Download Earth as a Living System

Earth as a
Living System
FOCUS ON ECOSYSTEM FUNCTIONS
AND ECOSYSTEM SERVICES
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Earth as a Living System
Earth itself is a system of
biological communities

Biota:


All the organisms of all
species living in an area
or region up to and
including the biosphere
Biosphere:
1.
That part of a planet
where life exists
2.
The planetary system
that includes and
sustains life
Structure

Ecosystems

A set of interacting species that occur in the same
place and functioning together
 Food
chains, food webs, trophic levels
(autotrophs, heterotrophs)

From a small pond to Biomes
Biomes: Areas with similar
climate and plant life
A heterotroph is an organism that cannot fix carbon
and uses organic carbon for growth.
An autotroph is an organism that produces complex organic
compounds from simple substances present in its surroundings,
generally using energy from light or inorganic chemical
reactions.
Ecosystem
A
community of organisms and its local
nonliving environment in which matter
(chemical elements) cycles and energy
flows.
 Life
sustained by interactions of many
different organisms, functioning together,
and interacting through their physical and
chemical environment
 Inherently
complex
Basic Characteristics of Ecosystems

Structure
Living (Ecological Communities) – Hierarchical interactions
 Non-living (physical/chemical environment)


Processes and organization
Growth (already covered)
 Cycling of chemical elements – important and complex



Inflows, recycling, no waste in nature, interactions

Food webs
Flow of energy


Between trophic levels
Change
Evolution
 Succession

TROPHIC LEVELS:
1: Plants and algae make their own food and are called primary producers.
2: Herbivores eat plants and are called primary consumers.
3: Carnivores which eat herbivores are called secondary consumers.
4: Carnivores which eat other carnivores are called tertiary consumers.
5: Apex predators which have no predators are at the top of the food chain
The Community Effect
Population: group of individuals belonging
to the same species living in the same area
 Species interact directly and indirectly

 Symbiosis
 Competition
 Predator
- prey
 Examples ?
Community level
interactions



Community-level interactions

Generalists vs. specialists

Niches
Keystone species

Have large effects on it’s community or
ecosystem

It’s removal changes the basic nature of
the community

Example: Sea otter
Holistic View Needed
Indirect effects

Sea otters, urchins and kelp

Sea otters promote recovery of
seagrass beds
http://phys.org/news/2013-08-seaotters-recovery-seagrass-beds.html

In the news Sep 2012:
http://www.sciencedaily.com/relea
ses/2012/09/120907161437.htm
Other species Types
Classification depends on:

Intrinsic growth rate, r

Carrying capacity, K

Specialization
r
– selected
K
- selected
Change
Evolution – change in genetic material
 Succession

–
–
–
The sequential change in the relative
abundances of the dominant species in a
biological community converging to a climax
state
Primary succession: beginning from an
abiotic environment following a catastrophic
disturbance.
Secondary succession: beginning from a
major disturbance, but all forms of life are not
destroyed
Change

Stages of Succession
Early: plants typically small with short
lifecycles (annuals…), rapid seed dispersal,
environmental stabilizers. r selected,
generalists
– Middle: plants typically longer lived, slower
seed dispersal, and in woodland systems:
larger.
– Late: plants and animal species are those
associated with older, more mature
ecosystem. K-selected species, niches
– “Climax”? - followed by a disturbance
–
Forest succession
Resiliency

An ecosystem is resilient if it can
maintain its functional integrity
when subjected to some
disturbance


Property of the system
How to maintain?

Threshold

Keystone species

Diversity
Evolution
The process of change over time
 Biological evolution



Change in the genetic material via
 Mutations
 Genetic drift
Natural selection
Genotypes
(the genetic makeup of a cell,
organism,
or individual)
 Phenotypes (observable
characteristics)


Survival of the fittest
 “fittest”?
http://www.cdhgenetics.c
om/genetic-overview.cfm
Co-evolution

One species is affected by the evolution of another species

A species is affected by change in the environment

Co-evolution between environment and the economy


Institutions e.g.
Can you think of any examples
of co-evolution?
Different productivity
of Biomes
Processes and Organization
Cycling of chemical elements
 No waste - Closed loops

 Food
webs
 Food
chains
 Trophic levels
 Autotrophs
 Heterotrophs
 Herbivores
 Carnivores
 Omnivores
A food-web for a woodland
ecosystem
The trophic pyramid –
Trophic level
Food Chains and Food Webs

A Terrestrial Food Chain
 Many
trophic levels:
 Autotrophs
 Herbivores
 Carnivores
 Decomposers
 People
are omnivores
(omnivores = animal that eats either other animals or plants)

The Food Web of the Harp Seal
Energy Flows in Ecosystems
10% efficiency between levels
Decomposers
Fungi, Bacteria
Animals
Resease nutrients
Energy flow
Ecosystem services (MEA)

Supporting services


Provisioning services


Food, raw materials, …
Regulating services


Nutrient recycling, primary production, soil
formation.
Waste decomposition, purification of water & air, …
Cultural services

Recreational, spiritual, cultural, education
Examples

In New York City, where the quality of drinking
water had fallen below standards required by
the U.S. Environmental Protection Agency (EPA),
authorities opted to restore the polluted Catskill
Watershed. The cost of this investment in natural
capital was estimated between $1–1.5 billion,
which contrasted dramatically with the estimated
$6–8 billion cost of constructing a water filtration
plant plus the $300 million annual running costs.[21]

Pollination of crops by bees
https://en.wikipedia.org/wiki/Ecosystem_services
Examples

In the 1980s, mineral water company Vittel (now a brand of Nestlé
Waters) faced a critical problem. Nitrates and pesticides were entering
the company’s springs in northeastern France. Local farmers had
intensified agricultural practices and cleared native vegetation that
previously had filtered water before it seeped into the aquifer used by
Vittel. In response Vittel developed an incentive package for farmers to
improve their agricultural practices and consequently reduce water
pollution that had affected Vittel's product. This is an example of
a Payment for ecosystem services program.[25]

It was counted that to plant 15 000 ha new woodland in UK, if we
consider only the value of timber, it would cost £ 79 000 000 which is
more than the benefit of £ 65 000 000. If, however, we include all other
benefits the trees in lowland could provide (like soil stabilization, wind
deflection, recreation wind defense, food production, air purification,
carbon storage, wildlife habitat, fuel production, cooling, flood
prevention), the costs will increase due to displacing the profitable
farmland (would be around £ 231 000 000) but will be overweight by
benefits of £ 546 000 000.[26]
https://en.wikipedia.org/wiki/Ecosystem_services