ISSN:
1440-1703
Keywords:
geological substrates
;
net N mineralization
;
redox potential
;
temperature gradient
;
tropical rainforest
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
Notes:
Mt Kinabalu, Borneo, is characterized by a deep elevational gradient and mosaics of geological substrates. We chose a pair of two geological substrates (sedimentary vs ultrabasic) at five altitudes (800, 1400, 2100, 2700 and 3100 m a.s.l.). We investigated soil nitrogen (N) mineralization and nitrification rates using an incubation technique to assay the pattern and control of soil N status in this environmental matrix. In situ net mineralization rates decreased with elevation on both substrates. The decreasing pattern was linear across altitudes on ultrabasic rock, whereas on sedimentary rock it was depressed in the middle slope wet cloud zone. Sedimentary sites in this zone had low soil redox potential values and this anoxic soil condition might be related to slow N mineralization. The in situ rates were significantly greater (P 〈 0.05, anova) on sedimentary than on ultrabasic rock at the same altitudes except in the cloud zone. Net mineralization rates of the soils that were collected from different elevations and incubated in the same conditions were statistically invariable (P 〉 0.05) among the original elevations for sedimentary rock, but were variable (P 〈 0.05) for ultrabasic rock. Those of the soils that were collected from the same elevation and incubated at different elevations decreased significantly across altitudes (P 〈 0.05) for sedimentary rock, while they were invariable (P 〉 0.05) for ultrabasic rock. Thus, temperature had stronger effects on net N mineralization on sedimentary rock, whereas inherent soil quality had stronger effects on ultrabasic rock. Controls of soil N mineralization might be different between the two substrates, leading to diverse biogeochemical site conditions on Kinabalu.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1046/j.1440-1703.1998.00264.x
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