Diversity

15 pages, 1650 KiB

Open AccessArticle

Competitive Interactions of Flowering Rush (Butomus umbellatus L.) Cytotypes in Submersed and Emergent Experimental Aquatic Plant Communities

by Nathan E. Harms

Diversity 2020, 12(1), 40; https://doi.org/10.3390/d12010040 - 20 Jan 2020

Cited by 3 | Viewed by 3901

Abstract

The ability to invade communities in a variety of habitats (e.g., along a depth gradient) may facilitate establishment and spread of invasive plants, but how multiple lineages of a species perform under varying conditions is understudied. A series of greenhouse common garden experiments [...] Read more.

The ability to invade communities in a variety of habitats (e.g., along a depth gradient) may facilitate establishment and spread of invasive plants, but how multiple lineages of a species perform under varying conditions is understudied. A series of greenhouse common garden experiments were conducted in which six diploid and four triploid populations of the aquatic invasive plant Butomus umbellatus L. (Butomaceae) were grown in submersed or emergent conditions, in monoculture or in a multispecies community, to compare establishment and productivity of cytotypes under competition. Diploid biomass overall was 12 times higher than triploids in the submersed experiment and three times higher in the emergent experiment. Diploid shoot:root ratio was double that of triploid plants in submersed conditions overall, and double in emergent conditions in monoculture. Relative interaction intensities (RII) indicated that triploid plants were sixteen times more negatively impacted by competition under submersed conditions but diploid plants were twice as impacted under emergent conditions. Recipient communities were similarly negatively impacted by B. umbellatus cytotypes. This study supports the idea that diploid and triploid B. umbellatus plants are equally capable of invading emergent communities, but that diploid plants may be better adapted for invading in submersed habitats. However, consistently lower shoot:root ratios in both monoculture and in communities suggests that triploid plants may be better-adapted competitors in the long term due to increased resource allocation to roots. This represents the first examination into the role of cytotype and habitat on competitive interactions of B. umbellatus. Full article

(This article belongs to the Special Issue Ecology of Invasive Aquatic Plants)

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13 pages, 1385 KiB

Open AccessArticle

The Effects of Habitat Heterogeneity at Distinct Spatial Scales on Hard-Bottom-Associated Communities

by Fabiane Gallucci, Ronaldo A. Christofoletti, Gustavo Fonseca and Gustavo M. Dias

Diversity 2020, 12(1), 39; https://doi.org/10.3390/d12010039 - 20 Jan 2020

Cited by 25 | Viewed by 4798

Abstract

For marine benthic communities, environmental heterogeneity at small spatial scales are mostly due to biologically produced habitat heterogeneity and biotic interactions, while at larger spatial scales environmental factors may prevails over biotic features. In this study, we investigated how community structure and β-diversity [...] Read more.

For marine benthic communities, environmental heterogeneity at small spatial scales are mostly due to biologically produced habitat heterogeneity and biotic interactions, while at larger spatial scales environmental factors may prevails over biotic features. In this study, we investigated how community structure and β-diversity of hard-bottom-associated meio- and macrofauna varied in relation to small-scale (cm–m) changes in biological substrate (an algae “turf” dominated by the macroalgae Gelidium sp., the macroalgae Caulerpa racemosa and the sponge Hymeniacidon heliophile) in a rocky shore and in relation to larger-scale (10’s m) changes in environmental conditions of the same biological substrate (the macroalgae Bostrychia sp) in different habitats (rocky shore vs. mangrove roots). Results showed that both substrate identity and the surrounding environment were important in structuring the smaller-sized meiofauna, particularly the nematode assemblages, whereas the larger and more motile macrofauna was influenced only by larger-scale changes in the surrounding ecosystem. This implies that the macrofauna explores the environment in a larger spatial scale compared to the meiofauna, suggesting that effects of spatial heterogeneity on communities are dependent on organism size and mobility. Changes in taxa composition between environments and substrates highlight the importance of habitat diversity at different scales for maintaining the diversity of the associated fauna. Full article

(This article belongs to the Special Issue Meiofauna Biodiversity and Ecology)

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16 pages, 2108 KiB

Open AccessArticle

Patterns in Alpha and Beta Phytoplankton Diversity along a Conductivity Gradient in Coastal Mediterranean Lagoons

by Natassa Stefanidou, Matina Katsiapi, Dimitris Tsianis, Maria Demertzioglou, Evangelia Michaloudi and Maria Moustaka-Gouni

Diversity 2020, 12(1), 38; https://doi.org/10.3390/d12010038 - 19 Jan 2020

Cited by 22 | Viewed by 4574

Abstract

Understanding the diversity patterns of phytoplankton assemblages in coastal lagoons is clearly important for water management. In this study, we explored alpha and beta diversity patterns in phytoplankton communities across five Mediterranean lagoons hydrologically connected to Vistonikos Gulf. We examined the phytoplankton community [...] Read more.

Understanding the diversity patterns of phytoplankton assemblages in coastal lagoons is clearly important for water management. In this study, we explored alpha and beta diversity patterns in phytoplankton communities across five Mediterranean lagoons hydrologically connected to Vistonikos Gulf. We examined the phytoplankton community composition and biomass on a monthly basis from November 2018 to October 2019. For this, water samples were collected from seven inshore, brackish and coastal waters, sampling sites covering a wide range of conductivity. We found significant spatial and temporal differences in phytoplankton alpha diversity and in phytoplankton biomass metrics explained by the high variation of conductivity. Evenness remained low throughout the study period, reflecting significant dominance of several phytoplankton blooms. Harmful algal blooms of Prorocentrum minimum, Alexandrium sp., Rhizosolenia setigera and Cylindrotheca closterium occurred. The system’s species pool was characterized by relatively high phytoplankton beta diversity (average ~0.7) resulting from high temporal species turnover (90%). Overall, alpha and beta diversity components were indicative of rather heterogeneous phytoplankton communities which were associated with the high differences in conductivity among the sampling sites. Full article

(This article belongs to the Special Issue Biodiversity of Marine Microbes)

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15 pages, 822 KiB

Open AccessArticle

Direct and Indirect Effects of Overstory Canopy and Sex-Biased Density Dependence on Reproduction in the Dioecious Shrub Shepherdia canadensis (Elaeagnaceae)

by Tyler J. Bateman and Scott E. Nielsen

Diversity 2020, 12(1), 37; https://doi.org/10.3390/d12010037 - 19 Jan 2020

Cited by 1 | Viewed by 3363

Abstract

This study assessed the reproductive success of a temperate dioecious shrub, Canada buffaloberry, Shepherdia canadensis (L.) Nutt., in central Alberta, Canada, by examining the effects of spatial patterns and overstory canopy on flower and fruit production. S. canadensis is more abundant and productive [...] Read more.

