Ranking Of Species Research Articles

Biodiverse food plants in the semiarid region of Brazil have unknown potential: A systematic review.

Food biodiversity presents one of the most significant opportunities to enhance food and nutrition security today. The lack of data on many plants, however, limits our understanding of their potential and the possibility of building a research agenda focused on them. Our objective with this systematic review was to identify biodiverse food plants occurring in the Caatinga biome, Brazil, strategic for the promotion of food and nutrition security. We selected studies from the following databases: Web of Science, Medline/PubMed (via the National Library of Medicine), Scopus and Embrapa Agricultural Research Databases (BDPA). Eligible were original articles, published since 2008, studying food plants occurring in the Caatinga. We assessed the methodological quality of the studies we selected. We reviewed a total of fifteen studies in which 65 plants that met our inclusion criteria were mentioned. Of this amount, 17 species, including varieties, subspecies, and different parts of plants, had data on chemical composition, in addition to being mentioned as food consumed by rural communities in observational ethnobotanical studies. From the energy and protein data associated with these plants, we produced a ranking of strategic species. The plants with values higher than the average of the set were: Dioclea grandiflora Mart. ex Benth (mucunã), Hymenaea courbaril L. (jatobá), Syagrus cearensis Noblick (coco-catolé), Libidibia ferrea (Mart. ex Tul.) L.P.Queiroz (jucá), Sideroxylon obtusifolium (Roem. & Schult.) T.D.Penn. (quixabeira). We suggest that the scientific community concentrates research efforts on tree legumes, due to their resilience and physiological, nutritional, and culinary qualities.

Seasonal and interannual variations in functional traits of sown and spontaneous species in vineyard inter‐rows

AbstractThe trait‐based approach can address questions in order to understand how the functioning of organisms scales up to that of ecosystems and controls some of the services they deliver to humans, including in agriculture. However, the importance of interspecific vs the intraspecific trait variability (ITV) for classifying species according to their traits in agrosystems on a large diversity of pedoclimatic situations and cropping systems remains still open. Here, we addressed three questions: How do measured traits vary across years and seasons? Are species rankings conserved across years and season? And which traits and species are the more stable and repeatable for sown and spontaneous species? We conducted a two‐year experiment in a vineyard, and we measured four leaf and plant functional traits of 14 sown species and 43 spontaneous species that grew among sown species. Traits were measured at two key phenological stages for grapevine: budburst and flowering during two successive years with contrasted rainfall (2017 and 2018). We studied seasonal and interannual trait variations, rankings between species, and variance partitioning. The species factor explained the greatest part of trait variations across years and seasons. Sown and spontaneous species traits varied in the same way, and traits related to plant dry matter contents were the more stable across periods. Moreover, species rankings were conserved across years and seasons for all traits except plant height. Sown species showed better ranking conservation than spontaneous species overall. The trait‐based approach seems promising for the comparison of various cropping systems involving sown and spontaneous species, and may help identifying service crop species related to specific agroecosystem services. Further research is needed to bring more knowledge on trait variations under a diversity of agrosystems, and to improve theoretical frameworks that would help the design of sustainable agrosystems that provide multiple ecosystem services.

Plant Communities in Harsh and Favorable Environments: Characteristics of Their Organization, Their Dominant Structure and Its Relationship to Species Richness

