Chapter 5 : Biomes, Landscapes, Restoration

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• Chapter 5 Biomes, Landscapes, Restoration
  Management
• Major terrestial and aquatic biomes factors
  that determine their distribution
• Humans disturbance of each ecossytem
• Principles of landscape ecology and ecosystem
  management
• Evaluation of the effects of restoration,
  replacement or substituting ecosystems and
  resources damaged by humans

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• Terrestrial Biomes
• Biomes are broad types of biological
  communities with similar climatic and topographic
  conditions with comparable
• communities.
• Temperature and precipitation are the two most
  important factors influencing the type of biome
  found in a location.

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• Deserts
• Desert biomes are characterized by low moisture
  levels and infrequent, unpredictable
  precipitation (2 - 4 in. annual precipitation)
• Desert plants have adapted to prevent water
  loss (leaf adaptations, water-storage tissues,
  thick epidermal layers) and to discourage
  predation (thorns and spines).
• Warm, dry descending air creates broad desert
  bands in continental interiors about 30o north
  latitude.
• Not all deserts are hot. Those found at high
  latitudes and elevations can be cool or even
  cold.
• Desert animals also have adapted to fight the
  heat and conserve water. Many have adopted
  burrowing behaviors to escape the sun, and many
  produce highly concentrated urine and feces in
  order to conserve water.
• Desert soils are easily disturbed by human
  activities (off-roading, overgrazing, etc.) and
  take large amounts of time to recover.

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• Grasslands Prairies and Savannas
• Grasslands are moderately dry areas of
  abundant grasses, herbaceous flowering plants,
  and open savannas. Seasonal cycles for
  precipitation and temperature contribute to the
  rich growth.
• Grasslands have few trees due to inadequate
  rainfall and frequent grassfires.
• In some parts of the world, native people
  use fire to create grasslands for grazing while
  in other parts, fire suppression has greatly
  reduced the amount of native grasslands.

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• Tundra
• Climates in high mountain areas or at far
  northern or southern latitudes are often too
  harsh for trees. This treeless landscape, called
  tundra, is characterized by a very short growing
  season, harsh winters, and the potential for
  frost any month of the year.
• The arctic tundra is a biome of low
  productivity, low diversity, and low resilience.
  Only the upper layer of soil thaws during the
  summer while the lower is permafrost and
  impermeable to plant roots.
• The alpine tundra differs from the arctic
  tundra. High, thin mountain air permits intense
  solar radiation causing many plants to have deep
  pigmentations. The sloping of the land allows for
  better drainage, increasing the chances of
  drought. There is also a wide day-night
  temperature range.
• Although the tundra may swarm with life during
  the brief growing season, few species are able to
  survive the harsh winter. Dominant tundra plants
  are mosses, lichens, grasses, sedges, and dwarf
  shrubs. Flocks of migratory birds and
  bloodsucking insects reside in the arctic
  wetlands. Larger animals (musk ox, caribou,
  mountain goats) must be specially adapted to deal
  with the climate and sparse food supply.
• Damage to the tundra is slow to heal because of
  the short growing season. For example, truck tire
  ruts and bulldozer tracks from the oil and
  natural gas industries may take centuries to
  repair.

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• Conifer Forests
• Coniferous forests are characterized by limited
  moisture which has caused the vegetation to
  develop thin, needlelike evergreen leaves with a
  thick waxy coating.
• The boreal (northern coniferous forest)
  stretches in a broad band of mixed coniferous and
  deciduous trees around the world between 45o and
  60o north latitude. Among the dominant conifers
  are spruce, pine, hemlock, cedar, and fir. Mosses
  and lichens form most of the ground cover.
• Wetlands abound in this biome, especially on
  recently glaciated landscapes. The taiga is the
  far northern border between the coniferous forest
  and the arctic tundra.
• Cold temperatures and wet soil inhibit full
  decay of organic matter. This semi-decayed matter
  is called peat.
• The southern pine forest is characterized by a
  warm, moist climate and sandy soil.
• The coniferous forests of the Pacific coast are
  characterized by mild temperatures and abundant
  precipitation which results in luxuriant plant
  growth and huge trees.
• The wettest part of the coastal forest becomes
  temperate rainforest.

