• Energy Research
• Open Access close
• Restricted close
• Embargo close
• agricultural and veterinary science... close
• 15. Life on land close

Climate change, environmental degradation, and limited resources are motivations for sustainable forest management. Forests, the most abundant renewable resource on earth, used to make a wide variety of forest-based products for human consumption. To provide a scientific measure of a product’s sustainability and environmental performance, the life cycle assessment (LCA) method is used. This article provides a comprehensive review of environmental performances of forest-based products including traditional building products, emerging (mass-timber) building products and nanomaterials using attributional LCA. Across the supply chain, the product manufacturing life-cycle stage tends to have the largest environmental impacts. However, forest management activities and logistics tend to have the greatest economic impact. In addition, environmental trade-offs exist when regulating emissions as indicated by the latest traditional wood building product LCAs. Interpretation of these LCA results can guide new product development using biomaterials, future (mass) building systems and policy-making on mitigating climate change. Key challenges include handling of uncertainties in the supply chain and complex interactions of environment, material conversion, resource use for product production and quantifying the emissions released.

Understanding N budgets of tundra ecosystems is crucial for projecting future changes in plant community composition, greenhouse gas balances and soil N stocks. Winter warming can lead to higher tundra winter nitrogen (N) mineralization rates, while summer warming may increase both growing season N mineralization and plant N demand. The undulating tundra landscape is inter-connected through water and solute movement on top of and within near-surface soil, but the importance of lateral N fluxes for tundra N budgets is not well known. We studied the size of lateral N fluxes and the fate of lateral N input in the snowmelt period with a shallow thaw layer, and in the late growing season with a deeper thaw layer. We used 15N to trace inorganic lateral N movement in a Low-arctic mesic tundra heath slope in West Greenland and to quantify the fate of N in the receiving area. We found that half of the early-season lateral N input was retained by the receiving ecosystem, whereas half was transported downslope. Plants appear as poor utilizers of early-season N, indicating that higher winter N mineralization may influence plant growth and carbon (C) sequestration less than expected. Still, evergreen plants were better at utilizing early-season N, highlighting how changes in N availability may impact plant community composition. In contrast, later growing season lateral N input was deeper and offered an advantage to deeper-rooted deciduous plants. The measurements suggest that N input driven by future warming at the study site will have no significant impact on the overall N2O emissions. Our work underlines how tundra ecosystem N allocation, C budgets and plant community composition vary in their response to lateral N inputs, which may help us understand future responses in a warmer Arctic. (Less)

To meet the increasing demands of precision agricultural and environmental management, more abundant and accurate information is needed to describe soil organic carbon (SOC) vertical variation. Based on 923 soil profiles (collected at the depths of 0–15, 15–30, 30–60, 60–90, 90–120, and 120–150 cm) in the central area of Changhua County, Taiwan, the distribution curve of the SOC content of each profile was fitted by the equal-area spline model, and it was possible to obtain the SOC content at all depths. Taking the 0–5 cm (L1), 5–10 cm (L2), and 10–15 cm (L3) sub-layers as examples, their SOC contents and stocks were compared to the mean values of the average 5-cm-thick sub-layers (Lm) derived from the value of the 0–15 cm layer. The results indicated that the SOC contents and stocks both reduced with increasing soil depths. The mean SOC contents of L1, L2, and L3 were 22.1, 21.0, and 18.7 g·kg−1, respectively, with significant variation, and the values of L2 and L3 were 5.0% and 15.4% lower than that of L1. Similarly, the mean SOC stocks were 1.29, 1.25, and 1.16 kg·m−2 of the L1, L2, and L3 layers, also with significant variation, and the values of L2 and L3 were 4.0% and 10.1% lower than that of L1. Meanwhile, it was found that the SOC content and stock of Lm were both close to the corresponding values in L2, but were significantly different to that of L1 and L3. Furthermore, the interpolation contours of the SOC contents and stocks in L1, L2, and L3 by digital soil mapping also presented regular variation with increasing soil depths, while the contours of Lm had nearly identical patterns to that of L2. The results demonstrate that the typically used mean SOC contents with certain thicknesses calculated from the sampling layer can only approximately inflect the SOC situation at intermediate depths, but the SOC content in the upper and lower parts within the sampling layer varies greatly. Therefore, the actual distribution of SOC varies gradually depending on the soil depth. This study indicates that the combination of the equal-area spline model and digital soil mapping can greatly enrich the current soil SOC database and provide more abundant and accurate SOC content and stock information for precision agricultural and environmental management based on legacy soil database.

SummaryThe adaptation of extra short duration (ESD) pigeonpea (Cajanus cajan) genotypes to rainfed environments was studied on Alfisols and Vertisols at the ICRISAT Center between 1987 and 1989. Despite a slightly shorter crop duration, the grain yield of ESD genotypes was twice as large on Alfisols as on Vertisols. On both soil types, the rate of growth and grain yield were better in crops sown on time than in those where sowing was delayed. The population levels necessary to maximize yield varied among genotypes on Alfisols, where the grain yield of several ESD genotypes compared favourably with that of ICPL 87, a standard short duration genotype. However, none of the ESD genotypes yielded more than ICPL 87 on the Vertisols.

