Anthromes, CO2 and Terrestrial Carbon – Session 1: What are anthromes? Their geography and relevance to the carbon cycle
Authors: Ellis Erle , Malhi Yadvinder , Stevens Nicola , Hoffman Forrest 
Published: October 2023

Full programme at https://anthromes-co2-and-terrestrial-carbon.evessiocloud.com/2023/en/page/full-programme

9.00 – 9.10: Welcome to the meeting

9.10 – 9.40: The history and evolution of anthromes, Erle Ellis*

9.40 – 10.10: Tropical forest anthromes and the past, present and future terrestrial carbon cycle, Yadvinder Malhi*

10.10 – 10.30: Change is in the air: The fate of grassy ecosystems in the Anthropocene , Nichola Stephens (presenting remotely)

10.30 – 10.50: Prospects for Satellite Remote Sensing to Identify Evolving Anthromes and Quantify Carbon Cycle Dynamics, Forrest Hoffman

The history and evolution of anthromes

Anthromes were introduced in 2007 in mapping the globally significant patterns of terrestrial ecology shaped by human populations and their use of land. Anthrome mapping and classification is analogous to the mapping of natural vegetation biomes in relation to the global patterns of climate and terrain, but instead stratifies regional landscapes into categories in relation to their population densities and areas of intensive land uses (crops, pastures, and cities). Rather than homogeneous landscapes, anthromes represent the diverse, multifunctional and heterogeneous landscape mosaics that emerge through sustained human-environment interactions and include less intensive land uses such as foraging, hunting, forestry, conservation, restoration, and fallow, together with the remnant habitats embedded within working landscapes. Ecologists, conservationists, land planners, educators, and others have used anthrome maps in global assessments of ecosystem change, biodiversity patterns, and conservation strategies, and in numerous textbooks and atlases. Most recently, anthromes have been mapped from 10,000 BCE to 2017 CE, characterizing the deep history and vast extent of human transformation of ecology across the planet, and their legacy in shaping biodiversity today. The utility of an anthrome approach to long-term global assessments of carbon sequestration and emissions will be discussed.

Tropical forest anthromes and the past, present and future terrestrial carbon cycle

Humans have interacted with, and to some extent modified, tropical forests since the origin of our species in Africa, and subsequently shown fairly rapid adaptation to tropical forest environments in Asia and the Americas. These interactions altered the biodiversity and structure of these forests, although unlikely to an extent that had a significant effect on global climate. The current carbon balance of tropical forests is the net result of two anthropogenic forces: a carbon source from deforestation or structural degradation of forests, and a carbon sink in intact and regrowing forests, most likely stimulated by elevated atmospheric carbon dioxide concentration. Our recent studies suggest that human use of forests, such as selective logging or wood harvesting, may enhance forest ecological function but still result in carbon emissions: loss in forest biomass does not necessarily equate with degradation of ecological function.

Restoration of tropical forest biomass can make a substantial contribution to achieving climate stabilization goals this century, whereas extensive tropical forest biomass loss, whether through direct action or indirectly through climate change, could make ambitious climate stabilization goals unattainable. Supporting indigenous peoples and other traditional forest users to protect and maintain forests is an essential part of achieving a stable climate.

Prospects for Satellite Remote Sensing to Identify Evolving Anthromes and Quantify Carbon Cycle Dynamics

Land ecosystems represent a large and growing natural sink of carbon attributable primarily to CO2-fertilization in response to increasing anthropogenic carbon being emitted into the atmosphere. This sink is mediated by the accompanying effects of increasing temperature, land use and land cover change, and changes in the frequency, intensity, and extent of extreme events. Satellite remote sensing offers the ability to estimate ecosystem carbon state and dynamics at a range of spatial and temporal scales. Vegetation phenoregions, geographic areas that exhibit similar seasonal phenology, represent a useful metric for distinguishing the evolving carbon dynamics of plant communities. Derived from remote sensing indices of greenness, annual phenological curves provide a representation of gross primary production that incorporate responses to climate variation, effects of urban heat islands and irrigation, human land management, disturbance, shifting ecological communities, and changing atmospheric CO2 concentration. The spatial areas of phenoregions vary interannually, and phenoregions shift across landscapes as climate change occurs. Thus, phenoregions can be considered one form of anthromes that directly incorporates carbon dynamics. When combined with ancillary meteorological and related data, the concept of phenoregions can be extended to encompass additional properties considered important for altering the carbon sink potential of terrestrial ecosystems.