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North America
Plant phenological observations and networks in North America have been largely local and regional in extent until recent decades. In the USA, cloned plant monitoring networks were the exception to this pattern, with data collection spanning the late 1950s until approximately the early 1990s. Animal observation networks, especially for birds have been more extensive. The USA National Phenology Network (USA-NPN), established in the mid-2000s is a recent effort to operate a comprehensive national-scale network in the United States. In Canada, PlantWatch, as part of Nature Watch, is the current national-scale plant phenology program.
Regional assessment of North America: Urbanization trends, biodiversity patterns, and ecosystem services
North America contains some of the most urbanized landscapes in the world. In the United States (U.S.) and Canada, approximately 80 % of the population is urban, with Mexico slightly less (Kaiser Family Foundation 2013). Population growth combined with economic growth has fueled recent urban land expansion in North America. Between 1970 and 2000, urban land area expanded at a rate of 3.31 % (Seto et al. 2011) creating unique challenges for conserving biodiversity and maintaining regional and local ecosystem services.
Sustainability of water-supply at military installations, Kabul Basin, Afghanistan
The Kabul Basin, including the city of Kabul, Afghanistan, is host to several military installations of Afghanistan, the United States, and other nations that depend on groundwater resources for water supply. These installations are within or close to the city of Kabul. Groundwater also is the potable supply for the approximately four million residents of Kabul. The sustainability of water resources in the Kabul Basin is a concern to military operations, and Afghan water-resource managers, owing to increased water demands from a growing population and potential mining activities. This study illustrates the use of chemical and isotopic analysis, groundwater flow modeling, and hydrogeologic investigations to assess the sustainability of groundwater resources in the Kabul Basin. Water supplies for military installations in the southern Kabul Basin were found to be subject to sustainability concerns, such as the potential drying of shallow-water supply wells as a result of declining water levels. Model simulations indicate that new withdrawals from deep aquifers may have less of an impact on surrounding community water supply wells than increased withdrawals from near- surface aquifers. Higher rates of recharge in the northern Kabul Basin indicate that military installations in that part of the basin may have fewer issues with long-term water sustainability. Simulations of groundwater withdrawals may be used to evaluate different withdrawal scenarios in an effort to manage water resources in a sustainable manner in the Kabul Basin.
Improving tsunami resiliency: California's Tsunami Policy Working Group
California has established a Tsunami Policy Working Group to facilitate development of policy recommendations for tsunami hazard mitigation. The Tsunami Policy Working Group brings together government and industry specialists from diverse fields including tsunami, seismic, and flood hazards, local and regional planning, structural engineering, natural hazard policy, and coastal engineering. The group is acting on findings from two parallel efforts: The USGS SAFRR Tsunami Scenario project, a comprehensive impact analysis of a large credible tsunami originating from an M 9.1 earthquake in the Aleutian Islands Subduction Zone striking California’s coastline, and the State’s Tsunami Preparedness and Hazard Mitigation Program. The unique dual-track approach provides a comprehensive assessment of vulnerability and risk within which the policy group can identify gaps and issues in current tsunami hazard mitigation and risk reduction, make recommendations that will help eliminate these impediments, and provide advice that will assist development and implementation of effective tsunami hazard risk communication products to improve community resiliency.
Plant invasions in protected areas of tropical pacific islands, with special reference to Hawaii
Isolated tropical islands are notoriously vulnerable to plant invasions. Serious management for protection of native biodiversity in Hawaii began in the 1970s, arguably at Hawaii Volcanoes National Park. Concerted alien plant management began there in the 1980s and has in a sense become a model for protected areas throughout Hawaii and Pacific Island countries and territories. We review the relative successes of their strategies and touch upon how their experience has been applied elsewhere. Protected areas in Hawaii are fortunate in having relatively good resources for addressing plant invasions, but many invasions remain intractable, and invasions from outside the boundaries continue from a highly globalised society with a penchant for horticultural novelty. There are likely few efforts in most Pacific Islands to combat alien plant invasions in protected areas, but such areas may often have fewer plant invasions as a result of their relative remoteness and/or socio-economic development status. The greatest current needs for protected areas in this region may be for establishment of yet more protected areas, for better resources to combat invasions in Pacific Island countries and territories, for more effective control methods including biological control programme to contain intractable species, and for meaningful efforts to address prevention and early detection of potential new invaders.
