Comparison of water-use characteristics of landscape tree (<Emphasis Type="Italic">Tabebuia argentea</Emphasis>) and palm (<Emphasis Type="Italic">Ptychosperma macarthurii</Emphasis>) species in a tropical roof garden with implications for urban water management

In cities, landscape palms and trees are planted for scenic views and normally maintained with frequent irrigation. With similar water input, their morphological difference may lead to different water-use that varies seasonally. Thus, evaluating their water-use patterns is necessary to achieve proper urban water management. Here, we examined water-use characteristics of Tabebuia argentea and Ptychosperma macarthurii, a tree and a palm species, in a roof garden in Bangkok, Thailand. Self-constructed Granier’s probes were used for sap flux measurement and monitored for five months in 2016. Results showed that palm transpired 3–4 times higher water than tree daily. With frequent watering, tree was more sensitive to increasing vapor pressure deficit (D) than palm on rain-free days. When rainfall occurred, however, both species became less sensitive to D and continued consuming more water at high D. Extending the analysis to include a hypothetical warming climate with +4.8 °C temperature, we found that tree saved more water than palm on rain-free days. However, daily transpiration of both species increased similarly by 14–18% on rainy days. These results imply that Tabebuia argentea may provide ecosystem benefits by conservatively using water under drought and decelerating runoff from the garden when storms come. In contrast, Ptychosperma macarthurii may provide ecosystem disservice with high water-use in dry season but may slow down runoff in wet season and therefore benefiting downstream ecosystems. These findings are useful for selective planting associated with future changes in precipitation patterns, leading to sustainable urban water management.     

Determining species specific nightly bat activity in sites with varying urban intensity

Time of peak bat activity during the night differs among bat species due to temperature, prey availability, habitat availability, and/or interactions between species. Habitat availability is altered in urban areas, which may affect insect prey availability and interspecies interactions. Our objectives were to use mobile acoustic monitoring to determine when bat species were active in a single night in urban and nonurban sites and if nightly bat activity patterns differed in urban versus nonurban sites. Bat echolocation call sequences were recorded using Anabat acoustic detectors while driving transects through the night at five sites (three “urban” and two “nonurban”) located in the Piedmont region of north-central North Carolina from May through August 2016. Transects were driven three times per night starting 45 min, 180 min, and 300 min after sunset. Recorded echolocation call sequences were analyzed manually using AnalookW and automatically using Bat Call Identification and Echoclass software. Total bat activity was not different between urban and nonurban sites. However, total bat activity was lower later in the night in urban sites, but stayed the same in nonurban sites. Species specifically, there were more Eptesicus fuscus, Lasionycteris noctivagans, and Tadarida brasiliensis call sequences and fewer Lasiurus borealis, Nycticeius humeralis, and Perimyotis subflavus call sequences in urban sites than nonurban sites. There were also fewer E. fuscus, L. noctivagans, and N. humeralis call sequences later in the night in both urban and nonurban sites. Only Lasiurus borealis activity in urban sites later in the night reduced and L. borealis activity in nonurban sites remained at the same. These results suggest that bats in urban areas partition time differently, which is important to consider for urban conservation efforts and planning.     

Ecohydrological model for the quantification of ecosystem services provided by urban street trees

Urban green spaces have been recognized as an important source of ecosystem services, whose quantification requires the determination of quantities related to energy, water, carbon and soil nutrient content. In this paper we propose a stochastic ecohydrological model that couples two existing models for water and nutrients in urban soil at the single street-tree scale. The model input are rainfall and irrigation, for water, and deposition and fertilization, for nitrogen, while the output are evapotranspiration, runoff and deep percolation, for water, and plant uptake and leaching, for nitrogen. The various terms are related to the amount of paved and impervious surfaces that surround the tree trunk and regulate the water and nutrient fluxes in and out the soil. Particular attention is paid to the effects of seasonal variations on plant water and nutrients through a temporal variation of the hydrologic variables (i.e., temperature and rainfall intensity and frequencies). The average model outputs are preliminarily compared with the scant existing literature data, supporting the model application to cities with different climatic conditions. The model results are used to estimate the potential for ecosystem services like tree cooling effects, soil carbon sequestration or storm-water management. Because of the minimal structure of the proposed model, it requires a very low amount of data, while accounting for the stochastic input of rainfall. In the context of climate change and increasing urbanization, the model may offer useful indications to urban planners to enhance ecosystem services while minimizing irrigation, fertilization and their related costs.     

Urbanization-related distribution patterns and habitat-use by the marine mesopredator,giant Pacific octopus (<Emphasis Type="Italic">Enteroctopus dofleini</Emphasis>)

Urbanization is a process that heavily alters marine and terrestrial environments, though terrestrial urban ecosystems have been studied far more intensively. Terrestrial studies suggest that urbanization can facilitate mesopredators by enhancing food and shelter resources and reducing predation pressure from apex consumers. This in turn has considerable consequences for ecological communities. We evaluated spatial distribution patterns and habitat-use of the marine mesopredator, giant Pacific octopus (Enteroctopus dofleini), relative to terrestrial urbanization intensity in Puget Sound, Washington, USA. Using field surveys and citizen-contributed data for E. dofleini, we examined whether: (1) Distribution was related to urbanization, (2) Abundance was related to the extent of benthic anthropogenic debris, and (3) Diet differed as a function of urbanization and den cover. Our results suggest that urbanization impacts may differ with depth. Mixed-effects logistic regression model estimates for the probability of occurrence increased with urbanization in deep-water (> 24 m), and decreased with urbanization in shallow water (< 18 m). Accompanying field surveys indicated that E. dofleini abundance was correlated with the number of benthic anthropogenic debris items, and that E. dofleini diets were not affected by urbanization intensity or den cover. Though E. dofleini may be synanthropic within certain urban environments, the mechanisms driving this pattern likely differ from those affecting common urban mesopredators on land, with den provisioning from man-made structures being more important than altered food resources.     

