Diversity

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Open AccessReview

Patterns of Macroinvertebrate and Fish Diversity in Freshwater Sulphide Springs

by Ryan Greenway, Lenin Arias-Rodriguez, Pete Diaz and Michael Tobler

Diversity 2014, 6(3), 597-632; https://doi.org/10.3390/d6030597 - 18 Sep 2014

Cited by 37 | Viewed by 12411

Extreme environments are characterised by the presence of physicochemical stressors and provide unique study systems to address problems in evolutionary ecology research. Sulphide springs provide an example of extreme freshwater environments; because hydrogen sulphide’s adverse physiological effects induce mortality in metazoans even at [...] Read more.

Extreme environments are characterised by the presence of physicochemical stressors and provide unique study systems to address problems in evolutionary ecology research. Sulphide springs provide an example of extreme freshwater environments; because hydrogen sulphide’s adverse physiological effects induce mortality in metazoans even at micromolar concentrations. Sulphide springs occur worldwide, but while microbial communities in sulphide springs have received broad attention, little is known about macroinvertebrates and fish inhabiting these toxic environments. We reviewed qualitative occurrence records of sulphide spring faunas on a global scale and present a quantitative case study comparing diversity patterns in sulphidic and adjacent non-sulphidic habitats across replicated river drainages in Southern Mexico. While detailed studies in most regions of the world remain scarce, available data suggests that sulphide spring faunas are characterised by low species richness. Dipterans (among macroinvertebrates) and cyprinodontiforms (among fishes) appear to dominate the communities in these habitats. At least in fish, there is evidence for the presence of highly endemic species and populations exclusively inhabiting sulphide springs. We provide a detailed discussion of traits that might predispose certain taxonomic groups to colonize sulphide springs, how colonizers subsequently adapt to cope with sulphide toxicity, and how adaptation may be linked to speciation processes. Full article

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240 KiB

Open AccessReview

DNA Markers for Food Products Authentication

by Daria Scarano and Rosa Rao

Diversity 2014, 6(3), 579-596; https://doi.org/10.3390/d6030579 - 5 Sep 2014

Cited by 76 | Viewed by 9856

Abstract

Media constantly refer of unscrupulous producers that adulterate, alter or replace premium products in food chains with the goal to maximize illegally profits. Food traceability is a central issue for the identification of improper labeling of processed food and feed and there are [...] Read more.

Media constantly refer of unscrupulous producers that adulterate, alter or replace premium products in food chains with the goal to maximize illegally profits. Food traceability is a central issue for the identification of improper labeling of processed food and feed and there are rules aimed to protect consumers and producers against fraudulent substitution of quality products in food chain, but the tools available are not always appropriate. DNA-based markers proved very effective for fresh and processed food molecular authentication. In this review, we illustrate potential and limits of different DNA markers focusing on low, medium and high-throughput markers, in order to monitor the genetic identity of food components in meat, fish and plants net-chains. Full article

(This article belongs to the Special Issue Use of Molecular Markers in Genetic Diversity Research)

321 KiB

Open AccessArticle

Impact of Dams on Riparian Frog Communities in the Southern Western Ghats, India

by Rohit Naniwadekar and Karthikeyan Vasudevan

Diversity 2014, 6(3), 567-578; https://doi.org/10.3390/d6030567 - 29 Aug 2014

Cited by 7 | Viewed by 6769

Abstract

The Western Ghats is a global biodiversity hotspot and home to diverse and unique assemblages of amphibians. Several rivers originate from these mountains and hydropower is being tapped from them. The impacts of hydrological regulation of riparian ecosystems to wildlife and its habitat [...] Read more.

