A gentle giant: Thomas Jefferson’s ground sloth

Early Holocene survival of megafauna in South America

Resolution of Respect: Professor Paul Schultz Martin 1928–2010

The relation between the Givetian and Serpukhovian biotic crises and long-term environmental trend changes

To manage acid mine drainage, some mine sites in Québec, Canada, have been reclaimed using a cover with capillary barrier effects (CCBE). The performance of this oxygen barrier cover system relies on maintaining a fine-grained material layer with a high degree of water saturation. However, after mine closure, CCBEs can be colonised by the surrounding ecosystem (plants, animals, and microorganisms) that can influence its hydraulic properties. Plant roots, for instance, can pump water and decrease the degree of saturation in fine-grained materials. Since CCBEs are expected to perform for hundreds of years, their designs must anticipate long-term environmental changes. Projections of how a changing environment could influence CCBE performance are crucial. Current numerical models to predict water balance can integrate vegetation effects but long-term environmental changes, such as climate change, soil development, and ecological succession, are usually not considered. Model input data associated with future environmental scenarios at reclaimed sites are required. Natural analogues are natural ecosystems that provide clues for more effective cover designs or indicate long-term changes in cover environment. A natural analogue (NA) of a CCBE can help to obtain data representative of long-term environmental changes that may influence the CCBE performance. In this paper, the methodology used to obtain an NA of a CCBE, including the influence of mature vegetation, is presented. The criteria developed to check the analogy between a constructed CCBE, and a natural equivalent are explained (for example, the water table level, hydrogeological properties of materials, and the required contrast between these properties). An example of vegetation data obtained from the natural CCBE analogue is described. Finally, the benefits of using NAs information for the design of engineered cover systems are discussed.

‘From the sky to the ground’: fishers' knowledge, landscape analysis and hydrological data indicate long-term environmental changes in Amazonian clear water rivers

As one of the world’s four Greater Bay Areas, the Guangdong–Hong Kong–Macao Greater Bay Area (GBA) faces many environmental challenges along with rapid economic development, causing significant degradation of aquatic ecosystems. However, there is limited knowledge on long-term environmental changes (i.e., >50 years), and restoration of the degraded aquatic ecosystems in the GBA has become increasingly difficult. This study selects a typical inland water body, the Miaotan Reservoir, from Huizhou City in the GBA, to explore long-term changes in water and the eco-environment over the past 70 years and to provide some restoration and management strategies for degrading aquatic ecosystems in the region. We collected a sediment core from the reservoir center and established an age–depth profile by integrating 210Pb and 137Cs dating. We then set up high-resolution diatom community succession stratigraphy and multiple indicators (grain size, element, geochemical and social indicators) as responses to environmental changes in the reservoir. Our results show that significant changes have occurred in the ecosystem and environment of the Miaotan Reservoir and its catchment over the past 70 years. The diatom community underwent a gradual transition from absolute dominance of the mesotrophic species Aulacoseira granulata to dominance of the eutrophic species Nicizschia gracilis, Nicizschia palea and Achanathes sp., indicating the onset of water quality degradation and ecosystem changes in the 1990s due to eutrophication. The RDA (Redundancy analysis) results demonstrate that exogenous pollutant inputs into the Miaotan Reservoir resulting from agricultural activities over the period led to serious environmental changes, e.g., toxic algal bloom and heavy metal pollution. This study enriches our understanding of long-term environmental changes in inland lakes and reservoirs in South China and provides insights into the restoration and management of aquatic ecosystems in the GBA.

How sloths got their sloth

Using Community-Led Mini-Grant Projects to Increase Access to Healthy, Affordable Food and Places to be Active

Revealing anthropogenic effects on lakes and wetlands: Pollen-based environmental changes of Liangzi Lake, China over the last 150 years

Soil is a dynamic natural body and fundamental resource. Human activities influence intensively the natural processes in soils. They modify and accelerate the development of soils. In this investigation, the deposition of colluvial sediments (colluviation) and soil formation are proposed as geoindicators for a better understanding of long-term environmental changes and environmental impact assessment. Deposition of colluvial sediments during several time periods and subsequent soil formation under different land-use systems reflect important aspects on the long-term human interference in the environment. In this study, we hypothesize that intensive human activities and environmental changes during middle and late Holocene are responsible for a strong modification of soils in an investigation area in Schleswig–Holstein (Germany). Soil age information together with geomorphological data, physical, chemical and biological soil properties provide the database which is necessary to study the types and rates of colluviation and soil formation. After the investigation with a high resolution in time and space, results show that middle and late Holocene land-use changes and land management are responsible for soil formation in colluvial layers. Properties of soils and sediments vary intensively from Mesolithic until Modern times. Intensive soil formation took place during periods of geomorphodynamic stability in dense woodland. Evidence in our investigations shows that colluviation has a strong relation with decision-making and environmental degradation in the past. This confirms, too, that a geoindicator concept is needed to understand and to monitor long-term environmental changes and degradation.

