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Le riz est une culture vivrière importante au Kenya et il est classé troisième culture céréalière la plus consommée après le maïs et le blé. La demande amplifiée de riz a entraîné la conversion des zones humides en rizières et l'utilisation accrue d'engrais, réduisant ainsi la capacité des zones humides à séquestrer le carbone. Par conséquent, il y a une augmentation des émissions de trois gaz à effet de serre (GES) puissants : le méthane (CH4), l'oxyde nitreux (N2O) et le dioxyde de carbone (CO2). Cette étude a évalué l'impact de l'application d'engrais sur les émissions de GES et les stocks de nutriments dans les rizières. L'étude a été réalisée de septembre 2018 à janvier 2019 dans des zones humides dominées par les papyrus dans l'ouest du Kenya. L'échantillonnage a été effectué sur une base hebdomadaire pendant les deux premiers mois, puis deux fois par mois dans les rizières Anyiko situées dans le bassin de la rivière Nzoia, au Kenya. Deux répliques de trois traitements ; standard, témoin et sous fertilisation ont été attribuées au hasard dans six parcelles. La méthode de la chambre statique a été utilisée pour collecter les GES et analysée par chromatographie en phase gazeuse. Des échantillons de sol ont été collectés et analysés pour les stocks d'azote et de carbone. Il n'y avait pas de différence significative dans les stocks de carbone et d'azote entre les trois scénarios de fertilisation (ANOVA unidirectionnelle, F (2,33)=0,219, P>0,05 pour le carbone et F(2,33)=0,134, P>0,05 pour l'azote). La quantité de NO3-N et de NH4-N n'était pas significativement différente dans tous les scénarios de fertilisation (Kruskal-Wallis, P>0,05). Le test de Kruskal-Wallis (P>0,05) a indiqué qu'il n'y avait pas de différence significative dans les flux moyens de CH4 et de CO2 entre les trois scénarios de fertilisation. Cependant, pour le N2O, les flux moyens diffèrent significativement (P<0,05). Les flux moyens ont indiqué que la parcelle sous-fertilisée était un puits probable de N2O (- 0,59±0,45 µgm- ²h-¹) et une source de CH4 (6,93±2,42 mgm-²h-¹) et de CO2 (208,81±36,20 mgm-²h-¹). La parcelle fertilisée standard était source de N2O, CO2 et CH4 (4,37±3,18µgm- ²h-¹,248,29 ±41,22mgm- ²h-¹, 4,00±6,34 mgm-²h-¹, respectivement). La parcelle témoin a servi de puits pour le N2O (-3,59±2,56 µgm- ²h-¹) et de source pour le CH4 (8,30±4,79 mgm-²h-¹) et le CO2 (174,80±26,81 mgm-²h-¹). Dans cette étude, différents scénarios de fertilisation ont eu un effet positif sur les émissions de N2O mais aucun effet sur les émissions de CO2 et de CH4 ainsi que sur les stocks de nutriments. El arroz es un cultivo alimentario importante en Kenia y ocupa el tercer lugar entre los cultivos de cereales más consumidos después del maíz y el trigo. La mayor demanda de arroz ha dado como resultado la conversión de humedales en arrozales y un mayor uso de fertilizantes, lo que reduce la capacidad de los humedales para secuestrar carbono. En consecuencia, hay una mayor emisión de tres potentes gases de efecto invernadero (GEI): metano (CH4), óxido nitroso (N2O) y dióxido de carbono (CO2). Este estudio evaluó el impacto de la aplicación de fertilizantes en las emisiones de GEI y las reservas de nutrientes en los arrozales. El estudio se llevó a cabo desde septiembre de 2018 hasta enero de 2019 en un humedal dominado por papiros en el oeste de Kenia. El muestreo se realizó semanalmente durante los primeros dos meses, y posteriormente dos veces al mes en los arrozales Anyiko ubicados en la cuenca del río Nzoia, Kenia. Dos réplicas de tres tratamientos; estándar, control y subfertilización se asignaron aleatoriamente en seis parcelas. Se utilizó el método de cámara estática para recoger los