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• Broad-Leaved Deciduous and Evergreen Forests
• Forests of broad-leaved trees where rainfall
  is plentiful are called deciduous forests. Trees
  found here are able to produce summer leaves and
  shed them at the end of the growing season. These
  include oak, maple, birch, ash, and elm trees.

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• Mediterranean/Chaparral/Thorn Shrub
• Mediterranean climates are characterized by
  warm, dry summers and cool, moist winters.
  Evergreen shrubs, scrub oaks, and pines dominate
  this landscape.
• Fires play an important role in plant
  succession here.
• In California, this landscape is called
  chaparral (Spanish for thicket) and is inhabited
  by jackrabbits, mule deer, chipmunks, lizards,
  and bird species.
• In drier areas, this landscape is dominated by
  spiny plants giving it the name thorn shrub.
• This biome is considered to be a hotspot for
  biological diversity.

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• Tropical Moist Forests
• Tropical moist forests are characterized by
  ample rainfall and uniform temperatures.
• Cool cloud forests are found high in
  mountains and cannot resist erosion from the
  abundant rains.

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• Tropical Seasonal Forests
• Tropical regions characterized by distinct
  wet-dry seasons with hot temperatures all year
  round give rise to tropical seasonal forests.
  These areas are dominated by semi-evergreen or
  partly deciduous forests tending toward open
  woodland or grassy savannas.
• Tropical rainforests occur where rainfall is
  abundant (200 cm per year) and temperatures are
  hot year round.
• The soil of these forest types tends to be old,
  thin, and nutrient poor yet the number of species
  present is mind-boggling. It is estimated that
  one-half to two-thirds of all terrestrial plants
  and insects live in tropical forests.
• Nutrient cycling is also unique here. Almost
  all nutrients are tied up in the bodies of
  organisms.
• The forest relies on rapid decomposition and
  recycling of dead organisms to maintain nutrient
  supplies.

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• Aquatic Ecosystems
• Freshwater and Saline Ecosystems
• Freshwater ecosystems include standing waters of
  ponds and lakes as well as flowing waters of
  rivers and streams.
• Freshwater ecosystems are influenced by
  climate, soil, resident communities, and by the
  terrestrial ecosystems surrounding them.
• Availability of essentials for life is
  influenced by dissolved substances, suspended
  matter, depth, temperature, flow rate, bottom
  characteristics, internal convective currents,
  and connections with other aquatic systems.
• Vertical stratification is an important aspect
  of standing water ecosystems, especially in
  regard to gradients of light, temperature,
  nutrients, and oxygen. Stratification of these
  essentials results in the stratification of
  biological communities in the water as well.

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• The bottom sub-community is called the benthos
  and is made up of low oxygen tolerating
  organisms.
• Deep lakes are stratified into an upper
  epilimnion, a middle thermocline, and a lower
  hypolimnion.
• Humans utilize freshwater systems a great deal
  for food, recreation, transportation, and
  industrial uses.
• Not all freshwater systems have what we think
  of as "fresh" water. Some may be salty (Dead Sea,
  Great Salt Lake) while others may contain high
  levels of minerals or be highly alkaline.

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• Estuaries Wetlands Transitional Communities
• Estuaries are bays of brackish water that form
  where rivers enter the ocean.
• They contain rich sediments that support a
  multitude of aquatic life and are important as
  "nurseries" to a variety of species.
• A fan shaped sediment deposit at the mouth of a
  river is called a delta.
• Wetlands are ecosystems in which the land
  surface is covered by standing water at least
  part of the year.
• There are three types of wetlands swamps
  (contain trees), marshes (no trees), and bogs and
  fens (may or may not have trees, tend to
  accumulate peat, low productivity).
• Wetlands are major breeding, nesting, and
  migration staging areas for waterfowl and
  shorebirds.
• Wetlands perform a variety of useful functions
  including detoxification of substances in water,
  clarifying water, and helping replenish
  underground aquifers.
• Wetland areas are being destroyed or degraded
  by human processes at an alarming rate.

