The alien cynipid wasp Dryocosmus kuriphilus Yasumatsu, 1951 is a serious pest of chestnuts (Castanea spp.) in Japan, North America and Europe, causing fruit losses while inducing galls in buds. While D. kuriphilus galls have a recognizable and roughly invariable globular shape, their size varies, reaching up to 4 cm in diameter. Among other factors, such variation may depend on different climatic conditions in different attacked areas. Here, we sampled and measured 375 D. kuriphilus galls from 25 localities throughout the Iberian Peninsula, including both cold and rainy northern (Eurosiberian) areas and warm and dry central-southern (Mediterranean) areas, to test the effects of climate and geographical location on gall morphology. The analyses indicate that gall mass and volume follow a pattern that can be associated with a climatic cline. In particular, the Eurosiberian galls were smaller than the Mediterranean galls according to differences in climatic conditions. In the southern areas, the greater insolation regime does not allow the chestnut trees to be distributed at lower altitudes, but the high rainfall and humidity regime of the mountain enclaves allow their presence. These conditions of insolation and precipitation seem to influence the morphological characteristics of the galls of D. kuriphilus.

In seasonal climates, germination timing is mainly controlled by temperature, especially in species with physiological seed dormancy. The germination response to temperature may, however, vary among populations across the distribution range of species. Understanding how populations along climate gradients vary in their sensitivity to temperature is important for determining their vulnerability to climate variability and change. Here, we investigated the germination response of two Erica species with physiological seed dormancy (E. australis and E. umbellata) to changes in temperature throughout the seasons (simulated autumn through to spring) and to the local climate in six localities across a latitudinal gradient in western Iberia. Effects were studied with and without exposing the seeds to a heat shock. The local climate of seed provenance emerged as a key factor in modifying the germination sensitivity to germination temperature and their variation through the seasons. Although each species showed idiosyncratic germination responses to temperature treatments and across the gradient, germination of both species was sensitive to warmer temperatures and to a heat shock. Both showed similar seasonal germination patterns: as we moved from south to north, populations tended to have a larger germination peak in spring, which was greater at colder temperatures. We conclude that rising temperatures associated with climate change will affect these species, particularly at their northern ranges, where many seeds will remain dormant during warmer winters. Arguably, models aiming at assessing climate change impacts in these species need to include such variability across latitude.

Many species of marine sponges on tropical reefs host abundant and diverse symbiont communities capable of varied metabolic pathways. While such communities may confer a nutritional benefit to some hosts (termed High Microbial Abundance (HMA) sponges), other sympatric species host only sparse symbiont communities (termed Low Microbial Abundance (LMA) sponges) and obtain a majority of their C and N from local sources. Sponge communities are widespread across large latitudinal gradients, however, and recent evidence suggests that these symbioses may also extend beyond the tropics. We investigated the role that symbionts play in the ecology of sponges from the temperate, hard-bottom reefs of Gray's Reef National Marine Sanctuary by calculating the niche size (as standard ellipse area (SEAc)) and assessing the relative placement of five HMA and four LMA sponge species within bivariate (δ13C and δ15N) isotopic space. Although photosymbiont abundance was low across most of these species, sponges were widespread across isotopic niche space, implying that microbial metabolism confers an ecological benefit to temperate sponges by expanding host metabolic capability. To examine how these associations vary across a latitudinal gradient, we also compared the relative placement of temperate and tropical conspecifics within isotopic space. Surprisingly, shifts in sponge δ13C and δ15N values between these regions suggest a reduced reliance on symbiont-derived nutrients in temperate sponges compared with their tropical conspecifics. Despite this, symbiotic sponges in temperate systems likely have a competitive advantage, allowing them to grow and compete for space within these habitats.

In intertidal poikilotherms with wide geographic distribution, physiological variations are ubiquitous, due to phenotypic plasticity and/or individual geographic variation. Using the grapsid crab, Cyclograpsus cinereus as a study model, acclimatization differences in respiratory physiology were evaluated among populations along the Chilean coast, covering a latitudinal gradient of about 2000 km. This species inhabits the supratidal zones and, therefore, is subject to constant immersion and emersion periods, producing physiological acidification due to CO2 retention, mainly in the branchial cavity. Individuals of six populations were collected along the coastline of Chile and were exposed to air for different time periods in the laboratory. The following parameters were measured: pH, Ca2+, Cl− and haemolymphatic lactate dehydrogenase (LDH) enzyme activity. Populations from lower latitudes were significantly different from those from central and southern Chile, with a higher haemolymphatic pH variation and higher Ca2+ level, along with lower levels of Cl− and LDH enzyme activity. This indicates that the populations from lower latitudes, which are subject to higher air temperatures during emersion, have a higher homeostatic capacity during emersion periods than those of intermediate and higher latitudes. This response seems to be determined by genetic bases due to adaptation to the local environment.

In austral summer 2004 benthic macrofauna was sampled along a latitudinal gradient along the northern Victoria Land coast (Ross Sea). An Agassiz trawl was used for semi-quantitative data collection of macrozoobenthos at depths from 84 to 537 m. Multivariate analysis of abundance of higher taxonomic units discriminated between the four sample sites along the latitudinal gradient. A SIMPROF analysis emphasized these geographical clusters, as the samples showed no significant differences within each cluster. A change in community structure with depth was not observed. The dominant taxonomic groups along the Victoria Land coast were Echinodermata (39%), Arthropoda (24%), Polychaeta (14%), and Mollusca (12%), not accounting for colonial organisms. Thus, the overall structure of the benthic community off the Victoria Land coast is comparable to other Antarctic regions and shows a closer relationship to the eastern Weddell Sea shelf, which may be attributable to the extensive impact of grounded ice affecting both areas.

