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Agroforestry has potential for strengthening the climate change resilience of smallholder farmers in Southeast Asia. In Indonesia, the food security challenges faced by smallholders will likely worsen due to climate change impacts. Agroforestry provides and option for strengthening climate change resilience, while contributing to food access, income, health, and environmental stability. To evaluate the evidence for such benefits, this systematic review identifies 22 peer-reviewed articles published between 2000 and 2019 which assess agroforestry’s contributions to food security in Indonesia, mostly in Java or Sumatra. Analysis of the studies indicate that traditional and commercial agroforestry contribute to food security in diverse ways: for example, traditional homegardens offer 20% more dietary diversity than commercial counterparts, while commercial homegardens may contribute up to five times more income. Agri-silviculture contributions fall along a timber versus non-timber forest product continuum that displays a similar tradeoff between diversity and income. Those systems with a commercial focus may receive 54% of their income from a single commodity crop such as coffee, while traditional systems allow greater access to plants with medicinal benefits. Nearly all agroforestry systems offered indirect benefits for food security, such as allowing more off-farm work than traditional agriculture and contributing to environmental stability: users of agroforestry were found by one study to collect 83% less fuelwood from natural forests. One study highlighted that agroforestry options have up to 98% greater net present value (for periods over 30 years) compared to slash and burn style agriculture. However, very few studies of Indonesian agroforestry focused explicitly on financial analysis and food security, indicating the need for further research. Given the similar situations faced by many Southeast Asia countries, our findings contribute to emerging trends throughout the region regarding the relationship between agroforestry and food security.

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.

Frequency distributions of tree diameters are a powerful tool for analyzing changes of tree populations in large areas. We analyzed the densities and mean volume estimates of trees in different size classes for the Finnish forests over the time-span of the National Forest Inventories (1921–2013). The results display a general increase in trees in all size classes, species group and geographical area, mainly after the 1970s. The densities of medium- and large-sized conifers showed large increases in the southern boreal subzone, spruces even more than pines. Small- to medium-sized pines have increased in the middle and northern boreal subzones. The shifts in growing stock are related to changing land use, resulting from the development of the society. The low quantities of both growing stock and large trees during the 1920s reflect a poor initial state of forests. Several land use forms of the former agriculture-based society were detrimental to forests, including slash and burn agriculture, cattle grazing and tar production. The pressure from alternative land use forms was stronger in southern Finland, where the population density (people per km2) is much higher. Between 1971 and 2013, the changes in size-class structure can be attributed mainly to intensified silviculture boosted by actions of the Finnish governments, including both legislation and financial support for management activities. Not only the development of growing stock has exceeded expectations, but the increase has also concentrated in the economically valuable trees in the large size classes.

Turmeric farming in slash and burn areas of Bangladesh plays an important role for generating cash income. This paper estimates technical efficiency of turmeric farmers in the slash and burn areas of Bangladesh and identifies sources of inefficiency using survey data obtained from 150 farmers over 6 villages throughout 2014/2015 growing season. Turmeric farming displayed much variability in technical efficiency ranging from 18 to 96% with mean technical efficiency of 84%, which suggested a substantial 16% of potential output of turmeric can be recovered by removing inefficiency. Besides improving technical efficiency, potential also exists for raising turmeric production through intensive training and extension services. For a land scarce country like Bangladesh this gain could help increase income and ensure better livelihood for the hilly farmers. The key policy implication of the analysis is that investment in training and extension service would greatly improve technical efficiency.

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 m2with a standard deviation of 546.1 m2). Size of 62.30% of the landslides was 2. The probability density of 50–100 m2landslides 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.

The dynamics of crop-fallow rotation cycles of shifting cultivation has been poorly understood in northeastern part of the country although it is one of the major land use systems in the hilly states of this region. The present study was conducted to understand the dynamics of shifting cultivation through the use of Landsat time-series data from 1999 to 2016 in Champhai district of Mizoram. We mapped the current jhum fields and abandoned areas of each imagery of the study period and performed a post classification comparison to assess the crop-fallow rotation cycle/jhum cycle. The chrono-sequential change of slash and burn area over the past 17 years showed a decreasing trend with the greater part of the shifting cultivation area being occupied by 2nd year crop fields, covering 48.81% of total jhum land. On average, 114.46 km2 area were annually slashed for current jhum, out of which 33.41% continued with current jhum 2nd year cropping and only 3.27% of jhumias continued with 3rd year cropping. The shifting cultivation patches were mostly confined to moderately steep slopes (15°–30°). East facing aspect was mostly preferred and North facing aspect was least preferred. During the study period, 10 years jhum cycle covered the maximum area followed by 9 years and 11 years jhum cycle. The end result of this study proved that the prevalent jhum cycle in Champhai district is 8–11 years with a fallow period of 6–9 years.

This research analyses the socio-economic implications of approaches to urban renewal on displaced populations in Ogun State, south-west Nigeria. In the last 5 years, massive renewal has been undertaken in five local government areas—Abeokuta North, Ado/Odo Ota, Sagamu, Yewa South and Ijebu Ode of the State from which two—Abeokuta North and Ado-Odo/Ota—were purposively selected to carry out this study. Primary data through administration of structured questionnaires to randomly selected 420 affected adults who either had their houses or shops demolished formed the source of data. However, 380 questionnaires were returned and cleaned upon which all were analyses based. Results from binary logistic regressions show that urban renewal has significant effects on the occupation (odds ratio = 3.0; p

Rainfall intensity, duration, frequency and magnitude influence both runoff generation and sediment yield. In this study, 176 rainfall events over a five-year period were classified into four regimes based on rainfall depth, duration and 30-minute maximum intensity, using hierarchical cluster analysis in the semiarid region of Brazil. Rainfall Regimes were grouped from higher to lower rainfall depth, longer to shorter duration, and higher to lower I30. Rainfall regime impact on surface runoff and sediment yield was studied in three watersheds under different land use - native tropical dry forest, thinned tropical dry forest, and slash and burn followed by grass cultivation. Thinning of native dry tropical forest reduced surface runoff and sediment yield due to the protective effect of the well-developed herbaceous layer. Runoff generation in the three watersheds showed strong dependence on antecedent soil moisture and the type of rain. Rainfall depth was the major factor for highest sediment yields.

