Midterm Flashcards
Two techniques that increased stream habitat damage caused by forestry?
Steam, diesel, gas machinery
Three negative consequences from logging on stream habitat?
Increase in sedimentation, altered drainage systems, loss of LWD cause habitat loss and stream simplification, hill slope failures, channelization, loss of fish passage, oligotrophication, thermal stress
At what rate of LWD in streams is lost and how long will the deficient last?
10%, 75-100 years
Two effects of decreased LWD on stream ecology and habitat
loss of refugia in heavy flows for fish, loss of leaf litter recruitment which supplies nutrients in the stream
Two processes that LWD is naturally recruited into steam
High winds, erosion
Two changes in urbanized watersheds that allow contaminated rainwater to low into streams rivers and lakes
Removal of vegetation, impervious surfaces
What are some modifications in urban watersheds to improve conditions?
Galleries, created wetlands, detention ponds, ,swales
What do infiltration galleries, created wetlands, detention ponds, ,swales do to urban watersheds?
Intercept overland and storm drain flows to allow water to slowly seep into ground and back into water courses
What year did the Fish-Forestry Clear-Cut Guidelines come into effect in COASTAL bc
1998
What year did the Fish-Forestry Clear-Cut Guidelines come into effect in INTERIOR bc
1995
What did the Fish-Forestry Clear-Cut Guidelines do?
Prohibited riparian logging to streambank
What is the stream order classification called and how does it work?
Strahler, when two streams meet they go up in number, two headwater streams becoming 2nd order
Meandering streams have a sinuosity of?
Greater than 1.5
What is a stream called when it is no longer degrading or agrading?
A graded stream
What is dynamic equilibrium of a stream?
The ability for a stream to transport all of its water and most / all of its sediment
What are the 4 parameters that adjust when a channel is trying to establish equilibrium?
Slope, depth, width, grain size
Rank following channel types in decreasing order of steepness: riffle pool, cascade pool, step pool
Step pool, cascade pool, riffle pool
What channel type will you have highest abundance and diversity of fish and why?
Riffle pools since it provides diversity of habitat and diversity of velocities through out the stream which provides refugia
Where in the drainage basin are there most often debris flows?
Headwaters
What channel morphology type would you not recommend for LWD restoration and why?
Cascades and step pools because flows are very strong and may shift or move LWD and they don’t naturally occur in those streams
What is lanes equation?
QS = QsD
The 4 H for cause of declining salmon stocks
Habitat, hydropower, over harvest, hatcheries, pollution
Why should we consider restoration of the watershed and what time frame?
River continuum concept, what happens upstream effects downstream. To restore downstream you must look at what is happening above. Short term 20-50 eyars
Two positive outcomes from proper planning for watershed restoration?
Higher likelihood of reaching goals, better use of funs
