Eastern Temperate Forests

Human activity in the last century has led to a substantial increase in nitrogen (N) emissions and deposition. This N deposition has reached a level that has caused or is likely to cause alterations to the structure and function of many ecosystems across the United States. One approach for quantifying the level of pollution that would be harmful to ecosystems is the critical loads approach. The critical load is dei ned as the level of a pollutant below which no detrimental ecological effect occurs over the long term according to present knowledge. The objective of this project was to synthesize current research relating atmospheric N deposition to effects on terrestrial and aquatic ecosystems in the United States and to identify empirical critical loads for atmospheric N deposition. The receptors that we evaluated included freshwater diatoms, mycorrhizal fungi and other soil microbes, lichens, herbaceous plants, shrubs, and trees. The main responses reported fell into two categories: (1) biogeochemical, and (2) individual species, population, and community responses. The range of critical loads for nutrient N reported for U.S. ecoregions, inland surface waters, and freshwater wetlands is 1 to 39 kg N ha-1 y-1. This broad range spans the range of N deposition observed over most of the country. The empirical critical loads for N tend to increase in the following sequence for different life forms: diatoms, lichens and bryophytes, mycorrhizal fungi, herbaceous plants and shrubs, trees. The critical loads approach is an ecosystem assessment tool with great potential to simplify complex scientii c information and effectively communicate with the policy community and the public. This synthesis represents the i rst comprehensive assessment of empirical critical loads of N for ecoregions across the United States.

Federal and state policy influence on woody biomass utilization

A considerable portion of public lands in the United States is at risk of uncharacteristically severe wildfires due to a history of fire suppression. Wildfires already have detrimental impacts on the landscape and on communities in the wildland-urban interface (WUI) due to unnatural and overstocked forests. Strategies to mitigate wildfire risk include mechanical thinning and prescribed burning in areas with high wildfire risk. The material removed is often of little or no economic value. Woody biomass utilization (WBU) could offset the costs of hazardous fuel treatments if removed material could be used for wood products, heat, or electricity production. However, barriers due to transportation costs, removal costs, and physical constraints (such as steep slopes) hinder woody biomass utilization. Various federal and state policies attempt to overcome these barriers. WBU has the potential to aid in wildfire mitigation and meet growing state mandates for renewable energy. This research utilizes interview data from individuals involved with on-the-ground woody biomass removal and utilization to determine how federal and state policies influence woody biomass utilization. Results suggest that there is not one over-arching policy that hinders or promotes woody biomass utilization, but rather woody biomass utilization is hindered by organizational constraints related to time, cost, and quality of land management agencies’ actions. However, the use of stewardship contracting (a hybrid timber sale and service contract) shows promise for increased WBU, especially in states with favorable tax policies and renewable energy mandates. Policy recommendations to promote WBU include renewal of stewardship contracting legislations and a re-evaluation of land cover types suited for WBU. Potential future policies to consider include the indirect role of carbon dioxide emission reduction activities to promote wood energy and future impacts of air quality regulations.

Classifying and mapping the urban transition in Vietnam

The urban transition almost always involves wrenching social adjustment as small agricultural communities are forced to adjust rapidly to industrial ways of life. Large-scale in-migration of young people, usually from poor regions, creates enormous demand and expectations for community and social services. One immediate problem planners face in approaching this challenge is how to define, differentiate, and map what is rural, urban, and transitional (i.e., peri-urban). This project established an urban classification for Vietnam by using national census and remote sensing data to identify and map the smallest administrative units for which data are collected as rural, peri-urban, urban, or urban core. We used both natural and human factors in the quantitative model: income from agriculture, land under agriculture and forests, houses with modern sanitation, and the Normalized Difference Vegetation Index. Model results suggest that in 2006, 71% of Vietnam's 10,891 communes were rural, 18% peri-urban, 3% urban, and 4% urban core. Of the communes our model classified as peri-urban, 61% were classified by the Vietnamese government as rural. More than 7% of Vietnam's land area can be classified as peri-urban and approximately 13% of its population (more than 11 million people) lives in peri-urban areas. We identified and mapped three types of peri-urban places: communes in the periphery of large towns and cities; communes along highways; and communes associated with provincial administration or home to industrial, energy, or natural resources projects (e.g., mining). We validated this classification based on ground observations, analyses of multi-temporal night-time lights data, and an examination of road networks. The model provides a method for rapidly assessing the rural–urban nature of places to assist planners in identifying rural areas undergoing rapid change with accompanying needs for investments in building, sanitation, road infrastructure, and government institutions.