This study assessed the reproductive success of a temperate dioecious shrub, Canada buffaloberry, Shepherdia canadensis (L.) Nutt., in central Alberta, Canada, by examining the effects of spatial patterns and overstory canopy on flower and fruit production. S. canadensis is more abundant and productive (more fruit) at forest edges and in forest gaps, suggesting a dependence on higher light conditions than is typical of late-seral forests. We used path analysis to demonstrate that flower and fruit production exhibited density-dependent effects at a scale of 50 m² around focal female plants. Fruit production was positively affected by male intraspecific density (pollen supply) and negatively affected by female intraspecific density (pollen competition), but not correlated with overall intraspecific density. The effects of sex-differentiated density are partly due to pollinator responses to male plant density. Flower production was positively affected by overall intraspecific density. A pollen supplementation trial doubled fruit production relative to a control, demonstrating that local male density (pollen availability) and pollinator activity can limit fruit production in S. canadensis. Canopy cover was negatively related to both flower and total fruit production, with approximately one-third (34%) of the total effect of canopy on fruit production due to the effect of canopy on flower production. The commonly observed negative association between canopy cover and fruit production in buffaloberry, therefore, is partly a result of the reduction first in flower number and second in fruit set. This study clarifies the mechanisms associated with the often-noted observation, but not previously assessed at the level of individuals, that reproductive output in S. canadensis is density dependent, limited by canopy cover through reductions in both flowering and fruit set, and pollinator limited. These findings hold implications for managing animal species that depend on the fruit of S. canadensis and suggest future directions for research on dioecious and actinorhizal species. Full article

(This article belongs to the Section Plant Diversity)

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9 pages, 255 KiB

Open AccessEditorial

Acknowledgement to Reviewers of Diversity in 2019

by Diversity Editorial Office

Diversity 2020, 12(1), 36; https://doi.org/10.3390/d12010036 - 17 Jan 2020

Viewed by 1929

Abstract

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26 pages, 4504 KiB

Open AccessArticle

Fewer Copepods, Fewer Anchovies, and More Jellyfish: How Does Hypoxia Impact the Chesapeake Bay Zooplankton Community?

by Wencheng L. Slater, James J. Pierson, Mary Beth Decker, Edward D. Houde, Carlos Lozano and James Seuberling

Diversity 2020, 12(1), 35; https://doi.org/10.3390/d12010035 - 17 Jan 2020

Cited by 15 | Viewed by 5479

Abstract

To understand dissolved oxygen deficiency in Chesapeake Bay and its direct impact on zooplankton and planktivorous fish communities, six research cruises were conducted at two sites in the Chesapeake Bay from spring to autumn in 2010 and 2011. Temperature, salinity, and dissolved oxygen [...] Read more.

To understand dissolved oxygen deficiency in Chesapeake Bay and its direct impact on zooplankton and planktivorous fish communities, six research cruises were conducted at two sites in the Chesapeake Bay from spring to autumn in 2010 and 2011. Temperature, salinity, and dissolved oxygen were measured from hourly conductivity, temperature, and depth (CTD) casts, and crustacean zooplankton, planktivorous fish and gelatinous zooplankton were collected with nets and trawls. CTD data were grouped into three temperature groups and two dissolved oxygen-level subgroups using principal component analysis (PCA). Species concentrations and copepod nonpredatory mortalities were compared between oxygenated conditions within each temperature group. Under hypoxic conditions, there usually were significantly fewer copepods Acartia tonsa and bay anchovies Anchoa mitchilli, but more bay nettles Chyrsaora chesapeakei and lobate ctenophores Mnemiopsis leidyi. Neutral red staining of copepod samples confirmed that copepod nonpredatory mortalities were higher under hypoxic conditions than under normoxia, indicating that the sudden decline in copepod concentration in summer was directly associated with hypoxia. Because comparisons were made within each temperature group, the effects of temperature were isolated, and hypoxia was clearly shown to have contributed to copepod decreases, planktivorous fish decreases, and gelatinous zooplankton increases. This research quantified the direct effects of hypoxia and explained the interactions between seasonality and hypoxia on the zooplankton population. Full article

(This article belongs to the Special Issue The Effects of Hypoxia on Marine Food Webs and Ecosystems)

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23 pages, 2958 KiB

Open AccessArticle

Beyond Endocasts: Using Predicted Brain-Structure Volumes of Extinct Birds to Assess Neuroanatomical and Behavioral Inferences

by Catherine M. Early, Ryan C. Ridgely and Lawrence M. Witmer

Diversity 2020, 12(1), 34; https://doi.org/10.3390/d12010034 - 17 Jan 2020

Cited by 18 | Viewed by 7759

Abstract

The shape of the brain influences skull morphology in birds, and both traits are driven by phylogenetic and functional constraints. Studies on avian cranial and neuroanatomical evolution are strengthened by data on extinct birds, but complete, 3D-preserved vertebrate brains are not known from [...] Read more.

The shape of the brain influences skull morphology in birds, and both traits are driven by phylogenetic and functional constraints. Studies on avian cranial and neuroanatomical evolution are strengthened by data on extinct birds, but complete, 3D-preserved vertebrate brains are not known from the fossil record, so brain endocasts often serve as proxies. Recent work on extant birds shows that the Wulst and optic lobe faithfully represent the size of their underlying brain structures, both of which are involved in avian visual pathways. The endocasts of seven extinct birds were generated from microCT scans of their skulls to add to an existing sample of endocasts of extant birds, and the surface areas of their Wulsts and optic lobes were measured. A phylogenetic prediction method based on Bayesian inference was used to calculate the volumes of the brain structures of these extinct birds based on the surface areas of their overlying endocast structures. This analysis resulted in hyperpallium volumes of five of these extinct birds and optic tectum volumes of all seven extinct birds. Phylogenetic ANCOVA (phyANCOVA) were performed on regressions of the brain-structure volumes and endocast structure surface areas on various brain size metrics to determine if the relative sizes of these structures in any extinct birds were significantly different from those of the extant birds in the sample. Phylogenetic ANCOVA indicated that no extinct birds studied had relative hyperpallial volumes that were significantly different from the extant sample, nor were any of their optic tecta relatively hypertrophied. The optic tectum of Dinornis robustus was significantly smaller relative to brain size than any of the extant birds in our sample. This study provides an analytical framework for testing the hypotheses of potential functional behavioral capabilities of other extinct birds based on their endocasts. Full article

(This article belongs to the Special Issue Origins of Modern Avian Biodiversity)

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20 pages, 2413 KiB

Open AccessArticle

Habitat Islands on the Aegean Islands (Greece): Elevational Gradient of Chasmophytic Diversity, Endemism, Phytogeographical Patterns and need for Monitoring and Conservation

by Anna Kontopanou and Maria Panitsa

Diversity 2020, 12(1), 33; https://doi.org/10.3390/d12010033 - 17 Jan 2020

Cited by 22 | Viewed by 5090

Abstract

The Aegean archipelago, characterized as a natural laboratory for research concerning plant species diversity and phytogeography has a complex geological and paleogeographical history that varies among its phytogeographical areas. A different combination of factors of variable intensity and duration time drives patterns of [...] Read more.

