Southwestern Site Research Articles

Latitudinal and elevational variation in the reproductive biology of house wrens, Troglodytes aedon.

While cross-species comparisons of birds suggest that as latitude decreases or elevation increases, clutch size decreases and the duration of developmental stages and parental attentiveness increases, studies comparing populations of the same species are rare. We studied populations of house wrens, Troglodytes aedon, at high and low elevations in California and Costa Rica, collecting data on clutch size, the duration of incubation and nestling periods, parental attentiveness, nestling growth rate, and nesting success. Our data support results from cross-species comparisons, but also revealed unanticipated results from low elevation temperate zone house wrens in the southwest. This population had prolonged incubation and nestling periods similar to those found in the tropics. We also found that temperate zone females, especially those at our higher elevation site, spent more of their day incubating than did tropical females. Nest temperature at our high elevation temperate zone site was higher than that at all other tropical sites. Age at fledging did not differ between sites. Total feeding rates per chick and male feedings per chick did not vary between sites. Nest success rates showed the predicted effect of latitude, but not the predicted effects of elevation. Our results extend low elevation house wren research into the southwestern US and contribute the first intraspecific elevational comparison in the Neotropics. Data from our low elevation southwestern site present a unique suite of life history traits that align more with tropical house wrens, although with a larger clutch size, and point to food limitation and/or high predation pressure as being possible drivers of some of these differences. These results highlight the need for additional studies of house wrens and other broadly distributed species at a more diverse array of sites to better understand which forces drive the evolution of different life history strategies across major biogeographical gradients.

Trajectories of adolescent psychopathology among youth who were maltreated and placed in out-of-home care

BackgroundAlthough researchers have found an increased risk for psychopathology among maltreated adolescents placed in out-of-home care, different trajectories of psychopathology by out-of-home placements have not been previously studied. ObjectiveThe current study is built on previous investigation of youth in different long-term out-of-home placements and examined the trajectories of adolescent psychopathology by out-of-home placement classes. Participants and settingWe leveraged data from the Southwestern site of the Longitudinal Studies of Child Abuse and Neglect. Participants included caregiver-youth dyads (N = 273), who had substantiated reports of child maltreatment (CM) prior to children's age four and were placed in out-of-home care. MethodsFive out-of-home placement classes from ages 4 to 12 (i.e., stable adopted, stable reunified, stable kinship care, stable non-kin foster care, and unstable placement) were identified from previous study and participants were interviewed at youth ages 12, 14, and 16 to assess adolescent psychopathology. Latent Growth Curve Analysis was used to examine trajectories of psychopathology by placement classes. ResultsAdolescents in unstable placement and stable adopted classes had higher intercepts and more positive or less negative slopes for psychopathology compared to those in stable kinship care and stable reunified classes. ConclusionsAdolescents in unstable placement and stable adopted classes were at similarly elevated risk for psychopathology, whereas adolescents in stable kinship care and stable reunified classes were at lower risk for psychopathology. We discuss the clinical implication to preventing and intervening risks for psychopathology among maltreated youth in unstable and adopted placements.

An Overview of Low‐Level Jet Winds and Corresponding Mixed Layer Depths During PECAN

AbstractThirty southerly low‐level jet (LLJ) events were observed during the Plains Elevated Convection at Night (PECAN) field campaign in the Great Plains region of the United States during summer 2015. Here we present Doppler lidar wind data from three PECAN instrumentation sites to explore characteristics of LLJs and the boundary layer as well as some of the heterogeneities possible within the wind field of a LLJ. Southerly LLJs were observed on 66% of nights at the southwestern site (Greensburg, KS) but only 56% and 53% of nights at the eastern and northern sites, respectively (Hesston and Ellis, KS). The northernmost site had a relative abundance of weaker jets or nonjet conditions due to fronts or convective systems that only affected part of the observation domain. Plotting mean wind fields of each LLJ type reveals that the strongest LLJs tend to develop under very similar conditions but begin to show variability in wind profile evolution after several hours. A robust mixed layer height retrieval algorithm is used to investigate the interplay between the jets and the turbulent convective boundary layer, showing that stronger LLJs are preceded by deeper afternoon mixed layers and often have a later decoupling of mixing between the upper convective mixed layer and the near‐surface layer. Only the strongest LLJs generated a shallow mixing layer overnight. Comparing jet strength and direction to pristine nocturnal convection initiation shows that the strongest southerly LLJs yielded the most pristine nocturnal convection initiation events per night, and the pristine nocturnal convection initiation occurred farther north.