A soil climate monitoring network, consisting of seven automated weather stations, was established between 1999 and 2003, ranging from Minna Bluff to Granite Harbour and from near sea level to about 1700 m on the edge of the polar plateau. Active layer depth was calculated for each site for eight successive summers from 1999/2000 to 2006/2007. The active layer depth varied from year to year and was deepest in the warm summer of 2001–02 at all recording sites. No trends of overall increase or decrease in active layer depth were evident across the up-to-eight years of data investigated. Average active layer depth decreased with increasing latitude from Granite Harbour (77°S, active layer depth of > 90 cm) to Minna Bluff (78.5°S, active layer depth of 22 ± 0.4 cm), and decreased with increasing altitude from Marble Point (50 m altitude, active layer depth of 49 ± 9 cm) through to Mount Fleming (1700 m altitude, active layer depth of 6 ± 2 cm). When all data from the sites were grouped together and used to predict active layer depth the mean summer air temperature, mean winter air temperature, total summer solar radiation and mean summer wind speed explained 73% of the variation (R2 = 0.73).

Fundamental to environmental conservation, the spatial location of biodiversity, people and protected areas has been studied for the species richness of various taxa, including plants, invertebrates and birds. However, few avian studies have analysed these three-way interactions for total versus breeding, and for threatened, human-avoiding and human–adapted species. Correlations between bird species richness, human population size and protected areas were studied across Italy's regions, controlling for variations in area, latitude, main land cover and spatial autocorrelation. Whilst total bird species richness increases with increasing human population size, breeding species richness does not vary with human population size. The number of globally threatened bird species is positively correlated with human population size, but this correlation is not significant when controlling for overall region bird species richness. There is no evidence that the increase in total bird species richness with human population size is owing to species typically found in urban habitats, and the proportion of human-avoiding species increases with human population size. For all groups of species, there is a negative correlation of the number of species with the proportion of protected area, indicating that the conservation of Italy's avifauna should be addressed over the entire landscape, and not just in protected areas.

The seed fly Mesoclanis polana (Diptera: Tephritidae) was released in Australia in 1996. Its impact on seed production of bitou bush (Chrysanthemoides monilifera subsp. rotundata) was monitored at eight sites along the New South Wales coast from 1996 to 2004. Peak flowerhead production occurred in autumn (March to May); therefore, samples collected in May of each year were used to compare abundance and impact of M. polana across sites and between years. Latitude had a significant effect on abundance and impact of M. polana. By May 2004, 99.6% of flowerheads at the five most northern sites contained at least one egg, while 64% of flowerheads from the two most southern sites contained at least one egg. In May 2004, mean numbers of M. polana eggs per flowerhead were between 13 and 17 at four of the six northern sites and below two at the two southern sites. In May 2004, average seed destruction by M. polana was 58% at the four most northern sites and 11% at the two most southern sites. The highest level of seed destruction recorded was 86% at Kingscliff in May 2003. Percentage seed destruction in May provided a reasonable estimate of seed destruction for the whole year. Parasitoids were found throughout the range of M. polana in Australia. Their attack rate on M. polana was less than 10% at all sites, except at the two most northern sites where parasitism of up to 27% was recorded. Parasitism results are compared with predictions made following an earlier study. The release of Mesoclanis magnipalpis, a species suited to cooler environments, is recommended for the southern range of C. monilifera subsp. rotundata.

Geographic body size variation was analysed in males and females of 19 populations of the South American grasshopper Dichroplus vittatus Bruner spanning 20 degrees of latitude and 2700 m of altitude. Using mean and maximum body length of each sex and factors obtained from principal components analyses of six morphometric linear characters it was shown that D. vittatus followed the converse to Bergmann's rule latitudinally but not altitudinally where no significant trends were observed. For males, variability of body size increased with latitude but not with altitude. Both types of trends were significantly correlated with mean annual temperature and minimum annual temperature (positive correlations), and two estimators of seasonality, the coefficients of variation of mean annual temperature (negative) and mean annual precipitation (positive). Some allometric relationships also showed geographic variation. It is suggested that the observed decrease in size with latitude together with the increase in morphological variability is a consequence of a number of factors: the shortening of the growing season southwards; the increasing seasonality and climatic unpredictability; and the fact that the species exhibits protandry which contributes to smaller and more variable size in males and smaller but more constant body size in females.

Tropical plants have been suggested to have higher levels of mechanical, chemical and biotic defences than temperate plants. However, comparisons have usually included deciduous species within the temperate group, which confounds the analysis since deciduous species are predicted to have a different strategy with respect to investment, nutrition and defence than evergreen species. In this study we examined levels of defence and nutrition in five evergreen species of Eucryphia occurring along a latitudinal gradient in eastern Australia, grown under common conditions in a glasshouse. From the resource-availability hypothesis we predicted the opposite gradient in defence investment, i.e. that lowest levels of defence will occur in tropical species with potentially high growth rates and annual productivity. However, we found an increase in cell wall content, total phenolics and tannin activity, and a decrease in protein availability, with decreasing latitude and/or increasing mean annual temperature. Hence, there was a trend of increasing defence (although not in leaf toughness) and declining nutritional quality towards the tropics. These latitudinal trends were recorded in both mature and expanding leaves. The same trends were observed in leaves of two species collected from the field, indicating that the results were not peculiar to the experimental growth regime. The latitudinal trend in defence did not support our prediction based on the resource availability hypothesis and may indicate that herbivore pressure is providing an overriding selection pressure, although there are alternative explanations.