Erny Poedjirahajoe

SIMULASI MODEL DINAMIK PENGARUH LEGUME COVER CROPS (LCC) TERHADAP LIMPASAN DAN SEDIMEN DI LAHAN HUTAN TANAMAN (Dynamic model simulation of the effects of Legume Cover Crops (LCC) on runoff and sediment in plantation forest land)

Declining productivity of plantation forest due to low soil fertility. This condition has forced managers to make efforts in manipulating the tree growing environment. One such effort is by introducing cover crops species from legumes (LCC), to control surface runoff, soil erosion and input nutrient into the soil. The research aims to determine the effectiveness of LCC in controlling total runoff and sedimentation in Eucalyptus pellita plantations, through dynamic model simulation. The dynamic model of STELLA version 9.0.2 was used to study water and nutrient cycles, focused on the application of LCC to reduce total runoff and sedimentation. The results showed that LCC could drop the total runoff of average 35% in the 1 - 2 years old. In the 1styear it decreased from 1,530 mm to 994 mm, while in the 2ndyear it decreased from 1,240 mm to 806 mm. The declining also occurred in the sediment content, in the 1st year it decreased from 12.20 tonnes/ha to 7.93 tonnes/ha, and the 2nd year it decreased from 6.63 tonnes/ha to 4.36 tonnes/ha. These research findings can be used by the environmental manager to minimize potential land degradation, especially during the post-harvest until the young plantations (0-2 years old) phases.

Roosting selection by red and blue Lory (Eos histrio Muller, 1776) in Karakelang Island North Sulawesi

The Red and blue lory is an endemic parrot species from Talaud Islands, North Sulawesi. The use of existing resources is suspected that occurs of selection including the roosting trees. The research aims to identifying the characteristics of Red and Blue Lory roost tree and determining variables in its selection. We measured 14 variables to identify the characteristics and selection of roost tree. Mann-Whitney test, T-test, Chi-sqare test and Binary Logistic Regression were employed to analyze data. We detected 11 roost trees in study field, there are Gehe (Pometia coriacea Radkl) nine individual, Binsar (Ficus variegata) and Lawean (Sterculia sp) one individual. The Chi-square test identified five variables which related to roost tree selection, i.e; branch-free bole length, canopy diameter, canopy density and the number of trees around the roost tree on diameter 20 - 40 cm and > 41 cm. The Logistic regression analysis detected three variables that gave the most influence on roost tree selection, but branch-free bole length gave the most influence on roost tree selection.