The record of prehistoric crop cultivation in central Europe dates as far back as 5500 bc. In the pile-dwellings of the north-western pre-alpine forelands, dating roughly from 4300 to 800 bc, favourable taphonomic conditions provide evidence for the ways of cereal cultivation and consumption in unmatched detail. Based on different sets of (bio-) archaeological and palynological evidence, different hypotheses of crop husbandry methods have been developed for the wetland settlements. During the late Neolithic, two partly antithetic ideas are discussed: On one hand Shifting Cultivation assumes frequently shifted crop fields and the use of fire to provide nitrogen for plant uptake; On the other hand Permanent Cultivation reconstructs longer-ranging use of the fields, to which nitrogen may have been provided by various means. From the Bronze Age onwards, most probably some form of extensive ard cultivation was applied. In this article, we explore the implications of the different hypotheses for the socio-ecological system of the wetland sites. We combine the capability of agent-based modelling to simulate dynamic processes with the benefits provided by geographical information systems and the possibilities provided by the use of modern agro-ecosystem modelling tools. First, we used a mechanistic crop growth model, MONICA, to evaluate the influence of important factors of prehistoric crop yield formation: the climatic conditions, the soil texture and the degree of nitrogen availability. Second, we applied an agent-based model (WELASSIMO_crops) to simulate the spatial and economic implications related to the different crop husbandry methods. Our results provide quantitative information on the extent of crop husbandry activities in the wetland sites and on the effect of natural and anthropogenic factors on prehistoric crop yields. Without manure application, initial average yields of 1.0 t ha−1 a−1 are shown to decrease rapidly to only 50 % after 10 years. A manuring rate of 10 t ha−1 a−1 allows for higher yields of 1.7 t ha−1 a−1 and a slower rate of fertility decrease, but requires high numbers of livestock per capita. In shifting cultivation, high yields of 2.7 t ha−1 a−1 are reasonable, while necessitating a very large area and high labour input. Using the model results and a case study, we argue that permanent cultivation is more likely to have been the standard method, while burning of the landscape may have had different objectives than crop husbandry. We find that the combination of agent-based social and process-based biophysical modelling is a powerful tool to study the complex interdependencies in human-environment systems in the past.

Swidden agriculture is an age-old, widespread but controversial farming practice in Montane Mainland Southeast Asia (MMSEA). In the uplands of northern Laos, swidden agriculture has remained a predominant human-dominated land-use type for centuries. However, swidden system has undergone dramatic transformations since the mid-1990s. Debates on changes in swidden cultivation are linked to globally critical issues, such as land use/cover changes (LUCC), biodiversity loss and environmental degradation. Since the implementation of Reducing Emissions from Deforestation and Forest Degradation (REDD), much attention has been paid nationally and internationally to swidden agriculture in the tropics. However, knowledge of the explicitly spatial characteristics of swidden agriculture and the consequences of these transitions at macroscopic scale is surprisingly scarce. In this study, the intensity of swidden use and fallow forest recovery in northern Laos in 1990, 2002, and 2011 were delineated by means of Landsat Thematic Mapper (TM) and Enhanced Thematic Mapper plus (ETM+) imagery (30 m) using a decision tree classification approach, followed by an analysis of the spatio-temporal changes in swidden agriculture. Next, annual successive TM/ETM+ images during 2000–2010 were used to delineate the dynamics of the burning and cropping phase. Subsequently, the burned pixels identified in 2000 were compared respectively with their counterparts in the following years (2001–2011) to investigate temporal trends, land-use frequency, and the swidden cycle using time-series Landsat-based Normalized Difference Vegetation Index (NDVI) data. Finally, as the swidden cycle changed from 1 to 11 years, the fallow vegetation recovery process was studied. The results showed that: (1) from 1990 to 2011, the area of swidden agriculture increased by 54.98%, from 1.54×105 ha to 2.38×105 ha in northern Laos. The increased swidden cultivation area was mainly distributed in Luang Prabang and southern Bokeo, whereas the decreased parts were mainly found in Phongsali; (2) swidden agriculture increased mainly at elevations of 500–800 m, 300–500 m, and 800–1000 m and on slopes of 10°–20° and 20°–30°. Over 80% of swidden fields were transformed from forests; (3) during 2000–2011, the frequency of swidden use in northern Laos was about two or three times. The interval between two successive utilization of a swidden ranged from one to seven years. Comparison of swidden cycles and the related proportions of swidden farming in 2000, 2003, and 2007 revealed that swidden cycles in most areas were shortened; and (4) there was a significant correlation (0.97) between fallow vegetation recovery and the swidden cycle. The NDVI of regenerated vegetation could approach the average level of forest when the swidden cycle reached 10 years.

Temporal changes in the amounts of trace elements (As, Co, Cu, Mn, Ni, Pb, and Zn) and their correlations with temporal changes in charcoal abundance in age-dated sediments collected from Lake Thompson in Patagonia, Chile, attest to the substantial pyrogenic remobilization of contaminants that occurred in Patagonia during the mid-1900s. This remobilization was concurrent with the extensive slash and burn period in the region during that period. The changes in concentrations of Co, Cu, and Ni in relation to charcoal abundance in the lacustrine sediments over time were small compared to those of As, Mn, Pb, and Zn. However, the relatively low enrichment factors of all those trace elements, normalized to Fe, indicate that they were predominantly derived from local, natural sources impacted by fires rather than industrial sources. The primarily local source of Pb in the sediments was corroborated by the temporal consistency of its isotopic ratios (206Pb/207Pb:208Pb/206Pb), which were similar to previously reported values for natural lead in Central and Southern Chile. However, the pyrogenic remobilization of both natural and industrial trace elements by forest fires in Chile and elsewhere is expected to rise as a consequence of climate change, which is projected to increase both the frequency and intensity of forest fires on a global scale.

Agroforestry systems are widely recognized as an important way to address numerous environmental challenges in tropical areas. They represent a sustainable alternative form of land-use for small-scale agriculture, responding to the economic development needs of communities and offering a number of ecosystem services. This article presents an evaluation of the short- and medium-term profitability of two experimental agroforestry systems where fruit trees are predominant, which were established in 2009 in the Tapajos region of the Brazilian Amazon, state of Para. An analysis of net present value (NPV) confirms that the two experimental systems studied recover their total implementation and operating costs within a 20 years time horizon. These results underlie that prices of inputs are stable and farmers have access to markets, credit, and agricultural knowledge. The two experimental systems are compared to plots under traditional slash-and-burn cultivation, and Bragantino system. The results support changes to public policies in order to facilitate alternatives to slash-and-burn cultivation by supporting access to credit, knowledge of alternative agricultural practices, transportation systems, and industries that transform agricultural products. The consideration of ecosystem services should add a supplementary argument in favour of policies that promote agroforestry systems and thus limit the practice of slash-and-burn subsistence agriculture.

