The ecological legacy effects of redlining on urban landscapes and bird communities in Durham, North Carolina

Bai, Jin1 ; Katti, Madhusudan1

Published Aug 16, 2024 on Dryad. https://doi.org/10.5061/dryad.w0vt4b91v

Abstract

Residential segregation's legacy effect persists today in many US cities that used to employ redlining policies by the Home Owner Loan Cooperation (HOLC) in the 1930s. Understanding how historical redlining affects modern-day environmental conditions and wildlife communities is of great importance for urban wildlife conservation and environmental justice. We examined how redlining affects modern-day tree canopy cover, impervious surfaces, and urban heat island effects at the HOLC zone level in Durham, NC, USA. We also randomly generated sampling points for avian point counts to examine the redlining effect on the bird communities in urban parks located in HOLC zones with three repeat visits to each point roughly a week apart during one breeding season and one non-breeding season.

README: The ecological legacy effects of redlining on urban landscapes and bird communities in Durham, North Carolina

https://doi.org/10.5061/dryad.w0vt4b91v

There are datasets from the 4 objectives of this study. (1) Our first objective is to examine the redlining effect on tree canopy cover, impervious surfaces, and urban heat island effects at the HOLC zone level. (2) Our second objective is to examine the redlining effect on bird community measures including species richness and abundance at the urban parks level. (3) Our third objective is to examine species-specific responses to redlining to identify which species’ abundance was influenced by redlining at the urban parks level. (4) Our fourth objective is to examine how redlining might influence bird community composition by comparing dissimilarity in species composition.

Description of the data and file structure

Objective 1

Dataset name	Dataset descriptions
Redlining_forest_imp_grid_08122024.csv	Contains data on percent forest cover and impervious surfaces across HOLC zones.
Redlining_af_hi_f_08122024.csv	Contains data on afternoon heat index across HOLC zones.
Redlining_af_t_f_08122024.csv	Contains data on afternoon temperature across HOLC zones.
Redlining_am_hi_f_08122024.csv	Contains data on morning heat index across HOLC zones.
Redlining_am_t_f_08122024.csv	Contains data on morning temperature across HOLC zones.
Redlining_pm_hi_f_08122024.csv	Contains data on evening heat index across HOLC zones.
Redlining_pm_t_f_08122024.csv	Contains data on evening temperature across HOLC zones.

Variable name	Variable descriptions
holc_id	The sub-category of HOLC zones.
holc_grade	The 4 grades of HOLC zones (A, B, C, D)
Percent_forest_cover	The percentage of forest cover at each 100 by 100 m grid across HOLC zones. "n/a" represent missing data.
Percent_imp_cover	The percentage of impervious surfaces at each 100 by 100 m grid across HOLC zones.
AF_HeatIndex_MEAN	The mean afternoon heat index at each 100 by 100 m grid across HOLC zones in July 2021. "n/a" represent missing data.
AF_Temp_MEAN	The mean afternoon temperature at each 100 by 100 m grid across HOLC zones in July 2021. "n/a" represent missing data.
AM_HeatIndex_MEAN	The mean morning heat index at each 100 by 100 m grid across HOLC zones in July 2021. "n/a" represent missing data.
AM_Temp_MEAN	The mean morning temperature at each 100 by 100 m grid across HOLC zones in July 2021. "n/a" represent missing data.
PM_HeatIndex_MEAN	The mean evening heat index at each 100 by 100 m grid across HOLC zones in July 2021. "n/a" represent missing data.
PM_Temp_MEAN	The mean evening temperature at each 100 by 100 m grid across HOLC zones in July 2021. "n/a" represent missing data.

Objective 2

Dataset name	Dataset descriptions
Bird_data_covariates_summer_08092024.csv	Bird species richness and abundance at the urban parks level during the breeding season.
Bird_data_covariates_winter_08092024.csv	Bird species richness and abundance at the urban parks level during the non-breeding season.

