GEOG 3000 Resource Management ECOLOGY, ECOSYSTEMS AND TRADE OFFS

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GEOG 3000 Resource ManagementECOLOGY,
ECOSYSTEMS AND TRADE OFFS

• M.D. Lee CSU Hayward Winter 2004

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Basic Ecology

• Understanding resource management and especially
  the environmental effects of different resource
  uses and management decisions requires a firm
  grounding in the principles of ecology.
• CRO summarize most of the basic concepts from
  this branch of environmental science in Chapter 3
  knowing for example the carbon and nitrogen
  cycles plays a key role in understanding the
  clean air debate and international dispute over
  global warming and greenhouse gases.
• Please be sure to read this chapter and how it
  relates to the notion of sustainability,
  particularly of renewable resources and
  environmental quality.

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Understanding Cycles
(Source Wright Nebel 2002)
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Ecosystems

• Our world is made up of interlocking and
  interdependent ecosystems the productive
  engines of the planet that provide all our
  renewable resources and are the reservoirs of all
  our non-renewable resources.
• In our use of natural resources, we modify
  ecosystems by changing the arrangement and
  balance of their biotic (living) and abiotic
  (non-living) components, introducing xenobiotic
  (non-natural) elements, and in turn changing the
  processes that govern nature.
• Sustainable natural resource management requires
  understanding the limits of each ecosystem to
  rebound from our impacts and continue to provide
  the materials or environmental services on which
  we have come to depend for our welfare and
  livelihood.

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Flows and Stores

• A key notion to remember is that much of our
  environmental quality and stability depends on
  the maintenance of dynamic equilibria in natural
  cycles.
• Many of these cycles involve complex transfers of
  chemicals to and from various stores in our
  biosphere, lithosphere, hydrosphere and
  atmosphere.
• Changing the rate of flow from one store to
  another can upset those dynamic equilibria,
  leading to negative feedback and unforeseen
  cascade effects.
• Our understanding of ecological complexities and
  inter-relationships is limited, with many effects
  occurring very gradually and cumulatively.
• Many effects are thus out-of-sight or off-site,
  making effective response difficult.

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Ecosystems Must Be Protected

• Resource conflicts have frequently led to a loss
  of sustainability in ecosystem resource
  production.
• WRI 2001 uses the examples of the Black Sea and
  its 2/3rd drop in fish production as a prime
  example of past management failures.
• WRI 2001 Box 1.1. provides an almost 10,000 year
  chronology of notable ecological degradation that
  followed different natural resource exploitation
  practices in different world regions.
• If we rely on our ecosystems for goods and
  services, why do we seem to use them so
  carelessly and degrade them so readily?

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Ecosystem Outputs

• WRI 2001 p9 outlines the principal goods and
  services provided by five major ecosystem types,
  three of which we will examine in some detail in
  this course (agro, forest and freshwater
  ecosystems).
• This list does not include the intrinsic values
  of ecosystems and their components, many of which
  can be considered in anthropocentric terms by
  invoking some of the alternative values like
  existence, bequest (intergenerational), etc.

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Ecosystem Benefits

• Benefits can be direct, indirect and intangible.
• Direct food, raw materials, DNA.
• Indirect broader services derived from
  physical, chemical or biological processes e.g.
  nutrient recycling, water purification, nitrogen
  fixing and oxygen production, pollination, etc.
• Intangible psychological or metaphysical e.g.
  enjoyment, aesthetics, spirituality.
• Note that many of the services, like water
  purification performed by natural wetlands, could
  be replaced by technological equivalents, like
  reverse osmosis treatment plants, but that these
  would create high costs and take resources away
  from other potential uses.

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Scales of Benefits

• Benefits can accrue at and across a variety of
  scales local, regional, even global.
• Some ecosystem components have mutually exclusive
  direct, indirect and intangible benefits, each
  with different scale associations e.g. a tree.
• A tree can be viewed as a single entity, as part
  of a forest or as part of the global carbon
  balance.
• A tree can be cut down or left in place. If it is
  cut down, another tree could be planted in its
  place, or the land could be left treeless. Each
  of these decisions must be viewed as to its
  resource benefits and trade offs.
• Frequently, deciding what to do at one location
  and scale requires consideration of another
  location or scale.
• Commonly, local clashes with regional and global.

