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The legacy of deep ploughing and liming : A 1990s experimental site revisited
Full text linkManagement of agricultural soils for increased productivity may exert positive or negative effects on soil structure, functions, and organic carbon (SOC) stocks. In this study, a field experiment established in 1993 on a clayey soil in southwest Finland was revisited to investigate the long-term effects of deep ploughing and liming on SOC concentration and stock, particulate (POC) and mineral-associated (MOC) fractions of SOC, pH, electrical conductivity (EC), bulk density (BD), porosity, critical pore size and cereal yield. The experiment comprised whole plots of conventional tillage (CT) to a maximum depth of ca. 20 cm, and plots deep ploughed to ca. 35 cm depth by a commercial (DP1) or by a self-made (DP2) plough. The tillage plots were divided into three split-plots assigned to liming treatments (low, medium and high). Three decades after implementation, the increasing liming rates still induced consistent differences in soil pH, a significant increasing effect on total porosity in the subsoil, and a marginally significant decrease in yield with an increase in soil acidity. The deep ploughing exerted a minor difference in topsoil texture, slightly lowered SOC concentration in the topsoil in DP2 in comparison to CT, and slightly higher subsoil SOC concentration in DP1 in comparison to CT, which indicated transfer of the topsoil SOC to deeper layers and dilution of the SOC in the new topsoil. However, no significant differences between the tillage treatments occurred in SOC stocks. In MOC and POC concentrations, there were no significant differences between the control and tillage treatments. The effects of deep ploughing on soil structural properties on the decadal time scale were minor and scattered. Cereal yield exhibited a slight negative trend for deep ploughing. For EC and BD, no treatment effects were recorded. Overall, the study showed that the legacy of soil management effects on soil properties can be persistent on decadal time scales, but no permanent structural damage due to deep ploughing nor gains in SOC stock accrual could be observed
Spatio-temporal dynamics and controls of forest-floor evapotranspiration across a managed boreal forest landscape
Full text linkForest-floor evapotranspiration (ETff) is a major pathway for water loss in terrestrial ecosystems, often accounting for more than half of ecosystem evapotranspiration. However, our understanding of the environmental and stand structural controls on the spatio-temporal dynamics of ETff across the managed boreal forest landscape remains limited. In this study, we conducted chamber-based flux measurements of ETff and its components, i.e., soil evaporation (Es) and forest-floor understory transpiration (Tu), on natural and vegetation removal plots across 50 diverse forest stands (ranging 5–211 years old) in Northern Sweden over two contrasting growing seasons. We found manifold variations in the growing season means of ETff, Es, and Tu, ranging from 0.008 to 0.048 mm h−1, 0.004 to 0.034 mm h−1, and 0.002 to 0.030 mm h−1, respectively, across the 50 forest stands. The contribution of Es and Tu to ETff ranged from 19 to 83 % and 38 to 85 %, respectively, with the average Es:Tu ratio shifting from 0.84 in 2017 to 0.63 during 2018, the latter experiencing an exceptional summer drought. Seasonal variations in ETff and its component fluxes were mainly controlled by below-canopy air temperature, while radiation was the main driver of their spatial variations across the forest stands. At the landscape-level, stand age was the dominant control of ETff by modifying overstory tree characteristics such as biomass and leaf area index. In contrast, neither tree species nor soil type had any effect on ETff or Tu. However, Es was higher in sediment compared to till soils. Thus, our results suggest that environmental and stand structural factors jointly control the spatio-temporal dynamics of ETff across the managed boreal forest landscape. Our study furthermore highlights the need for an in-depth understanding of ETff and its components when assessing the water cycle feedbacks of the boreal forest to changes in forest management and climate
Growth and Yield
Full text linkThere is still a lack of knowledge on growth and yield (G&Y) in continuous cover forestry (CCF). Most published studies are on the selection system with Norway spruce.
Published comparisons of the selection system with rotation forestry (RF) show contrasting results. Generally, there seems to be a trend toward faster stand growth in RF.
However, there are many uncertainties due to several confounding factors, such as stand-density effects, site-quality classification, and/or growth models used. Most studies do not properly account for all these factors, making it difficult to generalise their results.
The optimal stand density trade off for the selection system between stand growth and recruitment should be better investigated. Preliminary results show this could strongly affect stand growth.
There is even less knowledge related to G&Y during conversion, a potential bottleneck for full implementation of CCF in the region
Adapting the product group-specific nutritional functional units to the Spanish context
Full text linkPurpose
Nutritional aspects have recently been integrated into the life cycle assessment (LCA) of foods through the use of nutrient indices as functional units (nFU). In this study, we develop the nFU indices for each product group presented in the Spanish plate model, by adapting the approach introduced in our previous studies into a Spanish context.
Methods
The product grouping followed the Spanish plate model covering protein-rich foods, sources of carbohydrates, vegetables and fruits, and fats. For each group, separate nFUs were created by identifying the most important nutrients for each product group, based on the nutrients obtained from them in the current Spanish food consumption. Finally, the new nFUs were showcased by conducting cradle-to-plate nLCA for the selection of typical Spanish foods.
Results and discussion
Adapting the method to formulate the nFUs to different target population led to different selection of nutrients being included in the indices for each product group, highlighting the need to tailor the methodology depending on the population under study. The nLCA results demonstrated the importance of integrating nutritional aspects into comparative LCAs of foods in all the studied product groups, also including the new product group of fats, which was the first time used in nLCA in this study.
Conclusions
The results demonstrated that the product-group-specific approach is a systematic and reproducible method to formulate nFU indices and that it can be consistently adapted also to other target populations with relevant data available. For more extensive coverage of health aspects in LCA, the inclusion of non-nutrient compounds should be promoted
Aquatic vocalization activity indicates the timing of the mating season of Saimaa ringed seals
No full textBenchmarking tree species classification from proximally sensed laser scanning data: Introducing the FOR-species20K dataset
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Understanding Europe’s forest harvesting regimes
Full text linkEuropean forests are being shaped by active human use and management, and by harvesting of wood in particular. Yet, our understanding of how forests are harvested across Europe is limited, as the real harvest regimes are not well described by currently available data. Here, we analyse recent harvests, as observed in permanent plots of forest inventories in 11 European countries, totaling to 182,649 plots and covering all major forest types. We (a) characterize harvest regimes through the frequency and intensity of harvest events spatially across Europe, and (b) build models for the probability and intensity of harvest events at the plot-level and examine the links to potential drivers of harvest, including the pre-harvest forest structure and composition, climatic, topographic and socio-economic factors, and past natural disturbances. The results revealed notable variation in harvest regimes across Europe, ranging from high-frequency and low-intensity harvests in eastern Central Europe to low-frequency and high-intensity harvests in the north, with different strategies emerging in regions with similar total harvest rates. The harvest regimes were strongly driven by country-level variation, emphasizing the role of national-level factors. Pre-harvest forest properties were important drivers for the intensity of harvest, whereas the probability of harvest was more related to socio-economic factors and natural disturbances. The presented quantification of the forest harvesting regimes provides much needed detail in our understanding of the contemporary forest management practices in Europe, providing a baseline against which to assess future changes in management and strengthening the knowledge-base for decision-making on European level