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Abstract Shifting cultivation, an age-old agricultural practice, is a major factor in forest cover change across Southeast Asia, where repeated cycles of vegetation disturbance and regrowth lead to far-reaching environmental and socio-economic impacts. The present study aims to assess the spatio-temporal patterns of vegetation disturbance and regrowth caused by shifting cultivation in Tripura state of India, over the past three decades, utilizing temporal segmentation of time-series Landsat data. The study analyzed vegetation disturbance and regrowth patterns in a shifting cultivation landscape from 1991 to 2020 using normalized burn ratio trends through LandTrendr, validated by the TimeSync tool. Six land use and land cover classes, viz., forests and trees outside forests, rubber plantation, shifting cultivation, water bodies, agriculture, and settlements, were mapped with an accuracy of 83.08% using a random forest classifier. This classification enabled the identification of the effective study area, which included forest areas with shifting cultivation patches. The analysis revealed that 2533.96 km2 of the study area remained undisturbed, 568.43 km2 experienced low-magnitude disturbance, 1501.11 km2 were moderately disturbed, and 184.82 km2 were highly disturbed. The shifting cultivation cycles in the study area show considerable variation. Low-magnitude disturbance indicates a single slash-and-burn event in the past three decades, moderate-magnitude disturbance involves fallow periods of over 10 years, and high-magnitude disturbance occurs with fallow periods of less than 8 years. The study revealed a shift from traditional shifting cultivation to more permanent agricultural practices in parts of Tripura. In response to incentives for commercial crops, cultivators are increasingly adopting long-term cultivation, including the growing of pineapple, areca nut, and rubber, as well as intercropping with papaya, banana, lemon, tapioca, pepper, and ginger. These plots are, however, abandoned if the yields become economically unviable. The expansion of monoculture cultivation significantly reduces the available area for shifting cultivation, thereby compelling jhum cultivators to revisit their jhum patches more frequently. This study is a first-of-its-kind attempt in the Indian context and sheds light on changing patterns in an age-old agricultural practice.

Shifting cultivation, an age-old agricultural practice, is a major factor in forest cover change across Southeast Asia, where repeated cycles of vegetation disturbance and regrowth lead to far-reaching environmental and socio-economic impacts. The present study aims to assess the spatio-temporal patterns of vegetation disturbance and regrowth caused by shifting cultivation in Tripura state of India, over the past three decades, utilizing temporal segmentation of time-series Landsat data. The study analyzed vegetation disturbance and regrowth patterns in a shifting cultivation landscape from 1991 to 2020 using normalized burn ratio trends through LandTrendr, validated by the TimeSync tool. Six land use and land cover classes, viz., forests and trees outside forests, rubber plantation, shifting cultivation, water bodies, agriculture, and settlements, were mapped with an accuracy of 83.08% using a random forest classifier. This classification enabled the identification of the effective study area, which included forest areas with shifting cultivation patches. The analysis revealed that 2533.96 km2 of the study area remained undisturbed, 568.43 km2 experienced low-magnitude disturbance, 1501.11 km2 were moderately disturbed, and 184.82 km2 were highly disturbed. The shifting cultivation cycles in the study area show considerable variation. Low-magnitude disturbance indicates a single slash-and-burn event in the past three decades, moderate-magnitude disturbance involves fallow periods of over 10 years, and high-magnitude disturbance occurs with fallow periods of less than 8 years. The study revealed a shift from traditional shifting cultivation to more permanent agricultural practices in parts of Tripura. In response to incentives for commercial crops, cultivators are increasingly adopting long-term cultivation, including the growing of pineapple, areca nut, and rubber, as well as intercropping with papaya, banana, lemon, tapioca, pepper, and ginger. These plots are, however, abandoned if the yields become economically unviable. The expansion of monoculture cultivation significantly reduces the available area for shifting cultivation, thereby compelling jhum cultivators to revisit their jhum patches more frequently. This study is a first-of-its-kind attempt in the Indian context and sheds light on changing patterns in an age-old agricultural practice. [ABSTRACT FROM AUTHOR]

This study contributes to understanding ecological changes in land use following slash-and-burn land clearing. This study aimed to compare the richness and density of plant species and soil fertility in farmland cultivated for one year (1 Y), three years (3 Y), and five years (5 Y) after slash-and-burn, with the conditions in the secondary forest (SF) in Berau Regency of East Kalimantan. Understory plant taxon types, numbers, and soil organic matter were measured in each region using a series of nested plots. The size of each observation plot was 20 x 100 m. Data on understory vegetation composition was collected using 1 x 1 m mini plots at 20 sampling points and divided into five blocks, with a 10 m spacing between sampling points on each property. Understory vegetation species and cover percentage, litter cover percentage, open soil percentage, and soil fertility were measured for each observation plot. The results showed that the land cover percentage increased each year during the 5 years transition from secondary forest to farmland. Furthermore, within the 5 years, there was a change in understory species, particularly the presence of grasses and sedges at 3 and 5 years after the land use change. However, the transition from secondary forest to farmland within 5 years did not alter soil organic matter and total nitrogen.

