02.agroecosystem concept - medha...
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02. AGROECOSYSTEM CONCEPT
� What is an ecosystem, and how can we study one?
� Is the earth an open or closed system with respect to energy and elements?
� How do we define "biogeochemical cycles," and how are they important to ecosystems?
� What are the major controls on ecosystem function?
� What are the major factors responsible for the differences between ecosystems?
The concept of the agroecosystem is
based on ecological principles
NATURAL ECOSYSTEMSNATURAL ECOSYSTEMSNATURAL ECOSYSTEMSNATURAL ECOSYSTEMSNATURAL ECOSYSTEMSNATURAL ECOSYSTEMSNATURAL ECOSYSTEMSNATURAL ECOSYSTEMS
Mineral/materi
Gen Sel Organ Organisme Populasi Komunitas
Sel
Sistem
Organ
Sistem
Organisme
Sistem
Populasi
Sistem Ekosistem
Gambar. Spektrum Ekologi
Organization of Life
Organisms
Populations
Communities
Ecosystems
Biosphere
BiosphereBiosphere
Ecosystems
Communities
Populations
Organisms
Scales of Ecological Organization
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INDIVIDU?POPULASI ?
KOMUNITAS ?
A
B
C
INDIVIDUAL ORGANISM
OrgansTissuesMolecules Cells Organs
systems
Concerned :how is a organism response the environmental factors?
How is a individual organism tolerance to stresses in environment where it will live?
Autecology/Physiological ecology Organism
POPULATIONS
� A population is a group of individuals of the
same species inhabiting the same area at
the same time.
� Important characteristics:
○ Population size, density, and dispersion
○ Birth and death rates
○ Growth rates
○ Age structure
○ Genetic Diversity
Characteristics of Populations
1. Population size,
density, and
dispersion
2. Birth and death rates
3. Growth rates
4. Age structure
5. Genetic Diversity
POPULATIONS
� Concerned :
Important in determining the factors that control population size and growth
relation to the capacity of the environment to support population over time
Population ecology
Population Ecology
� A population is a group of plants, animals, or other organisms, all of the same species, that live together and reproduce.
� The important of population ecology
1. Numbers of individuals in a population
2. Population dynamics: how and why those numbers increase or decrease over time
3. Population ecologists try to determine the processes common to all populations
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Population Ecology in Action
� Biologists in applied disciplines such as
� Forestry
� Agronomy (crop science)
� Wildlife management
� Must manage populations of economic
importance
� Prevent threatened or endangered species
from extinction
COMMUNITIES� Communities an assemblage of populations
of many species living together in the same
location at the same time.
� The important thing :
1. Community structure and functioning
2. Community Biodiversity
○ Number and types of species
○ Relative abundance of species
○ Interactions among species
3. Community Development
○ Community resilience to disturbance
○ Nutrient and energy flow
COMMUNITIES
Community ecology
� Concerned :
How the interactions of organism affect the distribution and abundance of the different species
ECOSYSTEMS
� Ecosystems are composed of all the communities and their physical, chemical, and biological processes.� Ecosystems sustain
themselves entirely through energy flow through food chains, and nutrient recycling.
Flamboya n
Songgoriti
Baru
Brau Lebak
Toyom arto
Borolas ah
B orogon dang
Las ah
Ngudi
B rak
Dur ek
Sawa han
Sabr angbendo
Kedung
Cem bo
Ngu jung Dadap an
Pandan
Tlogorejo
Binang un
Beru
Rek esan W etan
Rek esa n Kulon
Cangar
Gi ntung
K lir an
P rumb ung
Brau
Clak et
Tala ngs ari
Ngebruk P agersa ri
Prambatan
P agergu nung
Kapr u Kandanga n
Selekta
Sidorejo
Sumb erbran tas
Gabes
Junggo
Gerdu
Kek ep
Tegalsari
Sengonan
Paya n
K ungku k
Gem bol
Sikorembug
Tinjomoyo
Santri an
Sum bersar i
Pes antren
Pes anggrahan
Wun ucari
Srebet Barat
Plam boyan
Tambuh
K lum us an
Ngemul
Nga gl ik Ut ara
Meduran
Kali putih
Leban
Krajan
Kajar
Banar an
Gem ulo
Ta langr ejo
Gondang
Segu ndu
P unten
Tonggolari
Sumberejo
Srebet Timur
S onggo kerto
Ngagl ik Selata n Krajan
B umiaji
Ngudi
Dadaptulis Utara
Ngandat
J eding
Rejoso
Tlekung
Ngukir
Kler ekK alimal ang
Dresel
Gondorejo
Toy omerto
Sreb et Tim ur
K ampun gteh
Glon ggong
Besu l Genengan
Suko mulyo
Kam punganyar
Temas Barat Putuk
Gentin g
Meduran
Kamp ungan yar
Ngem ul
Pend em
Kajang
Gangsiranputuk
Bej i
Krajan
Oro-or oom bo
Temas
Jun rejo
B atu
Ka
li B
ranta
s
DESA TULUNG REJO
KEL. TEMAS
DESA GI RIPU RN O
DESA BUM IAJI
DESA PANDANREJO
KEL. SI SIR
DESA BULU KERTO
DESA SUM BERGONDO
DESA BEJI
DESA TAWAN GARGO
KEL. NGAGLIK
DESA GUN UN GSARI
DESA TORONGREJO
DESA ORO-O ROOMBO
DESA PANDESAR I
DESA J UNR EJO
KEL. SO NGG OKERTO
AREAL KEHU TANAN
DESA S IDO MULYO
DESA PASANG GRAHAN
DESA MOJ OREJO
DESA SUMBEREJO
DESA PUNTEN
DESA PEND EM
DESA TLEKU NG
DESA DAD APREJO
KEL. PENCALUKAN
DESA T OYOMARTO
665000
665000
670 000
670 000
675000
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912
500
0 91250
00
913000
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30000
913
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PETA LANDUSE TAHUN 2006 DI SUB DAS BRANTAS HULU
2000 0 2000 4000 Meters
U
TB
S
Landuse:: Hutan Alami: Hutan Produksi: Hutan Reboisasi: Lahan Terbuka: Pemukiman: Perkebunan: Rumput: Sawah: Semak: Tegalan
Example:
In Watershed
ABIOTIC COMPONENTS BIOTIC COMPONENTS
Sunlight Primary producers
Temperature Herbivores
Precipitation Carnivores
Water or moisture Omnivores
Soil or water chemistry (e.g., P, NH4+) Detritivores
etc. etc.
