PENGARUH KERAPATAN MANGROVE TERHADAP LAJU SEDIMENTASI DI DESA BEDONO DEMAK (The Effect of Mangrove Density on Sedimentation Rate in Bedono Village, Demak) - Sihombing, Yuni Harvesty; Muskananfola, Max Rudolf; A’in, Churun (Departemen Sumberdaya Akuatik,Fakultas Perikanan dan Ilmu Kelautan, Universitas Diponegoro, 2017)
Mangrove di kawasan perairan Bedono, Kecamatan Sayung, Demak dimanfaatkan masyarakat untuk memenuhi kebutuhan hidupnya melalui alih fungsi lahan mangrove menjadi tambak, permukiman, industri, dan penebangan oleh masyarakat untuk berbagai kepentingan, sehingga mengurangi daya tangkap akar mangrove sebagai pemerangkap sedimen. Penelitian ini bertujuan untuk mengetahui pengaruh kerapatan mangrove terhadap laju sedimentasi. Penelitian dilaksanakan pada April 2017 di kawasan hutan mangrove Desa Bedono. Penentuan lokasi sampling dilakukan dengan melakukan beberapa kali observasi/studi pendahuluan. Observasi dilakukan dengan cara mencari tiga stasiun vegetasi mangrove dengan kerapatan yang berbeda yaitu rapat, sedang dan jarang. Pada tiap-tiap stasiun terdapat 3 titik pengambilan sampel. Pengambilan sampel dilakukan sebanyak 3 kali dengan interval waktu 2 minggu. Hasil penelitian menunjukkan bahwa laju sedimentasi paling tinggi terdapat pada stasiun I titik 3 dengan nilai rata-rata 30,935 mg/cm2/hari dimana pada lokasi ini memiliki kerapatan mangrove yang paling rendah yaitu 600 pohon/ha sedangkan nilai laju sedimentasi paling rendah terdapat pada stasiun III titik 2 dengan nilai rata-rata 4,891 mg/cm2/hari dimana pada lokasi ini memiliki kerapatan paling tinggi yaitu 3100 pohon/ha. Hubungan kerapatan mangrove dan laju sedimentasi menunjukkan korelasi negatif sebesar -0.842 artinya ketika kerapatan mangrove tinggi maka laju sedimentasi akan rendah dan sebaliknya ketika kerapatan mangrove rendah maka laju sedimentasi akan tinggi. Mangrove in the area of Bedono waters, Sayung District, Demak are utilized by the society to fulfill their life needs through land mangrove conversion into ponds, settlement, industry, and logging by the society for various purposes, thereby reducing the mangrove roots capability as a sediment traps. The purpose of this study was to determine the influence of mangrove density on sedimentation rate. The research was conducted in April 2017 in the mangrove forest area of Bedono Village. Determination of sampling location was done by conducting some initial observation. Observation was done by searching three mangrove vegetation stations with different density is high, medium and rare density. In each station there are 3 points of sampling. Samples were collected three times in 2 weeks time interval. The results showed that the highest sedimentation rate was found at station I point 3 with the average value of 30.935 mg/cm2/day where at this location has the lowest mangrove density of 600 trees/ha while the lowest sedimentation rate was found at station III Point 2 with the average value of 4.891 mg/cm2/day where at this location has the highest density of 3100 trees/ha. The relationship between mangrove density and sedimentation rate exhibits a negative correlation of -0,842 this means that when the mangrove density is high then the sedimentation rate will be low and otherwise when the mangrove density is low then the sedimentation rate will be high.