Peer Influence on Ethnic-Racial Identity Development: A Multi-Site Investigation.

The peer context features prominently in theory, and increasingly in empirical research, about ethnic-racial identity (ERI) development, but no studies have assessed peer influence on ERI using methods designed to properly assess peer influence. We examined peer influence on ERI centrality, private, and public regard using longitudinal social network analysis. Data were drawn from two sites: a predominantly Latina/o Southwestern (SW) school (N=1034; Mage=12.10) and a diverse Midwestern (MW) school (N=513; Mage=11.99). Findings showed that peers influenced each other's public regard over time at both sites. However, peer influence on centrality was evident in the SW site, whereas peer influence on private regard was evident in the MW site. Importantly, peer influence was evident after controlling for selection effects. Our integration of developmental, contextual, and social network perspectives offers a fruitful approach to explicate how ERI content may shift in early adolescence as a function of peer influence.

X-Ray Fluorescence Analysis of Fine Atmospheric Aerosols from a Site in Mexico City

A study was performed in the Winter of the year 2015 in a Southwestern site in the MAMC (Ciudad Universitaria), collecting PM2.5 samples with a Mini Vol. As a part of wider study focused to fully characterize aerosols at this site, an X-ray Fluorescence (XRF) spectrometer (based on an Rh X-ray tube) built to analyze environmental samples, was used to characterize the sample set. A total of 16 elements (Al, Si, P, S, Cl, K, Ca, Ti, V, Cr, Mn, Fe, Ni, Cu, Zn, and Pb) were detected in most samples and mean concentrations were calculated. Cluster analysis was also applied to the elemental concentrations to find possible correlations among the elements.

A Generic Algorithm to Estimate LAI, FAPAR and FCOVER Variables from SPOT4_HRVIR and Landsat Sensors: Evaluation of the Consistency and Comparison with Ground Measurements

The leaf area index (LAI) and the fraction of photosynthetically active radiation absorbed by green vegetation (FAPAR) are essential climatic variables in surface process models. FCOVER is also important to separate vegetation and soil for energy balance processes. Currently, several LAI, FAPAR and FCOVER satellite products are derived moderate to coarse spatial resolution. The launch of Sentinel-2 in 2015 will provide data at decametric resolution with a high revisit frequency to allow quantifying the canopy functioning at the local to regional scales. The aim of this study is thus to evaluate the performances of a neural network based algorithm to derive LAI, FAPAR and FCOVER products at decametric spatial resolution and high temporal sampling. The algorithm is generic, i.e., it is applied without any knowledge of the landcover. A time series of high spatial resolution SPOT4_HRVIR (16 scenes) and Landsat 8 (18 scenes) images acquired in 2013 over the France southwestern site were used to generate the LAI, FAPAR and FCOVER products. For each sensor and each biophysical variable, a neural network was first trained over PROSPECT+SAIL radiative transfer model simulations of top of canopy reflectance data for green, red, near-infra red and short wave infra-red bands. Our results show a good spatial and temporal consistency between the variables derived from both sensors: almost half the pixels show an absolute difference between SPOT and LANDSAT estimates of lower that 0.5 unit for LAI, and 0.05 unit for FAPAR and FCOVER. Finally, downward-looking digital hemispherical cameras were completed over the main land cover types to validate the accuracy of the products. Results show that the derived products are strongly correlated with the field measurements (R2 > 0.79), corresponding to a RMSE = 0.49 for LAI, RMSE = 0.10 (RMSE = 0.12) for black-sky (white sky) FAPAR and RMSE = 0.15 for FCOVER. It is concluded that the proposed generic algorithm provides a good basis to monitor the seasonal variation of the vegetation biophysical variables for important crops at decametric resolution.