Variable name	Variable descriptions
Site_ID	Site ID for each sampling point.
Study_location	Study locations of "A/B zone", "C/D zone", and "Rural".
Park Name	The name of the park where data collection took place.
Lat	Latitude of the sampling point.
Lon	Longitude of the sampling point.
Species_richness	The number of species documented for each visit.
Visit	The 3 visits to each sampling point ("first", "second", "third").
Abundance	The number of individual birds documented for each visit.
Species_richness_native	The number of native species documented for each visit.
Abundance_native	The number of individual birds of native species documented for each visit.
Species_richness_seasonal	The number of seasonal species documented for each visit.
Abundance_seasonal	The number of individual birds of seasonal species documented for each visit.
Species_richness_year_round	The number of year-round species documented for each visit.
Abundance_year_round	The number of individual birds of year-round species documented for each visit.
P_forest_cover	The percentage of forest cover at each sampling point's 100 m buffer in urban parks across HOLC zones.
P_imp	The percentage of impervious surfaces at each sampling point's 100 m buffer in urban parks across HOLC zones.
Dist_Stream_m	The distance from the sampling points to the closest stream in meters.
VHDI	Vertical habitat diversity index.

Objective 3

Breeding season: There is a total of 23 datasets for 23 study species. The naming convention of the 23 datasets are as follows [4-letter species code] + [N_mixture] + [Summer_08092024]. The 4-letter species codes are below.

Non-breeding season: There is a total of 22 datasets for 22 study species. The naming convention of the 22 datasets are as follows [4-letter species code] + [N_mixture] + [Winter_08092024]. The 4-letter species codes are below.

American Robin (Turdus migratorius) - AMRO,

Blue-gray Gnatcatcher (Polioptila caerulea) - BGGN,

Brown-headed Nuthatch (Sitta pusilla) - BHNU,

Blue Jay (Cyanocitta cristata) - BLJA,

Brown Creeper (Certhia americana) - BRCR,

Brown Thrasher (Toxostoma rufum) - BRTH,

Carolina Chickadee (Poecile carolinensis) - CACH,

Carolina Wren (Thryothorus ludovicianus) - CARW,

Chimney Swift (Chaetura pelagica) - CHSW,

Dark-eyed Junco (Junco hyemalis) - DEJU,

Downy Woodpecker (Dryobates pubescens) - DOWO,

Eastern Bluebird (Sialia sialis) - EABL,

Eastern Towhee (Pipilo erythrophthalmus) - EATO,

European Starling (Sturnus vulgaris) - EUST,

Fish Crow (Corvus ossifragus) - FICR,

Great Crested Flycatcher (Myiarchus crinitus) - GCFL,

Gray Catbird (Dumetella carolinensis) - GRCA,

Hermit Thrush (Catharus guttatus) - HETH,

House Sparrow (Passer domesticus) - HOSP,

House Wren (Troglodytes aedon) - HOWR,

Yellow-rumped Warbler (Setophaga coronata) - MYWA,

Northern Cardinal (Cardinalis cardinalis) - NOCA,

Northern Mockingbird (Mimus polyglottos) - NOMO,

Red-bellied Woodpecker (Melanerpes carolinus) - RBWO,

Ruby-crowned Kinglet (Corthylio calendula) - RCKI,

Red-eyed Vireo (Vireo olivaceus) - REVI,

Tufted Titmouse (Baeolophus bicolor) - TUTI,

White-breasted Nuthatch (Sitta carolinensis) - WBNU,

White-throated Sparrow (Zonotrichia albicollis) - WTSP,

Yellow-bellied Sapsucker (Sphyrapicus varius) - YBSA.

