Diversity

18 pages, 1878 KiB

Open AccessEditor’s ChoiceArticle

Unimodal Relationships of Understory Alpha and Beta Diversity along Chronosequence in Coppiced and Unmanaged Beech Forests

by Sándor Bartha, Roberto Canullo, Stefano Chelli and Giandiego Campetella

Diversity 2020, 12(3), 101; https://doi.org/10.3390/d12030101 - 13 Mar 2020

Cited by 17 | Viewed by 4350

Abstract

Patterns of diversity across spatial scales in forest successions are being overlooked, despite their importance for developing sustainable management practices. Here, we tested the recently proposed U-shaped biodiversity model of forest succession. A chronosequence of 11 stands spanning from 5 to 400 years [...] Read more.

Patterns of diversity across spatial scales in forest successions are being overlooked, despite their importance for developing sustainable management practices. Here, we tested the recently proposed U-shaped biodiversity model of forest succession. A chronosequence of 11 stands spanning from 5 to 400 years since the last disturbance was used. Understory species presence was recorded along 200 m long transects of 20 × 20 cm quadrates. Alpha diversity (species richness, Shannon and Simpson diversity indices) and three types of beta diversity indices were assessed at multiple scales. Beta diversity was expressed by a) spatial compositional variability (number and diversity of species combinations), b) pairwise spatial turnover (between plots Sorensen, Jaccard, and Bray–Curtis dissimilarity), and c) spatial variability coefficients (CV% of alpha diversity measures). Our results supported the U-shaped model for both alpha and beta diversity. The strongest differences appeared between active and abandoned coppices. The maximum beta diversity emerged at characteristic scales of 2 m in young coppices and 10 m in later successional stages. We conclude that traditional coppice management maintains high structural diversity and heterogeneity in the understory. The similarly high beta diversities in active coppices and old-growth forests suggest the presence of microhabitats for specialist species of high conservation value. Full article

(This article belongs to the Special Issue Monitoring Plant Diversity and Community Assembly in Forest Ecosystems)

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23 pages, 4214 KiB

Open AccessFeature PaperEditor’s ChoiceArticle

Patterns of Understory Community Assembly and Plant Trait-Environment Relationships in Temperate SE European Forests

by Janez Kermavnar and Lado Kutnar

Diversity 2020, 12(3), 91; https://doi.org/10.3390/d12030091 - 4 Mar 2020

Cited by 21 | Viewed by 6333

Abstract

We analyzed variation in the functional composition and diversity of understory plant communities across different forest vegetation types in Slovenia. The study area comprises 10 representative forest sites covering broad gradients of environmental conditions (altitude, geology, light availability, soil type and reaction, nutrient [...] Read more.

We analyzed variation in the functional composition and diversity of understory plant communities across different forest vegetation types in Slovenia. The study area comprises 10 representative forest sites covering broad gradients of environmental conditions (altitude, geology, light availability, soil type and reaction, nutrient availability, soil moisture), stand structural features and community attributes. The mean and variation of the trait values were quantified by community-weighted means and functional dispersion for four key plant functional traits: plant height, seed mass, specific leaf area and leaf dry matter content. At each study site, forest vegetation was surveyed at two different spatial scales (4 and 100 m²) in order to infer scale-dependent assembly rules. Patterns of community assembly were tested with a null model approach. We found that both trait means and diversity values responded to conspicuous gradients in environmental conditions and species composition across the studied forests. Our results mainly support the idea of abiotic filtering: more stressful environmental conditions (e.g., high altitude, low soil pH and low nutrient content) were occupied by communities of low functional diversity (trait convergence), which suggests a selective effect for species with traits adapted to such harsh conditions. However, trait convergence was also detected in some more resource-rich forest sites (e.g., low altitude, high soil productivity), most likely due to the presence of competitive understory species with high abundance domination. This could, at least to some extent, indicate the filtering effect of competitive interactions. Overall, we observed weak and inconsistent patterns regarding the impact of spatial scale, suggesting that similar assembly mechanisms are operating at both investigated spatial scales. Our findings contribute to the baseline understanding of the role of both abiotic and biotic constraints in forest community assembly, as evidenced by the non-random patterns in the functional structure of distinct temperate forest understories. Full article

(This article belongs to the Special Issue Monitoring Plant Diversity and Community Assembly in Forest Ecosystems)

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16 pages, 2286 KiB

Open AccessEditor’s ChoiceReview

The Role of Climate and Topography in Shaping the Diversity of Plant Communities in Cabo Verde Islands

by Carlos Neto, José Carlos Costa, Albano Figueiredo, Jorge Capelo, Isildo Gomes, Sónia Vitória, José Maria Semedo, António Lopes, Herculano Dinis, Ezequiel Correia, Maria Cristina Duarte and Maria M. Romeiras

Diversity 2020, 12(2), 80; https://doi.org/10.3390/d12020080 - 19 Feb 2020

Cited by 24 | Viewed by 8030

Abstract

The flora and vegetation of the archipelago of Cabo Verde is dominated by Macaronesian, Mediterranean, and particularly by African tropical elements, resulting from its southernmost location, when compared to the other islands of the Macaronesia (i.e., Azores, Madeira, Selvagens, and Canary Islands). Very [...] Read more.

