Field Habitats Research Articles

Profile of ectoparasites and biometric condition of snakehead (Channa striata Bloch 1793) collected from different habitats

Studies related to the comparison of ectoparasites that infect snakehead from different habitats and their relationship to biometric conditions have not been widely studied. Thus, present study aimed to investigate the prevalence, intensity, dominance, and predilection of ectoparasites on snakehead collected from ditches, paddy fields, and swamps and correlate them with biometric conditions. In total of 90 snakehead fish were collected from ditches, paddy fields, and swamps. The observation of ectoparasites was performed on the gills, fins, and skin. The parameters measured in this study were ectoparasite profiles and biometric condition of fish. Specifically, the parameters of the ectoparasite profile included prevalence, intensity, dominance, and predilection. Meanwhile, the parameters of the biometric conditions were the length-weight relationship, the distribution of length and weight classes, and condition factors. Five species of ectoparasites that have been identified as Tetrahymena sp., Epistylis sp., Trichodina sp., Dactylogyrus sp., and Gyrodactylus sp. Tetrahymena sp. infection in snakehead was reported for the first time. The ditch habitat had the highest prevalence and intensity, which were 76.7% and 15.4 ectoparasites/fish, respectively. Tetrahymena sp. and Epistylis sp. were detected in sneakhead from all habitats, Trichodina sp. was detected at ditch and paddy field habitats, whereas, Gyrodactylus sp. and Dactylogyrus sp. were only found in swamp habitats. The gill was the predilection organ that most vulnerable to ectoparasite infection. Infected Snakehead tend to have lower average weight and length than healthy snakehead. Snakehead with a weight range of 115.2-145.2 g and a length range of 258.5-268.5 mm tend to be more vulnerable to ectoparasite infection compared to other sizes.Keywords:Tetrahymena sp.PrevalenceIntensityPredilectionLength-weight relationship

KEANEKARAGAMAN JENIS CAPUNG PADA BERBAGAI TIPE HABITAT DI DESA CIPEUTEUY KECAMATAN KABANDUNGAN KABUPATEN SUKABUMI

Dragonflies are insects that mostly live as nymphs and are related to aquatic habitats and act as bioindicators of environmental quality. The purpose of the study was to identify the diversity of dragonflies in various habitat types in Cipeuteuy Village. This study uses the line transect method measuring 100 meters with a width of 20 meters right and left and the duration of observation is 15 minutes per each observation line. The study was conducted in nite habitat types from 52 locations. The total dragonfly found were 13 species from four families. The highest dragonfly richness was found in the rice field habitat as many as 12 species and the lowest species was found in the citrus garden habitat as many as three species. The dominant species of dragonfly found in all habitat types is Rhodothemis rufa. The overall dragonfly diversity index was 2.56 and ranged from 1.10 to 2.48, and the evenness index ranged from 0.57 to 0.90.

Comparative study on the larvicidal effect of some ciliated protists on Culex gelidus, Culex tritaeniorhynchus, and Aedes aegypti in Sri Lanka

Rice fields in Sri Lanka create suitable breeding places for vector mosquitoes. Such sites provide habitats for diversified naturally occurring microbiota. Ciliated protists, Zoothamnium sp., Chilodonella sp., and Vorticella microstoma are among such microbiota found in vector mosquito habitats especially in rice field habitats in Sri Lanka. The present study was carried out to determine the comparative larvicidal effect of these ciliated protists collected from naturally infested mosquito larvae in some rice-field habitats in Kurunegala, Sri Lanka, against vector mosquito larvae. Vector mosquito larvae, Culex tritaeniorhynchus, and Culex gelidus were reared in the laboratory from field-collected water samples while Aedes aegypti mosquito larvae were reared using egg sheets, for the laboratory bioassays. V. microstoma showed the potential for infection and mortality of Cx. tritaeniorhynchus larvae (71.33% ± 5.23). Results revealed a minimum of 1000V. microstoma is required to kill a single third instar larva of Cx. tritaeniorhynchus at 69.60 ± 2.40h of exposure. Cx. gelidus larvae showed 41.33% ± 3.43 mortality due to V. microstoma infestation. However, none of the ciliates were effective against Ae. aegypti larvae. Chilodonella sp. was very occasionally reported during this study hence was not possible to the mass rear for experimentations. This study concludes that V. microstoma is an effective ciliated parasite of Cx. tritaeniorhynchus larvae. Due to their effectiveness and eco-friendly nature, this species can be developed as an effective bio-controlling agent against Cx. tritaeniorhynchus mosquito species.

