Areas Of Low Productivity Research Articles

Revaluation of alluvial deposits residual reserves of boulder chrome ores of the Saranovsky ore field

Relevance of the work. After the collapse of the USSR, local ferroalloy industry experienced a deficit in certain types of mineral raw materials, in particular in chromium ores. In Perm Krai, in the vicinity of the village Sarany, medium and small-scale deposits of primary magmatic and fragmental slop wash ore of high iron content and alumina are known, previously used only as refractory raw materials. In the 1990–2000s, technologies for producing commercial and conversion ferrochrome with low chromium content (“charge-chromium”) using chromium ores of the Ural region, including ores from deposits of the Saranovsky group, were developed and introduced on an industrial scale. All this entailed the need for geological and economic revaluation of the reserves of known deposits, including placers of wash ores partially affected by mining operations of previous years. The revaluation included not only the residual natural reserves of deposits, but the technogenic formations in their areas containing underextracted ore round stones as well. Currently, the project for the development of boulder placers is being successfully implemented. The experience gained may be of interest in reassessing the residual reserves of objects of scarce types of mineral raw materials characterized by a complex "natural-technogenic" structure. Purpose of the work: to summarize the experience of joint revaluation of residual natural reserves and technogenic formations on the areas of placer deposits of boulder chrome ores aimed at ensuring the maximum completeness of excavation of scarce raw materials. Method and methodology of the work carried out. The main idea of the work is to jointly reassess the industrial importance of the residual reserves of boulder chrome ores contained in natural and man-made formations in placer areas. Given the relatively simple mining and geological conditions and small volumes of annual production, the criterion of “minimum industrial output of ore boulders”, which achieves equality of the recoverable value of mineral raw materials to the operating costs of obtaining marketable products, is proposed to be applied to the residual reserves of the placer, and not to individual geological blocks. This approach obliges the subsoil user to conduct continuous mining of the remaining reserves, to involve in the industrial development reserves of low-productive geological blocks, including those represented by technogenic formations, the average yield of ore boulders from which, as a rule, is lower than the estimated industrial minimum. The rational choice of placers that are simultaneously mined is justified by economic indicators used in the evaluation of mining projects (net present value, profitability index, budget efficiency, etc.), taking into account the “individual” characteristics of individual deposits. The proposed approach to involving in the development of reserves of low-productive areas (including technogenic formations) can be implemented not only at the level of individual deposits, but at the level of a group of “converging” differently productive placers as well, when both highly productive and “poor” placers are being developed, the reserves of which in the traditional assessment are classified only as off-balance sheet (potentially economic). Results of the works. The description is given of methodological approaches to the revaluation and rational use of residual reserves of boulder chrome ores disrupted by mining operations of previous years. The experience gained can be used to evaluate other mining facilities that contain natural and technogenic formations of different productivity on their area.

Passively Sampled Ambient Hydrocarbon Abundances in a Texas Oil Patch

The United States has experienced exceptional growth in oil production via unconventional extraction for over a decade. This boom has led to an increase in hydrocarbon emissions to the atmosphere. With Texas as the leading contributor to growing oil production, it is important to assess the effects the boom has had on the environment and communities at local and regional levels. We conducted a pilot study to investigate the use of passive samplers for evaluating potential off-site risk from hydrocarbon emissions in a relatively low production activity area of the Texas Eagle Ford shale. Emissions from production sites include benzene, a hazardous air pollutant and known carcinogen. Passive hydrocarbon sampling devices (Radiello samplers) were used to monitor hydrocarbon levels on a rural property near a production site with an occasional flare for one year. Selected hydrocarbons were analyzed using thermal desorption and gas chromatography with flame ionization detection. Benzene concentrations were found to be correlated with changes in season, with higher abundance in the winter months. Benzene levels at this site were similar or higher than those observed in urban areas, away from shale oil and gas production. Increased benzene concentrations were distinguished when winds advected hydrocarbons from the production site, suggesting that oil and gas site emissions have a greater impact on the local community when winds advect them towards those living downwind; however, hydrocarbon levels in this low production area never exceeded state air monitoring comparison standards.

