Dry Forest Species Research Articles

Exotic goats do not affect the seed bank but reduce seedling survival in a human-modified landscape of Caatinga dry forest

Livestock browsing and trampling can deplete plant regeneration and thus drive natural ecosystems towards degradation. This phenomenon may be particularly true in tropical dry forests, which support extensive livestock herds feeding on native vegetation, but has rarely been experimentally addressed. Here we examine how browsing and trampling by exotic goats impacts seed bank and seedling survivorship of woody plant species in a Caatinga dry forest by performing a 4-year exclosure experiment. Soil seed bank and transplanted seedlings from four woody plants species were monitored through a year across 14 and 10 paired plots (free goat-access vs exclosure plots), respectively. Regardless of treatment, the soil seed bank was low in density 14 seeds/m2 (±13, standard deviation) and taxonomically impoverished (24 species). Small to intermediate-sized seeds from dry fruits (75%) and abiotically dispersed species (65%) prevailed. The most common attractive structure was an elaiosome (33%), but pulp (14%) and aril (9.5%) were also recorded. 60% of the species presented some type of dormancy and 32% presented a pleurogram. 57% of the seeds were classified as forming a transient seed bank, while seasonally transient seeds accounted for 43% of the total seed bank. Seed bank attributes were not affected by goats, including proportion of viable seeds (25.85 ± 41.3 in exclosure plots vs 31.45 ± 42.49 in free-access plots) and diversity. However, seedling survival one year after transplantation was higher for the plant species in the exclosure plots (68.4%) as compared to the free-access plots (39%). Although there were no significant differences in seed bank, our results suggest that free-ranging goats in densities typical of the Caatinga region can impose elevated seedling mortality to the dominant woody dry forest species even considering a short period of time.

Dry forest decline is driven by both declining recruitment and increasing mortality in response to warm, dry conditions

AbstractAimAnticipating when and where changes in species' demographic rates will lead to range shifts in response to changing climate remains a major challenge. Despite evidence of increasing mortality in dry forests across the globe in response to drought and warming temperatures, the overall impacts on the distribution of dry forests are largely unknown because we lack comparable large‐scale data on tree recruitment rates. Here, our aim was to develop range‐wide population models for dry forest tree species (pinyon pine and juniper), quantifying both mortality and recruitment, to better understand where and under what conditions species range contractions are occurring.LocationWestern United States.Major taxa studiedTwo pinyon pine (Pinus spp.) and three juniper (Juniperus spp.) species.MethodsWe developed range‐wide demographic models for five species using forest inventory data from across the western United States and estimated population trends and climate vulnerability.ResultsWe find that four of the five species are declining in parts of their range, with Pinus edulis having the largest proportion of populations declining (24%). Population vulnerability increases with aridity and temperature, with up to ~50% of populations declining in the warmest and driest conditions. Mortality and recruitment were both essential to explaining where populations are declining.Main conclusionsOur results suggest that dry forest species are undergoing an active range shift driven by both changing recruitment and mortality, and that increasing temperatures and drought threaten the long‐term viability of many of these species in their current range. While four of the five species examined were experiencing some declines, P. edulis is currently most vulnerable. Management actions such as reducing tree density may be able to mitigate some of these impacts. The framework we present to estimate range‐wide demographic rates can be applied to other species to determine where range contractions are most likely.

Harvesting has variable effects on demographic rates and population growth across three dry forest tree species

AbstractUnderstanding how anthropogenic activities, such as harvesting, influence plant populations is important to quantify sustainable practices that conserve species of socioeconomic importance. There is limited knowledge on how harvesting of branches and non‐timber forest products affect populations of trees in the dry tropics. We measure demographic vital rates of three dry tropical tree species in the presence and absence of harvesting and apply integral projection models to quantify population growth rates, which represent the mean fitness across the life cycle. Our results show that the three species vary in their demographic rates and life history. Harvesting significantly decreases the growth of two species. Current levels of harvesting only significantly decreased the population growth rate of one species that experienced both branch and main stem harvesting. Life table response experiments reveal that the negative effect of harvesting on the population growth rate of this species is primarily due to individuals being forced to re‐sprout from their base. Few individuals were observed recruiting from seed, and this might be due to the presence of other threats, such as fire, soil erosion, and grazing. Our results provide knowledge on the demography and the effects of harvesting on endemic tree species of the Eastern Ghats, a region for which few demographic studies are available. These results are relevant to conserving forest biodiversity for the benefits of people and can contribute to quantitative threat assessment for IUCN red listing.

