@article{zhang_martin_stevenson_yao_2022, title={Equally green? Understanding the distribution of urban green infrastructure across student demographics in four public school districts in North Carolina, USA}, volume={67}, ISSN={["1610-8167"]}, url={https://doi.org/10.1016/j.ufug.2021.127434}, DOI={10.1016/j.ufug.2021.127434}, abstractNote={Green infrastructure (GI) provides a suite of ecosystem services that are widely recognized as critical to health, well-being, and sustainability on an urbanizing planet. However, the distribution of GI across urban landscapes is frequently uneven, resulting in unequal delivery of these services to low-income residents or those belonging to underserved racial/ethnic identities. While GI distribution has been identified as unequal across municipalities, we investigated whether this was true in public schoolyards within and among urban school districts. We examined schoolyards in four metropolitan areas of diverse socio-economic and demographic compositions in North Carolina, USA to determine if they provided equal exposure to GI, then compared whether this was true of the broader urban landscape. We first classified the land cover of elementary schoolyards and their neighborhoods, then used bivariate and multivariate approaches to analyze the relationships between GI (i.e. tree canopy cover and total GI) and the socioeconomic status and race/ethnicity of the schools and surrounding neighborhoods, respectively. We found that the extent of tree canopy cover and total GI in schoolyards was unrelated to the socioeconomic status and the race/ethnicity of students across the four school districts. In contrast, neighborhoods with lower socioeconomic status and larger populations of underserved race/ethnicity residents had less tree canopy cover and total GI. Although total GI was more evenly distributed in schoolyards, the extent of tree canopy cover and total GI in schoolyards was lower than that in the neighborhoods. This suggests opportunities for school districts to expand GI in schoolyards, leveraging their potential to increase ecosystem services to all children, from increased educational opportunities to improved mental, physical, and environmental well-being.}, journal={URBAN FORESTRY & URBAN GREENING}, publisher={Elsevier BV}, author={Zhang, Zhenzhen and Martin, Katherine L. and Stevenson, Kathryn T. and Yao, Yuan}, year={2022}, month={Jan} }
 @article{zhang_lan_2022, title={Understanding the Impacts of Plant Capacities and Uncertainties on the Techno-Economic Analysis of Cross-Laminated Timber Production in the Southern US}, volume={10}, ISSN={["2164-6341"]}, DOI={10.32604/jrm.2022.017506}, abstractNote={Understanding the economic feasibility of cross-laminated timber (CLT), an emerging and sustainable alternative to concrete and steel, is critical for the rapid expansion of the mass timber industry. However, previous studies on economic performance of CLT have not fully considered the variations in the feedstock, plant capacities, manufacturing parameters, and capital and operating costs. This study fills this gap by developing a techno-economic analysis of producing CLT panels in the Southern United States. The effects of those variations on minimum selling price (MSP) of CLT panels are explored by Monte Carlo simulation. The results show that, across all the plant capacities from 30,000 to 150,000 m3/year, the MSP ranges from $345 to $609/m3 with a ±6%–9% range caused by the variations in feedstocks, key manufacturing parameters, capital and operating cost. The MSP decreases significantly along the increasing capacities. A sensitivity analysis exhibits that the lumber price, lumber preparing loss, plant capacity, and the installed costs of layering and gluing, finishing, and miscellaneous, are the top driving factors to CLT MSP. Supported by Geographic Information System, this study also studies the transportation cost of delivering CLT to customers under three CLT demanding levels (1%, 5%, 15%). The results show that the transportation cost is 1%–8% of the MSP. Lower demanding level or higher plant capacity can increase the transportation cost due to average longer delivering distance. When considering the delivered cost that sums MSP and transportation cost, larger plant capacity does not necessarily generate lower delivered cost.}, number={1}, journal={JOURNAL OF RENEWABLE MATERIALS}, author={Zhang, Zhenzhen and Lan, Kai}, year={2022}, pages={53–73} }
 @article{zhang_stevenson_martin_2022, title={Use of nature-based schoolyards predicts students' perceptions of schoolyards as places to support learning, play, and mental health}, volume={1}, ISSN={["1469-5871"]}, url={https://doi.org/10.1080/13504622.2022.2032612}, DOI={10.1080/13504622.2022.2032612}, abstractNote={Although green schoolyards provide many benefits to children and communities, little research explores students’ perceptions of these benefits and how natural elements (e.g. gardens, trees) and associated use shape student experience. We examine the relationship between nature-based attributes, nature-based activities, and teacher-led activities with students’ perceptions of schoolyards’ benefits to self (e.g. feeling calm, good place to learn) and to community (e.g. contributions to cleaner water, increased biodiversity). We measured 199 3rd -6th grade students’ perceptions of schoolyards’ benefits from 9 schools in Raleigh, North Carolina. Overall, students viewed schoolyards positively, and recognized more benefits to self than community. We found that the relationship between the presence of nature-based attributes and students’ positive feelings was limited. Instead, we found that nature-based activities and teacher-led activities had a positive relationship with students’ positive feelings. Our findings suggest that school greening efforts need to be paired with policies and curricular practices to encourage interaction with natural elements to ensure benefits are fully realized by students.Supplemental data for this article is available online at https://doi.org/10.1080/13504622.2022.2032612 .}, number={9}, journal={ENVIRONMENTAL EDUCATION RESEARCH}, publisher={Informa UK Limited}, author={Zhang, Zhenzhen and Stevenson, Kathryn T. and Martin, Katherine L.}, year={2022}, month={Jan} }