The conquest of land by the Amphipoda (Senticaudata, Talitroidea) explained by global tectonics and vicariance

The Talitroidea originated from a marine ancestor in the amphipod family Hyalidae that colonised marshy land flooded occasionally by the sea. From there, some descendants migrated inland along river catchments, as their terrestrial adaptations evolved, becoming riparian. Over time they colonised moist habitats in fields and forests. The superfamily Talitroidea comprises all known terrestrial amphipods and it has an almost worldwide distribution, but families have discrete distributions. Because all amphipods release fully formed young and have no dispersive phase in their life history, their potential for dispersal is extremely limited. Terrestrial talitroids are particularly constrained on a global scale, because their adaptations for terrestrial life prevent them from crossing seas or oceans. It has been hypothesised that Talitridae living on marine shores might traverse oceans on rafts of detached wrack. Support for this might be the fact that beach hoppers are the most widely distributed of the Talitroidea. However, they have been shown to abandon floating objects actively and several attempts to explain specific cases of talitrid distributions by implicating rafting have been falsified. The broad distributions of Talitroidea across the globe can be explained parsimoniously only by vicariance. The family Arcitalitridae is, with one exception, endemic to Australasia and South Africa, which have been separated from one another since the late Jurrasic c.150Ma. The exception is provided by two genera in Indochina, which probably arrived in Laurasia when India, which had been part of east Gondwana, accreted to Laurasia in the Miocene. However, terranes separated from the margins of Gondwana in the late Triassic-early Jurrasic and then accreted as allochthonous terranes to Laurasia, so the possibility of arcitalitrids arriving in Laurasia at that time, cannot be excluded. The family Makawidae, which is endemic to Zealandia and Tasmania, probably attained it's current distribution through the expansion of the Tasman Sea in the Cretaceous.

Prospects for Integrating Augmentative and Conservation Biological Control of Leaffolders and Stemborers in Rice

Possibilities to combine augmentative biological control using Trichogramma spp. egg parasitoids and conservation biological control through habitat manipulation, for the management of rice leaffolder and rice stemborer pests have received only cursory mention in the literature. We reviewed information on the use of Trichogramma releases and on habitat manipulation to manage leaffolders and stemborers in rice. Stemborers have become a priority for biological control since the 1990s with research focusing mainly on Chilo suppressalis in China and Iran, Scirpophaga incertulas in South and Southeast Asia, and Chilo agamemnon in Egypt. In most cases, 100 K wasps (T. japonicum or T. chilonis) released over 30–100 release points ha−1 at least once during early crop stages, resulted in good control (>50% reduction in damage). Despite positive results accumulated over decades, larger scale releases in rice have only been conducted very recently. Research on conservation biological control of stemborers has focused on manipulating rice field habitat, particularly along rice bunds (levees). Several studies reported higher Trichogramma densities or greater egg parasitism in rice fields with flowering plants on bunds compared to control fields (without bund vegetation and usually with insecticides). These trends have mainly been attributed to nectar as a supplementary food for the adult wasps, although evidence for this mechanism is weak. Trap plants, such as vetiver grass (Chrysopogon zizanioides) attract ovipositing stemborers, but suppress larval development. Repellent and banker plants have not yet been identified for rice stemborers or leaffolders. We outline the opportunities and challenges for combining augmentative and conservation biological control of leaffolders and stemborers in rice.

Soras over Illinois: Nocturnal Settlement Patterns in Porzana carolina are Site-Specific But Show No Evidence of Visual or Acoustic Cues

Many birds migrate at night, but little is known about whether they base nocturnal settlement decisions on visual or acoustic cues. Studies of conspecific attraction have found that songbirds and seabirds are attracted by day to call playback or decoy models, and birds will also settle preferentially in certain environments based on the presence of vegetation or water bodies. Remotely activated broadcasts and Autonomous Recording Units were applied to study whether Soras (Porzana carolina), common nocturnally migrating rails in central Illinois, could be enticed to settle in farm field habitats. At three study areas (farms) we used cues to attempt to attract Soras, with our experimental design consisting of Sora vocalizations, small ponds (Sora habitat), both cues, and no cues. Neither conspecific playback, visual pond cues, nor their combination significantly influenced Sora settlement. However, there were significant differences between farms in Sora calls recorded. One study area, Franklin Farm, had the most Sora detections during the study period, consistent with its high-quality habitat status as a Nature Conservancy restored wetland. As nocturnal calls were detected at every farm sampled, these results may assist wetland managers in promoting Sora settlement in critical breeding habitats in Illinois and beyond.