Meiofaunal diversity at a seamount in the pacific ocean: A comprehensive study using environmental DNA and RNA

In deep-sea environments, which have low densities of large benthic animals, meiofauna are a useful indicator of biodiversity. However, in low-latitudes and in low-productivity areas, meiofaunal density is low, but is higher than that of megafaunal or macrofaunal density. Therefore, it is difficult to collect a sufficient number of specimens for statistical analysis. In addition, because faunal classification has been based on conventional microscopic observations, the use of meiofauna to estimate biodiversity in deep-sea environments is time-consuming. However, metabarcoding analyses focused on environmental DNA (eDNA) or RNA (eRNA) have recently been used to examine deep-sea eukaryotic diversity and communities. Here, we examined meiofaunal assemblages using microscopic, eDNA-, and eRNA-based methods at Xufu Guyot (JA06 Seamount), off the southeastern coast of Minami-Torishima Island in the North Pacific Ocean. Microscopic analysis failed to detect a significant difference in diversity or community structure between the seamount terrace and base. This was likely because of the low abundance of meiofauna, which was caused by the low surface productivity at the study area. However, eDNA/eRNA-based metabarcoding analyses revealed spatial variations in diversity and community structures within a single seamount. Therefore, metabarcoding analysis might be useful to elucidate meiofaunal assemblages in areas with low productivity and low faunal density.

Production and composition of biomass from short rotation coppice in marginal land: A 9-year study

The production and chemical composition of the biomass of four fast growing woody crops are studied across species and rotation cycles. High-density plantations of poplar, willow, black locust and sycamore were monitored for 9 years over 3-year rotation cycles in marginal land in the Mediterranean area. The fuel quality properties of the produced biomass was assessed using proximate and ultimate analysis, biomass and ash chemical composition (23 elements), and ash melting behaviour.Willow, poplar and black locust energy crops produced 12, 9 and 7 dry Mg ha−1 yr−1 on average, indicating that these species can be well adapted to the unfavourable conditions of poor soils in low productivity areas in the Mediterranean region. In contrast, sycamore was not well adapted to the particular climate and soil conditions and provided very poor yields. The chemical composition of the biomass varied across species and rotation cycles. The results obtained from the chemical analysis of these woody species showed that they provided good quality for use in combustion processes, with low amounts of trace elements and chlorine (≈0.01 wt%), sulphur (≈0.04 wt%) and nitrogen (≈0.5 wt%), with the exception of black locust (N = 0.86 wt%). No sintering problems are expected during the combustion of the studied biomass. This study provides valuable information for the large-scale implementation of fast growing woody species dedicated to energy crops in low productivity areas of the Mediterranean region.

Mapping Succession in Non-Forest Habitats by Means of Remote Sensing: Is the Data Acquisition Time Critical for Species Discrimination?

The process of secondary succession is one of the most significant threats to non-forest (natural and semi-natural open) Natura 2000 habitats in Poland; shrub and tree encroachment taking place on abandoned, low productive agricultural areas, historically used as pastures or meadows, leads to changes to the composition of species and biodiversity loss, and results in landscape transformations. There is a perceived need to create a methodology for the monitoring of vegetation succession by airborne remote sensing, both from quantitative (area, volume) and qualitative (plant species) perspectives. This is likely to become a very important issue for the effective protection of natural and semi-natural habitats and to advance conservation planning. A key variable to be established when implementing a qualitative approach is the remote sensing data acquisition date, which determines the developmental stage of trees and shrubs forming the succession process. It is essential to choose the optimal date on which the spectral and geometrical characteristics of the species are as different from each other as possible. As part of the research presented here, we compare classifications based on remote sensing data acquired during three different parts of the growing season (spring, summer and autumn) for five study areas. The remote sensing data used include high-resolution hyperspectral imagery and LiDAR (Light Detection and Ranging) data acquired simultaneously from a common aerial platform. Classifications are done using the random forest algorithm, and the set of features to be classified is determined by a recursive feature elimination procedure. The results show that the time of remote sensing data acquisition influences the possibility of differentiating succession species. This was demonstrated by significant differences in the spatial extent of species, which ranged from 33.2% to 56.2% when comparing pairs of maps, and differences in classification accuracies, which when expressed in values of Cohen’s Kappa reached ~0.2. For most of the analysed species, the spring and autumn dates turned out to be slightly more favourable than the summer one. However, the final recommendation for the data acquisition time should take into consideration the phenological cycle of deciduous species present within the research area and the abiotic conditions.

