Shade trees: a determinant to the relative success of organic versus conventional coffee production

Greater understanding of the influences on long-term coffee productivity are needed to develop systems that are profitable, while maximizing ecosystem services and lowering negative environmental impacts. We examine a long-term experiment (15 years) established in Costa Rica in 2000 and compare intensive conventional (IC) coffee production under full sun with 19 agroforestry systems combining timber and service tree species with contrasting characteristics, with conventional and organic managements of different intensities. We assessed productivity through coffee yield and coffee morphological characteristics. IC had the highest productivity but had the highest yield bienniality; in the agroforestry systems productivity was similar for moderate conventional (MC) and intensive organic (IO) treatments (yield 5.3 vs. 5.0 t ha^?1 year^?1). Significantly lower yields were observed under shade than full sun, but coffee morphology was similar. Low input organic production (LO) declined to zero under the shade of the non-legume timber tree Terminalia amazonia but when legume tree species were chosen (Erythrina poepiggiana, Chloroleucon eurycyclum) LO coffee yield was not significantly different than for IO. For the first 6 years, coffee yield was higher under the shade of timber trees (Chloroleucon and Terminalia), while in the subsequent 7 years, Erythrina systems were more productive; presumably this is due to lower shade covers. If IC full sun plantations are not affordable or desired in the future, organic production is an interesting alternative with similar productivity to MC management and in LO systems incorporation of legume tree species is shown to be essential.     

Transpiration of Arabica Coffee and Associated Shade Tree Species in Sub-optimal, Low-altitude Conditions of Costa Rica

Sap flows of coffee (Coffea arabica L. cv ‘Costa Rica 95’) and associated timber trees (Eucalyptus deglupta or Terminalia ivorensis) or leguminous tree (Erythrina poeppigiana) were measured simultaneously during 12 months in 4-year-old coffee agroforestry systems in sub-optimal ecological conditions of Costa Rica. In the wet period, coffee and shade tree transpiration followed the daily patterns of photosynthetic photon flux density (PPFD) and reference evapotranspiration (ETo) while their transpiration was restricted at higher air VPD values (>1.5 kPa) registered during the dry period. Coffee transpired more per unit leaf area in full sun than under shade, an indication of higher environmental coffee stress in non shaded conditions. Nonetheless, coffee daily water consumption per hectare was generally higher under shade than in full sun due higher vegetative growth of shade-grown coffee plants. Minimum and maximum daily transpiration were 0.74 and 4.08 mm for coffee, 0.35 and 1.06 mm for E. deglupta, 0.70 and 2.10 mm for T. ivorensis and 0.13 and 0.79 mm for E. poeppigiana. Estimation of the annual combined water transpiration by coffee and shade trees was 20–250% higher than that of coffee grown in full sun. Nevertheless, there was no evidence that water use by associated trees decreased soil water availability for coffee and hence limited coffee transpiration in the dry season due to its relatively short length (3 months) and the high annual rainfall (over 3100 mm). In the sub-optimal, low altitude conditions of this experiment, E. deglupta was the optimum shade species as it maintained a more constant shade level throughout the year and ensured a better protection to coffee underneath than T. ivorensis and E. poeppigiana which underwent a complete defoliation during the adverse meteorological conditions of the dry period.     

Effects of <Emphasis Type="Italic">Inga densiflora</Emphasis> on the microclimate of coffee (<Emphasis Type="Italic">Coffea arabica</Emphasis> L.) and overall biomass under optimal growing conditions in Costa Rica