Fire, a prevalent land management tool in rotational shifting cultivation (RSC), has long been debated for its immediate disruption of surface soil, vegetation, and microbial communities. While low-intensity and short-duration slash-and-burn techniques are considered beneficial for overall soil function, the dual nature of fire's impact warrants a comprehensive exploration. This review examines both the beneficial and detrimental effects of fire on soil properties within the context of RSC. We highlight that research on soil microbial composition, carbon, and nitrogen dynamics following fire events in RSC is gaining momentum. After fires, soil typically shows decreases in porosity, clay content, aggregation, and cation exchange capacity, while sand content, pH, available phosphorus, and organic nitrogen tend to increase. There remains ongoing debate regarding the effects on bulk density, silt content, electrical conductivity, organic carbon, total nitrogen, and exchangeable ions (K+, Ca2+, Mg2+). Certain bacterial diversity often increases, while fungal communities tend to decline during post-fire recovery, influenced by the soil chemical properties. Soil erosion is a major concern because fire-altered soil structures heighten erosion risks, underscoring the need for sustainable post-fire soil management strategies. Future research directions are proposed, including the use of advanced technologies like remote sensing, UAVs, and soil sensors to monitor fire impacts, as well as socio-economic studies to balance traditional practices with modern sustainability goals. This review aims to inform sustainable land management practices that balance agricultural productivity with ecological health in RSC systems. [ABSTRACT FROM AUTHOR]

This study contributes to understanding ecological changes in land use following slash-and-burn land clearing. This study aimed to compare the richness and density of plant species and soil fertility in farmland cultivated for one year (1 Y), three years (3 Y), and five years (5 Y) after slash-andburn, with the conditions in the secondary forest (SF) in Berau Regency of East Kalimantan. Understory plant taxon types, numbers, and soil organic matter were measured in each region using a series of nested plots. The size of each observation plot was 20 x 100 m. Data on understory vegetation composition was collected using 1 x 1 m mini plots at 20 sampling points and divided into five blocks, with a 10 m spacing between sampling points on each property. Understory vegetation species and cover percentage, litter cover percentage, open soil percentage, and soil fertility were measured for each observation plot. The results showed that the land cover percentage increased each year during the 5 years transition from secondary forest to farmland. Furthermore, within the 5 years, there was a change in understory species, particularly the presence of grasses and sedges at 3 and 5 years after the land use change. However, the transition from secondary forest to farmland within 5 years did not alter soil organic matter and total nitrogen. [ABSTRACT FROM AUTHOR]

Fire, a prevalent land management tool in rotational shifting cultivation (RSC), has long been debated for its immediate disruption of surface soil, vegetation, and microbial communities. While low-intensity and short-duration slash-and-burn techniques are considered beneficial for overall soil function, the dual nature of fire’s impact warrants a comprehensive exploration. This review examines both the beneficial and detrimental effects of fire on soil properties within the context of RSC. We highlight that research on soil microbial composition, carbon, and nitrogen dynamics following fire events in RSC is gaining momentum. After fires, soil typically shows decreases in porosity, clay content, aggregation, and cation exchange capacity, while sand content, pH, available phosphorus, and organic nitrogen tend to increase. There remains ongoing debate regarding the effects on bulk density, silt content, electrical conductivity, organic carbon, total nitrogen, and exchangeable ions (K+, Ca2+, Mg2+). Certain bacterial diversity often increases, while fungal communities tend to decline during post-fire recovery, influenced by the soil chemical properties. Soil erosion is a major concern because fire-altered soil structures heighten erosion risks, underscoring the need for sustainable post-fire soil management strategies. Future research directions are proposed, including the use of advanced technologies like remote sensing, UAVs, and soil sensors to monitor fire impacts, as well as socio-economic studies to balance traditional practices with modern sustainability goals. This review aims to inform sustainable land management practices that balance agricultural productivity with ecological health in RSC systems.

Abstract Shifting cultivation remains an important land system in many tropical landscapes, but transitions away from shifting cultivation are increasingly common. So far, our knowledge on the social–economic and environmental drivers and consequences of such shifting cultivation transitions is incomplete, focusing on certain transitions, drivers, consequences or regions. Here, we use an archetype approach, validated through systematically identified literature, to describe eight archetypes encompassing the transitions from shifting cultivation to (1) perennial plantation crops, (2) permanent agroforestry, (3) regrown secondary forest, (4) permanent non‐perennial crops, (5) pasture, (6) wood plantation, (7) non‐cultivated non‐forested land and (8) restored secondary forest (ordered in decreasing prevalence). We then discuss social–economic and environmental factors favouring and disfavouring each archetype. This reveals that higher expected land rents, resulting from increased market access, crop price surges, secure land tenure and state interventions, are the main drivers of archetypical transitions to perennial plantation crops, permanent agroforestry, permanent non‐perennial crops and wood plantation. The prioritisation of other activities, both on‐ and off‐farm, favours transitions to regrown secondary forest and non‐cultivated non‐forested land, depending on plot‐level environmental conditions. Active forest restoration is typically implemented through state or NGO interventions. Turning to the consequences of archetypical transitions for biodiversity, the environment and livelihoods, we find that positive environmental outcomes prevail for transitions to permanent agroforestry, regrown secondary forest and restored secondary forest. Negative environmental outcomes dominate for four typically economically profitable transitions to perennial plantation crops, permanent non‐perennial crops, pasture and wood plantation. Non‐income‐related social–economic outcomes are heterogeneous within all archetypes and highly context‐dependent. Our archetype analysis shows that shifting cultivation transitions are diverse in themselves, in their drivers and their consequences. This calls for a critical and contextualised appraisal of the continuation of shifting cultivation, as well as the transition away from it, when designing land system policies that work for people and nature. Read the free Plain Language Summary for this article on the Journal blog.