GEI y se analizó mediante cromatografía de gases. Se recogieron muestras de suelo y se analizaron las reservas de nitrógeno y carbono. No hubo diferencias significativas en las reservas de carbono y nitrógeno entre los tres escenarios de fertilización (ANOVA unidireccional, F (2,33)=0,219, P>0,05 para el carbono y F(2,33)=0,134, P>0,05 para el nitrógeno). La cantidad de NO3-N y NH4-N no fue significativamente diferente en todos los escenarios de fertilización (Kruskal-Wallis, P>0.05). La prueba de Kruskal-Wallis (P>0.05) indicó que no hubo diferencias significativas en los flujos medios de CH4 y CO2 entre los tres escenarios de fertilización. Sin embargo, para N2O los flujos medios difirieron significativamente (P<0.05). Los flujos medios indicaron que la parcela poco fertilizada era un probable sumidero para N2O (- 0.59±0.45µgm- ²h-¹) y una fuente para CH4 (6.93±2.42 mgm- ²h-¹) y CO2 (208.81±36.20 mgm-²h-¹). La gráfica fertilizada estándar fue la fuente de N2O, CO2 y CH4 (4.37±3.18 µgm- ²h-¹,248.29 ±41.22mgm- ²h-¹, 4.00±6.34mgm- ²h-¹,) respectivamente. La parcela de control actuó como sumidero para N2O (-3.59±2.56µgm- ²h-¹) y una fuente para CH4 (8.30±4.79 mgm-²h-¹) y CO2 (174.80±26.81 mgm-²h-¹). En este estudio, diferentes escenarios de fertilización tuvieron un efecto positivo sobre la emisión de N2O pero ningún efecto sobre la emisión de CO2 y CH4 y también sobre las reservas de nutrientes. Rice is an important food crop in Kenya and it is ranked third most consumed cereal crop after maize and wheat. The amplified demand for rice has resulted to conversion of wetlands to rice paddies and increased use of fertilizer, thus reducing wetlands ability to carbon sequestration. Consequently, there is enhanced emission of three potent greenhouse gases (GHGs); methane (CH4), nitrous oxide (N2O) and carbon dioxide (CO2). This study assessed the impact of fertilizer application on GHGs emission and the nutrient stocks in rice paddies. The study was carried out from September 2018 to January 2019 in papyrus dominated wetland in Western Kenya. Sampling was done on a weekly basis for the first two months, and thereafter twice per month in Anyiko rice paddies located in river Nzoia basin, Kenya. Two replicates of three treatments; standard, control and under fertilization were assigned randomly in six plots. Static chamber method was used to collect GHGs and analysed by gas chromatography. Soil samples were collected and analysed for nitrogen and carbon stocks. There was no significant difference in carbon and nitrogen stocks among the three fertilization scenarios (One-way ANOVA, F (2,33)=0.219, P>0.05 for carbon and F(2,33)=0.134, P>0.05 for nitrogen). The amount of NO3-N and NH4-N were not significantly different across all the fertilization scenarios (Kruskal-Wallis, P>0.05). Kruskal-Wallis test (P>0.05) indicated that there was no significant difference in the mean fluxes of CH4 and CO2 among the three fertilization scenarios. However, for N2O the mean fluxes differed significantly (P<0.05). The mean fluxes indicated that under-fertilized plot was a probable sink for N2O (- 0.59±0.45 µgm-²h-¹) and a source for CH4 (6.93±2.42 mgm-²h-¹) and CO2 (208.81±36.20 mgm-²h-¹). Standard-fertilized plot was source for N2O, CO2 and CH4 (4.37±3.18 µgm-²h-¹, 248.29±41.22 mgm-²h-¹, 4.00±6.34 mgm-²h-¹,) respectively. The control plot acted as sink for N2O (-3.59±2.56 µgm-²h-¹) and a source for CH4 (8.30±4.79 mgm-²h-¹) and CO2 (174.80±26.81 mgm-²h-¹). In this study, different fertilization scenarios had positive effect on N2O emission but no effect on CO2 and CH4 emission and also on nutrient stocks. يعتبر الأرز محصولًا غذائيًا مهمًا في كينيا ويحتل المرتبة الثالثة في محصول الحبوب الأكثر استهلاكًا بعد الذرة والقمح. وقد