Northern Nicaragua Research Articles

San Albino, Nicaragua: A Low-Angle, Thrust-Controlled Orogenic Gold Deposit

Abstract The San Albino deposit is an orogenic gold occurrence hosted by a low-angle thrust that is the site of a new open-pit mine in northern Nicaragua. The deposit is hosted in greenschist facies rocks of the Jurassic metasedimentary Neuvo Segovia Formation. The schist was uplifted and exposed during arc accretion and Cretaceous thin-skin deformation, forming the NE-striking Colon fold-and-thrust belt. Deformation included emplacement of the 119 to 113 Ma NE-trending Dipilto batholith into the regionally metamorphosed clastic rocks about 5 km northwest of the San Albino deposit. Mineralization is dominated by three laminated quartz vein systems (i.e., San Albino, Naranjo, Arras) that broadly follow shallowly dipping (approx. 30°) carbonaceous shears roughly concordant to schistosity along the limbs of a doubly plunging antiform. The three main parallel shears are each separated by about 90 m and individually reach a maximum thickness of about 8 m. Maximum thickness of ore zones is where post-ore local folding and reverse motion along the shallow shears has duplicated the laminated low-angle gold-bearing veins (D2 and early D3). Additional gold was added to the veins, with abundant sulfides, during a subsequent brecciation event of the early formed quartz veins that accompanied progressive thrusting (late D3). This predated boudinage of the veins during continued compression and thrust loading (D4); high gold grades are particularly notable along pyrite- and arsenopyrite-bearing stylolites formed during D4 pressure solution. The D2 to D3 gold event is likely coeval with Albian uplift of the Dipilto batholith and with back thrusting in the schist aided by the stress inhomogeneities provided by the igneous complex. Low-angle thrust-controlled orogenic gold deposits may represent world-class exploration targets because of their large linear footprints, although they are traditionally looked at as less favorable exploration targets relative to gold systems developed more commonly along high-angle reverse faults. Our case study of the San Albino deposit shows that although low-angle deposits are not inherently misoriented for failure like the more common subvertical reverse fault-related deposits, they may be sites of significant pressure buildup due to hydrothermal mineral precipitation during initial water-rock interaction or slight temperature decreases along the low-angle flow path. Resulting fluid cycling may lead to thick laminated vein development, such as seen at San Albino, where especially high-grade zones may be associated with local steepening and/or dilational zones within the broader, low-angle vein-hosting shear system.

False killer whales (Pseudorca crassidens Cetacea: Delphinidae) along the Pacific coast of Central America and Mexico: Long-term movements, association patterns and assessment of fishery interactions

Introduction: Worldwide, false killer whales (Pseudorca crassidens) are infrequently encountered, yet long-term studies have shown strong site fidelity as well as long-term associations among individuals in several locations. Detailed studies of this species have primarily been conducted around tropical oceanic islands or in the subtropical southern hemisphere.
 Objectives: We assess movements and association patterns among false killer whales along the Pacific coasts of the USA, Mexico, Guatemala, Nicaragua, Costa Rica including Isla del Coco, and Panama, representing one of the longest-running (albeit non-continuous) studies of this species. We also examine photos for evidence of interactions with fisheries, a known source of mortality to false killer whales.
 Methods: From Central America, we selected 212 individuals (50 encounter groups) out of 244 individuals (56 encounters) for inclusion in analyses based on photo quality and distinctiveness. Photos were collected on dedicated surveys from 1991-1994 and dedicated and opportunistic surveys from 1998-2022. Other than the effort off the oceanic Isla del Coco (1993-1994), surveys were undertaken in continental shelf waters. Additionally, we selected by photo quality and distinctiveness 124 (33 encounter groups) out of 189 individuals from southern California and Mexico for inclusion in these analyses. Association patterns were analyzed in SOCPROG and movements were analyzed in R.
 Results: Of the 328 total individuals, 158 (48.2 %) were encountered more than once, and 114 (34.8 %) were re-sighted after a year or more. The longest individual sighting history spanned 26.2 years with six re-sightings over that period between southern Costa Rica and Panama. Association and movement analyses revealed that individuals identified off southern Costa Rica and Panama linked into a single social network, with extensive movements between the two countries. Three individuals encountered off northern Costa Rica were re-sighted off northern Nicaragua, and individuals encountered off Nicaragua were encountered off Guatemala and central mainland Mexico. Nine matches were found among false killer whales between central mainland Mexico and Central America. There were no matches between the mainland coastal waters and the 33 individuals encountered around Isla del Coco. Dorsal fin disfigurements consistent with interactions with line fisheries ranged from 0 to 21 % for individuals within social clusters identified by community division.
 Conclusions: The infrequency of sightings combined with a high re-sighting rate of individuals and groups from the same area, suggests multiple small populations with large home ranges that include coastal waters. Small populations are sensitive to environmental changes, and as the human population grows, so do the demands on fisheries and ecotourism, which could directly impact the different populations. Additional effort in offshore areas is needed to determine the population status of false killer whales in pelagic waters, how often false killer whales using coastal waters move into pelagic waters, and the relationship between whales in the two habitats.