Carl Linnaeus' work on the 'economy of nature' was a major early development in what became the modern field of ecology. This analysis suggests that a key subject of this work that has been ignored or misunderstood for 250 years is the rural livelihoods, especially swidden (or slash-and-burn) agriculture, which Linnaeus studied during his expeditions through rural Sweden. Rereading his reports in the light of modern work on swiddens, political ecology, and the history of science affords a new appreciation of Linnaeus' insights into traditional systems of resource exploitation. The logic of nutrient cycling in swidden agriculture and its utilization of natural dynamics to serve human ends exemplify the principles of the 'economy of nature', and gave Linnaeus a philosophical basis for understanding and defending this system of agriculture as well as other rural resource use systems in Sweden. This analysis sheds new light on Linnaeus' ethnographic work, his view of folk environmental knowledge, and his often derided identification with Sweden's ethnic peoples.

Cocoa production in humid forest landscapes has been one of the main cash providers of West and Central African economies. Along with the liberalization of the perennial tree sector, there are increased fluctuations of cocoa income. At the same time, the demand and interest for timber production and non-wood forest products have also been increasing. With the continuous disappearance of natural forests, the production of these commodities is being shifted into cocoa agroforests and plantations. In view of helping research and development institutions in promoting sustainable tree crop systems, this paper attempts, for the main cocoa producing countries of West Africa (Cameroon, Nigeria, Ghana and Cote d’Ivoire), to: (1) document the temporal evolution of the market demand for forests and non-wood forest products both at the local and international levels; (2) explore the set of tree species that can be produced in cocoa agroforests of WCA to satisfy this demand. Deforestation resulting partly from the expansion of perennial orchards and slash and burn agriculture is: (i) leading to a shortage of suitable forest land necessary to stabilize or increase national cocoa production and (ii) increasing the gap between the demand and availability/supply of non-wood forest products (NWFP) and timber by reducing the main source of these products—the forest. Demand of these products is increasing with the growth of urban and peri-urban centers. At the same time, perennial agroforestry systems such as cocoa agroforest are increasingly perceived as assets for Payment for Environmental Services (PES) such as carbon storage and biodiversity conservation, because of the potential of the resources that they can generate. These demands of products and payment for ecosystem services that can be provided by sustainable cocoa agroforestry systems depends upon the appropriate combination of cocoa, timber and non-timber forest trees on the same land. Such demands is still to be properly exploited in the region. Cocoa agroforests in West Africa are characterized by fewer species than those of Central Africa. The level of market access influences the types of species that are managed inside cocoa agroforests. Among the species potentially associable with cocoa, those demanded by the local, regional and international markets are not necessarily the ones that are more frequent in the cocoa fields. The gradual reduction of natural forest, from which timber and non-timber products are gathered, aroused the need to integrate the growing of such species in cocoa agroforestry systems.

Conversion of pristine forests to agricultural lands is one of the leading causes of biodiversity loss worldwide. To assess the impact of such forest disturbance on microbial diversity, we investigated the diversity of arbuscular mycorrhizal fungi (AMF) in the rich forests of Karbi Anglong hills of Assam, a biodiversity hotspot part of Indo-Burma region. AMF spore diversity was assessed in distinct study sites with different intensities of disturbances that encompassed a pristine undisturbed forest (UF), slash-and-burn field (SBF), and monoculture forest (MF). A total of 35 arbuscular mycorrhizal (AM) fungal species belonging to 9 genera were isolated. Species forming glomoid spores were dominant in all the three sites followed by acaulosporoid spores. Highest spore density was found in UF and lowest in MF. Multivariate analyses revealed similarity in UF and SBF. It was found that in MF, AMF diversity was significantly modified and reduced, resulting in an ecological degraded ecosystem. Our results show that natural UF and SBF contained similar and a high AM fungal diversity. The AM fungal diversity is not significantly affected by the slash-and-burn agricultural land use practices practised by the ethnic hilly tribes and, therefore, could be a component of a tropical forest “conservation-agriculture matrix.” Also because of the high generic and species diversity found, this region can be considered as AMF hotspot and a priority place for conservation.

Experimental research into Neolithic agriculture has been underway in Forchtenberg, southwest Germany, since 1998. The experimental area is a medium age mixed-deciduous forest featuring different soils, mainly haplic and stagnic luvisols. In this experimental setting, research has focussed on comparisons of soil nutrients and crop yields resulting from slash and burn cultivation and from cultivation with hoeing. We show that slash and burn produces significantly higher yields, although always depending on soil quality. Hoe tilling is only profitable on the best soils in the first year after clearance. Continuous cultivation with hoeing produces too low yields, but repeated annual cultivation on slash and burn sites also resulted in progressively lower yields due to decreasing levels of nitrogen in the soil. Nitrogen originates not from burned wood but from the burning and mineralisation of organic matter in the topsoil. After burning and cultivation, a break of about 10–15 years is necessary, not only for forest re-growth, but also for the regeneration of the top soil and its nitrogen content. Slash and burn agriculture is therefore an easy and reliable tool for food production by a small population living in a large forested area.

Arunachal Pradesh in northeastern India is considered a biocultural diversity hotspot, with diverse tribal peoples and immense floral and faunal diversity. This rich diversity, sustained through the morang (community forests) and jhum (slash and burn) cultivation systems, is the backbone of native communities’ livelihood security. Kebung (Ratufa bicolor) and other squirrel species are intricately related to biocultural systems of the Adi people of Arunachal Pradesh. Primary surveys and participatory rural appraisals were carried out in 20 villages of East Siang and Upper Siang districts of the state. Results indicated that Kebung squirrels are hunted from successional forests, including from morang and jhum lands. They are an integral part of the Adi sociocultural, economic and livelihood systems, being used for food, medicinal, ceremonial and other purposes. Hunting methods vary in the traditional and transitional Adi villages. Recently, kebung populations have diminished, and this is attributed to overhunting. In particular, a decrease in kebung populations in some morang and jhum habitats has threatened the biocultural resources of the Adi. Knowledge and management practices relating to kebung hunting are gradually eroding among the younger Adi generations. However, the community recently passed a resolution for kebung conservation, supported by the customary norms. We conclude with a discussion of policy requirements for sustainable management of kebung populations to maintain Adi biocultural and livelihood security.

