Kuliah 4 SYSTEM EKOLOGI DAN PRINSIP PRINSIP DALAM HARMONISASI MANUSIA & ALAM. Mustika Anggraeni

(1)

Kuliah 4

SYSTEM EKOLOGI DAN PRINSIP–PRINSIP

(2)

KERANGKA DISKUSI

ECOLOG Y ECOLOG Y HUKUM TERMODI NAMIKA HUKUM TERMODI NAMIKA

SYSTEM

ECOLOG

Y

SYSTEM

ECOLOG

Y

ALIRAN ENERGI & DAUR MATERI ALIRAN ENERGI & DAUR MATERI DAYA DUKUN G LINGK. DAYA DUKUN G LINGK. DAYA LENTIN G LINGK. DAYA LENTIN G LINGK. FAKTOR PEMBA TAS FAKTOR PEMBA TAS HOMEO STASIS HOMEO STASIS

PRINSIP

HARMONI

MANUSIA

& ALAM

PRINSIP

HARMONI

MANUSIA

& ALAM

(3)

Hukum Termodinamika

Law of Conservation of Energy

• Energy is neither created nor destroyed. When we use

energy, it doesn’t disappear. We change it from one form

of energy into another.

• A car engine burns gasoline, converting the chemical energy in gasoline into mechanical energy. Solar cells change

radiant energy into electrical energy. Energy changes form, but the total amount of energy in the universe stays the same.

Energy Efficiency (Law of Energy Entropy )

Energy efficiency is the amount of useful energy you get from a system. A perfect, energy-efficient machine would change all the energy put in it into

useful work—an impossible dream. Converting one form of energy into another form always involves a loss of usable energy (entropy).

• Pencemaran selalu terjadi dan tidak dapat dihindari karena adanya entropy

(4)

Aliran Energi dan Daur Materi

ECOSYSTEM dapat berfungsi apa bila ada aliran energy dan daur materi.

Energy flows in a simple food chain. At each level of the food chain, about

90% of the energy is lost in the form of heat. Therefore, as you move up the food chain, there is less energy available.

Food chain adalah suatu sistem kehidupan yang berupa rantai terbuka

disusun oleh Konsumen I (produsen yaitu tanaman, konsumen II (herbivore), konsumen III (omnivore/carnivore) s/d konsumen ke–n)

Daur materi adalah rantai makanan sistem tertutup dimana merupakan rantai

makanan yang disambung oleh mikrobia yang menguraikan bangkai yang sudah mati menjadi mineral yang selanjutnya mineral ini menjadi bagian penyusun dari tumbuhan (produsen)

(5)

(6)

Tolerance Limits

• Every living organism has limits to the environmental conditions it can endure.

Environmental factors must be within appropriate levels for life to persist

– Temperature – Moisture levels – Nutrient supply

– Soil and water chemistry – Living space

• Leibig's Law of Minimum: In 1840, Justus von Liebig proposed that the

single factor in shortest supply relative to demand is the critical determinant in the distribution of that species.

• Sheldford's Law of Tolerance: Victor Shelford later expanded Liebig's principal by stating that each environmental factor has both minimum

and maximum levels called tolerance limits beyond which a particular species cannot survive.

(7)

• Hukum minimum Leibig

–

Pertumbuhan tanaman tergantung akan jumlah bahan

makanan yang tersedia dalam jumlah sedikit.

• Hukum Toleransi Shelford:

–

organisme mempunyai rentangan batas toleransi yang lebar

(eury…) untuk suatu faktor, dan sempit (steno…) untuk faktor

yang lain

–

Organisme dengan rentangan batas toleransi yang lebar,

mempunyai penyebaran yang luas.

–

Bila kondisi tidak optimum untuk suatu spesies mengenai

suatu faktor, maka batas toleransi menjadi berkurang

–

Organisme di alam tidak betul2 hidup dalam kondisi optimal

ditinjau dari satu sektor fisik tertentu.

–

Masa pertumbuhan adalah masa yang palingkritis karena

batas toleransi bibit/benih, telur/embryo, dan larva adalah

lebih sempit.

