Then, the question becomes how to obtain O 2 in native peatlands. We can observe
two methods: aerial roots and mound roots (Fig. 7.1, and refer to Chap. 1).
Aerial roots: absorb O 2 and probably fix N 2
Mound roots (roots intruding into litter-mounds): take up nutrients from litter and
absorb O 2
Thus, the question of tropical peatland function is resolved: oxygen and nutrients
are supplied from the land surface by aerial roots and mound roots. As aerial roots
and mound roots function in nutrient absorption from litter and fix nitrogen
(Chap. 1), aerial roots and mound roots likely develop symbiotic systems with
microorganisms; these systems are called rhizosphere functions.
Oxygen &
Nutrient
Bubbling Air
Oxygen &
Nutrient
Bubbling Air
Sago
(Metroxylon sagu)
Aerial Roots
Mound Roots
Fig. 7.1 Oxygen absorption mechanisms in deep water conditions. In water culture, O 2 is obtained
from air bubbling. At high ground water levels, O 2 is absorbed by aerial roots and mound roots
Table 7.1 Plot design
No Treatment
Koto Ringin Village
Siak District, Riau
Tane Jumpun,
Palangka
Raya, Central
Kalimantan
1
Number of replications (control and treatment)
4
4
2
Commodities
Oil palm
Oil palm, Sago
Shorea
balangeran
3
Number of trees within one
plot
25
16
4
Water management
Small canal blocking, permanent canal
blocking, water pumping
Small canal
blocking
252
R. I. Wetadewi et al.