أدى الطلب المتزايد على الأرز إلى تحويل الأراضي الرطبة إلى حقول للأرز وزيادة استخدام الأسمدة، مما يقلل من قدرة الأراضي الرطبة على عزل الكربون. وبالتالي، هناك انبعاثات معززة لثلاثة غازات دفيئة قوية (GHGs) ؛ الميثان (CH4) وأكسيد النيتروز (N2O) وثاني أكسيد الكربون (CO2). قيمت هذه الدراسة تأثير استخدام الأسمدة على انبعاثات غازات الدفيئة ومخزونات المغذيات في حقول الأرز. أجريت الدراسة في الفترة من سبتمبر 2018 إلى يناير 2019 في الأراضي الرطبة التي تهيمن عليها البردي في غرب كينيا. تم أخذ العينات على أساس أسبوعي خلال الشهرين الأولين، وبعد ذلك مرتين في الشهر في حقول أرز أنييكو الواقعة في حوض نهر نزويا في كينيا. تم تعيين نسختين متماثلتين من ثلاثة علاجات ؛ قياسية ومراقبة وتحت الإخصاب بشكل عشوائي في ست قطع. تم استخدام طريقة الغرفة الساكنة لجمع غازات الدفيئة وتحليلها بواسطة كروماتوغرافيا الغاز. تم جمع عينات التربة وتحليلها لمخزونات النيتروجين والكربون. لم يكن هناك فرق كبير في مخزونات الكربون والنيتروجين بين سيناريوهات التسميد الثلاثة (أحادي الاتجاه ANOVA، F (2,33)=0.219، P>0.05 للكربون و F(2,33)=0.134، P>0.05 للنيتروجين). لم تكن كمية NO3 - N و NH4 - N مختلفة بشكل كبير عبر جميع سيناريوهات الإخصاب (Kruskal - Wallis، P>0.05). أشار اختبار كروسكال واليس (P>0.05) إلى عدم وجود فرق كبير في متوسط تدفقات الميثان وثاني أكسيد الكربون بين سيناريوهات التسميد الثلاثة. ومع ذلك، بالنسبة لأكسيد النيتروز، اختلف متوسط التدفقات بشكل كبير (P<0.05). أشار متوسط التدفقات إلى أن قطعة الأرض غير المخصبة كانت بالوعة محتملة لأكسيد النيتروز (- 0.59±0.45 ميكروغرام- ²ح-¹) ومصدرًا للميثان (6.93±2.42 مجم- ²ح-¹) وثاني أكسيد الكربون (208.81±36.20 مجم- ²ح-¹). كان المخطط المخصب القياسي مصدرًا لأكسيد النيتروز وثاني أكسيد الكربون والميثان (4.37±3.18 ميكروغرام-²ساعة-¹، 248.29±41.22 مجم-²ساعة-¹، 4.00±6.34 مجم- ²ساعة-¹، على التوالي). كانت قطعة التحكم بمثابة حوض لأكسيد النيتروز (-3.59 ±2.56 ميكروغرام - ²h -¹) ومصدر للميثان (8.30±4.79 مجم - ²h -¹) وثاني أكسيد الكربون (174.80±26.81 مجم - ²h -¹). في هذه الدراسة، كان لسيناريوهات التسميد المختلفة تأثير إيجابي على انبعاثات أكسيد النيتروز ولكن لم يكن لها أي تأثير على انبعاثات ثاني أكسيد الكربون والميثان وكذلك على مخزونات المغذيات.

In recent decades, energy transition has been a major structural change worldwide to replace fossil fuels. Hydropower is a valuable renewable energy source which can mitigate the electricity demand of livelihoods and help to achieve the target of carbon neutrality goals. However, owing to the hydropower construction, involuntary resettles are suffering with land and socio-economic security. Non-governmental organizations (NGOs) play a vital role in promoting a just transition for reservoir migrants. The present study examines the work of local NGOs in a reservoir resettlement area in China through semi-structural interviews, and participant observations followed by qualitative analysis. Study explores how the NGOs organize reservoir migrants to participate in post-relocation support (PReS) projects. The study finds that the organized participation of reservoir migrants in PReS is the key process required to achieve a just transition. Moreover, NGOs ensure that all affected reservoir migrants have equal access to development opportunities through the three linked levels of co-construction, co-management, and co-sharing through the elite-driven establishment of benefit linkages and fair benefit distribution, and ultimately achieve a standard of living for migrants. Organized participation improves the equity and sustainability of benefits for reservoir migrants, but organizing reservoir migrants requires firm support from the local, regional and national governments, and the trust of migrants in local NGOs. Findings further stated that the PRes policy still has some blank spot, therefore, it is necessary to frame robust policy frameworks to restore the livelihoods of reservoir migrants.