Revision of the genus Agrostis (Poaceae, Pooideae, Poeae) in Megamexico.

Agrostis is one of the most diverse genera of the Poaceae, including ca. 198 species, principally distributed in cold and temperate regions of the world, but also found in the high mountains of the tropics. We present a revision based on morphoanatomical evidence, for the biogeographic region known as Megamexico 3 (i.e., Mexico including the desert areas of southern USA and the Central America territory, to northern Nicaragua). We include taxonomic descriptions and an identification key for the found taxa, maps with the known geographical distribution of the species, and figures with the morphoanatomical characteristics, elevation and phenology. Agrostis is represented in the study zone by 20 species, of which four are endemic and three are introduced. Most records of the genus are distributed in the mountains, above 1500 m a.s.l., in open areas of temperate forests, with conifers and Quercus. Specimens with spikelets occur year round, but most records occur during the wet season, in the months of July to October. We propose a preliminary conservation assessment for each species in the study zone, according to the International Union for Conservation of Nature categories: one with Deficient Data (DD), six as Endangered (EN), two as Vulnerable (VU), and 11 as Least Concern (LC).

Detrital zircon geochronology from the Nueva Segovia Schist, Nicaragua: evidence for the tectonic evolution of the Chortis Block?

Abstract The Chortis Block of Central America is a cratonic-type peri-Gondwanan terrane and is commonly included in Neoproterozoic–Paleozoic palaeogeographical reconstructions. At present, most research has focused on the Mesozoic evolution of the Chortis Block, however, its earlier history remains poorly constrained. As a result, there is considerable debate surrounding the internal complexities of the Chortis Block and its tectonothermal evolution has not been well established by geochronological and geochemical data. New field investigations from the Nueva Segovia Schist (Northern Nicaragua), considered one of the oldest exposed parts of the Chortis Block, reveal it is composed primarily of deformed sequences of greenschist facies marine clastic and chemical sediments in conformable contact with felsic volcanics. Laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) detrital zircon data from two samples taken from the Nueva Segovia Schist reveal a youngest age peak of c. 250 Ma with other significant peaks at c. 500 Ma, c. 1.0 Ga and c. 1.2 Ga. Taken together with field observations, these data suggest the Nueva Segovia Schist was likely deposited between c. 250 and 110 Ma proximal to Amazonia during the Late Paleozoic, and they support a Precambrian age for the basement of the East Chortis Terrane. Taken together the data support a Pangaean position of the Chortis Block, adjacent to Amazonia inboard of Oaxaquia.

