Riqueza y Distribución Ecológica de Especies de Pteridofitas en la Zona del Río Yavarí-Mirín, Amazonía Peruana

We studied the ecological distribution of pteridophytes (ferns and fern allies) along eight 8-km transects covering 12.7 ha in Peruvian Amazonia. Subunits of 200 m² of the transects have previously been classified into four different forest types, and here we document and quantify the floristic differences among these forest types. Pteridophytes have been suggested as an indicator group to classify rain forest habitats, but this requires that the ecological preferences of the species are well documented and consistent across geographic regions. Here we analyzed in detail the distribution and diversity patterns of 130 species across the four rain forest types. Relative species abundance and species diversity were similar among some of the forest types and differed among others, but the species composition differed markedly. Our results largely confirmed the earlier interpretation of the edaphic preferences of the pteridophyte species in western Amazonia. This supports the proposition that deterministic processes have an important role in influencing the floristic composition of Amazonian forests.     

Species interactions weakly modify climate‐induced tree co‐occurrence patterns

Aims

Species distributions are hypothesized to be underlain by a complex association of processes that span multiple spatial scales including biotic interactions, dispersal limitation, fine‐scale resource gradients and climate. Species disequilibrium with climate may reflect the effects of non‐climatic processes on species distributions, yet distribution models have rarely directly considered non‐climatic processes. Here, we use a Joint Species Distribution Model (JSDM) to investigate the influence of non‐climatic factors on species co‐occurrence patterns and to directly quantify the relative influences of climate and alternative processes that may generate correlated responses in species distributions, such as species interactions, on tree co‐occurrence patterns.

Location

US Rocky Mountains.

Methods

We apply a Bayesian JSDM to simultaneously model the co‐occurrence patterns of ten dominant tree species across the Rocky Mountains, and evaluate climatic and residual correlations from the fitted model to determine the relative contribution of each component to observed co‐occurrence patterns. We also evaluate predictions generated from the fitted model relative to a single‐species modelling approach.

Results

For most species, correlation due to climate covariates exceeded residual correlation, indicating an overriding influence of broad‐scale climate on co‐occurrence patterns. Accounting for covariance among species did not significantly improve predictions relative to a single‐species approach, providing limited evidence for a strong independent influence of species interactions on distribution patterns.

Conclusions

Overall, our findings indicate that climate is an important driver of regional biodiversity patterns and that interactions between dominant tree species contribute little to explain species co‐occurrence patterns among Rocky Mountain trees.     

Variability of esterase patterns in adult flies of the <Emphasis Type="Italic">saltans</Emphasis> species group of <Emphasis Type="Italic">Drosophila</Emphasis> (subgenus <Emphasis Type="Italic">Sophophora</Emphasis>)

Esterases are known for their involvement in several physiological processes and high degree of polymorphism, in many organisms. Such polymorphism has been used to characterize species and species groups and to study genetic changes occurred in their evolutionary history. In the present study, the esterase patterns of 19 strains from 10 species representative of the five subgroups of the saltans species group were analyzed using polyacrylamide gel electrophoresis and α- and β- naphthyl acetates as substrates. Fifty-one esterase bands were detected and classified as 31 α-esterases, 18 β-esterases and two α/β-esterases. On the basis of the inhibition patterns using Malathion and eserine sulfate, 34 bands were classified as carboxylesterases, 14 as acethylesterases and three as cholinesterases. Ten gene loci were tentatively established on the basis of data on band position in the gel, substrate preference and inhibition pattern. Twenty bands were species-specific, the remaining being shared by species from the same or different subgroups. Bands detected exclusively in males and bands with a different frequency or degree of expression between sexes were also detected. In the gels prepared for analysis of gene expression in the body parts (head, thorax and abdomen), the degree of expression of the β-esterases was higher in the thorax, while the α-esterases were expressed predominantly in the abdomen and thorax. A global view of the data available at present on the esterases of the species from the saltans group and their degree of polymorphism are presented, as well as the possibility of using some β-esterases, because of their characteristics in the gels, as markers for species identification.     