Shifting cultivation remains an important land system in many tropical landscapes, but transitions away from shifting cultivation are increasingly common. So far, our knowledge on the social–economic and environmental drivers and consequences of such shifting cultivation transitions is incomplete, focusing on certain transitions, drivers, consequences or regions.Here, we use an archetype approach, validated through systematically identified literature, to describe eight archetypes encompassing the transitions from shifting cultivation to (1) perennial plantation crops, (2) permanent agroforestry, (3) regrown secondary forest, (4) permanent non‐perennial crops, (5) pasture, (6) wood plantation, (7) non‐cultivated non‐forested land and (8) restored secondary forest (ordered in decreasing prevalence).We then discuss social–economic and environmental factors favouring and disfavouring each archetype. This reveals that higher expected land rents, resulting from increased market access, crop price surges, secure land tenure and state interventions, are the main drivers of archetypical transitions to perennial plantation crops, permanent agroforestry, permanent non‐perennial crops and wood plantation. The prioritisation of other activities, both on‐ and off‐farm, favours transitions to regrown secondary forest and non‐cultivated non‐forested land, depending on plot‐level environmental conditions. Active forest restoration is typically implemented through state or NGO interventions.Turning to the consequences of archetypical transitions for biodiversity, the environment and livelihoods, we find that positive environmental outcomes prevail for transitions to permanent agroforestry, regrown secondary forest and restored secondary forest. Negative environmental outcomes dominate for four typically economically profitable transitions to perennial plantation crops, permanent non‐perennial crops, pasture and wood plantation. Non‐income‐related social–economic outcomes are heterogeneous within all archetypes and highly context‐dependent.Our archetype analysis shows that shifting cultivation transitions are diverse in themselves, in their drivers and their consequences. This calls for a critical and contextualised appraisal of the continuation of shifting cultivation, as well as the transition away from it, when designing land system policies that work for people and nature. Read the free Plain Language Summary for this article on the Journal blog. Read the free Plain Language Summary for this article on the Journal blog. [ABSTRACT FROM AUTHOR]

The evolution and transformations of swidden agriculture closely relate to ongoing studies of carbon budget, biological diversity, ecosystem services, indigenous wellbeing, and ethnic identities. Remote sensing has become an important tool to quantify and display swidden agriculture in transition. Due to its diversity, dynamics, and complexity, however, the development of universal remote sensing algorithms for mapping swidden agriculture faces major challenges. Although swidden agriculture has increasingly become the focus of climate change and other sustainable initiatives, a systematic review on remote sensing of this farming system in the tropics is seldom reported. With 89 peer-reviewed journal articles related to the identification, mapping, monitoring or forecast of swidden agriculture since the 1970s, the methodological progresses and shortcomings of remote sensing of swidden agriculture were compared and summarized, followed by providing several perspectives on near-future research directions. The conclusions were drawn as follows. Firstly, the limited remote sensing studies of swidden agriculture were mostly reported in Southeast Asia (66%), followed by Latin America and Central Africa. Secondly, Landsat is the most (59%) widely applied to monitor swidden agriculture and also holds huge potential in delineating its trajectories. Thirdly, the spectral feature-based algorithms (76%) are more used than the counterparts of geometric-based and structure-based ones. Finally, several aspects including exploring new data and algorithms for the enhancement of remote sensing of swidden agriculture have been proposed. This review paper might be served as a long-delayed appeal for strengthening remote sensing of swidden agriculture in the tropics for accurately assessing the carbon budget of forest change and other ecological and social effects caused by the evolution and transformations of swidden agriculture.

On the outskirts of the city of Bangui, the capital of the Central African Republic, fuelwood production, slash-and-burn agriculture and artisanal timber exploitation are causing deforestation and forest ecosystem degradation.Within the framework of the REDD+ Component of the South-West Regional Development Project, the implementation of Assisted Natural Regeneration during weeding (ANRw) in the slash-and-burn system was proposed and set up by 23 volunteer farmers on 24 fields with an average area of 0.22 ha in two villages (Boteke and Salanga).The objective of the study was to characterise the floristic structure of the juvenile woody vegetation resulting from ANRw in these two villages. More specifically, it aimed to: 1) describe the methods used to inform and raise awareness amongst farmers who volunteer to practise ANRw; 2) identify the main species conserved by the farmers; 3) identify the reasons or factors that motivated farmers to choose these species; 4) identify the biological and ecological characteristics of these species; and 5) evaluate the height growth of young trees preserved by ANRw over a 14-month period.The third inventory of the 24 plots (volunteers' fields) gave 1,668 woody plants preserved by ANR on 5.35 ha (312 trees ha−1), divided into 42 genera, 47 species and 23 families.These results show that ANRw is a simple technique to implement and can help maintain trees in fields in areas where pressure on the forest is high. In the supported villages, communities have shown an interest in applying this technique to reintroduce trees in the fields. This technique should be popularised in other places to improve the sustainable management of anthropized forest landscapes. In addition, volunteers who have tested ANRw say they are willing to continue practicing it. However, despite this genuine initial enthusiasm, this restoration drive will need to be monitored and supported due to the current context of extreme poverty and economic, social and political instability.

