Traditional perennial crop-based agroforestry in West Java: the tradeoff between on-farm biodiversity and income

Agroforestry systems have been re-evaluated with a renewed scientific interest as appropriate models for achieving sustainable production while maintaining planned and associated biodiversity and agroecosystem functioning. Traditional bamboo-tree gardens in West Java are known to play substantial ecological and socioeconomic roles. In this study, we attempted to elucidate the relationship between income generation and biodiversity by studying 83 bamboo-tree gardens that varied in species composition and degree of commercialization. We conducted a survey of the vegetation and interviewed the owners or managers of each plot. We identified 42 planned and utilized species and 19 associated non-use species. Eight vegetation groups were identified by two-way indicator species analysis (TWINSPAN), each of which varied in individual densities of different utilization species types, Simpson’s diversity index, management intensities, and potential annual gross income. The group with the highest potential income generation was dominated by clove trees (Syzygium aromaticum); however, this group also had a lower level of diversity and higher levels of management intensity than the other groups, but all of the pairwise groups were not significantly different. About 60% of the villagers used at least some fuelwood as a domestic energy source, and almost all of them collected fuelwood from bamboo-tree gardens regardless of ownership. There were no significant differences in density of potential fuelwood species among the vegetation groups. There were significant positive correlations between income and most management activities. The regression model between gross income and Simpson’s diversity index with the best fit was a unimodal curve, which strongly suggests that maximum diversity can be conserved at an intermediate level of income. Nevertheless, this intermediate level of gross income is probably not adequate as the primary source of income for garden owners, although some gardens had the potential to achieve higher income levels with no decline in diversity. We suggest that maximizing individual density and multistratifying canopy layers could improve profitability within perennial crop-based agroforestry systems in West Java.     

Trade-offs between rubber production and maintenance of diversity: the structure of rubber gardens in West Kalimantan, Indonesia

The goal of this study was to assess the potential of small-holder rubber cultivation in agroforestry gardens to fulfill simultaneously the goals of conservation and sustainable rural development. I examined the structure and species composition of trees in 11 rubber gardens in West Kalimantan, Indonesia, using a single 0.10 ha plot per garden. Although 41 distinct morphotypes were encountered, rubber (Hevea brasiliensis) dominated the sample of 370 trees. Richness within plots varied (3–15 morphotypes), as did the predominance of rubber (24–97% of all basal area, 24–91% of all individuals). The importance of rubber within a garden was significantly negatively correlated with the number of morphotypes present. This result suggests that tree diversity may limit potential productivity of rubber gardens. Thus, small-holders may not be willing to maintain diversity at the scale of a single garden. Although species-accumulation curves indicate that substantial tree diversity may exist across all rubber holdings, diversity is likely to be lost from the system if individual owners reduce species richness in their gardens. Rubber agroforestry as currently practiced in West Kalimantan is not an ideal model for matching rural development needs with the achievement of conservation goals. Other models, such as tengkawang- and durian-based fruit gardens, do exist in Kalimantan and elsewhere, and should be evaluated for incorporation into policy and development strategies.     

Tree plantations on farms: Evaluating growth and potential for success

Interest in native species is growing across the tropics as reforestation of degraded lands becomes more widespread. In this study four tree species native to Panama - Cedrela odorata, Pachira quinata, Samanea saman, and Tabebuia rosea - were grown on rural farms at two dry tropical sites in Panama for up to five years. Survivorship and growth data at these “on-farm” trials are compared to data recorded from nearby experimental or “species selection” trial sites and evaluated in terms of soil fertility and management. Participant farmers were also asked about their interest in planting trees in general as well as their interest in 61 species grown in the species selection trial.Although, on-farm survivorship was variable and generally lower than that found on the species selection trial, one species (S. saman) experienced high and consistent survivorship. High survivorship combined with growth data from farms at both sites for this species suggests it would be a good candidate for extension projects working with rural farmers. Survivorship of other species appears more sensitive to farmer management and/or local site conditions. Generally lower growth on the Los Santos farms as compared to the species-selection trial is attributed to the lower soil fertility (plant available P) at the on-farm sites compared to the species selection trial. In contrast, only one species - P. quinata - had a growth variable found to be significantly lower between the on-farm and species selection trial sites in Rio Hato. C. odorata, P. quinata T. rosea can all be used in on-farm conditions with consideration to specific site and management conditions.By 2009, approximately 80% of the farmers planting trees still wished to participate in tree planting activities. All of the farmers no longer wishing to continue with the project expressed slow growth rates of trees as a principal reason. All but one of these farmers had growth rates for his/her trees markedly below those of the species selection trial nearby. Some farmers wishing to continue had very high mortality rates (>70% for all species), suggesting non-tangible benefits for participating in project activities. Other species that were not tested on-farm but grew well in the species-selection trials and were of interest to local farmers are discussed.As long as specific site and management conditions are carefully considered, data from species selection trials can be useful in informing tree planting projects with rural farmers; however, care should be taken to manage expectations.     