Smallholder Coffee in the Global Economy—A Framework to Explore Transformation Alternatives of Traditional Agroforestry for Greater Economic, Ecological, and Livelihood Viability

Sixty percent of global coffee is produced from farms of <5 ha. Studies show that returns from such farms do not generate a living income for producers or workers threatening supplies. Smallholders use agroforestry to reduce coffee production costs, diversify income and address livelihood needs. We undertook a three-phase analysis to test the following hypothesis. Current coffee agroforestry must shift from a low labor, low risk-stable return, slowly-changing matrix to more active management of species and stem turnover in system renovation cycles targeted to sustaining, reorienting and intensifying ecosystem-based benefits to coffee production, diversified income and household food. First, we conducted a document survey of current traditional tree diversity, research trends, and market drivers for more benefits-oriented agroforestry. Second, we proposed a framework for multiple benefits quantification converting tree use characteristics and density into five categories of benefits, each with sub-categories which we tested using previously collected data of stem density by species from coffee agroforestry in northern Nicaragua. Third, we modeled radiation in mixed canopy scenarios using the program SExI- FS based on modifications of species and density to target food and income diversification and tested our framework by quantifying benefits. We found that smallholder coffee faces farms decreasing coffee margins, labor scarcity, new pests and climate variability best addressed with targeted and adaptive shifts in coffee varieties and associated trees. Increasing data demands from certification and regulations provide a basis more data-driven coffee farm management. Our data bases of stem density by species of established agroforestry systems were sufficient to identify gaps in food and income benefits which were addressed in the scenarios thereby verifying the hypothesis. The benefits ranking both of current systems and three scenarios also provided insights into data collection specifications for a more rigorous academic test of the hypothesis and data-driven grower strategies for agroforestry transformation.

The tangled evolutionary history of a long-debated Mesoamerican taxon: The Velazquez Woodpecker (Melanerpes santacruzi, Aves: Picidae)

The Velazquez Woodpecker Melanerpes santacruzi is a highly polytypic species distributed from east-central Mexico to northern Nicaragua. The ample variation in body size, barring of the plumage, and the coloration of nasal tufts, neck, and belly have fueled debates about the taxonomy and evolutionary history of the species; however, the processes generating these patterns of variation and the underlying population dynamics throughout the species’ distribution remain poorly understood. Here, we employed reduced representation genome sequencing (NextRAD) and Ecological Niche Modeling methods to test the distinctiveness of the Velazquez Woodpecker based on this new set of genomic data and analyze the correspondence of the genetic structure and ecological differentiation with phenotypic variation and geographic distribution. From phylogenetic and demographic analyses including the Golden-Fronted (M. aurifrons) and Red-bellied Woodpecker (M. carolinus), we obtained results congruent with previous molecular phylogenies. The clades of M. santacruzi and M. carolinus-M. aurifrons are reciprocally monophyletic, although the sister group relationship of M. aurifrons is ambiguous. Using genetic and ecological analyses, we found that the species is structured into three genetically and ecologically differentiated groups comprising the subspecies (1) M. s. santacruzi, (2) M. s. dubius and (3) M. s. grateloupensis-polygrammus-veraecrucis. These groups diverged recently, with two splits between 250,000 and 150,000 years ago, and show a significant genetic admixture among them, especially in their current contact zones. Ecological and demographic models suggest the existence of intermittent areas of sympatry and connectivity among populations of M. santacruzi since the Last Interglacial period. We also found evidence of bi-directional gene flow between the species M. aurifrons and the nearby populations of M. santacruzi (M. s. grateloupensis), along the Sierra Madre Oriental in northeastern Mexico. Gene flow seems to be uneven, with prevalence of movement in the direction from M. aurifrons to M. s. grateloupensis.