The advantages of associating shade trees in coffee agroforestry systems (AFS) are generally thought to be restricted mostly to poor soil and sub-optimal ecological conditions for coffee cultivation whereas their role in optimal conditions remains controversial. Thus, the objective of this study was to investigate, under the optimal coffee cultivation conditions of the Central Valley of Costa Rica, the impact of Inga densiflora, a very common shade tree in Central America, on the microclimate, yield and vegetative development of shaded coffee in comparison to coffee monoculture (MC). Maximum temperature of shaded coffee leaves was reduced by up to 5°C relative to coffee leaf temperature in MC. The minimum air temperature at night was 0.5°C higher in AFS than air temperature in MC demonstrating the buffering effects of shade trees. As judged by the lower relative extractable water (REW) in the deep soil layers during the dry season, water use in AFS was higher than in MC. Nevertheless, competition for water between coffee and associated trees was assumed to be limited as REW in the 0–150 cm soil layer was always higher than 0.3 in shaded coffee compared to 0.4 in monoculture. Coffee production was quite similar in both systems during the establishment of shade trees, however a yield decrease of 30% was observed in AFS compared to MC with a decrease in radiation transmittance to less than 40% during the latter years in the absence of an adequate shade tree pruning. As a result of the high contribution (60%) of shade trees to overall biomass, permanent aerial biomass accumulation in AFS amounted to two times the biomass accumulated in MC after 7 years. Thus provided an adequate pruning, Inga-shaded plantations appeared more advantageous than MC in optimal conditions, especially considering the fact that coffee AFS provides high quality coffee, farmers’ revenue diversification and environmental benefits.     

Coffee agroforestry systems in Central America: I. A review of quantitative information on physiological and ecological processes

Research on coffee agroforestry systems in Central America has identified various environmental factors, management strategies and plant characteristics that affect growth, yield and the impact of the systems on the environment. Much of this literature is not quantitative, and it remains difficult to optimise growing area selection, shade tree use and management. To assist in this optimisation we developed a simple dynamic model of coffee agroforestry systems. The model includes the physiology of vegetative and reproductive growth of coffee plants, and its response to different growing conditions. This is integrated into a plot-scale model of coffee and shade tree growth which includes competition for light, water and nutrients and allows for management treatments such as spacing, thinning, pruning and fertilising. Because of the limited availability of quantitative information, model parameterisation remains fraught with uncertainty, but model behaviour seems consistent with observations. We show examples of how the model can be used to examine trade-offs between increasing coffee and tree productivity, and between maximising productivity and limiting the impact of the system on the environment.     

Coffee agroforestry systems in Central America: II. Development of a simple process-based model and preliminary results

Research on coffee agroforestry systems in Central America has identified various environmental factors, management strategies and plant characteristics that affect growth, yield and the impact of the systems on the environment. Much of this literature is not quantitative, and it remains difficult to optimise growing area selection, shade tree use and management. To assist in this optimisation we developed a simple dynamic model of coffee agroforestry systems. The model includes the physiology of vegetative and reproductive growth of coffee plants, and its response to different growing conditions. This is integrated into a plot-scale model of coffee and shade tree growth which includes competition for light, water and nutrients and allows for management treatments such as spacing, thinning, pruning and fertilising. Because of the limited availability of quantitative information, model parameterisation remains fraught with uncertainty, but model behaviour seems consistent with observations. We show examples of how the model can be used to examine trade-offs between increasing coffee and tree productivity, and between maximising productivity and limiting the impact of the system on the environment.     

Coffee agroecosystem performance under full sun, shade, conventional and organic management regimes in Central America

Changes in coffee economics are leading producers to reduce agrochemical use and increase the use of shade. Research is needed on how to balance the competition from shade trees with the provision of ecological services to the coffee. In 2000, long-term coffee experiments were established in Costa Rica and Nicaragua to compare coffee agroecosystem performance under full sun, legume and non-legume shade types, and intensive and moderate conventional and organic inputs. Coffee yield from intensive organic production was not significantly different from intensive conventional in Nicaragua, but in Costa Rica it was lower during three of the six harvests. Full sun coffee production over 6 years was greater than shaded coffee in Costa Rica (61.8 vs. 44.7 t ha^?1, P = 0.0002). In Nicaragua, full sun coffee production over 5 years (32.1 t ha^?1) was equal to coffee with shade that included Tabebuia rosea (Bertol.) DC., (27?C30 t ha^?1) and both were more productive (P = 0.03) than coffee shaded with Inga laurina (Sw.) Willd. (21.6 t ha^?1). Moderate input organic production was significantly lower than other managements under all shade types, except in the presence of Erythrina poepiggina (Walp.) O.F. Cook. Inga and Erythrina had greater basal area and nutrient recycling from prunings than other shade species. Intensive organic production increased soil pH and P, and had higher K compared to moderate conventional. Although legume shade trees potentially provide ecological services to associated coffee, this depends on management of the competition from those same trees.     