All of these vary over space/time
Components of Ecosystem
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The biosphere is the
global sum of all
ecosystems. It can also be
called the zone of life on
Earth. From the broadest
biophysiological point of
view, the biosphere is the
global ecological system
integrating all living beings
and their relationships,
including their interaction
with the elements of the
lithosphere, hydrosphere
and atmosphere
Biosphere Structural Properties of Communities
� Species Diversity
� Dominance and Relative Abundance
� Vegetative Structure (ex: grassland,
forest )
� Trophic Structure
� Stability
Figure. Relationships within an ecosystem
NATURAL ECOSYSTEMNATURAL ECOSYSTEMNATURAL ECOSYSTEMNATURAL ECOSYSTEM
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Processes of EcosystemsProcesses of EcosystemsProcesses of EcosystemsProcesses of Ecosystems
How ecosystems function:
1. Ecosystems have energy flows and
ecosystems materials cycles.
2. Ecosystems have nutrient cycles
Figure. Energy flows and material cycles.
1. Energy flows1. Energy flows1. Energy flows1. Energy flows and materials materials materials materials cyclescyclescyclescycles
Figure. Relationship between energy flow and nutrient cycle
2. Energy flows2. Energy flows2. Energy flows2. Energy flows and nutrient nutrient nutrient nutrient cyclescyclescyclescycles
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Biochemical Biochemical Biochemical Biochemical cycles in ecosystemcycles in ecosystemcycles in ecosystemcycles in ecosystem
1.
2. The carbon cycle
3. The phosphorus cycle
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AGROECOSYSTEMAGROECOSYSTEMAGROECOSYSTEMAGROECOSYSTEM
AGROECOSYSTEM VS. NATURAL ECOSYSTEM AGROECOSYSTEM VS. NATURAL ECOSYSTEM AGROECOSYSTEM VS. NATURAL ECOSYSTEM AGROECOSYSTEM VS. NATURAL ECOSYSTEM
� Natural ecosystem is closed, or at least, unmanaged ecosystem� Closed ecosystem—all elements recycled through ecosystem—
not often pure closed ecosystems anymore—humans frequently involved
� Agroecosystem is an open ecosystem, or managed ecosystem:� Producer moves plants, animals, environmental factors
(fertilizers, feed) in & out of ecosystem
� Will not continue on its own without management
� If left alone, would progress toward closed ecosystem, but probably not the same as original ecosystem before agriculture without human input again
Characteristics Agroecosystem Natural Ecosystem
Productivity High Low
Species diversity Low (monoculture)—can use crop rotation and
intercropping to stabilize more
High
Genetic diversity within species
Low High
Plant life-cycles present
Few All, more perennial
Competition Negative Tolerable (ecological niche)
Flowering, plant maturing
Synchronized Seasonal
Nutrient Cycles Open Closed
Permanence Short Long
Human Control High Low
Ecological Maturity Early, immature Mature, climax
ENERGY FLOWENERGY FLOWENERGY FLOWENERGY FLOW
Figure 2.7 Functional components of an agroecosystem.
Crop Populations Natural Plant Population(also true of weeds)
Seed brought in by producer Seed produced mostly by local plants
High seed viability Variable seed viability
Uniform seed dispersal Non-uniform seed dispersal
Low dormancy, carryover of seed
Possibility of dormancy, delayed germination (carryover)
Uniform soils Variable soil types
Uniform population age, genetics
Diverse population age, genetics
Even spacing within species Variable spacing within species
High allocation of plant resources to reproduction (seed)
Allocation to seed production may be lower
POPULATIONPOPULATIONPOPULATIONPOPULATION REGULATING MECHANISMREGULATING MECHANISMREGULATING MECHANISMREGULATING MECHANISM
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NUTRIENT CYCLING
AGROECOSYSTEM
� Inputs:Plant residueAnimal wastesAnimal residueAtmosphereNitrogen fixation
� Outputs:Plants� animals grazing on plantsDenitrificationRun-offleaching
NATURAL ECOSYSTEM
� Using the soil as a pool of nutrients:
� Inputs:FertilizersCrop residues AtmosphereNitrogen fixation
� Outputs:Crops � then removal from areaErosionLeaching
� Run-off
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