Land cover change and carbon stores in a tropical montane cloud forest in the Sierra Madre Oriental,Mexico

Tropical montane cloud forest is one of the ecosystems with the highest biomass worldwide, representing an important carbon store. Globally its deforestation index is –1.1%, but in Mexico it is higher than –3%. Carbon estimates are scarce globally, particularly in Mexico. The objective of this study was to simulate future land-cover scenarios for the Sierra Madre Oriental in Mexico, by analyzing past forest cover changes. Another objective was to estimate stored carbon in the two study areas. These objectives involve the generation of information that could be useful inputs to anti-deforestation public policy such as the REDD+ strategy. Remote sensing was used to measure land cover change and estimate carbon stocks. Satellite images from 2015, 2000 and 1986 were used, and Dinamica EGO freeware generatedmodels of future projections. Between 1986 and 2015, 5171 ha of forest were converted to pasture. The annual deforestation rates were –1.5% for Tlanchinol and –1.3% for the San Bartolo Tutotepec sites. Distance to roads and marginalization were highly correlated with deforestation. By 2030, an estimated 3608 ha of forest in these sites will have been converted to pasture. Stored carbon was estimated at 16.35 Mg C ha-1 for the Tlanchinol site and 12.7 Mg C ha-1 for the San Bartolo site. In the Sierra Madre Oriental deforestation due to land cover change(–1.4%) is higher than levels reported worldwide. Besides having high values of stored carbon(14.5 Mg C ha-1), these forests have high biodiversity. The models' outputs show that the deforestation process will continue if action is not taken to avoid the expansion of livestock pasturing. This can be done by paying incentives for forest conservation to the owners of the land. The results suggest that REDD+ is currently the most viable strategy for reducing deforestation rates in tropical montane cloud forests in Sierra Madre Oriental.     

Potential effects of future adoption of the REDD mechanism as a preventive measure against deforestation and forest degradation in North Korea

This study assesses potential effects of adaption to climate change in the future as a carbon related value using a baseline and credit approach, considering the implementation of the Reducing Emissions from Deforestation and forest Degradation(REDD) mechanism. Basic data were obtained for implementing the REDD mechanism in the Democratic People's Republic of Korea(DPRK) for scientific decision-making to prevent deforestation and forest degradation. The potential effects according to the implementation of the REDD mechanism in the DPRK based on forest status data(the latest) are as follows. If the deforestation rate is reduced to a level below 6% through a 20-year REDD mechanism beginning in 2011, 0.01–11.64 C-tons of carbon credit per ha could be issued for DPRK. Converted into CO?-tons per ha, this amounts to 0.03–42.68 CO?-tons, which translates to a minimum of 226,000 CO?-tons and a maximum of 289,082,000 CO?-tons overall for forests in DPRK. In terms of carbon price, this measures up to 1.10 million USD–1.4 billion USD, considering that the REDD carbon price in voluntary carbon markets in 2010 was around 5 USD.     

Forest carbon storage and tree carbon pool dynamics under natural forest protection program in northeastern China

The Natural Forest Protection(NFP) program is one of the Six Key Forestry Projects which were adopted by the Chinese Government since the 1980s to address important natural issues in China. It advanced to protecting and restoring the structures and functions of the natural forests through sustainable forest management. However, the role of forest carbon storage and tree carbon pool dynamics since the adoption of the NFP remains unknown. To address this knowledge gap, this study calculated forest carbon storage(tree, understory, forest floor and soil) in the forest region of northeastern(NE) China based on National Forest Inventory databases and field investigated databases. For tree biomass, this study utilized an improved method for biomass estimation that converts timber volume to total forest biomass; while for understory, forest floor and soil carbon storage, this study utilized forest type-specific mean carbon densities multiplied by their areas in the region. Results showed that the tree carbon pool under the NFP in NE China functioned as a carbon sink from 1998 to 2008, with an increase of 6.3 Tg C/yr, which was mainly sequestrated by natural forests(5.1 Tg C/yr). At the same time, plantations also acted as a carbon sink, reflecting an increase of 1.2 Tg C/yr. In 2008, total carbon storage in forests covered by the NFP in NE China was 4603.8 Tg C, of which 4393.3 Tg C was stored in natural forests and 210.5 Tg C in planted forests. Soil was the largest carbon storage component, contributing 69.5%–77.8% of total carbon storage; followed by tree and forest floor, accounting for 16.3%–23.0% and 5.0%–6.5% of total carbon storage, respectively. Understory carbon pool ranged from 1.9 to 42.7 Tg C, accounting for only 0.9% of total carbon storage.     