Fires in humid tropical forests are increasingly frequent due to severe dry seasons, forest degradation and agricultural expansion. One agent implicated in current discourse surrounding tropical forest fires is the small-scale farming peasantry who rely on fire in swidden (shifting cultivation, slash-and-burn) agriculture. The environmental degradation associated with fire has led to government responses at multiple scales (international, national, state, regional) via policies aimed mainly at managing ignition sources. However, continued increase in forest fires suggests that these policies may be having limited impact and a fresh evaluation of current policy approaches to fire management is needed. We review fire policy measures with insights of caboclo farming practices and perspectives from Eastern Amazonia and examine the congruence between policy and practice. We demonstrate a significant disparity between policy requirements such as firebreaks and actual fire management practices, in which measures rarely meet requirements outlined in legislation. We explore the origins and the impacts of these disparities, focussing on smallholder farm-level management measures and local capacity. Incomplete knowledge coupled with marginal awareness of legal requirements served to propagate widespread erroneous beliefs in what these are. This analysis at multiple scales (international, national, state, regional) will contribute to developing greater congruence between fire policies and smallholder farming practices.

Before it was destroyed by slash and burn practices, Brazil’s Atlantic Forest was one of the largest tropical forest biomes on Earth. Measurements from a river draining the region suggest that significant quantities of black carbon generated by the burning continue to be exported from the former forest. Humans have used fire extensively as a tool to shape Earth’s vegetation. The slash-and-burn destruction of Brazil’s Atlantic forest, which once covered over 1.3 million km2 of present-day Brazil and was one of the largest tropical forest biomes on Earth1, is a prime example. Here, we estimate the amount of black carbon generated by the burning of the Atlantic forest, using historical records of land cover, satellite data and black carbon conversion ratios. We estimate that before 1973, destruction of the Atlantic forest generated 200–500 million tons of black carbon. We then estimate the amount of black carbon exported from this relict forest between 1997 and 2008, using measurements of polycyclic aromatic black carbon collected from a large river draining the region, and a continuous record of river discharge. We show that dissolved black carbon (DBC) continues to be mobilized from the watershed each year in the rainy season, despite the fact that widespread forest burning ceased in 1973. We estimate that the river exports 2,700 tons of DBC to the ocean each year. Scaling our findings up, we estimate that 50,000–70,000 tons of DBC are exported from the former forest each year. We suggest that an increase in black carbon production on land could increase the size of the refractory pool of dissolved organic carbon in the deep ocean.

Here we present the results of fungal biodiversity studies from some selected Colombian Amazon forests in relationship to plant biodiversity and successional stages after slash and burn agriculture. Macrofungal diversity was found to differ between forests occurring in two regions (Araracuara vs Amacayacu) as well as between flooded forests and terra firme forests in the Amacayacu region. Macrofungal biodiversity differed between regeneration states of different age in the Araracuara region. Suitable substrates, especially dead wood that occurred as a result of recent slash and burn agriculture, resulted in the formation of many sporocarps of wood-inhabiting species. Putative ectomycorrhizal species were found in a dipterocarp forest. Fifty two percent of the macrofungal species could not be identified to the species level, but could be assigned to a genus, and it is likely that a significant portion of these represent species new to science. Long term studies are needed to obtain a comprehensive and complete understanding of the diversity and functioning of mycobiota in Amazon forest ecosystems.

Shifting cultivation is a common agricultural practice that is the basis of subsistence for many rural populations throughout the Tropics. The recent strong trend towards shorter fallow periods has led to widespread concern about declines in soil fertility, crop yields, and food security. Unlike most research on this problem, we focus here on steeply sloped regions such as Mizoram state in northeast India where most land is at an incline of >33°, and the potential for relatively large soil erosional losses may necessitate distinctive solutions. Our goal is to review the relevant literature so as to optimize the direction and quality of future science research on shifting cultivation in Mizoram. Our analysis suggests that the most promising options for improving shifting cultivation are nutrient and water supplementation, optimising crop choice, extending the site use period, enhancing the fallow recovery rate, and controlling the burns and their environmental impacts. Promising alternatives for replacing shifting cultivation include inter-row cropping between contour hedgerows of nitrogen-fixing shrubs, slope terracing, agroforestry with anti-erosional plants, and bamboo forest harvesting. In addition, we identify the principal research questions that should be addressed before each of these options can be evaluated and recommended as part of land use planning initiatives. Overall, we conclude that intelligent and careful use of commercial fertilizer in combination with organic matter additions is likely to be an important feature of many of the solutions to the problem of shortening fallow periods in shifting cultivation on steep slopes.

This paper analyzed forest land use change in Trans-Boundary Laos-China Biodiversity Conservation Area which is called Namha National Biodiversity Conservation Areas (Namha NBCAs), with 1992 and 2002 TM (ETM). Based on GIS and statistical methods, the intensity, state index of land use change and transfer matrix were used to study spatiotemporal land use change in the region. The results showed that the area of forest land decreased greatly, also the area of bamboo and grassland decreased. The other way round, the area of unstocked forest, slash and burn and rice paddy land increased. As a whole, the intensity of forest land change was higher, but others were lower. From the transfer matrix, most of the forest land changed into unstocked forest and urban area, some to slash and burn. The grassland and bamboo were mainly transferred to forest and unstocked forest. The unstocked forest land mostly came from forest land and grassland. It was showed there were three main causes of the land use change namely: opium poppy cultivation, rubber plantation and also ecotourism activities and finally some policies were developed in order to address the land use change in the study areas.

Root research needs to optimize sampling schemes to address different scales and dimensions of variability within a framework of feasible effort and, in some cases, acceptable soil perturbation. Both large and small sample volumes are utilized in root research, and this study is designed to help field researchers in optimizing root sampling. We evaluate the performance of three contrasting sampling strategies—large monoliths (LM, 25 dm−3), small monoliths (SM, 3 × 1 dm−3), and root auger (RA, 5 × 196.3 cm−3). We compare root biomass estimates obtained in a shifting cultivation agroecosystem in eastern Amazonia. We sampled a slash-and-burn field at 1/2 and 1 1/2 years of cultivation, and a paired 3-year-old spontaneous secondary forest regrowth down to 1 m soil depth, and we distinguish roots by diameter class and taxonomic origin (palm vs. non-palm roots). LMs are the only reliable quantification method for coarse roots. Both SM and RA methods are inadequate due to high variability and the frequent failure to detect the presence of coarse roots in the sampled soil. The SM method is acceptable for mid-sized (2–5 mm) roots, and both methods are adequate for fine root (