A comparison of mortality rates between top height trees and average site trees

? Although comparisons between methods of selecting trees for site index estimates are well documented in the literature, little is known on mortality rates of different canopy tree cohorts used for that purpose.

? This study was initiated to test the hypothesis that the mortality rates of top height trees are lower than those of codominants only or a combination of codominant and dominant trees. To test this hypothesis, we used records from a network of permanent sample plots in Québec and studied the fate of different cohorts of site trees for five different species.

? Our results did not show clear evidence of lower mortality rates for top height trees. Instead we found that depending on the species, top height trees have lower (Populus tremuloides, Pinus banksiana), higher (Picea mariana, Abies balsamea) or equal mortality rates (Betula papyrifera) than codominant trees or codominant and dominant trees combined.

? These results suggest a tendency for shade intolerant species to maintain lower top height tree mortality rates over time when compared to shade tolerant species. In the latter case, it is also shown that spruce budworm epidemics (Choristoneura fumiferana) did not change the pattern of mortality rates of site trees of A. balsamea.

     

Assessment of plant species diversity of ancient tea garden communities in Yunnan, Southwest of China

Ancient tea garden has existed in Lancang County, Yunnan Province for more than 1,300 years, and is regarded as the provenance of Pu’er Tea’s seed source. The ancient tea garden ecosystem is a typical model that integrates conservation biodiversity and utilization of natural resources. In order to reveal the role of biodiversity conservation of this ecosystem, plant diversity and application value of ancient tea gardens, normal tea gardens and secondary forestry communities in Lancang County were surveyed and compared. 360 households investigation were also conducted by using household-based agro-biodiversity assessment (HH-ABA). The results showed: (1) Ancient tea garden communities have high biodiversity, whose plant species diversity (H = 3.03) is lower than that of secondary forestry (H = 4.59) and higher than that of normal tea garden (H = 2.62); (2) Life forms analysis of plant species showed the vertical structure of the ancient tea garden communities are intact, herbs, trees, shrubs, vines, epiphytes are included, which is similar to that of secondary forest, while normal tea garden is dominant by herbs and no trees; (3) A large number of protected species, including five endangered, seven vulnerable and three rare, is well conserved in the ancient tea garden, while no protected species were found in secondary forest and normal tea garden; (4) The analysis of agro-biodiversity revealed that 56 % of plant species in the ancient tea garden are effectively used by households, while no plant except tea trees is used in normal tea garden; (5) The integrated values of ancient tea garden and normal tea garden illustrated that both biodiversity conservation and economic income of ancient tea garden are higher than that of normal tea garden. We suggest that the local peoples’ knowledge and experience on resource management and utilization should be well documented and encouraged, and effective conservation and reasonable utilization of ancient tea garden would be achieved through training and demonstration with the participation of the local government, research institution and farmer.     

Essential oil production increases value of Psiadia altissima fallows in Madagascar’s eastern forests

Fallow with Psiadia altissima is one of the most common post-‘slash and burn’ vegetation successions described in the evergreen forests of eastern Madagascar. Some fallows consist of almost pure stands of this species, of which the leaves produce an essential oil offering international commercial interest. The present research aims to evaluate the production potential of essential oil derived from different fallows rich in P. altissima. The study has revealed that fallows aged 4 and 6 years since the last crop abandonment produce the most essential oil (around 20 l ha⁻¹), but relative to fallow duration, the youngest fallows (1- or 2-year-old) are the most productive, respectively producing 12 and 6 l ha⁻¹ year⁻¹. Additionally, the trees from the youngest fallows have a substantial capacity for regeneration from coppice shoots, on condition that the cut is performed well above the root collar. Although farmers earn five times less from harvesting leaves than from cultivating rice from tavy, the possibility is there for them to complement their income and diversify their production. The overall results show that sustainable exploitation of fallows of P. altissima is a conceivable option. However, this can only be achieved through an integrated approach that takes into account the environmental and social constraints associated with the development of this new activity.     

