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What about riparian systems: who benefits from an early seral forest condition. Dr. Stan Gregory Department of Fisheries & Wildlife Oregon State University. Vannote et al. 1980. 24 hr NO 3 dynamics. Frady 2005. Banks 2005. Gregory et al. 1991. Large Wood Input to Streams.
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What about riparian systems: who benefits from an early seral forest condition Dr. Stan Gregory Department of Fisheries & Wildlife Oregon State University
Large Wood Input to Streams OG VanSickle & Gregory 1990 OG McDade et al.1990 OG Murphy and Koski 1989 CC VanSickle & Gregory 1990
Hypothesis Aquatic • Slow • Physical • Surface Terrestrial • Fast • Biological • Deep
Alnusrubra Decay Progression Year 2 Year 6 Year 14 Aquatic Terrestrial
Pseudotsugamenziesii Decay Progression Year 2 Year 6 Year 14 Aquatic Terrestrial
Interannual Variation in Salmonid Populations • Resident trout populations (Mack Creek) • CV = 26% • Anadromous salmon populations (Coast Range) • CV = 60%
Interannual Variation in Trout Populations • Flynn Creek • Before logging CV = 39% • After logging CV = 42% • Needle Branch • Before logging CV = 39% • After logging CV = 130%
Coho Salmon (g/m2) • Stream Flynn Deer Needle • 1959-65 2.24 3.01 2.34 • 1966-74 1.58 3.73 3.13 • 1988-96 1.75 2.20 3.24 • CV (standard deviation/mean) • 1959-65 23.7 17.2 33.5 • 1966-74 55.0 39.7 67.6 • 1988-96 28.6 39.1 55.7
Cutthroat Trout (g/m2) • Stream Flynn Deer Needle • 1959-65 3.65 2.74 3.34 • 1966-74 3.42 2.80 1.71 • 1988-96 2.16 2.10 1.79 • CV (standard deviation/mean) • 1959-65 47.9 40.3 16.6 • 1966-74 14.5 22.7 45.3 • 1988-96 35.3 24.8 66.5
Potential Positive Effects of Early Seral Riparian Forests • Increased aquatic primary production • Increased nutrient uptake by algae • Increased quality of allochthonous inputs • Increased temperature can increase growth and rates of biological processes
Potential Negative Effects of Early Seral Riparian Forests • Increased temperature can decrease growth, increase disease, increase competition, and cause mortality • Decreased uptake of nutrients by riparian plants
Potential Negative Effects of Early Seral Riparian Forests • Decreased inputs of large wood • Decreased habitat complexity • Decreased refuge during floods • Decreased channel stability • Decreased food and nutrient retention
Landscape Perspective • Proportion of landscape and river network in early seral forests • Proportion of riparian areas in early seral stages • Network patterns of environmental factors, nutrients, and physical structure • Network pattern of aquatic ecosystems