Large herbivore biomass in protected areas

Large herbivores provide key ecosystem processes, but have experienced massive historical losses and are under intense pressure, leaving current ecosystems with dramatically simplified faunas relative to the long-term evolutionary norm. Hampered by a shifting baseline, natural levels of large-herbivore biomass are poorly understood and seldom targeted. Here, we present a collation of large-herbivore biomass data from published sources as well as personal communication. The data includes continent, ecosystem name, latitude, longitude, large herbivore biomass in kg/km2 and the source of the data. It can be used together with net primary productivity (e.g., using satellite-derived NPP retrieved from http://files.ntsg.umt.edu/data/NTSG_Products/MOD17/GeoTIFF/MOD17A3/GeoTIFF_30arcsec/) to explore the scaling relationship between producer and consumer.

Methods
We collated published empirical data on large-herbivore biomass (kg/km2) from Hatton et al. (2015), Rodriguez et al. (2014) and from personal communication. Hatton et al. reports wild large-herbivore biomass (≥5 kg) for 73 protected areas. Opposite to Hatton et al. we included the biomass of megaherbivores (i.e., herbivores ≥1000 kg, e.g., elephants, rhinos, and hippos) and migratory species (species with seasonal, long-distance movement of individuals) weighted by the fraction of the year they spend in the ecosystem. Rodriguez et al. reports contemporary ungulate biomass of all species in the orders Perissodactyla, Artiodactyla or Proboscidea for 95 natural areas (national parks and protected areas with some degree of traditional pastoralism). We ensured no data overlap between Rodriguez et al and Hatton et al. From Rodriguez et al., we included the livestock biomass because grazing livestock in pastoralist systems also rely on the local primary production. In total, we included 289 data points from 146 ecosystems across Africa, Asia, Europe, North America and South America. GPS positions were checked using Google maps satellite images and place names. Doubtful positions were checked against primary literature and either placed accordingly or moved to reserve centers. We used data from the years 1926-2009 as well as data from unknown years.