Spring Density Research Articles

Climate drives body mass changes in a mountain ungulate: shorter winters lead to heavier Alpine ibex

Climate affects seasonality and plant phenology, which can influence seasonal body mass dynamics of herbivores in temperate environments. We investigated long‐term trends of seasonal body mass changes in male Alpine ibex Capra ibex. We used SEM to test direct and indirect relationships between body mass, mass changes and environmental and climatic variables. Individually recognizable Alpine ibex were weighed repeatedly between 2000 and 2022 in Gran Paradiso National Park (Italy). Autumn mass increased substantially over these two decades, up to 15% in some age classes. Over the same time frame, both summer mass gain and winter mass loss decreased, suggesting that heavier autumn body mass was due to the cumulative effects of reduced mass loss over several winters. The environmental factor with the strongest effects on winter mass changes was the starting date of vegetation green‐up at low altitude, where ibex gather after winter to feed on new growth vegetation. Early springs led to lower winter mass loss, likely because ibex relied on stored fat for a shorter period and had greater access to forage. High population density also increased winter mass loss. Environmental conditions and resource availability, possibly also influenced by density in winter and early spring, seem therefore to directly affect the body mass dynamics of male Alpine ibex, while the effect of summer conditions appears less relevant. By affecting seasonal body mass dynamics, climate change may have consequences for life history and population dynamics of mountain herbivores, for example via earlier access of young males to reproduction.

Cyanobacteria in cold waters: A study of nearshore cyanobacteria assemblages in Lake Superior

Cyanobacterial blooms, often associated with warm, eutrophic lakes, are of widespread concern owing to their potential disruption of ecological and public health. Recently, cyanobacterial blooms have been observed in oligotrophic lakes, including Lake Superior, a large cold-water system. Despite recent developments, limited research has targeted phytoplankton assemblages in the northern Lake Superior nearshore, where isolated cyanobacteria blooms have emerged since 2019. In 2019, the cyanobacteria assemblage at 10 nearshore monitoring stations was examined to understand potential bloom-forming taxa and their association with water quality. We observed a diverse cyanobacteria assemblage, with highest densities in spring and biomass in fall. Pseudanabaena limnetica, Dolichospermum flos-aquae and Limnothrix sp. were the most prevalent species across sites and seasons. Variation partitioning analysis revealed that water quality conditions were more influential drivers of cyanobacteria density and biomass than meteorological factors, particularly in regions with elevated nutrient inputs and following stormy conditions. However, at present, cyanobacteria compose <15 % of the total phytoplankton biomass in the study areas. Our monitoring data and recent reports of cyanobacteria blooms on the north shore, suggests that current blooms are not widespread. Nonetheless, we found a diverse array of cyanobacteria taxa, with most capable of producing cyanotoxins. Considering the global uncertainty in the factors contributing to cyanobacteria blooms, in association with the large-scale climatic changes affecting Lake Superior, a proactive approach to assessing risks of blooms is suggested. This should include data-generating efforts (e.g., frequent phytoplankton monitoring and reported blooms investigations) to support future collaborative initiatives focused on managing cyanobacterial blooms.

Long‐term shifts in phenology, thermal niche, population size, and their interactions in marine pelagic copepods

AbstractUnder climatic warming many species shift their seasonal timing of life cycle events (phenology) and seasonal abundance distribution, but whether they maintain the same thermal niche is still poorly understood. Here, we studied multidecadal trends in abundance and phenology of seven major copepod species across three stations (Stonehaven (SH), Helgoland Roads (HR), and Plymouth L4) on the North–West European shelf, spanning ~ 6.5° of latitude. All seven species consistently occupied colder temperatures at the northern station compared to the southerly station, but they maintained the same realized thermal niche over years. Expected phenological shifts (i.e., earlier when warmer) in some stations were obscured possibly by the long‐term drop of copepod density in spring–summer, which may be due to a variation in the food/predators abundance. The ongoing spring–summer declines in abundance (~ 50%) of many North Atlantic pelagic species over the last five decades, as found in recent studies, may have also influenced the metrics of seasonal timing. To separate the seasonal timing of life events from that of seasonal abundance distribution, we used a time series of egg production rate (EPR) of Calanus helgolandicus at L4, and found that this shifted later into the summer–autumn over the last 30 yr of warming, coincident with declining spring–summer food and increasing predator abundance. Overall, direct temperature effects do appear to influence the seasonal timing of the copepods, but to explain impacts at individual stations or long‐term trends in population size or phenology, understanding the changing balance of food and predators appears to be critical.

