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Calculate biomass with allometric equations from the allodb package and ForestGEO data

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Calculate biomass

lifecycle Travis build status Coverage status CRAN status

The goal of fgeo.biomass is to calculate biomass using ForestGEO data and equations from either the BIOMASS package or the allodb package.

  • The BIOMASS package is applicable to tropical forests. It was first published on CRAN in 2016 and on Methods on Ecology and Evolution in 2017. fgeo.biomass provides the main features of BIOMASS with a simpler interface, consistent with all fgeo packages.

  • The allodb package is work in progress, and aims to provide expert-selected allometric equations, both for tropical and temperate forests. fgeo.biomass provides a simple interface to automate the process of finding the right equation(s) for each stem and computing biomass.

Installation

Install the development version of fgeo.biomass with:

# install.packages("devtools")
devtools::install_github("forestgeo/fgeo.biomass")

Setup

In addition to the fgeo.biomass package we will use dplyr and ggplot2 for data wrangling and plotting.

library(ggplot2)
library(dplyr)
library(fgeo.biomass)

fgeo.biomass wrapping BIOMASS

We’ll use data from the Barro Colorado Island, Panama (BCI). We first pick alive trees and drop missing dbh values as we can’t calculate biomass for them.

bci_tree <- as_tibble(bciex::bci12t7mini) %>% 
  filter(status == "A", !is.na(dbh))
bci_tree
#> # A tibble: 538 x 20
#>    treeID stemID tag   StemTag sp    quadrat    gx    gy MeasureID CensusID
#>     <int>  <int> <chr> <chr>   <chr> <chr>   <dbl> <dbl>     <int>    <int>
#>  1    858      1 0008~ ""      apei~ 4402     899.  42         766      171
#>  2   1129      1 0011~ ""      quar~ 4308     867. 163.        995      171
#>  3   2143      1 0021~ ""      beil~ 3715     744  305.       1829      171
#>  4   2388     10 0023~ 1       lueh~ 3622     724. 447.       2007      171
#>  5   4448      1 0044~ ""      sima~ 2321     477. 428.       3741      171
#>  6   5877      1 0059~ ""      quar~ 1303     280.  70.4      4800      171
#>  7   6487      1 0065~ ""      alse~ 1108     221. 178.       5226      171
#>  8   8651      1 0105~ ""      hyba~ 4811     974. 228.       6832      171
#>  9   9480      1 0114~ ""      fara~ 4814     977. 290        7373      171
#> 10  10179     11 0121~ <NA>    hyba~ 4819     979. 395.       7898      171
#> # ... with 528 more rows, and 10 more variables: dbh <dbl>, pom <chr>,
#> #   hom <dbl>, ExactDate <chr>, DFstatus <chr>, codes <chr>,
#> #   nostems <dbl>, date <dbl>, status <chr>, agb <dbl>

We also need species data.

bci_species <- as_tibble(bciex::bci_species)
bci_species
#> # A tibble: 1,414 x 13
#>    sp    Latin Genus Species Family SpeciesID SubspeciesID Authority
#>    <chr> <chr> <chr> <chr>   <chr>      <int>        <int> <chr>    
#>  1 call~ Call~ Call~ laxa    Fabac~       131            1 (Benth.)~
#>  2 pout~ Pout~ Pout~ glomer~ Sapot~       811            2 (Miq.) R~
#>  3 pout~ Pout~ Pout~ glomer~ Sapot~       811            3 (Miq.) R~
#>  4 prot~ Prot~ Prot~ tenuif~ Burse~       828            4 (I.M. Jo~
#>  5 soro~ Soro~ Soro~ pubive~ Morac~       959            5 Hensl.   
#>  6 soro~ Soro~ Soro~ pubive~ Morac~       959            6 Hensl.   
#>  7 swar~ Swar~ Swar~ simplex Fabac~       980            7 (Raddi) ~
#>  8 hibi~ Tali~ Tali~ tiliac~ Malva~       997            9 (Arruda)~
#>  9 quar~ Quar~ Quar~ astero~ Malva~       871           10 (Pittier~
#> 10 inga~ Inga~ Inga  ciliata Fabac~      1278           11 T.D.Penn.
#> # ... with 1,404 more rows, and 5 more variables: IDLevel <chr>,
#> #   syn <chr>, subsp <chr>, wsg <dbl>, wsglevel <chr>

add_tropical_biomass() adds biomass to your census data.