The Western Ghats is a global biodiversity hotspot and home to diverse and unique assemblages of amphibians. Several rivers originate from these mountains and hydropower is being tapped from them. The impacts of hydrological regulation of riparian ecosystems to wildlife and its habitat are poorly documented, and in particular the fate of frog populations is unknown. We examined the effects of dams on riparian frog communities in the Thamirabarani catchment in southern Western Ghats. We used nocturnal visual encounter surveys constrained for time, to document the species richness of frogs below and above the dam, and also at control sites in the same catchment. While we did not find differences in species richness below and above the dams, the frog community composition was significantly altered as a likely consequence of altered flow regime. The frog species compositions in control sites were similar to above-dam sites. Below-dam sites had a distinctly different species composition. Select endemic frog species appeared to be adversely impacted due to the dams. Below-dam sites had a greater proportion of generalist and widely distributed species. Dams in the Western Ghats appeared to adversely impact population of endemic species, particularly those belonging to the genus Nyctibatrachus that shows specialization for intact streams. Full article

(This article belongs to the Special Issue Global Freshwater Biodiversity)

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311 KiB

Open AccessArticle

Genetic Diversity in Jatropha curcas L. Assessed with SSR and SNP Markers

by Juan M. Montes, Frank Technow, Matthias Martin and Klaus Becker

Diversity 2014, 6(3), 551-566; https://doi.org/10.3390/d6030551 - 7 Aug 2014

Cited by 38 | Viewed by 7638

Abstract

Jatropha curcas L. (jatropha) is an undomesticated plant that has recently received great attention for its utilization in biofuel production, rehabilitation of wasteland, and rural development. Knowledge of genetic diversity and marker-trait associations is urgently needed for the design of breeding strategies. The [...] Read more.

Jatropha curcas L. (jatropha) is an undomesticated plant that has recently received great attention for its utilization in biofuel production, rehabilitation of wasteland, and rural development. Knowledge of genetic diversity and marker-trait associations is urgently needed for the design of breeding strategies. The main goal of this study was to assess the genetic structure and diversity in jatropha germplasm with co-dominant markers (Simple Sequence Repeats (SSR) and Single Nucleotide Polymorphism (SNP) in a diverse, worldwide, germplasm panel of 70 accessions. We found a high level of homozygosis in the germplasm that does not correspond to the purely outcrossing mating system assumed to be present in jatropha. We hypothesize that the prevalent mating system of jatropha comprise a high level of self-fertilization and that the outcrossing rate is low. Genetic diversity in accessions from Central America and Mexico was higher than in accession from Africa, Asia, and South America. We identified makers associated with the presence of phorbol esters. We think that the utilization of molecular markers in breeding of jatropha will significantly accelerate the development of improved cultivars. Full article

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Open AccessArticle

Diversity and Spatial Distribution of Extant Freshwater Ostracodes (Crustacea) in Ancient Lake Ohrid (Macedonia/Albania)

by Julia Lorenschat, Liseth Pérez, Alexander Correa-Metrio, Mark Brenner, Ullrich Von Bramann and Antje Schwalb

Diversity 2014, 6(3), 524-550; https://doi.org/10.3390/d6030524 - 17 Jul 2014

Cited by 16 | Viewed by 12248

Abstract

We carried out an intensive sampling survey in ancient Lake Ohrid (Macedonia/Albania), covering all seasons, to determine total species number, relative species abundances and spatial distribution of Ostracoda. We identified 32 living species that belong to seven families (Candonidae, Ilyocyprididae, Cyprididae, Leptocytheridae, Limnocytheridae, [...] Read more.

