J. Jauhiainen - Academia.edu (original) (raw)

Papers by J. Jauhiainen

Plant and Soil, 2014

Background and Aims Tropical peat swamp forests (PSF) are great stores of terrestrial carbon and ... more Background and Aims Tropical peat swamp forests (PSF) are great stores of terrestrial carbon and host unique biodiversity. Despite their importance for carbon accounting, the peat characteristics are sparsely studied, and the effect of microtopography on peat properties has not been reported before. Methods We compared PSF peat soil characteristics down to 70 cm under differing microtopographical conditions and hydrology. Results Long-term water table level data combined with the data from peat structure and chemistry analyses showed differences in most of the measured properties between hummocks and hollows. Decomposition degree was lowest at hummock and hollow surfaces while bulk density and C content increased towards deeper peat. Ash, P, K, Ca and Mg had highest concentrations on hummock surfaces with declining trend downwards, whereas N had no clear concentration pattern along the elevation gradient. Conclusions The microtopographical features may not only differ in regards to the water table-induced oxygen conditions but also due to differences in nutrient dynamics.

CATENA, 2014

This version is distributed under a non-commencial no derivatives Creative Commons (CC-BY-NC-ND) ... more This version is distributed under a non-commencial no derivatives Creative Commons (CC-BY-NC-ND) user license, which permits use, distribution, and reproduction in any medium, provided the original work is properly cited and not used for commercial purposes. Further, the restriction applies that if you remix, transform, or build upon the material, you may not distribute the modified material.

Soil Biology and Biochemistry, 2018

Swamp forests on deep tropical peatlands have undergone extensive deforestation and draining for ... more Swamp forests on deep tropical peatlands have undergone extensive deforestation and draining for agriculture and plantations, consequently becoming globally significant carbon (C) sources. To study the effects of land-use change on peat as a biological environment, which directly affects decomposition dynamics and greenhouse gas emissions, we sampled peat from four common land-use types representing different management intensities in Central Kalimantan, Indonesia. The near-pristine swamp forest was used to describe unmanaged conditions, and the three other sites in order of increasing management intensity were reforested; degraded; and agricultural. We examined peat substrate quality (total C & nitrogen (N), dissolved organic C (DOC) and N (DON), and organic matter quality characterized by infrared spectroscopy) and microbial biomass and extracellular enzyme activity to describe both biotic and abiotic conditions in peat. We found that the peat at altered sites was poorer in quality, i.e. decomposability, as demonstrated by the higher intensity of aromatic and aliphatic compounds, and lower intensity of polysaccharides, and concentration of DOC, total N and DON compared to the peat in the swamp forest. The observed differences in peat properties can be linked to changes in litter input and decomposition conditions altered after deforestation and draining, as well as increased leaching and fires. The quality of the peat substrate was directly related to its biotic properties, with altered sites generally having lower microbial biomass and enzyme activity. However, irrespective of management 2 intensity or substrate quality, enzyme activity was limited primarily to the first 0 3 cm of the peat profile. Some differences between wet and dry seasons were observed in enzyme activity especially in swamp forest, where the most measured enzyme activities were higher in dry season. Reforestation 6 years before our measurements had not yet restored enzyme activity in the peat to the level of the swamp forest, although the topmost peat characteristics in the reforested site already resembled those in the swamp forest. This is likely contributed to by the chemical weed control performed at the site, and the limited capacity of the young plantation to produce litter to support peat formation and restore the quality and structure of the peat. Therefore, we conclude that intensive land management, including deforestation and draining, leads to the surface peat becoming poorer biological environment, and it may take long time to restore the peat properties.

Mires and Peat, 2015

Land-use change has transformed large areas of tropical peatland into globally significant carbon... more Land-use change has transformed large areas of tropical peatland into globally significant carbon sources. Associated changes in the properties of peat are important for soil processes including decomposition and nutrient cycling. To characterise the changes induced by stabilised land uses, we studied the physical and chemical properties of peat from four land management conditions (undrained and drained forest, degraded land, and managed agricultural land). Peat was sampled from depths of 10–15 cm, 40–45 cm, 80–85 cm and 110–115 cm then partitioned into woody (Ø >1.5 mm), fibric (Ø 0.15–1.5 mm) and amorphic (Ø < 0.15 mm) fractions. Bulk density and total concentrations of ash, C, N, P, K, Ca, Mg, Mn, Zn, Na, Al, Fe, S and Si were determined. There were clear differences between land uses in the characteristics of surface peat down to the 40–45 cm layer, the primary differences being between forested and open sites. Due to smaller particle sizes, the bulk density of peat was h...