The flora and vegetation of the archipelago of Cabo Verde is dominated by Macaronesian, Mediterranean, and particularly by African tropical elements, resulting from its southernmost location, when compared to the other islands of the Macaronesia (i.e., Azores, Madeira, Selvagens, and Canary Islands). Very likely, such a geographical position entailed higher susceptibility to extreme climatic fluctuations, namely those associated with the West African Monsoon oscillations. These fluctuations led to a continuous aridification, which is a clear trend shown by most recent studies based on continental shelf cores. Promoting important environmental shifts, such climatic fluctuations are accepted as determinant to explain the current spatial distribution patterns of taxa, as well as the composition of the plant communities. In this paper, we present a comprehensive characterization of the main plant communities in Cabo Verde, and we discuss the role of the climatic and topoclimatic diversity in shaping the vegetation composition and distribution of this archipelago. Our study reveals a strong variation in the diversity of plant communities across elevation gradients and distinct patterns of richness among plant communities. Moreover, we present an overview of the biogeographical relationships of the Cabo Verde flora and vegetation with the other Macaronesian Islands and northwestern Africa. We discuss how the distribution of plant communities and genetic patterns found among most of the endemic lineages can be related to Africa’s ongoing aridification, exploring the impacts of a process that marks northern Africa from the Late Miocene until the present. Full article

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

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26 pages, 2215 KiB

Open AccessEditor’s ChoiceReview

Systematic Review of the Roost-Site Characteristics of North American Forest Bats: Implications for Conservation

by Evan C. Drake, Sarah Gignoux-Wolfsohn and Brooke Maslo

Diversity 2020, 12(2), 76; https://doi.org/10.3390/d12020076 - 18 Feb 2020

Cited by 17 | Viewed by 6280

Abstract

Continued declines in North American bat populations can be largely attributed to habitat loss, disease, and wind turbines. These declines can be partially mitigated through actions that boost reproductive success; therefore, management aimed at promoting availability of high-quality roosting habitat is an important [...] Read more.

Continued declines in North American bat populations can be largely attributed to habitat loss, disease, and wind turbines. These declines can be partially mitigated through actions that boost reproductive success; therefore, management aimed at promoting availability of high-quality roosting habitat is an important conservation goal. Following the principles of the umbrella species concept, if co-occurring species share similar roost-tree preferences, then management practices targeting one species may confer conservation benefits to another. We conducted a systematic review of roost-site characteristics of thirteen species inhabiting eastern temperate forests to: (1) synthesize existing knowledge across species; (2) assess niche overlap among co-occurring species; and (3) evaluate the potential for currently protected species to serve as conservation umbrellas. We performed multivariate ordination techniques to group species based on the seven most-reported roost-site characteristics, including tree species, diameter at breast height, tree health, roost type, tree height, canopy closure, and roost height. Species sorted into three roosting guilds: (1) southern wetland inhabitants; (2) foliage specialists; and (3) dead tree generalists. Myotis septentrionalis and Perimyotis subflavus had significant roost-niche overlap with five and four other species respectively, and their existing protections make them suitable umbrellas for other bats in the North American eastern temperate forests. Full article

(This article belongs to the Special Issue Impacts of Pressure on Bat Populations)

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12 pages, 5981 KiB

Open AccessEditor’s ChoiceArticle

Analysis of Encystment, Excystment, and Cyst Structure in Freshwater Eutardigrade Thulinius ruffoi (Tardigrada, Isohypsibioidea: Doryphoribiidae)

by Kamil Janelt and Izabela Poprawa

Diversity 2020, 12(2), 62; https://doi.org/10.3390/d12020062 - 4 Feb 2020

Cited by 12 | Viewed by 5677

Abstract

Encystment in tardigrades is relatively poorly understood. It is seen as an adaptive strategy evolved to withstand unfavorable environmental conditions. This process is an example of the epigenetic, phenotypic plasticity which is closely linked to the molting process. Thulinius ruffoi is a freshwater [...] Read more.