Components of CO<Subscript>2</Subscript> exchange in leaves of C<Subscript>3</Subscript> species with different ability of starch accumulation

Using a radiogasometric method the rates of photorespiratory and respiratory decarboxylations of primary and stored photosynthates in the leaves of two groups of C₃ species, differing in the ability of starch accumulation, were determined. One group included starch-accumulating (SA) species with rates of starch synthesis on the average 38 % the rate of photosynthesis [Solanum tuberosum L., Arabidopsis thaliana (L.) Heynh, Helianthus annuus L., and Plantago lanceolata L.]. The second group represented starch-deficient (SD) species with rates of starch synthesis less than 8 % the rate of photosynthesis (Secale cereale L., Triticum aestivum L., Hordeum vulgare L., and Poa trivialis L.). In SA species the rate of respiration in the dark was significantly higher than in SD species. No differences were found in the rates of photosynthesis, photorespiration, and respiration under irradiation. Thus, the degree of inhibition of respiration by irradiation was in SA species higher than in SD species. It is concluded that starch does not provide substrates for respiratory and photorespiratory decarboxylations in irradiated photosynthesizing leaves.     

Cytogenetic and genetic data support Crossodactylus aeneus Müller, 1924 as a new junior synonym of C. gaudichaudii Duméril and Bibron, 1841 (Amphibia, Anura)

The nominal anuran species Crossodactylus gaudichaudii Duméril and Bibron, 1841 and Crossodactylus aeneus Müller, 1924 are indistinguishable based on adult and larval morphology, being subject of taxonomic doubts. Here, we describe the karyotypes of C. gaudichaudii and C. aeneus, using classical and molecular cytogenetic markers. In addition, we used sequences of the H1 mitochondrial DNA to infer their phylogenetic relationships by Maximum Likelihood (ML) and Maximum Parsimony (MP) approaches and species delimitation test (by bPTP approach). The karyotypic data do not differentiate C. gaudichaudii and C. aeneus in any of the chromosome markers assessed. In both phylogenetic analyses, C. gaudichaudii and C. aeneus were recovered into a strongly supported clade. The species delimitation analysis recovered the specimens assigned to C. gaudichaudii and C. aeneus as a single taxonomic unit. Taken the cytogenetic and genetic results together with previous studies of internal and external morphology of tadpoles and biacoustic pattern, C. gaudichaudii and C. aeneus could not be differentiated, which supports the hypothesis that they correspond to the same taxonomic unit, with C. aeneus being a junior synonym of C. gaudichaudii.     

“整合物种概念”和“分化路上的物种”

已有的各个物种概念对物种的认识类似盲人摸象, 只包含了物种的某一个方面; 而一个分化后期的成熟物种应涵盖了所有的物种概念。但是, 尚未到达分化后期的物种往往又已开始新一轮的物种分化; 自然中存在的多数“物种”处于分化路上。这种循环往复连续分化产生的物种, 存在种间生殖隔离不彻底、基因流频繁发生、网状进化突出等现象。此外, 对于不同的物种对, 最早开始分化的基因以及不同物种概念所要求的条件的分化顺序不是统一的, 而是随机的。定义一个适合所有“分化路上的物种”概念存在较大困难。但是, 应采用尽可能多的物种概念来界定分化路上的物种、发表新种和进行分类处理; 也应承认种间可能广泛存在不完全的生殖隔离和有限的基因流, 即有不属于两个物种群体的杂交或回交个体的存在。这样划分的物种比只依据一个物种概念认定的物种具有更高的客观性和科学性。     

Extensive contiguous north–south range expansion of the original population of an invasive lizard in Florida

Florida has one of the two worst non-indigenous invasive species problems in the United States, and all such species are considered by statute to be a potential ecological problem. Unfortunately, little information is available about most of Florida's invasive species. Here, we provide information on range expansion of a population of one of the lesser-known species. The Palm Beach County, Florida, population of the northern curly-tailed lizard, Leiocephalus carinatus armouri, was examined for north–south expansion of its previously documented range. Observations were conducted as contiguous expansion outward from the previously known range. We found a substantial contiguous range expansion by a minimum of 46.3 km to the south and 34.1 km to the north. This species appears to be closely associated with coastal habitat degradation in the form of human infrastructure, especially ageing pavement, sea walls, buildings, and bridge bases.     

Ethnobotany of the Rama of Southeastern Nicaragua and Comparisons with Miskitu Plant Lore<Superscript>1</Superscript>

Ethnobotany of the Rama of Southeastern Nicaragua and Comparisons with Miskitu Plant Lore. The Rama are one of the three Amerindian groups of eastern Nicaragua. This is the first systematic study of Rama ethnobotany. A total of 249 plant species, in 190 genera and 78 families, were documented as useful. Included are 190 species used as medicinals, 80 as food plants, and 99 for other uses. The ethnobotanical lore of two distinct indigenous groups, the Rama and Miskitu, were compared. Out of 249 species used by the Rama, 171, or 69%, were used by both groups, and 78 unique species were used by the Rama. These results have important implications for the understanding of ethnobotany as they demonstrate how unrelated indigenous groups sharing the same ecosystem, though separated by some physical distance, can have significantly similar ethnobotanical lore.

