Chromosome counts in the genus Festuca L. section Festuca (Poaceae) in the Iberian Peninsula

Chromosome numbers have been counted in 102 populations belonging to 34 taxa of Festuca L. section Festuca from the Iberian Peninsula. Four of these taxa have been counted for the first time and another three for the first time from the Iberian Peninsula. Furthermore, the levels of ploidy for another three taxa have been obtained for new populations within their distribution area, and for another 18 taxa the ploidy levels have been confirmed. Five levels of ploidy have been established for this section: diploid, tetraploid, hexaploid, octoploid and decaploid. There are 17 diploid taxa, eight tetraploid, three octoploid, two octoploid and one decaploid. The three remaining taxa represent polyploid complexes (one tetra-hexa-octoploid and two hexa-octoploids).     

Warming climate advances breeding and improves synchrony of food demand and food availability in a boreal passerine

Global climate change affects ecosystems via several trophic levels. We investigated changes in the timing of breeding in the willow tit (Poecile montanus) and timing of its caterpillar food resource in relation to warming springs in a boreal forest. We used generalized linear mixed effect models to study the importance of synchrony between the timing of breeding in willow tits and the caterpillar food availability on the breeding success, measured as nestling survival rate and mean nestling weight. Both the timing of breeding and the timing of the caterpillar peak advanced during the last decades, and were well explained by spring temperatures. Unlike in most passerine populations studied, synchrony has improved with rising spring temperatures. However, it had only a modest although statistically significant positive influence on breeding success. Spring temperatures do not seem to be used as cues for the timing of caterpillar food availability by willow tits. We conclude that responses to climatic warming seem to be population, species and habitat specific, necessitating research in a wide range of taxa in different climatic zones.     

Value of long‐term ecological studies

Long‐term ecological studies are critical for providing key insights in ecology, environmental change, natural resource management and biodiversity conservation. In this paper, we briefly discuss five key values of such studies. These are: (1) quantifying ecological responses to drivers of ecosystem change; (2) understanding complex ecosystem processes that occur over prolonged periods; (3) providing core ecological data that may be used to develop theoretical ecological models and to parameterize and validate simulation models; (4) acting as platforms for collaborative studies, thus promoting multidisciplinary research; and (5) providing data and understanding at scales relevant to management, and hence critically supporting evidence‐based policy, decision making and the management of ecosystems. We suggest that the ecological research community needs to put higher priority on communicating the benefits of long‐term ecological studies to resource managers, policy makers and the general public. Long‐term research will be especially important for tackling large‐scale emerging problems confronting humanity such as resource management for a rapidly increasing human population, mass species extinction, and climate change detection, mitigation and adaptation. While some ecologically relevant, long‐term data sets are now becoming more generally available, these are exceptions. This deficiency occurs because ecological studies can be difficult to maintain for long periods as they exceed the length of government administrations and funding cycles. We argue that the ecological research community will need to coordinate ongoing efforts in an open and collaborative way, to ensure that discoverable long‐term ecological studies do not become a long‐term deficiency. It is important to maintain publishing outlets for empirical field‐based ecology, while simultaneously developing new systems of recognition that reward ecologists for the use and collaborative sharing of their long‐term data sets. Funding schemes must be re‐crafted to emphasize collaborative partnerships between field‐based ecologists, theoreticians and modellers, and to provide financial support that is committed over commensurate time frames.     

An oxygen electrode-based assay of catalase activity as a rapid method for estimating the bacterial content of foods

An oxygen electrode-based assay of catalase was developed as a simple method of assessing contamination by bacteria capable of respiration. The method gave a rapid and reasonable quantification of cell numbers in pure cultures and was able to detect 10³ bacteria/ml in some cases. The sensitivity of the method was dependent on the identity of the culture and when applied to foods the sensitivity was reduced due to the presence of non-microbial catalase. The use of electropositively charged filters to remove the organisms from the food sample improved the sensitivity and the relationship between catalase activity and cell numbers in some foods.     