The objectives of this paper were to introduce frameworks for predicting the determinants and consequences of the great heterogeneity in benthic algal assemblages. A hierarchical framework of environmental factors affecting benthic algal spatial heterogeneity is presented with the ultimate determinants (climate, geology, land use, and biogeography) that are important constraints on benthic algal assemblage structure at large spatial scales. These ultimate determinants constrain expression of intermediate and proximate determinants of benthic algal function and structure. A similar framework for temporal heterogeneity distinguishes how assemblages respond to short-term and long-term environmental changes, referred to as disturbances and stresses, respectively. Assemblages recover from punctuated (short-term) environmental change (disturbance) by immigration and reproduction of both persistent and recolonizing species. Assemblages adapt to permanent (longterm) environmental change (stress) by changing speci...

As the world becomes increasingly urbanized and interconnected, the distinction between urban and rural areas is diminishing. Creation of new urban–rural interface areas causes immediate changes in local natural and social environments, and these areas are also susceptible to both short-term and long-term environmental changes. Different groups of people have varying levels of exposure to natural hazards and gradual climatic changes, as well as access to different coping and resiliency strategies that create unique sets of assets and vulnerabilities. Social vulnerability to hazards and environmental changes results from a complex mix of environmental, social, and economic factors and is often rooted in poverty and disenfranchisement. Mapping of projected environmental threats and census-based indicators of social vulnerability can signal areas that require more intensive ethnographic research, which can elucidate elements of social vulnerability and adaptive capacity that are difficult or impossible to understand from census data or to measure through surveys. Collaborative management of especially vulnerable urban–rural interface areas can present opportunities to enhance the coping strategies and adaptive capacity of individuals and communities, leading to outcomes that are more ecologically sustainable and socially just.

This volume is devoted to Earth surface environmental reconstructions and environmental changes that may be deciphered and modelled using stable isotopes along with mineralogical/chemical, sedimentological, palaeontological/biological and climatological methodologies. The book is divided into two sections, both using stable isotopes (δD, δ 18 O, δ 13 C, d 15 N, δ 34 S, clumped isotopes Δ 47 ) in various samples and phases as the main research tool. The first section is devoted to studies focusing on the distribution of isotopes in precipitation, groundwater, lakes, rivers, springs, tap water, mine water and their relationship with terrestrial environments at regional to continental scale. In relation to this, the second section includes case studies from a range of continental settings, investigating cave deposits (stalagmites, bat guano), animal skeletons (dinosaurs, alligators, turtles, bivalves), present and past soils (palaeosols) and limestones. The sections focus on the interaction between the surficial water cycle and underground water storage with deposits acting as archives of short- to long-term climatic and environmental changes. Examples from the Early Cretaceous to present time come from Europe, Asia, Africa, North and South America.

Long-Term Climatic Changes and Solar Insolation.- Long-Term Late Cenozoic Global Environmental Changes Inferred from Lake Baikal Sediments.- Rift Basin History and Geological Environment.- Paleoclimate Records from the Lake Baikal Sediments and Lava Formations of the South Baikal Volcanic Area.- Geothermal Studies of Underwater Boreholes in Lake Baikal.- Geomorphological Development of the Tunka Depression in the Baikal Rift Zone in Siberia, Russia.- Late Cenozoic Paleoenvironmental Changes Inferred from Long Baikal Sediment Cores.- Paleoenvironmental Changes in the Eurasian Continental Interior during the Last 12 Million Years Derived from Organic Components in Sediment Cores (BDP-96 and BDP-98) from Lake Baikal.- Paleoenvironmental Changes during the Last 12 Million Years in the Eurasian Continental Interior Estimated by Chemical Elements in Sediment Cores (BDP-96 and BDP-98) from Lake Baikal.- Pliocene-Quaternary Vegetation and Climate History of the Lake Baikal Area, Eastern Siberia.- Vegetation Changes in the Baikal Region during the Late Miocene Based on Pollen Analysis of the BDP-98-2 Core.- Residual Photosynthetic Pigments in the Sediment of Lake Baikal as Indicators of Phytoplankton History.- Late Pleistocene and Holocene Environmental Changes in the Lake Baikal Catchment.- Glacial/Interglacial Changes in the Carbon Cycle of Lake Baikal.- Lake Hovsgol in the Late Pleistocene and Holocene: On-Land Geological Evidence for a Change in Its Level.- Pollen Record from the Chivyrkui Bay Outcrop on the Eastern Shore of Lake Baikal since the Late Glacial.- Sedimentary Fe/Mn Layers in Lake Baikal as Evidence of Past and Present Limnological Conditions.- Dating Methods Applied to Baikal Sediments.- Paleomagnetism and Paleoenvironmental Magnetism Studied on BDP-98 Sedimentary Cores from Lake Baikal.- Exploratory Studies of Dating the Baikal Drilling Project Sediment Core (BDP-96) Using Cosmogenic 10Be: Observations and Implications of Higher 10Be Concentrations in Sediments Older than 2.7 Ma.- Evolution and Biodiversity.- Origin and Diversity of the Diatom Genus Eunotia in Lake Baikal: Some Preliminary Considerations.- Diatom Succession in Upper Miocene Sediments of Lake Baikal from the BDP-98 Drill Core.- Late Phocene Spongial Fauna in Lake Baikal (from Material from the Deep Drilling Core BDP-96-1).- Limnology in Lake Baikal and Lake Khubusgul.- A Conceptual Model of Sedimentation Processes for a Hydrogeomorphological Study in Lake Baikal.- Inorganic Characteristics of Surface Sediment from Lake Baikal: Natural Elemental Composition, Redox Condition, and Pb Contamination.- Suspended and Dissolved Forms of Carbon, Nitrogen, and Phosphorus in Lakes Baikal and Hovsgol (Snow, Tributaries, Water, Sediments).- The Contribution of Eolian Material in the Composition of Suspended Matter in the Snow Cover of Ice from the Buguldeika Saddle and Academician Ridge in Lake Baikal.- Key-word Index.

