title: Land management: data availability and process understanding for global change studies.
abstract: In the light of daunting global sustainability challenges such as climate change, biodiversity loss and food security, improving our understanding of the complex dynamics of the Earth system is crucial. However, large knowledge gaps related to the effects of land management persist, in particular those human-induced changes in terrestrial ecosystems that do not result in land-cover conversions. Here, we review the current state of knowledge of ten common land management activities for their biogeochemical and biophysical impacts, the level of process understanding and data availability. Our review shows that ca. one-tenth of the ice-free land surface is under intense human management, half under medium and one-fifth under extensive management. Based on our review, we cluster these ten management activities into three groups: (i) management activities for which data sets are available, and for which a good knowledge base exists (cropland harvest and irrigation); (ii) management activities for which sufficient knowledge on biogeochemical and biophysical effects exists but robust global data sets are lacking (forest harvest, tree species selection, grazing and mowing harvest, N fertilization); and (iii) land management practices with severe data gaps concomitant with an unsatisfactory level of process understanding (crop species selection, artificial wetland drainage, tillage and fire management and crop residue management, an element of crop harvest). Although we identify multiple impediments to progress, we conclude that the current status of process understanding and data availability is sufficient to advance with incorporating management in, for example, Earth system or dynamic vegetation models in order to provide a systematic assessment of their role in the Earth system. This review contributes to a strategic prioritization of research efforts across multiple disciplines, including land system research, ecological research and Earth system modelling.
authors.affiliation: Institute of Social Ecology Vienna (SEC), Alpen-Adria Universitaet Klagenfurt, Wien, Graz, Schottenfeldgasse 29, Vienna, 1070, Austria.
authors.forename: Karl-Heinz
authors.initials: KH
authors.lastname: Erb
authors.affiliation: LSCE-IPSL CEA-CNRS-UVSQ, Orme des Merisiers, Gif-sur-Yvette, F-91191, France.|Department of Ecological Sciences, Vrije Universiteit Amsterdam, Amsterdam, 1081 HV, The Netherlands.
authors.forename: Sebastiaan
authors.initials: S
authors.lastname: Luyssaert
authors.affiliation: Georges Lemaître Center for Earth and Climate Research, Earth and Life Institute, Université Catholique de Louvain, Place Louis Pasteur 3, Louvain-la-Neuve, 1348, Belgium.|F.R.S.-FNRS, Brussels, 1000, Belgium.
authors.forename: Patrick
authors.initials: P
authors.lastname: Meyfroidt
authors.affiliation: Max Planck Institute for Meteorology, Bundesstr. 53, Hamburg, D-20146, Germany.
authors.forename: Julia
authors.initials: J
authors.lastname: Pongratz
authors.affiliation: Thünen-Institute of Climate-Smart Agriculture, Bundesallee 50, Braunschweig, 38116, Germany.
authors.forename: Axel
authors.initials: A
authors.lastname: Don
authors.affiliation: Max Planck Institute for Meteorology, Bundesstr. 53, Hamburg, D-20146, Germany.
authors.forename: Silvia
authors.initials: S
authors.lastname: Kloster
authors.affiliation: Geography Department, Humboldt-University Berlin, Unter den Linden 6, Berlin, 10099, Germany.|Integrative Research Institute on Transformations in Human-Environment Systems (IRI THESys), Humboldt-University Berlin, Unter den Linden 6, Berlin, 10099, Germany.
authors.forename: Tobias
authors.initials: T
authors.lastname: Kuemmerle
authors.affiliation: Institute of Social Ecology Vienna (SEC), Alpen-Adria Universitaet Klagenfurt, Wien, Graz, Schottenfeldgasse 29, Vienna, 1070, Austria.
authors.forename: Tamara
authors.initials: T
authors.lastname: Fetzel
authors.affiliation: Department of Earth Sciences, VU University Amsterdam, Amsterdam, The Netherlands.
authors.forename: Richard
authors.initials: R
authors.lastname: Fuchs
authors.affiliation: Laboratory of Geoinformation Science and Remote Sensing, Wageningen University, Droevendaalsesteeg 3, Wageningen, 6708 PB, The Netherlands.
authors.forename: Martin
authors.initials: M
authors.lastname: Herold
authors.affiliation: Institute of Social Ecology Vienna (SEC), Alpen-Adria Universitaet Klagenfurt, Wien, Graz, Schottenfeldgasse 29, Vienna, 1070, Austria.
authors.forename: Helmut
authors.initials: H
authors.lastname: Haberl
authors.affiliation: Met Office Hadley Centre, FitzRoy Road, Exeter, EX1 3PB, UK.
authors.forename: Chris D
authors.initials: CD
authors.lastname: Jones
authors.affiliation: Department of Geography, University of Wisconsin-Madison, 550 North Park Street, Madison, WI, 53706, USA.
authors.forename: Erika
authors.initials: E
authors.lastname: Marín-Spiotta
authors.affiliation: Ecosystems Services & Management Program, International Institute for Applied Systems Analysis (IIASA), Schlossplatz 1, Laxenburg, A-2361, Austria.
authors.forename: Ian
authors.initials: I
authors.lastname: McCallum
authors.affiliation: Met Office Hadley Centre, FitzRoy Road, Exeter, EX1 3PB, UK.
authors.forename: Eddy
authors.initials: E
authors.lastname: Robertson
authors.affiliation: Institute for Resources, Environment and Sustainability (IRES), Liu Institute for Global Issues, University of British Columbia (UBC), 6476 NW Marine Drive, Vancouver, BC, V6T 1Z2, Canada.
authors.forename: Verena
authors.initials: V
authors.lastname: Seufert
authors.affiliation: Ecosystems Services & Management Program, International Institute for Applied Systems Analysis (IIASA), Schlossplatz 1, Laxenburg, A-2361, Austria.
authors.forename: Steffen
authors.initials: S
authors.lastname: Fritz
authors.affiliation: Institut Pierre Simon Laplace, IPSL-CNRS-UPMC, Paris, France.
authors.forename: Aude
authors.initials: A
authors.lastname: Valade
authors.affiliation: Met Office Hadley Centre, FitzRoy Road, Exeter, EX1 3PB, UK.
authors.forename: Andrew
authors.initials: A
authors.lastname: Wiltshire
authors.affiliation: Department of Earth Sciences, VU University Amsterdam, Amsterdam, The Netherlands.
authors.forename: Albertus J
authors.initials: AJ
authors.lastname: Dolman
mesh_terms: D044822:Biodiversity; D057231:Climate Change; D003247:Conservation of Natural Resources; D017753:Ecosystem; D014197:Trees
keywords: data availability; earth system models; global land-use data sets; land management; land-cover modification; process understanding