Food security and environmental health are directly linked with soil carbon (C). Soil C plays a crucial role in securing food and livelihood security for the Himalayan population besides maintaining the ecological balance in the Indian Himalayas. However, soil C is being severely depleted due to anthropogenic activities. It is well known that land use management strongly impacted the soil organic carbon (SOC) dynamics and also regulates the atmospheric C chemistry. Different types of cultivation practices, i.e., forest, plantations, and crops in the Kashmir Himalayas, India, has different abilities to conserve SOC and emit C in the form of carbon dioxide (CO2). Hence, five prominent land use systems (LUC) (e.g., natural forest, natural grassland, maize-field-converted from the forest, plantation, and paddy crop) of Kashmir Himalaya were evaluated to conserve SOC, reduce C emissions, improve soil properties and develop understanding SOC pools and its fractions variations under different land use management practices. The results revealed that at 0–20 cm and 20–40 cm profile, the soil under natural forest conserved the highest total organic carbon (TOC, 24.24 g kg−1 and 18.76 g kg−1), Walkley-black carbon (WBC, 18.23 g kg−1 and 14.10 g kg−1), very-labile-carbon (VLC, 8.65 g kg−1, and 6.30 g kg−1), labile-carbon (LC, 3.58 g kg−1 and 3.14 g kg−1), less-labile-carbon (VLC, 2.59 g kg−1, and 2.00 g kg−1), non-labile-carbon (NLC, 3.41 g kg−1 and 2.66 g kg-1), TOC stock (45.88 Mg ha−1 and 41.16 Mg ha−1), WBC stock (34.50 Mg ha−1 and 30.94 Mg ha−1), active carbon pools (AC, 23.14 Mg ha−1 and 20.66 Mg ha−1), passive carbon pools (PC, 11.40 Mg ha−1 and 10.26 Mg ha−1) and carbon management index (CMI, 100), followed by the natural grassland. However, the lowest C storage was reported in paddy cropland. The soils under natural forest and natural grassland systems had a greater amount of VLC, LC, LLC, and NLC fraction than other land uses at both depths. On the other hand, maize-field-converted-from-forest-land-use soils had a higher proportion of NLC fraction than paddy soils; nonetheless, the NLC pool was maximum in natural forest soil. LUS based on forest crops maintains more SOC, while agricultural crops, such as paddy and maize, tend to emit more C in the Himalayan region. Therefore, research findings suggest that SOC under the Kashmir Himalayas can be protected by adopting suitable LUS, namely forest soil protection, and by placing some areas under plantations. The areas under the rice and maize fields emit more CO2, hence, there is a need to adopt the conservation effective measure to conserve the SOC without compromising farm productivity.

The pollution caused by foreign investment has become a serious concern of the host government and academia. Many studies have discussed much about the environmental impact of China’s OFDI in countries along the Belt and Road Initiative (BRI) region, but ignored the impact of the BRI itself on China’s OFDI. This study uses the Global Malmquist–Luenberger index to measure the green technology spillover of China’s OFDI from 2005 to 2018 and studies the impact of BRI on this spillover effect with the DID (difference-in-difference) method. The results show that (1) the BRI has significantly increased the green technology spillover of China’s OFDI in countries along the routes. The heterogeneity study shows that such an effect is significant in middle- or low-income countries with high institutional quality or poor environmental performance, but not obvious in other countries. (2) The BRI promotes green technology spillover through the mechanism of increasing R&amp;D investment, improving the environmental system, and accelerating the flow of production factors. This study provides a useful reference for developing a greener OFDI and promoting the sustainable development of regional cooperation.

