Premium
Does flood rhythm drive ecosystem responses in tropical riverscapes?
Author(s) -
Jardine Timothy D.,
Bond Nicholas R.,
Burford Michele A.,
Kennard Mark J.,
Ward Douglas P.,
Bayliss Peter,
Davies Peter M.,
Douglas Michael M.,
Hamilton Stephen K.,
Melack John M.,
Naiman Robert J.,
Pettit Neil E.,
Pusey Bradley J.,
Warfe Danielle M.,
Bunn Stuart E.
Publication year - 2015
Publication title -
ecology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.144
H-Index - 294
eISSN - 1939-9170
pISSN - 0012-9658
DOI - 10.1890/14-0991.1
Subject(s) - ecology , flood myth , ecosystem , floodplain , disturbance (geology) , biodiversity , productivity , environmental science , riparian zone , predictability , climate change , species richness , surface runoff , geography , biology , habitat , paleontology , physics , macroeconomics , archaeology , quantum mechanics , economics
Biotic communities are shaped by adaptations from generations of exposure to selective pressures by recurrent and often infrequent events. In large rivers, floods can act as significant agents of change, causing considerable physical and biotic disturbance while often enhancing productivity and diversity. We show that the relative balance between these seemingly divergent outcomes can be explained by the rhythmicity, or predictability of the timing and magnitude, of flood events. By analyzing biological data for large rivers that span a gradient of rhythmicity in the Neotropics and tropical Australia, we find that systems with rhythmic annual floods have higher fish species richness, more stable avian populations, and elevated rates of riparian forest production compared with those with arrhythmic flood pulses. Intensification of the hydrological cycle driven by climate change, coupled with reductions in runoff due to water extractions for human use and altered discharge from impoundments, is expected to alter the hydrologic rhythmicity of floodplain rivers with significant consequences for both biodiversity and productivity.