Microclimate of Developed Peatland of the Mega Rice Project in Central Kalimantan

Microclimate of Developed Peatland of The Mega Rice Project in Central Kalimantan (A Jaya,T Inoue, SH Limin, U Darung and IS Banuwa): In Indonesia peatland covers an area of 16 to 27 Mha and this ecosystem is vitally linked to environmental and conservation issues, as well as its economic value for human survival. These peatlands are, however, the subject of various land use pressures, including forestry, agriculture, energy and horticulture. A field study was carried out 6 years after the end of failed peatland development project shows that inappropriate and unsustainable forms of peatland management have resulted in degradation of the natural forest vegetation, draw-down of the peat water table, increase of peat surface and air temperatures and recurrent surface and ground fires. Implications of microclimate for possible restoration options

Heterotrophic respiration in drained tropical peat is greatly affected by temperature-a passive ecosystem cooling experiment

Vast areas of deforested tropical peatlands do not receive noteworthy shading by vegetation, which increases the amount of solar radiation reaching the peat surface. Peat temperature dynamics and heterotrophic carbon dioxide (CO2), nitrous oxide (N2O) and methane (CH4) fluxes were monitored under four shading conditions, i.e. unshaded, 28%, 51% and 90% shading at experiment sites established on reclaimed fallow agricultural- and degraded sites in Central Kalimantan, Indonesia. Groundwater tables on the sites were at about 50 cm depth, the sites were maintained vegetation free and root ingrowth to gas flux monitoring locations was prevented. Half of the four shading areas received NPK-fertilization 50 kg ha−1 for each of N, P and K during the experiment and the other half was unfertilized. Increases in shading created a lasting decrease in peat temperatures, and decreased diurnal temperature fluctuations, in comparison to less shaded plots. The largest peat temperature difference in the topmost 50 cm peat profile was between the unshaded and 90% shaded surface, where the average temperatures at 5 cm depth differed up to 3.7 °C, and diurnal temperatures at 5 cm depth varied up to 4.2 °C in the unshaded and 0.4 °C in the 90% shaded conditions. Highest impacts on the heterotrophic CO2 fluxes caused by the treatments were on agricultural land, where 90% shading from the full exposure resulted in a 33% lower CO2 emission average on the unfertilized plots and a 66% lower emission average on the fertilized plots. Correlation between peat temperature and CO2 flux suggested an approximately 8% (unfertilized) and 25% (fertilized) emissions change for each 1 °C temperature change at 5 cm depth on the agricultural land. CO2 flux responses to the treatments remained low on degraded peatland. Fertilized conditions negatively correlated with N2O efflux with increases in temperature, suggesting a 12–36% lower efflux for each 1 °C increase in peat temperature (at 5 cm depth) at the sites. Despite the apparently similar landscapes of fallow agricultural land and degraded peatland sites, the differences in greenhouse gas dynamics are expected to be an outcome of the long-term management differences.Peer reviewe

PRELIMINARY STUDY ON LIMNOLOGICAL FEATURES OF LAKES AND RIVERS IN THE PEAT SWAMP AREA OF CENTRAL KALIMANTAN

Water quality, zoobenthos and epiphytic invertebrates were surveyed for waters in the peat swamp area of Central Kalimantan, Indonesia, during 22-25 February 1998. Water temperature was stratified markedly at depths of 0-1.5 m in Lekes Sabuah and Sembuluh. In Lake Sabuah, euphotic depth was as low as 0.76 m due to light attenuation by high concentration of dissolved organic matter as well as phytoplankton in the surface layer of water. Oxygen depletion was observed at bottom layers of Lake Sabuah and of northern inlet bay of Lake Sembuluh, where only a small number of zoobenthos (Oligochaeta) were collected. Water temperature was not stratified in the Kumai and Sekonyer Rivers. Dissolved oxygen concentration was low throughout the water column in the Sekonyer River. In the present lakes and rivers, biological production seemed to take place at depths of 0-1.5 m from water surface.Article信州大学理学部附属諏訪臨湖実験所報告 12: 81-88(2000)departmental bulletin pape