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• Shorelines and Barrier Islands
• Ocean shorelines are also particularly rich in
  life-forms, many of which grow attached to solid
  substrates such as exposed rock.
• Barrier islands are low, narrow, sandy islands
  that form offshore from a coastline.
• They protect inland shores from the onslaught
  of the surf. Human activity also destroys these
  fragile ecosystems quite easily.
• Coral reefs form in clear, warm, tropical seas.
  They are the
  accumulated skeletons of innumerable tiny
  colonial animals called
  corals. They support a wide
  variety of interesting organisms. Reefs
  are among the
  most endangered biological communities on earth.

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• Human Disturbance
• Humans have become the dominant organisms over
  most of the earth and have damaged or disturbed
  more than half the world's ecosystems.
• Conversion of natural habitat to human use is
  the largest single cause of loss of biodiversity.
  
• Temperate broad-leaved forests are the most
  completely human-dominated of any major biome.
• Mediterranean climates are also generally
  desirable for human habitation, leading to
  conflict between human preferences and biological
  values.
• Tundra and arctic deserts are among the least
  disturbed biomes in the world. That is changing,
  however, with the discovery of large reserves of
  oil and natural gas.

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• Landscape Ecology
• Landscape ecology is the study of reciprocal
  effects of spatial pattern on ecological
  processes. Reciprocal effects refers to the
• fact that complex spatial patterns shape, and are
  in turn shaped by, the ecological processes that
  occur in them.
• Landscape ecology considers humans important
  elements of most landscapes and take them into
  account in their studies.

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• Patchiness and Heterogeneity
• Landscape ecologists claim that if we look
  closely, all landscapes consist of similar
  mosaics of discrete, bounded patches with
  different abiotic or biotic composition. Often a
  predominant or continuous cover type acts as a
  matrix in which other patch types appear to be
  embedded.
• Landscape heterogeneity can exist across a wide
  range of scale from Yellowstone Park to the
  effects of soil crumb size and insect burrows in
  a few square centimeters of soil.

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• Landscape Dynamics
• Time and space are of special concern in
  landscape ecology.
• The boundaries between habitat patches are
  considered especially significant by landscape
  ecologists. Edges can induce, inhibit, or
  regulate movement of materials, energy, or
  organisms across a landscape.
• There are many similarities between
  landscape ecology and conservation biology.

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Restoration Ecology Restoration ecology seeks
to repair or reconstruct ecosystems damaged by
humans or natural forces.
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• Defining Some Terms
• Restoration involves active manipulation of
  nature to re-create species composition and
  ecosystem processes as close as possible to the
  state that existed before human disturbance.
• Rehabilitation refers to an attempt to
  rebuild elements of structure or function in an
  ecological system without necessarily achieving
  complete restoration to its original condition.
• Remediation is a process of cleaning
  chemical contaminants from a polluted area by
  physical or biological methods.
• Reclamation is used to describe chemical or
  physical manipulations carried out in severely
  degraded sites, such as open pit mines or
  large-scale construction.
• Re-creation attempts to construct a new
  biological community on a site so severely
  disturbed that there is virtually nothing left to
  restore.

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• Conflicting Views of Restoration
• There are conflicting views over the
  effectiveness and ideology of different
  approaches to protecting nature. Two of the
  different camps are preservationists and
  restorationists.
• Preservationists argue that the best
  strategy is to avoid destructive projects in the
  first place. Restorationists counter that we are
  unlikely to preserve more than small areas in
  pristine form. They believe that we should use
  science to repair damage done by destructive
  projects.
• An important question to consider is the
  place of humans in nature. Are we members of the
  biological community or are we separate from it?

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• Tools of Restoration
• There are many different ways to approach
  restoration. Curtis Prairie at the University of
  Wisconsin-Madison was restored through intensive
  horticultural and animal control methods.
• Sometimes, an alien species must be removed
  before native species may take hold again. For
  example, in Hawaii, feral pigs that root out
  native plants and eat native birds are being
  hunted and removed.
• Successional restoration uses fire to
  discourage invasion of exotic species. In
  southern Kansas, fire and native bison have been
  introduced to restore a 16,000 ha tall grass
  prairie.