Assessment of small mammal diversity in coffee agroforestry in the Western Ghats,India

Coffee agroforestry is a conservation strategy that has shown promise to support the diversity of bird, bat, and insect communities, but few studies have focused on non-volant mammals in coffee farms. We assessed mammal diversity within coffee agroforestry systems in Kodagu, India and investigated the impacts of the non-native shade tree species, Grevillea robusta, on mammal diversity. Twenty farms, with varying amounts of G. robusta planted within the coffee farm, were sampled throughout three rainfall zones during the 4-month study period. We captured six species of small mammals, with indirect methods yielding an additional five species, totaling 11 mammal species. Contrary to current ecological thought, we found that increased amounts of G. robusta did not have a negative impact on either abundance or richness of mammals. Small mammal abundances were higher at farms with greater amounts of herbaceous ground cover and larger, mature shade trees, while small mammal species richness was found to increase with an increase in tree species richness as well as greater amounts of herbaceous ground cover. Additionally, small mammal abundance was higher at coffee farms closer to forested areas. Based on these findings, we suggest the maintenance or cultivation of shade tree richness, mature shade trees, and herbaceous ground cover within coffee farms and preservation of forested areas within the landscape to enhance coffee agroforestry habitat for non-volant mammals. We hope that these habitat requirements will be incorporated into conservation strategies for the promotion of biodiversity within coffee agroforestry systems.     

Litter production and nutrient cycling in coffee (Coffea arabica) or cacao (Theobroma cacao) plantations with shade trees

The relative importance of N fixation, organic material inputs and nutrient inputs in litterfall, as justifications for including shade trees in plantations of coffee or cacao, is discussed. According to existing data, N fixation by leguminous shade trees does not exceed 60 kg.N/ha/a. However, these trees contribute 5,000–10,000 kg. organic material/ha/a.Comparisons are made between the leguminous shade tree Erythrina poeppigiana and the non-leguminous timber tree Cordia alliodora. The former, when pruned 2 or 3 times/a., can return to the litter layer the same amount of nutrients that are applied to coffee plantations via inorganic fertilizers, even at the highest recommended rates for Costa Rica of 270 kg.N, 60 kg.P, 150 kg.K/ha/a. The annual nutrient return in this litterfall represents 90–100 percent of the nutrient store in above-ground biomass of E. poeppigiana, and hence the consequences of competition with the crop should not be a serious limitation. In the case of C. alliodora, which is not pruned, nutrient storage in the tree stems, especially of K, is a potential limiting factor to both crop and tree productivity.It is concluded that, in fertilized plantations of cacao and coffee, litter productivity is a more important shade tree characteristic than N fixation.An early version of this review was presented at the CATIE-IUFRO meeting Los Arboles de Uso Multiple en Sistemas Agroforestales, June 1985, Turrialba, Costa Rica.     

Changes in arboreal ant populations following pruning of coffee shade-treesin Chiapas,Mexico

Reducing or eliminating shade cover in coffee (Coffea arabica L.) agroforestry systems affects fungal disease and pest outbreaks, coffee yields, and can result in biodiversity loss of important predators, such as ants. Less dramatic changes in shade structure or composition may also affect ants. Shade tree pruning, a common management practice in shaded coffee systems, has unknown consequences for ant communities. The effects of pruning on arboreal ant communities were investigated by measuring ant abundance, distribution, and species richness in the short (1 week) and long-term (6 months) after shade tree pruning in one 25×50 m plot. Shade tree pruning significantly affected the distribution and abundance of two of the most common ant species (Azteca instabilis F. Smith and Camponotus senex textor Forel), and in general did not affect other ants. After pruning, C. senex textor ants were 80% more abundant on coffee plants and shade trees, whereas A. instabilis abundance dropped by 40% on coffee plants and 73% on shade trees after pruning. Additionally, C. senex textor were significantly more widespread, whereas A. instabilis distributions were more restricted. The effects of pruning were strong over the short-term, but were not evident over the long-term. Shade tree pruning did not affect ant diversity. Thus shade tree pruning largely affected certain aspects of arboreal ant communities in one coffee agroforestry system, with important implications for biological control.     

