Biotic and abiotic variables influencing plant litter breakdown in streams: a global study.
Plant litter breakdown is a key ecological process in terrestrial and freshwater ecosystems. Streams and rivers, in particular, contribute substantially to global carbon fluxes. However, there is little information available on the relative roles of different drivers of plant litter breakdown in fresh waters, particularly at large scales. We present a global-scale study of litter breakdown in streams to compare the roles of biotic, climatic and other environmental factors on breakdown rates. We conducted an experiment in 24 streams encompassing latitudes from 47.8° N to 42.8° S, using litter mixtures of local species differing in quality and phylogenetic diversity (PD), and alder (Alnus glutinosa) to control for variation in litter traits. Our models revealed that breakdown of alder was driven by climate, with some influence of pH, whereas variation in breakdown of litter mixtures was explained mainly by litter quality and PD. Effects of litter quality and PD and stream pH were more positive at higher temperatures, indicating that different mechanisms may operate at different latitudes. These results reflect global variability caused by multiple factors, but unexplained variance points to the need for expanded global-scale comparisons.
Faculty of Science and Technology, University of the Basque Country (UPV/EHU), 48940 Leioa, Spain IKERBASQUE, Basque Foundation for Science, 48013 Bilbao, Spain College of Marine and Environmental Sciences and TropWater, James Cook University, Townsville, Queensland 4811, Australia luz.boyero@ehu.eus.
Luz
0000-0001-7366-9299
L
Boyero
College of Marine and Environmental Sciences and TropWater, James Cook University, Townsville, Queensland 4811, Australia.
Richard G
RG
Pearson
Centre for Invasion Biology, Department of Mathematical Sciences, University of Stellenbosch, Private Bag X1, Matieland 7602, South Africa African Institute for Mathematical Sciences, Muizenburg 7945, South Africa.
Cang
C
Hui
Department of Experimental Limnology, Leibniz Institute of Freshwater Ecology and Inland Fisheries (IGB), 16775 Stechlin, Germany Department of Ecology, Berlin Institute of Technology (TU Berlin), 10587 Berlin, Germany.
Mark O
MO
Gessner
Faculty of Science and Technology, University of the Basque Country (UPV/EHU), 48940 Leioa, Spain.
Javier
J
Pérez
Ecology, Evolution, and Marine Biology, University of California, Santa Barbara, CA 93106, USA.
Markos A
MA
Alexandrou
MARE-Marine and Environmental Sciences Centre, Department of Life Sciences, University of Coimbra, 3001-456 Coimbra, Portugal.
Manuel A S
MA
Graça
School of Natural Resources and Environment, University of Michigan, Ann Arbor, MI 48109, USA.
Bradley J
BJ
Cardinale
Laboratorio de Fotobiologia, INIBIOMA, CONICET, Universidad Nacional del Comahue, Quintral 1250, 8400 Bariloche, Argentina.
Ricardo J
RJ
Albariño
Sri Paramakalyani Centre for Environmental Sciences, Manonmaniam Sundaranar University, Alwarkurichi, 627412 Tamil Nadu, India.
Muthukumarasamy
M
Arunachalam
School of Biological Sciences, University of Tasmania, Private Bag 55, Hobart, Tasmania 7001, Australia.
Leon A
LA
Barmuta
Ecosystem Management, School of Environmental and Rural Science, University of New England, Armidale, NSW 2351, Australia.
Andrew J
AJ
Boulton
Department of Aquatic Ecology, Eawag: Swiss Federal Institute of Aquatic Science and Technology, Überlandstrasse 133, 8600 Dübendorf, Switzerland Institute of Integrative Biology (IBZ), ETH Zurich, 8092 Zurich, Switzerland.
Andreas
A
Bruder
Laboratório de Ecologia de Bentos, Departamento de Biologia Geral, ICB, Universidade Federal de Minas Gerais, 30161-970 Belo Horizonte, MG, Brazil.
Marcos
M
Callisto
UPS, INPT; EcoLab, Université de Toulouse, 118 Route de Narbonne, 31062 Toulouse, France EcoLab, CNRS, 31062 Toulouse, France.