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Resumen   Etnobotánica de los Ramas del Oriente Nicaragüense y Comparasiones con el Saber Etnobotánico de los Miskitus. Los Ramas constituyen uno de los tres grupos Amerindios del oriente Nicaragüense. Este es el primer studio sistemático de la etnobotánica Rama. Se documentó un total de 249 especies de plantas útiles en 190 géneros y 78 familias. Incluyendo 190 especies medicinales, 80 especies alimenticias y 99 especies para usos auxiliares. La erudición etnobotánica de los Ramas y los Miskitus fueron comparados. Un total de 171 de 249 especies documentadas son usados por ambos grupos y 78 especies solo por los Ramas. Estos resultados tienen implicaciones importantes para el entendimiento de la etnobotánica porque demuestran que grupos sin parentesco alguno que comparten el mismo ecosistema aunque separados por cierta distancia pueden tener una similitud significativa en la erudición etnobotánica.

     

Revision of the <Emphasis Type="Italic">Nepalomyia pallipilosa</Emphasis> species group (diptera,dolichopodidae, Peloropeodinae)

The genus Nepalomyia is the largest genus in the subfamily Peloropeodinae, with 47 described species. In the present paper the Nepalomyia pallipilosa species group is established for the following three described species and seven new species: Nepalomyia biseta sp. n., N. emeiensis sp. n., N. guangxiensis Zhang et Yang, N. liui sp. n., N. pallipilosa (Yang et Saigusa), N. ruiliensis Wang et Yang, N. sichuanensis sp. n., N. ventralis sp. n., N. yangi sp. n. and N. zengchengensis sp. n. Information on their distribution is also given or updated.     

Mating behaviour of the ‘cosmopolitan’ species Phyllognathopus viguieri (Copepoda: Harpacticoida) and its systematical significance

The mating behaviour was studied and recorded on video with individuals of four cultures of Phyllognathopus viguieri from different populations obtained from the interstitial water of a slow sand filter near the river Ruhr (Germany) (Ruhr population), from a compost heap in Bethesda (Maryland, USA) (Maryland population), from a rain gauge in Windsor Campbell farm (Jamaica) (Jamaica population), and a tree trunk with moss in a forest in the municipality of Rio de Janeiro (Brazil) (Brazil population). The mating behaviour was divided into the well‐known initial phase, copula phase and postcopulatory mate guarding phase. An additional phase prior to the initial phase serves to recognize the female, the recognition phase. The mating behaviour is identical in the males of the Jamaica and Brazil populations of P. viguieri. A postcopulatory mate guarding phase is not found in these two groups. Here, we refute the hypothesis, that a postcopulatory mate guarding phase is found in taxa in which only adult males grasp adult females. The males of the Ruhr and Maryland populations differ from each other in their mating behaviour. Generally, the males of all four populations do not mate with fertilized females which are equally unattractive to the males, i.e., females mate only once in their lifetime to produce offspring. These results corroborate the view that the different populations of P. viguieri do not belong to a single cosmopolitan species.     

Ecosystem function and species loss – a microcosm study

There are too many kinds of organisms to be able to study and manage each, yet the loss of a single species can sometimes unravel an ecosystem. Such `fusewire species'– critical in the same sense that an electrical fuse can cut out a whole circuit – would be a rewarding focus for research and management effort. However, this approach can only be effective if these `fusewires' represent but a small proportion of the number of species in the system.  

Aim

To demonstrate methods for measuring what proportion of the species in a system are critical to ecosystem function.  

Methods

The prevalence of fusewire species was measured in manipulative experiments on an aquatic microcosm.  

Results

No single genus deletion caused changes in key characteristics of the system.  

Main conclusions

Comparison of these results with other published studies shows that the proportion of critical fusewire species varies amongst different ecosystems. The oxidation pond microcosms were shown to contain no single species indispensable to system function. They appear to be ill-suited to a management strategy which focuses on priority eukaryote species. However, a single study provides no evidence that this result is general or even typical of other kinds of ecosystems; it is presented here as an empirical model. Other methods of investigation are available; they are less experimentally rigorous but more practical. These could provide important guidance in planning an approach to management in a particular ecosystem.     