The objective of this study was to evaluate the effect of fire on the transformation of the soil's physical (granulometry and porosity), chemical (organic matter and pH) and mineralogical properties in an area where slash-and-burn farming predominates. The study was conducted in the district of São Pedro da Serra, municipality of Nova Friburgo, Rio de Janeiro state, Brazil, with relief formed by steep slopes interspersed with valleys. The region has a Tropical Altitude Climate, characterized by hot, rainy summers and mild, dry winters. The average annual rainfall is 1.279 mm, with the wettest months from November to March, and the driest months from May to August, marking the seasonal rainy (summer) and dry (winter) period. We collected deformed and undeformed soil samples at three depths (0-5 cm, 5-10 cm and 10-15 cm), in two areas, one that had been subject to highintensity fire (HIF) and the other where traditional slash-and-burn agriculture is practiced (S&B), with low-intensity fire. The physical, chemical and mineralogical properties of the soil had distinct responses to the disruption caused by fire of varying intensity. In the HIF area, the soil was hydrophobic, accompanied by smaller pore size (microporosity). In the S&B area, in contrast, the soil had a greater percentage of macropores. The results suggest that slash-and-burn agriculture, where there are fallow intervals, less severely affects the soil properties. [ABSTRACT FROM AUTHOR]

The Congo Basin's rapidly growing population still largely depends on shifting cultivation for both energy and food security. This nexus of population growth and ecological impact will continue to exacerbate landscape degradation in the coming decades. To quantify the effects of land-use intensity on soil nutrient stocks and the functional composition of young regrowth forest in the Congo Basin, we used fallows of different ages that had been subjected to a varying number of clearing cycles. We show that repeated clearing substantially affected soil cation stocks, reducing total K, Mg and Ca in the upper 20 cm of soil by roughly 20% per clearing cycle. Additionally, we show that plant-available nitrogen (ammonium and nitrate) and phosphorus decline in the topsoil with increasing land-use intensity. Furthermore, the tree functional composition of young fallows changed after repeated clearing cycles: we observed a decrease in abundance of pioneer species and an increase in nitrogen fixing species early in succession. Variation in soil total nutrient stocks was decoupled from changes in vegetation, and soil plant-available nutrients only marginally explained tree functional composition changes. We conclude that land-use intensity substantially affects both soil total and plant-available nutrients in a shifting cultivation system, as well as the functional composition of the regenerating vegetation. However, compositional changes of the tree community are only partly driven by land-use intensity effects on soil plant-available nutrients. [ABSTRACT FROM AUTHOR]

Elucidating dynamics of soil microbial communities after disturbance is crucial for understanding ecosystem restoration and sustainability. However, despite the widespread practice of swidden agriculture in tropical forests, knowledge about microbial community succession in this system is limited. Here, amplicon sequencing was used to investigate effects of soil ages (spanning at least 60 years) after disturbance, geographic distance (from 0.1 to 10 km) and edaphic property gradients (soil pH, conductivity, C, N, P, Ca, Mg, and K), on soil bacterial and fungal communities along a chronosequence of sites representing the spontaneous succession following swidden agriculture in lowland forests in Papua New Guinea. During succession, bacterial communities (OTU level) as well as its abundant (OTU with relative abundance > 0.5%) and rare (

Shifting cultivation, the oldest farming system of the world and is the dominant land use in mountainous regions of South and Southeast Asia. North-East India (NEI) region, one of the world's biodiversity hotspots, covers 17.2 million ha of land under forests, constituting ~25% of India's total forest area. The population-driven abrupt decline of the fallow period's duration has aggravated soil erosion, depletion of nutrients, decreased productivity, reduced biodiversity, and weakening of essential ecosystem services. Therefore, the present research aims to explore whether the duration of the fallow period of up to 20-years can restore diversity of tree species, biomass carbon, and ecosystem carbon stock equivalent to those under natural forests. Based on the accessibility and availability of the fallow stands, three categories were selected for the study (1–2, 5–8, and 15–20 years), and these were replicated eight times for each age group. While the 20-years of fallow increased tree diversity, it was still 22% lower than that of the natural forest. Similarly, a 2.7-fold increase in biomass carbon storage was observed with an increase in the fallow period from 5–8-years (33.4 Mg ha−1) to 15–20-years (92.9 Mg ha−1), yet the latter was 40% lower than that under the natural forests. The very labile and labile carbon stocks decreased with increase in the fallow period. In contrast, the less labile and non-labile carbon stocks increased with increase in the fallow age. Because of the absence of a long fallow management system in the region, and to minimize the risks of ecosystem carbon degradation, adopting an integrated approach is recommended to enhance the ecological integrity of the degraded lands under shifting cultivation while also improving the livelihood of the shifting cultivators.