Effect of pollarding frequency on biomass of Erythrina poeppigiana as a coffee shade tree

The use of pollarded Erythrina poeppigiana as shade tree in coffee plantations is apparently an old practice in Costa Rica. The tree is not native to this country but was introduced between late 19th and 20th century and was rapidly dispersed in the coffee and cacao areas. Currently, the Erythrina tree is widespread in the Turrialba Valley (elevation 600—1300m) and in the Central Valley (elevation 1200m) where the species is always associated with present or past coffee crops. Pollarding carried out by Costa Rican farmers constitutes a long dated and functional practice, hence the objective of this study was to evaluate the amount of biomass produced by pollarding of Erythrina poeppigiana used as shade in coffee crop planted at a density of 280 trees/hectare under different pollarding frequencies. Results showed that by pollarding once a year, 18,470 kg of dry matter per hectare are produced; with two pollardings per year 11,800 kg/ha are produced and with three pollarding per year 7,850 kg/ha are produced. The total amount of nitrogen removed is very similar for pollarding once and twice a year, but is lower for three times a year. The amount of nitrogen removed was approximately 230 kg/ha/year in the first two cases and 170 kg/ha/year in the last one.The above observations suggest that a considerable supply of nutrients exist in the systems with shade trees, when they are periodically pollarded.Finally some conclusions and follow up activities related to research on the species are suggested, such as higher biomass production techniques, appropriate planting practices, selection of genetic material, nutrient depletion when biomass is harvested, conversion of leaves to marketable feed sources (flour, pellets), alley cropping and green manure production and restoration of degraded areas and improductive savannas by planting large cuttings that would improve the soil by adding biomass and shade out undesirable grasses.This work is part of a Ph.D. Dissertation submitted to the Southeastern University, New Orleans, Lousiana by R.O. Russo.     

Allometric models for estimating aboveground biomass of shade trees and coffee bushes grown together

Allometric models for dominant shade tree species and coffee plants (Coffea arabica) were developed for coffee agroforestry systems in Matagalpa, Nicaragua. The studied shade tree species were Cordia alliodora, Juglans olanchana, Inga tonduzzi and I. punctata. The models predict aboveground biomass based on diameter at breast height (for trees), and the stem diameter at a height of 15 cm and plant height (for coffee plants). In addition, the specific gravity of the studied species was determined.The total aboveground biomass of the shade trees varied between 3.5 and 386 kg per tree, and between 0.005 and 2.8 kg per plant for coffee. The aboveground biomass components (foliage, branch, and stem) are closely related with diameter at breast height (r > 0.75). The best-fit models for aboveground biomass of the shade trees were logarithmic, with adjusted R ² between 0.71 and 0.97. In coffee plants, a high correlation was found (r = 0.84) with the stem diameter at 15 cm height, and the best-fit model was logarithmic, as well. The mean specific gravity was 0.52 (± 0.11) for trees and 0.82 (± 0.06) for coffee plants.     

Research methods for multistrata agroforestry systems with coffee and cacao: recommendations from two decades of research at CATIE