Maternal effects on offspring size in a natural population of the viviparous tsetse fly

1. Theory predicts that mothers should adaptively adjust reproductive investment depending on current reserves and future reproductive opportunities. Females in better intrinsic state, or with more resources, should invest more in current reproduction than those with fewer resources. Across the lifespan, investment may increase as future reproductive opportunities decline, yet may also decline with reductions in intrinsic state. 2. Across many species, larger mothers produce larger offspring, but there is no theoretical consensus on why this is so. This pattern may be driven by variation in maternal state such as nutrition, yet few studies measure both size and nutritional state or attempt to tease apart confounding effects of size and age. 3. Viviparous tsetse flies (Glossina species) offer an excellent system to explore patterns of reproductive investment: females produce large, single offspring sequentially over the course of their relatively long life. Thus, per‐brood reproductive effort can be quantified by offspring size. 4. While most tsetse reproduction research has been conducted on laboratory colonies, maternal investment was investigated in this study using a unique field method where mothers were collected as they deposited larvae, allowing simultaneous mother‐offspring measurements under natural conditions. 5. It was found that larger mothers and those with a higher fat content produced larger offspring, and there was a trend for older mothers to produce slightly larger offspring. 6. The present results highlight the importance of measuring maternal nutritional state, rather than size alone, when considering maternal investment in offspring. Implications for understanding vector population dynamics are also discussed.     

Morphometric correlates of karyotype and host plant in genus Euceraphis (Hemiptera: Aphididae)

Abstract Samples of birch- and alder-feeding aphids of genus Euceraphis were measured and analysed using multiple discriminant analysis (canonical variates) to find out if morphological variation correlated with previously reported differences of karyotype and host association. The dataset comprised groups of specimens defined solely by locality and collection date. Mean scores on the first two canonical variates clustered the samples fully in accordance with their karyotypes and host plants, confirming the existence of a number of morphologically similar but distinct host-specific taxa within the E. betulae group. Three new species are described: Euceraphis borealis Blackman, sp.n. on Betula glandulosa and B. nana , Euceraphis papyrifericola Blackman, sp.n. on B. papyrifera , and Euceraphis quednaui Blackman, sp.n. on B. occidentalis . A key is provided to alate viviparae of the genus.     

Functional significance of the dark central floret of Daucus carota (Apiaceae) L.; is it an insect mimic?

In Daucus carota L. (Apiaceae) the florets comprising the central umbellet of inflorescences are usually pink or dark purple, presenting a marked contrast to the surrounding umbellets, which are generally white. The number of dark florets varies, and some inflorescences have no dark florets. It has been proposed that the dark florets function as an insect mimic, and in so doing serve to attract insects to the flower. In contrast, other authors, Darwin included, suggest that they are functionally redundant. The present study examined whether the dark florets attract insects, and also whether this effect can be replicated by replacing these florets with an insect. At the study site in Portugal the predominant insect visitor was the beetle Anthrenus verbasci L. (Dermestidae), which is similar in size and shape to the dark florets. Large inflorescences and those with more dark florets attracted more beetles than small inflorescences and those with fewer or no dark florets. Inflorescences with the dark florets removed attracted fewer beetles visitors compared with intact inflorescences. Inflorescences in which the dark florets were replaced with one or a cluster of five dead, freeze-killed A. verbasci attracted more beetles than inflorescences from which the dark florets had been removed. Replacement of the dark florets with a relatively large Meloid beetle resulted in the attraction of markedly fewer A. verbasci . We conclude that the dark florets can act as an insect attractant for some insect groups by acting as an insect mimic, and that they are adaptive, in contrast to the speculations of Darwin.     

Typification of three taxa of the genus Festuca L. (Poaceae)

Lectotypifications of Festuca infesta Hack. ex Trab., Festuca maroccana Trab. and Festuca rubra L. subsp. scabrescens Hack. ex Trab. are designated here. The principal diagnostic characters and chorology are also presented for each taxon. © 2008 The Linnean Society of London, Botanical Journal of the Linnean Society, 2008, 158 , 342–343.     

Seed micromorphology in the genus Neotinea Rchb.f. (Orchidaceae, Orchidinae)

The ultrastructure of testa seed in the genus Neotinea (Orchidaceae, Orchidinae) was examined for the first time. The morphology of the seed and of the anticlinal and periclinal walls was analysed by scanning electron microscopy. Quantitative data concerning the length and width of the seed and embryo, seed and embryo volume, free air space, and number of cells along the longitudinal axis are presented. In all species, the seeds are fusiform in shape with transverse ridges on the inner periclinal walls. This ornamentation pattern is characteristic for the genus Neotinea . It is a good diagnostic value supporting the monophyly of this genus, which has recently been proposed by several authors.  © 2007 The Linnean Society of London, Botanical Journal of the Linnean Society , 2007, 153 , 133–140.