Data sets used for analyses of FERP 1, 2, 3 censuses as in

Gilbert, G.S., S.G. Carvill, A.R. Krohn, and A.S. Jones. 2024. Three censuses of a mapped plot in coastal California mixed-evergreen and redwood forest. Forests 15(1), 164; https://doi.org/10.3390/f15010164

South-west coordinate for each 20×20-m quadrat are in quadrat_coords.csv
https://ferp.ucsc.edu/files/2025/04/quadrat_coords.csv

Species names, codes, and attributes are in FERPspecies.csv
https://ferp.ucsc.edu/files/2025/04/FERPspecies.csv

Data from all three censuses are in FERP123_merged_20231029.csv
https://ferp.ucsc.edu/files/2025/04/FERP123merged_20231029.csv

These are accessible from the web URLs below. All other data frames used are subsets or combinations of these data.
Metadata area available at:
https://ferp.ucsc.edu/files/2025/04/Metadata-for-UCSC-FERP123-data-Forests-2024.pdf

## Read in and create the fundamental data frames for use throughout analyses

# Read in data frame with SW coordinate for each quadrat
qc<-read.csv("https://ferp.ucsc.edu/files/2025/04/quadrat_coords.csv") 

# Read in data frame with names of all the FERP species
ferpspp<-read.csv("https://ferp.ucsc.edu/files/2025/04/FERPspecies.csv") 

# Read in complete data for three censuses 
a<-read.csv("https://ferp.ucsc.edu/files/2025/04/FERP123merged_20231029.csv") # read full data

#remove unneeded variables
a<-a[,-which(names(a) %in% c("basalarea1_m2","code6fix","locfix","notes1","notes2","notes3"))] 
a$date1<-as.Date(a$date1) #format as Date
a$date2<-as.Date(a$date2) #format as Date
a$date3<-as.Date(a$date3) #format as Date
a$CI12_wk<-as.numeric(a$date2-a$date1)/7 # interval FERP1 to FERP2 census in weeks
a$CI23_wk<-as.numeric(a$date3-a$date2)/7 # interval FERP2 to FERP3 census in weeks

#create separate data frames including only live stems present in each census
f1<-a[a$status1=='living',] # stems alive in FERP1
f2<-a[a$status2=='living',] # stems alive in FERP2
f3<-a[a$status3=='living',] # stems alive in FERP3

# Create data frames for each census with just the largest living stem of each individual
f1_largeststem <- f1 %>% group_by(tag) %>% slice(which.max(dsh1_mm))
f1indiv<-aggregate(f1_largeststem$code6,by=list(f1_largeststem$quadrat),FUN=length)
colnames(f1indiv)<-c("Quadrat","FERP1")

f2_largeststem <- f2 %>% group_by(tag) %>% slice(which.max(dsh2_mm))
f2indiv<-aggregate(f2_largeststem$code6,by=list(f2_largeststem$quadrat),FUN=length)
colnames(f2indiv)<-c("Quadrat","FERP2")

f3_largeststem <- f3 %>% group_by(tag) %>% slice(which.max(dsh3_mm))
f3indiv<-aggregate(f3_largeststem$code6,by=list(f3_largeststem$quadrat),FUN=length)
colnames(f3indiv)<-c("Quadrat","FERP3")

General description of census timing for FERP1 FERP2 FERP3

The first census (FERP1) included only the 6 ha in the southwester portion of the complete FERP; 0 to 200 m East and 0 to 300 m North.

The second census (FERP2) began with that 6 ha, and then expanded the FERP to 400 m East and 400 m North for the full 16 ha.

The third census (FERP3) then included the entire 16 ha.

The censuses proceed generally from West to East.
However, in some cases stems that were missed in the first pass were then re-visited later to get measurements – this can extend the intercensus interval for those stems, or potentially shorten the time if it was measured late in FERP2 and early in FERP3.

FERP1 began 2006-12-08 and ended 2007-09-13.
FERP2 began 2011-09-29 and ended 2015-06-17.
FERP3 began 2017-08-05 and ended 2021-11-29.

FERP2 of the original 6 ha included in FERP1 began 2011-09-29 and ended 2015-02-27.
Of those, 12859 stem observations were completed by 2012-07-06 with an additional 101 by 2015-02-27 to fill in missing data.

FERP3 of the original 6 ha included in FERP1 began 2017-09-28 and ended 2021-10-29.
Of those, 14986 stem observations were completed by 2018-11-12 with an additional 101 by 2021-10-29 to fill in missing data.

species<-"SEQUSE"
plot(f3$east_m[f3$code6==species],f3$north_m[f3$code6==species],asp=1,ylab=NA,xlab=NA,
     las=1, xlim=c(0,400),ylim=c(0,400),main=paste(species,"FERP3"),
     cex=sqrt(f3$dsh3_mm[f3$code6==species]/500),col="black")
abline(h=seq(0,400,20),lty=2,col="grey80"); abline(v=seq(0,400,20),lty=2,col="grey80")

st<-f3[f3$code6==species,]
hist(st$dsh3_mm[st$code6==species]/10,breaks=seq(0,floor(max(st$dsh3_mm,na.rm=T)/10+5),5),
     las=1, main=paste(species,"FERP3"), ylim=c(0,200),col="blue",xlab="Diameter standard height (mm)",ylab="Number of stems")

species<-"QUERAG"
plot(f2$east_m[f2$code6==species],f2$north_m[f2$code6==species],asp=1,ylab=NA,xlab=NA,
     las=1, xlim=c(0,400),ylim=c(0,400),main=paste(species,"FERP2"),
     cex=sqrt(f2$dsh2_mm[f2$code6==species]/500),col="black")
abline(h=seq(0,400,20),lty=2,col="grey80"); abline(v=seq(0,400,20),lty=2,col="grey80")

st<-f2[f2$code6==species,]
hist(st$dsh2_mm[st$code6==species]/10,breaks=seq(0,floor(max(st$dsh2_mm,na.rm=T)/10+5),5),
     las=1, main=paste(species,"FERP2"), ylim=c(0,200),col="blue",xlab="Diameter standard height (mm)",ylab="Number of stems")