One option to sustain full-sun coffee plantation is the use of a “cut-and-carry” system in which a stand of N-fixing trees is grown outside the coffee field and utilized as a source of mulch to capture the benefits of organic matter, nutrient additions, and continuous soil cover. The objectives of this study were to evaluate the potential of a cut-and-carry system of mulch additions from a multipurpose N-fixing tree for open-grown coffee in Hawaii to support high crop yield as well as improved soil organic matter and nitrogen. A stand of Leucaena variety KX2 trees were pollarded every 6 months, and the pollarded material was chipped and added to open-grown coffee plots. Approximately 65 Mg ha−1 of mulch dry matter was added over a 3-year period, including ~27.5 Mg ha−1 of C and ~530 kg ha−1 of total N. Plots without mulch addition were fertilized with equivalent amounts of inorganic N for comparison. Mulch decomposition averaged 64 % (weight basis) over the first year and followed first-order decay dynamics. Net N mineralization was positive by 3 months after addition. There was significant loss of all major biochemical components during the decomposition process. Mulching increased soil CO2 efflux by 2.89 Mg ha−1. Total soil C and N increased by 2.90 and 1.42 Mg ha−1, respectively. Mulch addition significantly increased all measures of coffee growth and yield over 2 years, except for average bean weight. Where space is available or shade is undesirable, a cut-and-carry mulching system using Leucaena-KX2 can increase soil C and N and achieve coffee yields similar to or greater than other full-sun systems.

While socioeconomic and environmental benefits of agroforestry are widely appreciated in the tropics, they were almost neglected from the plans for agronomic development implemented up to early 2000 as set by major policy schemes within the EU. However, such benefits had supported the rural economies of the Mediterranean EU countries—Greece included—in the past. Nowadays several unorganized traditional agroforestry systems persist, rather as remnants, and occupy extensive areas in Greece. Given its recognizable paramount importance as a lever for rural development, the EU included agroforestry in the forthcoming programming period of the Common Agricultural Policy (CAP 2014–2020) as a greening, agro-environmental tool. While the institutional environment in Greece and the EU generally favours the initiation of agroforestry projects, farmers do not have such experience. The present paper sets as its major goals to set up and explore the major characteristics of a Business Model for an agroforestry consulting company (ACC) in Greece, by applying the Pillar/Blocks methodology of Alexander Osterwalder and his co-workers. Details on Customer Value Proposition, Customer Segmentation and Relationship, necessary Resources, Costs and Revenue streams are presented. Greening primary production, sequence of harvests, additional income, prospects for entrepreneurship, and transfer of EU provisions to the farmers are the main Value Propositions of the ACC. Dedicated personal assistance and co-creation are the relationship types expected to be developed with its customers. Key partners are local representatives, academic specialists and stakeholders, while key suppliers are tubex manufacturers, software providers and NGOs. Main revenue streams for the ACC are usage fees, subscription fees and advertising. The establishment of such a consulting company in a central location of the country, such as the region of Thessaly, where the agri-market environment appears promising, is expected to generate additional revenues for farmers that will introduce and/or maintain agroforestry systems and cause major improvements in an area with decreasing soil and water quality and deteriorating landscape values due to intensification of farming over the last decades.

The importance of tropical timber is increasing worldwide. However, the timber supply of tropical forests has been greatly impacted by growing deforestation associated with complex and restrictive timber harvest laws. In Central America, as well as in other developing regions, reforestation programs have often fallen short of expectations. In these cases, agroforestry proves to be a useful strategy for providing tropical timber supplies for smallholder farmers, rural development and environmental services. Timber yields and their potential revenues in four types of agroforestry systems (silvopastoral, coffee, cocoa and living fences) were researched in Nicaragua and Honduras. The results suggest that smallholder timber production in agroforestry systems is a profitable activity despite lower market prices than commanded by timber from forests. The net value from timber sales represents 11–49 % of the total revenue from agroforestry systems. However, this amount could be 58 % higher if farmers were able to improve management practices. Encouraging the knowledge and adoption of silvicultural practices in agroforestry systems is important to increasing timber revenues among smallholder farmers in Central America.