AbstractAcross southern China, Moso bamboo has been encroaching on most neighboring secondary broad-leaved forests and/or coniferous plantations, leading to the land cover changes that alter abiotic and biotic conditions. Little is known about how this conversion alters soil carbon (C) and nitrogen (N). We selected three sites, each with three plots arrayed along the bamboo encroachment pathway: moso bamboo forest (BF); transition zone, mixed forest plots (MF); and broad-leaved forest (BLF), and examined how bamboo encroachment affects soil organic C (SOC), soil total N, microbial biomass C (MBC), microbial biomass N (MBN), water-soluble organic C (WSOC), and water-soluble organic N (WSON) in three forests. Over nine years, moso bamboo encroachment leads to a decrease in SOC and total soil N, an increase in MBC and WSOC, and a decrease in MBN and WSON. Changes in soil C and N occurred mainly in the topsoil. We conclude that moso bamboo encroachment on broadleaved forest not only substantially altered soil C and N pools, but also changed the distribution pattern of C and N in the studied forest soils. Continued bamboo encroachment into evergreen broadleaved forests seems likely to lead to net CO2 emissions to the atmosphere as ecosystem C stocks decline.

Although soils provide social and ecological services which are of a clearly transnational dimension, the management of soils needs to be addressed locally. Thus, an appropriate - or better, effective governance for sustainable soil management at national level is essential. This chapter provides some fundamental recommendations for an effective governance based on legal studies from several African countries, namely Cameroon, Kenya and Zambia.

This research looked at the state of soils faced with urbanization processes in the Arctic region of the Yamal-Nenets Autonomous District (YANAO). Soils recently used in agriculture, which are now included in the infrastructure of the cities of Salekhard, Labytnangi, Kharsaim, and Aksarka in the form of various parks and public gardens were studied. Morphological, physico-chemical, and agrochemical studies of selected soils were conducted. Significant differences in fertility parameters between urbanized abandoned agricultural soils and mature soils of the region were revealed. The quality of soil resources was also evaluated in terms of their ecotoxicology condition, namely, the concentrations of trace metals in soils were determined and their current condition was assessed using calculations of various individual and complex soil quality indices.

SUMMARY China’s growing presence in Africa’s extractive industries has been the subject of much debate in recent years, reflecting concerns about both environmental sustainability and the governance of resource wealth for long-term benefit. In Cameroon, since 2000 the largest timber concession in the country has been held by a Chinese company. This provides an opportunity to take a deeper look at corporate practices in the extractive industry and explore the extent to which corporate behaviour varies between Chinese and non-Chinese companies. Through a general analysis of Cameroonian timber production and trade, and a detailed analysis of two European companies (one FSC-certified) and one Chinese company (without FSC certification), this paper assesses the effects of Chinese capital and China-related trade on rural livelihoods and forest condition in the Cameroonian forestry sector. Our findings suggest that while the Chinese market shapes the trade patterns and management activities of logging companies, it does so irrespective of the companies’ nationality. Also, findings suggest that nationality of firms has a weak influence on the impacts on local livelihoods around the sampled logging concessions in Cameroon.

With an approach combining crop modelling and biotechnology to assess the performance of three durum wheat cultivars (Creso, Duilio, Simeto) in a climate change context, weather and agronomic datasets over the period 1973–2004 from two sites, Benatzu and Ussana (Southern Sardinia, Itay), were used and the model responses were interpreted considering the role of DREB genes in the genotype performance with a focus on drought conditions. The CERES-Wheat crop model was calibrated and validated for grain yield, earliness and kernel weight. Forty-eight synthetic scenarios were used: 6 scenarios with increasing maximum air temperature; 6 scenarios with decreasing rainfall; 36 scenarios combining increasing temperature and decreasing rainfall. The simulated effects on yields, anthesis and kernel weights resulted in yield reduction, increasing kernel weight, and shortened growth duration in both sites. Creso (late cultivar) was the most sensitive to simulated climate conditions. Simeto and Duilio (early cultivars) showed lower simulated yield reductions and a larger anticipation of anthesis date. Observed data showed the same responses for the three cultivars in both sites. The CERES-Wheat model proved to be effective in representing reality and can be used in crop breeding programs with a molecular approach aiming at developing molecular markers for the resistance to drought stress.

AbstractAfter dredged sediments have settled in a temporary upland disposal site, ripening starts, which turns waterlogged sediment into aerated soil. Aerobic biological mineralization of organic matter (OM) and chemical oxidation of reduced sulfur compounds are the major biochemical ripening processes. Quantitative data describing these processes are scarce. Therefore, aerobic oxidation and mineralization of five previously anaerobic dredged sediments were studied during a 160‐d laboratory incubation experiment at 30°C. A double exponential decay model could adequately describe sulfur oxidation and OM mineralization kinetics. During the first 7 d of incubation, 23 to 80% of the total sulfur was oxidized, after which no further sulfur oxidation was observed. Oxygen used for sulfur oxidation amounted up to 95% of the total oxygen uptake in the first 7 d and up to 45% of the oxygen uptake during the entire incubation period. Mineralization rates of the rapidly mineralizable OM fractions that degraded during the first 14 to 28 d of incubation were 102 to 103 times higher than the mineralization rates of the slowly mineralizable OM during the remaining period. First‐order mineralization rates of the slowly mineralizable OM were 0.22 × 10−3 to 0.54 × 10−3 d−1 and can be compared with those of terrestrial soils. Yields of biomass on substrate ranged from 0.08 to 0.45 g Cbiomass/g COM and appeared to be higher for rapidly mineralizing OM than for slowly mineralizing OM. The results of this study can be used to optimize conditions during temporary disposal of sediments, to estimate the potential decrease in OM, and for future studies on the possible link between OM mineralization and degradation of hydrophobic organic contaminants.