Forested tropical peatlands in Southeast Asia store at least 42 000 Million metric tonnes (Mt) of... more Forested tropical peatlands in Southeast Asia store at least 42 000 Million metric tonnes (Mt) of soil carbon. Human activity and climate change threatens the stability of this large pool, which has been decreasing rapidly over the last few decades owing to deforestation, drainage and fire. In this paper we estimate the carbon dioxide (CO 2) emissions resulting from drainage of lowland tropical peatland for agricultural and forestry development which dominates the perturbation of the carbon balance in the region. Present and future emissions from drained peatlands are quantified using data on peatland extent and peat thickness, present and projected land use, water management practices and decomposition rates. Of the 27.1 Million hectares (Mha) of peatland in Southeast Asia, 12.9 Mha had been deforested and mostly drained by 2006. This latter area is increasing rapidly because of increasing land development pressures. Carbon dioxide (CO 2) emission caused by decomposition of drained peatlands was between 355 Mt y −1 and 855 Mt y −1 in 2006 of which 82% came from Indonesia, largely Sumatra and Kalimantan. At a global scale, CO 2 emission from peatland drainage in Southeast Asia is contributing the equivalent of 1.3% to 3.1% of current global CO 2 emissions from the combustion of fossil fuel. If current peatland development and management practices continue, these emissions are predicted to continue for decades. This warrants inclusion of

Water in a peat swamp area in Kalampangan Central Kalimantan, Indonesia was sampled every four we... more Water in a peat swamp area in Kalampangan Central Kalimantan, Indonesia was sampled every four weeks from May 2004 to January 2007 and analyzed for total content of Ca, Mg, K, Na, and Fe. Water samples were collected at three permanent sites in a canal and six permanent sites in the adjacent peat area. The latter were established in (a) deforested peatland (4 sites) and (b) peat swamp forest (2 sites). At every site water samples were obtained from depths of 50, 150 and 250 cm below the surface. Water in the canal is very acid (pH between 3.32 ± 0.04 and 4.22 ± 0.05 and average 3.71 ±0.19) with a predominance of Ca and K. pH of water sampled from the peat at 50, 150, and 250 cm depth in the deforested area gives means of 3.98 ±0.60, 4.18 ± 0.36 and 4.31 ± 0.35, respectively. Meanwhile, pH of water sampled from the peat at 50, 150, and 250 cm depth in forest area has means of 3.68 ±0.55, 3.70 ± 0.38 and 3.92 ± 0.46, respectively. Similar to water sampled in the canal the predominant ...

Sphagnum fuscum, S. magellanicum, S. angustifolium and S. warnstorfii were treated with N deposit... more Sphagnum fuscum, S. magellanicum, S. angustifolium and S. warnstorfii were treated with N deposition rates (0, 10, 30 and 100 kg ha −1 a −1) and with four atmospheric CO 2 concentrations (350, 700, 1000 and 2000 ppm) in greenhouse for 71-120 days. Thereafter, concentrations of total N, P, K, Ca and Mg in the capitulae of the Sphagna were determined. The response of each species to N deposition was related to ecological differences. With increasing N deposition treatments, moss N concentrations increased and higher N:P-ratios were found, the increase being especially clear at the highest N load. Sphagnum fuscum, which occupies ombrotrophic habitats, was the most affected by the increased nitrogen load and as a consequence the other elements were decreased. Oligotrophic S. magellanicum, wide nutrient status tolerant S. angustifolium and meso-eutrophic S. warnstorfii tolerated better increased N deposition, though there were increased concentrations of Ca and Mg in S. warnstorfii and Mg in S. magellanicum. Nitrogen and P concentrations decreased with raised CO 2 concentrations, except for S. magellanicum. This seems to be the first time this kind of response in nutrient concentrations to enhanced CO 2 concentration has been shown to exist in bryophytes. The concentration of K clearly decreased in S. fuscum as did the concentration of Mg in the other Sphagna with increasing CO 2. Sphagnum angustifolium and S. magellanicum, which are the less specialized species, were the least affected by the CO 2 treatments.