It is believed that plant communities in harsh and favorable habitats are organized in different ways. The former are mainly organized by abiotic environment and random processes (S model), and the latter are mainly organized by competition (C-S-R model). It can be expected that the characteristics of the organization affect the structure of the dominance of plant communities and its relationship to species richness. The goal of our study was to test this assumption on the example of herbaceous plant communities of relatively stable habitats of several regions and high-altitude belts of the western Caucasus (alpine snowbeds, heaths and meadows, subalpine meadows and marshes, low mountain meadows, grass layer of forests, steppes). The aboveground biomass of communities at the time of its maximum development was used as a criterion of the degree of environmental severity. The relative participation of species was estimated as the ratio of their biomass to the total aboveground biomass on the site (D) or to the biomass of the community remaining after the removal of the biomass of higher-ranking species (K) from it. Under the structure of dominance, relative participation in community of the first rank species (degree of dominance) was understood, as well as the ratio of the values of D and K for two or three species with the largest participation in the aboveground-community biomass. The following results were obtained: (1) If the dominance structure is estimated based on D, then it varies widely and is almost unrelated to the production of the habitats (environmental conditions). (2) In C‑S-R-communities, the K values for species of first rank (K1) are on average higher than for less significant species (K2 and K3); in S-communities, they are on average approximately the same. Moreover, if we consider C-S-R- and S-communities separately, then the (K1 – K2) values are not related to the aboveground biomass of communities. The assumption is made that (K1 – K2) value can be considered as the index of the degree of expression in the dominants of C-strategy features. (3) The spatial variability of the parameters of the dominance structure is higher in areas of harsh habitats than in favorable ones. (4) C-S-R-communities are characterized by a closer relationship between the degree of dominance and species richness than S-communities. Our results suggest that this is due to the more intensive interspecies competition in C-S-R-communities and to the C-strategy of dominant species.

Socio Economic Contribution of Lowland Bamboo (Oxythenanthera Abyssinica) in Pawe District, Ethiopia

The Study was conducted in Pawe district, Benishangul-Gumuz National Regional State, northwestern Ethiopia. The objective of this study was to evaluate socio-economic aspects of low land bamboo (Oxythenanthera abyssinica). For this study, two villages were selected based on random sampling technique., Data were collected from a total of 136 households. Households were selected using simple random sampling technique. The collected raw data were systematically coded and analyzed using descriptive statistics. A weighed direct matrix likert scale ranking of species was used to evaluate low land bamboo and others tree species based on multipurpose value. Inferential statistical, linear regression model was employed to find out the relationship between incomes generated from Low Land Bamboo and some selected socioeconomic factors (independent variables). The study result indicated that Out of the sampled households, 50 % and 37.5% of the respondents ranked Mangifera indica and Lowland bamboo (Oxythenanthera abyssinica) first and second, respectively while Melia azedirachta L. and Cordia africana were preferred third (8.1%) and fourth (2.9%), respectively. Among the socio-economic characteristics considered land holding size was positively and highly significantly related to income generated by households (p < 0.01). Therefore, the policies and strategies that improve the welfare of rural people especially the poor and the land less HHs and use of bamboo for natural resource conservation should be given attention. Additionally, government and NGOs should support and encourage cultivation of lowland bamboo and lowland bamboo based activities as part of the diversified livelihood strategies. Keywords: Low Land Bamboo, socio economics, income. DOI: 10.7176/JNSR/10-9-03 Publication date: May 31 st 2020

Comparing experimental and field‐measured traits and their variability in Central European grassland species

AbstractQuestionsWhat are the relative effects of intra‐ and interspecific differences on variation in five functional traits measured in a garden pot experiment? Are species rankings based on trait means and intraspecific trait variability (ITV) stable across the garden experiment and field measurements?LocationExperimental garden and two grassland systems in Central Europe.MethodsWe measured five functional traits (plant height, leaf dry matter content [LDMC], leaf greenness, leaf thickness and specific leaf area SLA]) in 105 grassland species grown in a garden experiment subjected to fertilization, shading and waterlogging, complemented by a control. We also measured plant height, LDMC and SLA across grasslands in Germany, and used published values of the same traits from a field study in the Czech Republic. We then correlated speciesʼ trait means from different treatments in the experiment. We also compared garden‐ and field‐measured trait means and ITV in SLA, LDMC and plant height.ResultsMost variation in the experiment‐measured trait data was explained by interspecific differences, except for leaf greenness (where species explained less than 50% of the variance), and the treatments had little effect on close associations of trait means. Species rankings based on SLA and LDMC, but not plant height, were stable across garden and field measurements. Though garden and field‐measured ITV were positively associated with each other, the associations were not significant.ConclusionsOur study indicates that species can be stably ranked based on SLA and LDMC means across different datasets (experimental and field‐based). To what extent species vary in their functional traits under field conditions can be, however, less well predicted from experimentally measured ITV. Garden‐measured differences in ITV should be thus used with caution when associated with species’ performance and distribution patterns explored in the field.

