PENGARUH FAKTOR LINGKUNGAN TERHADAP EMISI CO2 DI TANAH HUTAN RAKYAT CANGKRINGAN, SLEMAN, YOGYAKARTA

SETYAWATI NURINDAH S, Eny Faridah, Haryono Supriyo

2011 | Skripsi | S1 KEHUTANAN

Jumlah karbon dioksida (CO2) di atmosfer semakin meningkat sehingga dapat mempercepat terjadinya pemanasan global. Respirasi tanah merupakan jalur utama karbon berpindah dari ekosistem ke atmosfer. Faktor lingkungan turut memengaruhi emisi CO2 dari hasil respirasi tanah. Penelitian ini bertujuan untuk mengetahui potensi emisi CO2 di tanah hutan yang dipengaruhi oleh faktor lingkungan, yaitu intensitas cahaya, suhu tanah, dan kadar lengas tanah serta membuat pemodelan pengaruh lingkungan tersebut terhadap emisi CO2 Plot pengamatan dengan ukuran 31,5 m x 31,5 m dibuat di 3 lokasi hutan rakyat Cangkringan yang memiliki kemiripan lahan. Pada setiap plot ditanam 3 soil collars sedalam + 3 cm di sekitar pohon sengon yang telah ditentukan untuk mengukur emisi CO dari respirasi tanah. 2 dari tanah hutan. Collar pertama ditempatkan sejarak 0,5 m dari pohon, collar ketiga sebatas tajuk terluar, dan collar kedua diantara collar pertama dan ketiga. Pengukuran emisi menggunakan IRGA dengan metode Closed Dynamic Chamber. Ketika pengukuran emisi CO2 Hasil penelitian menunjukkan emisi CO , dilakukan juga pengukuran suhu tanah dan intensitas cahaya matahari serta pengambilan sampel tanah di setiap titik pengamatan. Sampel tanah ditimbang kemudian dioven hingga mencapai berat kering konstan. 2 paling tinggi (44913,13 g CO2/m2/jam) terjadi ketika intensitas cahaya cenderung rendah (304 lux). Pada suhu tanah 25,6oC, emisi CO2 dari tanah berada pada titik tertinggi (35688,39 g CO2/m2/jam), dan kadar lengas yang memengaruhi emisi CO2 paling tinggi (32363,70 g CO2/m2/jam) yaitu sebesar 31%. Hasil analisis menunjukkan bahwa faktor suhu tanah dan kadar lengas memiliki korelasi terhadap emisi CO2 di Cangkringan namun korelasinya sangat lemah (koefisien korelasi 0,112 dan 0,132) yang disebabkan oleh kurangnya sampel/ulangan dan keragaman vegetasi yang tinggi. Persamaan regresi ganda untuk memprediksi emisi CO2 dari tanah hutan rakyat Cangkringan yaitu y = -6974,60 + 1074,05 suhu tanah + 121,74 kadar lengas. Faktor intensitas cahaya tidak diikutsertakan karena menunjukkan korelasi yang tidak signifikan.

The amount of carbon dioxide (CO2) in the atmosphere has increased and can cause global warming. Soil respiration is the main flux of carbon release from the ecosystem to the atmosphere. Environmental factors also influence the CO2 emissions from soil respiration. This research aimed to determine the potential for CO2 emissions in forest land that influenced by environmental factors, which are light intensity, soil temperature, and soil moisture and make the model of those environmental effects on CO2 Plot of observation 31,5 m x 31,5 m made in 3 Cangkringan forest which have similar physiognomi. In each plot, 3 soil collars were planted on + 3 cm depth near sengon trees that have choosen for replications for measuring CO emissions from soil respiration. 2 emissions from forest soil. The first collar placed 0,5 m from the tree, the third collar was placed on the outer canopy extent, and the second collar was placed between the first and the third collar. CO2 emission was measured by using Closed Dynamic Chamber method. Soil temperature and light intensity were also measured when CO2 The results showed the highest CO emission was measured. Soil samples were also taken in each observation point. The soil samples were weighed and then dried by using oven until reached a constant dry weight. 2 emissions (44913,13 g CO2/m2/h) occurred when light intensity was low (304 lux). When soil temperature was 25,6oC, CO2 emission was on peak (35688,39 g CO2/m2/h), and soil moisture that affected the highest CO2 emission (32363,70 g CO2/m2/h) was 31%. The result of analysis showed that soil temperature and soil moisture has a correlation with CO2 emission but very weak (correlation coefficient 0,112 and 0,132) caused by lack of samples/replications and high diversity of vegetation. Multiple regression equation obtained for predicting CO2 emission from forest land of Cangkringan is y = -6974,60 + 1074,05 soil temperature + 121,74 soil moisture. Factor of light intensity was not included because it has no significant correlation with CO2 emission.

Kata Kunci : emisi CO2, respirasi tanah, intensitas cahaya, suhu tanah, kadar lengas, hutan rakyat