Seasonal Behavior Research Articles

Seasonal Dynamics of Flux Footprint for a Measuring Tower in Southern Taiga via Modeling and Experimental Data Analysis

This paper reports on the location of sources contributing to a point flux measurement in the southern taiga, Russia. The measurement tower is surrounded by a coniferous forest with a mean aerodynamically active height of 27 m (h). Aerodynamical parameters of the forest, such as displacement height d and aerodynamic roughness z0, derived from wind speed profile measurements for 2017–2019, were used to estimate the seasonal and daily behavior of the flux footprint. Two analytical footprint models by Schuepp et al. and by Kormann and Meixner driven by d and z0 were used to estimate the footprint for canopy sources. The Lagrangian simulation (LS) approach driven by flow statistics from measurements and modeling was used to estimate the footprint for ground-located sources. The Flux Footprint Prediction (FFP) tool for assessing canopy flux footprint (Kljun et al.) applied as the option in the EddyPro v.7 software was inspected against analytical and LS methods. For model comparisons, two parameters from estimated footprint functions were used: the upwind distance (fetch) of the peak contribution in the measured flux (Xmax) and the fetch that contributed to 80% of the total flux (CF80). The study shows that Xmax varies slightly with season but relies on wind direction and time of day. All methods yield different Xmax values but fall in the same range (60–130 m, around 2–5 h); thus, they can estimate the maximum influence distance with similar confidence. The CF80 values provided by the FFP tool are significantly lower than the CF80 values from other methods. For instance, the FFP tool estimates a CF80 of about 200 m (7 h), whereas other methods estimate a range of 600–1100 m (25–40 h). The study emphasizes that estimating the ground source footprint requires either the LS method or more complex approaches based on Computational Fluid Dynamics (CFD) techniques. These findings have essential implications in interpreting eddy-flux measurements over the quasi-homogeneous forest.

A comparison of CO2 seasonal activity in Mars' northern and southern hemispheres

Carbon dioxide is Mars' most active volatile. The seasonal and diurnal processes of when and where it condenses and sublimates are determined by energy balance between the atmosphere and surface ice in Mars' vapor pressure equilibrium climate. Mars' current obliquity ensures that the polar caps are stable locations for seasonal condensation. The eccentricity of Mars' orbit is the major driver of differences in seasonal behavior of CO2 between the northern vs southern hemisphere. In particular, the current positions of perihelion and aphelion, in addition to the large elevation difference between the poles, dominate the ways seasonal processes transpire in the two hemispheres. We summarize and discuss the unprecedented observations of these processes that have been collected by the Mars Reconnaissance Orbiter over the last 8.5 Mars Years. The longer southern fall and winter allows more time for CO2 ice to accumulate and densify in the southern hemisphere. Northern winter coincides with the perihelion dust storm season, thus the north polar seasonal ice deposits are expected to contain a greater concentration of dust in relation to CO2 and H2O ices. With less time for densification and more contaminants the northern seasonal layer of CO2 ice is likely weaker than the southern layer.

Do both anticipated relief and anticipated regret predict decisions about influenza vaccination?

Anticipated regret has been found to predict vaccination intentions and behaviours. We examined whether anticipated relief also predicts seasonal influenza vaccination intentions and behaviour. Given claims about differences in their antecedents and function, we distinguished between counterfactual relief (relief that a worse outcome did not obtain) and temporal relief (relief that an unpleasant experience is over). Cross-sectional. Unvaccinated participants (N = 295) were recruited online in November 2020. Participants completed measures of anticipated regret, anticipated counterfactual relief, and anticipated temporal relief and measures of theory of planned behaviour constructs (attitudes, norms, perceived control, and intentions). One month later, the same participants were re-surveyed and asked to report their vaccination status. Although all anticipated emotion measures were associated with intentions and behaviour, only anticipated counterfactual relief and regret independently predicted vaccination intentions in regression analyses. Mediation analysis showed both anticipated counterfactual relief and regret were indirectly, via intentions, associated with behaviour. Results suggest that, regardless of valence, counterfactual emotions predict vaccination intention and, indirectly, behaviour. Furthermore, participants may differ in their sensitivity to the anticipation of positive versus negative counterfactual emotions. These findings may permit more precise targeting of interventions to increase vaccine uptake.