Elucidating dynamics of soil microbial communities after disturbance is crucial for understanding ecosystem restoration and sustainability. However, despite the widespread practice of swidden agriculture in tropical forests, knowledge about microbial community succession in this system is limited. Here, amplicon sequencing was used to investigate effects of soil ages (spanning at least 60 years) after disturbance, geographic distance (from 0.1 to 10 km) and edaphic property gradients (soil pH, conductivity, C, N, P, Ca, Mg, and K), on soil bacterial and fungal communities along a chronosequence of sites representing the spontaneous succession following swidden agriculture in lowland forests in Papua New Guinea. During succession, bacterial communities (OTU level) as well as its abundant (OTU with relative abundance > 0.5%) and rare (<0.05%) subcommunities, showed less variation but more stage-dependent patterns than those of fungi. Fungal community dynamics were significantly associated only with geographic distance, whereas bacterial community dynamics were significantly associated with edaphic factors and geographic distance. During succession, more OTUs were consistently abundant (n = 12) or rare (n = 653) for bacteria than fungi (abundant = 6, rare = 5), indicating bacteria were more tolerant than fungi to environmental gradients. Rare taxa showed higher successional dynamics than abundant taxa, and rare bacteria (mainly from Actinobacteria, Proteobacteria, Acidobacteria, and Verrucomicrobia) largely accounted for bacterial community development and niche differentiation during succession. [ABSTRACT FROM AUTHOR]

Aim: North‐eastern Madagascar is a hotspot of plant diversity, but vanilla and rice farming are driving land‐use change, including slash‐and‐burn management. It still remains unknown how land‐use change and land‐use history affect richness and composition of endemic, native and exotic herbaceous plant species. Location: North‐eastern Madagascar. Methods: We assessed herbaceous plants along a land‐use intensification gradient ranging from unburned land‐use types (i.e. old‐growth forest, forest fragment and forest‐derived vanilla agroforest) to burned land‐use types (i.e. fallow‐derived vanilla agroforest, woody fallow and herbaceous fallow) and rice paddy. We compared land‐use types and analysed the effects of land‐use history, canopy closure and landscape forest cover on species richness. Additionally, we analysed species compositional changes across land‐use types. Results: Across 80 plots, we found 355 plant species (180 native non‐endemics, 57 exotics, 60 endemics and 58 species of unknown origin). Native and exotic species richness increased with increasing land‐use intensity, whereas endemics decreased. Unburned land‐use types had higher endemic species richness (4.28 ± 0.37 [mean ± SE]) than burned ones (2.4 ± 0.21). Exotic and native species richness, but not endemics, decreased with increasing canopy closure. Increasing landscape forest cover reduced exotic, but not native or endemic richness. Species composition of old‐growth forests was unique compared to all other land uses and forest‐derived, not fallow‐derived vanilla agroforests, had a similar endemic species composition to forest fragments. Main conclusions: Our results indicate that old‐growth forests and forest fragments are indispensable for maintaining endemic herbaceous plants. We further show that the land‐use history of agroforests should be considered in conservation policy. In forest‐derived vanilla agroforests, management incentives are needed to halt loss of canopy closure, thereby maintaining or even enhancing endemics. In conclusion, considering species origin (endemic, native and exotic) and composition is essential for the identification of suitable management practices to avoid irreversible species loss. [ABSTRACT FROM AUTHOR]

This account describes the context, history and outcomes of a series of studies into the ecology of slash-and-burn (S-B) agriculture in the world's humid tropics. These studies, which began in the mid-1980s, identified promising lines of research and continued to field trials, in Central America, of candidate agricultural systems as possible sustainable alternatives to the practice. The only system to emerge from 7 years' comparative trial with any promise of sustainability, in this context, was the agroforestry technique known as alley-cropping; but only with trees of the genus Inga. Inga alley-cropping then underwent field trials with subsistence farming families in northern Honduras. The system was aimed at the twin objectives of achieving food security in basic grains, on minimal inputs, and of providing the means of eliminating further S-B in the region. Since then, Inga alley-cropping has become the heart of a sustainable and integrated rural livelihood model (the Guama Model) which is being implemented successfully in northern Honduras with some 300 families. These families had been attempting to subsist on a few hectares of land degraded by decades or centuries of S-B. The development of Inga alley-cropping, supplemented by rock phosphate and other mineral supplements, as a sustainable subsistence and cash crop alternative means that land previously being held in reserve for subsequent S-B operations can now be planted to permanent forms of agroforestry. Entire landscapes can be re-greened by productive agroforest vegetation. Achieving this at scale will require the investment of huge extension effort and funds. However, the environmental, social and economic returns are also huge; and they are sustainable. In this programme,we are seeing the vitality and goodwill of hundreds of families focussed on the raising, planting and management of trees in ways that feed the living organisms of the soil and, hence, feed themselves. In so cheerfully planting out their own futures, they plant and reshape the future of their own country. Replicating this at scale, as Rattan Lal outlines below, could reshape the future of this planet. In the mid-1980s, progress on sustainable alternatives to S-B, especially in rain forests, was frustrated by a lack of conclusiveness in the literature as to why soil fertility fails so rapidly post-burn; but also by a degree of contradiction on the impacts of the burn on certain plant nutrients. Hands (Hands 1988 The ecology of shifting cultivation. MSc thesis, University of Cambridge) concentrated on the role of soil phosphorus and attempted to resolve these contradictions. The Cambridge Alley-cropping Projects (1988–2002) continued this theme and threw light on the question of sustainable food production in rain forest environments.