Zoo animals as “proxy species” for threatened sister taxa: Defining a novel form of species surrogacy

The vast number of species threatened with extinction, coupled with the limited resources to support them, results in the need to prioritize species for conservation action. Similarly, zoo collection managers must prioritize species for inclusion at their institutions, which are also limited by space and resources. While conservation status is one factor considered by zoos, weight is also given to qualitative features and practical considerations when evaluating the fit of different species. Resultantly, the species prioritized by zoos have limited overlap with those prioritized for conservation. Several recent studies have highlighted that the majority of species maintained in zoos are ranked globally as least concern. Given the centrality of conservation to the modern mission of zoos, there is value in identifying clear connections between non‐threatened species in zoos and the roles they can play in conservation. Surrogate species approaches have been used in many instances to facilitate indirect conservation, and several distinctive types of surrogacy have been formally described. The aim of this study is to define a novel form of species surrogacy (i.e., “proxy species”) that draws utility from non‐threatened species maintained in zoos. A proxy species is here defined as a non‐threatened species managed ex situ that can be used as a flagship for a related threatened species that is morphologically similar but not otherwise represented in zoos. The benefits of this approach and opportunities for its application are here reviewed. This concept will provide opportunities to enhance the value of pre‐existing zoo collections, and ultimately, support conservation objectives.     

Using space‐for‐time substitution and time sequence approaches in invasion ecology

1. Invasion biologists use two main approaches to evaluate the effects of non‐native species (NNS) on diversity of native species (DNS), namely space‐for‐time and time approaches. These approaches have pitfalls related to lack of controls: the former lacks pre‐invasion data, while the latter often lacks data from non‐invaded sites. 2. We propose a framework that combines space‐for‐time and time approaches and which should result in more focused mechanistic hypotheses and experiments to test the causes of invasibility and the effects of NNS on DNS. We illustrate the usefulness of our framework using two case studies: one with the submersed macrophyte, Hydrilla verticillata, in reservoir and the other with the fish, Geophagus proximus, in a large river–floodplain system. 3. Hydrilla verticillata invaded sites with DNS similar to that found in non‐invaded sites, indicating that biotic and/or abiotic factors did not influence invasion success; however, DNS increased over time in invaded sites compared with non‐invaded sites, suggesting that H. verticillata facilitated natives. In contrast, G. proximus invaded sites with higher DNS than non‐invaded sites, suggesting that biotic and/or abiotic factors favouring natives were important for invasion success, but DNS increased in invaded and non‐invaded sites over time, indicating that an independent factor contributed to DNS increases. 4. Conclusions from both studies would have been inaccurate or incomplete if the space‐for‐time and time approaches had not been used in combination as proposed in our framework.     

Riverine networks constrain β‐diversity patterns among fish assemblages in a large Neotropical river

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The Mediterranean Sea as a ‘cul‐de‐sac’ for endemic fishes facing climate change

The Mediterranean Sea is a hotspot of biodiversity, and climate warming is expected to have a significant influence on its endemic fish species. However, no previous studies have predicted whether fish species will experience geographic range extensions or contractions as a consequence of warming. Here, we projected the potential future climatic niches of 75 Mediterranean Sea endemic fish species based on a global warming scenario implemented with the Mediterranean model OPAMED8 and a multimodel inference, which included uncertainty. By 2070–2099, the average surface temperature of the Mediterranean Sea was projected to warm by 3.1 °C. Projections for 2041–2060 are that 25 species would qualify for the International Union for the Conservation of Nature and Natural Resources (IUCN) Red List, and six species would become extinct. By 2070–2099, 45 species were expected to qualify for the IUCN Red List whereas 14 were expected to become extinct. By the middle of the 21st century, the coldest areas of the Mediterranean Sea (Adriatic Sea and Gulf of Lion) would act as a refuge for cold‐water species, but by the end of the century, those areas were projected to become a ‘cul‐de‐sac’ that would drive those species towards extinction. In addition, the range size of endemic species was projected to undergo extensive fragmentation, which is a potentially aggravating factor. Since a majority of endemic fishes are specialists, regarding substratum and diet, we may expect a reduced ability to track projected climatic niches. As a whole, 25% of the Mediterranean Sea continental shelf was predicted to experience a total modification of endemic species assemblages by the end of the 21st century. This expected turnover rate could be mitigated by marine protected areas or accelerated by fishing pressure or competition from exotic fishes. It remains a challenge to predict how these assemblage modifications might affect ecosystem function.     

Revision of the species of <Emphasis Type="Italic">Acropsilus</Emphasis> Mik (Diptera,Dolichopodidae) from China

The genus Acropsilus Mik, 1878 is reported from China for the first time. Seven species are described as new to science: Acropsilus guangdongensis sp. n., A. guangxiensis sp. n., A. jinxiuensis sp. n., A. luoxiangensis sp. n., A. yunnanensis sp. n., A. zengchengensis sp. n. and A. zhuae sp. n. A key is given to separate these Chinese species.