Seasonal effects of granivory on broadcast seeding restoration in a degraded semiarid grassland

Granivores, such as rodents and harvester ants, are common in dryland ecosystems. In intact dryland ecosystems, the effects of such granivores on soil seed banks, plant community structure, and ecosystem functioning are well established. However, the effects of granivores on dryland restoration have received much less attention. In this study, we evaluated the seasonality of seed removal by harvester ants, seed preference of harvester ants, and effects of granivore exclosure on the soil seed bank at four sites in southeastern Utah. We studied two species of harvester ants, Pogonomyrmex rugosus and P. occidentalis. The foraging behavior of Pogonomyrmex spp. was temperature‐dependent; they removed no seeds during winter months, and up to 80% of seeds during high activity in the summer. Despite seasonal differences in seed removal, Pogonomyrmex spp. did not show significant preferences for seed species. However, their seasonal foraging behavior translated into measurable differences in an experimental soil seed bank. Over the summer months, ants reduced the number of seeds in the seed bank by approximately 20%, but when ants were excluded during the winter, the number of seeds in the seed bank remained the same. This finding supports the timing of business‐as‐usual seeding practices of applying seeds in late fall. If seeds germinate in the first season after application, ant granivory is unlikely to pose a large barrier to establishment. However, if seeds remain dormant during the first year, as is common in many dryland species, seeds are vulnerable to ant granivory.

Seasonal behavior of pharmaceuticals and personal care products within Chilean rural WWTPs under COVID-19 pandemic conditions

During the COVID-19 pandemic, the consumption of pharmaceuticals and personal care products (PPCPs) increased exponentially. There is an associated risk concerning the presence of PPCPs from wastewater, mainly in rural zones of emerging countries, where sanitation tends to be poor or inefficient. Therefore, this study aimed to evaluate the seasonal behavior of PPCPs within Chilean rural wastewater treatment plants (WWTPs) under COVID-19 pandemic conditions. Ten Chilean rural WWTPs were monitored during 2021, both in the cold (May–September) and warm (November – December) months, being collected semi-composite samples (influent/effluent). WWTPs were based on activated sludge, aerobic lagoons, rotatory discs, activated sludge + bio discs, constructed wetlands, and vermifilter. Physicochemical parameters and PPCPs (azithromycin, ciprofloxacin, caffeine, ibuprofen, losartan, and triclosan) compounds were monitored. Results showed that PPCPs, such as antibiotics (azithromycin, ciprofloxacin: 14.7 – 100%), stimulants (caffeine: 41.5 – 100%), NSAIDs (ibuprofen: 32.9–100%), β-blockers (losartan: 43.5–100%), and disinfectants (triclosan: 45.9–100%) were variably removed. Non-significant differences (p > 0.05) of the PPPCs (effluent concentrations/efficiencies) were reported regarding seasonality and treatment typologies. Moreover, azithromycin, ciprofloxacin and triclosan reported positive correlations (Ɵ ≈ 0 °) with solids. Finally, this study evidenced that COVID-19 pandemic conditioned seasonally variability of PPCPs from wastewater.

Seasonal Effects of the Tibetan Plateau on Cyclonic Transient Eddies: A System-Centered View

Abstract Using an objective feature-tracking algorithm and the fifth major global reanalysis produced by ECMWF data (ERA5), the seasonal behaviors of cyclonic transient eddies (cyclones) at different levels around the Tibetan Plateau (TP) were examined to understand the effects of the TP on cyclones. Results show that the TP tends to change the moving directions of the remote cyclones when they are close to the TP, with only 2% of the 250-hPa eastward-moving cyclones directly passing over the TP. The sudden reductions of their moving speeds and relative vorticity intensities around the TP suggest a suppression effect of the plateau. Over 70% of these cyclones perish over the TP regardless of the altitude. This percentage decreases to around 65% during summertime, exhibiting a weaker summer suppression effect. On the other hand, the TP has a stimulation effect on local cyclones through its dynamic forcing in winter, thermodynamic forcing in summer, and both forcings in the transitional seasons. The numbers of locally generated cyclones, especially at 500 hPa, just above the TP, are significantly larger than those of the remote cyclones during all seasons. Although about one-half of the local cyclones dissipate over the TP, the cyclones moving off the plateau significantly outnumber the moving-in cyclones, with the differences ranging from 0 to 6 cyclones per month. Only the 250-hPa wintertime moving-off cyclones are fewer than the cyclones entering the TP, which may be caused by the weaker stimulation effect and stronger suppression effect of the TP on the wintertime upper-level cyclones. Significance Statement Cyclonic transient eddies (cyclones), steered by westerly jet streams, can influence climate and induce extreme weather processes under certain conditions. The Tibetan Plateau (TP), the highest and largest obstacle embedded in the westerly jet streams, suppresses remote cyclones entering the TP region, destroying over 70% of these cyclones. However, because of the excitation effect of the TP on local cyclones, the numbers of cyclones moving off the TP are still larger than or equal to those of the moving-in cyclones, except at the upper levels in winter. This feature suggests that the TP cannot significantly decrease the total cyclone numbers in most cases, but it indeed weakens the mean intensity and moving speed of the cyclones.