biomass <- add_tropical_biomass(bci_tree, bci_species)
#> <U+2714> Guessing dbh in [mm].
#> i You may provide the dbh unit manually via the argument`dbh_unit`.
#> i Wood density given in [g/cm^3].
#> <U+2714> Using 'Pantropical' `region`.
#> i Biomass is given in [kg].
#> <U+2714> Adding new columns:
#>   family, genus, species, wd_level, wd_mean, wd_sd, biomass
biomass
#> # A tibble: 538 x 27
#>    treeID stemID tag   StemTag sp    quadrat    gx    gy MeasureID CensusID
#>     <int>  <int> <chr> <chr>   <chr> <chr>   <dbl> <dbl>     <int>    <int>
#>  1    858      1 0008~ ""      apei~ 4402     899.  42         766      171
#>  2   1129      1 0011~ ""      quar~ 4308     867. 163.        995      171
#>  3   2143      1 0021~ ""      beil~ 3715     744  305.       1829      171
#>  4   2388     10 0023~ 1       lueh~ 3622     724. 447.       2007      171
#>  5   4448      1 0044~ ""      sima~ 2321     477. 428.       3741      171
#>  6   5877      1 0059~ ""      quar~ 1303     280.  70.4      4800      171
#>  7   6487      1 0065~ ""      alse~ 1108     221. 178.       5226      171
#>  8   8651      1 0105~ ""      hyba~ 4811     974. 228.       6832      171
#>  9   9480      1 0114~ ""      fara~ 4814     977. 290        7373      171
#> 10  10179     11 0121~ <NA>    hyba~ 4819     979. 395.       7898      171
#> # ... with 528 more rows, and 17 more variables: dbh <dbl>, pom <chr>,
#> #   hom <dbl>, ExactDate <chr>, DFstatus <chr>, codes <chr>,
#> #   nostems <dbl>, date <dbl>, status <chr>, agb <dbl>, family <chr>,
#> #   genus <chr>, species <chr>, wd_level <chr>, wd_mean <dbl>,
#> #   wd_sd <dbl>, biomass <dbl>

You may also provide a specific region or latitude and longitude.

biomass <- add_tropical_biomass(
  bci_tree, 
  bci_species,
  latitude = 9.154965, 
  longitude = -79.845884
)
#> <U+2714> Guessing dbh in [mm].
#> i You may provide the dbh unit manually via the argument`dbh_unit`.
#> i Wood density given in [g/cm^3].
#> <U+2714> Using `latitude` and `longitude` (ignoring `region`).
#> i Biomass is given in [kg].
#> <U+2714> Adding new columns:
#>   family, genus, species, wd_level, wd_mean, wd_sd, latitude, longitude, biomass

biomass %>% 
  select(biomass, everything())
#> # A tibble: 538 x 29
#>    biomass treeID stemID tag   StemTag sp    quadrat    gx    gy MeasureID
#>      <dbl>  <int>  <int> <chr> <chr>   <chr> <chr>   <dbl> <dbl>     <int>
#>  1 2397.      858      1 0008~ ""      apei~ 4402     899.  42         766
#>  2 1884.     1129      1 0011~ ""      quar~ 4308     867. 163.        995
#>  3  264.     2143      1 0021~ ""      beil~ 3715     744  305.       1829
#>  4  911.     2388     10 0023~ 1       lueh~ 3622     724. 447.       2007
#>  5  961.     4448      1 0044~ ""      sima~ 2321     477. 428.       3741
#>  6 2473.     5877      1 0059~ ""      quar~ 1303     280.  70.4      4800
#>  7  570.     6487      1 0065~ ""      alse~ 1108     221. 178.       5226
#>  8    2.12   8651      1 0105~ ""      hyba~ 4811     974. 228.       6832
#>  9   16.0    9480      1 0114~ ""      fara~ 4814     977. 290        7373
#> 10    2.49  10179     11 0121~ <NA>    hyba~ 4819     979. 395.       7898
#> # ... with 528 more rows, and 19 more variables: CensusID <int>,
#> #   dbh <dbl>, pom <chr>, hom <dbl>, ExactDate <chr>, DFstatus <chr>,
#> #   codes <chr>, nostems <dbl>, date <dbl>, status <chr>, agb <dbl>,
#> #   family <chr>, genus <chr>, species <chr>, wd_level <chr>,
#> #   wd_mean <dbl>, wd_sd <dbl>, latitude <dbl>, longitude <dbl>