Landscape urbanization threatens plant phylogenetic diversity in the Brazilian Atlantic Forest

Urbanization causes species loss around the world, but its effects on phylogenetic diversity are poorly known in tropical forests. Using a patch-landscape approach in an urbanizing region of the Brazilian Atlantic Forest, we tested whether the increase in landscape urbanization reduces plant species density, phylogenetic richness and divergence, and increases the relatedness among co-occurring individuals and species. We assessed plant responses to urbanization in adult (diameter at breast height?>?10 cm) and sapling communities (2.5–10 cm diameter) separately, as saplings are proxies of the future flora. We sampled 2860 woody plants belonging to 155 species in nine circular landscapes with urbanization level varying from 0% to 45%, and estimated the relatedness among the species that have increased and decreased in relative abundance in more urbanized landscapes (winner and losers, respectively). As expected, species density and phylogenetic richness decreased with the increase in urbanization. These responses were consistent for adult and sapling communities, suggesting a persistent loss of species and lineages in more urbanized landscapes. Contrary to our expectations, phylogenetic divergence and structure did not respond to urbanization, indicating that the more urbanized landscapes still retain much evolutionary history. However, because the relatedness among winners was greater than among losers, it is likely that the phylogenetic divergence gradually reduces and the relatedness increases, resulting in impoverished forests with uncertain ability to provide ecosystem services such as carbon storage and pest control. This environmental cost should be taken into account to align urban sprawl with biodiversity conservation.     

The Invisible Village: An Exploration of Undergraduate Student Mothers’ Experiences

This study explored the experiences of mothers in college using a qualitative design. Results showed that a lack of financial resources was the chief barrier for student mothers in their educational pursuits while social/emotional support was the most important contributor to student mothers’ success in college. Participants relied heavily on student loans to cover costs of childcare or family to help watch their children. Role conflict experienced by student mothers has implications on family and college retention. Implications of this study included the adaptation and revisions of policies at the state and federal levels in addition to implications at the university level. Limitations of the study included a lack of racial and ethnic diversity and only including student mothers currently enrolled in college. Several recommendations for future research are described.     

Federal Financial Aid and Family Formation: Examining the Social Security Student Benefit Program

A broad empirical literature asks if social policies designed to provide benefits to low-income families also affect family formation patterns. While most of the evidence suggests that family formation effects are small at best, and often nonexistent, recent research argues that policies that alter budget constraints considerably should have greater family formation impacts. We tested this hypothesis by investigating the Social Security Student Benefit Program (SSSBP), a program designed to provide large higher education subsidies for the children of disabled, retired, or deceased parents. Conditions for receipt of SSSBP created strong incentives to delay marriage. Utilizing data from the National Longitudinal Survey of Youth, 1979, and a difference-in-differences model, we found that women potentially qualifying for the SSSBP were much less likely to marry before age 22 and were older when they had children, while the program did not influence the probability of women ever marrying or having children. Impacts on men, however, were negligible.     

Quick,uncertain, and delayed adults: timing,sequencing and duration of youth-adult transitions in Canada

The transition from youth to adulthood in western societies has become more prolonged and complex as traditional societal norms have lost influence. Using retrospective data from a cohort of 43-year-old Canadians surveyed in 2010 (n?=?405), we mapped the timing, sequencing, and duration of ‘first stage’ youth-adult transitions (leaving home, finishing formal education, obtaining a full-time job) and ‘second stage’ youth-adult transitions (marriage, parenthood, home ownership). Latent profile analysis identified five distinct transition profiles – norm-setters, quick adults, uncertain adults, adult students, and delayed adults – with different amounts and timing of post-secondary educational investment playing an important profile-shaping role. Although youth-adult transitions have become less standardized and more individualized, especially for first stage transitions, these transitions are still quite structured and continue to be affected by gender and family socioeconomic status.     

Strategies and cues adolescents use to assess the age of an online stranger

A common risk among adolescents is sexual solicitation, in which an adolescent is asked to provide sexual information, engage in sexual talk, or in sexual activities. Although scholars increasingly address this topic from an intrapersonal perspective, there is little attention to factors of language use and message content. In two focus group studies, we investigated whether adolescent girls consider themselves capable of assessing whether an online stranger is an adult or a peer, the extent to which adolescent girls actually succeed in making this assessment, the strategies they apply to do so, and the content- and language-related cues focused on. Our findings suggest that most of the adolescent girls are confident in their ability to assess whether the stranger is a peer or an adult with possible sexual intentions. However, we also found that only 43% were able to correctly make this assessment. Most of the adolescents seem to apply the passive strategy of uncertainty reduction: They scan the profile page of the stranger, check contact information, and the profile picture. They may choose to apply the interactive strategy to find out more about the online stranger. Important content-related cues that alarm adolescent girls are: ignoring personal questions, showing an exaggerated amount of interest, acting as a friend, and being sexually oriented. Language cues mentioned related to word usage, abbreviations, sentence length, and tone.