Predictive Modeling of Ungulate-Vehicle Collision in the Republic of Korea.

Animal-vehicle collisions (AVC) threaten animals as well as human life and property. AVC with ungulates, called ungulate-vehicle collision (UVC), often seriously endangers human safety because of the considerable body size of ungulates. In the Republic of Korea, three ungulate species, Capreolus pygargus, Hydropotes inermis, and Sus scrofa, account for a large proportion of AVC. This study aimed to understand the characteristics of UVC by examining various parameters related to habitat, traffic, and seasonality using MaxEnt. The results showed that the peak UVC seasons coincided with the most active seasonal behaviors of the studied ungulates. For the modeling results, in C. pygargus, habitat variables are most important for models across seasons, and UVC events are most likely to occur in high mountain chains. In H. inermis, habitat and traffic variables are most important for models across seasons. Although the important habitat for the models were different across seasons for S. scrofa, the maximum speed was consistently critical for models across all seasons. Factors critical to UVC in the Republic of Korea were different for the three ungulate species and across seasons, indicating that seasonal behavior should be considered along with landscape and traffic characteristics to mitigate UVC.

Impacts of recent development processes on the temporal and spatial sea-level variations along the Suez Canal

This work investigates the impacts of the recent development processes on the temporal and spatial sea-level variations along the Suez Canal. Hourly sea-level data were collected at three locations representing the northern (PF), central (I) and southern (PT) regions of the Canal. The data extended from June 2010 to July 2015. The T_Tide package was used to obtain information on tides and residuals. Results revealed that PF and I exhibited almost the same pattern of monthly variations, with March being the month of the lowest mean sea level (MSL) and August the month of the highest one. PT had its own seasonal behaviour, with the lowest MSL in September and the highest in February. These seasonal variations are attributed to the atmospheric pressure scheme affecting the three regions. Moreover, from June to October, the MSL in the Canal’s northern tip was higher than its southern tip, while the reverse was true during the remaining seven months of the year. Along the Canal, the tidal cycle ratios were less than 0.25 reflecting its semidiurnal tidal cycle. The ratios of spring to neap tide ranges were 4.1, 1.5 and 1.7 at PF, I and PT, respectively. The majority of the significant tidal constituents were in the diurnal and semidiurnal bands. Most importantly, results showed that the development processes along the Canal have impacted its highest tidal ranges, which increased by about 29.5% and 37.5% at PF and PT, respectively, compared to the period 1980–1986. This was more obvious at Ismailia, where the range increased by about 176.5% compared to the period 1983–1985. Furthermore, PT experienced the highest percentage of storm surge among the three locations. This research strongly recommends further investigation on the relationship between the sea-level variations along the Suez Canal and the dominant atmospheric conditions.

Dynamics of a reaction-advection-diffusion model for cholera transmission with human behavior change

Cholera is a virulent intestinal infection caused by Vibrio cholerae strains. To explore multiple effects of spatial structure, seasonality and human behavior change on cholera transmission, we establish a reaction-advection-diffusion model with a general boundary condition at the downstream end of the river. We derive the basic reproduction number R0 and discuss its asymptotic behaviors. We further show that R0 is a strictly decreasing function of the bacterial loss c, which reveals that the bacterial loss at the downstream end of the river due to water flux reduces the risk of cholera transmission. Then we derive a threshold-type result in terms of R0. More precisely, (i) if R0<1, the disease-free periodic solution is globally attractive; (ii) if R0>1, the disease is uniformly persistent; (iii) if R0=1, the disease-free steady state is globally asymptotically stable in the absence of the advection term, in which the proof is quite challenging due to the introduction of human behavior change, involving some subtle inequalities and estimates. Numerically, an application is demonstrated by investigating the cholera outbreak in Somalia from 1995 to 2016.