A review of species of the genus <i>Theodoxus </i>(Gastropoda: Neritidae) of the Ponto-Caspian region, with considerations on available type materials

An illustrated overview of the type series of nominal taxa of the gastropod genus Theodoxus (Neritidae) inhabiting the Ponto-Caspian region is presented. It is made on the basis of a revision of large European malacological collections and includes descriptions of the type specimens of 16 taxa of different rank (species, variety, morph). Apart of these, the “type” specimens of four taxa with unavailable names have been traced in ZIN collection; we illustrate them to show the variability of Ponto-Caspian Theodoxus. In most cases, the photographs of the type specimens are published for the first time. We provide a taxonomic analysis of all studied type series, with comments on the nomenclature, systematic position and taxonomic rank of all nominal taxa of Theodoxus recorded from the Ponto-Caspian area.

Reduced co-occurrence and ion-specific preferences of soil microbial hub species after ten years of irrigation with brackish water

Irrigation with brackish water has been widely applied in many regions of the world as an efficient alternative to conserve freshwater resources. Although it has limited soluble salt content, brackish water can alter the physio-chemical properties and microbial communities of soil over time. In this study, a cotton field that utilized drip irrigation with brackish water for 10 years (Brackish field) was compared with a nearby field that utilized drip irrigation with fresh water (Fresh field). Our results show the following: 1) After 10 years, the Brackish field was saltier with a greater electrical conductivity and sodium adsorption ratio, as well as less soil organic carbon content when compared with the Fresh field. 2) The more polarized distribution of the most abundant operational taxonomic unit (OTU) was observed in the Brackish field, accompanied by significantly smaller beta diversity, a less clustered network and fewer co-occurrences (edges) within the soil microbial community compared with the less salty Fresh field, altogether demonstrating that long-term brackish irrigation was very likely to form a less diverse and more stressed environment for soil microbes to co-exist. 3) The mismatches between the edge ranking of hub species and the ranking of relative abundances highlight that the predominant abundances of salt tolerant species from genera Acinetobacter and Pseudomonas may help cotton to grow better in the saline soil but may not help to stabilize soil microbial communities. In future studies, sophisticated sampling protocols with high time-resolution are required to fully capture the possible soil microbial responses to event-sensitive ion redistributions across cotton rows as well during repeated irrigation cycles.

Comparative drought resistance of temperate grassland species: testing performance trade-offs and the relation to distribution

To improve projections of consequences of increasing intensity and frequency of drought events for grasslands, we need a thorough understanding of species performance responses to drought, of performance trade-offs and how drought resistance is related to species distributions. However, comparative and quantitative assessments of whole-plant drought resistance that allow to rigorously address these aspects are lacking for temperate grassland species. We conducted a common garden experiment with 40 common temperate grassland species to compare species survival and growth under intense drought and well-irrigated conditions. Overall, survival and growth were significantly reduced under drought, with the effect varying across species. Species ranking of drought damage and survival remained consistent with progressing drought. No performance trade-offs emerged between optimal growth and drought resistance of survival (‘growth–stress tolerance’ trade-off hypothesis), or between growth under well-watered and dry conditions (‘growth rates’ trade-off hypothesis). Species local- and large-scale association with moisture (Ellenberg F value and rainfall niche) was not related to their drought resistance. Overall, our results imply that trade-offs and differences of species fundamental drought resistance are not the main drivers of hydrological niche differentiation, species coexistence and their distribution across moisture gradients. The comparative experimental assessment of species whole-plant drought responses we present provides a basis to increase our understanding of current grassland responses to variation of moisture regimes and for projecting consequences of future changes.