This research investigated the effect of shade from Melia azedarach L. on the physiology, production, and forage quality of Megathyrsus maximus cv. Tanzania and cv. Mombaza, and the Urochloa hybrids Oaxaca and Yacaré. Evaluations were made during the rainy (August 2013) and windy (February 2014) seasons under sun and shade. Mombaza and Tanzania produced more forage biomass (4683 ± 4529 and 4279 ± 4745 kg DM ha−1 harvest−1; P < 0.05) than hybrids, and there was more biomass during the rainy (8236 ± 4257 kg DM ha−1 harvest−1; P < 0.0001) than the windy season, although biomass declined by 44 % (P < 0.05) under shade. Leaf crude protein was similar among grasses (P = 0.516), although Mombaza and Tanzania had higher neutral detergent (49.2 and 50.2 %, respectively; P < 0.05) and acid detergent fiber fractions (34.4 and 34.1 %, respectively; P < 0.05), making them less digestible (61.7 and 61.6 %, respectively; P < 0.05) than the hybrids. Overall, nutritional quality increased during the windy season (P < 0.05) and under shade (P < 0.05). Assimilation of CO2 was greater during the rainy season (P < 0.0001) and under sun (19.1 ± 8.2 vs. 8.6 ± 4.4 µmol m−2 s−1; P < 0.05). The most favorable conditions for biomass production occurred during the rainy season, although nutritional quality was better during the windy season. Shade affects photosynthetic rate and production, and promotes the nutritional quality of all grasses. Oaxaca and Yacaré appear to be more adapted to shade by responding with greater production stability and better forage nutritive quality.

The insertion of leguminous crops into temperate and Mediterranean agroforestry systems where few di-nitrogen-fixing trees can grow is attempted to improve soil N fertility. However, as the microenvironment created by trees could affect plant development, rates of legume growth and biological nitrogen fixation may prove inadequate. In this study, we analyze the nitrogen benefits of chickpea (Cicer arietinum L.) grown in rainfed conditions as a sole crop (SC) or in the alleys of a 15-year old hybrid walnut-based agroforestry system (AF). The fate of N derived from biological fixation by chickpea was assessed with the15N natural abundance method and the amount of N released from roots into the soil by rhizodeposition was quantified for the 0–30 cm horizon using the15N cotton-wick labeling method. The measurements were made in the middle of the crop alley, where the total cumulative radiation received by plants was 90 % of full sunlight, so as to focus on N cycling. The total plant N was 33 % higher in AF than in SC whereas plants had similar N concentrations in vegetative above-ground parts and roots in AF and in SC. This difference was due to a very high N concentration in grains and to twice as much seed biomass in AF plants as in SC ones. The percentage of plant N fixed from the atmosphere by chickpea plants grown in AF was half that in SC. The N rhizodeposition was 47.2 ± 10.2 mg plant−1 and 60.4 ± 15.3 for SC and AF respectively. Considering the chickpea plant density, we estimated the nitrogen soil supply to chickpea at 2.2 and 28.2 kg N ha−1 for SC and AF respectively. In conclusion, our results showed that environmental conditions in the middle of the AF crop alley were beneficial for chickpea growth, seed biomass and quality of the seed, probably because of the combination of a higher mineral N availability (higher N turnover) due to better conditions for organic nitrogen mineralization, created by the trees. The organic matter status and water balance modification after 15 years of agroforestry may increase nutrient availability, even for legumes.