Survey and population dynamics of land snails at Sharkia Governorate, Egypt.

Land snails are a destructive agricultural pest in economic crops, but the populations for that pest are highly influenced by temperature and humidity, therefore climatic changes affected their behavior, distribution and population dynamics, for these reasons researchers should follow up on the changes in their behavior, distribution, and population dynamics. In this study, a survey study was conducted to define land snail species existing at Sharkia Governorate, Egypt, from January 2019 to March 2022 in horticultural, vegetable, and field crops and study the population dynamics for the dominant land snail species. Results showed that there are six species of land snails, these species were, Monacha cartusiana, Succinea putris, Eobania vermiculata, Theba pisana, Helicella vestalis, and Cochlicella acuta. The population dynamics of two prevalent land snail species (M. cartusiana and S. putris), were conducted during two successive growing seasons, the Egyptian clover harbored the highest number of M. cartusiana followed by wheat, while the onion was the lowest one during the study period. In the same trends, the land snail S. putris recorded the highest numbers during the growing season of the Egyptian clover crop. Finally, it is concluded that the land snail M. cartusiana considered the first grade of infestation existed everywhere at Sharkia Governorate, and the population density of the land snail is increase gradually after winter till reach the maximum density in spring.

Distribution characteristics and assessment of wind energy resources in the coastal areas of Guangdong

In order to improve the efficiency, availability and economy during construction and operation of wind farms, characteristic analysis and evaluation of the regional wind energies are key components. In this paper, wind energy resource evaluation was conducted for coastal areas of Guangdong, including spatial and seasonal characteristics and overall evaluation. Results indicate that: ① Effective wind speed frequency is the highest in the seaward area of the study area, followed by the excessive area and the lowest in the landward area. The seaward area is relatively suitable for wind energy development. ② Total theoretical exploitable area in the study area is 5.15×105 MW, and the high production area is mainly concentrated in the outer sea areas. Developable areas are in the nearshore areas, and the potential development areas are in the sea-land interface and estuary areas. Annual effective wind energy density values along the coast of eastern Guangdong are larger than that of western Guangdong. Its development potential is larger than that of western Guangdong. ③ Wind energy variation coefficient has significant seasonal differences. Wind energy density in winter and spring is more stable than that in summer and autumn. Additionally, overall seasonal variation index is smaller, which can provide stable wind energy.

Mysterious microsporidians: springtime outbreaks of disease in Daphnia communities in shallow pond ecosystems.

Parasites can play key roles in ecosystems, especially when they infect common hosts that play important ecological roles. Daphnia are critical grazers in many lentic freshwater ecosystems and typically reach peak densities in early spring. Daphnia have also become prominent model host organisms for the field of disease ecology, although most well-studied parasites infect them in summer or fall. Here, we report field patterns of virulent microsporidian parasites that consistently infect Daphnia in springtime, in a set of seven shallow ponds in Georgia, USA, sampled every 3-4weeks for 18months. We detected two distinct parasite taxa, closely matching sequences of Pseudoberwaldia daphniae and Conglomerata obtusa, both infecting all three resident species of Daphnia: D. ambigua, D. laevis, and D. parvula. To our knowledge, neither parasite has been previously reported in any of these host species or anywhere in North America. Infection prevalence peaked consistently in February-May, but the severity of these outbreaks differed substantially among ponds. Moreover, host species differed markedly in terms of their maximum infection prevalence (5% [D. parvula] to 72% [D. laevis]), mean reduction of fecundity when infected (70.6% [D. ambigua] to 99.8% [D. laevis]), mean spore yield (62,000 [D. parvula] to 377,000 [D. laevis] per host), and likelihood of being infected by each parasite. The timing and severity of the outbreaks suggests that these parasites could be impactful members of these shallow freshwater ecosystems, and that the strength of their effects is likely to hinge on the composition of ponds' zooplankton communities.