Nonclinical species sensitivity to convulsions: An IQ DruSafe consortium working group initiative

Clinical development of compounds that carry a convulsion liability is typically limited by safety margins based on the most sensitive nonclinical species. To better understand differences in sensitivity to drug-induced convulsion of commonly used nonclinical species, a survey was distributed amongst pharmaceutical companies through an IQ consortium (International Consortium for Innovation and Quality in Pharmaceutical Development) resulting in convulsion-related data on 80 unique compounds from 11 companies. The lowest free drug plasma concentration at which convulsions were observed and the no observed effect level for convulsions were compared between species to determine their relative sensitivity. Additionally, data were collected on other endpoints including use of electroencephalography, premonitory signs, convulsion type, the reason why development was stopped, and the highest development phase reached. The key outcomes were: (1) the dog was most often determined to be the most sensitive species by both non-exposure and exposure-based analyses, (2) there was not a clear sensitivity ranking of other species (NHP, rat and mouse), (3) CNS symptoms were frequently present at exposures that were not associated with convulsions, but no single reliable premonitory indicator of convulsion was identified, and (4) the lack of convulsions when compounds were tested in humans in this dataset may suggest that convulsion liability is well mitigated via current drug development strategies.

Transforming even-aged coniferous stands to multi-aged stands: an opportunity to increase tree species diversity?

Abstract Transforming even-aged coniferous stands into multi-aged ones is attracting growing interest in Europe. However, applying this silvicultural treatment, maintaining a continuous cover and relying on natural regeneration require a deep understanding of the factors driving interspecific competition in the understorey. In particular, knowledge of species-specific response to different light conditions is needed to plan silvicultural treatments and forecast long-term stand composition. In this context, we assessed regeneration (±10–400 cm in height) and light conditions (±1–40 per cent of transmittance) in nine coniferous stands with ranging stand age (±20–120 years) and species composition (Norway spruce, Douglas fir, larch, silver fir and western hemlock) in Belgium. We then modelled interspecific differences in regeneration height growth to forecast the outcome of interspecific competition in different light conditions. Controlling understorey light seems an efficient way to control the interspecific competition, but with some limits, and taking into account sapling size. Maintaining low light conditions (transmittance < 15 per cent) probably reduces interspecific competition as it allows small saplings (height < 100 cm) of most species to grow at a comparable rate. Maintaining higher light conditions might allow a few species to rapidly overgrow the others. Species ranking in height growth changed across the studied light range only between spruce and larch, suggesting that the competition between these two species can be driven through the control of understorey light. On the other hand, controlling canopy openness was found to be insufficient, for example, to promote an advanced regeneration (height ≥ 200 cm) of fir over advanced regeneration of spruce, to promote any species over western hemlock or to promote Douglas fir. Western hemlock, a very shade-tolerant species, was found to grow three times faster than the other species in all the observed conditions (PACL = 5–20 per cent). Douglas fir saplings showed weak growth and marked defoliation, which we hypothetically relate to the recent outbreak of Contarinia pseudotsugae in Western Europe.

Counting and sampling gene family evolutionary histories in the duplication-loss and duplication-loss-transfer models