Reviewed by: Deep Time and the Texas High Plains: History and Geology Brian Frehner Deep Time and the Texas High Plains: History and Geology. By Paul H. Carlson. (Lubbock: Texas Tech University Press, 2005. Pp. 160. Preface, illustrations, charts, tables, maps, notes, select bibliography, index. ISBN 0896725529. $34.95, cloth. ISBN 0896725537. $19.95, paper.) Paul H. Carlson tackles an admirable but daunting task—explaining in only 117 pages how geological forces shaped history over the course of more than ten thousand years at an archaeological site and its surrounding region on the Texas High Plains. Drawing upon John McPhee's concept of "deep time," the author proposes to capture the "long geological past" of the Lubbock Lake archaeological site located in northwest Texas's Llano Estacado region (p. xv). At times, the vast scale and scope of change Carlson describes overwhelms the narrative and prevents him from focusing sufficiently on the Lubbock Lake site or even the Llano Estacado. Carlson sets a context of "deep time" by starting with the Big Bang approximately ten to fifteen billion years ago. He briefly surveys the evolution of stars, the Earth's internal structure, and the geologic time scale. "Then, over deep time, the great Pangaea separated" (p. 6). As geological processes formed different rocks, dinosaurs appeared and became extinct and mammals evolved. By the end of chapter one, the author has surveyed the prehistoric past up to approximately ten thousand years ago. The scope and impact of the change Carlson covers is so all-encompassing and global in its reach that the reader is left to wonder whether the author has provided too much context. Paleoindian cultures provide the subject matter for the next chapter, and here too the author struggles to strike a balance between generalizations about pre-Clovis, Clovis, and Folsom cultures and more specific assertions about choices people made accommodating their lives to the Lubbock Lake and Llano Estacado environments. Although archaeologists have uncovered extensive evidence of these cultures throughout North America, it is never entirely clear what lessons Paleoindians' lives illuminate for the modern reader about this particular environment which, after all, purports to serve as the book's focal point. Carlson does a better job of characterizing the impacts of long-term climate and environmental change on the Llano Estacado's people and land in chapter three, [End Page 417] which focuses on the Archaic period (8,500 to 2,000 years ago). Due to a semi-arid interval of time, animals dependent on the region's water supplies departed as vegetative cover gradually decreased at the Lubbock Lake site. People continued to use the site, though, to camp and gather plants. Carlson is on shakier ground when he characterizes social organization during the Archaic period. For example, he states that sharing, egalitarianism, and flexible social institutions "must have been present" and acknowledges that he can only "speculate" about mobility patterns (p. 65). The next two chapters cover the period from two thousand years ago to the present. Carlson discusses rather informatively and adroitly the process by which Indian people branched off into separate cultural groupings, contested one another for access to the area, and felt the impact of Europeans entering the area. He then narrates Americans' attempts to hunt bison and ranch the area, their impacts on the local environment, and archaeological activity that has uncovered much of the information that makes up this study. Historians should produce more studies of the kind Carlson has tackled. Geology significantly shapes history by defining the limits of the stage upon which environmental, biological, and human events unfold. The relationships between geology and history are manifold and complex, and Carlson unflinchingly sets out to articulate how the two intersect. This approach presents the Herculean task of identifying how the grand sweep of geological time unfolded in smaller regions and local environments in ways readers can comprehend. Brian Frehner Oklahoma State University Copyright © 2007 The Texas State Historical Association