Burn Agriculture Research Articles

Vegetation changes through recurrent fire affect soil water behavior and enhance landslides in the mountainous region of Rio de Janeiro state, southeast Brazil

The role of fire in vegetation-soil–water interactions and its implications for soil stability and slope failures is poorly documented in humid tropical regions. This paper focuses on the relationships between vegetation change through recurrent fire and its effects on hydraulic conductivity and soil suction. Two monitoring sites were chosen on steep slopes in the mountainous domain of the Atlantic rainforest: the first is representative of degraded secondary rainforest (DRf) 25–30 years after slash and burn agriculture; the other represents herbaceous-shrubby vegetation (HS) resulting from wildfires in short-time intervals (<5 years). Two fires had previously occurred on the HS slope, one in December 2014 and the other in September 2019. Continuous records of rainfall and soil suction at depths of 10, 20, 50, 100, 150, and 220 cm provided a 6-year data collection from January 2015 to December 2020. Hydraulic conductivity (Ksat) field tests were conducted around the two monitoring sites before and after the September 2019 fire. The main results include: a) soil suction in the topsoil of both vegetation covers follow the rainfall inputs with high values of Ksat (DRf = 195 mm/h; HS = 203 mm/h); b) while quick rainfall-suction responses prevail within the DRf soil profile, soil suction at HS maintains a mean suction value around -27 kPa below 100 cm deep; c) field observations attest to the occurrence of hydrophobicity after the 2019 fire; d) Ksat tests just after this fire indicated a decreasing mean value from 203 mm/h to 46 mm/h; and e) by the end of the dry season after fire, there is a delayed increase in soil suction reaching -143 kPa at a depth of 100 cm and in smaller proportions at 220 cm deep. These results indicate that post-fire soil changes tend to favor the sudden loss of soil stability and slope failure during extreme rainfall events.

Spatial variation of soil characteristics affected by biochar materials from traditional slash and burn agriculture in Sabah, Malaysia

ABSTRACT Traditional slash-and-burn agriculture has been practiced for centuries in Southeast Asia. Our past study has identified distinctly different soil profile characteristics over a very short distance within a sloping field. In order to accurately estimate the potential of the traditional slash and burn cropping system for soil C sequestration as well as the maintenance of soil fertility, the spatial variation of soil C stock, soil nutrient status, and soil reactions were studied in Sabah, Malaysia. A triangular grid was used to conduct intensive soil sampling with an interval of about 5.8 m and a total of 71 locations. Total C (TC) stock was high with a mean of 34.9 Mg ha−1 and the spatial variation was extreme with a CV of 57.3% within a field. The spatial range was also short at 14.3 m. All soil nutrients had high CVs especially for available phosphate at 90.2% and the lowest for exchangeable potassium at 44.0%. Available phosphate was the most limited major nutrient when referencing the Japanese fertilizer guidelines, and its spatial distribution was affected by soil acidity status, especially exchangeable Al. Potential improvements of the production systems can be made by the application of lime materials in locations where TC content was low. However, the introduction of any external inputs requires careful assessment of not just crop productivity but also its consequences for long-term sustainability of the system. Future studies are anticipated in order to understand the response of crop productivity by pH improvement as well as the use of fertilizers.

A DNA barcode reference library for CITES listed Malagasy Dalbergia species.

On Madagascar, the illegal and unsustainable exploitation and illegal international trade of Dalbergia (rosewood) precious woods remain a serious conservation problem. Members of this genus are at high risk of extinction as a consequence of logging, mining, and slash and burn agriculture. Morphological identification of these Malagasy species is difficult in the absence of flowers and fruits, especially in the case of cut trees, sawn wood, and finished product. In this study, we use molecular barcoding to identify the Dalbergia species with the intent to contribute to the control of their illegal trade. Thirty-six Dalbergia samples representing 12 Malagasy species of which 11 have high commercial value, were collected to test the efficacy of a region of the plastid genome (rbcL) and a nuclear-transcribed ITS for barcoding. These widely used markers, as well as DNA barcoding gaps, "best match" and "best close match" approaches, and the neighbor-joining method were employed. All samples were amplified and sequenced using the two markers. Using a single locus, the "best match" and "best close match" approaches revealed that ITS has high discriminatory power within the tested Malagasy species. The combination of rbcL + ITS revealed 100% species discrimination. This study confirms that ITS alone and in combination with chloroplast barcode rbcL allow non-ambiguous identification for the 12 species studied. The results contribute to the development of DNA barcoding as a useful tool to identify Malagasy Dalbergia and suggest that the approach developed should be expanded to all 56 potentially exploited species in reference to international CITES requirements and the sustainable management of valuable resources.