(8)

Indikator ekologi

Keadaan kehidupan organisme sangat dipengaruhui oleh

lingkungan tempat tinggalnya. Di darat, tumbuhan dipakai sbg

indikator ekologi, karena peka atas perubahan lingkungan. Di

dalam air ikan dapat berubah dari bentuk idealnya karena

(9)

Daya Dukung Lingkungan

(Carriying Capacity)

• Arti harfiah : rasio

antara organisme

biotik dengan

keberadaan

lingkungan hidup

• Arti modern (untuk

manusia):

– Limits to Growth

– Overshoot

(10)

Carrying Capacity Overshoot

To overshoot means to grow

rapidly beyond the limits of

carrying capacity. When this

overshoot occurs, it’s due to a

limit or barrier exceeded within

the system, and the system

corrects and begins to slow,

stop, or reverse growth. In

addition, as the limits of our

natural systems are

exceeded they are degraded,

which results in the overall

carrying capacity being

diminished. Overshoot leads

to a sudden and catastrophe

collapse.

(11)

WORLD’S POPULATION

Miller, 1975 7 6 5 4 3 2 1 20… 1998 1988 1975 1960 1930 1850 Population

(12)

Population Oscillations

• In the real world, there are limits

to growth.

• Dieback: when the population

decreases as fast as, or faster ,

than it grows

• Some limiting factor comes into

effect.

• Overshoot: extent to which a

population exceeds the carrying

capacity of its environment.

• Malthusian growth: pattern of

population explosion followed by

a population crash.

Populations may go through repeated oscillating cycles of exponential growth and

(13)

“As the environment is degraded, carrying

capacity actually shrinks, leaving the

environment no longer able to support even

the number of people who could formerly

have lived in the area on a sustainable

basis. No population can live beyond the

environment’s carrying capacity for very

long”

(14)

Daya Lenting Lingkungan

(Resilience Capacity )

• Kemampuan alam, jika diganggu keseimbangannya,

untuk kembali ke kondisi semula Æ seperti pendulum

• Setelah batas tertentu, tidak lentur lagi

– Suaka margasatwa di Afrika perubahan musim hujan

mengakibatkan naiknya air laut pasang dan mematikan tanaman

di sekitarnya.

– Contoh: bencana alam, bencana teknologi dianggap sebagai

‘gangguan’ terhadap alam.

(15)

Homeostasis

All lives seek balance? For what are lives looking?

Peace? Stillness? Zero change? Harmony? Symmetry?

The study of Homeostasis reveals that balance within living systems is

not peaceful, nor quiet, is filled with change, but does harmonize the

interior environment with the exterior environment.

For what are lives looking? Call it Dynamic equilibrium, a continuous

circle dance of adjustment and correction.

Maintaining this balance between a living system's internal conditions

and fluctuating environmental (external) conditions is called

(16)

Bagaimana keharmonisan hidup

kita dengan makhluk hidup

(17)

• Ada sekitar 10 juta spesies lain di bumi ini.

Spesies seperti tikus dan virus flu, hidup

mutualisma dengan kita. Manusia juga

mendorong kelangsungan hidup spesies

seperti jagung dan sapi, karena kita

memerlukan produknya. Spesies seperti

harimau, dan serangga di hutan hujan

tropis hampir punah karena perilaku

manusia.

• Ahli biologi konservasi percaya bahwa

dibutuhkan sekitar 30-70% biosfir utk

memelihara biodiversity. Saat ini sekitar

3% yg digunakan untuk taman atau suaka

margasatwa. Komisi Brundtland, PBB

(18)

Ending Overshoot

• Individuals and institutions worldwide must begin to recognize ecological limits. We must begin to make ecological limits central to our

decision-making and use human ingenuity to find new ways to live, within the Earth’s

bounds.

• This means investing in technology and infrastructure that will allow us

to operate in a resource constrained world. It means taking individual action, and creating the public demand for businesses and policy makers to participate.

• Using tools like the Ecological Footprint to manage our ecological

assets is essential for humanity’s survival and success. Knowing how

much nature we have, how much we use, and who uses what is the first step, and will allow us to track our progress as we work toward our goal of sustainable, one-planet living.

(19)

Hukum Ekologi (Commoner,

1972):

• Everything is connected to

everything else

- humans and other species

are connected/dependant on a number of other species.

• Everything must go

somewhere

- no matter what you do, and no

matter what you use, it has to go somewhere. For example, when you burn wood, it doesn't disappear, it turns into smoke which rises into the air, and ash, which falls back down to the earth.

• Nature knows best

- Like it says, nature

knows best.

• There is no such thing as a

(20)

(21)