Bamboo-based agroforestry is a promising option for sustainable land management in India. Optimal management of bamboo-based mixed species production systems, however, requires an understanding of bamboo spacing, root activity and distribution of bamboo roots, and the soil nutrient capital of the site. We examined the performance of turmeric as an understorey crop in 7-year old bamboo (Dendrocalamus strictus (Roxb.) Nees) stands of varying spacing treatments (4 × 4, 6 × 6, 8 × 8, 10 × 10 and 12 × 12 m) at Kerala Agricultural University Campus, Thrissur, Kerala, India. In order to better understand turmeric and bamboo growth parameters, soil physico-chemical properties, understorey light availability and turmeric root activity by soil injection of 32P were determined in mixed (turmeric + bamboo) and sole turmeric situations. To characterize root activity, 32P was applied at 10 cm depth to the turmeric plants in raised beds established between the two central rows of bamboo in all experimental plots. Growth attributes of bamboo were recorded and the soil was analyzed for physico-chemical properties before intercropping. Results revealed that spacing treatments exerted profound influence on bamboo growth. For instance, clump height decreased by 19 % in the widest (12 × 12 m) bamboo spacing compared to that of the closest (4 × 4 m) spacing. However, widely spaced bamboo exhibited better clump diameter, crown coverage and turmeric rhizome yield, whereas, closest (4 × 4 m) spacing of bamboo plot recorded least rhizome yield of 8 Mg/ha; this was 58 % less compared to widest spacing of 12 × 12 m (19.32 Mg/ha). Soil N, P and K at widest spacing was 56, 45 and 33 % less compared to that of the closest spacing. NPK uptake by turmeric also increased in the wider spacing treatments. Factors contributing to reduction in growth of turmeric in the denser bamboo stands may be the high LAI (6.77 in 4 × 4 m spacing) as compared to widest spacing (0.44 in 12 × 12 m spacing) of bamboo, low understorey PAR (107 µmol/sec/m2) and high root competition. Due to competition by bamboo, 89 % decline in 32P absorption by turmeric at closest spacing of bamboo was observed compared to the bamboo-less plot. On a final note, turmeric, although a shade tolerant Zingiberaceae crop, may perform better if light transmittance is between 66 and 86 % and for optimal performance of the understorey turmeric in mixed species systems, wider bamboo spacings beyond 8 × 8 m are recommended.

The introduction of trees in cropland may be a way to improve the mineral nitrogen (N) use efficiency since tree roots can intercept N leached below the crop rooting zone and recycle it as organic N. The aim of this study was to determine soil mineral N (SMN) and total N (STN) contents after 14 years of hybrid walnut tree growth in an agroforestry system. Soil cores were collected and analyses in mid-autumn 2009, in intercropped agroforestry (AF), pure tree (FC) and sole crop control (CC) plots. The SMN was significantly reduced in AF compared to CC (64, 58 and 51 % of reduction at 0.2, 1 and 2 m depth respectively). In the top 1 m of soil, the stock of SMN was 77.7 kg N ha−1 in CC versus 32.8 kg N ha−1 in AF. Trees in AF developed deeper fine roots than in FC, likely involved in the reduction of SMN when compared to CC. Despite this quantitative reduction, trees also progressively modified the form of mineral N in soil by decreasing the percentage of nitrate (NO3 −) in SMN, particularly in FC compared to CC, while AF was intermediate. The STN was not significantly different between AF and CC; but was higher in FC in the top soil, probably due to weeds and superficial tree root biomasses. Our results suggest that the introduction of hybrid walnut trees into cropland may be an efficient practice to reduce the potentially leachable N by winter rainfall.

Many have argued that monitoring conducted exclusively by scientists is insufficient to address ongoing environmental challenges. One solution entails the use of mobile devices in broadly-applied participatory monitoring (PM) programs. But how digital data entry affects programs with varying levels of stakeholder participation, from volunteer data collectors to those entirely administered by non-scientists, remains unclear. We reviewed the successes, in terms of management interventions and sustainability, of 107 published programs and compared this analysis with case studies from our PM experiences in Australia, Canada, Ethiopia, Ghana, Greenland, and Vietnam. Our meta-analysis found participatory programs were less likely to use digital devices, while two of our three most participatory cases were also slow to adopt digital data entry. Published programs that were participatory and used digital devices were more likely to report management actions, an association shared with our Ethiopian, Greenlandic, and Australian cases. We found published programs involving volunteers were more frequently sustained than those depending on paid data-collectors; but those involving digital data entry were less sustainable when engaging volunteer data-collectors. In our Vietnamese and Canadian cases, sustainability was undermined by a mismatch in stakeholder objectives; in our Ghanaian case, complex field protocols diminished monitoring sustainability. We propose the use of digital data entry in PM can be understood using a participatory adaptive monitoring framework. In this, technology is less important than collaboratively defined objectives, conceptual models, and protocols determined through effective partnerships. Implemented effectively, digital data entry can enable the collection of more data of higher quality. Implemented ineffectively, or where it is unnecessary, digital data entry can be an additional expense that distracts from core monitoring objectives and undermines project sustainability. The appropriate role of digital data entry in PM likely depends more on the context in which it is used and less on the technology itself.