Seasonal and daily effects of the sea on the surface urban heat island intensity: A case study of cities in the Caspian Sea Plain

This study aimed to explore the effect of the sea on the spatial and temporal changes in surface urban heat island (SUHI) intensity. Therefore, 11 cities located along the Caspian Sea Plain were selected as the case studies. Firstly, the SUHI intensity of both coastal and non-coastal cities was calculated for different seasons and times of day and night. Finally, the effect of distance from the sea on the SUHI intensity was calculated by modeling the relationship between the SUHI intensity and a set of independent parameters such as urban surface biophysical properties, population density, and distance from the coastline. The results showed that by increasing the distance of cities from the sea, the daily SUHI intensity increased, while it reversed during the night. The RMSE values between the actual and simulated SUHI intensities based on population density and surface biophysical properties in spring, summer, autumn, and winter were 0.9, 1.1, 0.5, and 0.3 °C, respectively. By factoring in the distance from the sea in the modeling, the RMSE values for different seasons were obtained at 0.7, 0.8, 0.3, and 0.2 °C, respectively. The results show that distance from the sea has a significant effect on UHI intensity.

Parasitoids and pathogens in a collapsingLymantria dispar(Lepidoptera: Erebidae) population in Lower Austria

AbstractA local population outbreak of the spongy moth,Lymantria disparL. (Lepidoptera: Erebidae), in Lower Austria, resulted in the defoliation of an oak forest in 2018 and 2019. In the study year 2020, the population density was still high but was expected to decline. In the present work, the role of parasitoids and pathogens in the collapse of the population was investigated. In total, 20 egg masses, 680 larvae and 12 pupae ofL. disparwere collected in the field from April to July 2020 and reared until the emergence of adult moths or death. Causes of mortality were determined based on emerging parasitoids and on microscope inspection of non‐parasitized cadavers. Stage‐specific mortality rates were calculated for eggs, larval stages (L1–L6) and pupae. Seven parasitoid species and three pathogens were responsible for the premature death of spongy moths. The egg parasitoidAnastatus disparis(Hymenoptera: Eupelmidae) emerged from 19% of all eggs. Larval parasitoids caused stage‐specific mortality rates from 15% to 61%. The dominant parasitoid of young and intermediate instars was the solitary waspGlyptapanteles porthetriae(Hymenoptera: Braconidae). Mature larvae were mainly parasitized by the parasitic fliesBlepharipa pratensis(Diptera: Tachinidae) andParasetigena silvestris(Diptera: Tachinidae). Pathogens caused stage‐specific mortality rates from 11% to 41%. The nuclear polyhedrosis virus (LdNPV; Lefavirales: Baculoviridae) was the dominant pathogen in all instars. The introduced fungusEntomophaga maimaiga(Entomophthorales: Entomopthoraceae)—detected for the first time in Austria in 2019—caused low mortality rates in older larvae. Starting from high egg mass densities in spring, the spongy moth population declined to negligible levels until summer.

Magnetic flux density analysis of magnetic spring in energy harvester by Hall-Effect sensors and 2D magnetostatic FE model

The paper investigates the magnetic properties and design of energy harvester system including the magnetic spring and vibration generator. The magnetic flux density measurements were conducted by means of Hall-Effect magnetic sensors mounted on the magnetic spring. The amplitude of variable component of the magnetic flux density in the magnetic spring depends on the vibrations frequency resembled by vibration generator. In the magnetic spring, two resonant frequencies at 86 Hz and 110 Hz are identified and the reached maximum amplitude value of magnetic flux density is ∼1mT. To confirm the usefulness of the manufactured magnetic spring, the calculation of the magnetic flux density in 2D axis-symmetric model of vibration generator and magnetic spring has been carried out using the Ansys Maxwell. The results of the simulation are in accordance with the measurements. Through simulation analysis and laboratory measurement tests, a better understanding of the properties of magnetic springs prototype has been achieved.