Given a set of species whose evolution is represented by a species tree, a gene family is a group of genes having evolved from a single ancestral gene. A gene family evolves along the branches of a species tree through various mechanisms, including—but not limited to—speciation ({mathbb {S}}), gene duplication ({mathbb {D}}), gene loss ({mathbb {L}}), and horizontal gene transfer ({mathbb {T}}). The reconstruction of a gene tree representing the evolution of a gene family constrained by a species tree is an important problem in phylogenomics. However, unlike in the multispecies coalescent evolutionary model that considers only speciation and incomplete lineage sorting events, very little is known about the search space for gene family histories accounting for gene duplication, gene loss and horizontal gene transfer (the {mathbb {D}}{mathbb {L}}{mathbb {T}}-model). In this work, we introduce the notion of evolutionary histories defined as a binary ordered rooted tree describing the evolution of a gene family, constrained by a species tree in the {mathbb {D}}{mathbb {L}}{mathbb {T}}-model. We provide formal grammars describing the set of all evolutionary histories that are compatible with a given species tree, whether it is ranked or unranked. These grammars allow us, using either analytic combinatorics or dynamic programming, to efficiently compute the number of histories of a given size, and also to generate random histories of a given size under the uniform distribution. We apply these tools to obtain exact asymptotics for the number of gene family histories for two species trees, the rooted caterpillar and complete binary tree, as well as estimates of the range of the exponential growth factor of the number of histories for random species trees of size up to 25. Our results show that including horizontal gene transfers induce a dramatic increase of the number of evolutionary histories. We also show that, within ranked species trees, the number of evolutionary histories in the {mathbb {D}}{mathbb {L}}{mathbb {T}}-model is almost independent of the species tree topology. These results establish firm foundations for the development of ensemble methods for the prediction of reconciliations.

Classifying Hawaiian plant species along a habitat generalist-specialist continuum: Implications for species conservation underclimate change.

Plant communities on tropical high islands, such as the Hawaiian Islands, are predicted to experience rapid climate change, resulting in novel climates. If increased temperature and/or drought exceed plant species’ current tolerances, species that are unable to adapt or shift ranges risk extinction. By definition, habitat generalists have a wide niche breadth and thrive in a variety of habitats, whereas habitat specialists have a narrow niche breadth, and typically thrive under more specific climatic characteristics (e.g., cold). The objectives of this study were to: (1) classify plant species in the Hawaiian Islands along a habitat generalist-specialist continuum; (2) independently test the validity of species rankings, using environmental and biogeographic ranges; and (3) identify species’ life-history traits that predict species location along the continuum. We quantified specialization for 170 plant species using species co-occurrence data from over one thousand plots to rank species’ realized habitat niche breadth using the Jaccard index. The distribution of species along this continuum differed by species biogeographic origin, with endemic plant species ranked on the specialist end and non-native plant species ranked on the generalist end. Habitat specialization rankings also differed for four of nine tested variables (while controlling for biogeographic origin): number of habitat moisture types, minimum elevation, number of Hawaiian Islands, and life form. Life form was the only trait tested that differed across the continuum, with woody species ranked as stronger generalists than herbaceous species; this pattern was particularly evident for non-native species. This indirect method of estimating species’ potential climatic flexibility uses increasingly available large plant community data sets with output rankings which represent species’ realized habitat niches. Identifying species and plant communities that are on the habitat specialist end of the continuum allows for their prioritization in conservation planning, as globally the loss of specialists is an indication of degradation.

Evaluation of analytical and statistical approaches for predicting in vitro nitrogen solubility and in vivo pre-caecal crude protein digestibility of cereal grains in growing pigs.

Different analytical (enzyme system and near-infrared spectroscopy (NIRS)) and statistical (single and multiple regressions) approaches were used to predict in vivo standardized pre-caecal digestibility (PCD) of crude protein (CP) and amino acids (AA) in cereal grains for growing pigs as well as in vitro nitrogen (N) solubility. Furthermore, different chemical and physical characteristics were categorized (e.g. crude nutrients, AA, minerals, fibre components or combinations of these) and used for generating prediction equations. There were strong linear relationships (p<.05) between in vivo PCD of CP and essential AA and in vitro N solubility when grain species was considered as covariate in the model. Predicting in vivo PCD values using various chemical and physical characteristics produced inconsistent results among different grain species and AA and could therefore not be used for predicting PCD. It is possible to predict in vitro N solubility from chemical and physical characteristics for some grain species. However, the relationships between some of these categories and the in vitro N solubility were not consistent and not always causative or physiologically explainable. The R2 of NIRS for predicting in vitro N solubility was at a relatively high level (up to R2 =0.80). This level of R2 indicates that a classification of the grain samples in, for example, high, medium and low in vitro N solubility levels is possible, but it does not allow for a quantitative prediction of the in vitro N solubility. In conclusion, the present database can be used for establishing a ranking of different cereal grain species for PCD of CP and essential AA values. However, it was not possible to create clear prediction equations for in vivo or in vitro digestibility values. Therefore, greater variation within grain species, for example due to different growing and harvesting conditions, is warranted for predicting PCD values of individual grain samples.