Characterization of biochar enriched with compost tea, its effects and after-effects in continuous cultivation of maize (Zea mays L.) on a ferralsol of Lubuya Bera, Tshopo Province, R.D.Congo

The cultivation of maize, the second crop after cassava in terms of consumption in the Kisangani region, is faced with edaphic constraints aggravated by itinerant slash and burn agriculture. Our study proposes the use of biochar enriched with compost tea to remove these constraints. The chemical characteristics of biochar are: 2.48 to 4.68 c. moL.g-1 for the acid functions; 0.64 to 1.03 c. moL.g-1 for basic functions; 8 for the pH at the point of zero load; 64 to 103% for retention capacity; 875.3 mg.g-1 for the iodine index. From a microbiological point of view, out of around thirty isolates, the majority of Gram-negative bacilli corresponding to the genera Nitrosomonas, Azotobacter and Nitrobacter were identified. The experimental site was arranged according to the Device in complete random blocks with 4 blocks and 4 plots of dimensions 6 m x 4.5 m each corresponding to the following 4 treatments: T0 (witness); T1 (Biochar over 2 mm in diameter); T2 (Biochar 2 mm in diameter); T3 (Biochar 2 mm in diameter and enriched with compost tea). The average yields obtained increase during 8 cropping seasons under all the treatments and vary from 2.38 t.ha-1 under T0 to 7.39 t.ha-1 under T3. They are relatively higher in the dry season than in the rainy season with an average increase of around 18% and a marginal rate of return for grain maize of 4.4 under T3. Compost tea-enriched biochar, due to its resilience, with substantial aftereffects is an important input for climate-smart agriculture.

Fire regime of peatlands in the Angolan Highlands.

The Angolan Highlands region includes the Angolan miombo woodland ecoregion which supports miombo woodland, grasslands, subsistence agricultural land, and peatland deposits. Extensive fires, slash and burn agriculture, peat fuel extraction, and peatland drainage are among the anthropogenic practices that threaten these peatland deposits. Peat fires cause peatland degradation, release significant amounts of greenhouse gases, deteriorate air quality, and contribute towards climate change and biodiversity loss. This study presents an analysis of the fire regimes over the period 2001 to 2020 in an under-studied area of the Angolan Highlands. Moderate Resolution Imaging Spectroradiometer (MODIS) fire and vegetation data were used in combination with a land use/land cover (LULC) classification map to calculate fire frequency, burn area, and fire regimes. The fire patterns within the study site are comparable to those found in African woodland savannas. Across the study site, 6976 km2 (11.31%) of the land surface area burned at least nine times from 2001 to 2020, occurring largely within in the river valley environment. Considering the different LULC classes, peatlands were calculated to (a) burn more frequently (average fire frequency from 2001 to 2020 = 9.12), (b) have the smallest proportion (4.11%) of area which remained unburnt over the fire archive, and (c) have the largest average proportion (45.65% or 746 km2) of burnt area per year. Peatland burning occurred predominantly during drier months from May to September. The results of this study highlight the strong influence of LULC on the fire frequency and distribution in the study area, requiring unique fire management strategies. As has been documented for boreal and tropical peatlands across the globe, we stress the importance of peatland conservation and protection; continued unsustainable management practices may lead to the loss of these important peatland deposits.