propagate_errors() allows you to propagate errors.

str(
  propagate_errors(biomass)
)
#> List of 5
#>  $ meanAGB       : num 20.9
#>  $ medAGB        : num 20.6
#>  $ sdAGB         : num 2.32
#>  $ credibilityAGB: Named num [1:2] 16.8 26.2
#>   ..- attr(*, "names")= chr [1:2] "2.5%" "97.5%"
#>  $ AGB_simu      : num [1:538, 1:1000] 1.49 1.907 0.219 1.487 1.125 ...
#>   ..- attr(*, "dimnames")=List of 2
#>   .. ..$ : NULL
#>   .. ..$ : chr [1:1000] "203" "817" "977" "933" ...

model_height() allows you to create a height model, which you can use to propagate height errors. This is what the entire pipeline looks like:

model <- model_height(bci_tree)
#> i Using `method` log1 (other methods: log2, weibull, michaelis).

errors <- bci_tree %>% 
  add_tropical_biomass(bci_species) %>% 
  propagate_errors(height_model = model)
#> <U+2714> Guessing dbh in [mm].
#> i You may provide the dbh unit manually via the argument`dbh_unit`.
#> i Wood density given in [g/cm^3].
#> <U+2714> Using 'Pantropical' `region`.
#> i Biomass is given in [kg].
#> <U+2714> Adding new columns:
#>   family, genus, species, wd_level, wd_mean, wd_sd, biomass
#> <U+2714> Propagating errors on measurements of wood density.
#> <U+2714> Propagating errors on measurements of height.

str(errors)
#> List of 5
#>  $ meanAGB       : num 21.6
#>  $ medAGB        : num 21.4
#>  $ sdAGB         : num 2.09
#>  $ credibilityAGB: Named num [1:2] 18.1 26.2
#>   ..- attr(*, "names")= chr [1:2] "2.5%" "97.5%"
#>  $ AGB_simu      : num [1:538, 1:1000] 2.506 0.881 0.376 1.277 1.019 ...

If you pass latitude and longitude to add_tropical_biomass(), and then you pass aheight_modeltopropagate_errors()`, then you will need to ignore the coordinates. On an interactive session, you should see something like this:

if (interactive()) {
  errors <- bci_tree %>% 
    add_tropical_biomass(
      bci_species, 
      latitude = 9.154965, 
      longitude = -79.845884
    ) %>% 
    propagate_errors(height_model = model)
  
  str(errors)
}

add_wood_density() adds wood density to your census data. It is not limited to tropical forests, and has support for all of these regions: AfricaExtraTrop, AfricaTrop, Australia, AustraliaTrop, CentralAmericaTrop, China, Europe, India, Madagascar, Mexico, NorthAmerica, Oceania, SouthEastAsia, SouthEastAsiaTrop, SouthAmericaExtraTrop, SouthAmericaTrop, and World.

wood_density <- add_wood_density(bci_tree, bci_species)
#> i Wood density given in [g/cm^3].

