Focus 4 - Land Use and Cover

ALCC eastasia comparison 
Anthropogenic deforestation in Eastern Asia at AD 1 simulated by three different approaches: A) Olofsson and Hickler (2008); (B) HYDE (History Database of the Global Environment) version 3.1 (Klein Goldewijk et al. 2010); and (C) Kaplan et al. (2009). Note the large differences in land-cover between the different models used. (From: Gaillard and Xu (2013) PAGES news 21 (2): 81) 

 

Introduction

This group emerged out of a meeting in London in July 2008 (link), where representatives met and discussed the structure of PAGES' Focus 4 and its place in PAGES' new science structure. Further, at this meeting they decided which themes would be pursued under Focus 4, with Land Use and Cover being one of them. Land Use and Cover ran until 2014, when the LandCover6k working group replaced it.

Scientific goals

The major goal of this theme was to produce land-cover records based on fossil pollen records for the last 11.5 kyr i.e. the entire Holocene. These reconstructions would be produced at global and continental-regional scale for the entire Holocene in various formats relevant for modelers.

Climate modelers increasingly focus on processes governing changes in the land surface and their coupling to the atmosphere. Thus, there is a growing need for past land use/cover records at global- to continental/regional-scales (e.g., Dearing et al., 2006b; Denman et al., 2007) which include:

1. curves and trends (site curves, regional syntheses)
2. figures (absolute numbers in percentage cover, biomass, plant functional types, biomes)
3. maps
4. databases
5. open vs. forested land
6. the extent and nature of permanent agriculture
7. the extent of grazing

Land-cover reconstructions are also needed to understand and model terrestrial processes such as soil erosion, a direct focus of the Focus 4 - Soil and Sediment theme.


Final outputs

The final synthesis of the land use/land cover theme will consist of three review papers to be submitted in 2015, one on the state-of-the-art of descriptions of past land-cover in Eastern Asia (the result of a PAGES workshop in China, October 2012), and two state-of-the art papers on pollen-based quantitative reconstructions of vegetation cover in Europe.

Moreover, the final output of the theme also includes:

State-of-the-art descriptions of the land-cover over the Holocene period in NW Europe and W Europe N of the Alps based on several approaches including pollen-based REVEALS reconstructions (results from the LANDCLIM project) (Mazier et al. 2012; Nielsen et al. 2012; Fyfe et al. 2013; Trondman et al. 2014, Marquer et al. 2014; Pirzamanbein et al. 2014).

A study of land cover-climate interactions in NW Europe using a regional climate model  (Strandberg et al. 2014).

Pollen productivity estimates for major plant taxa in Africa (Cameroon) and first applications of REVEALS and LOVE (results from the C3A project, papers to be submitted in 2015).

Initiation of projects aimed at estimating pollen productivity (PPEs) of major taxa in southern France, NW China and SE India (result from the PAGES workshop in China); first PPEs and pollen-based quantitative reconstructions of land cover in those areas.