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Letting Nature Heal Itself Sometimes to
reestablish a healthy ecosystem, all we have to
do is walk away and leave it alone. The DMZ
between North and South Korea is a perfect
example. An area shattered by war that has been
left alone for almost 50 years has become a
thriving wild life refuge.
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Authenticity An important question in
restoration is authenticity. How important is it
to restore a particular place to an exact replica
of its original ecosystem? If a similar, healthy
community can be restored, is that good enough or
must an exact replica be created?
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Back To What? Another important question is
what our goals in restoration should be. For
example, if a preserve is damage due to a
hurricane or fire, should we use science to tidy
up the area or let natural processes take care of
it? Also, if pollen grains preserved in sediment
near a river show the area was a marsh 1000 years
ago, should we restore the area to marshland?
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Creating Artificial Ecosystems Sometimes
artificial ecosystems may be created to solve
human problems. For example, Arcata, California,
created a wetland to deal with it sewage waste
from the city. The wetland allowed for
detoxification of the water and for a beautiful
nature preserve.
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Ecosystem Management Ecosystem management is a
relatively new discipline in environmental
science that attempts to integrate ecological,
economic, and social goals in a unified systems
approach to make environmental management
decisions.
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• Table 5.2 -- Principles of ecosystem management
• Managing across whole landscapes, watersheds,
  or regions over an ecological time scale.
• Considering human needs and promoting
  sustainable economic development and communities.
• Maintaining biological diversity and essential
  ecosystem processes.
• Utilizing cooperative institutional
  arrangements.
• Integrating science and management.
• Generating meaningful stakeholder and public
  involvement and facilitating collective
  decision-making.
• Adapting management over time, based on
  conscious experimentation and routine monitoring.

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• A Brief History of Ecosystem Management
• While the term ecosystem management is
  relatively new, a few ecologists had the
  foresight to advocate many specific elements of
  this science fifty years ago.
• In 1970, environmental policy expert Lynton
  Caldwell wrote that we should use ecosystems as
  the basis for public land policy.
• Currently, many state and federal natural
  resource agencies in the United States are
  attempting to implement ecosystem management as
  their guiding policy.

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• Principles and Goals of Ecosystem Management
• There are several important differences between
  the current integrated approach to ecosystem
  management and traditional policies of the past.
• Hierarchical context A focus on any one level
  of the biodiversity hierarchy is insufficient.
  Ecosystem managers must see interconnections
  between all levels.
• Ecological boundaries Rather than divide
  administrative units by political boundaries,
  natural units should be managed in an integrated
  fashion.
• Data collection and routine monitoring To
  function correctly, ecosystem management requires
  ongoing research and data collection so that
  successes and failures may be recognized and
  evaluated.
• Adaptive management Ecosystem management
  assumes that scientific knowledge is provisional
  and regards management plans as learning
  processes or continuous experiments where
  incorporating the results of previous actions
  allows managers to remain flexible and adapt to
  uncertainty.
• Organizational change Implementing ecosystem
  management requires changes in agency structure
  and ways of doing business.
• Humans in nature People cannot be separated
  from nature.
• Values Regardless of the role of scientific
  knowledge, human values play a dominant role in
  ecosystem management goals.

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• Table 5.3 -- Ecosystem management goals maintain
  viable populations of native species in situ.
• Represent, within protected areas, all native
  ecosystem types across their natural range of
  variation.
• Protect essential ecological processes such as
  nutrient cycles, succession, hydrologic
  processes, etc.
• Manage over long enough time periods to sustain
  the evolutionary potential of species and
  ecosystems.
• Accommodate human use and occupancy within these
  constraints.

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• Critiques of Ecosystem Management
• There are many criticisms of ecosystem
  management. Many ecologists say that due to their
  chaotic, unpredictable nature, we will never
  understand ecosystems and developing policies to
  manage them is a waste of time.
• Many people also fear that effective
  ecosystem management will allow humans to believe
  we can do damage to nature and that at may be
  repaired.