Characteristics of Large Area Perovskite Solar Cells from Electrodes of Used Car Batteries

Power conversion efficiency (PCE) of perovskite solar cells increases very rapidly and more than 22% is already achieved. However, some problems still need to be resolved for mass production and commercialization, including reducing production costs and development of large area solar cells. The best PCE is reached by very small active area, mostly below 0.5 cm2 which is mostly produced by spin-coating technique. Moreover, the perovskite precursor materials, mostly lead (II) iodide (PbI2) and hole-transport materials (HTM) Spiro-OMeTAD are expensive material in perovskite solar cells. Therefore, the use of low-cost perovskite precursors and low-cost HTM materials is one way to reduce the whole production costs of perovskite solar cells. Nowadays, many groups have been developed HTM-free perovskite solar cells using carbon-based mesoscopic solar cells for low cost production and large area perovskite solar cells, although the PCE of large area perovskite solar cells is still half than that very small area prepared by spin-coating technique. Here, we report our recent study to fabricate perovskite solar cells using mesoscopic carbon-based structure consisting of glass/ITO/TiO2/ZrO2/perovskite/carbon with active area larger than 1 cm2 by use of simple screen printing technique in ambient air with high humidity. We also synthesize PbI2 as perovskite precursor material from electrodes of used car battery to reduce the cost of solar cells production. Although, the PCE is still much lower than that reported by other groups, however, our study shows that perovskite solar cells from used car battery and with active area more than 1 cm2 can be fabricated in ambient air with high humidity by use of simple screen printing technique.

Yield mapping using satellite navigation systems

The paper presents the results of research and production experiments of spring wheat yield mapping. Five clusters were identified in terms of yield with an interval of 0.2 t/ha. With an average yield of spring wheat of 2.23 t/ha over an area of 13.7 hectares, it ranged from 1.91 t/ha to 2.71 t/ha. The reason for the heterogeneity of the spring wheat yield on this fragment of the field is a variety of soil cover. Detailing of soil fertility factors showed that in the low productivity area there was the lowest humus content (3.4%) in the 0-30 cm layer, nitrate nitrogen 5.1 mg/kg soil, mobile phosphorus - 46 mg/kg, exchangeable potassium - 55 mg/kg and pH - 4.2. The obtained data of yield mapping and detailed analysis of soil fertility factors in problem areas served as the basis for a technical solution with software for the differential application of mineral fertilizers in elementary areas in off-line mode.

HUMAN FACTOR AND ITS EFFICIENCY EVALUATION IN REVENUE CENTERS

Human factor is one of more important resources of the organization, reflecting status quo of its intangible assets. Skilful managing these components increases entity’s potential in the long run. So-called key performance factors (KPIs) can be regarded as a starting point for its measurement. Reviewing “work factor” in an enterprise helps “capturing” areas of low productivity, improving tasks implementation, appropriate employees motivating, making efforts for continuous development. KPIs are grouped within the framework of four perspectives referring: internal processes, client, learning and owner. This study sets out to assess achievements of individual divisions of a service company in each of these areas, by using properly designed indicators. The main thesis of the publication maintains that the statistic range based on arithmetic means of branch performance ratios allows to determine the size of the competence gap of a given revenue center.

Different cutting regimes improve species and functional diversity of insect‐pollinated plants in power‐line clearings

AbstractTo mitigate biodiversity loss, it is essential to understand how areas altered by human land use can act as alternative habitats for functional groups of species, which are in decline. In forested landscapes, power‐line clearings can be valuable habitats for early successional plant species, which in turn provide important food resources for pollinating insects. However, we know little about how management practices affect plant diversity, or how changes in species diversity translate into the functional diversity of floral resources. We conducted an experiment at 19 sites in power‐line clearings across southeast Norway where the woody vegetation was (1) cut and left to decay, (2) cut and removed, or (3) uncut. We assessed the effects of treatments on species diversity (richness, evenness, diversity) and functional diversity (functional evenness, functional dispersion) of understory plant communities of insect‐pollinated plants. We also investigated the influence of environmental conditions within the power‐line clearings, the surrounding landscape, and climatic factors on species and functional diversity. We found that the cut and cut–remove treatments were effective in increasing biological diversity of insect‐pollinated plants. The species and functional diversity showed contrasting responses to treatments, and the treatment effects depended on the environmental context. This shows that ecosystem functioning is not necessarily predictable from the ecological processes that drive species composition. The treatment effects on species diversity were partly explained by the stress‐gradient hypothesis; species richness was higher in the cleared plots in areas of low environmental stress from precipitation and elevation. In contrast, the treatment effects on functional diversity were positively influenced by productivity, stem density, temperature, available source habitats, elevation, and canopy density. Functional diversity, based on effect traits, should be emphasized when the aim is to maintain a broad range of pollination functions and services in power‐line clearings. This study shows that inclusion of power‐line clearings in conservation plans can mitigate biodiversity decline in forested landscapes. We recommend the cut–remove treatment in productive areas with available source habitats and high stem density. In low productive areas, with high stem density and high temperatures, the standard cut treatment is sufficient, but a higher cutting frequency is recommended.