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Water Filtration/Purification

• WRI 2001 provides a number of examples of how
  ecosystems yield many benefits and how their
  deterioration imposes costs.
• Box 1.3 describes the water filtration and
  purification provided by healthy soils, forests,
  rivers and lakes and wetlands.
• It tells us how we have eroded and deforested
  slopes, drained and converted 50 of wetlands at
  the same time as we have pumped massive amounts
  of pollutants into watersheds.
• The costs of such actions are many and varied
  from increased spending on home filtering and
  fuel to boil unsafe water to higher mortality and
  morbidity levels.

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Plant Pollination

• WRI Box 1.4 highlights the question of
  pollination.
• According to the data complied by Gary Nabhan and
  others, more than 70 of the worlds 100 most
  important crops need honey bees to pollinate.
• Due to broad ecological changes, pollinators like
  bees are showing serious declines on almost every
  continent.
• Honey bees are being exterminated by invasive
  mites, by pesticides, by habitat loss and by
  hybridization with African bees (in the
  Americas).
• If declines are not reversed, the results could
  be billions of dollars in lost harvest yields,
  extinction of many native flowering plants and
  trees, and a more volatile and unreliable global
  food supply.

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Ecological Modifications

• Since before humans became settled farmers, we
  have modified ecosystems to meet the needs of
  people.
• Sometimes modifications may be minor, like the
  rubber tappers of Brazil who merely use the
  tropical rainforest to extract a harmless
  proportion of trees sap.
• Oftentimes, they are extreme, like Brazilian
  cattle ranchers who slash and burn the rainforest
  to open up the land below to sunshine and allow
  free movement of animal grazing on the grass that
  grows.
• Each approach offers different trade offs,
  yielding one or more kinds of benefits to some,
  but eliminating one or more kinds of benefits to
  others (and/or imposing new or greater costs).

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Focus on Goods

• As can be seen from US resource history,
  ecosystem modifications to date have largely
  focused on satisfying human needs for products
  lumber, minerals, hydropower, building land, etc.
• Only the last 30 or so years have we seriously
  considered the trade offs with respect to
  services and intangibles and have begun to wonder
  if such modifications are sustainable.
• We now more greatly appreciate the notion that
  there are thresholds, beyond which we can
  experience irreversible cumulative impacts.
• However, we still lack good science on the nature
  of these thresholds, and particularly how changes
  in one ecosystem can lead to changes in others.

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The Global Scorecard

• WRI 2001 have compiled the following sobering
  statistics on where we stand vis-a-vis ecosystem
  conversion
• 75 of major marine fish stocks overfished or at
  their limits.
• 50 of the worlds forests gone and many others
  fragmented by roads, etc.
• 58 of coral reef systems threatened by physical
  damage or pollution.
• 65 of agricultural soils eroded or degraded.
• Massive overpumping of groundwater by the worlds
  farmers in excess of natural recharge rates.

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Ecosystem Pressures and Causes

• WRI 2001 p19 lists a table of pressures and
  causes for the five major ecosystem typologies
  they consider.
• Chief cause for each of the degradations is
  population growth and its corresponding demand
  for natural resources.
• Compounding these twin driving forces are a suite
  of economic and political factors imperfect
  market forces, government subsidies, terms of
  trade, dislocated sources and markets, corruption
  and illegal actions.
• Making matters worse are the more local issues
  that drive individuals to destroy or degrade
  their natural ecological capital poverty, lack
  of land ownership (incentive to invest time and
  money), and war.

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Land Conversion

• One of the topics we will tackle in this course
  is land.
• In order to produce food and to create a space on
  which to live, humans have already converted some
  29 of the global land area (WRI 2001 p24).
• Not content with converting wild lands to urban
  uses, we are increasingly converting farmlands
  and pastures to these uses.
• Conversion of land to urban uses has occurred at
  a faster rate than the growth in population,
  since settlements have continued to be extensive
  (sprawl).
• Best estimates suggest that in the next century,
  1/3 of the natural land still left could be
  converted to urban and agricultural uses to feed
  and house people.

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Why So Much Conversion?

• On pages 26-28, WRI 2001 begins to wrap up its
  introduction to ecosystem trade-offs by
  highlighting the two key drivers in more detail
  total and per capita consumption and the
  exponential rise in global population.
• This will be the subject of our next classes.