In RS-eco/bdc: Bavarian Data Cube

knitr::opts_chunk$set(collapse = TRUE, warning=F, message=F, fig.width=10, fig.height=8, eval=T)

# Load packages
library(dplyr); library(tidyr)
library(ggplot2); library(scico)

# Load bdc package
library(bdc)

# Load shapefile of Bavaria
data("bavaria", package="bdc")

mecofun package

# Install mecofun package if not available
if(!"mecofun" %in% installed.packages()[,"Package"]){
  remotes::install_git("https://gitup.uni-potsdam.de/macroecology/mecofun.git")
}

# Load mecofun package
library(mecofun)
#' This package includes the following functions:
#' predictSDM, crossvalSDM, evalSDM, TSS, expl_deviance, inflated_response
#' eo_mask, partial_response, range_size, range_centre, select07, select07_cv

Load species range and climate data

# Load Brachpieper species data
data("bird_bva_shape_tk4tel")
bird_bav <- bird_bva_shape_tk4tel %>% dplyr::select(c(QUADRANT_M, QMP_R_GK, QMP_H_GK, `Großer Brachvogel`))

# Load climate data
data("cordex_bioclim_bav_tk4tel")
head(cordex_bioclim_bav_tk4tel)

# Select for current conditions & calculate ensemble mean
curclim <- cordex_bioclim_bav_tk4tel %>% filter(time_frame == "1991-2020") %>%
  group_by(x,y) %>% summarise_at(vars(bio1:bio19), ~mean(.,na.rm=T))
head(curclim)

# Add landcover data to curclim
data("corine_lc_bav_tk4tel")
landcover_bav <- corine_lc_bav_tk4tel %>% dplyr::select(x,y,`2018`) %>% 
  pivot_longer(names_to="year", values_to="clc", -c(x,y)) %>%
  mutate(presence = 1) %>% pivot_wider(names_from=clc, values_from=presence, values_fill=0)

curclim <- raster::rasterFromXYZ(curclim, crs=sp::CRS("+init=epsg:31468"))
landcover_bav <- raster::rasterFromXYZ(landcover_bav, crs=sp::CRS("+init=epsg:31468")); gc()
curenv <- raster::stack(curclim, landcover_bav) %>% raster::rasterToPoints() %>%
  as.data.frame(); rm(curclim, landcover_bav)

# Select for future conditions and calculate ensemble mean across GCMs
futclim <- cordex_bioclim_bav_tk4tel %>% filter(time_frame != "1991-2015") %>%
  group_by(x,y,time_frame, rcp) %>% summarise_at(vars(bio1:bio19), ~mean(.,na.rm=T))
head(futclim)

Plot species & environmental data

# plot Brachvogel in bavaria using ggplot -------
bird_bav %>%
  mutate(`Großer Brachvogel` = replace_na(`Großer Brachvogel`, 0)) %>% # which dataset to use
  ggplot() +              # start plotting
  # type of plot, define x and y axis, define color as factor of Numenius arquata absence or presence, set shape and size
  geom_point(aes(x=QMP_R_GK, y=QMP_H_GK, color=as.factor(`Großer Brachvogel`)), shape=15, size=2) + 
  scale_color_manual(name="Presence", values=c("grey80", "blue"), na.value = "transparent") +   # define colors
  coord_equal() + theme_bw() + labs(x="", y="") +  # set x/y to equal, use custom map-theme
  ggtitle("Numenius arquata current range")+ # set plot title
  theme(legend.position = "right")                   # remove legend for the color

# plot environmental variables

#define two colour scales for annual mean temperature and annual precipitation
tempcol <- scale_fill_scico(name = "°C", palette="roma", direction=-1,
                                limits = c(min(curenv$bio1),max(cordex_bioclim_bav_tk4tel$bio1)))
preccol <- scale_fill_scico(name = "mm", palette="roma",
                                limits = c(min(curenv$bio12),max(cordex_bioclim_bav_tk4tel$bio12)))

curenv %>% # which dataset to use
  ggplot() + # start plotting
  # type of plot, define x and y axis, define fill the environmental variable
  geom_tile(aes(x=x, y=y, fill=bio1)) + 
  scale_fill_scico(name="°C", palette="roma", direction=-1) +
  coord_sf() + theme_bw() + labs(x="", y="") + # set x/y to equal, use custom map-theme
  ggtitle("Annual Mean Temperature") + # set plot title
  theme(legend.text = element_text(size=10)) # set font size for the legend

#different colour scales (see above):

#bio1: annual mean temperature

curenv %>% ggplot() + geom_tile(aes(x=x, y=y, fill=bio1)) + 
  tempcol + coord_sf() + theme_bw() + labs(x="", y="") + 
  ggtitle("Annual Mean Temperature") + 
  theme(legend.position = "right",
        panel.background = element_rect(fill="transparent"),
        plot.background = element_rect(fill="transparent"))

#bio12: annual precipitation

curenv %>% ggplot() + geom_tile(aes(x=x, y=y, fill=bio12)) + 
  preccol + coord_sf() + theme_bw() + labs(x="", y="") + 
  ggtitle("Annual Precipitation") + 
  theme(legend.position = "right",
        panel.background = element_rect(fill="transparent"),
        plot.background = element_rect(fill="transparent"))