Biosocial and bionumerical diversity of variously sized home gardens in Tabasco, Mexico

The evaluation of species and structural diversity of home gardens strongly depends on the methods used. We distinguish the biosocial and the bionumerical method. The first is widely used and takes data of the whole population of trees of home gardens to calculate diversity. The bionumerical method calculates diversity from data of a fixed number of randomly selected trees. We apply both methods to analyze if structural and species diversity varies with home garden size, a theme of considerable conservation interest, and compare results. We inventoried the tree component of a sample of 61 home gardens from rural areas in Tabasco, Mexico, which we assigned to three size categories: small (≤1,000 m²), medium sized (>1,000 and ≤2,000 m²), and large home gardens (>2,000 m²). Average species richness and Shannon diversity indices determined by the biosocial method were significantly different among home garden size classes. Average species richness determined by the bionumerical method did not differ among size classes. Both methods showed highest total observed and estimated species richness in the large home gardens, which contain many unique species. Both methods showed similar overall species composition among size classes and highest structural diversity in large home gardens. We conclude that it is important for conservation to maintain large home gardens in local mosaics, and that the biosocial and bionumerical methods are complementary. The bionumerical method allows straight comparison of population diversity within and among systems, but lacks attention for rare and unique species. The biosocial method evaluates how much diversity families custody.     

Traditional agroforestry practices in Zimbabwe

Traditional agroforestry systems in the communal areas of Zimbabwe are described. There are systems centered on main fields, on home gardens, on homesites and on grazing areas. In the main fields, the major tree-related management practice is the conservation of preferred indigenous fruit trees. Fruit trees are also the focus of forestry activities around the gardens and the homesite; but here it is the planting of exotic species. In a localized area of Zimbabwe Acacia albida is important in fields. There is almost no use of tree fallows in Zimbabwe. Trees in grazing areas have numerous roles, but at present there is little knowledge about traditional management practices in these areas. In the development of agroforestry systems in Zimbabwe it is suggested that those systems designed to improve fodder production will make a significant contribution to farm productivity because of the importance of cattle in the farming system and the present fodder shortage. Interventions involving the planting of fruit trees are likely to be very successful, as there is much interest in such planting. Another area that needs to be developed is that of tree plantings to improve soil fertility.     

Factors Affecting Small-Scale Farmers’ Land Allocation and Tree Density Decisions in an <Emphasis Type="Italic">Acacia decurrens</Emphasis>-Based <Emphasis Type="Italic">taungya</Emphasis> System in Fagita Lekoma District,North-Western Ethiopia

The development of woodlots as an additional source of livelihood and as a land management option for small-scale farmers is a challenging issue in the cereal-based subsistence farming systems of north-western Ethiopia. There is a need to understand why and which factors determine the decisions of small-scale farmers to grow short-rotation woodlots on their land. Data used in this study were collected from a survey of 200 randomly selected households in the region. A Tobit regression model was used to determine predictor variables for farmers’ decisions to allocate land to planting Acacia decurrens (J.C. Wendl.) Willd. and at what density trees are planted on the respective plots. The most important motivations for planting A. decurrens were income, soil fertility management, and soil and water conservation. Having a male head of household, long distance to markets and plots being on marginal land, among other factors, increased the allocation of land to A. decurrens woodlots. Having a male head of household, access to credit and plots being on marginal land, among other factors, increased tree planting density. Age had a negative effect on both allocation of land to woodlots and tree density, whereas farm size had an inverted U-shaped relationship with both decisions. These results suggest that wider expansion of A. decurrens-based plantation systems could be achieved through improving extension, credit access and road infrastructure to connect small-scale farmers to markets and finance.     

Guava (Psidium guajava L.) trees in a pasture: population model,sensitivity analyses,and applications

A preliminary demographic model is presented for a population of guava (Psidium guajava L.) trees in a pasture. In this paper special attention is devoted to describing both the calculation and testing of the parameters of the model. Some applications of the model are described. It is predicted that the guava population will gradually decline; low seedling survival (due to chemical control of pasture weeds) seems to be the factor governing this trend. Preliminary analyses of total gross energy production and economic income, with and without the guavas, favours the presence of the trees in pastures.     

