Potassium limitation of forest productivity – Part 1: A mechanistic model simulating the effects of potassium availability on canopy carbon and water fluxes in tropical eucalypt stands
2023
Cornut, Ivan | Delpierre, Nicolas | Laclau, Jean-Paul | Guillemot, Joannès | Nouvellon, Yann | Campoe, Otavio | Stape, Jose, Luiz | Fernanda Santos, Vitoria | Maire, Guerric, Le | Ecologie Systématique et Evolution (ESE) ; AgroParisTech-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS) | Ecologie fonctionnelle et biogéochimie des sols et des agro-écosystèmes (UMR Eco&Sols) ; Centre de Coopération Internationale en Recherche Agronomique pour le Développement (Cirad)-Institut de Recherche pour le Développement (IRD)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Institut Agro Montpellier ; Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro)-Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro) | Institut universitaire de France (IUF) ; Ministère de l'Education nationale, de l’Enseignement supérieur et de la Recherche (M.E.N.E.S.R.) | Cirad Direction Générale (Cirad-DG) ; Centre de Coopération Internationale en Recherche Agronomique pour le Développement (Cirad) | Département Performances des systèmes de production et de transformation tropicaux (Cirad-PERSYST) ; Centre de Coopération Internationale en Recherche Agronomique pour le Développement (Cirad) | Escola Superior de Agricultura "Luiz de Queiroz" (ESALQ) ; Universidade de São Paulo = University of São Paulo (USP) | Universidade Federal de Lavras = Federal University of Lavras (UFLA) | Universidade Estadual Paulista Júlio de Mesquita Filho = São Paulo State University (UNESP) | Suzano S/A | ANR-16-CONV-0003,CLAND,CLAND : Changement climatique et usage des terres(2016) | ANR-13-AGRO-0005,MACACC,Modélisation pour l'accompagnement des ACteurs, vers l'Adaptation des Couverts pérennes ou agroforestiers aux Changements globaux(2013) | ANR-10-LABX-0001,AGRO,Agricultural Sciences for sustainable Development(2010)
International audience
اظهر المزيد [+] اقل [-]إنجليزي. The extent of the potassium (K) limitation of forest productivity is probably more widespread than previously thought, and K limitation could influence the response of forests to future global changes. To understand the effects of K limitation on forest primary production, we have developed the first ecophysiological model simulating the K cycle and its interactions with the carbon (C) and water cycles. We focused on the limitation of the gross primary productivity (GPP) by K availability in tropical eucalypt plantations in Brazil. We used results from stand-scale fertilisation experiments as well as C flux measurements in two tropical eucalypt plantations to parameterise the model. The model was parameterised for fertilised conditions and then used to test for the effects of contrasting additions of K fertiliser. Simulations showed that K deficiency limits GPP by more than 50 % during a 6-year rotation, a value in agreement with estimations in K-limited eucalypt stands. Simulations showed a decrease of modelled canopy transpiration of around 50 % and a decrease in modelled water-use efficiency WUEGPP of 10 %. Through a sensitivity analysis, we used the model to identify the most critical processes to consider when studying K limitation of GPP. The inputs of K to the stands, such as the atmospheric deposition and weathering fluxes, and the regulation of the cycle of K within the ecosystem were critical for the response of the system to K deficiency. Litter leaching processes were of lower importance, since residence time of K in litter was low. The new forest K-cycle model developed in the present study includes multiple K processes interacting with the carbon and water cycles, and strong feedbacks on GPP were outlined. This is a first step in identifying the source or sink limitation of forest growth by K.
اظهر المزيد [+] اقل [-]المعلومات البيبليوغرافية
تم تزويد هذا السجل من قبل Institut national de la recherche agronomique