#bio1

futclim %>% filter(time_frame == "2071-2100", rcp == "rcp26") %>% 
  ggplot() + geom_tile(aes(x=x, y=y, fill=bio1)) + 
  tempcol + coord_sf() + theme_bw() + labs(x="", y="") +  
  ggtitle("Annual Mean Temperature RCP2.6, 2055") + 
  theme(legend.position = "none",
        panel.background = element_rect(fill="transparent"),
        plot.background = element_rect(fill="transparent"))

#bio12

futclim %>% filter(time_frame == "2071-2100", rcp == "rcp26") %>% 
  ggplot() + geom_tile(aes(x=x, y=y, fill=bio12)) + 
  preccol + coord_sf() + theme_bw() + labs(x="", y="") + 
  ggtitle("Annual Precipitation RCP2.6, 2055") + 
  theme(legend.position = "none",
        panel.background = element_rect(fill="transparent"),
        plot.background = element_rect(fill="transparent"))

Model calibration

# Convert data into a SpatialPointsDataFrame
bird_bav <- bird_bav %>% dplyr::select(QMP_R_GK, QMP_H_GK, `Großer Brachvogel`) %>% 
  drop_na(QMP_R_GK, QMP_H_GK)
summary(bird_bav)
sp::coordinates(bird_bav) <- ~QMP_R_GK+QMP_H_GK # set coordinates
raster::projection(bird_bav) <- sp::CRS("+init=epsg:31468") # set projection
curenv_r <- terra::rast(curenv, type="xyz",crs="+init=epsg:31468")
bird_r <- terra::rasterize(terra::vect(sf::st_as_sf(bird_bav)), curenv_r[[1]])
names(bird_r) <- "Großer_Brachvogel"

spec_clim <- terra::rast(list(bird_r, curenv_r)) %>% as.data.frame(xy=T, na.rm=F) %>% 
  dplyr::select(c(x,y, Großer_Brachvogel, bio1, bio12)) %>%
  mutate(Großer_Brachvogel = replace_na(Großer_Brachvogel,0)) %>% drop_na()

# 2 explanatory variables:
myExpl2 <- c("bio1", "bio12")

# Automatically create model formula from variables
(formExpl2 <- as.formula(paste("Großer_Brachvogel ~ ", 
                               paste(myExpl2, collapse="+"),sep = "")))

# Fit Generalized Linear Model (GLM) in the simplest form
glm_2 <- glm(formExpl2, family='binomial', data=spec_clim)

# You would need to specify polynomials and interactions manually in the formula:

# Fit Generalized Linear Model (GLM) in a bit more complex form (with polynomials)
glm_2_Pol <- glm(Großer_Brachvogel ~ bio1 + I(bio1^2) + bio12 + I(bio12^2), 
                        family='binomial', data=spec_clim)

# Fit Generalized Linear Model (GLM) in an even more complex form (with polynomials and interactions)
glm_2_PolInt <- glm(Großer_Brachvogel ~ bio1 + I(bio1^2) + bio12 + I(bio12^2) + 
                             bio1*bio12, family='binomial', data=spec_clim)

# check model summary ----
(sum_glm_2 <- summary(glm_2))
(sum_glm_2_PolInt <- summary(glm_2_PolInt))
(sum_glm_2_Pol <- summary(glm_2_Pol))

#par(mfrow=c(1,1))
#plot(glm_2)

Model evaluation

# basic plots of occurrence vs. explanatory variable
par(mfrow=c(1,2))
plot(spec_clim$bio1, spec_clim$Großer_Brachvogel, ylab="", xlab="bio1")
plot(spec_clim$bio12, spec_clim$Großer_Brachvogel, ylab="", xlab="bio12")

# check partial response curves
par(mfrow=c(3,2))
partial_response(glm_2, predictors = spec_clim[,myExpl2])
partial_response(glm_2_Pol, predictors = spec_clim[,myExpl2]) 
partial_response(glm_2_PolInt, predictors = spec_clim[,myExpl2])

#' This is needed for getting TSS, AUC and Kappa values

# Make cross-validated predictions for GLM:
crosspred_glm_2 <- crossvalSDM(glm_2, kfold=5, 
                                      traindat= spec_clim, colname_pred=myExpl2, 
                                      colname_species = "Großer_Brachvogel")
crosspred_glm_2_Pol <- crossvalSDM(glm_2_Pol, kfold=5, 
                                          traindat= spec_clim, colname_pred=myExpl2, 
                                          colname_species = "Großer_Brachvogel")

# Assess cross-validated model performance
(eval_glm_2 <- evalSDM(observation = spec_clim$Großer_Brachvogel, 
                              predictions = crosspred_glm_2))
(eval_glm_2_Pol <- evalSDM(observation = spec_clim$Großer_Brachvogel, 
                                  predictions = crosspred_glm_2_Pol))