Twentieth-century decline of large-diameter trees in Yosemite National Park,California, USA

Studies of forest change in western North America often focus on increased densities of small-diameter trees rather than on changes in the large tree component. Large trees generally have lower rates of mortality than small trees and are more resilient to climate change, but these assumptions have rarely been examined in long-term studies. We combined data from 655 historical (1932–1936) and 210 modern (1988–1999) vegetation plots to examine changes in density of large-diameter trees in Yosemite National Park (3027 km²). We tested the assumption of stability for large-diameter trees, as both individual species and communities of large-diameter trees. Between the 1930s and 1990s, large-diameter tree density in Yosemite declined 24%. Although the decrease was apparent in all forest types, declines were greatest in subalpine and upper montane forests (57.0% of park area), and least in lower montane forests (15.3% of park area). Large-diameter tree densities of 11 species declined while only 3 species increased. Four general patterns emerged: (1) Pinus albicaulis, Quercus chrysolepis, and Quercus kelloggii had increases in density of large-diameter trees occur throughout their ranges; (2) Pinus jeffreyi, Pinus lambertiana, and Pinus ponderosa, had disproportionately larger decreases in large-diameter tree densities in lower-elevation portions of their ranges; (3) Abies concolor and Pinus contorta, had approximately uniform decreases in large-diameter trees throughout their elevational ranges; and (4) Abies magnifica, Calocedrus decurrens, Juniperus occidentalis, Pinus monticola, Pseudotsuga menziesii, and Tsuga mertensiana displayed little or no change in large-diameter tree densities. In Pinus ponderosa–Calocedrus decurrens forests, modern large-diameter tree densities were equivalent whether or not plots had burned since 1936. However, in unburned plots, the large-diameter trees were predominantly A. concolor, C. decurrens, and Q. chrysolepis, whereas P. ponderosa dominated the large-diameter component of burned plots. Densities of large-diameter P. ponderosa were 8.1 trees ha⁻¹ in plots that had experienced fire, but only 0.5 trees ha⁻¹ in plots that remained unburned.     

Guava (Psidium guajava L.) trees in a pasture: population model,sensitivity analyses,and applications

A preliminary demographic model is presented for a population of guava (Psidium guajava L.) trees in a pasture. In this paper special attention is devoted to describing both the calculation and testing of the parameters of the model. Some applications of the model are described. It is predicted that the guava population will gradually decline; low seedling survival (due to chemical control of pasture weeds) seems to be the factor governing this trend. Preliminary analyses of total gross energy production and economic income, with and without the guavas, favours the presence of the trees in pastures.     

Chemical components of hardwood barks stripped by the alien squirrel Callosciurus erythraeus in Japan

The Pallas squirrel (Callosciurus erythraeus; common name in Japan: Formosan squirrel) was introduced in the 1950s and has established populations throughout southeastern Kanagawa Prefecture, Japan. Some tree species in natural forests, parks, and gardens in residential areas have been intensively debarked by the squirrels, especially in winter and spring. The amounts of chemical components, such as polyphenols, resins, flavanols, and sugars, in the bark were compared among species and individual trees collected in the forest of Yokohama Nature Sanctuary. Interspecific differences in the extent of stripping were not related to the amounts of the four chemical components. For individual trees, the bark with feeding scars tended to contain more sugar than that without scars.     

Physiological response of irrigated and non-irrigated Norway spruce trees as a consequence of drought in field conditions

Physiological reactions of 25-year-old Norway spruce (Picea abies (L.) Karst.) trees to drought were examined during 2009 vegetation period. During the second half of summer, the decrease in soil water content was observed and irrigation was applied to a group of spruce trees, while the second group was treated under natural soil drought. The response to water deficit was recorded at the level of leaf water potential (Ψ_L). However, it appears that Ψ_L plays minor role in early stomata regulation of Norway spruce as CO₂ assimilation rate (P _N) and stomatal conductance (g _S) were reduced already before water potential decrease. Leaf water potential decreased significantly only in case when soil water content was low in the long run and when transpiration losses were simultaneously relatively high. Almost complete stomatal closure even of the irrigated trees was caused by the increase in the vapour pressure deficit of the air (D) above the value of approximately 1.5?kPa. Low values of D were accompanied by partial stomata opening of drought-treated trees. In non-irrigated spruce trees, the values of P _N decreased by 35–55% in comparison with irrigated trees. No drought-induced significant changes were found either in chlorophyll and carotenoid concentration (chl a?+?b, car) or in maximal photochemical efficiency of photosystem II (F _v/F _m). High rates of sap flow (F) did not always lead to stomatal closure during midday. It?appears that high transpiration rates do not control stomatal response to D.     