wood_density %>% 
  select(starts_with("wd_"), everything())
#> # A tibble: 538 x 26
#>    wd_level wd_mean  wd_sd treeID stemID tag   StemTag sp    quadrat    gx
#>    <chr>      <dbl>  <dbl>  <int>  <int> <chr> <chr>   <chr> <chr>   <dbl>
#>  1 genus      0.255 0.0941    858      1 0008~ ""      apei~ 4402     899.
#>  2 species    0.454 0.0708   1129      1 0011~ ""      quar~ 4308     867.
#>  3 genus      0.563 0.0941   2143      1 0021~ ""      beil~ 3715     744 
#>  4 species    0.417 0.0708   2388     10 0023~ 1       lueh~ 3622     724.
#>  5 species    0.383 0.0708   4448      1 0044~ ""      sima~ 2321     477.
#>  6 species    0.454 0.0708   5877      1 0059~ ""      quar~ 1303     280.
#>  7 species    0.536 0.0708   6487      1 0065~ ""      alse~ 1108     221.
#>  8 species    0.67  0.0708   8651      1 0105~ ""      hyba~ 4811     974.
#>  9 species    0.584 0.0708   9480      1 0114~ ""      fara~ 4814     977.
#> 10 species    0.67  0.0708  10179     11 0121~ <NA>    hyba~ 4819     979.
#> # ... with 528 more rows, and 16 more variables: gy <dbl>,
#> #   MeasureID <int>, CensusID <int>, dbh <dbl>, pom <chr>, hom <dbl>,
#> #   ExactDate <chr>, DFstatus <chr>, codes <chr>, nostems <dbl>,
#> #   date <dbl>, status <chr>, agb <dbl>, family <chr>, genus <chr>,
#> #   species <chr>

The BIOMASS package provides a tool to correct taxonomic names. fgeo.biomass does not include that feature. You may use BIOMASS directly or the more focused taxize package.

fgeo.biomass wrapping allodb

Warning

These features are not ready for research. We are now building a Minimum Viable Product, with just enough features to collect feedback from alpha users and redirect our effort. The resulting biomass is still meaningless.

We’ll use the add_biomass() with these inputs:

  1. A ForestGEO-like stem or tree table.
  2. A species table (internally used to look up the Latin species names from the species codes in the sp column of the census table).

We’ll use data from the Smithsonian Conservation Biology Institute, USA (SCBI). We first pick alive trees and drop missing dbh values as we can’t calculate biomass for them.

census <- fgeo.biomass::scbi_tree1 %>% 
  filter(status == "A", !is.na(dbh))

census
#> # A tibble: 30,050 x 20
#>    treeID stemID tag   StemTag sp    quadrat    gx    gy DBHID CensusID
#>     <int>  <int> <chr> <chr>   <chr> <chr>   <dbl> <dbl> <int>    <int>
#>  1      1      1 10079 1       libe  0104     3.70  73       1        1
#>  2      2      2 10168 1       libe  0103    17.3   58.9     3        1
#>  3      3      3 10567 1       libe  0110     9    197.      5        1
#>  4      4      4 12165 1       nysy  0122    14.2  428.      7        1
#>  5      5      5 12190 1       havi  0122     9.40 436.      9        1
#>  6      6      6 12192 1       havi  0122     1.30 434      13        1
#>  7      8      8 12261 1       libe  0125    18    484.     17        1
#>  8      9      9 12456 1       vipr  0130    18    598.     19        1
#>  9     10     10 12551 1       astr  0132     5.60 628.     22        1
#> 10     11     11 12608 1       astr  0132    13.3  623.     24        1
#> # ... with 30,040 more rows, and 10 more variables: dbh <dbl>, pom <chr>,
#> #   hom <dbl>, ExactDate <chr>, DFstatus <chr>, codes <chr>,
#> #   nostems <dbl>, date <dbl>, status <chr>, agb <dbl>

We now use add_biomass() to add biomass to our census dataset.

species <- fgeo.biomass::scbi_species

with_biomass <- census %>% 
  add_biomass(species, site = "SCBI")
#> <U+2714> Guessing dbh in [mm].
#> i You may provide the dbh unit manually via the argument`dbh_unit`.
#> i biomass values are given in [kg].
#> <U+2714> Guessing dbh in [mm].
#> i You may provide the dbh unit manually via the argument`dbh_unit`.
#> <U+2714> Matching equations by site and species.
#> <U+2714> Refining equations according to dbh.
#> <U+2714> Using generic equations where expert equations can't be found.
#> Warning:   Can't find equations matching these species:
#>   acer sp, carya sp, crataegus sp, fraxinus sp, quercus sp, ulmus sp, unidentified unk
#> Warning: Can't find equations for 15028 rows (inserting `NA`).
#> Warning: Detected a single stem per tree. Do you need a multi-stem table?
#> Warning: * For trees, `biomass` is that of the main stem.
#> Warning: * For shrubs, `biomass` is that of the entire shrub.
#> <U+2714> Adding new columns:
#>   rowid, species, site, biomass

We are warned that we are using a tree-table (as opposed to a stem-table), and informed about how to interpret the resulting biomass values for trees and shrubs.