# check variable importances
par(mfrow=c(1,1))
(glm_imp <- caret::varImp(glm_2, scale=T))
barplot((glm_imp$Overall/sum(glm_imp$Overall)*100)[2:1], 
        names.arg=rownames(glm_imp)[2:1], horiz=T,
        main="GLM", xlab="Relative influence")

Projections

#' ### CURRENT CLIMATE

# Make predictions to current climate:
spec_clim$pred_glm_2 <- predictSDM(glm_2, spec_clim)

# Make binary/threshholded predictions:
spec_clim$bin_glm_2 <- ifelse(spec_clim$pred_glm_2 > eval_glm_2$thresh, 1, 0)

par(mfrow=c(1,1), mar=c(5,5,4,1))
boxplot(spec_clim$pred_glm_2 ~ spec_clim$Großer_Brachvogel, las=1, 
        xlab="Aktuelle Verbreitung", ylab="Vorkommenswahrscheinlichkeit", cex.lab=2,
        col="dodgerblue4", cex.axis=1.5, main="GLM-Modell mit 2 Klimavariablen", cex.main=2)

#---------------------------------------------------
#' ## plot species using ggplot 
#---------------------------------------------------

# plot histogramm

spec_clim %>% ggplot() + geom_histogram(aes(x=pred_glm_2), col="grey0", alpha=0.2) +
  labs(y="Number of grid cells", x="Occurrence probability",
       title="Distribution of Großer_Brachvogel") + 
  geom_hline(yintercept = 0, linetype="dashed", color="darkgrey") + theme_classic()

# plot maps

# probability map
(plot_curclim_GLM <- spec_clim %>% ggplot() + 
    geom_tile(aes(x=x, y=y, fill=pred_glm_2)) + 
    scale_fill_scico(name="Probability of occurrence", palette="roma", direction=-1)  +  
    coord_sf() + theme_bw() + labs(x="", y="") + 
    ggtitle("GLM current climate") + 
    theme(legend.text = element_text(size=10)))

# binary map
(plot_curclim_GLM_bin <- 
    spec_clim %>%
    ggplot() + geom_tile(aes(x=x, y=y, fill=as.factor(bin_glm_2))) + 
    scale_fill_manual(name="Occurrence", values=c("grey80", "blue")) + 
    coord_sf() + theme_bw() + ggtitle("GLM current climate") + 
    theme(legend.text = element_text(size=10)))
#---------------------------------------------------
# FUTURE CLIMATE ----
#---------------------------------------------------

# Assess novel environments in future climate layer:

# Values of 1 in the eo.mask will indicate novel environmental conditions
futclim$eo_mask <- eo_mask(spec_clim[,myExpl2], futclim[,myExpl2])
futclim %>% # which dataset to use
  ggplot() +              # start plotting
  # type of plot, define x axis, y axis is automatically a count, define color and transparency
  geom_tile(aes(x=x, y=y, fill=as.factor(eo_mask))) +
  scale_fill_manual(name="", values=c("grey80", "blue")) + 
  coord_sf() + theme_bw() + labs(x="", y="") +        # set x/y to equal, use custom map-theme
  ggtitle("Environmental novelty") +       # set plot title
  theme(legend.text = element_text(size=10)) # set font size for the legend

# Make predictions to futclim
futclim$pred_glm_2 <- predictSDM(glm_2, futclim)

# Make binary/threshholded predictions:
futclim$bin_glm_2 <- ifelse(futclim$pred_glm_2 > eval_glm_2$thresh, 1, 0)

# => using this framework you can proceed with other future climate data

#---------------------------------------------------
# plot species using ggplot 
#---------------------------------------------------

# plot histogramm
futclim %>% # which dataset to use
  ggplot() +              # start plotting
  # type of plot, define x axis, y axis is automatically a count, define color and transparency
  geom_histogram(aes(x=pred_glm_2), col="grey0", alpha=0.2) +
  labs(y="Number of grid cells", x="Occurrence probability",        # add axis labels
       title="Distribution of Großer_Brachvogel under CC2670 GLM") +      # add axis labels
  geom_hline(yintercept = 0, linetype="dashed", color="darkgrey") + # add a horizontal line
  theme_classic()

# plot maps

# probability map
(plot_CC6070_GLM <- 
    futclim %>% # which dataset to use
    ggplot() +  geom_tile(aes(x=x, y=y, fill=pred_glm_2)) + 
    scale_fill_scico(name="Probability of\noccurrence", palette = "roma", direction=-1) +
    coord_sf() + theme_bw() + labs(x="", y="") + 
    ggtitle("GLM CC6070") +       # set plot title
    theme(legend.text = element_text(size=10))) # set font size for the legend

# binary map
(plot_CC6070_GLM_bin <- 
    futclim %>% # which dataset to use
    ggplot() +                 # start plotting
    # type of plot, define x and y axis, define color by probability of occurrence, set shape and size
    geom_tile(aes(x=x, y=y, fill=as.factor(bin_glm_2))) + 
    scale_fill_manual(name="Occurrence", values=c("grey80", "blue")) + 
    coord_sf() + theme_bw() + labs(x="", y="") + 
    ggtitle("GLM CC6070") +       # set plot title
    theme(legend.text = element_text(size=10))) # set font size for the legend