Global prioritisation of renewable nitrogen for biodiversity conservation and food security

The continuing use of petrochemicals in mineral nitrogen (N) production may be affected by supply or cost issues and climate agreements. Without mineral N, a larger area of cropland is required to produce the same amount of food, impacting biodiversity. Alternative N sources include solar and wind to power the Haber-Bosch process, and the organic options such as green manures, marine algae and aquatic azolla. Solar power was the most land-efficient renewable source of N, with using a tenth as much land as wind energy, and at least 100th as much land as organic sources of N. In this paper, we developed a decision tree to locate these different sources of N at a global scale, or the first time taking into account their spatial footprint and the impact on terrestrial biodiversity while avoiding impact on albedo and cropland, based on global resource and impact datasets. This produced relatively few areas suitable for solar power in the western Americas, central southern Africa, eastern Asia and southern Australia, with areas most suited to wind at more extreme latitudes. Only about 2% of existing solar power stations are in very suitable locations. In regions such as coastal north Africa and central Asia where solar power is less accessible due to lack of farm income, green manures could be used, however, due to their very large spatial footprint only a small area of low productivity and low biodiversity was suitable for this option. Europe in particular faces challenges because it has access to a relatively small area which is suitable for solar or wind power. If we are to make informed decisions about the sourcing of alternative N supplies in the future, and our energy supply more generally, a decision-making mechanism is needed to take global considerations into account in regional land-use planning.

Organic Carbon Concentrations in High- and Low-Productivity Areas of the Sulu Sea

The sequestration of anthropogenic carbon dioxide in the form of organic carbon and its eventual deposition in the sediments is an important component of the marine carbon cycle. In the Sulu Sea, Philippines, organic carbon contents in the sediments have been relatively well studied, but the processes that describe the organic carbon distributions in the water column have not been elucidated. Dissolved and particulate organic carbon (DOC, POC) concentrations were measured at several stations in the Sulu Sea during the northeast monsoon of 2007/2008 to understand the dynamics of organic carbon in this unique internal sea. Analyses of primary productivity estimates, beam attenuation coefficient (at 660 nm) profiles, and correlation coefficients among DOC, POC and other parameters (e.g., apparent oxygen utilization) at different layers of the water column indicate that surface primary productivity, upwelling, bottom intensified flows across sills, and ventilation from shallow sills, which may contain semi-labile DOC that is estimated to largely contribute to microbial respiration in the bathypelagic layer, are the major processes that affect the DOC and POC distributions in the Sulu Sea. The variability of these processes should be taken into consideration when assessing the sustainability of internal and marginal seas as carbon sinks.

Assessment of the agro-climatic indices to improve crop yield forecasting

Weather has a major impact on agriculture. Statistical models have been used to estimate or forecast crop yield from weather information. In this paper, a general statistical framework is developed in order to rank and quantify the information content of weather information. The methodology is tested over the US, for corn yield. The weather sensitivity of different corn production areas is first analyzed. More than fifty agro-climatic indices have been compared. The study shows that variability in yield is more likely to be due to weather variability in medium and low production areas. The two best yield predictors are the temperature and then the Standardized Precipitation–Evapotranspiration Index (SPEI) in July. While corn in the north Eastern regions is not significantly affected by weather variation, on the East coast, the weather-based mixed model is able to explain about 32% (corr = 0.57) of the yield variability, but in some particularly weather-sensitive states, such as Virginia, this number can reach 64% (corr = 0.80). Two applications are tested: yield estimation at the end of the year for monitoring purpose, and seasonal prediction. It is shown that some agro-climatic indices can significantly improve crop yield modeling when compared to simpler direct weather information (average correlation increase of 0.12 at the US scale).