High Altitude Rangelands Invasion by Non-Palatable Plant Species in the Perception of Yak Herders

The biological and socio-ecological dimensions of alpine rangelands degradation by invasive species have been considered in a field survey conducted in two yaks (Bos grunniens) rearing areas i.e., Langtang National Park (LNP) and Kanchanjunga Conservation Area (KCA). Data were collected by herder’s interview using the well-prepared and pretested set of questionnaires (60), followed by a focus group discussion (FGD) and key informants survey (KIS) each five at each site by following a set of checklists. There was a common perception about the invasive species among the herders in the study sites. The Rumex nepalensis was the most invasive species reported (75% of the respondents) at altitudes up to 3000 m in the KCA, while it was additionally with Eupatorium adenophorum (60%) in the LNP, while the Lyonia and Juniperus were the common invasive species in both sites. Altogether, twelve plant species were reported as invasive and non-palatable species from various botanical groups were indifferent to the changes made by invasive species in rangelands soil characteristics but gave well insight into the declining productivity of grasslands and herbage productivity and quality. Herders established bush clearance and slash and burn agriculture in rangelands as traditional adaptation measures to control the invasive species. Mapping of risk zones of invasive and alien species in the alpine rangelands is necessary across the alpine rangelands of Nepal and a long-term monitoring framework is desirable to confirm the herder's information on invasive alpine species of Nepalese Himalayas.

Regeneration and Restoration Status of Miombo Woodland Following Land Use Land Cover Changes at the Buffer Zone of Gile National Park, Central Mozambique

In the context of the current intensified disturbances of Miombo woodland, its regenerating capacity is fundamental to endure such disturbances. Miombo woodland in the buffer zone of Gile National Park (GNAP) is facing land cover change. This study aimed to assess regeneration structure, the status of restoration, and factors affecting the regeneration of Miombo woodland in the buffer zone of GNAP. In total, 12 transects, 48 plots, and 240 subplots were sampled in dense Miombo woodland (DMWL), open Miombo woodland (OMWL), and abandoned agricultural land (AAL) to collect data. Household interviews, focus group discussions (FGD), and key informant interviews(KIIs) were used to collect socio-economic data. Descriptive statistics, Kruskal-Wallis, chi-square, and regression, were used to analyze data. A total of 1863 matured woody individuals representing 85 species and 29 families were identified. Matured woody species density was significantly different between AAL&DMWL and DMWL & OMWL. However, there was no significant difference between OMWL and AAL. Nine hundred three regenerated individuals representing 70 species and 23 families were registered. Regeneration density was significantly different between land-use types. The mean regeneration density in DMWL, AAL, and OMWL were 39.87±13.82, 50.25±21.1, and 23 ± 9.98 stems ha−1, respectively. The most regenerated family was Fabaceae. All respondents reported that no assisted restoration activity was/is taking place in the area. The five most important factors affecting the regeneration of Miombo woodland were identified. Slash and burn agriculture and animal grazing were ranked first and last, respectively. Increasing pressure for land demand is determining factor for Miombo woodland regeneration. The buffer zone of GNAP is characterized by a moderate diversity of woody species, with the number of regenerated woody species increasing in AAL. Our findings suggest the importance of diversifying sources of income, creating a market value chain for their product, and strengthening collaboration between the park and the community surrounding the park could reduce the dependence of the community on slash and burn agriculture as well as safeguard the park from degradation and at the same time maintain the livelihood of the community.

Agricultural and Extension Education for Sustainability Approach

The study analyzed the emerging land rights and the extent of the relationship between agricultural and extension education and soil conservation practices. A survey of 376 household heads randomly sampled respondents was administered using a well-structured questionnaire. Results from correlation analysis revealed that the relationship between "agricultural and extension education" and the soil conservation variables "mulching, zero tillage, and the use of crop residues or household refuse" was positive, moderate in strength, and statistically significant. However, the relationship between "agricultural and extension education" and "slash and burn agriculture" was negative, moderate in strength, and statistically significant. The results from the linear probability model show that the coefficients of "Agricultural and Extension education" are statistically significant at a 1% level of significance for all the model specifications except the case where "organic fertilizer" is used as the dependent variable. Specifically, the results indicate that Agricultural and Extension education increases the probability of farmers practising mulching, use of crop or household residues, and zero tillage by 59.4, 16.1, and 33.6 percentage points, respectively. Also, Agricultural and Extension Education decreases the probability of farmers practising slash and burn agriculture by about 16.2 percentage points. Agricultural and Extension education increases the probability of farmers practising at least two of the soil conservations by 25 percentage points, while it increases the probability of farmers practising at least three of those soil conservations by 5.5 percentage points. Based on the results, we propose the Agricultural and Extension Education for Sustainability approach. This approach consists of knowledge, skills, motivation, awareness, concern, responsibility, and action. Therefore, policies geared towards agricultural and extension services should be highly prioritized.

