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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.

Plastic film mulching (FM) became a general practice to enhance crop productivity and its net primary production (NPP), but it can increase greenhouse gas (GHG) emissions. The proper addition of organic amendments might effectively decrease the impact of FM on global warming. To evaluate the feasibility of biomass addition on decreasing this negative influence, cover crop biomass as a green manure was incorporated with different recycling levels (0-100% of aboveground biomass) under FM and no-mulching. The net global warming potential (GWP) which integrated with soil C stock change and GHG (N2O and CH4) fluxes with CO2-equivalent was evaluated during maize cultivation. Under the same biomass incorporation, FM significantly enhanced the grain productivity and NPP of maize by 22-61 and 18-58% over no-mulching, respectively. In contrast, FM also highly increased the respired C loss, which was 11-95% higher than NPP increase, over no-mulching. Irrespective with biomass recycling ratio and mulching system, negative NECB which indicates the decrease of soil C stock was observed, mainly due to big harvest removal. FM decreased more soil C stock by 57-158% over no-mulching, but its C stock was clearly increased with increasing biomass addition. FM significantly increased total N2O and CH4 fluxes by 4-61 and 140-600% over no-mulching, respectively. Soil C stock changes mainly decided net GWP scale, but N2O and CH4 fluxes negligibly influenced. As a result, FM highly increased net GWP over no-mulching, while this net GWP was clearly decreased with increasing biomass application. However, cover cropping, and its biomass recycling was not enough to compensate the negative impact of FM on global warming. Therefore, more biomass incorporation might be essential to compensate this negative effect of FM.

Forest soil acidification caused by acid deposition is a serious threat to the forest ecosystem. To investigate the liming effects of biomass ash (BA) and alkaline slag (AS) on the acidic topsoil and subsoil, a three-year field experiment under artificial Masson pine was conducted at Langxi, Anhui province in Southern China. The surface application of BA and AS significantly increased the soil pH, and thus decreased exchangeable acidity and active Al in the topsoil. Soil exchangeable Ca2+ and Mg2+ in topsoil were significantly increased by the surface application of BA and AS, while an increase in soil exchangeable K+ was only observed in BA treatments. The soil acidity and active Al in subsoil were decreased by the surface application of AS. Compared with the control, soluble monomeric and exchangeable Al in the subsoil was decreased by 38.0% and 29.4% after 3 years of AS surface application. There was a minimal effect on soluble monomeric and exchangeable Al after the application of BA. The soil exchangeable Ca2+ and Mg2+ in the subsoil increased respectively by 54% and 141% after surface application of 10 t ha-1 AS. The decrease of soil active Al and increase of base cations in subsoil were mainly attributed to the high migration capacity of base cations in AS. In conclusion, the effect of surface application of AS was superior to BA in ameliorating soil acidity and alleviating soil Al toxicity in the subsoil of this Ultisol.

Este estudio evaluó los determinantes de la elección de estrategias indígenas relacionadas con el clima por parte de pequeños agricultores en el norte de Ghana utilizando datos primarios obtenidos a través de discusiones de grupos focales comunitarios y encuestas de hogares, y sujetos al modelo de regresión Multinomial Logit. Los resultados empíricos revelan que la presencia de un mercado, el crédito informal de amigos y familiares, la ubicación del agricultor, la extensión de agricultor a agricultor, notar una disminución de las precipitaciones y notar un aumento de la temperatura influyen en la elección de las estrategias indígenas relacionadas con el clima. Por lo tanto, existe la necesidad de mejorar el acceso de los pequeños agricultores al mercado, los servicios de extensión agrícola y su conocimiento de los cambios en las precipitaciones y la temperatura. Cette étude a évalué les déterminants du choix des stratégies autochtones liées au climat par les petits exploitants agricoles du nord du Ghana à l'aide de données primaires obtenues lors de groupes de discussion communautaires et d'enquêtes auprès des ménages, et soumises au modèle de régression Multinomial Logit. Les résultats empiriques révèlent que la présence d'un marché, le crédit informel d'amis et de parents, l'emplacement de l'agriculteur, l'extension de l'agriculteur à l'agriculteur, la constatation d'une diminution des précipitations et d'une augmentation de la température influencent le choix des stratégies autochtones liées au climat. Il est donc nécessaire d'améliorer l'accès des petits agriculteurs au marché, aux services de vulgarisation agricole et leur sensibilisation aux changements de précipitations et de température. This study assessed the determinants of Choice of Indigenous Climate Related Strategies by Smallholder Farmers in Northern Ghana using primary data obtained through community focus group discussions and household survey, and subjected to the Multinomial Logit regression model. The empirical results reveal that presence of a market, informal credit from friends and relatives, location of farmer, farmer-to-farmer extension, noticing of a decrease in rainfall and noticing an increase in temperature influence the choice of indigenous climate related strategies. There is therefore the need to improve smallholder farmers' access to market, agricultural extension services and their awareness of changes in rainfall and temperature. قيمت هذه الدراسة محددات اختيار الاستراتيجيات المتعلقة بالمناخ للسكان الأصليين من قبل المزارعين أصحاب الحيازات الصغيرة في شمال غانا باستخدام البيانات الأولية التي تم الحصول عليها من خلال مناقشات مجموعات التركيز المجتمعية والمسح الأسري، وتخضع لنموذج انحدار اللوغاريتم متعدد الحدود. تكشف النتائج التجريبية أن وجود سوق، والائتمان غير الرسمي من الأصدقاء والأقارب، وموقع المزارع، والإرشاد من مزارع إلى مزارع، وملاحظة انخفاض في هطول الأمطار وملاحظة زيادة في درجة الحرارة يؤثر على اختيار الاستراتيجيات المتعلقة بالمناخ المحلي. لذلك هناك حاجة إلى تحسين وصول صغار المزارعين إلى الأسواق وخدمات الإرشاد الزراعي ووعيهم بالتغيرات في هطول الأمطار ودرجة الحرارة.

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.

It's a slow death, but bolts still slay rainforest trees.