Hasil untuk "General. Including nature conservation, geographical distribution"

Lei Xu, Lei Xu, Lei Xu et al.

Grasping the genetic structure of marine fish populations is vital for comprehending species connectivity patterns and determining the appropriate spatiotemporal scales for conservation management strategies. Here, we analyzed the population genetics of the Orangefin Ponyfish (Photopectoralis bindus Valenciennes, 1835) by examining a portion of the gene coding for the mitochondrial cytochrome c oxidase subunit I. The aim was to evaluate the haplotype pattern, genetic structure, demographic history, as well as the influence of ecological connectivity through the Qiongzhou Strait on the distribution patterns of this species in the northern South China Sea and the Beibu Gulf. In total, 257 specimens yielded only 13 haplotypes, with the predominant haplotype present at all sampling locations. The analysis revealed a “star-like” haplotype pattern, indicating low levels of both haplotype and nucleotide diversity. Additionally, a small but significant genetic structure was observed between the coastal regions flanking the Leizhou Peninsula. These patterns in the haplotype network and genetic structure may be significantly influenced by contemporary currents, particularly through the connectivity of the Qiongzhou Strait. Tajima’s D and Fu’s Fs demonstrated pronouncedly negative values, along with a unimodal mismatch distribution, suggested a recent demographic expansion of Photopectoralis bindus during the late Pleistocene, likely influenced by fluctuations in sea levels.

Peng Zhou, Peng Zhou, Yu-Xin Bu et al.

P.J. Stephenson

María Virginia Palchetti, Fernando Zamudio, Sebastián Zeballos et al.

Plants are essential for our lives because they provide food, medicine, fuel, shelter, and immaterial resources. Understanding patterns of plant uses through large-scale plant use analysis may contribute to the development of a biocultural conservation approach. We conducted a systematic review to assess current knowledge of the ethnoflora of Argentina, as well as to identify taxonomic and geographic patterns of ethnobotanical uses of native plants at the large scale. We analyzed 124 articles reporting the use of 1706 species. We found that the most widely studied region and use category were Chaco and medicine, respectively. The number of useful native species within a family was positively related to the total native species in each family at the country level. In general, species of greatest cultural importance at the country level had a wide distribution. Almost 70% of native plants used in one phytogeographic province were exclusive to it, and species with the highest importance were characteristic elements of its vegetation. We found that southern Argentina has an exclusive ethnoflora that differs from that in a large area of central and northern Argentina. Our review highlights that plants used by people are intimately associated with the local environment, and that species with great cultural importance across phytogeographic provinces are frequent in the landscape. We provide the first analysis of ethnobotanical studies and a database of useful native plants across Argentina. This information highlights strengths and gaps in knowledge of useful native species, which is crucial for conservation, sustainability and human well-being.

Bin Wang, Bin Wang, Bin Wang et al.

The summer hypoxia off the Changjiang Estuary is one of the largest coastal hypoxic systems in the world and has displayed spatial heterogeneity in recent years. Based on observation data in the summer of 2014, hypoxia was identified both in the bottom and mid-layers. Except for the typical bottom hypoxia in the submarine canyon, the subsurface oxygen minima (SOM) were captured in the mid-layer of 10~15 m, with lower dissolved oxygen in the mid-layer than at the bottom (30–50 m). This SOM phenomenon was located in the lower boundary of the pycnocline and above the Taiwan warm current (TWC) and Kuroshio subsurface water (KSSW). Due to the southern expansion of Changjiang diluted water (CDW), a high phytoplankton biomass (the maximum chlorophyll a of 25 μg L−1, pH of 8.6, and DO of 11 mg L−1) band occupied the surface area along 123°E. By analyzing the 24-h continuous observation and high-resolution profile data, we revealed that the subsurface oxygen minima were predominantly controlled by remineralization and bottom-flushing effects. Fast local consumption occurred near the pycnocline layer, while the lateral transport of oxygen-rich ambient water replenished the bottom oxygen deficit from south to north. We summarize and contextualize three hot spots of hypoxia into a conceptual diagram and emphasize the influences of advection, mixing, and respiration on their location and severity. Overall, compared with the discussion about the low DO background of TWC/KSSW, this research highlights the flushing effects of TWC/KSSW that will reshape the hypoxia structure and alleviate the hypoxia severity in the south hypoxia area off the Changjiang Estuary.