Characterization of seasonal behaviors of naturally occurring radioactive materials in a groundwater borehole using an in situ monitoring system

Understanding the temporal behaviors of naturally occurring radioactive materials is important for safeguarding groundwater as a secure water resource for drinking, agriculture, and industry usage. This study reports the vertical profiles of 238U concentration and 222Rn activity and the management of in situ monitoring systems during intensive field sampling of a national groundwater-monitoring borehole for seven years (2015–2021). The aim was to capture the seasonal characteristics of the 238U concentrations and 222Rn activity. Both factors were low in the rainy season and high in the winter season, reflecting the dilution effect of rainfall recharge. The 238U and 222Rn behaviors were associated with water–rock interactions of calcite dissolution in fracture zones filled with carbonate minerals. Furthermore, multilayer perceptron models estimated the 238U concentration and 222Rn activity with reasonable regression and classification accuracy. Hydrometeorological indicators (temperature and groundwater-level fluctuations) were more important estimators of 238U concentration and 222Rn activity than geochemical process indicators. The regression accuracy performance was higher at deeper sampling depths, where seasonality in the 238U and 222Rn behaviors dominated. From the predicted distributions of 238U concentrations and 222Rn activities, we could estimate the ranges of 238U concentrations and 222Rn activities emerging from groundwater boreholes. High exposure threats from 238U and 222Rn during groundwater usage were found in the winter season. When the multilayer perceptron models use the entire in situ monitoring data at refined temporal resolution, we can quickly determine the naturally occurring radioactive materials and further develop the national groundwater-monitoring borehole equipped with the in-situ monitoring system, supplementing the occasionally obtained field-measurement data.

Arctic observations of hydroperoxymethyl thioformate (HPMTF) – seasonal behavior and relationship to other oxidation products of dimethyl sulfide at the Zeppelin Observatory, Svalbard

Abstract. Dimethyl sulfide (DMS), a gas produced by phytoplankton, is the largest source of atmospheric sulfur over marine areas. DMS undergoes oxidation in the atmosphere to form a range of oxidation products, out of which sulfuric acid (SA) is well known for participating in the formation and growth of atmospheric aerosol particles, and the same is also presumed for methanesulfonic acid (MSA). Recently, a new oxidation product of DMS, hydroperoxymethyl thioformate (HPMTF), was discovered and later also measured in the atmosphere. Little is still known about the fate of this compound and its potential to partition into the particle phase. In this study, we present a full year (2020) of concurrent gas- and particle-phase observations of HPMTF, MSA, SA and other DMS oxidation products at the Zeppelin Observatory (Ny-Ålesund, Svalbard) located in the Arctic. This is the first time HPMTF has been measured in Svalbard and attempted to be observed in atmospheric particles. The results show that gas-phase HPMTF concentrations largely follow the same pattern as MSA during the sunlit months (April–September), indicating production of HPMTF around Svalbard. However, HPMTF was not observed in significant amounts in the particle phase, despite high gas-phase levels. Particulate MSA and SA were observed during the sunlit months, although the highest median levels of particulate SA were measured in February, coinciding with the highest gaseous SA levels with assumed anthropogenic origin. We further show that gas- and particle-phase MSA and SA are coupled in May–July, whereas HPMTF lies outside of this correlation due to the low particulate concentrations. These results provide more information about the relationship between HPMTF and other DMS oxidation products, in a part of the world where these have not been explored yet, and about HPMTF's ability to contribute to particle growth and cloud formation.

Contribution of Reverse Dune Migration to Stabilization of a Transgressive Coastal Dune Field at Lagoa do Peixe National Park Dune Field (South of Brazil)