Factors Influencing the Growth and Production of auxin in two locally isolated Synechocystis Species from Variant rice field Habitats

Synechocystis species have been assessed for their capacity to produce IAA (Indole acetic acid) in the rhizosphere and water of a rice field. Temp, acid levels, treatment time, and multiple tryptophan proportions were analyzed to see how they affected growth and phytohormones content. Different temperatures and pH levels ranges were preferred by habitat-isolated strains for development and auxin production. The ideal pH and temperature for water isolate growth were 8 and 30°C, respectively, while for rhizospheric isolate growth, 7 and 25°C. Both strains produced the most auxin at pH 6 and 35°C. The production of auxin by both isolates was positively related to incubation and tryptophan quantity.

Moth sex pheromones affect interspecific competition among sympatric species and possibly population distribution by modulating pre-mating behavior.

Premating behaviors mediated by pheromones play pivotal roles in animal mating choices. In natural populations of the striped stem borer Chilo suppressalis and the rice leaf roller Cnaphalocrocis medinalis in the rice field habitat, we discovered that Z11-16:Ald, a major component of the C. suppressalis pheromone, modulated the premating behavior of C. medinalis. Z11-16:Ald evoked a strong olfactory response in male antennae and strongly inhibited the sex pheromone trapping of male C. medinalis in the field. The functions of three C. medinalis sex pheromone receptor genes (CmedPR1-3) were verified through heterologous expression in Xenopus oocytes. CmedPR1 responded to Z11-18:OH and Z11-18:Ald, as well as the interspecific pheromone compound Z11-16:Ac of sympatric species; CmedPR2 responded to Z13-18:OH and Z13-18:Ald, as well as the sex pheromone compounds Z11-16:Ald and Z9-16:Ald of sympatric species; and CmedPR3 responded to Z11-18:OH and Z13-18:OH, as well as the interspecific pheromones Z11-16:OH, Z9-16:Ald, Z11-16:Ac, and Z11-16:Ald of sympatric species. Thus, CmedPR2 and CmedPR3 share the ligand Z11-16:Ald, which is not a component of the C. medinalis sex pheromone. Therefore, the sex pheromones of interspecific species affected the input of neural signals by stimulating the sex pheromone receptors on the antennae of male C. medinalis moths, thereby inhibiting the olfactory responses of the male moths to the sex pheromones. Our results demonstrate chemical communication among sympatric species in the rice field habitat, the recognition of intra- and interspecific sex pheromones by olfactory receptors, and how insect premating behaviors are modulated to possibly affect resource partitioning.

Agricultural management intensity determines the strength of weed seed predation

Agricultural intensification both increases disturbances at the field level and reduces habitat heterogeneity at the landscape level and this can have detrimental effects on biodiversity-driven ecosystem services. A few studies have shown that agricultural intensification can diminish the ecosystem service of weed seed predation, but it is not known to what extent availability of crop and non-crop habitat can provide disturbance refugia for weed seed predators and how those effects cascade to ecosystem service provisioning. Using data from 13 fields in Southern Sweden, we first combined diet preference traits, activity density and metabolic theory, in order to develop a metric that approximates the community strength of seed predation. We then explored how the impact of field management intensity and habitat refugia on seed card predation rates mediated by weed seed availability and the metric of community strength of seed predation. We found that increasing field management intensity directly reduced seed card predation rates and weed seed availability and that reduced weed seed availability in turn impaired the community strength of seed predation. This suggests an indirect mechanism by which field management limits seed predator potential for weed seed predation. We found no evidence that either crop or non-crop refugia can increase seed card predation rates or community strength of seed predation during disturbances in the crop. Consequently, weed seed predation can be promoted by reducing disturbances at the field level, regardless of the availability of disturbance refugia in the landscape. Reduction of field management intensity can directly increase weed seed predation and indirectly seed predator communities’ potential for weed seed predation by increasing weed seed availability. Future research is needed to explore if supporting a diversity of non-competitive weeds to enhance seed availability can improve the suppression of dominant and competitive weed species.