Composition,diversity and distribution of tree species in response to changing soil properties with increasing distance from water source – a case study of Gobind Sagar Reservoir in India

Construction of big dams on rivers develops artificial lakes or water reservoirs which conceive alterations in soil properties of the upstream catchment area. An undulating topography and freckly soil properties cause ups and downs in tree diversity, composition and distribution. The study aimed to evaluate the effect of Gobind Sagar reservoir on soil properties relative to the distance from it and assess its effect on tree diversity, evenness and their distribution in tropical and subtropical forests. Based on data analysis it was found that the soil moisture and organic carbon decreased along with increasing distance from the reservoir. It played a significant role in varying tree diversity. The sites distributed within0-2 km showed significantly higher α and β-diversity indices. Tree species richness and diversity indices showed a strong correlation(p 0.05) with soil moisture and organic carbon content. Simpson's and Mc Intosh evenness indices showed a strong negative correlation with soil bulk density. Indirect Detrended Correspondence Analysis(DCA) identified soil moisture and soil organic carbon as two major environmental gradients that influenced tree diversity and their distribution in five tropical and four subtropical forests in an upstream catchment of the reservoir. Mixed forests inhabited moist sites andAcacia-Pinus forests showed an inclination to dry areas. Canonical Correspondence Analysis(CCA)revealed that the tree species in tropical forests were mainly affected by driving forces such as soil moisture,organic carbon and bulk density whereas, in subtropical forest tree species were influenced by elevation, soil p H, EC and clay content.     

Interrelationship between soil depth and soil properties of Pieniny National Park forest(Poland)

The purpose of this research was to investigate the relationship between soil biota such as microbial activity, soil fauna(e.g., earthworms and enchytraeids), and soil physical and chemical properties. The study area was located in Pieniny National Park(PNP) in the Carpathian Mountains in southern Poland. Soil samples were collected from six forest monitoring areas of PNP from two soil layers(at 0–15 cm and 15–30 cm down, respectively). The investigated soils were classified to eutric cambisols and had silt or silt loam soil texture. Upon analysis, soil aggregate stability index was connected with other physical, chemical, and biological soil properties.It was noted that the stability index of 3 mm to 5 mm soil aggregates influenced pH and dissolved organic carbon. The stability index of 2 mm to 3 mm soil aggregates was positively correlated with dissolved organic carbon, soil moisture, microbial biomass carbon, total organic carbon, total nitrogen, and enchytraeid density, and negatively correlated with bulk density, particle density, porosity, and permanent wilting point. The stability index of 1 mm to 2 mm soil aggregates was positively correlated with total nitrogen, enchytraeid and earthworm density and negatively correlated with particle density, porosity, and permanent wilting point. The study has shown what factors create a stable soil structure in the forest soils of PNP.     

Deforestation Trends and Spatial Modelling of its Drivers in the Dry Temperate Forests of Northern Pakistan–A Case Study of Chitral

Deforestation is a major environmental challenge in the mountain areas of Pakistan. The study assessed trends in the forest cover in Chitral tehsil over the last two decades using supervised land cover classification of Landsat TM satellite images from 1992, 2000, and 2009, with a maximum likelihood algorithm. In 2009, the forest cover was 10.3% of the land area of Chitral(60,000 ha). The deforestation rate increased from 0.14% per annum in 1992–2000 to 0.54% per annum in 2000–2009, with 3,759 ha forest lost over the 17 years. The spatial drivers of deforestation were investigated using a cellular automaton modelling technique to project future forest conditions. Accessibility(elevation, slope), population density, distance to settlements, and distance to administrative boundary were strongly associated with neighbourhood deforestation. A model projection showed a further loss of 23% of existing forest in Chitral tehsil by 2030, and degradation of 8%, if deforestation continues at the present rate. Arandu Union Council, with 2212 households, will lose 85% of its forest. Local communities have limited income resources and high poverty and are heavily dependent on non-timber forest products for their livelihoods. Continued deforestation will further worsen their livelihood conditions, thus improved conservation efforts are essential.     