Some equations couldn’t be found. There may be two reasons:

  • Some stems in the data belong to species with no matching species in allodb.
  • Some stems in the data belong to species that do match species in allodb but the available equations were designed for a dbh range that doesn’t include actual dbh values in the data.

Here are the most interesting columns of the result:

with_biomass %>% 
  select(treeID, species, biomass)
#> # A tibble: 30,050 x 3
#>    treeID species              biomass
#>     <int> <chr>                  <dbl>
#>  1      1 lindera benzoin       NA    
#>  2      2 lindera benzoin       NA    
#>  3      3 lindera benzoin       NA    
#>  4      4 nyssa sylvatica       58.5  
#>  5      5 hamamelis virginiana  17.6  
#>  6      6 hamamelis virginiana   0.400
#>  7      8 lindera benzoin        5.69 
#>  8      9 viburnum prunifolium  NA    
#>  9     10 asimina triloba       NA    
#> 10     11 asimina triloba       NA    
#> # ... with 30,040 more rows

Let’s now visualize the relationship between dbh and bbiomass by species (black points), in comparison with agb (above ground biomass) values calculated with allometric equations for tropical trees (grey points).

with_biomass %>% 
  # Convert agb from [Mg] to [kg]
  mutate(agb_kg = agb * 1e3) %>% 
  ggplot(aes(x = dbh)) +
  geom_point(aes(y = agb_kg), size = 1.5, color = "grey") +
  geom_point(aes(y = biomass), size = 1, color = "black") +
  facet_wrap("species", ncol = 4) +
  ylab("Reference `agb` (grey) and calculated `biomass` (black) in [kg]") +
  xlab("dbh [mm]") +
  theme_bw()
#> Warning: Removed 15028 rows containing missing values (geom_point).

Above, the species for which biomass couldn’t be calculated show no black points, although they do show grey reference-points.

To better understand the distribution of biomass values for each species we can use a box-plot.

with_biomass %>% 
  ggplot(aes(species, biomass)) +
  geom_boxplot() +
  ylab("biomass [kg]") +
  coord_flip()
#> Warning: Removed 15028 rows containing non-finite values (stat_boxplot).

For some species the maximum dbh for which biomass was calculated is much lower than the maximum dbh value for which the reference agb was calculated. This is because most equations in allodb are defined for a specific range of dbh values. Eventually allodb might provide equations beyond the dbh limits currently available.

To explore this issue, here we use add_component_biomass() which allows us to see intermediary results that add_biomass() doesn’t show.

detailed_biomass <- suppressWarnings(suppressMessages(
  add_component_biomass(census, species, site = "SCBI")
))
#> <U+2714> Guessing dbh in [mm].
#> i You may provide the dbh unit manually via the argument`dbh_unit`.
#> i biomass values are given in [kg].
#> <U+2714> Guessing dbh in [mm].
#> i You may provide the dbh unit manually via the argument`dbh_unit`.

# Maximum `dbh` values by species
max_by_species <- detailed_biomass %>% 
  select(species, dbh_max_mm) %>% 
  group_by(species) %>% 
  arrange(desc(dbh_max_mm)) %>% 
  filter(row_number() == 1L) %>% 
  ungroup()

