forest ecosystem services
water purification, flow control, withdrawal/storage of carbon, conserve biodiversity,
provide recreation/inspiration, wood products
wood products
fuel, paper, building materials
building materials
>1 billion cubic meters harvested for building materials annually, majority of which is
lumber and plywood
paper
540 million cubic meters converted to pulp annually
110 lbs of paper for everyone on earth annually
Americans: ~700 lbs Africans: >2.2 lbs
non wood products found in forests
pharma
fuel from wood
provides 7% of energy used
conifers
seeds grow in cones
angiosperms
seeds grow in flowers
primary growth of trees
upward growth of shoot, downward growth of root
phloem
medium through which carbs are transferred to roots
xylem
medium through which water/nutrients transported up the stem
secondary growth of trees
increase in xylem growth
4 stages of tree community development
1. establishment
2. thinning
3. transition
4. old growth
deforestation
removal of forest to allow alternative land uses
causes: agricultural expansion, wood harvest, roads, urban development, economics,
politics
halting deforestation
improved agricultural practices, manage population growth, reduce demand for virgin
wood, reforestation/sustainable management
degradation of forests
primary vs. secondary forests
causes: cutting/high grading, fragmentation, altered disturbance patterns, non-native
species
, harvesting of forests
clear cutting: complete renewal, even-aged management, uneven-aged management:
trees, dead snags, woody debris, to produce more heterogeneous age structure
criteria for sustainable forest management
1. biodiversity
2. produce capacity
3. ecosystem health and vitality
4. soil and water resources
5. global carbon cycle
6. socioeconomic benefits
hydrology
study of earth's water
fluvial geomorphology
erosion and deposition
geomorphic work
interaction of force vs. resistance
stream order
a way of classifying streams based on number of streams feeding into them
types of streams
intermittent and perennial
intermittent streams
dry most of the year, except when groundwater is high enough or after a rainfall event
perennial streams
flows throughout the year
higher above stream base level
more potential energy
stream base level
water flows down hill until reaching this flat level
above base level
erosion and transportation
closer to base level
meandering and floodplain building
3 basic stream channel patterns
straight, meandering, braided
riffle pool sequences
form 5-7 bankfull widths apart
alluvial terraces
old floodplains
sediment sources
landscape, bed, banks
stream competence
streams ability to move particles of a specific size, is a function of velocity and energy
available to suspend materials
stream capacity
total amount of sediment a stream can carry
point source pollution