Seasonal changes in soil properties caused by slash and burn agriculture practice in a humid temperate region of northeast Japan

ABSTRACT We investigated the influence of slash and burn (SBA) practice on selected soil properties and its influence on the dynamics of mineral nutrients in a typical humid temperate climate region of northeast Japan. Soils were sampled from an SBA site and compared to an adjacent original forest site (control) located in Shonai area, Yamagata Prefecture, from August 2018 to August 2019 with monthly intervals for SBA and bi-monthly intervals for control, except the snow cover period. The results showed that SBA could not evidently affect soil pH, electric conductivity, available phosphorus, exchangeable cations (Ca2+, Mg2+ and K+), and effective cation exchange capacity. This was likely due to the low severity of fire in the SBA site. On the other hand, cultivation of turnip affected seasonal changes of soil NH4 + and NO3 − mainly attributed to crop absorption. Soil MBC and MBN were significantly increased after one month of burning due to available soil nutrients from plant biomass burning which stimulated microbial growth. There were no significant changes in SOC and TN between the clear-cut stage (before SBA), and after one year at the end of the study period. This was largely due to the short turnip cultivation period and the quick covering by succession plants. In conclusion, our results showed the SBA practice affected soil properties in this study was not relatively significant.

Studying recent hydroclimatic variability in Madagascar despite deficient measurement networks: use of CHIRPS and GRACE data at the scale of the Mahajunga province

Abstract. Given the lack of in situ hydroclimatic measurements and networks in Madagascar, the GRACE (2003–2016) spatial gravimetry data, combined with other satellite data such as CHIRPS rainfall estimates or fire monitoring using GFED products, make it possible to establish an interannual assessment of certain climatic and environmental covariations at the northwest scale of the country. The results show a negative trend in continental rainfall and water content, especially after 2007, but also a time lag in the linear variations and trends of the Water Equivalent Height as well as the number of detected fires (variable indirectly measuring the pressure of deforestation by slash and burn agriculture).

COVID-19 slowdown induced improvement in air quality in India: rapid assessment using Sentinel-5P TROPOMI data

The COVID-19 lock/slow down affected humanity and livelihood, while it showed some positive effects on the environment with improvement in air quality indicators. Though many studies published after COVID-19 first phase lockdown observed reduction in pollutants over India, no studies yet compared the air quality indicators over the two lock/slow down windows during 2020–2021. This study reports results of rapid assessment of seven air quality indicators such as Nitrogen dioxide (NO2), Sulphur dioxide (SO2), Formaldehyde (HCHO), Methane (CH4), Carbon monoxide (CO), Aerosol (Ultraviolet Aerosol Index, UVAI), and Ozone (O3) for the past three years on monthly time scale using TROPOMI (Tropospheric Monitoring Instrument) data on GEE (Google Earth Engine) platform over India, with focus on the Gangetic plain, an air pollution hotspot. Significant reduction in NO2, SO2, HCHO and Absorbing Aerosol Index (AAI) was observed during March–May 2020 as compared to the same period in 2019, while the levels of NO2, SO2, HCHO and CO increased significantly in 2021 compared to March–May 2020. This suggests that COVID-19 lock/slow down in 2020 played a significant role in improving air quality indicators, while the relaxation in 2021 has led to detoriation, compared to 2020. The pyrogenic (forest fire and slash and burn agriculture) and agricultural (wet crop) sources were identified to contaminate the expression of slow/lock down effects on air quality indicators such as HCHO, CO and CH4 over India.

Seven new giant pill-millipede species and numerous new records of the genus Zoosphaerium from Madagascar (Diplopoda, Sphaerotheriida, Arthrosphaeridae)