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Recovery planning for species listed under the Endangered Species Act has been hampered by a lack of consistency and transparency, which can be improved by implementing a standardized approach for evaluating species status and developing measurable recovery criteria. However, managers lack an assessment method that integrates threat abatement and can be used when demographic data are limited. To help meet these needs, we demonstrate an approach for evaluating species status using data on habitat configuration. We applied three established persistence measures to compare two conservation strategies (critical habitat designated by the U.S. Fish and Wildlife Service and the Forest Service's Carbonate Habitat Management Strategy) and two threat scenarios (limestone mining at two intensities: removal of all habitat areas with mining claims – “maximum mining”, or removal of only areas with existing operations and high-quality ore – “minimum mining”) against a baseline of existing habitat for three federally listed plant species. We found that protecting all area within the designated critical habitat would maintain a similar level (83.9-99.9%) of species persistence as the baseline, whereas maximum mining would greatly reduce persistence (0.51-38.4% maintained). The three persistence measures provided complementary insights reflecting different aspects of habitat availability (habitat area, number of patches, patch size and connectivity). These measures can be used to link recovery criteria developed following the “3 R principles” (representation, redundancy, and resilience) to the resulting improvements in species viability. By focusing on amount and distribution of habitat, our analysis provides a means of assessing the status of data-poor species to inform decision-making under the Act.

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Population viability analysis is widely used for assessing population-level impacts of environmental changes on species. When combined with sensitivity analysis, PVA yields insights into the effects of parameter and model structure uncertainty. This helps researchers to prioritize efforts for further data collection so that model improvements are efficient, and helps managers prioritize conservation and management actions. Usually sensitivity is analyzed by varying one input parameter at a time and observing the influence that variation has over model outcomes. This approach does not account for interactions among parameters. Global sensitivity analysis (GSA) overcomes this limitation by varying several model inputs simultaneously. Then regression techniques allow measuring the importance of input parameter uncertainties. In many conservation applications, the goal of demographic modeling is to assess how different scenarios of impact or management cause changes in a population. This is challenging because the uncertainty of input parameter values can be confounded with the effect of impacts and management actions. We developed a GSA method that separates model outcome uncertainty resulting from parameter uncertainty from that resulting from projected ecological impacts or simulated management actions; effectively separating the two main questions that sensitivity analysis asks. We applied this method to Snowy Plover, assessing the effects of predicted sea-level rise. A relatively small number of replicate models (approximately 100) resulted in consistent measures of variable importance when not trying to separate the effects of ecological impacts from parameter uncertainty. However, many more replicate models (approximately 500) were required to separate these effects. These differences are important to consider when using demographic models to estimate ecological impacts of management actions.

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The trade in wild animals involves one third of the world's bird species and thousands of other vertebrate species. While a few species are known to be imperiled as a result of the wildlife trade, the lack of field studies makes it difficult to gauge how serious a threat it is to biodiversity. We combined data on changes in bird abundances across space and time with trapper interviews to evaluate the effects of trapping wild birds for pets in Sumatra, Indonesia, an international pet trade hotspot. In southern Sumatra we analyzed bird abundance changes over time using a rare 14-year dataset of repeated bird surveys from the same extensive forest. In northern Sumatra we surveyed birds along a gradient of trapping accessibility, from the edge of roads to five km into the forest interior. We also interviewed 49 bird trappers in northern Sumatra to learn which species they target and how far they go into the forest to trap. We found that market price was a significant predictor of species declines over time in southern Sumatra, implicating the pet trade in those declines. In northern Sumatra, we found no relationship between price and change in abundance as a function of remoteness. However, high-value species were rare or absent across our surveys there. Notably, the median maximum distance trappers went into the forest each day was 5.0 km. This suggests that trapping has depleted bird populations across our remoteness gradient. Alarmingly, we found that less than half of Sumatra's remaining forests are >5km from a major road. These results indicate that trapping for the pet trade is a threat to birds in Sumatra. Given the popularity of pet birds across Southeast Asia, additional studies are urgently needed to determine the extent and magnitude of the threat posed by the pet trade.