… on Tropical Peatlands, …, 2002

... By combining data from remote sensed images with field measurements, it has been possible to ... more ... By combining data from remote sensed images with field measurements, it has been possible to determine fire impact, carbon storage in the peatlands and carbon ... 796,906 ha); the largest scars are in areas impacted by logging forest clearance and peatland drainage. ...

Conversion of tropical peatlands to agriculture leads to a release of carbon from previously stab... more Conversion of tropical peatlands to agriculture leads to a release of carbon from previously stable, longterm storage, resulting in land subsidence that can be a surrogate measure of CO 2 emissions to the atmosphere. We present an analysis of recent large-scale subsidence monitoring studies in Acacia and oil palm plantations on peatland in SE Asia, and compare the findings with previous studies. Subsidence in the first 5 yr after drainage was found to be 142 cm, of which 75 cm occurred in the first year. After 5 yr, the subsidence rate in both plantation types, at average water table depths of 0.7 m, remained constant at around 5 cm yr −1. The results confirm that primary consolidation contributed substantially to total subsidence only in the first year after drainage, that secondary consolidation was negligible, and that the amount of compaction was also much reduced within 5 yr. Over 5 yr after drainage, 75 % of cumulative subsidence was caused by peat oxidation, and after 18 yr this was 92 %. The average rate of carbon loss over the first 5 yr was 178 t CO 2eq ha −1 yr −1 , which reduced to 73 t CO 2eq ha −1 yr −1 over subsequent years, potentially resulting in an average loss of 100 t CO 2eq ha −1 yr −1 over 25 yr. Part of the observed range in subsidence and carbon loss values is explained by differences in water table depth, but vegetation cover and other factors such as addition of fertilizers also influence peat oxidation. A relationship with groundwater table depth shows that subsidence and carbon loss are still considerable even at the highest water levels theoretically possible in plantations. This implies that improved plantation water management will reduce these impacts by 20 % at most, relative to current conditions, and that high rates of carbon loss and land subsidence are inevitable consequences of conversion of forested tropical peatlands to other land uses.

In the Swiss Jura mountains most of the remaining ombrotrophic peat bogs have been exploited to s... more In the Swiss Jura mountains most of the remaining ombrotrophic peat bogs have been exploited to some extent for peat. In these sites, natural regeneration processes are taking place. The dominant process is paludification, where a cut over drained surface is colonised by key species, usually either Polytrichum strictum or Eriophortum vaginatum. These early colonisers of bare peat surfaces create

Global change biology, Mar 27, 2016

The first International Peat Congress (IPC) held in the tropics - in Kuching (Malaysia) - brought... more The first International Peat Congress (IPC) held in the tropics - in Kuching (Malaysia) - brought together over 1000 international peatland scientists and industrial partners from across the world ("International Peat Congress with over 1000…

Environmental Research Letters, 2014

Vast areas of deforested tropical peatlands do not receive noteworthy shading by vegetation, whic... more 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 (CO 2 ), nitrous oxide (N 2 O) and methane (CH 4 ) 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 CO 2 fluxes caused by the treatments were on agricultural land, where 90% shading from the full exposure resulted in a 33% lower CO 2 emission average on the unfertilized plots and a 66% lower emission average on the fertilized plots. Correlation between peat temperature and CO 2 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. CO 2 flux responses to the treatments remained low on degraded peatland. Fertilized conditions negatively correlated with N 2 O 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. Environ. Res. Lett. 9 (2014) 105013 J Jauhiainen et al 3 Environ. Res. Lett. 9 (2014) 105013 J Jauhiainen et al 4 Environ. Res. Lett. 9 (2014) 105013 J Jauhiainen et al 12 Environ. Res. Lett. 9 (2014) 105013 J Jauhiainen et al 18 Environ. Res. Lett. 9 (2014) 105013 J Jauhiainen et al View publication stats View publication stats

