Life Zones:  usually very large regions, with distinct physical characteristics
     distinct climate (if on land), distinct temperature/salinity/current (if at sea)
     distinct organisms adapted to those particular physical conditions
     terrestrial life zone = biome, exclusive of water (but transitional)
          forests, tiaga, grasslands, plains, deserts, subalpine, alpine, tundra, etc.
     aquatic life zones: divided into fresh water (continental) and saltwater (oceanic)
          fresh water:  lakes, rivers, streams, groundwater, marshes, swamps, bogs, etc.
          marine:  bays, estuaries, sounds, continental shelf-slope-rise, abyssal plain, etc.
     habitat: small part of biome, the place where an organism lives

Ecosystem: community of organisms and their interaction with each other and abiota
     species:  individual organism, genetically very similar, breeds with own kind
     population:  all members of the same specie; human population, Bengal tigers....
     community:  all of the organisms from one place/biome/habitat
          the forest community, the swamp community, the wheat field community
     ecosystems can be found at many scales, no sharp boundaries
          ex:  tropical rainforest of central South America (Costa Rica, etc.)
               huge region, high density of biota (high biomass), high diversity of biota
          ex:  side of a rock in North Greenland; small area, low density & diversity of biota

Interactions Among Organisms: all species within a region/ecosystem = community
     can arrange biota into a food chain/food web: shows movement of energy & matter
      producers at base, converting abiotic components to biotic material
      predators and parasites  at top feeding on producers and consumers
     mutuals (mutually beneficial) and commensals (neutral) do not consume each other
     organisms compete with same species and other species for habitat, food, mates, etc.

Biomass : total mass of organisms.  can be very difficult to actually measure in practice
     in a food chain, most of the biomass usually at the base (= producers), unless eaten fast
     least amount of biomass at the top (= tertiary consumers); yields biomass pyramid
     high biomass ecosystems:  estuaries, swamps, forests (wet and warm and sunny)
     low biomass ecosystems:  deserts, tundra, deep ocean (dry and cold and dark)

Biodiversity:
     species diversity:  number of different species in a community (species richness)
          variability = stability in interactions among organisms; the "one prey" rule
     genetic diversity:  genetic variability in each specie (not all gannets look alike)
          important for adaptation to short term changes, species survival and evolution
     ecological diversity:  variability in ecosystems and communities

Natural Forests: only a few percent left around Earth, mostly in tropics
          extended across all continents up to timberline (controlled by altitude and latitude)
          many terrestrial ecosystems were forests, except deserts, swamps, grasslands, etc.
     tropical rain forests: warm and humid, mostly broadleaf evergreen, very dense
          palms, rubber, neem, mahogany, teak, ohia, eucalyptus, banana, etc.
     temperate rain forests: cooler moderate, mostly softwood coniferous evergreens
          firs, spruce, hemlocks, redwoods, pines, etc.  "boreal forests"
     temperate hardwood forests: cooler seasonal, mostly hardwood deciduous
          maples, oaks, sycamore, beech, poplar, hickory, etc.
     taiga: cold lowland, typical of subpolar/subarctic areas
          pines, spruce, firs, birch, etc.  low density, scattered trees
     alpine forests:  cold upland, slow growing coniferous evergreens, very low density

Trees as Natural Resources: for humans, in addition to other plants and animals
          huge variety of trees, therefore huge variety of derivative products
     foodstuffs:  fruits, nuts, oils, sugars, syrups, flavorings, etc.
     fuel:  wood and charcoal, still one of most widely used fuels on planet
          very inefficient source of heat, also very highly polluting, but renewable ±
     construction products: poles, beams, lumber, plywood, particle board, etc.
          excellent construction material:  light, durable, fungible, low tech, locally available
     chemical compounds:  turpentine, dyes, tannin, alcohol, resins, glues, drugs.    [paper]

Logging Natural Forests:
     old growth forests: variable definition (virgin to >75 years)
          highly prized because of high yield, straight grain, long timbers, special trees
     second growth forests:  logged one or more times, replanted manually or naturally
          lower yields, smaller trees for poles, plywood, paper, etc.  pedestrian species
     logging practices:  vary tremendously between and among LICs and MICs
         clear cutting: every tree in certain area; highest negative impact but efficient
         selective logging:  "thinning" some trees.  even-aged vs variable-aged logging
         strip or alley logging: regenerates quickly but lots of road damage, incursions
     many obvious to subtle effects of cutting natural forests: alter ecosystem in many ways
          e.g. reduce amount of fog drip captured by tall trees, up to 10% decrease in water
          e.g. alter microscopic fungi in humic layer necessary for tree root uptake of nutrients

Logging Tree Plantations:  cut all trees, replant with one or more species, harvest
          replanted trees often genetically engineered through breeding, etc.
     monoculture plantations: single fast growing specie such as Douglas fir, cottonwood
          practiced mostly on private lands (e.g. Weyerhaeuser), but also on public too
         --concentrate logging activities on smaller acreage, leave natural forests alone
          utilize same set of roads, etc. for several generations of logging
         --lowest value timber ("stick forests"), doesn't produce value added products
         --monoculture susceptible to disease, infestation because no biodiversity
         --rapid depletion of selected soil nutrients, must rotate "crop" or fertilize (sludge)

It wasn't the spotted owl, it was the modernization of wood processing equipment....

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