Vulnerability of African mammals to anthropogenic climate change under conservative land transformation assumptions

Recent observations show that human‐induced climate change (CC) and land transformation (LT) are threatening wildlife globally. Thus, there is a need to assess the sensitivity of wildlife on large spatial scales and evaluate whether national parks (NPs), a key conservation tools used to protect species, will meet their mandate under future CC and LT conditions. Here, we assess the sensitivity of 277 mammals at African scale to CC at 10′ resolution, using static LT assumptions in a ‘first‐cut’ estimate, in the absence of credible future LT trends. We examine the relationship between species' current distribution and macroclimatic variables using generalized additive models, and include LT indirectly as a filter. Future projections are derived using two CC scenarios (for 2050 and 2080) to estimate the spatial patterns of loss and gain in species richness that might ultimately result. We then apply the IUCN Red List criteria A3(c) of potential range loss to evaluate species sensitivity. We finally estimate the sensitivity of 141 NPs in terms of both species richness and turnover. Assuming no spread of species, 10–15% of the species are projected to fall within the critically endangered or extinct categories by 2050 and between 25% and 40% by 2080. Assuming unlimited species spread, less extreme results show proportions dropping to approximately 10–20% by 2080. Spatial patterns of richness loss and gain show contrasting latitudinal patterns with a westward range shift of species around the species‐rich equatorial zone in central Africa, and an eastward shift in southern Africa, mainly because of latitudinal aridity gradients across these ecological transition zones. Xeric shrubland NPs may face significant richness losses not compensated by species influxes. Other NPs might expect substantial losses and influxes of species. On balance, the NPs might ultimately realize a substantial shift in the mammalian species composition of a magnitude unprecedented in recent geological time. To conclude, the effects of global CC and LT on wildlife communities may be most noticeable not as a loss of species from their current ranges, but instead as a fundamental change in community composition.     

Repeated matings and sperm depletion in the freshwater crayfish Austropotamobius italicus

1. In sexually reproducing organisms, the energetic costs of spermatogenesis can be considerable, and can limit the reproductive potential of the males. In species where males mate more than once during the reproductive season, the costs of sperm production are generally predicted to result in a decrease of ejaculate size and quality with successive fertilizations. 2. In this study we examined the variation in ejaculate size among successive fertilizations in a long‐lived freshwater crayfish species, Austropotamobius italicus. 3. Sexually active adult males of various sizes were allowed to mate repeatedly with different females on consecutive days. Trials for a given male ended when he copulated but did not release any sperm or refused to mate. 4. Males fertilized between 0 and 4 females, and most (42.5%) fertilized a single female. The overall number of females fertilized by a given male decreased with increasing male body size. Ejaculate size decreased markedly with consecutive fertilizations in a similar fashion among both large and small males, while simultaneously increasing with female body size. The total ejaculate size over successive fertilizations decreased with increasing male size. 5. Our study indicates that either sperm production or release involves non‐trivial costs in freshwater crayfish, and suggests that large/old males may face greater difficulties in gamete release than small/young ones, as shown by the lower number of females fertilized by large compared with small males, which may reflect the ongoing senescence of their reproductive performance.     

Predictable changes in trophic community structure along a spatial disturbance gradient in streams

1. We assessed insect and resource standing stocks along a spatial gradient of flood disturbance in 19 sub-alpine Swedish streams to test the prediction that change in trophic structure arises from the joint action of disturbance, which affect basal resources, and resource-control, which ties the response of the consumers to the response of the resources.
2. Trophic structure, quantified as scores of non-metric multidimensional scaling based on the biomass of insect trophic groups, changed predictably along the disturbance gradient. In early summer, predators and algae feeders decreased relative to suspension feeders with increasing disturbance; in autumn, algae feeders decreased relative to leaf feeders with increasing disturbance.
3. Across the disturbance gradient, the biomass of algae-, deposit- and leaf-feeders was principally controlled by the availability of the respective resource (algae, fine detritus and coarse detritus), while disturbance only had subsidiary effects on algae feeders in early summer.
4. Overall, patterns in trophic-group biomass along the disturbance gradient were more likely to reflect indirect effects of disturbance via impact on the resources, which reverberated to the consumers because of resource-control, rather than direct effects. In contrast with the view that stream communities are the result of stochastic colonization following disturbance events, in the study streams the trophic structure of insect assemblages is predictable and partly organized by resource-control across a broad range of disturbance conditions.     

Morphometric study and taxonomy of Genista pulchella Vis. s.l. (Fabaceae), a south European species

A morphometric study of the known populations of Genista pulchella has been undertaken, based on herbarium specimens and field research. This has made it possible to provide a new taxonomic outline as the disjunct populations of G. pulchella (western part of the Balkan peninsula, central Italy and southern France) seem to be distinct. A new taxon is described: G. pulchella ssp. aquilana ssp. nov. (central Italy), a new combination G. pulchella ssp. villarsiana comb. nov. is proposed for the population from southern France, while G. pulchella ssp. pulchella can be considered endemic to the Balkan Peninsula. Genista pulchella Vis., G. villarsii Clementi and G. villarsiana Jord. are lectotypified.  © 2007 The Linnean Society of London, Botanical Journal of the Linnean Society, 2007, 153 , 245–254.     