The Aegean archipelago, characterized as a natural laboratory for research concerning plant species diversity and phytogeography has a complex geological and paleogeographical history that varies among its phytogeographical areas. A different combination of factors of variable intensity and duration time drives patterns of its impressive plant species richness and endemism. Cliffs, a conspicuous feature of the Aegean landscape, consist of biologically closed communities that serve as refugia for obligate chasmophytes, the majority of which are Greek or Aegean endemics, and for this reason, they are also considered as habitat islands on the Aegean islands. A synoptic analysis is presented concerning chasmophytic plant diversity focusing on endemic obligate chasmophytes. Phytogeographical patterns of obligate chasmophytes, and especially the endemic ones as well as their elevational range and distribution and zeta diversity, are analyzed and discussed in the frame of climatic change, mentioning that the most threatened endemic obligate chasmophytes are those specialized in high elevation areas, and focusing on the need for monitoring and conservation. Full article

(This article belongs to the Special Issue Conservation and Management of Island Ecosystems)

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16 pages, 1148 KiB

Open AccessReview

Reciprocal Role of Salamanders in Aquatic Energy Flow Pathways

by Javier Sánchez-Hernández

Diversity 2020, 12(1), 32; https://doi.org/10.3390/d12010032 - 17 Jan 2020

Cited by 11 | Viewed by 10675

Abstract

Many species of salamanders (newts and salamanders per se) have a pivotal role in energy flow pathways as they include individuals functioning as prey, competitors, and predators. Here, I synthesize historic and contemporary research on the reciprocal ecological role of salamanders as predators [...] Read more.

Many species of salamanders (newts and salamanders per se) have a pivotal role in energy flow pathways as they include individuals functioning as prey, competitors, and predators. Here, I synthesize historic and contemporary research on the reciprocal ecological role of salamanders as predators and prey in aquatic systems. Salamanders are a keystone in ecosystem functioning through a combination of top–down control, energy transfer, nutrient cycling processes, and carbon retention. The aquatic developmental stages of salamanders are able to feed on a wide variety of invertebrate prey captured close to the bottom as well as on small conspecifics (cannibalism) or other sympatric species, but can also consume terrestrial invertebrates on the water surface. This capacity to consume allochthonous resources (terrestrial invertebrates) highlights the key role of salamanders as couplers of terrestrial and aquatic ecosystems (i.e., aquatic–terrestrial linkages). Salamanders are also an important food resource for other vertebrates such as fish, snakes, and mammals, covering the energy demands of these species at higher trophic levels. This study emphasizes the ecological significance of salamanders in aquatic systems as central players in energy flow pathways, enabling energy mobility among trophic levels (i.e., vertical energy flow) and between freshwater and terrestrial habitats (i.e., lateral energy flow). Full article

(This article belongs to the Special Issue The Ecological Role of Salamanders as Predators and Prey)

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21 pages, 4655 KiB

Open AccessArticle

The Afro–Oriental Genus Yaeprimus Sasa et Suzuki (Diptera: Chironomidae: Chironomini): Phylogeny, New Species and Expanded Diagnoses

by Wu Han, Jinxing Wei, Xiaolong Lin and Hongqu Tang

Diversity 2020, 12(1), 31; https://doi.org/10.3390/d12010031 - 15 Jan 2020

Cited by 7 | Viewed by 3246

Abstract

Expanded generic diagnoses of all life stages of Yaeprimus Sasa et Suzuki, 2000 (Lunditendipes Harrison, 2000, syn. n.) are given. Yaeprimus tropicus comb. n. is redescribed as an adult based on type material. Additionally, a new species Y. balteatus sp. n. [...] Read more.

Expanded generic diagnoses of all life stages of Yaeprimus Sasa et Suzuki, 2000 (Lunditendipes Harrison, 2000, syn. n.) are given. Yaeprimus tropicus comb. n. is redescribed as an adult based on type material. Additionally, a new species Y. balteatus sp. n. from Oriental China is described based on the adult male and pupa. The phylogenetic position of Yaeprimus within Chironomini and the validity of the new species are explored based on concatenated five genetic markers (18S, 28S, CAD1, CAD4, and COI-3P) through both mixed–model Bayesian inference and maximum likelihood methods. The results strongly support Yaeprimus as sister to Imparipecten Freeman, 1961, which counters a previously proposed systematical position based solely on morphology. Full article

(This article belongs to the Special Issue Biodiversity of Insect)

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19 pages, 3139 KiB

Open AccessArticle

Afromontane Forest Diversity and the Role of Grassland-Forest Transition in Tree Species Distribution

by Iveren Abiem, Gabriel Arellano, David Kenfack and Hazel Chapman

Diversity 2020, 12(1), 30; https://doi.org/10.3390/d12010030 - 15 Jan 2020

Cited by 24 | Viewed by 8352

Abstract

Local factors can play an important role in defining tree species distributions in species rich tropical forests. To what extent the same applies to relatively small, species poor West African montane forests is unknown. Here, forests survive in a grassland matrix and fire [...] Read more.

Local factors can play an important role in defining tree species distributions in species rich tropical forests. To what extent the same applies to relatively small, species poor West African montane forests is unknown. Here, forests survive in a grassland matrix and fire has played a key role in their spatial and temporal dynamics since the Miocene. To what extent these dynamics influence local species distributions, as compared with other environmental variables such as altitude and moisture remain unknown. Here, we use data from the 20.28 ha montane forest plot in Ngel Nyaki Forest Reserve, South-East Nigeria to explore these questions. The plot features a gradient from grassland to core forest, with significant edges. Within the plot, we determined tree stand structure and species diversity and identified all trees ≥1 cm in diameter. We recorded species guild (pioneer vs. shade tolerant), seed size, and dispersal mode. We analyzed and identified to what extent species showed a preference for forest edges/grasslands or core forest. Similarly, we looked for associations with elevation, distance to streams and forest versus grassland. We recorded 41,031 individuals belonging to 105 morphospecies in 87 genera and 47 families. Around 40% of all tree species, and 50% of the abundant species, showed a clear preference for either the edge/grassland habitat or the forest core. However, we found no obvious association between species guild, seed size or dispersal mode, and distance to edge, so what leads to this sorting remains unclear. Few species distributions were influenced by distance to streams or altitude. Full article

(This article belongs to the Special Issue Biodiversity of Vegetation and Flora in Tropical Africa)

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18 pages, 2983 KiB

Open AccessReview

Neural Network Recognition of Marine Benthos and Corals

by Alina Raphael, Zvy Dubinsky, David Iluz and Nathan S. Netanyahu

Diversity 2020, 12(1), 29; https://doi.org/10.3390/d12010029 - 13 Jan 2020

Cited by 32 | Viewed by 8029

Abstract

We present thorough this review the developments in the field, point out their current limitations, and outline its timelines and unique potential. In order to do so we introduce the methods used in each of the advances in the application of deep learning [...] Read more.

We present thorough this review the developments in the field, point out their current limitations, and outline its timelines and unique potential. In order to do so we introduce the methods used in each of the advances in the application of deep learning (DL) to coral research that took place between the years: 2016–2018. DL has unique capability of streamlining the description, analysis, and monitoring of coral reefs, saving time, and obtaining higher reliability and accuracy compared with error-prone human performance. Coral reefs are the most diverse and complex of marine ecosystems, undergoing a severe decline worldwide resulting from the adverse synergistic influences of global climate change, ocean acidification, and seawater warming, exacerbated by anthropogenic eutrophication and pollution. DL is an extension of some of the concepts originating from machine learning that join several multilayered neural networks. Machine learning refers to algorithms that automatically detect patterns in data. In the case of corals these data are underwater photographic images. Based on “learned” patterns, such programs can recognize new images. The novelty of DL is in the use of state-of-art computerized image analyses technologies, and its fully automated methodology of dealing with large data sets of images. Automated Image recognition refers to technologies that identify and detect objects or attributes in a digital video or image automatically. Image recognition classifies data into selected categories out of many. We show that Neural Network methods are already reliable in distinguishing corals from other benthos and non-coral organisms. Automated recognition of live coral cover is a powerful indicator of reef response to slow and transient changes in the environment. Improving automated recognition of coral species, DL methods already recognize decline of coral diversity due to natural and anthropogenic stressors. Diversity indicators can document the effectiveness of reef bioremediation initiatives. We explored the current applications of deep learning for corals and benthic image classification by discussing the most recent studies conducted by researchers. We review the developments in the field, point out their current limitations, and outline their timelines and unique potential. We also discussed a few future research directions in the fields of deep learning. Future needs are the age detection of single species, in order to track trends in their population recruitment, decline, and recovery. Fine resolution, at the polyp level, is still to be developed, in order to allow separation of species with similar macroscopic features. That refinement of DL will allow such comparisons and their analyses. We conclude that the usefulness of future, more refined automatic identification will allow reef comparison, and tracking long term changes in species diversity. The hitherto unused addition of intraspecific coral color parameters, will add the inclusion of physiological coral responses to environmental conditions and change thereof. The core aim of this review was to underscore the strength and reliability of the DL approach for documenting coral reef features based on an evaluation of the currently available published uses of this method. We expect that this review will encourage researchers from computer vision and marine societies to collaborate on similar long-term joint ventures. Full article