In northern Laos, shortened fallows in the slash-and-burn upland rice system are not sustainable either from a production or economic standpoint. This paper evaluates the potential for using the indigenous fast-growing tree, Broussonetia papyrifera L. Vent. (paper mulberry) as an economic fallow crop. The objectives of this study are to assess the inner bark yield of paper mulberry, and to evaluate rice productivity following paper mulberry cultivation. In addition, allometric models for estimating the inner bark yield of paper mulberry are developed. Inner bark yield of paper mulberry stands ranging in age from 9 to 48 months ranged from 10 to 208 g m−2, and increased with age. The models using diameter at breast height and stem height, or diameter at breast height only as independent variables explained well the variation in inner bark yield. When paper mulberry was completely removed during the rice growing season, rice yields in these areas were similar to those following weedy bush fallow. When paper mulberry was allowed to grow, rice yields were negatively correlated to paper mulberry stem density. When paper mulberry lateral branches were pruned back, rice yields could be maintained if the paper mulberry stem density was

In the city of Biguaçu, state of Santa Catarina in southern Brazil, family farmers practice a kind of natural land use in which agriculture, forestry and energy production are related. These farmers regularly practice fallow agriculture in secondary subtropical forests (Atlantic Forest biome), with production of energy in the form of charcoal. We aim at assessing the sustainability of the livelihoods of farm families through the analysis of access to assets or capital, categorized as natural, human, financial, social, physical and cultural capital, according to the approach of sustainable livelihoods. The fieldwork involved various techniques of ethnographic approach with members of 5 families of Três Riachos community, from 2012 to 2014. It is concluded that the natural capital asset access is possible in their own family property, and still be a renewable resource. As for human, physical and financial capital, it appears that in this production system, there is excessive and often unhealthy labor, using poor technologies and infrastructure. In the social capital, we emphasize the relationships of trust and reciprocity existing among farmers and external actors. Allied to this asset, there is the cultural capital, highlighting reciprocity characteristics with external agents, especially their customers. To promote the sustainability of livelihoods it is essential to facilitate full access to this capital, or increase access to those assets already established, such as the cultural capital. Thus, it is concluded that the analyzed livelihoods have the potential to be sustainable.

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Remnant tree presence affects forest recovery after slash-and-burn agriculture. However, little is known about its effect on above-ground carbon stocks, especially in Africa. We focused our study on Sierra Leone, part of the Upper Guinean forests, an important centre of endemism threatened by encroachment and forest degradation. We studied 99 (20-m-radius) plots aged 2-10 years with and without remnant trees and compared their above-ground carbon stocks, vegetation structure (stem density, basal area) and tree diversity. Above-ground carbon stocks, stem density, basal area, species richness and tree diversity increased significantly with fallow age. Remnant tree presence affected significantly tree diversity, species dominance and above-ground carbon stocks, but not vegetation structure (stem density, basal area). Number of remnant trees and number of species of remnant trees were also important explanatory variables. Although other factors should be considered in future studies, such as the size and dispersal modes of remnant trees, our results highlight that more strategic inclusion of remnant trees is likely to favour carbon stock and forest recovery in old fallows. To our knowledge, this is the first study on early succession regrowing fallows in West Africa. [ABSTRACT FROM AUTHOR]

For millennia, Maya farmers (i.e., milperos) throughout Mesoamerica have managed milpa : sequential agroforests initiated by slashing and burning patches of secondary forest and then cultivating a diverse polyculture of trees and annual crops. To reduce greenhouse gas emissions associated with deforestation, the Mexican government and non-governmental organizations have urged milperos to cease burning. We collaborated with Maya milperos in several communities in the Montes Azules Biosphere Reserve region in Chiapas, Mexico to determine carbon retained as char in traditional milpas , carbon loss associated with burning, and effects of burning on soil quality. We found the carbon retention of char in Maya milpas (24 ± 6.5% of C in vegetation) is 4–1400% higher than other slash-and-burn agroecosystems reported in the literature. Burning resulted in significant carbon loss of 12.6 (±3.6) t C ha−1 yr−1, but this was partially mitigated by char production (3.0 [±0.6] t C ha−1 yr−1) and incomplete combustion of woody biomass. The effects of burning on soil were minimal, with the only significant changes observed being increases in pH, potassium availability, and cation exchange capacity (2, 100, and 7%, respectively). The mean residence times of charred materials were at least double that of uncharred biomass. While there is a risk that shortening fallow periods would undermine the sustainability of Maya swidden agroecology, proper management and secure land tenure can help maintain intensive production without enduring environmental degradation. The char produced in these swiddens and successional management could allow this agroforestry system to be a long-term carbon sink. [Display omitted] • Slash-and-burn/swidden management can be sustainable and offset carbon emissions. • Traditional Maya swiddening converts, on average, 24% of biomass carbon into char. • Maya farmers recognize the threats climate changes pose to their agroecosystems. [ABSTRACT FROM AUTHOR]