Coastal dunes that transgress typically move landward, while their reverse movement is not well understood. The article discusses the study of barchan and barchanoid dunes in the Lagoa do Peixe National Park in the coastal plain of Rio Grande do Sul, Brazil. The aim of the study is to analyze seasonal patterns and long-term trends in the direction and migration rates of these dunes, which can pose a threat to the lagoon if they invade its space. The crest migration of 12 dunes was monitored by satellite images between July 2003 and December 2018, and DGPS topographic surveys were performed on five dunes between 2010 and 2018. The migration rates obtained were combined with an analysis of the meteorological data and calculations of the drift potential for eolian sediment transport. The wind regime in the study area shows a multidirectional pattern, with the predominant wind direction being from the NE, followed by the ENE direction. The wind direction also exhibits a seasonal behavior, with the winds from the first quadrant being dominant during spring and summer months and a gradual increase in winds from the second and third quadrants from the end of summer to winter. The dune crest migration rates in the Lagoa do Peixe National Park show an average of 16.55 m·yr−1 towards WSW–W, mainly controlled by the direction of the effective winds. However, intense SSW–WSW winds caused by cold fronts in the past generate the reverse migration of dunes towards ENE–E. The reverse migration of dunes explains the steadiness of the dune fields at CPRGS and is a factor controlling dune stabilization and the geomorphological evolution of transgressive coastal dune fields. The article highlights the importance of monitoring dune movement to understand their responses to natural and anthropogenic stressors and to protect sensitive ecosystems.

Climatology and interannual variability of the migrating quarterdiurnal tide (QW4) seen in the SABER/TIMED temperatures (2002–2022)

This paper presents a climatological global view on the spatial structure and interannual variability of the high-frequency migrating quarterdiurnal tide (QW4) built on a large statistics of the 21 years (2002–2022) SABER/TIMED temperature measurements. The obtained consistent picture for the vertical structure and phase coherence provide strong support that the observed oscillation is a tide which is a permanent feature of middle atmospheric dynamics while the repeating seasonal variability during all 21 years reaffirms the validity and effectiveness of the satellite data analysis method previously proposed by the same authors and used for analyzing the satellite data. The climatological tidal amplitudes rapidly growth with the height, as the 21-yearly mean amplitude changes from ∼1.6 K at 84 km to ∼7.9 K at 110 km; the latter is the largest climatologically mean tidal amplitude observed at latitude of 20°S. The tide is stronger in the SH than that in the NH particularly in the lower thermosphere and it is stronger at low latitudes than that at middle latitudes at all considered heights in the ±50° latitude range. The latitude tidal structure changes quite rapidly with height. While it is definitely asymmetric about the equator in the lower thermosphere with main enhancements at 110 km height situated around the equator, at ∼20°S and around ±(40–50°), the tidal structures at lower height levels become more symmetric as that at 84 km height with enhancements at the equator, ±35° and around ±50°. The seasonal variability based on the latitude and altitude climatological tidal structures indicated that at least four seasonal components have to be included in correctly describing the tidal seasonal behavior. The 21-year QW4 climatology reports for the first time the presence of the vertically upward propagating QW4 tide around the latitudes of ∼(0°–20°N) with a wavelength of ∼30 km, hence for correct description of the QW4 tide it is necessary besides the trapped and propagating Hough modes with very large wavelengths some propagating modes with shorter wavelengths to be included as well. This study also presents the QW4 responses to the 11-year solar cycle and the quasi-biennial oscillation at 30 hPa which define the tidal interannual variability.

Seasonal Variation in Gut Microbiota of the Wild Daurian Ground Squirrel (Spermophilus dauricus): Metagenomic Insights into Seasonal Breeding.

The Spermophilus dauricus, the wild Daurian ground squirrel, is known to exhibit seasonal breeding behavior. Although the importance of gut microbiota in animal digestion, metabolism, and immunity is well-established, the correlation between gut microbiota and seasonal breeding in this species remains inadequately explored. In the present study, using metagenomic sequencing technology, the compositions and functions of the gut microbiota of wild Daurian ground squirrels in different breeding seasons were explored. The dominant gut microbial phyla were Firmicutes and Bacteroidetes. The Firmicutes were predominant in the breeding season, whereas Bacteroidetes were predominant in the non-breeding season. At the genus level, Lactobacillus accumulated during the breeding season, whereas Odoribacter and Alistipes increased during the non-breeding season. GO (Gene Ontology) and KEGG (Kyoto Encyclopedia of Genes and Genome) annotations indicated that genes in gut samples were highly associated with metabolic functions. The differential expression gene analysis showed that genes related to the phosphotransferase system, cysteine, and methionine metabolism were highly expressed during the breeding season, whereas the non-breeding season upregulated genes were enriched in starch and sucrose metabolism and bacterial chemotaxis pathways. In conclusion, this study could provide a reference for investigating gut microbiota in seasonal breeding animals and offer new insight into gut microbial function.