Eric
E
Chauvet
Institute of Agriculture and Environment-Ecology, Massey University, 4442 Palmerston North, New Zealand.
Russell G
RG
Death
School of Biological Sciences, The University of Hong Kong, Pokfulam, Hong Kong SAR, People's Republic of China.
David
D
Dudgeon
MARE-Marine and Environmental Sciences Centre, Department of Life Sciences, University of Coimbra, 3001-456 Coimbra, Portugal Laboratorio de Ecología Acuatica, Colegio de Ciencias Biologicas y Ambientales, Universidad de San Francisco de Quito, Campus Cumbayá, PO Box 17, 1200841 Quito, Ecuador.
Andrea C
AC
Encalada
MARE-Marine and Environmental Sciences Centre, Department of Life Sciences, University of Coimbra, 3001-456 Coimbra, Portugal.
Verónica
V
Ferreira
Faculty of Environmental Science and Water Research Center for Agriculture and Mining, University of Concepción, Box 160-C, Concepción, Chile.
Ricardo
R
Figueroa
Department of Ecology and Evolutionary Biology, Cornell University, Ithaca, NY 14853, USA.
Alexander S
AS
Flecker
Laboratório de Limnologia/AquaRiparia, Departamento de Ecologia, ECL/IB, Universidade de Brasilia, 70910-900 Brasilia, Distrito Federal, Brazil.
José F
JF
Gonçalves
Surface and Groundwater Ecology Research Group, Department of Biological Sciences, University of Toronto at Scarborough, 1265 Military Trail, Toronto, Ontario, Canada M1C 1A4.
Julie
J
Helson
Department of Environmental Sciences, University of Yamanashi, Kofu, Yamanashi 400-8510, Japan.
Tomoya
T
Iwata
School of Science, Monash University, Jalan Lagoon Selatan, Bandar Sunway, Selangor 47500, Malaysia.
Tajang
T
Jinggut
Department of Biological Sciences, Egerton University, PO Box 536, Egerton, Kenya.
Jude
J
Mathooko
Instituto de Investigaciones en Ecosistemas y Sustentabilidad, Universidad Nacional Autónoma de México, Ciudad de México 04510, DF, México.
Catherine
C
Mathuriau
Department of Biological Sciences, Egerton University, PO Box 536, Egerton, Kenya.
Charles
C
M'Erimba
Laboratory of Aquatic Insect Ecology, University of Vila Velha, Vila Velha 29 102-920, Brazil.
Marcelo S
MS
Moretti
Odum School of Ecology, University of Georgia, Athens, GA 30602, USA.
Catherine M
CM
Pringle
Department of Environmental Science, University of Puerto Rico, Rio Piedras, San Juan 00919, Puerto Rico.
Alonso
A
Ramírez
School of Biological Sciences, University of Tasmania, Private Bag 55, Hobart, Tasmania 7001, Australia Institute for Marine and Antarctic Studies and Antarctic Climate and Ecosystems Cooperative Research Centre, University of Tasmania, Hobart, Tasmania 7001, Australia.
Lavenia
L
Ratnarajah
Laboratorio de Contaminación Acuática y Contaminación Fluvial, Departamento de Biología, Facultad de Ciencias, Universidad del Zulia, Apartado Postal 526, Maracaibo, Venezuela Programa Prometeo, Senescyt, Escuela de Biología, Ecología y Gestión, Universidad del Azuay, Apartado 981, Cuenca, Ecuador.
José
J
Rincon
School of Science, Monash University, Jalan Lagoon Selatan, Bandar Sunway, Selangor 47500, Malaysia.
Catherine M
CM
Yule
D001673:Biodegradation, Environmental; D044822:Biodiversity; D058448:Biota; D057486:Carbon Cycle; D002980:Climate; D017753:Ecosystem; D006863:Hydrogen-Ion Concentration; D010802:Phylogeny; D010944:Plants; D045483:Rivers
biodiversity; climate; decomposition; detritivore shredders; latitudinal gradient; litter quality