Denitrification at two nitrogen-polluted, ombrotrophic Sphagnum bogs in Central Europe: Insights from porewater N2O-isotope profiles

Measurements of nitrogen isotope ratios (δ15N) along vertical porewater profiles are instrumental in localizing sources and sinks of nitrous oxide (N2O) in wetland ecosystems. We present the first N2O concentration and isotope data for porewaters of ombrotrophic, mountain-top bogs. Our two study sites, situated in the Czech Republic at elevations higher than 1000 m, have been affected by atmospheric N pollution for more than 100 years. In recent decades, the northeastern site KB received over 30 kg Nha−1yr−1via atmospheric deposition, the southwestern site BS was 3 times less polluted. Both peat bogs were surrounded by defoliated, dead spruce stands. We hypothesized that elevated nitrate (NO3−) inputs in rain-fed bogs may cause sizeable N2O emissions. Porewater N2O concentrations in the studied ombrotrophic bogs were 400–800 times higher, compared to fens in nearby Bavaria (Germany). The highest N2O concentrations and the lowest δ15N–N2O values were found at the bottom of the sampled porewater profiles, 40–60 cm below surface. Low δ15N–N2O values resulted from a N isotope fractionation associated with denitrification. The site with the lower historical N pollution, BS, exhibited up to 7 times higher porewater N2O concentrations than KB, possibly due to a higher denitrification potential determined as abundance of nirK and nirS genes. Upcore, N2O abundance decreased and δ15N–N2O increased, indicating N2O reduction. Processes of N2O formation and consumption at different depths were integrated by measuring N2O fluxes across the peat – atmosphere interface. These fluxes were minute (<0.02 μmol N2O m−2h−1). We even observed scavenging of air-borne N2O by the bog substrate. Nitrogen pollution of ombrotrophic bogs led to vigorous N cycling, manifested by extremely high peat porewater N2O concentrations. However, effective in-situ consumption of the produced N2O greatly reduced its warming potential.

Factors associated with caregiver stability in permanent placements: A classification tree approach

Objective Identify individual and environmental variables associated with caregiver stability and instability for children in diverse permanent placement types (i.e., reunification, adoption, and long-term foster care/guardianship with relatives or non-relatives), following 5 or more months in out-of-home care prior to age 4 due to substantiated maltreatment. Methods Participants were 285 children from the Southwestern site of Longitudinal Studies of Child Abuse and Neglect (LONGSCAN). Caregiver instability was defined as a change in primary caregiver between ages 6 and 8 years. Classification and regression tree (CART) analysis was used to identify the strongest predictors of instability from multiple variables assessed at age 6 with caregiver and child reports within the domains of neighborhood/community characteristics, caregiving environment, caregiver characteristics, and child characteristics. Results One out of 7, or 14% of the 285 children experienced caregiver instability in their permanent placement between ages 6 and 8. The strongest predictor of stability was whether the child had been placed in adoptive care. However, for children who were not adopted, a number of contextual factors (e.g., father involvement, expressiveness within the family) and child characteristics (e.g., intellectual functioning, externalizing problem behaviors) predicted stability and instability of permanent placements. Conclusions Current findings suggest that a number of factors should be considered, in addition to placement type, if we are to understand what predicts caregiver stability and find stable permanent placements for children who have entered foster care. These factors include involvement of a father figure, family functioning, and child functioning. Practice implications Adoption was supported as a desired permanent placement in terms of stability, but results suggest that other placement types can also lead to stability. In fact, with attention to providing biological parents, relative, and non-relative caregivers with support and resources (e.g., emotional, financial, and optimizing father involvement or providing a stable adult figure) the likelihood that a child will have a stable caregiver may be increased.