The effects of atmospheric nitrogen deposition on terrestrial and freshwater biodiversity
This chapter reports the findings of a Working Group on how atmospheric nitrogen (N) deposition affects both terrestrial and freshwater biodiversity. Regional and global scale impacts on biodiversity are addressed, together with potential indicators. Key conclusions are that: the rates of loss in biodiversity are greatest at the lowest and initial stages of N deposition increase; changes in species compositions are related to the relative amounts of N, carbon (C) and phosphorus (P) in the plant soil system; enhanced N inputs have implications for C cycling; N deposition is known to be having adverse effects on European and North American vegetation composition; very little is known about tropical ecosystem responses, while tropical ecosystems are major biodiversity hotspots and are increasingly recipients of very high N deposition rates; N deposition alters forest fungi and mycorrhyzal relations with plants; the rapid response of forest fungi and arthropods makes them good indicators of change; predictive tools (models) that address ecosystem scale processes are necessary to address complex drivers and responses, including the integration of N deposition, climate change and land use effects; criteria can be identified for projecting sensitivity of terrestrial and aquatic ecosystems to N deposition. Future research and policy-relevant recommendations are identified.
Water depth tolerances of dominant tree island species: What do we know?
Common woody species growing on tree islands in the Water Conservation Areas of South Florida include redbay, sweetbay, coastal-plain willow, wax myrtle, dahoon holly, cocoplum, pond-apple, red maple, cypress, gumbo-limbo, strangler fig and buttonbush. Very little is known about the flooding tolerance of most of these species. In this paper, we review flooding impact studies, describe the most common species and discuss two methods that might be used to examine woody plant growth response to water level fluctuations. Although tree coring has been used effectively in many areas, the general lack of discernible rings and poor quality rings observed in these species makes this method of questionable use. Dendrometer bands, however, work well in any environment with any species and are recommended for further studies on tree islands.
Paleoecological insights on fixed tree island development in the Florida Everglades: I. environmental controls
Palynological and geochemical analyses of sediment cores collected on two tree islands in the Florida Everglades indicate long-term hydrologic and chemical differences between tree islands and surrounding marshes and sloughs. Gumbo Limbo and Nuthouse tree islands are elongate, teardrop-shaped islands in Water Conservation Area 3B. Prior to tree island formation at both sites, pollen records indicate that sites on modern tree island heads were covered with sawgrass marshes with abundant weedy annuals. Such vegetation is characteristic of moderate water depths and hydroperiods with frequent droughts or disturbances. Contemporaneously deposited sediments on tree island tails indicate progressively deeper water conditions with increasing distance from the head; wetlands surrounding tree islands were covered by sloughs with deep water and long hydroperiods. Tree island formation occurred at about 1200 BC on Gumbo Limbo Island, with mature tree island vegetation established by about 800 AD. On Nuthouse Island, tree island formation occurred around 300 AD, shifting to mature tree island vegetation around 1400 AD. Thus, tree island formation began on these islands between 3.2 Ka and 1.7 Ka. Maturation of tree islands took between 1,000 and 2,000 years, and vegetation on these tree islands has been relatively stable for the last 600–1,200 years. Phosphorus levels on tree island heads have been extremely high (approximately six times greater than baseline levels in marshes) throughout the history of the sites, and phosphorus content in tree island tails began increasing when tree island formation occurred. Elevated phosphorus content may reflect the long-term presence of wading birds at these sites and provide a proxy for reconstructing the historic distribution of wading bird populations.
Microbial cycling of methyl bromide
Environmental concern about brominated halocarbons like methyl bromide (MeBr) is focused on their potential to destroy stratospheric ozone. Photocatalysis of MeBr and other halocarbons in the stratosphere results in the liberation of reactive CI and Br atoms. Because Br atoms are perhaps as much as 100-fold more efficient at attacking ozone than are CI atoms, bromine’s lower abundance is partly compensated for by its higher reactivity.