Plant and Soil, 2014

Background and Aims Tropical peat swamp forests (PSF) are great stores of terrestrial carbon and ... more Background and Aims Tropical peat swamp forests (PSF) are great stores of terrestrial carbon and host unique biodiversity. Despite their importance for carbon accounting, the peat characteristics are sparsely studied, and the effect of microtopography on peat properties has not been reported before. Methods We compared PSF peat soil characteristics down to 70 cm under differing microtopographical conditions and hydrology. Results Long-term water table level data combined with the data from peat structure and chemistry analyses showed differences in most of the measured properties between hummocks and hollows. Decomposition degree was lowest at hummock and hollow surfaces while bulk density and C content increased towards deeper peat. Ash, P, K, Ca and Mg had highest concentrations on hummock surfaces with declining trend downwards, whereas N had no clear concentration pattern along the elevation gradient. Conclusions The microtopographical features may not only differ in regards to the water table-induced oxygen conditions but also due to differences in nutrient dynamics.

CATENA, 2014

This version is distributed under a non-commencial no derivatives Creative Commons (CC-BY-NC-ND) ... more This version is distributed under a non-commencial no derivatives Creative Commons (CC-BY-NC-ND) user license, which permits use, distribution, and reproduction in any medium, provided the original work is properly cited and not used for commercial purposes. Further, the restriction applies that if you remix, transform, or build upon the material, you may not distribute the modified material.

Soil Biology and Biochemistry, 2018

Swamp forests on deep tropical peatlands have undergone extensive deforestation and draining for ... more Swamp forests on deep tropical peatlands have undergone extensive deforestation and draining for agriculture and plantations, consequently becoming globally significant carbon (C) sources. To study the effects of land-use change on peat as a biological environment, which directly affects decomposition dynamics and greenhouse gas emissions, we sampled peat from four common land-use types representing different management intensities in Central Kalimantan, Indonesia. The near-pristine swamp forest was used to describe unmanaged conditions, and the three other sites in order of increasing management intensity were reforested; degraded; and agricultural. We examined peat substrate quality (total C & nitrogen (N), dissolved organic C (DOC) and N (DON), and organic matter quality characterized by infrared spectroscopy) and microbial biomass and extracellular enzyme activity to describe both biotic and abiotic conditions in peat. We found that the peat at altered sites was poorer in quality, i.e. decomposability, as demonstrated by the higher intensity of aromatic and aliphatic compounds, and lower intensity of polysaccharides, and concentration of DOC, total N and DON compared to the peat in the swamp forest. The observed differences in peat properties can be linked to changes in litter input and decomposition conditions altered after deforestation and draining, as well as increased leaching and fires. The quality of the peat substrate was directly related to its biotic properties, with altered sites generally having lower microbial biomass and enzyme activity. However, irrespective of management 2 intensity or substrate quality, enzyme activity was limited primarily to the first 0 3 cm of the peat profile. Some differences between wet and dry seasons were observed in enzyme activity especially in swamp forest, where the most measured enzyme activities were higher in dry season. Reforestation 6 years before our measurements had not yet restored enzyme activity in the peat to the level of the swamp forest, although the topmost peat characteristics in the reforested site already resembled those in the swamp forest. This is likely contributed to by the chemical weed control performed at the site, and the limited capacity of the young plantation to produce litter to support peat formation and restore the quality and structure of the peat. Therefore, we conclude that intensive land management, including deforestation and draining, leads to the surface peat becoming poorer biological environment, and it may take long time to restore the peat properties.

Mires and Peat, 2015

Land-use change has transformed large areas of tropical peatland into globally significant carbon... more Land-use change has transformed large areas of tropical peatland into globally significant carbon sources. Associated changes in the properties of peat are important for soil processes including decomposition and nutrient cycling. To characterise the changes induced by stabilised land uses, we studied the physical and chemical properties of peat from four land management conditions (undrained and drained forest, degraded land, and managed agricultural land). Peat was sampled from depths of 10–15 cm, 40–45 cm, 80–85 cm and 110–115 cm then partitioned into woody (Ø >1.5 mm), fibric (Ø 0.15–1.5 mm) and amorphic (Ø < 0.15 mm) fractions. Bulk density and total concentrations of ash, C, N, P, K, Ca, Mg, Mn, Zn, Na, Al, Fe, S and Si were determined. There were clear differences between land uses in the characteristics of surface peat down to the 40–45 cm layer, the primary differences being between forested and open sites. Due to smaller particle sizes, the bulk density of peat was h...