The hydrological and geomorphological impacts of traditional swidden cultivation in Montane Mainland Southeast Asia are virtually inconsequential, whereas the impacts associated with intensified replacement agricultural systems are often much more substantial. Negative perceptions toward swiddening in general by governments in the region beginning half a decade ago have largely been based on cases of forest conversion and land degradation associated with (a) intensified swidden systems, characterized by shortened fallow and extended cropping periods and/or (b) the widespread cultivation of opium for cash after the Second World War. Neither of these practices should be viewed as traditional, subsistence-based swiddening. Other types of intensive agriculture systems are now replacing swiddening throughout the region, including semi-permanent and permanent cash cropping, monoculture plantations, and greenhouse complexes. The negative impacts associated with these systems include changes in streamflow response, increased surface erosion, a higher probability of landslides, and the declination in stream water quality. Unlike the case for traditional swiddening, these impacts result because of several factors: (1) large portions of upland catchments are cultivated simultaneously; (2) accelerated hydraulic and tillage erosion occurs on plots that are cultivated repetitively with limited or no fallowing to allow recovery of key soil properties, including infiltration; (3) concentrated overland flow and erosion sources are often directly connected with the stream network; (4) root strength is reduced on permanently converted hillslopes; (5) surface and ground water extraction is frequently used for irrigation; and (6) and pesticides and herbicides are used. Furthermore, the commercial success of these systems relies on the existence of dense networks of roads, which are linear landscape features renowned for disrupting hydrological and geomorphological systems. A new conservation focus is needed to reduce the impacts of these intensified upland agricultural practices.

We examined the effect of traditional swidden agriculture on biodiversity using the litter arthropod top predator, the army ant Aenictus (Hymenoptera: Formicidae) as an indicator species in and around an intact tropical rain forest in Sarawak, Borneo, Malaysia. We compared the encounter rates with Aenictus colonies among five forest types: continuous primary forest, isolated primary forest, old secondary forest (>20 years elapsed after abandonment of the fields), young secondary forest (5 years after abandonment), and new fallow (2 years after abandonment) by intensive area searching in 2003 and 2005. In total, seven Aenictus species (15 colonies) and six Aenictus species (11 colonies) were encountered in 2003 and 2005, respectively. The encounter rates were the highest in continuous and isolated primary forests, intermediate in old and young secondary forests, and the lowest in new fallow. Year and the interaction between year and forest type were not significant. That is, abundance of top predators, which is rare and likely to be vulnerable to disturbance, has never fully recovered even 20 years after the termination of cultivation. We discuss forest management strategies to sustain biological diversity.

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

The worlds’ current food production system is focused on a limited number of crops. However, international food demand is increasingly looking for more diversified supplies. In the Venezuelan State Amazonas, the Piaroa indigenous people collect and cultivate several indigenous species with local, regional, national and even international potential. A participatory approach was used to select, in cooperation with these Piaroa people, a list of products for in-depth economic analysis and for introduction in agroforestry trials in a later phase. Seven agroforestry food products of this list were identified as underutilized. Primary data collected through consumer and trader surveys on the local markets and participatory exercises in selected Piaroa communities revealed that the main causes of underutilization are the general lack of transport, processing and market infrastructure in Amazonas; the lack of demand, due to a lack of product information; the lack of market information and cooperation between the different market chain actors; and the low productivity of the traditional slash and burn plots. Solutions to overcome the infrastructural constraints are sought by looking at the example set by a local NGO.

The role of seed bank, seed rain, and regeneration from seedlings and sprouts after swidden agriculture was compared in 5-, 10- and 20-year-old secondary forest and in a primary forest in Bragantina, Para, Brazil. The seed bank (0–5 cm soil depth) was largest in the 5-year-old forest (1190 ± 284 seeds m−2) and decreased nearly ten-fold with age to 137 ± 19 seeds m−2 in the primary forest. The highest seed rain was in the 5-year-old forest (883 ± 230 seeds m−2 year−1) and the least in the primary forest (220 ± 80 seeds m−2 year−1). Large plants (≥5 cm dbh) had more individuals and species that regenerated from sprouts than from seeds and the most abundant tree species in the secondary forest stands of all ages appear to be maintained by sprouting. The smaller individuals (≥1 m tall

Where long forest-fallows are no longer practiced, productivity declines in the absence of input substitution, as does the ability of subsistence farmers to earn an adequate livelihood from shifting cultivation. Land availability, population density and productivity-related factors such as soil fertility and labour requirements are not the only factors that affect fallow length and land use intensification in shifting cultivation agroforestry systems. Households surveyed indicated that various other decision criteria (e.g., proximity to other fields and the protection of land use rights) are important in land use decisions. Even though one quarter of households reported insufficient land resources to maintain soil fertility, few actually indicated that their choices were constrained by land availability. In fact, many cleared much younger fallows than strictly necessary based on the age of fallows available in their land holdings – even those with fallows of sufficient age to maintain long-term productivity. This paper outlines an approach to quantify information about the household preferences that influence land use decisions, discusses the implications of these decision criteria for land use intensification and uses them to model household decision-making in a way that effectively simulates the spatial and dynamic mosaic of land use characteristic of shifting cultivation. Not only are non-productivity related decision criteria important in land use decisions in general; they also have a significant impact on land use intensification. In fact, the research described here demonstrates that both household-specific preferences and household-specific initial conditions can lead to intensification of land use apart from that arising due to increasing population density.

In northern Laos, upland rice is grown as a subsistence crop under rainfed conditions with no fertilizer inputs. It has traditionally been grown under slash-and-burn systems with long fallows, which restore soil fertility and reduce insect and weed pressure. However, increasing population density and government policies aimed at reducing the area under slash-and-burn have reduced fallows to as little as two or three years between rice crops. In this paper the impact of intensifying upland rice cultivation and rainfall on upland rice productivity was evaluated using yield and rainfall data from Luang Prabang province from 1992 to 2004. In addition, an experiment was conducted in 2004 to evaluate the effect of upland rice cropping intensification on soil nitrogen (N) and phosphate (P) availability and root pests (Tetraneura nigriabdominalis-root aphids and Meloidogyne graminicola Golden & Birchfield-nematodes). Rice yields were associated with total rainfall from June through August, corresponding to mid-tillering through flowering growth stages of upland rice. Increased cropping intensity resulted in a significant reduction of upland rice yields with higher rice yields being associated with longer fallows. Furthermore, when rice was annually cropped in the same field without fallows, rice yields rapidly declined. A study conducted in 2004 indicated that increasing cropping intensity reduced the soil N and P availability and increased root aphid infection of rice. The long-term productivity of upland rice can not be sustained with increased cropping intensity using the current management practices. Therefore, improved crop and resource management technologies are necessary for sustainable production.