Test-Retest repeatability of automated threshold audiometry in Nicaraguan schoolchildren

Objective Automated threshold audiometry (ATA) could increase access to paediatric hearing assessment in low- and middle-income countries, but few studies have evaluated test-retest repeatability of ATA in children. This study aims to analyse test-retest repeatability of ATA and to identify factors that affect the reliability of this method. Design ATA was performed twice in a cohort of Nicaraguan schoolchildren. During testing, the proportion of responses occurring in the absence of a stimulus was measured by calculating a stimulus response false positive rate (SRFP). Absolute test-retest repeatability was determined between the two trials, as well as the impact of age, gender, ambient noise, head circumference, and SRFP on these results. Study Sample 807 children were randomly selected from 35 schools in northern Nicaragua. Results Across all frequencies, the absolute value of the difference between measurements was 5.5 ± 7.8 dB. 89.6% of test-retest differences were within 10 dB. Intra-class correlation coefficients between the two measurements showed that lower SRFP was associated with improved repeatability. No effect of age, gender, or ambient noise was found. Conclusions ATA produced moderate test-retest repeatability in Nicaraguan schoolchildren. Participant testing behaviours, such as delayed or otherwise inappropriate response patterns, significantly impacts the repeatability of these measurements.

Leaf economics in a three‐dimensional environment: Testing leaf trait responses in vascular epiphytes to land use, climate and tree zone

Abstract The study of functional traits offers predictive power for community ecology. Particularly in cases where individual species are difficult to study, known properties of trait spectra, such as the leaf economics spectrum (LES), and trait–environment relationships can provide crucial generalizable information that can contribute to forecasts of distributional shifts in response to the abiotic effects of climate and land use changes. Vascular epiphytes have been proposed as indicators of environmental change, but we know little about the ecology of most species. Key functional trait assumptions are based on terrestrial plants; testing these in epiphytes verifies their universality and will inform applying functional traits in predicting epiphyte responses to climate and land use change. In this study, we use functional traits from 37 vascular epiphyte species from forests and shade coffee farms at two sites in northern Nicaragua. We compare correlations among traits and intraspecific trait variances with those of terrestrial plants and among epiphyte taxonomic groups. We also test trait responses to environmental differences between sites and land use types, and within zones of the tree. We find that epiphyte leaf traits fall towards the slower end of the LES, but with about one‐third lower leaf nitrogen per change in specific leaf area (SLA) relative to terrestrial herbaceous plants. Bromeliads show less relationship between these traits than other epiphyte groups and also deviate in other trait interrelationships, suggesting unique leaf construction. Trait–environment relationships varied most strongly along vertical gradients within trees, but some traits, including SLA and carbon isotope ratio, also responded to land use and site differences. We present evidence that trait relationships established for terrestrial plants appear to translate to epiphytes, but identify some possible caveats. Strong trait response to vertical gradients within trees suggests that within‐canopy shifts could provide resilience to climate and land use changes for some epiphyte species.

Toward a feminist political ecology of household food and water security during drought in northern Nicaragua

Bacon, C., L. C. Kelley, and I. T. Stewart. 2021. Toward a feminist political ecology of household food and water security during drought in northern Nicaragua. Ecology and Society 27(1):16. https://doi.org/10.5751/ES-12716-270116

Trends and factors related to adolescent pregnancies: an incidence trend and conditional inference trees analysis of northern Nicaragua demographic surveillance data

