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Anthropogenic BiomesAnthropogenic BiomesA 21A 21stst century framework for ecology & the earth sciences century framework for ecology & the earth sciences
Erle C. Ellis
Navin Ramankutty
Department of Geography & Environmental SystemsUniversity of Maryland, Baltimore County, Baltimore, MD 21250
Department of Geography & Earth System Science Program
McGill University, Montreal, QC, H3A 2K6, Canada
Humans now shape ecological pattern and process across most of the terrestrial biosphere.
“Nature” is embedded within human systems.
Ecology needs to move beyond human footprints, impacts & domination.
Anthropogenic Biomes
• Why care about Biomes?
• Why do we need Anthropogenic Biomes?– A missing persons detective story
• How to identify & map the biomes– An empirical approach
• Anthropogenic Biomes of the World
• The way forward….– A new model for ecological research & education
Overview
On Biomes…• Biomes describe global patterns of species
composition and ecological processes– Basic units in the ecological hierarchy…
• Identified as a function of Climate, moderated
by Altitude (conventionally)
• Basic units for global ecosystem models– IGBP (17 classes; International Geosphere-Biosphere Programme)
• Core units in ecoregion analysis of biodiversity– Olson “global 200” (16 biomes, 200 ecoregions)
Why Anthropogenic Biomes?• Humans control biodiversity & ecosystem processes as
much as climate.
• Global biome maps are not realistic.– Much of biome area does not even exist (potential vegetation).– At most includes urban & agriculture (& agriculture+tree mosaic).
• Conventional, climate-based biomes are not static anyway:– Anthropogenic climate change is altering biome location &
composition.
• Biomes derived from global patterns of human interaction with landscapes may be a stronger model of global ecological patterns & processes.
Grazing
Agriculture
Urbanization
Deforestation
Habitat Fragmentation
etc…
Conventional Biomesecosystem processes are a function of macroclimate (latitude, altitude, circulation)
Ecosystem processes = f(C)
C = Climate (precipitation & temperature)
A Working Hypothesis:ecosystem processes in anthropogenic
biomes are primarily a function of human populations and their ecosystem interactions (land use)
Ecosystem processes = f(P,T) (in anthropogenic biomes)
P = Population density
T = Land use (how land & resources are used)
Anthropogenic Biomes
Anthropogenic Biomes of the WorldUrban & dense settlements
11 Urban 12 Dense settlements
Villages
21 Rice villages 22 Irrigated villages 23 Cropped & pastoral villages 24 Pastoral villages 25 Rainfed villages 26 Rainfed mosaic villages
*Mosaic: >25% tree cover mixed with > 25% pasture and/or cropland
Croplands 31 Residential irrigated cropland
32 Residential rainfed mosaic
33 Populated irrigated cropland
34 Populated rainfed cropland 35 Remote croplands
Rangelands 41 Residential rangelands
42 Populated rangelands
43 Remote rangelands
Wildlands 61 Wild forests
62 Sparse trees
63 Barren
Forested 51 Populated forests
52 Remote forests
*
Ellis & Ramankutty, in press
CroplandsAtlas Mountains, Morocco
WildlandsAlaska, USA
Credit: © BigFoto. < http://www.bigfoto.com/sites/galery/nature1/natur015.jpg >
Populated ForestKoh Samai, Thailand
Credit: © Yenit Company Ltd. <http://www.kohsamui.org/seaview.jpg>
CroplandsAtlas Mountains, Morocco
Remote RangelandsSouth Dakota, USA
Credit: © Alexander Smart. <http://ars.sdstate.edu/faculty/smarta/Range415/Image035.jpg>
Populated RangelandsAtlas Mountains, Morocco
Remote CroplandsColombia Basin, Washington, USA
Credit: © GWMA <http://www.gwma.org/images/CroplandAdjusted.jpg>
Croplands - Residential Rainfed MosaicNormandy, France
Credit: © JH.Bernard. <http://pagesperso-orange.fr/rmc14/images/IMAGES-RMC/RMC-6.JPG>
Anthropogenic Biomes of the World
Rice villages Irrigated villages Cropped & pastoral villages
Pastoral villages Rainfed villages Rainfed mosaic villages
Ellis & Ramankutty, in press
Village Biomes
Villages Jintang County, Sichuan Province, China
Rice VillagesDanyang County, Jiangsu Province, China
UrbanManhattan, New York, USA Credit: © Josh
<http://picasaweb.google.com/jiltdotorg/NewYorkCity/photo#5129550626737389474>
UrbanBaltimore County, Maryland, USA
Anthropogenic Biomes of the WorldUrban & dense settlements
11 Urban 12 Dense settlements
Villages
21 Rice villages 22 Irrigated villages 23 Cropped & pastoral villages 24 Pastoral villages 25 Rainfed villages 26 Rainfed mosaic villages
*Mosaic: >25% tree cover mixed with > 25% pasture and/or cropland
Croplands 31 Residential irrigated cropland
32 Residential rainfed mosaic
33 Populated irrigated cropland
34 Populated rainfed cropland 35 Remote croplands
Rangelands 41 Residential rangelands
42 Populated rangelands
43 Remote rangelands
Wildlands 61 Wild forests
62 Sparse trees
63 Barren
Forested 51 Populated forests
52 Remote forests
*
Ellis & Ramankutty, in press
Anthropogenic biomes
A new framework for ecologyA new framework for ecology
• Only 22% of land and 11% of NPP are wild
• Nature is now embedded within human systems– It is no longer possible to conserve nature by avoiding
human interactions
• Human interactions with the biosphere go far beyond a single dimension of impact or domination.
• Beyond the “urban + agriculture + wild” model– Forests, rangelands & croplands include people!– A wide range of population interactions.
Wildlands Forested Rangelands Croplands Villages Dense settlements
builtup
ornamentalpastureforestry
Population density
Biodiversity
Land use
Land cover baretrees
native
NPP
Carbon emissions
Reactive Nitrogen
+-
irrigated
Anthropogenic Biomes: Conceptual Model
WildlandsUrban& denseForestedRangelands VillagesCroplands
Ellis & Ramankutty, in press
Anthropogenic Biomes
Results
Anthropogenic Biomes are Mosaics– Anthropogenic landscapes are heterogeneous
mixtures of different land use and land cover classes.
– Urban areas are embedded in agricultural areas.
– Trees mixed with croplands and housing.– Managed vegetation is mixed with semi-natural
vegetation (e.g. croplands in rangelands and forests).
– Hillslopes & mountains are often islands of semi-natural vegetation
Villages Pohkara, Nepal
A better story…
“Human systems, with natural ecosystems embedded within them”.
We own the biosphere: we have altered it irreversibly. Now we control its future.
The old biosphere story… “Natural ecosystems with humans disturbing them”.
Anthropogenic biomes A new framework for educationA new framework for education