Forested tropical peatlands in Southeast Asia store at least 42 000 Million metric tonnes (Mt) of... more Forested tropical peatlands in Southeast Asia store at least 42 000 Million metric tonnes (Mt) of soil carbon. Human activity and climate change threatens the stability of this large pool, which has been decreasing rapidly over the last few decades owing to deforestation, drainage and fire. In this paper we estimate the carbon dioxide (CO 2) emissions resulting from drainage of lowland tropical peatland for agricultural and forestry development which dominates the perturbation of the carbon balance in the region. Present and future emissions from drained peatlands are quantified using data on peatland extent and peat thickness, present and projected land use, water management practices and decomposition rates. Of the 27.1 Million hectares (Mha) of peatland in Southeast Asia, 12.9 Mha had been deforested and mostly drained by 2006. This latter area is increasing rapidly because of increasing land development pressures. Carbon dioxide (CO 2) emission caused by decomposition of drained peatlands was between 355 Mt y −1 and 855 Mt y −1 in 2006 of which 82% came from Indonesia, largely Sumatra and Kalimantan. At a global scale, CO 2 emission from peatland drainage in Southeast Asia is contributing the equivalent of 1.3% to 3.1% of current global CO 2 emissions from the combustion of fossil fuel. If current peatland development and management practices continue, these emissions are predicted to continue for decades. This warrants inclusion of

Water in a peat swamp area in Kalampangan Central Kalimantan, Indonesia was sampled every four we... more Water in a peat swamp area in Kalampangan Central Kalimantan, Indonesia was sampled every four weeks from May 2004 to January 2007 and analyzed for total content of Ca, Mg, K, Na, and Fe. Water samples were collected at three permanent sites in a canal and six permanent sites in the adjacent peat area. The latter were established in (a) deforested peatland (4 sites) and (b) peat swamp forest (2 sites). At every site water samples were obtained from depths of 50, 150 and 250 cm below the surface. Water in the canal is very acid (pH between 3.32 ± 0.04 and 4.22 ± 0.05 and average 3.71 ±0.19) with a predominance of Ca and K. pH of water sampled from the peat at 50, 150, and 250 cm depth in the deforested area gives means of 3.98 ±0.60, 4.18 ± 0.36 and 4.31 ± 0.35, respectively. Meanwhile, pH of water sampled from the peat at 50, 150, and 250 cm depth in forest area has means of 3.68 ±0.55, 3.70 ± 0.38 and 3.92 ± 0.46, respectively. Similar to water sampled in the canal the predominant ...

Sphagnum fuscum, S. magellanicum, S. angustifolium and S. warnstorfii were treated with N deposit... more Sphagnum fuscum, S. magellanicum, S. angustifolium and S. warnstorfii were treated with N deposition rates (0, 10, 30 and 100 kg ha −1 a −1) and with four atmospheric CO 2 concentrations (350, 700, 1000 and 2000 ppm) in greenhouse for 71-120 days. Thereafter, concentrations of total N, P, K, Ca and Mg in the capitulae of the Sphagna were determined. The response of each species to N deposition was related to ecological differences. With increasing N deposition treatments, moss N concentrations increased and higher N:P-ratios were found, the increase being especially clear at the highest N load. Sphagnum fuscum, which occupies ombrotrophic habitats, was the most affected by the increased nitrogen load and as a consequence the other elements were decreased. Oligotrophic S. magellanicum, wide nutrient status tolerant S. angustifolium and meso-eutrophic S. warnstorfii tolerated better increased N deposition, though there were increased concentrations of Ca and Mg in S. warnstorfii and Mg in S. magellanicum. Nitrogen and P concentrations decreased with raised CO 2 concentrations, except for S. magellanicum. This seems to be the first time this kind of response in nutrient concentrations to enhanced CO 2 concentration has been shown to exist in bryophytes. The concentration of K clearly decreased in S. fuscum as did the concentration of Mg in the other Sphagna with increasing CO 2. Sphagnum angustifolium and S. magellanicum, which are the less specialized species, were the least affected by the CO 2 treatments.