Seven new species of the giant pill-millipede genus Zoosphaerium Pocock, 1895 are described from Madagascar: Z. nigrum sp. nov., Z. silens sp. nov., Z. ambatovaky sp. nov., Z. beanka sp. nov., Z. voahangy sp. nov., Z. masoala sp. nov. and Z. spinopiligerum sp. nov. All species are described based on drawings and scanning electron microscopy, while genetic barcoding of the COI gene was successful for six of the seven new species. Additional COI barcode information is provided for the first time for Z. album Wesener, 2009 and Z. libidinosum (de Saussure &amp; Zehntner, 1897). Zoosphaerium nigrum sp. nov. and Z. silens sp. nov. belong to the Z. libidinosum species-group, Z. ambatovaky sp. nov. to the Z. coquerelianum species-group, Z. beanka sp. nov., Z. voahangy sp. nov. and Z. masoala sp. nov. to the Z. platylabum species-group and Z. spinopiligerum sp. nov. to the Z. piligerum species-group. Updated identification keys are provided for each species-group. Two western dry forest species, Z. silens sp. nov. and Z. voahangy sp. nov. are recorded from two localities, while the other five species are currently only known from their type localities. Of special conservation concern might be Z. ambatovaky sp. nov. from the lowland rainforest fragment of Ambatovaky, a nowadays isolated lowland rainforest, rapidly shrinking due to slash and burn agriculture. In addition to the new species, new locality data is provided for 11 species and numerous unidentifiable species of Zoosphaerium: Z. neptunus (Butler, 1872), Z. platylabum (de Saussure &amp; Zehntner, 1902) and Z. piligerum (de Saussure &amp; Zehntner, 1897) from the central eastern montane forests, as well as Z. ambrense Wesener, 2009, Z. aureum Wesener, 2009, Z. libidinosum, Z. corystoides Wesener, 2009, Z. discolor Wesener, 2009, Z. smaragdinum Wesener, 2009, Z. villosum Wesener &amp; Sierwald, 2005 and Microsphaerotherium anjozorobe Wesener, 2009.

Analysis of Land Cover Change and Its Implication on the Environment around the Dja Biosphere Reserve, Southeastern Cameroon

Land cover change is a growing concern around the world. This is especially true for protected areas which are rapidly degrading owing to pressure from anthropogenic activities. The aim of this study was to analyze land cover change for the periods 1980, 2008 and 2020 and its implication on the environment in and around the Dja Biosphere Reserve in south eastern Cameroon. This was done using remote sensing and geographical information systems techniques to quantify and measure the extent of land cover change in the study area for forty years. Household surveys were equally undertaken through the administration of questionnaires to farmers in villages located within the Dja Biosphere Reserve. Collected data was analyzed through the use of GIS software as well as Microsoft Excel. From the land cover maps, four classes were found: dense forest, cultivated areas, water surface, and buildings and bare soils. The transition matrix between 1980 and 2008 showed that 6477.81 ha of dense forest was lost to cultivated areas and between 2008 and 2020, 722.84 ha of dense forest was lost. Between 1980 and 2008 cultivated areas lost 0.07% and gain 0.72% between 2008 and 2020. Building and bare soils increase by 0.28% between 1980 and 2020. The Kappa index of agreement was 0.91 % between 1980 and 2008 and 0.88% between 2008 and 2020. Slash and burn agriculture (43.3%), hunting (36.3%) and harvesting of tree-based products (20.3%) were identified by farmers as the human activities with the most negative impact on the reserve. Results revealed that, there are still opportunities to safe this vulnerable reserve from the negative effects of land cover change through the practice of agroforestry.

Ecosystem-based disaster risk reduction concept for forest and land fire disaster

