KEANEKARAGAMAN NEMATODA DALAM TANAH PADA BERBAGAI TIPE TATAGUNA LAHAN DI ASB-BENCHMARK AREA WAY KANAN

Abstract

The soil nematode diversity in several land-use types in Way Kanan ASB-Benchmark Area.  The conversion  of forest to intensive agroecosystem such as monoculture system reduces biodiversity of the plant, herbivore, and decomposer subsystems.   Those changes affected  the litter and plant root quality.  Consequently, few soil nematode species could be dominant and cause of disturbance of the stability of the below ground  community.   The increasing  populations of plant parasitic nematodes usually occur on monoculture system .   The research was conducted to study the effect of forest changes in several land use types on soil nematode diversity in Way Kanan Benchmark Area.  Soil sampling on five land use types (secondary forest,  agroforest or tree based agriculture, plantation, cassava field, and Imperata grass land) was conducted in November1996 and December 1997.   Nematodes  were extracted by decantation-centrifugation with sugar method.  The soil  nematodes were grouped into order and generic level including plant parasitic and  non- parasitic. The results show that the order of  Rhabditida, Dorylaimida, and Tylenchida were found from  those five land-use types.  The total genera of  plant parasitic nematodes in Imperata grass land were the highest among the other four land use types.  The total number of  non-plant parasitic nematodes in secondary forest (28.0 individual per 300 cc of soil) was higher than total number in the plantation ( 2.6 individual per 300 cc of soil), cassava field (4.0 individual per 300 cc of soil) or Imperata grass land (6.6 individual per 300 cc of soil).  The total number of  plant parasitic nematodes in Imperata grass land (59.8 individual per 300 cc of soil), agroforest (59.0 individual per 300 cc of soil), secondary forest (48.2 individual per 300 cc of soil), and  plantation (17.6 individual per 300 cc of soil) were not significantly different, but  total number in Imperata grass land and  agroforest  were significantly  higher than that in cassava field (11,6 individual per 300 cc of soil).