This paper reviews the theoretical and empirical literature on labor productivity in shifting cultivation systems, and relationships between labor productivity and production parameters are analyzed in two case studies of Iban communities in Sarawak, Malaysia, during two farming seasons. In addition, the labor productivity in shifting cultivation compared to off-farm wage labor opportunities is explored. Establishing firm relationships between labor productivity and production parameters, such as fallow length, fertilizer use, and herbicide use was not possible. We are thus unable to verify or reject the thesis that more labor is required for managing fields after short fallow compared to long fallow periods. We do demonstrate that shifting cultivation of hill rice can compete economically with common off-farm employment opportunities, and conclude that farmers’ decisions to maintain their practices is based as much on economic rationales as on tradition.

Swidden cultivation is the traditional agricultural system in most parts of the Amazonian rain forest. In a remote area in the Manu National Park, Peru, this system was analysed in two indigenous Matsiguenka communities. Diversity of cultivated plants on fields and in homegardens are presented in the current study. Cultivated plants were noted on two to four plots per field on 46 fields, making a total of 126 survey plots. Nineteen homegardens were studied as well. Dominating species cultivated on fields is cassava (Manihot esculenta). Fruit trees such as the peach palm (Bactris gasipaes), guava (Psidium guajava) or Inga edulis, but also cotton (Gossypium barbadense) and a medicinal plant (Cyperus sp.) predominate in more than 75 % of the homegardens analysed. Species diversity increases steadily from 18 and 24 species on 1- and 2-year-old fields to 26, 29 and 66 species in young, medium old and old homegardens, respectively. Seventy-one different species in total were found in all homegardens analysed and 25 in swidden fields. Diversity of species cultivated in homegardens is low compared to other studies in the rain forest of the Amazon. This seems to be due to their remoteness from the next urban centre and to the fact that they are native communities with still low external exchange of information. These findings are in contrast to the hypothesis that remoteness from urban centres increases species richness because subsistence production is based on a broad variety of species. In contrast to species richness in homegardens, differences in species richness in swidden fields between the present and other studies could not be found.

Farmers are often blamed for destroying the tropical forest, especially in Laos. Converting shifting cultivation into cash crop based agriculture is frequently presented as the solution for merging forest protection and poverty alleviation, but many attempts have ended in failure. A rural development project has attempted to introduce medicinal cardamom (Amomum villosum) cultivation in the notably remote region of Phongsaly (northern Laos), for export to China. With nearly 300 ha planted, the crop now involves about 75% of the farmers in the region. Farmers fitted cardamom into their farming system, to suit their needs for sustainability with a crop compatible with existing practices. Results indicate that introducing a cash crop into a shifting cultivation region is possible if a greater attention is paid to: (i) appraise how the new crop fits into the farming systems; (ii) prioritise economic issues over agronomic matters, in particular identify markets, traders or commercial risks.

Trade theory predicts that the expansion of markets induces households to specialize and intensify production. We use plot-level data (n = 64) from a panel study of 2 village and cross-sectional data from 511 households in 59 villages of Tsimane’ Amerindians (Bolivia) to test the predictions. Results of bivariate analyses using both data sets suggest that as households integrate into the market economy they: (1) deforest more, (2) expand the area under rice cultivation, the principal cash crop, (3) sell more rice, and (4) intensify production by replanting more and by replanting newly cleared plots with maize, another cash crop. Results mesh with predictions about production specialization and intensification of trade theory. The analysis also produced results running counter to predictions from trade theory. For example, households and villages more integrated into the market planted more cassava and rice varieties, intercropped more, and put more crops in new fields than more autarkic households. Although the expansion of markets induces specialization and intensification in selected cash crops, it does not erase completely agricultural diversity. We hypothesize that despite the expansion of markets, households retain agricultural diversity because the market does not yet provide modern forms of self-insurance or well-functioning labor, credit, and product markets that would allow households to protect food consumption when faced with shocks. Without better insurance mechanisms, some agricultural diversity might still allow households to smooth consumption.

Native food production in the Eastern Woodlands of North America before, and at the time of, European contact has been described by several writers as “slash-and-burn agriculture,” “shifting cultivation,” and even “swidden.” Select quotes from various early explorers, such as John Smith of Pocahontas fame, have been used out of context to support this position. Solid archaeological evidence of such practices is next to non-existent, as are ethnographic parallels from the region. In reality, the best data are documentary. Unlike previous assessments, this paper evaluates sixteenth and seventeenth century ethnohistorical references to anything that can be even remotely construed as supportive of previous claims. Analyzed as a group these sources reveal something completely different from what common knowledge would have us believe. References to the slashing, the burning, and the shifting of fields are reasonably abundant. Rarely, however, are all three activities mentioned in a single passage, or by one chronicler. Furthermore, subtleties often overlooked in these quotes reveal great insight into native practices. This paper assesses explorers' and early settlers' descriptions in the context of the larger body of literature dealing with the ecology of swidden agriculture today. Indigenous fields in the Eastern Woodlands tended to be large, numerous, contiguous, and cleared of roots and stumps. Fields previously cleared of trees were covered with grass prior to preparation for planting. They were permanently cultivated. This condition stands in marked contrast to present-day swidden fields in other parts of the world that tend to be small, few, scattered, partially cleared of trees, and cultivated for only a year or two before being abandoned. Slash-and-burn shifting cultivation became common only after European settlers introduced steel axes. It was then practiced on uplands, not the formerly cultivated floodplains that were usurped by interlopers.

A FLORES-type model in the Simile modelling environment is being developed for three villages in the Humid Forest Benchmark area of southern Cameroon. The modelling project seeks to investigate the effects of introduction of new crop varieties and improved farming systems on the long-term maintenance of stable mosaics of forest and agriculture, within the context of the international Alternatives to Slash and Burn programme. Biophysical data have been collated, and socio-econnomic and tenure data have been acquired in spatially-explicit ways. Maps of land-cover at village and benchmark scale are being prepared from detailed and semi-detailed satellite imagery, using a nested legend system that allows linking of maps at different scales. These data enable the initial construction and parameterisation of the model, and will permit the extrapolation of the results of modelling from the villages to the benchmark, and ultimately to the whole of the Congo Basin humid forests. The prototype version of the model involves 10 households and about 500 land patches, and includes the three agricultural systems dominant in the southern more forested portion of the Benchmark (mixed food-fallow systems, forest melon fields, cocoa plantations) with no rental, sale or other transfer of land. Decision-making at the household level is essentially modelled deterministically, and labour productivity is assumed to be constant between households. This model is now complete, and once it has been adjusted and suitably parameterised, it will be applied to real data from the three test villages. This will require the addition of new farming systems, the introduction of modes of permanent or temporary transfer of land, and modification of the decision model to render it more realistic.