Female breeding dispersal in wolverines, a solitary carnivore with high territorial fidelity

Individuals’ fidelity to an area provides insight into the stability of the spatial and temporal organisation of animals. Territorial fidelity is often influenced by reproductive success, age, the dispersion and predictability of resources, and intraspecific competition. We examined between-year territorial fidelity in wolverines (Gulo gulo), using location data from 47 individuals collected during 1993–2013 in northern Sweden, to assess the stability of the spatial organisation of this solitary carnivore. For females, we also determined residency status from 1 year to the next. The study population is characterized by a stable distribution of resident individuals, with both males and females showing higher fidelity at the total territory level compared to more intensively used core areas. In 86% of the yearly residency status estimates (n = 122), the female remained stationary. In the remaining 14% of the cases, females either vacated their territory (8% of residency statuses), or expanded into a neighbouring territory (6% of residency statuses). We documented six cases of breeding dispersal, representing one of the few known cases of breeding dispersal in long-lived large mammals. We suggest that this high territorial fidelity is enabled by wolverines’ caching and scavenging behaviours, which buffer the unpredictable and large spatiotemporal variation in resource abundance in this low-productivity area. Breeding dispersal may occur due to competition for high-quality territories in this saturated population, where females are forced to abandon their territory by competitors or bequeath territories to offspring. This study further highlights the complexity of the social and spatial dynamics for solitary carnivores.

<sup>231</sup>Pa and <sup>230</sup>Th in the ocean model of the Community Earth System Model (CESM1.3)

Abstract. The sediment 231Pa ∕ 230Th activity ratio is emerging as an important proxy for deep ocean circulation in the past. In order to allow for a direct model–data comparison and to improve our understanding of the sediment 231Pa ∕ 230Th activity ratio, we implement 231Pa and 230Th in the ocean component of the Community Earth System Model (CESM). In addition to the fully coupled implementation of the scavenging behavior of 231Pa and 230Th with the active marine ecosystem module (particle-coupled: hereafter p-coupled), another form of 231Pa and 230Th have also been implemented with prescribed particle flux fields of the present climate (particle-fixed: hereafter p-fixed). The comparison of the two forms of 231Pa and 230Th helps to isolate the influence of the particle fluxes from that of ocean circulation. Under present-day climate forcing, our model is able to simulate water column 231Pa and 230Th activity and the sediment 231Pa ∕ 230Th activity ratio in good agreement with available observations. In addition, in response to freshwater forcing, the p-coupled and p-fixed sediment 231Pa ∕ 230Th activity ratios behave similarly over large areas of low productivity on long timescales, but can differ substantially in some regions of high productivity and on short timescales, indicating the importance of biological productivity in addition to ocean transport. Therefore, our model provides a potentially powerful tool to help the interpretation of sediment 231Pa ∕ 230Th reconstructions and to improve our understanding of past ocean circulation and climate changes.

Use of agricultural land by breeding waders in low‐intensity farming landscapes

AbstractAgriculture is one of the primary threats to biodiversity but agricultural land can also provide key resources for many species and, in some parts of the world, agricultural land supports important populations of species of conservation concern. In these cases, it is important to understand species’ use of agricultural land before further expansion or intensification of agricultural activities occurs. Agriculture in Iceland is still relatively low in intensity and extent, and internationally important populations of several breeding bird species are abundant in farmed regions. In these high latitude landscapes, agricultural land could provide resources that help to support these species, and the consequences of future agricultural expansion will depend on the nature of these relationships. To address these issues, we conducted surveys of bird abundance at 64 farms in areas of Iceland that vary in underlying soil productivity, and quantified (a) levels of breeding bird use of farmed land managed at three differing intensities, ranging from cultivated fields to semi‐natural land and (b) changes in patterns of use throughout the breeding season, for an assemblage of species. Breeding birds use all three land management types in large numbers but, overall, bird abundance is lower in more intensively managed farmland. However, more intensively managed agricultural land supports higher densities of birds than semi‐natural habitats in areas with lower underlying productivity. This suggests that in landscapes in which agricultural land does not yet dominate, conservation and commercial production can co‐exist, especially in areas of low productivity. Areas like Iceland, in which agricultural land still supports large populations of internationally important species, are rare and this study highlights the need to protect these systems from the agricultural development that has led to widespread biodiversity loss throughout most of the world.