INITIAL SCREENING OF FAST-GROWING TREE SPECIES BEING TOLERANT OF DRY TROPICAL PEATLANDS IN CENTRAL KALIMANTAN, INDONESIA

An investigation of the recruit, survivorship and growth of naturally regenerating tree species on canal bank was conducted to select tree species which are suitable for preceding planting in drained and burnt peat swamp lands in Central Kalimantan, Indonesia. Top of the canal bank were open, with greater soil moisture deficit and higher soil temperatures than on the next intact forest floor. The abundant trees were asam-asam (Ploiarium alternifolium),garunggang (Cratoxylon arborescens) and tumih (Combretocarpus rotundatus). New regeneration of these trees on the canal bank was confirmed during this investigation and mortality was very low. These results indicated that P. alternifolium,C. arborescens and C. rotundatuswere tolerant of intensive radiation, soil drought and high soil temperatures during germination. The annual height increments were 189-232 cm y-1 (P. alternifolium),118-289 cm y-1 (C. arborescens)and 27-255 cm y-1 (C. rotundatus); thus, these three species could be classified as fast-growing with tolerance to open and dry conditions. Such characteristics were important to avoid competition with herbs, ferns,and/ or climbers. The results·suggest that P.alternifolium,C. arborescens and C. rotundatusare suitable for preceding planting for the rehabilitation of the disturbed peat swamp forests of Central Kalimantan

Initial Screening of Fast-growing Tree Species Being Tolerant of Dry Tropical Peatlands in Central Kalimantan, Indonesia

An investigation of the recruit, survivorship and growth of naturally regenerating tree species on canal bank was conducted to select tree species which are suitable for preceding planting in drained and burnt peat swamp lands in Central Kalimantan, Indonesia. Top of the canal bank were open, with greater soil moisture deficit and higher soil temperatures than on the next intact forest floor. The abundant trees were asam-asam (Ploiarium alternifolium),garunggang (Cratoxylon arborescens) and tumih (Combretocarpus rotundatus). New regeneration of these trees on the canal bank was confirmed during this investigation and mortality was very low. These results indicated that P. alternifolium,C. arborescens and C. rotundatuswere tolerant of intensive radiation, soil drought and high soil temperatures during germination. The annual height increments were 189-232 cm y-1 (P. alternifolium),118-289 cm y-1 (C. arborescens)and 27-255 cm y-1 (C. rotundatus); thus, these three species could be classified as fast-growing with tolerance to open and dry conditions. Such characteristics were important to avoid competition with herbs, ferns,and/ or climbers. The results·suggest that P.alternifolium,C. arborescens and C. rotundatusare suitable for preceding planting for the rehabilitation of the disturbed peat swamp forests of Central Kalimantan

Linear 3-Hydroxybutyrate Tetramer (HB4) Produced by Sphingomonas sp. Is Characterized as a Growth Promoting Factor for Some Rhizomicrofloral Composers

Sphingomonas spp. of α-proteobacteria often play a role in assisting the development of microfloral communities under adverse soil conditions. Using a Frateuria sp. as an indicator for bacterial growth assay, we investigated the bacterial growth-promoting factor in the culture fluids of Sphingomonas sp. EC-K085. This factor was successfully isolated and identified as linear (R,R,R,R)-3-hydroxybutyrate tetramer (HB4), having a hydroxy-end and a carboxy-end group. When 28 μg of HB4 was charged on a paper disc, impregnated Frateuria sp. cells in modified Winogradsky agar medium exhibited a promoted cell growth to form a clear colony emerging zone after a 2-day incubation

Characteristics of fire-generated gas emission observed during a large peatland fire in 2009 at Kalimantan, Indonesia

To investigate the characteristics of gas emissions from a tropical peatland fire, ground-level measurement of fire-generated gases was conducted during a large fire event in Kalimantan, Indonesia in 2009. Concentrations of CO and CH4 showed positive linear correlations with that of CO2. The relationship between concentrations of N2O and CO2 were divided into two parts, suggesting the influence of additional N2O generation during sample storage. The CO2-normalized emission ratio was calculated for CO, CH4, and N2O. The molar ratio of these fire-generated gas emissions was summarized as CO2:CO:CH4:N2O = 1.00:0.382:0.0261:0.000156, whereas the emission ratio calculated on the global warming potential (GWP) basis was CO2:CH4:N2O = 1.00:0.237:0.0465. The GWP emission based on this ratio was 87.8-91.2% of a simple evaluation in which all carbon was assumed to be emitted as CO2. This is the first trial to evaluate the emission ratios of major greenhouse gases on the basis of ground-level observation during an actual tropical peatland fire. (C) 2013 Elsevier Ltd. All rights reserved