The effects of selective logging and other types of forest exploitation on bird communities are often studied latitudinally, i.e. a contemporaneous comparison of disturbed and pristine areas. Such an approach assumes that before disturbance those areas were equivalent. By comparing communities at a single site before and after disturbance, a so called longitudinal approach does not make that assumption but such studies can be resource intensive. In this study we adopt a latitudinal approach to explore the effects of disturbance on birds, but pay specific attention to whether natural geographically-based variation in the forest ecosystem may be a major contributory factor equal to, or greater than, effects of disturbance. Bird census data were collected from two Indonesian islands, Sumba and Buru. On Sumba the differences between habitat types in terms of species richness, species accumulation rates, and numbers of birds were swamped by simple site differences between the forest blocks sampled. On Buru, disturbed areas were more diverse than mature forest but it was still not possible to discount the effects of natural variation between forest areas. Although the islands support bird faunas which are rather similar in size and origin, local species diversities and abundances were significantly greater on Sumba. Substituting space for time is a common strategy in ecological research but the results of such studies should be viewed with caution.

Archaeobotanical data from Late Neolithic lake-shore dwellings (4300-3500 cal B.C.) in the northern Pre-alpine lowlands are interpreted in different ways. The presence of permanent arable fields as well as arable fields with short fallow phases and shifting cultivation with slash-and-burn has been discussed. To test these hypotheses experimentally we have been conducting tests in a forest northeast of Stuttgart since 1994. The slightly south-exposed experimental area of approximately 4.5 ha on a loess soil is covered by mixed deciduous forest, is available for at least 20 years and has been divided into 34 plots of 30 × 30 m. Up to 2001, five plots were used for experiments. The normal procedure is clearing, burning the dry small timber (less than 10 cm in diameter) and then growing winter cereals (bread wheat) for one season. The yields were between 2000 and 4000 kg grains per ha. The harvest was more or less free from weeds. First attempts with summer crops gave much lower yields of about 1100 kg grains per ha. Continuous cereal growing on the same place in the following years resulted in minimal to zero yields, mainly due to vigorous weed growth. These weeds are not crop weeds, but forest perennials of clearings and forest fringes. Ploughing to remove the weeds is not possible, because of the presence of roots and tree-stumps, most of them still living. Weed regulation by hoeing, burning or cattle grazing remains to be tested. Protection of the crop from game and birds is by fences and nets, but protection from mice seems difficult. In the spectra from the pollen traps, clearing and burning are strongly indicated, but cereal growing only slightly.

Rethinking the relationship between length of fallow and crop yields inshifting cultivation?The theory that a correlation between shortened fallow periods and yielddecline in shifting cultivation exists is questioned in this paper. Thisrelationship has been taken for granted, and because it shows that shiftingcultivation will break down under pressure, it has partly been responsible fornegative government views on shifting cultivation. Yield levels in shiftingcultivation are influenced by a wide range of biophysical, socioeconomic, andcultural factors and it is difficult to isolate fallow length as a singledetermining factor. A total of 330 studies were reviewed and fifteen withempirical data were chosen for in-depth analysis. Although most of the empiricalstudies support the theory, the data sets are often ambiguous and importantparameters are insufficiently taken into account. Several studies found norelationship between fallow length and yield, but these also lack information toverify the validity of the data. It is concluded that empirical studiesfocussing on this problem are needed to fully understand this relationship anddevelop feasible scenarios for the numerous attempts at modelling shiftingcultivation development. Moreover, the use of gloomy `breakdown' scenarios asjustification for improving shifting cultivation should be avoided.

Fallow periods used in slash-and-burn agriculture in the Bragantina region, the oldest agricultural frontier in the Brazilian Amazon, are being reduced. The objective of this study was to analyze the effects of a shortened fallow period on the Bragantina landscape dynamics and equilibrium. Dynamics were characterized by landscape structural changes, particularly in the spatial distribution of secondary forests, and by transition matrix. Equilibrium was defined by temporal and spatial parameters, and by the increment of agricultural areas from 1985 to 1996, analyzed with 6 LANDSAT-TM images. I worked with 6 areas of 250 ha each, 3 with short fallow periods (2‐4 years) and 3 with long fallow periods (about 10 years). Results showed that short fallow period areas did not present an equilibrium situation. In these areas, developed secondary vegetation tended to disappear and agricultural areas were being expanded at an average rate of 3% per year. Landscape structure changes pointed out that a reduction in fallow period was occurring in already short fallow period areas. Long fallow period areas presented a shifting mosaic steady-state condition, where punctual changes due to agricultural uses were compensated by field abandonment rate. Both agricultural uses and field abandonment rates were lower in long fallow period areas when compared with short ones. Comparisons with indigenous traditional cropping-fallow cycles indicate that sustainable conditions could be maintained with 11 years of fallow for each cropping year, while shorter cycles would break down the system if agricultural improvements are not implemented.

The influence of slash-and-burn agriculture and tree extraction on the spatial and temporal pattern of forest fragmentation in two municipalities in the highlands of Chiapas, Mexico was analyzed. The data series were derived from two subsets of satellite images taken in 1974 and 1996. The analysis was based on area, edge, shape, core area, and neighbor indices. During the 22 years, the dense forest decreased by 8.9%/yr in Huistan and by 8.6%/yr in Chanal, while open/disturbed forest, secondary vegetation, and developed area increased in both municipalities. The total number of fragments increased by 1.4%/yr and 2.3%/yr in Huistan and Chanal, respectively. Dense forest showed the highest increase in the number of fragments (6%/yr in Huistan and 12%/yr in Chanal), while edge length, core area, and number of dense forest core areas decreased. The larger fragments of dense forest present in 1974 were divided into smaller fragments in 1996; at the same time, they experienced a process of degradation toward open/disturbed forest and secondary vegetation. Two different fragmentation patterns could be distinguished based on agricultural or forestry activities. Forest fragmentation did not occur as a continuous process; the pattern and degree of fragmentation were functions of land tenure, environmental conditions, and productive activities. The prevalence of rather poor soil conditions, small-holdings, growing human population densities, increasing poverty, and the absence of alternative economic options will maintain a high rate of deforestation and forest fragmentation in the studied region.