Density-dependent plasticity in territoriality revealed using social network analysis.

Territories are typically defined as spatially exclusive areas that are defended against conspecifics. Given the spatial nature of territoriality, it is inherently density dependent, but the economics of territoriality also depend on the distribution and abundance of defended resources. Our objectives were to assess the effects of changing population density and food availability on individually based territorial phenotypes. We developed a novel analytical framework that bridges spatially explicit territories with social network analysis to model density-dependent territorial phenotypes. Using the outputs from our data pipeline, we modelled plasticity in territory size and territory intrusion rates in a long-term study population of North American red squirrels Tamiasciurus hudsonicus. Red squirrels defend year-round territories around a central hoard (midden) of white spruce Picea glauca cones. Importantly, white spruce is a masting species that produces large cone crops every 4-7 years (i.e. mast years) in our study area interspersed with non-mast years when few cones are produced. In the spring following mast years, populations are approximately double in size, but are lower in the spring of non-mast years. We predicted that territory size and intrusion rates would decrease as resource abundance, and consequently population density, increased. By contrast, as resource abundance decreased via depletion, and therefore density decreased, territories should increase in size and intrusions should also increase. As we expected, individual territory size and territorial intrusions were negatively density dependent, such that increased density after mast years resulted in smaller territories and fewer intrusions. When considering between-individual variation in plasticity across a density gradient, individuals responded differently to changes in population density within their lifetime. Our results show that territory size and intrusion rates display negative density dependence. When food becomes available in the autumn of a mast year and density in spring of the following year increases, territories shrink in size to effectively a small area around the midden. While our findings for red squirrels are unique compared to other systems, they serve as a reminder that the direction and strength of fundamental ecological relationships can depend on the nature of the system.

Seasonal Characteristics of Agricultural Product Circulation Network: A Case Study in Beijing, China

Agricultural product circulation is an appropriate way to optimize the distribution of agricultural resources and maintain food safety. The seasonality of agriculture leads to seasonal variations in agricultural product circulation. Previous studies constructed origin–destination networks based on annual statistics to investigate the static structure of agricultural product circulation networks from a single view, failing to capture the seasonal and multi-dimensional characteristics in agricultural product circulation. This study presents a multi-view analytical framework used to investigate the seasonal characteristics of an agricultural product circulation network. First, agricultural product circulation networks in different seasons were constructed with mass freight trajectory data through trajectory mining technology. Then, the seasonal characteristics of agricultural product circulation were, respectively, analyzed from a macro-view (networks), meso-view (edges) and micro-view (nodes). A case study was conducted in Beijing, China. It is argued that: (1) The presented method for extracting agricultural trip chains based on massive freight trajectories is feasible for the construction of agricultural product circulation networks. (2) The agricultural product circulation networks in four seasons exhibit an obvious hierarchical and radial structure. South China has a higher network density in winter and spring, whereas northeast and northwest China are the opposite. (3) A total of 80% of the linkage strength is concentrated, on average, in 35.3% of city-pairs in four seasons, where the agglomeration effect and hub status of the linking cities is more prominent in summer and autumn. (4) A total of 316 cities form Beijing agricultural product circulation networks, 48.1% of which are mainly served by Beijing agricultural product circulation in winter and spring, which is 2.7 times more than cities served in summer and autumn. These findings extend the scientific understanding of the agricultural product supply chain from a dynamic and multi-dimensional view, which provides essential information for optimizing sustainable agri-food systems and ensuring food security.

