Links between green space and public health:A bibliometric review of global research trends and future prospects from 1901 to 2019

Considerable specific cross-sectional and review studies have linked exposure to green spaces to improving public health, but there is no bibliometric review attempting to systemically and retrospectively analyze these existing articles. Here we aim to uncover global research status, trends, and future prospects in green spaces and health (G-H) research then propose a framework for the underlying mechanisms and pathways that link green space to public health. We obtained 18 961 G-H research publications from the core Web of Science collection from 1901 to 2019, analyzing the characteristics of publication outputs, key scientific disciplines, and differences in performance between countries and institutions. Besides, content analysis was conducted to analyze the keywords, including keyword co-occurrence analysis and keyword clustering analysis. We found: (1) a steady quantitative increase in publications, active journals, and involved countries and institutions since the 1990s; (2) a significant increase and changes in G-H related interdisciplinary categories, with environment-related disciplines becoming the mainstream; (3) research focus and trends that were identified based on the analysis of high-frequency co-occurring keywords; (4) three main knowledge domains, namely, green spaces and physical health, mental health, and ecosystem health, that were identified and visualized based on keyword clustering analysis; (5) a framework of underlying mechanisms and pathways linking green space to public health that is proposed based on visualization of the three main knowledge domains. We suggest that the main challenge of G-H research is to further clarify in-depth the underlying mechanisms and pathways from multiple perspectives, including multiple nations, disciplines, and study designs. The lack of co-occurring keywords and clustering information related to social well-being suggests that research related to ‘social health’ is lacking. Based on a clear understanding of the quantity, quality, and characteristics of green space for public health, a health-based environmental plan should be proposed in the future

Supplementary file.xlsx

The concentrations of Cu, Ni, Pb, Zn, Cd, and Cr were analyzed from 87 topsoil samples in the pre-rainy season and 115 samples in the post-rainy season. The Cd concentration was determined through inductively coupled plasma mass spectrometry (ICP-MS, Baird ICP2070, USA). The concentrations of Cu, Ni, Pb, Zn, and Cr were determined using an inductively coupled plasma optical emission spectrometer (ICP-OES, Baird ICP2070, USA). The pollution index (PI) of heavy metals was calculated from the measured and background concentrations. The ecological risk index (RI) was assessed based on the PI values and toxic-response parameters

Supply-demand analysis of ecosystem services based on socioeconomic and climate scenarios in North China

The demand and supply of ecosystem services (ESs) play a crucial role in the sustainable development of regional nature-society systems. With complex climate change and multiple pathways of social development, there is an urgent need for predictive research on how to combine both social and natural factors to determine the comparatively optimal regional development pathway. Based on the shared socioeconomic pathways (SSPs)–representative concentration pathways (RCPs) framework and the pattern-process-service-management research paradigm, this study analyzed the various trends of regional landscape patterns for 2030–2050 and predicted the state of ecosystem services supply and demand (ESSD) in 2030 under multiple scenarios (SSP1-2.6, SSP2-4.5, SSP5-8.5) in the Beijing-Tianjin-Hebei regions. The results show that: 1) area of cropland will decrease in multiple future scenarios. There is a smaller landscape variation and an upward trend of urban area in the SSP5-8.5 scenario. The transfer types among different landscapes will be concentrated between forest and grassland under SSP1-2.6 and SSP2-4.5. 2) The average provisioning capacity of ES will increase in the future, with a spatial pattern of high in the northwest and low in the southeast. Habitat quality has the least interdistrict variation in service distribution, while the recreation service exhibits the opposite trend. 3) The average comprehensive ecological supply and demand ratio (CESDR) is higher in Beijing city than in Hebei Province and Tianjin city. The primary imbalance services are water yield, soil retention, and habitat quality in Beijing city, Hebei Province, and Tianjin city, respectively. Moreover, the SSP5-8.5 scenario has the highest number of ES deficit regions. 4)The ESSD state of each ES had an inverse relationship with the local economic level in 2020, in which water yield had the highest negative correlation degree (-0.191) and soil retention had the lowest (-0.041). In addition, the relationship between gross domestic product and CESDR will change from negative to positive along with different future scenarios (SSP1-2.6: −0.05, SSP2-4.5: 0.05, SSP5-8.5: 0.12). The study provides useful implications for policy-makers to coordinate regional resources and implement sustainable development by integrating both ecological and economic aspects

Identification of Natural and Anthropogenic Drivers of Vegetation Change in the Beijing-Tianjin-Hebei Megacity Region