Fruits of Cyrtocarpa procera Kunth (Anacardiaceae) as resource for medium to large-sized terrestrial mammals species in a tropical dry forest

ABSTRACT The fruits of some Anacardiaceae tree species are important sources of food and water for vertebrate species in seasonal tropical forest. During a monitoring study using camera-traps in a tropical dry forest of the Tehuacán-Cuicatlán Biosphere Reserve, Mexico, we documented tree visitation and fruit consumption in the ‘Chupandillo’ Cyrtocarpa procera by medium to large-sized terrestrial mammals species. From 2012 to 2017, we established cameras-traps in front of six adult chupandillo trees during 385–499 days. A total of 4,831 photographs were obtained during a total of 2,706 days. The camera-traps recorded 12 mammals species visiting, passing in front the tree, or consuming its fruits. The white-tailed deer, cotton rabbit, collared peccary and gray fox were the species that presented the highest number of visit events, with the two ungulate species recorded visiting all of the sampled trees. These species, as well as coati, consumed fruits of this tree species from September to October. The white-tailed deer visited during the day, while the collared peccary mainly visited during the twilight-night time period. We propose that fruits of C. procera are an important resource for mammals in this region, in particular for white-tailed deer and collared peccary.

Variation in thermal and hydrotime requirements for seed germination of Chaco seasonally dry forest species in relation to population environmental conditions and seed mass

AbstractThermal and hydrotime requirements for seed germination can vary with the species, environment in which the seeds developed and/or seed mass. We investigated seed germination responses to temperature and water potential of Aspidosperma quebracho‐blanco, Bulnesia retama, Parasenegalia visco, Parkinsonia praecox and Tecoma stans, all of which are native tree species of Chaco seasonally dry forests in northwest Argentina. We determined inter‐and intraspecific variability in seed germination through thermal and hydrotime models and correlated model parameters with environmental variables of seed provenance and seed mass. Seeds of all species germinated to high percentage over a range of temperatures. Seeds of A. quebracho‐blanco, P. praecox and T. stans were more tolerant to water stress than those of B. retama and P. visco. Thermal and hydrotime parameters for germination varied amongst species and populations. There was a negative correlation between thermal (θT(50)) and hydrotime (θH) constants and base temperature (Tb) and water potential (Ψb(50)). Seed mass correlated negatively with Tb and positively with θT(50). Species and populations were grouped according to thermal and hydrotime parameters and seed mass but not according to seed provenance. These results suggest that seed germination traits related to temperature, water potential and seed mass are species specific, and the variations within a species are probably due to a high phenotypic plasticity. These species showed a complex set of germination strategies that give them a competitive advantage in different environments, depending on dispersal time, seed mass and local environmental conditions during the germination period.

Above- and below-ground trait coordination in tree seedlings depend on the most limiting resource: a test comparing a wet and a dry tropical forest in Mexico.

The study of above- and below-ground organ plant coordination is crucial for understanding the biophysical constraints and trade-offs involved in species’ performance under different environmental conditions. Environmental stress is expected to increase constraints on species trait combinations, resulting in stronger coordination among the organs involved in the acquisition and processing of the most limiting resource. To test this hypothesis, we compared the coordination of trait combinations in 94 tree seedling species from two tropical forest systems in Mexico: dry and moist. In general, we expected that the water limitation experienced by dry forest species would result in stronger leaf-stem-root coordination than light limitation experienced by moist forest species. Using multiple correlations analyses and tools derived from network theory, we found similar functional trait coordination between forests. However, the most important traits differed between the forest types. While in the dry forest the most central traits were all related to water storage (leaf and stem water content and root thickness), in the moist forest they were related to the capacity to store water in leaves (leaf water content), root efficiency to capture resources (specific root length), and stem toughness (wood density). Our findings indicate that there is a shift in the relative importance of mechanisms to face the most limiting resource in contrasting tropical forests.