한국 서해안 곰소만에서 곰소옆새우 Sinocorophium homoceratum (Yu, 1938)의 계절별 현존량 변동 및 염분 내성

The physiochemical factors and seasonal variation in abundance of Sinocorophium homoceratum were examined at the intertidal flat in Gomso Bay, west coast of Korea, for one year. The salt tolerance of S. homoceratum was also investigated in the laboratory. S. homoceratum showed relatively high density in spring and summer, which were relatively high temperature (12 - 28°C) and low salinity (20.0 - 22.0 psu), and the lowest density in winter, which was low temperature (5°C or less) and high salinity (30-32 psu). Although immature individuals appeared throughout the year and juveniles did in all seasons except winter, ovigerous females were only collected from April to June. Relative growth of the head length and head width against the body length was best described by the primary regression equation. In experiments on salt tolerance in S. homoceratum, all individuals died after 24 hours at 0 psu. Six days after the start of the experiment, its survival rates (20.0 - 22.2%) at 28 - 35 psu were significantly lower than those (80.0 -82.3%) at 7 - 21 psu. The results of this study suggest that S. homoceratum is a species well adapted to estuarine mudflat by digging burrows in a silt mudflat and maintaining a relatively high density in all seasons except winter.

Annual and Semiannual Variation in the Ionospheric F2-Layer Electron Density over the Indian Zone and Effect of Solar Activity on It

In situ measurement carried out by the Retarding potential Analyzer (RPA) on board SROSS C2 and ROCSAT during 1995 to 2003 covering ascending and descending periods of solar cycle 23 over Indian equatorial and low latitude were used to study the annual and semiannual variation of electron density at the topside F region. The ‘Semiannual anomaly’ which represent the electron density in equinox (March, April, September and October) is greater than that at solstice (May, June, July, August, November, December, January and February). The ‘annual anomaly’ which represents the electron density in winter (November, December, January, February) is higher than that in summer (May, June, July, August). The analysis has been carried out for the geomagnetic equator and ±10o magnetic latitudes. Observations reveal the existence of an equatorial asymmetry during daytime (10:00 – 14:00 hrs.) with higher electron density in spring (March, April) than in autumn (September, October) for both ascending and descending leg of the solar cycle. At the peak of the solar cycle, the density becomes equal for both equinoxes. Nighttime (22:00 – 00:00 hrs.) density in autumn is higher than that in spring for the ascending half of the solar cycle, becomes equal for both the equinoxes around the peak of the solar cycle. In the descending half the vernal density becomes higher than the autumnal density. The periodograms obtained from a Fourier analysis of the daytime average density shows that the annual variation is dominant over the semiannual variations for low to moderate solar activity whereas the semiannual peak becomes dominant over annual peak for high solar activity irrespective of the latitudes. At night, however, latitudinal differences have been observed. The annual variation is stronger than the semiannual variation at 10o N for low to moderate solar activity while for high solar activity the situation reverses. At 10o S and the magnetic equator, the annual variation is dominant for all levels of solar activity. Amplitude of the annual variation is higher in winter compared to that in summer. The physical and dynamical processes responsible for the observed annual and semi-annual trends in topside density will be identified and discussed.

Irrigation and Nitrogen Application Promote Population Density through Altered Bud Bank Size and Components in Leymus chinensis

The bud bank of perennial grasses is a controlling factor in population dynamics and is estrongly affected by soil water and nitrogen status. To explore how the bud bank size and its components affect shoot population density under different soil moisture and nitrogen contents in spring and autumn. A three-full-factorial field experiment with factors of treatment timing (spring and autumn), nitrogen rate (control and 10 g N m−2 yr−1) and irrigation rate (control and +40 mm rainfall) was conducted in Leymus chinensis (a C3 plant) in the northeast of China. The number of two types of buds (axillary shoot bud and rhizome bud), shoot population density, soil properties and rhizome traits (rhizome length and rhizome number) were determined to explore what and how changes in bud bank composition influences shoot population density in spring and autumn. The results showed that: (1) Regardless of the irrigation and nitrogen application timing, the simultaneous irrigation and nitrogen application significantly increased the number of two types of buds and promoted the shoot population density in spring and autumn by 56.75% and 47.74%, respectively. (2) The bud bank was dominated by rhizome buds in spring under control and dominated by axillary shoot buds under the combined irrigation and nitrogen treatment in autumn. Axillary shoot bud was the determining component in the population density increases in both spring and autumn, which were significantly associated with soil available phosphorus, available nitrogen and rhizome length and number. In summary, the number of different buds was strongly impacted by irrigation and nitrogen application at the crucial bud-bank formation stage. Agronomically, the forage yield could be largely increased through the increase in the axillary shoot bud density by using irrigation and nitrogen application in L. chinensis and other rhizomatous perennial grasses.

