title: Defining functional biomes and monitoring their change globally.
abstract: Biomes are important constructs for organizing understanding of how the worlds' major terrestrial ecosystems differ from one another and for monitoring change in these ecosystems. Yet existing biome classification schemes have been criticized for being overly subjective and for explicitly or implicitly invoking climate. We propose a new biome map and classification scheme that uses information on (i) an index of vegetation productivity, (ii) whether the minimum of vegetation activity is in the driest or coldest part of the year, and (iii) vegetation height. Although biomes produced on the basis of this classification show a strong spatial coherence, they show little congruence with existing biome classification schemes. Our biome map provides an alternative classification scheme for comparing the biogeochemical rates of terrestrial ecosystems. We use this new biome classification scheme to analyse the patterns of biome change observed over recent decades. Overall, 13% to 14% of analysed pixels shifted in biome state over the 30-year study period. A wide range of biome transitions were observed. For example, biomes with tall vegetation and minimum vegetation activity in the cold season shifted to higher productivity biome states. Biomes with short vegetation and low seasonality shifted to seasonally moisture-limited biome states. Our findings and method provide a new source of data for rigorously monitoring global vegetation change, analysing drivers of vegetation change and for benchmarking models of terrestrial ecosystem function.
authors.affiliation: Department of Botany, University of Otago, PO Box 56, Dunedin, 9054, New Zealand. steven.higgins@otago.ac.nz.|Biodiversity and Climate Research Centre (BiK-F), Senckenberg Gesellschaft für Naturforschung, Senckenberganlage 25, 60325, Frankfurt am Main, Germany. steven.higgins@otago.ac.nz.
authors.forename: Steven I
authors.initials: SI
authors.lastname: Higgins
authors.affiliation: Landcare Research, PO Box 69040, Lincoln, 7640, New Zealand.
authors.forename: Robert
authors.initials: R
authors.lastname: Buitenwerf
authors.affiliation: Fynbos Node, South African Environmental Observation Network (SAEON), Centre for Biodiversity Conservation, Kirstenbosch Gardens, Private Bag X7, Rhodes Drive, Claremont, 7735, Cape Town, South Africa.|Department of Botany and Zoology, Stellenbosch University, Private Bag X1, Matieland, 7602, Stellenbosch, South Africa.
authors.forename: Glenn R
authors.initials: GR
authors.lastname: Moncrieff
mesh_terms: D002980:Climate; D017753:Ecosystem; D008962:Models, Theoretical; D012621:Seasons
keywords: biome shifts; land cover change; phenology; plant function; vegetation