Tropical wet and dry forest tree species exhibit contrasting hydraulic architecture

Forest tree species in wet and dry habitats are generally considered functionally divergent in leaf and stem functional traits such as leaf area, leaf mass per area, wood density and tree height. Yet, these traits have limited utility for characterizing plant water transport adaptations and strategies. We tested the hypothesis that wet and dry forest trees are functionally divergent in their water conducting apparatus. To assess trait differences and adaptations, we sampled branch wood from nine same-genus species-pairs, each species-pair occurring respectively in the wet (>1500 mm annual rainfall) and dry forest (<800 mm annual rainfall) in tropical Queensland, Australia. From branch wood sections, we measured anatomical traits involved in water conduction (stem vessel dimensions, fractions and their spatial distributions, theoretical water conductivities), storage (parenchyma), and providing hydraulic safety functions (fibres fractions, vulnerability index). Relative to wet forest species, we found on overall that dry forest trees had trait combinations showing adaptations to aridity such as more storage tissue and greater vessel connectivity which may provide alternative pathways for water transport should vessel embolism occur. Habitat is an environmental filter that influences trait behaviour across related species. However, depending on the genera, species in both dry and wet forest habitats also exhibit various tradeoffs in trait values, highlighting the existence of diverse hydraulic strategies within wet forest and dry forest trees.

Lianas and Trees From a Seasonally Dry and a Wet Tropical Forest Did Not Differ in Embolism Resistance but Did Differ in Xylem Anatomical Traits in the Dry Forest

One of the most prominent changes in neotropical forests has been the increase in abundance and size of lianas. Studies suggest that lianas have more acquisitive strategies than trees, which could allow them to take advantage of water more effectively when it is available in water-limited forests, but few studies compared across growth form (i.e., lianas vs. trees) and forest type (i.e., wet vs. seasonally dry). We measured hydraulic and anatomical traits of co-occurring lianas and trees that convey drought resistance (xylem embolism resistance and intervessel pit membranes) and water transport capacity (xylem vessel diameter and density) in a seasonally dry and a wet evergreen tropical forest to address: (1) Are there differences between vulnerability to embolisms (P50—water potential at 50% loss of hydraulic conductivity) and hydraulic safety margins (HSM) across growth form and forest type? (2) How do vessel diameter and density vary across growth form and forest type? (3) Are there differences in xylem intervessel pit membrane thickness across growth form and forest type and does it predict xylem embolism vulnerability in trees and lianas? We examined hydraulic and xylem anatomical traits of 32 species—eight lianas and eight trees in each forest type. We found no difference in P50and HSMs between lianas and trees and between the wetter and drier forest. Dry forest lianas had 81% greater maximum vessel diameter and 125% greater range in vessel diameter sizes than dry forest trees but, there was no significant difference between life forms in the wet forest. Dry forest species had 50% greater vessel density and 30% greater maximum pit membrane thickness than wet forest ones. Maximum pit membrane thickness was correlated to P50and HSMs. The main difference between lianas and trees occurred in the dry forest, where lianas had larger maximum xylem vessel size than trees, implying that they have proportionally greater hydraulic conductive capacity than the trees in seasonal forests.

