KEPENTINGANPERANAN CAHAYA Mempertahankan suhu Proses fotosintesis Siklus hidrologi

KEPENTINGAN/PERANAN CAHAYA : Mempertahankan suhu Proses fotosintesis Siklus hidrologi SATUAN CAHAYA : Watt, Joule, Lux, Langley, Kalori Foot candle, S 2 Produktivitas Perairan

Siklus hidrologi Sumber: Max Planck Institut For Meteorology (1999) S 2 Produktivitas Perairan

PANJANG GELOMBANG ( λ ) : 100 – 3. 000 nm (10 -9 m) < 300 nm : Ultra Violet 300 – 700 nm : PAR – Photosynthetic Active Radiation Visible Light 300 – 490 nm Biru 490 – 585 nm Hijau 585 – 700 nm Merah 555 nm Kuning Hijau, Pusat Cahaya > 700 nm : Infra Red S 2 Produktivitas Perairan

The electromagnetic spectrum: The electromagnetic spectrum. Image from Purves et al. , Life: The Science of Biology, 4 th Edition, by Sinauer Associates (www. sinauer. com) and WH Freeman (www. whfreeman. com). http: //www. emc. maricopa. edu/faculty/farabee/BIOBK/Bio. Book. PS. html S 2 Produktivitas Perairan

ALAT PENGUKUR CAHAYA : LUX METER, PYRHELIOMETER ALBEDOMETER PHOTOCELL IMMERGEABLE SECCHI DISK/DISC S 2 Produktivitas Perairan

Penurunan cahaya karena : 1. Refleksi – dipantulkan 2. Absorpsi – diserap Refleksi + Absorpsi + Transmisi = 1 3. Transmisi – Dibiaskan datang pantul α 1 α 2 α 1 = α 2 α 1 > α 3 bias SCATTERING S 2 Produktivitas Perairan

CAHAYA DARI MATAHARI (%) YANG SAMPAI KE BUMI Total ; Asal Hilang ; Asal Sisa ; Asal Luar Atmosfir 100 ; 100 48 ; 48 52 ; 52 Atmosfir 100 ; 52 60 ; 31 40 ; 21 Permukaan air 100 ; 21 50 ; 10, 5 Dari matahari : 1, 92 gcal/cm 2/menit Daerah ekuator : 800 -900 gcal/cm 2/hari Kutub pada musim panas : 1. 100 gcal/cm 2/hari S 2 Produktivitas Perairan

Rumus LAMBERT-BEER RUMUS LAMBERT-BEER Iz =Iz. Io= Ieo. -kz e-kz z = Kedalaman Iz = Intensitas cahaya pada kedalaman z Io = Intensitas cahaya pada kedalaman 0 (permukaan) e = Bilangan eksponensial k = Coeficient of Extinction, ( Koefisien Peredaman, Pemadaman, Peredupan) Kz = K air + K Partikel Tersuspensi + K Diss. coll. compound Nilai K berbeda : Setiap Perairan Setiap Waktu Setiap Panjang Gelombang Setiap Kedalaman S 2 Produktivitas Perairan

Iz = I 0. e-kz Ln Iz = Ln Io. e-kz = Ln Io + Ln e-kz = Ln Io – kz Ln e = Ln Io – kz Ln Iz + kz = Ln Io dikalikan Ln (Ln e = 1) Kz = Ln Io – Ln Iz S 2 Produktivitas Perairan

Kz = Ln Io – Ln Iz Depth (m) Nilai Cahaya (%) Ln 0 100 4, 61 K 0, 16 2 86 4, 45 0, 15 4 74 4, 30 0, 52 6 44 3, 78 0, 15 8 38 3, 63 0, 14 10 33 3, 49 Jumlah 1, 12 S 2 Produktivitas Perairan

ZONASI VERTIKAL CAHAYA DI DALAM AIR 01 D e p t h 50 Fotosintesis > Respirasi 100 Incident Light (%) ZONE PHOTIC Fotosintesis = Respirasi Compensation Depth Fotosintesis < Respirasi ZONE APHOTIC S 2 Produktivitas Perairan

Pukul 08 10 12 14 Cahaya di permukaan % Lux 100 100 500 1. 000 100 900 Cahaya di kedalaman 5 m % Lux 1 1 1 5 1 10 1 9 Misalnya agar fotosintesis = respirasi diperlukan cahaya 5 lux S 2 Produktivitas Perairan

KESUBURAN PERAIRAN DILIHAT DARI CAHAYA 1. Subur (Eutrophe) 0 – 3 m 2. Moderat/Sedang (Mesotrphe) 3 – 6 m 3. Miskin/tidak subur (Oligotrophe) >6 m Catatan : - Perairan Tawar - Kedalaman perairan > 6 m

RATA-RATA NILAI PRODUKSI PRIMER BERSIH BERBAGAI LINGKUNGAN (Valiela, 1984) Lingkungan g/m 2 /Tahun Laut Terbuka 125 Upwelling 500 Continental shelf 300 Hamparan alga dan terumbu 2. 500 Estuari tanpa rawa (marsh) 1. 500 Total Laut (marine) Terrestrial (daratan) Rawa (swamp and marsh) Danau dan sungai Total kontinental 4. 925 737 3. 000 4. 137 S 2 Produktivitas Perairan

Images from Purves et al. , Life: The Science of Biology, 4 th Edition, by Sinauer Associates (www. sinauer. com) and WH Freeman (www. whfreeman. com) http: //www. emc. maricopa. edu/faculty/farabee/BIOBK/Bio. Book. PS. html S 2 Produktivitas Perairan

Chlorophyll http: //www. chemsoc. org/networks/learnn et/cfb/Photosynthesis. htm Chlorophylls Two types of chlorophyll are found in plants and the green algae. · chlorophyll a, & · chlorophyll b The difference in their structures is shown in the figure (red disks). http: //users. rcn. com/jkimball. ma. ultranet/Biology. Pages/C/Chlorophyll. html S 2 Produktivitas Perairan

http: //users. rcn. com/jkimball. ma. ultranet/Biology. Pages/C/Chlorophyll. html the structure of beta-carotene, one of the most abundant carotenoids. Note: the system of alternating single and double bonds that in this molecule runs along the hydrocarbon chain that connects the two benzene rings. http: //www 2. mcdaniel. edu/Biology/botf 99/photo/p 3 igments. htm Xanthophylls are essentially oxidized Carotenoids and contain oxygen. They are usually red and yellow and do not absorb energy as well as cartenoids. They are also fat soluble. S 2 Produktivitas Perairan

http: //www 2. mcdaniel. edu/Biology/botf 99/photo/p 3 igments. htm S 2 Produktivitas Perairan

http: //www. globalchange. umich. edu/globalchange 1/current/lectures/kling/energyflow. html S 2 Produktivitas Perairan

THE LIGHT REACTIONS OF PHOTOSYNTHESIS S 2 Produktivitas Perairan http: //employees. csbsju. edu/hjakubowski/classes/ch 331/oxphos/olphotsynthesis. html

Figure 2. Absorption spectrum of isolated chlorophyll and carotenoid species. The color associated with the various wavelengths is indicated above the graph. S 2 Produktivitas Perairan

ENAN M ADIWILAGA Lantai 2 Wing 14 (N) Nomor 2 – Menghadap ke danau Telp. Facs 8421731 Rumah : Jl Soka No 18 Kampus IPB Darmaga (Perumdos) Bogor 16680 Telp. Facs. 8621325 HP 0811118108 S 2 Produktivitas Perairan