The olive (Olea europaea L.) industry in China: its status, opportunities and challenges

Olive groves are among the most significant agroforestry systems for ecological, social and economic benefits not only in the Mediterranean area but also in China. Over the long course of olive cultivar introduction, the great majority of global olive development has taken place in Mediterranean regions, and later, it spread to the rest of the world, including China. A true picture of the current status of the olive industry in China is still lacking. This unique study aims to gain a better understanding of the opportunities and challenges in the Chinese olive industry. This study involved both a literature review as well as a field investigation to analyze the study questions, and it consisted of the historical perspective, current status, trends, policies, opportunities and challenges. The introduction and domestication of the olive has been performed in China since 1964. The olive is a suitable tree with a high survival rate in many regions in the southern part of the country, but the olive industry was just recently built up in Gansu, Sichuan, Yunnan after 2000 because only a few areas could produce olive fruit-bearing trees. By 2030, the total plantation areas are expected to increase from 66,400 ha (2016) to approximately 193,400 ha. In the past, approximately 165 cultivars were introduced, among which 28 cultivars that exhibited excellent performance were preliminarily selected. Among the dominant areas for these olives, Longnan has been shown to be the best representative region through the rapid development of its olive industry. Olive oil imports exceeded 90% of total consumption in China, and this import volume increased rapidly by 60 to 70%, except in the last 3 years. A lack of research advances still remains a large challenge for the scientific community. Olive is one of the most important fruit trees can grow in agroforestry systems. At present, the Chinese olive industry is at its initial stage of development, it will be a great potential in the next 20 years especially for olive agroforestry in the low olive fruit production areas. Whether developing olive monoculture or agroforestry more practical measures should be made in the future. This study analyzes the Chinese olive industry from an ultramodern global perspective, with the aim of providing effective measures through a multi-analysis of low production. This study may help to enhance the olive industry.

Business as usual for the human use of Moreton Bay following marine park zoning

The multiple-use Moreton Bay Marine Park in eastern Australia was rezoned in 2009, increasing the total no-take marine national park (MNP) from 0.5 to 16%. In the present study we measured trends in the human use of no-take areas using observed vessel position and categorisation during on-water and aerial surveys before and after rezoning. Measured changes in spatial patterns of fishing showed that the effects of rezoning on most fishing activity was minimal. After rezoning, the proportion of recreational fishing declined from 6.3 to 2.6% of the footprint in the new MNPs. The proportion of commercial fishing declined from 25 to 1%, although the amount of commercial fishing was low. There was an overall increase in fishing activity on Moreton Bay. Low recreational fisher displacement suggests that the expansion of the MNP area did not have a high social cost. However, most of the no-take zones were areas not previously subject to high recreational fishing pressure. If a significant proportion of the no-take zones were placed in areas of low ecological production, the biodiversity conservation impact achieved by the rezoning of Moreton Bay may have been less than the 16% increase in no-take areas would imply.

Interacting effects of wildlife loss and climate on ticks and tick-borne disease.

Both large-wildlife loss and climatic changes can independently influence the prevalence and distribution of zoonotic disease. Given growing evidence that wildlife loss often has stronger community-level effects in low-productivity areas, we hypothesized that these perturbations would have interactive effects on disease risk. We experimentally tested this hypothesis by measuring tick abundance and the prevalence of tick-borne pathogens (Coxiella burnetii and Rickettsia spp.) within long-term, size-selective, large-herbivore exclosures replicated across a precipitation gradient in East Africa. Total wildlife exclusion increased total tick abundance by 130% (mesic sites) to 225% (dry, low-productivity sites), demonstrating a significant interaction of defaunation and aridity on tick abundance. When differing degrees of exclusion were tested for a subset of months, total tick abundance increased from 170% (only mega-herbivores excluded) to 360% (all large wildlife excluded). Wildlife exclusion differentially affected the abundance of the three dominant tick species, and this effect varied strongly over time, likely due to differences among species in their host associations, seasonality, and other ecological characteristics. Pathogen prevalence did not differ across wildlife exclusion treatments, rainfall levels, or tick species, suggesting that exposure risk will respond to defaunation and climate change in proportion to total tick abundance. These findings demonstrate interacting effects of defaunation and aridity that increase disease risk, and they highlight the need to incorporate ecological context when predicting effects of wildlife loss on zoonotic disease dynamics.