A Predictive Model of Leaf Flammability Using Leaf Traits and Radiant Heat Flux for Plants of Fire-Prone Dry Sclerophyll Forest

The differential flammability of individual plant species in landscape-scale fire behaviour is an important consideration, but one that is often overlooked. This is in part due to a relative dearth in the availability of plant flammability data. Here, we present a highly accurate predictive model of the likelihood of plant leaves entering flaming combustion as a function of leaf mass per area (LMA), leaf area (LA) and radiant heat flux using species of fire-prone dry sclerophyll forests of south-eastern Australia. We validated the performance of the model on two separate datasets, and on plant species not included in the model building process. Our model gives accurate predictions (75–84%) of leaf flaming with potential application in the next generation of fire behaviour models. Given the global wealth of species’ data for LMA and LA, in stark contrast to leaf flammability data, our model has the potential to improve understanding of forest flammability in the absence of leaf flammability information.

Individual Tree Volume Models and Form Factors for Woody Species in Dry Afromontane Forest, Central Ethiopia

Individual Tree Volume Models and Form Factors for Woody Species in Dry Afromontane Forest, Central Ethiopia

Allometric relationships to estimate aboveground biomass of species in a tropical dry forest of Central Mexico

The estimation of biomass in seasonally tropical dry forests requires basic information that for some species is scarce. To help solve this deficit, we generated allometric equations for five species of tropical dry forest (TDF). Equations for each tree species studied, for two groups of species, and all species together are reported. The equations were of the power type, based on diameter at breast height (dbh). The allometric model of each species included was fitted resulting in high values of the coefficient of determination using only the vari­able dbh. The allometric equations for each of the five forest species differed from each other (p &lt; 0.05). Species grouped according to similar specific wood density showed a better fit of the model (p &lt; 0.05), particularly those with high values for this parameter, than when considering only one species. The biomass of all species was predicted correctly by using only the measures of the basal area. However, the coefficient of determination increased, and the estimated error decreased, when the specific wood density was added to the model. Finally, the best fit of the model is attained by adding the tree height to the equation. The last two characteristics, however, were not significant when determining the individual models for each species.

Climate-growth relations of congeneric tree species vary across a tropical vegetation gradient in Brazil

Seasonally dry tropical forests are an important global climatic regulator, a main driver of the global carbon sink dynamics and are predicted to suffer future reductions in their productivity due to climate change. Yet, little is known about how interannual climate variability affects tree growth and how climate-growth responses vary across rainfall gradients in these forests. Here we evaluate changes in climate sensitivity of tree growth along an environmental gradient of seasonally dry tropical vegetation types (evergreen forest – savannah – dry forest) in Northeastern Brazil, using congeneric species of two common neotropical genera: Aspidosperma and Handroanthus. We built tree-ring width chronologies for each species × forest type combinations and explored how growth variability correlated with local (precipitation, temperature) and global (the El Niño Southern Oscillation - ENSO) climatic factors. We also assessed how growth sensitivity to climate and the presence of growth deviations varied along the gradient. Precipitation stimulates tree growth and was the main growth-influencing factor across vegetation types. Trees in the dry forest site showed highest growth sensitivity to interannual variation in precipitation. Temperature and ENSO phenomena correlated negatively with growth and sensitivity to both climatic factors were similar across sites. Negative growth deviations were present and found mostly in the dry-forest species. Our results reveal a dominant effect of precipitation on tree growth in seasonally dry tropical forests and suggest that along the gradient, dry forests are the most sensitivity to drought. These forests may therefore be the most vulnerable to the deleterious effects of future climatic changes. These results highlight the importance of understanding the climatic sensitivity of different tropical forests. This understanding is key to predict the carbon dynamics in tropical regions, and sensitivity differences should be considered when prioritizing conservation measures of seasonally dry topical forests.

Molecular evidence and ecological niche modeling reveal an extensive hybrid zone among three Bursera species (section Bullockia).