(This article belongs to the Special Issue Freshwater Algal Diversity and Bio-Indication of Water Resources)

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26 pages, 5270 KiB

Open AccessArticle

Thalassic Rotifers from the United States: Descriptions of Two New Species and Notes on the Effect of Salinity and Ecosystem on Biodiversity

by Francesca Leasi and Willem H. De Smet

Diversity 2020, 12(1), 28; https://doi.org/10.3390/d12010028 - 13 Jan 2020

Cited by 5 | Viewed by 4500

Abstract

This study shows the results of a rotifer faunistic survey in thalassic waters from 26 sites located in northeastern U.S. states and one in California. A total of 44 taxa belonging to 21 genera and 14 families were identified, in addition to a [...] Read more.

This study shows the results of a rotifer faunistic survey in thalassic waters from 26 sites located in northeastern U.S. states and one in California. A total of 44 taxa belonging to 21 genera and 14 families were identified, in addition to a group of unidentifiable bdelloids. Of the fully identified species, 17 are the first thalassic records for the U.S., including Encentrum melonei sp. nov. and Synchaeta grossa sp. nov., which are new to science, and Colurella unicauda Eriksen, 1968, which is new to the Nearctic region. Moreover, a refined description of Encentrum rousseleti (Lie-Pettersen, 1905) is presented. During the survey, we characterized samples by different salinity values and ecosystems and compared species composition across communities to test for possible ecological correlations. Results indicate that both salinities and ecosystems are a significant predictor of rotifer diversity, supporting that biodiversity estimates of small species provide fundamental information for biomonitoring. Finally, we provide a comprehensive review of the diversity and distribution of thalassic rotifers in the United States. The results of the present study increase the thalassic rotifer record for the U.S. from about 105 (87 at species level) to 124 (106 at species level) taxa. Full article

(This article belongs to the Special Issue Biodiversity of Rotifers)

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17 pages, 5141 KiB

Open AccessArticle

Diversity of a Large Collection of Natural Populations of Mango (Mangifera indica Linn.) Revealed by Agro-Morphological and Quality Traits

by Cuixian Zhang, Dehong Xie, Tianqi Bai, Xinping Luo, Faming Zhang, Zhangguang Ni and Yufu Chen

Diversity 2020, 12(1), 27; https://doi.org/10.3390/d12010027 - 11 Jan 2020

Cited by 19 | Viewed by 7526

Abstract

Collection, characterization and utilization of genetic resources are crucial for developing varieties to meet current and future needs. Although mango is an economically important fruit tree, its genetic resources are still undocumented and are threatened in their natural habits. In this study, the [...] Read more.

Collection, characterization and utilization of genetic resources are crucial for developing varieties to meet current and future needs. Although mango is an economically important fruit tree, its genetic resources are still undocumented and are threatened in their natural habits. In this study, the variability of 452 mango accessions from three regions in China (Nujiang, Lancang river and Honghe) was assessed using 41 descriptors including qualitative and quantitative traits, with the aim to identify mango accessions with excellent agronomic and quality traits. To this end, descriptive and multivariate analyses were performed. Based on Shannon–Weaver diversity index, qualitative traits including pericarp color, fruit aroma, flesh color, and fruit flavor recorded the highest variability in the germplasm. Fruit related traits including pulp weight, peel weight, and fruit weight were the most diverse traits in the germplasm with a high coefficient of variation (CV > 40%). Significant differences (MANOVA test, p < 0.000) were observed among the three regions for most of the quantitative traits. Biologically significant and positive correlations were found among agronomically important traits such as fruit weight and pulp weight, fruit weight and edible rate. The hierarchical cluster analysis revealed tree clusters, indicating a low diversity in the germplasm. The majority of the descriptors contributed to the differentiation of the accessions. Accessions with good fruits quality (high fruit weight, pulp weight, and edible rate) were found in Cluster 2. Accessions in this cluster could be used for fruit quality improvement in mango breeding programs. Our study sheds light on the diversity of a large collection of natural mango population in China and provides relevant information for efficient conservation and harnessing of mango genetic resources. Full article

(This article belongs to the Section Plant Diversity)

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9 pages, 3301 KiB

Open AccessArticle

Snapshot of Macroalgae and Fish Assemblages in Temperate Reefs in the Southern European Atlantic Ecoregion

by João N. Franco, Francisco Arenas, Isabel Sousa-Pinto and Carmen B. de los Santos

Diversity 2020, 12(1), 26; https://doi.org/10.3390/d12010026 - 10 Jan 2020

Cited by 5 | Viewed by 3907

Abstract

Most of the biodiversity studies in the South European Atlantic Shelf ecoregion are limited to shallow subtidal or intertidal habitats, while deeper reef habitats, also of relevant ecological importance, are particularly understudied. Macroalgal communities, associated fauna, and sea surface temperature were studied in [...] Read more.

Most of the biodiversity studies in the South European Atlantic Shelf ecoregion are limited to shallow subtidal or intertidal habitats, while deeper reef habitats, also of relevant ecological importance, are particularly understudied. Macroalgal communities, associated fauna, and sea surface temperature were studied in deep reefs (25–30 m) at two locations in this ecoregion: Parcel, North of Portugal (41° N), and Tarifa, Southern Spain (35° N). Specifically, algal assemblages were assessed using biomass collection and associated ichthyofauna was assessed using visual census techniques using scuba. Seawater surface temperature was higher (>3 °C) in the southern region—Tarifa, compared to the northern region—Parcel. Our survey revealed 18 fish species and 23 algae species. The highest abundance of cold-water species (both macroalgae and fish species) was recorded in Parcel and warm-water species were dominant in Tarifa. In light of climate global trends, both regions might experience biodiversity shifts towards tropicalization. Current knowledge on their biodiversity is imperative to further evaluate potential shifts. Full article

(This article belongs to the Special Issue Biodiversity of Macroalgae)

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27 pages, 2393 KiB

Open AccessArticle

Negative Effects of Diurnal Changes in Acidification and Hypoxia on Early-Life Stage Estuarine Fishes

by Brooke K. Morrell and Christopher J. Gobler

Diversity 2020, 12(1), 25; https://doi.org/10.3390/d12010025 - 8 Jan 2020

Cited by 16 | Viewed by 3586

Abstract

Estuaries serve as important nursery habitats for various species of early-life stage fish, but can experience cooccurring acidification and hypoxia that can vary diurnally in intensity. This study examines the effects of acidification (pH 7.2–7.4) and hypoxia (dissolved oxygen (DO) ~ 2–4 mg [...] Read more.