This paper reviews the research themes and methodologies used by CATIE in agroforestry research with shade trees over coffee (Coffea arabica) and cacao (Theobroma cacao) during the past 20 years. Initially research focused on characterization and production studies (of crop and timber including border areas) of traditional systems using temporary and permanent sample plots on private farms. The assessment area of traditional shade-coffee (or cacao) systems should be the whole plot, including the border areas, and not some subjectively selected central area which supposedly represents unit area productivity. Uncontrolled crop, tree, and management heterogeneity limited extrapolation of early on-farm research results to other farmers' fields. Replicated case studies of best bet technologies (traditional or experimental) on different farms are often preferable to the use of formal experimental designs. On-station research included the use of systematic spacing designs to test extreme shade tree density treatments of coffee. Most nutrient cycling studies were also carried out on-station, using service and timber shade species over coffee and cacao to evaluate the ability of these agroforestry systems to maintain nutrient reserves and diversify production. Plot size (even 36 × 36 m) was limiting for long term research because of inter-plot interference, both below- and above ground, when using fast growing, tall timber trees as shade. These experiences suggest a minimum plot size of 2,500 m². Individual tree designs and tree-crop interface studies (e.g. regression analysis of data taken along transects) are promising experimental/sampling approaches that need further development. The principal research thrusts proposed for the next five years are bio-physical process research on coffee responses to shade and competition with trees (growth, carbon allocation, phenology, disease-pest tolerance, yields and coffee quality effects) and socioeconomic analyses of both traditional and new or improved shade – coffee combinations vs. monocultures. This revised version was published online in June 2006 with corrections to the Cover Date.     

Growth and yield of coffee plants in agroforestry and monoculture systems in Minas Gerais, Brazil

This research compared coffee plants (Coffea arabica L.) grown in an agroforestry and monoculture systems. Data were collected during two years, on vegetative growth, reproductive development, nutritional status and yield of coffee, besides monitoring air temperature and the tree growth. All trees in agroforestry system increased in growth, resulting in a reduction in the magnitude of the diurnal temperature variation and also maximum temperature. Coffee plants in agroforestry system had less branch growth and leaf production, more persistent and larger leaves, and presented earlier flowering, with a smaller number of productive nodes and flower buds, leading to smaller berry yield than plants in monoculture system. In both systems, the coffee plants showed adequate leaf nutrient levels, except for P and K. The yield of 2443 kg ha^-1 of coffee from the monoculture was greater than 515 kg ha^-1 of coffee from the agroforestry system.     

Semi-forest coffee cultivation and the conservation of Ethiopian Afromontane rainforest fragments

Coffea arabica shrubs are indigenous to the understorey of the moist evergreen montane rainforest of Ethiopia. Semi-forest coffee is harvested from semi-wild plants in forest fragments where farmers thin the upper canopy and annually slash the undergrowth. This traditional method of coffee cultivation is a driver for preservation of indigenous forest cover, differing from other forms of agriculture and land use which tend to reduce forest cover. Because coffee farmers are primarily interested in optimizing coffee productivity, understanding how coffee yield is maximized is necessary to evaluate how, and to what extent, coffee production can be compatible with forest conservation.Abiotic variables and biotic variables of the canopy were recorded in 26 plots within 20 forest fragments managed as semi-forest coffee systems near Jimma, SW Ethiopia. In each plot, coffee shrub characteristics and coffee yield were recorded for four coffee shrubs. Cluster and indicator species analyses were used to differentiate plant communities of shade trees. A multilevel linear mixed model approach was then used to evaluate the effect of abiotic soil variables, shade tree plant community, canopy and stand variables, coffee density and coffee shrub size variables on coffee yield.Climax species of the rainforest were underrepresented in the canopy. There were three impoverished shade tree communities, which differed in tree species composition but did not exhibit significant differences in abiotic soil variables, and did not directly influence coffee yield. Coffee yield was primarily determined by coffee shrub branchiness and basal diameter. At the stand level a reduced crown closure increased coffee yield. Yield was highest for coffee shrubs in stands with crown closure less than median (49 ± 1%). All stands showed a reduced number of stems and a lower canopy compared to values reported for undisturbed moist evergreen montane rainforests.Traditional coffee cultivation is associated to low tree species diversity and simplified forest structure: few stems, low canopy height and low crown closure. Despite intensive human interference some of the climax species are still present and may escape local extinction if they are tolerated and allowed to regenerate. The restoration of healthy populations of climax species is critical to preserve the biodiversity, regeneration capacity, vitality and ecosystem functions of the Ethiopian coffee forests.     