PurposeThe purpose of this study is to develop an ecosystem-based DRR concept and explore how far the concept can be applied in a disaster-management context.Design/methodology/approachThe authors used the ecosystem concept established by Tsujimoto et al. (2018) as the foundation of this study. They then conducted a literature search to adapt the ecosystem concept to fit the context of disaster management. Thus, they developed an ecosystem-based DRR concept. They used a case study method to test whether the adapted ecosystem concept can be applied to examine a real-life case of disaster management. For data collection, they used qualitative methods; a semi-structured interview with practitioners and other actors involved in disaster-management practice as well as document review. For data analysis, they used thematic analysis to find themes within the data.FindingsBy using this concept, the authors found some actors fulfil their role in the ecosystem toward the DRR effort, some actors are ill-equipped, and some actors are actively working against DRR effort. There are also implementation challenges, as numerous programs are only halfway done due to a lack of resources. However, the main problems of this disaster can be summarized into three categories: technical problems, socio-economic problems and law-enforcement problems. All three problems need to be addressed altogether because even neglecting only one problem would lead to a flawed solution.Research limitations/implicationsOne of the limitations is the respondents' bias. This research aims to find out their part, or more accurately what they are representative of, regarding disaster management for forest and land fire case. As some of the questions may reveal unflattering action or may even hurting their credibility, respondents might not have provided an entirely honest answer. Another limitation is the differing respondents' roles within the disaster. As each of the respondents is a representative of an actor in disaster management, they all have different traits. Thus, this situation makes it challenging to produce similar quality and quantity data for each of them.Practical implicationsAs concluded, the ecosystem-based DRR concept can be used as a framework to examine a real-life case of disaster management. It can be utilized to explain roles, relationships and the whole network of disaster-management actors. The authors hope that this concept could help decision-makers in designing their policies.Social implicationsThe main problems of this disaster can be summarized into three categories: technical problems, socio-economic problems and law-enforcement problems. All three problems need to be addressed altogether for even neglecting only one problem would lead to a flawed solution. However, the yearly reoccurrences of fires and the widespread of illegal and dangerous practice, slash and burn agriculture, are evidence that the government mishandles the other two problems. There is a need for reform within legal institutions and government's treatment regarding local farmers. There is a need for trust, cooperation and synergy between disaster-management actors.Originality/valueThe ecosystem concept has been used widely in the field of management of technology and innovation. However, while ecosystem concept is commonly used in the management of technology and innovation, it is rarely used in a disaster-management context.

AEROSOL INFLUENCE ON PHOTOVOLTAIC SOLAR ENERGY GENERATION FOR THE STATE OF GOIÁS (BRAZIL)

Abstract. The presence of aerosols in atmosphere has the potential to decrease the efficiency of solar photovoltaic energy generation. The central region of Brazil presents a remarkable growth of these aerosols between March and October, when the region undergoes a period of intensive slash and burn agriculture. This paper aims to evaluate the impact of this anthropogenic aerosol on electric power generation by comparing data from geostationary satellites with photovoltaic power generation data.

El nacimiento de los “Sin fuego”: caso Parque Nacional Lagunas de Montebello, Chiapas, México

Introducción: El objetivo de esta investigación es comprender los cambios en las prácticas de uso del fuego en dos comunidades indígenas del Parque Nacional Lagunas de Montebello, Chiapas, México, donde a raíz de la implementación de políticas públicas sobre la supresión del uso del fuego, se han presentado repercusiones sociales y ecológicas. El incendio de 1998 ha sido considerado como el punto de quiebre para los cambios y tensiones que están ocurriendo actualmente en la región.Método: Se realizaron 66 entrevistas semiestructuradas y a profundidad a pobladores de dos comunidades indígenas ubicadas dentro (Tziscao) y fuera (Antelá) del Parque. Los temas tratados fueron: las experiencias durante el incendio de 1998; las políticas públicas en torno al uso del fuego; y la voz de la comunidad para comprender quiénes son, dónde y cómo se ha producido el nacimiento de los “Sin fuego”.Resultados y discusión: En las narrativas de las personas entrevistadas se mencionan diversas interpretaciones en cuanto a las prácticas del uso del fuego, principalmente en las actividades agrícolas, donde el uso del fuego ha sido severamente criminalizado. Estas políticas de supresión, implementadas después del gran incendio ocurrido en 1998, han influido negativamente en el territorio, marcando un antes y un después del catastrófico evento. En general, estas políticas públicas se contraponen a la lógica tradicional, y generan un “epistemicidio” o liquidación de formas de conocimiento y de prácticas de uso del fuego en territorios donde ancestralmente culturas lo han utilizado con diversos objetivos. Algunas prácticas que incluían el uso del fuego, como la roza-tumba-quema, han desaparecido por completo en Tziscao, una comunidad donde el fuego era un elemento central de la cultura, de las formas de vida y una manera de construcción del territorio. Actualmente, los habitantes están temerosos de utilizar el fuego en sus prácticas, por las repercusiones en multas al provocar incendios y el riesgo de la disminución del turismo. En Antelá, ubicada fuera del Parque y que no depende en gran parte del turismo sino de la milpa, la relación con el fuego no está ausente, se mantiene activa y la práctica de roza-tumba-quema se conserva. Conclusión: De mantenerse esta tendencia de supresión del fuego, no solamente se intensificará un proceso de transformación cultural, sino también de degradación ambiental con relación a la construcción del territorio. De manera más significativa, se puede generar una modificación drástica del paisaje, que puede desencadenar nuevos incendios catastróficos. El desafío a largo plazo no es invisibilizar ni excluir al fuego, sino incluirlo en el mantenimiento del paisaje, partiendo de la experiencia y conocimientos que tienen las comunidades campesinas; la investigación de ecología del fuego disponible; y sensibilizar e integrar a las autoridades gubernamentales para la elaboración de planes de manejo del fuego que integren las prácticas locales.