Why Did Brown Hare Lepus europaeus Disappear from Some Areas in Central Poland?

Brown hares originated in the open steppe grasslands of Eurasia and have adapted very successfully to a mixed, arable agriculture environment. In the last decades of the 20th century, a decline in brown hare populations has been observed in many European countries. In this study, we documented a long-term (1965–2018) decline in the hare population in a field and forest mosaic in central Poland (from over 30 ind./100 ha in the mid-1960s to 1–2 ind./100 ha in the past decade). We showed that the recent autumn densities were the same as compared to the preceding spring densities (suggesting a low recruitment rate) and that the recent densities recorded in the fields were no longer higher than in the forests (probably due to a decrease in the habitat quality of arable lands). We also showed that the share of hares in a red fox diet was now very low (0.1% vs. 13% in the past). We compared the recent (2004–2018) population estimates to another area that was located 70 km east (with a similar habitat structure, a community of predators and climate conditions, but with less intense agriculture), where the hare population was increasing. We suggested that the farming practices were the most important factor for the hare population decrease in our study area.

Climate change impact on the population dynamics of exotic pathogens: The case of the worldwide pathogen Phytophthora cinnamomi

Worldwide, Mediterranean-climate type forests are seriously threatened by climate change and Phytophthora cinnamomi, an extremely aggressive soilborne pathogen listed among the 100 worst invasive alien species. This study examines for first time the effects of annual and seasonal changes in temperature and rainfall under different climatic scenarios on P. cinnamomi dynamics in a Mediterranean forest naturally infested. We followed seasonally and during four years (2016–2020) P. cinnamomi abundance in the soil taking advantage of a climate change infrastructure that simulates a 30% rainfall reduction using rainout shelters and an increase in soil temperature using open top chambers. Seasonal abundance of P. cinnamomi was strongly linked to spring precipitation: the large inoculum density during this season suffered a strong decrease during the dry summer that was maintained until the next spring, despite of fall rains. Thus, inoculum density in spring may be considered the best indicator of the potential of P. cinnamomi infection in natural ecosystems. The two climatic treatments had significant effects on P. cinnamomi abundance, but only in some combinations of seasons and years. Rainfall exclusion had a negative effect on the spring abundance of P. cinnamomi mostly in wet years, causing a reduction as large as 30% in comparison with the control treatment. Meanwhile, warming effect varied from slightly negative in winter to positive in spring and early summer, causing increases as large as 31% in comparison with the control treatment. Overall, we provide novel experimental evidence suggesting that a drier climate might limit the abundance and activity of P. cinnamomi in water-limited forests, but that this negative effect might be at least partly counteracted by the positive effects of warming. These results also imply that P. cinnamomi represents an increasing threat under climate change for the conservation of forest ecosystems where water is not a limiting factor.

Relationship of isotopic variations with spring density in the structurally controlled springs and related geosystem services in Alaknanda Valley, Garhwal Himalaya, India

As a traditional water source, springs are vital for Himalayan communities and it is essential to consciously focus on springs conservation. We report oxygen isotopes (δ18O) of spring water before, within, and after the tectonically active zones of the Alaknanda Valley, Uttarakhand. Higher variation of δ18O in the spring waters is found in highly tectonically disturbed zone i.e., Zone-2 with δ18O range − 4.9‰ to − 9.0‰ compared to tectonically less disturbed zones: Zone-1 and Zone-3 with δ18O value range − 7.9‰ to − 9.9‰ and − 7.4 to − 10.2‰ respectively. We hypothesize that the highly active thrust zones (Zone-2) with increased permeability compared to other Zones, manifested as greater spring density, results in higher water recharge in Zone-2. Very high to high spring density stretches are dominant in Zone-2 compared to Zone-1 and Zone-3. Stretches in Zone-2 with high spring density formed due to its highly tectonically active nature leads to the higher isotopic variation in Zone-2. The study also identifies the geosystem services provided by thrust zones as water resources to the local people and need of conservation modalities to manage the spring water resources in the thrust zones.