Reducing financial risk in agroforestry planning: a case study in Costa Rica

We used fluctuations in net income from alternative cropping systems to assess the financial risk associated with an agroforestry system. Mean-variance analysis was used to derive a set of minimum-risk farm plans for a 15-hectare farm in Costa Rica. Monocultural coffee production provided the highest expected net income, but also had the greatest economic risk. As risk was reduced, the optimal agroforestry system diversified to include other cropping systems in addition to the coffee monoculture. Risk aversion was, however, accompanied by significant reductions in expected net income for the cropping systems studied. The inclusion of additional cropping systems whose net incomes are negatively correlated with the systems considered here could help reduce the economic risk facing rural agriculturalists in this region.This research was supported by the Utah Agricultural Experiment Station, Utah State University, Logan, Utah 84322-4845. Approved as journal paper no. 4211.     

The pejibaye palm (Bactris gasipaes H.B.K.) as an agroforestry component

The pejibaye palm was domesticated by the Amerindians as part of their indigenous agroforestry systems. The multiple uses of its fruit make it an attractive food species, while high production makes it an attractive economic proposition. Its growth habit is ideal for a canopy strata in some types of agroforestry schemes and, by controlling the number of stems to be maintained, may be modified to fit different species mixes. Several Brazilian mixed cropping experiments are mentioned, although results are not yet available. The Costa Rican experience with pejibaye * coffee mixed cropping is examined, with special reference to Tucurrique, Cartago. Two hectares of pejibaye, with coffee and banana are shown to lucrative. Research needs are discussed, with special emphasis on the question of multiple versus single stemmed plantings and modifications of the pejibaye ideotype for use in multi-stemmed, multi-species plantations. The pejibaye has significant potential for the small farmer and a greater potential if improved for both agroforestry and monoculture.Earlier versions of parts of this paper were presented at the 2nd Reunion IUFRO Working Group 51.07.07 and at the Seminar on Advances in Agroforestry Research, both in Turrialba, Costa Rica.     

Productivity and profitability of multistrata organic versus conventional coffee farms in Costa Rica

In areas where traditional multistrata coffee systems have been transformed to systems with patchy or no shade at all, often dependent on high chemical inputs, ecological and socioeconomic degradation has become an increasing issue. During the 1990s, rising environmental and health concerns have promoted the interest in organic production systems and their environmental services for natural resource conservation. This study compared productivity, profitability, producer-defined constraints, and goals and research priorities between ten individually paired organic and conventional coffee farms in Costa Rica. Although five of the organic farms matched or exceeded the production of their conventional counterparts, the three-year mean yield of the organic farms as a group was 22% lower than that of the conventional farms. However, excluding organic certification costs, mean variable costs and net income (NI) were similar for both groups, mainly because organic price premiums received by the farmers compensated for lower yields. If current organic certification costs are included, the price premiums paid to organic producers would have to increase to 38% in order to equal the NI from conventional coffee. Conventional farmers indentified low and unstable prices as the main constraints to sustained production and stated further intensification of production as their main goal. In contrast, the key issues for future development of the organic group centered on farm diversification, agroecological self-sufficiency, and agronomic practices that permit organic farm management. This revised version was published online in June 2006 with corrections to the Cover Date.     

Coffee Agroforestry Systems for Conservation and Economic Development

Abstract

The agroforestry program of the AMISCONDE Initiative was implemented in 13 buffer zone communities of La Amistad Biosphere Reserve. This program introduced citrus (Citrus spp.) and promoted the widespread inclusion of poró (Erythrina poeppigiana) shade trees, ground story vegetation, and soil conservation techniques to the local cultivation of coffee (Coffea arabica var caturra). This program sought long-term socioeconomic and ecological health in these buffer zone communities through conservation and development projects such as coffee agroforestry systems. This paper examines the ecological and socioeconomic benefits of two introduced coffee agroforestry systems: coffee-poró and coffee-citrus. The project has decreased agrochemical inputs, integrated multi-strata vegetation, and implemented soil conservation techniques such as vetiver grass, cover crops, terraces, water channeling, and shade trees in an effort to sustainably manage coffee production on the steep buffer zone slopes. The agroforestry project of the AMISCONDE Initiative has likely improved the production of coffee ecologically and economically. However, new specialty markets should be explored to increase economic and ecological gains. Organic and fair trade coffee niche markets are suggested as alternatives for meeting the long-term AMISCONDE objectives of community development and conservation.     