Encystment in tardigrades is relatively poorly understood. It is seen as an adaptive strategy evolved to withstand unfavorable environmental conditions. This process is an example of the epigenetic, phenotypic plasticity which is closely linked to the molting process. Thulinius ruffoi is a freshwater eutardigrade and a representative of one of the biggest eutardigrade orders. This species is able to form cysts. The ovoid-shaped cysts of this species are known from nature, but cysts may also be obtained under laboratory conditions. During encystment, the animals undergo profound morphological changes that result in cyst formation. The animals surround their bodies with cuticles that isolate them from the environment. These cuticles form a cuticular capsule (cyst wall) which is composed of three cuticles. Each cuticle is morphologically distinct. The cuticles that form the cuticular capsule are increasingly simplified. During encystment, only one, unmodified and possibly functional buccal-pharyngeal apparatus was found to be formed. Apart from the feeding apparatus, the encysted specimens also possess a set of claws, and their body is covered with its own cuticle. As a consequence, the encysted animals are fully adapted to the active life after leaving the cyst capsule. Full article

(This article belongs to the Special Issue Tardigrades Taxonomy, Biology and Ecology)

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19 pages, 320 KiB

Open AccessEditor’s ChoiceArticle

An Italian Research Culture Collection of Wood Decay Fungi

by Carolina Elena Girometta, Annarosa Bernicchia, Rebecca Michela Baiguera, Francesco Bracco, Simone Buratti, Marco Cartabia, Anna Maria Picco and Elena Savino

Diversity 2020, 12(2), 58; https://doi.org/10.3390/d12020058 - 1 Feb 2020

Cited by 30 | Viewed by 5881

Abstract

One of the main aims of the University of Pavia mycology laboratory was to collect wood decay fungal (WDF) strains in order to deepen taxonomic studies, species distribution, officinal properties or to investigate potential applications such as biocomposite material production based on fungi. [...] Read more.

One of the main aims of the University of Pavia mycology laboratory was to collect wood decay fungal (WDF) strains in order to deepen taxonomic studies, species distribution, officinal properties or to investigate potential applications such as biocomposite material production based on fungi. The Italian Alps, Apennines and wood plains were investigated to collect Basidiomycota basidiomata from living or dead trees. The purpose of this study was to investigate the wood decay strains of the Mediterranean area, selecting sampling sites in North and Central Italy, including forests near the Ligurian and Adriatic seas, or near the Lombardy lakes. The isolation of mycelia in pure culture was performed according to the current methodology and the identity of the strains was confirmed by molecular analyses. The strains are maintained in the Research Culture Collection MicUNIPV of Pavia University (Italy). Among the 500 WDF strains in the collection, the most interesting isolates from the Mediterranean area are: Dichomitus squalens (basidioma collected from Pinus pinea), Hericium erinaceus (medicinal mushroom), Inocutis tamaricis (white-rot agent on Tamarix trees), Perenniporia meridionalis (wood degrader through Mn peroxidase) and P. ochroleuca. In addition, strains of species related to the Mediterranean climate (e.g., Fomitiporia mediterranea and Cellulariella warnieri) were obtained from sites with a continental-temperate climate. Full article

(This article belongs to the Special Issue Fungal Diversity in the Mediterranean Area)

19 pages, 1805 KiB

Open AccessEditor’s ChoiceReview

More Than a Functional Group: Diversity within the Legume–Rhizobia Mutualism and Its Relationship with Ecosystem Function

by Benton N. Taylor, Ellen L. Simms and Kimberly J. Komatsu

Diversity 2020, 12(2), 50; https://doi.org/10.3390/d12020050 - 28 Jan 2020

Cited by 45 | Viewed by 11033

Abstract

Studies of biodiversity and ecosystem function (BEF) have long focused on the role of nitrogen (N)-fixing legumes as a functional group that occupies a distinct and important niche relative to other plants. Because of their relationship with N-fixing rhizobial bacteria, these legumes access [...] Read more.