Estuaries serve as important nursery habitats for various species of early-life stage fish, but can experience cooccurring acidification and hypoxia that can vary diurnally in intensity. This study examines the effects of acidification (pH 7.2–7.4) and hypoxia (dissolved oxygen (DO) ~ 2–4 mg L⁻¹) as individual and combined stressors on four fitness metrics for three species of forage fish endemic to the U.S. East Coast: Menidia menidia, Menidia beryllina, and Cyprinodon variegatus. Additionally, the impacts of various durations of exposure to these two stressors was also assessed to explore the sensitivity threshold for larval fishes under environmentally-representative conditions. C. variegatus was resistant to chronic low pH, while M. menidia and M. beryllina experienced significantly reduced survival and hatch time, respectively. Exposure to hypoxia resulted in reduced hatch success of both Menidia species, as well as diminished survival of M. beryllina larvae. Diurnal exposure to low pH and low DO for 4 or 8 h did not alter survival of M. beryllina, although 8 or 12 h of daily exposure through the 10 days posthatch significantly depressed larval size. In contrast, M. menidia experienced significant declines in survival for all intervals of diel cycling hypoxia and acidification (4–12 h). Exposure to 12-h diurnal hypoxia generally elicited negative effects equal to, or of greater severity, than chronic exposure to low DO at the same levels despite significantly higher mean DO exposure concentrations. This evidences a substantial biological cost to adapting to changing DO levels, and implicates diurnal cycling of DO as a significant threat to fish larvae in estuaries. Larval responses to hypoxia, and to a lesser extent acidification, in this study on both continuous and diurnal timescales indicate that estuarine conditions throughout the spawning and postspawn periods could adversely affect stocks of these fish, with diverse implications for the remainder of the food web. Full article

(This article belongs to the Special Issue The Effects of Hypoxia on Marine Food Webs and Ecosystems)

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18 pages, 1967 KiB

Open AccessArticle

Monitoring the Field-Realistic Exposure of Honeybee Colonies to Neonicotinoids by An Integrative Approach: A Case Study in Romania

by Eliza Căuia, Adrian Siceanu, Gabriela Oana Vișan, Dumitru Căuia, Teodora Colța and Roxana Antoaneta Spulber

Diversity 2020, 12(1), 24; https://doi.org/10.3390/d12010024 - 6 Jan 2020

Cited by 6 | Viewed by 5316

Abstract

Honeybees (Apis mellifera L.) are excellent biosensors that can be managed to collect valuable information about environmental contamination. The main objective of the present study was to design and apply an integrative protocol to monitor honeybee colony activity and sample collection by [...] Read more.

Honeybees (Apis mellifera L.) are excellent biosensors that can be managed to collect valuable information about environmental contamination. The main objective of the present study was to design and apply an integrative protocol to monitor honeybee colony activity and sample collection by using electronic technologies combined with classical methods in order to evaluate the exposure of honeybees to the neonicotinoids that are used in melliferous intensive crops. The monitored honeybee colonies were especially prepared and equipped to maximize their chances to collect representative samples in order to express, as well as possible, the pesticide residues that existed in the targeted crops. The samples of honey, pollen and honeybees were collected, preserved and prepared to fulfill the required quality and quantity criteria of the accredited laboratories. In total, a set of fifty samples was collected from fields, located in different areas of intensive agriculture in Romania, and was analyzed for five neonicotinoids. The obtained results show that 48% of the total analyzed samples (n = 50) contained one or more detected or quantified neonicotinoid residues. The main conclusion is that the proposed approach for sample collection and preparation could improve the evaluation methodologies for analyzing honeybees’ exposure to pesticides. Full article

(This article belongs to the Special Issue Monitoring of Honey Bee Colony Losses)

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18 pages, 6212 KiB

Open AccessArticle

Development of Active Numerating Side-scan for a High-Density Overwintering Location for Endemic Shortnose Sturgeon (Acipenser brevirostrum) in the Saint John River, New Brunswick

by Samuel N. Andrews, Antóin M. O’Sullivan, Jani Helminen, Daniel F. Arluison, Kurt M. Samways, Tommi Linnansaari and R. Allen Curry

Diversity 2020, 12(1), 23; https://doi.org/10.3390/d12010023 - 5 Jan 2020

Cited by 22 | Viewed by 4146

Abstract

In 1979, the Shortnose Sturgeon (Acipenser brevirostrum) population of the Saint John River, New Brunswick, was estimated at 18,000 ± 5400 individuals. More recently, an estimate of 4836 ± 69 individuals in 2005, and between 3852 and 5222 individuals in 2009 [...] Read more.

In 1979, the Shortnose Sturgeon (Acipenser brevirostrum) population of the Saint John River, New Brunswick, was estimated at 18,000 ± 5400 individuals. More recently, an estimate of 4836 ± 69 individuals in 2005, and between 3852 and 5222 individuals in 2009 and 2011, was made based on a single Shortnose Sturgeon winter aggregation in the Kennebecasis Bay of the Saint John River, a location thought to contain a large proportion of the population. These data, in combination with the Saint John River serving as the sole spawning location for Shortnose Sturgeon in Canada prompted a species designation of “Special Concern” in 2015 under Canada’s Species at Risk Act (SARA). A three-decade span of scientific observations amplified by the traditional knowledge and concerns of local indigenous groups have pointed to a declining population. However, the endemic Shortnose Sturgeon population of the Saint John River has not been comprehensively assessed in recent years. To help update the population estimate, we tested a rapid, low-cost side-scan sonar mapping method coupled with supervised image classification to enumerate individual Sturgeon in a previously undescribed critical winter location in the Saint John River. We then conducted an underwater video camera survey of the area, in which we did not identify any fish species other than Shortnose Sturgeon. These data were then synchronized with four years of continuous acoustic tracking of 18 Shortnose Sturgeon to produce a population estimate in each of the five identified winter habitats and the Saint John River as a whole. Using a side-scan sonar, we identified > 12,000 Shortnose Sturgeon in a single key winter location and estimated the full river population as > 20,000 individuals > ~40 cm fork length. We conclude that the combined sonar/image processing method presented herein provides an effective and rapid assessment of large fish such as Sturgeon when occurring in winter aggregation. Our results also indicate that the Shortnose Sturgeon population of the Saint John River could be similar to the last survey estimate conducted in the late 1970s, but more comprehensive and regular surveys are needed to more accurately assess the state of the population. Full article

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29 pages, 2667 KiB

Open AccessFeature PaperArticle

New Chorological Data for the Italian Vascular Flora

by Leonardo Rosati, Simonetta Fascetti, Vito Antonio Romano, Giovanna Potenza, Maria Rita Lapenna, Antonio Capano, Pietro Nicoletti, Emmanuele Farris, Peter James de Lange, Eva Del Vico, Laura Facioni, Emanuele Fanfarillo, Edda Lattanzi, Ana Cano-Ortiz, Michela Marignani, Maria Caterina Fogu, Erika Bazzato, Erik Lallai, Valentina Lucia Astrid Laface, Carmelo Maria Musarella, Giovanni Spampinato, Giacomo Mei, Giuseppe Misano, Giovanni Salerno, Assunta Esposito and Adriano Stinca Show full author list Hide full author list

Diversity 2020, 12(1), 22; https://doi.org/10.3390/d12010022 - 5 Jan 2020

Cited by 29 | Viewed by 5716

Abstract

Despite the importance for scientific and conservation purposes, the knowledge of the Italian territory is far from exhaustive. New chorological data for 87 vascular taxa regarding the central-southern part of Italy and its two main islands (Sicilia and Sardegna) are presented. Among these [...] Read more.

