Search

In Finland, the widespread drainage of boreal peatlands has led to increased forest productivity. The cost is a dramatic increase in soil greenhouse gas emissions. Empirical research of drained peatlands has found a correlation between greenhouse gas emissions and the ground water table. This suggests an opportunity to mitigate greenhouse gas emissions through forest management. We explore this opportunity at the landscape level through a simulation and optimization framework. We explore how forest management actions can impact the ground water table and the related greenhouse gas emissions. There are various economic and societal constraints for a set of forested peatland landscapes in Finland. First, we link forest simulations with hydrological and statistical models to predict C[O.sub.2], C[H.sub.4], and [N.sub.2]O emissions from the drained peatlands. We then present the range of landscape level solutions that prioritize between minimizing the net ecosystem greenhouse gas emissions, the economic timber value, and the even flow of timber income over time. Our results highlight the impact that integrating peatland soil greenhouse gas emissions will have on the planning process. This promotes the use of management options that benefit both biomass growth and reduced peatland soil greenhouse gas emissions. Key words: climate change mitigation, forest planning, optimization, boreal forests, Introduction Drained peatland forests are a major source of greenhouse gas (GHG) emissions in the boreal and temperate zones (Paavilainen and Paivanen 1995; Forsell et al. 2016). Their appropriate management [...]

Accurate knowledge of site conditions and their effects on regeneration establishment is important for selecting the most appropriate tree species and regeneration methods for a given regeneration site. This study examined the response of the first-year field performance of Scots pine (Pinus sylvestris L.), Norway spruce (Picea abies (L.) Karst.) and silver birch (Betula pendula Roth.) seedlings in boreal forests to variables available in open forest and natural resources datasets. Survival, height increment and damage of planted tree seedlings and the success of direct seeding of pine were analysed on a total of 284 plots (1000 m2) in 18 regeneration experiments established in 2020–2022 in southern and central Finland. The height increment of silver birch was higher than that of conifers, while the lowest mortality rate was found for spruce. In the generalised linear mixed models, topographic wetness index, soil texture, site type and growing stock at clearcut explained the species-specific survival and height increment of planted seedlings and the success of pine seeding. Low-cost, open geospatial data effectively provide useful details on the site conditions suitable for diversifying tree species composition in boreal forests instead of monocultures. [ABSTRACT FROM AUTHOR]

Vegetation is known to have strong influence on evapotranspiration (ET), a major component of terrestrial water balance. Yet hydrological models often describe ET by methods unable to sufficiently include the variability of vegetation characteristics in their predictions. To take advantage of increasing availability of high-resolution open GIS-data on land use, vegetation and soil characteristics in the boreal zone, a modular, spatially distributed model for upscaling ET and other hydrological processes from a grid cell to a catchment level is presented and validated. An improved approach to upscale stomatal conductance to canopy scale using information on plant type (conifer / deciduous) and stand leaf-area index (LAI) is proposed by coupling a common leaf-scale stomatal conductance model with a simple canopy radiation transfer scheme. Further, a generic parametrization for vegetation and snow-related hydrological processes for Nordic boreal forests is derived based on literature and data from a boreal FluxNet site. With the generic parametrization, the model was shown to well reproduce daily ET measured by eddy-covariance technique at ten conifer-dominated Nordic forests whose LAI ranged from 0.2 to 6.8 m² m-2. Topography, soil and vegetation properties at 21 small boreal headwater catchments in Finland were derived from open GIS-data at 16 x 16 m grid size to upscale water balance from a stand to catchment level. The predictions of annual ET and specific discharge were successful in all catchments, located from 60 to 68°N, and daily discharge also reasonably well predicted by calibrating only one parameter against discharge data measurements. The role of vegetation heterogeneity on soil moisture and partitioning of ET was demonstrated. The proposed approach can support e.g. in forest trafficability forecasting and predicting the impacts of climate change and forest management on stand and catchment water balance. With appropriate parametrization it can be generalized outside the boreal coniferous forests. [ABSTRACT FROM AUTHOR]

ABSTRACT Climate variability has major impacts on crop yields and food production in South Asia. The spatial differences of the impact are not, however, well understood. In this study, we thus aim to analyse the spatio-temporal relationship between precipitation and rice yields in the Ganges-Brahmaputra-Meghna region. The effects of rainfall variation on yields were analysed with regression models using the Standardized Precipitation Index ( SPI) as an explanatory variable. Our results indicate that in large part of the study region, a strong relationship between precipitation and rice yields exists and the SPI at various lags chosen as the predictor variable performed well in describing the inter-annual yield variability. However, the study demonstrated large spatial variations in the strength of this relationship or optionally in the suitability of the chosen methodology for investigating it. In the mid-plains of the Ganges, which represent very important agricultural areas, precipitation variability has a strong impact on rice yields, while in downstream Ganges as well as in Brahmaputra, where precipitation is more abundant, the relationship was less pronounced. Where the performance of the regression models was weaker, it is likely that yield variation depended on other factors such as management practices or on other climate factors such as temperature. The results further showed that the SPI at 1, 3, 6 and 12 month lags calculated for the monsoon time (June-October) are most commonly the best at explaining the rice yield variability. The SPI can thus be considered a very useful predictor of rice yield variability in some parts of the study region, demonstrating that they could be used for agricultural applications and policy decisions to improve the region's food security. [ABSTRACT FROM AUTHOR]

An overview is presented of the contemporary societal and environmental development situation in the six major transboundary river basins that drain south from China: the Red River, Mekong, Salween, Irrawaddy, Ganges-Brahmaputra-Meghna and Indus. The overall societal and environmental vulnerability of the basins is assessed using multidimensional river basin vulnerability analysis. The analysis shows that while China has a fairly low level of vulnerability in these basins, its downstream influence is substantial. This setting offers a plethora of opportunities for transboundary cooperation and calls for a high level of responsibility from the upstream riparian countries. [ABSTRACT FROM AUTHOR]