Plant functional type classification for earth system models: results from the European Space Agency's Land Cover Climate Change Initiative

Abstract

Abstract. Global land cover is a key variable in the earth system with feedbacks on climate, biodiversity and natural resources. However, global land cover data sets presently fall short of user needs in providing detailed spatial and thematic information that is consistently mapped over time and easily transferable to the requirements of earth system models. In 2009, the European Space Agency launched the Climate Change Initiative (CCI), with land cover (LC_CCI) as 1 of 13 essential climate variables targeted for research development. The LC_CCI was implemented in three phases: first responding to a survey of user needs; developing a global, moderate-resolution land cover data set for three time periods, or epochs (2000, 2005, and 2010); and the last phase resulting in a user tool for converting land cover to plant functional type equivalents. Here we present the results of the LC_CCI project with a focus on the mapping approach used to convert the United Nations Land Cover Classification System to plant functional types (PFTs). The translation was performed as part of consultative process among map producers and users, and resulted in an open-source conversion tool. A comparison with existing PFT maps used by three earth system modeling teams shows significant differences between the LC_CCI PFT data set and those currently used in earth system models with likely consequences for modeling terrestrial biogeochemistry and land-atmosphere interactions. The main difference between the new LC_CCI product and PFT data sets used currently by three different dynamic global vegetation modeling teams is a reduction in high-latitude grassland cover, a reduction in tropical tree cover and an expansion in temperate forest cover in Europe. The LC_CCI tool is flexible for users to modify land cover to PFT conversions and will evolve as phase 2 of the European Space Agency CCI program continues.

Anthropogenic land use estimates for the Holocene – HYDE 3.2

“…Additionally, we define the fraction of an ESA land cover class that is actually covered by cropland and pasture (numbers in Table 1): on cropland and grassland land cover types this is assumed to be 90 % to account for small areas of infrastructure, wetlands, unsuitable terrain, steep slopes or small patches of vegetation that are not explicitly identified in the original land cover product (Verburg et al, 2009). The mosaic cropland land cover types are defined to have 60 and 40 % of cropland or pasture following the managed grass definition of Poulter et al (2015). First, cropland is allocated, then grazing land.…”

Towards a more detailed representation of high-latitude vegetation in the global land surface model ORCHIDEE (ORC-HL-VEGv1.0)

“…The product is based on medium-resolution satellite observation and provides information on the vegetation distribution us- ing land cover classes (LCC) defined by the United Nations Land Cover Classification System (UNLCCS). In order to match the satellite land cover classes with the PFTs coverage in ORCHIDEE, we use a conversion table established by Poulter et al (2015). Note that the climate classification system of Köppen (Peel et al, 2007) is also used to further partition some vegetation types into tropical, temperate and boreal zones (see also Poulter et al, 2015).…”

“…"Lichens and mosses" LCC were classified by Poulter et al (2015) into C 3 grasses and bare soil PFTs, and now are used to define a separate NVP PFT (Table S1). However, the NVP coverage that corresponds to the lichens and mosses LCC is clearly underestimated with the CCI product over Eurasia compared to North America and to other pan-Arctic land cover maps (i.e.…”

“…In order to match the satellite land cover classes with the PFTs coverage in ORCHIDEE, we use a conversion table established by Poulter et al (2015). Note that the climate classification system of Köppen (Peel et al, 2007) is also used to further partition some vegetation types into tropical, temperate and boreal zones (see also Poulter et al, 2015). The new vegetation map is thus obtained from this Land Cover data set (version 1.6.1) transformed with a conversion table (tool available from http://maps.elie.ucl.ac.be/CCI/viewer/), from 300 m LCC data.…”

Sensitivity of biogenic volatile organic compound emissions to leaf area index and land cover in Beijing

“…The PFT map layer of the MODIS MCD12Q1 product was directly used. CCI LC uses the default cross-walking table given by Poulter et al (2015) to convert the LC class maps to PFT maps. The FROM-GLC conversion process used the class legend description, with each LC type being classified into the corresponding PFT.…”