Javier Montenegro, Allen G. Collins, Russell R. Hopcroft et al.

IntroductionBotrynema, a genus of medusozoans in the trachyline family Halicreatidae, currently contains two species: B. brucei and B. ellinorae, distinguished by the presence or absence, respectively, of an apical knob as a diagnostic character. However, no study has corroborated if these taxonomic diagnoses have a biological and evolutionary basis. Therefore, in this study we attempted to address the question “do the two nominal species in the genus Botrynema represent independent phylogenetic lineages, or two phenotypic variants of a single species?MethodsIn this study we took advantage of legacy collections from different research expeditions across the globe from 2000 to 2021 to study the phylogenetics and taxonomy of the genus Botrynema.ResultsB. brucei and B. ellinorae present partially overlapping vertical distributions in the Arctic and as a whole in the Arctic the genus seems to be limited to the Atlantic water masses. The phylogenetic reconstruction based on the concatenated alignment corroborates the validity of the family Halicreatidae and of genus Botrynema as monophyletic groups. However no clear differentiation was found between the two presently accepted species, B. ellinorae and B. brucei.DiscussionBased on the evidence we gathered, we conclude that while the genus Botrynema does contain at least two species lineages, these lineages are not concordant with current species definitions. The species B. ellinorae is reassigned as a subspecies of B. brucei and diagnostic characters are provided.

Ariane Aspirault, Gesche Winkler, Aurélie Jolivet et al.

Anthropogenic noise is a pervasive feature of the coastal ocean soundscape and is intensifying as vessel traffic activity increases. Low-frequency sounds from wave action on coastal reefs or anthropogenic noise have been shown to initiate larval settlement of marine invertebrates and accelerate metamorphosis to juvenile stages. These results suggest that some planktonic species can perceive and be impacted by anthropogenic sound. Hence, we tested the hypothesis that vessel noise has an impact on the feeding behavior of blue mussel (Mytilus edulis) veligers and of the copepod Eurytemora herdmani as well as on the growth of the rotifer Brachionus plicatilis. The results show that microalgae and feeding behavior of early life stages of mussels and copepods are not influenced by the presence of vessel noise. The growth of the rotifers was similar between the two sound treatments, but rotifers’ egg production in the absence of vessel noise was higher and eggs were also larger. Our results suggest that the effects of noise on plankton are complex; much more work is needed to unravel these often subtle effects.

Pedro Medrado Krainovic, Angélica Faria de Resende, Nino Tavares Amazonas et al.

Restoring tropical forests still relies on expensive tree planting. Timber production from native trees offers a promising opportunity to make restoration financially viable, but species growth data are lacking. We assessed the potential of tropical forest restoration plantations for producing native timber in the Atlantic Forest. For that we inventoried a chronosequence of unmanaged restoration plantation sites with ten commercial native tree species. Then we developed growth models and used the Growth-Oriented Logging (GOL) method to inform targeted management decisions, including an optimized timber-focused scenario, based on growth and bole quality assessment. Usually, growth-rate classes for saw wood production would be defined according to the time necessary for achieving 35 cm in DBH. Harvesting age was markedly reduced using GOL for species of fast-growth (from <50 to <25 years), intermediate-growth (from 50 to 70 to 25–50 years), slow-growth (from >70 to 50–75 years). Following GOL, basal area was 42 ± 30% larger at harvest (taking 35 ± 23% more time) or 60 ± 16.5% smaller (taking 66 ± 16% less time). The optimized scenario speeded tree-size achievement and anticipated harvesting in an average of 58 years. Species selection, individualization, and silvicultural management are critical for producing timber in forest restoration programs.