수질관리를 위한 시화호의 환경용량 산정

본 연구는 생태계 모델을 이용하여 수질오염이 심각한 시화호의 수질을 재현하고, 시화호 내로 유입하는 육상기원 오염부하량의 변동에 따른 시화호의 수질변화를 살펴보았다. 모델에 의해 계산된 화학적 산소요구량 결과는 관측치와의 상관성이 양호하였으며, 하천이 밀집한 호의 내측 수역에서 <TEX>$8{\sim}9mg/L$</TEX>의 높은 농도분포를 나타내었고, 방조제 수문이 위치한 남서쪽 수역에서 5 mg/L 내외의 가장 낮은 농도분포 특성을 보였다. 시화호로 유입하는 육상오염부하가 시화호의 수질에 미치는 영향을 살펴보았는데, 육상오염부하량을 95% 삭감시켜도 시화호의 화학적산소요구량 농도는 3 mg/L 내외로 계산되었으며, 이것은 해역생활환경 II등급 기준인 2mg/L를 초과하는 것으로써 육상으로부터 유입되는 오염부하의 삭감만으로는 수질개선에 한계가 있는 것으로 예측되었다. 한편, 퇴적물을 인위적으로 개선하여 퇴적물로부터 인과 질소의 용출량과 저층 산소소비율을 삭감시켰을 경우에 시화호 수질의 개선효과가 나타났다. 특히, 육상으로부터 유입하는 유기물 및 영양염류 부하와 퇴적물에 의한 영양염류 용출부하 및 산소소비율을 동시에 삭감하였을 경우에 시화호 내 대부분의 수역에서 <TEX>$1.5{\sim}2.0mg/L$</TEX> 이내로 수질이 크게 개선되는 것으로 나타났다. 따라서, 시화호는 육상기원 오염부하량을 상당량 삭감하여도 목표수질 기준을 만족하기가 상당히 어려울 것으로 예측되었고, 퇴적물을 인위적으로 개선시키면 보다 뚜렷한 수질 개선의 효과를 얻을 수 있는 것으로 나타났다. 시화호 내측과 외측수역과의 해수 교환량이 적고 퇴적물의 오염이 심한 현 상태의 환경조건에서 해역생활환경 III등급 기준인 4 mg/L 이하를 달성하기 위한 시화호의 환경용량은 화학적산소요구량 기준으로 5 톤/일로 산정되었다. 향후 시화호의 수질관리를 위해서는 시화호를 포함한 유역별로 뚜렷한 개선목표를 설정하고 배출원별 할당부하량을 산정하여 오염물질 총량관리를 통해 시화호 주변 유역의 점원, 비점원 및 시화호 내퇴적물 등을 종합적으로 고려하여 관리해 나가야 할 것으로 판단된다. The mechanism of water pollution in Lake Shihwa, one of highly eutrophicated artificial lakes in Korea, has been studied using a numerical 3D physical-biochemical coupled model. In this study, the model was applied to estimate the contribution of land-based pollutant load to water quality of heavily polluted Lake Shihwa. The chemical oxygen demand(COD) was adopted as an index of the lake water quality, and the spatial distribution of an average COD concentration during the summer from 1999 to 2000 was simulated by the model. The simulated COD showed a good agreement with the observed data. According to reproducibility of COD, the high-est levels between 8 and 9 mg/L were shown at the inner site of the lake with inflow of many rivers and ditches, while the lowest was found to be about 5 mg/L at the southwestern site near to dike gate. In the pre-diction of water quality of Lake Shihwa, COD showed still higher levels than 3 mg/L in case of reduction of 95% for land-based pollutant load. This suggests that the curtailment of land-based pollutant load is not only sufficient but the improvement of sediment quality or the increase of seawater exchange should be considered together to improve a water quality in Lake Shihwa.