Despite the importance for scientific and conservation purposes, the knowledge of the Italian territory is far from exhaustive. New chorological data for 87 vascular taxa regarding the central-southern part of Italy and its two main islands (Sicilia and Sardegna) are presented. Among these taxa, Epilobium nummularifolium, Metrosideros excelsa, and Salvinia minima are recorded as casual aliens for the first time in Europe (excluding Azores and Madeira for M. excelsa), while Cyclamen balearicum and Polygala rupestris are reported for the first time and confirmed for Italian native flora, respectively. Furthermore, several taxa are new or confirmed at regional level. Finally, Lathyrus cirrhosus, Urginea fugax, and Linum tenuifolium are excluded from Italy, continental and peninsular Italy, and Sardegna, respectively. Full article

(This article belongs to the Section Plant Diversity)

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16 pages, 2072 KiB

Open AccessEditor’s ChoiceArticle

Zooplankton Community Response to Seasonal Hypoxia: A Test of Three Hypotheses

by Julie E. Keister, Amanda K. Winans and BethElLee Herrmann

Diversity 2020, 12(1), 21; https://doi.org/10.3390/d12010021 - 1 Jan 2020

Cited by 18 | Viewed by 3887

Abstract

Several hypotheses of how zooplankton communities respond to coastal hypoxia have been put forward in the literature over the past few decades. We explored three of those that are focused on how zooplankton composition or biomass is affected by seasonal hypoxia using data [...] Read more.

Several hypotheses of how zooplankton communities respond to coastal hypoxia have been put forward in the literature over the past few decades. We explored three of those that are focused on how zooplankton composition or biomass is affected by seasonal hypoxia using data collected over two summers in Hood Canal, a seasonally-hypoxic sub-basin of Puget Sound, Washington. We conducted hydrographic profiles and zooplankton net tows at four stations, from a region in the south that annually experiences moderate hypoxia to a region in the north where oxygen remains above hypoxic levels. The specific hypotheses tested were that low oxygen leads to: (1) increased dominance of gelatinous relative to crustacean zooplankton, (2) increased dominance of cyclopoid copepods relative to calanoid copepods, and (3) overall decreased zooplankton abundance and biomass at hypoxic sites compared to where oxygen levels are high. Additionally, we examined whether the temporal stability of community structure was decreased by hypoxia. We found evidence of a shift toward more gelatinous zooplankton and lower total zooplankton abundance and biomass at hypoxic sites, but no clear increase in the dominance of cyclopoid relative to calanoid copepods. We also found the lowest variance in community structure at the most hypoxic site, in contrast to our prediction. Hypoxia can fundamentally alter marine ecosystems, but the impacts differ among systems. Full article

(This article belongs to the Special Issue The Effects of Hypoxia on Marine Food Webs and Ecosystems)

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9 pages, 894 KiB

Open AccessReview

Sustainable Utilization of Indigenous Goats in Southern Africa

by Phetogo Monau, Kethusegile Raphaka, Plaxedis Zvinorova-Chimboza and Timothy Gondwe

Diversity 2020, 12(1), 20; https://doi.org/10.3390/d12010020 - 1 Jan 2020

Cited by 56 | Viewed by 8175

Abstract

Goats have a key role in ensuring food security and economic livelihood to smallholder farmers in rural areas. Women play a vital role in goat rearing, promoting economic autonomy within households. Indigenous goats dominate and are of high significance due to their adaptive [...] Read more.

Goats have a key role in ensuring food security and economic livelihood to smallholder farmers in rural areas. Women play a vital role in goat rearing, promoting economic autonomy within households. Indigenous goats dominate and are of high significance due to their adaptive traits that are relevant for climate change and low maintenance. However, lack of emphasis on farmer-centered technology development and proper breed characterization remains a hitch to sustainable utilization and breed development of indigenous goats. This can be over come through proper linkage between market and production, workable regional and national agricultural policies, community breeding programs, collaborative research work within the region, and consistent government support. Full article

(This article belongs to the Special Issue Conservation of Rare Breeds of Livestock)

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19 pages, 9662 KiB

Open AccessArticle

Two New Marine Free-Living Nematodes from Jeju Island Together with a Review of the Genus Gammanema Cobb 1920 (Nematoda, Chromadorida, Selachinematidae)

by Alexei Tchesunov, Raehyuk Jeong and Wonchoel Lee

Diversity 2020, 12(1), 19; https://doi.org/10.3390/d12010019 - 1 Jan 2020

Cited by 7 | Viewed by 4290

Abstract

In the context of exploration of meiofauna in a sandy intertidal zone of Jeju Island (South Korea), over 70 nematode species are identified, some which have been proven to be new for science. Two new free-living marine nematode species of the family Selachinematidae [...] Read more.

In the context of exploration of meiofauna in a sandy intertidal zone of Jeju Island (South Korea), over 70 nematode species are identified, some which have been proven to be new for science. Two new free-living marine nematode species of the family Selachinematidae (Chromadorida, Selachinematidae, Choniolaiminae) are described from the intertidal sandy sediments of Jeju Island (South Korea). Gammanema okhlopkovi sp. n. is closest to Gammanema anthostoma (Okhlopkov, 2002) and differs by having longer cephalic setae (8.5–19 μm in G. okhlopkovi versus 6–7.5 μm in G. anthostoma) and by the presence of precloacal supplementary organs. The genus diagnosis of Gammanema is updated. The genus includes fourteen valid species, while three species are considered species inquirendae due to incomplete diagnoses and illustrations impeding their correct recognition. An annotated list of valid and invalid Gammanema species is provided. A pictorial key for valid Gammanema species is constructed, which consists of two components: (1) simplified images of heads, and (2) a table summarizing most of the significant measured and numeric characters between species. Latronema obscuramphis sp. n. differs from its related species Latronema aberrans (Allgén 1934), Latronema annulatum (Gerlach, 1953), and Latronema spinosum (Andrássy, 1973) by body size, number of supplementary organs, tail shape, length of spicules, and cuticle ornamentation. Full article

(This article belongs to the Special Issue Meiofauna Biodiversity and Ecology)

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10 pages, 2015 KiB

Open AccessArticle

Hydroxymethylfurfural Affects Caged Honey Bees (Apis mellifera carnica)

by Aleš Gregorc, Snežana Jurišić and Blair Sampson

Diversity 2020, 12(1), 18; https://doi.org/10.3390/d12010018 - 31 Dec 2019

Cited by 12 | Viewed by 5172

Abstract

A high concentration of hydroxymethylfurfural (HMF) (e.g., 15 mg HMF per kg honey) indicates quality deterioration for a wide range of foods. In honey bee colonies, HMF in stored honey can negatively affect bee health and survival. Therefore, in the laboratory, we experimentally [...] Read more.