Studies of biodiversity and ecosystem function (BEF) have long focused on the role of nitrogen (N)-fixing legumes as a functional group that occupies a distinct and important niche relative to other plants. Because of their relationship with N-fixing rhizobial bacteria, these legumes access a different pool of N than other plants and therefore directly contribute to increases in productivity and N-cycling. Despite their recognized importance in the BEF literature, the field has not moved far beyond investigating the presence/absence of the legume functional group in species mixtures. Here, we synthesize existing information on how the diversity (species richness and functional diversity) of both legumes and the rhizobia that they host impact ecosystem functions, such as nitrogen fixation and primary productivity. We also discuss the often-overlooked reciprocal direction of the BEF relationship, whereby ecosystem function can influence legume and rhizobial diversity. We focus on BEF mechanisms of selection, complementarity, facilitation, competitive interference, and dilution effects to explain how diversity in the legume–rhizobia mutualism can have either positive or negative effects on ecosystem function—mechanisms that can operate at scales from rhizobial communities affecting individual legume functions to legume communities affecting landscape-scale ecosystem functions. To fully understand the relationship between biodiversity and ecosystem function, we must incorporate the full diversity of this mutualism and its reciprocal relationship with ecosystem function into our evolving BEF framework. Full article

(This article belongs to the Special Issue Symbioses and the Biodiversity-Ecosystem Function Relationship)

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12 pages, 5310 KiB

Open AccessEditor’s ChoiceArticle

First Complete Wing of a Stem Group Sphenisciform from the Paleocene of New Zealand Sheds Light on the Evolution of the Penguin Flipper

by Gerald Mayr, Vanesa L. De Pietri, Leigh Love, Al A. Mannering, Joseph J. Bevitt and R. Paul Scofield

Diversity 2020, 12(2), 46; https://doi.org/10.3390/d12020046 - 26 Jan 2020

Cited by 12 | Viewed by 8885

Abstract

We describe a partial skeleton of a stem group penguin from the Waipara Greensand in New Zealand, which is tentatively assigned to Muriwaimanu tuatahi. The fossil includes the first complete wing of a Paleocene penguin and informs on previously unknown features of [...] Read more.

We describe a partial skeleton of a stem group penguin from the Waipara Greensand in New Zealand, which is tentatively assigned to Muriwaimanu tuatahi. The fossil includes the first complete wing of a Paleocene penguin and informs on previously unknown features of the mandible and tibiotarsus of small-sized Sphenisciformes from the Waipara Greensand. The wing is distinguished by important features from that of all geologically younger Sphenisciformes and documents an early stage in the evolution of wing-propelled diving in penguins. In particular, the wing of the new fossil exhibits a well-developed alular phalanx and the distal phalanges are not flattened. Because the wing phalanges resemble those of volant birds, we consider it likely that the wing feathers remained differentiated into functional categories and were not short and scale-like as they are in extant penguins. Even though the flippers of geologically younger penguins may favor survival in extremely cold climates, they are likely to have been shaped by hydrodynamic demands. Possible selective drivers include a diminished importance of the hindlimbs in subaquatic propulsion, new foraging strategies (the caudal end of the mandible of the new fossil distinctly differs from that of extant penguins), or increased predation by marine mammals. Full article

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

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14 pages, 1832 KiB

Open AccessEditor’s ChoiceArticle

Genetic Structure and Phylogeography of Tuber magnatum Populations

by Beatrice Belfiori, Valentina D’Angelo, Claudia Riccioni, Marco Leonardi, Francesco Paolocci, Giovanni Pacioni and Andrea Rubini

Diversity 2020, 12(2), 44; https://doi.org/10.3390/d12020044 - 24 Jan 2020

Cited by 15 | Viewed by 5342

Abstract

The ectomycorrhizal fungus Tuber magnatum produces the white truffle appreciated worldwide for its unique aroma. With respect to other Tuber spp. of economic interest, T. magnatum presents a narrower geographical range. This species has, in fact, long been considered endemic to Italy. However, [...] Read more.

The ectomycorrhizal fungus Tuber magnatum produces the white truffle appreciated worldwide for its unique aroma. With respect to other Tuber spp. of economic interest, T. magnatum presents a narrower geographical range. This species has, in fact, long been considered endemic to Italy. However, over the last few decades several reports have documented the presence of white truffles in different Mediterranean countries and in particular in various areas of south-east Europe. In this study, samples from several Pannonian and Balkan countries such as Hungary, Serbia, Romania, Bulgaria and Greece have been collected and genotyped with microsatellite markers and the data merged with those available for Italian populations. Our objectives were to test whether Italian and south-east European populations are differentiated and to evaluate the genetic diversity of T. magnatum all over its distributional range. We show the genetic structure of T. magnatum populations with the differentiation of four main groups: northern Italy, central-northern Italy, southern Italy and the Balkan/Pannonian region. The present study allowed us to refine the evolutionary history of T. magnatum and track the possible post-glacial expansion route of this species. The assessment of T. magnatum’s genetic structure is not only of scientific relevance, but it is also important for the conservation and market traceability of this prestigious fungus. Full article

(This article belongs to the Special Issue Fungal Diversity in the Mediterranean Area)

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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 19 | Viewed by 4313

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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