A comprehensive review of the environmental impacts and human health risks associated with the occurrence of waste pharmaceuticals in water sources of the United States, and policy implications

The occurrence of waste pharmaceuticals has been identified and well documented in water sources throughout North America and Europe. Many studies have been conducted which identify the occurrence of various pharmaceutical compounds in these waters. This project is an extensive review of the documented evidence of this occurrence published in the scientific literature. This review was performed to determine if this occurrence has a significant impact on the environment and public health. This project and review found that pharmaceuticals such as sex hormone drugs, antibiotic drugs and antineoplastic/cytostatic agents as well as their metabolites have been found to occur in water sources throughout the United States at levels high enough to have noticeable impacts on human health and the environment. It was determined that the primary sources of this occurrence of pharmaceuticals were waste water effluent and solid wastes from sewage treatment plants, pharmaceutical manufacturing plants, healthcare and biomedical research facilities, as well as runoff from veterinary medicine applications (including aquaculture). ^ In addition, current public policies of US governmental agencies such as the Environmental Protection Agency (EPA), Food and Drug Administration (FDA), and Drug Enforcement Agency (DEA) have been evaluated to see if they are doing a sufficient job at controlling this issue. Specific recommendations for developing these EPA, FDA, and DEA policies have been made to mitigate, prevent, or eliminate this issue.^ Other possible interventions such as implementing engineering controls were also evaluated in order to mitigate, prevent and eliminate this issue. These engineering controls include implementing improved current treatment technologies such as the advancement and improvement of waste water treatment processes utilized by conventional sewage treatment and pharmaceutical manufacturing plants. In addition, administrative controls such as the use of “green chemistry” in drug synthesis and design were also explored and evaluated as possible alternatives to mitigate, prevent, or eliminate this issue. Specific recommendations for incorporating these engineering and administrative controls into the applicable EPA, FDA, and DEA policies have also been made.^

Assemblages and isotopic signals of modern ostracodes and host waters from Patagonia, Argentine

Ostracode species assemblages and stable oxygen and carbon isotope ratios of living and recent ostracodes, together with delta18O and delta13C_DIC values of host water samples, provide a first data set that characterizes a wide range of modern aquatic environments in the Laguna Cari-Laufquen (41°S, 68 - 69°W) and the Lago Cardiel area (48 - 49°S, 70 - 71°W) in Patagonia, Argentina. This data set will ultimately be used to interpret and calibrate data acquired from lake sediment cores with the goal of reconstructing past climate. Species assemblages and isotope values can be assigned to three groups; (1) springs, seeps and streams, (2) permanent ponds and lakes, and (3) ephemeral ponds and lakes. Springs, seeps and streams are characterized by Darwinula sp., Heterocypris incongruens, Eucypris fontana, Amphicypris nobilis and Ilyocypris ramirezi. Ostracode and water isotope values range between -13 and -5 per mil for oxygen, and between -15 and -3 per mil for carbon. They are the most negative of the entire sample set, reflecting ground water input with little or no evaporative enrichment. Limnocythere patagonica, Eucypris labyrinthica, Limnocythere sp. and Eucypris aff. fontana are typical species of permanent ponds and lakes. Isotope values indicate high degree of evaporation of lake waters relative to feeder springs and streams and range between -7 and +5 per mil for oxygen, and -5 and +4 per mil for carbon. Limnocythere rionegroensis is the dominant species in ephemeral ponds and lakes. These systems display the most enriched isotope values in both ostracodes and host waters, extending from -5 to +7 per mil for oxygen, and from -5 to +6 per mil for carbon. Living ostracodes show a positive offset from equilibrium values of up to 2 per mil for oxygen. Carbon-isotope values are up to 6? more negative than equilibrium values in highly productive pools. Comparison of ostracode and host water isotope signals permits assessment of the life span of the aquatic environments. Valves from dead ostracodes collected from ephemeral ponds and lakes show a wide scatter with each sample providing a snapshot of the seasonal history of the host water. The presence of the stream species Ilyocypris ramirezi and a wide range of ostracode isotope values suggest that ephemeral ponds and lakes are fed by streams during spring run-off and seasonally dry. A temporary character is also indicated by Heterocypris incongruens, a drought-resistant species that occupies most springs and seeps. In addition, Limnocythere rionegroensis has adjusted its reproduction strategies to its environment. Whereas only females were collected in fresh host waters, males were found in ephemeral ponds and lakes with higher solute content. Sexual reproduction seems to be the more successful reproduction strategy in high and variable salinities and seasonal droughts. The temporary character of the aquatic environments shows that the availability of meteoric water controls the life span of host waters and underlines the sensitivity of the area to changes in precipitation.

