Hello,
sure, the core idea behind of these bioclimatic variables is very simple:
bio6: apply(X = minimum.temperature.data.frame, MARGIN = 1, FUN = min)
bio13: apply(X = precipitation.data.frame, MARGIN = 1, FUN = max)
bio15: apply(X = precipitation.data.frame, MARGIN = 1, FUN =
\(precipitations) return(sd(precipitations) / mean(precipitations)))
Of course, in the case of 8-days-resolution dataset, these functions
calculate the minimum temperature of the 8-days periods, the
precipitation of the wettest 8-days period, and the seasonality of the
8-days periods. If you need months, then firstly you should aggregate
your 8-days-resolution dataset to monthly resolution.
Also note that there are discrepancies between the definition/mane of
bio6 ("minimum temperature of the coldest month", i.e., of the month
that has the lowest monthly MEAN temperature) and the way it is usually
calculated ("minimum of the monthly MINIMUM temperatures"). The two
might differ.
This script might give you further help/ideas in this topic:
https://github.com/bfakos/bioclimatic_variables/blob/main/calculate_BCVs.r
Hope this helps,
Ákos
_____________
Ákos Bede-Fazekas
Centre for Ecological Research, Hungary
2024. 05. 09. 7:22 keltezéssel, Helen írta:
I am running a MaxEnt model and we would like to see the seasonal pattern of the
habitat suitability. Instead of doing the regular BIOVARS (R package) that
calculate the annual bio-climate variables, we want to apply the similar concept
and get the bio climate variable for just a season of 3-4 months. We are looking
into BIO 6, BIO 13, and BIO 15 soecifically. However, the package biovars only take
12 layers (for the annual calculation). My understanding is that we can also
interpret it for however long of period we would like (eg, 12 weeks and change the
interpretation to 12 weeks of period instead of the annual definition in the
example of R documentation). The only limitation is that the function needs to take
12 inputs. Is there a way to work around this to calculate the same variables but
only for 3 or 4 months of period? All the temperature and precipitation variables
are taken from remote sensing data that comes in different frequency (monthly &
8 days). Thank you !
_______________________________________________
R-sig-ecology mailing list
R-sig-ecology@r-project.org
https://stat.ethz.ch/mailman/listinfo/r-sig-ecology
_______________________________________________
R-sig-ecology mailing list
R-sig-ecology@r-project.org
https://stat.ethz.ch/mailman/listinfo/r-sig-ecology