Soil organic carbon stock as affected by land use/cover changes in the humid region of northern Iran

This study was conducted to determine the changes in the soil carbon stocks as influenced by land use in a humid zone of Deylaman district(10,876 ha), a mountainous region of northern Iran. For this, land use maps were produced from TM and ETM+ images for 1985, 2000 and 2010 years; and this was supplemented by field measurement of soil carbon in 2010. The results showed that the mean soil organic carbon(SOC) density was 6.7±1.8 kg C m-2, 5.2±3.4 kg C m-2 and 3.2±1.8 kg C m-2 for 0-20 cm soil layer and 4.8±1.9 kg C m-2, 3.1±2 kg C m-2 and 2.7±1.8 kg C m-2 for 20-40 cm soil layer in forest, rangeland and cultivated land, respectively. During the past 25 years, 14.4% of the forest area had been converted to rangeland; and 28.4% of rangelands had been converted to cultivated land. According to the historical land use changes in the study area, the highest loss of SOC stocks resulted from the conversion of the forest to rangeland(0.45×104 Mg C in 0-40 cm depth layer); and the conversion of rangeland to cultivated land(0.37×104 Mg C in 0-40 cm), which typically led to the loss of soil carbon in the area studied. The knowledge on the historical land use changes and its influence on overall SOC stocks could be helpful for making management decision for farmers and policy managers in the future, for enhancing the potential of C sequestration in northern Iran.     

Forest fragmentation and human population varies logarithmically along elevation gradient in Hindu Kush Himalaya - utility of geospatial tools and free data set

Hindu Kush Himalaya(HKH) is the largest and the most diverse mountain region in the world that provides ecosystem services to one fifth of the total world population. The forests are fragmented to different degrees due to expansion and intensification of human land use. However, the quantitative relationship between fragmentation and demography has not been established before for HKH vis-à-vis along elevation gradient. We used the globally available tree canopy cover data derived from Landsat-TM satellite to find out the decadal forest cover change over 2000 to 2010 and their corresponding fragmentation levels. Using SRTMderived DEM, we observed high forest cover loss up to2400 m that highly corroborated with the population distribution pattern as derived from satellite observation. In general, forest cover loss was found to be higher in south-eastern part of HKH. Forest fragmentation obtained using ‘area-weighted mean radius of gyration' as indicator, was found to be very high up to 2400 m that also corroborated with high human population for the year 2000 and 2010. We observed logarithmic decrease in fragmentation change(area-weighted mean radius of gyration value),forest cover loss and population growth during 2000-2010 along the elevation gradient with very high R~2 values(i.e., 0.889, 0.895, 0.944 respectively). Our finding on the pattern of forest fragmentation and human population across the elevation gradient in HKH region will have policy level implication for different nations and would help in characterizing hotspots of change. Availability of free satellite derived data products on forest cover and DEM, griddata on demography, and utility of geospatial tools helped in quick evaluation of the forest fragmentation vis-a-vis human impact pattern along the elevation gradient in HKH.     

Evaluation of soil erosion from chestnut forests: A case study in the Yanshan Mountains,China

Soil erosion from chestnut forests has many types and intensities. However, less attention has been paid to the increasing soil erosion in the chestnut forests of Yanshan Mountains region, North China. The objective of this study was to discuss forest ages(5, 5~10, 10~20, and 20~ yr), slopes(5°~15°, 15°~25°, 25°~35°, and 35°~), slope positions(upslope, midslope, downslope, and whole slope), and slope aspects(sunny, half-sunny, shade, and half-shade) effects on soil erosion types and intensities in chestnut forests. A field survey was applied to investigate in detail the contiguous chestnut forests near Changfu village of Hebei Province, China on October 9-30, 2016. Results showed that chestnut forests are dominated by moderate erosion in this region, and the soil erosionfrom chestnut forests tended to deteriorate gradually. The average land degradation index was 0.31. The erosion intensity from chestnut forests will gradually increase with the year of planting. Most of the slopes are greater than 15°, accounting for 86.7% of the total chestnut forests. Most of the chestnut forests occupy the whole slope, accounting for 47.5% of the total area. Moderate erosion occurs most commonly for different slope aspects. In conclusion, improving the preparation efficiency of chestnut forests and enhancing the construction standards of soil and water conservation measures would be useful measures to avoid soil erosion from chestnut forests reaching a more severe level.     