Monitoring Energy Balance, Turbulent Flux Partitioning, Evapotranspiration and Biophysical Parameters of Nopalea cochenillifera (Cactaceae) in the Brazilian Semi-Arid Environment.

The in-situ quantification of turbulent flux and evapotranspiration (ET) is necessary to monitor crop performance in stressful environments. Although cacti can withstand stressful conditions, plant responses and plant-environment interactions remain unclear. Hence, the objective of our study was to investigate the interannual and seasonal behaviour of components of the surface energy balance, environmental conditions, morphophysiological parameters, biomass yield and water relations in a crop of Nopalea cochenillifera in the semi-arid region of Brazil. The data were collected from a micrometeorological tower between 2015 and 2017. The results demonstrate that net radiation was significantly higher during the wet season. Latent heat flux was not significant between the wet season and dry season. During the dry-wet transition season in particular, sensible heat flux was higher than during the other seasons. We observed a large decline in soil heat flux during the wet season. There was no difference in ET during the wet or dry seasons; however, there was a 40% reduction during the dry-wet transition. The wet seasons and wet-dry transition showed the lowest Evaporative Stress Index. The plants showed high cladode water content and biomass during the evaluation period. In conclusion, these findings indicate high rates of growth, high biomass and a high cladode water content and explain the response of the cactus regarding energy partitioning and ET.

Deep-Water Dynamics along the 2012–2020 Observations on the Continental Margin of the Southern Adriatic Sea (Mediterranean Sea)

This work presents the results of long-term deep-water observations carried out in the southwestern Adriatic margin. Hydrodynamics and thermohaline measurements were carried out in the last 100 m of the water column using two long-term moorings placed at two different locations along the western sector of the Adriatic continental margin (open slope vs. submarine canyon). The observations, carried out over a period of almost 10 years, made it possible to define the intra- and interannual deep-water dynamics, which are mainly influenced by the passage of cold, dense water. The hydrodynamic field is influenced by seasonal behavior and varies from year to year, with no clear temporal trend or periodicity. Thermohaline properties follow hydrodynamics but also show a climatological trend toward higher temperatures and salinity. The combination and variability of preconditioning factors explains the interannual variability in dense water passage at the mooring sites triggering the formation of dense water in the northern Adriatic. The impulsive nature of the dense water flow, which is difficult to capture with sporadic oceanographic surveys, and its linkage with the large-scale atmospheric circulation make continuous monitoring essential to answer open questions about cascading processes and deep-water dynamics under a global change scenario.

Monitoring seasonal deformation behavior of an immersed tunnel with distributed optical fiber sensors

Seasonal joint deformations within an immersed tunnel are important indicators to assess structural behavior and therefore should be monitored in detail. In this study, distributed optical fiber sensors (DOFS) are applied to precisely measure the seasonal joint deformations in an immersed tunnel for the first time. Measurements over a one-year period specifically reveal the impact of seasonal temperature variations on the joint opening and uneven settlement deformation. Field monitoring shows that the variation in joint opening exhibits a cyclic behavior and is strongly correlated with temperature change. The immersion joints generally show a larger range of seasonal opening (with a maximum of about 6 mm) than dilation joints, but at several dilation joints significant opening also occurs. The uneven or differential settlement at most joints stays below 1 mm, except at a few joints where the range is above 1 mm, which are indications of underlying structural defects in the tunnel. The observed joint uneven settlement also shows a seasonal variation, but the correlation with temperature is weak. The impacts of seasonal deformation on the structural integrity and watertightness of the tunnel are assessed, and further suggestions on tunnel maintenance and inspection are made.

Vomeronasal Receptors Associated with Circulating Estrogen Processing Chemosensory Cues in Semi-Aquatic Mammals.

In numerous animals, one essential chemosensory organ that detects chemical signals is the vomeronasal organ (VNO), which is involved in species-specific behaviors, including social and sexual behaviors. The purpose of this study is to investigate the mechanism underlying the processing of chemosensory cues in semi-aquatic mammals using muskrats as the animal model. Muskrat (Ondatra zibethicus) has a sensitive VNO system that activates seasonal breeding behaviors through receiving specific substances, including pheromones and hormones. Vomeronasal organ receptor type 1 (V1R) and type 2 (V2R) and estrogen receptor α and β (ERα and ERβ) were found in sensory epithelial cells, non-sensory epithelial cells and lamina propria cells of the female muskrats' VNO. V2R and ERα mRNA levels in the VNO during the breeding period declined sharply, in comparison to those during the non-breeding period, while V1R and ERβ mRNA levels were detected reversely. Additionally, transcriptomic study in the VNO identified that differently expressed genes might be related to estrogen signal and metabolic pathways. These findings suggested that the seasonal structural and functional changes in the VNO of female muskrats with different reproductive status and estrogen was regulated through binding to ERα and ERβ in the female muskrats' VNO.