BackgroundWe aimed to identify the 2001–2013 incidence trend, and characteristics associated with adolescent pregnancies reported by 20–24-year-old women.MethodsA retrospective analysis of the Cuatro Santos Northern Nicaragua Health and Demographic Surveillance 2004–2014 data on women aged 15–19 and 20–24. To calculate adolescent birth and pregnancy rates, we used the first live birth at ages 10–14 and 15–19 years reported by women aged 15–19 and 20–24 years, respectively, along with estimates of annual incidence rates reported by women aged 20–24 years. We conducted conditional inference tree analyses using 52 variables to identify characteristics associated with adolescent pregnancies.ResultsThe number of first live births reported by women aged 20–24 years was 361 during the study period. Adolescent pregnancies and live births decreased from 2004 to 2009 and thereafter increased up to 2014. The adolescent pregnancy incidence (persons-years) trend dropped from 2001 (75.1 per 1000) to 2007 (27.2 per 1000), followed by a steep upward trend from 2007 to 2008 (19.1 per 1000) that increased in 2013 (26.5 per 1000). Associated factors with adolescent pregnancy were living in low-education households, where most adults in the household were working, and high proportion of adolescent pregnancies in the local community. Wealth was not linked to teenage pregnancies.ConclusionsInterventions to prevent adolescent pregnancy are imperative and must bear into account the context that influences the culture of early motherhood and lead to socioeconomic and health gains in resource-poor settings.

“A Very Noble Crop”: Financial Stability, Agronomic Expertise, and Personal Values Support Conservation in Shade-Grown Coffee Farms

Shade-grown coffee is an important reservoir for tropical biodiversity, but habitat quality hinges on decisions made by farmers. Our research aims to investigate the link between coffee producers’ decisions and outcomes for biodiversity, using epiphytes as our focal group. Using qualitative methods, we interviewed 33 producers in northern Nicaragua to understand how they connect trees and epiphytes on their farms to ecosystem services and how personal values, access to agronomic expertise, labor supply, and financial stability influence decision-making. We used interview responses to construct six producer typologies. Most producers had strong positive attitudes toward trees and associated them with a variety of important ecosystem services. Smallholders were more likely to connect trees with provisioning services, while producers on larger farms and with greater agronomic knowledge emphasized regulating services. Most producers connected epiphytes primarily with aesthetic values. Across demographics, producers emphasized the restorative potential for shade coffee in repairing damage to soil, water, and nutrient cycles caused by other forms of agriculture. The conservation significance and sustainability of this social-ecological system can be maintained and expanded through economic and capacity-building conservation interventions, especially when those can be connected to values already held by farmers.

Ecosystem services and gender in rural areas of Nicaragua: Different perceptions about the landscape

The study of Ecosystem services (ES) is a prolific field of research. Despite the great biological and cultural diversity, in Latin America, research in this field has been growing at a much slower rate than in the rest of the world. The study of ES is called upon to contribute to informed decision-making for the planning and conservation of the territory and to improve well-being. However, this can only be achieved if the various stakeholders' vision about their environment is considered, since they are the ones most impacted by such decisions. Our study was carried out in nine rural communities in three municipalities in central and northern Nicaragua, a rural country with high rates of rural poverty. We questioned the perceptions of rural land uses as providers of ES by rural communities, from a gender perspective. We addressed this question from the framework of the Sustainable Livelihoods Approach (SLA) that allowed us to interrelate such diverse topics as the study of ES, gender and land uses. In each community, we first requested the endorsement of the community leaders, and then we carried out semi-structured interviews and separate focus groups for men and women. We used participatory mapping and the pebble distribution method (PDM), to identify how gender identity influences perceptions about benefits, location, and access to ES. Both men and women recognized the benefits of nature but differed in the identification of land uses that most provide ES. Exceptions were the forest areas, agroforestry systems and rivers, all of which were recognized as providing the greatest amount of services. These results are especially useful in the development of public policies to reduce poverty and address gender gaps in rural communities.

Impact of Weed Control by Hand Tools on Soil Erosion under a No-Tillage System Cultivation

In conservation agriculture, the no-tillage cultivation system and the retention of permanent vegetal cover are crucial to the control of soil erosion by water. This paper analyses the cultivation of maize under no-tillage, with particular reference to the effect produced on soil erosion when weed control is performed by a hand tool (machete), which disturbs the surface of the soil, and to the behavior of the soil cover in these circumstances. The study area is located in the humid tropical mountains of northern Nicaragua (Peñas Blancas Massif Nature Reserve). The results obtained show that 59.2% of the soil surface was affected by appreciable levels of sheet and splash erosion, although the vegetal cover of the soil was relatively high (with average weed and litter cover of 33.9% and 33.8%, respectively). The use of machetes for weed control provoked considerable soil disturbance, which explained the high rates of erosion observed. Moreover, this form of soil management disturbs the litter layer, making it less effective in preventing erosion. The litter remains loose on the soil surface, and so an increase in soil cover does not achieve a proportionate reduction in the area affected by erosion; thus, even with 80–100% weed and litter cover, 42% of the cultivated area continued to present soil erosion.