Spatial modelling of deforestation in Romanian Carpathian Mountains using GIS and Logistic Regression

Deforestation process represents a wide concern mainly in the mountain environments due to its role in global warming, biodiversity loss, land degradation and natural hazards occurrence. Thus, the present study is focused on the largest afforested landform unit of Romania and, consequently, the most affected area by forest losses: Carpathian Mountains. The main goal of the paper is to examine and analyze the various explanatory variables associated with deforestation process and to model the probability of deforestation using GIS spatial analysis and logistic regression. The forest cover for 1990 and 2012, derived from CORINE Land Cover(CLC) database, were used to quantify historical forest cover change included in the modelling. To explain the biophysical and anthropogenic effects, this study considered several explanatory factors related to local topography, forest cover pattern, accessibility, urban growth and population density. Using ROC(Receiver Operating Characteristic) and 500 controlling sampling points, the statistical and spatial validations were assessed in order to evaluate the performance of the resulted data. The analysis showed that the area experienced a continuous forest cover change, leading to the loss of over 250,000 ha of forested area during the period 1990–2012. The most significant influence of the explanatory factors of deforestation were noticed in case of distance to forest edge(β=–4.215), forest fragmentation(β=2.231), slope declivity(β=–1.901), elevation(β=1.734) and distance to roads(β=–1.713). The statistical and spatial validation indicates a good accuracy of the model with reasonably AUC(0.736) and Kappa(0.739) values. The model's results suggest an intensification of the deforestation process in the area, designing numerous new clusters with high probability in the Apuseni Mountains, northern and central part of the Eastern Carpathians, western part of the Southern Carpathians and northern part of the Banat Mountains. The study could represent a useful outcome to identify the forests more vulnerable to logging and to adopt appropriate policies and decisions in forest management and conservation. In addition, the resulted probability map could be used in other studies in order to investigate potential environmental implications(e.g. geomorphological hazards or impact on biodiversity and landscape diversity).     

Multi-temporal forest cover dynamics in Kashmir Himalayan region for assessing deforestation and forest degradation in the context of REDD+ policy

The role of forests is being actively considered under the agenda of REDD+ (Reducing Emissions from Deforestation and Forest Degradation plus) aimed at reducing emissions related to changes in forest cover and forest quality. Forests in general have undergone negative changes in the past in the form of deforestation and degradation, while in some countries positive changes are reported in the form of conservation, sustainable management of forests and enhancement of carbon stock. The present study in the Kashmir Himalayan forests is an effort to assess historical forest cover changes that took place from 1980 to 2009 and to predict the same for 2030 on the basis of past trend using geospatial modeling approach. Landsat data (Multispectral Scanner (MSS), Thematic Mapper (TM) and Enhanced Thematic Mapper (ETM+)) was used for the years 1980, 1990 and (2001, 2009) respectively and change detection analysis between the dates was performed. The maps generated were validated through ground truthing. The study area (3375.62 km²) from 1980-2009 has uffered deforestation and forest degradation of about 126 km² and 139.02 km² respectively which can be claimed under negative options of REDD+, while as the area that experienced no change (1514 km²) can be claimed under conservation. A small area (23.31 km2) observed as positive change can be claimed under positive options. The projected estimates of forest cover for 2030 showed increased deforestation and forest degradation on the basis of trend analysis using Cellular Automata (CA) Markov modeling. Despite the fact that country as a whole has registered a net positive change in the past few decades, but there are regions like Kashmir region of western Himalaya which have constantly undergoing deforestation as well as degradation in the past few decades.     