Previous literature documented the importance of natural disasters and their impact on economic performance, but it ignored the effects on the environment. This study examines the effect of natural disasters on the economic and environmental performance of BRICS economies over the period 1995–2019. This study applies panel autoregressive distributed lag (ARDL) and panel quantile regression approaches. The empirical findings show that natural disasters decrease economic growth but increase CO2 emissions. The findings of panel quantile regression display a significant negative impact of natural disasters on economic growth from the middle (30th) to higher (80th) quantiles. However, natural disasters significantly increase carbon emissions from the middle (50th) to higher (95th) quantiles. This study suggests the importance of proper planning for the management of natural disasters.

In recent decades, the risk of Wildland-Urban Interface (WUI) fires has increased due to urban growth, particularly in regions with a Mediterranean climate. The identification of the WUI is crucial for formulating fire prevention and management measures. However, there is no unified methodology for defining the WUI and it is not clear if proposals that emerge from scientific research are implemented by fire management agencies. Our objectives were to identify, describe, and compare the methods and criteria used by land and fire management agencies to define the WUI in Mediterranean-climate countries. We conducted a review of laws and fire prevention and management plans and protocols on the official websites of administrative bodies and agencies of the USA, Spain, Portugal, France, Italy, Greece, South Africa, Australia, Chile, and Argentina. Each document was read and analyzed and we conducted searches for the terminology used to name the WUI, the methodology and criteria used for defining the WUI, the fire prevention and management actions implemented in the WUI, the level of territorial organization and the responsible agencies for implementing the actions, and the presence of a methodology and a map at national scale. We found no consensus on the terminology for the WUI, the most common terms used being: wildland-urban interface, urban-rural interface, and urban-forest interface. With the exception of the USA and Portugal, there is no unified methodology at the national scale. We identified three general methods for defining the WUI: considering buffer distance for urban and vegetation areas (USA, Italy, Chile, South Africa), employing networks of strips (Spain, Portugal), and delineating risk-prone zones (Australia, France). All countries undertake fire prevention actions (e.g., fuel reduction and firebreak creation) often implemented at the municipal level. There is almost no interaction between academia and fire management agencies. Our review addresses the gap in the methods to define the WUI effectively implemented by fire management agencies. We highlight the need to implement actions aimed at enhancing the interaction between fire scientists and fire managers, which is essential for formulating and implementing effective strategies for fire prevention and optimizing resources.

https://v2.sherpa.ac.uk/id/publication/26071 Editorial on the Research Topic Waste Challenges in the Context of Broad Sustainability Challenges info:eu-repo/semantics/publishedVersion

Prescribed fire frequencies have been widely used to reduce the risk of severe wildfire occurrences. In addition, several studies have been conducted to assess the impact of fire frequencies on vegetation, vertebrate, and invertebrate species, as well as soil physical and chemical properties. However, there is a lack of empirically based knowledge concerning the impact of fire frequency on soil microorganisms. This study assessed the effect of different fire frequencies on the diversity and composition of soil fungal communities in a semi-arid savanna rangeland. Soil samples were collected from an ongoing long-term trial at the University of Fort Hare (South Africa) on the following treatments: (i) no burning; (ii) annual burning (burned once every year); (iii) biennial burning (burned once every 2 years); (iv) triennial burning (burned once every 3 years); (v) quadrennial burning (burned once every 4 years); and (vi) sexennial burning (burned once every 6 years). Fungi were identified using high-throughput sequencing, with Shannon-Wiener and Inverse Simpson diversity indexes being used for diversity and network analysis. Principal coordinate analysis was used for Bray-Curtis distance matrices to visualise the relationships between treatments. The highest diversity was found in biennial burning, which was significantly different (p &lt; 0.05) from the sexennial, quadrennial, and no burning treatments but was not different from the triennial and annual burning treatments. Regarding the taxa, Ascomycota and Basidiomycota were the phyla with the highest relative abundance, followed by Mortierellomycota, Chytridiomycota, and Rozellomycota. The different fire frequencies had an influence on soil fungi diversity and taxonomic composition in semi-arid savanna rangelands.