Biplot Analysis of Test Sites and Trait Relations of Soybean in Ontario

Superior crop cultivars must be identified through multi-environment trials (MET) and on the basis of multiple traits. The objectives of this paper were to describe two types of biplots, the GGE biplot and the GT biplot, which graphically display genotype by environment data and genotype by trait data, respectively, and hence facilitate cultivar evaluation on the basis of MET data and multiple traits. Genotype main effect plus genotype by environment interaction effect (GGE) biplot analysis of the soybean [Glycine max (L.) Merr.] yield data for the 2800 crop heat unit area of Ontario for MET in the period 1994-1999 revealed yearly crossover genotype by site interactions. The eastern Ontario site Winchester showed a different genotype response pattern from the three southwestern Ontario sites in four of the six years. The interactions were not large enough to divide the area into different mega-environments as when analyzed over years, a single cultivar yielded the best in all four sites. The southwestern site, St. Pauls, was found to always group together with at least one of the other three sites; it did not provide unique information on genotype performance. Therefore, in future cultivar evaluations, Winchester should always be used but St. Pauls can be dismissed. Applying GT biplot to the 1994-1999 multiple trait data illustrated that GT biplots graphically displayed the interrelationships among seed yield, oil content, protein content, plant height, and days to maturity, among other traits, and facilitated visual cultivar comparisons and selection. It was found that selection for seed yield alone was not only the simplest, but also the most effective strategy in the early stages of soybean breeding.

Biplot Analysis of Test Sites and Trait Relations of Soybean in Ontario

Superior crop cultivars must be identified through multi-environment trials (MET) and on the basis of multiple traits. The objectives of this paper were to describe two types of biplots, the GGE biplot and the GT biplot, which graphically display genotype by environment data and genotype by trait data, respectively, and hence facilitate cultivar evaluation on the basis of MET data and multiple traits. Genotype main effect plus genotype by environment interaction effect (GGE) biplot analysis of the soybean [Glycine max (L.) Merr.] yield data for the 2800 crop heat unit area of Ontario for MET in the period 1994–1999 revealed yearly crossover genotype by site interactions. The eastern Ontario site Winchester showed a different genotype response pattern from the three southwestern Ontario sites in four of the six years. The interactions were not large enough to divide the area into different mega-environments as when analyzed over years, a single cultivar yielded the best in all four sites. The southwestern site, St. Pauls, was found to always group together with at least one of the other three sites; it did not provide unique information on genotype performance. Therefore, in future cultivar evaluations, Winchester should always be used but St. Pauls can be dismissed. Applying GT biplot to the 1994–1999 multiple trait data illustrated that GT biplots graphically displayed the interrelationships among seed yield, oil content, protein content, plant height, and days to maturity, among other traits, and facilitated visual cultivar comparisons and selection. It was found that selection for seed yield alone was not only the simplest, but also the most effective strategy in the early stages of soybean breeding.

A receptor model for atmospheric aerosols from a southwestern site in Mexico City

Samples of atmospheric aerosols were taken in a southwestern site in Mexico City, during the Fall of 1993, using a Stacked Filter Unit (SFU). This allowed separation of particles with sizes between 2.5 and 15 μm (coarse, deposited on Nuclepore filters), and smaller than 2.5 μm (fine, deposited on Teflon filters). The samples were analyzed using Proton Induced X-ray Emission (PIXE) for elements with atomic numbers between 13 and 26 (Al to Fe), Proton Elastic Scattering (PESA) for hydrogen in the fine fraction, and X-ray Fluorescence (XRF) for elements heavier than Fe. A receptor model is presented using Principal Components Analysis (PCA) in order to find possible sources of the pollutants. Cluster Analysis for each of the fractions was also performed, to assist PCA in the source identification. The multivariate analyses permitted to identify four major sources in each fraction, with soil as the major contributor in both cases.