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Continuing coral-reef degradation in the western Atlantic is resulting in loss of ecological and geologic functions of reefs. With the goal of assisting resource managers and stewards of reefs in setting and measuring progress toward realistic goals for coral-reef conservation and restoration, we examined reef degradation in this region from a geological perspective. The importance of ecosystem services provided by coral reefs—as breakwaters that dissipate wave energy and protect shorelines and as providers of habitat for innumerable species—cannot be overstated. However, the few coral species responsible for reef building in the western Atlantic during the last approximately 1.5 million years are not thriving in the 21st century. These species are highly sensitive to abrupt temperature extremes, prone to disease infection, and have low sexual reproductive potential. Their vulnerability and the low functional redundancy of branching corals have led to the low resilience of western Atlantic reef ecosystems. The decrease in live coral cover over the last 50 years highlights the need for study of relict (senescent) reefs, which, from the perspective of coastline protection and habitat structure, may be just as important to conserve as the living coral veneer. Research is needed to characterize the geological processes of bioerosion, reef cementation, and sediment transport as they relate to modern-day changes in reef elevation. For example, although parrotfish (family Scaridae) remove nuisance macroalgae, possibly promoting coral recruitment, they will not save Atlantic reefs from geological degradation. In fact, these fish are quickly nibbling away significant quantities of Holocene reef framework. The question of how different biota covering dead reefs affect framework resistance to biological and physical erosion needs to be addressed. Monitoring and managing reefs with respect to physical resilience, in addition to ecological resilience, could optimize the expenditure of resources in conserving Atlantic reefs and the services they provide.

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Linking diversity to biological processes is central for developing informed and effective conservation decisions. Unfortunately, observable patterns provide only a proportion of the information necessary for fully understanding the mechanisms and processes acting upon a particular population or community. Here, we suggest conservation managers utilise the often overlooked information imbedded in species absences, paying particular attention to the dark diversity (i.e. a set of species that are absent from a site but can potentially disperse to and establish there, in other words, the absent portion of a habitat-specific species pool). Together with existing ecological metrics, concepts and conservation tools, dark diversity can be used to complement and further develop conservation prioritisation and management decisions through an understanding of biodiversity relativized by its potential (i.e. its species pool). Furthermore, through a detailed understanding of the population, community and functional dark diversity, the restoration potential of degraded habitats can be more rigorously assessed further, and so to, the likelihood of successful species invasions. We suggest the application of the dark diversity concept is currently an underappreciated source of information that is valuable for conservation applications ranging from macro-scale conservation prioritization to more locally-scaled restoration ecology and the management of invasive species.

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The invasive ant Pheidole megacephala, listed on “100 of the World's Worst Invasive Alien Species”, has caused serious impacts on native ecosystems in tropical and subtropical areas. In Japan, P. megacephala was introduced to the Ryukyu Islands and the Ogasawara Islands. However, P. megacephala demonstrates no invasiveness in Ryukyu, so this species is not registered on the list of “Invasive Alien Species” (IASs), species of which are subjected to strict monitoring and prohibition of their trafficking under the IAS Act. Therefore, potential threats of this species have been overlooked in Ogasawara, despite the area's status as a UNESCO World Heritage Site (WHS). In the present study, the current distribution range of P. megacephala was surveyed in the Minamizaki area of Hahajima Island of Ogasawara, designated as a core zone of the WHS. We investigated how P. megacephala affects endemic achatinellid snails because these snails are excellent indicators for assessing the impact of ants. In addition, land snails have high conservation value in Ogasawara as a WHS. The present study documents that P. megacephala has dispersed into the natural forests of the Minamizaki area. Achatinellid snails were mostly absent in the area invaded by P. megacephala, whereas these snails were abundant in other areas. Comparison of the current distribution and density of the snails with those of 10 years ago demonstrates that P. megacephala mostly decimated achatinellid snails in the natural forests. Feeding experiments conducted in the laboratory support this conclusion. The decline of achatinellid snails is an important sign of impacts of P. megacephala on ecosystem. The present findings raise an issue and limitation in using an official “black list” such as IAS. Any stakeholders using the list of invasive species to develop conservation programs should recognize that invasiveness of the nonnative species differ depending on an ecosystem's properties.