An investigation of the characteristics, causes, and consequences of June 13, 2017, landslides in Rangamati District Bangladesh

The primary purpose of this study is to find out and discuss the characteristics, causes, and consequences of the landslides of June 13, 2017, in the Rangamati district Bangladesh. Since rainfall triggered the landslides, debris flow accounts for 40.45% of the landslides. Most of the landslides are small (mean 274. 2 m2 with a standard deviation of 546.1 m2). Size of 62.30% of the landslides was < 100 m2. The probability density of 50–100 m2 landslides is the highest and with the increase of the size of landslides, probability density decreases. It indicates the chance of large landslides (> 1000 m2) is low. Frequency ratio, logistic regression, and Spearman’s rank correlation were used to find out the relationship between 15 landslide causal factors including elevation, slope, rainfall, aspect, land use/land cover, land use/land cover change and distance to the road network with the occurrences and size of landslides. Among the land use/land cover types built-up areas [frequency ratio (FR) = 5.67], among land-use land-cover change types: vegetation to built-up (FR = 5.31) are the most prone areas to landslides. Logistic regression models found six causal factors were statistically significant, including slope (Coefficient, ß = 1.05), and distance to the road network (ß = 0.44). The size of the landslides had a significant relationship with five causal factors, including annual rainfall (ρ = 0.52), and elevation (ρ = 0.24). Paired sample t-test on pre-event and post-event monthly incomes revealed that landslides had a significant impact on different occupations of the local people. People involved in primary economic activities like the slash and burn agriculture (locally known as jhum cultivation) and fishing are the worst sufferers of landslides as they experienced a significant fall of income after the landslides. The findings of the study would help the policymakers to mitigate landslide hazards in the Rangamati district.

Distribution of surface carbon monoxide over the Indian subcontinent: Investigation of source contributions using WRF-Chem

This study investigates fractional contribution of different carbon monoxide (CO) sources over the Indian subcontinent at the surface in 2015 using a tagged tracer approach in the Weather Research and Forecasting model coupled with Chemistry (WRF-Chem). Model simulations are evaluated with respect to in-situ and satellite observations. The simulated CO levels reproduced in-situ observations in Pune, Anantapur, Udaipur, Ahmedabad, and Chennai reasonably well with mean bias ranging from −89.9 to 87.0 ppbv and RMSE ranging from 28 to 40% but a poor model performance was noticed in Hyderabad, Jabalpur, and Kanpur with larger mean bias (−259.0–190.9 ppbv) and RMSE (45–96%). Simulated CO concentrations are also compared with CO retrieved by MOPITT at 800 hPa and 200 hPa. At 800 hPa (200 hPa), the annual average WRF-Chem CO varies from 195 ± 69 to 224 ± 93 ppbv (102 ± 25 to 136 ± 21 ppbv) while MOPITT CO varies from 103 ± 26 to 114 ± 29 ppbv (103 ± 30 to 134 ± 33) over different Indian sub-regions. Over most of the regions, good correlation (coefficient of correlation > 0.7) is observed between simulated and satellite observed CO with mean bias of 92–118 ppbv at 800 hPa and −4 to 3 ppbv at 200 hPa. Over the total Indian region, we find the highest contribution from anthropogenic emissions (CO-ANT) and inflow into the model domain from domain boundaries (CO-BACK) with 45–46% contribution each and very small contribution (<5%) of biomass burning (CO-BIOM), biogenic (CO-BIOG) emissions, and photochemical production (CO-CHEM). Fractional contribution of these tracers are analysed over different Indian sub-regions. CO-ANT (21–69%) and CO-BACK (22–66%) contributions are found high throughout the year over all the Indian landmass regions. CO-BACK contribution is found to be maximum (70–95%) over the Bay of Bengal and Arabian Sea. During winter season, CO-ANT and CO-BACK contribute 32–69% and 27–56% respectively over landmass regions of India. During spring, highest CO-BACK (66%) over Western India as compared to other landmass regions is attributed to CO inflow from the Arabian Peninsula and Middle East region. CO-BIOM contributes more than 22% in NE&M (North-East India and Myanmar) during spring due to slash and burn agriculture practice. During summer, transport of cleaner marine air and stronger vertical mixing are major causes of lower CO concentration over all sub-regions. During autumn, CO-ANT contributes 33–70% over different landmass regions. Surface CO concentration is found to be mainly controlled by the direct anthropogenic emission in Indian megacities with a contribution exceeding 70% to CO in Delhi and Kolkata throughout the year.