Assessment of groundwater potential using multi-criteria decision analysis and geoelectrical surveying

ABSTRACT A precise map of the dispersion of the groundwater potential across each watershed can help decision-makers to exert optimal water management in each region. In this research, the potential of groundwater resources in both the Zanjanrood Catchment and the Tarom Region, located in the northwest of Iran, has been studied. Seven effective criteria including slope, land-use, drainage density, spring density, lithology, lineament density, and rainfall are considered. Criteria were first weighted using the Analytical Hierarchical Process (AHP) method and then overlaid by the Technique for Order Preferences by Similarity to Ideal (TOPSIS) model. Finally, the spatial zoning map of groundwater potential was obtained in four categories. A sensitivity analysis was performed to determine the influence of each criterion on the obtained map. The model was verified using both the spatial distribution of the high-discharged production wells and the geophysical-based geoelectric field surveys. The results indicate that the high-discharged wells (>40 l/s) in both regions are dispersed predominantly in the very good zone and, in several cases, in the good zone. Besides, the results from the two-dimensional models of resistivity and induced polarization of geoelectrical field survey are inappropriate agreement with those from the TOPSIS method. Notably, there is no suitable potential zone of groundwater in the surrounding highlands to be used in the future for drinking purposes since the highlands water supply is a strategic supply for drinking. The strategies employed in this study, the results of GIS modeling, and the geoelectrical analysis can be considered for sustainable development of similar arid and semi-arid areas since groundwater is considered as the main supplier of water in such regions.

Identification and Mapping of Groundwater Dependent Ecosystems in the AZORES Volcanic Archipelago (Portugal)

Groundwater contributes to the maintenance of the functioning of ecosystems, through aspects related to hydrodynamics and chemical composition. Groundwater-dependent ecosystems (GDE) also offer a wide spectrum of ecosystem services to populations; therefore, their identification and mapping, which is the focus of the present paper, is of high value to environmental policies; for example, WFD envisages protecting both water bodies and GDE. An ecosystem dependence index was applied to proceed with this task in the Azores archipelago, being estimated by adding the values of three partial variables (spring density; wetlands/lakes; river baseflow) over a 10 by 10 m2 grid; with this methodology avoiding pitfalls due to lack of data. The results enabled the identification and mapping of five GDE, in Flores and São Miguel islands, supported by only three of the 28 groundwater bodies delimited in the Azores RBD. Those groundwater bodies are considered to have a good status according to the WFD requirements; thus, GDE, regardless of their typology, are not at risk of deterioration as a result of the interaction with groundwater. Nevertheless, other studies have shown that some GDE are in conflicting ecological areas and require specific management and protection measures, coupling land use and water resource planning.

Effects of Slip-Spring Parameters and Rouse Bead Density on Polymer Dynamics in Multichain Slip-Spring Simulations.

The multichain slip-spring (MCSS) model is one of the coarse-grained models of polymers developed in the niche between bead-spring models and tube type descriptions. In this model, polymers are represented by Rouse chains connected by virtual springs that temporally connect the chains, hop along the chain, and are constructed and annihilated at the chain ends. Earlier studies have shown that MCSS simulations can nicely reproduce entangled and unentangled polymer dynamics. However, the model parameters have been chosen arbitrarily, and their effects have not been reported. In this study, for the first time, we systematically investigated the effects of model parameters: fugacity of virtual springs, its intensity, and the Rouse bead density. We validated the employed simulation code by confirming that the statistics of the system follow the theoretical setup. Namely, the virtual spring density is correctly controlled, and polymer chains exhibit ideal chain statistics irrespective of the chosen parameter values. For diffusion and linear viscoelasticity, simulation results obtained for different parameters can be superposed with each other by conversion factors for the bead number per chain and units of length, time, and modulus. These conversion factors follow scaling laws concerning the number of Rouse segments between two consecutive anchoring points of virtual springs along the polymer chain. Besides, diffusion and viscoelasticity excellently agree with literature data for the standard bead-spring simulation. These results imply that the coarse-graining level for the MCSS model can be arbitrarily chosen and controlled by model parameters.