DOI: 10.5061/dryad.547d7wmdg
title: Trait-based mechanistic approach highlights global patterns and losses of herbivore biomass functional diversity

description: Mammalian herbivores play a pivotal role in Earth System processes by
 affecting biogeochemical cycles and ecosystem functioning, potentially
 leading to significant repercussions on atmosphere-biosphere feedbacks.
 Global dynamic models of mammalian populations can improve our
 understanding of their ecological role at large scales and the
 consequences of their extinctions. However, such models are still lacking
 and mammals are poorly integrated in Earth System science. We developed a
 mechanistic global model of terrestrial herbivore populations simulated
 with 37 functional groups defined through the analysis of
 eco-physiological traits across all extant herbivores (2599 species). We
 coupled this model with a global vegetation model to predict herbivores’
 maximum potential biomass in pre-industrial and at present-day and to
 study the environmental drivers explaining the distribution of herbivore
 biomass. Present-day biomass was estimated by accounting for anthropogenic
 activity causing habitat and range losses. We show that natural ecosystems
 could have sustained a potential wild herbivore wet biomass of 330 Mt [95%
 CI 245–417], comprised of 193 Mt [95% CI 177–208] by large species (body
 mass &gt; 1–10 kg, depending on functional group) and 138 Mt [95% CI
 68-209] by small species. We estimate that the remaining present-day large
 herbivores biomass is 82 Mt [95% CI 32–133], reduced by 57% due to
 anthropogenic activity; consequently, small herbivores currently dominate
 global herbivore biomass with 98 Mt (95% CI 91–106, -29%). Losses vary
 greatly across climatic zones and functional groups, suggesting that size
 is not the only discriminant feature of biomass decline. Actual
 evapotranspiration is the most important driver of total, large, and small
 herbivore biomass and explains 64%, 59%, and 49% of its variation,
 respectively. Distribution of modeled and observed large herbivores’
 biomass suggested a high dependency on energy and water with more biomass
 in hot and wet areas. These results challenge the notion that large
 herbivore biomass peaks primarily in ecosystems with intermediate
 precipitation levels such as savannas. Outside Africa and the Tropics,
 pre-industrial biomass hotspots occur in areas today dominated by humans;
 this could undermine the recovery of larger species biomass in certain
 areas. These herbivore biomass estimates provide a quantitative benchmark
 for setting conservation and rewilding goals at large spatial scales. The
 herbivore model and functional classification create new opportunities to
 integrate mammals into Earth System science and models.
description: Data are primarily a collection of data from different datasets.
 Any new data is indicated in the table as described in the manuscript
 methodology.
description: # Trait-based mechanistic approach highlights global patterns and losses
 of herbivore biomass functional diversity --- Purpose of data: the dataset
 contains species trait data used for creation of Herbivore Functional
 Types and density data used for calculating empirical-derived biomass.
 Authors: F Berzaghi*, D Zhu, J Alroy, P Ciais. *contact author:
 Date of data collection (single date, range,
 approximate date): 2019-2020 the years when the data was recorded from
 published sources. The data was collected in the field in the years
 1958-2007. Geographic extension of collected data: data pertains to the
 global domain and was extracted from published articles and existing
 datasets. The specific location and sources of the data are indicated in
 the spreadsheet. ## Sharing/Access information **1**.
 Licenses/restrictions placed on the data: CC0 1.0 Universal (CC0 1.0)
 Public Domain **2.** Links to publications that cite or use the data:
 Fabio Berzaghi, Dan Zhu, John Alroy, Philippe Ciais (2024). Trait-based
 mechanistic approach highlights global patterns and losses of herbivore
 biomass functional diversity. Functional Ecology **3.** Links to other
 publicly accessible locations of the data: None **4.** Links/relationships
 to ancillary data sets: None **5.** Was data derived from another source?