Quantification of the Antioxidant Activity of Plant Extracts: Analysis of Sensitivity and Hierarchization Based on the Method Used.

Plants have a large number of bioactive compounds with high antioxidant activity. Studies for the determination of the antioxidant activity of different plant species could contribute to revealing the value of these species as a source of new antioxidant compounds. There is a large variety of in vitro methods to quantify antioxidant activity, and it is important to select the proper method to determine which species have the highest antioxidant activity. The aim of this work was to verify whether different methods show the same sensitivity and/or capacity to discriminate the antioxidant activity of the extract of different plant species. To that end, we selected 12 species with different content of phenolic compounds. Their extracts were analyzed using the following methods: 2,2-di-phenyl-1-picrylhydrazyl (DPPH) radical scavenging capacity assay, ferric reducing (FRAP) assay, Trolox equivalent antioxidant capacity (ABTS) assay, and reducing power (RP) assay. The four methods selected could quantify the antioxidant capacity of the 12 study species, although there were differences between them. The antioxidant activity values quantified through DPPH and RP were higher than the ones obtained by ABTS and FRAP, and these values varied among species. Thus, the hierarchization or categorization of these species was different depending on the method used. Another difference established between these methods was the sensitivity obtained with each of them. A cluster revealed that RP established the largest number of groups at the shortest distance from the root. Therefore, as it showed the best discrimination of differences and/or similarities between species, RP is considered in this study as the one with the highest sensitivity among the four studied methods. On the other hand, ABTS showed the lowest sensitivity. These results show the importance of selecting the proper antioxidant activity quantification method for establishing a ranking of species based on this parameter.

Applying a floristic originality index in tropical forests of south Sinaloa, Mexico

Sinaloa is among the states of Mexico harboring the highest deforestation rates. Reforestation programs have been put up in south Sinaloa with species chosen for their high seedling rates, structural importance or strong restoration value. However, species criteria such as level of endemism as well as rarity appear to be underestimated. Eight sampling sites were randomly selected and a botanical survey was carried out at least every month from 2015 to 2017. In order to rank species over conservation stakes, a Floristic Originality Index method was elaborated using species level of endemism, rarity and conservation status. The floristic inventory enabled the identification of a set of 250 species with the Fabaceae being the most represented family with 51 species. Using the Floristic Originality Index, a subset of 51 species was selected as priority for conservation along with 23 other species all displaying characteristics of “framework” species. Features of reproduction and types of ideal soil conditions for reforestation are presented for each species. The method developed to determine floristic originality has proven a set of most vulnerable and rare species to select “priority” and “framework” tree species able to restore forests structure and biodiversity as well as ecosystem functions. This evaluation is made from a conservation biology point of view and appears to be well adapted for studies at a local scale.