Lateral transport of settling particles in the Ross Sea and implications for the fate of biogenic material

The Ross Sea, Antarctica, with its high rates of primary productivity and biogenic accumulation, provides an important location to test the validity of a one‐dimensional particle‐settling model. As part of an interdisciplinary field project performed from 1990 to 1992 to examine cycling and accumulation of biogenic matter in the Ross Sea, water‐column particulate and current data were collected at three sites. At each of the sites, a current meter and sediment trap were placed 240 m below the water surface, and a similar set of instruments was located 40 m above the seabed. The moorings were deployed for 1‐ to 2‐years duration. The current‐meter records showed that the speed of flow in the southwestern Ross Sea is relatively slow (&lt; 20 cm s−1) and current direction is highly variable. Currents in the south‐central Ross Sea have moderate speeds (&lt;40 cm s−1) and less directional variability. The northwestern Ross Sea has the strongest flows (&gt;50 cm s−1) and least variability in direction. To examine the validity of a one‐dimensional approximation for fluxes of biogenic material, two models were developed to determine the net displacement of particles settling through the water column. Current‐meter data and particle‐settling characteristics were incorporated in both models. One model produced a time‐varying, linearly interpolated current field between the moorings in which particle advection was evaluated. The second model used time‐averaged progressive‐vector plots to estimate lateral particle advection. Results show that particles are displaced the least at the southwestern site (&lt;20 km), moderate distances at the south‐central site (&lt;50 km), and the greatest at the northwestern site (&gt;50 km). The pattern in displacement trends correlates well with observed sediment types and accumulation rates at each site. A one‐dimensional model for the settling of biogenic material is most applicable at the southwestern site and least applicable at the northwestern site.

Fossil Leaves and Fruits as Indicators of Paleotransport in a Miocene Lake from Northern Idaho

ABSTRACT Fossil leaves in clayey lake sediments of the Miocene Oviatt Creek Flora, Idaho, were mapped in order to determine their usefulness for indicating paleocurrent flow. Leaves from the Oviatt Creek florule P-42 were measured with respect to their size, orientation, and position within a 0.5-m-thick section over an area of about 20 m2 to determine patterns in leaf sorting, orientation, and species distribution. Leaf taphonomy indicates that the P-42 lake deposits represent infilling from a southwestern site by a slow-moving source. Preliminary geological mapping in the area supports this interpretation. None of these leaf parameters could be used alone to make this interpretation. Leaf orientation appears to be reliable only for determining flow lineation. This is because leaf etioles may point either up or down flow. Leaves with heavy petioles (i.e., Platanus) were aligned almost exclusively parallel to flow. Fruits of Acer longer than 4 cm were consistently orientated in the same direction. Both types of plant parts provide useful data to assist in the determination of paleocurrents in fine-grained sediments where primary sedimentary structures are lacking. Also, leaf orientation perpendicular to flow appears to be a possibility in weak currents.

Calculating Southwestern Ponderosa Pine Site Index with an HP-41 Calculator

Calculating Southwestern Ponderosa Pine Site Index with an HP-41 Calculator

Neural-tube defects in a prehistoric south-western Indian population.

Concern with the frequency and patterning of the occurrence of midline neural-tube defects among contemporary human populations is widespread. These defects are, however, quite old and occur in unusually high numbers of prehistoric skeletons. A common explanation offered for such high incidence has been inbreeding among small, reproductively isolated populations. In a sample of 54 skeletons from the prehistoric south-western Indian site of Tijeras Pueblo in New Mexico, failure of neural-tube closure occurs in 10% of sacra recovered. While a more homogeneous genetic background and inbreeding may account for a portion of this elevated prevalence, the cause appears to lie with cultural-environmental factors. It is suggested that the aetiology of these conditions has become more complex in recent human history.