We carried out an intensive sampling survey in ancient Lake Ohrid (Macedonia/Albania), covering all seasons, to determine total species number, relative species abundances and spatial distribution of Ostracoda. We identified 32 living species that belong to seven families (Candonidae, Ilyocyprididae, Cyprididae, Leptocytheridae, Limnocytheridae, Cytherideidae, and Darwinulidae) and 15 genera (Candona, Fabaeformiscandona, Candonopsis, Cypria, Cyclocypris, Ilyocypris, Eucypris, Prionocypris, Bradleystrandesia, Herpetocypris, Dolerocypris, Amnicythere, Paralimnocythere, Cytherissa, and Darwinula). Six additional species were identified from empty carapaces and valves. Dominant families in Lake Ohrid were Candonidae and Limnocytheridae, representing 53% and 16% of all species, respectively. Prevalence of species flocks in these two families confirms the “young” ancient status of the lake. Amnicythere displays a preference for oligo-haline to meso-haline waters, but some species are found in saline environments, which suggests Lake Ohrid has a marine history. Recent studies, however, indicate fluvial/glaciofluvial deposition at the onset of Lake Ohrid sedimentation. Candona is the most diverse genus in Lake Ohrid, represented by 12 living species. Paralimnocythere is represented by five living species and all other genera are represented by one or two species. Reports of Candona bimucronata, Ilyocypris bradyi, Eucypris virens, Eucypris sp., Prionocypris zenkeri, Bradleystrandesia reticulate, Herpetocypris sp. 2, and Dolerocypris sinensis are firsts for this lake. Living ostracodes were collected at the maximum water depth (280 m) in the lake (Candona hadzistei, C. marginatoides, C. media, C. ovalis, C. vidua, Fabaeformiscandona krstici, Cypria lacustris, C. obliqua and Amnicythere karamani). Cypria lacustris was overall the most abundant species and Cypria obliqua displayed the highest abundance at 280 m water depth. Principal environmental variables that influence ostracode distributions in Lake Ohrid are water depth and conductivity. In general, species richness, diversity and evenness were greater in waters <60 m deep, with highest values often found in the littoral zone, at depths <30 m. Candonids, however, displayed highest diversity in the sublittoral (30–50 m) and profundal (50–280 m) zones. The most frequent species encountered are taxa endemic to the lake (14 living species), which have a wide depth range (≤280 m), and display higher abundance with greater water depth. Non-endemic species were rare, limited to water depths <50 m, and were found mainly in the north part of the lake where anthropogenic pressure is high. Several cosmopolitan species were encountered for the first time, which suggests that these widespread species are new arrivals that may replace endemics as human impacts increase. Full article

(This article belongs to the Special Issue Global Freshwater Biodiversity)

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265 KiB

Open AccessReview

Economics of Harmful Invasive Species: A Review

by George Marbuah, Ing-Marie Gren and Brendan McKie

Diversity 2014, 6(3), 500-523; https://doi.org/10.3390/d6030500 - 15 Jul 2014

Cited by 130 | Viewed by 17356

Abstract

The purpose of this study is to review theoretical and empirical findings in economics with respect to the challenging question of how to manage invasive species. The review revealed a relatively large body of literature on the assessment of damage costs of invasive [...] Read more.

The purpose of this study is to review theoretical and empirical findings in economics with respect to the challenging question of how to manage invasive species. The review revealed a relatively large body of literature on the assessment of damage costs of invasive species; single species and groups of species at different geographical scales. However, the estimated damage costs show large variation, from less than 1 million USD to costs corresponding to 12% of gross domestic product, depending on the methods employed, geographical scale, and scope with respect to inclusion of different species. Decisions regarding optimal management strategies, when to act in the invasion chain and which policy to choose, have received much less attention in earlier years, but have been subject to increasing research during the last decade. More difficult, but also more relevant policy issues have been raised, which concern the targeting in time and space of strategies under conditions of uncertainty. In particular, the weighting of costs and benefits from early detection and mitigation against the uncertain avoidance of damage with later control, when the precision in targeting species is typically greater is identified as a key challenge. The role of improved monitoring for detecting species and their spread and damage has been emphasized, but questions remain on how to achieve this in practice. This is in contrast to the relatively large body of literature on policies for mitigating dispersal by trade, which is regarded as one of the most important vectors for the spread of invasive species. On the other hand, the literature on how to mitigate established species, by control or adaptation, is much more scant. Studies evaluating causes for success or failure of policies against invasive in practice are in principal non-existing. Full article

(This article belongs to the Special Issue Biological Invasions)

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572 KiB

Open AccessReview

Diversity of Secondary Metabolites in the Genus Silene L. (Caryophyllaceae)—Structures, Distribution, and Biological Properties

by Nilufar Z. Mamadalieva, Rene Lafont and Michael Wink

Diversity 2014, 6(3), 415-499; https://doi.org/10.3390/d6030415 - 11 Jul 2014

Cited by 50 | Viewed by 10842

Abstract

The genus Silene (family Caryophyllaceae) comprises more than 700 species, which are widely distributed in temperate zones of the Northern Hemisphere, but are also present in Africa and have been introduced in other continents. Silene produces a high diversity of secondary metabolites and [...] Read more.