Sturnira hondurensis(Chiroptera: Phyllostomidae)

AbstractThe Honduran yellow-shouldered bat (Sturnira hondurensis Goodwin, 1940) is a medium-sized Stenodermatinae with a vestigial uropatagium and no tail; it typically has reddish or yellowish patches on the shoulders. It is found in temperate habitats from Mexico to northern Nicaragua, and it is one of 24 described species of the genus Sturnira. S. hondurensis is considered a common species and is listed as “Least Concern” (LC) by the International Union for Conservation of Nature and Natural Resources. Nevertheless, it primarily depends on the preservation of native and continuous forest, so maintaining the connectivity of vegetation patches and the availability of food in modified landscapes are strategies for the preservation of S. hondurensis and the ecosystem services that it provides.

Towards smallholder food and water security: Climate variability in the context of multiple livelihood hazards in Nicaragua

• We develop a framework and case study for jointly assessing household food and water security in a multi-hazard environment. • Water insecurity and food insecurity are positively related across households, even after controlling for household characteristics. • In 2017, a drought ended, contributing to improved food and water security, but adverse agrifood price risks persist. • Higher incomes, larger farm areas, and diversified farm production are correlated with improved food and water security. • Climate risks should be assessed within the context of interactions with other hazards and changing terms of access. Climate variability and change affect both food and water security, as do other hazards, such as shifting food prices, plant pathogens, and political economic changes. Although household food and water insecurity affect billions, most studies analyze them separately. This article develops a relational approach to explaining household access to food and water in a multi-hazard context. We identify pathways linking hazards to livelihood vulnerability and assess the relative importance of climate-related hazards. Analyzing longitudinal data collected from two surveys of the same 311 smallholder households in northern Nicaragua, conducted in 2014 and again in 2017, we find that peak seasons of food and water stress are asynchronous across the agricultural calendar, resulting in a total of five to six months of food and/or water stress. Across households, we find a significant positive relationship between water and food insecurity, even after adjusting for household fixed effects. Households experienced less food and water insecurity in 2017 than in 2014, due in part to the end of a severe drought in 2016, but remained concerned about damage from a severe coffee leaf rust outbreak and unfavorable agrifood prices that reduce income and threaten food security. Higher incomes and larger farm areas correlated with improved food and water security. We propose a generalizable approach for the joint assessment of household food and water security, which foregrounds the influence of seasonality and climate variability in the context of multiple hazards. This approach and our findings can contribute to developing integrated risk reduction strategies, building resilient livelihoods, and informing policy changes and partnerships with organized smallholders to improve resource access and sovereignty.

Assessing the strength of climate and land-use influences on montane epiphyte communities.

