the importance of floodplains and off channel habitats for stream
TRANSCRIPT
The Importance of Floodplains and Off Channel Habitats for StreamOff Channel Habitats for Stream
Food Webs and Biota(and vice versa)
Dr. Matthew CoverC lif i St t U i it St i lCalifornia State University Stanislaus
Take‐home points1. Floodplains are among the most dynamic and endangered ecosystems in the world
2. Stream, riparian, and floodplain food webs and ecosystems are inextricably connected, especially in alluvial valleysalluvial valleys
3. Channel incision results in the loss of geomorphic processes, loss of floodplain connectivity, loss of riparianprocesses, loss of floodplain connectivity, loss of riparian habitat complexity, and loss of animal and plant biodiversity in aquatic, riparian, and upland habitats
Floodplains are dynamicFloodplains are dynamicGeomorphic processes + riparian plant community succession = a shifting habitat mosaicCut and fill alluviation Avulsion
Latterell, J.J. et al. 2006. Dynamic patch mosaics and channel movement in an unconfined river valley of the Olympic Mountains. Freshwater Biology 51:523‐544.
Shifting Habitat MosaicShifting Habitat Mosaic
Rio Parana:Brazil, Paraguay, , g y,Argentina
Robinson, C.T., Tockner, K., and Ward, J.V. 2002. The fauna of dynamic riverine landscapes. Freshwater Biology 47:661‐677.
Geomorphic‐Biotic feedbacks d d ll l h bproduce diverse alluvial habitats
No Beavers BeaversMouw J E B et al 2012 Recruitment and successsionalMouw, J.E.B. et al. 2012. Recruitment and successsional
dynamics diversify the shifting habitat mosaic of an Alaskan floodplain.
“…elevated bank strength (provided by alfalfa sprouts) relative to the cohesionless bed material and the blocking of troughs (chutes) in the lee of point bars via suspended sediment deposition were the necessary ingredients to successful meandering.”
Braudrick, C.A., et al. 2009. Experimental evidence for the conditions necessary to sustain meandering in coarse‐bedded rivers. PNAS 106:16936‐16941.
Polvi, L.E., and Wohl, E. 2013. Biotic drivers of stream planform. Bioscience.
2. Stream‐Riparian Food Webs2. Stream Riparian Food Webs
Baxter, C., Fausch, K., and Saunders, C. 2005. Tangled webs: reciprocal flows of invertebrate prey link streams and riparian zones. Freshwater Biology 50:201‐220.
• 18‐25% of f li Nfoliar N from marinemarine sources
Merz, J.E., and Moyle, P.B. 2006. Salmon, wildlife, and wine. Marine‐derived nutrients in human‐dominated ecosystems of central California. Ecological Applications 16:999‐1009.
3. Ecogeomorphic Effects of Channel Incision
Incision ‐> loss of floodplain connectivityIncision > loss of floodplain connectivityloss of geomorphic processesloss of riparian habitat complexityloss of riparian habitat complexityloss of animal and plant biodiversity i ti i i d l d h bit tin aquatic, riparian, and upland habitats
Hohensinner, S. et al. 2011. Spatio‐temporal habitat p pdynamics in a changing Danube River landscape 1812‐2006. river research and Applications 27: 939‐and Applications 27: 939955.
Laesser, S.R., Baxter, C.V., Fausch, K.D. 2005. Riparian vegetation loss, stream channelization, and web‐weaving spiders in northern Japan. Ecological Research 20:646‐651.
Take‐home points1. Floodplains are among the most dynamic and endangered ecosystems in the world
2. Stream, riparian, and floodplain food webs and ecosystems are inextricably connected, especially in alluvial valleysalluvial valleys
3. Channel incision results in the loss of geomorphic processes, loss of floodplain connectivity, loss of riparianprocesses, loss of floodplain connectivity, loss of riparian habitat complexity, and loss of animal and plant biodiversity in aquatic, riparian, and upland habitats