https://cdnsciencepub.com/doi/10.1139/anc-2017-0001
This script generates the condition of saltmarsh. Based on the following references, global saltmarsh has decreased by 25-50% from historical extent (no idea of the timeframe this refers to) and there is an estimated 1-2% decrease every year. Given this, we will apply a condition of 0.75 globally (using the more conservative 25% decline estimate).
No code or data updates in 2023, copied over from v2021.
Mcowen, C., Weatherdon, L., Bochove, J.-W., Sullivan, E., Blyth, S., Zockler, C., Stanwell-Smith, D., Kingston, N., Martin, C., Spalding, M., Fletcher, S., 2017. A global map of saltmarshes. BDJ 5, e11764. https://doi.org/10.3897/BDJ.5.e11764
Downloaded: October 5, 2021
Description: “Despite their importance, saltmarsh areas are declining around the world, having lost between 25% and 50% of their global historical coverage (Crooks et al. 2011, Duarte et al. 2008).”
Time range: NA
Apply a global value to each region.. not satisfying.
## read in extent data
<- read.csv(file.path(here("globalprep/hab_saltmarsh/v2021/data/habitat_extent_saltmarsh_updated.csv")))
all
# specify trend
<- all %>%
all filter(km2 > 0) %>%
filter(rgn_id < 255) %>%
::select(-year) %>%
dplyrmutate(health = 0.75)
# Save gapfilling
<- all %>%
health_gaps mutate(variable = "health") %>%
mutate(habitat = "saltmarsh") %>%
mutate(gapfill = 1) %>%
::select(-km2)
dplyrwrite.csv(health_gaps, here('globalprep/hab_saltmarsh/v2021/data/health_saltmarsh_gf.csv'), row.names=FALSE)
### save trend data:
<- trend_gaps %>%
health ::select(rgn_id, habitat, health) %>%
dplyrmutate(year = 2021)
write.csv(health, here('globalprep/hab_saltmarsh/v2021/data/habitat_health_saltmarsh_updated.csv'), row.names=FALSE)