Microsatellite allele sequencing in population analyses of the South American cactophilic species Drosophila antonietae (Diptera: Drosophilidae)

Drosophila antonietae belongs to the Drosophila buzzatii cluster, a cactophilic group of species naturally endemic to South America. Morphological and genetic analyses indicate that its populations are the most homogenous in the cluster and that the diversity observed is mainly a result of variation within populations. Seven polymorphic microsatellite loci were described for this species and used in the present study to investigate the genetic diversity of natural populations of D. antonietae by both length and sequence variation. The study aimed to understand how homoplasy and null alleles affect inferences about the population history of this species and to obtain an accurate interpretation of population inferences where these loci could be applied. The results provide useful information on the interpretation of genetic data derived from the microsatellite loci described for D. antonietae and on evolutionary aspects of cactophilic Drosophila. Importantly, the results indicate that size homoplasy and null alleles do not represent significant problems for the population genetics analyses because the large amount of variability at microsatellite loci compensate the low frequency of these problems in the populations. © 2010 The Linnean Society of London, Biological Journal of the Linnean Society, 2010, 100 , 573–584.     

Relax and refill: xylem rehydration prior to hydraulic measurements favours embolism repair in stems and generates artificially low PLC values

Diurnal changes in percentage loss of hydraulic conductivity (PLC), with recorded values being higher at midday than on the following morning, have been interpreted as evidence for the occurrence of cycles of xylem conduits' embolism and repair. Recent reports have suggested that diurnal PLC changes might arise as a consequence of an experimental artefact, that is, air entry into xylem conduits upon cutting stems, even if under water, while under substantial tension generated by transpiration. Rehydration procedures prior to hydraulic measurements have been recommended to avoid this artefact. In the present study, we show that xylem rehydration prior to hydraulic measurements might favour xylem refilling and embolism repair, thus leading to PLC values erroneously lower than those actually experienced by transpiring plants. When xylem tension relaxation procedures were performed on stems where refilling mechanisms had been previously inhibited by mechanical (girdling) or chemical (orthovanadate) treatment, PLC values measured in stems cut under native tension were the same as those measured after sample rehydration/relaxation. Our data call for renewed attention to the procedures of sample collection in the field and transport to the laboratory, and suggest that girdling might be a recommendable treatment prior to sample collection for PLC measurements.     

Phylogenetic relationships of nonbiting midges in the subfamily Tanypodinae (Diptera: Chironomidae) inferred from morphology

The nonbiting midge subfamily Tanypodinae represents one of the most diverse lineages of Chironomidae. Despite the wide distribution and high diversity of tanypodine chironomids, the evolutionary history of the subfamily remains poorly understood. Here, we present the first phylogenetic analysis of the subfamily Tanypodinae based on morphological data. Cladistic analyses were conducted using 86 morphological characters from 115 species belonging to 54 tanypodine genera, including the eight currently recognised tribes: Anatopyniini, Clinotanypodini, Coelopyniini, Macropelopiini, Natarsiini, Pentaneurini, Procladiini and Tanypodini. We use characters from fourth‐instar larvae, pupae and adults of both sexes. We examine the effects of implied weighting by reanalysing the data with varying values of concavity constant (k). Our analysis supports the monophyly of Tanypodinae with Podonominae as its sister group. All previously proposed tribes are recovered as monophyletic assemblages under a wide range of weighting factors. Under these conditions, the genus Fittkauimyia is the sister group of the remaining Macropelopiini and is erected as a new monobasic tribe, Fittkauimyiini trib.n . The tribe Pentaneurini is recovered as monophyletic with some internal relationships resolved. The genus Paramerina, recovered as sister of Reomyia + Zavrelimyia, is formally synonymised with Zavrelimyia syn.n. , based on morphological similarity in all three life stages and treated as a subgenus of the latter. Finally, the recently suggested synonymies of Gressittius and Guassutanypus with Alotanypus and the establishment of the subgenera Conchapelopia (Helopelopia), Macropelopia (Bethbilbeckia), Monopelopia (Cantopelopia), Thienemannimyia (Hayesomyia) and Zavrelimyia (Reomyia and Schineriella) are investigated. Our results support all proposed changes, except for the subgenus‐level status of Helopelopia and Cantopelopia. We suggest re‐establishment of Helopelopia as a genus, but refrain from promoting genus‐level status of Cantopelopia at present because the apparent sister‐relationship between Monopelopia + Nilotanypus likely is due to wing vein reduction caused by miniaturisation. This published work has been registered in ZooBank, http://zoobank.org/urn:lsid:zoobank.org:pub:DF012C17‐AFB3‐4904‐83DC‐30DD94D0B376 .     

MYGALOMORPH SPIDERS (ARANEAE: DIPLURIDAE) FROM THE LOWER CRETACEOUS CRATO LAGERSTÄTTE, ARARIPE BASIN, NORTH-EAST BRAZIL

Abstract:  The first mygalomorph spiders from the Lower Cretaceous Crato Lagerstätte of Cearà Province, north-east Brazil, are described, from adult males and females, in two new genera and species: Cretadiplura ceara Selden, gen. et sp. nov. and Dinodiplura ambulacra Selden, gen. et sp. nov. They belong to the extant family Dipluridae, hitherto known as fossils only from Tertiary strata; thus this occurrence extends the family record by some 90 myr.