Diversity and distribution of fish species in Upper Watershed of Citanduy, West Java, Indonesia

Citanduy is one of the major rivers in West Java, Indonesia, which empties into the Segara Anakan Lagoon. This river has streams originating from the Galunggung and Sawal Mountains. Information about freshwater fish in this area has not been fully documented and explored regarding fish diversity and distribution. This study aims to assess the fish diversity, abundance, distribution, and potential uses. The survey method was conducted upstream of the Citanduy River in the Regency of Tasikmalaya and Ciamis from 2012 to 2013. The sampling stations were grouped into the primary forest (1), secondary forest (2), shrubs (3), and (4) rice fields or plantations. In total, there are four stations in Sawal Mount and three groups of stations in Galunggung Mount. The collected fish were caught using electrofishing equipped with cast nets at each station. The results showed that there were 12 families with 24 species. Cichlidae is the dominant family with six species, followed by Cyprinidae with five species, and the remaining families only have one or two species. Both the Sawal and Galunggung Mountains have diverse habitats in rice fields or plantations. Based on the species, Barbodes binotatus was the most abundant species (128 ind./st.), followed by Nemacheilus fasciatus (64 ind./st.), Rasbora lateristriata (48 ind./st.) and the rest species with a range of 1-38 ind./st. Barbodes binotatus and Poecillia reticulata were widely distributed at 85.7%, followed by Channa gachua 71.4%; and the remaining species with a range of 14.3-57.1%. Most species have the potential as consume fish. Based on the species authenticity status, nine species (37.5%) were detected as introduced species.

Keanekaragaman Jenis Capung (Ordo Odonata) Pada Berbagai Tipe Habitat Di Kecamatan Leuwiliang Kabupaten Bogor

Dragonflies and damselflies (Odonata) are insects with an important role for biological control and environmental quality indicators. Odonata are scattered in various types of habitats, especially those associated with freshwater ecosystems. The aim of this research is to study the diversity of odonata in various habitat types in Leuwiliang District, Bogor Regency. The study was conducted on 10 habitat types with a total of 1289 observation lines. In total found 23 species of odonatan from eight families and two sub-orders. The highest species richness was found in stream water habitats (22 species) and the lowest in field habitats (five species). The chi-square test for the number of species and the number of individuals differed significantly between habitat types. The species diversity index ranged from 1.23-2.24 and the similarity index ranged from 0.39-0.71. The highest community similarity index was between lakes habitats and field habitats. The results of the MDS analysis resulted in three groups of odonata communities according to their habitat type.

Abyssal vent field habitats along plate margins in the Central Indian Ocean yield new species in the genus Anatoma (Vetigastropoda: Anatomidae)

New species in Anatoma Woodward, 1859 (Anatomidae, Vetigastropoda) are found in abyssal hydrothermal vent field habitats on the oceanic plate margins in the Indian Ocean. Six species are identified using molecular sequence analyses of which four species are described as new based on their morphological characters: Anatoma discapex sp. nov., Anatoma declivis sp. nov., Anatoma laevapex sp. nov. and Anatoma paucisculpta sp. nov. Inadequate material was available for a morphological description of the other two species with genetic identification, but it is likely that all six species are new to science and endemic to the Indian Ocean. The northern Central Indian Ridge localities are dominated by Anatoma declivis sp. nov.; its closest relative is Anatoma discapex sp. nov. which occurs in the central area near the Rodriguez Triple Junction. Anatoma laevapex sp. nov. and Anatoma paucisculpta sp. nov. as well as a fifth undescribed species are mainly found on the Southeast Indian Ridge.

Seasonal changes in questing efficiency of wild Amblyomma americanum (Acari: Ixodidae) nymphs

Understanding the factors which influence host-seeking behavior of ticks is essential to determine the risk they pose as a vector of pathogens. While many studies have evaluated the impact of environmental variables on tick behavior, few have examined how seasonal changes in physiological status may further modify patterns of activity. In this study, we measured differences in questing behavior of mid spring- and early summer-caught Amblyomma americanum nymphs held under standardized laboratory conditions. As both groups represent the same cohort of overwintered nymphs, we hypothesized that age-related changes in the older summer ticks may influence questing behavior. In each season, we collected nymphs from field and forest habitats in northeast Missouri, after which we placed each nymph individually in a desiccating vertical questing apparatus with a hydrating microenvironment at the base. On the day following collection, we recorded the height of each nymph in the apparatus bi-hourly from 04:00 to 22:00 and calculated the vertical displacement between consecutive observations. Despite displaying no differences in mean questing height throughout the experiment, active ticks collected in the summer group (n = 89) travelled greater cumulative distances between desiccating and hydrating microenvironments than those collected in the spring (n = 119). This suggests that questing efficiency decreases in summer nymphs to accommodate increased time allocation towards rehydration. While we observed no direct association between body size and distance travelled, body size of the nymphal population also decreased significantly from spring to summer. Overall, our results demonstrate that there are seasonal changes in how A. americanum responds to environmental conditions. To more accurately predict host-seeking behavior of ticks across seasons, models should incorporate physiological parameters of the active ticks in a given population.