# `dbh` is above the maximum limit, so `biomass` is missing (agb has a value)
detailed_biomass %>% 
  filter(dbh > 1000) %>% 
  select(-dbh_max_mm) %>% 
  left_join(max_by_species) %>% 
  mutate(agb_kg = agb * 1e3) %>%
  select(species, biomass, agb, dbh, dbh_max_mm) %>% 
  arrange(species) %>%
  print(n = Inf)
#> Joining, by = "species"
#> # A tibble: 23 x 5
#>    species                 biomass   agb   dbh dbh_max_mm
#>    <chr>                     <dbl> <dbl> <dbl>      <dbl>
#>  1 fagus grandifolia            NA 13.7  1030.        890
#>  2 fraxinus americana           NA 14.2  1053.        550
#>  3 liriodendron tulipifera      NA  8.24 1012.        650
#>  4 liriodendron tulipifera      NA 11.2  1159.        650
#>  5 liriodendron tulipifera      NA 10.3  1118.        650
#>  6 liriodendron tulipifera      NA 10.6  1135.        650
#>  7 liriodendron tulipifera      NA  8.48 1025.        650
#>  8 liriodendron tulipifera      NA 15.9  1365.        650
#>  9 liriodendron tulipifera      NA  8.12 1006.        650
#> 10 liriodendron tulipifera      NA 11.5  1173.        650
#> 11 liriodendron tulipifera      NA 11.5  1174.        650
#> 12 liriodendron tulipifera      NA  9.02 1054         650
#> 13 liriodendron tulipifera      NA 13.9  1280.        650
#> 14 quercus alba                 NA 15.0  1018.        890
#> 15 quercus rubra                NA 27.7  1418.        890
#> 16 quercus rubra                NA 28.2  1432.        890
#> 17 quercus rubra                NA 25.5  1366.        890
#> 18 quercus rubra                NA 17.3  1143.        890
#> 19 quercus rubra                NA 21.9  1272.        890
#> 20 quercus velutina             NA 16.1  1107         890
#> 21 quercus velutina             NA 26.6  1393.        890
#> 22 quercus velutina             NA 15.6  1092.        890
#> 23 quercus velutina             NA 31.6  1511.        890

Biomass via BIOMASS versus allodb

temperate_biomass <- add_biomass(census, species, site = "scbi")
#> <U+2714> Guessing dbh in [mm].
#> i You may provide the dbh unit manually via the argument`dbh_unit`.
#> i biomass values are given in [kg].
#> <U+2714> Guessing dbh in [mm].
#> i You may provide the dbh unit manually via the argument`dbh_unit`.
#> <U+2714> Matching equations by site and species.
#> <U+2714> Refining equations according to dbh.
#> <U+2714> Using generic equations where expert equations can't be found.
#> Warning:   Can't find equations matching these species:
#>   acer sp, carya sp, crataegus sp, fraxinus sp, quercus sp, ulmus sp, unidentified unk
#> Warning: Can't find equations for 15028 rows (inserting `NA`).
#> Warning: Detected a single stem per tree. Do you need a multi-stem table?
#> Warning: * For trees, `biomass` is that of the main stem.
#> Warning: * For shrubs, `biomass` is that of the entire shrub.
#> <U+2714> Adding new columns:
#>   rowid, species, site, biomass

# Warning: Aplying tropical equations to a temperate forest for comparison
tropical_biomass <- add_tropical_biomass(census, species)
#> <U+2714> Guessing dbh in [mm].
#> i You may provide the dbh unit manually via the argument`dbh_unit`.
#> i Wood density given in [g/cm^3].
#> <U+2714> Using 'Pantropical' `region`.
#> i Biomass is given in [kg].
#> <U+2714> Adding new columns:
#>   family, genus, species, wd_level, wd_mean, wd_sd, biomass

dbh_biomsss <- tibble(
  dbh = temperate_biomass$dbh,
  species = temperate_biomass$species,
  temperate_biomass = temperate_biomass$biomass, 
  tropical_biomass = tropical_biomass$biomass
)
dbh_biomsss %>% 
  ggplot(aes(x = dbh)) +
  geom_point(aes(y = tropical_biomass), size = 1.5, color = "grey") +
  geom_point(aes(y = temperate_biomass), size = 1) +
  facet_wrap("species", ncol = 4) +
  ylab("Biomass [kg] (via the BIOMASS (grey) and allodb (black) packages)") +
  xlab("dbh [mm]") +
  theme_bw()
#> Warning: Removed 15028 rows containing missing values (geom_point).

General information