Carbonate parameters in high and low productivity areas of the Sulu Sea, Philippines

Abstract To further understand dissolved carbon dioxide (CO 2 ) dynamics and the link between surface productivity and carbon content in the sediments of the Sulu Sea, seawater samples were obtained from high and low productivity areas during the northeast monsoon of December 2007/January 2008, which also corresponded to a period of weak La Nina. CO 2 concentrations in surface waters of the Sulu Sea are mostly governed by productivity, while sub-surface CO 2 concentrations are influenced by physical processes including vertical mixing and bottom-intensified flow southwest of Mindoro and Panay Straits (central Philippines), and upwelling off the west coast of Zamboanga in Mindanao (south Philippines). These physical processes are manifested in the downward sloping isolines of carbonate parameters near the straits and weak upwelling of waters saturated with respect to atmospheric CO 2 . Deep waters ventilated from the Sulu Sea have lower dissolved inorganic carbon (DIC) and total alkalinity (TA), and higher pH T (pH in the total scale) and carbonate ion concentrations (CO 3 2 − ) than the deep waters of the South China Sea. Nevertheless, TA in the deep waters of the Sulu Sea increases below 2000 m at almost twice the rate as DIC, suggesting possible dissolution of sedimentary CaCO 3 . A small positive “excess” alkalinity signal is observed in the South China Sea but negative values in the Sulu Sea may reflect the possible contribution of organic acids. This study suggests that the upwelling area within the Sulu Sea, albeit limited in size, could be a source of CO 2 to the atmosphere especially during the stronger northeast monsoon periods. Other processes such as dissolution of CaCO 3 in the sediments and possible organic acidity should be considered in understanding the Sulu Sea's CO 2 sink capacity for the coming years.

Return of warm conditions in the southeastern Bering Sea: Phytoplankton - Fish.

In 2014, the Bering Sea shifted back to warmer ocean temperatures (+2 oC above average), bringing concern for the potential for a new warm stanza and broad biological and ecological cascading effects. In 2015 and 2016 dedicated surveys were executed to study the progression of ocean heating and ecosystem response. We describe ecosystem response to multiple, consecutive years of ocean warming and offer perspective on the broader impacts. Ecosystem changes observed include reduced spring phytoplankton biomass over the southeast Bering Sea shelf relative to the north, lower abundances of large-bodied crustacean zooplankton taxa, and degraded feeding and body condition of age-0 walleye pollock. This suggests poor ecosystem conditions for young pollock production and the risk of significant decline in the number of pollock available to the pollock fishery in 2–3 years. However, we also noted that high quality prey, large copepods and euphausiids, and lower temperatures in the north may have provided a refuge from poor conditions over the southern shelf, potentially buffering the impact of a sequential-year warm stanza on the Bering Sea pollock population. We offer the hypothesis that juvenile (age-0, age-1) pollock may buffer deleterious warm stanza effects by either utilizing high productivity waters associated with the strong, northerly Cold Pool, as a refuge from the warm, low production areas of the southern shelf, or by exploiting alternative prey over the southern shelf. We show that in 2015, the ocean waters influenced by spring sea ice (the Cold Pool) supported robust phytoplankton biomass (spring) comprised of centric diatom chains, a crustacean copepod community comprised of large-bodied taxa (spring, summer), and a large aggregation of midwater fishes, potentially young pollock. In this manner, the Cold Pool may have acted as a trophic refuge in that year. The few age-0 pollock occurring over the southeast shelf consumed high numbers of euphausiids which may have provided a high quality alternate prey. In 2016 a retracted Cold Pool precluded significant refuging in the north, though pollock foraging on available euphausiids over the southern shelf may have mitigated the effect of warm waters and reduced large availability of large copepods. This work presents the hypothesis that, in the short term, juvenile pollock can mitigate the drastic impacts of sustained warming. This short-term buffering, combined with recent observations (2017) of renewed sea ice presence over southeast Bering Sea shelf and a potential return to average or at least cooler ecosystem conditions, suggests that recent warm year stanza (2014–2016) effects to the pollock population and fishery may be mitigated.