 Yes A. If yes, list source(s): The main sources are the datasets: Tetra
 Density, Elton Traits, Phylacine 1.2, MammalDIET2, all other sources are
 indicated in the spreadsheet and in the manuscript. **6.** Recommended
 citation for this dataset: Fabio Berzaghi, Dan Zhu, John Alroy, Philippe
 Ciais (2024). Data from: Trait-based mechanistic approach highlights
 global patterns and losses of herbivore biomass functional diversity.
 Dryad Digital Repository. 
 ## DATA & FILE OVERVIEW **1.** File List: A) species_density_data.csv
 B) Supplementary_data_HFT_classification.xlsx **2.** Relationship between
 files, if important: None **3.** Additional related data collected that
 was not included in the current data package: None **4.** Are there
 multiple versions of the dataset? No
 \#########################################################################
 DATA-SPECIFIC INFORMATION FOR: species_density_data.csv **1.** Number of
 variables: 24 **2.** Number of cases/rows: 432 Variable meanings are
 self-explanatory, units are reported directly in the spreadsheet, here we
 provide details on the ones that need further explanation: * Locality: was
 recorded based on the description given by the authors, if no name was
 given the locality was determined using latitude/longitude. *
 Longitude/latitude: were taken directly from the text when reported or
 estimated based on the description of the study site. * Year: refers to
 the year when the species density was estimated * Habitat: was only
 recorded when specified in the source * Notes: we provide any additional
 information, such as if the locality was estimated from lat/long or if the
 specific coordinates were estimated * Disturbance: any particular human
 intervention that could have reduced the population density of the studied
 species. * Reference_containing_data: this is the reference that reports
 the data, however not always the data was collected directly by the
 authors of the manuscript. Sometimes the data was taken from another
 source. In such cases we report the original source of the data indicated
 in the "Reference_to_source_data" variable. *
 Reference_to_source_data: As explained above, this contains the primary
 source of the data, in the cases were this is mentioned in the manuscript.
 * Code: a unique code to define a locality, the same reference might
 include data from multiple localities **4.** Missing data codes: NA
 indicated that the data or information was not reported in the text, it
 means "Not Available". In the case for subspecies it means
 "Not applicable", as not all species have a subspecies. **5.**
 Specialized formats or other abbreviations used: None
 \#########################################################################
 DATA-SPECIFIC INFORMATION FOR: Supplementary_data_HFT_classification.xlsx
 **1.** Number of variables: 18 **2.** Number of cases/rows: 2599 Variable
 meanings are self-explanatory, the only numeric column is
 "Mass.kg" which indicates the body mass of the species in Kg;
 here we provide details on the variables that need further explanation: *
 Diet source: the database or article used to determine the diet
 composition of the species * Diet correction notes: here we indicate if we
 made any corrected on the diet composition reported from the original
 source * Digestive: indicates the digestive system of the species, either
 "hindgut" or "foregut" * Digestive.level: indicates
 the taxonomic level at which the digestive system was determined, as
 described in the Methods * Digestive.source: the database or article used
 to determine the digestive system of the species. "Inferred"
 indicates that it was determined using other species in the same taxonomy.
 Complete sources are indicated in the "Digestive sytem
 references" sheet. * Folivory: if the species consumes leaf in its
 diet this column indicates if it consumes leaves from herbaceous (grazing)
 or woody (browsing) vegetation or both (Mixed-feeding). NA indicates that
 the species does not consume leaves. * Folivory.level: indicates the
 taxonomic level at which the type of folivory was determined, as described
 in the Methods * Folivory.source: the database or article used to
 determine folivory type of the species. "Inferred" indicates
 that it was determined using other species in the same taxonomy. Complete
 sources are indicated in the "folivory type references" sheet. *
 Size.class: one of the three size classes discussed in the publication. *
 hftname: The name of the Herbivore Functional Type to which the species
 was assigned. B, G, and M in parenthesis indicated browsing, grazing, and
 mixed-feeding. * Diet group: one of the eight diet groups discussed in the
 publication. **4.** Missing data codes: NA mean "Not applicable"
 for folivory-related columns and for the "correction" columns it
 means that no correction was applied. **5.** Specialized formats or other
 abbreviations used: None