Epiphytes, air plants that are structurally dependent on trees, are a keystone group in tropical forests; they support the food and habitat needs of animals and influence water and nutrient cycles. They reach peak diversity in humid montane forests. Climate predictions for Central American mountains include increased temperatures, altered precipitation seasonality, and increased cloud base heights, all of which may challenge epiphytes. Although remaining montane forests are highly fragmented, many tropical agricultural systems include trees that host epiphytes, allowing epiphyte communities to persist even in landscapes with lower forest connectivity. I used structural equations models to test the relative effects of climate, land use, tree characteristics, and biotic interactions on vascular epiphyte diversity with data from 31 shade coffee farms and 2 protected forests in northern Nicaragua. I also tested substrate preferences of common species with randomization tests. Tree size, tree diversity, and climate all affected epiphyte richness, but the effect of climate was almost entirely mediated by bryophyte cover. Bryophytes showed strong sensitivity to mean annual temperature and insolation. Many ferns and some orchids were positively associated with bryophyte mats, whereas bromeliads tended to establish among lichen or on bare bark. The tight relationships between bryophytes and climate and between bryophytes and vascular epiphytes indicated that relatively small climate changes could result in rapid, cascading losses of montane epiphyte communities. Currently, shade coffee farms can support high bryophyte cover and diverse vascular epiphyte assemblages when larger, older trees are present. Agroforests serve as valuable reservoirs for epiphyte biodiversity and may be important early-warning systems as the climate changes.

Phylogenomic species delimitation in the ants of the Temnothorax salvini group (Hymenoptera: Formicidae): an integrative approach

ABSTRACTThe members of the Temnothorax salvini (Forel) species group are rarely collected, arboreally nesting ants of Central American forests. Previously thought to consist of two broadly dispersed species, recent collections have revealed a diversity of specimens that defy the two‐species salvini group concept, but these are difficult to distinguish from each other based solely on morphology. I contrast several model‐based approaches to species delimitation based on target‐enriched genomic data. With molecular data from thousands of ultraconserved elements (UCEs), mitochondrial genome sequences and morphometric data, I use an integrated approach to species delimitation within the salvini group. Morphometric data were analysed using cluster analysis of principal component analysis (PCA) output. I use several popular methods of molecular species delimitation, including bPTP, BPP and STACEY, using a novel approach to filtering UCE data based on posterior predictive checks of nucleotide substitution model adequacy. In addition, I use iBPP to integrate morphometric PCA data and filtered UCE data in a ‘total evidence’ analysis. I use geographical range data for an independent contrast to discriminate among competing species delimitation hypotheses. Furthermore, I investigate the evolutionary timescale and biogeographical history of the group and find that it arose roughly 13 Ma ago in habitats associated with present day mid‐to‐high elevations of the mountain complex spanning southern Mexico to northern Nicaragua. In addition, dispersal of the salvini group into the Southern Sierra Madre in Mexico, lowland habitats and the southern Central American cordilleras in Costa Rica and Panama subsequent to mountain building in southern Central America 5–8 Ma ago appears to follow a taxon‐cycle dynamic, with the lowland‐adapted T. aztecus representing the most recent expansion phase. I find that the salvini group, which previously contained two named species, is composed of nine, all of which are morphologically diagnosable a posteriori.

Tree longevity drives conservation value of shade coffee farms for vascular epiphytes

Forest loss and fragmentation threaten the high diversity of tropical forests. Tropical epiphytes are a key component of plant diversity and significant for ecosystem functioning, and they are vulnerable to these forces. We explored the potential of shade trees in agroforestry systems to sustain and restore epiphyte communities where forest cover has been lost. We investigated epiphyte colonization patterns using surveys of 748 trees within 87 variously-aged plots in coffee agroecosystems in northern Nicaragua. Species richness increased with stand age, reflecting effects of area, time, and the niche differentiation possible within larger trees. Young trees near mature trees were almost five times more likely to support epiphytes than those surrounded by other young trees, suggesting that propagule sources severely limit colonization in young, even-aged stands. We identified three stages of epiphyte colonization: an initial stage where trees lack epiphytes; a colonization stage where epiphyte abundance increases slowly; and a mature stage where accumulation accelerates as trees become large enough to support distinct microhabitats. Atmospheric bromeliads and several fern species with traits that facilitate dispersal, colonization, and persistence under open, sunny environmental conditions colonized young trees first. Thus, both environmental filtering and dispersal limitation drive community assembly in these agroforests. Because epiphytes colonize gradually, consistent land tenure and long-term management allow time for newly planted trees in shade coffee farms to develop to the size and structural complexity needed to support diverse epiphyte communities. Because ideal conditions for epiphytes may be at odds with managing for maximum coffee yields and some epiphyte species may never colonize coffee farms, even mature shade trees in coffee plantations cannot replace protecting native forests.