The genus Silene (family Caryophyllaceae) comprises more than 700 species, which are widely distributed in temperate zones of the Northern Hemisphere, but are also present in Africa and have been introduced in other continents. Silene produces a high diversity of secondary metabolites and many of them show interesting biological and pharmacological activities. More than 450 compounds have been isolated; important classes include phytoecdysteroids (which mimic insect molting hormones), triterpene saponins (with detergent properties), volatiles, other terpenoids and phenolics. This review focusses on the phytochemical diversity, distribution of Silene secondary metabolites and their biological activities. Full article

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Open AccessArticle

Employing Measures of Heterogeneity and an Object-Based Approach to Extrapolate Tree Species Distribution Data

by Trevor G. Jones, Nicholas C. Coops, Sarah E. Gergel and Tara Sharma

Diversity 2014, 6(3), 396-414; https://doi.org/10.3390/d6030396 - 3 Jul 2014

Cited by 3 | Viewed by 6158

Abstract

Information derived from high spatial resolution remotely sensed data is critical for the effective management of forested ecosystems. However, high spatial resolution data-sets are typically costly to acquire and process and usually provide limited geographic coverage. In contrast, moderate spatial resolution remotely sensed [...] Read more.

Information derived from high spatial resolution remotely sensed data is critical for the effective management of forested ecosystems. However, high spatial resolution data-sets are typically costly to acquire and process and usually provide limited geographic coverage. In contrast, moderate spatial resolution remotely sensed data, while not able to provide the spectral or spatial detail required for certain types of products and applications, offer inexpensive, comprehensive landscape-level coverage. This study assessed using an object-based approach to extrapolate detailed tree species heterogeneity beyond the extent of hyperspectral/LiDAR flightlines to the broader area covered by a Landsat scene. Using image segments, regression trees established ecologically decipherable relationships between tree species heterogeneity and the spectral properties of Landsat segments. The spectral properties of Landsat bands 4 (i.e., NIR: 0.76–0.90 µm), 5 (i.e., SWIR: 1.55–1.75 µm) and 7 (SWIR: 2.08–2.35 µm) were consistently selected as predictor variables, explaining approximately 50% of variance in richness and diversity. Results have important ramifications for ongoing management initiatives in the study area and are applicable to wide range of applications. Full article

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The British Columbian southern Gulf Islands as shown in the near infrared band of a Landsat-5 TM satellite image. The extent of hyperspectral/LiDAR flightlines are shown in green/purple. Full article ">Figure 2
For a portion of the study area: (a) 2 m tree species distribution data derived from fused airborne hyperspectral/LiDAR data. The background is area outside of the flightlines, represented by Landsat band 4 (NIR), (b) tree species richness calculated at a 30 m grain within the extent of airborne hyperspectral/LiDAR flightlines. The background is area outside of the flightlines, represented by Landsat band 4 (NIR), (c) Landsat-5 TM objects/segments falling within appropriate size thresholds and within the extent of airborne hyperspectral/LiDAR flightlines, and (d) 30 m tree species richness extrapolated beyond the extent of flightlines, wherein eight richness classes range from low to high. Full article ">Figure 3
The effect of coarsening spatial resolution on the amount (%) of forested land occupied by each species. Full article ">Figure 4
Comparison of frequency distribution for tree species heterogeneity values based on 30 m pixels for richness (a), diversity (b) and evenness (c), and for image objects for richness (d), diversity (e) and evenness (f). Full article ">Figure 5
Decision rules generated through regression tree analysis, wherein tree species richness was the dependent response variable, and segment-level spectral properties of Landsat data were selected as independent predictor variables. Landsat values relate to the statistical properties of reflectance values in specific portions of the electromagnetic spectrum (i.e., bands). Full article ">Figure 6
Tree species richness, derived from 2 m spatial resolution species distribution maps extrapolated to the extent of the British Columbian Southern Gulf Islands. The background image is Landsat band 4 (NIR) coverage. Full article ">

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Diversity, Volume 6, Issue 3 (September 2014) – 8 articles , Pages 396-632

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