Allometric parameters and species functional traits for Paracou and Tapajos were used both as input to the TROLL assessment and as output to assess the functional composition of the forest. Many allometric parameters and functional traits did not exist and were inferred from dbh and height data or by using the relationship between traits with a predictive mean match.
Allometric parameters
We took advantage of the TALLO database (Jucker et al. 2022) to infer species allometric parameters of the 496 species present in Amazonia (latitude between 10 and -18 and longitude between -78 and -39).
Code
ggplot(map_data("world"), aes(x = long, y = lat)) +geom_polygon(aes(group = group), fill="lightgray", colour ="white") +geom_point(data =read_csv("data/species/tallo.csv") %>%mutate(amazonia =ifelse(longitude <=-39& longitude >=-79& latitude >=-18& latitude <=10, "amazonia", "other")),aes(x = longitude, y = latitude, col = amazonia)) +theme_bw() +geom_hline(yintercept =c(10, -18)) +geom_vline(xintercept =c(-39, -79)) +theme(axis.title =element_blank(), legend.position ="bottom") +scale_color_manual("", values =c("darkgreen", "black")) +coord_equal()
Posterior post-predictive check of simulated response variable against observed values indicating a good representation of the whole distribution in posteriors.
We thus inferred 496 additional \(a_h\), \(h_{max}\) couple of parameters.
All databases together included 20 traits across 2,921 species but with numerous missing data. Traits distribution were similar across datasets. However, for the same species, allometric parameters inferred from TALLO were lower than those inside TROLL V4 and leaf area from Guillemot was higher than those from TROLL and Vleminckx. As all Paracou TROLL species are in Vleminckx dataset and 109 species from Tapajos we will use only the species from Vleminckx to limit missing data in predictive mean matching (PMM) data imputation.
Missing data were too important to use random forest for imputation with missForest even with phylogenetic eigen values. Thus, we used simple predictive mean matching (PMM) data imputation with mice without phylogenetic eigen values. However, phylogenetic eigen values could also been used with phylomice (not done here). As we focused on species in common with Vlemincks data we only had to impute ah, dbhmax, hmax and TLP with values from Maréchaux, Tapajos and inferred with TALLO. Obtained imputed distributions matched well the observed distribution of the raw data and imputed functional space match the one of the raw data (PCA). The PCA also revealed similar functional spaces between species from Paracou and Tapajos, whereas Tapajos functional space is a bit wider.
Forest functional composition was simply assessed using functional trait distribution in each plots (repeted lines in Paracou data) at the species level in Paracou and genus level in Tapajos.
Functional composition at the Paracou site expressed in terms of density distribution per trait. The analyses have been done at the species level in Paracou.
Code
read_tsv("outputs/functional_composition.tsv") %>%filter(site =="Tapajos") %>%ggplot(aes(trait_value, group = plot)) +geom_density() +facet_wrap(~ trait, scales ="free") +theme_bw() +ggtitle("Tapajos Genus level", "19,188 inds represented on 19,499 (98.65%)") +theme(axis.title =element_blank(), legend.position ="bottom") +scale_color_discrete("")
Functional composition at the Tapajos site expressed in terms of density distribution per trait. The analyses have been done at the genus level in Tapajos.
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