 @article{zhang_stevenson_martin_2021, title={Exploring geographical, curricular, and demographic factors of nature use by children in urban schoolyards in Raleigh, NC, USA}, volume={65}, ISSN={["1610-8167"]}, url={http://dx.doi.org/10.1016/j.ufug.2021.127323}, DOI={10.1016/j.ufug.2021.127323}, abstractNote={Experience in nature provides a host of benefits to children, but today’s children who live in urban environments spend less time with nature compared to previous generations. Because children spend a large amount of time at school, greening schoolyards is one strategy for providing children with more access to nature and its benefits. However, installing nature-rich spaces in schoolyards may not guarantee their use, and research is needed to understand how the physical make-up of schoolyards may interact with teacher and student-related factors to predict use of natural elements on schoolyards. We inventoried 9 urban schoolyards and surveyed an associated 199 3rd-6th grade students and 14 teachers to measure children’s awareness and use of nature-rich vs. traditional outdoor spaces as predicted by teachers’ behavior (i.e. taking students outdoors) and environmental education-related training, student demography, and schoolyard physical environment. We found that children were less aware of nature-rich spaces (gardens 69 %, woodlands 28 %) compared to traditional outdoor spaces (playgrounds 73 %, athletic fields 77 %) and spent less time there (once a month versus several times a week). However, teachers taking children outdoors (p = 0.001) and trained in environmental education (p = 0.10) positively predicted student awareness of gardens. Teacher training in environmental education was also predictive of children exploring woodlands (p = 0.04), highlighting the importance of teacher training in successful green schoolyard efforts. We provide a glimpse of schoolyards as places for urban children to access nature's benefits by studying different school factors that influence children’s nature-based activities. Simply implementing natural spaces in schoolyards cannot guarantee the use of natural spaces by children. Providing institutional support and professional development for teachers may help to enhance children's awareness of different nature-rich areas and promote nature-base activities in schoolyards.}, journal={URBAN FORESTRY & URBAN GREENING}, publisher={Elsevier BV}, author={Zhang, Zhenzhen and Stevenson, Kathryn T. and Martin, Katherine L.}, year={2021}, month={Nov} }
 @article{larson_zhang_oh_beam_ogletree_bocarro_lee_casper_stevenson_hipp_et al._2021, title={Urban Park Use During the COVID-19 Pandemic: Are Socially Vulnerable Communities Disproportionately Impacted?}, volume={3}, ISSN={2624-9634}, url={http://dx.doi.org/10.3389/frsc.2021.710243}, DOI={10.3389/frsc.2021.710243}, abstractNote={The COVID-19 pandemic altered human behavior around the world. To maintain mental and physical health during periods of lockdown and quarantine, people often engaged in outdoor, physically distanced activities such as visits to parks and greenspace. However, research tracking outdoor recreation patterns during the pandemic has yielded inconsistent results, and few studies have explored the impacts of COVID-19 on park use across diverse neighborhoods. We used a mixed methods approach to examine changes in park use patterns in cities across North Carolina, USA, during the COVID-19 pandemic, with an emphasis on impacts in socially vulnerable communities (based on racial/ethnic composition and socioeconomic status). First, we surveyed a demographically representative sample of 611 urban residents during August 2020 to assess their use of outdoor park spaces before and during the pandemic. Second, we used cell phone location (i.e., geo-tracking) data to document changes in park visits within 605 socioeconomically diverse urban census tracts before (July 2019) and during (July 2020) the pandemic. Data from both methods revealed urban park use declined during the pandemic; 56% of survey respondents said they stopped or reduced park use, and geo-tracked park visits dropped by 15%. Park users also became more homogenous, with visits increasing the most for past park visitors and declining the most in socially vulnerable communities and among individuals who were BIPOC or lower-income. Our results raise concerns about urban park use during the COVID-19 pandemic and suggest pre-existing health disparities in socially vulnerable communities might be exacerbated by inequitable access and utilization of parks and greenspace.}, journal={Frontiers in Sustainable Cities}, publisher={Frontiers Media SA}, author={Larson, Lincoln R. and Zhang, Zhenzhen and Oh, Jae In and Beam, Will and Ogletree, S. Scott and Bocarro, Jason N. and Lee, KangJae Jerry and Casper, Jonathan and Stevenson, Kathryn T. and Hipp, J. Aaron and et al.}, year={2021}, month={Sep} }