Mechanisms of Cenozoic tectonic rotation, Pacific Northwest Convergent Margin, U.S.A.
Large clockwise rotations (15–80°) are characteristic of Cenozoic volcanic and sedimentary rocks along the convergent margin of the northwestern United States. Abundant paleomagnetic data from 62–12 m.y. old rocks in forearc, arc, and backarc regions show that rotation increases with age and with proximity to the coast. Paleomagnetic and structural studies both support dextral shear as a significant contributor to tectonic rotation in the Pacific Northwest, with an added contribution from Basin-Range extension. Paleomagnetism of individual Miocene (15-12 Ma) flows of the Columbia River Basalt Group show a well-defined, progressive increase in rotation across the forearc region toward the trench which is most readily explained by shear. This progressive increase in rotation toward the coast is also seen in Oligocene and Eocene rocks, although with steeper gradients, indicating that shear rotation has been important throughout Cenozoic time. The dextral shear may be accommodated by abundant, small-scale strike-slip faults which are acting as Riedel shears. Coast Range faults, usually with well-developed subhorizontal slickensides, occur throughout the stratigraphie section and are most abundant in the oldest rocks. Displacements are small to moderate (10 2 –10 3 m), and both dextral and sinistral faults are common. Fault trends are variable, with N20°–45°W faults showing dextral slip and N60°W-S70°W faults showing sinistral slip. The driving force for dextral shear presumably results from coupling of the overlying plate with the subducting Farallon plate, which has been moving northeast throughout most of Cenozoic time. The increase in rotation from north to south along the coast probably represents the contribution of extension in the Basin- Range region to the rotations in Oregon.
Resource assessments, geologic deposit models, and offshore minerals with an example of heavy-mineral sands
A resource assessment method for offshore minerals based on descriptive and grade-tonnage models is proposed. Historical development and applications of this method are summarized. Based on this approach, descriptive and quantitative deposit models for strand-line titanium placer deposits have been developed. Descriptive statistics were also computed using the worldwide deposit data set upon which the grade-tonnage models are based. Certain guidelines and limitations in applying onshore titanium deposit models to offshore assessment and exploration must, however, be observed. The descriptive model points out the specific features of strandline titanium placer deposits which can be of use in selection of areas for exploration; the grade-tonnage models display the expected size distribution for this type of deposit. Used with an estimate of expected number of deposits, this information can be applied to quantify probable values associated with deposits of this type within a given area.
Geomorphologic evidence for ground ice on Mars
For ground ice to exist on Mars, two conditions have to be met. One is the presence of permafrost; the second is the availability of water. Because the mean temperature of Mars’surface is − 80 C., permafrost 1–3 km thick occurs over the entire planet. Remote-sensing measurements suggest that water presently exists in the atmosphere and in the polar caps; frost has been observed at the Viking landing sites. Landforms that support the contention that ground ice exists on Mars include lobate ejecta from craters, small valley networks, and numerous features that may be attributed to thermokarst. Chaotically collapsed terrain, chain craters, irregular depressions, and valleys tributary to canyons all appear to be related to loss of ground ice. Patterned ground has dimensions similar to that on Earth as well as dimensions of giant size. Masswasting features are common on scarps Even though individual features may be explained as results of other processes, the combined evidence indicates that a large reservoir of ground ice has existed on Mars.