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Documented patterns of specialization and species interactions often omit plasticity in resource use across space and time, yet such variation is an important part of species interactions. To examine temporal variation in resource use, we compared species- and community-level patterns of host plant use by folivorous caterpillars between the dry and rainy seasons in four preserved areas of cerrado vegetation in the Distrito Federal, Brazil. We sampled plants and caterpillars in 10 m circular plots monthly from March 2010 to March 2011. At the community level, we found a significant increase in the mean diet breadth of dry season caterpillars relative to those collected in the rainy season. Families and species of moths varied in diet breadth, but most exhibited a seasonal expansion. In particular, intraspecific comparisons showed a 30% increase in the number of host plants used in the dry season compared to the rainy season. These results provide a clear example of how temporal variation in resource use is heterogeneous, and more generalized patterns of resource use can emerge from studies at large temporal scales. Thus, seasonal or annual heterogeneity may obscure ecologically relevant specialized interactions that occur at smaller scales.

Os padrões disponíveis na literatura sobre as especializações e as interações das espécies, geralmente não tratam da plasticidade dos recursos no tempo e no espaço apesar, deste fator ser considerado uma parte importante das interações. Para verificar a variação temporal do uso do recurso, este estudo comparou os padrões do uso de plantas hospedeiras pelas lagartas em dois níveis: especifico e comunitário, nas estações seca e chuvosa, em quatro áreas de cerrado com vegetação preservada no Distrito Federal, Brasil. As plantas e as lagartas foram amostradas em 275 parcelas circulares e temporárias (10 m diâmetro) com, pelo menos, 20 parcelas amostradas mensalmente de Março de 2010 a Março de 2011. No nível de comunidade encontramos um aumento significativo na média da amplitude de dieta das lagartas, na estação seca, quando comparada às lagartas coletadas na estação chuvosa. Entre as famílias e espécies de mariposas, a variação na amplitude de dieta foi evidente, e a maioria mostrou uma expansão sazonal da amplitude de dieta. Em particular, as comparações intraespecíficas entre as estações indicaram um aumento de 30% no número de plantas hospedeiras utilizadas na estação seca em comparação com a chuvosa. Estes resultados sugerem um exemplo claro de como a variação no uso do recurso é heterogênea e, que os padrões mais generalizados sobre o uso de recursos que emergem dos estudos em grandes escalas temporais, podem esconder interações especializadas, ecologicamente relevantes, que ocorrem em pequenas escalas.

Phylogenetic information provides insight into the ecological and evolutionary processes that organize species assemblages. We compared patterns of phylogenetic diversity among macromycete and woody plant communities along a steep elevational gradient in eastern Mexico to better understand the evolutionary processes that structure their communities. Macrofungi and trees were counted and identified in eight sites from 100 to 3500 m asl, and sequence data retrieved from GenBank for the same or closely related species were used to reconstruct their phylogenies. Patterns of species richness and phylogenetic diversity were similar for both macrofungi and trees, but macromycete richness and diversity peaked at mid-elevations, whereas woody plant richness and diversity did not show significant trends with elevation. Phylogenetic similarity among sites was low for both groups and decreased as elevational distance between sites increased. Macromycete communities displayed phylogenetic overdispersion at low elevations and phylogenetic clustering at high elevations; the latter is consistent with environmental filtering at high elevation sites. Woody plants generally exhibited phylogenetic clustering, consistent with the potential importance of environmental filtering throughout the elevational gradient.