The genus Bursera, includes ~100 shrub and trees species in tropical dry forests with its center of diversification and endemism in Mexico. Morphologically intermediate individuals have commonly been observed in Mexican Bursera in areas where closely related species coexist. These individuals are assumed to result from interspecific hybridization, but no molecular evidence has supported their hybrid origins. This study aimed to investigate the existence of interspecific hybridization among three Mexican Bursera species (Bullockia section: B. cuneata, B. palmeri and B. bipinnata) from nine populations based on DNA sequences (three nuclear and four chloroplast regions) and ecological niche modeling for three past and two future scenario projections. Results from the only two polymorphic nuclear regions (PEPC, ETS) supported the hybrid origin of morphologically intermediate individuals and revealed that B. cuneata and B. bipinnata are the parental species that are genetically closer to the putative hybrids. Ecological niche modeling accurately predicted the occurrence of putative hybrid populations and showed a potential hybrid zone extending in a larger area (74,000 km2) than previously thought. Paleo-reconstructions showed a potential hybrid zone existing from the Last Glacial Maximum (~ 21 kya) that has increased since the late Holocene to the present. Future ecological niche projections show an increment of suitability of the potential hybrid zone for 2050 and 2070 relative to the present. Hybrid zone changes responded mostly to an increase in elevational ranges. Our study provides the first insight of an extensive hybrid zone among three Mexican Bursera species based on molecular data and ecological niche modeling.

The seasonally dry tropical forest species Cavanillesia chicamochae has a middle Quaternary origin

AbstractWe use DNA sequence data to understand the evolutionary history of the genus Cavanillesia (Malvaceae), with particular emphasis on C. chicamochae, an emblematic succulent‐trunked tree endemic to seasonally dry tropical forests (SDTFs) of the Chicamocha Canyon of Colombia, South America. Based on field sampling of multiple individuals from different populations, we inferred a phylogeny calibrated into absolute time using robust macrofossil information. We show strong support for a monophyletic Cavanillesia chicamochae, with a mean stem age of 1.46 Ma. Two different mechanisms could explain its origin, either a late uplift age of the eastern cordillera or increased dryness of the Chicamocha Canyon during the Middle Pleistocene Transition. We also find marked genetic differentiation of its populations within the Chicamocha Canyon, likely driven by a combination of climate change and local landscape processes. Our results suggest that within northern inter‐Andean SDTFs, as has been demonstrated in the central Andes, dispersal limitation leads to species and even population monophyly within individual valleys. The genetic differentiation of populations of C. chicamochae, together with the presence of other endemic and threatened species in the Chicamocha Canyon, calls for urgent management to conserve the unique biodiversity in the region.Abstract in Spanish is available with online material.

Pollination Biology of an Endemic Hawaiian Tree, Erythrina sandwicensis (Fabaceae: Papilionoideae), in a Novel Ecosystem1

Tropical dry forest ecosystems are among the most endangered ecosystems globally. In Hawai‘i, dry forest species are under threat due to habitat destruction, invasive species, and a loss of mutualisms including pollinators. Understanding the pollination biology of species at risk can inform conservation strategies. This study aimed to identify the breeding system and types of floral visitors to Erythrina sandwicensis (Fabaceae) or wiliwili, an iconic Hawaiian tree in decline and with little regeneration. We conducted hand-pollination trials and observed visitors in two sites: a botanical garden and a forest site. We compared fruit set, seed set, seed germination, seedling growth rate, and seedling size across four pollination treatments: open control, autogamy, geitonogamy, and xenogamy. We found that wiliwili is visited by a novel suite of non-native visitors. All treatments produced seeds, but the xenogamous (cross) treatment produced significantly more fruit and seeds than the control or other treatments. Seedlings produced from cross-pollinated treatments were also taller and had wider basal diameters after twenty-eight days of growth. These results indicate that wiliwili employs a mixed-mating system, and that trees are pollen limited. Enhancing current populations of wiliwili to promote cross-pollination could help increase population regeneration.

Beyond leaf habit: generalities in plant function across 97 tropical dry forest tree species.