Effect on maize growth of the interaction between increased nitrogen availability and competition with trees in alley cropping

Maize growing next toErythrina hedgerows had 44% lower biomass (p<0.01) and 35% lower N content (p<0.1) than maize growing in the middle of the alleys. Maize growing next toGliricidia hedgerows had the same biomass but 56% higher N content (p<0.1) than maize growing in the middle of the alleys. However these differences did not develop until 2 months after sowing of the maize.Spatial variability in soil nitrogen mineralization and mulch nitrogen release did not explain any of the differences in growth or N uptake of the maize with respect to distance from the trees. It is hypothesized that the slower growth of the maize next to theErythrina trees after 2 months is due to increasing light and/or nutrient competition from the trees as the trees recover from pollarding. The apparent lack of competition fromGlirigidia may be due to different rates of regrowth or different shoot and root architecture.A theoretical model is described demonstrating that if a crop is to take advantage of the higher nutrient availability under alley cropping it must complete the major part of its growth before the trees recover significantly from pollarding, and start competing strongly with the crop.     

Response of bark beetles and their natural enemies to fire and fire surrogate treatments in mixed-conifer forests in western Montana

Four treatments (control, burn-only, thin-only, and thin-and-burn) were evaluated for their effects on bark beetle-caused mortality in both the short-term (one to four years) and the long-term (seven years) in mixed-conifer forests in western Montana, USA. In addition to assessing bark beetle responses to these treatments, we also measured natural enemy landing rates and resin flow of ponderosa pine (Pinus ponderosa) the season fire treatments were implemented. All bark beetles were present at low population levels (non-outbreak) for the duration of the study. Post-treatment mortality of trees due to bark beetles was lowest in the thin-only and control units and highest in the units receiving burns. Three tree-killing bark beetle species responded positively to fire treatments: Douglas-fir beetle (Dendroctonus pseudotsugae), pine engraver (Ips pini), and western pine beetle (Dendroctonus brevicomis). Red turpentine beetle (Dendroctonus valens) responded positively to fire treatments, but never caused mortality. Three fire damage variables tested (height of crown scorch, percent circumference of the tree bole scorched, or degree of ground char) were significant factors in predicting beetle attack on trees. Douglas-fir beetle and pine engraver responded rapidly to increased availability of resources (fire-damaged trees); however, successful attacks dropped rapidly once these resources were depleted. Movement to green trees by pine engraver was not observed in plots receiving fire treatments, or in thinned plots where slash supported substantial reproduction by this beetle. The fourth tree-killing beetle present at the site, the mountain pine beetle, did not exhibit responses to any treatment. Natural enemies generally arrived at trees the same time as host bark beetles. However, the landing rates of only one, Medetera spp., was affected by treatment. This predator responded positively to thinning treatments. This insect was present in very high numbers indicating a regulatory effect on beetles, at least in the short-term, in thinned stands. Resin flow decreased from June to August. However, resin flow was significantly higher in trees in August than in June in fire treatments. Increased flow in burned trees later in the season did not affect beetle attack success. Overall, responses by beetles to treatments were short-term and limited to fire-damaged trees. Expansions into green trees did not occur. This lack of spread was likely due to a combination of high tree vigor in residual stands and low background populations of bark beetles.     

Modelling species and spacing effects on root zone water dynamics using Hydrus-2D in an Amazonian agroforestry system

Modelling the root zone water dynamics in a tree crop agroforestry system is a useful approach to understanding small-scale effects in tree crop systems and may be helpful for optimizing tree spacing in agroforestry system planning. The agroforestry system in this study consists of the species Theobroma grandiflorum (Willd ex Spreng) Schum (Cupuaçu), Bactris gasipaes H.B.K. (peach palm) and the cover crop Pueraria phaseoloides (Roxb.) Benth (Pueraria). The soiltype is an oxisol. Calibration was conducted for each of the three species separately. Calibration results show good conformity between simulated and measured data. Simulated scenarios examine the influence of different spacing between trees on root water uptake, evaporation and drainage. Mean interception and crop factors of the whole flow region vary with spacing or are held constant to examine below-ground effects only. Also a fictitious scenario of an older agroforestry system with deeper roots is calculated. In order to overcome restrictions of the computer program Hydrus-2D, correction factors in the root zone were introduced and a calculation scheme for root water uptake of a flow subregion was developped. Below-ground effects of spacing between trees are not or almost not present, but the depth of the tree roots has a significant influence on root water uptake, evaporation and drainage. When mean interception and crop factor vary, drainage increases and root water uptake decreases slightly with spacing. The modelling approach has been found promising for optimizing agroforestry systems although it can only be seen as a first beginning. In an agroforestry systems under drier conditions differences in results will probably be larger.     

