title: Forest biomass density across large climate gradients in northern South America is related to water availability but not with temperature.
abstract: Understanding and predicting the likely response of ecosystems to climate change are crucial challenges for ecology and for conservation biology. Nowhere is this challenge greater than in the tropics as these forests store more than half the total atmospheric carbon stock in their biomass. Biomass is determined by the balance between biomass inputs (i.e., growth) and outputs (mortality). We can expect therefore that conditions that favor high growth rates, such as abundant water supply, warmth, and nutrient-rich soils will tend to correlate with high biomass stocks. Our main objective is to describe the patterns of above ground biomass (AGB) stocks across major tropical forests across climatic gradients in Northwestern South America. We gathered data from 200 plots across the region, at elevations ranging between 0 to 3400 m. We estimated AGB based on allometric equations and values for stem density, basal area, and wood density weighted by basal area at the plot-level. We used two groups of climatic variables, namely mean annual temperature and actual evapotranspiration as surrogates of environmental energy, and annual precipitation, precipitation seasonality, and water availability as surrogates of water availability. We found that AGB is more closely related to water availability variables than to energy variables. In northwest South America, water availability influences carbon stocks principally by determining stand structure, i.e. basal area. When water deficits increase in tropical forests we can expect negative impact on biomass and hence carbon storage.
authors.affiliation: Departamento de Ciencias de la Vida, Universidad de Alcalá, Alcalá, Spain.|Grupo de Servicios Ecosistemicos y Cambio Climático, Fundación Convida, Medellín, Colombia.|Escuela de Ciencias Agrícolas, Pecuarias y del Medio Ambiente, Universidad Nacional Abierta y a Distancia, Medellín, Colombia.
authors.forename: Esteban
authors.identifier: http://orcid.org/0000-0001-9032-0099
authors.initials: E
authors.lastname: Álvarez-Dávila
authors.affiliation: Área de Biodiversidad y Conservación, Escuela Superior de Ciencias Experimentales y Tecnológicas, Universidad Rey Juan Carlos, Departamental I, Madrid, Spain.
authors.forename: Luis
authors.initials: L
authors.lastname: Cayuela
authors.affiliation: Herbario JAUM, Jardín Botánico de Medellín, Medellín, Colombia.
authors.forename: Sebastián
authors.initials: S
authors.lastname: González-Caro
authors.affiliation: Departamento de Ciencias Biológicas, Universidad de Los Andes, Bogotá, Colombia.
authors.forename: Ana M
authors.initials: AM
authors.lastname: Aldana
authors.affiliation: Departamento de Ciencias Biológicas, Universidad de Los Andes, Bogotá, Colombia.
authors.forename: Pablo R
authors.initials: PR
authors.lastname: Stevenson
authors.affiliation: School of Geography, University of Leeds, Leeds, United Kingdom.
authors.forename: Oliver
authors.initials: O
authors.lastname: Phillips
authors.affiliation: Herbario JAUM, Jardín Botánico de Medellín, Medellín, Colombia.
authors.forename: Álvaro
authors.initials: Á
authors.lastname: Cogollo
authors.affiliation: Universidad Regional Amazónica, Napo, Ecuador.
authors.forename: Maria C
authors.initials: MC
authors.lastname: Peñuela
authors.affiliation: Fundación Puerto Rastrojo, Bogotá, Colombia.
authors.forename: Patricio
authors.initials: P
authors.lastname: von Hildebrand
authors.affiliation: Grupo de Ecología de Ecosistemas Terrestres Tropicales, Universidad Nacional de Colombia, Bogotá, Colombia.
authors.forename: Eliana
authors.initials: E
authors.lastname: Jiménez
authors.affiliation: Facultad de Ingeniería Forestal, Universidad del Tolima, Ibagué, Colombia.
authors.forename: Omar
authors.initials: O
authors.lastname: Melo
authors.affiliation: Independent investigator, Medellín, Colombia.
authors.forename: Ana Catalina
authors.initials: AC
authors.lastname: Londoño-Vega
authors.affiliation: Grupo de Servicios Ecosistemicos y Cambio Climático, Fundación Convida, Medellín, Colombia.
authors.forename: Irina
authors.initials: I
authors.lastname: Mendoza
authors.affiliation: Facultad de Ciencias Agronómicas, Universidad Nacional de Colombia, Medellín, Colombia.
authors.forename: Oswaldo
authors.initials: O
authors.lastname: Velásquez
authors.affiliation: Facultad de Ingeniería Forestal, Universidad del Tolima, Ibagué, Colombia.
authors.forename: Fernando
authors.initials: F
authors.lastname: Fernández
authors.affiliation: Institución Universitaria Tecnológico de Antioquia, Facultad de Ingeniería, Medellín, Colombia.
authors.forename: Marcela
authors.initials: M
authors.lastname: Serna
authors.affiliation: Grupo de Servicios Ecosistemicos y Cambio Climático, Fundación Convida, Medellín, Colombia.
authors.forename: Cesar
authors.initials: C
authors.lastname: Velázquez-Rua
authors.affiliation: Herbario JAUM, Jardín Botánico de Medellín, Medellín, Colombia.
authors.forename: Doris
authors.initials: D
authors.lastname: Benítez
authors.affiliation: Departamento de Ciencias de la Vida, Universidad de Alcalá, Alcalá, Spain.
authors.forename: José M
authors.initials: JM
authors.lastname: Rey-Benayas
mesh_terms: D018533:Biomass; D065928:Forests; D008962:Models, Theoretical; D013020:South America; D013696:Temperature; D014329:Tropical Climate; D014867:Water
chemical_list: D014867:Water