest is well understood. Sediment cores were obtained from two lakes, 10 km apart and occupying different terraces (83 m elevational difference), and these were compared to existing fire-history and paleoclimate reconstructions. Radiocarbon dates and a mapped terrain classification indicate the upper terrace formed as a lacustrine and glaciofluvial kame terrace hundreds of years prior to the lower terrace, which was formed by glaciolacustrine sediments of a proglacial lake. The minimum limiting ages of these terraces correlate with dated jökulhlaup deposits of the Fraser River. The upper site’s first detectable pollen at >11.0 ka was dominated by light-seeded pioneer taxa (Poaceae [grasses], Artemisia [sagebrush], and Populus [aspen]) followed by a peak in Pinus (pine) and finally dominance by Betula (birch) at 10.2 ka. Pollen data suggest an earlier invasion of T. heterophylla (western hemlock) (by ca. 8 ka) than previously understood. Wetlands on extensive, poorly drained, glaciolacustrine soils promoted the persistence of boreal taxa and open forests (e.g., Picea mariana [black spruce]), while the better-drained upper kame terrace promoted development of closed-canopy shade-tolerant taxa. Invasion and expansion of mesic cedar-hemlock taxa progressed since at least the middle Holocene but was highly constrained by edaphic controls.

Abstract Swelling and shrinking soils are soils that can experience large changes in volume due to changes in water content. This may be due to seasonal changes in moisture content, local site changes such as leakage from water supply pipes or drains, changes to surface drainage and landscaping, or following the planting, removal or severe pruning of trees or hedges. These soils represent a significant hazard to structural engineers across the world due to their shrink–swell behaviour, with the cost of mitigation alone running into several billion pounds annually. These soils usually contain some form of clay mineral, such as smectite or vermiculite, and can be found in humid and arid/semi-arid environments where their expansive nature can cause significant damage to properties and infrastructure. This chapter discusses the properties and costs associated with shrink–swell soils, their formation and distribution throughout the UK and the rest of the world, and their geological and geotechnical characterization. It also considers the mechanisms of shrink-swell soils and their behaviour, reviewing strategies for managing them in an engineering context, before finally outlining the problem of trees and shrink–swell soils.

ABSTRACT Hotspots represent the ephemeral introduction of nutrients into an environment, and occur in both the modern and geologic past. The annual deposition of deciduous leaves in temperate forests, tree falls, animal excrement, and vertebrate carcass deposition all result in the pulsed introduction of nutrients to an ecosystem. Hotspots are critical for providing limiting nutrients, including nitrogen and carbon, to be incorporated into soil microbial biomass and plant biomass. For vertebrate ­carcasses, following the release of labile compounds from soft tissues, bones are often left behind, and provide a more recalcitrant reservoir of organic carbon and nitrogen, phosphorus, calcium, and, in some environments, water, for micro- and macro-fauna. Taphonomy—the physical, chemical, and biological processes following plant or animal death—studied in modern systems can be used to interpret hotspot processes operating in the past. East Tennessee is a region where studies of modern and fossil vertebrate hotspots have provided new insights into taphonomy. This guide describes two hotspot localities in east Tennessee—the Miocene-aged Gray Fossil Site in Gray, Tennessee, and the Anthropology Research Facility (“the Body Farm”) at the University of Tennessee, Knoxville, a human decomposition experimental site. The goal of this interdisciplinary field guide is to provide a view of nutrient hotspots from their formation in the modern to their preservation over geologic time.