title: Urban Vegetative Cover Fragmentation in the U.S.: Associations With Physical Activity and BMI.
abstract: BACKGROUND
  Urban vegetative cover provides a range of ecosystem services including contributions to human health and well-being. Urbanization exerts tremendous pressure on this natural resource, causing fragmentation and loss of urban greenspace. This study aimed to examine associations between vegetative cover fragmentation and physical activity and BMI at the county scale in the U.S. metropolitan statistical areas greater than 1 million in population.
  
  
  METHODS
  National Land Cover Database 2006 and Behavioral Risk Factor Surveillance System 2008 provided land cover and human health data, respectively. Analyses were performed in 2013 at the county scale where the health data were reported. Spearman rank correlation and stepwise and hierarchical regression models were applied to estimate relationships between land cover and health variables.
  
  
  RESULTS
  After controlling for median household income and race, greater forest edge density (β=0.272, p<0.05) and larger size of herbaceous patches (β=0.261, p<0.01) were associated with a higher percentage of participation in physical activity within counties. More connections between forest and developed area (β=0.37, p<0.01) and greater edge density of shrubland (β=0.646, p<0.001) were positively associated with a higher percentage of normal BMI (<25) within counties.
  
  
  CONCLUSIONS
  Forest land cover and some degree of fragmentation are associated with population physical activity. Future studies should examine how built environments and varying land cover configurations influence physical activity and weight status.
authors.affiliation: Department of Parks, Recreation and Tourism Management, North Carolina State University, Raleigh, North Carolina. Electronic address: wtsai@ncsu.edu.
authors.forename: Wei-Lun
authors.initials: WL
authors.lastname: Tsai
authors.affiliation: Department of Parks, Recreation and Tourism Management, North Carolina State University, Raleigh, North Carolina.
authors.forename: Myron F
authors.initials: MF
authors.lastname: Floyd
authors.affiliation: Department of Parks, Recreation and Tourism Management, North Carolina State University, Raleigh, North Carolina.
authors.forename: Yu-Fai
authors.initials: YF
authors.lastname: Leung
authors.affiliation: Department of Forestry and Environmental Resources, North Carolina State University, Raleigh, North Carolina.
authors.forename: Melissa R
authors.initials: MR
authors.lastname: McHale
authors.affiliation: Department of Statistics, North Carolina State University, Raleigh, North Carolina.
authors.forename: Brian J
authors.initials: BJ
authors.lastname: Reich
mesh_terms: D015992:Body Mass Index; D017753:Ecosystem; D004779:Environment Design; D015444:Exercise / Q000502:physiology*; D065928:Forests; D006801:Humans; D012044:Regression Analysis; D014481:United States; D014504:Urban Health; D014507:Urbanization