Variable name	Variable descriptions
Site_ID	Site ID for each sampling point.
V1	The number of individual birds (from a given species) detected at the first visit for each sampling point.
V2	The number of individual birds (from a given species) detected at the second visit for each sampling point.
V3	The number of individual birds (from a given species) detected at the third visit for each sampling point.
Study_area	Study locations of "A/B zone" and "C/D zone".
Park Name	The name of the park where data collection took place.
Lat	Latitude of the sampling point.
Lon	Longitude of the sampling point.
P_forest_cover	The percentage of forest cover at each sampling point's 100 m buffer in urban parks across HOLC zones.
P_imp	The percentage of impervious surfaces at each sampling point's 100 m buffer in urban parks across HOLC zones.
AF_T_MEAN	The mean afternoon temperature at each sampling point's 100 m buffer in urban parks across HOLC zones in July 2021.
PM_HI_MEAN	The mean evening heat index at each sampling point's 100 m buffer in urban parks across HOLC zones in July 2021.
PM_T_MEAN	The mean evening temperature at each sampling point's 100 m buffer in urban parks across HOLC zones in July 2021.
Dist_Stream_m	The distance from the sampling points to the closest stream in meters.
Temp1	The temperature at the time of avian point count at the first visit for each sampling point (F).
Temp2	The temperature at the time of avian point count at the second visit for each sampling point (F).
Temp3	The temperature at the time of avian point count at the third visit for each sampling point (F).
Weather1	The cloud condition at the time of avian point count at the first visit for each sampling point (0 = clear, 1 = partly cloudy, 2 = mostly cloudy, 3 = overcast).
Weather2	The cloud condition at the time of avian point count at the second visit for each sampling point (0 = clear, 1 = partly cloudy, 2 = mostly cloudy, 3 = overcast).
Weather3	The cloud condition at the time of avian point count at the third visit for each sampling point (0 = clear, 1 = partly cloudy, 2 = mostly cloudy, 3 = overcast).
Wind1	The wind condition at the time of avian point count at the first visit for each sampling point (0 = no wind, 1 = low wind, 2 = moderate wind, 3 = extreme wind).
Wind2	The wind condition at the time of avian point count at the second visit for each sampling point (0 = no wind, 1 = low wind, 2 = moderate wind, 3 = extreme wind).
Wind3	The wind condition at the time of avian point count at the third visit for each sampling point (0 = no wind, 1 = low wind, 2 = moderate wind, 3 = extreme wind).
Noise1	The background noise condition at the time of avian point count at the first visit for each sampling point (0 = no noise, 1 = low noise, 2 = moderate noise, 3 = extreme noise).
Noise2	The background noise condition at the time of avian point count at the second visit for each sampling point (0 = no noise, 1 = low noise, 2 = moderate noise, 3 = extreme noise).
Noise3	The background noise condition at the time of avian point count at the third visit for each sampling point (0 = no noise, 1 = low noise, 2 = moderate noise, 3 = extreme noise).
Natural_Ground_layer	The prevalence of the presence of the natural ground layer at each sampling point (0 = absence, 12 = full presence, the number between 0 and 12 indicate the prevalence level with higher number indicating higher prevalence). Please see detailed descriptions in the methods section of the manuscript.
Herbaceous_layer	The prevalence of the presence of the herbaceous layer at each sampling point (0 = absence, 12 = full presence, the number between 0 and 12 indicate the prevalence level with higher number indicating higher prevalence). Please see detailed descriptions in the methods section of the manuscript.
Shrub_layer	The prevalence of the presence of the shrub layer at each sampling point (0 = absence, 12 = full presence, the number between 0 and 12 indicate the prevalence level with higher number indicating higher prevalence). Please see detailed descriptions in the methods section of the manuscript.
Understory_layer	The prevalence of the presence of the understory layer at each sampling point (0 = absence, 12 = full presence, the number between 0 and 12 indicate the prevalence level with higher number indicating higher prevalence). Please see detailed descriptions in the methods section of the manuscript.
Canopy_layer	The prevalence of the presence of the canopy layer at each sampling point (0 = absence, 12 = full presence, the number between 0 and 12 indicate the prevalence level with higher number indicating higher prevalence). Please see detailed descriptions in the methods section of the manuscript.
VHDI	Vertical habitat diversity index.

Objective 4

Dataset name	Dataset descriptions
Summer_matrix_08122024.csv	The bird community data in a matrix format during the breeding season.
Winter_matrix_08122024.csv	The bird community data in a matrix format during the non-breeding season.

Variable name	Variable descriptions
site	Site ID for each sampling point.
HOLC	Study locations of "A/B zone parks" and "C/D zone parks".
visit	The visit to each sampling point (V1 = the first visit; V2 = the second visit; V3 = the third visit).
date	The date of the avian point count.
time	The time of the day of the avian point count.
nspecies	The number of species documented for each avian point count.
(species common name)	For the rest of the columns in the dataset, they are the number of individual birds documented for each species.