 @article{zhang_lucia_2020, title={Improved reswelling behaviors and thermal stability of polyvinyl alcohol composite gels assisted by salt}, volume={281}, ISSN={["1873-4979"]}, DOI={10.1016/j.matlet.2020.128743}, abstractNote={Deswelling and reswelling behaviors of polyvinyl alcohol (PVOH) gel systems were studied in which natural polymers promoted reswelling capacity of PVOH gels, while salt (NaCl) solutions de-swelled the hydrogels but improved the reswelling performance. Thermogravimetric analysis (TGA) results indicated that the salt treatment considerably improved the thermal stability. Differential scanning calorimetry (DSC) results indicated that the salt treatment hindered crystallization of all the systems except the urea system. The improved reswelling capacity might be attributed to changes in the crystalline region caused by the salt.}, journal={MATERIALS LETTERS}, author={Zhang, Zhen and Lucia, Lucian}, year={2020}, month={Dec} }
 @article{zhang_meerow_newell_lindquist_2019, title={Enhancing landscape connectivity through multifunctional green infrastructure corridor modeling and design}, volume={38}, ISSN={["1618-8667"]}, DOI={10.1016/j.ufug.2018.10.014}, abstractNote={Landscape connectivity is critical for ecosystem health and biodiversity conservation, yet urbanization is increasing habitat fragmentation. Green corridors that connect isolated remnant habitat patches (e.g. parks) can increase connectivity and provide ecosystem services in cities. Vacant land, especially prevalent in shrinking cities, presents a unique opportunity to reconnect these landscapes. This paper provides a practical and replicable approach for assessing landscape connectivity patterns and identifying priority locations for green corridors. The methodology integrates social and ecological factors coupled with site-scale multifunctional greenway designs and is applied to the city of Detroit as a proof of concept. First, we use FRAGSTATS to evaluate structural landscape connectivity patterns at a census tract scale. A functional connectivity assessment based on graph theory and Conefor software is used to validate the results, which indicate that habitat is highly fragmented in Detroit. To identify opportunities to reduce this fragmentation, we use a least-cost path approach to map potential green corridors linking city parks through vacant parcels, alleys, and smaller green spaces, and prioritize these corridors using a gravity model and network analysis. To make the model more concrete and useful for decision-makers, we develop site-level multifunctional corridor design typologies. This study presents a novel approach to assessing urban connectivity and a multi-scalar, systematic methodology for planning urban green infrastructure networks that connects landscape ecology with practical planning and design considerations to maximize social and ecological functions.}, journal={URBAN FORESTRY & URBAN GREENING}, author={Zhang, Zhenzhen and Meerow, Sara and Newell, Joshua P. and Lindquist, Mark}, year={2019}, month={Feb}, pages={305–317} }
 @article{bergen_zhang_tyrrell_kluge_rumschlag_2018, title={Mapping Forest and Surrounding Landscape Changes 1949-2015 at the University of Michigan's Historic Forestry Education Properties}, volume={45}, url={http://dx.doi.org/10.7245/0026-2005-45.2.241}, DOI={10.7245/0026-2005-45.2.241}, abstractNote={ABSTRACT Three forested properties owned by the University of Michigan and near to Ann Arbor were the sites of some of the earliest forestry field education in the USA. No longer managed solely for this purpose after the mid-1960s, and at the same time nested within a rapidly developing area of Michigan, current planning for the properties focuses on melding their historic legacy with renewed ecologically and sustainably sound uses. We developed new maps and knowledge of forest and land change within and surrounding the properties between 1949 and 2015. We acquired aerial photography at 5-10 year intervals, created land-cover/land-use and change data, and identified key trajectories of change. Results within Saginaw Forest (established 1904) showed a consistent amount of forest area, but transitions in some observed overstory composition from coniferous to mixed forest between 1949 and 2015. Within the present-day extent of Stinchfield Woods and the Newcomb Tract (established 1925-1955), forest area increased from 68% to 98% and 51% to 93% respectively between 1949 and 2015, as forest plantations and other regrowth replaced former cleared lands. In 0.5 km-wide buffer areas surrounding the properties, agriculture decreased, and urban uses increased dramatically between 1949 and 2015 for all three sites. Forested land cover has also increased on the surrounding landscapes, again replacing agriculture and grassland. The properties today still display the legacies of their historic forestry education and research, and are living laboratories of natural succession in planted forests. The properties now also represent some of the most protected local lands while the landscapes surrounding them continue to change.}, number={2}, journal={Michigan Academician}, publisher={Michigan Academy of Science, Arts and Letters}, author={BERGEN, KATHLEEN and ZHANG, ZHENZHEN and TYRRELL, GERALD and KLUGE, KAREN VON and RUMSCHLAG, JACOB}, year={2018}, month={Jan}, pages={241–264} }