Altitude and species identity drive leaf litter decomposition rates of ten species on a 2950 m altitudinal gradient in Neotropical rain forests

AbstractIdentifying the environmental factors controlling litter decomposition is key to understanding the magnitude and rates of nutrient cycling in tropical forests, and how they may be influenced by climate variability and environmental change. We carried out a leaf litter translocation experiment in mature rain forest over a 2,520 m altitudinal gradient in Costa Rica. Leaf litter decomposition rates (k) of ten tree species, two dominant species from each ecosystem, plus two standard species, were calculated over 540 days in four life zones. k was lowest in montane with 0.83 per year and lower montane forests with 2.21 per year. k did not differ between lowland and premontane forests at 3.12 per year, in spite of the 3℃ difference of mean annual temperature between these life zones. k varied fourfold among species. Species decomposition rates ranked as follows, and were predictably related to leaf economic spectrum traits of the species: Acalypha communis (standard, fast decomposer)» Hyeronima oblonga &gt; Alchornea latifolia, Quercus bumelioides, Jarava ichu (standard, slow decomposer)&gt; Minquartia guianensis &gt; Magnolia sororum &gt; Vochysia allenii &gt; Pourouma bicolor, Carapa guianensis. These two slowest‐decomposing species were native premontane and lowland forest dominants, respectively, with tough, low‐nutrient leaves. The ranking of species by k varied very little among life zones suggesting that decomposer organisms in very different ecosystems and environments react in similar ways to the litter quality in general. We conclude that while k decreases with temperature in rain forests on tropical mountains, bioclimatic zones defined as premontane may be “functionally lowland.” The effects of species identity on decomposition rates on tropical mountains are consistent and independent of environment for both standard and native species. Under climate change on these mountains, if moisture regimes do not change, decomposition rates will increase due to rising temperatures. Soil carbon storage may therefore decrease. Changes in the altitudinal distributions of currently dominant species will also affect this critically important biogeochemical process.

Arboreal twig-nesting ants form dominance hierarchies over nesting resources.

Interspecific dominance hierarchies have been widely reported across animal systems. High-ranking species are expected to monopolize more resources than low-ranking species via resource monopolization. In some ant species, dominance hierarchies have been used to explain species coexistence and community structure. However, it remains unclear whether or in what contexts dominance hierarchies occur in tropical ant communities. This study seeks to examine whether arboreal twig-nesting ants competing for nesting resources in a Mexican coffee agricultural ecosystem are arranged in a linear dominance hierarchy. We described the dominance relationships among 10 species of ants and measured the uncertainty and steepness of the inferred dominance hierarchy. We also assessed the orderliness of the hierarchy by considering species interactions at the network level. Based on the randomized Elo-rating method, we found that the twig-nesting ant species Myrmelachista mexicana ranked highest in the ranking, while Pseudomyrmex ejectus was ranked as the lowest in the hierarchy. Our results show that the hierarchy was intermediate in its steepness, suggesting that the probability of higher ranked species winning contests against lower ranked species was fairly high. Motif analysis and significant excess of triads further revealed that the species networks were largely transitive. This study highlights that some tropical arboreal ant communities organize into dominance hierarchies.

Caching Propensities and Effectiveness of Five Coexisting Heteromyid Rodent Species as Dispersers of Indian Ricegrass (Achnatherum hymenoides) Seeds

Recruitment of Indian ricegrass (Achnatherum hymenoides) seedlings occurs primarily from surface seed caches made by scatter-hoarding desert rodents of the family Heteromyidae. We used radiolabeled Indian ricegrass seeds in field seed-caching experiments with 5 coexisting heteromyid species (Dipodomys deserti, D. merriami, D. microps, Microdipodops pallidus, and Perognathus longimembris) to compare their potential effectiveness as dispersers. Dipodomys microps individuals deposited seeds almost exclusively in larders rather than in scatter hoards, implying that this species is unlikely to be an important seed disperser. Among the other species, individual caches made by larger species had more seeds than those made by smaller species, but smaller species made more caches. At the level of individual animals, M. pallidus was the most effective disperser in a quantitative sense; they made more caches than other species tested and placed fewer excess seeds in caches relative to optimal cache sizes for Indian ricegrass seedling establishment. However, because D. merriami individuals were considerably more abundant at the study site than other species and were also avid scatter hoarders, D. merriami is likely to be the most quantitatively effective disperser of Indian ricegrass seeds at the species level. Ranking species according to qualitative effectiveness (e.g., by considering effects such as the caching microsite on seedling establishment) was more ambiguous. For example, P. longimembris made relatively shallow caches that most closely match optimal planting depths for Indian ricegrass seedling emergence, but such shallow caches are probably more likely than deeper caches to be discovered by foraging rodents before they can germinate. With the possible exception of D. microps, any of the species we tested may be effective dispersers of Indian ricegrass seeds.