… on Tropical Peatlands, …, 2002

... By combining data from remote sensed images with field measurements, it has been possible to ... more ... By combining data from remote sensed images with field measurements, it has been possible to determine fire impact, carbon storage in the peatlands and carbon ... 796,906 ha); the largest scars are in areas impacted by logging forest clearance and peatland drainage. ...

Conversion of tropical peatlands to agriculture leads to a release of carbon from previously stab... more Conversion of tropical peatlands to agriculture leads to a release of carbon from previously stable, longterm storage, resulting in land subsidence that can be a surrogate measure of CO 2 emissions to the atmosphere. We present an analysis of recent large-scale subsidence monitoring studies in Acacia and oil palm plantations on peatland in SE Asia, and compare the findings with previous studies. Subsidence in the first 5 yr after drainage was found to be 142 cm, of which 75 cm occurred in the first year. After 5 yr, the subsidence rate in both plantation types, at average water table depths of 0.7 m, remained constant at around 5 cm yr −1. The results confirm that primary consolidation contributed substantially to total subsidence only in the first year after drainage, that secondary consolidation was negligible, and that the amount of compaction was also much reduced within 5 yr. Over 5 yr after drainage, 75 % of cumulative subsidence was caused by peat oxidation, and after 18 yr this was 92 %. The average rate of carbon loss over the first 5 yr was 178 t CO 2eq ha −1 yr −1 , which reduced to 73 t CO 2eq ha −1 yr −1 over subsequent years, potentially resulting in an average loss of 100 t CO 2eq ha −1 yr −1 over 25 yr. Part of the observed range in subsidence and carbon loss values is explained by differences in water table depth, but vegetation cover and other factors such as addition of fertilizers also influence peat oxidation. A relationship with groundwater table depth shows that subsidence and carbon loss are still considerable even at the highest water levels theoretically possible in plantations. This implies that improved plantation water management will reduce these impacts by 20 % at most, relative to current conditions, and that high rates of carbon loss and land subsidence are inevitable consequences of conversion of forested tropical peatlands to other land uses.

In the Swiss Jura mountains most of the remaining ombrotrophic peat bogs have been exploited to s... more In the Swiss Jura mountains most of the remaining ombrotrophic peat bogs have been exploited to some extent for peat. In these sites, natural regeneration processes are taking place. The dominant process is paludification, where a cut over drained surface is colonised by key species, usually either Polytrichum strictum or Eriophortum vaginatum. These early colonisers of bare peat surfaces create

Global change biology, Mar 27, 2016

The first International Peat Congress (IPC) held in the tropics - in Kuching (Malaysia) - brought... more The first International Peat Congress (IPC) held in the tropics - in Kuching (Malaysia) - brought together over 1000 international peatland scientists and industrial partners from across the world ("International Peat Congress with over 1000…

Environmental Research Letters, 2014

Vast areas of deforested tropical peatlands do not receive noteworthy shading by vegetation, whic... more 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 (CO 2 ), nitrous oxide (N 2 O) and methane (CH 4 ) 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 CO 2 fluxes caused by the treatments were on agricultural land, where 90% shading from the full exposure resulted in a 33% lower CO 2 emission average on the unfertilized plots and a 66% lower emission average on the fertilized plots. Correlation between peat temperature and CO 2 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. CO 2 flux responses to the treatments remained low on degraded peatland. Fertilized conditions negatively correlated with N 2 O 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. Environ. Res. Lett. 9 (2014) 105013 J Jauhiainen et al 3 Environ. Res. Lett. 9 (2014) 105013 J Jauhiainen et al 4 Environ. Res. Lett. 9 (2014) 105013 J Jauhiainen et al 12 Environ. Res. Lett. 9 (2014) 105013 J Jauhiainen et al 18 Environ. Res. Lett. 9 (2014) 105013 J Jauhiainen et al View publication stats View publication stats