La información filogenética se ha utilizado cada vez más para entender los procesos ecológicos y evolutivos que organizan los ensambles de especies. Nuestro objetivo fue comparar patrones de diversidad filogenética entre comunidades de macromicetos y plantas leñosas a través de un gradiente altitudinal en el este de México, y entender los procesos evolutivos que pudieron estructurar estas comunidades. Los macromicetes y árboles fueron contados e identificados en ocho sitios entre 100 y 3500 m s.n.m. Se utilizaron secuencias de GenBank de las especies registradas o especies cercanas para la reconstrucción filogenética de macromicetes y árboles. Los patrones de riqueza de especies y diversidad filogenética fueron similares tanto en hongos como en árboles, pero los macromicetes mostraron un pico de riqueza y diversidad a altitud media mientras que la riqueza y diversidad de plantas leñosas no mostraron tendencias significativas. La similitud filogenética en comunidades fue baja para ambos grupos y decreció con el incremento en distancia altitudinal entre sitios. Las comunidades macrofúngicas fueron filogenéticamente dispersa a baja altitud y filogenéticamente agrupada en sitios altos; esto último en concordancia con los factores ambientales de sitios altos. Las plantas leñosas mostraron principalmente un agrupamiento filogenético, lo cual es consistente con el potencial efecto de los factores ambientales a través del gradiente.

Niche differentiation among tropical forest plants can generate species turnover along gradients of soil, topography, climate, and land use history. In this study we explore the relative importance of these variables as drivers of floristic composition in Cueva de Los Guacharos National Park. We established twenty 0.1-ha plots, within which trees, lianas, and shrubs (diameter ≥ 2.5 cm) were censused. We selected plot locations in primary and disturbed forests, and we measured topography and soil variables. Despite their structural similarity, primary and disturbed forests differed floristically, and also differed in environmental variables measured. A NMDS ordination showed that variation in the floristic composition across plots is highly correlated to the exchangeable acidity, elevation, temperature, and magnesium availability. Variance partitioning analysis shows that together spatial and environmental variables explain 24.2 percent of the variation in species composition. ‘Pure environmental’ variables were more important in explaining compositional variability than ‘pure spatial’ processes (9.8% and 1.4%, respectively). Residual variance may be attributed to stochastic process or non-measured biotic effects.

La diferenciación de nicho entre plantas en bosques tropicales puede generar un recambio de especies a lo largo de gradientes de suelo, topografía, clima e historia del uso del suelo. En este estudio evaluamos la importancia relativa de estas variables determinando la composición florística en el Parque Nacional Cueva de los Guacharos. Se establecieron veinte parcelas de 0.1-ha dentro de las cuales se censaron árboles, lianas y arbustos (diámetro ³ 2.5 cm). Las parcelas se encuentran en bosques maduros y secundarios; dentro de cada una se midieron variables de suelo y topografía. A pesar de que los bosques maduros y secundarios presentaron similitud estructural, la composición florística entre ellos fue diferente, al igual que las variables ambientales medidas. Una ordenación de NMDS mostró que la variación en la composición florística entre las parcelas está altamente correlacionada con la acidez intercambiable, la elevación, la temperatura y disponibilidad de Magnesio. El análisis de partición de varianza mostró que en conjunto, las variables espaciales y ambientales explican un 24.2% de la variación de la composición de especies. Las variables “puramente ambientales” fueron más importantes para explicar la variación en la composición que los procesos “puramente espaciales” (9.8% y 1.4%, respectivamente). Los residuos de la varianza pueden ser atribuidos a los procesos estocásticos o a efectos bióticos que no fueron medidos.

Wet tropical forest trees display a wide range of leaf phenology dynamics. However, the interrelation between deciduousness, water status, and leaf and stem characteristics have been poorly investigated compared with dry forests. We studied wet forest trees to answer the following questions: (1) do water regulation modes (iso/anisohydric behavior) of evergreen species differ from those found in deciduous species? (2) Does leaf water potential (ΨL) influences leaffall and emergence dynamics? (3) Are leaf and stem characteristics consistent across evergreen and deciduous trees? We evaluated vegetative phenology, ΨL, and leaf and stem characteristics of six evergreen and three deciduous species monthly for 2 yr. Species exhibited different leaffall and emergence dynamics, as well as different water regulation modes, independent of their deciduousness. Thus, the relationship between leaf phenology and water regulation behaviors appears to be a species-specific property rather than a functional group attribute. ΨL had no direct influence on the dynamics of leaffall and/or emergence, indicating that this process is not modulated by water availability alone. Individual groups of evergreen and deciduous species could not be identified using principal component analysis (PCA), but a decoupling was observed in the leaf and stem economics spectra. The lack of an interrelation between deciduousness and iso/anisohydry, as well as the independence of leaf and stem trade-offs, emphasizes that more systematic measurements of vegetative phenology and ecophysiological characteristics are necessary to advance our knowledge of leaf habit and water regulation behaviors based on the functional traits of wet forest plants.