Main environmental drivers of abundance, diversity and community structure of comammox Nitrospira in paddy soils

The recently discovered complete ammonia oxidizers comammox Nitrospira contain clades A and B that can establish an independent one-step nitrification process; however, little is known about their environmental drivers or habitat distributions in agricultural soils. Previous studies on comammox Nitrospira in paddy soils have mainly focused on small-scale samples, and there is a lack of multisite research on comammox Nitrospira in paddy soils. In this study, we conducted a survey of 36 paddy soils to understand the community structure, abundance, and diversity of comammox Nitrospira and the degree to which they are affected by environmental factors at a large scale. Comammox Nitrospira were found to be widely distributed among the paddy soils. The abundance of comammox Nitrospira clade A was mostly lower than that of clade B, whereas its diversity was mostly higher than that of clade B. Correlation analysis showed that multiple factors affected (P < 0.05) the abundance of comammox Nitrospira, including soil pH, organic matter, total carbon, and total nitrogen, latitude, mean annual temperature, and mean annual precipitation. Moreover, there was a clear relationship between the comammox Nitrospira community and habitat, indicating that some amplicon sequence variants (ASVs) had a unique dominant position in specific habitats. Phylogenetic analysis showed that the ASVs of comammox Nitrospira clade A clustered with the known sequences in the paddy soils and were significantly different from the known sequences in other habitats, which may be related to the unique paddy field habitat. In contrast, comammox Nitrospira clade B showed no clear habitat dependence. These results support the wide distribution and high abundance of comammox Nitrospira in paddy soils and provide novel insights into nitrogen cycling and nutrient management in agricultural ecosystems.

Variation in Survival and Gut Microbiome Composition of Hatchery-Grown Native Oysters at Various Locations within the Puget Sound.

ABSTRACTThe Olympia oyster (Ostrea lurida) of the Puget Sound suffered a dramatic population crash, but restoration efforts hope to revive this native species. One overlooked variable in the process of assessing ecosystem health is association of bacteria with marine organisms and the environments they occupy. Oyster microbiomes are known to differ significantly between species, tissue type, and the habitat in which they are found. The goals of this study were to determine the impact of field site and habitat on the oyster microbiome and to identify core oyster-associated bacteria in the Puget Sound. Olympia oysters from one parental family were deployed at four sites in the Puget Sound both inside and outside of eelgrass (Zostera marina) beds. Using 16S rRNA gene amplicon sequencing of the oyster gut, shell, and surrounding seawater and sediment, we demonstrate that gut-associated bacteria are distinct from the surrounding environment and vary by field site. Furthermore, regional differences in the gut microbiota are associated with the survival rates of oysters at each site after 2 months of field exposure. However, habitat type had no influence on microbiome diversity. Further work is needed to identify the specific bacterial dynamics that are associated with oyster physiology and survival rates.IMPORTANCE This is the first exploration of the microbial colonizers of the Olympia oyster, a native oyster species to the West Coast, which is a focus of restoration efforts. The patterns of differential microbial colonization by location reveal microscale characteristics of potential restoration sites which are not typically considered. These microbial dynamics can provide a more holistic perspective on the factors that may influence oyster performance.

Entomophagy practices in Bodoland Territorial Region, Assam: nutritional potential and implications for food security