Characteristics of an ecosystem are altered both as sudden modifications induced by the passage of the fire and the delayed changes derived from the simultaneous modifications of various soil physical and chemical parameters. Effects of fire on soil properties was performed in experimental plots, whose fuel amount was altered in order to obtain different heating intensities with the aim of determining changes in the soil physico-chemical parameters at varying heating temperatures. The research was conducted in a continuous cropped arable experimental plots located at the University of Uyo Teaching and Research Farm (UUTRF), Use-Offot, Uyo, Nigeria for four growing seasons, between March, 2010 to October, 2011. Core and bulk samples from the burned and adjacent unburned plots (control) were collected for physico-chemical analysis using standard procedures. These induced temperatures were highly variable on the soil surface. Temperature differences significantly (P < 0.05) affected sand, total nitrogen, organic carbon and pH contents of the soils positively (r = 0.518, 0.478, 0.582, 0.595 respectively), whereas a reduction in the soil temperature increased the concentrations of clay, 1mm, 0.05mm and 0.25 mm stable soil aggregates in the soil (r = -0.619, -0.578, -0.780, -0.526 respectively) after burning. Exchange acidity increased to 5.12 cmolkg-1 at 400C from 0.80 cmolkg-1 at initial temperature of 250C at the surface soil. Though aggregates formation was significantly higher (P = 0.05) after burning than the control soil locations, this soil will easily be distressed with the least application of force. The pH decreased to 5.4 at higher temperatures following burning before ashes mineralized. However, both organic matter and ECEC increased at increasing soil temperature. Potassium content remained surprisingly constant as the soil temperature increased. Despite the merits of quick release of occluded nutrients, heating temperatures of slash-and-burn method of land clearing altered soil quality attributes.

Este estudo investigou a composição florística das plantas daninhas em área queimada durante três anos agrícolas. A pesquisa foi conduzida no município de Zé Doca, Maranhão. O preparo da área no primeiro ano agrícola (2006/2007) foi realizado com corte e queima da vegetação para o cultivo de milho seguido do feijão-caupi. No segundo e no terceiro ano agrícola, o preparo da área consistiu de aração para o cultivo do milho seguido de mandioca (2007/2008) e depois para o feijão-caupi em sucessão à cultura de mandioca (2008/2009). A coleta das plantas daninhas ocorreu nas culturas de feijão-caupi e mandioca aos 30 e 60 dias após a semeadura (DAS), no primeiro e no segundo ano agrícola, respectivamente, e no feijão-caupi aos 30 DAS do terceiro ano agrícola, com retângulo (0,5 x 0,3 m) lançado 10 vezes ao acaso na área cultivada. A cada lançamento, as plantas daninhas foram colhidas, para contagem, identificação, secagem e, assim, obter os índices fitossociológicos. O fogo reduziu a diversidade e o número das plantas daninhas. As espécies com maior valor de IVI foram Imperata brasiliensis, Sida glomerata e Corchorus argutus, após o fogo na cultura do feijãocaupi; e Juncus sp., Spermacoce verticillata, Aeschynomene americana e Cyperus sp., após preparo da área com aração nas culturas de mandioca e feijão-caupi. As plantas de capoeira ocorreram depois da queima, porém sua importância foi reduzida com o passar do tempo.This study investigated the floristic composition of weeds in a burnt area in Zé Doca, Maranhão, during three agricultural years. The preparation of the area at the first crop year (2006/ 2007) was by slash-and-burn for maize cultivation, followed by cowpea. In the second and third crop years, the preparation of the area consisted of plowing for maize cultivation, followed by cassava (2007/2008) and later, by cowpea in rotation with cassava (2008/2009). Weed collection in the cowpea and cassava crops was carried out 30 and 60 days after sowing (DAS) during the first and second agricultural year, respectively, and cowpea crop at 30 DAS in the third crop year with a rectangle (0.5 x 0.3 m) randomly placed in the area. Every launch was conducted to evaluate the aerial parts of the weeds harvested for counting, identification and drying to obtain the phytosociological indices. The slash-and-burn practice reduces the variety and number of weeds. Species with the highest IVI were Imperata brasiliensis, Sida glomerata and Corchorus argutus after slash-and-burn in the cowpea culture; and Juncus sp., Spermacoce verticillata, Aeschynomene americana and Cyperus sp. after plowing in the cassava and cowpea cultures. Secondary vegetation plants occurred after burn, but were reduced over time.