Zhi Li, Minyu Zhou, Yao Ruan et al.

The Pacific white shrimp Litopenaeus vannamei is an economically important penaeid species worldwide. Under farming conditions, the full ovarian maturation of L. vannamei generally depends on the combination of artificial ablation of unilateral eyestalk and feeding high-quality natural diets, suggesting that nutrient accumulation is important to ovarian maturation. In this study, we aimed to investigate the gene expression related to nutritional accumulation in L. vannamei during ovarian development by transcriptomic analysis. A total of 52.45 Gb of high-quality transcriptome data were obtained from 8 samples from the hepatopancreas and ovaries from shrimp in gonadal developmental stages I-IV. A total of 23,149 expressed genes were detected, of which 19,852 were known genes and 3,297 were novel genes. Our study found that genes related to amino acid, carbohydrate and lipid metabolism were expressed at higher levels in the hepatopancreas than in the ovary. The genes for most lipoproteins and their receptors were predominantly expressed in the hepatopancreas, while vitellogenin receptor (VgR) was specifically expressed in the ovary. Moreover, two vitellogenin (Vg) genes were identified, in which one was specifically expressed in the hepatopancreas and defined as Hp-Vg, and the other was specifically expressed in the ovary and defined as Ov-Vg. In addition, genes related to carotenoid metabolism were enriched in the hepatopancreas. This study provides solid evidence that the hepatopancreas is the major exogenous vitellogenesis site for ovarian maturation of L. vannamei. Two distinct Vg genes perform exogenous and endogenous vitellogenesis in the hepatopancreas and ovary in L. vannamei, respectively. The results of this study also presented some new insights for understanding the nutritional dynamics from the hepatopancreas to ovary during ovarian maturation in penaeids.

Kui-Ching Hsu, Mu-Rong Yi, Mu-Rong Yi et al.

Sequences of the complete mitochondrial cytochrome oxidase subunit I gene were used to identify Trichiurus species and examine their population genetic structure and demographic history along the coast of China. Three Trichiurus species were found. Trichiurus japonicus lives in colder waters along the continental shelves in the China Seas, while Trichiurus nanhaiensis lives warmer waters along continental slopes in the South China Sea, and Trichiurus brevis lives in shallow and warmer waters in the South China Sea. The migrations of these species were mainly associated with feeding and spawning preferences. Two major wintering and spawning grounds in the East China Sea and South China Sea were found. All species showed a lack of population genetic structure resulting from their oceanodromous life cycle (the degree of population substructure index NST = 0.000–0.149), but the results of approximate Bayesian computational approaches suggested population declines or stabilization and differentiation. The results of the TMRCA (time to the most recent common ancestor) showed that during glaciations, the Yellow Sea and the East China Sea were completely exposed, and the South China Sea acted as a refugium. Thus, the populations of these three species experienced differentiation during glaciations. This study also examined the limitations of Bayesian skyline plot analysis.

Adriano Sfriso, Alessandro Buosi, Katia Sciuto et al.

In the last decade, the Venice Lagoon showed a significant environmental recovery that changed the assemblages of macroalgal and aquatic angiosperm dominant species and significantly increased the primary production. The decreasing of anthropogenic impacts, such as eutrophication and clam harvesting, favored a strong reduction of Ulvaceae, replaced by species with higher ecological value, and the recolonization of aquatic angiosperms. Consequently, hypo-anoxic conditions, once frequently occurring in the lagoon, have been considerably reduced and aquatic angiosperms have recolonized the area, covering 94.8 km2 in comparison to the 55.9 km2 recorded in 2003 (+70%). Cymodocea nodosa, Zostera marina, and Zostera noltei expanded by 37.5%, 44.6%, and 191%, respectively, with a significant increase in biomass and primary production. In late spring 2018, angiosperms showed a standing crop of approximately 372 ktonnes (+77%) and a net primary production of approximately 1189 ktonnes FW (+67%). In the meantime, Ruppia cirrhosa, which since the 1980s had disappeared from the lagoon areas subjected to tidal expansion, but was still present in some fishing valleys, recolonized the bottoms of the northern lagoon with meadows of over 6 km2; this accounted for a standing crop and net primary production of 8.9 and 18.0 ktonnes, respectively. Based on surveys carried out in 2021, ecological conditions are still improving, and this is increasing both the biodiversity and the production of macroalgae and aquatic angiosperms.