Leaf habit has been hypothesized to define a linkage between the slow-fast plant economic spectrum and the drought resistance-avoidance trade-off in tropical forests ('slow-safe vs fast-risky'). However, variation in hydraulic traits as a function of leaf habit has rarely been explored for a large number of species. We sampled leaf and branch functional traits of 97 tropical dry forest tree species from four sites to investigate whether patterns of trait variation varied consistently in relation to leaf habit along the 'slow-safe vs fast-risky' trade-off. Leaf habit explained from 0% to 43.69% of individual trait variation. We found that evergreen and semi-deciduous species differed in their location along the multivariate trait ordination when compared to deciduous species. While deciduous species showed consistent trait values, evergreen species trait values varied as a function of the site. Last, trait values varied in relation to the proportion of deciduous species in the plant community. We found that leaf habit describes the strategies that define drought avoidance and plant economics in tropical trees. However, leaf habit alone does not explain patterns of trait variation, which suggests quantifying site-specific or species-specific uncertainty in trait variation as the way forward.

Seasonality and landscape characteristics impact species community structure and temporal dynamics of East African butterflies

Species community structures respond strongly to habitat changes. These are either driven by nature or human activities. The biota of East African drylands responds highly sensitively to natural and anthropogenic impacts. Thus, seasonality strongly influences resource availability in a cyclic manner during the year, with cyclic appearance of the different developmental stages of invertebrates, while man-made landscape transformations profoundly and permanently modify habitat structures and, as a consequence, species communities. Butterflies are an excellent model group for the study of the effects of seasonality, and to test for biodiversity responses to anthropogenic activities such as habitat modification, degradation and destruction. We performed transect counts of adult butterflies in riparian forests and their adjoining areas, either dry savannahs with occasional pasturing (i.e. near-natural status) or farmland areas with fields, gardens and settlements (i.e. highly degraded status with lack of original vegetation). Transects were set along the river beds as well as at 250 m and 500 m distances parallel to these rivers, with eight transects per distance class and site (i.e. 48 transects in total). We recorded habitat structures for each transect. Counts were conducted during the dry and the rainy season, with 16 repetitions for each single transect, i.e. eight per season and transect. We compiled trait data on morphology, geographic distribution, ecology, behaviour, and life-history for all butterfly species encountered. Our results show higher species richness and numbers of individuals in farmland transects compared with the savannah region. Seasonal fluctuations of the detectable species abundances between the rainy and dry season were severe. These fluctuations were much more pronounced for the savannah than the farmland area, i.e. was buffered by human activities. Farmland and savannah support two distinct butterfly communities, with generalist species being more common in the farmland communities. Strict habitat associations were comparatively weak and typical dry savannah and riparian forest species were not clearly restricted to the near natural landscape.

Limited evidence of coupling between above and belowground functional traits in tropical dry forest seedlings

Introduction: Water availability is one of the main factors determining the distribution of woody species in the tropics. Although the functional mechanisms that determine the species tolerance to water deficit have been extensively studied in adult individuals, the responses of early ontogenetic stages have been less explored. Objective: To identify functional strategies and trait correlations between different seedlings' dimensions (leaf, stem, and root). We expect limited coordination between above and below-ground functional traits due to a single conservation-acquisition trade-off cannot capture the variability of functions and environmental pressures to which the root system is subjected. Methods: We measured 12 functional traits belonging to 38 seedling species in a tropical dry forest in Colombia. We explored the relationships between pairs of traits using Pearson correlations, and to obtain an integrated view of the functional traits, a principal component analysis (PCA) was performed. Results: The results showed limited evidence of linkage between above- and below-ground traits, but we did find significant correlations between traits for the continuum of conservative and acquisitive strategies. Root traits related to water and nutrient take capacity formed an orthogonal axis to the acquisitive-conservative continuum. Conclusions: Our results showed that dry forest seedlings have different functional strategies to cope with water deficit. The incorporation of root traits helps to explain new functional strategies not reported for leaf and stem traits. This study contributes to understanding the mechanisms that explain species coexistence and is particularly relevant for predicting future forest trajectories.

