Seasonal variation of macroinvertebrates in a temporary wetland in northern California Michael Peterson, Lisa Hunt, Ming-Chih Chiu and Vincent Resh University of California, Berkeley Society for Freshwater Science – May 2016

Seasonal wetlands provide aquatic habitat during certain seasons

Temporary wetlands are significant sources of biodiversity

WetDryWet Aquatic invertebrates have a diversity of life history strategies to utilize seasonal habitats

WetDryWet > Desiccant-resistant eggs > Fast larval development > Colonization from permanent aquatic habitats Aquatic invertebrates have a diversity of life history strategies to utilize seasonal habitats

Research objectives Examine the seasonal progression of abiotic conditions during the hydroperiod of a seasonal wetland over multiple years

Research objectives Examine the seasonal progression of abiotic conditions during the hydroperiod of a seasonal wetland over multiple years Describe seasonal variability in taxonomic composition and taxa abundances in the macroinvertebrate community

Research objectives Examine the seasonal progression of abiotic conditions during the hydroperiod of a seasonal wetland over multiple years Describe seasonal variability in taxonomic composition and taxa abundances in the macroinvertebrate community Assess the succession and co-occurrence of common macroinvertebrate predators

Hog lake is a seasonal wetland in northern California a small wetland (3,200 m) Mediterranean climate

We sampled repeatedly throughout the hydroperiod Every 2-4 weeks during the wet seasons of 2007 – 2009: Measured temperature, dissolved oxygen, conductivity, wetland physical dimensions Invertebrates collected using a sweep net Visual observations of aquatic vertebrates

The hydroperiod of hog lake Dec - FebMarch Apr May June July - Nov

Physical dimensions of wetland change during hydroperiod Dec - FebMarch Apr May June July - Nov

Surface area decreased and temperature increased over the hydroperiod Dec - FebMarch Apr May June July - Nov 3200 m1800 m 1340 m 600 m Temperature over the hydroperiod Conductivity over the hydroperiod

Progression of macroinvertebrate community Dec - FebMarch Apr May June July - Nov Aquatic insect abundances over the hydroperiod Number of predator taxa over the hydroperiod

Biological community changes during hydroperiod Dec -FebMarch Apr May June July - Nov Fairy shrimp and clam shrimp Lestes damselflies

Biological community changes during hydroperiod Dec -FebMarch Apr May June July - Nov Limnephilus caddisflies present Notonecta backswimmers present Fairy shrimp and clam shrimp Lestes damselflies and Libellulid dragonflies

Biological community changes during hydroperiod Dec -FebMarch Apr May June July - Nov Limnephilus caddisflies present Notonecta backswimmers present Pulse of baetid mayfly nymphs Fairy shrimp and clam shrimp Lestes damselflies and Libellulid dragonflies

Biological community changes during hydroperiod Dec -FebMarch Apr May June July - Nov Larval California newts absent Larval California newts present Fairy shrimp and clam shrimp Limnephilus caddisflies present Notonecta backswimmers present Lestes damselflies and Libellulid dragonflies Pulse of baetid mayfly nymphs

Seasonal wetlands provide aquatic habitat during certain seasons March April May June

Seasonal wetlands provide aquatic habitat during certain seasons March April May June

Life history traits may explain species progression Crustaceans, such as fairy shrimp and clam shrimp, may be early colonizers because of desiccant tolerant eggs Limnephilus caddisflies were exclusive to March samples

Life history traits may explain species progression Crustaceans, such as fairy shrimp and clam shrimp, may be early colonizers because of desiccant tolerant eggs Limnephilus caddisflies were exclusive to March samples The presence of amphibians as top predators in seasonal wetlands can influence the composition of the macroinvertebrate community Notonecta and Lestes may co-occur late in the hydroperiod because they have different foraging behaviors and can therefore feed in different microhabitats.

Climate may exacerbate life-history tradeoffs Hydroperiod is likely to decrease with warmer air temperatures Species reliant on cool, early season conditions may be vulnerable to weak November/December precipitation

Climate may exacerbate life-history tradeoffs Hydroperiod is likely to decrease with warmer air temperatures Species reliant on cool, early season conditions may be vulnerable to weak November/December precipitation Species with long development times may be vulnerable to extreme variability in abiotic conditions late in the season Proximity to permanent wetlands and streams may be important refuges for biodiversity

Syntheses of natural history Sensitive species Water resources The role of natural history studies in temporary wetlands

Acknowledgements Research support Hopland Research and Extension Center Patina Mendez and Joan Ball Funding support Edward Colman Watershed Management Fellowship Steven J. Souja Award in Entomology Robert Usinger Award in Aquatic Entomology Margaret C. Walker Fund for research in Systematic Entomology Department of Environmental Science, Policy, and Management