David Beaune, Yann Sellier

Hun Jun Ha, Ho Kyung Ha

Erosion of cohesive sediments is a ubiquitous phenomenon in estuarine and intertidal environments. Several methods have been proposed to determine the surface erosion threshold (τc0), which are still debatable because of the numerous and uncertain definitions. Based on erosion microcosm experiments, we have compared three different methods using (1) eroded mass (EM), (2) erosion rate (ER), and (3) suspended sediment concentration (SSC), and suggested a suitable method for revealing the variation of erodibility in intertidal sediments. Erosion experiments using a microcosm system were carried out in the Muuido tidal flat, west coast of South Korea. The mean values of τc0 for three methods were: 0.20 ± 0.08 Pa (EM); 0.18 ± 0.07 Pa (ER); and (3) 0.17 ± 0.09 Pa (SSC). The SSC method yielded the lowest τc0, due to the outflow of suspended sediment from the erosion chamber of the microcosm. This was because SSC gradually decreased with time after depleting the erodible sediment at a given bed shear stress (τb). Therefore, the regression between SSC and applied τb might skew an x-intercept, resulting in the underestimation (or “not-determined”) of τc0. The EM method yielded robust and accurate (within the range of τb step at which erosion begins) results. The EM method represents how the erodible depth thickens as τb increases and therefore seems better suited than the SSC and ER methods for representing depth-limited erosion of cohesive sediments. Furthermore, this study identified the spatiotemporal variations of τc0 by EM method in an intertidal flat. The τc0 in mud flat was about two times higher than that in mixed flat. Compared to the end of tidal emersion, the sediment was 10–40% more erodible at the beginning stage.

Suvarna S. Khadakkar, Ashish D. Tiple, Arun M. Khurad

Immature stages of Scaptodera rhadamistus (Fabricius) are described for the first time along with notes on nidification and biology.  The larvae differ from other Scarabaeinae species in the structure of raster on tenth sternum with two irregular bunches of serrations ventrally one on either half.  Pupae with pronotum transverse having rounded margins resemble adults, and consist of four lateral, single caudal and single pteronotal support projection.  Adult males and females differ in coloration, structure of pronotum, presence of spine like process on mesosternum and, in the structure of male and female genitalia.

Fernanda de Vasconcellos Pegas, J. Guy Castley

Robert John Wilson, Michael Heath, Douglas Speirs

The North Atlantic copepods Calanus finmarchicus and C. helgolandicus are moving north in response to rising temperatures. Understanding the drivers of their relative geographic distributions is required in order to anticipate future changes. To explore this, we created a new spatially explicit stage-structured model of their populations throughout the North Atlantic. Recent advances in understanding Calanus biology, including U-shaped relationships between growth and fecundity and temperature, and a new model of diapause duration are incorporated in the model. Equations were identical for both species, but some parameters were species-specific. The model was parameterized using Continuous Plankton Recorder Survey data and tested using time series of abundance and fecundity. The geographic distributions of both species were reproduced by assuming that only known interspecific differences and a difference in the temperature influence on mortality exist. We show that differences in diapause capability are not necessary to explain why C. helgolandicus is restricted to the continental shelf. Smaller body size and higher overwinter temperatures likely make true diapause implausible for C. helgolandicus. Known differences were incapable of explaining why only C. helgolandicus exists southwest of the British Isles. Further, the fecundity of C. helgolandicus in the English Channel is much lower than we predict. We hypothesize that food quality is a key influence on the population dynamics of these species. The modelling framework presented can potentially be extended to further Calanus species.