Simulating carbon sequestration and GHGs emissions in <Emphasis Type="Italic">Abies fabric</Emphasis> forest on the Gongga Mountains using a biogeochemical process model Forest-DNDC

The process-oriented model Forest-DNDC describing biogeochemical cycling of C and N and GHGs （greenhouse gases） fluxes （CO2, NO and N2O） in forest ecosystems was applied to simulate carbon sequestration and GHGs emissions in Abies fabric forest of the Gongga Mountains at southeastern edge of the Tibetan Plateau. The results indicated that the simulated gross primary production （GPP） of Abies fabric forest was strongly affected by temperature. The annual total GPP was 24,245.3 kg C ha^-1 yr^-1 for 2005 and 26,318.8 kg C ha^-1 yr^-1 for 2006, respectively. The annual total net primary production （NPP） was 5,935.5 and 4,882.2 kg C ha^-1 yr^-1 for 2005 and 2006, and the annual total net ecosystem production （NEP） was 4,815.4 and 3,512.8 kg C ha^-1 yr^-1 for 2005 and 2006, respectively. The simulated seasonal variation in CO2 emissions generally followed the seasonal variations in temperature and precipitation. The annual total CO2 emissions were 3,109.0 and 4,821.0 kg C ha^-1 yr^-1 for 2005 and 2006, the simulated annual total N2O emissions from forest soil were 1.47 and 1.36 kg N ha^-1 yr^-1 for 2005 and 2006, and the annual total NO emissions were 0.09 and o.12 kg N ha^-1 yr^-1 for 2005 and 2006, respectively.     

Soil respiration under three different land use types in a tropical mountain region of China

Soil respiration (SR) Wis one of the largest contributors of terrestrial CO_2 to the atmosphere.Environmental as well as physicochemical parameters influence SR and thus, different land use practices impact the emissions of soil CO_2. In this study, we measured SR, bi-monthly, over a one-year period in a terrace tea plantation, a forest tea plantation and a secondary forest, in a subtropical mountain area in Xishuangbanna, China. Along with the measurement of SR rates, soil characteristics for each of the land use systems were investigated. Soil respiration rates in the different land use systems did not differ significantly during the dry season, ranging from2.7±0.2 μmol m~(-2) s~(-1) to 2.8±0.2 μmol m~(-2) s~(-1). During the wet season, however, SR rates were significantly larger in the terrace tea plantation(5.4±0.5 μmol m~(-2)s~(-1)) and secondary forest(4.9±0.4 μmol m~(-2)s~(-1)) than in the forest tea plantation(3.7±0.2 μmol m~(-2) s~(-1)).This resulted in significantly larger annual soil CO_2 emissions from the terrace tea and secondary forest,than from the forest tea plantation. It is likely that these differences in the SR rates are due to the 0.5times lower soil organic carbon concentrations in thetop mineral soil in the forest tea plantation, compared to the terrace tea plantation and secondary forest.Furthermore, we suggest that the lower sensitivity to temperature variation in the forest tea soil is a result of the lower soil organic carbon concentrations. The higher SR rates in the terrace tea plantation were partly due to weeding events, which caused CO_2 emission peaks that contributed almost 10% to the annual CO_2 flux. Our findings suggest that moving away from heavily managed tea plantations towards low-input forest tea can reduce the soil CO_2 emissions from these systems. However, our study is a casestudy and further investigations and upscaling are necessary to show if these findings hold true at a landscape level.     

Estimation of non-CO2 GHGs emissions by analyzing burn severity in the Samcheok fire, South Korea

This study was performed to estimate the emission of non-CO 2 greenhouse gases(GHGs) from biomass burning at a large fire area.The extended methodology adopted the IPCC Guidelines(2003) equation for use on data from the Samcheok forest fire gathered using 30 m resolution Landsat TM satellite imagery,digital forest type maps,and growing stock information per hectare by forest type in 1999.Normalized burn ratio(NBR) technique was employed to analyze the area and severity of the Samcheok forest fire that occurred in 2000.The differences between NBR from pre-and post-fire datasets are examined to determine the extent and degree of change detected from burning.The results of burn severity analysis by dNBR of the Samcheok forest fire area revealed that a total of 16,200 ha of forest were burned.The proportion of the area characterized by a ’Low’ burn severity(dNBR below 152) was 35%,with ’Moderate’(dNBR 153-190) and ’High’(dNBR 191-255) areas were at 33% and 32%,respectively.The combustion efficiency for burn severity was calculated as 0.43 for crown fire where burn severity was ’High’,as 0.40 for ’Moderate’ severity,and 0.15 for ’Low’ severity surface fire.The emission factors for estimating non-CO 2 GHGs were separately applied to CO 130,CH 4 9,NO x 0.7 and N 2 O 0.11.Non-CO 2 GHGs emissions from biomass burning in the Samcheok forest fire area were estimated to be CO 44.100,CH 4 3.053,NO x 0.238 and N 2 O 0.038 Gg.     