Organic compounds in sediments and pore waters of ODP Sites 117-723 and 117-724

Total organic carbon, amino compounds, and carbohydrates were measured in pore waters and sediments of Pliocene to Pleistocene age from Sites 723 and 724 (ODP Leg 117) to evaluate (1) relationships between organic matter in the sediment and in the pore water, (2) the imprint of lithological variations on the abundance and contribution of organic substances, (3) degradation of amino compounds and carbohydrates with time and/or depth, and (4) the dependence of the ammonia concentration in the pore water on the degradation of amino compounds in the sediment. Total organic carbon concentrations (TOC) of the investigated sediment samples range from 0.9% to 8.7%, and total nitrogen concentrations (TN) from 0.1% to 0.5%. Up to 4.9% of the TOC is contributed by hydrolyzable amino acids (THAA) which are present in amounts between 1.1 and 21.3 µmol/g dry sediment and decrease strongly downhole. Hydrolyzable carbohydrates (THCHO) were found in concentrations from 1.3 to 6.6 ?mol/g sediment constituting between 0.1% and 2.0% of the TOC. Differences between the distribution patterns of monomers in Sites 723 and 724 indicate higher terrigenous influence for Site 724 and, furthermore, enhanced input of organic matter that is relatively resistant to microbial degradation. Lithologically distinct facies close to the Pliocene/Pleistocene boundary yield different organic matter compositions. Laminated horizons seem to correspond with enhanced amounts of biogenic siliceous material and minor microbiological degradation. Total amounts of dissolved organic carbon (DOC) in pore waters vary between 11 and 131 mg/L. Concentrations of DOC as well as of dissolved amino compounds and carbohydrates appear to be related to microbial activity and/or associated redox zones and not so much to the abundance of organic matter in the sediments. Distributions of amino acids and monosaccharides in pore waters show a general enrichment in relatively stable components in comparison to those of the sediments. Nevertheless, the same trend appears between amino acids present in the sediments from Sites 723 and 724 as well as between amino acids in pore waters from these two sites, indicating a direct relation between the dissolved and the sedimentary organic fractions. Different ammonia concentrations in the pore waters of Sites 723 and 724 seem to be related to enhanced release of ammonia from degradation of amino compounds in Site 723.

Lithium and strontium isotopic compositions of sediments and pore waters at ODP Sites 152-918 and 152-919

The distribution of Li isotopes in pore waters to a depth of 1157 m below seafloor is presented for ODP Sites 918 and 919 in the Irminger Basin, offshore Greenland. Lithium isotope data are accompanied by strontium isotope ratios to decipher diagenetic reactions in the sediments which are characterized by the pervasive presence of volcanic material, as well as by very high accumulation rates in the upper section. The lowering of the 87Sr/86Sr ratio below contemporaneous seawater values indicates several zones of volcanic material alteration. The Li isotope profiles are complex suggesting a variety of exchange reactions with the solid phases. These include cation exchange with NH4+ and mobilization from sediments at depth, in addition to the alteration of volcanic matter. Lithium isotopes are, therefore, a sensitive indicator of sediment-water interaction. d6Li values of pore waters at these two sites vary between -42 and -25?. At shallow depths (<100 mbsf), rapid decreases in the Li concentration, accompanied by a shift to heavier isotopic compositions, indicate uptake of Li into alteration products. A positive anomaly of d6Li observed at both sites is coincident with the NH4+ maximum produced by organic matter decomposition and may be related to ion exchange of Li from the sediments by NH4+. In the lower sediment column at Site 918, dissolved Li increases with depth and is characterized by enrichment of 6Li. The Li isotopic compositions of both the waters and the solid phase suggest that the enrichment of Li in deep interstitial waters is a result of release from pelagic sediments. The significance of sediment diagenesis and adsorption as sinks of oceanic Li is evaluated. The maximum diffusive flux into the sediment due to volcanic matter alteration can be no more than 5% of the combined inputs from rivers and submarine hydrothermal solutions. Adsorption on to sediments can only account for 5-10% of the total inputs from rivers and submarine hot springs.