A high concentration of hydroxymethylfurfural (HMF) (e.g., 15 mg HMF per kg honey) indicates quality deterioration for a wide range of foods. In honey bee colonies, HMF in stored honey can negatively affect bee health and survival. Therefore, in the laboratory, we experimentally determined the effects of HMF on the longevity and midgut integrity of worker Apis mellifera carnica by feeding bees standard diets containing five concentrations of HMF (100, 500, 1000, and 1500 ppm). Simultaneously, we also examined HMF’s effect on Nosema ceranae spore counts within infected honey bees. We performed an immunohistochemical analysis of the honey bee midgut to determine possible changes at the cellular level. No correlation was established between HMF concentration and N. ceranae spore counts. Negative effects of HMF on bees were not observed in the first 15 days of exposure. However, after 15 to 30 days of exposure, HMF caused midgut cells to die and an increased mortality of honey bee workers across treatment groups. Full article

(This article belongs to the Special Issue Monitoring of Honey Bee Colony Losses)

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11 pages, 982 KiB

Open AccessArticle

Variability of A Subterranean Prey-Predator Community in Space and Time

by Sebastiano Salvidio, Andrea Costa, Fabrizio Oneto and Mauro Valerio Pastorino

Diversity 2020, 12(1), 17; https://doi.org/10.3390/d12010017 - 31 Dec 2019

Cited by 13 | Viewed by 2925

Abstract

Subterranean habitats are characterized by buffered climatic conditions in comparison to contiguous surface environments and, in general, subterranean biological communities are considered to be relatively constant. However, although several studies have described the seasonal variation of subterranean communities, few analyzed their variability over [...] Read more.

Subterranean habitats are characterized by buffered climatic conditions in comparison to contiguous surface environments and, in general, subterranean biological communities are considered to be relatively constant. However, although several studies have described the seasonal variation of subterranean communities, few analyzed their variability over successive years. The present research was conducted inside an artificial cave during seven successive summers, from 2013 to 2019. The parietal faunal community was sampled at regular intervals from outside to 21 m deep inside the cave. The community top predator is the cave salamander Speleomantes strinatii, while invertebrates, mainly adult flies, make up the rest of the faunal assemblage. Our findings indicate that the taxonomic composition and the spatial distribution of this community remained relatively constant over the seven-year study period, supporting previous findings. However, different environmental factors were shaping the distribution of predators and prey along the cave. Invertebrates were mainly affected by the illuminance, while salamanders were influenced by both illuminance and distance from the cave’s entrance. The inter-annual spatial distribution of the salamander population was highly repeatable and age specific, confirming a gradual shift towards the deeper parts of the cave with an increasing age. In general, the spatial distribution along the cave of this prey-predator system remained relatively constant during the seven-year study, suggesting that strong selective constraints were in action, even in this relatively recent subterranean ecosystem. Full article

(This article belongs to the Special Issue The Ecological Role of Salamanders as Predators and Prey)

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16 pages, 3887 KiB

Open AccessArticle

Benthic Marine Ciliate Assemblages from Southern Brazil and Their Relationship with Seasonality and Urbanization Level

by Luana D. Tarragô, Pedro M. A. Ferreira and Laura R. P. Utz

Diversity 2020, 12(1), 16; https://doi.org/10.3390/d12010016 - 31 Dec 2019

Cited by 3 | Viewed by 2864

Abstract

Sandy beaches represent two-thirds of littoral zones worldwide. Complex factors such as winds, waves, and sediment characterize this environment. Ciliophora is one of the most diversified unicellular eukaryotic phyla and, in marine sediments, can reach 40 species per cm³. Despite its importance, knowledge [...] Read more.

Sandy beaches represent two-thirds of littoral zones worldwide. Complex factors such as winds, waves, and sediment characterize this environment. Ciliophora is one of the most diversified unicellular eukaryotic phyla and, in marine sediments, can reach 40 species per cm³. Despite its importance, knowledge about interstitial communities is still lacking. In the present work, we characterized the assemblage of interstitial ciliates from sandy beaches in the north coastal area of Rio Grande do Sul state, southern Brazil. Fourteen sampling sites distributed along the swash zone of seven beaches with different degrees of urban development were sampled over the course of one year. At each site, eight sediment samples were taken, and a total of 51 species distributed in 37 ciliate genera were identified. Classes Spirotrichea (29%) and Karyorelictea (21%) accounted for 50% of ciliate species richness, with the highest richness being observed within the context of an intermediately urbanized setting. Community analyses revealed that ciliate community is influenced by urbanization degree and season, with distinct assemblages occurring in highly urbanized areas. In beaches affected by a high level of human activity, disturbance effects increased diversity, while in areas showing a milder influence of urbanization, the level of disturbance may be low, resulting in lower richness. Full article

(This article belongs to the Section Marine Diversity)

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16 pages, 890 KiB

Open AccessArticle

A Survey from 2015 to 2019 to Investigate the Occurrence of Pesticide Residues in Dead Honeybees and Other Matrices Related to Honeybee Mortality Incidents in Italy

by Marianna Martinello, Chiara Manzinello, Alice Borin, Larisa Elena Avram, Nicoletta Dainese, Ilenia Giuliato, Albino Gallina and Franco Mutinelli

Diversity 2020, 12(1), 15; https://doi.org/10.3390/d12010015 - 27 Dec 2019

Cited by 30 | Viewed by 4845

Abstract

Honeybee health can be compromised not only by infectious and infesting diseases, but also by the acute or chronic action of certain pesticides. In recent years, there have been numerous reports of colony mortality by Italian beekeepers, but the investigations of these losses [...] Read more.

Honeybee health can be compromised not only by infectious and infesting diseases, but also by the acute or chronic action of certain pesticides. In recent years, there have been numerous reports of colony mortality by Italian beekeepers, but the investigations of these losses have been inconsistent, both in relation to the type of personnel involved (beekeepers, official veterinarians, members of the police force, etc.) and the procedures utilized. It was therefore deemed necessary to draw up national guidelines with the aim of standardizing sampling active ties. In this paper, we present the results of a survey carried out in Italy from 2015 to 2019, following these guidelines. Residues of 150 pesticides in 696 samples were analyzed by LC-MS/MS and GC-MS/MS. On average, 50% of the honeybee samples were positive for one or more pesticides with an average of 2 different pesticides per sample and a maximum of seven active ingredients, some of which had been banned in Europe or were not authorized in Italy. Insecticides were the most frequently detected, mainly belonging to the pyrethroid group (49%, above all tau-fluvalinate), followed by organophosphates (chlorpyrifos, 18%) and neonicotinoids (imidacloprid, 7%). This work provides further evidence of the possible relationship between complex pesticide exposure and honeybee mortality and/or depopulation of hives. Full article

(This article belongs to the Special Issue Monitoring of Honey Bee Colony Losses)

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16 pages, 650 KiB

Open AccessReview

The Current Status of Indigenous Ovine Genetic Resources in Southern Africa and Future Sustainable Utilisation to Improve Livelihoods

by Annelin Henriehetta Molotsi, Bekezela Dube and Schalk Willem Petrus Cloete

Diversity 2020, 12(1), 14; https://doi.org/10.3390/d12010014 - 25 Dec 2019

Cited by 17 | Viewed by 6399

Abstract

Indigenous sheep play an important role in the livelihoods of communal farmers in the Southern Africa Development Community (SADC), and this underlines the need to curb the genetic erosion of these valuable resources. This contribution reports that the phenotypic performance and genetics gains [...] Read more.