A spatial dataset of forest mensuration collected in black pine plantations in central Italy

Key message

The dataset provides an exhaustive tree inventory with forest mensuration and spatial location carried out in 54 plots sampled in 45- to 55-year-old black pine plantations, located in two areas of Tuscany (central Italy). Forest mensuration includes horizontal and vertical structure measurements and a total of 4171 trees were geo-referenced. The most abundant species was the black pine, Pinus nigra spp. laricio , for which a total of 3631 trees were observed. The dataset was collected as part of the SelPiBio LIFE project (LIFE13 BIO/IT/000282). Dataset access at   http://doi.org/10.5281/zenodo.438681 . Associated metadata available at https://metadata-afs.nancy.inra.fr/geonetwork/apps/georchestra/?uuid=73591027-0f1e-40a3-95d0-b614517c1290&hl=eng .

Context

The main aim of the SelPiBio LIFE project (www.selpibio.eu) is to demonstrate the effects of two thinning regimes, selective and from below, on soil biodiversity in young black pine stands. The spatial structure of forests and the relationships between trees are a good proxy of overall biodiversity level. Spatial datasets with geo referenced trees and related mensurational data represent the highest level of information for forest inventories and research activities.

Aims

This dataset has been developed during the A2 Action (Assessment of structural and mensurational parameters of the forest stands and the dead wood) of the project, to record the main mensurational parameters of the studied black pine stands. A tree-level database was compiled to describe the vertical and horizontal structure of 54 monitoring plots before the application of the silvicultural treatment.

Methods

In addition to classical in-field measurements (e.g. diameters at breast height, total height of the tree, crown depth etc.), all trees were georeferenced by means of polar coordinates collected from the centre of each monitoring plot, including crown projection on the ground, described with eight points. Then, a polynomial spline function was fitted across the recorded data to obtain a convex polygon and to calculate crown area and crown perimeter of each measured tree in GIS environment.

Results

A polygonal ESRI shapefile in ETRS89/UTM32N reference system (EPSG: 25832) with 4171 records representing the crown projections on the ground of each measured tree with all the mensurational parameters included into the attribute table. The database is freely available under the Creative Commons Attribution-NonCommercial 4. 182 0 License.

Conclusion

With this database, a wide range of forestry-related indices could be easily calculated, including geostatistical analysis and autocorrelation functions, to compare Italian artificial black pine stands with other studied forests.

     

Coffee yields and soil nutrients under the shades of Inga sp. vs. multiple species in Chiapas, Mexico

For many decades, simplification of traditionally shaded coffee-production systems has been an idealised model for increasing yields. In Mexico, coffee producers have been interested in replacing diverse natural shade with Inga species monocultures due to this practice having the supposed advantages of producing higher coffee yields than diverse shade. However, the effect of different shade systems on yields is little known. The purpose of this study was to evaluate the effect of two types of shaded-coffee systems on coffee yields and soil nutrient content; the first shade system is mainly dominated by Inga latibracteata Harms and the other composed of species-rich natural vegetation. The investigation took place in producer plots in the Francisco I. Madero Community, Municipality of Jitotol, Chiapas, Mexico. Collected data included species richness, shade-tree density, number of strata, tree diameter, tree height, shade-cover percentage, direct and diffused light, coffee yields, soil-nutrient concentrations (N, P, K, Ca and Mg), soil-organic matter and pH. Evaluated shade type did not have an effect on grain yield or soil nutrients. The perceived advantage of the Inga shade system is reduced weed emergence, saving farmers one annual weed-clearing. There was no significant correlation between total N and organic matter. The presence of fewer products and services in comparison to the multiple shade system was thought to be an additional disadvantage to the Inga dominated system. Organic matter in the multiple shade system correlated positively with total N. Due to its complex structure and diversity, the multiple shade system could be certified as shade or bird-friendly coffee. This revised version was published online in June 2006 with corrections to the Cover Date.