Eh and pH values in sediments and composition of interstitial waters from the Frolikha Bay, Baikal Lake

Redox conditions and compositions of bottom sediments and sedimentary pore waters in the area of the hydrothermal vent in the Frolikha Bay (Baikal Lake) are under discussion. According to obtained results, the submarine vent and its companion spring nearby on the land originate from a common source. The most convincing evidence for their relation comes from proximity of stable oxygen and hydrogen isotope compositions in the pore waters and spring water. The isotope composition indicates meteoric origin of the pore waters, but their major- and minor element compositions have influence of deep water, which may seep through the permeable faulted crust. Although the pore waters near the submarine vent have specific enrichment in major and minor constituents, hydrothermal discharge at the Baikal bottom causes minor influence on water composition of the Baikal Lake, unlike freshwater lakes in rifts of the East Africa and North America.

Sr/Ca, U/Ca, and stable isotope data and bimonthly records of Ogasawara coral core OGA-02-1

Instrumental climate observations provide robust records of global land and ocean temperatures during the twentieth century. Unlike for temperature, continuous salinity observations in the surface ocean are scarce prior to 1970, and the magnitude of salinity changes during the twentieth century is largely unknown. Surface ocean salinity is a major component in climate dynamics, as it influences ocean circulation and water mass formation. Here we present an annually resolved reconstruction of salinity variations in the surface waters of the western subtropical North Pacific Ocean since 1873, based on bimonthly records of d18O, Sr/Ca, and U/Ca in a coral from the Ogasawara Islands. The reconstruction indicates that an abrupt regime shift toward fresher surface ocean conditions occurred between 1905 and 1910. Observational atmospheric data suggest that the abrupt freshening was associated with a weakening of the winds that drive the Kuroshio Current system and the associated subtropical gyre circulation. We note that the abrupt early-twentieth-century freshening in the western subtropical North Pacific precedes abrupt climate change in the northern North Atlantic by a few years. The potential for abrupt regime shifts in surface ocean salinity should be considered in climate predictions for the coming decades.

Chemical composition of bottom sediments and interstitial waters from DSDP Sites 252, 285, 315, 317, 336, and 386

Six Deep Sea Drilling Project (DSDP) Sites (252, 285, 315, 317, 336, 386) were examined for the chemical composition of the dissolved salts in interstitial waters, the oxygen isotopic composition of the interstitial waters, and the major ion composition of the bulk solid sediments. An examination of the concentration-depth profiles of dissolved calcium, magnesium, potassium, and H218O in conjunction with oxygen isotope mass balance calculations confirms the hypothesis that in DSDP pelagic drill sites concentration gradients in Ca. Mg. K, and H218O are largely due to alteration reactions occurring in the basalts of Layer 2 and to alteration reactions involving volcanic matter dispersed in the sediment column. Oxygen isotope mass balance calculations require substantial alteration of Layer 2 (up to 25% of the upper 1000 m). but only minor exchange of Ca, Mg, and K occurs with the overlying ocean. This implies that alteration reactions in Layer 2 are almost isochemical.

Abiotic characteristics and diatom abundance and biomass in different sectors of the Argentinien Shelf and antartic waters

A large spatial scale study of the diatom species inhabiting waters from the subantarctic (Argentine shelf) to antarctic was made for the first time in order to understand the relationships between these two regions with regard to the fluctuations in diatom abundances in relation with environmental features, their floristic associations and the effect of the Polar Front as a biogeographic barrier. Species-specific diatom abundance, nutrient and chlorophyll-a concentration were assessed from 64 subsurface oceanographic stations carried out during the austral summer 2002, a period characterized by an anomalous sea-ice coverage corresponding to a ''warm year". Significant relationships of both diatom density and biomass with chlorophyll-a (positive) and water temperature (negative) were found for the study area as a whole. Within the Subantarctic region, diatom density and biomass values were more uniform and significantly (in average: 35 and 11 times) lower than those of the Antarctic region, and did not correlate with chlorophyll-a. In antarctic waters, instead, biomass was directly related with chlorophyll-a, thus confirming the important contribution of diatoms to the Antarctic phytoplanktonic stock. A total of 167 taxa were recorded for the entire study area, with Chaetoceros and Thalassiosira being the best represented genera. Species richness was maximum in subantarctic waters (46; Argentine shelf) and minimum in the Antarctic region (21; Antarctic Peninsula), and showed a significant decrease with latitude. Floristic associations were examined both qualitatively (Jaccard Index) and quantitatively (correlation) by cluster analyses and results allowed differentiating a similar number of associations (12 vs. 13, respectively) and two main groups of stations. In the Drake Passage, the former revealed that the main floristic change was found at the Polar Front, while the latter reflected the Southern ACC Front as a main boundary, and yielded a higher number of isolated sites, most of them located next to different Antarctic islands. Such differences are attributed to the high relative density of Fragilariopsis kerguelensis in Argentine shelf and Drake Passage waters and of Porosira glacialis and species of Chaetoceros and Thalasiosira in the Weddell Sea and near the Antarctic Peninsula. From a total of 84 taxa recorded in antarctic waters, only 17 were found exclusively in this region, and the great majority (67) was also present in subantarctic waters but in extremely low (< 1 cell/l) concentrations, probably as a result of expatriation processes via the ACC-Malvinas Current system. The present results were compared with those of previous studies on the Antarctic region with respect to both diatom associations in regular vs. atypically warm years, and the distribution and abundance of some selected planktonic species reported for surface sediments.