Soil carbon stock and flux in plantation forest and grassland ecosystems in Loess Plateau,China

Carbon sequestration occurs when cultivated soils are re-vegetated. In the hilly area of the Loess Plateau, China, black locust(Robinia pseudoacacia) plantation forest and grassland were the two main vegetation types used to mitigate soil and water loss after cultivation abandonment. The purpose of this study was to compare the soil carbon stock and flux of these two types of vegetation which restored for 25 years. The experiment was conducted in Yangjuangou catchment in Yan′an City, Shaanxi Province, China. Two adjacent slopes were chosen for this study. Six sample sites were spaced every 35–45 m from summit to toe slope along the hill slope, and each sample site contained three sampling plots. Soil organic carbon and related physicochemical properties in the surface soil layer(0–10 cm and 10–20 cm) were measured based on soil sampling and laboratory analysis, and the soil carbon dioxide(CO2) emissions and environmental factors were measured in the same sample sites simultaneously. Results indicated that in general, a higher soil carbon stock was found in the black locust plantation forest than that in grassland throughout the hill slope. Meanwhile, significant differences in the soil carbon stock were observed between these two vegetation types in the upper slope at soil depth 0–10 cm and lower slope at soil depth 10–20 cm. The average daily values of the soil CO2 emissions were 1.27 μmol/(m2·s) and 1.39 μmol/(m2·s) for forest and grassland, respectively. The soil carbon flux in forest covered areas was higher in spring and less variation was detected between different seasons, while the highest carbon flux was found in grassland in summer, which was about three times higher than that in autumn and spring. From the carbon sequestration point of view, black locust plantation forest on hill slopes might be better than grassland because of a higher soil carbon stock and lower carbon flux.     

Residential energy consumption and associated carbon emission in forest rural area in China: A case study in Weichang County

Rural energy consumption in China has increased dramatically in the last decades, and has become a significant contributor of carbon emissions. Yet there is limited data on energy consumption patterns and their evolution in forest rural areas of China. In order to bridge this gap, we report the findings of field surveys in forest villages in Weichang County as a case study of rural energy consumption in northern China. We found that the residential energy consumption per household is 3313 kgce yr-1(kilogram standard coal equivalent per year), with energy content of 9.7 × 107 kJ yr-1, including 1783 kgce yr-1 from coal, 1386 kgce yr-1 from fuel wood, 96 kgce yr-1 from electricity, and 49 kgce yr-1 from LPG. Per capita consumption is 909 kgce yr-1 and its energy content is 2.7 × 107 kJ yr-1. Due to a total energy utilization efficiency of 24.6%, all the consumed energy can only supply about 2.4 × 107 kJ yr-1 of efficient energy content. Secondly, household energy consumption is partitioned into 2614 kgce yr-1 for heating, 616 kgce yr-1 for cooking, and 117 kgce yr-1 for home appliances. Thirdly, the associated carbon emissions per household are 2556 kgC yr-1, including1022 kgC yr-1 from unutilized fuel wood(90% of the total fuel wood). The rest of emissions come from the use of electricity(212 kgC yr-1), coal(1301 kgC yr-1) and LPG(21 kgC yr-1). Fourthly, local climate, family size and household income have strong influences on rural residential energy consumption. Changes in storage and utilization practices of fuel can lead to the 10%-30% increase in the efficiency of fuel wood use, leading to reduced energy consumption by 924 kgce yr-1 per household(27.9% reduction) and 901 kgC yr-1 of carbon emissions(35.3% reduction).     