Seven new giant pill-millipede species and numerous new records of the genus Zoosphaerium from Madagascar (Diplopoda, Sphaerotheriida, Arthrosphaeridae)

Seven new species of the giant pill-millipede genus Zoosphaerium Pocock, 1895 are described from Madagascar: Z. nigrum sp. nov., Z. silens sp. nov., Z. ambatovaky sp. nov., Z. beanka sp. nov., Z. voahangy sp. nov., Z. masoala sp. nov. and Z. spinopiligerum sp. nov. All species are described based on drawings and scanning electron microscopy, while genetic barcoding of the COI gene was successful for six of the seven new species. Additional COI barcode information is provided for the first time for Z. album Wesener, 2009 and Z. libidinosum (de Saussure &amp; Zehntner, 1897). Zoosphaerium nigrum sp. nov. and Z. silens sp. nov. belong to the Z. libidinosum species-group, Z. ambatovaky sp. nov. to the Z. coquerelianum species-group, Z. beanka sp. nov., Z. voahangy sp. nov. and Z. masoala sp. nov. to the Z. platylabum species-group and Z. spinopiligerum sp. nov. to the Z. piligerum species-group. Updated identification keys are provided for each species-group. Two western dry forest species, Z. silens sp. nov. and Z. voahangy sp. nov. are recorded from two localities, while the other five species are currently only known from their type localities. Of special conservation concern might be Z. ambatovaky sp. nov. from the lowland rainforest fragment of Ambatovaky, a nowadays isolated lowland rainforest, rapidly shrinking due to slash and burn agriculture. In addition to the new species, new locality data is provided for 11 species and numerous unidentifiable species of Zoosphaerium: Z. neptunus (Butler, 1872), Z. platylabum (de Saussure &amp; Zehntner, 1902) and Z. piligerum (de Saussure &amp; Zehntner, 1897) from the central eastern montane forests, as well as Z. ambrense Wesener, 2009, Z. aureum Wesener, 2009, Z. libidinosum, Z. corystoides Wesener, 2009, Z. discolor Wesener, 2009, Z. smaragdinum Wesener, 2009, Z. villosum Wesener &amp; Sierwald, 2005 and Microsphaerotherium anjozorobe Wesener, 2009.

Host-Feeding Patterns of the Mosquito Assemblage at Lomas Barbudal Biological Reserve, Guanacaste, Costa Rica.

Mosquito-borne pathogens have spread throughout tropical regions of the Western Hemisphere causing increased burden of disease in the region. Outbreaks of dengue fever, yellow fever, chikungunya, West Nile, and Zika have occurred over the past several years. Mosquito blood-feeding patterns need to be assayed to assist in determining which vertebrates could act as hosts of these mosquito-borne pathogens and which mosquito species could act as vectors. We conducted bloodmeal analyses of mosquitoes collected at Lomas Barbudal Biological Reserve, a dry tropical forest reserve in Costa Rica. Mosquitoes were collected using backpack aspirators and light, gravid, and resting traps, and then identified morphologically. Blood-fed mosquitoes underwent DNA extraction, PCR amplification, and sequencing of the vertebrate cytochrome b and cytochrome c oxidase 1 genes to identify vertebrate bloodmeal hosts. Several mosquitoes known to vector pathogens were found including Culex (Melanoconion) erraticus Dyar & Knab (Diptera: Culicidae), Cx. (Mel.) pedroi Sirivanakarn & Belkin, Aedes (Stegomyia) albopictus Skuse, Ae. (Ochlerotatus) scapularis Rondani, Ae. (Och.) serratus Theobald, and Ae. (Och.) taeniorhynchus Wiedemann. The most common bloodmeal hosts were basilisk lizards (Basiliscus vittatus) Wiegmann (Squamata: Corytophanidae) in Culex (Linnaeus) species and white-tailed deer (Odocoileus virginianus) Zimmermann (Artiodactyla: Cervidae) in Aedes (Meigen) species. These results show the diversity of mosquito species in a tropical dry deciduous forest and identify associations between mosquito vectors and potential pathogen reservoir hosts. Our study highlights the importance of understanding interactions between vector species and their hosts that could serve as predictors for the potential emergence or resurgence of mosquito-borne pathogens in Costa Rica.