Assessing the Multiple Dimensions of Poverty. Data Mining Approaches to the 2004-14 Health and Demographic Surveillance System in Cuatro Santos, Nicaragua.

We identified clusters of multiple dimensions of poverty according to the capability approach theory by applying data mining approaches to the Cuatro Santos Health and Demographic Surveillance database, Nicaragua. Four municipalities in northern Nicaragua constitute the Cuatro Santos area, with 25,893 inhabitants in 5,966 households (2014). A local process analyzing poverty-related problems, prioritizing suggested actions, was initiated in 1997 and generated a community action plan 2002–2015. Interventions were school breakfasts, environmental protection, water and sanitation, preventive healthcare, home gardening, microcredit, technical training, university education stipends, and use of the Internet. In 2004, a survey of basic health and demographic information was performed in the whole population, followed by surveillance updates in 2007, 2009, and 2014 linking households and individuals. Information included the house material (floor, walls) and services (water, sanitation, electricity) as well as demographic data (birth, deaths, migration). Data on participation in interventions, food security, household assets, and women's self-rated health were collected in 2014. A K-means algorithm was used to cluster the household data (56 variables) in six clusters. The poverty ranking of household clusters using the unsatisfied basic needs index variables changed when including variables describing basic capabilities. The households in the fairly rich cluster with assets such as motorbikes and computers were described as modern. Those in the fairly poor cluster, having different degrees of food insecurity, were labeled vulnerable. Poor and poorest clusters of households were traditional, e.g., in using horses for transport. Results displayed a society transforming from traditional to modern, where the forerunners were not the richest but educated, had more working members in household, had fewer children, and were food secure. Those lagging were the poor, traditional, and food insecure. The approach may be useful for an improved understanding of poverty and to direct local policy and interventions.

Predicting poverty. Data mining approaches to the health and demographic surveillance system in Cuatro Santos, Nicaragua

BackgroundIn order to further identify the needed interventions for continued poverty reduction in our study area Cuatro Santos, northern Nicaragua, we aimed to elucidate what predicts poverty, measured by the Unsatisfied Basic Need index. This analysis was done by using decision tree methodology applied to the Cuatro Santos health and demographic surveillance databases.MethodsUsing variables derived from the health and demographic surveillance update 2014, transferring individual data to the household level we used the decision tree framework Conditional Inference trees to predict the outcome “poverty” defined as two to four unsatisfied basic needs using the Unsatisfied Basic Need Index. We further validated the trees by applying Conditional random forest analyses in order to assess and rank the importance of predictors about their ability to explain the variation of the outcome “poverty.” The majority of the Cuatro Santos households provided information and the included variables measured housing conditions, assets, and demographic experiences since the last update (5 yrs), earlier participation in interventions and food security during the last 4 weeks.ResultsPoverty was rare in households that have some assets and someone in the household that has a higher education than primary school. For these households participating in the intervention that installed piped water with water meter was most important, but also when excluding this variable, the resulting tree showed the same results. When assets were not taken into consideration, the importance of education was pronounced as a predictor for welfare. The results were further strengthened by the validation using Conditional random forest modeling showing the same variables being important as predicting the outcome in the CI tree analysis. As assets can be a result, rather than a predictor of more affluence our results in summary point specifically to the importance of education and participation in the water installation intervention as predictors for more affluence.ConclusionPredictors of poverty are useful for directing interventions and in the Cuatro Santos area education seems most important to prioritize. Hopefully, the lessons learned can continue to develop the Cuatro Santos communities as well as development in similar poor rural settings around the world.