Insects as food have been consumed all over the world, mostly by ethnic communities, since time immemorial. With the ever-increasing human population causing an imbalance between food production and nutrition, edible insects are gaining importance as an alternative food source. The aim of this paper is to record the region-specific current practices of entomophagy and their implications in food security. The study involved field investigation to find out the pattern of entomophagy among the scheduled tribes of the Bodoland Territorial Region (BTR), Assam. Following this, we made an effort to estimate the diversity of edible insects at different sampling sites in the studied area. Nutritional profiling of some of the edible insects was carried out to know their potential as a measure of food security. A total of 25 edible insects belonging to 9 orders and 18 families were recorded during the study period. Species diversity was recorded highest in forest/backyard forest habitat followed by agricultural field habitat, open field habitat and swampy area habitat in all the four districts in BTR, Assam. During the consumer survey, a total of 4,051 people belonging to four different scheduled tribes, Bodo, Rabha, Garo and Sarania were interviewed and out of them, 3,840 (94.79%) people were found to consume insects as food. The insects are mostly consumed in fried form, followed by smoked, raw, paste, roasted and curry form. The biochemical analysis of nutrient contents of 11 commonly consumed edible insects showed that they are a rich source of protein, vitamins and micronutrients with a reasonable amount of carbohydrates and lipids with higher radical scavenging activity. To manage insects in the context of food security, increased attention should be given to sustainable collection and successful farming of edible insects for the creation of export potential, giving emphasis on the nutritional advantages.

Herpetofaunal Assemblages in the Lowland Regions of Sumatera Barat

The habitat destruction and land-use changes caused the decline of animal composition in many tropical regions. Here, we study the diversity of herpetofauna in the lowland areas in Sumatera Barat, a midwestern province in Sumatera island, using a visual encounter survey method. The surveyed habitat included rubber plantations, streams, paddy fields, and peat swamps. We observed 338 individuals representing 44 species from 14 families of herpetofauna with almost 90% individuals were amphibians. Overall, the rubber plantations contained a higher number of species than other types of habitat. For amphibians, Ranidae and Dicroglossidae represented the first and the second highest both in the species and individual number. For reptiles, Agamidae and Colubridae or Gekkonidae accounted for the first and the second highest in the individual number while Colubridae and Scincidae consisted of the highest species number. Our data showed that the diversity index was mostly in moderate level except in paddy field. The species composition in rubber plantations were more similar to those of streams rather than paddy field or peat swamp Sago habitat.

Changes in the feeding behavior and habitat use of the desert hedgehog Paraechinus aethiopicus (Ehrenberg 1832, Eulipotyphla: Erinaceidae), in Saudi Arabia

Abstract Due to the urbanization and human invasion of the natural environments, great changes have been occurred on the food composition and feeding ecology of several animals especially those are sharing human his habitat in fields, wadis and gardens. The desert hedgehogs Paraechinus aethiopicus populations inhabiting different localities in Saudi Arabia were studied by using stomach contents analysis between February 2015 and October 2019. Precise analysis of stomach contents of 55 hedgehogs showed that the food of P. aethiopicus is highly diverse and highly influenced with effect of human on the environment including cooked rice, insects, plant materials, eggshells, worms, garbage and remnants of mammals and birds. Diet composition showed seasonal variations that are apparently associated with changes in the availability of different food items. The present results clearly showed that P. aethiopicus is an omnivorous mammal, capable of adapting to a great variety of dietary compositions in the study sites.

Tracking Earthworm Fluxes at the Interface between Tree Rows and Crop Habitats in a Mediterranean Alley Cropping Field

Tracking Earthworm Fluxes at the Interface between Tree Rows and Crop Habitats in a Mediterranean Alley Cropping Field

Seedling performance, allocation patterns and phenotypic plasticity of two sympatric hawthorn species and their natural hybrid

Hybridization followed by introgression is common between European Crataegus species, while hybrids of numerous sympatric taxa are abundant and widespread in several natural and seminatural environments. No study to the present day has compared the development of Crataegus species and their hybrids in their seedling stage. Our aim was to compare seedling performance, biomass allocation and phenotypic plasticity of two sympatric Crataegus species (C. monogya and C. rhipidophylla) with contrasting shade tolerance and their natural hybrid along light and water availability gradients in a controlled pot experiment. By this means we tested which of the existing models can successfully explain the field distribution and habitat preference of the hybrid. The performance of both species and their hybrid decreased in deep shade as well as under high water availability. Variation in light availability had a more pronounced effect on seedling development than that in water availability. These results evidence that habitat differentiation between the two species under natural conditions is probably mainly driven by competitive interactions. The shade tolerant forest species C. rhipidophylla had shorter, more dense stems compared to the shade intolerant C. monogyna, with the hybrid being intermediate in these characters. This suggests a steadier growth and higher resource allocation into stems in the case of the shade tolerant species. Furthermore, the hybrid was phenotypically more plastic in biomass allocation relative to at least one of its parental species under various water availabilities, suggesting an advantage on behalf of the hybrid in establishment under a wider range of environmental conditions. Our results support the “mosaic-model” that describes most accurately the hybrid zone.