OHI Science | Citation policy
This script generates the trend of saltmarsh.
“The global loss rate of threatened coastal ecosystems is estimated at 4–9% year−1 for corals (Gardner et al. 2003, Bellwood et al. 2004), a minimum of 1–2% year−1 for saltmarshes (Adam 2002; Lotze et al. 2006)” https://link.springer.com/article/10.1007%2Fs12237-008-9038-7
Apply a decreasing rate of 2% per year, or -0.015 over five years to each region.
Duarte, C.M., Dennison, W.C., Orth, R.J.W., Carruthers, T.J.B., 2008. The Charisma of Coastal Ecosystems: Addressing the Imbalance. Estuaries and Coasts: J CERF 31, 233–238. https://doi.org/10.1007/s12237-008-9038-7
Downloaded: October 5, 2021
Description: Estimate of a global percentage of loss of saltmarsh habitat per year.
Time range: NA
## read in extent data
all <- read.csv(file.path(here("globalprep/hab_saltmarsh/v2021/data/habitat_extent_saltmarsh_updated.csv")))
# specify trend
all <- all %>%
filter(km2 > 0) %>%
filter(rgn_id < 255) %>%
dplyr::select(-year) %>%
mutate(trend = -0.015)
# Save gapfilling
trend_gaps <- all %>%
mutate(variable = "trend") %>%
mutate(habitat = "saltmarsh") %>%
mutate(gapfill = 1)
write.csv(trend_gaps, here('globalprep/hab_saltmarsh/v2021/data/trend_saltmarsh_gf.csv'), row.names=FALSE)
### save trend data:
trend <- trend_gaps %>%
dplyr::select(rgn_id, habitat, trend) %>%
mutate(year = 2021)
write.csv(trend, here('globalprep/hab_saltmarsh/v2021/data/habitat_trend_saltmarsh_updated.csv'), row.names=FALSE)