Species selection in hardwoods research: variations in baseline physiological responses of select temperate hardwood tree species

Drought periods are becoming more extreme worldwide and the ability of plants to contribute towards atmospheric flux is being compromised. Properly functioning stomata provide an exit for water that has been absorbed by the roots, funneled into various cell parts, and eventually released into the atmosphere via transpiration. By observing the effects that weather conditions such as climate change may have on stomatal density, distribution, and functioning, it may be possible to elucidate a portion of the mechanisms trees use to survive longer periods of water stress. This study analyzed stomatal density (SD), stomatal conductance (gs ), CO2 assimilation (A), instantaneous water-use efficiency (WUEi ), and transpiration (E) rates in six native tree species in the Midwestern USA and showed that trees within the same ecotype followed similar trends, but that trees within the same family did not when exposed to identical greenhouse conditions. Naturally drought tolerant tree species demonstrated lower g s and higher WUEi , while intolerant species had higher SD. This study showed negative or no correlation between SD and g s , A, E, and WUEi and positive correlations between E and A and gs and E.     

Deterioration of a sustainable agro-silvo-pastoral system in the Sudan: the gum gardens of Kordofan

The development and establishment of agroforestry systems is often suggested as a way to stabilize rural economies in developing countries [King, 1979]. At the same time, some traditional systems are being lost, due to an inability to protect the perennial or tree crop components of the system. These traditional systems and the forces that reinforce or destroy them should be carefully studied by those in the process of encouraging adoption of agroforestry systems in the developing world. The gum gardens of Western Sudan are a case in point.Acacia senegal (hashab) andAcacia seyal (talh) are the two major marketable gum-producing trees found in the western region of Sudan. TheAcacias are grown as part of an agro-silvo-pastoral system that has persisted for more than a hundred years in Kordofan Province, where 70% of Sudan's gum Arabic was once produced, as well as most of its grain and livestock products. After a lengthy drought lasting from 1979 to 1985 gum production in Sudan drastically decreased. It was reported that pest attacks and drought were major causal agents in the decline of gum production [Awouda, 1989; Sungar, 1986]. A survey executed in Northern Kordofan Province, starting in August of 1986, did uncover a great number of deadAcacias due to drought and pest attack, but from interviews with gum farmers we conclude that the decline in gum production is largely due to unfavorable socioeconomic relationships exacerbated by the drought, leading to the deterioration of the agroforestry system of production. An inability to get a fair price for gum at the local level and increasing emphasis on a cash economy led to the neglect of the tree components of the system. The gum gardens have long flourished with the intensive husbandry of small-scale farmers. Once these farmers were no longer able to care for them, the gum trees disappeared from the system, indicating that a lack of community stability can be fatal to even a well-developed agroforestry system.     

Mango trees as components of agroforestry sytsems in Mangwende,Zimbabwe

This study investigates the role of mango (Manifera indica L.) within agroforestry systems in Mangwende, Zimbabwe. Eighty two percent of households had mango trees. Neither the degree of natural woodland depletion nor the wealth status of a household had an influence on mango planting. Most mango trees were planted in the homefields. Mango trees provide fruit, firewood, poles, organic matter for soil amendment, living fence post, shade, soil conservation and cattle feed (the rotting fruits). Wealthy and poor households managed mango trees in the same way. Trees were pruned primarily to increase fruit yields and to reduce competition with crops, although prunings were utilised for firewood and poles. The relative importance of different uses of mango trees did not differ among households with different numbers of mango trees or with different wealth status, with fruits universally acknowledged as the most important product. Ninety four percent of households sold mangoes from their farms, but mangoes earned farmers the least income, in comparison with the four most important crops grown in Mangwende. Two thirds of households intercropped mangoes with herbaceous crops. The mangocrop associations were managed to optimise the yields of both crops and mangoes. Mango trees on croplands were widely perceived as having a positive effect on soil fertility and soil moisture and a negative effect on crop yield. About one third of the households used mango litter for soil amelioration, while litter from indigenous woodland was used by most households, especially in gardens.