Species prioritisation for the development of multiannual management plans for the Basque demersal fishery

Multiannual management plans are increasingly used to manage fishery systems in Europe. Initially, they were focused on single species, however in the last decade mixed-fishery management plans have emerged to ensure sustainable exploitation of stocks and ecosystems. However, quantitative evaluations of the management plans are generally focused on data-rich and/or target stocks and most of the data-limited and/or bycatch species are not included. Even if they are not included in the evaluation, they could be at high risk of overexploitation or constrain the economic performance of the fishery. Thus, it is crucial to identify the species that should be included in the evaluation of multiannual management plans. The objectives of this study are to assess the potential risk of the species caught by the Basque demersal fishery following the productivity-susceptibility analysis approach, and to identify the most exploited, vulnerable, and/or economically important species for the Basque demersal fishery modifying an existing prioritisation approach. The prioritisation facilitates the selection of the species that should be considered in an integral evaluation of the Basque demersal fishery management plan. According to the results, including the top-ten ranked species in the evaluation of the Basque demersal fishery management plans would ensure an adequate evaluation of the management measures effects.

Island blues: indigenous knowledge of indigo-yielding plant species used by Hainan Miao and Li dyers on Hainan Island, China

BackgroundHistorically, indigo-yielding plant species were important cash crops from Central Asia to the southern United States and Central America. Indigo-dyed textiles were widely traded along the legendary Silk Road that linked China to Europe. Today, due to the labor-intensive nature of indigo extraction at the household level, lifestyle changes and the widespread availability of commercially produced indigo paste, traditional indigo extraction methods have declined in villages. Yet Li textile weavers on Hainan Island are internationally recognized as producers of indigo-dyed textile using warp ikat techniques. In contrast, Hainan Miao weavers produce indigo-dyed textiles using batik (wax resist) techniques. The aim of this study was to document the indigenous knowledge on indigo-yielding plant species used by both Hainan Miao and Li people on Hainan Island, China.MethodEthnic uses were documented during three field surveys, through a questionnaire survey of 193 respondents, comprising 144 Hainan Miao and 49 Li traditional dyers. Mention index (QI), Availability index (AI), and Preference ranking (PR) of each indigo-yielding plant species were calculated to screen out plant resources with potential development value.ResultsFive indigo-yielding plant species (from four plant families and four genera) were historically used by Hainan Miao and Li dyers. However, just four species are still in use. Strobilanthes cusia was the main indigo source for Hainan Miao dyers. Li dyers also commonly use Indigofera species (I. tinctoria and I. suffruticosa) for indigo extraction. Wrightia laevis is less commonly used as a contemporary indigo source. Indigo extraction by steeping in water to which lime is added to increase the pH is sharing by the five indigo-yielding plant species. Strobilanthes cusia had the highest QI, AI and PR values in Hainan Miao villages. Indigofera tinctoria had the highest QI and AI values, but Indigofera suffruticosa was preferred by Li dyers.ConclusionIn the process of modernization and urbanization, some Hainan Miao and Li dyers retain the traditional indigo extraction methods. We found that Strobilanthes cusia and Indigofera tinctoria have the most potential for sustainable indigo production in the future. Furthermore, this study documents the details of extraction method from Wrightia laevis for the first time and the use of Ricinus communis seeds in that process. As one of the last places globally where Wrightia laevis is still used for indigo production, the may also be a nice market among textile collectors and museums that keeps the tradition of Wrightia laevis production and use for indigo extraction alive.