Midstory removal of encroaching species has minimal impacts on fuels and fire behavior regardless of burn season in a degraded pine-oak mixture

Anthropogenic fire exclusion has contributed to forest structural and compositional shifts, resulting in the encroachment of shade-tolerant, often fire-sensitive and/or opportunistic species throughout forest ecosystems. In the central and eastern U.S., encroaching species often exhibit fire-suppressing leaf litter and crown traits, reducing prescribed fire efficacy to restore and maintain fire-dependent mixed pine (Pinus spp.) and oak (Quercus spp.) forests. Despite fire’s natural role in these forests, management using prescribed fire alone is unlikely to reverse encroachment impacts due to the degree of forest change since fire exclusion. Consequently, additional management techniques (e.g., chemical, mechanical) are often combined with fire to ensure persistence of pine-oak mixtures and their associated ecosystem services. In current-day degraded pine-oak mixtures in the southeastern U.S., where no one species represents > 75% dominance by stand basal area, encroaching species (e.g., Liquidambar styraciflua, Quercus nigra) commonly form a dense midstory and occupy overstory positions. To quantify how encroaching species in degraded mixed pine-oak forests impact fuels, canopy cover, and seasonal fire behavior, we thinned the midstory (<20 cm DBH) of all non-pyrophytic species in 12 0.10-ha blocks within a mixed pine-oak stand at the Mary Olive Thomas Demonstration Forest (Auburn, Alabama, USA) in July 2021. Midstory thinning reduced basal area by 6.7 m2 ha−1 and canopy cover by 9.1%. In general, midstory thinning reduced shrub and fine woody debris fuel loads while having no impact on herbaceous, leaf litter, and duff fuel loads. When compared to pre-treatment levels, midstory thinning increased the relative proportion of pine leaf litter contribution to the fuelbed by 10.9% while reducing that of encroaching species by 11.4%. Despite changes to residual basal area, canopy cover, and leaf litter contribution, midstory thinning had no statistical impact on fire behavior, regardless of burn season. Early (January) and late dormant season (April) experimental fires had higher fireline intensities, consumed more surface fuels, had faster rates of spread, and higher average maximum temperatures compared to growing season (September) fires. We also noted an increase in these fire parameters with increased pine litter contribution to the fuelbed. In degraded pine-oak mixtures where encroaching species now occupy overstory canopy positions, we recommend investigating the efficacy of more intense thinning treatments that remove overstory individuals with known fire-suppressing traits to have a larger impact on canopy openness, fuels, and fire behavior.

Seasonal Abundance and Feeding Behaviour of &lt;i&gt;Oxyopes birmanicus&lt;/i&gt; Thorell on Tea Mosquito Bug &lt;i&gt;Helopeltis theivora&lt;/i&gt; Water House

The Burmese lynx spider, Oxyopes birmanicus Thorell (Araneae: Oxyopidae) is one of the endemic and entomophagous predatory arthropod species in India. This present study describes the seasonal abundance, vertical distribution, and feeding behaviour of O.birmanicus on nymph (4 th /5 th instar) and the adults of the tea mosquito bug, Helopeltis theivora Waterhouse (Hemiptera: Miridae) under laboratory conditions. The seasonal abundance of the O. birmanicus spider was considerably high from June to November and low from January to April. The abundance of O. birmanicus significantly correlated with the TMB infestation percentage. In a vertical distribution study, the O. birmanicus spider largely preferred the top level of the tea bush, the observed population was shared by the top and middle levels with 76% and 24% respectively. The feeding potential of the female O. birmanicus spider was significantly higher than the male and egg-guarding female. Both, male and egg-guarding female O. birmanicus showed on-par feeding efficacy. The study found that O. birmanicus was an efficient predator against TMB and the results may be useful in developing an integrated pest management strategy for TMB.