Occurrence, abundance and biomass of photo- and heterotrophic plankton in Norwegian coastal waters

The purpose of the present study was to explore the composition and variation of the pico-, nano- and micro-plankton communities in Norwegian coastal waters and Skagerrak, and the co-occurrence of bacteria and viruses. Samples were collected along three cruise transects from Jaeren, Lista and Oksoy on the south coast of Norway and into the North Sea and Skagerrak. We also followed a drifting buoy for 55 h in Skagerrak in order to observe diel variations. Satellite ocean color images (SeaWiFS) of the chlorophyll a (chl a) distribution compared favorably to in situ measurements in open waters, while closer to the shore remote sensing chl a data was overestimated compared to the in situ data. Using light microscopy, we identified 49 micro- and 15 nanoplankton sized phototrophic forms as well as 40 micro- and 12 nanoplankton sized heterotrophic forms. The only picoeukaryote (0.2-2.0 µm) we identified was Resultor micron (Pedinophyceae). Along the transects a significant variation in the distribution and abundance of different plankton forms were observed, with Synechococcus spp and autotrophic picoeukaryotes as the most notable examples. There was no correlation between viruses and chl a, but between viruses and bacteria, and between viruses and some of the phytoplankton groups, especially the picoeukaryotes. Moreover, there was a negative correlation between nutrients and small viruses (Low Fluorescent Viruses) but a positive correlation between nutrients and large viruses (High Fluorescent Viruses). The abundance of autotrophic picoplankton, bacteria and viruses showed a diel variation in surface waters with higher values around noon and late at night and lower values in the evening. Synechococcus spp were found at 20 m depth 25-45 nautical miles from shore apparently forming a bloom that stretched out for more than 100 nautical miles from Skagerrak and up the south west coast of Norway. The different methods used for assessing abundance, distribution and diversity of microorganisms yielded complementary information about the plankton community. Flow cytometry enabled us to map the distribution of the smaller phytoplankton forms, bacteria and viruses in more detail than has been possible before but detection and quantification of specific forms (genus or species) still requires taxonomic skills, molecular analysis or both.

Determination of ages and fossil Coleoptera fauna from eight sites in the London region

These data sets report the fossil beetle assemblages identified from the Mesolithic to Late Bronze Age at eight sites in the London region. All but one of the study sites are within 2 km of the modern course of the Thames. The sites produced 128 faunal assemblages that yielded 218 identified species in 41 families of Coleoptera (beetles).  Beetle faunas of Mesolithic age indicate extensive wetlands near the Thames, bordered by rich deciduous woodlands. The proportion of woodland species declined in the Neolithic, apparently because of the expansion of wetlands, rather than because of human activities. The Early Bronze Age faunas contained a greater proportion of coniferous woodland and aquatic (standing water) species. An increase in the dung beetle fauna indicates the presence of sheep, cattle and horses, and various beetles associated with crop lands demonstrate the local rise of agriculture, albeit several centuries after the beginnings of farming in other regions of Britain. Late Bronze Age faunas show the continued development of agriculture and animal husbandry along the lower Thames. About 33% of the total identified beetle fauna from the London area sites have limited modern distributions or are extinct in the U.K. Some of these species are associated with the dead wood found in primeval forests; others are wetland species whose habitat has been severely reduced in recent centuries. The third group is stream-dwelling beetles that require clean, clear waters and river bottoms.