Christopher J. Miller, Andrew L. Rose, T. David Waite

The reaction between Fe(II) and H2O2 to yield hydroxyl radicals (HO•), the Fenton reaction, is of interest due to its role in trace metal and natural organic matter biogeochemistry, its utility in water treatment and its role in oxidative cell degradation and associated human disease. There is significant dispute over whether HO•, the most reactive of the so-called reactive oxygen species, is formed in this reaction, particularly under circumneutral conditions relevant to natural systems. In this work we have studied the oxidation kinetics of Fe(II) complexed by L = citrate, ethylenediaminetetraacetic acid (EDTA) and diethylenetriaminepentaacetic acid (DTPA) and also measured HO• production using phthalhydrazide as a probe compound at pH 8.2. It is shown that HO• is the sole product of the Fe(II)L-H2O2 reaction for L = EDTA and DTPA, with kinetic modelling of the full reaction pathway utilized to confirm this finding. Quantitative HO• production also appears likely for L = citrate, although uncertainties with the speciation of Fe(II)-citrate complexes as well as difficulties in modelling the oxidation kinetics of these complexes has prevented a definitive conclusion. In the absence of ligands at circumneutral pH, inorganic Fe(II) reacts with H2O2 to yield a species other than HO•, contrary to the well-established production of HO• from inorganic Fe(II) at low pH. Our results suggest that at high pH Fe(II) must be complexed for HO• production to occur.

Stacie J. Robinson, Ryan D. Walrath, Timothy R. Van Deelen et al.

Abstract Social structure and behavioral interactions between individuals shape basic biological processes, such as breeding; foraging and predator avoidance; movement and dispersal; and disease transmission. We used a targeted trapping strategy to capture kin groups of white‐tailed deer (Odocoileus virginianus) during 2007 and 2008 in Sandhill Wildlife Research Area, Wisconsin, USA, in order to observe social behaviors. Because inferring family relationships from observation of behavior is subjective, we used measures of genetic relatedness and parentage assignment tests to determine that our capture strategy was efficient for capturing related pairs (78% of groups contained ≥1 dyad of related animals). The results of our genetic tests verified that study animals were related; therefore, our capture strategy was successful and the assumptions of the research design were met. This demonstrates both the utility of a targeted sampling approach, and the importance of genetic techniques to verify relationships among animals, especially when kin association forms a basis for further biological study or management action. Published 2012. This article is a U.S. Government work and is in the public domain in the USA.

Peter F. Newton

The objectives of this study were to (1) quantitatively summarize the early yield responses of black spruce (Picea mariana (Mill.) B.S.P.) to forest vegetation management (FVM) treatments through a meta-analytical review of the scientific literature, and (2) given (1), estimate the rotational consequences of these responses through model simulation. Based on a fixed-effects meta-analytic approach using 44 treated-control yield pairs derived from 12 experiments situated throughout the Great Lakes—St. Lawrence and Canadian Boreal Forest Regions, the resultant mean effect size (response ratio) and associated 95% confidence interval for basal diameter, total height, stem volume, and survival responses, were respectively: 54.7% (95% confidence limits (lower/upper): 34.8/77.6), 27.3% (15.7/40.0), 198.7% (70.3/423.5), and 2.9% (−5.5/11.8). The results also indicated that early and repeated treatments will yield the largest gains in terms of mean tree size and survival. Rotational simulations indicated that FVM treatments resulted in gains in stand-level operability (e.g., reductions of 9 and 5 yr for plantations established on poor-medium and good-excellent site qualities, resp.). The challenge of maintaining coniferous forest cover on recently disturbed sites, attaining statutory-defined free-to-grow status, and ensuring long-term productivity, suggest that FVM will continue to be an essential silvicultural treatment option when managing black spruce plantations.

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