As árvores das florestas tropicais úmidas mostram uma ampla gama de fenodinâmicas vegetativas, mas as interações entre deciduidade, status hídrico, características foliares e caulinares têm sido pouco estudados nestas florestas em comparação com as florestas secas. Este estudo envolvendo árvores de uma floresta úmida buscou responder se: (1) A forma de regulação hídrica (comportamento iso/anisohídrico) difere entre espécies sempre-verdes e decíduas? (2) O potencial hídrico foliar (ΨL) influencia a dinâmica de queda e brotamento foliar? (3) Características foliares e caulinares são consistentes entre espécies sempre-verdes e decíduas? A fenodinâmica vegetativa, o ΨL e as características foliares e caulinares de seis espécies sempre verdes e três decíduas foram avaliados durante dois anos. As espécies apresentaram diferenças na dinâmica de queda e brotamento foliar, bem como diferentes modos de regulação hídrica, independentemente de seu hábito foliar. Assim, a relação entre fenologia foliar e comportamento de regulação hídrica destas espécies parece ser mais uma característica espécie-específica do que um atributo do grupo funcional. O ΨL não teve influência direta sobre a queda de folhas e/ou dinâmica de brotamento, indicando que estas fenofases não são moduladas apenas pela disponibilidade de água. Grupos formados por espécies sempre-verdes e decíduas não foram distinguidos através da análise de componentes principais (PCA), sendo que houve uma dissociação entre espectros de economia da folha e do caule. A ausência de relação entre deciduidade e iso/anisohidria, bem como a independência nos balanços de características foliares e caulinares reforçam que medições mais sistematizadas da fenologia vegetativa e de características ecofisiológicas são necessárias para avanço nas pesquisas sobre atributos funcionais das plantas, com base em hábito foliar e modos de regulação hídrica, nas florestas tropicais úmidas.

A study was carried out to assess the growth, flowering and fruiting of stecklings (rooted cuttings), grafts and seedlings of Allanblackia floribunda in Cameroun. Thirty-one individuals of each plantlet type were planted in May 2006. Height, collar and crown diameters were recorded in September and October, while flowering and fruiting were recorded each month from January to December. In 2014, the trees with the greatest height were those from seeds (6.98 ± 0.25 m), followed by those from grafts (1.65 ± 0.23 m) and cuttings (1.09 ± 0.21 m). Grafts started flowering and fruiting 3 years after planting, while seedlings started flowering and fruiting after four and 6 years, respectively. Stecklings still had not flowered 8 years after planting. Fruit weight and length from seed-origin trees are about seven times higher than grafts. Correlations between height and crown diameter were significant and positive irrespective of the nature of the planting material. In conclusion, grafts fruited earlier, while seedlings grew faster and had greater yields than grafts and stecklings of A. floribunda.

In recent time, yields from cocoa producing states have been decreasing while farmers are faced with a number of challenges that predispose them to risks and uncertainties. The study therefore assessed the major production and marketing risks in Ondo State, Nigeria. The socio-economic characteristics of the cocoa farmers were analysed using descriptive analysis while Kruskal–Wallis ranking analysis was used to assess the farmer’s perception on sources of risks. Ranking on top of the ten identified cocoa production risks was pest and diseases attack while undue exploitation by exporters ranked on top of marketing risks. The major coping strategies adopted by the farmers of the cocoa include diversification of production system by growing substitute crops (47.5 %), and involvement in non-farm business to generate additional income (35.0 %). In other to reduce risks faced by the farmers, government should put in place a marketing scheme aimed at assisting cocoa farmers through price regulation and monitoring. Cocoa farmers also needed to be introduced to the current technologies of production with the provision of necessary incentives such as improved varieties of cocoa seedling, as well as provision of fertiliser and approved pesticides, financial assistance, and simple processing technologies that produce standard cocoa beans.