Indigenous sheep play an important role in the livelihoods of communal farmers in the Southern Africa Development Community (SADC), and this underlines the need to curb the genetic erosion of these valuable resources. This contribution reports that the phenotypic performance and genetics gains of institutional and commercial sheep in Southern Africa are well recorded. In contrast, there is a dearth of knowledge as far as the performance and genetic gains of indigenous ovine genetic resources utilized by smallholder farmers are concerned. High levels of genetic diversity have been observed in exotic breeds, whereas low levels of genetic diversity were found in the Zulu and Namaqua Afrikaner breeds. Phenotypic measurements for indigenous resources include linear measurements indicative of size and reproduction for Zulu sheep. Lamb survival, reproduction and resistance to ticks of the indigenous, fat-tailed Namaqua Afrikaner sheep, as well as growth and reproduction have also been recorded for Sabi and Landim sheep. This review discusses ways to sustainably utilize ovine genetic resources, which includes the suggested implementation of structured breeding and conservation programs, marketing, improving feed resources, health and diseases, as well as gender and age issues. Clearly, there is ample room for further research and development as far as the performance and improvement of African indigenous sheep are concerned. Full article

(This article belongs to the Special Issue Conservation of Rare Breeds of Livestock)

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22 pages, 2739 KiB

Open AccessReview

Seaweed Biodiversity of India: Reviewing Current Knowledge to Identify Gaps, Challenges, and Opportunities

by Vaibhav A. Mantri, Monica Gajanan Kavale and Mudassar Anisoddin Kazi

Diversity 2020, 12(1), 13; https://doi.org/10.3390/d12010013 - 25 Dec 2019

Cited by 44 | Viewed by 29082

Abstract

Seaweeds are a renewable marine resources and have not yet received considerable attention in the field of taxonomy in India as compared to their terrestrial counterparts, essentially due to the lack of awareness of their economic potential. Although the recent inventory from the [...] Read more.

Seaweeds are a renewable marine resources and have not yet received considerable attention in the field of taxonomy in India as compared to their terrestrial counterparts, essentially due to the lack of awareness of their economic potential. Although the recent inventory from the Indian region documented the presence of approximately 865 seaweed taxa, of which only a few are taxonomically well characterized, more precise information still awaits with respect to microscopic and molecular examinations of many. Thus far, in terms of spatial extent, probably only a few of the total hospitable seaweed habitats have been explored, and large portions, including island territories and subtidal waters, remain virtually untouched. Surveying those may lead to the reporting of several taxa new to science. Furthermore, more focused efforts are required to understand the endemic and endangered taxa which have high conservation implications. Considering the unprecedented pressures seaweeds are facing, including coastal pollution and human-induced global warming, it is critical to reinforce our knowledge of seaweed biodiversity. In the present communication, we intended to address the status of seaweed biodiversity in India along with the gaps, challenges, and opportunities. Full article

(This article belongs to the Special Issue Biodiversity of Macroalgae)

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14 pages, 2220 KiB

Open AccessArticle

Control of Varroa destructor Mite Infestations at Experimental Apiaries Situated in Croatia

by Ivana Tlak Gajger, Lidija Svečnjak, Dragan Bubalo and Tomislav Žorat

Diversity 2020, 12(1), 12; https://doi.org/10.3390/d12010012 - 25 Dec 2019

Cited by 10 | Viewed by 4153

Abstract

Experimental varroacidal treatments of honey bee colonies were conducted on five apiaries (EA1–EA5) situated at five different geographical and climatic locations across Croatia. The aim of this study was to assess the comparative efficacy of CheckMite+ (Bayer, Germany), Apiguard (Vita Europe Ltd.; England), [...] Read more.

Experimental varroacidal treatments of honey bee colonies were conducted on five apiaries (EA1–EA5) situated at five different geographical and climatic locations across Croatia. The aim of this study was to assess the comparative efficacy of CheckMite+ (Bayer, Germany), Apiguard (Vita Europe Ltd.; England), Bayvarol, C, (Bayer, Germany), Thymovar, (Andrma BioVet GmbH, Germany), and ApiLife Var, (Chemicals Laif SPA; Vigonza, Italy) for controlling the honey bee obligatory parasitic mite Varroa destructor in different conditions in the field during summer treatment. The relative varroa mite mortality after treatments with applied veterinary medicinal products were EA1 (59.24%), EA2 (47.31%), EA3 (36.75%), EA4 (48.33%), and EA5 (16.78%). Comparing the relative efficacy of applied varroacides, the best effect was achieved with CheckMite+, and the lowest for honey bee colonies treated with Apiguard (statistically significant difference was confirmed; p < 0.05). Considering the lower efficacy of thymol-based veterinary medicinal products observed on all EA in these study conditions, it may be concluded that their use is limited under different treatment regimes. Despite unfavourable weather and environmental conditions, with exceptions of EA5/EA5′ and EA1, the relative varroacidal efficacy of authorized veterinary medicinal product treatments in moderately infested honey bee colonies ensured normal overwintering and colony development during next spring. Full article

(This article belongs to the Special Issue Monitoring of Honey Bee Colony Losses)

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12 pages, 283 KiB

Open AccessArticle

Disentangling the Effects of Disturbance from Those of Dominant Tall Grass Features in Driving the Functional Variation of Restored Grassland in a Sub-Mediterranean Context

by Alessandro Bricca, Federico Maria Tardella, Fabio Tolu, Irina Goia, Arianna Ferrara and Andrea Catorci

Diversity 2020, 12(1), 11; https://doi.org/10.3390/d12010011 - 24 Dec 2019

Cited by 20 | Viewed by 3072

Abstract

Land abandonment in sub-Mediterranean grasslands causes the spread of tall-grasses, affecting biodiversity and ecosystem functioning. Mowing allows the recovery of the coenological composition after invasion, but the mechanisms acting at the fine-scale are poorly investigated. Since 2010 in the Central Apennines, we fenced [...] Read more.

Land abandonment in sub-Mediterranean grasslands causes the spread of tall-grasses, affecting biodiversity and ecosystem functioning. Mowing allows the recovery of the coenological composition after invasion, but the mechanisms acting at the fine-scale are poorly investigated. Since 2010 in the Central Apennines, we fenced a grassland invaded by Brachypodium rupestre, divided it into two areas, half of each was mowed biyearly and half remained unmown. In 2017 we selected ten 20 × 20 cm experimental units per half-area, collecting data on species occurrences, plant traits, B. rupestre height and phytomass. We used generalized linear mixed-effect modelling to disentangle the role of mowing from the impact of B. rupestre features in driving the community functional variations. Mowing was the main driver in the recovery process, acting as an abiotic filter (enhancement of tolerance-avoidance strategies). Furthermore, the reduction of weaker competitor exclusion processes fostered the increase of functional variation between coexisting species. Both drivers acted on different plant traits (e.g., mowing on life span, vegetative propagation types and plant height, mowing and B. rupestre features on space occupation types, seed mass and leaf anatomy), generally enhancing the extent of functional strategies related to resource acquisition and storage, reproduction, space occupation and temporal niche exploitation. Full article

(This article belongs to the Special Issue Plant Community Ecology: From Theory to Practice)

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