Exploring perspectives in assessing the quality of governance of the Reducing Emissions from Deforestation and Forest Degradation (REDD+) pilot project in Cambodia: Use of Q Methodology

Public and policy makers alike are concerned about national and global deforestation and forest degradation. These issues pose a significant threat to social, economic and environmental welfare.Attempts to prevent forest loss and increased attention to pilot REDD+ projects in community forestry sites would both deliver rural livelihood benefits and help to reduce adverse climate impacts.However, there has been no significant exploration of the viewpoints of local experts to determine the monitoring and action needed to support communitybased forestry and improve the governance of REDD+pilot projects in Cambodia. Therefore, this study aimed to assess the perceptions of local stakeholders towards the quality of governance of the first community forest REDD+ pilot project in Cambodia,employing Q-methodology. We adapted 11 indicators of the hierarchical framework of assessment of governance quality to design 40 Q-statements related to REDD+ governance or achievements. The 52 P-set ranked these Q-statements with respect to the community-based REDD+ pilot project. Our study revealed that local stakeholders held four distinct, and partially opposite, views, that:(1) the REDD+ project is successful because it is inclusiveness and capable of causing behavioral change;(2) REDD+ pilot projects should be led by government, not external or locally;and needs more resources;(3) the REDD+ pilot project has raised unrealistic expectations, would likely be a source of corruption and will probably not be successful for local people or halting deforestation;and(4) the REDD+ pilot project is inclusive but not very transparent and probably ineffective at protecting forest. Through these four varied perspectives from local people involved in the project,we can see that there remain serious challenges to the future of pilot community forestry REDD+ projects,including the complex interaction between the multinational actors and the local socio-ecological systems.To move forwards, this study suggested Cambodia should make a pro-poor REDD+ program,implementing more community-based REDD+projects which explicitly build the assets and capacity of the poorest households. This study also shows that Q-methodology can highlight the diverse viewpoints of local stakeholders concerning the quality of community forest REDD+ governance, helping policy makers, implementers and local stakeholders to better identify the challenges to be addressed.     

Crop residue incorporation and nitrogen fertilizer effects on greenhouse gas emissions from a subtropical rice system in Southwest China

Crop residue incorporation has been widely accepted as a way to increase soil carbon (C) sequestration and sustain soil fertility in agroecosystems. However, effect of crop residue incorporation on greenhouse gas (GHG) emissions in rice paddy soils remains uncertain. A field experiment was conducted to quantify emissions of CH₄ and N₂O and soil heterotrophic respiration (R_H) from a paddy rice field under five different crop residue treatments (i.e., 150 kg N ha^-1 of synthetic N fertilizer application only [NF], 150 kg N ha^-1 of synthetic N fertilizer plus 5.3 Mg ha^-1 wheat residue [NF-WR1], 150 kg N ha^-1 of synthetic N fertilizer plus 10.6 Mg ha^-1 wheat residue [NF-WR2], 75 kg N ha^-1 of synthetic N fertilizer plus 10.6 Mg ha^-1 wheat residue [50%NF-WR2] and 150 kg N ha^-1 of synthetic N fertilizer plus 21.2 Mg ha^-1 wheat residue [NF-WR3]) in southwest China. Our results showed that crop residue incorporation treatments (NF-WR1, NF-WR2, 50%NF-WR2, NF-WR3) significantly increased CH₄ emissions by at least 60%, but N₂O emissions were not enhanced and even suppressed by 25% in the NF-WR3 treatment as compared to the NF treatment. Soil R_H emissions were comparable among experimental treatments, while crop residue incorporation treatments significantly increased soil carbon sequestrations relative to the NF treatment. Overall, CH₄ emissions dominated total global warming potentials (GWP) across all experimental treatments. The average yieldscaled GWPs for the NF and NF-WR1 treatments were significantly lower than for the NF-WR2, 50%NFWR2 and NF-WR3 treatments. Given the comparable yield-scaled GWPs between the NF and NF-WR1 treatments, the NF-WR1 treatment could gain net carbon sequestration as compared with the NF treatment with net soil carbon loss. Our findings suggest that the NF-WR1 treatment should be an effective option to sustain rice production while mitigating GHG emissions from the rice field in China.