Environmental Reconstructions in the Upper Tana region, Kenya

This article sets out to unravel aspects of environmental changes in the Upper Tana during the second millennium AD. This aspect has not been adequately addressed in the Upper Tana. This makes it clear that a lacuna exists in the study of communities of the Upper Tana and the way they interact with their environment in the past and present times. The objective of this article is to evaluate the relationship between human activities and environmental change in the Upper Tana from AD 1000 to 1950. It is hypothesized that the advent of iron technology and its attendant economic activities led to the depletion of indigenous forests and the general environmental degradation. The article has employed archaeological, ethnographic, oral and historical methodologies to gather data on vegetation change in the Upper Tana and other related regions. The article, argues that livestock grazing, iron smelting, slush and burn agriculture, and the clearing of forests for housing are key contributors to vegetation change in the Upper Tana. Results from oral reconstruction of the past vegetation of the area, and using the plant succession theory, shows that the lowland area of the Upper Tana is actually savanna with scattered trees probably inhabited by grazers. It is posited that the above factors, together with persistent droughts have altered the vegetation cover of the area. What we have today is colonization of less desirable stunted growth. The theory advanced here is that the vegetation change has been a result of human activities. Overwhelmingly, results the study that the researcher carried out, showed that the causes of these changes have been socio-economically associated with the expansion of agricultural communities into the area; rather than through climatic factors. Colonisation and other forces of modernistion have also contributed to the underlying problem. The article concludes that anthropogenetic factors have greatly contributed to environmental change in the upper Tana. Certainly, environmental change is a global phenomenon that has elicited research interests due to its negative impacts on human population. It is recommended that knowledge of environmental change in the past should be used to extrapolate modern environmental challenges affecting African ecosystems.

English

The present study aims to explore smallholder’s household living standard relevant to slash-and-burn agriculture, and determine trend of key crops grown with respect to their production and related generated average gross income in the region of Faradje, in the far northeastern region of the Democratic Republic of Congo (DRC). Surveys were conducted on agronomic and social economic characteristics prevailing in the area, in five localities, involving 50 farming households based on a questionnaire designed. Questions asked were about yield and gross income, considered as dependent variables as well as household size, farmland area, farming systems, crop types, distance between farms and home, farm task allocation, duration of fallowing, types of off-farm activities and number of reared animals taken as independent variables. Graphs were plotted using R statistic package (Version 3.6.1, 2019-07-05) and correlation analysis was conducted using Genstat 12th edition. The results showed that each household produced yearly on average 793.71 kg of paddy rice, 194.96 kg of maize grain, 175 kg of cassava chips, 70.50 kg of groundnut seeds and 8.60 kg of beans on an average of 0.81 ha of cropland in two cropping seasons. The results also showed that the total annual average income earned by one household was US $ 940.60 with individual average income of US $188.90. This was slightly higher than the national average real gross domestic product (GDP) in 2008 estimated at US $171; however, the figure was still unfortunately below the minimum of US $1 per day (0.52 US $/day) suggesting that slash-and–burn agriculture cropping system is far to achieve food security and accordingly improvement of economic situation in Faradje DRC. The household size and number of agricultural workers/households were weakly correlated with the average gross income (respectively, r = 0.29 and r = 0.35) whereas cropland surface area was moderately associated with the average gross income (r = 0.74). This demonstrates the importance of cropland surface in this cropping system in Faradje; suggesting that increasing farmers’ gross average income through slash-and-burn cropping system requires cropland expansion. Consequently, much should be undertaken to mitigate adverse effects of the established cropping system over the overall environment. Key words: Slash-and-burn agriculture, gross income, Faradje, DR Congo.