Paddies are a potential source of anthropogenic nitrous oxide (N₂O) emission. In paddies, both the soil and the rice plants emit N₂O into the atmosphere. The rice plant in the paddy is considered to act as a channel between the soil and the atmosphere for N₂O emission. However, recent studies suggest that plants can also produce N₂O, while the mechanism of N₂O formation in plants is unknown. Consequently, the rice plant is only regarded as a channel for N₂O produced by soil microorganisms. The emission of N₂O by aseptically grown plants and the distinct dual isotopocule fingerprint of plant-emitted N₂O, as reported by various studies, support the production of N₂O in plants. Herein, we propose a potential pathway of N₂O formation in the rice plant. In rice plants, N₂O might be formed in the mitochondria via the nitrate–nitrite–nitric oxide (NO₃–NO₂–NO) pathway when the cells experience hypoxic or anoxic stress. The pathway is catalyzed by various enzymes, which have been described. So, N₂O emitted from paddies might have two origins, namely soil microorganisms and rice plants. So, regarding rice plants only as a medium to transport the microorganism-produced N₂O might be misleading in understanding the role of rice plants in the paddy. As rice cultivation is a major agricultural activity worldwide, not understanding the pathway of N₂O formation in rice plants would create more uncertainties in the N₂O budget.

As a basic component of the forest ecosystem, the forest structure refers to the general distribution of plant species of different life forms and sizes. The characterization of forest structure is the key to understanding the vegetation history, present status, and future development trajectory of the forest ecosystems. The Chure region of Nepal covers about 12.78% of the country’s land area and extends east to west along the southern foothills. This biologically rich but geologically fragile region is home to many species and provides many ecosystem services to millions of people. The Chure landscape is severely suffered from anthropogenic disturbances including logging, grazing, fuelwood collection, solid waste disposal, encroachment, forest fire, and excavation of sand, gravel, and boulders. In this study, we aim to characterize the forest ecosystem types outside the protected areas in the Chure region of Nepal and analyze the threat and vulnerability of the landscape from the biodiversity point of view. We sampled 62 sites to study the dominant vegetation type, regeneration status, and major threats to the forest ecosystems. A distribution map of the forest ecosystem types in Chure was prepared. We identified 14 forest ecosystem types in Chure including seven new ones. The newly reported forest ecosystems are Hymenodictyon excelsum Forest, Syzygium cumini Forest, Terminalia anogeissiana Forest, Schima wallichii–Shorea robusta Forest, Pinus roxburghii–Shorea robusta Forest, Pinus roxburghii Forest, and Bamboo thickets. We conclude that intensified human activities including forest encroachment and deforestation are mainly responsible for the ecological imbalance in the Chure region. We emphasize an in-depth analysis of biophysical linkage and immediate conservation efforts for the restoration of the Chure landscape in Nepal.

Litter decomposition is a prominent pathway for nutrient availability and management in terrestrial ecosystems. An in-situ litter decomposition experiment was carried out for different land use types along an elevation gradient in the Taihang Mountain area restored after heavy forest degradation in the past. Four land use types, i.e., cropland, shrubland, grassland, and forest, selected randomly from a 300–700 m elevation were investigated for the experiment using the litter bag technique. Litter mass loss ranged from 26.9% (forest) to 44.3% (cropland) varying significantly among land use types. The initial litter quality, mainly N and C/N, had a significant effect on the litter loss rate. The interaction of elevation × land use types × time was significant (p < 0.001). Litter nutrient mobility (K > P ≈ N > C) of the decomposing litter was sporadic with substantial stoichiometric effects of C/N, N/P, and C/P. The residual litters were enriched in ¹⁵N and depleted in ¹³C as compared to the initial litter. Increment of N, P, and δ¹⁵N values in residual litter indicates that, even in the highly weathered substrate, plant litter plays a crucial role in conserving nutrients. This study is a strong baseline for monitoring the functioning of the Taihang Mountain ecosystem restored after the complete destruction in the early 1990s.

Livestock herding is a widespread practice in the mountains of Nepal, and grazing in the forest and pastures within protected areas is a main source of cattle fodder. Given the implications of grazing on biodiversity conservation and the need for sustainable management of pastures in the Manaslu Conservation Area of Nepal, we assessed grazing intensity along an elevational gradient following the Budhi Gandaki valley. The data set consisted of grazing intensities recorded every 250 m along a transect from 1400 to 5200 m above sea level and farmer interviews, after an initial satellite data analysis. Grazing and herd size were found to increase with increasing elevation, reflecting local livelihood dependency on cattle herding. Species richness was then analyzed along a grazing disturbance gradient at 7 goths (summer cattle shed) in heavily grazed areas. Disturbance was found to be moderate at intermediate distances, where species richness was found to be higher; the results agree with the generally accepte...

The agroforestry and intercropping systems are recognized as important options for greenhouse gas mitigation. The primary objective of this study was to assess the impacts of land use change from Orange (O) monoculture to Coffee-Orange (CO) intercropping and Coffee-Forest (CF) agroforest systems, implemented 20 years ago, on soil properties at three different soil depth layers (0–10 cm, 10–20 cm, 20–30 cm), with a particular focus on microbial biomass carbon (MBC) and soil organic carbon (SOC) levels. Although there were no changes in most of the soil’s physical properties, the soil’s chemical properties varied significantly across different land use types. SOC was higher in CF and CO systems compared to the O system; however, only in the CO system was the SOC incorporated evenly across all depths. Regression analysis showed that, in the CO system, microbial biomass carbon increased significantly, suggesting that these systems are more promising for carbon sequestration. The low pH and phosphorus values in the agroforest system were identified as limiting factors for microbial biomass enhancement. Importantly, the integration of coffee into orange cultivation not only enhances economic benefits but also contributes to long-term carbon sequestration by increasing SOC in deeper soil layers.