Page 173 - Enzymes in Tropical Soils

Enzymes in Tropical Soils 161

The above observations clearly indicates that land-use conversion induced a
very significant influence on the soil environment. Related to the soil enzymatic
activities, land-use conversion changes not only the soil enzymatic activities but
also the optimum pH values. In addition to land-use conversion, Geiger et al.
(1998b) also reported that Cu also caused a shift in the optimum pH of -
glucosidase towards lower pH values.

Important Questions

1. Explain the causes and the effects of forest clearing and land-use conversion on the
environment!
2. Compare the changes in forest coverage of West Lampung, Indonesia, in the period
of 1978 – 1990! What land-uses increased and decreased? Explain why!
3. Explain the probabilities causing the increase in the secondary forest between 1984
– 1990 in West Lampung!
4. Explain the effects of forest clearing and land-use conversion to secondary forest,
plantations, and cultivated lands on the soil chemical properties!
5. Explain the effects of forest clearing and land-use conversion to secondary forest,
plantations, and cultivated lands on the soil physical properties!
6. Explain the effects of forest clearing and land-use conversion to secondary forest,
plantations, and cultivated lands on the soil biological properties!
7. Explain the effects of forest clearing and land-use conversion to secondary forest,
plantations, and cultivated lands on the soil enzymatic properties! How do this
relate to the soil organic C and total N?
8. How do the vegetations affect the soil enzymatic activities? Give some examples!
How do this relate to the soil organic C and total N?
9. How do the vegetations affect the soil enzymatic activities? Give some example!
How do this relate to the soil organic C and total N?
10. How do forest fires affect the changes in soil physical, chemical, biological, and
enzymetic activities? Explain!
11. How does the long-term land cultivation affect the soil enzymatic activities? Give
some example!
12. How different do the grassland, needle-leaf plants, and broad-leaf plants affect the
soil pH, organic matter content, and enzymatic activities? Why?
13. How do the forest clearing and land-use conversion shift the optimum pH? Explain.
14. How can Cu contamination shift the optimum pH for -Glucosidase. Explain!

Abdul Kadir Salam - 2014