Identifying the natural and anthropogenic mechanisms of vegetation changes is the basis for adapting to climate change and optimizing human activities. The Beijing-Tianjin-Hebei megacity region, which is characterized by significant geomorphic gradients, was chosen as the case study area. The ordinary least squares (OLS) method was used to calculate the NDVI trends and related factors from 2000 to 2015. A geographic weighted regression (GWR) model of NDVI trends was constructed using 14 elements of seven categories. Combined with the GWR calculation results, the mechanisms of the effects of explanatory variables on NDVI changes were analyzed. The findings suggest that the overall vegetation displayed an increasing trend from 2000 to 2015, with an NDVI increase of ca. 0.005/year. Additionally, the NDVI fluctuations in individual years were closely related to precipitation and temperature anomalies. The spatial pattern of the NDVI change was highly consistent with the gradients of geomorphology, climate, and human activities, which have a tendency to gradually change from northwest to southeast. The dominant climate-driven area accounted for only 5.98% of the total study area. The vegetation improvement areas were regionally concentrated and had various driving factors, and vegetation degradation exhibited strong spatial heterogeneity. The vegetation degradation was mainly caused by human activities. Natural vegetation was improved because of natural factors and reductions in human activities. Moreover, cropland vegetation as well as urban and built-up area improvements were related to increased human actions and decreased natural effects. This study can assist in ecological restoration planning and ecological engineering implementation in the study area

A Method to Estimate Clear-Sky Albedo of Paddy Rice Fields

As a major crop type in the global agroecosystem, paddy rice fields contribute to global greenhouse gas emissions. Surface albedo plays a vital role in estimating carbon emissions. However, it is difficult to find a broadband albedo estimation over paddy rice fields. The objective of this study was to derive an applicable method to improve albedo estimation over a paddy rice field. Field multiangle reflectance and surface albedo were collected throughout the growing season. A physically based model (AMBRALS) was utilized to reconstruct the directional reflectance into the spectral albedo. Multiple spectral albedos (at the wavelengths of 470, 550, 660, 850, 1243, 1640 and 2151 nm) were calculated, and new narrowband to broadband conversion coefficients were derived between the observed spectral albedo and broadband albedo. The conversion schemes showed high consistency with the field albedo observations in the shortwave (285–3000 nm), infrared (700–3000 nm), and visible (400–700 nm) bands. This method can help improve albedo estimation in partially submerged environments

Difference of pollution index (PI ± SD) and statistical test (* <i>p</i> < 0.05) between the pre- and post- rainy seasons.

<p>F (Forest), G (grass), S (shrub), M (mixed farmland), O (orchard), SP (spring maize), SM (summer maize), W (wheat), and C (cotton).</p

Assessment of Heavy Metal Pollution in Topsoil around Beijing Metropolis

<div><p>The topsoil around Beijing metropolis, China, is experiencing impacts of rapid urbanization, intensive farming, and extensive industrial emissions. We analyzed the concentrations of Cu, Ni, Pb, Zn, Cd, and Cr from 87 topsoil samples in the pre-rainy season and 115 samples in the post-rainy season. These samples were attributed to nine land use types: forest, grass, shrub, orchard, wheat, cotton, spring maize, summer maize, and mixed farmland. The pollution index (PI) of heavy metals was calculated from the measured and background concentrations. The ecological risk index (RI) was assessed based on the PI values and toxic-response parameters. The results showed that the mean PI values of Pb, Cr, and Cd were > 1 while those of Cu, Ni, and Zn were < 1. All the samples had low ecological risk for Cu, Ni, Pb, Zn, and Cr while only 15.35% of samples had low ecological risk for Cd. Atmospheric transport rather than land use factors best explained the seasonal variations in heavy metal concentrations and the impact of atmospheric transport on heavy metal concentrations varied according to the heavy metal types. The concentrations of Cu, Cd, and Cr decreased from the pre- to post-rainy season, while those of Ni, Pb, and Zn increased during this period. Future research should be focused on the underlying atmospheric processes that lead to these spatial and seasonal variations in heavy metals. The policymaking on environmental management should pay close attention to potential ecological risks of Cd as well as identifying the transport pathways of different heavy metals.</p></div

Heavy metal concentrations (mg/kg) of measurement (MV), background (BV), and environmental quality standard for soils (EQSS).

<p>Heavy metal concentrations (mg/kg) of measurement (MV), background (BV), and environmental quality standard for soils (EQSS).</p