PowerPoint Presentation - No Slide TitlePamela A. Matson
Harold A. Mooney
Integrationregulation and management
Ecosystem ecology provides a mechanistic basis for understanding
the Earth System
Ecosystems provide goods and services to society
Human activities are changing ecosystems (and therefore the Earth
System)
Complex: human activity influence
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Study of interactions among organisms and their physical
environment as an integrated system
What is Ecosystem Ecology?
What is an ecosystem?
bounded ecological system consisting of all the organisms in an
area and the physical environment with which they interact
Biotic and abiotic processes
Uptake
Exudation
Washout
Living roots
Dead roots
Living shoot
Ecosystem Structure:
Trophic relations
Trophic relationships determine an ecosystem’s routes of energy
flow and chemical cycling
Trophic structure refers to the feeding relations among organisms
in an ecosystem
Trophic level refers to how organisms fit in based on their main
source of nutrition, including
Trophic levels
Tertiary consumers (quatenary consumers);
Detritivores (organisms that feed on decaying organic matter,
bacteria, fungi, and soil fauna)
Omnivores (feed on everything), frugivore, fungivore…….
Other Definitions
An ecosystem is a bounded ecological system that includes all the
organisms and abiotic pools with which they interact.
An ecosystems is the sum of all of the biological and nonbiological
parts that interact to cause plants grow and decay, soil or
sediments to form, and the chemistry of water to change.
Ecosystem Ecology
The study of the movement of energy and materials, including water,
chemicals, nutrients, and pollutants, into, out of, and within
ecosystems.
The study of the interactions among organisms and their environment
as an integrated systems.
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Small scale: e.g., soil core, appropriate for studying microbial
interactions with the soil environment, microbial nutrient
transformations, trace gas fluxes,…
Example 2
Stand: an area of sufficient homogeneity with regard to vegetation,
soils, topography, microclimate, and past disturbance history to be
treated as a single unit.
Appropriate for studying whole-ecosystem gas exchange, net primary
productivity, plant-soil-microbial nutrient and carbon fluxes
Example 3
Appropriate questions include whole-lake trophic dynamics and
energy fluxes (e.g. Lindeman)
Example 4
Watershed: a stream and all the terrestrial surface that drains
into it.
Watershed studies use stream as “sample device”, recording surface
exports of water, nutrients, carbon, pollutants, etc., from the
watershed.
Temporal Scale
Margalef: Information transfer
Tansley, British plant ecoslogist
The use and abuse of vegetational concepts and terms. Ecology 16:
284-307
First to coin term, “ecosystem”
Emphasized interactions between biotic and abiotic factors
Argued against exclusive focus on organisms
Hans Jenny, Soil scientist
Factors of soil formation, 5 state factors that constrain soil and
ecosystem development
Soil = function of Climate, organisms, parent material, relief
(topography) and time, or s=f(clorpt)
Many patterns of soil and ecosystem properties correlate with state
factors (climate and vegetation structure and function)
Ramond Lindeman
Qualified pools and fluxes of energy in a lake ecosystem
emphasizing biotic and abiotic components and exchange
Fluxes of energy, critical “currency” in ecosystem ecology, basis
for comparison among ecosystems
Synthesized with mathematical model
J. D. Ovington, English forester
Central question, how much water and nutrients are needed to
produce a given amount of wood?
Constructed ecosystem budgets for nutrients, water, and
biomass
Also included inputs and outputs: exports of logs involves exports
of nutrients (thus inputs of nutrients required to maintain
productivity
One of the first to state the need for more basic understanding of
ecosystem function for managing natural resources
H. T. Odum and E. P. Odum
Used radioactive tracers to study movement of energy and materials
through a coral reef, documenting patterns of whole system
metabolism
System analysis- ecosystem as a life-support system concept
Earth System and Global Change
Making history in ecosystem ecology
Impact of human activities on Earth has led to the need to
understand how ecosystem processes affect the atmosphere and
oceans
Large spatial scale, requiring new tools in ecosystem ecology
(fluxes tower measurements of gas exchange over large regions,
remote sensing from satellites,global networks of atmospheric
sampling, global models of ecosystem metabolism).
Frontiers in ecosystem ecology
Integrating systems analysis, process understanding, and global
analysis
How do changes in the environment alter the controls over ecosystem
processes? What are the integrated consequences of these changes?
How do these changes in ecosystem properties influence the Earth
system?
Rapid human-induced changes occurring in ecosystems have blurred
any previous distinction between basic research and management
application
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