Peasants of the northeastern Para cultivate cassava (manioc esculenta) using shifting cultivation. This paper discusses some factors in support of cassava production, even though it has some negative environmental impacts. These factors are the importance of cassava in the region's history, dietary traditions, and the cooperative labor systems employed in its cultivation and processing.

This paper presents an application of an innovative methodological tool for the integrated assessment of farming systems (Multi-Objective Multiple-Scale Integrated Representation). It describes the effect of rural development in parallel on economic and ecological reading at different levels: household, village, and the “commune” comprising 3 villages. Socio-economic and environmental indicators are organized into integrated packages across scales. This is an ex-post facto analysis of a program of rural development implemented in the Central Vietnamese uplands in 1995 by the central government with the collaboration of FAO. We conclude that two classic problems can only be faced by using an integrated analysis across levels: “Large scale” generalizations can miss important “location-specific” characteristics, and exclusive focus on “location specific” issues carries the risk of loosing the “big picture.”

The optimal use of Amazonian flood-recession soils in contexts of dense settlement is, according to many anthropologists, agronomists, and ecologists, the cultivation of proteinaceous cereals and legumes. Storable protein is thought to be necessary for nutritional security through the fish-poor season. Campo Alegre, a Tikuna floodplain community of over 1300 people, is one of the largest indigenous Amazonian communities in the contemporary ethnographic record. Furthermore, some two-thirds of its agricultural production is directed toward market sale. However, in the summers of 1994 and 1995, residents cultivated no proteinaceous crops on their extensive floodplain to store for later consumption. Their utilization of these soils, a relatively new resource for them, is best understood in relation to the intensification of two traditional resource bases—fisheries and upland soils, the resulting pressures on their production flows, and the desire to maintain them.

Vietnam, in the ongoing transition to market economies, has to cope with high rural poverty and a dramatic process of forest loss and environment degradation, particularly in the mountainous regions. The government considers rural poverty as the main cause of environment degradation, associated with slash-and-burn cultivation and to an unclear definition of property rights on forest land. In 1993, the government launched a Forest Land Allocation programme aiming to lease forest lands to individual households and, on this basis, to solve food security problems, halt the increasing environment degradation and preserve the remaining forests.

The most commonly observed change in soil following slash-and-burn clearing of tropical forest is a short-term increase in nutrient availability. Studies of shifting cultivation commonly cite the incorporation of nutrient-rich ash from consumed aboveground biomass into soil as the reason for this change. The effects of soil heating on nutrient availability have been examined only rarely in field studies of slash-and-burn, and soil heating as a mechanism of nutrient release is most often assumed to be of minor importance in the field. Few budgets for above and belowground nutrient flux have been developed in the tropics, and a survey of results from field and laboratory studies indicates that soils are sufficiently heated during most slash-and-burn events, particularly in dry and monsoonal climates, to cause significant, even substantial release of nutrients from non-plant-available into plant-available forms in soil. Conversely, large aboveground losses of nutrients during and after burning often result in low quantities of nutrients that are released to soil. Assessing the biophysical sustainability of an agricultural practice requires detailed information about nutrient flux and loss incurred during management. To this end, current conceptual models of shifting cultivation should be revised to more accurately describe these fluxes and losses.

The shortened fallow period in traditional slash and burn agriculture of the Maya of Quintana Roo, Mexico, has reduced soil fertility, crop yields, biodiversity, and mature forest vegetation. Studies have shown that agroforests that mimic local ecosystem processes can be used to provide for the farmers' well-being while protecting and preserving forest resources and biodiversity. The objective of this investigation was to identify, describe, and evaluate Mayan crop plants that could be used as analog species in agroforest design. We used participant observation, interviews with farmers, and field measurements to collect information on the social, agricultural, and ecological aspects of the plants. We identified five horizontal and one vertical strata in mature homegardens: the herbaceous stratum, the low shrub stratum, the tall shrub stratum, the fruit tree stratum, the timber tree stratum, and the viny stratum. We categorized 77 forbes, shrubs, and vines identified for their temporal and spatial placement in an agroforest. The plants evaluated can be placed in one of the four developmental stages of an agroforest: the herbaceous stage, and the shrub stage, the fruit tree stage, and the timber tree stage. By using the identified plants and the analog hypothesis, we can design an agroecological system that provides for the farmers' needs, and efficiently utilizes the resources on-site for the production of food, timber, medicinal plants, and nontimber products in a manner that protects the natural resource base of the region.

There is a prohibition on the use of modern external inputs, such as chemical fertilizers, in Baduy swidden farming. Ordinarily, the consequence of this in a situation of acute forest pressure would be a decrease in fallow times, and an inevitable depletion of soil fertility. The Baduy (particularly Outer Baduy) have several ways of alleviating this problem, one of which is the introduction of Paraserianthes (Albizia) falcataria. By alternating this commercially valuable perennial leguminous tree with rice, soil fertility is maintained and the socio-economic position of the Baduy improved. As a result, swidden farming, which is considered by the Baduy to be central to their cultural identity, continues to be viable, despite increasing population density and the continuing depletion of mature forest.

Shifting cultivation continues as the economic mainstay of upland communities in many countries in Southeast Asia. However, the conditions that historically underpinned the sustainability of rotations with long fallows have largely vanished. The imperative to evolve more permanent forms of land use has been exacerbated by rapid population growth, gazettement of remnant wildlands into protected areas, and state policies to sedentarize agriculture and discourage the use of fallows and fire. There are many compelling examples where shifting cultivators have successfully managed local resources to solve local problems. Technical approaches to stabilizing and improving productivity of shifting cultivation systems have not been notably successful. Farmer rejection of researcher-driven solutions has led to greater recognition of farmer constraints. This experience underlined the need for participatory, on-farm research approaches to identify solutions. The challenge is to document and evaluate indigenous strategies for intensification of shifting cultivation through a process of research and development. This process involves identification of promising indigenous practices, characterization of the practices, validation of the utility of the practice for other communities, extrapolation to other locations, verification with key farmers, and wide-scale extension.

The national park model originating in the unique circumstances of mid-19th century North America has been widely applied in the developing countries of the late 20th century, provoking numerous land-use conflicts between parks and resident peoples. Key factors in understanding these conflicts are examined using the field experience of the Ranomafana National Park in Madagascar. A conflict management strategy is suggested for alleviating such antagonism and facilitating the investigation of mutually acceptable conservation and development pathways.