Geologic information for aggregate resource planning
Construction and maintenance of the infrastructure is dependent on such raw materials as aggregate (crushed stone, sand, and gravel). Despite this dependence, urban expansion often works to the detriment of the production of those essential raw materials. The failure to plan for the protection and extraction of aggregate resources often results in increased consumer cost, environmental damage, and an adversarial relation between the aggregate industry and the community. As an area grows, the demand for aggregate resources increases, and industries that produce these materials are established. Aggregate is a low-cost commodity, and to keep hauling costs at a minimum, the operations are located as close to the market as possible. As metropolitan areas grow, they encroach upon established aggregate operations. New residents in the vicinity of pits and quarries object to the noise, dust, and truck traffic associated with the aggregate operation. Pressure is applied to the local government to limit operation hours and truck traffic. In addition to encroaching on established aggregate operations, urban growth commonly covers unmined aggregate resources. Frequently urban growth occurs without any consideration of the resource or an analysis of the impact of its loss. The old idea that aggregate resources can be found anywhere is false. New aggregate operations may have to be located long distances from the markets. The additional expense of the longer transport of resources must be passed on to consumers in the community. In many instances, the new deposit is of inferior quality compared with the original source, yet it is used to avoid the expense of importing high-quality material from a more-distant source. Some governmental, including city, provincial or state, and national, agencies, have enacted regulations to help maintain access to prime aggregate resources. Although regulations have met with variable success, some policy or regulation to protect aggregate resources is worth consideration. A basic requirement of any aggregate resource policy or regulation is the knowledge of the geographic distribution, volumes, and quality of aggregate resources. This knowledge commonly is obtained through geologic mapping and characterization of aggregate resources. Geographic Information Systems (GIS) and Decision Support Systems (DSS) provide excellent tools to help present and evaluate the information in a manner that is understandable by public decisionmakers.
Integrated surface and borehole strong-motion, soil-response arrays in San Francisco, California
An integrated set of four borehole arrays and ten surface installations is installed in the city of San Francisco, California to measure the response of soft-soil deposits to strong earthquake ground motions. The borehole arrays extend through thick layers of softwater-saturated soils of Holocene age and older more consolidated soils of Pleistocene age into bedrock at depths up to 100 m. The surface installations are configured in pairs to provide simultaneous comparative surface measurements of soft soils and nearby rock. The rock locations also permit comparative measurements of rock as observed at the surface and in nearby boreholes. Complementary structural response arrays alsoare installed near each array. The arrays are designed to address a wide variety of scientific and engineering issues, and especially the issue of anelastic and nonlinear soil response at high strain levels. Exact anelastic models have been developed to account for contrasts in anelastic properties at boundaries and the resultant inhomogeneity of propagating wave fields. These models predict that significant amounts of energy may be trapped in soil basins with resultant larger amplifications than can be predicted using conventional homogeneous wave-field models with damping. Results of these models are discussed.
Three-dimensional D4Z renumbering for iterative solution of ground-water flow and transport equations
No abstract available.
Applications of the transient tracers tritium/helium-3, and chlorofluorocarbons for tracing and age-dating yound ground water: Field examples from the USA and Germany
The transient tracers tritium/helium-3 ( 3 H/ 3 He) and chlorofluorocarbons (CFC-11, CFC-12, CFC-113) are well suited for tracing and age-dating young ground water. Their detection in ground water indicates waters recharged within the past 30 ( 3 H/ 3 He, CFC-113) to 50 (CFC-11, CFC-12) years, or ground water mixtures that contain at least a portion of young water. The ground water age can be determined independently from measurements of 3 H/ 3 He, CFC-11, CFC-12, and CFC-113, and in each case refers to the time elapsed since the recharge water was isolated from the soil air. Ground water age can be used to define recharge rates and refine numerical models of ground water flow. Transient tracers are particularly useful in characterising ground water flow in hydrologic systems where, because of insufficient geologic and hydro-logic data, numerical simulation may be difficult. Transient tracers are also useful in defining movement of ground water contaminants in studies aimed, for example, at the design of strategies to safeguard drinking water supplies.
Reintroduction of the black-footed ferret ( Mustela nigripes )
The black-footed ferret ( Mustela nigripes ) (Figure 27.1) is a small, secretive, nocturnal member of the family Mustelidae (Hall, 1981; Honacki, Kurman and Koeppl, 1982). Ferrets have an obligate dependence on the prairie dog ( Cynomys spp.) community, utilizing the prairie dog for food and its burrows for shelter (Campbell et al., 1987).