Se condujo un estudio para determinar el efecto de los principios de manejo del Sistema Agroforestal Quesungual (SAQ) en la dinámica de nitrógeno (N) y fósforo (P) del suelo y el impacto de estos en su productividad en el sur-occidente de Honduras, Centroamérica. Se compararon cinco sistemas: (1) tala-y-quema (TQ); (2, 3 & 4) SAQ de A study was carried out to determine the effect of management principles in the Quesungual Slash and Mulch Agroforestry System (QSMAS) on the dynamics of soil nitrogen (N) and phosphorus (P), and their impact on QSMAS’ productivity in southwestern Honduras, Central America. Five land use systems were compared: (1) Slash-and-burn traditional system; (2, 3 and 4) QSMAS of 10 years old, respectively; and (5) Secondary forest. Local practices were applied to produce maize Zea mays, and bean Phaseolus vulgaris, with (101 kg N + 55 kg P /ha for maize, 46 kg N + 51 kg P /ha for bean) and without addition of fertilizers. Measurements included decomposition and nutrient release from biomass, aerobic mineralization of N, sequential fractionation of P, size-density fractionation of soil organic matter, and crop yield. Similarities in N dynamics indicate that QSMAS and slash-and-burn system were equally effective in providing N, although in QSMAS it is also result of a biologically mediated process. P pools in QSMAS were more dynamic and favorable by reducing their flows towards unavailable forms. Based on nutrient availability and grain yields over time, QSMAS could be a suitable option to replace the slash-and-burn system in smallholder agroecosystems.

In northern Laos, weeds are a major constraint to upland rice production in slash-and-burn systems. Two experiments were conducted to assess genotypic variation in ability to recover from weed competition at the early vegetative stage. Three traditional and two improved (IR 55423-01 and B6144F-MR-6-0-0) cultivars were grown with or without maize as an artificial weed. Maize was seeded at the same time as rice and removed at 37 d after rice sowing. The two improved cultivars out-yielded the traditional cultivars without weed competition. Larger yield loss due to the competition was associated with longer delay in days to flowering and smaller plant height at 37 d after sowing. The use of B6144F-MR-6-0-0 with high yield potential as well as strong ability to recover from weed competition appears to improve and stabilize rice productivity in this region.

Bordering Thailand, the southern part of Xayabury province is engaged in international trade and has experienced agricultural growth like nowhere else in Laos. The rapid transformation from manual slash-and-burn agriculture to mechanized, chemical-based cropping systems is often cited by Laotian authorities as a model of development. But a careful study of changes underway indicates that the reality is far less encouraging than it would appear at first. If many farmers have indeed bolstered their incomes over the last twenty years, it is no less true that some of the poorest peasants have become increasingly poorer and that the new techniques cause serious erosion, as they have not been able to prevent the expansion of cultivated areas on sloping lands.

Shifting cultivation is often described as “traditional”, inflexible and outdated, in contrast with “modern”, mechanised and chemical agriculture. This belief leads to overlooking farmer know-how, accumulated over generations to exploit natural resources while adapting itself to the mutations of the physical, social and economic environment.Research conducted in Phongsaly provides an idea about how complex and consistent a shifting cultivation system can be and how farmers optimise family labour but also limit their risks. External interventions—policies, projects, etc.—are aimed at improving the farmers’ livelihood by converting their farming practices. When these interventions overlook how diversified slash-and-burn agriculture is, they often lead to oversimplifying the farming systems, impoverishing people and exposing them to natural and economic risks. These actions are then counterproductive. In the interest of the Lao nation, as a community, the policies and their implementation should be rethought so as to hold highland farmers of ethnic minorities in higher esteem and to widen the viewpoint, currently limited to a caricature of the mountains and forest, upheld by the culturally and politically dominant lowland inhabitants.

Recurrent haze in Southeast Asian countries including Singapore is largely attributable to rampant forest fires in Indonesia due to, for example, extensive slash-and-burn (S & B) culture. Drawing on the "treadmill of production" and environmental governance approach, we examine causes and consequences of this culture. We found that, despite some perceived benefits, its environmental consequences include deforestation, soil erosion and degradation, global warming, threats to biodiversity, and trans-boundary haze pollution, while the societal consequences comprise regional tension, health risks, economic and productivity losses, as well as food insecurity. We propose sustainability through a plural coexistence framework of governance for targeting S & B that incorporates strategies of incentives, education and community resource management. [ABSTRACT FROM AUTHOR]

Increasing global human population and per-capita food consumption are expected to exacerbate the already massive agricultural footprint in tropical ecosystems. Madagascar is home to exceptional levels of biodiversity and is in the midst of severe land-use change, mostly driven by slash-and-burn, smallholder agriculture. Understanding the consequences of these agricultural practices for Malagasy native species is therefore of the foremost importance for the conservation of the nation's biodiversity. We surveyed bird assemblages inside and surrounding Ranomafana National Park, southeastern Madagascar, obtaining nearly 1,000 records of more than 60 species. At each study point, habitat structure was characterized by its vegetation complexity, and forest cover was quantified within circles of radii of 100, 500 and 750 m. We found that species richness was higher in forest than in agricultural areas, and responses to land-use change were found to be guildspecific, with frugivores being especially depleted outside forest areas, whereas granivores had higher species richness in the agricultural matrix. The number of recorded species with forest affinities was highly associated with landscape-scale forest cover, while open area and generalist species responded mainly to site-scale habitat structure. Our results demonstrate a turnover from forest-associated species to open area and habitat generalist species in Madagascar's smallholder agricultural areas. Our study underscores the conservation value of landscape-scale forest cover and of site-scale vegetation complexity. A double-stranded conservation approach, in which both landscape-scale forest cover and vegetation complexity are preserved would benefit conservation of the island's forest avifauna. [ABSTRACT FROM AUTHOR]